144 research outputs found
Modelo de gerenciamento de serviços, utilizando o valor do cliente no tempo : uso de mineração de dados em um serviço de telecomunicações
Orientador : Prof. Dr. Pedro Jose Steiner NetoTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Programa de Pós-Graduação em Administração. Defesa: Curitiba, 30/09/2009Inclui bibliografi
Pathophysiology of nasal congestion
Nasal congestion is a common symptom in rhinitis (both allergic and nonallergic), rhinosinusitis and nasal polyposis. Congestion can also be caused by physical obstruction of nasal passages and/or modulation of sensory perception. Mucosal inflammation underlies many of the specific and interrelated factors that contribute to nasal congestion, as well as other symptoms of both allergic rhinitis and rhinosinusitis. A wide range of biologically active agents (eg, histamine, tumor necrosis factor-α, interleukins, cell adhesion molecules) and cell types contribute to inflammation, which can manifest as venous engorgement, increased nasal secretions and tissue swelling/edema, ultimately leading to impaired airflow and the sensation of nasal congestion. Inflammation-induced changes in the properties of sensory afferents (eg, expression of peptides and receptors) that innervate the nose can also contribute to altered sensory perception, which may result in a subjective feeling of congestion. Increased understanding of the mechanisms underlying inflammation can facilitate improved treatment selection and the development of new therapies for congestion
Connectivity differences between Gulf War Illness (GWI) phenotypes during a test of attention
One quarter of veterans returning from the 1990–1991 Persian Gulf War have developed Gulf War Illness (GWI) with chronic pain, fatigue, cognitive and gastrointestinal dysfunction. Exertion leads to characteristic, delayed onset exacerbations that are not relieved by sleep. We have modeled exertional exhaustion by comparing magnetic resonance images from before and after submaximal exercise. One third of the 27 GWI participants had brain stem atrophy and developed postural tachycardia after exercise (START: Stress Test Activated Reversible Tachycardia). The remainder activated basal ganglia and anterior insulae during a cognitive task (STOPP: Stress Test Originated Phantom Perception). Here, the role of attention in cognitive dysfunction was assessed by seed region correlations during a simple 0-back stimulus matching task (“see a letter, push a button”) performed before exercise. Analysis was analogous to resting state, but different from psychophysiological interactions (PPI). The patterns of correlations between nodes in task and default networks were significantly different for START (n = 9), STOPP (n = 18) and control (n = 8) subjects. Edges shared by the 3 groups may represent co-activation caused by the 0-back task. Controls had a task network of right dorsolateral and left ventrolateral prefrontal cortex, dorsal anterior cingulate cortex, posterior insulae and frontal eye fields (dorsal attention network). START had a large task module centered on the dorsal anterior cingulate cortex with direct links to basal ganglia, anterior insulae, and right dorsolateral prefrontal cortex nodes, and through dorsal attention network (intraparietal sulci and frontal eye fields) nodes to a default module. STOPP had 2 task submodules of basal ganglia–anterior insulae, and dorsolateral prefrontal executive control regions. Dorsal attention and posterior insulae nodes were embedded in the default module and were distant from the task networks. These three unique connectivity patterns during an attention task support the concept of Gulf War Disease with recognizable, objective patterns of cognitive dysfunction
Covariates of corticotropin-releasing hormone (CRH) concentrations in cerebrospinal fluid (CSF) from healthy humans
BACKGROUND: Define covariates of cerebrospinal corticotropin-releasing hormone (CRH) levels in normal humans. CRH(CSF )was measured in 9 normal subjects as part of an intensive study of physiological responses stressors in chronic pain and fatigue states. CRH(CSF )was first correlated with demographic, vital sign, HPA axis, validated questionnaire domains, baseline and maximal responses to pain, exercise and other stressors. Significant factors were used for linear regression modeling. RESULTS: Highly significant correlations were found despite the small number of subjects. Three models were defined: (a) CRH(CSF )with blood glucose and sodium (explained variance = 0.979, adjusted R(2 )= 0.958, p = 0.02 by 2-tailed testing); (b) CRH(CSF )with resting respiratory and heart rates (R(2 )= 0.963, adjusted R(2 )= 0.939, p = 0.007); and (c) CRH(CSF )with SF-36 Vitality and Multidimensional Fatigue Inventory Physical Fatigue domains (R(2 )= 0.859, adjusted R(2 )= 0.789, p = 0.02). CONCLUSIONS: Low CRH(CSF )was predicted by lower glucose, respiratory and heart rates, and higher sodium and psychometric constructs of well being. Responses at peak exercise and to other acute stressors were not correlated. CRH(CSF )may have reflected an overall, or chronic, set-point for physiological responses, but did not predict the reserves available to respond to immediate stressors
Nova saznanja o neuralnoj regulaciji nosne sluznice kod ljudi
