62,006 research outputs found
Targeting inflammatory pathways in axial spondyloarthritis.
The triggers and pathogenesis of axial spondyloarthritis (axSpA) are not yet completely understood. However, therapeutic agents targeting tumor necrosis factor-α and interleukin-17 inflammatory pathways have proven successful in suppressing many of the clinical symptoms and signs of axSpA, giving us an indication of which pathways are responsible for initiating and maintaining the inflammation. The mechanisms that eventuate in syndesmophytes and ankyloses are less clear. This review addresses these two critical pathways of inflammation, discussing their nature and these factors that may activate or enhance the pathways in patients with axSpA. In addition, genetic and other markers important to the inflammatory pathways implicated in axSpA are explored, and prognostic biomarkers are discussed. Treatment options available for the management of axSpA and their associated targets are highlighted
Kalman Filtering With Relays Over Wireless Fading Channels
This note studies the use of relays to improve the performance of Kalman
filtering over packet dropping links. Packet reception probabilities are
governed by time-varying fading channel gains, and the sensor and relay
transmit powers. We consider situations with multiple sensors and relays, where
each relay can either forward one of the sensors' measurements to the
gateway/fusion center, or perform a simple linear network coding operation on
some of the sensor measurements. Using an expected error covariance performance
measure, we consider optimal and suboptimal methods for finding the best relay
configuration, and power control problems for optimizing the Kalman filter
performance. Our methods show that significant performance gains can be
obtained through the use of relays, network coding and power control, with at
least 30-40 less power consumption for a given expected error covariance
specification.Comment: 7 page
Renal Function in Suckling and Fasting Pups of the Northern Elephant Seal
Elephant seals fast for prolonged periods without access to water. This is made possible, in part, by reductions in urine production. However, the mechanisms involved in reducing urine production are not understood. In this study, glomerular filtration rate (GFR) was measured in five northern elephant seal pups (Mirounga angustirostris) via the inulin clearance technique. Measurements were made during day 9 and day 18–22 of nursing and the second and eighth week of the postweaning fast. Plasma aldosterone and cortisol concentrations, quantified by radioimmunoassay, were measured in eight other weanlings during the second and eighth week of the fast. Mean GFR was 79.3±29.3 ml/min during the early suckling period and 78.2±17.1, 89.8±52.7, and 80.4±12.2 ml/min during the late suckling, early fasting and late fasting periods, respectively. Differences between nursing and fasting were insignificant, possibly because reduced protein oxidation during suckling and rapid recruitment of protein for tissue synthesis obviated the need for postprandial hyperfiltration. Alternatively, maintenance of GFR during fasting may facilitate urea concentration by compensating for reductions in the fractional excretion of urea. It is further hypothesized that aldosterone is primarily responsible for mediating renal water reabsorption in this system
The Diversity of Type Ia Supernovae from Broken Symmetries
Type Ia supernovae result when carbon-oxygen white dwarfs in binary systems
accrete mass from companion stars, reach a critical mass, and explode. The near
uniformity of their light curves makes these supernovae good standard candles
for measuring cosmic expansion, but a correction must be applied to account for
the fact that the brighter supernovae have broader light curves.
One-dimensional modelling, with a certain choice of parameters, can reproduce
this general trend in the width-luminosity relation, but the processes of
ignition and detonation have recently been shown to be intrinsically
asymmetric. Here we report on multi-dimensional modelling of the explosion
physics and radiative transfer that reveals that the breaking of spherical
symmetry is a critical factor in determining both the width luminosity relation
and the observed scatter about it. The deviation from sphericity can also
explain the finite polarization detected in the light from some supernovae. The
slope and normalization of the width-luminosity relation has a weak dependence
on certain properties of the white dwarf progenitor, in particular the trace
abundances of elements other than carbon and oxygen. Failing to correct for
this effect could lead to systematic overestimates of up to 2% in the distance
to remote supernovae.Comment: Accepted to Natur
Interactions between empathy and resting heart rate in early adolescence predict violent behavior in late adolescence and early adulthood.
