Search

High mortality rates of cultured Pacific oysters (Crassostrea gigas) during the summer months have regularly occurred on oyster farms in British Columbia, Canada over the last 10 years, but little is known about the microbial and environmental conditions that contribute to such mortality events. The objective of the study was to determine correlative factors associated with the onset of a summer mortality event in oysters (mean ± SD shell height: 14.2 ± 0.5 mm) grown in suspended culture at four stocking densities (150, 300, 450, 600 oysters tray−1) from May 11 to September 17, 2018. Variables examined included both biotic (oyster growth, mortality, reproductive development, and microbiome (approximately every week); Vibrio and harmful algal species abundance) and abiotic (temperature, salinity, turbidity, dissolved oxygen, pCO2, pH, and aragonite saturation) ones. Both the absolute abundance of V. aestuarianus and the relative abundance of Vibrio spp. increased with observed oyster mortality and declining health. Mortality was highest on August 12 and associated with a prior period of elevated temperatures (i.e., increasing temperatures from early July to early August) and increased oyster growth/reproductive development. At that time, systemic mixed microbial infections and necrotic gill tissue in histological cross sections were observed in 19% of oysters that appeared healthy macroscopically. Cumulative percent mortalities per tray ranged from 34 to 75%, the highest-density trays having significantly less mortality and smaller shell width, shell length, and gonad length than lower-density trays. This study demonstrates the significant impact of summer mortality on Pacific oysters and highlights the biotic (host growth, reproductive development, and microbiome composition as well as Vibrio spp. abundance) and abiotic (water temperature) factors associated with the observed mortality in this region. [ABSTRACT FROM AUTHOR]

Aim: Lichens are often regarded as paradigms of mutualistic relationships. However, it is still poorly known how lichen‐forming fungi and their photosynthetic partners interact at a community scale. We explored the structure of fungus‐alga networks of interactions in lichen communities along a latitudinal transect in continental Antarctica. We expect these interactions to be highly specialized and, consequently, networks with low nestedness degree and high modularity. Location: Transantarctic Mountains from 76° S to 85° S (continental Antarctica). Time Period: Present. Major Taxa Studied: Seventy‐seven species of lichen‐forming fungi and their photobionts. Methods: DNA barcoding of photobionts using nrITS data was conducted in 756 lichen specimens from five regions along the Transantarctic Mountains. We built interaction networks for each of the five studied regions and a metaweb for the whole area. We explored the specialization of both partners using the number of partners a species interacts with and the specialization parameter d'. Network architecture parameters such as nestedness, modularity and network specialization parameter H2' were studied in all networks and contrasted through null models. Finally, we measured interaction turnover along the latitudinal transect. Results: We recovered a total of 842 interactions. Differences in specialization between partners were not statistically significant. Fungus‐alga interaction networks showed high specialization and modularity, as well as low connectance and nestedness. Despite the large turnover in interactions occurring among regions, network parameters were not correlated with latitude. Main Conclusions: The interaction networks established between fungi and algae in saxicolous lichen communities in continental Antarctica showed invariant properties along the latitudinal transect. Rewiring is an important driver of interaction turnover along the transect studied. Future work should answer whether the patterns observed in our study are prevalent in other regions with milder climates and in lichen communities on different substrates. [ABSTRACT FROM AUTHOR]

This article explores the benefits of arts-based interventions for refugees and asylum seekers in the UK who are experiencing mental health issues and trauma. The report highlights the high levels of stress, trauma, and mental health problems that refugees often face due to displacement and resettlement experiences. It also discusses the role of art in promoting mental health and wellbeing among refugees, citing various organizations and projects that have utilized art as a means of generating therapeutic benefits. The report emphasizes the importance of funding, resources, and research to further develop and evaluate the effectiveness of art-based interventions. Overall, arts organizations can have a positive impact on the mental health and wellbeing of refugees and asylum seekers, contributing to social cohesion and benefiting society as a whole. [Extracted from the article]

Improving the productivity of the allied health workforce is a global priority in response to the increasing incidence of chronic disease, associated healthcare costs, and insufficient workforce volume. Team-based healthcare, specifically allied health transdisciplinary teams, might be a solution to improve the utilization of workforce while maintaining high-quality and value-based healthcare. Allied health transdisciplinary teams can be a valuable solution in settings where care is delivered by different allied health professionals. Transdisciplinary teams embrace overlapping skills and blur traditional professional boundaries, allowing one professional to deliver certain aspects of care without eroding the skills and knowledge that each profession offers. The objective of this scoping review is to systematically examine and map the characteristics, outcomes, facilitators, and barriers of contemporary allied health transdisciplinary models of care that have been implemented in hospital settings. The scoping review was guided by the Joanna Briggs Institute methodology and reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Three screening rounds were completed by two independent reviewers. Included sources were synthesized using descriptive and tabular analysis. Nine studies that evaluated hospital-based allied health transdisciplinary teams were included. One study was a randomized controlled trial, five were experimental quantitative studies, two utilized qualitative analyses, and one was a conference abstract. Most studies reported improvements in time-efficiency, quality of care, and positive stakeholder perceptions. One study reported labor and capital cost savings. Barriers and facilitators of transdisciplinary teams were categorized by the authors as person/interpersonal, workflow, organizational or implementation factors. This review presents some evidence that demonstrates the potential of hospital-based allied health transdisciplinary teams, however high-quality evidence is scarce. Further primary research should focus on stakeholder perceptions, and labor and capital cost outcomes. [ABSTRACT FROM AUTHOR]

