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Current rates of habitat degradation and climate change are causing unprecedented declines in global biodiversity. Studies on vertebrates highlight how conservation genomics can be effective in identifying and managing threatened populations, but it is unclear how vertebrate‐derived metrics of genomic erosion translate to invertebrates, with their markedly different population sizes and life histories. The Black‐veined White butterfly (Aporia crataegi) was extirpated from Britain in the 1920s. Here, we sequenced historical DNA from 17 specimens collected between 1854 and 1924 to reconstruct demography and compare levels of genomic erosion between extirpated British and extant European mainland populations. We contrast these results using modern samples of the Common Blue butterfly (Polyommatus icarus); a species with relatively stable demographic trends in Great Britain. We provide evidence for bottlenecks in both these species around the period of post‐glacial colonization of the British Isles. Our results reveal different demographic histories and Ne for both species, consistent with their fates in Britain, likely driven by differences in life history, ecology and genome size. Despite a difference, by an order of magnitude, in historical effective population sizes (Ne), reduction in genome‐wide heterozygosity in A. crataegi was comparable to that in P. icarus. Symptomatic of A. crataegi's disappearance were marked increases in runs‐of‐homozygosity (RoH), potentially indicative of recent inbreeding, and accumulation of putatively mildly and weakly deleterious variants. Our results provide a rare glimpse of genomic erosion in a regionally extinct insect and support the potential use of genomic erosion metrics in identifying invertebrate populations or species in decline. [ABSTRACT FROM AUTHOR]

This study demonstrates a multi‐spectrum camouflage control via microfluidic methods within a thermally and visibly semi‐transparent polymer (polyethylene). Microfluidic devices have a high potential for achieving multiband camouflage including both visible and infrared (IR) spectrums because they can manipulate fluids that may be dyed, transparent, or opaque to different parts of the electromagnetic spectrum. However, most traditional polymers used for microfluidics are not very transparent in the thermal IR region (≈8–14 um wavelengths), which limits their effectiveness in this spectrum. It develops a high‐speed, low‐cost robust process to fabricate microfluidic devices entirely made from polyethylene using xurography and thermocompression molding techniques. Moreover, a novel method that thermally bond macro‐scale polyethylene tubing to micro‐scale channels is developed. The simplicity and flexibility of the method allow the fabrication of devices with different channel heights, widths, and patterns. Upon filling the microfluidic devices with dyed liquids and testing them with different backgrounds, the devices show fast and high visible camouflage capabilities. Moreover, the thermal IR appearance of microfluidic systems can be altered without changing temperature by incorporating a metalized surface which can be covered by an IR opaque liquid to alter the apparent temperature when reflecting IR sources. [ABSTRACT FROM AUTHOR]

This work utilizes predictive modeling techniques to guide and inform metamaterial design for heat management solutions and thermal radiation control. Specifically, micro‐ and macro‐scale polyethylene‐based solutions are proposed for passive and active thermal camouflage. A micro‐scale post design is proposed for highly‐tunable infrared emissivity based on varying unit cell geometrical configurations. Actively modulating these micro‐features through lateral straining of up to 3% allows for redshifting the emissivity spectrum by up to 0.5 µm. Macro‐scale lenticular lens designs allow for a more passive form of camouflage due to its emissive stability for a range of configurations (e.g., single and sandwiched structures, increasing lens radii and height). Overall, the proposed metamaterial designs allow the tailoring of optical properties to improve thermal radiating performance. [ABSTRACT FROM AUTHOR]

Determining when animal populations have experienced stress in the past is fundamental to understanding how risk factors drive contemporary and future species' responses to environmental change. For insects, quantifying stress and associating it with environmental factors has been challenging due to a paucity of time‐series data and because detectable population‐level responses can show varying lag effects. One solution is to leverage historic entomological specimens to detect morphological proxies of stress experienced at the time stressors emerged, allowing us to more accurately determine population responses.Here we studied specimens of four bumblebee species, an invaluable group of insect pollinators, from five museums collected across Britain over the 20th century. We calculated the degree of fluctuating asymmetry (FA; random deviations from bilateral symmetry) between the right and left forewings as a potential proxy of developmental stress.We: (a) investigated whether baseline FA levels vary between species, and how this compares between the first and second half of the century; (b) determined the extent of FA change over the century in the four bumblebee species, and whether this followed a linear or nonlinear trend; (c) tested which annual climatic conditions correlated with increased FA in bumblebees.Species differed in their baseline FA, with FA being higher in the two species that have recently expanded their ranges in Britain. Overall, FA significantly increased over the century but followed a nonlinear trend, with the increase starting c. 1925. We found relatively warm and wet years were associated with higher FA.Collectively our findings show that FA in bumblebees increased over the 20th century and under weather conditions that will likely increase in frequency with climate change. By plotting FA trends and quantifying the contribution of annual climate conditions on past populations, we provide an important step towards improving our understanding of how environmental factors could impact future populations of wild beneficial insects. [ABSTRACT FROM AUTHOR]

