The Constrained Application Protocol (CoAP) is a transfer protocol for constrained nodes and networks, such as those that will form the Internet of Things. Much like its older and heavier cousin ...HTTP, CoAP uses the REST architectural style. Based on UDP and unencumbered by historical baggage, however, CoAP aims to achieve its modest goals with considerably less complexity.
Proton conducting BaZr0.9-xCexY0.1O3-δ electrolytes have been intensively investigated in the past years. The zirconium rich stoichiometry of this perovskite type material shows good chemical ...stability coupled with high proton conductivity. However, this material remains highly refractory. Therefore, high sintering temperatures (1800 °C) are required to fully densify the electrolyte layer. This study focuses on using different sintering strategies, such as cold-sintering and sintering aids, during the fabrication of the electrolyte to decrease the sintering temperature. After various densification protocols, the electrical conductivity of the zirconate (BaZr0.7Ce0.2Y0.1O3-δ) electrolytes are compared to study the influence of the densification process on the bulk, grain boundary and total conductivity of the electrolyte layer.
•Cold-sintering and sintering aids for the densification of BaZr0.7Ce0.2Y0.1O3-δ.•Comparison of the morphological and electrochemical properties.•The protonic charge diffusion at intermediate temperature (350–600 °C).•ZnO–Li electrolyte yields a conductivity of 2·10−3 S cm−1 at 450 °C.•The specific protonic conductivity extracted yields 1.2·10−3 S cm−1
Incidence of sepsis is increasing, representing a tremendous burden for health-care systems. Death in acute sepsis is attributed to hyperinflammatory responses, but the underlying mechanisms are ...still unclear. We report here that proton pump inhibitors (PPIs), which block gastric acid secretion, selectively inhibited tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) secretion by Toll-like receptor (TLR)-activated human monocytes in vitro, in the absence of toxic effects. Remarkably, the oversecretion of IL-1β that represents a hallmark of monocytes from patients affected by cryopyrin-associated periodic syndrome is also blocked. Based on these propaedeutic experiments, we tested the effects of high doses of PPIs in vivo in the mouse model of endotoxic shock. Our data show that a single administration of PPI protected mice from death (60% survival versus 5% of untreated mice) and decreased TNF-α and IL-1β systemic production. PPIs were efficacious even when administered after lipopolysaccharide (LPS) injection. PPI-treated mice that survived developed a long-term cross-tolerance, becoming resistant to LPS- and zymosan-induced sepsis. In vitro, their macrophages displayed impaired TNF-α and IL-1β to different TLR ligands. PPIs also prevented sodium thioglycollate-induced peritoneal inflammation, indicating their efficacy also in a non-infectious setting independent of TLR stimulation. Lack of toxicity and therapeutic effectiveness make PPIs promising new drugs against sepsis and other severe inflammatory conditions.
The quest for sustainable energy models is the main factor driving research on smart grid technology. SGs represent the bridging paradigm to enable highly efficient energy production, transport, and ...consumption along the whole chain, from the source to the user. Although this concept promises to be very fruitful, the research on how to deploy it in the real world has just begun. A discussion on the enabling technologies for SGs and a possible roadmap for the profitable evolution thereof is the focus of this article. After introducing the recent trends that are pushing the SG paradigm, we will discuss various key scenarios for the SG, and briefly introduce some of its key requirements. We will then provide an analysis of how current and future standard solutions in the areas of communications and networking can be engineered into a system that fulfills the needs of the SG vision. We advocate the use of small, cheap, and resource-constrained devices with pervasive computing capabilities as the key component to deploy a ubiquitous energy control system. To this end, the recent efforts carried out by Internet standardization bodies such as the IETF and W3C toward the vision of the Internet of Things (IoT) are especially relevant. The various components of the proposed solution have been successfully showcased in real-world implementations, and relevant actors such as ETSI, ZigBee, and IPSO are already evaluating their potential for future IoT applications, making the Internet-based smart grid vision considered in this article practically achievable in the not too distant future.
