2,098 research outputs found
Conceptual mechanization studies for a horizon definition spacecraft electrical power subsystem
Solar cell-battery electrical power subsystem for horizon definition spacecraf
Not fitting in and getting out : psychological type and congregational satisfaction among Anglican churchgoers in England
Listening to the motivations reported by individuals for ceasing church attendance and becoming church leavers, Francis and Richter identified high on the list the sense of "not fitting in". Drawing on psychological type theory, several recent studies have documented the way in which some psychological types are over-represented in church congregations and other psychological types are under-represented. Bringing these two observations together, the present study tested the hypothesis that church congregations have created type-alike communities within which individuals displaying the opposite type preferences are more likely to feel marginalised and to display lower levels of satisfaction with the congregations they attend. Data were provided by 1867 churchgoers who completed a measure of psychological type, together with measures of frequency of attendance and congregational satisfaction. These data confirmed that congregations were weighted towards preferences for introversion, sensing, feeling and judging, and that individuals displaying the opposite preferences (especially intuition, thinking and perceiving) recorded lower levels of congregational satisfaction. The implications of these findings are discussed for promoting congregational retention by enhancing awareness of psychological type preferences among those who attend
Consequentialism and Virtue
We examine the following consequentialist view of virtue: a trait is a virtue if and only if
it has good consequences in some relevant way. We highlight some motivations for this basic
account, and offer twelve choice points for filling it out. Next, we explicate Julia Driver’s
consequentialist view of virtue in reference to these choice points, and we canvass its merits and
demerits. Subsequently, we consider three suggestions that aim to increase the plausibility of her
position, and critically analyze them. We conclude that one of those proposed revisions would
improve her account. NOTE: I will self-archive the paper after the 24 month embargo period ends. If you want a copy, just email me
Parents and Teachers Make Different Contributions to a Shared Perspective on Hyperactive–Impulsive and Inattentive Symptoms: A Multivariate Analysis of Parent and Teacher Ratings on the Symptom Domains of ADHD
Attention deficit hyperactivity disorder (ADHD) is characterised by developmentally inappropriate and impairing levels of inattentive and hyperactive–impulsive behaviours. We aimed to investigate the differential effects of parent and teacher ratings on inattention and hyperactivity–impulsivity and the extent of genetic overlap between the two behavioural dimensions. Multivariate structural equation modelling was performed on DSM-IV based ADHD ratings by parents and teachers collected on a general population sample of 672 twin pairs, at ages 7–10 years. This study is the first to simultaneously use parent and teacher ratings in twin modelling to examine the effects of different raters on the two behavioural dimensions of ADHD. The findings indicated that hyperactivity–impulsivity and inattention load on to separate latent factors that represent a common behavioural view for both parents and teachers, although there are additional aspects to the observations of these behaviours that are unique to each type of rater. The findings further indicate some shared aetiology for hyperactivity–impulsivity and inattention as measured by both parent and teacher ratings, in agreement with previous findings on the aetiology of the two symptom dimensions of ADHD
High Energy Neutrinos from Quasars
We review and clarify the assumptions of our basic model for neutrino
production in the cores of quasars, as well as those modifications to the model
subsequently made by other workers. We also present a revised estimate of the
neutrino background flux and spectrum obtained using more recent empirical
studies of quasars and their evolution. We compare our results with other
thoeretical calculations and experimental upper limits on the AGN neutrino
background flux. We also estimate possible neutrino fluxes from the jets of
blazars detected recently by the EGRET experiment on the Compton Gamma Ray
Observatory. We discuss the theoretical implications of these estimates.Comment: 14 pg., ps file (includes figures), To be published in Space Science
Review
Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways
It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers
Accreting Millisecond X-Ray Pulsars
Accreting Millisecond X-Ray Pulsars (AMXPs) are astrophysical laboratories
without parallel in the study of extreme physics. In this chapter we review the