Insect declines are a global issue with significant ecological and economic ramifications. Yet, we have a poor understanding of the genomic impact these losses can have. Genome‐wide data from historical specimens have the potential to provide baselines of population genetic measures to study population change, with natural history collections representing large repositories of such specimens. However, an initial challenge in conducting historical DNA data analyses is to understand how molecular preservation varies between specimens.Here, we highlight how Next‐Generation Sequencing methods developed for studying archaeological samples can be applied to determine DNA preservation from only a single leg taken from entomological museum specimens, some of which are more than a century old. An analysis of genome‐wide data from a set of 113 red‐tailed bumblebee Bombus lapidarius specimens, from five British museum collections, was used to quantify DNA preservation over time. Additionally, to improve our analysis and further enable future research, we generated a novel assembly of the red‐tailed bumblebee genome.Our approach shows that museum entomological specimens are comprised of short DNA fragments with mean lengths below 100 base pairs (BP), suggesting a rapid and large‐scale post‐mortem reduction in DNA fragment size. After this initial decline, however, we find a relatively consistent rate of DNA decay in our dataset, and estimate a mean reduction in fragment length of 1.9 bp per decade. The proportion of quality filtered reads mapping to our assembled reference genome was around 50%, and decreased by 1.1% per decade.We demonstrate that historical insects have significant potential to act as sources of DNA to create valuable genetic baselines. The relatively consistent rate of DNA degradation, both across collections and through time, mean that population‐level analyses—for example for conservation or evolutionary studies—are entirely feasible, as long as the degraded nature of DNA is accounted for. [ABSTRACT FROM AUTHOR]

Climate change is expected to alter rainfall and temperature regimes across the world. The hydrology and riparian zone vegetation of lotic ecosystems are tightly linked to rainfall and a mechanistic understanding of the effects of rainfall on lotic ecosystems is needed to forecast the ecological impacts of climate change. However, it is difficult to isolate rainfall effects from other environmental variables that covary across climates. To address this, we leveraged a unique steep rainfall gradient with few covarying changes in elevation, temperature, and geology to evaluate the effects of rainfall on stream invertebrate communities.We surveyed nine streams in the Texas Gulf Coast Prairie distributed along a 550–1,350 mm/year rainfall gradient. Four sites were classified as drier semi‐arid streams (<750 mm annual rainfall) and five sites were classified as wetter sub‐humid streams (>750 mm annual rainfall). A suite of characteristics including benthic invertebrate community metrics, flow conditions, and water quality variables were assessed monthly for 14 months at each site to relate precipitation regime to stream structure and function.Precipitation regime was observed to be a master explanatory variable. As annual rainfall increased, the flow environment became more stable within seasons and predictable across seasons, influencing spatial structure and temporal variability of invertebrate community composition. Wetter streams were dominated by slower growing taxa without adaptions for desiccation resistance and strong dispersal. Wetter sites displayed seasonal variation in community composition and species richness, whereas temporal variation in communities in drier streams was controlled by stochastic variation in flow conditions.These observations show that differences in local annual rainfall correlated with major changes to community structure and functional composition. We hypothesise that this association is related to the connection of rainfall to hydrological stability, particularly the frequency of low flow disturbances, and the subsequent effects on riparian vegetation and temporally available niches to stream invertebrates. Our work adds to evidence that alterations in precipitation patterns associated with climate change have sweeping impacts on lotic fauna. [ABSTRACT FROM AUTHOR]

Summary: The root economics space (RES) is multidimensional and largely shaped by belowground biotic and abiotic influences. However, how root–fungal symbioses and edaphic fertility drive this complexity remains unclear.Here, we measured absorptive root traits of 112 tree species in temperate and subtropical forests of China, including traits linked to functional differences between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) hosts.Our data, from known mycorrhizal tree species, revealed a 'fungal‐symbiosis' dimension distinguishing AM from ECM species. This divergence likely resulted from the contrasting mycorrhizal evolutionary development of AM vs ECM associations. Increased root tissue cortical space facilitates AM symbiosis, whereas increased root branching favours ECM symbiosis. Irrespective of mycorrhizal type, a 'root‐lifespan' dimension reflecting aspects of root construction cost and defence was controlled by variation in specific root length and root tissue density, which was fully independent of root nitrogen content. Within this function‐based RES, we observed a substantial covariation of axes with soil phosphorus and nitrate levels, highlighting the role played by these two axes in nutrient acquisition and conservation.Overall, our findings demonstrate the importance of evolved mycorrhizal symbiosis pathway and edaphic fertility in framing the RES, and provide theoretical and mechanistic insights into the complexity of root economics. [ABSTRACT FROM AUTHOR]

Naturally regenerated forests have been shown to achieve the level of species richness similar to old-growth forests in several decades, but a much longer time is required for them to regain the species composition and structural complexity of typical old-growth forests (Aide et al., 2000; Brown & Lugo, 1990). A culture of conservation: How an ancient forest plantation turned into an old-growth forest reserve - The story of the Wamulin forest Keywords: biodiversity; ecosystem services; old-growth forest; secondary succession; unity between humans and the nature; Wanmulin Nature Reserve EN biodiversity ecosystem services old-growth forest secondary succession unity between humans and the nature Wanmulin Nature Reserve 1014 1024 11 10/11/21 20211001 NES 211001 INTRODUCTION Forest plantations are an important component of global forest cover with a global extent of 294 million ha (FAO, 2020). Thus, it is unwise to interpret the example of the Wanmulin Nature Reserve to claim that forest plantations are ecologically and culturally as valuable as old-growth forests, because it is the multiple centuries of natural succession without human disturbance, not the establishment of forest plantation, that contributes most to the high levels of ecosystem services found in the Wanmulin Nature Reserve. [Extracted from the article]

