8,233 research outputs found
Social contact structures and time use patterns in the Manicaland Province of Zimbabwe.
BACKGROUND: Patterns of person-to-person contacts relevant for infectious diseases transmission are still poorly quantified in Sub-Saharan Africa (SSA), where socio-demographic structures and behavioral attitudes are expected to be different from those of more developed countries. METHODS AND FINDINGS: We conducted a diary-based survey on daily contacts and time-use of individuals of different ages in one rural and one peri-urban site of Manicaland, Zimbabwe. A total of 2,490 diaries were collected and used to derive age-structured contact matrices, to analyze time spent by individuals in different settings, and to identify the key determinants of individuals' mixing patterns. Overall 10.8 contacts per person/day were reported, with a significant difference between the peri-urban and the rural site (11.6 versus 10.2). A strong age-assortativeness characterized contacts of school-aged children, whereas the high proportion of extended families and the young population age-structure led to a significant intergenerational mixing at older ages. Individuals spent on average 67% of daytime at home, 2% at work, and 9% at school. Active participation in school and work resulted the key drivers of the number of contacts and, similarly, household size, class size, and time spent at work influenced the number of home, school, and work contacts, respectively. We found that the heterogeneous nature of home contacts is critical for an epidemic transmission chain. In particular, our results suggest that, during the initial phase of an epidemic, about 50% of infections are expected to occur among individuals younger than 12 years and less than 20% among individuals older than 35 years. CONCLUSIONS: With the current work, we have gathered data and information on the ways through which individuals in SSA interact, and on the factors that mostly facilitate this interaction. Monitoring these processes is critical to realistically predict the effects of interventions on infectious diseases dynamics
Nasopharyngeal angiofibroma: review of literature
Angiofibroma of nasopharynx is a highly vascular, rare and benign tumor, with a high a incidence of recurrence and local invasity which nature always defied the researchers on the subject. The controversies start on its site of origin, till therapeutical modalities, passing by clinical and diagnostic aspects. The most serious and baffling feature, however, is the occurrence of hemorrhagic outbreaks, sometimes very intense, which may lead the patient to death. In view of this, the efforts developed towards of minimizing this problematic fact have been many, aiming adequate control of the illness. The present article presents a global review on this subject and intends to discuss the main aspects related to angiofibroma of nasopharynx in a simple and didatic form.O angiofibroma de nasofaringe é um tumor benigno, raro, altamente vascularizado, com elevado índice de recorrência e invasividade local, cuja natureza sempre desafiou os estudiosos do assunto. As controvérsias vão desde o seu local de origem, até modalidades terapêuticas, passando por aspectos clínicos e diagnósticos. A característica mais grave e desconcertante, no entanto, é a ocorrência de surtos hemorrágicos, por vezes muito intensos, podendo levar o paciente à morte. Frente a esse fato, muitos foram os esforços desenvolvidos no sentido de minimizar esse problema, visando o controle adequado da doença. Esse estudo apresenta uma revisão global sobre o tema e se propõe a expor de forma simples e didática os principais aspectos relacionados ao angiofibroma nasofaríngeo.Instituto de Assistência Médica ao Servidor Público Estadual de São PauloUNIFESP-EPMHSPE FMO Departamento de OtorrinolaringologiaHospital do Servidor Público Municipal Serviço de OtorrinolaringologiaUniversidade de São Paulo Faculdade de MedicinaHospital do Servidor Público Estadual FMO Departamento de OtorrinolaringologiaUNIFESP, EPMSciEL
The Lie derivative of spinor fields: theory and applications
Starting from the general concept of a Lie derivative of an arbitrary
differentiable map, we develop a systematic theory of Lie differentiation in
the framework of reductive G-structures P on a principal bundle Q. It is shown
that these structures admit a canonical decomposition of the pull-back vector
bundle i_P^*(TQ) = P\times_Q TQ over P. For classical G-structures, i.e.
reductive G-subbundles of the linear frame bundle, such a decomposition defines
an infinitesimal canonical lift. This lift extends to a prolongation
Gamma-structure on P. In this general geometric framework the concept of a Lie
derivative of spinor fields is reviewed. On specializing to the case of the
Kosmann lift, we recover Kosmann's original definition. We also show that in
the case of a reductive G-structure one can introduce a "reductive Lie
derivative" with respect to a certain class of generalized infinitesimal
automorphisms, and, as an interesting by-product, prove a result due to
Bourguignon and Gauduchon in a more general manner. Next, we give a new
characterization as well as a generalization of the Killing equation, and
propose a geometric reinterpretation of Penrose's Lie derivative of "spinor
fields". Finally, we present an important application of the theory of the Lie
derivative of spinor fields to the calculus of variations.Comment: 28 pages, 1 figur
Operation of a LAr-TPC equipped with a multilayer LEM charge readout
A novel detector for the ionization signal in a single phase LAr-TPC, based
on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the
traditional anodic wire arrays, has been experimented in the ICARINO test
facility at the INFN Laboratories in Legnaro. Cosmic muon tracks were detected
allowing the measurement of energy deposition and a first determination of the
signal to noise ratio. The analysis of the recorded events demonstrated the 3D
reconstruction capability of ionizing events in this device in liquid Argon,
collecting a fraction of about 90% of the ionization signal with signal to
noise ratio similar to that measured with more traditional wire chambersComment: 9 pages, 7 Figure
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Reduced Hedonic Capacity in Major Depressive Disorder: Evidence from a Probabilistic Reward Task
Objective:
Anhedonia, the lack of reactivity to pleasurable stimuli, is a cardinal feature of depression that has received renewed interest as a potential endophenotype of this debilitating disease. The goal of the present study was to test the hypothesis that individuals with major depression are characterized by blunted reward responsiveness, particularly when anhedonic symptoms are prominent.
