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Above‐band gap optical excitation of non‐centrosymmetric semiconductors can lead to the spatial shift of the center of electron charge in a process known as shift current. Shift current is investigated in single‐crystal SnS2, a layered semiconductor with the band gap of ≈2.3 eV, by THz emission spectroscopy and first principles density functional theory (DFT). It is observed that normal incidence excitation with above gap (400 nm; 3.1 eV) pulses results in THz emission from 2H SnS2 (P3−m1$P\stackrel{-}{3}m1\ $) polytype, where such emission is nominally forbidden by symmetry. It is argued that the underlying symmetry breaking arises due to the presence of stacking faults that are known to be ubiquitous in SnS2 single crystals and construct a possible structural model of a stacking fault with symmetry properties consistent with the experimental observations. In addition to shift current, it is observed THz emission by optical rectification excited by below band gap (800 nm; 1.55 eV) pulses but it requires excitation fluence more than two orders of magnitude higher to produce same signal amplitude. These results suggest that ultrafast shift current in which can be excited with visible light in blue–green portion of the spectrum makes SnS2 a promising source material for THz photonics. [ABSTRACT FROM AUTHOR]

Aim: The geography and genesis of diversity remain an enduring topic in ecology and evolution. Mediterranean Climate Ecosystems (MCEs), with their high plant diversities in winter rainfall climates, pose a challenge to popular hypotheses evoking high water availability and temperature as necessary for the evolution of high diversity. We test the hypothesis of environmental stability as a driver for the evolution of regional‐scale floristic diversity using speleothem oxygen (δ18O) and carbon (δ13C) isotopic values as proxies for past climatic variability in the Cape Floristic Region (CFR) and other MCEs. Location: south‐western Africa, California, Mediterranean Basin. Taxon: Plantae. Methods: We present new speleothem δ18O and δ13C records from a cave near Robertson in the western CFR. Stable isotope samples included in the analyses cover the time intervals between 240 and 670 ka BP with hiatuses at 630–500 ka and 360–310 ka. The dispersion of these stable isotope records is used as a measure for climatic variability. We compare our new analyses to speleothem records that cover full glacial and interglacial conditions in other MCEs (California and the Mediterranean Basin) as well as in eastern regions of the CFR. All sites used in this comparison have lower vascular plant biodiversity than the western CFR. Results: Analyses of the dispersion of the δ18O and δ13C datasets suggest that the highly diverse western CFR experienced climatic stability across several glacial–interglacial cycles, compared with the less diverse regions within and outside of the CFR. Main Conclusion: This result provides support for the hypothesis that lower extinction rates associated with Pleistocene biome stability may explain the higher diversity in the CFR relative to other MCEs. [ABSTRACT FROM AUTHOR]

This study utilizes geostatistical modelling of magnetic susceptibility (MS) for geophysical prospection of archaeological stratigraphy at the Middle Stone Age rock shelter site of Pinnacle Point 5‐6 North. These models are overlaid onto high‐resolution photography of the stratigraphic sequence to study the lateral and vertical changes within the magnetic signature of the archaeological sequence and correlate these changes to micromorphological interpretations previously made at the site. In situ analysis is reinforced by laboratory magnetic mineralogical analysis utilizing MS; frequency‐dependent susceptibility (χFD); isothermal remanent magnetization; and anhysteric remanent magnetization to understand the composition of the magnetic minerals creating the in situ signature. This study shows that there is consistent variation in the magnetic signatures of the sequence that can be mapped with in situ MS; there is a correlation with laboratory analysis of magnetic mineralogy, which provides insight into changes in human behaviour; and our models correlate well with micromorphological interpretations of the site. [ABSTRACT FROM AUTHOR]

The 1989, Mw = 6.9 Loma Prieta earthquake resulted in tens of lives lost and cost California almost 3% of its gross domestic product. Despite widespread damage, the earthquake did not clearly rupture the surface, challenging the identification and characterization of these hidden hazards. Here, we show that they can be illuminated by inverting fluvial topography for slip‐and moment accrual‐rates—fundamental components in earthquake hazard assessments—along relief‐generating geologic faults. We applied this technique to thrust faults bounding the mountains along the western side of Silicon Valley in the San Francisco Bay Area, and discovered that these structures may be capable of generating a Mw = 6.9 earthquake every 250–300 years based on moment accrual rates. This method may be deployed broadly to evaluate seismic hazard in developing regions with limited geological and geophysical information. Plain Language Summary: Large, shallow earthquakes nucleated along geologic faults promoting vertical motion of rocks produce instantaneous uplift of the Earth's surface on the order of meters. This process and the intervening deformations, repeated over thousands of earthquake cycles, build up mountain ranges, which are subsequently carved by rivers thanks to the action of climate forces counteracting tectonic uplift. Consequently, the incision pattern along mountain rivers, resulting from rock resistance to erosion and long‐lived distribution of fault‐induced rock uplift, contains information about the past activity of underlying relief‐generating faults. Our study tested this fundamental idea, integrating the topography with simple, yet standard mechanical and erosional modeling, to estimate the accrual of earthquake magnitude potential over time. We applied this new methodology, particularly useful to illuminate hazards posed by difficult‐to‐characterize‐faults not well exposed to direct observation, to the fault‐bounded mountains along the western side of the San Francisco Bay Area. We discovered that a quake of similar size to the 1989 Loma Prieta event, the last devastating earthquake affecting this populous economic hub, could occur every 250–300 years. More importantly, given the wide availability of topographic datasets, this method may be deployed broadly to evaluate seismic hazards in poorly instrumented and studied areas. Key Points: The topographic structure of mountain rivers can be inverted for long‐term slip‐and moment accrual‐rates along relief‐generating faultsThrust faults along the western side of Silicon Valley have the potential for generating a Mw = 6.9 earthquake every 250–300 yearsThis approach may be deployed more broadly to evaluate seismic hazard in regions with limited geological and geophysical information [ABSTRACT FROM AUTHOR]