Simple Summary: Temperatures are increasing globally, but polar regions (including Antarctica) are warming much faster than the rest of the globe. Increased temperatures in Antarctica can impact the distribution and performance of plants, the majority of which on this continent are mosses. This study aims to investigate whether Bryum argenteum var. muticum, a moss species found in Antarctica, is capable of acclimation (adjustment of its physiology, specifically photosynthesis and respiration) to increased temperatures. We used short-term warming experiments that mimicked heatwaves and compared them to seasonal rates of photosynthesis and respiration in order to better understand how resilient this important moss species is to climate change. We found that this moss can acclimate very quickly (within 7 days) by increasing its photosynthesis (carbon gain). This shows that B. argenteum is highly resilient, and it may potentially benefit from short- and long-term climatic changes. Climate warming in Antarctica involves major shifts in plant distribution and productivity. This study aims to unravel the plasticity and acclimation potential of Bryum argenteum var. muticum, a cosmopolitan moss species found in Antarctica. By comparing short-term, closed-top chamber warming experiments which mimic heatwaves, with in situ seasonal physiological rates from Cape Hallett, Northern Victoria Land, we provide insights into the general inherent resilience of this important Antarctic moss and into its adaptability to longer-term threats and stressors associated with climate change. Our findings show that B. argenteum can thermally acclimate to mitigate the effects of increased temperature under both seasonal changes and short-term pulse warming events. Following pulse warming, this species dramatically increased its carbon uptake, measured as net photosynthesis, while reductions in carbon losses, measured as dark respiration, were not observed. Rapid growth of new shoots may have confounded the effects on respiration. These results demonstrate the high physiological plasticity of this species, with acclimation occurring within only 7 days. We show that this Antarctic moss species appears to have a high level of resilience and that fast acclimation processes allow it to potentially benefit from both short-term and long-term climatic changes. [ABSTRACT FROM AUTHOR]

Prices of the highly liquid S&P 500 exchange-traded fund (SPY) and the E-mini future (ES) respond to macroeconomic announcement surprises within five milliseconds, with trading intensity increasing over 100-fold following the news release. However, profits from trading quickly are relatively small, roughly $\$$ 19,000 (⁠ $\$$ 50,000) per event for SPY (ES). Although the speed of information incorporation has increased in recent years, profits have not. Order flow has become less informative, consistent with prices responding directly to news rather than indirectly through trading. Our evidence indicates that low-latency liquidity demanders do not benefit materially from short-term monopolistic access to information. Received April 18, 2017; editorial decision November 4, 2017 by Editor Andrew Karolyi. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online. [ABSTRACT FROM AUTHOR]

Against a changing climate, the development of evidence‐based and progressive conservation policies depends on robust and quantitative baseline studies to resolve habitat natural variability and rate of change. Despite Antarctica's significant role in global climate regulation, climate trend estimates for continental Antarctica are ambiguous due to sparse long‐term in situ records. Here, we present the longest, spatially explicit survey of Antarctic vegetation by harmonizing historic vegetation mapping with modern remote sensing techniques. In 1961, E. D. Rudolph established a permanent survey plot at Cape Hallett, one of the most botanically diverse areas along the Ross Sea coastline, harboring all known types of non‐vascular Antarctic vegetation. Following a survey in 2004 using ground‐based photography, we conducted the third survey of Rudolph's Plot in 2018 using near‐ground remote sensing and methodologies closely mirroring the two historic surveys to identify long‐term changes and trends. Our results revealed that the vegetation at Cape Hallett remained stable over the past six decades with no evidence of transformation related to a changing climate. Instead, the local vegetation shows strong seasonal phenology, distribution patterns that are driven by water availability, and steady perennial growth of moss. Given that East Antarctica is at the tipping point of drastic change in the near future, with biological change having been reported at certain locations, this record represents a unique and potentially the last opportunity to establish a meaningful biological sentinel that will allow us to track subtle yet impactful environmental change in terrestrial Antarctica in the 21st century. Plain Language Summary: In early 2022, record‐breaking high temperatures were recorded all over Antarctica, sparking concerns about the icy continent's future. Although the effects of climate change have been observed in West Antarctica, much less observation is available for East Antarctica, where almost 90% of the Antarctic ice mass is located. It is now, that East Antarctica is at a tipping point for change, and it is now, that we need to establish progressive conservation measures. What is at stake? The vegetation in East Antarctica is distinct. Any organism that managed to survive here has highly specialized traits, and we only find lichens, mosses, cyanobacteria, and green algae. Especially the mosses are used biological sentinels because they live long and with high specificity. However, because they grow so slowly, any attempt to monitor variation in their fitness has to span decades rather than years or even seasons. This constitutes a key problem when trying to understand the natural dynamics of a functional ecosystem in East Antarctica. By applying machine learning and advanced statistics to modern aerial survey data as well as historic vegetation maps (the oldest in Antarctica, from 56 years ago), we created a unique harmonized data set and gained unique ecological insight. This allows us to establish a biological sentinel for change in East Antarctica, just before it is too late. Key Points: The longest plant cover record in Antarctica revealed Cape Hallett, unlike sites around the Peninsula, unaffected by climate changeAntarctic vegetation shows high plasticity, for which most of the changes can be explained by seasonal variation and water availabilityBy harmonizing historic and modern monitoring methodologies we establish a sustainable biological sentinel for change in East Antarctica [ABSTRACT FROM AUTHOR]