past fifteen years of discoveries in the field. We summarize the observations
of the fifteen known AMXPs, with a particular emphasis on the multi-wavelength
observations that have been carried out since the discovery of the first AMXP
in 1998. We review accretion torque theory, the pulse formation process, and
how AMXP observations have changed our view on the interaction of plasma and
magnetic fields in strong gravity. We also explain how the AMXPs have deepened
our understanding of the thermonuclear burst process, in particular the
phenomenon of burst oscillations. We conclude with a discussion of the open
problems that remain to be addressed in the future.Comment: Review to appear in "Timing neutron stars: pulsations, oscillations
and explosions", T. Belloni, M. Mendez, C.M. Zhang Eds., ASSL, Springer;
[revision with literature updated, several typos removed, 1 new AMXP added
The centrosome and spindle as a ribonucleoprotein complex
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Chromosome Research 19 (2011): 367-376, doi:10.1007/s10577-011-9186-7.The presence of nucleic acids in centrosomes and the spindle have been proposed,
observed, and reported since the 1950s. Why did the subject remain, perhaps even until
today, such a controversial issue? The explanation is manifold, and includes legitimate
concern over contamination from other cellular compartments in biochemical
preparations. With a typically high background of cytoplasmic ribosomes, even
microscopic images of stained intact cells could be difficult to interpret. Also, evidence
for RNA and DNA in centrosomes accumulated for approximately 40 years but was
interspersed with contradictory studies, primarily regarding the presence of DNA
(reviewed in Johnson and Rosenbaum, 1991; Marshall and Rosenbaum, 2000). Perhaps
less tangible but still a likely cause for lingering controversy is that the presence of
nucleic acids in the spindle or centrosomes will require us to look differently at these
structures from a functional, and more to the point, evolutionary standpoint.This work was supported by grants from the NIH (GM088503) and NSF (MCB0843092)
to MCA
The Imperforate Anus Psychosocial Questionnaire (IAPSQ): Its construction and psychometric properties
The origin of the present study was to develop the liaison work between the disciplines of child and adolescent psychiatry and paediatric surgery and nursing, so as to improve the quality of treatment and care of a group of children with imperforate anus (IA) and their families. Imperforate anus is a congenital disease involving a deformity of the anorectum. The early surgery and invasive follow-up treatment associated with IA may affect the child psychosocially, including the child-parent relationship. By developing and testing a questionnaire for children born with anorectal anomalies, a tool for measuring psychosocial functioning can be realized
Persistent Cell Motion in the Absence of External Signals: A Search Strategy for Eukaryotic Cells
Eukaryotic cells are large enough to detect signals and then orient to them
by differentiating the signal strength across the length and breadth of the
cell. Amoebae, fibroblasts, neutrophils and growth cones all behave in this
way. Little is known however about cell motion and searching behavior in the
absence of a signal. Is individual cell motion best characterized as a random
walk? Do individual cells have a search strategy when they are beyond the range
of the signal they would otherwise move toward? Here we ask if single,
isolated, Dictyostelium and Polysphondylium amoebae bias their motion in the
absence of external cues. We placed single well-isolated Dictyostelium and
Polysphondylium cells on a nutrient-free agar surface and followed them at 10
sec intervals for ~10 hr, then analyzed their motion with respect to velocity,
turning angle, persistence length, and persistence time, comparing the results
to the expectation for a variety of different types of random motion. We find
that amoeboid behavior is well described by a special kind of random motion:
Amoebae show a long persistence time (~10 min) beyond which they start to lose
their direction; they move forward in a zig-zag manner; and they make turns
every 1-2 min on average. They bias their motion by remembering the last turn
and turning away from it. Interpreting the motion as consisting of runs and
turns, the duration of a run and the amplitude of a turn are both found to be
exponentially distributed. We show that this behavior greatly improves their
chances of finding a target relative to performing a random walk. We believe
that other eukaryotic cells may employ a strategy similar to Dictyostelium when
seeking conditions or signal sources not yet within range of their detection
system.Comment: 15 pages, 11 figures, accepted for publication in PLOS On
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