2,049 research outputs found
Predicting Northern Goshawk Dynamics Using an Individual-based Spatial Model
The northern goshawk (Accipiter gentilis) is a US Forest Service Region 2 Sensitive Species, requiring the Black Hills National Forest to manage for its viability. Previous studies have suggested that a model integrating goshawk population demographics, habitat availability, and territoriality would have the ability to predict population dynamics including goshawk locations, population size, and population viability. An individual-based spatial model was created for the Black Hills goshawk population. This project focused on evaluating our current understanding of goshawk dynamics, and making individual- and population-level predictions as appropriate following model validation. The model simulated demographics and behavior of individuals and usage patterns of selected habitat types. Data sources included published literature (demographic information) and GIS analysis of 50 Black Hills National Forest nest locations (habitat information). Model performance was assessed by comparing input data to the modeled data, and model validation compared observed data not used to build the model to results. Parameters were estimated for which no known published data exists, including: carrying capacity of the Black Hills National Forest, lifespan of adults, proportion of the population made up of juveniles, and age structure of the adult population. Raster maps from 100 simulations were used to create probability surfaces predicting nest site, post-fledging area, and territory occurrences, although 10,000 or more simulations would produce more reliable probability surfaces. The modeled population was based on demographic data from studies in the Kaibab National Forest, and depicted a declining trend. This outcome was not expected, as the observed population is assumed to be stable. Nest surveys in areas not related to proposed timber sales, and local estimates for adult survival and proportion of breeding pairs laying eggs annually would greatly improve the model. Future versions of the model should assess population stability by varying input parameters such as adult and juvenile survival and parameters contributing to fledging success. Suggestions for future research include a better understanding of goshawk movements such as dispersal, immigration, emigration, and seasonal migration. Future applications model include testing for a population threshold response to habitat loss and evaluating potential impacts of proposed management activities. If sufficient data existed, this model could be adapted for other forests, or other similar raptor species
Drip water electrical conductivity as an indicator of cave ventilation at the event scale
The use of speleothems to reconstruct past climatic and environmental change through chemical proxies is becoming increasingly common. Speleothem chemistry is controlled by hydrological and atmospheric processes which vary over seasonal time scales. However, as many reconstructions using speleothem carbonate are now endeavouring to acquire information about precipitation and temperature dynamics at a scale that can capture short term hydrological events, our understanding of within cave processes must match this resolution. Monitoring within Cueva de Asiul (N. Spain) has identified rapid (hourly resolution) changes in drip water electrical conductivity (EC), which is regulated by the pCO2 in the cave air. Drip water EC is therefore controlled by different modes of cave ventilation. In Cueva de Asiul a combination of density differences, and external pressure changes control ventilation patterns. Density driven changes in cave ventilation occur on a diurnal scale at this site irrespective of season, driven by fluctuations in external temperature across the cave internal temperature threshold. As external temperatures drop below those within the cave low pCO2 external air enters the void, facilitating the deposition of speleothem carbonate and causing a reduction in measured drip water EC. Additionally, decreases in external pressure related to storm activity act as a secondary ventilation mechanism. Reductions in external air pressure cause a drop in cave air pressure, enhancing karst air draw down, increasing the pCO2 of the cave and therefore the EC measured within drip waters. EC thereby serves as a first order indicator of cave ventilation, regardless of changes in speleothem drip rates and karst hydrological conditions. High resolution monitoring of cave drip water electrical conductivity reveals the highly sensitive nature of ventilation dynamics within cave environments, and highlights the importance of this for understanding trace element incorporation into speleothem carbonate at the event scale
Metacognitive and metamemory beliefs in the development and maintenance of posttraumatic stress disorder
Can metacognition increase trauma sufferersâ risk for developing and maintaining posttraumatic stress disorder (PTSD)? We assessed the role of a range of cognitive and metacognitive belief domainsâincluding metamemoryâon PTSD symptoms. Adult participants reported their existing meta/cognitions and lifetime exposure to trauma, then 12 weeks later, they reported meta/cognitions and PTSD symptoms in relation to new trauma exposure since the initial assessment. Participants with more PTSD symptoms held more problematic metacognitions than participants with fewer distress symptoms. Moreover, people who endorsed maladaptive metacognitions before trauma exposure were more likely to experience symptoms of PTSD after exposure. Metacognition predicted the maintenance of elevated PTSD symptoms over the 12-week delay. Our findings support the metacognitive model of PTSD and highlight the importance of metamemory, an understudied factor in PTSD research
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Psychopathology in Williams syndrome: the effect of individual differences across the lifespan
The present research aimed to comprehensively explore psychopathology in Williams syndrome (WS) across the lifespan and evaluate the relationship between psychopathology and age category (child or adult), gender and cognitive ability. The parents of 50 participants with WS, aged 6-50 years, were interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS-PL). The prevalence of a wide range of Axis I DSM-IV disorders was assessed. In addition to high rates of anxiety and Attention Deficit Hyperactivity Disorder (ADHD) (38% and 20% respectively), 14% of our sample met criteria for a depressive disorder and 42% of participants were not experiencing any significant psychopathological difficulties. There was some evidence for different patterns of psychopathology between children and adults with WS and between males and females. These relationships were largely in keeping with those found in the typically developing population, thus supporting the validity of applying theory and treatment approaches for psychopathology in the typically developing population to WS