Disaster recovery is not a time of exception, it is a time when existing social, economic, and racial inequalities are reproduced and exacerbated. Housing institutions can amplify inequality during disaster recovery. We use quantitative methods to ask whether evictions increase during disaster recovery periods in four states. We stratify our case selection by the type of statutory protections for landlords and tenants in state law. In three cases that have pro-business or a mixture of pro-business and tenant protections, we find strong, significant increases in eviction rates in disaster-affected neighborhoods relative to neighborhoods in adjacent areas with no disaster declaration. By contrast, in the case that has primarily tenant protections, there is no statistically significant rise in evictions following the disaster. We conclude that tenant protections are not sufficient to prevent swift increases in evictions following disasters in states with a policy environment that is also characterized by landlord protections. We close with policy recommendations to prevent evictions after disasters, and suggestions for further research. [ABSTRACT FROM AUTHOR]

Background: ReIMAGINE aims to improve the current prostate specific antigen (PSA)/biopsy risk stratification for prostate cancer (PCa) and develop a new image-based method (with biomarkers) for diagnosing high/low risk PCa in men. ReIMAGINE's varied patient and public involvement (PPI) and engagement (PE) strategy maximises the impact of its scientific output by informing and shaping the different stages of research. Aims: Through including the voice of patients and the public, the ReIMAGINE Consortium aims to translate these different perspectives into the design and implementation process. This will improve the overall quality of the research by: reflecting the needs and priorities of patients and the public, ensuring methods and procedures are feasible and appropriate ensuring information is relevant and accessible to those being recruited to the study identifying dissemination channels relevant to patients/the public and developing outputs that are accessible to a lay audience With support from our patient/user groups, the ReIMAGINE Consortium aims to improve our ability to derive prognostic information and allocate men to the most appropriate and effective therapies, using a novel image-based risk stratification with investigation of non-imaging biomarkers. Findings: We have been working with patients and the public from initiation of the project to ensure that the research is relevant to men and their families. Our PPI Sub-Committee, led by a PCa patient, has been involved in our dissemination strategy, outreach activities, and study design recommendations. For example, the sub-committee have developed a variety of informative videos relevant and accessible to those being recruited, and organised multiple online research engagement events that are accessible to a lay audience. As quoted by one of the study participants, "the more we present the benefits and opportunities to patients and the public, the more research commitment we obtain, and the sooner critical clinical questions such as PCa diagnostics will be addressed". Plain English Summary: One in eight men will be diagnosed with prostate cancer (PCa). Most will not die of it, but our ability to identify those men whose cancer poses the greatest threat to life has, thus far, been poor. Some men are diagnosed with small cancers which will never cause them a problem, some will have treatment which is unnecessary, others will have their cancers missed, and others will be misclassified as either having low risk cancer and will therefore miss out on the appropriate treatment, or told their cancer is high risk and have unnecessary treatment. Nowhere else in modern medicine are these errors of over-diagnosis, over-treatment, missed-diagnoses, and poor risk-stratification more common. The ReIMAGINE Consortium has been developed to undertake discoveries that will correct these four key errors in the PCa diagnostic pathway. We will investigate how to best identify which men have, or will develop, aggressive prostate cancer using imaging combined with advanced biomarker analyses of blood and urine (i.e., OMICs technologies such as whole genome sequencing, targeted sequencing (e.g.: = , methylation). We will achieve this by building on established partnerships between patients, advocacy organisations, clinicians, imaging experts, molecular biologists, methodologists, and a broad range of industrial partners. The Patient and Public Involvement (PPI) sub-committee is an integral part of the study workflow, contributing to study design and recruitment, results analysis, and dissemination. The committee, led by a funded PPI co-ordinator and a patient chair, have given invaluable insight into the study modifications due to COVID-19 restrictions. [ABSTRACT FROM AUTHOR]

