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Статті в журналах з теми "Irreversible losse"
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Perelomova, Anna. "Hysteresis curves for some periodic and aperiodic perturbations in gases." Canadian Journal of Physics 92, no. 11 (November 2014): 1324–29. http://dx.doi.org/10.1139/cjp-2013-0666.
Повний текст джерелаАнотація:
Evolution of sound in a medium whose properties irreversibly vary in the course of wave propagation, is studied. For example, a gas that is a particular case of a Newtonian fluid is considered. Hysteresis curves, pictorial representations of irreversible attenuation of the sound energy, in the plane of thermodynamic states are plotted. The irreversible losses in internal energy are proportional to the total attenuation and depend on the intensity and shape of sound waveform. Curves and loops for some periodic (including the sawtooth wave) and aperiodic impulse sounds are discussed and compared.
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Ripl, W., and M. Eiseltová. "Sustainable land management by restoration of short water cycles and preventionof irreversible matter losses from topsoils." Plant, Soil and Environment 55, No. 9 (October 14, 2009): 404–10. http://dx.doi.org/10.17221/133/2009-pse.
Повний текст джерелаАнотація:
Sustainable land management requires that water and matter (nutrients and base cations) are efficiently recycled within ecosystems so that irreversible losses of matter from topsoils are minimised. Matter losses are connected to water flow. The division of water into evapotranspiration that is loss-free, and seepage to groundwater or surface water flow that both carry material losses, is decisive in determining total losses of dissolved matter in a given catchment. Investigations of areal matter losses confirmed the instrumental role of vegetation cover. Areal matter losses measured in agricultural catchments in Germany were on average between 1–1.5 tons of dissolved matter per ha per year, i.e. some 50 to 100 times higher than those from unmanaged land in a virgin forest. Such high losses continuously reduce soil fertility and can hardly be compensated by fertilisation. Some suggestions on how to achieve sustainable management of agricultural land and maintain high soil fertility are presented – the priority is to close water and matter cycles through the incorporation of more natural vegetation cover into our landscapes and to restore the energy-dissipative properties of ecosystems.
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el Haj Assad, Mamdouh. "Effect of Feedwater Temperature Rise in Heaters on Regenerative Rankine Cycle Performance." International Journal of Mechanical Engineering Education 25, no. 2 (April 1997): 103–10. http://dx.doi.org/10.1177/030641909702500203.
Повний текст джерелаАнотація:
In this article, the performance of regenerative power plants in terms of second law of thermodynamics is discussed. The performance of the cycle is improved with the addition of backward cascaded-type and open-type feedwater heaters. This improvement is obtained by the reduction in irreversible losses as the number of feedwater heaters increases. A conventional energy-balance approach is used to calculate the irreversible losses in the cycle. The irreversible losses of each component of the cycle is given in a dimensionless ratio and from that ratio one can easily see the fraction of the irreversible losses of each component with respect to the power output, which means the irreversible losses can be obtained directly from the power output. The boiler causes the maximum fraction of the total irreversible losses among the components of the cycle. These losses are reduced by introducing feedwater heaters into the cycle. The irreversibilities in the cycle are examined according to the effect of varying the total temperature rise across the feedwater heaters.
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YEO, L. M. W., D. S. A. SWABY, R. D. SITUNAYAKE, and P. I. MURRAY. "IRREVERSIBLE VISUAL LOSS IN DERMATOMYOSITIS." Rheumatology 34, no. 12 (1995): 1179–81. http://dx.doi.org/10.1093/rheumatology/34.12.1179.
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Liu, Michael, Antonia Alafris, Anthony J. Longo, and Henry Cohen. "Irreversible Atorvastatin-Associated Hearing Loss." Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy 32, no. 2 (January 24, 2012): e27-e34. http://dx.doi.org/10.1002/phar.1040.
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Liss, Leopold, and Nancy S. Raptou. "Irreversible Loss of Cognition? A Caveat." Alzheimer Disease & Associated Disorders 4, no. 4 (1990): 232. http://dx.doi.org/10.1097/00002093-199040400-00005.
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Sengupta, Debanjan, Paul R. Estrada, Jeffrey N. Cuzzi, and Munir Humayun. "Depletion of Moderately Volatile Elements by Open-system Loss in the Early Solar Nebula." Astrophysical Journal 932, no. 2 (June 1, 2022): 82. http://dx.doi.org/10.3847/1538-4357/ac6dcc.
Повний текст джерелаАнотація:
Abstract Rocky bodies of the inner solar system display a systematic depletion of “moderately volatile elements” (MVEs) that correlates with the expected condensation temperature of their likely host materials under protoplanetary nebula conditions. In this paper, we present and test a new hypothesis in which open-system loss processes irreversibly remove vaporized MVEs from high nebula altitudes, leaving behind the more refractory solids residing much closer to the midplane. The MVEs irreversibly lost from the nebula through these open-system loss processes are then simply unavailable for condensation onto planetesimals forming even much later, after the nebula has cooled, overcoming a critical difficulty encountered by previous models of this type. We model open-system loss processes operating at high nebula altitudes, such as resulting from disk winds flowing out of the system entirely, or layered accretion directly onto the young Sun. We find that mass-loss rates higher than those found in typical T-Tauri disk winds, lasting short periods of time, are most satisfactory, pointing to multiple intense early outburst stages. Using our global nebula model, incorporating realistic particle growth and inward drift for solids, we constrain how much the MVE-depletion signature in the inner region is diluted by the drift of undepleted material from the outer nebula. We also find that a significant irreversible loss of the common rock-forming elements (Fe, Mg, Si) can occur, leading to a new explanation of another long-standing puzzle of the apparent “enhancement” in the relative abundance of highly refractory elements in chondrites.
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YAVUZ, Haluk. "Valproic Acid-induced Bilateral Irreversible Hearing Loss." Turkiye Klinikleri Journal of Case Reports 28, no. 4 (2020): 245–49. http://dx.doi.org/10.5336/caserep.2020-75906.
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Coulston, J. "Irreversible sensorineural hearing loss due to clarithromycin." Postgraduate Medical Journal 81, no. 951 (January 1, 2005): 58–59. http://dx.doi.org/10.1136/pgmj.2004.020412.
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Hänninen, Ismo K., Craig S. Lent, and Gregory L. Snider. "Quantifying Irreversible Information Loss in Digital Circuits." ACM Journal on Emerging Technologies in Computing Systems 11, no. 2 (November 18, 2014): 1–17. http://dx.doi.org/10.1145/2629523.
Повний текст джерелаДисертації з теми "Irreversible losse"
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Johansson, Magnus. "On noise and hearing loss : Prevalence and reference data." Doctoral thesis, Linköping : Univ, 2003. http://www.ep.liu.se/diss/science_technology/07/97/index.html.
