| 1. |
- Trac, Quang Thinh, et al.
(författare)
-
Prediction model for drug response of acute myeloid leukemia patients
- 2023
-
Ingår i: npj Precision Oncology. - : Springer Nature. - 2397-768X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Despite some encouraging successes, predicting the therapy response of acute myeloid leukemia (AML) patients remains highly challenging due to tumor heterogeneity. Here we aim to develop and validate MDREAM, a robust ensemble-based prediction model for drug response in AML based on an integration of omics data, including mutations and gene expression, and large-scale drug testing. Briefly, MDREAM is first trained in the BeatAML cohort (n = 278), and then validated in the BeatAML (n = 183) and two external cohorts, including a Swedish AML cohort (n = 45) and a relapsed/refractory acute leukemia cohort (n = 12). The final prediction is based on 122 ensemble models, each corresponding to a drug. A confidence score metric is used to convey the uncertainty of predictions; among predictions with a confidence score >0.75, the validated proportion of good responders is 77%. The Spearman correlations between the predicted and the observed drug response are 0.68 (95% CI: [0.64, 0.68]) in the BeatAML validation set, -0.49 (95% CI: [-0.53, -0.44]) in the Swedish cohort and 0.59 (95% CI: [0.51, 0.67]) in the relapsed/refractory cohort. A web-based implementation of MDREAM is publicly available at https://www.meb.ki.se/shiny/truvu/MDREAM/.
|
|
| 2. |
- Akhtar, Monira, et al.
(författare)
-
Cell type and context-specific function of PLAG1 for IGF2 P3 promoter activity
- 2012
-
Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 41:6, s. 1959-1966
-
Tidskriftsartikel (refereegranskat)abstract
- The fetal transcription factor PLAG1 is found to be overexpressed in cancers, and has been suggested to bind the insulin like growth factor 2 (IGF2) P3 promoter, and to activate the IGF2 gene. The expression of IGF2 has partly been linked to loss of CTCF-dependent chromatin insulator function at the H19 imprinting control region (ICR). We investigated the role of PLAG1 for IGF2 regulation in Hep3B and JEG-3 cell lines. Chromatin immunoprecipitation revealed cell type-specific binding of PLAG1 to the IGF2 P3 promoter, which was substantially insensitive to recombinant PLAG1 overexpression in the endogenous context. We hypothesized that the H19 chromatin insulator may be involved in the cell type-specific PLAG1 response. By using a GFP reporter gene/insulator assay plasmid construct with and without the H19 ICR and/or an SV40 enhancer, we confirm that the effect of the insulator is specifically associated with the activity of the IGF2 P3 promoter in the GFP reporter system, and furthermore, that the reporter insulator is functional in JEG-3 but not in Hep3B cells. FACS analysis was used to assess the function of PLAG1 in low endogenously expressing, but Zn-inducible stable PLAG1 expressing JEG-3 cell clones. Considerable increase in IGF2 expression upon PLAG1 induction with a partial insulator overriding activity was found using the reporter constructs. This is in contrast to the effect of the endogenous IGF2 gene which was insensitive to PLAG1 expression in JEG-3, while modestly induced the already highly expressed IGF2 gene in Hep3B cells. We suggest that the PLAG1 binding to the IGF2 P3 promoter and IGF2 expression is cell type-specific, and that the PLAG1 transcription factor acts as a transcriptional facilitator that partially overrides the insulation by the H19 ICR.
|
|
| 3. |
- Brännvall, Rickard, et al.
(författare)
-
Data center excess heat recovery : A case study of apple drying
- 2020
-
Ingår i: ECOS 2020 - Proceedings of the 33rd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : ECOS 2020 Local Organizing Committee. ; , s. 2165-2174, s. 2165-2174
-
Konferensbidrag (refereegranskat)abstract
- Finding synergies between heat producing and heat consuming actors in an economy provides opportunity for more efficient energy utilization and reduction of overall power consumption. We propose to use low-grade heat recovered from data centers directly in food processing industries, for example for the drying of fruit and berries. This study analyses how the heat output of industrial IT-load on servers can dry apples in a small-scale experimental set up. To keep the temperatures of the server exhaust airflow near a desired set-point we use a model predictive controller (MPC) re-purposed to the drying experiment set-up from a previous work that used machine learning models for cluster thermal management. Thus, conditions with for example 37 C for 8 hours drying can be obtained with results very similar to conventional drying of apples. The proposed solution increases the value output of the electricity used in a data center by capturing and using the excess heat that would otherwise be exhausted. The results from our experiments show that drying foods with excess heat from data center is possible with potential of strengthening the food processing industry and contribute to food self-sufficiency in northern Sweden.
|
|
| 4. |
- Brännvall, Rickard, et al.
(författare)
-
EDGE : Microgrid Data Center with Mixed Energy Storage
- 2020
-
Ingår i: e-Energy 2020 - Proceedings of the 11th ACM International Conference on Future Energy Systems. - New York, NY, USA : Association for Computing Machinery, Inc. - 9781450380096 ; , s. 466-473, s. 466-473
-
Konferensbidrag (refereegranskat)abstract
- Low latency requirements are expected to increase with 5G telecommunications driving data and compute to EDGE data centers located in cities near to end users. This article presents a testbed for such data centers that has been built at RISE ICE Datacenter in northern Sweden in order to perform full stack experiments on load balancing, cooling, micro-grid interactions and the use of renewable energy sources. This system is described with details on both hardware components and software implementations used for data collection and control. A use case for off-grid operation is presented to demonstrate how the test lab can be used for experiments on edge data center design, control and autonomous operation. © 2020 Author.
|
|
| 5. |
- Chan, Sherwin, et al.
(författare)
-
Regulation of PfEMP1-VAR2CSA translation by a Plasmodium translation-enhancing factor
- 2017
-
Ingår i: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 2:7
-
Tidskriftsartikel (refereegranskat)abstract
- Pregnancy-associated malaria commonly involves the binding of Plasmodium falciparum-infected erythrocytes to placental chondroitin sulfate A (CSA) through the PfEMP1-VAR2CSA protein. VAR2CSA is translationally repressed by an upstream open reading frame. In this study, we report that the P. falciparum translation enhancing factor (PTEF) relieves upstream open reading frame repression and thereby facilitates VAR2CSA translation. VAR2CSA protein levels in var2csa-transcribing parasites are dependent on the expression level of PTEF, and the alleviation of upstream open reading frame repression requires the proteolytic processing of PTEF by PfCalpain. Cleavage generates a C-terminal domain that contains a sterile-alpha-motif-like domain. The C-terminal domain is permissive to cytoplasmic shuttling and interacts with ribosomes to facilitate translational derepression of the var2csa coding sequence. It also enhances translation in a heterologous translation system and thus represents the first non-canonical translation enhancing factor to be found in a protozoan. Our results implicate PTEF in regulating placental CSA binding of infected erythrocytes.
|
|
| 6. |
- Forsgren, Henrik, et al.
(författare)
-
Homomorphic Encryption Enables Data and Algorithm Confidentiality for Remote Monitoring and Control : An Application to Data Center Systems
- 2023
-
Ingår i: Companion Proceedings of the 14th ACM International Conference on Future Energy Systems. - : Association for Computing Machinery. ; , s. 85-90
-
Konferensbidrag (refereegranskat)abstract
- The design of intelligent algorithms used for device monitoring and control can be costly and is an investment that must be protected against reverse engineering by competitors. An algorithm can be safeguarded by running remotely from the cloud instead of locally on the equipment hardware. However, such a setup requires that sensitive data is sent from the device to the cloud. Fully Homomorphic Encryption (FHE) is an emerging technology that offers a solution to this problem since it enables computation on encrypted data. A cloud service using FHE can protect its proprietary algorithms while simultaneously offering customer data confidentiality. The computational overhead for the technology is, however, still very high. This work reports on a practical investigation of using FHE for data center remote control problems: What applications are feasible today? And at what cost?
|
|
| 7. |
- Fotouhi, Omid, et al.
