Analysis of Topaz II and Space-R Space Nuclear Power Plants Using a Modified Thermionic Model

Models based on the TDS thermionic diode model were developed for TOPAZ II and SPACER nuclear power systems. Several parameter studies were conducted with the TOPAZ II model. These determined system performance and efficiency while varying the following: (1) Coolant flow inlet temperatures. (2) Rate of coolant temperature change. (3) Power profile of the core. (4) Cesium reservoir temperature. Analysis of results indicate the model accurately represented the TOPAZ II system, underestimating published data by 10%. Coolant flow studies indicate that raising coolant temperatures up to 100 K higher increases system power by up to 5%. Additional increases in temperature result in gradual performance degradation. Varying the axial power profile of the core from the actual peaked profile to a flat profile results in a negligible 0.3% change in system performance. The peaked profile used in TOPAZ H produces the highest system efficiency of all the profiles modeled. The cesium pressure study indicates the system is operating above optimum cesium pressure and system performance is strongly dependent on cesium pressure. Increasing cesium reservoir temperature above design temperature by 30 K decreases system efficiency by 30%

Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation

Background: There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO2AT) could identify these patients. Methods: Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial applanation tonometry were performed. Results: There were 70 participants (age 41.7614.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced anaerobic threshold (VO2AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27–0.68; p,0.001) and in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12–0.59; p = 0.001). The area under the receiveroperating- characteristic curve was 0.93, based on a risk prediction model that incorporated VO2AT, body mass index and desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU admission. Conclusions: To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO2AT has the potential to predict perioperative morbidity in kidney transplant recipients

Piperonylbutoxide and the Necessity of Toxicological Assessment of Insecticide Mixtures; a Letter to Editor

  With great interest we read the letter by Dr. Faress et al. (1) in which they explain the clinical impression of pyrethroid poisoning in relation to the addition of piperonylbutoxide (PBO). The authors include our case report of an insecticide spray formulation containing cypermethrin, tetramethrin and PBO that induced a myocardial infarction type II in a patient with cardiac comorbidity (2). We fully agree with the authors that the “presence or absence of piperonylbutoxide” may induce different types of pyrethroid poisoning and determination of all suspicious ingredients is “necessary for all clinical toxicologists”. However, we think it is necessary to discuss the current assessment of PBO, and to analyze in detail some of the case reports cited

Alternate without alternative: Neither preference nor learning explains behaviour of C57BL/6J mice in the T-maze

In rodents, the T-maze is commonly used to investigate spontaneous alternating behaviour, but it can also be used to investigate preference between goods. However, for T-maze preference tests with mice there is no recommended protocol and researchers frequently report reproduction difficulties. Here, we tried to develop an efficient protocol with female C57BL/6J CrL mice for preference tests. We used two different designs, adapting habituation, cues and trial timing. However, in both experiments mice did not show any preference, although we used goods which we knew mice find rewarding. Instead, they alternated choices indicating that exploratory behaviour overruled preference. We argue that this behavioural strategy has evolved as an adaptive trait in saturated conditions where there is no need to take the reward immediately. Therefore, we deem the T-maze unsuitable for preference testing with the procedures we used here

Static and Dynamic Lung Volumes in Swimmers and Their Ventilatory Response to Maximal Exercise

Purpose While the static and dynamic lung volumes of active swimmers is often greater than the predicted volume of similarly active non-swimmers, little is known if their ventilatory response to exercise is also different. Methods Three groups of anthropometrically matched male adults were recruited, daily active swimmers (n = 15), daily active in fields sport (Rugby and Football) (n = 15), and recreationally active (n = 15). Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximal voluntary ventilation (MVV) was measured before and after exercise to volitional exhaustion. Results Swimmers had significantly larger FVC (6.2 ± 0.6 l, 109 ± 9% pred) than the other groups (5.6 ± 0.5 l, 106 ± 13% pred, 5.5 ± 0.8, 99% pred, the sportsmen and recreational groups, respectively). FEV1 and MVV were not different. While at peak exercise, all groups reached their ventilatory reserve (around 20%), the swimmers had a greater minute ventilation rate than the recreational group (146 ± 19 vs 120 ± 87 l/min), delivering this volume by breathing deeper and slower. Conclusions The swimmers utilised their larger static volumes (FVC) differently during exercise by meeting their ventilation volume through long and deep breaths

O mouse, where art thou? The Mouse Position Surveillance System (MoPSS)—an RFID-based tracking system

Existing methods for analysis of home cage-based preference tests are either time-consuming, not suitable for group management, expensive, and/or based on proprietary equipment that is not freely available. To correct this, we developed an automated system for group-housed mice based on radio frequency identification: the Mouse Position Surveillance System (MoPSS). The system uses an Arduino microcontroller with compatible components; it is affordable and easy to rebuild for every laboratory because it uses free and open-source software and open-source hardware with the RFID readers as the only proprietary component. The MoPSS was validated using female C57BL/6J mice and manual video comparison. It proved to be accurate even for fast-moving mice (up to 100% accuracy after logical reconstruction), and is already implemented in several studies in our laboratory. Here, we provide the complete construction description as well as the validation data and the results of an example experiment. This tracking system will allow group-based preference testing with individually identified mice to be carried out in a convenient manner. This facilitation of preference tests creates the foundation for better housing conditions from the animals’ perspective

SEDIMENTOLOGY AND CITIZEN SCIENCE: ECOLOGICAL MONITORING IN CARPENTER CREEK, KINGSTON, WA.

