352 research outputs found
“Crusades Against Bolshevism”?: International Dimensions of the Russian Civil War in Four Countries
The Russian Civil War (1917-1922), fought between Bolshevik and anti-Bolshevik factions, was one of the most pivotal conflicts of the 20th century. It led directly to the rise of the world’s first socialist state, the Soviet Union, which for decades was at the forefront of the international communist movement and a major global power until its collapse in 1991, around 70 years after its founding. The victory of the Bolsheviks was not always a guaranteed outcome, however. In fact, to an outside observer in February of 1917, it would have appeared one of the less likely. The six months that followed would produce the conditions for a communist takeover, and the Russian Civil War was the conflict that would decide that outcome. The war itself was multidimensional, and to portray it merely as a bipolar conflict between White and Red armies misrepresents its true nature, which was the fragmenting of one of the largest land empires in history. Countless nationalities that had formerly been subjects under the Russian Empire made a break for independence, some successfully and others not. It is for this reason that historian Jonathan Smele insists on applying the term Russian Civil Wars to the series of conflicts that erupted across the territory of the Russian Empire over a ten-year period from 1916 to 1926
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The Impact of Melatonin, Melatonin Analogues, Caffeine, and Bright Light on Sleep and Thermoregulatory Physiology
doses under controlled conditions during the daytime, when endogenous levels are low. Study findings have demonstrated that exogenous melatonin improves sleep, increases peripheral heat loss, and decreases core body temperature (CBT). These thermoregulatory adjustments mimic those that occur around habitual bedtime, when endogenous melatonin levels are high. The emergences of artificial light and stimulants i.e., caffeine have impacted the behavior and physiology that normally precede sleep. Caffeine may independently impact sleep/wakefulness, or in conjunction with the thermoregulatory system. Bright light during the biological night suppresses melatonin and changes the thermoregulatory pattern that precedes nocturnal sleep; these changes may ultimately impact the sleep/wakefulness system. To improve our understanding of physiological mechanisms promoting and disrupting sleep/wakefulness, it is important to examine the connection between melatonin and the sleep/wakefulness and thermoregulatory systems, and the impact of environmental and behavioral factors on these systems. Therefore, the aims of this dissertation were to: 1) determine the effect of a melatonin receptor analogue ramelteon, on daytime sleep and body temperature, and the relationship between the two variables; 2) determine the effect of daytime exogenous melatonin on resting energy expenditure, (REE); and 3) determine the individual and compound effects of caffeine and bright light on thermoregulatory and sleep physiology at night.
Consistent with our hypotheses, 1) ramelteon significantly improved daytime sleep, lowered CBT, and increased peripheral heat loss 2) exogenous melatonin decreased REE during the daytime, and 3) caffeine delayed the nocturnal rise in peripheral heat loss, attenuated the fall in CBT, while the combination of caffeine and bright light decreased slow wave sleep and increased sleep onset latency.
