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- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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- Arndt, D. S., et al.
(författare)
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State of the Climate in 2016
- 2017
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 98:8, s. S1-S280
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Tidskriftsartikel (refereegranskat)abstract
- In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
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- Lorenz, M. W., et al.
(författare)
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Predictive value for cardiovascular events of common carotid intima media thickness and its rate of change in individuals at high cardiovascular risk - Results from the PROG-IMT collaboration
- 2018
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Aims Carotid intima media thickness (CIMT) predicts cardiovascular (CVD) events, but the predictive value of CIMT change is debated. We assessed the relation between CIMT change and events in individuals at high cardiovascular risk. From 31 cohorts with two CIMT scans (total n = 89070) on average 3.6 years apart and clinical follow-up, subcohorts were drawn: (A) individuals with at least 3 cardiovascular risk factors without previous CVD events, (B) individuals with carotid plaques without previous CVD events, and (C) individuals with previous CVD events. Cox regression models were fit to estimate the hazard ratio (HR) of the combined endpoint (myocardial infarction, stroke or vascular death) per standard deviation (SD) of CIMT change, adjusted for CVD risk factors. These HRs were pooled across studies. In groups A, B and C we observed 3483, 2845 and 1165 endpoint events, respectively. Average common CIMT was 0.79mm (SD 0.16mm), and annual common CIMT change was 0.01mm (SD 0.07mm), both in group A. The pooled HR per SD of annual common CIMT change (0.02 to 0.43mm) was 0.99 (95% confidence interval: 0.95-1.02) in group A, 0.98 (0.93-1.04) in group B, and 0.95 (0.89-1.04) in group C. The HR per SD of common CIMT (average of the first and the second CIMT scan, 0.09 to 0.75mm) was 1.15 (1.07-1.23) in group A, 1.13 (1.05-1.22) in group B, and 1.12 (1.05-1.20) in group C. We confirm that common CIMT is associated with future CVD events in individuals at high risk. CIMT change does not relate to future event risk in high-risk individuals.
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5. |
- Liao, X., et al.
(författare)
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Normative values for carotid intima media thickness and its progression: Are they transferrable outside of their cohort of origin?
- 2016
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Ingår i: European Journal of Preventive Cardiology. - : Oxford University Press (OUP). - 2047-4873 .- 2047-4881. ; 23:11, s. 1165-1173
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Tidskriftsartikel (refereegranskat)abstract
- Background The clinical use of carotid intima media thickness (cIMT) requires normal values, which may be subject to variation of geographical factors, ethnicity or measurement details. The influence of these factors has rarely been studied. The aim of this study was to determine whether normative cIMT values and their association with event risk are generalizable across populations. Design Meta-analysis of individual participant data. Method From 22 general population cohorts from Europe, North America and Asia we selected subjects free of cardiovascular disease. Percentiles of cIMT and cIMT progression were assessed separately for every cohort. Cox proportional hazards models for vascular events were used to estimate hazard ratios for cIMT in each cohort. The estimates were pooled across Europe, North America and Asia, with random effects meta-analysis. The influence of geography, ethnicity and ultrasound protocols on cIMT values and on the hazard ratios was examined by meta-regression. Results Geographical factors, ethnicity and the ultrasound protocol had influence neither on the percentiles of cIMT and its progression, nor on the hazard ratios of cIMT for vascular events. Heterogeneity for percentiles of cIMT and cIMT progression was too large to create meaningful normative values. Conclusions The distribution of cIMT values is too heterogeneous to define universal or regional population reference values. CIMT values vary widely between different studies regardless of ethnicity, geographic location and ultrasound protocol. Prediction of vascular events with cIMT values was more consistent across all cohorts, ethnicities and regions. © 2016 European Society of Cardiology.
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- Li, S. J., et al.
