First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV.

We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.

Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground.

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.

Constraints on Lightly Ionizing Particles from CDMSlite.

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7} cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5 MeV/c^{2} to 100 TeV/c^{2}) and cover a wide range of ßγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with ßγ as small as 0.1 for the first time.

In pursuit of the unicorn.

This short review was prompted by The Physiological Society's recent online symposium on variability. It does not deal with a specific methodology, but rather with the myth that certain environmentally-induced clinical conditions can be identified, quantified, simplified and monitored with a single methodology. Although this might be possible with some clinical conditions, others resist the prevailing reductionist approach of minimizing rather than exploring variation in pathogenesis and pathology, and will not be understood fully until the variation in cause and effect are embraced. This is likely to require comprehensive methodologies and collaboration.

Human factors in preventing complications in anaesthesia: a systematic review.

Human factors in anaesthesia were first highlighted by the publication of the Anaesthetists Non-Technical Skills Framework, and since then an awareness of their importance has gradually resulted in changes in routine clinical practice. This review examines recent literature around human factors in anaesthesia, and highlights recent national reports and guidelines with a focus on team working, communication, situation awareness and human error. We highlight the importance of human factors in modern anaesthetic practice, using the example of complex trauma.

Cold water immersion: kill or cure?

NEW FINDINGS: What is the topic of this review? This is the first review to look across the broad field of 'cold water immersion' and to determine the threats and benefits associated with it as both a hazard and a treatment. What advances does it highlight? The level of evidence supporting each of the areas reviewed is assessed. Like other environmental constituents, such as pressure, heat and oxygen, cold water can be either good or bad, threat or treatment, depending on circumstance. Given the current increase in the popularly of open cold water swimming, it is timely to review the various human responses to cold water immersion (CWI) and consider the strength of the claims made for the effects of CWI. As a consequence, in this review we look at the history of CWI and examine CWI as a precursor to drowning, cardiac arrest and hypothermia. We also assess its role in prolonged survival underwater, extending exercise time in the heat and treating hyperthermic casualties. More recent uses, such as in the prevention of inflammation and treatment of inflammation-related conditions, are also considered. It is concluded that the evidence base for the different claims made for CWI are varied, and although in most instances there seems to be a credible rationale for the benefits or otherwise of CWI, in some instances the supporting data remain at the level of anecdotal speculation. Clear directions and requirements for future research are indicated by this review.

A multistudy examination of organizational stressors, emotional labor, burnout, and turnover in sport organizations.

While a growing body of research has examined the types of organizational stressors encountered by individuals and their allied responses, little is known about how such individuals manage their emotional responses to these stressors or the consequences of such behaviors. This article presents novel findings from two studies examining the moderating role that emotional labor plays in the relationship between the frequency of organizational stressor experience, burnout, turnover intentions, and actual turnover in sport. In study 1, participants (n=487) completed measures of organizational stressors (OSI-SP), emotional labor (ELS), burnout (ABQ), and turnover intentions. In study 2, a 6-month longitudinal design was used to examine measures of organizational stressors (OSI-SP), emotional labor (ELS), turnover intentions, and actual turnover. Study 1 showed that surface acting moderated the relationship between the frequency of organizational stressors and burnout in sport. Further, surface acting acted as an important mechanism through which burnout mediated the relationship between the frequency of organizational stressors and turnover intentions. Study 2 showed that surface acting moderated the relationship between the organizational stressor frequency and turnover intentions-but not actual turnover-over time. These results highlight the importance of surface acting in understanding how individuals respond to organizational stressors encountered in sport, expanding our understanding of the positive and negative responses component of the meta-model of stress, emotions, and performance. These findings also highlight potentially deleterious emotion-management behaviors that practitioners might consider when aiming to support individuals encountering organizational stressors in sport.

Orbital mass as first presentation of metastatic p16-positive oropharyngeal squamous cell carcinoma.

We describe a case in which a 67-year-old man was diagnosed with a metastatic recurrence of p16-positive oropharyngeal squamous cell carcinoma after presenting with a medial orbital mass in the region of the nasolacrimal apparatus. A review of the literature revealed that metastasis to the orbit from any malignancy is an uncommon occurrence, and no cases of p16-positive oropharyngeal squamous cell carcinoma have previously been reported. Our case highlights the importance of maintaining a high index of suspicion during surveillance visits with such patients.