BackgroundAlthough resting heart rate (RHR) and empathy are independently and negatively associated with violent behavior, relatively little is known about the interplay between these psychophysiological and temperament-related risk factors.MethodsUsing a sample of 160 low-income, racially diverse men followed prospectively from infancy through early adulthood, this study examined whether RHR and empathy during early adolescence independently and interactively predict violent behavior and related correlates in late adolescence and early adulthood.ResultsControlling for child ethnicity, family income, and child antisocial behavior at age 12, empathy inversely predicted moral disengagement and juvenile petitions for violent crimes, while RHR was unrelated to all measures of violent behavior. Interactive effects were also evident such that among men with lower but not higher levels of RHR, lower empathy predicted increased violent behavior, as indexed by juvenile arrests for violent offenses, peer-reported violent behavior at age 17, self-reported moral disengagement at age 17, and self-reported violent behavior at age 20.ConclusionsImplications for prevention and intervention are considered. Specifically, targeting empathic skills among individuals at risk for violent behavior because of specific psychophysiological profiles may lead to more impactful interventions
The interaction between monoamine oxidase A and punitive discipline in the development of antisocial behavior: Mediation by maladaptive social information processing.
Previous studies demonstrate that boys' monoamine oxidase A (MAOA) genotype interacts with adverse rearing environments in early childhood, including punitive discipline, to predict later antisocial behavior. Yet the mechanisms by which MAOA and punitive parenting interact during childhood to amplify risk for antisocial behavior are not well understood. In the present study, hostile attributional bias and aggressive response generation during middle childhood, salient aspects of maladaptive social information processing, were tested as possible mediators of this relation in a sample of 187 low-income men followed prospectively from infancy into early adulthood. Given racial-ethnic variation in MAOA allele frequencies, analyses were conducted separately by race. In both African American and Caucasian men, those with the low-activity MAOA allele who experienced more punitive discipline at age 1.5 generated more aggressive responses to perceived threat at age 10 relative to men with the high-activity variant. In the African American subsample only, formal mediation analyses indicated a marginally significant indirect effect of maternal punitiveness on adult arrest records via aggressive response generation in middle childhood. The findings suggest that maladaptive social information processing may be an important mechanism underlying the association between MAOA Ă— Parenting interactions and antisocial behavior in early adulthood. The present study extends previous work in the field by demonstrating that MAOA and harsh parenting assessed in early childhood interact to not only predict antisocial behavior in early adulthood, but also predict social information processing, a well-established social-cognitive correlate of antisocial behavior
Beauty, Productivity and Discrimination: Lawyers' Looks and Lucre
We propose several models in which an ascriptive characteristic generates earnings differentials and is sorted across sectors. The general approach shows how to distinguish the ultimate sources of labor-market returns to such characteristics; the specific example uses longitudinal data on a large sample of attorneys who graduated from one law school. Beauty is measured by ratings of their matriculation photographs. 1) Better-looking attorneys who graduated in the 1970s earned more after 5 years of practice than their worse- looking classmates, other things equal, an effect that grew even larger by the fifteenth year of practice. There is no impact of beauty on earnings among 1980s graduates. 2) Attorneys in the private sector are better-looking than those in the public sector, with the differences rising as workers sort across sector based on their beauty. 3) Male attorneys' probability of attaining an early partnership rises with beauty. The results support a theory of dynamic sorting and the role of customer behavior. We cannot determine whether this is because clients discriminate or because better-looking lawyers are able to obtain greater pecuniary gains for their clients.
Cycles of Wage Discrimination
Using CPS data from 1979-2009 we examine how cyclical downturns and industry-specific demand shocks affect wage differentials between white non-Hispanic males and women, Hispanics and African-Americans. Women's and Hispanics' relative earnings are harmed by negative shocks, while the earnings disadvantage of African-Americans may drop with negative shocks. Negative shocks also appear to increase the earnings disadvantage of bad-looking workers. A theory of job search suggests two opposite-signed mechanisms that affect these wage differentials. It suggests greater absolute effects among job-movers, which is verified using the longitudinal component of the CPS.women, minorities, beauty, search models
Topology and Nematic Ordering II: Observable Critical Behavior
This paper is the second in a pair treating a new lattice model for nematic
media. In addition to the familiar isotropic (I) and nematically ordered (N)
phases, the phase diagram established in the previous paper (Paper I) contains
a new, topologically ordered phase (T) occuring at large suppression of
topological defects and weak nematic interactions. This paper (Paper II) is
concerned with the experimental signatures of the proposed phase diagram.
Specific heat, light scattering and magnetic susceptibility near both the N/T
and I/T transitions are studied, and critical behavior determined. The singular
dependences of the Frank constants (, , ) and the dielectric
tensor anisotropy () on temperature upon approaching the N/T
transition are also found.Comment: 10 pages, RevTeX 3.
- …