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Regnault, Timothy Robert Hume, of Western Sydney Hawkesbury University, Faculty of Agriculture and Horticulture, and School of Agriculture and Rural Development. "Orchestrated partitioning of maternal nutrients during ovine pregnancy." THESIS_FAH_ARD_Regnault_T.xml, 1997. http://handle.uws.edu.au:8081/1959.7/15.
Повний текст джерелаАнотація:
Ovine placental lactogen (oPL) is postulated to be involved in the repartitioning of maternal nutrients during pregnancy, through its effect on insulin metabolism. Ovine pancreatic insulin responses to exogenous glucose are depressed during pregnancy and this depression becomes more pronounced as gestation advances. In addition, under the hormonal environment of rising oPL and growth hormone (oGH) concentrations, maternal whole body glucose irreversible loss (GIL) increases. The percentage of GIL accounted for by uterine glucose uptake also increases with advancing gestation and increasing litter size. Regression analysis of oPL concentration with glucose uterine uptake as a percentage of GIL, accounts for 39% of variation. Maternal oPL concentrations which increase with gestational age, were significantly greater in multiple bearing ewes and ewes subjected to reduced metabolisable energy (ME) intakes. It is postulated that through actions on pancreatic sensitivity, oPL plays a major role as a homeorhetic control during pregnancy. Elevated oPL concentrations were strongly associated with continually depressed pancreatic insulin secretory ability. The reduction in pancreatic sensitivity to glucose was not as a result of elevation in GH or non-esterified fatty acid (NEFA) concentrations. Muscle insulin receptor number and affinity were found to increase with increasing litter size, suggesting that pregnancy associated insulin resistance occurs predominantly in adipose tissue. During ovine pregnancy there is a specific stimulation of maternal gluconeogenesis. As gestation advances, an increasingly greater proportion of this glucose is partitioned to the gravid uterus. The development of insulin resistance, together with the suppression of pancreatic activity, ensures the preferential uptake of glucose by non-insulin dependent tissues over insulin dependent tissues. These activities favour uterine glucose uptake, decrease adipose glucose uptake, and also promote adipose mobilisation and hepatic gluconeogenesis, so as to meet the increasing energy requirement of pregnancy. It is postulated that through these effects on insulin secretion and associated adipose tissue mobilisation factors, oPL plays a major role in homeorhesis during pregnancy.Doctor of Philosophy (PhD)
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Yi, Jihaeng. "Optical Sensors for High-Temperature Pressure Measurement and Real-Time Particle Detection." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77229.
Повний текст джерелаАнотація:
In this thesis, we report the development of two types of optical sensors, one for high temperature pressure measurements and the other for real-time particle detection. With a high melting temperature (over 2000°C), low optical loss, and excellent corrosion resistance, sapphire (α-Al₂O₃) is ideal for high temperature sensing applications. Fabry-Perot (FP) cavity with optical interrogation of pressure response. The prototype is based on an extrinsic FP interferometer design and is constructed by combining reactive ion etching (RIE) with direct wafer bonding. Long-term testing proves that the adhesive-free wafer bond is sufficient to create a sealed Fabry-Perot cavity as a pressure transducer. Pressure measurement over a range of 6 to 200 psi has been demonstrated at room temperature using white-light interferometry.
For the other sensor, the goal is to detect the presence of micro- and nanoparticles in real time. The sensor is based on a silica fiber taper, and we aim to detect particle presence by measuring optical scattering and absorption induced by particles attached to the taper surface. To establish the relationship between particle density and optical transmission loss, we first consider a model where Au nanospheres are self-assembled on taper surface through electrostatic interaction. An analytical model is established to describe the adsorption of gold nanospheres onto cylindrical and spherical silica surfaces from quiescent aqueous particle suspensions. The curved surfaces of the fiber taper and microspheres are coated with nm-thick layer of a polycation, enabling irreversible adsorption of the negatively charged spheres. Our results fit well with theory, which predicts that the rates of particle adsorption will depend strongly on the surface geometry. In particular, adsorption is significantly faster on curved than on planar surfaces at times long enough that the particle diffusion length is large compared to the surface curvature. This is of particular importance for plasmonic sensors and other devices where particles are deposited from a suspension onto surfaces which may have non-trivial geometries.
We have established a theoretical model that can describe optical loss generated by particles on taper surface. This theory is validated by measuring, in real time, optical loss during the self-assembly of gold nanoparticles. We find that the measured optical loss can be quantitatively explained by the presence of multiple guided modes within the fiber taper region. Based on this work, we incorporate a fiber taper into a cascade impactor and show that welding aerosols attached to the fiber taper surface can induce measurable transmission loss during the welding process.Ph. D.
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Regnault, Timothy Robert Hume. "Orchestrated partitioning of maternal nutrients during ovine pregnancy." Thesis, View thesis View thesis, 1997. http://handle.uws.edu.au:8081/1959.7/15.
Повний текст джерелаАнотація:
Ovine placental lactogen (oPL) is postulated to be involved in the repartitioning of maternal nutrients during pregnancy, through its effect on insulin metabolism. Ovine pancreatic insulin responses to exogenous glucose are depressed during pregnancy and this depression becomes more pronounced as gestation advances. In addition, under the hormonal environment of rising oPL and growth hormone (oGH) concentrations, maternal whole body glucose irreversible loss (GIL) increases. The percentage of GIL accounted for by uterine glucose uptake also increases with advancing gestation and increasing litter size. Regression analysis of oPL concentration with glucose uterine uptake as a percentage of GIL, accounts for 39% of variation. Maternal oPL concentrations which increase with gestational age, were significantly greater in multiple bearing ewes and ewes subjected to reduced metabolisable energy (ME) intakes. It is postulated that through actions on pancreatic sensitivity, oPL plays a major role as a homeorhetic control during pregnancy. Elevated oPL concentrations were strongly associated with continually depressed pancreatic insulin secretory ability. The reduction in pancreatic sensitivity to glucose was not as a result of elevation in GH or non-esterified fatty acid (NEFA) concentrations. Muscle insulin receptor number and affinity were found to increase with increasing litter size, suggesting that pregnancy associated insulin resistance occurs predominantly in adipose tissue. During ovine pregnancy there is a specific stimulation of maternal gluconeogenesis. As gestation advances, an increasingly greater proportion of this glucose is partitioned to the gravid uterus. The development of insulin resistance, together with the suppression of pancreatic activity, ensures the preferential uptake of glucose by non-insulin dependent tissues over insulin dependent tissues. These activities favour uterine glucose uptake, decrease adipose glucose uptake, and also promote adipose mobilisation and hepatic gluconeogenesis, so as to meet the increasing energy requirement of pregnancy. It is postulated that through these effects on insulin secretion and associated adipose tissue mobilisation factors, oPL plays a major role in homeorhesis during pregnancy.
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Chang, Ya Ting, та 張雅婷. "Molecular mechanisms underlying total MHC class I loss caused by irreversible β2–microglobulin defects in the breast carcinoma cell line MDA-MB-157". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68044335512145671408.