How much does natural selection, as opposed to genetic drift, admixture, and gene flow, contribute to the evolution of invasive species following introduction to a new environment? Here we assess how evolution can shape biological invasions by examining population genomic variation in non‐native guppies (Poecilia reticulata) introduced to the Hawaiian Islands approximately a century ago. By examining 18 invasive populations from four Hawaiian islands and four populations from the native range in northern South America, we reconstructed the history of introductions and evaluated population structure as well as the extent of ongoing gene flow across watersheds and among islands. Patterns of differentiation indicate that guppies have developed significant population structure, with little natural or human‐mediated gene flow having occurred among populations following introduction. Demographic modeling and admixture graph analyses together suggest that guppies were initially introduced to O'ahu and Maui and then translocated to Hawai'i and Kaua'i. We detected evidence for only one introduction event from the native range, implying that any adaptive evolution in introduced populations likely utilized the genetic variation present in the founding population. Environmental association tests accounting for population structure identified loci exhibiting signatures of adaptive variation related to predators and landscape characteristics but not nutrient regimes. When paired with high estimates of effective population sizes and detectable population structure, the presence of environment‐associated loci supports the role of natural selection in shaping contemporary evolution of Hawaiian guppy populations. Our findings indicate that local adaptation may engender invasion success, particularly in species with life histories that facilitate rapid evolution. Finally, evidence of low gene flow between populations suggests that removal could be an effective approach to control invasive guppies across the Hawaiian archipelago. [ABSTRACT FROM AUTHOR]

The quasi‐static confined uniaxial compaction of granular alumina and boron carbide was studied, and the effect of triaxial stress on the materials as a function of increasing particle size was observed. The average particle sizes studied for granular alumina were 170 ± 63, 230 ± 55, 330 ± 67, and 450 ± 83 µm. The average particle size studied for granular boron carbide were 170 ± 40, 190 ± 34, 320 ± 59, and 470 ± 90 µm. The material response at hydrostatic pressure as a function of porosity, the bulk modulus as a function of hydrostatic pressure, and the transmission ratio as a function of applied load was evaluated for increasing particle size. For alumina, the increase in particle size resulted in an increase in strength for a fixed porosity, the bulk modulus of this material did not show clear particle size‐dependent trends, and the transmission ratio increased with increase in particle size. Conversely, for granular boron carbide, the hydrostatic pressure‐porosity curve shifted to the right with increasing particle size, the change in bulk modulus increased with increasing particle size, and no clear particle size‐dependent trends were observed when looking at the transmission ratio during the experiment. Post‐experiment scanning electron microscopy revealed that alumina powder fragmented from elongated shapes to block‐like structures, while boron carbide powder appeared more circular before the experiments and fragmented into smaller comminuted pieces. This paper discusses the implication of the work in the context of the limited experimental data in the field and the modeling of granular advanced ceramics behavior. [ABSTRACT FROM AUTHOR]

We assessed the prevalence of life history variation across four of the five native amphidromous Hawai'ian gobioids to determine whether some or all exhibit evidence of partial migration. Analysis of otolith Sr.: Ca concentrations affirmed that all are amphidromous and revealed evidence of partial migration in three of the four species. We found that 25% of Lentipes concolor (n = 8), 40% of Eleotris sandwicensis (n = 20) and 29% of Stenogobius hawaiiensis (n = 24) did not exhibit a migratory life‐history. In contrast, all individuals of Sicyopterus stimpsoni (n = 55) included in the study went to sea as larvae. Lentipes concolor exhibited the shortest mean larval duration (LD) at 87 days, successively followed by E. sandwicensis (mean LD = 102 days), S. hawaiiensis (mean LD = 114 days) and S. stimpsoni (mean LD = 120 days). These findings offer a fresh perspective on migratory life histories that can help improve efforts to conserve and protect all of these and other at‐risk amphidromous species that are subject to escalating anthropogenic pressures in both freshwater and marine environments. [ABSTRACT FROM AUTHOR]

Abstract: Interannual changes in global climate and weather disturbances may influence reproduction in tropical forests. Phenomena such as the El Niño Southern Oscillation (ENSO) are known to produce interannual variation in reproduction, as do severe storms such as hurricanes. Using stationary trap‐based phenology data collected fortnightly from 1993 to 2014 from a hurricane‐affected (1989 Hugo, 1998 Georges) subtropical wet forest in northeastern Puerto Rico, we conducted a time series analysis of flowering and seed production. We addressed (1) the degree to which interannual variation in flower and seed production was influenced by global climate drivers and time since hurricane disturbance, and (2) how long‐term trends in reproduction varied with plant lifeform. The seasonally de‐trended number of species in flower fluctuated over time while the number of species producing seed exhibited a declining trend, one that was particularly evident during the second half of the study period. Lagged El Niño indices and time series hurricane disturbance jointly influenced the trends in numbers of flowering and fruiting species, suggesting complex global influences on tropical forest reproduction with variable periodicities. Lag times affecting flowering tended to be longer than those affecting fruiting. Long‐term patterns of reproduction in individual lifeforms paralleled the community‐wide patterns, with most groups of lifeform exhibiting a long‐term decline in seed but not flower production. Exceptions were found for hemiepiphytes, small trees, and lianas whose seed reproduction increased and then declined over time. There was no long‐term increase in flower production as reported in other Neotropical sites. [ABSTRACT FROM AUTHOR]

Effects of microstructure and material properties on the mechanical behavior of hot-pressed boron carbide are presented. The microstructure and intrinsic microstructural inhomogeneities have been characterized using scanning electron microscopy characterization techniques (SEM/EDS/EBSD). In situ mechanical characterizations of the boron carbide microstructure and its larger inhomogeneities have been performed by nanoindentation. Macroscopic dynamic and quasi-static compressive responses have been studied in two characteristic orientations (parallel and perpendicular to the hot-pressing direction) using a modified compression Kolsky bar setup (strain rates of [ABSTRACT FROM AUTHOR]

