364 research outputs found
A novel method for transmission electron microscopy study of cytoplasmic fragments from preimplantation human embryos
Transmission electron microscopy (TEM) is the main tool for exploring the intracellular damage and organelle distribution. The cause of producing embryo cytoplsamic fragmentation is not completely understood. Since the fragments have detrimental effects on embryo development, the ultrastructural analysis of fragments may play an important role in fragmentation etiology and in embryo development as well. There are no studies regarding the ultrastructure of fragments in transferable embryos, because the preparation for TEM is not vital and embryos are discarded inevitably. This study aims to introduce a new method for ultrastructural evaluation of fragments without damaging the human cleaving embryos
The role of biomass gasification in the future flexible power system – BECCS or CCU?
In this work we study if biomass gasification for production of advanced biofuels can also play a role in managing variability in the electricity system. The idea is a CCU/power-to-gas concept to enhance methane production from biomass gasification. The suggested process is flexible in that CO2 not used for methane production can be stored through a BECCS concept that implies negative GHG emissions. For this purpose, rigorous models of three different gasification process configurations were simplified through surrogate modeling and integrated into a dynamic optimization model of regional electricity systems. The results show the diverse advantages of flexible operation between CCU and BECCS and that it is economically beneficial for the system to invest in gasification at the investigated levels of CO2 charge. The gasification option also provides value for low-priced electricity and thus stimulate increased investments in renewable electricity generation, which indicates the importance of considering geographical diversities in the assessment and highlights the importance of studying this type of concept with a time-resolved model. It is clear that the BECCS option is the most used, however, the limited quantities of CO2 used for the CCU option has a large impact on the investments made in the electricity system
Pumppukäyrän konstruointi Ahlströmin pumpulle
MEMO No CFD/THERMO-10-96
Date: 4. lokakuuta 1996Tiivistelmä: Tämän laskennan tarkoituksena on tutkia Ahlströmin keskipakopumpun nostokorkeuden riippuvuutta massavirrasta. Tuloksista voidaan konstruoida pumppukäyrä eli pumpun nostokorkeus massavirran funktiona.
Pääkohdat: Pumppukäyrä
Homogenization based macroscopic model of phase transformations and cyclic plasticity in pearlitic steel
In this contribution macroscopic modeling of phase transformations and mechanical behavior of low alloy steels are developed and investigated. Such modeling is of importance in simulations of transient thermo-mechanical processes which can cause phase transformations, examples from the railway industry include train braking induced frictional heating as well as rail grinding and welding operations. We adopt a modeling approach which includes phase transformation kinetics and individual constitutive models for the phases in combination with different homogenization methods. Algorithmic implementations of the isostrain, isostress and self-consistent homogenization methods are presented and demonstrated in finite element simulations of a laser heating experiment. Stress field results from the different homogenization methods are compared against each other and also against experimental data. The importance of including transformation induced plasticity in the modeling is highlighted, as well as the multi-phase stages of the heating and cooling
Performance management: a qualitative study of relational boundaries in personal assistance
Personal assistance (PA) is a model of support where disabled people take control of recruiting, training and managing the people that support them. Personal assistance differs from other forms of care, such as domiciliary or informal care, because the disabled person is in control of how, when and by whom they are supported. With the advent of personal health budgets, PA is no longer limited to social care but is also central to future NHS services and funding arrangements. The aims of this study were to gain a deeper understanding of PA relationships, and to explore how both parties manage interpersonal challenges. We report on data from 58 qualitative interviews with disabled employers and personal assistants. Applying concepts from Goffman's (1959) scheme of impression management, we present an analysis of the relational dynamics that occur when two people cooperate in shared endeavours. Goffman's concepts of team members and non‐persons, in addition to the themes of regions and information control, aid a more fundamental understanding of the relational dynamics that occur between disabled employers and their PAs
Trend analysis of CO2 and CH4 recorded at a semi-natural site in the northern plateau of the Iberian Peninsula
CO2 and CH4 were recorded from October 2010 to February 2016 with a Picarro G1301 analyser at the centre of the upper plateau of the Iberian Peninsula. Large CO2 values were observed during the vegetation growing season, and were reinforced by the stable boundary layer during the night. Annual CH4 evolution may be explained by ecosystem activity and by the dispersion linked with the evolution of the boundary layer. Their trends were studied using an equation that considers one polynomial and one harmonic part. The polynomial part revealed an increasing trend from 0.8 to 2.3 ppm year 1 for CO2 and from 0.004 to 0.011 ppm year 1 for CH4. The harmonic part considered four harmonics whose amplitudes were noticeable for the first and second harmonics for CO2 and for the first harmonic for CH4. Long-term evolution was similar with alternative equations. Finally, seasonal study indicated summer minima for both gases, which may be explained by the lack of vegetation in this season. Harmonic analysis showed two maxima for CO2, one in spring linked with vegetation growth, which decreased with time, and another in autumn related with the onset of plant activity after the summer, which increased with time. CH4 presented only one maximum in winter and a short time with steady concentration in spring where the evolution of the boundary layer may play a noticeable role. The harmonic equation, which takes into account all the observations, revealed opposite behaviour between CO2, whose minima decreased, and CH4, whose maxima increased.Ministry of Economy and Competitiveness and ERDF funds (projects CGL2009-11979 and CGL2014-53948-P)