Objective
The U.S. Army uses sex‐specific circumference‐based prediction equations to estimate percent body fat (%BF) to evaluate adherence to body composition standards. The equations are ...periodically evaluated to ensure that they continue to accurately assess %BF in a diverse population. The objective of this study was to develop and validate alternative field expedient equations that may improve upon the current Army Regulation (AR) body fat (%BF) equations.
Methods
Body size and composition were evaluated in a representatively sampled cohort of 1904 active‐duty Soldiers (1261 Males, 643 Females), using dual‐energy X‐ray absorptiometry (%BFDXA), and circumferences obtained with 3D imaging and manual measurements. Sex stratified linear prediction equations for %BF were constructed using internal cross validation with %BFDXA as the criterion measure. Prediction equations were evaluated for accuracy and precision using root mean squared error, bias, and intraclass correlations. Equations were externally validated in a convenient sample of 1073 Soldiers.
Results
Three new equations were developed using one to three circumference sites. The predictive values of waist, abdomen, hip circumference, weight and height were evaluated. Changing from a 3‐site model to a 1‐site model had minimal impact on measurements of model accuracy and performance. Male‐specific equations demonstrated larger gains in accuracy, whereas female‐specific equations resulted in minor improvements in accuracy compared to existing AR equations. Equations performed similarly in the second external validation cohort.
Conclusions
The equations developed improved upon the current AR equation while demonstrating robust and consistent results within an external population. The 1‐site waist circumference‐based equation utilized the abdominal measurement, which aligns with associated obesity related health outcomes. This could be used to identify individuals at risk for negative health outcomes for earlier intervention.
This study developed and validated alternative field expedient equations that improved upon the current Army Regulation body fat (%BF) equations. Three new equations were developed using one to three circumference sites, which included waist, abdomen and hip circumferences and weight. Changing from a 3‐site model to a 1‐site model had minimal impact on measurements of model accuracy and performance.
This paper outlines the development of a finite element human thermoregulatory model using an anatomically and geometrically correct human body model. The finite element body model was constructed ...from digital Phantoms and is anatomically realistic, including 13 organs and tissues: skin, muscles, fat, bones, heart, lungs, brain, bladder, intestines, stomach, kidneys, liver, and eyes. The model simulates thermal responses through a passive and active system. The passive system describes heat balance within the body and between the skin surface and environment. The active system describes thermoregulatory mechanisms, i.e., vasodilation, vasoconstriction, sweating, and shivering heat production. This model predicts temperature distribution across the body at high spatial resolution, and provides insight into human thermoregulatory responses to non-uniform and transient environments. Predicted temperatures (i.e., core, skin, muscle and fat) at 29 sites were compared with measured values in comfort, hot, and cold conditions. The comprehensive validation shows predictions are accurate and acceptable.
•Finite element model of human thermoregulation is developed•Body model is anatomically and geometrically realistic, includes 13 organs/tissues•The model predicts spatial temperature distribution across body at high resolution•Predicted core, skin, muscle and fat temperatures at 29 body sites are validated
Numerous human thermoregulatory models have been developed and widely used in various applications such as aerospace, medicine, public health, and physiology research. This paper is a review of three ...dimensional (3D) models for human thermoregulation. This review begins with a short introduction of thermoregulatory model development followed by key principles for mathematical description of human thermoregulation systems. Different representations of 3D human bodies are discussed with respect to their detail and prediction capability. The human body was divided into fifteen layered cylinders in early 3D models (cylinder model). Recent 3D models have utilized medical image datasets to develop geometrically correct human models (realistic geometry model). The finite element method is mostly used to solve the governing equations and get numerical solutions. The realistic geometry models provide a high degree of anatomical realism and predict whole-body thermoregulatory responses at high resolution and at organ and tissue levels. Thus, 3D models extend to a wide range of applications where temperature distribution is critical, such as hypothermia/hyperthermia therapy and physiology research. The development of thermoregulatory models will continue with the growth in computational power, advancement in numerical methods and simulation software, advances in modern imaging techniques, and progress in the basic science of thermal physiology.