(författare)
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The 1p36 Tumor Suppressor KIF 1B beta Is Required for Calcineurin Activation, Controlling Mitochondrial Fission and Apoptosis
- 2016
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 36:2, s. 164-178
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Tidskriftsartikel (refereegranskat)abstract
- KIF1B beta is a candidate 1p36 tumor suppressor that regulates apoptosis in the developing sympathetic nervous system. We found that KIF1B beta activates the Ca2+-dependent phosphatase calcineurin (CN) by stabilizing the CN-calmodulin complex, relieving enzymatic autoinhibition and enabling CN substrate recognition. CN is the key mediator of cellular responses to Ca2+ signals and its deregulation is implicated in cancer, cardiac, neurodegenerative, and immune disease. We show that KIF1B beta affects mitochondria! dynamics through CN-dependent dephosphorylation of Dynamin-related protein 1 (DRP1), causing mitochondria! fission and apoptosis. Furthermore, KIF1B beta actuates recognition of all known CN substrates, implying a general mechanism for KIF1B beta in Ca2+ signaling and how Ca2+-dependent signaling is executed by CN. Pathogenic KIF1B beta mutations previously identified in neuroblastomas and pheochromocytomas all fail to activate CN or stimulate DRP1 dephosphorylation. Importantly, KIF1B beta and DRP1 are silenced in 1p36 hemizygous-deleted neuroblastomas, indicating that deregulation of calcineurin and mitochondria! dynamics contributes to high-risk and poor-prognosis neuroblastoma.
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8. |
- Lorenz, M. W., et al.
(författare)
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Carotid Intima-Media Thickness Progression and Risk of Vascular Events in People With Diabetes: Results From the PROG-IMT Collaboration
- 2015
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 38:10, s. 1921-1929
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVECarotid intima-media thickness (CIMT) is a marker of subclinical organ damage and predicts cardiovascular disease (CVD) events in the general population. It has also been associated with vascular risk in people with diabetes. However, the association of CIMT change in repeated examinations with subsequent CVD events is uncertain, and its use as a surrogate end point in clinical trials is controversial. We aimed at determining the relation of CIMT change to CVD events in people with diabetes.RESEARCH DESIGN AND METHODSIn a comprehensive meta-analysis of individual participant data, we collated data from 3,902 adults (age 33-92 years) with type 2 diabetes from 21 population-based cohorts. We calculated the hazard ratio (HR) per standard deviation (SD) difference in mean common carotid artery intima-media thickness (CCA-IMT) or in CCA-IMT progression, both calculated from two examinations on average 3.6 years apart, for each cohort, and combined the estimates with random-effects meta-analysis.RESULTSAverage mean CCA-IMT ranged from 0.72 to 0.97 mm across cohorts in people with diabetes. The HR of CVD events was 1.22 (95% CI 1.12-1.33) per SD difference in mean CCA-IMT, after adjustment for age, sex, and cardiometabolic risk factors. Average mean CCA-IMT progression in people with diabetes ranged between -0.09 and 0.04 mm/year. The HR per SD difference in mean CCA-IMT progression was 0.99 (0.91-1.08).CONCLUSIONSDespite reproducing the association between CIMT level and vascular risk in subjects with diabetes, we did not find an association between CIMT change and vascular risk. These results do not support the use of CIMT progression as a surrogate end point in clinical trials in people with diabetes.
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- Jakola, Asgeir Store, et al.
(författare)
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Surgical resection versus watchful waiting in low-grade gliomas.
- 2017
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Ingår i: Annals of oncology : official journal of the European Society for Medical Oncology. - : Elsevier BV. - 1569-8041. ; 28:8, s. 1942-1948
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Tidskriftsartikel (refereegranskat)abstract
- Background: Infiltrating low-grade gliomas (LGG; WHO grade 2) typically present with seizures in young adults. LGGs grow continuously and usually transform to higher grade of malignancy, eventually causing progressive disability and premature death. The effect of up-front surgery has been controversial and the impact of molecular biology on the effect of surgery is unknown. We now present long-term results of upfront surgical resection compared to watchful waiting in light of recently established molecular markers. Material and methods: Population-based parallel cohorts were followed from two Norwegian university hospitals with different surgical treatment strategies and defined geographical catchment regions. In region A watchful waiting was favored while early resection was favored in region B. Thus, the treatment strategy in individual patients depended on their residential address. The inclusion criteria were histopathological diagnosis of supratentorial LGG from 1998 through 2009 in patients 18 years or older. Follow-up ended 1st January 2016. Making regional comparisons, the primary end-point was overall survival. Results 153 patients (66 from region A, 87 from region B) were included. Early resection was carried out in 19 (29%) patients in region A compared to 75 (86%) patients in region B. Overall survival was 5.8 years (95% CI 4.5–7.2) in region A compared to 14.4 years (95% CI 10.4–18.5) in region B (P<0.01). The effect of surgical strategy remained after adjustment for molecular markers (P=0.001). Conclusion In parallel population based cohorts of LGGs, early surgical resection resulted in a clinical relevant survival benefit. The effect on survival persisted after adjustment for molecular markers.
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- Klevebro, F., et al.
