Temperature coefficients and radiation induced DLTS spectra of MOCVD grown n(+)p InP solar cells

The effects of temperature and radiation on n(+)p InP solar cells and mesa diodes grown by metallorganic chemical vapor deposition (MOCVD) were studied. It was shown that MOCVD is capable of consistently producing good quality InP solar cells with Eff greater than 19 percent which display excellent radiation resistance due to minority carrier injection and thermal annealing. It was also shown that universal predictions of InP device performance based on measurements of a small group of test samples can be expected to be quite accurate, and that the degradation of an InP device due to any incident particle spectrum should be predictable from a measurement following a single low energy proton irradiation

Cowbird Control: Management Issues, Controversies and Perceptions, and the Future

Brood-parasitic brown-headed cowbirds (Molothrus ater) have been implicated as a cause of songbird population declines. Cowbirds can have particularly severe negative impacts on already endangered hosts. Removal of cowbirds by trapping has become a popular management action to benefit hosts. Cowbird trapping often decreases parasitism frequency and can help to increase the reproductive success of hosts. However, its role in the recovery of host populations is equivocal. Based on our experience at Fort Hood Military Reservation, Texas, the site of a long-term, landscape-scale trapping program, we discuss factors that we believe are important for the success of a trapping program (e.g., timing of trapping). Although cowbird removal is generally accepted as a songbird conservation tool, its use is not without controversy. So, we also review some of the economic, ethical, legal, and scientific issues associated with cowbird trapping. Ultimately, our continued ability to remove cowbirds as a tool for songbird conservation may depend on the resolution of these controversies. Although cowbird removal may not be a viable long-term solution to songbird population declines in of itself, it can be an integral part of integrated songbird management strategies

The Role for Coagulation Markers in Mild Snakebite Envenomations

Introduction: The majority of patients seeking medical treatment for snakebites do not suffer from severe envenomation. However, no guidelines exist for ordering coagulation markers in patients with minimal or moderate envenomation, nor in those who do not receive antivenom. In this study, we sought to determine whether it was possible to limit the practice of ordering coagulation studies to those patients suffering severe envenomation, rattlesnake envenomation, or both.Methods: A retrospective chart review was performed on all cases of crotalid snakebite presenting to an adult emergency department (ED) from April 1998 to June 2006. Each chart was abstracted for patient’s age, gender, type of snake (if known), severity of envenomation at initial presentation, coagulation test results, whether antivenom was administered, and whether the patient was admitted.Results: Over an approximately 8-year period, 131 snakebite cases presented that met the inclusion criteria, of which 35 (26.7%) had some type of coagulation marker abnormality. Limiting coagulation testing to patients suffering severe envenomation or rattlesnake envenomation would have resulted in failure to identify 89% or 77%, respectively, of the 35 patients who were found to have at least 1 abnormal coagulation marker.Conclusion: Our study failed to identify a subset of patients that could be defined as low risk or for whom coagulation marker testing could be foregone. This study suggests that coagulation tests should be routinely performed on all patients presenting to the ED with complaints of envenomation by copperheads, moccasins, or rattlesnakes. Further clarification of when coagulation markers are indicated may require a prospective study that standardizes snake identification and the timing of coagulation marker testing. [West J Emerg Med. 2012;13(1):68–74.

DigitalHuman (DH): An Integrative Mathematical Model ofHuman Physiology

Mathematical models and simulation are important tools in discovering the key causal relationships governing physiological processes and improving medical intervention when physiological complexity is a central issue. We have developed a model of integrative human physiology called DigitalHuman (DH) consisting of -5000 variables modeling human physiology describing cardiovascular, renal, respiratory, endocrine, neural and metabolic physiology. Users can view time-dependent solutions and interactively introduce perturbations by altering numerical parameters to investigate new hypotheses. The variables, parameters and quantitative relationships as well as all other model details are described in XML text files. All aspects of the model, including the mathematical equations describing the physiological processes are written in XML open source, text-readable files. Model structure is based upon empirical data of physiological responses documented within the peer-reviewed literature. The model can be used to understand proposed physiological mechanisms and physiological interactions that may not be otherwise intUitively evident. Some of the current uses of this model include the analyses of renal control of blood pressure, the central role of the liver in creating and maintaining insulin resistance, and the mechanisms causing orthostatic hypotension in astronauts. Additionally the open source aspect of the modeling environment allows any investigator to add detailed descriptions of human physiology to test new concepts. The model accurately predicts both qualitative and more importantly quantitative changes in clinically and experimentally observed responses. DigitalHuman provides scientists a modeling environment to understand the complex interactions of integrative physiology. This research was supported by.NIH HL 51971, NSF EPSCoR, and NAS

HumMod: A Modeling Environment for the Simulation of Integrative Human Physiology

