X-ray variability of the quasar 3C273

Observations of the quasar 3C273 made during 1975-77 have shown that the X-ray flux varied on a time scale of several months. No similar variation was present in radio and optical data taken at similar times. If this variation results from luminosity variations of a central compact object, then an upper limit of ≤4 x 1017cm can be set on its dimensions

A Latent Profile Analysis of Age of Onset in Pathological Skin Picking

Background Pathological Skin Picking (PSP) may begin at any age, but the most common age of onset is during adolescence. Age of onset is a potentially useful clinical marker to delineate subtypes of psychiatric disorders. The present study sought to examine empirically defined age of onset groups in adults with PSP and assess whether groups differed on clinical characteristics. Method Participants were 701 adult respondents to an internet survey, who endorsed recurrent skin picking with tissue damage and impairment. Latent profile analysis (LPA) was conducted to identify subtypes of PSP based on age of onset. Then subgroups were compared on demographic and clinical characteristics. Results The best fitting LPA model was a two-class solution comprised of a large group with average age of onset in adolescence (n = 650; 92.9% of the sample; Mean age of onset = 13.6 years) and a small group with average onset in middle adulthood (n = 50; 7.1% of the sample; Mean age of onset = 42.8 years). Relative to the early onset group, the late onset group reported significantly less focused picking, less skin picking-related impairment, lower rates of co-occurring body-focused repetitive behaviors, and trends towards reduced family history of PSP. Individuals in the late onset group also reported increased rates of comorbid depression, anxiety and posttraumatic stress disorder, and were more likely to report that initial picking onset seemed related to or followed depression/anxiety and physical illness. Conclusion Findings suggest the presence of two distinct PSP age of onset groups: (1) an early onset group with average onset in adolescence, clinical characteristics suggestive of greater picking-related burden and familiality, and a profile more representative of the general PSP population; and (2) a late onset group with average onset in middle adulthood, increased co-occurring affective and trauma conditions, and initial onset associated with or following other mental health and physical problems. Future replication is needed to assess the validity and clinical utility of these subgroups

Battery-operated Independent Radiation Detector Data Report from Exploration Flight Test 1

Citation: Bahadori AA, Semones EJ, Gaza R, Kroupa M, Rios RR, Stoffle NN, Campbell-Ricketts T, Pinsky LS, and Turecek D 2015 Battery-operated Independent Radiation Detector Data Report from Exploration Flight Test 1 NASA/TP-2015-218575 NASA Johnson Space Center: Houston, TX http://ston.jsc.nasa.gov/collections/TRS/397.refer.htmlThis report summarizes the data acquired by the Battery-operated Independent Radiation Detector (BIRD) during Exploration Flight Test 1 (EFT-1). The BIRD, consisting of two redundant subsystems isolated electronically from the Orion Multi-Purpose Crew Vehicle (MPCV), was developed to fly on the Orion EFT-1 to acquire radiation data throughout the mission. The BIRD subsystems successfully triggered using on-board accelerometers in response to launch accelerations, acquired and archived data through landing, and completed the shut down routine when battery voltage decreased to a specified value. The data acquired are important for understanding the radiation environment within the Orion MPCV during transit through the trapped radiation belts

Effect of different toxic compounds on ATP content and acid phosphatase activity in axenic cultures of Tetrahymena pyriformis

The sensitivity of protozoa, and particularly ciliated protozoa, to environmental changes suggested a study on the physiological responses arising from exposure to toxic compounds. Tetrahymena pyriformis was used as a test organism in a set of miniaturized assays. The physiological response of this ciliate was assessed in terms of adenosine-5'-triphosphate content and acid phosphatase activity after exposure of the cultures of T. pyriformis to four toxicants: copper, zinc, Triton X-100, and cycloheximide. In the range of concentrations used, stimulation and inhibition of these two parameters were observed. The correlation between the two parameters is analyzed.Fundação para a Ciência e a Tecnologia (FCT) – PRAXIS XXI - Grant BPD/11594/02

The Living Planet Index: using species population time series to track trends in biodiversity.