Monitoring is a key component of any successful ecological restoration project. Being able to see how an ecosystem responds to restoration treatments is not only vital for planning out future restoration work, but also for more fully understanding how an ecosystem functions. The aim of this study was to examine the relationship between two culvert removals done in Carpenter Creek, a tidal creek feeding an estuarine wetland in North Kitsap, and the texture of the alluvial sediments bedded by the creek. To accomplish this task, we used the R programming language to analyze and visualize sediment texture data collected by Stillwaters Environmental Center, an environmental monitoring non-profit operating out of the local area. Our data visualizations suggest that the first culvert removal, done near the mouth of the creek in 2012, resulted in a change in overall texture and an increase in fine sediments, while in 2014 and 2016 sediment texture drifted back towards the base state seen in 2011. In 2018, when the second culvert, this time located upstream near the marsh, was removed, a greater change in texture and increase in fine sediment was observed. These results suggest that an increased level of stream connectivity has been achieved, thereby allowing a freer and more natural sediment transportation regime. This increased understanding of Carpenter Creek’s evolution was made possible through a long-term monitoring effort

A study of collider signatures for two Higgs doublet models with a Pseudoscalar mediator to Dark Matter

Two Higgs doublet models with an additional pseudoscalar particle coupling to the Standard Model and to a new stable, neutral particle, provide an attractive and fairly minimal route to solving the problem of Dark Matter. They have been the subject of several searches at the LHC. We study the impact of existing LHC measurements on such models, first in the benchmark regions addressed by searches and then after relaxing some of their assumptions and broadening the parameter ranges considered. In each case we study how the new parameters change the potentially visible signatures at the LHC, and identify which of these signatures should already have had a significant impact on existing measurements. This allows us to set some first constraints on a number of so far unstudied scenarios.Comment: 20 pages, 9 figures; added EW constraints contours, extended explanation of WW model-dependency, extended motivation for pseudoscalar mediators, corrected typo

Flipbook-ENA: Towards a dynamic Ecological Network Analysis under changing environmental conditions

Changes in abiotic parameters can affect ecosystem structure and function. Network models with subsequent Ecological Network Analysis (ENA) are often used for the quantification of ecosystem-wide properties with descriptive system indices. However, dynamic abiotic alterations of an ecosystem cannot be resolved with the “state of the art” ENA as the methodology of analyses is static in both space and time. In this study, we present a new, almost dynamic ENA “Flipbook-ENA” which allows for the trend analysis of system indices over a defined range of abiotic factors. Flipbook-ENA enables an approximation of the dynamic system response by discretizing the continuous influence of abiotic factors and by calculating the corresponding changes in the model for each discretization step. ENA indices are therefore obtained as a discrete function of the abiotic conditions. We applied this new concept to two aquatic food web models as case studies, using temperature as the influencing abiotic factor. Flipbook-ENA can be considered an enhancement of ENA flexibility, also facilitating the provision of a quantitative assessment basis for socially, economically and ecologically-balanced management of ecosystems in unstable environmental conditions under the pressure of climate change

Guppies Prefer to Follow Large (Robot) Leaders Irrespective of Own Size

Body size is often assumed to determine how successfully an individual can lead others with larger individuals being better leaders than smaller ones. But even if larger individuals are more readily followed, body size often correlates with specific behavioral patterns and it is thus unclear whether larger individuals are more often followed than smaller ones because of their size or because they behave in a certain way. To control for behavioral differences among differentially-sized leaders, we used biomimetic robotic fish (Robofish) of different sizes. Live guppies (Poecilia reticulata) are known to interact with Robofish in a similar way as with live conspecifics. Consequently, Robofish may serve as a conspecific-like leader that provides standardized behaviors irrespective of its size. We asked whether larger Robofish leaders are preferentially followed and whether the preferences of followers depend on own body size or risk-taking behavior (“boldness”). We found that live female guppies followed larger Robofish leaders in closer proximity than smaller ones and this pattern was independent of the followers’ own body size as well as risk-taking behavior. Our study shows a “bigger is better” pattern in leadership that is independent of behavioral differences among differentially-sized leaders, followers’ own size and risk-taking behavior.Peer Reviewe