Throughout much of the Quaternary, lower sea levels in the southern Cape of South Africa exposed a different landscape to what we see today, the Palaeo‐Agulhas Plain (PAP). The PAP was dominated by large‐bodied and gregarious grazing species contrasting with the small‐bodied predominantly solitary species we find in the region today. The distribution of these herbivores would likely have been driven by similar drivers we see in contemporary herbivore ecology. Importantly, the occurrence of early humans and their associated technology would have also influenced the probability of herbivores occurring in an area. Here we create a predictive model for large herbivores using probability of occurrence of functional grouping in relation to environmental drivers and humans. We show how early humans influenced the distribution of large herbivores on the PAP alongside other environmental drivers. In the fynbos biome, probability of occurrence was highest for the medium‐sized social mixed feeders' functional group in the thicket for small non‐social browsers, large browsers, and non‐ruminants and in grasslands for water‐dependent grazers. In our models, human influence affected functional groups to varying degrees but had the strongest effect on medium‐sized social mixed feeders. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulations of melt films of poly(alkyl methacrylate)s (PAMAs) with methyl, ethyl, and n‐butyl substituents, respectively, have been performed using an all‐atom model to investigate their surface and thin film properties. The applied all‐atom force fields predict the bulk densities of PAMAs in good agreement with experiments. Moreover, predictions of the surface tensions of PMMA, PEMA, and Pn‐BMA melts are in reasonably good agreement with experiments. The density profiles and orientational‐order parameters of chain segments show atomic‐scale characteristics in the air/polymer interfacial region. In the surface region, the backbone segments of PAMAs form a well‐defined layer structure with the chain vectors oriented parallel to the surface, while the ester side‐chains strongly segregate to the surface region and show perpendicular orientation to the surface, with the most pronounced surface segregation noted for Pn‐BMA. Such surface segregations of chain segments make it difficult to apply a simple relationship between the cohesive energy density and the surface tension of polymers, for example, and should be taken into account in relating the surface/thin film characteristics to the bulk properties of polymers in general. [ABSTRACT FROM AUTHOR]

Wildfire activity is increasing in parts of the world where extreme drought and warming temperatures contribute to fireprone conditions, including the western United States. The elderly are among the most vulnerable, and those in long‐term care with preexisting conditions have added risk for adverse health outcomes from wildfire smoke exposure. In this study, we report continuous co‐located indoor and outdoor fine particulate matter (PM2.5) measurements at four skilled nursing facilities in the western United States. Throughout the year 2020, over 8000 h of data were collected, which amounted to approximately 300 days of indoor and outdoor sampling at each facility. The highest indoor 24 h average PM2.5 recorded at each facility was 43.6 µg/m3, 103.2 µg/m3, 35.4 µg/m3, and 202.5 µg/m3, and these peaks occurred during the wildfire season. The indoor‐to‐outdoor PM2.5 ratio and calculated infiltration efficiencies indicated high variation in the impact of wildfire events on Indoor Air Quality between the four facilities. Notably, infiltration efficiency ranged from 0.22 to 0.76 across the four facilities. We propose that this variability is evidence that PM2.5 infiltration may be impacted by modifiable building characteristics and human behavioral factors, and this should be addressed in future studies. [ABSTRACT FROM AUTHOR]

Changes in CO2 emissions from volcanoes may evidence volcanic unrest. We use a multiyear time series of CO2 flux collected at the Horseshoe Lake Tree Kill area on Mammoth Mountain, CA, to understand processes that cause variations in flux from this system. Seasonal variations are systematically lowest during the winter months and reach maximum values during the summer season. A persistent ∼20% reduction in CO2 flux occurred during the Spring of 2017, coincident with the emergence of the area from drought and earthquake swarms in Long Valley Caldera. We used continuous GNSS measurements to calculate seasonal strains and stresses across the Mammoth Mountain area, and resolved resultant stresses onto the Mammoth Mountain Fault, which appears to facilitate gas transport to the surface. The normal stress changes are consistent with seasonal and multiyear changes in CO2 flux, suggesting that fault valving by solid earth processes can alter surface gas fluxes. Plain Language Summary: Changes in the rates of volcanic gas emissions may be harbingers of impending eruptions. New methodologies allow us to measure these changes continuously and in near‐real time. With this information, new and unexpected signals have been observed at Mammoth Mountain, California, such as the seasonal ebb and flow of volcanic CO2 emissions. Understanding the processes that produce these seasonal changes is required to distinguish them from the signs of volcanic unrest. This work investigates a number of potential mechanisms for these seasonal changes, and concludes that they can be explained by the seasonal flexing of the solid earth under changing water and ice loads, and subsurface pressurization due to infiltrating water. This flexing of the solid earth can be measured by GNSS, allowing us to filter these effects from the CO2 flux time series, as well as highlight the ways in which volcanic systems may "breathe" over the course of a year with changing hydrologic conditions. Key Points: Time series of volcanic CO2 fluxes from Mammoth Mountain, California, show seasonal variations between 2014 and 2020Local hydrologic and micro‐meteorological variations cannot account for the amplitude and phase of these variationsLong‐wavelength hydrologic processes produce stress changes in a way that can explain the seasonal variations in CO2 flux [ABSTRACT FROM AUTHOR]