Climatic Drivers for Multi-Decadal Shifts in Solute Transport and Methane Production Zones within a Large Peat Basin.

Northern peatlands are an important source for greenhouse gases but their capacity to produce methane remains uncertain under changing climatic conditions. We therefore analyzed a 43-year time series of pore-water chemistry to determine if long-term shifts in precipitation altered the vertical transport of solutes within a large peat basin in northern Minnesota. These data suggest that rates of methane production can be finely tuned to multi-decadal shifts in precipitation that drive the vertical penetration of labile carbon substrates within the Glacial Lake Agassiz Peatlands. Tritium and cation profiles demonstrate that only the upper meter of these peat deposits was flushed by downwardly moving recharge from 1965 through 1983 during a Transitional Dry-to-Moist Period. However, a shift to a moister climate after 1984 drove surface waters much deeper, largely flushing the pore waters of all bogs and fens to depths of 2 m. Labile carbon compounds were transported downward from the rhizosphere to the basal peat at this time producing a substantial enrichment of methane in Δ14C with respect to the solid-phase peat from 1991 to 2008. These data indicate that labile carbon substrates can fuel deep production zones of methanogenesis that more than doubled in thickness across this large peat basin after 1984. Moreover, the entire peat profile apparently has the capacity to produce methane from labile carbon substrates depending on climate-driven modes of solute transport. Future changes in precipitation may therefore play a central role in determining the source strength of peatlands in the global methane cycle.

Effect of short-term heat acclimation with permissive dehydration on thermoregulation and temperate exercise performance.

We examined the effect of short-term heat acclimation with permissive dehydration (STHADe) on heat acclimation (HA) and cycling performance in a temperate environment. Ten trained male cyclists [mean (SD) maximal oxygen uptake: 63.3(4.0) mL/kg/min; peak power output (PPO): 385(40) W; training: 10 (3) h/week] underwent a STHADe program consisting of 5 days of exercise (maximum 90 min/day) in a hot environment (40 °C, 50% RH) to elicit isothermic heat strain [rectal temperature 38.64(0.27) °C]. Participants abstained from fluids during, and 30 min after, HA sessions. Pre- and post-STHADe HA was evaluated during euhydrated fixed-intensity exercise (60 min) in hot conditions; the effect of STHADe on thermoregulation was also examined under temperate conditions (20 min fixed-intensity exercise; 22 °C, 60% RH). Temperate cycling performance was assessed by a graded exercise test (GXT) and 20-km time trial (TT). STHADe reduced thermal and cardiovascular strain in hot and temperate environments. Lactate threshold [Δ = 16 (17) W] and GXT PPO [Δ = 6 (7) W] were improved following STHADe (P < 0.05), but TT performance was not affected (P > 0.05), although there was a trend for a higher mean power (P = 0.06). In conclusion, STHADE can reduce thermal and cardiovascular strain under hot and temperate conditions and there is some evidence of ergogenic potential for temperate exercise, but longer HA regimens may be necessary for this to meaningfully influence performance.

Peri-operative renal dysfunction: prevention and management.

Postoperative increases in serum creatinine concentration, by amounts historically viewed as trivial, are associated with increased morbidity and mortality. Acute kidney injury is common, affecting one in five patients admitted with acute medical disease and up to four in five patients admitted to intensive care, of whom one in two have had operations. This review is focused principally on the identification of patients at risk of acute kidney injury and the prevention of injury. In the main, there are no interventions that directly treat the damaged kidney. The management of acute kidney injury is based on correction of dehydration, hypotension, and urinary tract obstruction, stopping nephrotoxic drugs, giving antibiotics for bacterial infection, and commencing renal replacement therapy if necessary.

Relieving thermal discomfort: Effects of sprayed L-menthol on perception, performance, and time trial cycling in the heat.