(författare)
-
Proteomics identifies neddylation as a potential therapy target in small intestinal neuroendocrine tumors
- 2019
-
Ingår i: Oncogene. - : NATURE PUBLISHING GROUP. - 0950-9232 .- 1476-5594. ; 38:43, s. 6881-6897
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with small intestinal neuroendocrine tumors (SI-NETs) frequently develop spread disease; however, the underlying molecular mechanisms of disease progression are not known and effective preventive treatment strategies are lacking. Here, protein expression profiling was performed by HiRIEF-LC-MS in 14 primary SI-NETs from patients with and without liver metastases detected at the time of surgery and initial treatment. Among differentially expressed proteins, overexpression of the ubiquitin-like protein NEDD8 was identified in samples from patients with liver metastasis. Further, NEDD8 correlation analysis indicated co-expression with RBX1, a key component in cullin-RING ubiquitin ligases (CRLs). In vitro inhibition of neddylation with the therapeutic agent pevonedistat (MLN4924) resulted in a dramatic decrease of proliferation in SI-NET cell lines. Subsequent mass spectrometry-based proteomics analysis of pevonedistat effects and effects of the proteasome inhibitor bortezomib revealed stabilization of multiple targets of CRLs including p27, an established tumor suppressor in SI-NET. Silencing of NEDD8 and RBX1 using siRNA resulted in a stabilization of p27, suggesting that the cellular levels of NEDD8 and RBX1 affect CRL activity. Inhibition of CRL activity, by either NEDD8/RBX1 silencing or pevonedistat treatment of cells resulted in induction of apoptosis that could be partially rescued by siRNA-based silencing of p27. Differential expression of both p27 and NEDD8 was confirmed in a second cohort of SI-NET using immunohistochemistry. Collectively, these findings suggest a role for CRLs and the ubiquitin proteasome system in suppression of p27 in SI-NET, and inhibition of neddylation as a putative therapeutic strategy in SI-NET.
|
|
| 8. |
- Galkin, Nikolai, et al.
(författare)
-
On Modelling of Edge Datacentre Microgrid for Participation in Smart Energy Infrastructures
- 2022
-
Ingår i: IEEE Open Journal of the Industrial Electronics Society. - : Institute of Electrical and Electronics Engineers Inc.. - 2644-1284. ; 3, s. 50-64
-
Tidskriftsartikel (refereegranskat)abstract
- Datacentres are becoming a sizable part of the energy system and are one of the biggest consumers of the energy grid. The so-called “Green Datacentre” is capable of not only consuming but also producing power, thus becoming an important kind of prosumers in the electric grid. Green datacentres consist of a microgrid with a backup uninterrupted power supply and renewable generation, e.g., using photovoltaic panels. As such, datacentres could realistically be important participants in demand/response applications. However, this requires reconsidering their currently rigid control and automation systems and the use of simulation models for online estimation of the control actions impact. This paper presents such a microgrid simulation model modelled after a real edge datacentre. A case study consumption scenario is presented for the purpose of validating the developed microgrid model against data traces collected from the green edge datacentre. Both simulation and real-time validation tests are performed to validate the accuracy of the datacentre model. Then the model is connected to the automation environment to be used for the online impact estimation and virtual commissioning purposes.
|
|
| 9. |
- Gao, Yu, et al.
(författare)
-
SOCS3 Expression by Thymic Stromal Cells Is Required for Normal T Cell Development
- 2021
-
Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- The suppressor of cytokine signaling 3 (SOCS3) is a major regulator of immune responses and inflammation as it negatively regulates cytokine signaling. Here, the role of SOCS3 in thymic T cell formation was studied in Socs3fl/fl Actin-creER mice (Δsocs3) with a tamoxifen inducible and ubiquitous Socs3 deficiency. Δsocs3 thymi showed a 90% loss of cellularity and altered cortico-medullary organization. Thymocyte differentiation and proliferation was impaired at the early double negative (CD4-CD8-) cell stage and apoptosis was increased during the double positive (CD4+CD8+) cell stage, resulting in the reduction of recent thymic emigrants in peripheral organs. Using bone marrow chimeras, transplanting thymic organoids and using mice deficient of SOCS3 in thymocytes we found that expression in thymic stromal cells rather than in thymocytes was critical for T cell development. We found that SOCS3 in thymic epithelial cells (TECs) binds to the E3 ubiquitin ligase TRIM 21 and that Trim21−/− mice showed increased thymic cellularity. Δsocs3 TECs showed alterations in the expression of genes involved in positive and negative selection and lympho-stromal interactions. SOCS3-dependent signal inhibition of the common gp130 subunit of the IL-6 receptor family was redundant for T cell formation. Together, SOCS3 expression in thymic stroma cells is critical for T cell development and for maintenance of thymus architecture.
|
|
| 10. |
- Herr, Patrick, et al.
(författare)
-
Cell Cycle Profiling Reveals Protein Oscillation, Phosphorylation, and Localization Dynamics
- 2020
-
Ingår i: Molecular & Cellular Proteomics. - : Elsevier BV. - 1535-9476 .- 1535-9484. ; 19:4, s. 608-623
-
Tidskriftsartikel (refereegranskat)abstract
- The cell cycle is a highly conserved process involving the coordinated separation of a single cell into two daughter cells. To relate transcriptional regulation across the cell cycle with oscillatory changes in protein abundance and activity, we carried out a proteome- and phospho-proteome-wide mass spectrometry profiling. We compared protein dynamics with gene transcription, revealing many transcriptionally regulated G2 mRNAs that only produce a protein shift after mitosis. Integration of CRISPR/Cas9 survivability studies further highlighted proteins essential for cell viability. Analyzing the dynamics of phosphorylation events and protein solubility dynamics over the cell cycle, we characterize predicted phospho-peptide motif distributions and predict cell cycle-dependent translocating proteins, as exemplified by the S-adenosylmethionine synthase MAT2A. Our study implicates this enzyme in translocating to the nucleus after the G1/S-checkpoint, which enables epigenetic histone methylation maintenance during DNA replication. Taken together, this data set provides a unique integrated resource with novel insights on cell cycle dynamics.
|
|
| 11. |
|
|
| 12. |
- Johansson, Henrik J., et al.
(författare)
-
Breast cancer quantitative proteome and proteogenomic landscape
- 2019
-
Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- In the preceding decades, molecular characterization has revolutionized breast cancer (BC) research and therapeutic approaches. Presented herein, an unbiased analysis of breast tumor proteomes, inclusive of 9995 proteins quantified across all tumors, for the first time recapitulates BC subtypes. Additionally, poor-prognosis basal-like and luminal B tumors are further subdivided by immune component infiltration, suggesting the current classification is incomplete. Proteome-based networks distinguish functional protein modules for breast tumor groups, with co-expression of EGFR and MET marking ductal carcinoma in situ regions of normal-like tumors and lending to a more accurate classification of this poorly defined subtype. Genes included within prognostic mRNA panels have significantly higher than average mRNA-protein correlations, and gene copy number alterations are dampened at the protein-level; underscoring the value of proteome quantification for prognostication and phenotypic classification. Furthermore, protein products mapping to non-coding genomic regions are identified; highlighting a potential new class of tumor-specific immunotherapeutic targets.
|
|
| 13. |
- Johansson, Tim, et al.