•3D human thermoregulation models have been advancing and evolving continuously.•3D models predict thermal responses, and organ/tissue temperatures at high resolution.•Representations of the human body are becoming more complex and realistic.•Realistic-geometry models are sourced from medical images and are anatomically correct.•3D model predictions are useful for applications where temperature distribution is critical.
This study validates the Six Cylinder Thermoregulatory Model (SCTM) during prolonged warm water immersion, which underpins the Probability of Survival Decision Aid (PSDA) currently in use by the ...United States Coast Guard (USCG). PSDA predicts survival time for hypothermia and dehydration. USCG has been using PSDA for search and rescue operation since 2010. In 2019, USCG organized a workshop to review PSDA performance and concluded that PSDA is an essential tool for operation, although it occasionally overestimates survival times in warm waters above 16 °C. Forty-six human subjects were immersed from the neck down in 18, 22, and 26 °C water for 45 min up to 10 h. Rectal temperature (Tcore), 10-site mean skin temperature (Tsk), and water loss were measured. At the end of immersion, Tcore ranged from 35.2 to 38.0 °C, and Tsk ranged from 19.7 to 27.4 °C. The SCTM-predicted Tcore, Tsk and water loss were compared to the measured values. Root mean squared deviation (RMSD) was used to test for acceptable predictions. Tcore RMSDs were 0.2, 0.14, and 0.3 °C in 18, 22, and 26 °C water respectively. Tsk RMSDs were 1.44, 0.76, and 1.1 °C in 18, 22, and 26 °C water respectively. SCTM underpredicted water loss by 84%. Overall, SCTM predicted Tcore and Tsk with acceptable accuracy in 18 and 22 °C water for up to 10 h, but overpredicted in 26 °C water. Future studies and algorithm development are required to improve water loss prediction as well as Tcore and Tsk prediction in 26 °C water.
•Thermal responses in 18, 22 and 26 °C water for up to 10 h were studied.•A six cylinder thermoregulatory model was validated for prolonged warm water immersion.•The model accurately predicts core and skin temperatures in 18 and 22 °C water.
this study describes the development of a female finite element thermoregulatory model (FETM)
the female body model was developed from medical image datasets of a median U.S. female and was ...constructed to be anatomically correct. The body model preserves the geometric shapes of 13 organs and tissues, including skin, muscles, fat, bones, heart, lungs, brain, bladder, intestines, stomach, kidneys, liver, and eyes. Heat balance within the body is described by the bio-heat transfer equation. Heat exchange at the skin surface includes conduction, convection, radiation, and sweat evaporation. Vasodilation, vasoconstriction, sweating, and shivering are controlled by afferent and efferent signals to and from the skin and hypothalamus.
the model was validated with measured physiological data during exercise and rest in thermoneutral, hot, and cold conditions. Validations show the model predicted the core temperature (rectal and tympanic temperatures) and mean skin temperatures with acceptable accuracy (within 0.5 °C and 1.6 °C, respectively)
this female FETM predicted high spatial resolution temperature distribution across the female body, which provides quantitative insights into human thermoregulatory responses in females to non-uniform and transient environmental exposure.
•The first female 3D thermoregulatory model has been developed.•The model was validated with data from previous studies.•The model can predict thermal responces in a wide range of environments.
In this paper we address the design of network architectures for the Internet of Things by proposing practical algorithms to augment IETF CoAP/6LoWPAN protocol stacks with congestion control ...functionalities. Our design is inspired by previous theoretical work on back pressure routing and is targeted toward Web-based architectures featuring bidirectional data flows made up of CoAP request/response pairs. Here, we present three different cross-layer and fully decentralized congestion control schemes and compare them against ideal back pressure and current UDP-based protocol stacks. Hence, we discuss results obtained using ns-3 through an extensive simulation campaign for two different scenarios: unidirectional and upstream flows and bidirectional Web-based CoAP flows. Our results confirm that the proposed congestion control algorithms perform satisfactorily in both scenarios for a wide range of values of their configuration parameters, and are amenable to the implementation onto existing protocol stacks for embedded sensor devices.
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