Background: Vermiculite ore from Libby, Montana contains on average 24% of a mixture of toxic and carcinogenic amphibole asbestiform fibers. These comprise primarily winchite (84%), with smaller quantities of richterite (11%) and tremolite (6%), which are together referred to as Libby amphibole (LA). Methods: A total of 1883 individuals who were occupationally and/or environmentally exposed to LA and were diagnosed with asbestos‐related pleuropulmonary disease (ARPPD) following participation in communitywide screening programs supported by the Agency for Toxic Substances and Disease Registry (ATSDR) and followed up at the Center for Asbestos Related Disease (CARD) between 2000 and 2010. There were 203 deaths of patients with sufficient records and radiographs. Best clinical and radiologic evidence was used to determine the cause of death, which was compared with death certificates. Results: Asbestos‐related mortality was 55% (n = 112) in this series of 203 patients. Of the 203 deaths, 34 (17%) were from asbestos‐related malignancy, 75 (37%) were from parenchymal asbestosis, often with pleural fibrosis, and 3 (1.5%) were from respiratory failure secondary to pleural thickening. Conclusions: Asbestos is the leading cause of mortality following both occupational and nonoccupational exposure to LA in those with asbestos‐related disease. [ABSTRACT FROM AUTHOR]

Populations of many species of grassland‐associated butterflies, moths, and bumblebees in the Great Plains of North America are experiencing steep declines due to habitat loss and degradation—primarily conversion of grasslands to row‐crop agriculture and invasion of woody plants and exotic cool‐season grasses—and insecticide use. These declines are exacerbated by the generally limited dispersal ability of insects, which make local populations susceptible to extirpation following habitat fragmentation. Interest in pollinator conservation has grown substantially in recent years, but information to guide pollinator conservation across the region is limited. We used pollinator biology along with principles of landscape ecology and metapopulation dynamics to develop a simple decision matrix based on patch size and inter‐patch distances to guide landscape‐scale grassland conservation efforts in the U.S. northern Great Plains. When applied to spatial land cover data depicting potential pollinator habitat, the matrix uses landscape characteristics to guide placement of conservation treatments to help ensure persistence of target pollinator populations. Patch size and connectivity thresholds can be set to match characteristics of target species, but in all cases, local management will be necessary to ensure that fine‐grained features such as nectar sources and host plants are present. Applying the matrix to habitat layers for a nine‐state analysis region showed substantial geographic variation in conservation needs, opportunities, and potential treatments. We also demonstrate that non‐native planted cover such as alfalfa and certain grasslands enrolled in the Conservation Reserve Program can substantially enhance landscape structure by increasing grassland patch size and core area while decreasing distance between patches. Pollinators dependent on native prairie will also benefit from planted cover that provides nectar sources and serves as a buffer from pesticides associated with croplands. Consistent with the principles of strategic habitat conservation, targeted monitoring and research will be necessary to validate and adapt the model to meet local conditions. [ABSTRACT FROM AUTHOR]

Household heating using wood stoves is common practice in many rural areas of the United States (US) and can lead to elevated concentrations of indoor fine particulate matter (PM2.5). We collected 6‐day measures of indoor PM2.5 during the winter and evaluated household and stove‐use characteristics in homes at three rural and diverse study sites. The median indoor PM2.5 concentration across all homes was 19 µg/m3, with higher concentrations in Alaska (median = 30, minimum = 4, maximum = 200, n = 10) and Navajo Nation homes (median = 29, minimum = 3, maximum = 105, n = 23) compared with Montana homes (median = 16, minimum = 2, maximum = 139, n = 59). Households that had not cleaned the chimney within the past year had 65% higher geometric mean PM2.5 compared to those with chimney cleaned within 6 months (95% confidence interval [CI]: −1, 170). Based on a novel wood stove grading method, homes with low‐quality and medium‐quality stoves had substantially higher PM2.5 compared to homes with higher‐quality stoves (186% higher [95% CI: 32, 519] and 161% higher; [95% CI:27, 434], respectively). Our findings highlight the need for, and complex nature of, regionally appropriate interventions to reduce indoor air pollution in rural wood‐burning regions. Higher‐quality stoves and behavioral practices such as regular chimney cleaning may help improve indoor air quality in such homes. [ABSTRACT FROM AUTHOR]

Monodispersed metal and semiconductor nanocrystals have attracted great attention in fundamental and applied research due to their tunable size, morphology, and well‐defined chemical composition. Utilizing these nanocrystals in a controllable way is highly desirable especially when using them as building blocks for the preparation of nanostructured materials. Their deposition onto oxide materials provide them with wide applicability in many areas, including catalysis. However, so far deposition methods are limited and do not provide control to achieve high particle loadings. This study demonstrates a general approach for the deposition of hydrophobic ligand‐stabilized nanocrystals on hydrophilic oxide supports without ligand‐exchange. Surface functionalization of the supports with primary amine groups either using an organosilane ((3‐aminopropyl)trimethoxysilane) or bonding with aminoalcohols (3‐amino‐1,2‐propanediol) were found to significantly improve the interaction between nanocrystals and supports achieving high loadings (>10 wt. %). The bonding method with aminoalcohols guarantees the opportunity to remove the binding molecules thus allowing clean metal/oxide materials to be obtained, which is of great importance in the preparation of supported nanocrystals for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Background: Degenerative myelopathy (DM) in dogs is a progressive neurodegenerative condition that causes white matter spinal cord lesions. These lesions are undetectable on standard magnetic resonance imaging (MRI), limiting diagnosis and monitoring of the disease. Spinal cord lesions cause disruption to the structural integrity of the axons causing water diffusion to become more random and less anisotropic. These changes are detectable by the technique of diffusion tensor imaging (DTI) which is highly sensitive to diffusion alterations secondary to white matter lesion development. Objective: Perform spinal DTI on cohorts of dogs with and without DM to identify if lesions caused by DM will cause a detectable alteration in spinal cord diffusivity that correlates with neurological status. Animals Thirteen dogs with DM and 13 aged‐matched controls. Methods: All animals underwent MRI with DTI of the entire spine. Diffusivity parameters fractional anisotropy (FA) and mean diffusivity (MD) were measured at each vertebral level and statistically compared between groups. Results: Dogs with DM had significant decreases in FA within the regions of the spinal cord that had high expected lesion load. Decreases in FA were most significant in dogs with severe forms of the disease and correlated with neurological grade. Conclusions and Clinical Importance: Findings suggest that FA has the potential to be a biomarker for spinal cord lesion development in DM and could play an important role in improving diagnosis and monitoring of this condition. [ABSTRACT FROM AUTHOR]