Повний текст джерелаАнотація:
碩士國立清華大學
分子與細胞生物研究所
97
Abstract Major histocompatibility complex (MHC) class I molecules play an important role in eliciting host tumor-specific immune response since they present tumor antigen-derived peptides to CD8+ cytotoxic T lymphocytes. Accordingly, loss or downregulaton of MHC class I expression in tumor cells represents an immune escape mechanism utilized by a variety of tumor cell types including breast carcinoma. In this study, we have examined the mechanisms underlying MHC class I loss by the human breast carcinoma cell line MDA-MB-157, which was derived from a metastatic medulallary breast carcinoma lesion. Flow cytometry did not detect MHC class I expression on MDA-MB-157 cells but showed robust expression on MDA-MB-231 cells, a positive-control cell line. Western blot analysis of various antigen processing machinery components and MHC class I subunits in the presence and absence of IFN-�� stimulation identified loss of�n��2–microglobulin (��2m), a 12 kDa subunit critical for MHC class I assembly and transport, as a major defect in MDA-MB-157 cells. Subsequently, quantitative real-time RT-PCR and nucleotide sequencing analysis of the ��2m mRNA in MDA-MB-157 cells detected fair amounts of steady-state ��2m transcripts with no mutations in the coding region, suggesting a post-transcriptional/translational defect. Treatment of MDA-MB-157 cells with the proteasome inhibitor MG-132 did not restore ��2m expression, ruling out accelerated ��2m protein degradation as a possible mechanism. To investigate whether mutations exist in the ��2m mRNA untranslated regions (UTR), Rapid Amplification of cDNA Ends (RACE) was employed but, surprisingly, did not detect any UT fragments compared to controls. Moreover, genomic PCR with walking primers failed to amplify a large internal region of the ��2m gene in MDA-MB-157 cells except exon 1 and exon 4. The critical role of ��2m in the proper assembly and surface expression of MHC class I was indicated by the restoration of HLA class I on MDA-MB-157 cells stably transfected with a ��2m-encoding plasmid. Lastly, cytotoxicity assay demonstrated that MDA-MB-157 cells were resistant to NK cell-mediated cytolysis, suggesting the development of tumor NK-resistance in the absence of HLA class I expression. Taken together, our results revealed novel genetic and post-transcriptional mechanisms underlying total HLA class I loss by a breast carcinoma cell line and its NK-resistance phenotype. These findings may suggest new therapeutic strategies to increase the susceptibility of tumor cells to immune destruction in patients.
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Pedrosa, Mariana Miguel. "Viver com esclerose lateral amiotrófica - um estudo fenomenológico." Master's thesis, 2017. http://hdl.handle.net/10400.12/5378.
Повний текст джерелаАнотація:
Dissertação de Mestrado realizada sob a orientação de Vítor Amorim Rodrigues, apresentada no ISPA – Instituto Universitário para obtenção de grau de Mestre na especialidade de Psicologia ClínicaO presente estudo tem como objetivo descrever, analisar e compreender a experiência subjetiva da vivência da doença de Esclerose Lateral Amiotrófica (ELA). Na análise que permitiu analisar o fenómeno em causa, foi usado o Método Fenomenológico de Amedeu Giorgi, um método qualitativo e essencialmente descritivo. A metodologia usada neste estudo, insere-se numa investigação qualitativa de natureza fenomenológica, com o objetivo de alcançar uma descrição final com os constituintes essenciais e invariáveis desta experiência. A aplicação deste método permitiu analisar, no presente estudo, de forma criteriosa e intimista, as descrições de cinco participantes, três do sexo masculino e dois do sexo feminino, diagnosticados com ELA, com idades compreendidas entre os 40 e os 81 anos, de forma a melhor compreender como é experienciada a doença, através dos seus “modus vivendi”. Os resultados encontrados, decorrentes da aplicação do referido método, indicam a perceção de uma vivência que modifica negativamente e abruptamente, a vivência dos indivíduos, quer a nível individual, social, quer familiar, sendo que cada um deles tenta, através dos recursos que possui, adaptar-se à nova realidade. Constata-se que este fenómeno é bastante complexo e afeta várias dimensões do sujeito, causando perdas irreversíveis, que causam alterações profundas no seu dia a dia.
The present study aims to describe, analyze and understand the subjective experience of the disease of Amyotrophic Lateral Sclerosis (ALS). In the analysis that allowed to analyze the phenomenon in question, Amedeu Giorgi's Phenomenological Method was used, a qualitative and essentially descriptive method. The methodology used in this study is part of a qualitative research of a phenomenological nature, aiming to reach a final description with the essential and invariable constituents of this experience. The application of this method allowed us to analyze in the present study, in a careful and intimate manner, the descriptions of five participants, diagnosed with ALS, three males and two females, aged between 40 and 81 years, of way to better understand how the disease is experienced through its "modus vivendi". The results obtained, due to the application of this method, indicate the perception of an experience that negatively and abruptly modifies the individuals experience, both individually, socially and family, and each of them tries, through the resources they possess , adapt to the new reality. It is observed that this phenomenon is quite complex and affects several dimensions of the subject, causing irreversible losses, that cause profound changes in their day to day.
Книги з теми "Irreversible losse"
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Martos, Ana. Adelgazar para siempre: Cómo tomar la decisión libre, irreversible y voluntaria de adelgazar para no engordar nunca más. Móstoles (Madrid), España: Neo Person, 2003.
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(Organization), GAPWUZ, and Research & Advocacy Unit (Zimbabwe), eds. Reckless tragedy: Irreversible? : a survey of human rights violations and losses suffered by commercial farmers and farm workers in Zimbabwe from 2000 to 2008. Harare]: Research and Advocay Unit, 2008.
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Mullin, E. G. Goldman Chronicles: Irreversible Loss. Independently Published, 2017.
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Macauley, Robert C. Death and Organ Donation (DRAFT). Edited by Robert C. Macauley. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199313945.003.0016.
Повний текст джерелаАнотація:
The concept of death by neurological criteria (i.e., brain death) was formulated in 1968 to describe a state of complete and irreversible loss of brain function. While there remain philosophical debates about the validity of the concept, it is enshrined in state law—with a few notable limitations—and impacts both the role of continued somatic support as well as making possible the donation of vital organs. In light of the shortage of organs available for transplantation, greater attention has recently been paid to death by circulatory criteria procurement protocols. One significant source of disagreement is the duration of pulselessness required to declare death and whether circulation needs to be irreversibly ceased or only permanently so.
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Wise, Matt, and Paul Frost. Brain death. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0154.