(författare)
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Morbidity and mortality after surgery for cancer of the oesophagus and astro-oesophageal junction : a randomized clinical trial of neoadjuvant hemotherapy vs. neoadjuvant chemoradiation
- 2015
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Ingår i: European Journal of Surgical Oncology. - : Elsevier BV. - 0748-7983 .- 1532-2157. ; 41:7, s. 920-926
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare the incidence and severity of postoperative omplications after oesophagectomy for carcinoma of the oesophagus and astro-oesophageal junction (GOJ) after randomized accrual to eoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT). ackground: Neoadjuvant therapy improves long-term survival after esophagectomy. To date, evidence is insufficient to determine whether ombined nCT, or nCRT alone, is the most beneficial. ethods: Patients with carcinoma of the oesophagus or GOJ, resectable ith a curative intention, were enrolled in this multicenter trial onducted at seven centres in Sweden and Norway. Study participants re andomized to nCT or nCRT followed by surgery with two-field ymphadenectomy. Three cycles of cisplatin/5-fluorouracil was dministered in all patients, while 40 Gy of concomitant radiotherapy as administered in the nCRT group. esults: Of the randomized 181 patients, 91 were assigned to nCT and 90 o nCRT. One-hundred-and-fifty-five patients, 78 nCT and 77 nCRT, nderwent resection. There was no statistically significant difference etween the groups in the incidence of surgical or nonsurgical omplications (P-value = 0.69 and 0.13, respectively). There was no 0-day mortality, while the 90-day mortality was 3% (2/78) in the nCT roup and 6% (5/77) in the nCRT group (P = 0.24). The median lavien-Dindo complication severity grade was significantly higher in he nCRT. group (P = 0.001). onclusion: There was no significant difference in the incidence of omplications between patients randomized to nCT and nCRT. However, omplications were significantly more severe after nCRT. Registration rial database: The trial was registered in the Clinical Trials tabase registration number NCT01362127).
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- Pascal, Mathilde M.V., et al.
(författare)
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DOLORisk : Study protocol for a multi-centre observational study to understand the risk factors and determinants of neuropathic pain [version 2; referees: 2 approved]
- 2019
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Ingår i: Wellcome Open Research. - : F1000 Research Ltd. - 2398-502X. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neuropathic pain is an increasingly prevalent condition and has a major impact on health and quality of life. However, the risk factors for the development and maintenance of neuropathic pain are poorly understood. Clinical, genetic and psychosocial factors all contribute to chronic pain, but their interactions have not been studied in large cohorts. The DOLORisk study aims to study these factors. Protocol: Multicentre cross-sectional and longitudinal cohorts covering the main causes leading to neuropathic pain (e.g. diabetes, surgery, chemotherapy, traumatic injury), as well as rare conditions, follow a common protocol for phenotyping of the participants. This core protocol correlates answers given by the participants on a set of questionnaires with the results of protocol for phenotyping of the participants. This core protocol correlates answers given by the participants on a set of questionnaires with the results of their genetic analyses. A smaller number of participants undergo deeper phenotyping procedures, including neurological examination, nerve conduction studies, threshold tracking, quantitative sensory testing, conditioned pain modulation and electroencephalography. Ethics and dissemination: All studies have been approved by their regional ethics committees as required by national law. Results are disseminated through the DOLORisk website, scientific meetings, open-access publications, and in partnership with patient organisations. Strengths and limitations: • Large cohorts covering many possible triggers for neuropathic pain • Multi-disciplinary approach to study the interaction of clinical, psychosocial and genetic risk factors • High comparability of the data across centres thanks to harmonised protocols • One limitation is that the length of the questionnaires might reduce the response rate and quality of responses of participants.
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- Agnihotri, Swarnima, et al.