(författare)
-
Energy performance certificates and 3-dimensional city models as a means to reach national targets : A case study of the city of Kiruna
- 2016
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 116, s. 42-57
-
Tidskriftsartikel (refereegranskat)abstract
- Enhanced dissemination of information regarding energy saving and climate change targeted toward property owners is considered to be an important strategy in order to reach the Swedish national target of energy efficiency in the building sector by 2050. Here the municipality energy advisors and the national register for energy performance certificates can facilitate the mitigation of energy use in the building stock. So far few studies have focused on the practical road map to the national target of energy use on the city/district level and to the communication aspects with stakeholders in the creation of energy city models.In this paper a city energy model is developed based on the requests and need for visualization from a group of energy advisors. Six different scenarios are studied in order to analyze the possibility of reaching the energy targets specified by the government in the town of Kiruna. The results show that: (1) it is possible to automatically create city energy models using extract, transform and load tools based on spatial and non-spatial data from national registers and databases; (2) city energy models improve the understanding of energy use in buildings and can therefore be a valuable tool for energy advisors, real estate companies and urban planners. The case study of Kiruna showed that the proposed energy saving measures in the energy performance certificates need to be implemented and new buildings in the urban transformation must be of high energy standard in order to reach the national target in Kiruna.
|
|
| 14. |
- Joshi, Rubin Narayan, et al.
(författare)
-
TcellSubC : An Atlas of the Subcellular Proteome of Human T Cells
- 2019
-
Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- We have curated an in-depth subcellular proteomic map of primary human CD4+ T cells, divided into cytosolic, nuclear and membrane fractions generated by an optimized fractionation and HiRIEF-LC-MS/MS workflow for limited amounts of primary cells. The subcellular proteome of T cells was mapped under steady state conditions, as well as upon 15 min and 1 h of T cell receptor (TCR) stimulation, respectively. We quantified the subcellular distribution of 6,572 proteins and identified a subset of 237 potentially translocating proteins, including both well-known examples and novel ones. Microscopic validation confirmed the localization of selected proteins with previously known and unknown localization, respectively. We further provide the data in an easy-to-use web platform to facilitate re-use, as the data can be relevant for basic research as well as for clinical exploitation of T cells as therapeutic targets.
|
|
| 15. |
- Larsson, Martin, et al.
(författare)
-
Innovativa energieffektiva växthus - designade för lågtempererade energikällor och värmeåtervinning
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Lågtempererad restvärme är i dag en underutnyttjad resurs i samhället trots stor tillgång. I den här förstudien har växthus studerats, dvs system med stort behov av värmeenergi under delar av året. Projektet studerade teoretiskt ett växthuskoncept som använder lågvärdiga (30 – 40 °C) externa och interna värmekällor för uppvärmning, samt nyttjandet av frikyla (daggpunkt ca 25–10 °C) via termiskt lager för avfuktning. Syftet med förstudien är att skapa förutsättningar för hållbar och konkurrenskraftig växthusodling i Sverige genom synergier mellan olika branscher och tekniker. Som möjliggörare föreslås ett nytt koncept, som utvecklas för växthusodling, där energi- och odlingseffektivitet samspelar. Genom att utvärdera konceptet avser förstudien besvara frågeställningar om hur energieffektiv teknik dels kan minska energibehovet för växthus, dels använda sig av lågtempererade värmekällor, i kombination med värmeåtervinning, samtidigt som klimatet i växthuset styrs så odlingskapaciteten och CO2-gödsling förbättras. Resultatet visar att potentialen är mycket årstidsberoende och mycket beroende av hur stor värmekällan från växtbelysning är. Värmeåtervinning av växthusets interna värme kan minska värmeenergibehovet med ca 85% och växthuset kan använda lågtempererad värmekälla på ca 30–40 °C. Ytterligare resultat är att produktionen även kan ökas med ca 30–50% (beroende på årstid) med effektiv CO2-gödning och bättre klimat för växterna.
|
|
| 16. |
- Leo, Isabelle Rose, et al.
(författare)
-
Integrative multi-omics and drug response profiling of childhood acute lymphoblastic leukemia cell lines
- 2022
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Although standard-of-care chemotherapeutics are sufficient for most ALL cases, there are subsets of patients with poor response who relapse in disease. The biology underlying differences between subtypes and their response to therapy has only partially been explained by genetic and transcriptomic profiling. Here, we perform comprehensive multi-omic analyses of 49 readily available childhood ALL cell lines, using proteomics, transcriptomics, and pharmacoproteomic characterization. We connect the molecular phenotypes with drug responses to 528 oncology drugs, identifying drug correlations as well as lineage-dependent correlations. We also identify the diacylglycerol-analog bryostatin-1 as a therapeutic candidate in the MEF2D-HNRNPUL1 fusion high-risk subtype, for which this drug activates pro-apoptotic ERK signaling associated with molecular mediators of pre-B cell negative selection. Our data is the foundation for the interactive online Functional Omics Resource of ALL (FORALL) with navigable proteomics, transcriptomics, and drug sensitivity profiles at https://proteomics.se/fora.
|
|
| 17. |
- Lionello, M., et al.
(författare)
-
Graph-based modelling and simulation of liquid immersion cooling systems
- 2020
-
Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 207
-
Tidskriftsartikel (refereegranskat)abstract
- Currently, most of the existing data centers use chilled air to remove the heat produced by the servers. However, liquids have generally better heat dissipation capabilities than air, thus liquid cooling systems are expected to become a standard choice in future data centers. Designing and managing these cooling units benefit from having control-oriented models that can accurately describe the thermal status of both the coolant and the heat sources. This manuscript derives a control-oriented model of liquid immersion cooling systems, i.e., systems where servers are immersed in a dielectric fluid having good heat transfer properties. More specifically, we derive a general lumped-parameters gray box dynamical model that mimics energy and mass transfer phenomena that occur between the main components of the system. The proposed model is validated against experimental data gathered during the operation of a proof-of-concept immersion cooling unit, showing good approximation capabilities.
|
|
| 18. |
- Lionello, M., et al.
(författare)
-
Lumped-parameters control-oriented gray-box modelling of liquid immersion cooling systems
- 2019
-
Ingår i: 2019 18th European Control Conference, ECC 2019. - : Institute of Electrical and Electronics Engineers Inc.. - 9783907144008 ; , s. 3861-3866
-
Konferensbidrag (refereegranskat)abstract
- Liquid cooling systems have better heat dissipation capabilities than air based ones, and are expected to become a standard choice in future data centers, due to the ever increasing power density and heat rejection needs of the compute infrastructure. A convenient side-effect of implementing liquid cooling is that it facilitates the efficient recovery of the heat waste. However designing and managing these heat recovery infrastructures benefit from having control-oriented models that can accurately describe how different operating conditions of the to-be-cooled heat sources will affect the thermal status of the coolant. The aim of this manuscript is to derive control-oriented models of liquid immersion cooling systems, i.e., systems where the compute infrastructure is immersed in a vessel filled with dielectric fluid. More specifically we derive, starting from physical interpretations, a general lumped-parameters gray box dynamical model that has-as inputs-the electrical consumption of the heat sources and the working point of the heat recovery system, and has-as outputs-the temperature distribution of the coolant in the most relevant points of the system. Beyond proposing this modelling methodology we also validate the generalization capabilities of the obtainable models. In specific, we test the achievable statistical performances in a field case, plus compare with the ones of classical black box system identification strategies. We thus report that in the considered field case our gray box model reached a fit index of 91.08% when simulating test sets, while the best black box model we have been able to identify reached (on the same test sets) fit indexes of only 72.56%.
|
|
| 19. |
- Markeby Ljungqvist, Hampus, et al.
