Long Duration Exposure Facility (LDEF) low temperature Heat Pipe Experiment Package (HEPP) flight results

The Low Temperature Heat Pipe Flight Experiment (HEPP) is a fairly complicated thermal control experiment that was designed to evaluate the performance of two different low temperature ethane heat pipes and a low-temperature (182 K) phase change material. A total of 390 days of continuous operation with an axially grooved aluminum fixed conductance heat pipe and an axially grooved stainless steel heat pipe diode was demonstrated before the data acquisition system's batteries lost power. Each heat pipe had approximately 1 watt applied throughout this period. The HEPP was not able to cool below 188.6 K during the mission. As a result, the preprogrammed transport test sequence which initiates when the PCM temperature drops below 180 K was never exercised, and transport tests with both pipes and the diode reverse mode test could not be run in flight. Also, because the melt temperature of the n-heptane PCM is 182 K, its freeze/thaw behavior could not be tested. Post-flight thermal vacuum tests and thermal analyses have indicated that there was an apparent error in the original thermal analyses that led to this unfortunate result. Post-flight tests have demonstrated that the performance of both heat pipes and the PCM has not changed since being fabricated more than 14 years ago. A summary of HEPP's flight data and post-flight test results are presented

Reconstructing long-term ecological data from annual census returns: a test for observer bias in counts of bird populations on Skokholm 1928–2002

Long-term ecological data are essential for conservation and to monitor and evaluate the effects of environmental change. Bird populations have been routinely assessed on islands off the British coast for many years and here long term data for one such island, Skokholm, is evaluated for robustness in the light of some 20 changes in observers (wardens) on the island over nearly eight decades. It was found that the dataset was robust when compared to bootstrap data with no species showing significant changes in abundance in years when wardens changed. It is concluded that the breeding bird populations on Skokholm and other British offshore islands are an important scientific resource and that protocols should be enacted to ensure the archiving of records, the continuance of data collection using standardised protocols into the future, and the recognition of such long-term data for science in terms of an appropriate conservation designation

Entrepreneurship Skills Development in Higher Education Courses for Teams Leaders

This article analyses the concept of skills and identifies the skills needed by entrepreneurs to lead their teams. To accomplish these goals, the primary step was to determine the leadership skills developed by the universities in the entrepreneurship and innovation courses and to compare it with the needed skills perceived by entrepreneurs. This research approach is framed in the Management Sciences, and the research problem is anchored to the following research questions: What leadership skills are required by students for them to be effective in entrepreneurial endeavors upon graduation? Are the skills identified by the entrepreneurs sufficiently learned in Universities in Portugal? Does the student work experience, gender or age contribute to a level of leadership skills attainment? The leadership skills identified by the entrepreneurs were pointed out by two focus groups with 15 entrepreneurs and by conceptual content analysis, establishing the existence and frequency of concepts represented by the words or phrases in the entrepreneur's discourse. To verify if those skills are being developed in the entrepreneurship and innovation of higher education courses, an online survey was conducted with the students from the 3rd year of 2016/2017 academic year of several universities. The primary outcome of the research will be a proposal for a model of leadership skills development for students to potentiate their leadership capacity as entrepreneurs

Prior hospital admission predicts thirty-day hospital readmission for heart failure patients

Background: Hospital readmission is a significant health burden. More than 20% of heart failure (HF) patients are readmitted within 30 days of discharge leading to billions of dollars in health care expenditures. However, the role of prior hospital admissions to predict 30-day readmission for HF patients is not fully understood. Methods: We retrospectively analyzed HF hospitalization data for 4 years at a single medical center. Association between prior admission and 30-day readmission after HF hospitalization was assessed using a multivariate logistic regression model. Results: A total of 1,999 patients with index HF hospitalizations were identified, and 366 of them (18%) were readmitted within 30 days. The rate of readmission was 14%, 20%, and 33% in patients with 0, 1, ≥ 2 prior admissions. Patients with one prior admission had a 50% higher risk (confidence interval [CI] 1.10–2.05, p = 0.011) for readmission, while those with ≥ 2 prior admissions had a more than 3-fold increase in readmission (CI 2.27–4.09, p < 0.001), after adjustments for relevant clinical covariates. Prior hospital admission provided incremen­tal value in predicting readmissions, shown by the significant improvement in the readmission predictive model (C-statistics increased from 0.57 to 0.63). However, neither the length of stay nor recency of prior admission was a significant factor in predicting readmissions. Conclusions: Hospital admission prior to an index HF hospitalization is associated with a significantly increased risk for 30-day hospital readmission and could be used to identify patients at high-risk for readmission and potentially target interventions to reduce the risk of readmission for these patient