The use of conventional multi‐fractionated radiotherapy for the treatment of glial tumours is well documented in the literature. Recently, stereotactic radiotherapy (SRT) has become more widely available allowing for hypo‐fractionated protocols; however, its usefulness in the treatment of canine intracranial gliomas is largely undetermined. We conducted a retrospective analysis, including 21 dogs diagnosed with presumptive intracranial gliomas treated with one or more courses of three fractions of 8 to 10 Gy CyberKnife SRT. The objective of this study was to evaluate the efficacy, safety and prognostic factors associated with the use of SRT for the treatment of canine intracranial gliomas. Overall MST for all dogs was 636 days (d). Dogs treated with one course of the described SRT protocol had a MST of 258 days while those treated with >1 course had a MST of 865 days (P =.0077 log rank, 0.0139 Wilcoxon). Dogs treated with one course of SRT who received adjuvant chemotherapy had a MST of >658 days and lived significantly longer than those who did not receive chemotherapy (MST, 230 days) (P =.0414 log rank, 0.0453 Wilcoxon). The most common adverse event included presumptive transient demyelination in 3/21 dogs, which was treated successfully with corticosteroids in all patients. This study provides evidence that SRT is effective in prolonging survival in dogs with intracranial gliomas, and may provide similar results to conventional fractionated protocols, while decreasing the number of hospital visits and anaesthetic episodes. Additionally, it appears that patients can be safely treated with multiple rounds of SRT resulting in improved survival times. [ABSTRACT FROM AUTHOR]

Chemical characterization of cryptotephra is critical for temporally linking archaeological sites. Here, we describe cryptotephra investigations of two Middle–Upper Paleolithic sites from north‐west Italy, Arma Veirana and Riparo Bombrini. Cryptotephra are present as small (<100 µm) rhyolitic glass shards at both sites, with geochemical signatures rare for volcanoes in the Mediterranean region. Two chemically distinct shard populations are present at Arma Veirana (P1 and P2). P1 is a high silica rhyolite (>75 wt.%) with low FeO (<1 wt.%) and a K2O/Na2O > 1 and P2 is also a high silica rhyolite (>75 wt.%) but with higher FeO (2.33–2.65 wt.%). Shards at Riparo Bombrini (P3) are of the same composition as P1 shards at Arma Veirana, providing a distinct link between deposits at both sites. Geochemical characteristics suggest three possible sources for P1 and P3: eruptions from Lipari Island (56–37.7 ka) in Italy, the Acigöl volcanic field (200–20 ka) in Turkey and the Miocene Kirka‐Phrigian caldera (18 Ma) in Turkey. Eruptions from Lipari Island are the most likely source for P1,3 cryptotephra. This study highlights how cryptotephra can benefit archaeology, by providing a direct link between Arma Veirana and Riparo Bombrini as well as other deposits throughout the Mediterranean. [ABSTRACT FROM AUTHOR]

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ABSTRACT: Prosthetic joint infection (PJI) is a devastating complication of joint arthroplasty surgery typified by biofilm formation. Currently, mechanisms whereby biofilms persist and evade immune‐mediated clearance in immune competent patients remain largely ill‐defined. Therefore, the current study characterized leukocyte infiltrates and inflammatory mediator expression in tissues from patients with PJI compared to aseptic loosening. CD33+HLA‐DR−CD66b+CD14−/low granulocytic myeloid‐derived suppressor cells (G‐MDSCs) were the predominant leukocyte population at sites of human PJI compared to aseptic tissues. MDSCs inhibit T cell proliferation, which coincided with reduced T cells in PJIs compared to aseptic tissues. IL‐10, IL‐6, and CXCL1 were significantly elevated in PJI tissues and have been implicated in MDSC inhibitory activity, expansion, and recruitment, respectively, which may account for their preferential increase in PJIs. This bias towards G‐MDSC accumulation during human PJI could account for the chronicity of these infections by preventing the pro‐inflammatory, antimicrobial actions of immune effector cells. Clinical significance: Animal models of PJI have revealed a critical role for MDSCs and IL‐10 in promoting infection persistence; however, whether this population is prevalent during human PJI and across distinct bacterial pathogens remains unknown. This study has identified that granulocytic‐MDSC infiltrates are unique to human PJIs caused by distinct bacteria, which are not associated with aseptic loosening of prosthetic joints. Better defining the immune status of human PJIs could lead to novel immune‐mediated approaches to facilitate PJI clearance in combination with conventional antibiotics. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1605–1613, 2018. [ABSTRACT FROM AUTHOR]

Conjugation of whey protein isolate (WPI) and maltodextrin (MD, dextrose equivalent of 6) was achieved by dry‐heating at an initial pH of 7.0, at 60 °C and 79% relative humidity, with WPI: MD6 ratio of 1:1, for up to 24 h. Conjugation was achieved with limited development of colour and advanced Maillard products on 24 h of heating. Conjugation increased the protein solubility at pH 4.5, by 7.1–8.5%, compared to the unheated and heated WPI controls. Conjugation of WPI with MD6 enhanced the stability and retention of clarity in protein solutions heated at 85 °C for 10 min with 50 mM added NaCl. [ABSTRACT FROM AUTHOR]