(författare)
-
A realistic view on heat reuse from direct free air-cooled data centres
- 2023
-
Ingår i: Energy Conversion and Management. - : Elsevier. - 2590-1745. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- This paper examines the opportunities to reuse excess heat from direct free air-cooled data centres without incorporating heat pumps to upgrade the heat. The operation of a data centre in northern Sweden, Luleå, was simulated for a year. It was established that heat losses through the thermal envelope and from the humidification of the cooling airflow influenced the momentary energy reuse factor, iERF, with up to 7%. However, for the annual energy reuse factor, ERF, the heat losses could be neglected since they annually contributed to an error of less than 1%. It was shown that the ideal heat reuse temperature in Luleå was 13, 17, and 18 °C with an exhaust temperature of 30, 40 and 50 °C. The resulting ERF was 0.50, 0.59 and 0.66, meaning that a higher exhaust temperature resulted in potentially higher heat reuse. It could also be seen that raising the exhaust temperature lowered the power usage effectiveness, PUE, due to more efficient cooling. Using heat reuse applications with different heat reuse temperatures closer to the monthly average instead of an ideal heat reuse temperature for the whole year improved the ERF further. The improvement was 11–31% where a lower exhaust temperature meant a higher relative improvement.
|
|
| 20. |
- Markeby Ljungqvist, Hampus, et al.
(författare)
-
Data center heated greenhouses, a matter for enhanced food self-sufficiency in sub-arctic regions
- 2021
-
Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 215
-
Tidskriftsartikel (refereegranskat)abstract
- This paper examines the possibility of increasing Northern Sweden's degree of self-sufficiency in food supply, at the 65th latitude, by using a data center as a heating source for greenhouse production. A dynamic building energy simulation software was used to compute both the hourly exhaust air output from a 1 MW data center for one year and the corresponding heating demand for two different greenhouse sizes, 2000 m2 and 10 000 m2, and two different production scenarios. Partial year production, 1 Mars – 15 October, without grow lights and full-year production with grow lights. The study showed that 5.5–30.5% of the electrical input to a 1 MW data center could be recovered. The 2000 m2 greenhouse could operate almost entirely, 89.7–97.9%, on excess heat while only 50.0–61.5% of the 10 000 m2 greenhouse heating demand could be met for full- and partial-year production, respectively. Furthermore, it is concluded that the 10 000 m2 greenhouse with full year production was the most prominent case and would cost-effectively yield 7.6% of northern Sweden's vegetable self-sufficiency.
|
|
| 21. |
- Mou, Tian, et al.
(författare)
-
The transcriptome-wide landscape of molecular subtype-specific mRNA expression profiles in acute myeloid leukemia
- 2021
-
Ingår i: American Journal of Hematology. - : John Wiley & Sons. - 0361-8609 .- 1096-8652. ; 96:5, s. 580-588
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular classification of acute myeloid leukemia (AML) aids prognostic stratification and clinical management. Our aim in this study is to identify transcriptome-wide mRNAs that are specific to each of the molecular subtypes of AML. We analyzed RNA-sequencing data of 955 AML samples from three cohorts, including the BeatAML project, the Cancer Genome Atlas, and a cohort of Swedish patients to provide a comprehensive transcriptome-wide view of subtype-specific mRNA expression. We identified 729 subtype-specific mRNAs, discovered in the BeatAML project and validated in the other two cohorts. Using unique proteomics data, we also validated the presence of subtype-specific mRNAs at the protein level, yielding a rich collection of potential protein-based biomarkers for the AML community. To enable the exploration of subtype-specific mRNA expression by the broader scientific community, we provide an interactive resource to the public.
|
|
| 22. |
- Orre, Lukas Minus, et al.
(författare)
-
SubCellBarCode : Proteome-wide Mapping of Protein Localization and Relocalization
- 2019
-
Ingår i: Molecular Cell. - : Elsevier BV. - 1097-2765 .- 1097-4164. ; 73:1, s. 166-182.e7
-
Tidskriftsartikel (refereegranskat)abstract
- Subcellular localization is a main determinant of protein function; however, a global view of cellular proteome organization remains relatively unexplored. We have developed a robust mass spectrometry-based analysis pipeline to generate a proteome-wide view of subcellular localization for proteins mapping to 12,418 individual genes across five cell lines. Based on more than 83,000 unique classifications and correlation profiling, we investigate the effect of alternative splicing and protein domains on localization, complex member co-localization, cell-type-specific localization, as well as protein relocalization after growth factor inhibition. Our analysis provides information about the cellular architecture and complexity of the spatial organization of the proteome; we show that the majority of proteins have a single main subcellular location, that alternative splicing rarely affects subcellular location, and that cell types are best distinguished by expression of proteins exposed to the surrounding environment. The resource is freely accessible via www.subcellbarcode.org.
|
|
| 23. |
- Pericault, Youen, 1992-, et al.
(författare)
-
A novel freeze protection strategy for shallow buried sewer pipes : temperature modelling and field investigation
- 2016
-
Ingår i: Proceedings of the 8th International Conference on Sewer Processes & Networks.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The burial of sewer and water pipes below the maximum ground frost depth can be very costly and laborious in regions with cold winters. If a freeze protection measure is applied, the utility lines can be installed in a shallower trench to reduce the excavation needs during construction and maintenance works. One freeze protection measure, so called heat tracing, consist in supplying heat along the pipes. In this work, the use of 4th generation district heating as a heat tracing solution was investigated at a pilot site in Kiruna, Sweden. The influence of the system on sewer and water pipes temperatures was studied experimentally and numerically at a snow-free and snow-covered cross section. The study showed that, under the climatic conditions of the experiment, a heat tracing temperature of 25 ˚C allowed to prevent freezing of the pipes while keeping drinking water pipes in safe temperature range at both cross sections. The other main result was that a finite volume model of the sections was developed and showed a good fitting to the experimental data.
|
|
| 24. |
- Pericault, Youen, 1992-, et al.
(författare)
-
A novel freeze protection strategy for shallow buried sewer pipes : temperature modelling and field investigation
- 2017
-
Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 76:2, s. 294-301
-
Tidskriftsartikel (refereegranskat)abstract
- The burial of sewer and water pipes below the maximum ground frost depth can be very costly and laborious in regions with cold winters. If a freeze protection measure is applied, the utility lines can be installed in a shallower trench to reduce the excavation needs. One freeze protection measure, so called heat tracing, consists in supplying heat along the pipes. In this work, the use of 4th generation district heating as a heat tracing solution was investigated at a pilot site in Kiruna, Sweden. The influence of the system on sewer and water pipe temperatures was studied at a snow-free and snow-covered cross section. To this end, five heat tracing temperatures were tested and the corresponding sewer and water pipe temperatures were measured. The field experiment was also simulated with a two dimensional finite volume model. The study showed that, under the climatic conditions of the experiment, a heat tracing temperature of 25 °C allowed to prevent freezing of the pipes while keeping drinking water pipes in a safe temperature range at both cross sections. The other main result was that the developed finite volume model of the sections showed a good fitting to the experimental data
|
|
| 25. |
|
|
| 26. |
- Ramos Caceres, Cristina, et al.
(författare)
-
Data-Center Farming: Exploring the Potential of Industrial Symbiosis in a Subarctic Region
- 2022
-
Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 14:5
-
Tidskriftsartikel (refereegranskat)abstract
- As our world becomes increasingly digitalized, data centers as operational bases for these technologies lead to a consequent increased release of excess heat into the surrounding environment. This paper studies the challenges and opportunities of industrial symbiosis between data centers’ excess heat and greenhouse farming, specifically utilizing the north of Sweden as a case study region. The region was selected in a bid to tackle the urgent urban issue of self-sufficiency in local food production. A synergetic approach towards engaging stakeholders from different sectors is presented through a mix of qualitative and quantitative methods to facilitate resilient data-center-enabled food production. The paper delivers on possible future solutions on implementing resource efficiency in subarctic regions.
|
|
| 27. |
- Risberg, Daniel, et al.