Millennial scale control of European climate by the North Atlantic Oscillation from 12,500 BP: the Asiul speleothem record
Contemporary climate in Europe is strongly influenced by the North Atlantic Oscillation (NAO), the atmospheric pressure dipole between Iceland and the Azores1. Under positive NAO conditions winter storm tracks associated with the Atlantic Westerly Jet (AWJ) migrate northwards, leading to wetter and warmer winter conditions in north-western Europe and dry conditions in southern Europe; including the Iberian Peninsula. Under the negative NAO phase, storm tracks weaken and shift southwards reversing the pattern1. Existing proxy records of the NAO suggest that this atmospheric process only began to dominate European climate at approximately 8000 years BP, related to the final breakup of the Laurentide ice shelf2. However, here we present evidence of precipitation changes from a high-resolution speleothem ÎŽ18O record from northern Iberia, which indicates NAO-like forcing extending throughout the Holocene and into the Younger Dryas (YD) at 12,500 years BP. These variations in precipitation delivery relate to an underlying millennial scale cycle in NAO dynamics. The speleothem ÎŽ18O is strongly correlated to existing records of North Atlantic Ocean ice rafted debris (IRD)3, indicating an NAO-like connection with oceanic circulation during the Holocene2. These large-scale atmospheric processes have dramatically influenced the delivery of precipitation to northern Iberia and may have played a decisive role in environmental and human development in the region, throughout the Holocene
Screening for Group B Streptococcus: A Private Hospital's Experience
Objective. To assess the effect of universal screening and administration of intrapartum antibiotic prophylaxis to prevent early-onset neonatal GBS sepsis at a private tertiary care hospital since issuance of the 2002 CDC guidelines for preventing perinatal GBS disease. Methods. Retrospective analysis of women delivering between January 1, 2003 and December 31, 2004 at a private tertiary care hospital in Houston, Texas. The percentage of women screened, GBS positive women receiving intrapartum antibiotic prophylaxis, and infants developing early-onset GBS sepsis were determined. Results. 2,108 women delivered 2,135 infants with 1,874 (89%) screened for GBS. Of those screened, 1,322 (71%) tested negative and 552 (29%) tested positive for GBS. In this analysis of 2,135 infants, 3 (0.94 cases/1,000 live births) were diagnosed with invasive GBS sepsis. Conclusion. High rates of screening of pregnant women for GBS colonization and use of intrapartum antibiotic prophylaxis for GBS carriers can be achieved in a private tertiary care hospital setting. âSynopsis: High screening rates for group B streptococcus in a private tertiary care hospital reduce the incidence of maternal and early onset neonatal GBS infection.
Methacholine challenge in young children as evaluated by spirometry and impulse oscillometry
SummaryBackgroundIn young children, it is difficult to obtain a reproducible flow-volume curve throughout all stages of bronchial challenge. The forced oscillation technique (FOT) is especially established in paediatrics because this method does not require forced or maximal manoeuvres and is less cooperation-dependent than conventional spirometry.ObjectivesTo evaluate the association of spirometric and impulse oscillometric (IOS) indices in a short protocol for methacholine provocation.MethodsThe primary endpoint was the methacholine dose that caused a 20% decrease in FEV1 (PDâ20FEV1) compared to baseline. Changes in respiratory resistance (Rrs5) and reactance (Xrs5) acquired by IOS were compared with FEV1.ResultsForty-eight children (5.3 ± 0.9 years) were challenged. The mean maximal reduction in FEV1 was 29.8% ± 14.7 (p < 0.0001), the mean increase in Rsr5 was 55.3% ± 31.7, and the mean decrease in Xrs5 was 0.37 kPa s Lâ1 ± 0.23 (p < 0.001). An increase in Rrs5 of 45.2% and a decrease in Xrs5 of 0.69 kPa s Lâ1 showed the optimal combination of sensitivity and specificity to detect a 20% reduction in FEV1 (0.72 and 0.73; 0.80 and 0.76, respectively), and the area under the ROC curve was 0.76 and 0.81, respectively (p < 0.005). In 28 patients with significant changes in FEV1 and Rsr5, the PDâ20FEV1 was 0.48 mg methacholine ±0.59 and the PD+40Rrs5 was 0.28 mg methacholine ±0.45 (p = 0.03).ConclusionsA short protocol for methacholine challenge testing is feasible in young children. IOS detected 70â80% of patients who responded in spirometry. During the challenge, the Rrs5 response preceded the FEV1 response
North Atlantic forcing of moisture delivery to Europe throughout the Holocene
Century-to-millennial scale fluctuations in precipitation and temperature are an established feature of European Holocene climates. Changes in moisture delivery are driven by complex interactions between ocean moisture sources and atmospheric circulation modes, making it difficult to resolve the drivers behind millennial scale variability in European precipitation. Here, we present two overlapping decadal resolution speleothem oxygen isotope (ÎŽ18O) records from a cave on the Atlantic coastline of northern Iberia, covering the period 12.1â0âka. Speleothem ÎŽ18O reveals nine quasi-cyclical events of relatively wet-to-dry climatic conditions during the Holocene. Dynamic Harmonic Regression modelling indicates that changes in precipitation occurred with a ~1500âyear frequency during the late Holocene and at a shorter length during the early Holocene. The timing of these cycles coincides with changes in North Atlantic Ocean conditions, indicating a connectivity between ocean conditions and Holocene moisture delivery. Early Holocene climate is potentially dominated by freshwater outburst events, whilst ~1500âyear cycles in the late Holocene are more likely driven by changes internal to the ocean system. This is the first continental record of its type that clearly demonstrates millennial scale connectivity between the pulse of the ocean and precipitation over Europe through the entirety of the Holocene
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