There is considerable scientific interest as to how terrestrial biodiversity in Antarctica might respond, or be expected to respond, to climate change. The two species of vascular plant confined to the Antarctic Peninsula have shown clear gains in density and range extension. However, little information exists for the dominant components of the flora, lichens and bryophytes. One approach has been to look at change in biodiversity using altitude as a proxy for temperature change and previous results for Livingston Island suggested that temperature was the controlling factor. We have extended this study at the same site by using chlorophyll fluorometers to monitor activity and microclimate of the lichen, Usnea aurantiaco-atra, and the moss, Hymenoloma crispulum. We confirmed the same lapse rate in temperature but show that changes in water relations with altitude is probably the main driver. There were differences in water source with U. aurantiaco-atra benefitting from water droplet harvesting and the species performed substantially better at the summit. In contrast, activity duration, chlorophyll fluorescence and photosynthetic modelling all show desiccation to have a large negative impact on the species at the lowest site. We conclude that water relations are the main drivers of biodiversity change along the altitudinal gradient with nutrients, not measured here, as another possible contributor. [ABSTRACT FROM AUTHOR]

Climatically extreme regions such as the polar deserts of the McMurdo Dry Valleys (78° S) in Continental Antarctica are key areas for a better understanding of changes in ecosystems. Therefore, it is particularly important to analyze and communicate current patterns of biodiversity in these sensitive areas, where precipitation mostly occurs in form of snow and liquid water is rare. Humidity provided by dew, clouds, and fog are the main water sources, especially for rock-dwelling crustose lichens as one of the most common vegetation-forming organisms. We investigated the diversity and interaction specificity of myco-/photobiont associations of 232 crustose lichen specimens, collected along an elevational gradient (171–959 m a.s.l.) within the McMurdo Dry Valleys. The mycobiont species and photobiont OTUs were identified by using three markers each (nrITS, mtSSU, RPB1, and nrITS, psbJ-L, COX2). Elevation, positively associated with water availability, turned out to be the key factor explaining most of the distribution patterns of the mycobionts. Pairwise comparisons showed Lecidea cancriformis and Rhizoplaca macleanii to be significantly more common at higher elevations and Carbonea vorticosa and Lecidea polypycnidophora at lower elevations. Lichen photobionts were dominated by the globally distributed Trebouxia OTU, Tr_A02 which occurred at all habitats. Network specialization resulting from myco-/photobiont bipartite network structure varied with elevation and associated abiotic factors. Along an elevational gradient, the spatial distribution, diversity, and genetic variability of the lichen symbionts appear to be mainly influenced by improved water relations at higher altitudes. [ABSTRACT FROM AUTHOR]

In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in‐stream water quality and process interactions, soil health and land management, and (peri‐)urban areas. In addition, we provide insights into the contemporary challenges in the practices of watershed water quality modeling, including quality control of monitoring data, model parameterization and calibration, uncertainty management, scale mismatches, and provisioning of modeling tools. Finally, we make three recommendations to provide a path forward for improving watershed water quality modeling science, infrastructure, and practices. These include building stronger collaborations between experimentalists and modelers, bridging gaps between modelers and stakeholders, and cultivating and applying procedural knowledge to better govern and support water quality modeling processes within organizations. Key Points: We assess four potential improvements in water quality modeling: environmental interfaces, in‐stream processes, soil health, and urban areasChallenges include data quality control, model calibration, uncertainty management, scale mismatches, and model tool provisionModelers need to strengthen connections with experimentalists and stakeholders and cultivate procedural knowledge for modeling processes [ABSTRACT FROM AUTHOR]

During austral summer field seasons between 1999 and 2018, we sampled at 91 locations throughout southern Victoria Land and along the Transantarctic Mountains for six species of endemic microarthropods (Collembola), covering a latitudinal range from 76.0°S to 87.3°S. We assembled individual mitochondrial cytochrome c oxidase subunit 1 (COI) sequences (n = 866) and found high levels of sequence divergence at both small (<10 km) and large (>600 km) spatial scales for four of the six Collembola species. We applied molecular clock estimates and assessed genetic divergences relative to the timing of past glacial cycles, including collapses of the West Antarctic Ice Sheet (WAIS). We found that genetically distinct lineages within three species have likely been isolated for at least 5.54 My to 3.52 My, while the other three species diverged more recently (<2 My). We suggest that Collembola had greater dispersal opportunities under past warmer climates, via flotation along coastal margins. Similarly increased opportunities for dispersal may occur under contemporary climate warming scenarios, which could influence the genetic structure of extant populations. As Collembola are a living record of past landscape evolution within Antarctica, these findings provide biological evidence to support geological and glaciological estimates of historical WAIS dynamics over the last ca. 5 My. [ABSTRACT FROM AUTHOR]

This study has examined the effect of water on the electrodeposition of copper from a deep eutectic solvent (DES). Initial physiochemical measurements showed that the viscosity and resistivity of the DES decreased with added water in the range 1–15 wt%. This reduction in viscosity resulted in an increase in the mass transfer limiting current, without narrowing the electrochemical window or altering the speciation of the copper chloro-complexes. This shows that metal deposition rates can be increased by water additions. The effect of water on the electrochemical kinetics of the Cu(I) and Cu(II) chloro-complexes was also studied. It was found that the kinetics of the Cu(I)/Cu(0) reaction is largely irreversible, while the Cu(II)/Cu(I) couple was quasi-reversible. The rate constants for Cu(II)/Cu(I) and Cu(I)/Cu(0) reactions were accelerated by water additions, although the transfer coefficients remained unchanged. The effect of increased deposition rates, electrolyte conductivity and reaction kinetics on deposit uniformity was estimated and subsequently verified by experiments. It was found that, although higher deposition rates could be achieved, the thickness of the deposit was non-uniform since the Wagner numbers remained relatively low. [ABSTRACT FROM AUTHOR]

