Validity of a noninvasive estimation of deep body temperature when wearing personal protective equipment during exercise and recovery

©2019 The Authors. Published by BMC. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1186/s40779-019-0208-7© 2019 The Author(s). Background: Deep body temperature is a critical indicator of heat strain. However, direct measures are often invasive, costly, and difficult to implement in the field. This study assessed the agreement between deep body temperature estimated from heart rate and that measured directly during repeated work bouts while wearing explosive ordnance disposal (EOD) protective clothing and during recovery. Methods: Eight males completed three work and recovery periods across two separate days. Work consisted of treadmill walking on a 1% incline at 2.5, 4.0, or 5.5 km/h, in a random order, wearing EOD protective clothing. Ambient temperature and relative humidity were maintained at 24 °C and 50% [Wet bulb globe temperature (WBGT) (20.9 ± 1.2) °C] or 32 °C and 60% [WBGT (29.0 ± 0.2) °C] on the separate days, respectively. Heart rate and gastrointestinal temperature (TGI) were monitored continuously, and deep body temperature was also estimated from heart rate (ECTemp). Results: The overall systematic bias between TGI and ECTemp was 0.01 °C with 95% limits of agreement (LoA) of ±0.64 °C and a root mean square error of 0.32 °C. The average error statistics among participants showed no significant differences in error between the exercise and recovery periods or the environmental conditions. At TGI levels of (37.0-37.5) °C, (37.5-38.0) °C, (38.0-38.5) °C, and > 38.5 °C, the systematic bias and ± 95% LoA were (0.08 ± 0.58) °C, (-0.02 ± 0.69) °C, (-0.07 ± 0.63) °C, and (-0.32 ± 0.56) °C, respectively. Conclusions: The findings demonstrate acceptable validity of the ECTemp up to 38.5 °C. Conducting work within an ECTemp limit of 38.4 °C, in conditions similar to the present study, would protect the majority of personnel from an excessive elevation in deep body temperature (> 39.0 °C).This project was financially supported by the Australian Government, managed by the National Security Science & Technology Centre within the Defence Science & Technology Organisation, and the US Government through the Technical Support Working Group within the Combating Terrorism Technical Support Office.Published versio

Perceptions of E-Cigarettes among Black Youth in California.

Research suggests that Black youth are less likely to use e-cigarettes than their white counterparts, yet little is known as to why. We examined perceptions of e-cigarettes among Black young adults (ages 18-25) to explore the meanings these youth ascribe to e-cigarettes and the role that identity plays in how these devices are viewed. Analysis of in-depth interviews with 36 Black smokers and non-smokers in the San Francisco Bay Area suggests that Black youth perceive e-cigarettes as serving distinct, yet overlapping roles: a utilitarian function, in that they are recognized as legitimate smoking cessation tools, and a social function, insofar as they serve to mark social identity, specifically a social identity from which our participants disassociated. Participants described e-cigarette users in highly racialized and classed terms and generally expressed disinterest in using e-cigarettes, due in part perhaps to the fact that use of these devices would signal alignment with a middle class, hipster identity. This analysis is discussed within a highly charged political and public health debate about the benefits and harms associated with e-cigarette use

A study of the effects of electric field on two-dimensional inviscid nonlinear free surface flows generated by moving disturbances

Two-dimensional free surface flows generated by a moving disturbance are considered. The flows are assumed to be potential. The effects of electric field, gravity and surface tension are included in the dynamic boundary condition. The disturbance is chosen to be a distribution of pressure moving at a constant velocity. Both linear and nonlinear results are presented. For some values of the parameters, the linear theory predicts unbounded displacements of the free surface. It is shown that this nonuniformity is removed by developing a weakly nonlinear theory. There are then solutions which are perturbations of a uniform stream and others which are perturbations of solitary waves with decaying tails

An ABC transporter containing a forkhead-associated domain interacts with a serine-threonine protein kinase and is required for growth of Mycobacterium tuberculosis in mice

