Cosmid Cloning of Five \u3cem\u3eZymomonas trp\u3c/em\u3e Genes by Complementation of \u3cem\u3eEscherichia coli\u3c/em\u3e and \u3cem\u3ePseudomonas putida trp\u3c/em\u3e Mutants

A library of Zymomonas mobilis genomic DNA was constructed in the broad-host-range cosmid pLAFR1. The library was mobilized into a variety of Escherichia coli and Pseudomonas putida trp mutants by using the helper plasmid pRK2013. Five Z. mobilis trp genes were identified by the ability to complement the trp mutants. The trpF, trpB, and trpA genes were on one cosmid, while the trpD and trpC genes were on two separate cosmids. The organization of the Z. mobilis trp genes seems to be similar to the organization found in Rhizobium spp., Acinetobacter calcoaceticus, and Pseudomonas acidovorans. The trpF, trpB, and trpA genes appeared to be linked, but they were not closely associated with trpD or trpC genes

Evaluation of Fluorapatite as a Waste-Form Material

Argonne National Laboratory has proposed a new extraction procedure to handle TRISO-coated fuels, the Fluoride Extraction Process, or FLEX. The FLEX process is designed to separate the uranium in the fuel from the actinides and most fission products by taking advantage of the unique properties of uranium hexafluoride (UF6). In the FLEX process, the used TRISO fuel is reacted with zirconium fluoride salt, forming UF6 and the fluoride salts of the actinides and fission products. At process temperatures, the UF6 volatizes into a gas, and is released from the molten salt mixture. This leaves behind the actinides and most fission products in a fluoride salt, which is subsequently processed using pyrochemical techniques to recover the actinides and other long lived fission products for transmutation. The UF6 is then cooled, causing it to sublime into solid form, which is then further processed for disposal or reuse. Originally, the research effort had been divided along two parallel paths: the Fabrication Path, led by collaborators at the Khlopin Radium Institute (KRI) in St. Petersburg, Russia; and the Characterization Path, led by researchers from UNLV. The Fabrication Path is focused on examining and evaluating various techniques for fabricating synthetic fluorapatite; synthesizing synthetic fluorapatite; and examining the impacts of waste loading and other fabrication process factors on the performance of the synthetic fluorapatite as a potential waste form. The Characterization Path is focused on adapting and refining the X-ray spectroscopy techniques currently used to characterize borosilicate glass for use in examining the fluorapatite system. This path also encompassed the examination of the ceramic and synthetic mineral waste forms created at KRI, with subsequent examination of these techniques to develop a molecular-level understanding of natural fluorapatite and other fluorine-bearing natural phases as natural analogs for the waste form. These techniques will also be used to examine the changes in surface chemistry caused by environmental degradation of these materials

Weight loss strategies in combat sports and concerning habits in mixed martial arts

Context: Combat sports are typically divided into weight classes, and body-mass manipulation to reach a weight class is commonplace. Previous research suggests that weight loss practices in mixed martial arts (MMA) may be more extreme than in other combat sports. Purpose: To investigate the magnitude of weight loss and the prevalence of weight loss strategies in different combat sports. Methods: Competitors (N = 637) from Brazilian jiu-jitsu, boxing, judo, MMA, Muay Thai/kickboxing, taekwondo, and wrestling completed an online questionnaire seeking information regarding their weight loss practices. Results: Body-mass manipulation was commonly undertaken by all combat-sport athletes, with a particularly high incidence of gradual dieting, increased exercise, and fluid restriction. Skipping meals was higher in taekwondo and wrestling (84%) compared with the other combat sports (∼58%), whereas training in heated rooms and forced oral fluid loss (spitting) was higher in wrestling (83% and 47%, respectively) compared with other combat sports (∼45% and ∼19%, respectively). MMA athletes reported the highest usage of sauna (76%) and water loading (67%) while also reporting the second-highest use of training in rubber/plastic suits (63%). Conclusions: Body-mass manipulation was present in all combat sports, with the prevalence and magnitude of acute weight loss greater in MMA. The incidence of and practices reported will help support staff be fully aware of the variety of methods these athletes and coaches may use to achieve weight loss. Additionally, the results could aid regulatory bodies in the further development of policies on weight cutting