Many investors confine their mutual fund holdings to a single fund family either for simplicity or through restrictions placed by their retirement savings plan. We find evidence that mutual fund returns are more closely correlated within than between fund families. As a result, restricting investment to one fund family leads to a greater total portfolio risk than diversifying across fund families. We examine the sources of this increased correlation and find that it is due primarily to common stock holdings, but is also more generally related to families having similar exposures to economic sectors or industries. Fund families also show a propensity to focus on high or low risk strategies, which leads to a greater dispersion of risk across restricted investors. An investor considering adding an additional fund, either in the same family or outside the family, would need to believe the inside fund offered an extra 50 to 70 basis points to have the same Sharpe ratio. [ABSTRACT FROM AUTHOR]

Early access to stock recommendations provides brokerage firm clients with incremental investment value. After controlling for transaction costs, purchasing (selling) quickly following upgrades (downgrades) results in average two-day returns of 1.02% (1.50%). Short-term profit opportunities persist for two hours following the pre-market release of new recommendations. The results are robust within sub-periods and a calendar-based strategy produces positive abnormal daily returns of over 10 basis points, or roughly 30% annualized. Recommending firms' market makers shift their quotes accordingly, providing indirect evidence that clients make use of the informational advantage that arises from analysts' opinion changes. [ABSTRACT FROM AUTHOR]

This paper studies the impact of trading on government bond prices surrounding the release of macroeconomic news. The results show a significant increase in the informational role of trading following economic announcements, which suggests the release of public information increases the level of information asymmetry in the government bond market. The informational role of trading is greater after announcements with a larger initial price impact, and the relation is associated with the surprise component of the announcement and the precision of the public information. The results provide evidence that government bond order flow reveals fundamental information about riskless rates. [ABSTRACT FROM AUTHOR]

This paper uses intraday data from the interdealer government bond market to investigate the effects of scheduled macroeconomic announcements on prices, trading volume, and bid-ask spreads. We find that 17 public news releases, as measured by the surprise in the announced quantity, have a significant impact on the price of at least one of the following instruments: a three-month bill, a two-year note, a 10-year note, and a 30-year bond. These effects vary significantly according to maturity. Public news can explain a substantial fraction of price volatility in the aftermath of announcements, and the adjustment to news generally occurs within one minute after the announcement. We document significant and persistent increases in volatility and trading volume after the announcements. Bid-ask spreads, on the other hand, widen at the time of the announcements, but then revert to normal values after five to 15 minutes. The effects that we document have relevant implications for yield curve modeling and for the microstructure of bond markets. [ABSTRACT FROM AUTHOR]

Reports that an optically pumped intersubband laser generator is proposed in which the continuum states above an Al[sub 0.2]Ga[sub 0.8]As-GaAs-Al[sub 0.2]Ga[sub 0.8]As single quantum well with a width of L=17nm serve as the highest level in a four-level laser system. Flexibility in the choice of pumping source; Simplification of the device fabrication.

Derivatives valuation and risk management involve heavy use of quantitative models. To develop a quantitative assessment of model risk as it affects the basic option writing strategy that might be followed by a financial institution, we conduct an empirical simulation, with and without hedging, using data from 1976 to 1996. Results indicate that imperfect models and inaccurate volatility forecasts create sizable risk exposure for option writers. We consider to what extent the damage due to model risk can be limited by pricing options using a higher volatility than the best estimate from historical data. [ABSTRACT FROM AUTHOR]

Daily data from interdealer government bond brokers are examined for tax and liquidity effects. We use two approaches to create cash flow matching portfolios of similar securities and look for pricing discrepancies associated with liquidity or tax effects. We also look for the presence of tax and liquidity effects by including a liquidity term when fitting a cubic spline to the after-tax yield curve. We find evidence of tax timing options and liquidity effects. However, the effects are much smaller than previously reported and the effects of liquidity are primarily due to high volume bonds with long maturities. [ABSTRACT FROM AUTHOR]