(författare)
-
CFD simulation and evaluation of different heating systems installed in low energy building located in sub-arctic climate
- 2015
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 89, s. 160-169
-
Tidskriftsartikel (refereegranskat)abstract
- Computational Fluid Dynamics (CFD) simulations were used to study the indoor climate in a low energy building in northern Sweden. The building’s low heat requirement raise the prospect of using a relatively simple and inexpensive heating system to maintain an acceptable indoor environment, even in the face of extremely low outdoor temperature. To explore the viability of this approach, the indoor climate in the building was studied considering three different heating systems: a floor heating system, air heating through the ventilation system and an air heat pump installation with one fan coil unit. The floor heating system provided the most uniform operative temperature distribution and was the only heating system that fully satisfied the recommendations to achieve tolerable indoor climate set by the Swedish authorities. On the contrary, air heating and the air heat pump created a relatively uneven distribution of air velocities and temperatures, and none of them fulfills the specified recommendations. From the economic point of view, the air heat pump system was cheaper to be installed but produced a less pleasant indoor environment than the other investigated heating systems.
|
|
| 28. |
- Risberg, Daniel, et al.
(författare)
-
CFD simulations of the indoor climate of a low energy building in a sub-Arctic climate: an evaluationof different heating systems.
- 2013
-
Konferensbidrag (refereegranskat)abstract
- Computational Fluid Dynamics (CFD) simulations were used to study the indoor climate in a low energy building in northern Sweden. The building’s low heat requirements raise the prospect of using relatively simple and inexpensive heating systems to maintain an acceptable indoor environment, even in the face of extremely low outdoor temperatures. To explore the viability of this approach, the indoor temperature and air velocity distribution inside the building were studied assuming that it was fitted with one of four different heating systems: radiators, an underfloor heating system, a pellet stove, and an air/air heat pump. The radiators produced a relatively uniform horizontal temperature distribution throughout the house. The underfloor system provided an even more uniform temperature distribution. In contrast, the heat pump created a relatively uneven internal temperature distribution. Several locations for the pump were considered, all of which had significant drawbacks. The pellet stove produced a more even temperature distribution than the pump but not to the same extent as the underfloor system or the radiators. Overall, point source heating systems cost less to fit and operate over a given period of time but produce a less clement indoor environment than distributed heating systems.
|
|
| 29. |
|
|
| 30. |
- Rykaczewska, Urszula, et al.
(författare)
-
PCSK6 Is a Key Protease in the Control of Smooth Muscle Cell Function in Vascular Remodeling
- 2020
-
Ingår i: Circulation Research. - : LIPPINCOTT WILLIAMS & WILKINS. - 0009-7330 .- 1524-4571. ; 126:5, s. 571-585
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale: PCSKs (Proprotein convertase subtilisins/kexins) are a protease family with unknown functions in vasculature. Previously, we demonstrated PCSK6 upregulation in human atherosclerotic plaques associated with smooth muscle cells (SMCs), inflammation, extracellular matrix remodeling, and mitogens. Objective: Here, we applied a systems biology approach to gain deeper insights into the PCSK6 role in normal and diseased vessel wall. Methods and Results: Genetic analyses revealed association of intronic PCSK6 variant rs1531817 with maximum internal carotid intima-media thickness progression in high-cardiovascular risk subjects. This variant was linked with PCSK6 mRNA expression in healthy aortas and plaques but also with overall plaque SMA+ cell content and pericyte fraction. Increased PCSK6 expression was found in several independent human cohorts comparing atherosclerotic lesions versus healthy arteries, using transcriptomic and proteomic datasets. By immunohistochemistry, PCSK6 was localized to fibrous cap SMA+ cells and neovessels in plaques. In human, rat, and mouse intimal hyperplasia, PCSK6 was expressed by proliferating SMA+ cells and upregulated after 5 days in rat carotid balloon injury model, with positive correlation to PDGFB (platelet-derived growth factor subunit B) and MMP (matrix metalloprotease) 2/MMP14. Here, PCSK6 was shown to colocalize and cointeract with MMP2/MMP14 by in situ proximity ligation assay. Microarrays of carotid arteries from Pcsk6(-/-) versus control mice revealed suppression of contractile SMC markers, extracellular matrix remodeling enzymes, and cytokines/receptors. Pcsk6(-/-) mice showed reduced intimal hyperplasia response upon carotid ligation in vivo, accompanied by decreased MMP14 activation and impaired SMC outgrowth from aortic rings ex vivo. PCSK6 silencing in human SMCs in vitro leads to downregulation of contractile markers and increase in MMP2 expression. Conversely, PCSK6 overexpression increased PDGFBB (platelet-derived growth factor BB)-induced cell proliferation and particularly migration. Conclusions: PCSK6 is a novel protease that induces SMC migration in response to PDGFB, mechanistically via modulation of contractile markers and MMP14 activation. This study establishes PCSK6 as a key regulator of SMC function in vascular remodeling.
|
|
| 31. |
- Sjölund, Johannes, et al.
(författare)
-
Validated Thermal Air Management Simulations of Data Centers Using Remote Graphics Processing Units
- 2018
-
Ingår i: Proceedings. - : IEEE. ; , s. 4920-4925
-
Konferensbidrag (refereegranskat)abstract
- Simulation tools for thermal management of data centers help to improve layout of new builds or analyse thermal problems in existing data centers. The development of LBM on remote GPUs as an approach for such simulations is discussed making use of VirtualGL and prioritised multi-threaded implementations of an existing LBM code. The simulation is configured to model an existing and highly monitored test data center. Steady-state root mean square averages of measured and simulated temperatures are compared showing good agreement. The full capability of this simulation approach is demonstrated when comparing rack temperatures against a time varying workload, which employs time-dependent boundary conditions.
|
|
| 32. |
|
|
| 33. |
- Struyf, Nona, et al.
(författare)
-
Delineating functional and molecular impact of ex vivo sample handling in precision medicine
- 2024
-
Ingår i: npj Precision Oncology. - : Springer Nature. - 2397-768X. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- Consistent handling of samples is crucial for achieving reproducible molecular and functional testing results in translational research. Here, we used 229 acute myeloid leukemia (AML) patient samples to assess the impact of sample handling on high-throughput functional drug testing, mass spectrometry-based proteomics, and flow cytometry. Our data revealed novel and previously described changes in cell phenotype and drug response dependent on sample biobanking. Specifically, myeloid cells with a CD117 (c-KIT) positive phenotype decreased after biobanking, potentially distorting cell population representations and affecting drugs targeting these cells. Additionally, highly granular AML cell numbers decreased after freezing. Secondly, protein expression levels, as well as sensitivity to drugs targeting cell proliferation, metabolism, tyrosine kinases (e.g., JAK, KIT, FLT3), and BH3 mimetics were notably affected by biobanking. Moreover, drug response profiles of paired fresh and frozen samples showed that freezing samples can lead to systematic errors in drug sensitivity scores. While a high correlation between fresh and frozen for the entire drug library was observed, freezing cells had a considerable impact at an individual level, which could influence outcomes in translational studies. Our study highlights conditions where standardization is needed to improve reproducibility, and where validation of data generated from biobanked cohorts may be particularly important.
|
|
| 34. |
- Vesterlund, Mattias, et al.
(författare)
-
A method for the simulation and optimization of district heating systems with meshed networks
- 2015
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 89, s. 555-567
-
Tidskriftsartikel (refereegranskat)abstract
- There are two main methods nowadays for modeling district heating systems, but a key disadvantage of both is that a real network containing loops cannot be described without artificial simplifications in order to eliminate those distinguishing features. However, loops are very common in mature networks that have developed a meshed structure, and make the distribution of mass and heat flows quite characteristic. For this reason, a new process integration method for modeling complex district heating systems containing loops is described in this paper. This method makes it possible to analyze how loops and bottlenecks affect the behavior of the network, as well as the distribution path of the thermal energy in it. The district heating system in the town of Kiruna (located in the north of Sweden) has a complex design with several loops and part of it is used in the paper as an example of application.
|
|
| 35. |
- Vesterlund, Mattias, et al.