Nasal mucosa is innervated by multiple subsets of nociceptive, parasympathetic and sympathetic nerves. These play carefully coordinated roles in regulating glandular, vascular and other processes. These functions are vital for cleaning and humidifying ambient air before it is inhaled into the lungs. The recent recognition of distinct classes of nociceptive nerves with unique patterns of sensory receptors that include seven transmembrane G-protein coupled receptors, new families of transient receptor potential and voltage and calcium gated ion channels, and combinations of neurotransmitters that can be modulated during inflammation by neurotrophic factors has revolutionized our understanding of the complexity and subtlety of nasal innervation. These findings may provide a rational basis for responses to air temperature changes, culinary and botanical odorants ("aromatherapy"), and inhaled irritants in conditions as diverse as idiopathic nonallergic rhinitis, occupational rhinitis, hyposmia, and multiple chemical sensitivity.Nosnu sluznicu prožimaju višestruke podskupine nociceptivnih, parasimpatičkih i simpatičkih živaca koji imaju podrobno usklađene uloge u reguliranju žljezdanih, žilnih i drugih procesa. Ove funkcije su presudne za čišćenje i ovlaživanje zraka iz okoline prije negoli se udahne u pluća. Naše shvaćanje složene i fine naravi inervacije nosne sluznice radikalno se mijenja nedavnim prepoznavanjem različitih vrsta nociceptivnih živaca s jedinstvenim obrascima senzornih receptora koji obuhvaćaju sedam transmembranskih receptora vezanih s G-proteinom, nove porodice prolaznog receptorskog potencijala i napona te kalcijem ograničene (gated) ionske kanale i kombinacije neurotransmitora koje tijekom upale mogu mijenjati neurotropni čimbenici. Ovi nalazi mogli bi pružiti razumnu osnovu za odgovore na promjene u temperaturi zraka, kulinarske i botaničke mirise ("aromaterapija") i udisajne iritante u uvjetima tako ranovrsnim kao što su idiopatski nealergijski rinitis, profesionalni rinitis, hiposmija i višestruka kemijska osjetljivost
Human neuroglobin protein in cerebrospinal fluid
BACKGROUND: Neuroglobin is a hexacoordinated member of the globin family of proteins. It is predominantly localized to various brain regions and retina where it may play a role in protection against ischemia and nitric oxide-induced neural injury. Cerebrospinal fluid was collected from 12 chronic regional or systemic pain and 5 control subjects. Proteins were precipitated by addition of 50% 0.2 N acetic acid, 50% ethanol, 0.02% sodium bisulfite. The pellet was extensively digested with trypsin. Peptides were separated by capillary liquid chromatography using a gradient from 95% water to 95% acetonitrile in 0.2% formic acid, and eluted through a nanoelectrospray ionization interface into a quadrapole – time-of-flight dual mass spectrometer (QToF2, Waters, Milford, MA). Peptides were sequenced (PepSeq, MassLynx v3.5) and proteins identified using MASCOT (®). RESULTS: Six different neuroglobin peptides were identified in various combinations in 3 of 9 female pain subjects, but none in male pain, or female or male control subjects. CONCLUSION: This is the first description of neuroglobin in cerebrospinal fluid. The mechanism(s) leading to its release in chronic pain states remain to be defined
Sparse Representation of Astronomical Images
Sparse representation of astronomical images is discussed. It is shown that a
significant gain in sparsity is achieved when particular mixed dictionaries are
used for approximating these types of images with greedy selection strategies.
Experiments are conducted to confirm: i)Effectiveness at producing sparse
representations. ii)Competitiveness, with respect to the time required to
process large images.The latter is a consequence of the suitability of the
proposed dictionaries for approximating images in partitions of small
blocks.This feature makes it possible to apply the effective greedy selection
technique Orthogonal Matching Pursuit, up to some block size. For blocks
exceeding that size a refinement of the original Matching Pursuit approach is
considered. The resulting method is termed Self Projected Matching Pursuit,
because is shown to be effective for implementing, via Matching Pursuit itself,
the optional back-projection intermediate steps in that approach.Comment: Software to implement the approach is available on
http://www.nonlinear-approx.info/examples/node1.htm
Vasoactive intestinal peptide in human nasal mucosa
Vasoactive intestinal peptide (VIP), which is present with acetylcholine in parasympathetic nerve fibers, may have important regulatory functions in mucous membranes. The potential roles for VIP in human nasal mucosa were studied using an integrated approach. The VIP content of human nasal mucosa was determined to be 2.84 +/- 0.47 pmol/g wet weight (n = 8) by RIA. VIP-immunoreactive nerve fibers were found to be most concentrated in submucosal glands adjacent to serous and mucous cells. 125I-VIP binding sites were located on submucosal glands, epithelial cells, and arterioles. In short-term explant culture, VIP stimulated lactoferrin release from serous cells but did not stimulate [3H]glucosamine-labeled respiratory glycoconjugate secretion. Methacholine was more potent than VIP, and methacholine stimulated both lactoferrin and respiratory glycoconjugate release. The addition of VIP plus methacholine to explants resulted in additive increases in lactoferrin release. Based upon the autoradiographic distribution of 125I-VIP binding sites and the effects on explants, VIP derived from parasympathetic nerve fibers may function in the regulation of serous cell secretion in human nasal mucosa. VIP may also participate in the regulation of vasomotor tone
UTILIZAÇÃO DE RECURSOS PARA MUDANÇA DE CONTEÚDO ESTRATÉGICO: UM ESTUDO COMPARATIVO DE CASOS EM PEQUENAS EMPRESAS DE MASSAS ALIMENTÍCIAS NO PARANÁ
Este estudo procura identificar quais são os principais recursos utilizados
para execução de mudanças de conteúdo estratégico em três pequenas empresas de
massas alimentícias. A coleta de dados constituiu-se de entrevistas com utilização de
questionário semi-estruturado, bem como anotações de campo, observação não
participante e, ainda, informações obtidas por meio de dados secundários. São
entrevistados os dirigentes do nível tático-estratégico. A partir de análise de conteúdo e
técnica de triangulação chega-se aos principais recursos utilizados pelas empresas. Num
primeiro momento, destacam-se os recursos arquitetura estratégica e os organizacionais.
A arquitetura estratégica está vinculada aos relacionamentos da empresa com outras
organizações, enquanto que os organizacionais são de caráter interno. Em sentido estrito,
recursos organizacionais e arquitetura estratégica formam um único tipo de recurso
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