Summary: Chronosequences at the forefront of retreating glaciers provide information about colonization rates of bare surfaces. In the northern hemisphere, forest development can take centuries, with rates often limited by low nutrient availability. By contrast, in front of the retreating Pia Glacier (Tierra del Fuego, Chile), a Nothofagus forest is in place after only 34 yr of development, while total soil nitrogen (N) increased from near zero to 1.5%, suggesting a strong input of this nutrient.We measured N‐fixation rates, carbon fluxes, leaf N and phosphorus contents and leaf δ15N in the dominant plants, including the herb Gunnera magellanica, which is endosymbiotically associated with a cyanobacterium, in order to investigate the role of N‐fixing and mycorrhizal symbionts in N‐budgets during successional transition.G. magellanica presented some of the highest nitrogenase activities yet reported (potential maximal contribution of 300 kg N ha−1 yr−1). Foliar δ15N results support the framework of a highly efficient N‐uptake and transfer system based on mycorrhizas, with c. 80% of N taken up by the mycorrhizas potentially transferred to the host plant.Our results suggest the symbiosis of G. magellanica with cyanobacteria, and trees and shrubs with mycorrhizas, to be the key processes driving this rapid succession. [ABSTRACT FROM AUTHOR]

During incomplete skeletal muscle recovery from ischemia, such as that occurs with critical limb ischemia, the temporal relationship between recovery of muscle capillary perfusion and contractile function is poorly defined. We examined this relationship in BALB/cJ mice (N = 24) following unilateral hindlimb ischemia (HLI), which pre-clinically mimics the myopathy observed in critical limb ischemia patients. Specifically, we examined this relationship in two phenotypically distinct muscles (i.e., "oxidative" soleus – Sol and "glycolytic" extensor digitorum longus – EDL) 14- or 56-days after HLI. Although overall limb blood flow (LDPI) reached its' recovery peak (48% of control) by HLI d14, the capillary networks in both the Sol and EDL (whole mount confocal imaging) were disrupted and competent muscle capillary perfusion (perfused lectin+μm2/muscle μm2) remained reduced. Interestingly, both Sol and EDL muscles recovered their distinct capillary structures and perfusion (Con Sol; 0.056 ± 0.02 lectin+μm2/muscle μm2, and Con EDL; 0.039 ± 0.005 lectin+μm2/muscle μm2) by HLI d56 (Sol; 0.062 ± 0.011 lectin+μm2/muscle μm2 and EDL; 0.0035 ± 0.005 lectin+μm2/muscle μm2), despite no further improvement in limb blood flow (LDPI). Both muscles suffered severe myopathy, indicated by loss of dystrophin positive immunostaining and the absence of stimulation induced isometric force production at HLI d14. Dystrophin immunofluorescence returned at HLI d56, although neither myofiber CSA (μm2) nor isometric force production (58 and 28% sustained deficits, Sol and EDL, respectively) recovered completely in either muscle. In summary, we reveal that the temporal relationship between the restoration of muscle capillary perfusion and functional ischemic skeletal muscle regeneration favors competent muscle capillary perfusion recovery in BALB/c mice in a phenotypically non-distinct manner. [ABSTRACT FROM AUTHOR]

Psychology research identifies extraversion as the personality trait most closely associated with leadership emergence. We examine executive extraversion, as measured by speech patterns during conference calls, and find extraverts experience significant career benefits. Controlling for executive and firm characteristics, including firm fixed effects, we find that extraverted CEOs and CFOs earn 6–9 percent higher salaries. Moreover, extraverted CEOs are less likely to experience job turnover, have longer tenures, serve on more outside boards, and hold directorships at larger firms, and extraverted CFOs are more likely to be promoted to CEO. Executive extraversion is also linked with firm outcomes. Analyzing a sample of manager transitions, we find that increases in CEO extraversion are associated with improvements in investor recognition and sales growth. Further, extraverted CEOs are associated with higher acquisition announcement returns. Our findings highlight the role of personality traits in explaining executive career and firm outcomes. JEL Classifications: G14. [ABSTRACT FROM AUTHOR]

Restricted Hartree–Fock calculations at the double-zeta level are performed for the closed-shell isoelectronic molecules B12H-212, CB11H-12 , and 1,12-C2 B10 H12 . The geometries are optimized and the vibrational spectra are obtained. The behavior of the molecular orbitals upon carbon substitution is analyzed. The results are compared with the available experimental and theoretical results from the literature. The main features of the electronic structure are correctly described at this level of approximation. The new results can aid in the interpretation of photoemission, infrared absorption, and Raman scattering experiments on these molecules. [ABSTRACT FROM AUTHOR]

Describes a technique for generating homogenous volume of ionized gas and for making time-resolved measurements of its electron density. Absolute photoionization coefficients for a number of molecules; Use of a microwave interferometer; Description of photoionization efficiency by the two-photon ionization coefficient.

Background and aims: Due to the well-known importance of biocrusts for several ecosystem properties linked to soil functionality, we aim to go deeper into the physiological performance of biocrusts components. Possible functional convergences in the physiology of biocrust constituents would facilitate the understanding of both species and genus distributional patterns and improve the possibility of modelling their response to climate change.Methods: We measured gas exchange in the laboratory under controlled conditions of lichen- and moss-dominated biocrusts from four environmentally different locations in Europe. Field data were used to determine the natural hydration sources that drive metabolic activity of biocrusts.Results: Our results show different activity drivers at the four sites. Within site analyses showed similar C fixation for the different crust types in the three sites without hydric stress whilst light use related parameters and respiration at 15 °C were similar in the between sites analyses. There were significant differences in water relations between the biocrusts types, with moss-dominated crusts showing higher maximum and optimum water contents.Conclusions: The functional type approach for biocrusts can be justified from a physiological perspective when similar values are found in the within and between site analyses, the latter indicating habitat independent adaptation patterns. Our multi-site analyses for biocrusts functional performance provide comparisons of C fluxes and water relations in the plant-soil interface that will help to understand the adaptation ability of these communities to possible environmental changes. [ABSTRACT FROM AUTHOR]