Background The purpose of Pre-Adult Latency Study was to evaluate lung findings among adults who had been environmentally exposed to Libby Amphibole only during childhood and adolescence. Methods Recruitment was restricted to volunteers who attended primary and/or secondary school, lived in Libby, MT, prior to age 23 years for males and 21 years for females and subsequently left the area. Subjects completed exposure and respiratory questionnaires, underwent pulmonary function tests (PFTs), and chest CT scans. A Pleural Score was calculated for degree and extent of pleural thickening. Logistic regression and multivariate linear regression were used. Results Of the 219 who met inclusion criteria, 198 participated. Pleural thickening was found in 96 (48%) of 198 participants. In almost half of these, it was of the lamellar type, not generally seen in exposure to other asbestos. Environmental Libby amphibole exposure was associated with pleural thickening, and the likelihood of pleural thickening increased with the number of years lived in the area. An inverse association between Pleural Score and PFT was found, which remained significant for FVC and DLco after additional sensitivity analyses. Conclusions Cumulative environmental exposure was associated with risk of pleural thickening. Among this cohort, quantitative measures of pleural thickening were associated with decreased PFT. Am. J. Ind. Med. 60:20-34, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

ABSTRACT Pleistocene palaeoclimates and palaeoenvironments of southernmost Africa are important for understanding southern hemisphere climate dynamics and for reconstructing human evolution and early human settlement in this region. Measurements of δ13C in tooth enamel of 136 faunal specimens from the archaeological site of Boomplaas Cave, South Africa, show significant shifts in proportions of C3 and C4 vegetation from the earliest deposits, probably dating to Marine Isotope Stage (MIS) 5, to the late Holocene. Vegetation communities during the Last Glacial Maximum were strongly C3-dominated, indicating an eastward expansion of the winter rainfall zone at this time. This is consistent with climate models postulating northwards shift and/or intensification of the circumpolar westerly frontal systems during glacials. Winter rainfall and lower temperatures, both of which favour C3 grasses, were clearly more important than lower pCO2 (which favours C4 grasses) in determining the nature of the vegetation. The intervals 40-36 and 17-14k cal a BP supported substantial quantities of C4 grasses, indicating a greater proportion of summer rainfall at these times. These two intervals correspond with warmer climates as reflected in Antarctic ice cores. δ13C of an as yet unnamed caprine indicate that these animals were primarily C3 grazers. [ABSTRACT FROM AUTHOR]

Background Little is known regarding the impact of long-term wildland firefighting on health. Our objective was to investigate associations between duration of wildland firefighting experience and the prevalence of self-reported health outcomes. Methods We ascertained employment, health, and demographic information on 499 current wildland firefighters (WLFFs) via questionnaire. Results Relative to those with less than 10 years of experience as a WLFF, those with 10-19 years of experience had significantly greater odds of having ever been diagnosed with hypertension, as did those with 20 or more years of experience. Significant associations were observed for report of physician-diagnosed heart arrhythmia and previous knee surgery. Conclusions We observed significant links between a greater number of years as a WLFF and self-report of two subclinical cardiovascular risk factors as well as markers of musculoskeletal health. Additional studies are needed to determine if findings can be generalized to all WLFFs. Am. J. Ind. Med. 59:330-335, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

A systematic computational investigation of hydrogen abstraction by OH from the full series of fluorinated ethyl methyl ethers (EME) containing at least one H and one F, C2HnX5-nOCHmX3-m (n=0–5, m=0–3; and n=m=0 not allowed), including 147 reactants and 469 transition states, has been carried out, employing the MP2/6-31G(d) level of theory. Results for optimized geometries, including evidence of intramolecular hydrogen bonding in transition states, and barrier heights are presented. Trends pertaining to the number of fluorines substituted, key bond lengths, barrier heights, and key bond angles were found with good correlations and were investigated. An increase in the number of F increases the barrier height of the reaction. An increase in some parameters such as C–H length of TS, relative change in C–H from reactants to TS, ∠COC of reactants, ∠HOH in the TS, and relative change in ∠HOH between TS and free water bond angle also correlates with increased barrier height. An increase in other parameters like C–H length in the reactants and hydrogen bonding can decrease the barrier height. [ABSTRACT FROM AUTHOR]

We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 months. Rabbits were evaluated monthly. After the assigned period, eyes were enucleated, and corneas were processed for histology and immunohistochemistry. There were clear corneas in three of six rabbits that had implantation of hydrogel for 2 months. In the six rabbits with implant for 6 months or longer, the corneas remained clear in four. There was a high rate of epithelial defect and corneal thinning in these six rabbits. One planned 9-month rabbit developed extrusion of implant at 4 months. The cornea remained clear in the 16-month rabbit but histology revealed epithelial in-growth. Intrastromal implantation of PEG/PAA resulted in a high rate of long-term complications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3157-3165, 2015. [ABSTRACT FROM AUTHOR]