Reviewing the current methods of assessing hydration in athletes

Background Despite a substantial body of research, no clear best practice guidelines exist for the assessment of hydration in athletes. Body water is stored in and shifted between different sites throughout the body complicating hydration assessment. This review seeks to highlight the unique strengths and limitations of various hydration assessment methods described in the literature as well as providing best practice guidelines. Main body There is a plethora of methods that range in validity and reliability, including complicated and invasive methods (i.e. neutron activation analysis and stable isotope dilution), to moderately invasive blood, urine and salivary variables, progressing to non-invasive metrics such as tear osmolality, body mass, bioimpedance analysis, and sensation of thirst. Any single assessment of hydration status is problematic. Instead, the recommended approach is to use a combination, which have complementary strengths, which increase accuracy and validity. If methods such as salivary variables, urine colour, vital signs and sensation of thirst are utilised in isolation, great care must be taken due to their lack of sensitivity, reliability and/or accuracy. Detailed assessments such as neutron activation and stable isotope dilution analysis are highly accurate but expensive, with significant time delays due to data analysis providing little potential for immediate action. While alternative variables such as hormonal and electrolyte concentration, bioimpedance and tear osmolality require further research to determine their validity and reliability before inclusion into any test battery. Conclusion To improve best practice additional comprehensive research is required to further the scientific understanding of evaluating hydration status

The current state of weight-cutting in combat sports

In combat sports, athletes are divided into categories based on gender and body mass. Athletes attempt to compete against a lighter opponent by losing body mass prior to being weighed (i.e., \u27weight-cutting\u27). The purpose of this narrative review was to explore the current body of literature on weight-cutting and outline gaps for further research. Methods of weight-loss include energy intake restriction, total body fluid reduction and pseudo extreme/abusive medical practice (e.g., diuretics). The influence of weight-cutting on performance is unclear, with studies suggesting a negative or no effect. However, larger weight-cuts (~5% of body mass inh) do impair repeat-effort performance. It is unclear if the benefit from competing against a smaller opponent outweighs the observed reduction in physical capacity. Many mechanisms have been proposed for the observed reductions in performance, ranging from reduced glycogen availability to increased perceptions of fatigue. Athletes undertaking weight-cutting may be able to utilise strategies around glycogen, total body water and electrolyte replenishment to prepare for competition. Despite substantial discussion on managing weight-cutting in combat sports, no clear solution has been offered. Given the prevalence of weight-cutting, it is important to develop a deeper understanding of such practices so appropriate advice can be given

Investigating the insulin-like growth factor axis in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth commonest cancer in the UK. Despite recent therapeutic developments, survival rates remain poor, particularly in advanced cancer and Human Papilloma Virus (HPV) negative disease. Novel treatments approaches are therefore urgently required. The type-1 insulin-like growth factor receptor (IGF-1R) regulates cellular growth and survival and is over-expressed in a range of cancer types. Other groups reported that inhibition of IGF-1R reduces HNSCC cell survival and sensitises to ionising radiation, but a clinical trial of IGF-1R inhibition as monotherapy was inactive in unselected palliative patients with HNSCC. These data suggest that predictive biomarkers for response to IGF-1R inhibition are required. The aims of this project were threefold. The first objective was to define factors associated with morbidity and mortality in patients with oropharyngeal cancer (OPSCC) treated with primary surgery alone or with adjuvant chemoradiotherapy. The five-year overall and disease specific survival rates were 68% and 78% respectively. In line with previous data, HPV negative status, current smoking status, high tumour T stage and the presence of perineural spread of tumour or lymphovascular invasion were associated with adverse survival outcomes. In surviving patients, quality of life outcomes were evaluated using the University of Washington Quality of Life score and functional outcomes were assessed with the MD Anderson Dysphagia Inventory. Increasing age, higher tumour T stage, lip-splitting mandibulotomy and free flap reconstruction were associated with reduced quality of life outcome scores following multivariate analysis. The second aim was to assess the significance of IGF-1R expression in HNSCC and test for correlates with clinico-pathological variables. Immunostaining of cores from 346 primary HNSCCs showed that IGF-1R expression was higher in tumour tissue than matched benign epithelium. High IGF-1R was significantly associated with reduced overall and disease specific survival, HPV negative status and high tumour T stage, although was not an independent predictor of survival in multivariate analysis. The final aim was to test the utility of IGF-1R inhibition in HNSCC cell lines as monotherapy and in combination with established treatments, aiming to identify predictive biomarkers for resistance to IGF-1R inhibition. In a panel of 6 HNSCC cell lines, the IGF-1R inhibitor BMS-754807 reduced IGF-1R, AKT and ERK phosphorylation in a dose dependent manner. IGF-1R inhibition with BMS-754807 reduced cell survival and sensitised cells to ionising radiation in clonogenic assay, although the magnitude of this effect varied between cell lines. Combination of BMS-754807 with the EGFR inhibitor Gefitinib caused supra-additive reduction in cell survival. Correlation analysis showed a trend towards an association between high levels of phosphorylated AKT and resistance to BMS-754807 monotherapy. To test the hypothesis that RAS signalling conferred resistance to IGF-1R inhibition, cells were infected with retroviral constructs encoding wild-type or mutant activated HRAS. Cells expressing mutant HRAS were more resistant to BMS-754807 than empty vector or wild-type HRAS infected controls, suggesting that HRAS mutation status may represent a biomarker of resistance to IGF-1R inhibition in HSNCC. Taken together, the results from this project highlight the significance of IGF-1R biology in HNSCC, and form the basis for further in-vivo and clinical research