Environmental heterogeneity influences the species composition of tropical forests, with implications for patterns of diversity and species coexistence in these hyperdiverse communities. Many studies have examined how variability in soil nutrients and topography influence plant community composition, with differing results. None have quantified the relative contribution of environmental heterogeneity versus endogenous processes to variability in forest community composition over time and with respect to successional recovery., Using five consecutive trees censuses of a forest plot in Puerto Rico, conducted between 1990 and 2011, we evaluated the influence of edaphic and topographic variability on community composition. The plot has a well-documented land-use history and is subject to periodic hurricane disturbance. Using multiple canonical distance-based redundancy analyses, we studied how spatial heterogeneity in soil nutrients and topography structure community composition over time, as the forest recovers from long-term land-use effects and two major hurricanes in 1989 and 1998., For the entire plot, spatial variables (principle coordinates of neighbourhood matrices), representing the autocorrelation of tree species in the community, explained the majority (49-57%) of the variability in tree community composition. The explanatory power of spatial variables decreased over time, as forest structure recovered from hurricane damage and the stems in the understorey died. Soil nutrients and topography, collectively, explained a moderate portion (33-37%) of the species compositional variation and were slightly more robust in explaining compositional differences in areas of more intense past land use., Areas of less-intense past land use showed weaker community-environmental trends overall, illustrating a tendency for stronger resource competition (i.e. light, water and soil nutrients) between species in these areas. This illustrates how environmental-plant community interactions are strengthened by the lasting effects of human land-use legacies, which persist for decades to centuries., Synthesis. Our findings confirm past land use to be a fundamental driver of the structure and composition of secondary forests through its impacts on the tree community, the abiotic terrestrial environment and their interaction. Since the extent of second-growth tropical forests continues to increase, our findings highlight the importance of understanding the processes that determine the rate and nature of their succession. [ABSTRACT FROM AUTHOR]

Disturbance shapes plant communities over a wide variety of spatial and temporal scales. How natural and anthropogenic disturbance interact to shape ecological communities is highly variable and begs a greater understanding. We used five censuses spanning the years 1990-2011 from the 16-ha Luquillo Forest Dynamics Plot (LFDP) in northeast Puerto Rico to investigate the interplay of human land-use legacies dating to the early 20th century and two recent hurricanes (Hugo, 1989 and Georges, 1998). The LFDP is a landscape mosaic comprised of an area of mature subtropical wet forest and three areas of secondary forest with differing past land-use intensities. We examined the degree to which hurricane disturbance--effect and subsequent community recovery varied across past land-use classes. We expected areas with greater intensity of human land use to be more affected by hurricane disturbance therefore exhibiting greater initial damage and longer successional recovery times. Structurally, areas of secondary forest contained smaller trees than old-growth areas; hurricanes caused widespread recruitment of shrubs and saplings that thinned with time since the first hurricane. Species richness of the plot declined over time, mostly due to the loss of rare species, but also due to the loss of some heliophilic, pioneer species that became abundant after the first hurricane. Species composition differed strongly between areas of secondary and mature forest, and these differences were largely constant over time, except for an increase in compositional differences following the second hurricane. An indicator species analysis attributed this pattern to the longer persistence of pioneer species in areas of greater past land-use intensity, likely due to the more open canopy in secondary forest. When secondary forest areas of differing past land-use intensity were considered separately, few species of low community rank were found as indicators. When these areas were combined, more and higher-ranked species emerged as indicators, creating ecologically meaningful indicator species combinations that better captured the broad-scale plant community response to past land use. Our findings support the idea that effects of past land use can persist for decades to centuries following land-use abandonment, illustrating the importance of land-use legacies in shaping regenerating tropical secondary forests. [ABSTRACT FROM AUTHOR]

Dynamic brittle fragmentation is typically described using analytical and computational approaches for tensile stress-states. However, most fragmentation applications (e.g., impact, blast) involve very large initial compressive stresses and deformations. In this study, the compressive fragmentation of brittle materials is investigated experimentally across a range of materials: silicon carbide, boron carbide, spinel, basalt and a stony meteorite. Analysis of our experimental results suggests that there exists two different regimes in the fragment size distributions, based on two brittle fragmentation mechanisms. The first is a mechanism that produces larger fragments and is associated with the structural failure of the sample being tested. This mechanism is influenced by the loading conditions (rate, stress state) and sample geometry. The second fragmentation mechanism produces comparatively smaller fragments and arises from the coalescence of fractures initiating and coalescence between defects in regions of large stresses and contact forces (e.g., between two fractured surfaces from the larger fragments). A framework is developed for comparing experimental compressive fragmentation results with tensile fragmentation theories. The compressive experimental results are shown to be adequately described by the theories using the new framework. [ABSTRACT FROM AUTHOR]

We investigate the rate-dependent compressive failure and fragmentation of a hot-pressed boron carbide, under both uniaxial and confined biaxial compression, using quantitative fragment analysis coupled with quantitative microstructural analysis. Two distinct fragmentation regimes are observed, one of which appears to be more sensitive to the microstructural length scales in the material, while the second is more sensitive to the structural character and boundary conditions of the compressed sample. The first regime, which we refer to as "microstructuredependent," appears to be associated with smaller fragments arising from the coalescence of fractures initiating from graphitic inclusions. This regime appears to become more dominant as the strain rate is increased and as the stress-state becomes more confined. The second regime generates larger fragments with the resulting fragment size distribution dependent on the specific structural mechanisms that are activated during macroscopic failure (e.g., buckling of local columns developed during the compression). The average fragment size in the latter regime appears to be reasonably predicted by current fragmentation models. This improved understanding of the effects of microstructure and confinement on fragmentation then provides new insights into prior ballistic studies involving boron carbide. [ABSTRACT FROM AUTHOR]

