864 research outputs found
Network conduciveness with application to the graph-coloring and independent-set optimization transitions
We introduce the notion of a network's conduciveness, a probabilistically
interpretable measure of how the network's structure allows it to be conducive
to roaming agents, in certain conditions, from one portion of the network to
another. We exemplify its use through an application to the two problems in
combinatorial optimization that, given an undirected graph, ask that its
so-called chromatic and independence numbers be found. Though NP-hard, when
solved on sequences of expanding random graphs there appear marked transitions
at which optimal solutions can be obtained substantially more easily than right
before them. We demonstrate that these phenomena can be understood by resorting
to the network that represents the solution space of the problems for each
graph and examining its conduciveness between the non-optimal solutions and the
optimal ones. At the said transitions, this network becomes strikingly more
conducive in the direction of the optimal solutions than it was just before
them, while at the same time becoming less conducive in the opposite direction.
We believe that, besides becoming useful also in other areas in which network
theory has a role to play, network conduciveness may become instrumental in
helping clarify further issues related to NP-hardness that remain poorly
understood
Enumerating Cyclic Orientations of a Graph
Acyclic and cyclic orientations of an undirected graph have been widely
studied for their importance: an orientation is acyclic if it assigns a
direction to each edge so as to obtain a directed acyclic graph (DAG) with the
same vertex set; it is cyclic otherwise. As far as we know, only the
enumeration of acyclic orientations has been addressed in the literature. In
this paper, we pose the problem of efficiently enumerating all the
\emph{cyclic} orientations of an undirected connected graph with vertices
and edges, observing that it cannot be solved using algorithmic techniques
previously employed for enumerating acyclic orientations.We show that the
problem is of independent interest from both combinatorial and algorithmic
points of view, and that each cyclic orientation can be listed with
delay time. Space usage is with an additional setup cost
of time before the enumeration begins, or with a setup cost of
time
Metformin Increases HDL3-Cholesterol and Decreases Subcutaneous Truncal Fat in Nondiabetic Patients with HIV-Associated Lipodystrophy
The purpose of this study was to assess metformin effects on high-density lipoprotein (HDL) composition of patients with HIV-associated lipodystrophy (LDHIV). Twenty-four adult outpatients were enrolled to receive metformin ( 1700 mg/d) during 6 months, but 2 were lost to follow-up and 6 stopped the drug due to adverse events ( gastrointestinal in 5, and excessive weight loss in 1). From the 16 subjects who completed the study, 69% were female. At baseline, 3 and 6 months, we assessed: weight, waist and hip circumferences, blood pressure, fasting glucose and insulin, homeostasis model assessment of insulin resistance (HOMA2-IR), lipids, and HDL subfractions by microultracentrifugation. At 0 and 6 months, body fat distribution was assessed by computed tomography (CT) scan (L4 and middle femur). Metformin use was associated with reduction of mean weight (-2.4Kg at 6 months; p < 0.001), body mass index, waist, waist-to-hip ratio and a marked decrease in blood pressure (p < 0.001). Subcutaneous ( p = 0.01) and total abdominal fat (p = 0.002) were reduced, but no change was found in visceral or thigh fat. No difference was detected on plasma glucose, insulin, HOMA2-IR, cholesterol or triglycerides, except for an increase in HDL3-cholesterol (from 21 mg/dL to 24 mg/dL, p = 0.002) and a reduction of nascent HDL ( the fraction of plasma HDL-cholesterol not associated to subfractions HDL2 or HDL3) (p = 0.008). Adverse effects were very common, but most were gastrointestinal and mild. Thus, metformin use in LDHIV increases HDL3-cholesterol ( probably due to improved maturation of HDL) and decreases blood pressure, weight, waist, and subcutaneous truncal fat, making this an attractive option for preventing cardiovascular disease in this population.221077978
Evaluation of prenatal care in unit with family health strategy
