13,193 research outputs found
Ethnicity, voter alignment and political party affiliation - an African case: Zambia
Conventional wisdom holds that ethnicity provides the social cleavage for voting behav-iour and party affiliation in Africa. Because this is usually inferred from aggregate data of national election results, it might prove to be an ecological fallacy. The evidence based on individual data from an opinion survey in Zambia suggests that ethnicity matters for voter alignment and even more so for party affiliation, but it is certainly not the only factor. The analysis also points to a number of qualifications which are partly methodology-related. One is that the degree of ethnic voting can differ from one ethno-political group to the other depending on various degrees of ethnic mobilisation. Another is that if smaller eth-nic groups or subgroups do not identify with one particular party, it is difficult to find a significant statistical correlation between party affiliation and ethnicity - but that does not prove that they do not affiliate along ethnic lines.Wahlverhalten und Mitgliedschaft in politischen Parteien Afrikas ist nur wenig untersucht worden. Gewöhnlich wird argumentiert, dass Ethnizität als soziale Konfliktlinie das Wahlverhalten und die Parteienmitgliedschaft strukturiert. Da dieses Argument auf hoch aggregierten Wahldaten beruht, kann hier ein ökologischer Fehlschuss vorliegen. Die vorliegende Analyse beruht deshalb auf individuellen Umfragedaten aus Sambia. Das Ergebnis ist, dass Ethnizität tatsächlich eine Rolle für das Wahlverhalten und die Parteienmitgliedschaft spielt, aber keineswegs den einzigen Erklärungsfaktor darstellt. Die Analyse offenbart zudem eine Reihe von Einschränkungen und Qualifizierungen, die teilweise methodischer Natur sind. Eine ist, dass ethnisches Wahlverhalten und Parteienmitgliedschaft von einer ethnischen Gruppe zur anderen unterschiedlich ist, dass, wenn sich kleinere ethnische Gruppen oder Untergruppen mit keiner Partei identifizieren, es schwierig wird, statistisch signifikante Korrelationen zu finden - was indessen noch nicht beweist, dass Ethnizität keine Rolle spielt
A generative framework for the study of delusions
Despite the ubiquity of delusional information processing in psychopathology and everyday life, formal characterizations of such inferences are lacking. In this article, we propose a generative framework that entails a computational mechanism which, when implemented in a virtual agent and given new information, generates belief updates (i.e., inferences about the hidden causes of the information) that resemble those seen in individuals with delusions. We introduce a particular form of Dirichlet process mixture model with a sampling-based Bayesian inference algorithm. This procedure, depending on the setting of a single parameter, preferentially generates highly precise (i.e. over-fitting) explanations, which are compartmentalized and thus can co-exist despite being inconsistent with each other. Especially in ambiguous situations, this can provide the seed for delusional ideation. Further, we show by simulation how the excessive generation of such over-precise explanations leads to new information being integrated in a way that does not lead to a revision of established beliefs. In all configurations, whether delusional or not, the inference generated by our algorithm corresponds to Bayesian inference. Furthermore, the algorithm is fully compatible with hierarchical predictive coding. By virtue of these properties, the proposed model provides a basis for the empirical study and a step toward the characterization of the aberrant inferential processes underlying delusions
Mucous membrane and lower respiratory building related symptoms in relation to indoor carbon dioxide concentrations in the 100-building BASE dataset
Indoor air pollutants are a potential cause of building related symptoms and can be reduced by increasing ventilation rates. Indoor carbon dioxide (CO 2 ) concentration is an approximate surrogate for concentrations of occupant-generated pollutants and for ventilation rate per occupant. Using the US EPA 100 office-building BASE Study dataset, we conducted multivariate logistic regression analyses to quantify the relationship between indoor CO 2 concentrations (dCO 2 ) and mucous membrane (MM) and lower respiratory system (LResp) building related symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. In addition, we tested the hypothesis that certain environmentally mediated health conditions (e.g., allergies and asthma) confer increased susceptibility to building related symptoms. Adjusted odds ratios (ORs) for statistically significant, dose–dependent associations ( P < 0.05) for combined mucous membrane, dry eyes, sore throat, nose/sinus congestion, sneeze, and wheeze symptoms with 100 p.p.m. increases in dCO 2 ranged from 1.1 to 1.2. Building occupants with certain environmentally mediated health conditions were more likely to report that they experience building related symptoms than those without these conditions (statistically significant ORs ranged from 1.5 to 11.1, P < 0.05).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73439/1/j.1600-0668.2004.00298.x.pd
Physics Analysis Expert PAX: First Applications
PAX (Physics Analysis Expert) is a novel, C++ based toolkit designed to
assist teams in particle physics data analysis issues. The core of PAX are
event interpretation containers, holding relevant information about and
possible interpretations of a physics event. Providing this new level of
abstraction beyond the results of the detector reconstruction programs, PAX
facilitates the buildup and use of modern analysis factories. Class structure
and user command syntax of PAX are set up to support expert teams as well as
newcomers in preparing for the challenges expected to arise in the data
analysis at future hadron colliders.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 10 eps figures. PSN
THLT00
Concepts, Developments and Advanced Applications of the PAX Toolkit
The Physics Analysis eXpert (PAX) is an open source toolkit for high energy
physics analysis. The C++ class collection provided by PAX is deployed in a
number of analyses with complex event topologies at Tevatron and LHC. In this
article, we summarize basic concepts and class structure of the PAX kernel. We
report about the most recent developments of the kernel and introduce two new
PAX accessories. The PaxFactory, that provides a class collection to facilitate
event hypothesis evolution, and VisualPax, a Graphical User Interface for PAX
objects
Tripartite phase separation of two signal effectors with vesicles priming B cell responsiveness.
