2,746 research outputs found
The Voluntary Association in The Slum
1 / Voluntary Associations in a Zone of Transition
This report is a study of formal voluntary associations in a zone of transition. It seeks information on the various kinds of voluntary organizations to be found in such an area, the characteristics of the members, the manner in which people become affiliated with organizations, and the functions that organizations serve for their members. The specific associations studied include such diverse groups as a neighborhood improvement council, an old-age club, and various children\u27s associations. In this study such groups fall under the province of voluntary associations. That such groups are found in a zone of transition warrants special attention because it has been common to assume that formal associations are nonexistent or at a minimum in the slum, an assumption which has an important bearing on theory in urban sociology and ecology,
This study was initiated with the knowledge that groups had been formed in an interstitial area through the efforts of a community organizer. The organizations created through his efforts provided a focus for the problem, and the membership of these groups provided a major portion of the universe studied. Thus, it was known prior to the study that there were persons belonging to voluntary associations in the area. It was assumed, however, that an extensive network of organizational participation could be found in the area independent of the affiliations created by the professional community organizer. This assumption was borne out readily. A cursory examination of the total membership for the city of such diverse organizations as the YWCA, Boy Scouts, Veterans of Foreign Wars, and so forth, indicated that many of the persons who were members of these groups also inhabited the area mapped out for study.
Were the members of formal organizations in the slum similar to their counterparts who lived in the suburbs? For instance, were they likely to have relatively high educational achievement, to be Protestant rather than Catholic in faith, and be voters more often than nonvoters? Such questions were posed at the inception of the study. Still other questions concerned the similarities and differences between persons who became members of organizations created by the community organizer and persons living in the same slum area but affiliated with other voluntary associations. And in a different vein, did children who belonged to associations come from families where their parents had a tradition of association, or was parental affiliation incidental to a child\u27s participation? To answer such questions and to formulate hypotheses for testing, this inquiry drew heavily from studies dealing with voluntary associations. The relation of such studies to the present work will be noted shortly
Testable polarization predictions for models of CMB isotropy anomalies
Anomalies in the large-scale CMB temperature sky measured by WMAP have been
suggested as possible evidence for a violation of statistical isotropy on large
scales. In any physical model for broken isotropy, there are testable
consequences for the CMB polarization field. We develop simulation tools for
predicting the polarization field in models that break statistical isotropy
locally through a modulation field. We study two different models: dipolar
modulation, invoked to explain the asymmetry in power between northern and
southern ecliptic hemispheres, and quadrupolar modulation, posited to explain
the alignments between the quadrupole and octopole. For the dipolar case, we
show that predictions for the correlation between the first 10 multipoles of
the temperature and polarization fields can typically be tested at better than
the 98% CL. For the quadrupolar case, we show that the polarization quadrupole
and octopole should be moderately aligned. Such an alignment is a generic
prediction of explanations which involve the temperature field at recombination
and thus discriminate against explanations involving foregrounds or local
secondary anisotropy. Predicted correlations between temperature and
polarization multipoles out to l = 5 provide tests at the ~ 99% CL or stronger
for quadrupolar models that make the temperature alignment more than a few
percent likely. As predictions of anomaly models, polarization statistics move
beyond the a posteriori inferences that currently dominate the field.Comment: 17 pages, 15 figures; published in PRD; references adde
A Low CMB Quadrupole from Dark Energy Isocurvature Perturbations
We explicate the origin of the temperature quadrupole in the adiabatic dark
energy model and explore the mechanism by which scale invariant isocurvature
dark energy perturbations can lead to its sharp suppression. The model requires
anticorrelated curvature and isocurvature fluctuations and is favored by the
WMAP data at about the 95% confidence level in a flat scale invariant model. In
an inflationary context, the anticorrelation may be established if the
curvature fluctuations originate from a variable decay rate of the inflaton;
such models however tend to overpredict gravitational waves. This isocurvature
model can in the future be distinguished from alternatives involving a
reduction in large scale power or modifications to the sound speed of the dark
energy through the polarization and its cross correlation with the temperature.
The isocurvature model retains the same polarization fluctuations as its
adiabatic counterpart but reduces the correlated temperature fluctuations. We
present a pedagogical discussion of dark energy fluctuations in a quintessence
and k-essence context in the Appendix.Comment: 16 pages, 12 figures, typos in Table 1 correcte
The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy.
