838 research outputs found

    Multiscale approaches to analyse risks and vulnerabilities in the coastal zone (Brazil).

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    The objectives of this work were: (i) identified the risk areas of landslides, flooding and sea level rise and social vulnerabilities in different scales of analysis; (ii) analyse the risk perception of people living in this risk areas; (iii) found a common dialogues between sciences and communities to inform policy and decision-making in the different socioeconomic sectors

    Riscos geotécnicos e vulnerabilidades: aplicação de grade regular para representação espacial da população na zona costeira.

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    Considerando o contexto de riscos e vulnerabilidades (UNISDR, 2004; 2013; BRASIL/PNPDC, 2012; IPCC, 2012) e de mudanças climáticas (BRASIL/PNMC, 2009; IPCC, 2007; 2014) no âmbito da gestão ou de políticas públicas, caracterizar as situações de riscos e vulnerabilidades nas zonas costeiras tem sido fundamental para as agendas científicas relacionadas à temática das dimensões humanas das mudanças climáticas e ambientais. Nesse sentido que esse trabalho buscou, mais do que caracterizar essas situações, identificar possíveis padrões no perfil socioeconômico da população que influenciam sua situação de vulnerabilidade, trazendo também ao debate uma reflexão sobre as limitações dos métodos propostos para a análise da vulnerabilidade, que muitas vezes (ou quase sempre), é apenas tangencial (MARANDOLA Jr., 2009). Por meio de uma análise geoespacial, buscou-se identificar quais são os principais elementos indicativos de vulnerabilidade na zona costeira de São Paulo, por meio da integração de dois conjuntos de dados organizados em um Sistema de Informações Geográficas (SIG): riscos geotécnicos sobrepostos em uma grade regular de células de tamanho de 250 m para as áreas urbanas e de 1000 m para áreas rurais (proposta por BUENO, 2014 ? em prep.; BUENO; DAGNINO, 2011). As variáveis do meio físico consistiram em: (a) riscos geotécnicos associados com processos geológicos e hidrológicos ? escorregamentos, inundação e recalques ou subsidência do solo; (b) declividade; (c) altitude e modelo digital de elevação e variáveis. As variáveis sociodemográficas foram: (d) número de pessoas (moradores); (e) gênero (pessoas responsáveis pelo domicílio de sexo masculino e feminino); (f) renda; (g) idade; (h) raça ou cor e (i) alfabetização, todas agregadas por grades regulares ou células como unidade de análise

    Popular matchings in the marriage and roommates problems

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    Popular matchings have recently been a subject of study in the context of the so-called House Allocation Problem, where the objective is to match applicants to houses over which the applicants have preferences. A matching M is called popular if there is no other matching M′ with the property that more applicants prefer their allocation in M′ to their allocation in M. In this paper we study popular matchings in the context of the Roommates Problem, including its special (bipartite) case, the Marriage Problem. We investigate the relationship between popularity and stability, and describe efficient algorithms to test a matching for popularity in these settings. We also show that, when ties are permitted in the preferences, it is NP-hard to determine whether a popular matching exists in both the Roommates and Marriage cases

    Climate change, hazards and vulnerability: multiscale analysis in northern coast of São Paulo, Brazil.

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    This study focus into two different approaches to assess hazards and vulnerabilities: (1) the geospatial indicators and (2) modelling of debris flow and flooding events. The integration of both methods through a multiscale analysis: (i) in a regional scale, geospatial indicators show the priority watersheds for risk reduction in the different hazards - landslides, flooding and rising sea level, (ii) locally, the analysis based on a 1967s extreme event in Caraguatatuba - with rainfall variation of 115-420mm and max. 841mm - show the consistent analysis of historical data of tidal levels and the rainfall effects of flooding and debris flow in the districts of ?Santo Antônio' river basin

    Finite formation time effects in quasi-elastic (e,e)(e,e') scattering on nuclear targets

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    The problem of the final state interaction in quasi-elastic (e,e)(e,e') scattering at large Q2Q^2, is investigated by exploiting the idea that the ejected nucleon needs a finite amount of time to assume its asymptotic form. It is shown that when the dependence of the scattering amplitude of the ejected nucleon on its virtuality is taken into account, the final state interaction is decreased. The developed approach is simpler to implement than the one based on the color transparency description of the damping of the final state interaction, and is essentially equivalent to the latter in the case of the single rescattering term. The (e,e)(e,e') process on the deuteron is numerically investigated and it is shown that, at x=1x=1, appreciable finite formation time effects at Q2Q^2 of the order of 10 (GeV/c)2^2 are expected.Comment: 23 pages, 3 figure

    On continuous variable quantum algorithms for oracle identification problems

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    We establish a framework for oracle identification problems in the continuous variable setting, where the stated problem necessarily is the same as in the discrete variable case, and continuous variables are manifested through a continuous representation in an infinite-dimensional Hilbert space. We apply this formalism to the Deutsch-Jozsa problem and show that, due to an uncertainty relation between the continuous representation and its Fourier-transform dual representation, the corresponding Deutsch-Jozsa algorithm is probabilistic hence forbids an exponential speed-up, contrary to a previous claim in the literature.Comment: RevTeX4, 15 pages with 10 figure