We analyzed prenatal care (PN) provided at a unit of the Family Health Strategy Service in São Paulo, according to the indicators of the Program for the Humanization of Prenatal and Birth (PHPB). We compared adequacy of PN in terms of sociodemographic variables, procedures, examinations and maternal and perinatal outcomes. Cross-sectional study with data from records of 308 pregnant women enrolled in 2011. We observed early initiation of PN (82.1%), conducting of a minimum of six consultations (84.1%), puerperal consultation (89.0%); to the extent that there is a sum of the actions, there is a significant drop in the proportion of adequacy. Prenatal care was adequate for 67.9%, with a significant difference between adequacy groups in relation to gestational age and birth weight. Prenatal care deficiencies exist, especially in regards to registration of procedures, exams and immunization. The difference between adequacy groups with respect to perinatal outcomes reinforces the importance of prenatal care that adheres to the parameters of the PHPB
VISCERAL LEISHMANIASIS IN BRAZIL: SCENARIOS AND CHALLENGES FOR THE SURVEILLANCE AND CONTROL
Adaptation of the vector and displacement of infected dogs to previously disease-free areas challenges visceral leishmaniasis (VL) control, and leads to geographic dispersion and occurrence in urban and peri-urban areas. Continuous VL control measures over time must be applied with a wide geographic reach, along with better diagnosis practices and timely treatment. The high case-fatality of human VL in areas of recent introduction and its growing association with HIV impose the need for an early diagnosis, treatment and the adoption of active search for human and canine cases incorporated into the routine of periodic home visits by health professionals. The increasing on public rejection of canine euthanasia as a control measure, the limitations of canine therapy with the current available drugs, and the controversies regarding available vaccines for canine protection are discussed. Good prospects on the insecticide-impregnated collars as an effective control measure are emphasized
Avaliação das estratégias de acolhimento na Unidade de Terapia Intensiva
Trata-se de uma pesquisa qualitativa, realizada na Unidade de Terapia Intensiva (UTI) adulto de um hospital público no Sul do Brasil, que teve como objetivo avaliar as estratégias de acolhimento implementadas. Participaram 13 pacientes e 23 familiares. A coleta foi realizada de julho a outubro de 2008, com entrevistas semiestruturadas e gravadas. Para análise dos dados, utilizou-se o Discurso do Sujeito Coletivo. As informações deram origem a dois discursos: a família percebe o acolhimento e o paciente considera a equipe da UTI atenciosa. Ao incluir a família no cuidado como cliente da enfermagem, os familiares sentiram-se seguros e confiantes. Ao avaliar os resultados alcançados, destaca-se que, ao assumirem o compromisso e a responsabilidade de transformações da prática assistencial, os enfermeiros experienciaram um novo olhar para o cuidado em UTI, com enfoque no ser humano, aliando o acolhimento ao modelo assistencial que privilegia a objetividade do cuidado.Investigación cualitativa realizada en Unidad de Terapia Intensiva (UTI) de adultos de hospital público del Sur de Brasil, que objetivó evaluar las estrategias de recepción implementadas. Participaron 13 pacientes y 23 familiares. La recolección de datos se realizó entre julio y octubre de 2008, con entrevistas semiestructuradas y grabadas. Para análisis de datos, se usó Discurso del Sujeto Colectivo. Las informaciones originaron dos discursos: la familia percibe la recepción y el paciente considera al equipo de UTI atento. Al incluir a la familia en el cuidado como pacientes de enfermería, los familiares se sintieron seguros y confiados. Al evaluar los resultados alcanzados, se destaca que al asumir el compromiso y responsabilidad de transformaciones de la práctica de atención, los enfermeros experimentaron nueva visión para el cuidado en UTI, con enfoque en el ser humano, aliando la recepción al modelo de atención que privilegia la objetividad del cuidado.This qualitative study was performed at the adult Intensive Care Unit (ICU) of a public hospital in Southern Brazil with the objective to evaluate the implemented welcoming strategies. Participants included 13 patients and 23 relatives. Data collection was performed from July to October 2008, utilizing semi-structured interviews. All interviews were recorded. Data analysis was performed using the Collective Subject Discourse. The collected information yielded two discourses: the family recognized the welcoming strategies and the patients found the ICU team to be considerate. By including the family as a client of nursing care, relatives felt safe and confident. Results show that by committing to the responsibility of making changes in heath care practices, nurses experience a novel outlook towards ICU care, focused on human beings and associating the welcoming to the health care model that promotes the objectivity of care
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