(författare)
-
A new method for modeling district heating systems
- 2012
-
Konferensbidrag (refereegranskat)abstract
- Due to the mining of iron ore by the local mining industry (LKAB) a deformation zone is approaching the town of Kiruna, which is situated in the north of Sweden. The town is going through an urban transformation and parts of the town is about to be relocated. The relocating of the town is affecting all the infrastructure of the town, one of those is the district heating system. The aim of this paper is to apply a process integration method to study how the existing district heating system is behaving and to create a model for the whole district heating system.The district heating system in the town has a complex design with several loops. When dealing with modeling of a district heating system there are two methods that are most common, the Danish- and the German methods. These methods allow for simplification of the network shape, still with good accuracy in system behavior compared to real system behavior. A disadvantage with these two methods is that they cannot handle a district heating system that contains loops without making changes compared to the real physical system.A method that allows modeling of loops in the district heating system has been developed, using the remind-software. This method makes it possible to analyze how loops in the district heating system are behaving, without making physical changes when modeling the district heating system. The model will be used as a default model for redesigning the district heating system when moving the town. It will also be used to optimize heat deliveries from LKAB district heating system and for analyzing the possibility for seasonal storage of waste energy from LKAB and municipality energy company TVAB or how new heat production plants should optimized.In this paper the method is described and applied in order to model the whole present district heating system for the town.
|
|
| 36. |
- Vesterlund, Mattias, et al.
(författare)
-
Data center excess heat for mealworm farming, an applied analysis for sustainable protein production
- 2024
-
Ingår i: Applied Energy. - Malmö : IVL Svenska Miljöinstitutet AB. - 0306-2619 .- 1872-9118. ; 353, s. 121990-121990
-
Tidskriftsartikel (refereegranskat)abstract
- Since Sweden joined the EU in 1995, importing food became easier and cheaper, leading to certain parts of thecountry, such as Norrbotten, becoming highly dependent on imports. This dependency, along with the inherentenvironmental impact of imports, could be significantly reduced by local farming. The environmental emissionsoriginating from animal farming could be lowered even further by substituting the highly polluting soybean feedwith, e.g., insect feed.This study examines the farming of mealworms, utilizing excess heat from a data center,part of a growing industry in Norrbotten county, as a means of alternative feedstock for animal production and acase study for industrial symbiosis. This industrial symbiosis project is in line with the EU’s incentive to use othersources of protein and thus lower the EU’s reliance on the import of foreign protein. Three different feedingapproaches are tested, in a room heated with data center excess heat of 30 ◦C and at room temperature of about20 ◦C. After the adult mealworms were harvested, a sample was taken to analyze their nutritional values. Theresults show that protein, lipid, and fiber content is 19,1 g, 12,6 g, and 2,7 g per 100 g, respectively. All aminoacids except tryptophan were detected. This project concludes that it is possible to reach full-grown mealwormsin about 8 weeks, which is about half the time stated in the literature.
|
|
| 37. |
- Vesterlund, Mattias, et al.
(författare)
-
Data center for biomass drying
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Arctiq-DC is a InterReg North funded project with a total budget of about €1´430´000 where 9 partners from Sweden and Finland are collaborating: Oulu University, Oulun Data Center, Aurora Data Center, SFTec, Xarepo, Hushållningssällskapet, Älvsbyns municipality, Hydro 66 and RISE Research Institutes of Sweden as coordinator. The project duration is almost three years and consist of six main activities where the fourth is about cooling and heat reuse from data center. This report describes the trails that were made for evaluating data center excess heat as heat source for biomass drying.
|
|
| 38. |
- Vesterlund, Mattias, et al.
(författare)
-
Design optimization of a district heating network expansion : a case study for the town of Kiruna
- 2017
-
Ingår i: Applied Sciences. - Basel : MDPI. - 2076-3417. ; 7:5
-
Tidskriftsartikel (refereegranskat)abstract
- The urbanization of new areas beyond the existing perimeter of a town implies the expansion of several infrastructures, including the district heating network. The main variables involved in the design of the district heating network expansion are the layout of the new pipes, their diameters, and the capacity of the new heat production sites that are required to satisfy the increased demand of room heating and hot tap water. In this paper, a multi-objective evolutionary algorithm is applied to the minimization of the costs related to the expansion of the district heating network of the town of Kiruna, in northern Sweden. The results show that the spectrum of the optimal design compromises between investment costs for the new pipes and the new heat generation site on one side, and operating costs due to overall fuel consumption and pumping power in the network on the other. The presented methodology is a tool meant for the decision makers in the company who own the district heating network, to evaluate all the possible best design alternatives before making a decision.
|
|
| 39. |
- Vesterlund, Mattias, 1980-
(författare)
-
District heating system analysis and challenges within the urban transformation of Kiruna
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is currently an ongoing urban transformation in a small Swedish town named Kiruna, it is located in the very north of Sweden well above the Arctic Circle in a sub-arctic climate. Large part of the town will be relocated due to the ground deformation that is caused by the progressing iron ore mining activity and it is affecting all infrastructures of the town. This thesis aims to accomplish a holistic analysis on the district heating (DH) system for the town of Kiruna and its future challenges.Energy companies with a DH system recognize the importance in having a good understanding about the network characteristics, for obtaining an efficient and stabile heat delivery to the end-users. In this thesis, a method for modeling and simulation of meshed DH networks is described, that makes it possible to study and analyze the flow pattern in order to locate non-obvious paths, bottlenecks and overloaded pipes.For carrying out the DH simulations a fundamental input is to set the thermal losses for each pipe segment in the model, a fictitious series with all pipe diameters is created which corresponds to the annual losses in the real network. In comparison with the pipes series manufactured today the created one is best described by the series with least insulation and highest thermal losses. The studied network has its origin in the 60th and is the sum of the different piping technics that has been valid over time, this mixture is positioning the thermal performance as a close to a worst-case scenario.To the meshed DH network a number of heat production sites are connected for delivering the thermal requested by the end-users, each site consisting of several boilers and using different resources. A hybrid evolutionary-Mixed Integer Linear Programing (MILP) optimization approach is developed and applied for finding the cost-optimal heat production for three scenarios in combination of two heating demand levels. It is stated that no matter the geographically location of the site the cheapest resource should always be favorable as fuel, in the case when the same resource is viable at different sites a differentiated heat production is obtained. The supply temperature from each site is found to be the one lowest possible in order to serve all site-concerned end-users with a temperature level high enough for hot water production. The findings recommend a network temperatures reduction with the consequence in higher cost related to pumping work, but is lower than the savings due to the reduction in thermal losses.In order to provide the relocated part of the town with DH the hybrid evolutionary-MILP optimization routine is reshaped for finding different alternatives for network expansion layouts. The result is presented as a multi objective analysis between the operation cost and installation cost, showing the complete spectra of all optimal possible solutions and how the different cost correlate to each other. In this way, the outcome can be used for support in decision making, helping network owners is their planning and pipe sizing for new areas.For constructing the buildings that will populate the new city-area the Swedish government has stated a number of recommendations for achieving livable thermal indoor climate. An investigation is carried out analyzing the impact from the usage of three different heating system; air/air heat pump, air heating and floor heating in a low energy family house, where the first two system are aimed to use heat from the DH network. The analysis show that only the floor heating system satisfies the recommendations stated, but with carefully planning an air heating system could also fulfill the recommendations. Further, a techno-economical evaluation declares that the cheapest heating cost over 30 years is by using an air/air heat pump. In order to make DH competitive as heating source the needed price reduction is found for the hydronic floor and air heating system.Finally, three different building energy performance scenarios are studied in conjunction with the urban transformation in combination with the suggested energy measures from the Energy Performance certificates (EPC). In order to reach the national target entailing a reduction of 50% until 2050 all re-built buildings have to be built with passive standard and all advised measures in the EPC has to be carried out. Wort noticing is that the scenarios is analyzed as part of a 3-D City Model, which is found to be a worthwhile working tool for staff dealing with energy related issues.