Повний текст джерелаАнотація:
Mechanical ventilation has made it possible for the heart to continue to beat and perfuse other organs even when the brain is dead. This means that death can be diagnosed in two distinct ways: first, in the traditional manner, as permanent cessation of cardiorespiratory function; and, second, while the patient is ventilated, as brain death (BD). In 1976 the Conference of Medical Royal Colleges and their Faculties in the United Kingdom, in a statement on the diagnosis of BD, recognized the brainstem as the centre of brain activity, without which life was not possible. Brainstem death (BSD) occurs when there is complete, irreversible loss of brainstem function, that is, irreversible loss of the capacity for consciousness, coupled with irreversible loss of the capacity to breathe. In the UK, the terms BD and BSD are used interchangeably and are legally synonymous with somatic death. This chapter covers examination for BSD, complications, diagnosis, investigation, and actions arising after BSD, as well as a definition of BD.
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Martos, Ana. Adelgazar para siempre/ Loose Weight Forever: Como tomar la desicion libre, irreversible y voluntaria de adelgazar para no engordar nunca mas/How to Make ... Irreversible and Voluntary Weigh (Autoayuda). Neoperson, 2003.
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Henderson, Lorna K., Brian J. Nankivell, and Jeremy R. Chapman. Chronic allograft dysfunction. Edited by Jeremy R. Chapman. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0286.
Повний текст джерелаАнотація:
Despite improvements in short-term renal allograft survival, long-term survival has not appreciably changed. Excepting death with a functioning graft, most late graft loss results from chronic allograft dysfunction. Immune and non-immune-mediated injuries contribute to graft dysfunction over time, ultimately leading to a non-specific and irreversible histological end-point of fibrosis, tubular atrophy, and glomerulosclerosis. Screening and early identification of pathology is crucial to allow timely intervention in order to prevent permanent nephron damage and graft loss. This chapter outlines assessment of renal dysfunction following transplantation, defines the causes of chronic allograft failure, and their pathophysiology, and evaluates current therapeutic strategies used to improve or stabilize chronic allograft dysfunction.
Частини книг з теми "Irreversible losse"
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Struchtrup, Henning. "Efficiencies and Irreversible Losses." In Thermodynamics and Energy Conversion, 235–55. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-43715-5_11.
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Hainzelin, Etienne. "Risks of irreversible biodiversity loss." In Food systems at risk. New trends and challenges, 59–62. Rome, Italie: CIRAD; FAO, 2019. http://dx.doi.org/10.19182/agritrop/00093.
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Proelss, Alexander, and Robert C. Steenkamp. "Geoengineering: Methods, Associated Risks and International Liability." In Corporate Liability for Transboundary Environmental Harm, 419–503. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-13264-3_9.
Повний текст джерелаАнотація:
AbstractClimate change arguably constitutes one of the greatest risks to the long-term health of the world’s environment. In 2015, the Intergovernmental Panel on Climate Change (IPCC) highlighted that the Earth’s climate system has consistently been warming since the 1950s and that a “large fraction of anthropogenic climate change resulting from CO2 emissions is irreversible on a multi-century to millennial time scale, except in the case of a large net removal of CO2 from the atmosphere over a sustained period”. Initial responses to climate change revolved around States attempting to reduce, rather than remove, greenhouse gas emissions. However, as the global economy expands, greenhouse gas emissions have continued to rise and cooperative arrangements aimed at reducing emissions have had limited, if any, impact. If recent predictions are to be believed, the remaining “carbon budget” needed to prevent average global temperatures from increasing by more than 1.5 °C may be exhausted by 2030. Climate Analytics estimates that the current Nationally Determined Contributions (NDCs) made by States under the Paris Agreement indicate that average global temperatures will rise by 2.8 °C by 2100—almost double the stipulated efforts to limit the temperature increase to 1.5 °C above pre-industrial levels mentioned in Article 2(1)(a) of the Paris Agreement. The recent IPCC Special Report on 1.5 °C Global Warming concludes that without “increased and urgent mitigation ambition in the coming years, leading to a sharp decline in greenhouse gas emissions by 2030, global warming will [cause] irreversible loss of the most fragile ecosystems and crisis after crisis for the most vulnerable people and societies”.
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Reimer, Uwe, Werner Lehnert, Yaovi Holade, and Boniface Kokoh. "Irreversible Losses in Fuel Cells." In Fuel Cells and Hydrogen, 15–40. Elsevier, 2018. http://dx.doi.org/10.1016/b978-0-12-811459-9.00002-5.
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Hutchinson, P. J., and J. D. Pickard. "Brain death and the vegetative state." In Oxford Textbook of Medicine, 4847–50. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.240506.
Повний текст джерелаАнотація:
Death can be defined as the irreversible loss of the capacity for consciousness and brain stem function, combined with irreversible loss of the capacity to breathe. The irreversible cessation of brainstem function, whether caused by a primary intracranial catastrophe (e.g. trauma, haemorrhage) or the result of extracranial cranial events (e.g hypoxia), will result in the same clinical state, hence brain stem death is the same as death of the patient....
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Samec, Pavel, Aleš Kučera, and Gabriela Tomášová. "Soil Degradation Processes Linked to Long-Term Forest-Type Damage." In Sustainable Development. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106390.
Повний текст джерелаАнотація:
Forest degradation impairs ability of the whole landscape adaptation to environmental change. The impacts of forest degradation on landscape are caused by a self-organization decline. At the present time, the self-organization decline was largely due to nitrogen deposition and deforestation which exacerbated impacts of climate change. Nevertheless, forest degradation processes are either reversible or irreversible. Irreversible forest degradation begins with soil damage. In this paper, we present processes of forest soil degradation in relation to vulnerability of regulation adaptability on global environmental change. The regulatory forest capabilities were indicated through soil organic matter sequestration dynamics. We devided the degradation processes into quantitative and qualitative damages of physical or chemical soil properties. Quantitative soil degradation includes irreversible loss of an earth’s body after claim, erosion or desertification, while qualitative degradation consists of predominantly reversible consequences after soil disintegration, leaching, acidification, salinization and intoxication. As a result of deforestation, the forest soil vulnerability is spreading through quantitative degradation replacing hitherto predominantly qualitative changes under continuous vegetation cover. Increasing needs to natural resources using and accompanying waste pollution destroy soil self-organization through biodiversity loss, simplification in functional links among living forms and substance losses from ecosystem. We concluded that subsequent irreversible changes in ecosystem self-organization cause a change of biome potential natural vegetation and the land usability decrease.
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Ercole, Ari, Peter J. Hutchinson, and John D. Pickard. "Brainstem death and prolonged disorders of consciousness." In Oxford Textbook of Medicine, edited by Christopher Kennard, 5908–12. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0580.