Key points Hypoxia is thought to depolarize glomus cells by inhibiting the outward K+ current, which sets in motion a cascade of ionic events that lead to transmitter secretion, increased afferent carotid sinus nerve activity and increased ventilation., Our study of Na+-permeable channels in glomus cells has revealed that hypoxia not only inhibits TASK background K+ channels but also indirectly activates a non-selective cation channel with a single channel conductance of 20 pS. Under physiological conditions, the reversal potential of the cation channel is ∼ -28 mV, indicating that Na+ influx is also involved in hypoxia-induced excitation of glomus cells., Activation of the 20 pS cation channel is present when the O2 content is 5% or less, indicating that Na+ influx occurs during moderate to severe hypoxia (<5% O2), but not mild hypoxia (>5% O2)., The 20 pS cation channel is directly activated by a rise in intracellular Ca2+. Thus, factors that elevate intracellular Ca2+ such as hypoxia, extracellular acidosis and high external KCl all activate the cation channel. A feed-forward mechanism may be present in which an initial depolarization-induced rise in intracellular Ca2+ opens the Na+-permeable cation channel, and the Na+ influx causes additional depolarization and influx of Ca2+ into glomus cells., Abstract The current model of O2 sensing by carotid body chemoreceptor (glomus) cells is that hypoxia inhibits the outward K+ current and causes cell depolarization, Ca2+ influx via voltage-dependent Ca2+ channels and a rise in intracellular [Ca2+] ([Ca2+]i). Here we show that hypoxia (<5% O2), in addition to inhibiting the two-pore domain K+ channels TASK-1/3 (TASK), indirectly activates an ∼20 pS channel in isolated glomus cells. The 20 pS channel was permeable to K+, Na+ and Cs+ but not to Cl− or Ca2+. The 20 pS channel was not sensitive to voltage. Inhibition of TASK by external acid, depolarization of glomus cells with high external KCl (20 m m) or opening of the Ca2+ channel with FPL64176 activated the 20 pS channel when 1 m m Ca2+ was present in the external solution. Ca2+ (10 μ m) applied to the cytosolic side of inside-out patches activated the 20 pS channel. The threshold [Ca2+]i for activation of the 20 pS channel in cell-attached patches was ∼200 n m. The reversal potential of the 20 pS channel was estimated to be −28 mV. Our results reveal a sequential mechanism in which hypoxia (<5% O2) first inhibits the K+ conductance and then activates a Na+-permeable, non-selective cation channel via depolarization-induced rise in [Ca2+]i. Our results suggest that inhibition of K+ efflux and stimulation of Na+ influx both contribute to the depolarization of glomus cells during moderate to severe hypoxia. [ABSTRACT FROM AUTHOR]

R4744 --> 717.5 --> Sex differences in obesity‐induced microvascular dysfunction have been reported, however, the mechanisms are poorly understood. We previously identified macrophages as key cells that mediate microvascular dysfunction in obesity. Interestingly, sex differences in the inflammatory response to obesity have also been described. The current aim was to define the interaction between biological sex and macrophages on obesity‐dependent microvascular dysfunction. We placed male and female mice (C57BL/6) on either a high‐fat diet to induce obesity or a low‐fat control diet. After twelve weeks mice were treated with either clodronate‐containing liposomes to deplete macrophages or PBS‐containing control liposomes. Macrophage depletion had no effect on body weight, glycemia, or mean arterial pressure, which were all increased by obesity in both male and female. Obesity also caused an expansion of the macrophage population in both male and female mesenteric perivascular adipose tissue, as quantified by flow cytometry, which was similarly attenuated by clodronate treatment. We then assessed microvascular function in third order mesenteric arterioles using pressure myography. The sensitivity of vasoconstriction to norepinephrine was increased by obesity in both male and female. Macrophage depletion dramatically attenuated vasoconstriction in male but only minimally affected vessels from females. In contrast, macrophage depletion had no effect on acetylcholine‐dependent vasodilation in either male or female. Taken together, these data show that macrophages contribute to obesity‐dependent microvascular hypercontractility in males but not females. [ABSTRACT FROM AUTHOR]

R2543 --> 616.2 --> Carotid body (CB) glomus cells serve as peripheral chemoreceptors that detect changes in arterial O2 pressure (pO2) and pH, and adjust the level of ventilation to help maintain a normal level of blood pO2 and pH. Severe levels of hypoxia and acidosis are well known to cause sustained rise in cytosolic Ca2+ concentration ([Ca2+]c) in CB glomus cells. We showed recently that isolated gloms cells exhibit spontaneous [Ca2+]c oscillations and that mild levels of hypoxia increase the frequency and amplitude of Ca2+oscillations to augment the secretory response. To understand how mild levels of acidosis regulate Ca2+signaling in glomus cells, we studied the effects of small changes in extracellular pH (pHo) on the kinetics of Ca2+oscillations and the roles of Cav, ASIC and TASK. A decrease in pHo from 7.4 to 7.3 (mild acidosis) and 7.2 (moderate acidosis) produced significant increases in the frequency and amplitude of Ca2+ oscillations without affecting the resting basal [Ca2+]c. These effects on Ca2+ oscillations were not blocked by 0.1 mM amiloride (an ASIC inhibitor) that blocked Na‐H exchange in glomus cells. Mild acidosis was associated with a small but significant inhibition of TASK current and cell depolarization. The increase in Ca2+oscillations produced by mild acidosis was strongly inhibited by nifedipine (1 µM; L‐type Cav inhibitor), as well as by TTA‐P2 (20 µM; T‐type Cav inhibitor). Mild acidosis (0.1 pH unit decrease) and mild hypoxia (~5% O2) produced similar levels of change in the kinetics of Ca2+oscillations and produced an additive effect on Ca2+oscillations. Our study shows that mild to moderate levels of acidosis inhibit TASK to increase Ca2+ influx via both L‐ and T‐type Cav, resulting in increased frequency and amplitude of Ca2+ oscillations. Our study also indicate that ASICs are not involved in the stimulatory effects of mild acidosis on Ca2+oscillations. [ABSTRACT FROM AUTHOR]