Sex‐Specific Variability in the Immune System across Life‐History Stages.

Organisms theoretically manage their immune systems optimally across their life spans to maximize fitness. However, we lack information on (1) how the immune system is managed across life‐history stages, (2) whether the sexes manage immunity differentially, and (3) whether immunity is repeatable within an individual. We present a within‐individual, repeated‐measures experiment examining life‐history stage variation in the inflammatory immune response in the zebra finch (Taeniopygia guttata). In juveniles, age‐dependent variation in immune response differed in a sex‐ and context‐specific manner, resulting in no repeatability across stages. In adults, females displayed little stage‐dependent variation in immune response when laying while receiving a high‐quality (HQ) diet; however, laying while receiving a low‐quality (LQ) diet significantly reduced both immune responses and reproductive outputs in a manner consistent with a facultative (resource‐driven) effect of reproduction on immunity. Moreover, a reduced immune response in females who were raising offspring while receiving an HQ diet suggests a residual effect of the energetic costs of reproduction. Conversely, adult males displayed no variation in immune responses across stages, with high repeatability from the nonbreeding stage to the egg‐laying stage, regardless of diet quality (HQ diet, $r=0.51$; LQ diet, $r=0.42$). Females displayed high repeatability when laying while receiving the HQ diet ($r=0.53$); however, repeatability disappeared when individuals received the LQ diet. High‐response females receiving the HQ diet had greater immune flexibility than did low‐response females who were laying while receiving the LQ diet. Data are consistent with immunity being a highly plastic trait that is sex‐specifically modulated in a context‐dependent manner and suggest that immunity at one stage may provide limited information about immunity at future stages

Why do spatial abilities predict mathematical performance?

Spatial ability predicts performance in mathematics and eventual expertise in science, technology and engineering. Spatial skills have also been shown to rely on neuronal networks partially shared with mathematics. Understanding the nature of this association can inform educational practices and intervention for mathematical underperformance. Using data on two aspects of spatial ability and three domains of mathematical ability from 4174 pairs of 12-year-old twins, we examined the relative genetic and environmental contributions to variation in spatial ability and to its relationship with different aspects of mathematics. Environmental effects explained most of the variation in spatial ability (~70%) and in mathematical ability (~60%) at this age, and the effects were the same for boys and girls. Genetic factors explained about 60% of the observed relationship between spatial ability and mathematics, with a substantial portion of the relationship explained by common environmental influences (26% and 14% by shared and non-shared environments respectively). These findings call for further research aimed at identifying specific environmental mediators of the spatial–mathematics relationship

Considerations when assessing endurance in combat sport athletes

Combat sports encompass a range of sports, each involving physical combat between participants. Such sports are unique, with competitive success influenced by a diverse range of physical characteristics. Effectively identifying and evaluating each characteristic is essential for athletes and support staff alike. Previous research investigating the relationship between combat sports performance and measures of strength and power is robust. However, research investigating the relationship between combat sports performance and assessments of endurance is less conclusive. As a physical characteristic, endurance is complex and influenced by multiple factors including mechanical efficiency, maximal aerobic capacity, metabolic thresholds, and anaerobic capacities. To assess endurance of combat sports athletes, previous research has employed methods ranging from incremental exercise tests to circuits involving sports-specific techniques. These tests range in their ability to discern various physiological attributes or performance characteristics, with varying levels of accuracy and ecological validity. In fact, it is unclear how various physiological attributes influence combat sport endurance performance. Further, the sensitivity of sports specific skills in performance based tests is also unclear. When developing or utilizing tests to better understand an athletes\u27 combat sports-specific endurance characteristic, it is important to consider what information the test will and will not provide. Additionally, it is important to determine which combination of performance and physiological assessments will provide the most comprehensive picture. Strengthening the understanding of assessing combat sport-specific endurance as a physiological process and as a performance metric will improve the quality of future research and help support staff effectively monitor their athlete\u27s characteristics