These findings suggest that melatonin may play an important role in the regulation of sleep/wakefulness as evidenced by the effect of daytime ramelteon administration on sleep and thermoregulatory physiology and the effect of daytime exogenous melatonin on REE. Finally, caffeine and bright light had a negative impact on nocturnal sleep and these effects may be mediated in part by their impact on the thermoregulatory system
Welcome to The new anatomist
No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34282/1/1_ftp.pd
The living scar - cardiac fibroblasts and the injured heart
Cardiac scars, often dubbed ‘dead tissue’, are very much alive, with heterocellular activity contributing to the maintenance of structural and mechanical integrity following heart injury. To form a scar, non-myocytes such as fibroblasts are recruited from intra- and extra-cardiac sources. Fibroblasts perform important autocrine and paracrine signaling functions. They also establish mechanical and, as is increasingly evident, electrical junctions with other cells. While fibroblasts were previously thought to act simply as electrical insulators, they may be electrically connected among themselves and, under some circumstances, to other cells including cardiomyocytes. A better understanding of these biophysical interactions will help to target scar structure and function, and will facilitate the development of novel therapies aimed at modifying scar properties for patient benefit
Role of periostin
Periostin, also termed osteoblast-specific factor 2, is a matricellular protein with known functions in osteology, tissue repair, oncology, cardiovascular and respiratory systems, and in various inflammatory settings. However, most of the research to date has been conducted in divergent and circumscribed areas meaning that the overall understanding of this intriguing molecule remains fragmented. Here, we integrate the available evidence on periostin expression, its normal role in development, and whether it plays a similar function during pathologic repair, regeneration, and disease in order to bring together the different research fields in which periostin investigations are ongoing. In spite of the seemingly disparate roles of periostin in health and disease, tissue remodeling as a response to insult/injury is emerging as a common functional denominator of this matricellular molecule. Periostin is transiently upregulated during cell fate changes, either physiologic or pathologic. Combining observations from various conditions, a common pattern of events can be suggested, including periostin localization during development, insult and injury, epithelial–mesenchymal transition, extracellular matrix restructuring, and remodeling. We propose mesenchymal remodeling as an overarching role for the matricellular protein periostin, across physiology and disease. Periostin may be seen as an important structural mediator, balancing appropriate versus inappropriate tissue adaption in response to insult/injury
Leaning in to Address Sleep Disturbances and Sleep Disorders in Department of Defense and Defense Health Agency
Letter to the Editor, Military Medicine, 187, 5/6:155, 202217 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1177/0018720820906050In their article entitled, “Engaging Stakeholders to Optimize Sleep Disorders Management in the U.S. Military: A Qualitative Analysis,” Abdelwadoud and colleagues conducted focus groups of service members, primary care managers (PCMs), and administrative stakeholders about their perceptions, experiences, roles in sleep management, stated education needs, and management of sleep disorders.1 The qualitative methods are rigorous, and the findings reinforce and nuance prior results, especially regarding key requirements from PCMs. We feel compelled, however, to further nuance the authors’ conclusion that “current military sleep management practices are neither satisfactory nor maximally effective” and offer specific examples of actions taken by the Department of Defense (DoD) and Defense Health Agency (DHA) in recognition of the significance of optimal sleep in combat readiness and overall health of service members. We offer here a succinct list of concrete efforts to support and implement substantial clinical, operational, research, or educational efforts by the DoD or DHA to improve sleep in service members and associated clinical challenges in this unique population.Identified in text as U.S. Government work
Small arms combat modeling: a superior way to evaluate marksmanship data