Forkhead-associated (FHA) domains are modular phosphopeptide recognition motifs with a striking preference for phosphothreonine-containing epitopes. FHA domains have been best characterized in eukaryotic signaling pathways but have been identified in six proteins in Mycobacterium tuberculosis, the causative organism of tuberculosis. One of these, coded by gene Rv1747, is an ABC transporter and the only one to contain two such modules. A deletion mutant of Rv1747 is attenuated in a mouse intravenous injection model of tuberculosis where the bacterial load of the mutant is 10-fold lower than that of the wild type in both lungs and spleen. In addition, growth of the mutant in mouse bone marrow-derived macrophages and dendritic cells is significantly impaired. In contrast, growth of this mutant in vitro was indistinguishable from that of the wild type. The mutant phenotype was lost when the mutation was complemented by the wild-type allele, confirming that it was due to mutation of Rv1747. Using yeast two-hybrid analysis, we have shown that the Rv1747 protein interacts with the serine-threonine protein kinase PknF. This interaction appears to be phospho-dependent since it is abrogated in a kinase-dead mutant and by mutations in the presumed activation loop of PknF and in the first FHA domain of Rv1747. These results demonstrate that the protein coded by Rv1747 is required for normal virulent infection by M. tuberculosis in mice and, since it interacts with a serine-threonine protein kinase in a kinase-dependent manner, indicate that it forms part of an important phospho-dependent signaling pathway

Linear and nonlinear free surface flows in electrohydrodynamics

This thesis examines free surface flows in electrohydrodynamics under forcing in the form of a moving pressure distribution or topography. The ideas from examining free surface flows with forcing and those ideas andmethods coming from examining solitary waves within electrohydrodynamics are combined to study free surface flows under forcing in electrohydrodynamics. Chapter 1 gives a brief introduction to the ideas and work that have gone into investigating free surface flows and solitary waves in general and gives an idea of what will happen in the thesis. Chapter 2 formulates the general problem for the full nonlinear case and then examines the linear solution for both a moving pressure distribution and topography and presents profiles of the free surfaces and then shows that the solutions are nonuniform by examining the deep water case. Chapter 3 introduces the scaling for the weakly nonlinear problem and produces an equation which there is no nonuniformity and the amplitude of the free surface is finite. The case when the Bond number is around a 1/3 is also examined. Stokes analysis is performed to look for Wilton ripples. Chapter 4 examines conducting fluids adhering to an upper surface, the basic equations are set up and then the dispersion relation is derived to examine the existence of linear waves for certain values of the wavenumber k. A set of weakly nonlinear equations are examined and then solved numerically with examples of periodic profiles presented. A Stokes analysis is carried out for small amplitudes to look for Wilton ripples. An analysis is carried out for the approximation of long wavelength but finite depth, where the wave amplitude is the depth of the fluid. Chapter 5 considers surface flows and generalised the results from chapters 2 and 3 from two dimensions to three, linear free surface profiles are calculated and plotted and the weakly nonlinear equation is derived for the cases where the Bond number is close to 1/3 and not close to 1/3 giving a 5th order (Kadomstev-Petviashvili) (KP) equation. Chapter 6 is the set of conclusions and avenues of future research

New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

Outcomes of total hip arthroplasty, as a salvage procedure, following failed internal fixation of intracapsular fractures of the femoral neck: a systematic review and meta-analysis.

AIMS: The optimal management of intracapsular fractures of the femoral neck in independently mobile patients remains open to debate. Successful fixation obviates the limitations of arthroplasty for this group of patients. However, with fixation failure rates as high as 30%, the outcome of revision surgery to salvage total hip arthroplasty (THA) must be considered. We carried out a systematic review to compare the outcomes of salvage THA and primary THA for intracapsular fractures of the femoral neck. PATIENTS AND METHODS: We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) compliant systematic review, using the PubMed, EMBASE and Cochrane libraries databases. A meta-analysis was performed where possible, and a narrative synthesis when a meta-analysis was not possible. RESULTS: Our analyses revealed a significantly increased risk of complications including deep infection, early dislocation and peri-prosthetic fracture with salvage THA when compared with primary THA for an intracapsular fracture of the femoral neck (overall risk ratio of 3.15). Functional outcomes assessment using EuroQoL (EQ)-5D were not significantly different (p = 0.3). CONCLUSION: Salvage THA carries a significantly higher risk of complications than primary THA for intracapsular fractured neck of femur. Current literature is still lacking well designed studies to provide a full answer to the question. TAKE HOME MESSAGE: Salvage THA is associated with more complications than primary THA for intracapsular neck of femur fractures