Повний текст джерелаАнотація:
Advances in resuscitation and the advent of modern intensive care techniques to support the circulation challenge the simple definition of death in terms of loss of spontaneous circulation (‘cardiac death’). Instead, death is now better regarded as an irreversible loss of the capacity for consciousness combined with irreversible loss of the capacity to breathe. Since the brainstem is required for both consciousness and spontaneous breathing, irreversible loss of brainstem function (e.g. after trauma, haemorrhage, or hypoxia/ischaemia) defines the state of ‘brainstem death’. Clinical criteria for the diagnosis of brainstem death have been published, but practice varies around the world. Brainstem death lies at the extreme end of this spectrum and is, by definition, permanent. Unlike those with brainstem death, patients with prolonged disorders of consciousness may survive for many years without physiological support. The care of such patients has huge social, societal, ethical, and economic implications.
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Ilnicki, Piotr, and Jutta Zeitz. "Irreversible Loss of Organic Soil Functions after Reclamation." In Organic Soils and Peat Materials for Sustainable Agriculture, 15–32. CRC Press, 2002. http://dx.doi.org/10.1201/9781420040098-2.
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Ilnicki, Piotr, and Jutta Zeitz. "Irreversible Loss of Organic Soil Functions after Reclamation." In Organic Soils and Peat Materials for Sustainable Agriculture. CRC Press, 2002. http://dx.doi.org/10.1201/9781420040098.ch2.
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Shah Alam Panna, Md. "Determination of Death: Ethical and Biomedical Update with International Consensus." In Bioethical Issues in Healthcare [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100604.
Повний текст джерелаАнотація:
Humanity has been confronted with the concept and criteria of death for millennia and the line between life and death sustains to be debated. The profound change caused by life support technology and transplantation continues to challenge our notions of life and death. Despite scientific progress in the previous few decades, there remain big variations in diagnosis criteria applied in each country. Death is a process involving cessation of physiological function and determination of death is the final event in that process. Legally, a patient could be declared dead due to lack of brain function, and still may have a heartbeat when on a mechanical ventilator. Though there is no point in supporting ventilation in a dead person, withdrawing a ventilator before the legal criteria for death may involve the physician in both civil and criminal proceedings. To identify the moment of death is vital to avoid the use of unnecessary medical intervention on a patient who has already died and to ensure the organ donation process, clear and transparent. The age-old standard of determination of death is somatic standard and cardiopulmonary standard. Harvard report (1968) defines irreversible coma as a replacement criterion for death and prescribed clinical criteria for the permanently nonfunctioning brain. The current unifying concept of death: irreversible loss of the capacity for consciousness combined with irreversible loss of the capacity to breathe. WHO (2014) adopted minimum determinant death criteria, acceptable for medical practice globally, achieving international consensus on clinical criteria to maintain public trust and promote ethical practices that respect fundamental rights of individuals and minimize philosophical and biomedical debate in human death. AAN (2019) endorses that the brain death is the irreversible loss of all functions of the entire brain and equivalent to circulatory death.
Тези доповідей конференцій з теми "Irreversible losse"
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Bartz, Wilfried J. "Evaluation of Reversible and Irreversible Viscosity Losses Using the Viscosity Loss Trapezoid*." In International Fuels & Lubricants Meeting & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1994. http://dx.doi.org/10.4271/941980.
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Camberos, Jose, David Moorhouse, and Charles Suchomel. "Quantifying Irreversible Losses for Magnetohydrodynamic (MHD) Flow Simulation." In 36th AIAA Thermophysics Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2003. http://dx.doi.org/10.2514/6.2003-3647.
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Allcorn, Eric, Teal Harbour, David Arnot, Jill Langendorf, and Linda Johnson. "Operando Microcalorimetry Study on Irreversible Losses in Silicon Anodes." In Proposed for presentation at the ECS PRiME 2020 held October 4-9, 2020 in Honolulu, HI, US. US DOE, 2020. http://dx.doi.org/10.2172/1823235.
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Lyall, M. Eric, Paul I. King, and Rolf Sondergaard. "Endwall Loss and Mixing Analysis of a High Lift Low Pressure Turbine Cascade." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68709.
Повний текст джерелаАнотація:
A high lift LPT profile designated L2A is used as a test bed for studying the origin of endwall mixing loss and the role of vortical structures in loss development. It is shown analytically and experimentally that the mixing forces within the endwall wake can be decoupled into either mean flow or turbulent forces, and can be further classified as either reversible or irreversible. Among the irreversible forces, mean flow shear is negligible compared to turbulent shear, suggesting that turbulence dissipation is the dominant cause of loss generation. As a result, the mean flow components of the vortical structures do not generate significant mixing losses. Rather than mixing effects, the mean flow of the vortices cause the suction surface boundary layer to separate inside the passage, thereby generating the large low energy regions typical of endwall flows. Losses are generated as the low energy regions mix out. This vortex separation effect is demonstrated with an experiment using a profile fence and pressure surface modification near the endwall. The findings in this paper suggest that profile modifications near the endwall that suppress suction surface separation may provide loss reductions additive to those that weaken vortical structures, such as endwall contouring.
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Redondo-Iglesias, Eduardo, Pascal Venet, and Serge Pelissier. "Measuring Reversible and Irreversible Capacity Losses on Lithium-Ion Batteries." In 2016 IEEE Vehicle Power and Propulsion Conference (VPPC). IEEE, 2016. http://dx.doi.org/10.1109/vppc.2016.7791723.
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Tsirlin, Anatoly M., and Alexander I. Balunov. "Irreversible losses in the processes of heat exchange at different flow hydrodynamics." In INTERNATIONAL SCIENTIFIC-TECHNICAL SYMPOSIUM (ISTS) «IMPROVING ENERGY AND RESOURCE-EFFICIENT AND ENVIRONMENTAL SAFETY OF PROCESSES AND DEVICES IN CHEMICAL AND RELATED INDUSTRIES». The Kosygin State University of Russia, 2021. http://dx.doi.org/10.37816/eeste-2021-1-199-203.
Повний текст джерелаАнотація:
The influence of flow hydrodynamics on the production of entropy in the processes of irreversible heat transfer in two-flow heat exchangers is considered. A comparison is made with a heat exchanger having the lowest possible irreversibility at a given heat load and heat transfer coefficient.
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Jiang, W., X. Song, K. Kinoshita, and T. Tran. "Analysis of the Irreversible Capacity Loss on Carbons for Li-Ion Batteries." In 34th Intersociety Energy Conversion Engineering Conference. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1999. http://dx.doi.org/10.4271/1999-01-2464.
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Brussell, Edward M., Olga Overbury, Charles W. White, and Gordon A. Balazsi. "Multi-Flash Campimetry as an Indicator of Visual Field Loss in Glaucoma." In Noninvasive Assessment of Visual Function. Washington, D.C.: Optica Publishing Group, 1985. http://dx.doi.org/10.1364/navf.1985.tub6.
Повний текст джерелаАнотація:
Ocular hypertension (OHT), or elevated pressure in the ocular media, is a condition that is closely monitored by the ophthalmologist. The reason is that it can lead to irreversible visual field loss at which time the diagnosis is changed from OHT to glaucoma. Field losses that are observed are usually attributed to ischemia (1) and mechanical pressure (2, 3) at the optic disk. More recently, however, Regan and his colleagues have suggested that there may also be ganglion cell dendritic pathology associated with OHT that is accompanied by visual loss to which conventional perimetry is not sensitive (4,5). In particular, the dendritic pathology may affect temporal (i.e. , flicker) more than spatial aspects of vision.