Objective. To assess and compare the impact of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA). Methods. Patients with rheumatologist-diagnosed arthritis undergoing primary TKA during 1999-2012 were identified. Indices of pain (overall, index knee, and contralateral knee) and health-related quality of life (HRQOL) were obtained in 3 consecutive 6-month intervals: preoperative (baseline), perioperative, and postoperative (recovery). Descriptive statistics and one-way analysis of variance were used to compare TKA outcomes by diagnosis. Effect sizes and standardized response means (SRMs) were calculated between baseline and recovery. Results. Of the participating 18,897 patients, 834 of those with RA (5.3%) and 315 of those with OA (10.2%) had undergone index TKA at similar mean ages (65 and 68 years). Post-TKA, significant improvements were observed for most domains of pain, function, and HRQOL within both disease groups, with greater impact in OA. Based on the SRM, the maximum improvement was shown in index knee pain (SRM 21.33 in RA and 21.34 in OA; effect size 21.75 and 21.94, respectively). The Health Assessment Questionnaire II and the Short Form 36 physical component summary were the most responsive HRQOL indices in detecting post-TKA improvement in RA. A diagnosis of RA, lower income, and preoperative anxiety were independently associated with a lower degree of improvement in index knee pain following TKA. Conclusion. TKA is highly effective in reducing clinically relevant knee pain (to a greater extent than its effect on other subjective HRQOL indices in patients with RA), although this improvement is less marked as compared to that among patients with OA. TKA serves as a "time machine" via which patients can return to a lifestyle with less disability, before the arthritis process catches up in RA. [ABSTRACT FROM AUTHOR]

There is a delicate balance between ion exchange capacity (IEC), conductivity, and dimensional stability in anion exchange membranes as higher charge content can lead to increased water uptake, causing excessive swelling and charge dilution. Using highly-charged benzyltrimethylammonium polysulfone (IEC=2.99 mEq g−1) as a benchmark (which ruptured in water even at room temperature), we report the ability to dramatically decrease water uptake using a semi-interpenetrating network wherein we reinforced the linear polyelectrolyte with a crosslinked poly(styrene-co-divinylbenzene) network. These membranes show enhanced dimensional stability as a result of lower water uptake (75 % vs. 301 % at 25 °C) while maintaining excellent hydroxide conductivity (up to 50 mS cm−1 at 25 °C). These improvements produced an enhanced alkaline fuel cell capable of generating 236 mW cm−2 peak power density at 80 °C. This method is easily adaptable and can be a viable strategy for stabilizing existing systems. [ABSTRACT FROM AUTHOR]

ABSTRACT An understanding of the structure and properties of polymer electrolyte systems can be crucial to a variety of different applications. The current work performs a study of the composition, structure and properties of poly(ethylene glycol) (PEG)-aromatic polyimide systems incorporating ionic liquids that are relevant to several applications especially fuel cell membranes. Composition was varied through using different aromatic dianhydrides, aromatic diamines and in some cases synthesis solvent. Properties were characterized using Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, small-angle x-ray scattering, electrochemical impedance spectroscopy and cyclic voltammetry. By varying solvent, aromatic regularity and expected rigidity can be tuned, impacting average conductivity by 30%. Varying the aromatic diamine can influence the length scale and amount of aromatic regularity, which can ultimately affect the conductivity by a factor of four. The maximum conductivity reached was 83 mS/cm at 80 °C and 70 %RH. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 509-521 [ABSTRACT FROM AUTHOR]

ABSTRACT Current fuel cell technology demands improvements for widespread use, and novel polymer materials may be able to achieve the necessary enhancements. This work inspects the composition, structure, and properties of poly(ethylene glycol) (PEG)-aromatic polyimide systems aimed at polymer electrolyte membrane applications, as PEG is a known ion conductor and aromatic polyimides are quite stable. Liquid electrolytes were incorporated into the polymers through soaking to achieve ionic conductivity. By varying polyimide and liquid electrolyte, the polymers were analyzed for their structure and conductivity. Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, small-angle X-ray scattering, electrochemical impedance spectroscopy, and cyclic voltammetry were used as characterization tools. Electrolyte identity impacts liquid uptake and conductivity. Polyimide identity can influence the size and variability of the doped polymer structure, which ultimately can change conductivity by up to 28%, with the maximum conductivity being 102 mS/cm at 80°C and 70% RH. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41675. [ABSTRACT FROM AUTHOR]

Paleoanthropologists (scientists studying human origins) universally recognize the evolutionary significance of ancient climates and environments for understanding human origins. Even those scientists working in recent phases of human evolution, when modern humans evolved, agree that hunter-gatherer adaptations are tied to the way that climate and environment shape the food and technological resource base. The result is a long tradition of paleoanthropologists engaging with climate and environmental scientists in an effort to understand if and how hominin bio-behavioral evolution responded to climate and environmental change. Despite this unusual consonance, the anticipated rewards of this synergy are unrealized and, in our opinion, will not reach potential until there are some fundamental changes in the way the research model is constructed. Discovering the relation between climate and environmental change to human origins must be grounded in a theoretical framework and a causal understanding of the connection between climate, environment, resource patterning, behavior, and morphology, then move beyond the strict correlative research that continues to dominate the field. [ABSTRACT FROM AUTHOR]