Chronic traumatic encephalopathy (CTE) is a neurodegeneration characterized by the abnormal accumulation of hyperphosphorylated tau protein within the brain. Like many other neurodegenerative conditions, at present, CTE can only be definitively diagnosed by post-mortem examination of brain tissue. As the first part of a series of consensus panels funded by the NINDS/NIBIB to define the neuropathological criteria for CTE, preliminary neuropathological criteria were used by 7 neuropathologists to blindly evaluate 25 cases of various tauopathies, including CTE, Alzheimer's disease, progressive supranuclear palsy, argyrophilic grain disease, corticobasal degeneration, primary age-related tauopathy, and parkinsonism dementia complex of Guam. The results demonstrated that there was good agreement among the neuropathologists who reviewed the cases (Cohen's kappa, 0.67) and even better agreement between reviewers and the diagnosis of CTE (Cohen's kappa, 0.78). Based on these results, the panel defined the pathognomonic lesion of CTE as an accumulation of abnormal hyperphosphorylated tau (p-tau) in neurons and astroglia distributed around small blood vessels at the depths of cortical sulci and in an irregular pattern. The group also defined supportive but non-specific p-tau-immunoreactive features of CTE as: pretangles and NFTs affecting superficial layers (layers II-III) of cerebral cortex; pretangles, NFTs or extracellular tangles in CA2 and pretangles and proximal dendritic swellings in CA4 of the hippocampus; neuronal and astrocytic aggregates in subcortical nuclei; thorn-shaped astrocytes at the glial limitans of the subpial and periventricular regions; and large grain-like and dot-like structures. Supportive non-p-tau pathologies include TDP-43 immunoreactive neuronal cytoplasmic inclusions and dot-like structures in the hippocampus, anteromedial temporal cortex and amygdala. The panel also recommended a minimum blocking and staining scheme for pathological evaluation and made recommendations for future study. This study provides the first step towards the development of validated neuropathological criteria for CTE and will pave the way towards future clinical and mechanistic studies
Self-similarity and long-time behavior of solutions of the diffusion equation with nonlinear absorption and a boundary source
This paper deals with the long-time behavior of solutions of nonlinear
reaction-diffusion equations describing formation of morphogen gradients, the
concentration fields of molecules acting as spatial regulators of cell
differentiation in developing tissues. For the considered class of models, we
establish existence of a new type of ultra-singular self-similar solutions.
These solutions arise as limits of the solutions of the initial value problem
with zero initial data and infinitely strong source at the boundary. We prove
existence and uniqueness of such solutions in the suitable weighted energy
spaces. Moreover, we prove that the obtained self-similar solutions are the
long-time limits of the solutions of the initial value problem with zero
initial data and a time-independent boundary source
Cultivating Agricultural Literacy: Challenge for the Liberal Arts
A review and analysis of 11 pacesetting experiments funded by the W. K. Kellogg Foundation to generate greater awareness among liberal arts students and faculty about the role and importance ofthe agriculture enterprise to the nation
The IGF1 small dog haplotype is derived from Middle Eastern grey wolves
<p>Abstract</p> <p>Background</p> <p>A selective sweep containing the insulin-like growth factor 1 (<it>IGF1</it>) gene is associated with size variation in domestic dogs. Intron 2 of <it>IGF1 </it>contains a SINE element and single nucleotide polymorphism (SNP) found in all small dog breeds that is almost entirely absent from large breeds. In this study, we surveyed a large sample of grey wolf populations to better understand the ancestral pattern of variation at <it>IGF1 </it>with a particular focus on the distribution of the small dog haplotype and its relationship to the origin of the dog.</p> <p>Results</p> <p>We present DNA sequence data that confirms the absence of the derived small SNP allele in the intron 2 region of <it>IGF1 </it>in a large sample of grey wolves and further establishes the absence of a small dog associated SINE element in all wild canids and most large dog breeds. Grey wolf haplotypes from the Middle East have higher nucleotide diversity suggesting an origin there. Additionally, PCA and phylogenetic analyses suggests a closer kinship of the small domestic dog <it>IGF1 </it>haplotype with those from Middle Eastern grey wolves.</p> <p>Conclusions</p> <p>The absence of both the SINE element and SNP allele in grey wolves suggests that the mutation for small body size post-dates the domestication of dogs. However, because all small dogs possess these diagnostic mutations, the mutations likely arose early in the history of domestic dogs. Our results show that the small dog haplotype is closely related to those in Middle Eastern wolves and is consistent with an ancient origin of the small dog haplotype there. Thus, in concordance with past archeological studies, our molecular analysis is consistent with the early evolution of small size in dogs from the Middle East.</p> <p>See associated opinion by Driscoll and Macdonald: <url>http://jbiol.com/content/9/2/10</url></p
Information propagation within the Genetic Network of Saccharomyces cerevisiae
Background: A gene network's capacity to process information, so as to bind past events to future actions, depends on its structure and logic. From previous and new microarray measurements in Saccharomyces cerevisiae following gene deletions and overexpressions, we identify a core gene regulatory network (GRN) of functional interactions between 328 genes and the transfer functions of each gene. Inferred connections are verified by gene enrichment. Results: We find that this core network has a generalized clustering coefficient that is much higher than chance. The inferred Boolean transfer functions have a mean p-bias of 0.41, and thus similar amounts of activation and repression interactions. However, the distribution of p-biases differs significantly from what is expected by chance that, along with the high mean connectivity, is found to cause the core GRN of S. cerevisiae's to have an overall sensitivity similar to critical Boolean networks. In agreement, we find that the amount of information propagated between nodes in finite time series is much higher in the inferred core GRN of S. cerevisiae than what is expected by chance. Conclusions: We suggest that S. cerevisiae is likely to have evolved a core GRN with enhanced information propagation among its genes.Peer reviewe
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