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Saxena, Samveg, Iván Dario Bedoya, Nihar Shah, and Amol Phadke. "Understanding Loss Mechanisms and Identifying Areas of Improvement for HCCI Engines Using Detailed Exergy Analysis." In ASME 2012 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icef2012-92052.
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This paper presents a detailed exergy analysis of homogeneous charge compression ignition (HCCI) engines, including a crank-angle resolved breakdown of mixture exergy and exergy destruction. Exergy analysis is applied to a multi-zone HCCI simulation including detailed chemical kinetics. The HCCI simulation is validated against engine experiments for ethanol-fueled operation. The exergy analysis quantifies the relative importance of different loss mechanisms within HCCI engines over a range of engine operating conditions. Specifically, four loss mechanisms are studied for their relative impact on exergy losses, including 1) the irreversible combustion process (16.4–21.5%), 2) physical exergy lost to exhaust gases (12.0–18.7%), 3) heat losses (3.9–17.1%), and 4) chemical exergy lost to incomplete combustion (4.7–37.8%). The trends in each loss mechanism are studied in relation to changes in intake pressure, equivalence ratio, and engine speed as these parameters are directly used to vary engine power output. This exergy analysis methodology is proposed as a tool to inform research and design processes, particularly by identifying the relative importance of each loss mechanism in determining engine operating efficiency.
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Young, J. B., and R. C. Wilcock. "Modelling the Air-Cooled Gas Turbine: Part 1 — General Thermodynamics." In ASME Turbo Expo 2001: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/2001-gt-0385.
Повний текст джерелаАнотація:
This paper is Part I of a study concerned with developing a formal framework for modelling air-cooled gas turbine cycles and deals with basic thermodynamic issues. Such cycles involve gas mixtures with varying composition which must be modelled realistically. A possible approach is to define just two components, air and gas, the latter being the products of stoichiometric combustion of the fuel with air. If these components can be represented as ideal gases, the entropy increase due to compositional mixing, although a true exergy loss, can be ignored for the purpose of performance prediction. This provides considerable simplification. Consideration of three idealised simple cycles shows that the introduction of cooling with an associated thermal mixing loss does not necessarily result in a loss of cycle efficiency. This is no longer true when real gas properties and turbomachinery losses are included. The analysis clarifies the role of the cooling losses and shows the importance of assessing performance in the context of the complete cycle. There is a strong case for representing the cooling losses in terms of irreversible entropy production as this provides a formalised framework, clarifies the modelling difficulties and aids physical interpretation. Results are presented which show the effects on performance of varying cooling flowrates and cooling losses. A comparison between simple and reheat cycles highlights the rôle of the thermal mixing loss. Detailed modelling of the heat transfer and cooling losses is discussed in Part II of this paper.
Звіти організацій з теми "Irreversible losse"
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van der Meulen, J., P. van Wikselaar, and A. J. M. Jansman. Determination of the irreversible loss rate of amino acids in broilers. Wageningen: Wageningen Livestock Research, 2019. http://dx.doi.org/10.18174/477672.
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Abdi, Parsa, Christian Awad, Michelle Robert Anthony, and Christopher Farkouh. Effectiveness of Multimodality Therapy using Minoxidil and Microneedling for the Treatment of Alopecia: A Systematic Review and Meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, January 2023. http://dx.doi.org/10.37766/inplasy2023.1.0031.
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Review question / Objective: To test the effectiveness of multimodality therapy using minoxidil and micmroneedling, in comparison to minoxodil alone for the treatment of alopecia. In terms of the PICO framework: Population: Includes patients with any form of clinically diagnosed alopecia. Intervention: Includes using combination therapy with microneedling and minoxidil in the treatment of alopecia. Comparison: Includes comparison to minoxidil alone as control group. Outcome: Primary outcome: Increased hair density. Secondary outcome: Increased hair diameter. Condition being studied: Alopecia (hair loss) is a condition that is frequently seen in dermatology. When a thorough examination is made, the root of the issue is frequently revealed, allowing for an explanation and the most suitable treatments. Nevertheless, hair loss can occasionally be the first indicator of a serious underlying medical problem, be observed in conjunction with other conditions, or be a side effect of treatment. Furthermore, alopecia may result in distressingly noticeable symptoms, cause significant patient distress, and cause alopecia with lifelong scars and irreversible hair loss. Therefore, with these illnesses, a precise diagnosis and quick therapy are essential for the most beneficial outcomes.
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Bustelo, Monserrat, Karen Martinez, Sofía González, and Agustina Suaya. Gender and Inclusion in the Green Agenda: Where Are We and How to Move Forward? Inter-American Development Bank, June 2022. http://dx.doi.org/10.18235/0004285.
Повний текст джерелаАнотація:
Current carbon emission trends threaten inevitable and irreversible changes to the environment that could cost the region US$100 billion annually by 2050 and the loss of up to 2.5 million jobs by 2030. Climate change affects us all. However, women, indigenous peoples, African descendants, and persons with disabilities are particularly vulnerable to the environmental, economic, and social disruptions caused by climate change. At the same time, these groups are decisive agents of change for the mitigation of climate change and the transition to a green and sustainable economy. This document presents evidence of the challenges faced by these populations, as well as the main opportunities and lessons learned about their role in the transition to a zero net carbon future in the region.
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Bustelo, Monserrat, Karen Martinez, Sofía González, and Agustina Suaya. Gender and Inclusion in the Green Agenda: Where Are We and How to Move Forward? Inter-American Development Bank, June 2022. http://dx.doi.org/10.18235/0004285.
Повний текст джерелаАнотація:
Current carbon emission trends threaten inevitable and irreversible changes to the environment that could cost the region US$100 billion annually by 2050 and the loss of up to 2.5 million jobs by 2030. Climate change affects us all. However, women, indigenous peoples, African descendants, and persons with disabilities are particularly vulnerable to the environmental, economic, and social disruptions caused by climate change. At the same time, these groups are decisive agents of change for the mitigation of climate change and the transition to a green and sustainable economy. This document presents evidence of the challenges faced by these populations, as well as the main opportunities and lessons learned about their role in the transition to a zero net carbon future in the region.
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Kamma, Dr Prudhvi Srujan, and Dr Aishwarya Badugu. AN UNUSUAL PRESENTATION OF EXTRAPULMONARY TUBERCULOSIS AS FEVER WITH PANCYTOPENIA: A CASE REPORT. World Wide Journals, February 2023. http://dx.doi.org/10.36106/ijar/5105754.