Mathematical models and simulations are important tools in discovering key causal relationships governing physiological processes. Simulations guide and improve outcomes of medical interventions involving complex physiology. We developed HumMod, a Windows-based model of integrative human physiology. HumMod consists of 5000 variables describing cardiovascular, respiratory, renal, neural, endocrine, skeletal muscle, and metabolic physiology. The model is constructed from empirical data obtained from peer-reviewed physiological literature. All model details, including variables, parameters, and quantitative relationships, are described in Extensible Markup Language (XML) files. The executable (HumMod.exe) parses the XML and displays the results of the physiological simulations. The XML description of physiology in HumMod's modeling environment allows investigators to add detailed descriptions of human physiology to test new concepts. Additional or revised XML content is parsed and incorporated into the model. The model accurately predicts both qualitative and quantitative changes in clinical and experimental responses. The model is useful in understanding proposed physiological mechanisms and physiological interactions that are not evident, allowing one to observe higher level emergent properties of the complex physiological systems. HumMod has many uses, for instance, analysis of renal control of blood pressure, central role of the liver in creating and maintaining insulin resistance, and mechanisms causing orthostatic hypotension in astronauts. Users simulate different physiological and pathophysiological situations by interactively altering numerical parameters and viewing time-dependent responses. HumMod provides a modeling environment to understand the complex interactions of integrative physiology. HumMod can be downloaded at http://hummod.or

A Review of the Federal Guidelines That Inform and Influence Relationships Between Physicians and Industry

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73492/1/j.1553-2712.2009.00460.x.pd

A guide to laboratory use of the squid Loligo pealei

From the Preface: Unfortunately, a guide like this one does not happen simply. It is the product of polite requests (at first polite, anyway) from colleagues, of mutual nagging, and of wives with persistant memories. What we are attempting to achieve with this contribution is a consolidation of many years of personal experience with squid into a source of practical information hopefully useful to the increasing number of people working with the squid. One does not undertake the task of preparing such a guide for a limited audience with unreserved enthusiasm. It always seems the same amount of work could produce something for a larger audience and therefore, hopefully, of greater significance. On the other hand when the hours and days spent on developing handling procedures, techniques, and "tricks of the squid trade" are considered it seems untenable not to pass this otherwise unpublishable data on in hope of saving others like pain and time. Therefore, what we have attempted to do is informally put together information that should prove useful to people interested in all aspects of squid biology. In this way we hope to make the laboratory utilization of the squid more efficient not only from the standpoint of the investigator and the collector but also for the future of the species Loligo pealei

Characteristics and Outcomes of Patients with Vasoplegic Versus Tissue Dysoxic Septic Shock

Background: The current consensus definition of septic shock requires hypotension after adequate fluid challenge or vasopressor requirement. Some patients with septic shock present with hypotension and hyperlactatemia greater than 2 mmol/L (tissue dysoxic shock), whereas others have hypotension alone with normal lactate (vasoplegic shock). Objective: The objective of this study was to determine differences in outcomes of patients with tissue dysoxic versus vasoplegic septic shock. Methods: This was a secondary analysis of a large, multicenter randomized controlled trial. Inclusion criteria were suspected infection, two or more systemic inflammatory response criteria, and systolic blood pressure less than 90 mmHg after a fluid bolus. Patients were categorized by presence of vasoplegic or tissue dysoxic shock. Demographics and Sequential Organ Failure Assessment scores were evaluated between the groups. The primary outcome was in-hospital mortality. Results: A total of 247 patients were included, 90 patients with vasoplegic shock and 157 with tissue dysoxic shock. There were no significant differences in age, race, or sex between the vasoplegic and tissue dysoxic shock groups. The group with vasoplegic shock had a lower initial Sequential Organ Failure Assessment score than did the group with tissue dysoxic shock (5.5 vs. 7.0 points; P = 0.0002). The primary outcome of in-hospital mortality occurred in 8 (9%) of 90 patients with vasoplegic shock compared with 41 (26%) of 157 in the group with tissue dysoxic shock (proportion difference, 17%; 95% confidence interval, 7%–26%; P < 0.0001; log-rank test P = 0.02). After adjusting for confounders, tissue dysoxic shock remained an independent predictor of in-hospital mortality. Conclusions: In this analysis of patients with septic shock, we found a significant difference in in-hospital mortality between patients with vasoplegic versus tissue dysoxic septic shock. These findings suggest a need to consider these differences when designing future studies of septic shock therapies

Theoretical analysis of the mechanisms of a gender differentiation in the propensity for orthostatic intolerance after spaceflight

<p>Abstract</p> <p>Background</p> <p>A tendency to develop reentry orthostasis after a prolonged exposure to microgravity is a common problem among astronauts. The problem is 5 times more prevalent in female astronauts as compared to their male counterparts. The mechanisms responsible for this gender differentiation are poorly understood despite many detailed and complex investigations directed toward an analysis of the physiologic control systems involved.</p> <p>Methods</p> <p>In this study, a series of computer simulation studies using a mathematical model of cardiovascular functioning were performed to examine the proposed hypothesis that this phenomenon could be explained by basic physical forces acting through the simple common anatomic differences between men and women. In the computer simulations, the circulatory components and hydrostatic gradients of the model were allowed to adapt to the physical constraints of microgravity. After a simulated period of one month, the model was returned to the conditions of earth's gravity and the standard postflight tilt test protocol was performed while the model output depicting the typical vital signs was monitored.</p> <p>Conclusions</p> <p>The analysis demonstrated that a 15% lowering of the longitudinal center of gravity in the anatomic structure of the model was all that was necessary to prevent the physiologic compensatory mechanisms from overcoming the propensity for reentry orthostasis leading to syncope.</p

Risk Stratification in Women Enrolled in the Acute Decompensated Heart Failure National Registry Emergency Module (ADHERE-EM)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75587/1/j.1553-2712.2008.00030.x.pd