Lichens are one of the common dominant biota in biological soil crusts (biocrusts), a community that is one of the largest in extent in the world. Here we present a summary of the main features of the lifestyle of soil crust lichens, emphasizing their habitat, ecophysiology and versatility. The soil crust is exposed to full light, often to high temperatures and has an additional water source, the soil beneath the lichens. However, despite the open nature of the habitat the lichens are active under shady and cooler conditions and avoid climate extremes of high temperature and light. In temperate and alpine habitats they can also be active for long periods, several months in some cases. They show a mixture of physiological constancy (e.g. similar activity periods and net photosynthetic rates) but also adaptations to the habitat (e.g. the response of net photosynthesis to thallus water content can differ for the same lichen species in Europe and the USA and some species show extensive rhizomorph development). Despite recent increased research, aspects of soil crust ecology, for example under snow, remain little understood. [ABSTRACT FROM AUTHOR]

Background/objectives: Zinc is a negative acute-phase reactant; hence, its concentration decreases in the presence of inflammation. There is no current consensus on how to control for the effect of inflammation on serum zinc, which has implications for accurate estimates of population-level zinc status. We aimed to measure the association between inflammation and serum zinc concentrations and to compare the means and the prevalence of zinc deficiency using unadjusted and inflammation-adjusted serum zinc concentrations among Congolese children.Subjects/methods: Non-fasting blood was collected in the afternoon in trace element-free vacutainers from 744 apparently healthy children aged 6-59 months in the Democratic Republic of the Congo. Serum was analyzed for zinc, C-reactive protein (CRP) and α-1 acid glycoprotein (AGP) for 665 children with complete data for all three biomarkers. Linear regression was used to generate correction factors (CFs) based on three stages of inflammation: incubation (CRP >5 mg/l and normal AGP), early convalescence (CRP >5 mg/l and AGP >1 g/l) and late convalescence (AGP >1 g/l and normal CRP), relative to no inflammation.Results: Overall unadjusted mean±s.d. serum zinc concentration was 9.4±2.1 μmol/l. Study-generated CFs (95% confidence interval) for incubation, early and late convalescence were 1.01 (0.88, 1.14), 1.15 (1.11, 1.21) and 1.07 (1.03, 1.11), respectively. After applying the CFs, overall adjusted mean±s.d. serum zinc concentration was 10.1±2.2 μmol/l, and prevalence of zinc deficiency (<8.7 μmol/l) decreased from 35% (n=234/665) to 24% (n=160/665).Conclusions: Adjustment of zinc concentrations for inflammation is warranted when assessing population-level zinc status.European Journal of Clinical Nutrition advance online publication, 23 August 2017; doi:10.1038/ejcn.2017.127. [ABSTRACT FROM AUTHOR]

Within Antarctica there are large gradients both in climate and in vegetation which offer opportunities to investigate links between the two. The activity (% total time active) of lichens and bryophytes in hydric and xeric environments was monitored at Livingston Island (62°39'S). This adds a northern site with a maritime, cloudy climate to previous studies in the southern Antarctic Peninsula and the Dry Valleys (78°S). Annual activity increases northwards from less than 1% to nearly 100%. There is a major and consistent difference between hydric sites which, with snow melt, can be 100% active in summer months even in the Dry Valleys, and xeric sites which, depending on precipitation, rarely exceed 80% activity even at Livingston Island. Mosses dominate hydric sites and lichens the xeric sites all along the gradient. Mean temperatures when active are 2-4°C at all sites, as liquid water is required. Light is a potential major stress reaching 880 µmol m-2 s-1 when active in continental sites. The lack of extremes in temperatures and light combined with high activity levels means that summer at Livingston Island is one of the better sites for lichen and bryophyte growth in the world. [ABSTRACT FROM AUTHOR]