Повний текст джерелаАнотація:
Background: In the developing countries, tuberculosis is a signicant health issue. The vague presentation causes extrapulmonary tuberculosis to take longer to be diagnosed. Pancytopenia is one of the haematological symptoms of extrapulmonary tuberculosis. Pancytopenia may result from hypersplenism, maturation arrest, hemophagocytic lymphohistiocytosis, or inltration of the bone marrow by caseating or noncaseating granulomas causing reversible or irreversible brosis. We Case presentation: report a case of a 70 year-old man who presented with pyrexia of unknown origin with signicant loss of weight and loss of appetite. He had pallor with mild hepatosplenomegaly. He had high inammatory markers with pancytopenia in a peripheral blood smear. His chest radiograph was normal, and he had a negative Mantoux. The common risk factors such as diabetes, human immunodeciency virus (HIV) infection, chronic kidney disease, malnutrition, and immunosuppressant therapy which might contribute him to be vulnerable to TB, were not found. The denite diagnosis of disseminated tuberculosis was made on the basis of caseating tuberculous granulomas in the bone marrow. Due to its Conclusions: ambiguous and nonspecic presentation, widespread TB continues to be difcult to diagnose. Particularly in places where tuberculosis is endemic, the possibility of disseminated tuberculosis should be taken into account in cases of pyrexia of unknown origin with peripheral cytopenia. In such cases, it is crucial to perform a bone marrow culture and histopathological examination simultaneously because ndings of routine diagnostics like chest radiography or Mantoux tests may be negative.
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Yahav, Shlomo, John Brake, and Noam Meiri. Development of Strategic Pre-Natal Cycling Thermal Treatments to Improve Livability and Productivity of Heavy Broilers. United States Department of Agriculture, December 2013. http://dx.doi.org/10.32747/2013.7593395.bard.
Повний текст джерелаАнотація:
The necessity to improve broiler thermotolerance and live performance led to the following hypothesis: Appropriate comprehensive incubation treatments that include significant temperature management changes will promote angiogenesis and will improve acquisition of thermotolerance and carcass quality of heavy broilers through epigenetic adaptation. It was based on the following questions: 1. Can TM during embryogenesis of broilers induce a longer-lasting thermoregulatory memory (up to marketing age of 10 wk) that will improve acquisition of thermotolerance as well as increased breast meat yield in heavy broilers? 2. The improved sensible heat loss (SHL) suggests an improved peripheral vasodilation process. Does elevated temperature during incubation affect vasculogenesis and angiogenesis processes in the chick embryo? Will such create subsequent advantages for heavy broilers coping with adverse hot conditions? 3. What are the changes that occur in the PO/AH that induce the changes in the threshold response for heat production/heat loss based on the concept of epigenetic temperature adaptation? The original objectives of this study were as follow: a. to assess the improvement of thermotolerance efficiency and carcass quality of heavy broilers (~4 kg); b. toimproveperipheral vascularization and angiogenesis that improve sensible heat loss (SHL); c. to study the changes in the PO/AH thermoregulatory response for heat production/losscaused by modulating incubation temperature. To reach the goals: a. the effect of TM on performance and thermotolerance of broilers reared to 10 wk of age was studied. b. the effect of preincubation heating with an elevated temperature during the 1ˢᵗ 3 to 5 d of incubation in the presence of modified fresh air flow coupled with changes in turning frequency was elucidated; c.the effect of elevated temperature on vasculogenesis and angiogenesis was determined using in ovo and whole embryo chick culture as well as HIF-1α VEGF-α2 VEGF-R, FGF-2, and Gelatinase A (MMP2) gene expression. The effects on peripheral blood system of post-hatch chicks was determined with an infrared thermal imaging technique; c. the expression of BDNF was determined during the development of the thermal control set-point in the preoptic anterior hypothalamus (PO/AH). Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” Recently, Piestunet al. (2008) demonstrated for the first time that TM (an elevated incubation temperature of 39.5°C for 12 h/d from E7 to E16) during the development/maturation of the hypothalamic-hypophyseal-thyroid axis (thermoregulation) and the hypothalamic-hypophyseal-adrenal axis (stress) significantly improved the thermotolerance and performance of broilers at 35 d of age. These phenomena raised two questions that were addressed in this project: 1. was it possible to detect changes leading to the determination of the “set point”; 2. Did TM have a similar long lasting effect (up to 70 d of age)? 3. Did other TM combinations (pre-heating and heating during the 1ˢᵗ 3 to 5 d of incubation) coupled with changes in turning frequency have any performance effect? The improved thermotolerance resulted mainly from an efficient capacity to reduce heat production and the level of stress that coincided with an increase in SHL (Piestunet al., 2008; 2009). The increase in SHL (Piestunet al., 2009) suggested an additional positive effect of TM on vasculogenesis and angiogensis. 4. In order to sustain or even improve broiler performance, TM during the period of the chorioallantoic membrane development was thought to increase vasculogenesis and angiogenesis providing better vasodilatation and by that SHL post-hatch.
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Yahav, Shlomo, John Brake, and Orna Halevy. Pre-natal Epigenetic Adaptation to Improve Thermotolerance Acquisition and Performance of Fast-growing Meat-type Chickens. United States Department of Agriculture, September 2009. http://dx.doi.org/10.32747/2009.7592120.bard.
Повний текст джерелаАнотація:
: The necessity to improve broiler thermotolerance and performance led to the following hypothesis: (a) thethermoregulatory-response threshold for heat production can be altered by thermal manipulation (TM) during incubation so as to improve the acquisition of thermotolerance in the post-hatch broiler;and (b) TM during embryogenesis will improve myoblast proliferation during the embryonic and post-hatch periods with subsequent enhanced muscle growth and meat production. The original objectives of this study were as follow: 1. to assess the timing, temperature, duration, and turning frequency required for optimal TM during embryogenesis; 2. to evaluate the effect of TM during embryogenesis on thermoregulation (heat production and heat dissipation) during four phases: (1) embryogenesis, (2) at hatch, (3) during growth, and (4) during heat challenge near marketing age; 3. to investigate the stimulatory effect of thermotolerance on hormones that regulate thermogenesis and stress (T₄, T₃, corticosterone, glucagon); 4. to determine the effect of TM on performance (BW gain, feed intake, feed efficiency, carcass yield, breast muscle yield) of broiler chickens; and 5. to study the effect of TM during embryogenesis on skeletal muscle growth, including myoblast proliferation and fiber development, in the embryo and post-hatch chicks.This study has achieved all the original objectives. Only the plasma glucagon concentration (objective 3) was not measured as a result of technical obstacles. Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” In order to sustain or even improve broiler performance, TM during the period of embryogenesis when satellite cell population normally expand should increase absolute pectoralis muscle weight in broilers post-hatch. Major conclusions: Intermittent TM (39.5°C for 12 h/day) during embryogenesis when the thyroid and adrenal axis was developing and maturing (E7 to E16 inclusive) had a long lasting thermoregulatory effect that improved thermotolerance of broiler chickens exposed to acute thermal stress at market age by lowering their functional Tb set point, thus lowering metabolic rate at hatch, improving sensible heat loss, and significantly decreasing the level of stress. Increased machine ventilation rate was required during TM so as to supply the oxygen required for the periods of increased embryonic development. Enhancing embryonic development was found to be accomplished by a combination of pre-incubation heating of embryos for 12 h at 30°C, followed by increasing incubation temperature to 38°C during the first 3 days of incubation. It was further facilitated by increasing turning frequency of the eggs to 48 or 96 times daily. TM during critical phases of muscle development in the late-term chick embryo (E16 to E18) for 3 or 6 hours (39.5°C) had an immediate stimulatory effect on myoblast proliferation that lasted for up to two weeks post-hatch; this was followed by increased hypertrophy at later ages. The various incubation temperatures and TM durations focused on the fine-tuning of muscle development and growth processes during late-term embryogenesis as well as in post-hatch chickens.