Antibody-mediated immune responses rely on antigen recognition by the B cell antigen receptor (BCR) and the proper engagement of its intracellular signal effector proteins. Src homology (SH) 2 domain-containing leukocyte protein of 65 kDa (SLP65) is the key scaffold protein mediating BCR signaling. In resting B cells, SLP65 colocalizes with Cbl-interacting protein of 85 kDa (CIN85) in cytoplasmic granules whose formation is not fully understood. Here we show that effective B cell activation requires tripartite phase separation of SLP65, CIN85, and lipid vesicles into droplets via vesicle binding of SLP65 and promiscuous interactions between nine SH3 domains of the trimeric CIN85 and the proline-rich motifs (PRMs) of SLP65. Vesicles are clustered and the dynamical structure of SLP65 persists in the droplet phase in vitro. Our results demonstrate that phase separation driven by concerted transient interactions between scaffold proteins and vesicles is a cellular mechanism to concentrate and organize signal transducers
The Midpoint Rule as a Variational--Symplectic Integrator. I. Hamiltonian Systems
Numerical algorithms based on variational and symplectic integrators exhibit
special features that make them promising candidates for application to general
relativity and other constrained Hamiltonian systems. This paper lays part of
the foundation for such applications. The midpoint rule for Hamilton's
equations is examined from the perspectives of variational and symplectic
integrators. It is shown that the midpoint rule preserves the symplectic form,
conserves Noether charges, and exhibits excellent long--term energy behavior.
The energy behavior is explained by the result, shown here, that the midpoint
rule exactly conserves a phase space function that is close to the Hamiltonian.
The presentation includes several examples.Comment: 11 pages, 8 figures, REVTe
Radiation hardness of CMS pixel barrel modules
Pixel detectors are used in the innermost part of the multi purpose
experiments at LHC and are therefore exposed to the highest fluences of
ionising radiation, which in this part of the detectors consists mainly of
charged pions. The radiation hardness of all detector components has thoroughly
been tested up to the fluences expected at the LHC. In case of an LHC upgrade,
the fluence will be much higher and it is not yet clear how long the present
pixel modules will stay operative in such a harsh environment. The aim of this
study was to establish such a limit as a benchmark for other possible detector
concepts considered for the upgrade.
As the sensors and the readout chip are the parts most sensitive to radiation
damage, samples consisting of a small pixel sensor bump-bonded to a CMS-readout
chip (PSI46V2.1) have been irradiated with positive 200 MeV pions at PSI up to
6E14 Neq and with 21 GeV protons at CERN up to 5E15 Neq.
After irradiation the response of the system to beta particles from a Sr-90
source was measured to characterise the charge collection efficiency of the
sensor. Radiation induced changes in the readout chip were also measured. The
results show that the present pixel modules can be expected to be still
operational after a fluence of 2.8E15 Neq. Samples irradiated up to 5E15 Neq
still see the beta particles. However, further tests are needed to confirm
whether a stable operation with high particle detection efficiency is possible
after such a high fluence.Comment: Contribution to the 11th European Symposium on Semiconductor
Detectors June 7-11, 2009 Wildbad Kreuth, German
Phylogeography of the crown-of-thorns starfish in the Indian Ocean
Background: Understanding the limits and population dynamics of closely related sibling species in the marine realm is particularly relevant in organisms that require management. The crown-of-thorns starfish Acanthaster planci, recently shown to be a species complex of at least four closely related species, is a coral predator infamous for its outbreaks that have devastated reefs throughout much of its Indo-Pacific distribution.
Methodology/Principal Findings: In this first Indian Ocean-wide genetic study of a marine organism we investigated the genetic structure and inferred the paleohistory of the two Indian Ocean sister-species of Acanthaster planci using mitochondrial DNA sequence analyses. We suggest that the first of two main diversification events led to the formation of a Southern and Northern Indian Ocean sister-species in the late Pliocene-early Pleistocene. The second led to the formation of two internal clades within each species around the onset of the last interglacial. The subsequent demographic history of the two lineages strongly differed, the Southern Indian Ocean sister-species showing a signature of recent population expansion and hardly any regional structure, whereas the Northern Indian Ocean sister-species apparently maintained a constant size with highly differentiated regional groupings that were asymmetrically connected by gene flow.
Conclusions/Significance: Past and present surface circulation patterns in conjunction with ocean primary productivity were identified as the processes most likely to have shaped the genetic structure between and within the two Indian Ocean lineages. This knowledge will help to understand the biological or ecological differences of the two sibling species and therefore aid in developing strategies to manage population outbreaks of this coral predator in the Indian Ocean
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