Investigations of biogeochemical processes in semiarid environments have largely focused on either plot studies in the uplands or on in-stream and near stream reaction or transport studies. Recent research permits us to synthesize a conceptual model of how uplands and riparian systems are linked in semiarid climates specific to the San Pedro River basin in Arizona. These studies have demonstrated significant export of both dissolved and sediment associated carbon and nitrogen from the uplands into the channel network of semiarid river systems. Likewise research has demonstrated that riparian areas are biogeochemically active, with the potential to rapidly respire inputs of organic matter, releasing carbon back to the atmosphere and inorganic nitrogen into the water column or back to the atmosphere through denitrification. For the San Pedro, a total of more than 80% of both carbon and nitrogen export from the uplands that is observed in small catchments is not observed at the larger river system scale, indicating that this carbon and nitrogen must be either stored, taken up by vegetation or returned to the atmosphere at scales between the small catchment (1-1000 ha) and large river systems scale (∼320,000 ha). In summary, existing research shows that the uplands contribute significant amounts of material into the stream and near stream zone, and that this imported material influences nutrient conditions in aquatic systems. These conclusions point out significant gaps in developing a complete understanding of the reactions of carbon and nitrogen as material is transported from the uplands through ephemeral and perennial channel networks. [ABSTRACT FROM AUTHOR]

Climate variability and change impact groundwater resources by altering recharge rates. In semi-arid Basin and Range systems, this impact is likely to be most pronounced in mountain system recharge (MSR), a process which constitutes a significant component of recharge in these basins. Despite its importance, the physical processes that control MSR have not been fully investigated because of limited observations and the complexity of recharge processes in mountainous catchments. As a result, empirical equations, that provide a basin-wide estimate of mean annual recharge using mean annual precipitation, are often used to estimate MSR. Here North American Regional Reanalysis data are used to develop seasonal recharge estimates using ratios of seasonal (winter vs. summer) precipitation to seasonal actual or potential evapotranspiration. These seasonal recharge estimates compared favorably to seasonal MSR estimates using the fraction of winter vs. summer recharge determined from isotopic data in the Upper San Pedro River Basin, Arizona. Development of hydrologically based seasonal ratios enhanced seasonal recharge predictions and notably allows evaluation of MSR response to changes in seasonal precipitation and temperature because of climate variability and change using Global Climate Model (GCM) climate projections. Results show that prospective variability in MSR depends on GCM precipitation predictions and on higher temperature. Lower seasonal MSR rates projected for 2050-2099 are associated with decreases in summer precipitation and increases in winter temperature. Uncertainty in seasonal MSR predictions arises from the potential evapotranspiration estimation method, the GCM downscaling technique and the exclusion of snowmelt processes. [ABSTRACT FROM AUTHOR]

RIPGIS-NET, an Environmental System Research Institute (ESRI's) ArcGIS 9.2/9.3 custom application, was developed to derive parameters and visualize results of spatially explicit riparian groundwater evapotranspiration (ETg), evapotranspiration from saturated zone, in groundwater flow models for ecohydrology, riparian ecosystem management, and stream restoration. Specifically RIPGIS-NET works with riparian evapotranspiration (RIP-ET), a modeling package that works with the MODFLOW groundwater flow model. RIP-ET improves ETg simulations by using a set of eco-physiologically based ETg curves for plant functional subgroups (PFSGs), and separates ground evaporation and plant transpiration processes from the water table. The RIPGIS-NET program was developed in Visual Basic 2005, .NET framework 2.0, and runs in ArcMap 9.2 and 9.3 applications. RIPGIS-NET, a pre- and post-processor for RIP-ET, incorporates spatial variability of riparian vegetation and land surface elevation into ETg estimation in MODFLOW groundwater models. RIPGIS-NET derives RIP-ET input parameters including PFSG evapotranspiration curve parameters, fractional coverage areas of each PFSG in a MODFLOW cell, and average surface elevation per riparian vegetation polygon using a digital elevation model. RIPGIS-NET also provides visualization tools for modelers to create head maps, depth to water table (DTWT) maps, and plot DTWT for a PFSG in a polygon in the Geographic Information System based on MODFLOW simulation results. [ABSTRACT FROM AUTHOR]

Water managers in arid and semiarid regions increasingly view treated wastewater (effluent) as an important water resource. Artificial recharge basins allow effluent to seep into the ground relieving stressed aquifers, however these basins frequently clog due to physical, chemical, and biological processes. Likewise effluent is increasingly used to maintain perennial base flow for dry streambeds, however, little is known about the impact of effluent on streambed hydraulic conductivity and stream-aquifer interactions. We address this issue by investigating: if a clogging layer forms, how the formation of a clogging layer alters stream-aquifer connections, and what hydrologic factors control the formation and removal of clogging layers. We focused on the Upper Santa Cruz River, Arizona where effluent from the Nogales International Waste Water Treatment Plant sustains perennial flow. Monthly sampling, along a 30 km river reach, was done with two foci: physical streambed transformations and water source identification using chemical composition. Historical dataset were included to provide a larger context for the work. Results show that localized clogging occurs in the Upper Santa Cruz River. The clogging layers perch the stream and shallow streambed causing desaturation below the streambed. With these results, a conceptual model of clogging is established in the context of a semiarid hydrologic cycle: formation during the hot premonsoon months when flow is nearly constant and removal by large flood flows (>10 m3/s) during the monsoon season. However, if the intensity of flooding during the semiarid hydrologic cycle is lessened, the dependent riparian area can experience a die off. This conceptual model leads us to the conclusion that effluent dominated riparian systems are inherently unstable due to the clogging process. Further understanding of this process could lead to improved ecosystem restoration and management. [ABSTRACT FROM AUTHOR]