Methods:
A probabilistic reward task rooted within signal-detection theory was utilized to objectively assess hedonic capacity in 23 unmedicated subjects meeting DSM-IV criteria for major depressive disorder (MDD) and 25 matched control subjects recruited from the community. Hedonic capacity was defined as reward responsiveness – i.e., the participants’ propensity to modulate behavior as a function of reward.
Results:
Compared to controls, MDD subjects showed significantly reduced reward responsiveness. Trial-by-trial probability analyses revealed that MDD subjects, while responsive to delivery of single rewards, were impaired at integrating reinforcement history over time and expressing a response bias toward a more frequently rewarded cue in the absence of immediate reward. This selective impairment correlated with self-reported anhedonic symptoms, even after considering anxiety symptoms and general distress.
Conclusions:
These findings indicate that MDD is characterized by an impaired tendency to modulate behavior as a function of prior reinforcements, and provides initial clues about which aspects of hedonic processing might be dysfunctional in depression.Psycholog
Preliminary tests on a wireless sensor network for pervasive dust monitoring in construction sites
One of the critical aspects in health and safety is the control of fine particle emissions from demolition and construction activities. Such exposure is very often the cause of professional illnesses causing a relevant economic burden for welfare and insurance institutions, besides harming workers. Hence this paper performs a feasibility study of a realtime control system of fine particle concentration on construction sites. It was conceived as a ZigbeeTM based wireless, pervasive and non-invasive system, which is easy to deploy over the site and relatively cheap. Dust sensors were interfaced with the system and calibrated in the laboratory. The prototype is described in detail and tested under controlled and real conditions, in order to determine its potential for application. The prototype was shown to be an excellent tool to support health and safety inspectors, to provide in real-time a broad map of dust concentration over the whole extension of the site, provided that calibration coefficients are worked out for the various types of dust which can be encountered on the site
A hardware implementation of Region-of-Interest selection in LAr-TPC for data reduction and triggering
Large Liquid Argon TPC detectors in the range of multikton mass for neutrino
and astroparticle physics require the extraction and treatment of signals from
some 105 wires. In order to enlarge the throughtput of the DAQ system an
on-line lossless data compression has been realized reducing almost a factor 4
the data flow. Moreover a trigger system based on a new efficient on-line
identification algorithm of wire hits was studied, implemented on the actual
ICARUS digital read- out boards and fully tested on the ICARINO LAr-TPC
facility operated at LNL INFN Laboratory with cosmic-rays. Capability to
trigger isolated low energy events down to 1 MeV visible energy was also
demonstrated.Comment: 26 pages, 26 Figure; to be submitted to JINS
Composites materials for food packaging and from food industry by-products only : the EcoBioCAP EU project
Definition of Naturally Processed Peptides Reveals Convergent Presentation of Autoantigenic Topoisomerase I Epitopes in Scleroderma.
ObjectiveAutoimmune responses to DNA topoisomerase I (topo I) are found in a subset of scleroderma patients who are at high risk for interstitial lung disease (ILD) and mortality. Anti-topo I antibodies (ATAs) are associated with specific HLA-DRB1 alleles, and the frequency of HLA-DR-restricted topo I-specific CD4+ T cells is associated with the presence, severity, and progression of ILD. Although this strongly implicates the presentation of topo I peptides by HLA-DR in scleroderma pathogenesis, the processing and presentation of topo I has not been studied.MethodsWe developed a natural antigen processing assay (NAPA) to identify putative CD4+ T cell epitopes of topo I presented by monocyte-derived dendritic cells (mo-DCs) from 6 ATA-positive patients with scleroderma. Mo-DCs were pulsed with topo I protein, HLA-DR-peptide complexes were isolated, and eluted peptides were analyzed by mass spectrometry. We then examined the ability of these naturally presented peptides to induce CD4+ T cell activation in 11 ATA-positive and 11 ATA-negative scleroderma patients.ResultsWe found that a common set of 10 topo I epitopes was presented by Mo-DCs from scleroderma patients with diverse HLA-DR variants. Sequence analysis revealed shared peptide-binding motifs within the HLA-DRβ chains of ATA-positive patients and a subset of topo I epitopes with distinct sets of anchor residues capable of binding to multiple different HLA-DR variants. The NAPA-derived epitopes elicited robust CD4+ T cell responses in 73% of ATA-positive patients (8 of 11), and the number of epitopes recognized correlated with ILD severity (P = 0.025).ConclusionThese findings mechanistically implicate the presentation of a convergent set of topo I epitopes in the development of scleroderma
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