669 research outputs found

    Field Spectroscopy in the VNIR-SWIR region to discriminate between Mediterranean native plants and exotic-invasive shrubs based on leaf tannin content

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    The invasive shrub, Acacia longifolia, native to southeastern Australia, has a negative impact on vegetation and ecosystem functioning in Portuguese dune ecosystems. In order to spectrally discriminate A. longifolia from other non-native and native species, we developed a classification model based on leaf reflectance spectra (350–2500 nm) and condensed leaf tannin content. High variation of leaf tannin content is common for Mediterranean shrub and tree species, in particular between N-fixing and non-N-fixing species, as well as within the genus, Acacia. However, variation in leaf tannin content has not been studied in coastal dune ecosystems in southwest Portugal. We hypothesized that condensed tannin concentration varies significantly across species, further allowing for distinguishing invasive, nitrogen-fixing A. longifolia from other vegetation based on leaf spectral reflectance data. Spectral field measurements were carried out using an ASD FieldSpec FR spectroradiometer attached to an ASD leaf clip in order to collect 750 in situ leaf reflectance spectra of seven frequent plant species at three study sites in southwest Portugal. We applied partial least squares (PLS) regression to predict the obtained leaf reflectance spectra of A. longifolia individuals to their corresponding tannin concentration. A. longifolia had the lowest tannin concentration of all investigated species. Four wavelength regions (675–710 nm, 1060–1170 nm, 1360–1450 nm and 1630–1740 nm) were identified as being highly correlated with tannin concentration. A spectra-based classification model of the different plant species was calculated using a principal component analysis-linear discriminant analysis (PCA-LDA). The best prediction of A. longifolia was achieved by using wavelength regions between 1360–1450 nm and 1630–1740 nm, resulting in a user’s accuracy of 98.9%. In comparison, selecting the entire wavelength range, the best user accuracy only reached 86.5% for A. longifolia individuals

    A Systematic Review of Genetic Influence on Psychological Resilience

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    When exposed to adversity, some individuals are at an increased risk of posttraumatic stress disorder, experiencing persistent biopsychosocial disturbances, whereas others adapt well, described as resilience. Resilience is a complex biopsychosocial phenomenon conceptualized as adaptation to adversity influenced by an individual’s genetic variants, epistasis, epigenetics, and gene-by-environment interactions. Studies on psychological resilience have focused on behavioral and psychosocial variables with far less examination of the genetic contributions. The purpose of this review is to identify specific genetic variants contributing to the biological capacity for psychological resilience. PubMed and PsycINFO were searched using the following key words: psychological resilience AND genotype(s). Additional articles were identified from the Human Genome Epidemiology Navigator using the term resilience, psychological. Ten studies met the criteria. Six genes were empirically associated with psychological resilience: serotonin-transporter-linked polymorphic region (5-HTTLPR), dopamine receptor D4, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone receptor 1, oxytocin receptor and regulator of G-protein signaling 2. The findings of this systematic review suggest that the L/L or L′/L′ genotype of 5-HTTLPR and rs25531 in children/adolescents and the S/S or S′/S′ genotype in adults are most frequently related to resilience. Additionally, the Val/Val genotype of rs6265 in BDNF in Caucasians was also associated with resilience. There are numerous factors contributing to the complexity of determining the genetic influence on resilience including analysis of rs25531, assumptions of the mode of inheritance, operationalization of resilience, demographic and population characteristics, sample size, and other types of genetic influence including epistasis and epigenetics. While current evidence is supportive, further investigation of the genetic influence on resilience is required

    Nexus of Despair: A Network Analysis of Suicidal Ideation among Veterans

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    The objective of this study was to estimate a network model of risk and resilience factors of suicidal ideation among veterans. Two network models of suicidal ideation among Operation Iraqi Freedom/ Operation Enduring Freedom/Operation New Dawn veterans (N = 276) incorporated key disorders, traumatic stress, and resilience constructs to contextualize suicidal ideation. Childhood trauma was positively connected with suicidal ideation and harassment and inversely connected with social support and distress tolerance. This exemplifies long-lasting associations between childhood trauma and revictimization, emotion regulation, and ability to form supportive social relationships. A subsequent model including lower-order facets indicated that combat trauma was predominantly associated with posttraumatic stress disorder–intrusion symptoms. This study highlights the importance of addressing both risk and resilience to reduce suicide risk among veterans and increases understanding of factors that contribute to suicidal ideation