Purpose – Marksmanship data is a staple of military and law enforcement evaluations. This ubiquitous nature creates a critical need to use all relevant information and to convey outcomes in a meaningful way for the end users. The purpose of this study is to demonstrate how simple simulation techniques can improve interpretations of marksmanship data. Design/methodology/approach – This study uses three simulations to demonstrate the advantages of small arms combat modeling, including (1) the benefits of incorporating a Markov Chain into Monte Carlo shooting simulations; (2) how small arms combat modeling is superior to point-based evaluations; and (3) why continuous-time chains better capture performance than discrete-time chains. Findings – The proposed method reduces ambiguity in low-accuracy scenarios while also incorporating a more holistic view of performance as outcomes simultaneously incorporate speed and accuracy rather than holding one constant. Practical implications – This process determines the probability of winning an engagement against a given opponent while circumventing arbitrary discussions of speed and accuracy trade-offs. Someone wins 70% of combat engagements against a given opponent rather than scoring 15 more points. Moreover, risk exposure is quantified by determining the likely casualties suffered to achieve victory. This combination makes the practical consequences of human performance differences tangible to the end users. Taken together, this approach advances the operations research analyses of squad-level combat engagements. Originality/value – For more than a century, marksmanship evaluations have used point-based systems to classify shooters. However, these scoring methods were developed for competitive integrity rather than lethality as points do not adequately capture combat capabilities. The proposed method thus represents a major shift in the marksmanship scoring paradigm
Roles of Proteoglycans and Glycosaminoglycans in Wound Healing and Fibrosis
A wound is a type of injury that damages living tissues. In this review, we will be referring mainly to healing responses in the organs including skin and the lungs. Fibrosis is a process of dysregulated extracellular matrix (ECM) production that leads to a dense and functionally abnormal connective tissue compartment (dermis). In tissues such as the skin, the repair of the dermis after wounding requires not only the fibroblasts that produce the ECM molecules, but also the overlying epithelial layer (keratinocytes), the endothelial cells, and smooth muscle cells of the blood vessel and white blood cells such as neutrophils and macrophages, which together orchestrate the cytokine-mediated signaling and paracrine interactions that are required to regulate the proper extent and timing of the repair process. This review will focus on the importance of extracellular molecules in the microenvironment, primarily the proteoglycans and glycosaminoglycan hyaluronan, and their roles in wound healing. First, we will briefly summarize the physiological, cellular, and biochemical elements of wound healing, including the importance of cytokine cross-talk between cell types. Second, we will discuss the role of proteoglycans and hyaluronan in regulating these processes. Finally, approaches that utilize these concepts as potential therapies for fibrosis are discussed
Investigation of three new mouse mammary tumor cell lines as models for transforming growth factor (TGF)-β and Neu pathway signaling studies: identification of a novel model for TGF-β-induced epithelial-to-mesenchymal transition
INTRODUCTION: This report describes the isolation and characterization of three new murine mammary epithelial cell lines derived from mammary tumors from MMTV (mouse mammary tumor virus)/activated Neu + TβRII-AS (transforming growth factor [TGF]-β type II receptor antisense RNA) bigenic mice (BRI-JM01 and BRI-JM05 cell lines) and MMTV/activated Neu transgenic mice (BRI-JM04 cell line). METHODS: The BRI-JM01, BRI-JM04, and BRI-JM05 cell lines were analyzed for transgene expression, their general growth characteristics, and their sensitivities to several growth factors from the epidermal growth factor (EGF) and TGF-β families (recombinant human EGF, heregulin-β(1 )and TGF-β(1)). The BRI-JM01 cells were observed to undergo a striking morphologic change in response to TGF-β(1), and they were therefore further investigated for their ability to undergo a TGF-β-induced epithelial-to-mesenchymal transition (EMT) using motility assays and immunofluorescence microscopy. RESULTS: We found that two of the three cell lines (BRI-JM04 and BRI-JM05) express the Neu transgene, whereas, unexpectedly, both of the cell lines that were established from MMTV/activated Neu + TβRII-AS bigenic tumors (BRI-JM01 and BRI-JM05) do not express the TβRII-AS transgene. The cuboidal BRI-JM01 cells exhibit a short doubling time and are able to form confluent monolayers. The BRI-JM04 and BRI-JM05 cell lines are morphologically much less uniform, grow at a much slower rate, and do not form confluent monolayers. Only the BRI-JM05 cells can form colonies in soft agar. In contrast, all three cell lines form colonies in Matrigel, although the BRI-JM04 and BRI-JM05 cell lines do so more efficiently than the BRI-JM01 cell line. All three cell lines express the cell surface marker E-cadherin, confirming their epithelial character. Proliferation assays showed that the three cell lines respond differently to recombinant human EGF and heregulin-β(1), and that all are growth inhibited by TGF-β(1), but that only the BRI-JM01 cell line undergoes an EMT and exhibits increased motility upon TGF-β(1 )treatment. CONCLUSION: We suggest that the BRI-JM04 and BRI-JM05 cell lines can be used to investigate Neu oncogene driven mammary tumorigenesis, whereas the BRI-JM01 cell line will be useful for studying TGF-β(1)-induced EMT
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