1. |
- Akkoyun, S., et al.
(författare)
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AGATA - Advanced GAmma Tracking Array
- 2012
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087 .- 1872-9576. ; 668, s. 26-58
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Tidskriftsartikel (refereegranskat)abstract
- The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation γ-ray spectrometer. AGATA is based on the technique of γ-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a γ ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of γ-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector- response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer. © 2011 Elsevier B.V. All rights reserved.
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2. |
- Carvalho, Ricardo L., et al.
(författare)
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Bioenergy strategies to address deforestation and household air pollution in western Kenya
- 2019
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Ingår i: European Biomass Conference and Exhibition Proceedings. - : ETA-Florence Renewable Energies. ; , s. 1536-1542
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Konferensbidrag (refereegranskat)abstract
- Over 640 million people in Africa are expected to rely on solid-fuels for cooking by 2040. In Western Kenya, cooking inefficiently persists as a major cause of burden disease due to household air pollution. The Long-Range Energy Alternatives Planning (LEAP) system and the Life-Cycle Assessment tool Simapro 8.5 were applied for analyzing biomass strategies for the region. The calculation of the residential energy consumption and emissions was based on scientific reviews and original data from experimental studies. The research shows the effect of four biomass strategies on the reduction of wood fuel use and short-lived climate pollutant emissions. A Business As Usual scenario (BAU) considered the trends in energy use until 2035. Transition scenarios to Improved Cookstoves (ICS), Pellet-fired Gasifier Stoves (PGS) and Biogas Stoves (BGS) considered the transition to wood-logs, biomass pellets and biogas, respectively. An Integrated (INT) scenario evaluated a mix of the ICS, PGS and BGS. The study shows that, energy use will increase by 8% (BGS), 20% (INT), 26% (PGS), 42% (ICS) and 56% (BAU). The BGS has the lowest impact on global warming, particle formation, terrestrial acidification, fossil resource scarcity, water consumption, as well as on eutrophication followed by the PGS and INT.
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3. |
- Emilsson, Gustav, 1989, et al.
(författare)
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Identifying bacteria using DNA binding maps
- 2013
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Ingår i: 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013; Freiburg; Germany; 27 October 2013 through 31 October 2013. - 9781632666246 ; 1, s. 473-475
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Konferensbidrag (refereegranskat)abstract
- We have developed an assay, based on nanofluidic channels and fluorescence microscopy, for optical mapping of DNA based on competitive binding between two molecules - one fluorescent and one sequence selective. From the experimental data we can extract binding constants for the two competing DNA binders, which may be subsequently used to calculate a theoretical reference map of any DNA with known sequence. The goal is to create a method for fast identification of bacteria from single DNA molecules without the need for additional cultivation or amplification. We here demonstrate a proof-of-principle experiment on phage DNA and furthermore show that the method can be used to distinguish between two strains of E. coli DNA and to map pieces of DNA onto the full genome.
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4. |
- Jansson, Magnus, et al.
(författare)
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Characterization of ligand binding of a soluble human insulin-like growth factor I receptor variant suggests a ligand-induced conformational change.
- 1997
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 272:13, s. 8189-8197
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Tidskriftsartikel (refereegranskat)abstract
- Details of the signal transduction mechanisms of the tyrosine kinase family of growth factor receptors remain elusive. In this work, we describe an extensive study of kinetic and thermodynamic aspects of growth factor binding to a soluble extracellular human insulin-like growth factor-I receptor (sIGF-IR) variant. The extracellular receptor domains were produced fused to an IgG-binding protein domain (Z) in transfected human 293 cells as a correctly processed secreted alpha-beta'-Z dimer. The receptor was purified using IgG affinity chromatography, rendering a pure and homogenous protein in yields from 1 to 5 mg/liter of conditioned cell media. Biosensor technology (BIAcore) was applied to measure the insulin-like growth factor-I (IGF-I), des(1-3)IGF-I, insulin-like growth factor-II, and insulin ligand binding rate constants to the immobilized IGF-IR-Z. The association equilibrium constant, Ka, for the IGF-I interaction is determined to 2.8 x 10(8) M-1 (25 degrees C). Microcalorimetric titrations on IGF-I/IGF-IR-Z were performed at three different temperatures (15, 25, and 37 degrees C) and in two different buffer systems at 25 degrees C. From these measurements, equilibrium constants for the 1:1 (IGF-I:(alpha-beta'-Z)2) receptor complex in solution are deduced to 0.96 x 10(8) M-1 (25 degrees C). The determined heat capacity change for the process is large and negative, -0.51 kcal (K mol)-1. Further, the entropy change (DeltaS) at 25 degrees C is large and negative. Far- and near-UV circular dichroism measurements display significant changes over the entire wavelength range upon binding of IGF-I to IGF-IR-Z. These data are all consistent with a significant change in structure of the system upon IGF-I binding.
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6. |
- Xia, Q. L., et al.