|
|
| 40. |
- Vesterlund, Mattias
(författare)
-
District heating system analysis within the urban transformation of Kiruna
- 2014
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The urban transformation that is taking place in Kiruna, a Swedish town well above the Arctic Circle in the sub-arctic climate, is due to the ground deformation caused by iron ore mining and it is affecting all the infrastructures of the town. This thesis focuses on the studies about the district heating for the town of Kiruna. In the field of district heating it is important to have a good knowledge about network behavior, especially if network structure is meshed, in order to understand how the flow is distributed in each pipe within the network. This thesis describes the development of a method for the simulation of district heating networks that makes it possible to analyze and study complex networks with meshed structure, something that has not been possible before. The thermal losses for each pipe type are required as a fundamental input for the simulation. A fictitious pipe series has been created so that its loss matches the losses in the real network. It has been found that the created series is close to the series with the highest losses that is manufactured today. When redesigning the network structure to deal with the urban transformation, an investigation is performed regarding how new low energy building can be heated. This investigation shows that the only heating system that fulfills the guidelines stated by the Swedish authorities about indoor climate is the floor heating. A techno-economical evaluation shows that the cheapest heating technology is an air to air heat pump. In order to make district heating attractive as a heating source for house owners a vigorous price reduction is needed.
|
|
| 41. |
- Vesterlund, Mattias, et al.
(författare)
-
Evaluation of losses in district heating system, a case study
- 2013
-
Konferensbidrag (refereegranskat)abstract
- To be able to create a model that accurately describes a district heating system, it is important to identify the thermal losses and how they are distributed. However, general methods targeting the determination of losses are scarce in the literature. In the current case the losses for a district heating system in Kiruna, a town in northern Sweden, has been estimated in the year 2010 to be 12%, which is in the range for a typical Swedish network. Unfortunately, detailed information of the thermal losses is lacking.In this paper two methods to determine loss distribution in a district heating system are presented.Two databases of pipe lengths and diameters have been compiled for two piping categories, loops and feeds. Any missing data regarding pipe diameters in the map has then been determined with the two different methods.In the first method average pipe diameters for loops and feeds are calculated. All pipes with unknown diameter are then assumed to have the average one. The second method considers a percentage based distribution of known diameters and assigns the same distribution to the missing pipe diameters. The losses were estimated in the whole system according to the data from a pipe producer catalogue, in which losses are calculated according to current European standard. The results show that the losses in the system are similar to the losses caused by pipes with the lowest insulating capacity.By using the two methods two fictitious pipe series reproducing exactly the losses in the system are created by scaling the calculated losses of the catalogue pipe series which would give the most similar losses (the one with the lowest insulating capacity). This adjustment was +3.1% by using the first method, and +4.9% by using the second method.The major conclusion of this study is that, both methods can be used for calculating the distribution of thermal losses in the district heating system of Kiruna; moreover, this kind of analysis can be an important tool for analyzing investments in the district heating network in Kiruna.
|
|
| 42. |
- Vesterlund, Mattias, et al.
(författare)
-
Optimization of multi-source complex district heating network : a case study
- 2016
-
Ingår i: Proceeding of 29th International Conference on efficiency, Cost, Optimization, Simulation and Enviromental Impact of Energy Systems.
-
Konferensbidrag (refereegranskat)abstract
- The level of complexity for a district heating network increases with the maturity of the network, and this affects the pattern of the distribution of the hot water from the heat production sites to the end users. The majority of district heating systems are also multi-source networks, typically supported with heat from one main production site and other smaller satellite sites that are activated when required. In general, local energy companies have a lack of knowledge regarding how a meshed network behaves when different production sites are operated. The schedule of heat generation at the different sites is often based on staff experience and some general rules of thumb.In this paper a method for modeling and simulating complex district networks is further developed in order to optimize the total operating costs of a multi-source network, with constraints on the pressure and temperature levels in the user areas and on the heat generation characteristics at each production site.The optimization results show that the usage of the cheapest resources is preferred to a distributed generation of heat, even if some of the pipes may exceed the recommended thermal load capacity. The main site water supply temperature is found to be the lowest allowed by the constraint on the temperature of the water supplied to the end users, since the decrease of the costs associated with the lower thermal losses in the network is not counterbalanced by the increase of those associated with the pumping power of a larger water mass flow rate.
|
|
| 43. |
- Vesterlund, Mattias, et al.
(författare)
-
Optimization of multi-source complex district heating network, a case study
- 2017
-
Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 126, s. 53-63
-
Tidskriftsartikel (refereegranskat)abstract
- The level of complexity for a district heating network increases with the maturity of the network, and this affects the pattern of the distribution of the hot water from the heat production sites to the end users. The majority of district heating systems are also multi-source networks, typically supported with heat from one main production site and other smaller satellite sites that are activated when required. In general, local energy companies have a lack of knowledge regarding how a meshed network behaves when different production sites are operated. The schedule of heat generation at the different sites is often based on staff experience and some general rules of thumb.In this paper a method for modeling and simulating complex district networks is further developed in order to optimize the total operating costs of a multi-source network, with constraints on the pressure and temperature levels in the user areas and on the heat generation characteristics at each production site.The optimization results show that the usage of the cheapest resources is preferred to a distributed generation of heat, even if some of the pipes may exceed the recommended thermal load capacity. The main site water supply temperature is found to be the lowest allowed by the constraint on the temperature of the water supplied to the end users, since the decrease of the costs associated with the lower thermal losses in the network is not counterbalanced by the increase of those associated with the pumping power of a larger water mass flow rate.
|
|
| 44. |
- Vesterlund, Mattias, et al.
(författare)
-
Simulation and analysis of a meshed district heating network
- 2015
-
Ingår i: ECOS 2015. - : International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - 9782955553909
-
Konferensbidrag (refereegranskat)abstract
- The maturity of a district heating system can be estimated from its complexity. In fact, a mature network has a meshed structure while a younger network is often in the form of small network islands or has a tree structure. When a district heating system is developing and its complexity is increasing the flow distribution in the network is no longer obvious. As a consequence, the network owner, often the local energy company, is in need of a simulation program to have the possibility of analysing it and enlarge their network understanding. In this paper, a simulation tool developed in MATLAB/Simulink is applied in order to analyse the flow distribution in the district heating network of the town of Kiruna (Sweden). The Kiruna network has been developing since the 60s and is today a mature network with the meshed structure. The method has specifically been developed to analyse the flow pattern in such kind of networks without altering their physical structure, and it is expected to be a valuable tool for the redesign of the network in the forthcoming relocation of some of the urban districts. The results about the current network configuration show that only a few pipes in the network are exceeding the recommended level of flow in terms of thermal power. The temperature and pressure drop from heat production site to the nodes serving the main consumer areas is within 1.6 bar and 10°C in the days of highest demand.
|
|
| 45. |
- Vesterlund, Mattias, et al.