Analysis of a typical semiarid mountain system recharge (MSR) setting demonstrates that geochemical tracers help resolve the location, rate, and seasonality of recharge as well as ground water flowpaths and residence times. MSR is defined as the recharge at the mountain front that dominates many semiarid basins plus the often-overlooked recharge through the mountain block that may be a significant ground water resource; thus, geochemical measurements that integrate signals from all flowpaths are advantageous. Ground water fluxes determined from carbon-14 (14C) age gradients imply MSR rates between 2 × 106 and 9 × 106 m3/year in the Upper San Pedro Basin, Arizona, USA. This estimated range is within an order of magnitude of, but lower than, prior independent estimates. Stable isotopic signatures indicate that MSR has a 65% ± 25% contribution from winter precipitation and a 35% ± 25% contribution from summer precipitation. Chloride and stable isotope results confirm that transpiration is the dominant component of evapotranspiration (ET) in the basin with typical loss of more than 90% of precipitation-less runoff to ET. Such geochemical constraints can be used to further refine hydrogeologic models in similar high-elevation relief basins and can provide practical first estimates of MSR rates for basins lacking extensive prior hydrogeologic measurements. [ABSTRACT FROM AUTHOR]

Relationships between discharge, land use, and nitrogen sources and sinks were developed using 5 years of synoptic sampling along a 300 km reach of the Rio Grande in central New Mexico. Average river discharge was higher during 2001 and 2005 ‘wet years’ (15 m3/s) than during the drought years of 2002-04 ‘dry years’ (8.9 m3/s), but there were no differences in nitrogen loading from wastewater treatment plants (WWTPs) which were the largest and most consistent source of nitrogen to the river (1,330 kg/day). Average total dissolved nitrogen (TDN) concentrations remained elevated for 180 km downstream of the Albuquerque WWTP averaging 1.2 mg/I in wet years and 0.52 mg/I in dry years. Possible explanations for the constant elevated TDN concentrations downstream of the major point source include reduced nitrogen retention capacity, minimal contact with riparian or channel vegetation, large suspended sediment loads, and low algal biomass. Somewhat surprisingly, agricultural return flows had lower average nitrogen concentrations than river water originally diverted to agriculture in both wet (0.81 mg/I) and dry years (0.19 mg/I), indicating that the agricultural system is a sink for nitrogen. Lower average nitrogen concentrations in the river during the dry years can be explained by the input of agricultural returns which comprise the majority of river flow in dry years. [ABSTRACT FROM AUTHOR]

A recurring obstacle for structural genomics is the expression of insoluble, aggregated proteins. In these cases, the use of alternative salvage strategies, like in vitro refolding, is hindered by the lack of a universal refolding method. To overcome this obstacle, fractional factorial screens have been introduced as a systematic and rapid method to identify refolding conditions. However, methodical analyses of the effectiveness of refolding reagents on large sets of proteins remain limited. In this study, we address this void by designing a fractional factorial screen to rapidly explore the effect of 14 different reagents on the refolding of 33 structurally and functionally diverse proteins. The refolding data was analyzed using statistical methods to determine the effect of each refolding additive. The screen has been miniaturized for automation resulting in reduced protein requirements and increased throughput. Our results show that the choice of pH and reducing agent had the largest impact on protein refolding. Bis-mercaptoacetamide cyclohexane (BMC) and tris (2-carboxyethylphosphine) (TCEP) were superior reductants when compared to others in the screen. BMC was particularly effective in refolding disulfide-containing proteins, while TCEP was better for nondisulfide-containing proteins. From the screen, we successfully identified a positive synergistic interaction between nondetergent sulfobetaine 201 (NDSB 201) and BMC on Cdc25A refolding. The soluble protein resulting from this interaction crystallized and yielded a 2.2 Å structure. Our method, which combines a fractional factorial screen with statistical analysis of the data, provides a powerful approach for the identification of optimal refolding reagents in a general refolding screen. [ABSTRACT FROM AUTHOR]

Natural variations in 87Sr/86Sr, [Ca]/[Sr], [Ba]/[Sr], and δ18O were used to investigate changing hydrologic flow paths during storm events in an 11.8 ha first-order watershed of the Hubbard Brook Experimental Forest. Throughfall, soil water, and stream water were sampled during several storm events and a single snowmelt event. Throughfall had 87Sr/86Sr, [Ca]/[Sr], and δ18O values that were distinct from other water types. Soil water was highly variable in composition but could be separated into three distinct elevation zones in the watershed with 87Sr/86Sr and [Ba]/[Sr] both increasing with elevation in the watershed. Changes in 87Sr/86Sr, [Ba]/[Sr], and δ18O of stream water during storm events yielded complementary information about watershed hydrologic flow paths. Traditional hydrograph separation using δ18O values indicated that new water was only a small component of storm flow (9-18%), whereas 87Sr/86Sr and [Ba]/[Sr] ratios indicated that shallow subsurface flow (soil water) contributed significantly to storm flow in amounts up to 40%, depending on soil moisture conditions. [ABSTRACT FROM AUTHOR]

