A survey on key management mechanisms for distributed Wireless Sensor Networks

Wireless Sensor Networks (WSNs) have a vast field of applications, including deployment in hostile environments. Thus, the adoption of security mechanisms is fundamental. However, the extremely constrained nature of sensors and the potentially dynamic behavior of WSNs hinder the use of key management mechanisms commonly applied in modern networks. For this reason, many lightweight key management solutions have been proposed to overcome these constraints. In this paper, we review the state of the art of these solutions and evaluate them based on metrics adequate for WSNs. We focus on pre-distribution schemes well-adapted for homogeneous networks (since this is a more general network organization), thus identifying generic features that can improve some of these metrics. We also discuss some challenges in the area and future research directions. (C) 2010 Elsevier B.V. All rights reserved.

Integrating toxicity testing in the wastewater management of chemical storage terminals - A proposal based on a ten-year study

Wastewater control at storage terminals of liquid chemical products in bulk is very difficult because of the variety of products handled in the facilities generating effluents of variable composition. The main objective of this work was to verify if the Vibrio fischeri acute toxicity test could be routinely included in the wastewater management of those facilities along with physical and chemical analysis in order to evaluate and improve the quality of the generated effluents. The study was performed in two phases before and after the implementation of better operational practices/treatment technologies. Chemical oxygen demand (COD) and toxicity of treated effluents did not correlate showing that effluents with low COD contain toxic substances and non-biodegradable organic matter, which may be not degraded when discharged into the aquatic environment. Segregation of influents or pre-treatment based on toxicity results and biodegradability index were implemented in the facilities generating significant improvements in the quality of final effluents with reduction of Biochemical oxygen demand (BOD) and toxicity. The integration of physical and chemical analysis with the V.fischeri toxicity test turned out to be an excellent tool for wastewater management in chemical terminals allowing rapid decision making for pollution control and prevention measures. Reuse of rain water was also proposed and when implemented by the facilities resulted in economical and environmental benefits. (C) 2010 Elsevier B.V. All rights reserved.

Surgical management of glomus jugulare tumors: a proposal for approach selection based on tumor relationships with the facial nerve Clinical article

Object. The goal of this paper is to analyze the extension and relationships of glomus jugulare tumor with the temporal bone and the results of its surgical treatment aiming at preservation of the facial nerve. Based on the tumor extension and its relationships with the facial nerve, new criteria to be used in the selection of different surgical approaches are proposed. Methods. Between December 1997 and December 2007, 34 patients (22 female and 12 male) with glomus jugulare tumors were treated. Their mean age was 48 years. The mean follow-up was 52.5 months. Clinical findings included hearing loss in 88%, swallowing disturbance in 50%, and facial nerve palsy in 41%. Magnetic resonance imaging demonstrated a mass in the jugular foramen in all cases, a mass in the middle ear in 97%, a cervical mass in 85%, and an intradural mass in 41%. The tumor was supplied by the external carotid artery in all cases, the internal carotid artery in 44%, and the vertebral artery in 32%. Preoperative embolization was performed in 15 cases. The approach was tailored to each patient, and 4 types of approaches were designed. The infralabyrinthine retrofacial approach (Type A) was used in 32.5%; infralabyrinthine pre- and retrofacial approach without occlusion of the external acoustic meatus (Type B) in 20.5%; infralabyrinthine pre- and retrofacial approach with occlusion of the external acoustic meatus (Type C) in 41 W. and the infralabyrinthine approach with transposition of the facial nerve and removal of the middle ear structures (Type D) in 6% of the patients. Results. Radical removal was achieved in 91% of the cases and partial removal in 9%. Among 20 patients without preoperative facial nerve dysfunction, the nerve was kept in anatomical position in 19 (95%), and facial nerve function was normal during the immediate postoperative period in 17 (85%). Six patients (17.6%) had a new lower cranial nerve deficit, but recovery of swallowing function was adequate in all cases. Voice disturbance remained in all 6 cases. Cerebrospinal fluid leakage occurred in 6 patients (17.6%), with no need for reoperation in any of them. One patient died in the postoperative period due to pulmonary complications. The global recovery, based on the Karnofsky Performance Scale (KPS), was 100% in 15% of the patients, 90% in 45%, 80% in 33%, and 70% in 6%. Conclusions. Radical removal of glomus jugulare tumor can be achieved without anterior transposition of the facial nerve. The extension of dissection, however, should be tailored to each case based on tumor blood supply, preoperative symptoms, and tumor extension. The operative field provided by the retrofacial infralabyrinthine approach, or the pre- and retrofacial approaches. with or without Closure of the external acoustic meatus, allows a wide exposure of the jugular foramen area. Global functional recovery based on the KPS is acceptable in 94% of the patients. (DOI: 10.3171/2008.10.JNS08612)