Highly Variable Objects in the Palomar-QUEST Survey: A Blazar Search using Optical Variability

We identify 3,113 highly variable objects in 7,200 square degrees of the Palomar-QUEST Survey, which each varied by more than 0.4 magnitudes simultaneously in two broadband optical filters on timescales from hours to roughly 3.5 years. The primary goal of the selection is to find blazars by their well-known violent optical variability. Because most known blazars have been found in radio and/or X-ray wavelengths, a sample discovered through optical variability may have very different selection effects, elucidating the range of behavior possible in these systems. A set of blazars selected in this unusual manner will improve our understanding of the physics behind this extremely variable and diverse class of AGN. The object positions, variability statistics, and color information are available using the Palomar-QUEST CasJobs server. The time domain is just beginning to be explored over large sky areas; we do not know exactly what a violently variable sample will hold. About 20% of the sample has been classified in the literature; over 70% of those objects are known or likely AGN. The remainder largely consists of a variety of variable stars, including a number of RR Lyrae and cataclysmic variables.Comment: 22 pages (preprint format), 2 figures. Accepted for publication in ApJ. References update

The Biological Records Centre: a pioneer of citizen science

People have been recording wildlife for centuries and the resulting datasets lead to important scientific research. The Biological Records Centre (BRC), established in 1964, is a national focus for terrestrial and freshwater species recording in the United Kingdom (UK). BRC works with the voluntary recording community (i.e. a mutualistic symbiosis) through support of national recording schemes (i.e. ‘citizen science’, but unlike most citizen science it is volunteer led) and adds value to the data through analysis and reporting. Biological recording represents a diverse range of activities, involving an estimated 70 000 people annually in the UK, from expert volunteers undertaking systematic monitoring to mass participation recording. It is an invaluable monitoring tool because the datasets are long term, have large geographic extent and are taxonomically diverse (85 taxonomic groups). It supports a diverse range of outputs, e.g. atlases showing national distributions (12 127 species from over 40 taxonomic groups) and quantified trends (1636 species). BRC pioneers the use of technology for data capture (online portals and smartphone apps) and verification (including automated verification) through customisable, inter-operable database systems to facilitate efficient data flow. We are confident that biological recording has a bright future with benefits for people, science, and nature

Gravito-electromagnetism

We develop and apply a fully covariant 1+3 electromagnetic analogy for gravity. The free gravitational field is covariantly characterized by the Weyl gravito-electric and gravito-magnetic spatial tensor fields, whose dynamical equations are the Bianchi identities. Using a covariant generalization of spatial vector algebra and calculus to spatial tensor fields, we exhibit the covariant analogy between the tensor Bianchi equations and the vector Maxwell equations. We identify gravitational source terms, couplings and potentials with and without electromagnetic analogues. The nonlinear vacuum Bianchi equations are shown to be invariant under covariant spatial duality rotation of the gravito-electric and gravito-magnetic tensor fields. We construct the super-energy density and super-Poynting vector of the gravitational field as natural U(1) group invariants, and derive their super-energy conservation equation. A covariant approach to gravito-electric/magnetic monopoles is also presented.Comment: 14 pages. Version to appear in Class. Quant. Gra

How mimicry influences the neural correlates of reward: an fMRI study

Mimicry has been suggested to function as a “social glue”, a key mechanism that helps to build social rapport. It leads to increased feeling of closeness toward the mimicker as well as greater liking, suggesting close bidirectional links with reward. In recent work using eye-gaze tracking, we have demonstrated that the reward value of being mimicked, measured using a preferential looking paradigm, is directly proportional to trait empathy (Neufeld and Chakrabarti, 2016). In the current manuscript, we investigated the reward value of the act of mimicking, using a simple task manipulation that involved allowing or inhibiting spontaneous facial mimicry in response to dynamic expressions of positive emotion. We found greater reward-related neural activity in response to the condition where mimicry was allowed compared to that where mimicry was inhibited. The magnitude of this link from mimicry to reward response was positively correlated to trait empathy

Micro-finance Competition: Motivated Micro-lenders, Double-dipping and Default

Published in Journal of Comparative Economics https://doi.org/10.1016/j.jdeveco.2013.07.006</p