    Many-to-one matchings with lower quotas : algorithms and complexity

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    We study a natural generalization of the maximum weight many-to-one matching problem. We are given an undirected bipartite graph G = (AUP,E) with weights on the edges in E, and with lower and upper quotas on the vertices in P. We seek a maximum weight many-toone matching satisfying two sets of constraints: vertices in A are incident to at most one matching edge, while vertices in P are either unmatched or they are incident to a number of matching edges between their lower and upper quota. This problem, which we call maximum weight many-toone matching with lower and upper quotas (wmlq), has applications to the assignment of students to projects within university courses, where there are constraints on the minimum and maximum numbers of students that must be assigned to each project. In this paper, we provide a comprehensive analysis of the complexity of wmlq from the viewpoints of classic polynomial time algorithms, fixed-parameter tractability, as well as approximability. We draw the line between NP-hard and polynomially tractable instances in terms of degree and quota constraints and provide efficient algorithms to solve the tractable ones. We further show that the problem can be solved in polynomial time for instances with bounded treewidth; however, the corresponding runtime is exponential in the treewidth with the maximum upper quota umax as basis, and we prove that this dependence is necessary unless FPT = W[1]. Finally, we also present an approximation algorithm for the general case with performance guarantee umax+1, which is asymptotically best possible unless P = NP

    Early aggressive intervention for infantile atopic dermatitis to prevent development of food allergy : a multicenter, investigator‑blinded, randomized, parallel group controlled trial (PACI Study) : protocol for a randomized controlled trial

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    Background: Atopic dermatitis is the first clinical manifestation of the atopic march, with the highest incidence in the first year of life. Those affected often go on to develop other allergic diseases including food allergy, asthma, and allergic rhinitis. Recent evidence suggests that sensitization to foods may occur through a defective skin barrier which is common in atopic dermatitis in early life. We hypothesize that therapeutic aggressive intervention to treat new onset atopic dermatitis may prevent the development of later allergen sensitization, and associated food allergy, asthma, and allergic rhinitis. Methods: This study is a multi-center, pragmatic, two-parallel group, assessor-blind, superiority, individually randomized controlled trial. Atopic dermatitis infants (N = 650) 7–13 weeks old who develop an itchy rash within the previous 28 days are randomly assigned to the aggressive treatment or the conventional treatment in a 1:1 ratio. The primary outcome is oral food challenge-proven IgE-mediated hen’s egg allergy at the age of 28 weeks. Discussion: This is a novel pragmatic RCT study to examine the efficacy of early aggressive treatment for atopic dermatitis to prevent later food allergy. If our hypothesis is correct, we hope that such a strategy might impact on disease prevention in countries where food allergy is common, and that our results might reduce the frequency and associated costs of all food allergies as well as hens egg food allergy. Long-term follow and other similar studies will help to determine whether such a strategy will reduce the burden of other allergic diseases such as asthma and allergic rhinitis

    Severe airway stenosis associated with Crohn's disease: Case report

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    BACKGROUND: Symptomatic respiratory tract involvement is not common in Crohn's disease. Upper-airway obstruction has been reported before in Crohn's disease and usually responds well to steroid treatment. CASE PRESENTATION: We report a case of a 32-year old patient with Crohn's disease who presented with progressively worsening dyspnea on exertion. Magnetic Resonance Imaging of the chest and bronchoscopy revealed severe tracheal stenosis and marked inflammation of tracheal mucosa. Histopathology of the lesion showed acute and chronic inflammation and extended ulceration of bronchial mucosa, without granulomas. Tracheal stenosis was attributed to Crohn's disease after exclusion of other possible causes and oral and inhaled steroids were administered. Despite steroid treatment, tracheal stenosis persisted and only mild symptomatic improvement was noted after 8 months of therapy. The patient subsequently underwent rigid bronchoscopy with successful dilatation and ablation of the stenosed areas and remission of her symptoms. CONCLUSION: Respiratory involvement in Crohn's disease might be more common than appreciated. Interventional pulmonology techniques should be considered in cases of tracheal stenosis due to Crohn's disease refractory to steroid treatment

    Intramucosal adenocarcinoma of the ileum originated 40 years after ileosigmoidostomy

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    <p>Abstract</p> <p>Background</p> <p>Small bowel adenocarcinomas (SBAs) are rare carcinomas. They are asymptomatic and usually neither endoscopy nor contrast studies are performed for screening</p> <p>Case presentation</p> <p>A 72-year-old Japanese male had a positive fecal occult blood test at a regular check-up in 2006. He suffered appendicitis and received an ileosigmoidostomy in 1966. A colonoscopy revealed an irregular mucosal lesion with an unclear margin at the ileum side of the anastomosis. A mucosal biopsy specimen showed adenocarcinoma histopathologically. Excision of the anastomosis was performed for this patient. The resected specimen showed a flat mucosal lesion with a slight depression at the ileum adjacent to the anastomosis. Histological examination revealed a well differentiated intramucosal adenocarcinoma (adenocarcinoma in situ). Immunohistological staining demonstrated the overexpression of p53 protein in the adenocarcinoma.</p> <p>Conclusion</p> <p>Adenocarcinoma of the ileum at such an early stage is a very rare event. In this case, there is a possibility that the ileosigmoidostomy resulted in a back flow of colonic stool to the ileum that caused the carcinogenesis of the small intestine.</p
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