The Living Planet Index was developed to measure the changing state of the world's biodiversity over time. It uses time-series data to calculate average rates of change in a large number of populations of terrestrial, freshwater and marine vertebrate species. The dataset contains about 3000 population time series for over 1100 species. Two methods of calculating the index are outlined: the chain method and a method based on linear modelling of log-transformed data. The dataset is analysed to compare the relative representation of biogeographic realms, ecoregional biomes, threat status and taxonomic groups among species contributing to the index. The two methods show very similar results: terrestrial species declined on average by 25% from 1970 to 2000. Birds and mammals are over-represented in comparison with other vertebrate classes, and temperate species are over-represented compared with tropical species, but there is little difference in representation between threatened and non-threatened species. Some of the problems arising from over-representation are reduced by the way in which the index is calculated. It may be possible to reduce this further by post-stratification and weighting, but new information would first need to be collected for data-poor classes, realms and biomes

The Academic Resilience Scale (ARS-30) : a new multidimensional construct measure

Resilience is a psychological construct observed in some individuals that accounts for success despite adversity. Resilience reflects the ability to bounce back, to beat the odds and is considered an asset in human characteristic terms. Academic resilience contextualises the resilience construct and reflects an increased likelihood of educational success despite adversity. The paper provides an account of the development of a new multidimensional construct measure of academic resilience. The 30 item Academic Resilience Scale (ARS-30) explores process—as opposed to outcome—aspects of resilience, providing a measure of academic resilience based on students’ specific adaptive cognitive-affective and behavioural responses to academic adversity. Findings from the study involving a sample of undergraduate students (N=532) demonstrate that the ARS-30 has good internal reliability and construct validity. It is suggested that a measure such as the ARS-30, which is based on adaptive responses, aligns more closely with the conceptualisation of resilience and provides a valid construct measure of academic resilience relevant for research and practice in university student populations

Is Landscape Context Important for Riparian Conservation? Birds in Grassy Woodland

An important challenge for riparian management is to determine the extent to which landscape context influences the faunal assemblages of riparian habitats. We examined this challenge in the variegated landscapes of southeastern Queensland, Australia where riparian vegetation is surrounded by both extensive grazing and intensive cropping. We investigated whether riparian habitats adjacent to different landuses support similar bird assemblages. Three types of riparian habitat condition were sampled (uncleared ungrazed; uncleared grazed; cleared grazed) in four different land-use contexts (ungrazed woodland; grazed woodland; native pasture; crop) although only six of the twelve possible treatment combinations were available. Eighty percent of bird species responded significantly to changes in both riparian habitat condition and landscape context, while fewer than 50% of species were significantly influenced by landscape context alone. The influence of landscape context on the bird assemblage increased as the surrounding land use became more intensive (e.g. woodland to native pasture to crop). Riparian zones have been shown to have consistently high biodiversity values relative to their extent. These findings suggest it is not enough to conserve riparian habitats alone, conservation and restoration plans must also take into consideration landscape context, particularly when that context is intensively used land

Measurement of boundary layer ozone concentrations on-board a Skywalker unmanned aerial vehicle

This study demonstrates novel measurements of in situ ozone (O3) concentrations and thermodynamics sampled on?board an instrumented Skywalker Unmanned Aerial Vehicle (UAV). Small spatial and temporal gradients were observed over a localized region, which nearby ground?based in situ measurements lack the ability to resolve. It was found that the UAV?measured O3 concentrations provided a useful additional indicator of O3 variability at the sub?urban scale. The ability to sample subtle variability over a localized area highlights the important and novel capabilities of UAVs to rapidly characterize local area micrometeorology and chemistry

The Impact of Critical Thinking Disposition on Learning Using Business Simulations

This research seeks to determine the relationship between students’ critical thinking disposition and their learning while engaging in a business simulation at a UK higher education institution (HEI). The research informs educators making decisions about the use of simulations as to the value of considering critical thinking dispositions. Previous research has found that simulations are an effective way for students to engage actively in learning, bridging the gap between theory and practice. It has also been found that such simulations can develop students’ critical thinking skills. However, hitherto no research has been undertaken into the role that existing critical thinking disposition has on the learning of students, as measured by the degree to which students perceived that they met the module’s intended learning outcomes. This research offers insights into the role and importance of critical thinking disposition and its component dimensions and how this impacts student learning. The results indicate that the level of critical thinking disposition is positively related to the students’ learning. The implications of the research suggest educators should target business simulations at specific cohorts of students. The relative importance of the critical thinking disposition constructs and the practical educational implications of these findings are discussed