Biodegradable polymer foams have the potential to lessen environmental burdens caused by traditional petroleum-based plastics. One such family of alternatives, poly(hydroxyalkanoates), have tremendous potential in this regard, but have poor foamability owing to a narrow thermal processing window. Of particular interest for this study is poly(hydroxybutyrate- co-valerate) (PHBV). Two chemical blowing agents were tested for their ability to create low density, closed-cell PHBV foams, and it is shown here that sodium bicarbonate decreases the bulk density compared to azodicarbonamide blowing agents but with the loss of a closed-cell structure. To counter this, PHBV foams were quenched with water, leading to faster crystalline formation in the polymer matrix. As a result of faster solidification, a more uniform, closed-cell bubble morphology was entrapped in the final foam product, leading to high-expansion ratio foam. Thus, PHBV, a material with poor melt strength, has enhanced melt properties for foaming applications when crystallization is induced on the same time scale as cell coalescence. POLYM. ENG. SCI., 54:2877-2886, 2014. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Foaming studies on poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) were performed to evaluate the potential impact of nitrogen gas solubility on foam microstructure and properties. It was found that there was a step change from low to high cell density below and above a specific pressure threshold. This pressure threshold, which is associated with nitrogen gas solubility in PHBV, was calculated in order to inform processing requirements for extrusion foaming of PHBV. In the process, the PVT properties of PHBV were also calculated to account for polymer swelling at high temperature and pressure. To validate the predictive method applied in this work, gas solubility of nitrogen was also determined for polypropylene (PP) and poly(lactic acid) (PLA), which have similar thermal and rheological properties to PHBV. Predicted PVT properties for PP were found to be similar to experimental values in the literature, with the predicted solubility having a 10-14% error for PP and 20-24% error for PLA. Application of the same error range to the solubility predicted for PHBV aligned well with experimental observations. POLYM. ENG. SCI., 54:2683-2695, 2014. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Objective In previous studies conducted outside the US, ∼20% of total knee arthroplasty (TKA) surgeries were judged to be inappropriate. The present study was undertaken to determine the prevalence rates of TKA surgeries classified as appropriate, inconclusive, and inappropriate in a knee osteoarthritis population in the US. Methods We used a modification of a validated appropriateness classification system and applied it to patients in the Osteoarthritis Initiative data set who underwent TKA. A variety of preoperative data were used in the classification, including Western Ontario and McMaster Universities Osteoarthritis Index pain and physical function scores, radiographic features, knee motion and laxity measures, and age. Results Data on 205 patients who underwent TKA were examined. The prevalence rates for classification of the procedure as appropriate, inconclusive, and inappropriate were 44.0% (95% confidence interval [95% CI] 37-51%), 21.7% (95% CI 16-28%), and 34.3% (95% CI 27-41%), respectively. Conclusion Approximately one-third of TKA surgeries were judged to be inappropriate. Variation in the characteristics of patients undergoing TKA was extensive. These data support the need for consensus development of criteria for patient selection among US practitioners treating patients who are potential candidates for TKA. Among the important issues, consensus development needs to address variation in patient characteristics and the relative importance of preoperative status and subsequent outcome. [ABSTRACT FROM AUTHOR]

Despite a body of evidence supporting an association between asbestos exposure and autoantibodies indicative of systemic autoimmunity, such as antinuclear antibodies (ANA), a strong epidemiological link has never been made to specific autoimmune diseases. This is in contrast with another silicate dust, crystalline silica, for which there is considerable evidence linking exposure to diseases such as systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis. Instead, the asbestos literature is heavily focused on cancer, including mesothelioma and pulmonary carcinoma. Possible contributing factors to the absence of a stronger epidemiological association between asbestos and autoimmune disease include (a) a lack of statistical power due to relatively small or diffuse exposure cohorts, (b) exposure misclassification, (c) latency of clinical disease, (d) mild or subclinical entities that remain undetected or masked by other pathologies, or (e) effects that are specific to certain fiber types, so that analyses on mixed exposures do not reach statistical significance. This review summarizes epidemiological, animal model, and in vitro data related to asbestos exposures and autoimmunity. These combined data help build toward a better understanding of the fiberassociated factors contributing to immune dysfunction that may raise the risk of autoimmunity and the possible contribution to asbestos-related pulmonary disease. [ABSTRACT FROM AUTHOR]

ABSTRACT Adult acquired flatfoot deformity (AAFD) is a degenerative disease resulting in malalignment of the mid- and hindfoot secondary to posterior tibial tendon dysfunction and increasing implication of ligament pathologies. Despite the complex 3D nature of AAFD, 2D radiographs are still employed to diagnose and stage the disease. Computer modeling techniques allow for accurate 3D recreations of musculoskeletal systems for the investigation of biomechanical factors contributing to disease. Following Institutional Review Board approval, the lower limbs of six diagnosed AAFD sufferers were imaged with MRI, photographs, and X-ray. Next, a radiologist graded the MRI attenuation of eight soft-tissues implicated in AAFD. Six patient-specific rigid-body models were then created and loaded according to patient weight, graded soft-tissues, and extrinsic muscles. Model function was validated using clinically relevant kinematic measures in three planes. Agreement varied depending on the measure, with average absolute deviations of <7° for angles and <4 mm for distances. Additionally, the clinically favored AP talonavicular coverage angle, ML talo-1st metatarsal angle, and ML 1st cuneiform height showed strong correlations of R2 = 0.63, 0.75, and 0.85, respectively. Thus, computer modeling offers a promising methodology for the non-invasive investigation of in vivo kinematic behavior in pathologic feet and, once validated, may further be used to investigate biomechanical parameters that are difficult to measure clinically. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1861-1868, 2013 [ABSTRACT FROM AUTHOR]

Objective The primary objective of this study was to determine the prevalence of oral lesions of autoimmune etiology ( OLAIE) in a cohort of patients with primary Sjögren's syndrome ( pSS). Materials and methods A multi-center retrospective cohort study was conducted at the oral medicine practices of Carolinas Medical Center ( CMC), Baylor College of Dentistry ( BCD), and the University of Florida ( UF). Each site performed a chart review of patients with well-characterized pSS. Clinical variables such as OLAIE, traumatic lesions, and medical conditions were compiled at each site. The association between clinical variables and the presence of OLAIE was then assessed for significance. Results We evaluated 155 patients diagnosed with pSS. Nineteen patients with pSS (12.3%) had an OLAIE. CMC reported 11 (21.2%) patients with OLAIE, while BCD and UF reported 4 (7.3%) and 4 (8.3%), respectively. Eleven of the 19 (58%) patients with OLAIE had lichen planus, 6 (32%) had aphthous stomatitis, 1 (5%) had chronic ulcerative stomatitis, and 1 (5%) had lesions of systemic connective tissue disease by immunofluorescence. Conclusion The results of our analysis suggest that patients with pSS have a 12% prevalence of OLAIE with a wide range (7.3-21.2%) found between practices. This difference is likely related to the different screening protocols for oral dryness between sites. [ABSTRACT FROM AUTHOR]