(författare)
-
Simulation and analysis of a meshed district heating network
- 2016
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 122, s. 63-73
-
Tidskriftsartikel (refereegranskat)abstract
- The flow distribution in a district heating network tends to become no longer obvious when system design is developed and its complexity increased. As a consequence, the network owner, often the local energy company, is in need of a simulation program to have the possibility of analysing network behaviour and expand the understanding about the operation of district heating system. In this paper, a simulation tool developed in MATLAB/Simulink is applied in order to analyse the flow distribution in the district heating network of the town of Kiruna (Sweden). The network in Kiruna has been developing since the 60s and is today a complex network with a meshed structure, i.e. it is formed by a set of loops from which secondary branches depart. The simulation tool is part of a methodology that has specifically been developed to analyse the flow pattern in such kind of networks without altering their physical structure, and it is expected to be a valuable tool for the redesign of the network in the forthcoming relocation of some of the urban districts. The results about the current network configuration show that only a few pipes in the network are exceeding the levels of heat flow recommended by pipe manufacturers. The largest drops in pressure and temperature from the heat production site to the nodes serving the main consumer areas are within 1.2 bar and 9 °C in the days of highest demand.
|
|
| 46. |
- Vesterlund, Mattias
(författare)
-
The mechanism of action of SOCS2 and its role in metabolism and growth
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A well-known function of Growth Hormone (GH) is the regulation of postnatal longitudinal growth but it also affects other biological processes, for instance metabolism and inflammation. Actions of GH are tightly regulated at several levels and by several different factors and are initiated by GH binding to membrane bound GH receptors (GHR). The intracellular signaling of GH and other related hormones and cytokines is predominately mediated by the JAK-STAT pathway. This pathway is regulated in a negative feedback manner by the Suppressors of Cytokine Signaling (SOCS) family of proteins. One of the family members, SOCS2, is intimately tied to GH by virtue of the phenotype that results from its absence. SOCS2-/- mice are 40% larger than wildtype littermates due to increased GH sensitivity. Here, the molecular mechanism behind SOCS2s negative regulation of GH signaling, and its effects on metabolism and inflammation are described. We demonstrate that SOCS2 assembles a canonical E3 ubiquitin ligase complex with Elongin B, Elongin C, Cullin 5 and Rbx2 and that this complex has intrinsic E3 ligase activity in vitro. Overexpression of SOCS2 and its complex members leads to ubiquitination and proteasomal degradation of the GHR. We also outline the importance of the different domains of SOCS2, and demonstrate the necessity of the SOCS-box for proper SOCS2 activity. In a follow up study the claim that the naturally occurring Ser52Asn polymorphism of SOCS2 affects its activity and may contribute to acromegaly in humans was investigated. The Ser52Asn mutant was however found to be as efficient at regulating GH signaling as the wildtype and we conclude that it is unlikely to contribute to increased GH sensitivity. In Paper III the phenotype of SOCS2-/- mice under conditions of dietary stress is described. We report that SOCS2 deletion protects against high fat diet (HFD) induced hepatic steatosis but simultaneously leads to decreased insulin sensitivity. SOCS2-/- mice were found to have increased triglyceride output from the liver but also increased plasma levels of proinflammatory cytokines without apparent macrophage infiltration. In vitro examination of macrophages revealed increased phagocytic activity and cytokine production in the absence of SOCS2 and suggests a direct role for SOCS2 in the regulation of TLR4 signaling. Finally, the results of a screening effort to identify SOCS2-modulating, drug-like molecules are included. We have identified a prospective hit that binds to and inhibits SOCS2 activity in vitro. In summary, SOCS forms an E3 ligase complex which targets the GHR for degradation. This forms the molecular basis of its physiological actions. SOCS2-/- mice are protected from HFD induced hepatic steatosis but suffer from deteriorated insulin sensitivity related to increased inflammation.
|
|
| 47. |
- Yang, Minjun, et al.
(författare)
-
Proteogenomics and Hi-C reveal transcriptional dysregulation in high hyperdiploid childhood acute lymphoblastic leukemia
- 2019
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Hyperdiploidy, i.e. gain of whole chromosomes, is one of the most common genetic features of childhood acute lymphoblastic leukemia (ALL), but its pathogenetic impact is poorly understood. Here, we report a proteogenomic analysis on matched datasets from genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of >8,000 genes and proteins as well as Hi-C of primary patient samples from hyperdiploid and ETV6/RUNX1-positive pediatric ALL. We show that CTCF and cohesin, which are master regulators of chromatin architecture, display low expression in hyperdiploid ALL. In line with this, a general genome-wide dysregulation of gene expression in relation to topologically associating domain (TAD) borders were seen in the hyperdiploid group. Furthermore, Hi-C of a limited number of hyperdiploid childhood ALL cases revealed that 2/4 cases displayed a clear loss of TAD boundary strength and 3/4 showed reduced insulation at TAD borders, with putative leukemogenic effects.
|
|
| 48. |
- Zhabelova, Gulnara, et al.
(författare)
-
A Comprehensive Model of Data Center : From CPU to Cooling Tower
- 2018
-
Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 6, s. 61254-61266
-
Tidskriftsartikel (refereegranskat)abstract
- Aiming at addressing environmental challenges, large data centers, such as Facebook, Google, and Yahoo, are increasing share of green power in their daily energy consumption. Such trends drive research into new directions, e.g., sustainable data centers. The research often relies on expressive models that provide sufficient details, however, practical to re-use and expand. There is a lack of available data center models that capture internal operating states of the facility from the CPU to the cooling tower. It is a challenge to develop a model that allows to describe complete data center of any scale including its connection to the grid. This paper proposes such a model building on the existing work. The challenge was to put the pieces of data center together and model behavior of each element so that interdependencies between components and parameters and operating states are captured correctly and in sufficient details. The proposed model was used in the project 'Data center microgrid integration' and proven to be adequate and important to support such study.
|
|
| 49. |
- Zhabelova, Gulnara, et al.
(författare)
-
Towards an Open Model for Data Center Research : From CPU to Cooling Tower
- 2018
-
Ingår i: Proceedings. - : IEEE. ; , s. 4913-4919
-
Konferensbidrag (refereegranskat)abstract
- Data centers are important players in the energy infrastructure. Aiming at addressing environmental challenges, large data centers such as Facebook, Google, Yahoo, etc., are increasing share of green power in their daily energy consumption. Such trends drive research into new directions, e.g. sustainable data centers. The research often relies on expressive models that provides sufficient details however practical to re-use and expand. There is a lack of available data center models that capture dynamics of the facility from the CPU to the cooling tower. It is a challenge to develop a model that allows to describe complete data center of any scale including its connection to the grid. This paper proposes such a model building on existing work. The challenge was to put the pieces of data center together and describe dynamics of each element so that interdependencies between components and parameters are captured correctly and in sufficient details. The proposed model was used in the project “Data center microgrid integration” and proven to be adequate and important to support such study.
|
|
| 50. |
- Zhu, Yafeng, et al.
(författare)
-
Discovery of coding regions in the human genome by integrated proteogenomics analysis workflow
- 2018
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Proteogenomics enable the discovery of novel peptides (from unannotated genomic protein-coding loci) and single amino acid variant peptides (derived from single-nucleotide polymorphisms and mutations). Increasing the reliability of these identifications is crucial to ensure their usefulness for genome annotation and potential application as neoantigens in cancer immunotherapy. We here present integrated proteogenomics analysis workflow (IPAW), which combines peptide discovery, curation, and validation. IPAW includes the SpectrumAI tool for automated inspection of MS/MS spectra, eliminating false identifications of single-residue substitution peptides. We employ IPAW to analyze two proteomics data sets acquired from A431 cells and five normal human tissues using extended (pH range, 3-10) high-resolution isoelectric focusing (HiRIEF) pre-fractionation and TMT-based peptide quantitation. The IPAW results provide evidence for the translation of pseudogenes, lncRNAs, short ORFs, alternative ORFs, N-terminal extensions, and intronic sequences. Moreover, our quantitative analysis indicates that protein production from certain pseudogenes and lncRNAs is tissue specific.
|
|