(författare)
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Ethanol organosolv pretreatment of softwood (Picea abies) and sugarcane bagasse for biofuel and biorefinery applications
- 2015
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 0043-7719 .- 1432-5225. ; 49:5, s. 881-896
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Tidskriftsartikel (refereegranskat)abstract
- Ethanol derived from biomass has the potential to be a renewable transportation fuel that can replace gasoline. This work was carried out to establish an optimized ethanol organosolv pretreatment of Norway spruce (Picea abies) for bioethanol production (63 wt% EtOH, pH ~3.5 in aqueous phase, 170–240 °C, 90 min) utilizing hydrolytic enzymes in the saccharification step. To test the generality of the method, a series of ethanol organosolv pretreatments were also performed on sugarcane bagasse (50 wt% EtOH, pH ~3.5 in aqueous phase, 155–210 °C, 90–120 min). The degree of delignification increased with increasing temperature during pretreatment, and the fastest increase was observed with sugarcane bagasse. The pretreatments were carried out in a batch mode. The maximum degree of delignification of ~65 % was reached at ~235 °C for Norway spruce, while sugarcane bagasse reached ~80 % at ~210 °C. Cellulose was subjected to degradation (5–10 % points) at these temperatures. Subsequent enzymatic hydrolysis (30 FPU/g cellulose, 32 pNPGU/g cellulose, 50 °C, 48 h) of ethanol organosolv-pretreated biomass achieved complete conversion for both raw materials at the highest degrees of delignification.
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Applied Social Science Research in a Regional Knowledge System : Balancing validity, meaning and convenience
- 2016
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- This book illustrates how applied social scientists and their research are integrated with stakeholders and practitioners in a local/regional setting, and how knowledge development is a mutual concern, made in, and dependent on, ongoing dialogue. Focusing on the Agder region, the southernmost region in Norway, researchers and contributors question what impact the changing economic environment will have on applied researchers around the world. Applied research is seen as a vital part of the infrastructure for economic and social development, in the Agder region and beyond. The chapters are divided into four parts:the spatial dimension of knowledge development;understanding regional practice;explaining regional practice;influencing regional social practice.A useful resource for both policy makers and researchers, the book helps readers reflect on the type of mutual competence building that applied social science research implies, and depends on, in a regional knowledge development process. It represents a voice on how to understand the development of the knowledge society at regional and global levels.
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22. |
- Brandauer, Stephan, et al.
(författare)
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Parallel Objects for Multicores : A Glimpse at the Parallel Language ENCORE
- 2015
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Ingår i: Formal Methods for Multicore Programming. - Cham : Springer International Publishing. - 9783319189413 - 9783319189406 ; , s. 1-56
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Konferensbidrag (refereegranskat)abstract
- The age of multi-core computers is upon us, yet current programming languages, typically designed for single-core computers and adapted post hoc for multi-cores, remain tied to the constraints of a sequential mindset and are thus in many ways inadequate. New programming language designs are required that break away from this old-fashioned mindset. To address this need, we have been developing a new programming language called Encore, in the context of the European Project UpScale. The paper presents a motivation for the Encore language, examples of its main constructs, several larger programs, a formalisation of its core, and a discussion of some future directions our work will take. The work is ongoing and we started more or less from scratch. That means that a lot of work has to be done, but also that we need not be tied to decisions made for sequential language designs. Any design decision can be made in favour of good performance and scalability. For this reason, Encore offers an interesting platform for future exploration into object-oriented parallel programming.
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- Cramer, Emily R. A., et al.
(författare)
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Females discriminate against heterospecific sperm in a natural hybrid zone
- 2016
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 70:8, s. 1844-1855
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Tidskriftsartikel (refereegranskat)abstract
- When hybridization is maladaptive, species-specific mate preferences are selectively favored, but low mate availability may constrain species-assortative pairing. Females paired to heterospecifics may then benefit by copulating with multiple males and subsequently favoring sperm of conspecifics. Whether such mechanisms for biasing paternity toward conspecifics act as important reproductive barriers in socially monogamous vertebrate species remains to be determined. We use a combination of long-term breeding records from a natural hybrid zone between collared and pied flycatchers (Ficedula albicollis and F. hypoleuca), and an in vitro experiment comparing conspecific and heterospecific sperm performance in female reproductive tract fluid, to evaluate the potential significance of female cryptic choice. We show that the females most at risk of hybridizing (pied flycatchers) frequently copulate with multiple males and are able to inhibit heterospecific sperm performance. The negative effect on heterospecific sperm performance was strongest in pied flycatcher females that were most likely to have been previously exposed to collared flycatcher sperm. We thus demonstrate that a reproductive barrier acts after copulation but before fertilization in a socially monogamous vertebrate. While the evolutionary history of this barrier is unknown, our results imply that there is opportunity for it to be accentuated via a reinforcement-like process.
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- Ekman, S, et al.