The capacity to detect remnants of fire usage in archaeological sites, along with a better understanding of its use by prehistoric populations, can help us to shed light on hominin cognition, social organization, and technology. The application of phytolith studies to understand fire and its use can be widely applicable since plants typically contain phytoliths that are identifiable to different taxonomic levels. Pinnacle Point 13 B ( PP13 B) is one of several South African Middle Stone Age ( MSA) sites that shows an abundant presence of lenses of burnt material and intact hearths. Phytolith analyses at PP13 B have been used to identify the types of plants used as fuel in the hearths. The phytoliths overall show high levels of alteration, and varying alteration is used to identify areas with higher alkaline conditions related to dripping water. In some areas of the site, there is excellent preservation of multicellular structures from the epidermal leaves of dicotyledonous plants, suggesting in situ structures with practically no chemical or post-depositional alteration. A notable pattern is the abundance of dicotyledonous leaves from the rear of the cave, which might indicate specific leaf-fuels for the fires, short-term fire activities, or other actions such as cooking. [ABSTRACT FROM AUTHOR]

Extrusion foaming of poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) and two blends of PHBV with cellulose acetate butyrate (CAB) were studied using an azodicarbonamide (AZ) blowing agent and a single-screw extruder. The concentration of the blowing agent was systematically varied from 0 to 4.0 phr to achieve maximum density reduction reaching 41%, as well as to obtain information on the dependence of cell growth on blowing agent concentration. Extruded foams were characterized in terms of their bulk densities and cellular morphologies. Stereological and statistical methods permitted full characterization of the three-dimensional cell size distributions, assessing the average cell diameters (ranging from 58 to 290 μm) and cell densities (ranging from 650 to 180,000 cm−3). The variation in cellular morphology among foams consisting of different polymer matrix or blowing agent concentration was compared. The results were analyzed by considering the influence of viscoelastic properties of the polymer matrix on the bubble growth during foaming. Significantly higher melt viscosity and elasticity and reduced gas solubility of the PHBV/CAB blends are believed to retard cell coalescence and collapse during foam expansion, resulting in more uniform cell size distribution and better homogeneity of cellular morphology. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A novel interpenetrating network (IPN) based on poly(ethylene glycol) (PEG) and poly(acrylic acid) was developed and its use as an artificial cornea was evaluated in vivo. The in vivo results of a first set of corneal inlays based on PEG-diacrylate precursor showed inflammation of the treated eyes and haze in the corneas. The insufficient biocompatibility could be correlated to poor long-term stability of the implant caused by hydrolytic degradation over time. Adapting the hydrogel chemistry by replacing hydrolysable acrylate functionalities with stable acrylamide functionalities was shown to increase the long-term stability of the resulting IPNs under hydrolytic conditions. This new set of hydrogel implants now shows increased biocompatibility in vivo. Rabbits with corneal inlay implants are healthy and have clear cornea and non-inflamed eyes for up to 6 months after implantation. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the predictive utility of the pattern of low back pain (LBP) in detecting the source of LBP as internal disk disruption (IDD), facet joint pain (FJP), or sacroiliac joint pain (SIJP). Design: Retrospective chart review. Setting: University spine center. Patient sample: A total of 170 cases from 156 patients presenting with LBP whose low back disorder was definitively diagnosed. The mean age was 54.4 years (SD, 16.2) and median duration of LBP was 12 months (interquartile ranges, 6-32). Methods: Charts of consecutive LBP patients who underwent definitive diagnostic spinal procedures including provocation diskography, facet joint blocks, and sacroiliac joint blocks were retrospectively reviewed. Each patient with LBP was queried as to the exact location of their LBP: midline, defined as in-line with the spinous processes, and/or paramidline, defined as lateral to 1 fingerbreadth adjacent to the midline. Outcome Measures: In patients with a definitive diagnosis for the source of LBP, the proportion of each diagnosed source of pain was calculated. χ2 tests were used to identify differences in the percentages of midline and paramidline LBP among the groups of patients testing positive for IDD, FJP, or SIJP. Diagnostic measures of sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and likelihood ratios of positive and negative tests using the presence/absence of midline and paramidline pain for the diagnosis of IDD, FJP, and SIJP were estimated. Results: With cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ2 = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). In cases of IDD, significantly lower percentages of patients reported paramidline pain (67.3%; χ2 = 16.1, df = 2, P = .0003) as compared with cases of FJP (95.0%) or SIJ (96.0%). In cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ2 = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). The specificity of midline LBP for IDD, FJP, and SIJP was 74.8% (95% CI = 65.0%-82.9%), 28.0% (20.1%-37.0%), and 36.0% (28.0%-44.5%), respectively. The negative predictive value of paramidline LBP for IDD, FJP, and SIJP was 29.2% (95% CI = 12.6%-51.1%), 91.7% (73.0%-99.0%), and 95.8% (78.9%-99.9%). The diagnostic accuracy of midline LBP for IDD, FJP, and SIJP was 83.5%, 24.1%, and 31.8%, respectively. Conclusions: The presence of midline LBP increases the probability of lumbar IDD and reduces the probability of symptomatic FJ and SIJ dysfunction. The presence of isolated paramidline LBP increases the probability of symptomatic FJ or SIJ but mildly reduces the likelihood of lumbar IDD. [Copyright &y& Elsevier]