(författare)
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Infrared Laser Pulses Excite Action Potentials in Primary Cortex Neurons in Vitro∗
- 2019
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Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. ; , s. 5184-5187
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Konferensbidrag (refereegranskat)abstract
- Infrared neural modulation (INM) has been well studied in the peripheral nervous system (PNS) for potential clinical applications. However, limited research has been conducted on the central nervous systems (CNS). In this study, we aimed at investigating the feasibility of using pulsed infrared (IR) laser with a wavelength of 1940 nm to excite network activity of cultivated rat cortex neurons.We cultured rat cortex neurons, forming neural networks with spontaneous neural activity, on glass multi-electrode arrays (MEAs). Laser at a power of 600 mW and a pulse rate of 10 Hz were used to stimulate the neural networks using the optics of an inverted microscope. Pulse durations were varied from 200 μs to 1 ms. The spike rate was calculated to evaluate the change of the neural network activity during the IR stimuli and the corresponding frequency components of neural response were calculated to examine whether recorded spikes were evoked by the IR pulse or not. A temperature model was adapted from a previous study to estimate the temperature rise during laser pulsing.We observed that the IR irradiation with a pulse duration of 800 μs and 1 ms could excite neuronal action potentials. The temperature rose 18.5 and 23.9 °C, for pulse durations of 800 μs and 1 ms, respectively. Thus, in addition to previously shown inhibition of IR irradiation with a wavelength of 1550 nm, we demonstrate an optical method that can modulate neural network activity in vitro. The preliminary results from this paper also suggested that MEA recording technology coupled with a laser and microscope systems can be exploited as a new approach for future studies to understand mechanisms and characterize laser parameters of INM for CNS neurons.
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7. |
- Armengol Llobet, J., et al.
(författare)
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Minimal Structurally Overdetermined Sets for Residual Generation: A Comparison of Alternative Approaches
- 2009
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Ingår i: <em>Proceedings of IFAC Safeprocess'09</em>. - Barcelona, Spain. - 9783902661463 ; , s. 1480-1485
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Konferensbidrag (refereegranskat)abstract
- The issue of residual generation using structural analysis has been studied by several authors. Structural analysis does not permit to generate the analytical expressions of residuals since the model of the system is abstracted by its structure. However, it determines the set of constraints from which residuals can be generated and it provides the computation sequence to be used. This paper presents and compares four recently proposed algorithms that solve this problem.
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8. |
- Carvalho, Ricardo L., et al.
(författare)
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Household air pollution mitigation with integrated biomass/cookstove strategies in Western Kenya
- 2019
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Ingår i: Energy Policy. - : Elsevier. - 0301-4215 .- 1873-6777. ; 131, s. 168-186
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Tidskriftsartikel (refereegranskat)abstract
- Traditional cooking is today's largest global environmental health risk. Over 640 million people in Africa are expected to rely on biomass for cooking by 2040. In Kenya, cooking inefficiently with wood and charcoal persists as a cause of deforestation and household air pollution. This research analyses the effects of four biomass cookstove strategies on reducing air pollutant emissions in Kisumu County between 2015 and 2035 using the Long-Range Energy Alternatives Planning system. The Business as Usual scenario (BAU) was developed considering the historical trends in household energy use. Energy transition scenarios to Improved Cookstoves (ICS), Pellet Gasifier Stoves (PGS) and Biogas Stoves (BGS) were applied to examine the impact of these systems on energy savings and air pollution mitigation. An integrated scenario (INT) was evaluated as a mix of the ICS, PGS and BGS. The highest energy savings, in relation to the BAU, are achieved in the BGS (30.9%), followed by the INT (23.5%), PGS (19.4%) and ICS (9.2%). The BGS offers the highest reduction in the GHG (37.6%), CH4 (94.3%), NMVOCs (85.0%), CO (97.4%), PM2.5 (64.7%) and BC (48.4%) emissions, and the PGS the highest reduction in the N2O (83.0%) and NOx (90.7%) emissions, in relation to the BAU.
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9. |
- Elfstrand, Lidia, et al.
(författare)
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Immunoglobulins, growth factors and growth hormone in bovine colostrum and the effects of processing
- 2002
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Ingår i: International Dairy Journal. - 0958-6946. ; 12:11, s. 879-887
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Tidskriftsartikel (refereegranskat)abstract
- In colostrum collected 0-80 h postpartum the contents of immunoglobulins (Igs), transforming growth factor beta-2 (TGF-beta2), insulin-like growth factor-1 (IGF-1) and growth hormone (GH) were analysed. Colostrum initially contained 90 mg mL(-1) IgG1, 2.8 mg mL(-1) IgG2, 1.6 mg mL(-1) IgA, 4.5 mg mL(-1) IgM, and these concentrations declined by 92%, 87%, 93% and 84%, respectively, in the samples collected later. Of the growth factors, colostrum initially contained 289-310 ng mL(-1) TGF-beta2 and the concentration diminished to 66 ng mL(-1). The content of IGF-1 and GH postpartum decreased from 870 to 150 ng mL(-1), and from 0.17 to < 0.03 ng mL(-1), respectively. Heat treatment and freeze-drying of colostral whey decreased the content of Igs to 75%, while the contents of IGF-1 and TGF-beta2 were unaffected. A similar processing, including filtration steps reduced also the IGF-1 and TGF-beta2 by 25%. IgM seems to be the most sensitive of the Igs to processing. (C) 2002 Elsevier Science Ltd. All rights reserved.
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