Clinical management and subsequent healing of teeth with horizontal root fractures

Horizontal root fractures are uncommon, mainly occurring on the cervical and middle third of the root of permanent upper incisors. The diagnosis is essentially radiographic and requires different healing patterns, depending on some pre- and postinjury factors. The aim of this article was to report the clinical management and different healing types in three cases of horizontal root fractures on permanent dentition. In case 1, the pulp tissue was vital and no treatment was necessary. In case 2, a root canal treatment of the cervical fragment was necessary and in case 3, pulpal necrosis was verified and an apical surgery was performed.

Clinical management for epidermolysis bullosa dystrophica

Epidermolysis bullosa (EB) consists of a group of genetic hereditary disorders in which patients frequently present fragile skin and mucosa that form blisters following minor trauma. More than 20 subtypes of EB have been recognized in the literature. Specific genetic mutations are well characterized for most the different EB subtypes and variants. The most common oral manifestations of EB are painful blisters affecting all the oral surfaces. Dental treatment for patients with EB consists of palliative therapy for its oral manifestations along with typical restorative and periodontal procedures. The aim of this article is to describe two dental clinical treatments of recessive dystrophic EB cases and their specific clinical manifestations. The psychological intervention required during the dental treatment of these patients is also presented.

Management of a complex dentoalveolar trauma: a case report

This paper describes the case of a 12-year-old male patient who presented a severe lateral luxation of the maxillary central incisors due to a bicycle fall. Treatment involved suture of the soft tissues lacerations, and repositioning and splinting of the injured teeth, followed by endodontic treatment and periodontal surgery. After a 2-year follow-up, clinical and radiographic evaluation revealed that the incisors presented satisfactory esthetic and functional demands.

Production and body composition traits of broilers in relation to breast weight evaluated by path analysis

Breast weight has great economic importance in poultry industry, and may be associated with other variables. This work aimed to estimate phenotypic correlations between performance (live body weight at 7 and 28 days, and at slaughter, and depth of the breast muscle measured by ultrasonography), carcass (eviscerated body weight and leg weight) and body composition (heart, liver and abdominal fat weight) traits in a broiler line, and quantify the direct and indirect influence of these traits on breast weight. Path analysis was used by expanding the matrix of partial correlation in coefficients which give the direct influence of one trait on another, regardless the effect of the other traits. The simultaneous maintenance of live body weight at slaughter and eviscerated body weight in the matrix of correlations might be harmful for statistical analysis involving systems of normal equations, like path analysis, due to the observed multicollinearity. The live body weight at slaughter and the depth of the breast muscle as measured by ultrasonography directly affected breast weight and were identified as the most responsible factors for the magnitude of the correlation coefficients obtained between the studied traits and breast weight. Individual pre-selection for these traits could favor an increased breast weight in the future reproducer candidates of this line if the broilers' environmental conditions and housing are maintained, since the live body weight at slaughter and the depth of breast muscle measured by ultrasonography were directly related to breast weight.

Fire management and the nesting of Athene cunicularia (Aves, Strigidae) in grasslands in central Cerrado, Brazil