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Stall, Nathan M., Kevin A. Brown, Antonina Maltsev, Aaron Jones, Andrew P. Costa, Vanessa Allen, Adalsteinn D. Brown, et al. COVID-19 and Ontario’s Long-Term Care Homes. Ontario COVID-19 Science Advisory Table, January 2021. http://dx.doi.org/10.47326/ocsat.2021.02.07.1.0.
Повний текст джерелаАнотація:
Key Message Ontario long-term care (LTC) home residents have experienced disproportionately high morbidity and mortality, both from COVID-19 and from the conditions associated with the COVID-19 pandemic. There are several measures that could be effective in preventing COVID-19 outbreaks, hospitalizations, and deaths in Ontario’s LTC homes, if implemented. First, temporary staffing could be minimized by improving staff working conditions. Second, homes could be further decrowded by a continued disallowance of three- and four-resident rooms and additional temporary housing for the most crowded homes. Third, the risk of SARS-CoV-2 infection in staff could be minimized by approaches that reduce the risk of transmission in communities with a high burden of COVID-19. Summary Background The Province of Ontario has 626 licensed LTC homes and 77,257 long-stay beds; 58% of homes are privately owned, 24% are non-profit/charitable, 16% are municipal. LTC homes were strongly affected during Ontario’s first and second waves of the COVID-19 pandemic. Questions What do we know about the first and second waves of COVID-19 in Ontario LTC homes? Which risk factors are associated with COVID-19 outbreaks in Ontario LTC homes and the extent and death rates associated with outbreaks? What has been the impact of the COVID-19 pandemic on the general health and wellbeing of LTC residents? How has the existing Ontario evidence on COVID-19 in LTC settings been used to support public health interventions and policy changes in these settings? What are the further measures that could be effective in preventing COVID-19 outbreaks, hospitalizations, and deaths in Ontario’s LTC homes? Findings As of January 14, 2021, a total of 3,211 Ontario LTC home residents have died of COVID-19, totaling 60.7% of all 5,289 COVID-19 deaths in Ontario to date. There have now been more cumulative LTC home outbreaks during the second wave as compared with the first wave. The infection and death rates among LTC residents have been lower during the second wave, as compared with the first wave, and a greater number of LTC outbreaks have involved only staff infections. The growth rate of SARS-CoV-2 infections among LTC residents was slower during the first two months of the second wave in September and October 2020, as compared with the first wave. However, the growth rate after the two-month mark is comparatively faster during the second wave. The majority of second wave infections and deaths in LTC homes have occurred between December 1, 2020, and January 14, 2021 (most recent date of data extraction prior to publication). This highlights the recent intensification of the COVID-19 pandemic in LTC homes that has mirrored the recent increase in community transmission of SARS-CoV-2 across Ontario. Evidence from Ontario demonstrates that the risk factors for SARS-CoV-2 outbreaks and subsequent deaths in LTC are distinct from the risk factors for outbreaks and deaths in the community (Figure 1). The most important risk factors for whether a LTC home will experience an outbreak is the daily incidence of SARS-CoV-2 infections in the communities surrounding the home and the occurrence of staff infections. The most important risk factors for the magnitude of an outbreak and the number of resulting resident deaths are older design, chain ownership, and crowding. Figure 1. Anatomy of Outbreaks and Spread of COVID-19 in LTC Homes and Among Residents Figure from Peter Hamilton, personal communication. Many Ontario LTC home residents have experienced severe and potentially irreversible physical, cognitive, psychological, and functional declines as a result of precautionary public health interventions imposed on homes, such as limiting access to general visitors and essential caregivers, resident absences, and group activities. There has also been an increase in the prescribing of psychoactive drugs to Ontario LTC residents. The accumulating evidence on COVID-19 in Ontario’s LTC homes has been leveraged in several ways to support public health interventions and policy during the pandemic. Ontario evidence showed that SARS-CoV-2 infections among LTC staff was associated with subsequent COVID-19 deaths among LTC residents, which motivated a public order to restrict LTC staff from working in more than one LTC home in the first wave. Emerging Ontario evidence on risk factors for LTC home outbreaks and deaths has been incorporated into provincial pandemic surveillance tools. Public health directives now attempt to limit crowding in LTC homes by restricting occupancy to two residents per room. The LTC visitor policy was also revised to designate a maximum of two essential caregivers who can visit residents without time limits, including when a home is experiencing an outbreak. Several further measures could be effective in preventing COVID-19 outbreaks, hospitalizations, and deaths in Ontario’s LTC homes. First, temporary staffing could be minimized by improving staff working conditions. Second, the risk of SARS-CoV-2 infection in staff could be minimized by measures that reduce the risk of transmission in communities with a high burden of COVID-19. Third, LTC homes could be further decrowded by a continued disallowance of three- and four-resident rooms and additional temporary housing for the most crowded homes. Other important issues include improved prevention and detection of SARS-CoV-2 infection in LTC staff, enhanced infection prevention and control (IPAC) capacity within the LTC homes, a more balanced and nuanced approach to public health measures and IPAC strategies in LTC homes, strategies to promote vaccine acceptance amongst residents and staff, and further improving data collection on LTC homes, residents, staff, visitors and essential caregivers for the duration of the COVID-19 pandemic. Interpretation Comparisons of the first and second waves of the COVID-19 pandemic in the LTC setting reveal improvement in some but not all epidemiological indicators. Despite this, the second wave is now intensifying within LTC homes and without action we will likely experience a substantial additional loss of life before the widespread administration and time-dependent maximal effectiveness of COVID-19 vaccines. The predictors of outbreaks, the spread of infection, and deaths in Ontario’s LTC homes are well documented and have remained unchanged between the first and the second wave. Some of the evidence on COVID-19 in Ontario’s LTC homes has been effectively leveraged to support public health interventions and policies. Several further measures, if implemented, have the potential to prevent additional LTC home COVID-19 outbreaks and deaths.