The authors have previously shown that conditioning of the diaphragm for continuous bilateral pacing is a feasible and effective means of ventilation in patients with complete respiratory paralysis from high cervical (above C3) quadriplegia. The present study reports the long-term results of continuous diaphragmatic pacing. Twelve quadriplegia patients underwent bilateral phrenic nerve pacemaker placement and diaphragm conditioning from 1981 to 1987. Pacing was initiated at 11 Hz and progressively decreased to 7.1 Hz. A pulse train duration of 1.3 seconds for adults and 0.9 seconds for children was used. Long-term follow-up information obtained included pacing status (full-time, part-time, or mechanical ventilation), ventilation parameters, and social circumstances. Of the 12 patients, 6 continued to pace full time (mean 14.8 years); all were living at home. Three patients paced for an average of 1.8 years before stopping; two were institutionalized. One patient who paced full time for 6.5 years before lapsing to part time, lived at home. Two patients were deceased; one paced continuously for 10 years before his demise, the other stopped pacing after 1 year. Patients who stopped full-time pacing did so mainly for reasons of inadequate social or financial support or associated medical problems. AU patients demonstrated normal tidal volumes and arterial blood gases while pacing full time. Despite theoretical concerns about long-term nerve damage, no patient lost the ability to pace the phrenic nerve. Threshold currents did not increase over time (original/follow-up: 0.46/0.47 for right, 0.45/0.46 for left), nor did maximal currents (original/follow-up: 1.16/1.14 for right, 1.37/1.26 for left). This follow-up confirms that quadriplegic patients are able to meet long-term, full-time ventilation requirements using phrenic nerve stimulation of the conditioned diaphragm. Careful review of diaphragmatic pacing candidates with respect to associated medical conditions, social support, and motivation is essential for appropriate patient selection and successful long-term results. [ABSTRACT FROM AUTHOR]

A review of the electrical design of a r/inductively coupled phrenic nerve stimulator/or the diaphragm developed in our laboratories will be discussed. Modifications of the original circuit are based on long-term laboratory and clinical studies. A total implant battery powered stimulator was designed exclusively for animal studies to evaluate the effects of several stimulating parameters on diaphragm fatigue and neuromuscular structure. On the basis of these studies the optimum current level, stimulus frequency, respiratory rate, electrode configuration, and waveform were selected for clinical use to pace the diaphragm. A multiprogrammable dual output stimulator responsive to interrogation has been constructed and used in the experimental laboratory in anticipation of clinical application. There was an insignificant difference between the effect on neural structure or diaphragm function of stimulation with pulse width modulated constant voltage or with amplitude-modulated constant current. Demand pacing: maintenance of normal PACO2 by monitoring ET PACO2 with feedback to the diaphragm pacemaker to adjust the pacing rate has been successful in the experimental animal. [ABSTRACT FROM AUTHOR]

Recounts a clinical experience in the treatment of patients with chronic ventilatory insufficiency using phrenic nerve stimulation to diaphragm pacemakers. Historical background for the development of diaphragm pacing; Types of diseases treated by diaphragm pacemakers; Major complications of the approach.

An index of Socially Desirable Responding (SDR) was developed to measure the extent of impression management exhibited in applicant and incumbent samples when responding to a biodata form. The sample consisted of 2,262 incumbent sales representatives and 2,726 applicants for sales positions. Greater applicant versus incumbent SDR was observed, but differences varied across a priori item content areas. Impression management was minimal in item categories such as Previous Work Experience and Economic Motivation, but it was more prevalent in categories such as Work Style and Preferences and Self-Evaluations of Prior Sales Success. Using a smaller sample of 810 incumbents and 555 applicants, largely equated for experience, an item-keyed biodata inventory was developed for selection. When regression procedures were used to develop final keys, no comparable items existed across the keys from the two samples. SDR was more highly related to the applicant key than to the incumbent key. Results for option-keyed instruments developed and validated on the same samples were compared with the results associated with the item-keyed instruments, and the conclusions were similar. Implications for the development of biodata forms for selection are discussed. [ABSTRACT FROM AUTHOR]

Background Deficiencies in daily ward rounds are increasingly identified. A ward safety checklist has recently been devised to improve the fast-paced surgical ward round. Methods Over 2 weeks the morning post-take surgical ward round was evaluated using the ward safety checklist. In order to avoid the Hawthorne effect, doctors involved were not aware their performance was being observed. Results One hundred patient encounters were evaluated. The three phases of the card safety checklist showed statistically significant improvement but for many components compliance was below 100%. Conclusion Implementing this simple checklist has provided our unit with a starting point in how to overcome some of the deficiencies of the post-take surgical ward round. [ABSTRACT FROM AUTHOR]

Ultrathin metal films have a wide variety of applications, especially in microelectronics. A key method to deposit these films is plasma‐enhanced atomic layer deposition (PEALD), which is known for its ability to deposit thin films conformally and at relatively low temperatures. Building on the recent work, an improved recipe is reported on for the development of nickel PEALD technology, through which fully epitaxial nickel thin films are deposited. The effect of continuous heating on the phase structure and agglomeration in the metastable thin films is investigated in this paper. The variations of the phase structure are monitored via in situ synchrotron X‐ray diffraction, as well as optical roughness analysis. The temperature windows for phase transformation and particle formation are determined. It is noted that, after the hcp‐to‐fcc transformation and particle coalescence processes are complete, the particles reshape to acquire the thermodynamically stable shapes dictated by the Wulff theorem. Additionally, a crystallographic orientation relationship between the fcc particles and the sapphire substrate is observed, i.e., Ni (111)||Sapphire(002). Epitaxial nickel thin films are prepared via atomic layer deposition. These films have a hexagonal crystal structure, as dictated by the sapphire substrate. The nickel hexagonal phase is metastable at lower temperatures. The effect of continuous heating of the films to various temperatures is investigated, and the nature of phenomena such as phase transformation and particle formation is discussed. [ABSTRACT FROM AUTHOR]