Fire management is a common practice in several reserves in the Cerrado, but its influences on bird reproduction remain unknown. In addition, the nesting biology of the Burrowing Owl (Athene cunicularia) has been studied in numerous environments, but not in tropical grasslands managed by fire. This study examined the effects of fire management on the nesting biology of A. cunicularia in Emas National Park, State of Goias, central Brazilian Cerrado. We compared the number of breeding pairs and their burrows in October and November 2009 at 15 study sites in grasslands managed by fire (firebreaks) and unmanaged grasslands adjacent to and distant from firebreaks. We visited active burrows two-four times and described the burrow entrances and sentinel sites and counted and observed adults and young. A total of 19 burrows were found at firebreaks. One and two burrows were found in grasslands adjacent to and distant from firebreaks, respectively. For all burrows found, one to three young reached the adult size, being able to fly and/or run in early November. The 22 burrows found were in the ground, associated or not with termite and ant nests. Most (86.4%) burrows had only one entrance. Only three burrows had two or three entrances. Structures used as sentinel perches by adults were mounds in front of the burrow entrances, termite nests, shrubs and trees. Most of these sentinel sites were shorter than 2 m high and located less than 10 m from the burrow entrance. At Emas National Park, firebreaks appear to provide more attractive conditions to the nesting of A. cunicularia than unmanaged grasslands, likely because of the short herbaceous stratum due to frequent burning of firebreaks. This study suggests that fire management provides suitable conditions for the successful reproduction of A. cunicularia in firebreaks at Emas National Park.

Pre-processing for noise detection in gene expression classification data

Due to the imprecise nature of biological experiments, biological data is often characterized by the presence of redundant and noisy data. This may be due to errors that occurred during data collection, such as contaminations in laboratorial samples. It is the case of gene expression data, where the equipments and tools currently used frequently produce noisy biological data. Machine Learning algorithms have been successfully used in gene expression data analysis. Although many Machine Learning algorithms can deal with noise, detecting and removing noisy instances from the training data set can help the induction of the target hypothesis. This paper evaluates the use of distance-based pre-processing techniques for noise detection in gene expression data classification problems. This evaluation analyzes the effectiveness of the techniques investigated in removing noisy data, measured by the accuracy obtained by different Machine Learning classifiers over the pre-processed data.

Reuniões de pais na educação infantil: modos de gestão

O artigo discute a relação entre escolas e famílias no contexto da educação infantil por meio da análise de reuniões de pais. Fundamenta-se em um estudo de caso qualitativo sobre 11 reuniões, realizadas em duas escolas municipais de educação infantil paulistanas. Foram analisados os diferentes modos de gestão pelo professor, segundo três aspectos: forma (pauta), conteúdo (temas), dinâmica (relações entre professor e pais). Os resultados indicaram modos de gestão que dificultam a participação dos pais e descaracterizam os objetivos das reuniões: forma desorganizada e rígida; conteúdo burocrático e comportamental; dinâmica fragmentada e centralizada. Ao mesmo tempo, identificaram-se indicadores que favorecem a construção de uma relação mais cooperativa durante as reuniões, correspondentes aos modos de gestão: forma compartilhada, conteúdo educacional e dinâmica coletiva. Os autores destacam a necessidade de registro e de avaliação coletiva das reuniões de pais, visando à articulação com o projeto pedagógico, o currículo e a dimensão didática

Evaluation of a simple hyphenated system for flow injection solid-phase pre-concentration and capillary electrophoresis

In this work, the development and evaluation of a hyphenated flow injection-capillary electrophoresis system with on-line pre-concentration is described. Preliminary tests were performed to investigate the influence of flow rates over the analytical signals. Results revealed losses in terms of sensitivity of the FIA-CE system when compared to the conventional CE system. To overcome signal decrease and to make the system more efficient, a lower flow rate was set and an anionic resin column was added to the flow manifold in order to pre-concentrate the analyte. The pre-concentration FIA-CE system presented a sensitivity improvement of about 660% and there was only a small increase of 8% in total peak dispersion. These results have confirmed the great potential of the proposed system for many analytical tasks especially for low concentration samples.

Hydrodynamics and suspended sediment transport in the Camboriú estuary - Brazil: pre jetty conditions

Estuarine hydrodynamics is a key factor in the definition of the filtering capacity of an estuary and results from the interaction of the processes that control the inlet morphodynamics and those that are acting in the mixing of the water in the estuary. The hydrodynamics and suspended sediment transport in the Camboriú estuary were assessed by two field campaigns conducted in 1998 that covered both neap and spring tide conditions. The period measured represents the estuarine hydrodynamics and sediment transport prior to the construction of the jetty in 2003 and provides important background information for the Camboriú estuary. Each field campaign covered two complete tidal cycles with hourly measurements of currents, salinity, suspended sediment concentration and water level. Results show that the Camboriú estuary is partially mixed with the vertical structure varying as a function of the tidal range and tidal phase. The dynamic estuarine structure can be balanced between the stabilizing effects generated by the vertical density gradient, which produces buoyancy and stratification flows, and the turbulent effects generated by the vertical velocity gradient that generates vertical mixing. The main sediment source for the water column are the bottom sediments, periodically resuspended by the tidal currents. The advective salt and suspended sediment transport was different between neap and spring tides, being more complex at spring tide. The river discharge term was important under both tidal conditions. The tidal correlation term was also important, being dominant in the suspended sediment transport during the spring tide. The gravitational circulation and Stokes drift played a secondary role in the estuarine transport processes.