(författare)
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I-O Optimise: a novel multinational real-world research platform in thoracic malignancies
- 2019
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Ingår i: Future oncology (London, England). - : Future Medicine Ltd. - 1744-8301 .- 1479-6694. ; 15:14, s. 1551-1563
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To describe I-O Optimise, a multinational program providing real-world insights into lung cancer management. Materials & methods: Real-world data source selection for I-O Optimise followed a structured approach focused on population coverage, key variable capture, continuous/consistent data availability, record duration and data latency, and database expertise. Results: As of 31 October 2018, seven real-world data sources were included in I-O Optimise, providing data on characteristics, treatment patterns and clinical outcomes from more than 45,000 patients/year with non-small-cell lung cancer, small-cell lung cancer and mesothelioma across Denmark, Norway, Portugal, Spain, Sweden and the UK. Conclusion: The ongoing I-O Optimise initiative has the potential to provide a broad, robust and dynamic research platform to continually address numerous research objectives in the lung cancer arena.
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- Eroukhmanoff, Fabrice, et al.
(författare)
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Experimental evidence for ovarian hypofunction in sparrow hybrids
- 2016
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Ingår i: Avian Research. - : Elsevier BV. - 2053-7166. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPostzygotic isolation in the form of reduced viability and/or fertility of hybrids may help maintain species boundaries in the face of interspecific gene flow. Past hybridization events between house sparrows (Passer domesticus) and Spanish sparrows (P. hispaniolensis) have given rise to a homoploid hybrid species, the Italian sparrow (P. italiae). Although genetic incompatibilities are known to isolate these three species, the biological consequences of these incompatibilities are still unknown in early generation hybrids.MethodsWe investigated whether F1 hybrids between house and Spanish sparrows experience reduced viability or fertility. More specifically, we generated hybrids through controlled crosses in aviaries, and compared ovaries of female hybrids with female of pure-species sparrows.ResultsWe found that overall, hybrid ovaries were underdeveloped and that half of all female hybrids exhibited symptoms of ovarian hypofunction (ovarian atrophy and complete absence of developed follicles).ConclusionsFertility in hybrids is a common consequence or post-zygotic barriers between species. We discuss these results in light of previous findings on genetic incompatibilities between the parent species and the potential role of incompatibilities in hybrid speciation, a rare evolutionary process in birds.
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- Haaland, S., et al.
(författare)
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Estimation of cold plasma outflow during geomagnetic storms
- 2015
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 120:12, s. 10622-10639
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Tidskriftsartikel (refereegranskat)abstract
- Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in regions of space where spacecraft attain a positive charge due to solar illumination. Cold ions are therefore shielded from the satellite particle detectors. Furthermore, spacecraft can only cover key regions of ion outflow during segments of their orbit, so additional complications arise if continuous longtime observations, such as during a geomagnetic storm, are needed. In this paper we suggest a new approach, based on a combination of synoptic observations and a novel technique to estimate the flux and total outflow during the various phases of geomagnetic storms. Our results indicate large variations in both outflow rates and transport throughout the storm. Prior to the storm main phase, outflow rates are moderate, and the cold ions are mainly emanating from moderately sized polar cap regions. Throughout the main phase of the storm, outflow rates increase and the polar cap source regions expand. Furthermore, faster transport, resulting from enhanced convection, leads to a much larger supply of cold ions to the near-Earth region during geomagnetic storms.
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- Johnsen, Hans Christian Garmann, et al.
(författare)
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Introduction : The regional knowledge system
- 2016
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Ingår i: Applied Social Science Research in a Regional Knowledge System. - : Taylor & Francis. - 9781315411408 - 9781472487827 ; , s. 1-21
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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- Knutsen, H. R., et al.
(författare)
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Fish welfare, fast muscle cellularity, fatty acid and body-composition of juvenile spotted wolffish (Anarhichas minor) fed a combination of plant proteins and microalgae (Nannochloropsis oceanica)
- 2019
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 506, s. 212-223
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Tidskriftsartikel (refereegranskat)abstract
- Spotted wolffish (Anarhichas minor) is a promising candidate for diversification of cold-water aquaculture. An increased knowledgebase is needed concerning the capacity of spotted wolffish to utilize a variety of feed ingredients such as microalgae and terrestrial plants. The aim of the study was therefore to investigate the effect of incorporating graded levels of microalgae (Nannochloropsis oceanica) on fish welfare indicators (growth, hepasomatic index, hematological parameters), fast muscle cellularity, chemical and fatty acid composition. Three isonitrogenous and isocaloric diets were formulated; one control diet (0% N. oceanica) and two diets with low (7.5% N. oceanica) and high (15% N. oceanica) levels of microalgae replacing fishmeal and wheat in the diets. After 12 weeks of feeding, the fish showed low growth compared to previous wolffish studies (0.26% SGR). However, this effect was not treatment dependent as there were no differences in growth or fast muscle cellularity among the three treatment groups and hematological parameters showed no indications of stress in the fish fed microalgae. Hepatosomatic index decreased over the course of the experiment for all treatment groups; a significantly larger reduction was noted in the algae-fed fish compared to the control. The omega-3 fatty acid EPA increased in the whole body of the fish fed diets containing microalgae. The results suggest that spotted wolffish has potential to utilize inclusions of up to 15% of the microalgae N. oceanica.