L-menthol stimulates cutaneous thermoreceptors and induces cool sensations improving thermal comfort, but has been linked to heat storage responses; this could increase risk of heat illness during self-paced exercise in the heat. Therefore, L-menthol application could lead to a discrepancy between behavioral and autonomic thermoregulatory drivers. Eight male participants volunteered. They were familiarized and then completed two trials in hot conditions (33.5 °C, 33% relative humidity) where their t-shirt was sprayed with CONTROL-SPRAY or MENTHOL-SPRAY after 10 km (i.e., when they were hot and uncomfortable) of a 16.1-km cycling time trial (TT). Thermal perception [thermal sensation (TS) and comfort (TC)], thermal responses [rectal temperature (Trec ), skin temperature (Tskin )], perceived exertion (RPE), heart rate, pacing (power output), and TT completion time were measured. MENTHOL-SPRAY made participants feel cooler and more comfortable and resulted in lower RPE (i.e., less exertion) yet performance was unchanged [TT completion: CONTROL-SPRAY 32.4 (2.9) and MENTHOL-SPRAY 32.7 (3.0) min]. Trec rate of increase was 1.40 (0.60) and 1.45 (0.40) °C/h after CONTROL-SPRAY and MENTHOL-SPRAY application, which were not different. Spraying L-menthol toward the end of self-paced exercise in the heat improved perception, but did not alter performance and did not increase heat illness risk.

Physiological cost and thermal envelope: a novel approach to cycle garment evaluation during a representative protocol.

This study aimed to examine thermoregulation in different clothing assemblies during a representative cycling exercise protocol. Six men undertook cycling exercise simulating representative thermal exchange challenges while wearing low (LOW), intermediate (INT1 and INT2), or high (HI) amounts of clothing. Exercise was conducted at 14.5 °C, 46.8% relative humidity and included a "flat" [45 min at 35% peak power output (PPO), wind speed 8.3 m/s], "uphill" (30 min at 55% PPO, wind speed 3.6 m/s), and "downhill" (20 min at 50 W, wind speed 16.7 m/s) stage. Rectal temperature changed with the exercise stage and was independent of clothing assembly. In contrast, an "envelope" was evident for mean body temperature, resulting from differences in mean skin temperature between the LOW and HI conditions. The elevated mean body temperature in HI was associated with increased physiological "cost," in the form of increased sweat production and heart rate. Physiological cost provides a better index of clothing performance than deep body temperature in the "thermoregulatory zone," as a consequence sports clothing should attempt to optimize the balance between comfort and reduced physiological cost.

Spraying with 0.20% L-menthol does not enhance 5 km running performance in the heat in untrained runners.

BACKGROUND: L-Menthol stimulates cutaneous thermoreceptors and induces cool sensations improving thermal comfort but has also been linked to heat storage responses. Therefore, L-Menthol application could lead to a conflict in behavioural and thermoregulatory drivers improving comfort but leading to a higher rate of deep body temperature rise; the present study examined this possibility. METHODS: Six untrained male participants (age 21 [1] years; height 1.80 [0.07] m; mass 78.9 [6.9] kg; surface area 1.98 [0.13] m2) took part. They completed three trials in hot conditions (34 °C) where their clothing was sprayed (CONTROL-SPRAY or MENTHOL-SPRAY) or not sprayed (CONTROL) after a fixed intensity exercise period (15-minutes), which induced thermal discomfort, before completing a 5 km treadmill time trial (TT). Thermal perception (thermal sensation and comfort; TS, TC), thermal responses (aural temperature [Tau], skin temperature [Tskin]), perceived exertion (RPE), heart rate, pacing (1 km split time) and performance (TT completion time) were measured. RESULTS: MENTHOL-SPRAY induced improvements in TS (up to 3 km of TT) and TC (up to 1 km) with Tau showing a tendency to be higher than CONTROL-SPRAY (+0.20 [0.29] °C) and CONTROL condition (0.30 [0.34] °C); this was not statistically significant and the rate of rise in Tau was linear. Tau was continuing to rise between the 4th and 5th kilometre of the TT. The other variables were unchanged. TT completion time and pace were not different: CONTROL 27.92 [1.65], CONTROL-SPRAY 28.10 [1.12], MENTHOL-SPRAY 27.53 [2.85] minutes. CONCLUSION: Spraying L-MENTHOL prior to exercise in the heat culminated in improved perception but not altered performance.

Spectrum of physiological and pathological cardiac and pericardial uptake of FDG in oncology PET-CT.