Following the retreat of a glacier, microbial colonization paves the way for future plant successions as nutrients are gradually introduced into the ecosystem. Characterizing the dynamics of this initial microbial colonization process is a key to understanding how these rapidly receding glacier areas are colonized. This study examines primary successions of bacteria, fungi and algae in two glacier forefields chronosequences on opposite slopes of Cordillera Darwin (Tierra del Fuego, Chile). Both slopes (southern and northern) show contrasting climate factors along with rapid rates of plant succession. Through a high-throughput sequencing approach, we identified Cyanobacteria as the dominant bacteria in younger soils close to the glacier terminus, whereas abundances of Alphaproteobacteria and Acidobacteria increased with soil surface age. Lichen-forming fungi and parasitic fungi were the most abundant fungal groups in younger succession stages, while saprophytic and mycorrhizal orders dominated later stages. The order Prasiolales predominated algal communities close to the glacier terminus, while Microthamniales and Chlamydomonadales orders dominated subsequent succession stages. Our observations reflect a changing community structure over time of the three microbial groups examined, and the replacement of taxa during the succession. Changes in composition are especially marked between the youngest succession states and subsequent ones in both forefields. Simultaneous analysis of bacterial, fungal and algal communities revealed the different trajectories of the three groups, with bacterial and fungal communities showing more marked succession patterns. Our results point to more relevant roles for bacteria at the initial stages of succession, while fungi could play a dominant role over bacteria as succession progresses. The ubiquity of algal taxa along the chronosequences was also observed. The two glacier forefields showed different microbial temporal dynamics, indicating that local factors affect the rate of microbial community assembly and, consequently, drive the primary succession process. [ABSTRACT FROM AUTHOR]

Periodic preventive maintenance (PPM) is a significant measure to ensure reliable operation of the modular multilevel converter (MMC), but to date has always been neglected in the reliability evaluation. A mathematical reliability model of MMC considering PPM is proposed in this paper. The model is derived rigorously by the reliability function and finally described by the indices equivalent failure rate and the forced outage rate. Two operation modes related to redundant submodules are considered and described by the standby model and k-out-of-n model, respectively. Employing this model, we can analyze the sensitivity of reliability to redundancy and maintenance interval and provide some reliability indices for planning, which is especially valuable for the offshore cases. The necessity of the considered PPM and the effectiveness of the proposed model are verified by case studies. A method to include PPM in reliability modeling is provided. [ABSTRACT FROM PUBLISHER]

A key challenge in understanding the feedback mechanism of active galactic nucleus (AGN) in Brightest Cluster Galaxies (BCGs) is the inherent rarity of catching an AGN during its strong outburst phase. This is exacerbated by the ambiguity of differentiating between AGN and clusters in X-ray observations. If there is evidence for an AGN then the X-ray emission is commonly assumed to be dominated by the AGN emission, introducing a selection effect against the detection of AGN in BCGs. In order to recover these 'missing' clusters, we systematically investigate the colour-magnitude relation around some ~3500 ROSAT All-Sky Survey selected AGN, looking for signs of a cluster red sequence. Amongst our 22 candidate systems, we independently rediscover several confirmed systems, where a strong AGN resides in a central galaxy. We compare the X-ray luminosity to red sequence richness distribution of our AGN candidate systems with that of a similarly selected comparison sample of ~1000 confirmed clusters and identify seven 'best' candidates (all of which are BL Lac objects), where the X-ray flux is likely to be a comparable mix between cluster and AGN emission. We confirm that the colours of the red sequence are consistent with the redshift of the AGN, that the colours of the AGN host galaxy are consistent with AGN, and, by comparing their luminosities with those from our comparison clusters, confirm that the AGN hosts are consistent with BCGs. [ABSTRACT FROM AUTHOR]

Introduction Hemoglobin (Hb) concentration is often measured in global health and nutrition surveys to determine anemia prevalence using a portable hemoglobinometer such as the Hemocue® Hb 201+. More recently, a newer model was released (Hemocue Hb 301) utilizing slightly different methods to measure Hb as compared to the older model. The objective was to measure bias and concordance between Hb concentrations using the Hemocue Hb 301 and Hb 201+ models in a rural field setting. Methods Hemoglobin (Hb) concentration was measured using one finger prick of blood (approximately 10 μL) from 175 Cambodian women (18-49 years) using three Hemocue Hb 201+ and three Hb 301 machines. Bias and concordance were measured and plotted. Results Overall, mean ± SD Hb concentration was 116 ± 13 g/L using the Hb 201+ and 118 ± 12 g/L using the Hb 301; and anemia prevalence (Hb < 120 g/L) was 58% ( n = 102) and 58% ( n = 101), respectively. Overall bias ± SD was 2.0 ± 10.5 g/L and concordance (95% CI) was 0.63 (0.54, 0.72). Despite the 2 g/L bias detected between models, anemia prevalence was very similar in both models. Conclusions The two models measured anemia prevalence comparably in this population of women in rural Cambodia. [ABSTRACT FROM AUTHOR]

The application of Ibl’s duplex diffusion layer model to the analysis of mass transport in pulse reverse plating with bipolar current pulses has been investigated. Although originally proposed to describe normal pulse plating, Yin has recently extended Ibl’s model to include pulse reverse plating. Using the expressions derived by Yin the pulse limiting current density was determined over a wide range of pulse plating conditions, and then compared to values calculated using more accurate numerical solutions. In general, there was good agreement between the two approaches which demonstrated the essential validity of Yin’s extension to Ibl’s original model. The simplified model is most accurate at long duty cycles, small dimensionless pulse times and for low values of the dimensionless pulse reverse current where its underlying assumptions are most likely to be valid. At very long dimensionless pulse times (i.e.T* > 1) the model becomes increasingly inaccurate and its use in these circumstances cannot be justified. [ABSTRACT FROM AUTHOR]