First genome-wide association study on rocuronium dose requirements shows association with SLCO1A2
Background: Rocuronium, a common neuromuscular blocking agent, is mainly excreted unchanged in urine (10-25%) and bile ( 70%). Age, sex, liver blood flow, smoking, medical conditions, and ethnic background can affect its pharmacological actions. However, reasons for the wide variation in rocuronium requirements are mostly unknown. We hypothesised that pharmacogenetic factors might explain part of the variation. Methods: One thousand women undergoing surgery for breast cancer were studied. Anaesthesia was maintained with propofol (50-100 mg kg(-1) min(-1)) and remifentanil (0.05-0.25 mg kg(-1) min(-1)). Neuromuscular block was maintained with rocuronium to keep the train-of-four ratio at 0-10%. DNA was extracted from peripheral blood and genotyped with a next-generation genotyping array. The genome-wide association study (GWAS) was conducted using an additive linear regression model with PLINK software. The FINEMAP tool and data from the Genotype-Tissue Expression project v8 were utilised to study the locus further. Results: The final patient population comprised 918 individuals. Of the clinical variables tested, age, BMI, ASA physical status, and total dose of propofol correlated significantly (all P Conclusions: Genetic variation in the gene SLCO1A2, encoding OATP1A2, an uptake transporter, accounted for 4% of the variability in rocuronium consumption. The underlying mechanism remains unknown.Peer reviewe
Collaborative Research: High-resolution studies of glacier dynamics at two major outlet glaciers in East Greenland
The Principal Investigators request support for an interdisciplinary, high-resolution study involving remote sensing and field investigations at two of Greenland\u27s largest outlet glaciers. The study of the Helheim and Kangerdlugssuaq Glaciers will integrate seismological, glaciological, and geodetic observations to build an understanding of flow dynamics at major outlet glaciers, which represent a critical junction between the atmosphere, cryosphere, and hydrosphere. The project would be the first long-term occupation of an outlet glacier by a GPS receiver network, and would address questions of flow variation on earthquake to interannual time scales. Recent discoveries have made it clear that our understanding of the dynamics of flow at large outlet glaciers is limited and inadequate for understanding the ways in which the outlet glaciers, and the ice sheets they drain, respond to external forcings. The spectrum of timescales over which significant velocity variations in outlet glacier flow can occur appears to be much broader than previously believed, with significant variations occurring on timescales of 10s of seconds to several years. Analysis of glacial earthquakes suggests that significant volumes of ice may move at speeds 1000 times faster than their average annual velocities for periods of a minute or two and a doubling of average annual flow speeds over only a few years has been observed at some glaciers. Multiple observations now indicate that glacier flow behavior can respond quickly to environmental changes, including rapid climate change. It is not currently clear, however, what mechanisms or combination of mechanisms allow for, or drive, the temporal variations, nor is it clear how variations in flow behavior at different timescales are related to one another. Understanding the changes in force balance that control variations across the range of timescales from minutes to years requires observations at higher resolution in both space and time than are currently available, and achieving a comprehensive picture of the interactions between short- and long-timescale processes, and between external forcings and glacier flow behavior, requires the integration of data and expertise from several traditionally separate disciplines.. Intellectual Merit. The research will lead to a greatly improved understanding of the dynamics of flow at the large, fast-moving outlet glaciers that drain the Greenland ice sheet and of the temporal variability in their rates and modes of flow. It will provide insight into the processes controlling glacial earthquakes and possible connections between glacial-earthquake activity and global climate change.Broader Impacts. Understanding the controls on flow configuration at major outlet glaciers, and the timescales over which they may respond to climatic forcing, is of great importance for proper modeling of systems affected by the transfer of fresh polar meltwater to the world\u27s oceans. A better understanding of glacier and ice-sheet response to climate change will allow for improvements in modeling of the coupled ice ocean atmosphere system, and of its interactions with the solid Earth. The geodetic instrumentation and processing techniques developed under this proposal will benefit researchers in a variety of environments such as glacier and volcano monitoring involving rapid, large-scale motions and the risk of instrument loss
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