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- Ramirez, Jorge, et al.
(författare)
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Difference in Clinical Presentation between Female and Male Patients with Primary Sjogren's Syndrome at Diagnosis and in Long-Term Follow-up
- 2017
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Ingår i: Arthritis & Rheumatology. - : Wiley-Blackwell. - 2326-5191 .- 2326-5205. ; 69
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background/Purpose: Despite men being less prone to develop autoimmune diseases, male sex has been associated with a more severe disease course in several systemic autoimmune diseases. In the present study, we aimed to identify differences in clinical presentation between the sexes at the time of diagnosis and during long-term follow-up of primary Sjögren's syndrome (pSS), and to establish whether male sex is associated with a more severe form of pSS. Methods: Incident, treatment naïve patients (n=199, 186 females and 13 males) from Stockholm, Sweden were prospectively included during a 5-year period and examined for items of classification criteria for pSS as well as extraglandular manifestations (EGM). Serum was sampled at the time of diagnosis and anti-Ro52/SSA levels measured by ELISA. Replication of significant findings was confirmed in an independent cohort of incident pSS patients from Pisa, Italy (n=377, 368 females and 9 males), and meta-analysis performed. We further studied a cohort of 967 patients with prevalent pSS (899 females and 68 males) from Scandinavian clinical centers. The mean follow-up time (years) was 8.8 ± 7.6 for women and 8.5 ± 6.2 for men (ns). Clinical data including serological and hematological parameters, glandular, EGM and comorbidities were compared between men and women. Results: An increased frequency of EGM in men at diagnosis was observed and replicated (p=0.05, p=0.0003, and pmeta=0.002, respectively). This related to pulmonary involvement, vasculitis and lymphadenopathy being more common in men, for whom a lower age at diagnosis was observed in the exploratory cohort. Additionally, SSA positive male patients had significantly higher levels of anti-Ro52 levels than their female counterparts (p=0.02). After long-term follow-up, male patient serology was characterized by more frequent positivity for anti-SSA and anti-SSB (p=0.02), and ANA (p=0.02). Also, men with pSS were more frequently diagnosed with interstitial lung disease (p=0.008), lymphadenopathy (p=0.04) and lymphoma (p=0.007). Conversely, concomitant hypothyroidism was more common among female patients (p=0.009). Conclusion: Our analysis of two independent cohorts of incident pSS and a large cohort of prevalent pSS demonstrates significant differences between women and men with pSS. Notably, men present with more EGM, enhanced serological profile and a higher frequency of lymphoma development.
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- Tison, J.-L., et al.
(författare)
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Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core
- 2015
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Ingår i: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 9:4, s. 1633-1648
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Tidskriftsartikel (refereegranskat)abstract
- An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (delta D-delta O-18(ice), delta O-18(atm), total air content, CO2, CH4, N2O, dust, high-resolution chemistry, ice texture) of the bottom 60 m of the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core from central Antarctica. These bottom layers were subdivided into two distinct facies: the lower 12 m showing visible solid inclusions (basal dispersed ice facies) and the upper 48 m, which we will refer to as the basal clean ice facies. Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies It is demonstrated that neither large-scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end term from a previous/initial ice sheet configuration) can explain the observed bottom-ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom-ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom-ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate from within, and not from incorporation processes of debris from the ice sheet's substrate. We further discuss how the proposed mechanism is compatible with the other ice properties described. We conclude that the paleoclimatic signal is only marginally affected in terms of global ice properties at the bottom of EPICA Dome C, but that the timescale was considerably distorted by mechanical stretching of MIS20 due to the increasing influence of the subglacial topography, a process that might have started well above the bottom ice. A clear paleoclimatic signal can therefore not be inferred from the deeper part of the EPICA Dome C ice core. Our work suggests that the existence of a flat monotonic ice bedrock interface, extending for several times the ice thickness, would be a crucial factor in choosing a future oldest ice drilling location in Antarctica.
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