    PTSD Symptoms and Alcohol-Related Problems among Veterans: Temporal Associations and Vulnerability

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    Posttraumatic stress disorder (PTSD) is associated with elevated risk of both alcohol use disorder (AUD) and related conduct problems, which are associated with behavioral and emotional dysregulation. We conducted an intensive longitudinal burst design study with 10 weeks of experience sampling over the course of 1.5 years with 250 veterans of recent conflicts. We tested time-series models of daily associations between posttraumatic stress symptoms (PTSS), alcohol dependence syndrome, and conduct problems. Exacerbations of PTSS predicted higher dependence syndrome and conduct problems the next day. This effect was significant after controlling for both concurrent (i.e., same-day) associations between drinking and the outcomes as well as the strength of associations between the outcomes from one day to the next (i.e., autoregression). Affect lability and disinhibition were hypothesized vulnerability factors increasing the strength of within-person predictors of dependence syndrome and conduct problems. Lability and disinhibition were associated with greater dependence syndrome symptoms and conduct problems over the follow-up period. Consistent with expectation, lability rather than disinhibition increased the association between drinking and dependence syndrome as well as the strength of association between dependence syndrome symptoms from one day to the next. Moderating effects of disinhibition in the conduct problems model were not significant. Importantly, results indicated reciprocal associations over time. Lability potentiated the association between dependence syndrome symptoms and next-day PTSS, whereas disinhibition potentiated the association between conduct problems and next-day PTSS. Results demonstrate complex dynamic associations between PTSS, AUD symptoms, and conduct problems over time indicative of broad regulatory impairments

    Effects of Prairie Dogs and Cattle on Vegetation Disappearance on Prairie Dog Towns in Mixed-Grass Prairie

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    Quantitative data is lacking on competition between prairie dogs and cattle for forage on mixed-grass prairie pastures. The objective of this study was to determine the disappearance of vegetation attributable to cattle and prairie dogs on pastures with prairie dog towns. During the summers of 2002 and 2003, biomass estimates were made periodically on three mixed-grass prairie pastures in south central South Dakota that had varying degrees of prairie dog town coverage (percent of pasture area). Two types of grazing exclosures were established. Cattle exclosures allowed grazing by prairie dogs only. Cattle/prairie dog exclosures excluded both herbivores. Permanent plots outside cages were established that allowed grazing by both species. Biomass estimates on individual vegetation species were obtained both inside the exclosures and on permanent plots outside the exclosures two times in 2002 and 2003. Forage removed was estimated and compared for cattle alone, prairie dogs alone, and cattle and prairie dogs together in each year. Forage removed by prairie dogs on the on-town sites was nearly three times as great as forage removed by cattle on the on-town sites for the June and July sampling periods. Cattle removed two times more forage on off-town sites than on on-town sites. Total forage removed on on-town sites (cattle + prairie dogs) was almost two times greater than on off-town sites. Livestock forage was significantly reduced on prairie dog towns compared to unoccupied sites. Classic carrying capacity calculations overestimate forage availability when prairie dog towns are present. Stocking rates on pastures with prairie dog towns should be adjusted to account for forage disappearance due to prairie dogs

    Supervisors’ Experiences of Providing Difficult Feedback in Cross-Ethnic/Racial Supervision

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    Seventeen clinical supervisors were interviewed regarding their experience of providing difficult feedback in cross-ethnic/racial supervision, and their responses were analyzed using consensual qualitative research (CQR). European American supervisors described supervisees of color who had difficulty in their clinical work with culturally different clients. These supervisors then shared with supervisees their concern that supervisees’ interpersonal skills may negatively affect their clinical and/or supervision work. Supervisors of color described European American supervisees who exhibited insensitivity toward clients of color in session or during supervision. These supervisors shared their concern that supervisees’ lack of cultural sensitivity may negatively affect their clinical work. These contrasting feedback experiences had a profound effect on supervisory relationships and the processes within supervision