Origem e distribuição dos nervos isquiáticos do preá

O preá do semiárido nordestino (Galea spixii Wagler, 1831) é um roedor pertencente à família Caviidae. Pouca literatura é encontrada sobre essa espécie em relação a sua morfologia e seu comportamento ambiental e reprodutivo. Com o objetivo de entender a morfologia geral, em foco, na inervação do membro pélvico dessa espécie, neste trabalho, foi explorado o nervo isquiático, o qual é o maior de todos os nervos do organismo. Foram utilizados 10 preás (cinco machos e cinco fêmeas) que vieram a óbito por causas naturais, oriundos do Centro de Multiplicação de Animais Silvestres da Universidade Federal Rural do Semiárido (CEMAS/UFERSA). Os animais foram fixados após o óbito em solução aquosa de formaldeído 10% e, após 48 horas de imersão nessa solução, foram dissecados para exposição do nervo isquiático. Dessa forma, os dados obtidos foram compilados em tabelas e expressos em desenhos esquemáticos e fotografias. Os pares de nervos isquiáticos originaram-se de raízes ventrais de L6L7S1 (70%) e de L7S1S2 (30%) e distribuíram-se pelos músculos glúteo profundo, bíceps femural, semitendinoso e semimembranoso.

Situação epidemiológica da brucelose bovina no Estado do Espírito Santo

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado do Espírito Santo. O Estado foi dividido em dois circuitos produtores. Em cada circuito foram amostradas aleatoriamente cerca de 300 propriedades e, dentro dessas, foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total, foram amostrados 5.351 animais, provenientes de 622 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração e as práticas de criação e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo quando pelo menos um animal foi reagente às duas provas sorológicas. Para o Estado, as prevalências de focos e de animais infectados foram, respectivamente, de 9,0% [7,0-11,6%] e 3,5% [1,9-6,4%]. Para os circuitos, as prevalências de focos e de animais infectados foram, respectivamente, de: circuito 1, 6,8% [4,5-10,2%] e 3,4% [1,3-8,6%]; circuito 2, 10,9% [7,9%-14,8%] e 3,7% [2,1-6,3%]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: utilização de inseminação artificial (OR = 7,05 [2,51-19,82]) e confinamento/semiconfinamento dos animais (OR = 2,98 [1,22-7,26]). A vacinação de fêmeas entre três e oito meses de idade foi um fator protetor (OR = 0,03 [0,01-0,1]).

Características de carcaça de ovelhas de descarte das raças Ideal e Texel terminadas em dois sistemas de alimentação

Avaliaram-se as características de carcaça de ovelhas de descarte das raças Ideal e Texel terminadas em dois sistemas de alimentação. Utilizaram-se 20 ovelhas (10 da raça Ideal e 10 da raça Texel) aleatoriamente distribuídas de acordo com o grupo genético em dois manejos alimentares (confinamento e pastagem cultivada). Os abates foram realizados quando os animais atingiram 3,5 pontos de condição corporal. Os pesos de carcaça quente (PCQ) e de carcaça fria (PCF) e os rendimentos de carcaça quente (RCQ) e de carcaça fria (RCF) das ovelhas Texel foram maiores que os das ovelhas Ideal: 27,85 e 19,04 kg; 27,08 e 18,43 kg; 47,25 e 45,20% e 45,95 e 43,72%, respectivamente. O peso dos cortes perna, paleta, pescoço e costela e os pesos de músculos, ossos e gordura da perna dos animais da raça Texel foram superiores aos obtidos na raça Ideal. Quando avaliadas em porcentagem do peso corporal, no entanto, essas características não diferiram entre as duas raças. O manejo alimentar não influenciou as características de carcaça de ovelhas de descarte. Ovelhas Texel apresentam cortes maiores que os de ovelhas Ideal.