Cardiac uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) is frequently observed on FDG positron-emission tomography combined with computed tomography (PET-CT) performed for diagnosis, staging, and assessment of therapeutic response of lymphoma and solid cancers, despite careful patient preparation to limit myocardial glucose substrate utilisation. We illustrate the varied physiological patterns of cardiac FDG uptake, and show a spectrum of pathological conditions causing FDG uptake within myocardial and pericardial structures, due to clinically important benign and malignant diseases. Recognition and awareness of these various causes of FDG uptake in the heart, along with the appropriate use of correlative contrast-enhanced CT and magnetic resonance imaging (MRI) will facilitate correct interpretation.

Molecular biomarkers for assessing the heat-adapted phenotype: a narrative scoping review.

Heat acclimation/acclimatisation (HA) mitigates heat-related decrements in physical capacity and heat-illness risk and is a widely advocated countermeasure for individuals operating in hot environments. The efficacy of HA is typically quantified by assessing the thermo-physiological responses to a standard heat acclimation state test (i.e. physiological biomarkers), but this can be logistically challenging, time consuming, and expensive. A valid molecular biomarker of HA would enable evaluation of the heat-adapted state through the sampling and assessment of a biological medium. This narrative review examines candidate molecular biomarkers of HA, highlighting the poor sensitivity and specificity of these candidates and identifying the current lack of a single 'standout' biomarker. It concludes by considering the potential of multivariable approaches that provide information about a range of physiological systems, identifying a number of challenges that must be overcome to develop a valid molecular biomarker of the heat-adapted state, and highlighting future research opportunities.

Microbial community structure and activity linked to contrasting biogeochemical gradients in bog and fen environments of the Glacial Lake Agassiz Peatland.

The abundances, compositions, and activities of microbial communities were investigated at bog and fen sites in the Glacial Lake Agassiz Peatland of northwestern Minnesota. These sites contrast in the reactivity of dissolved organic matter (DOM) and the presence or absence of groundwater inputs. Microbial community composition was characterized using pyrosequencing and clone library construction of phylogenetic marker genes. Microbial distribution patterns were linked to pH, concentrations of dissolved organic carbon and nitrogen, C/N ratios, optical properties of DOM, and activities of laccase and peroxidase enzymes. Both bacterial and archaeal richness and rRNA gene abundance were >2 times higher on average in the fen than in the bog, in agreement with a higher pH, labile DOM content, and enhanced enzyme activities in the fen. Fungi were equivalent to an average of 1.4% of total prokaryotes in gene abundance assayed by quantitative PCR. Results revealed statistically distinct spatial patterns between bacterial and fungal communities. Fungal distribution did not covary with pH and DOM optical properties and was vertically stratified, with a prevalence of Ascomycota and Basidiomycota near the surface and much higher representation of Zygomycota in the subsurface. In contrast, bacterial community composition largely varied between environments, with the bog dominated by Acidobacteria (61% of total sequences), while the Firmicutes (52%) dominated in the fen. Acetoclastic Methanosarcinales showed a much higher relative abundance in the bog, in contrast to the dominance of diverse hydrogenotrophic methanogens in the fen. This is the first quantitative and compositional analysis of three microbial domains in peatlands and demonstrates that the microbial abundance, diversity, and activity parallel with the pronounced differences in environmental variables between bog and fen sites.

T cell-extrinsic IL-1 signaling controls long-term gammaherpesvirus infection by suppressing viral reactivation.

Gammaherpesviruses establish life-long infection in over 95% of adults and are associated with several cancers, including B cell lymphomas. Using the murine gammaherpesvirus 68 (MHV68) animal model, we previously showed a pro-viral role of Interleukin-1 (IL-1) signaling that supported viral reactivation during the establishment of chronic infection. Unexpectedly, in this study we found that the proviral effects of IL-1 signaling originally observed during the establishment of chronic gammaherpesvirus infection convert to antiviral effects during the long-term stage of infection. Specifically, IL-1 signaling promoted expansion of antiviral CD8+ T cells and control of viral reactivation in the peritoneal cavity of a long-term infected host. Using a novel mouse model of T cell-specific IL-1 signaling deficiency, we found that the antiviral effects of IL-1 signaling were T cell extrinsic. Our study highlights a dynamic nature of host factors that shape the parameters of chronic gammaherpesvirus infection.