    Remission, continuation and incidence of eating disorders during early pregnancy: a validation study in a population-based birth cohort

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    Background—The objective of this study was to validate previously published rates of remission, continuation, and incidence of broadly defined eating disorders during pregnancy. The previous rate modeling was done by our group (Bulik et al. 2007) and yielded participants halfway into recruitment of the planned 100,000 pregnancies in the Norwegian Mother and Child (MoBa) Cohort at the Norwegian Institute of Public Health. This study aimed to internally validate the findings with the completed cohort. Methods—77267 pregnant women enrolled at 17 weeks gestation between 2001 and 2009 were included. Participants were split into a “training” sample (n=41243) based on participants in the MoBa version 2 dataset of the original study and a “validation” sample (n=36024) comprising individuals in the MoBa version 5 dataset that were not in the original study (Bulik et al. 2007). Internal validation of all original rate models involved fitting a calibration model to compare model parameters between the “training” and “validation” samples as well as bootstrap estimates of bias in the entire version 5 dataset. Results—Remission, continuation, and incidence estimates from the “training” sample remained stable when evaluated via a split sample validation procedure. Pre-pregnancy prevalence estimates in the “validation” sample were 0.1% for anorexia nervosa, 1.0% for bulimia nervosa (BN), 3.3% for binge eating disorder (BED), and 0.1% for purging disorder (EDNOS-P). In early pregnancy, estimates were 0.2% for BN, 4.8% for BED, and <0.01% for EDNOS-P. Consistent with the original study, incident BN and EDNOS-P during pregnancy were rare. For BED, the adjusted incidence rate in the “validation” sample was 1.17 per 1000 person-weeks. The highest rates were for full or partial remission for BN and EDNOS-P, and continuation for BED. Conclusions—This study provides evidence of validity of previously estimated rates of remission, continuation, and incidence of eating disorders during pregnancy. Eating disorders during pregnancy were relatively common, occurring in nearly 1 in every 20 women, although almost all were cases of BED. Pregnancy was a window of remission from BN but a window of vulnerability for onset and continuation of BED. Training to detect the signs and symptoms of eating disorders by obstetricians/gynecologists and interventions to enhance pregnancy and neonatal outcomes warrant attention

    The connection between the initial and unique solutions of domain equations in the partial order and metric approach

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    The purpose of this paper is twofold: First, we show in which way the initial solution of a domain equation for cpo’s and the unique solution of a corresponding domain equation for metric spaces are related. Second, we present a technique to lift a given domain equation for cpo’s to a corresponding domain equation for metric spaces

    Case Studies of Potential Facility-Scale and Utility-Scale Non-Hydro Renewable Energy Projects across Reclamation

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    This report summarizes the results of an assessment and analysis of renewable energy opportunities conducted for the U.S. Department of the Interior, Bureau of Reclamation by the National Renewable Energy Laboratory. Tasks included assessing the suitability for wind and solar on both a utility and facility scale

    Diel Temperature and pH Variability Scale With Depth Across Diverse Coral Reef Habitats

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    Coral reefs are facing intensifying stressors, largely due to global increases in seawater temperature and decreases in pH. However, there is extensive environmental variability within coral reef ecosystems, which can impact how organisms respond to global trends. We deployed spatial arrays of autonomous sensors across distinct shallow coral reef habitats to determine patterns of spatiotemporal variability in seawater physicochemical parameters. Temperature and pH were positively correlated over the course of a day due to solar heating and light‐driven metabolism. The mean temporal and spatial ranges of temperature and pH were positively correlated across all sites, with different regimes of variability observed in different reef types. Ultimately, depth was a reliable predictor of the average diel ranges in both seawater temperature and pH. These results demonstrate that there is widespread environmental variability on diel timescales within coral reefs related to water column depth, which needs to be included in assessments of how global change will locally affect reef ecosystems
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