The NiSi melting curve to 70 GPa

The melting curve of NiSi has been determined to 70 GPa on the basis of laser-heated diamond anvil cell (LH-DAC) experiments in which changes in the gradient of temperature vs. laser power functions were used as the melting criterion. The melting curve was corroborated with in situ X-ray diffraction experiments in both the LH-DAC and multi-anvil press in which the appearance of liquid diffuse scattering in the diffraction patterns was used as the melting criterion. At all pressures, the NiSi melting curve is lower than that of FeSi, with the difference in melting temperature reaching a maximum of 900 K at 14 GPa. The location of the B31 + B20 + L triple point has been constrained to 12 ± 2 GPa and 1550 ± 100 K and the B20 + B2 + L triple point to 28.5 ± 1.5 GPa and 2165 ± 60 K. On the basis of the in situ LH-DAC experiments the Clapeyron slope of the B20 → B2 transition is estimated at −67 MPa K−1. Extrapolation of the B2-NiSi liquidus to core-mantle boundary (CMB) conditions (135 GPa) suggests the melting point of NiSi (3700 ± 400 K) will be only marginally lower than that of isostructural FeSi (4000 ± 200 K). Thus any (Fe,Ni)Si solid solution present within the D″ layer is expected to remain solid, with the possible exception of the very hottest region adjacent to the CMB

Prevalence and correlates of 30-day suicidal ideation and intent: Results of the South African National Student Mental Health Survey

Background. Although suicide prevention is recognised as a priority among university students in South Africa (SA), it is unclear what proportion of students require urgent indicated interventions and what the characteristics are of these students. Objective. To assess the prevalence and sociodemographic correlates of 30-day suicidal ideation, frequency of ideation and self-reported intention to act on ideation in the next year among a national sample of SA university students. Methods. Self-report cross-sectional data were collected online from students (N=28 268) at 17 universities across SA as part of the national student mental health survey. Students reported suicidal ideation in the past 30 days, frequency of ideation and intention to act on ideation in the next year. Data were weighted within institutions by gender and population group, and across the four main types of universities (historically white, historically disadvantaged, technical and distance learning) to correct for response rate discrepancies. Prevalence was estimated with these weighted in the total sample and across types of universities. Poisson regression with robust error variances was used to investigate associations of sociodemographic characteristics with ideation and intention to act on suicidal ideation. Results are reported as relative risks (RRs) with design-based 95% confidence intervals (CIs). Results. Thirty-day prevalence of suicidal ideation was 24.4% (standard error (SE) 0.3), with 2.1% (SE 0.1) and 4.1% (SE 0.1), respectively, reporting suicidal ideation all/almost all the time, or most of the time. A total of 1.5% (SE 0.1) of respondents reported being very likely to act on their suicidal ideation, while 3.9% (SE 0.2) were somewhat likely, 8.7% (SE 0.2) were not very likely and 85.8 (SE 0.5) either reported no suicidal ideation or that they were not at all likely to act on this ideation. Risk of suicidal ideation with high intent in the total sample was elevated among females (RR 1.9, 95% CI 1.3 - 2.7) and gender non-conforming students (RR 4.3, 95% CI 1.4 - 13.0) relative to males, black African students compared with white students (RR 3.6, 95% CI 1.9 - 7.1), students whose parents did not progress to secondary school compared with students whose parents had a university education (RR 1.6, 95% CI 1.0 - 2.5) and sexual minority students compared with heterosexual students (RR 1.9, 95% CI 1.3 - 2.6). Among students with 30-day ideation (controlling for frequency of ideation), only two of these predictors of high intent remained significant: identifying as black African (RR 2.7, 95% CI 1.4 - 5.1), and having parents with less than secondary education (RR 1.5, 95% CI 1.0 - 2.1). Conclusion. Scalable suicide prevention interventions are needed to reach the large number of SA students who report suicidal ideation with intent