Self-organized public key management in MANETs with enhanced security and without certificate-chains

In the self-organized public key management approaches, public key verification is achieved through verification routes constituted by the transitive trust relationships among the network principals. Most of the existing approaches do not distinguish among different available verification routes. Moreover, to ensure stronger security, it is important to choose an appropriate metric to evaluate the strength of a route. Besides, all of the existing self-organized approaches use certificate-chains for achieving authentication, which are highly resource consuming. In this paper, we present a self-organized certificate-less on-demand public key management (CLPKM) protocol, which aims at providing the strongest verification routes for authentication purposes. It restricts the compromise probability for a verification route by restricting its length. Besides, we evaluate the strength of a verification route using its end-to-end trust value. The other important aspect of the protocol is that it uses a MAC function instead of RSA certificates to perform public key verifications. By doing this, the protocol saves considerable computation power, bandwidth and storage space. We have used an extended strand space model to analyze the correctness of the protocol. The analytical, simulation, and the testbed implementation results confirm the effectiveness of the proposed protocol. (c) 2014 Elsevier B.V. All rights reserved.

The art of human rights : enriching the life of the law school through drawings and other visual resource

In the life of the Law School, focus on the “visual” can operate at three different levels: learning, teaching, and examining (legal concepts). My main interest in this paper is to explore the latter level, “examining”, broadly considered so as to encompass evaluation in general. Furthermore, that interest is pinned down here to the area of constitutional rights and human rights in general, even though the conclusions reached can (and should) likely be extrapolated to other areas of the law... In effect, the first logical step regarding the relevance of the visual approach has to do with using it yourself when you study —assuming that you came to the conclusion that you are a “visual learner”. As you know, VARK theorists propose a quadripartite classification of learners. The acronym VARK stands for Visual, Aural, Read/write, and Kinesthetic sensory modalities that are used for learning information. This model was designed in the late 80s by Neil Fleming and it has received some acceptance and a lot of attention...

Sediment budget: principals and applications

The framework of sediment budget concepts provides a formalized procedure to account for the various components of sediment flux and the changes of volume that occur within a given region. Sediment budget methodology can be useful in a number of coastal engineering and research applications, including: inferring the amount of onshore sediment transport for a nearshore system that contains an "excess of sediment", determining sediment deficits to downdrift beaches as a result of engineering works at navigational entrances, evaluating the performance of a beach nourishment project, inferring the distribution of longshore sediment transport across the surf zone, etc. This chapter reviews briefly the governing equations for sediment budget calculations, considers various measurement and other bases for determining the sediment flux components necessary to apply the sediment budget concept and finally for illustration purposes, applies the sediment budget concept to several examples. (PDF contains 52 pages.)

Student Engagement in the School: Interpersonal and Inter-Center Differences

Traducido al castellano e inglés

The use of aerial photographs for estimating school sizes of cetaceans

ENGLISH: The accuracy and precision of dolphin school size estimates based on aerial photograph counts were examined using data collected on recent aerial and ship surveys. These estimates were found to be accurate during a 1979research cruise aboard a tuna purse-seiner; dolphin schools were photographed from the ship’s helicopter, encircled with the purse-seine, and then counted as the dolphins were released from the net. A comparison of photographic estimates with these counts indicated that the relationship was fairly close and gave no indication of significantly differing from 1:1. During a 1980 aerial study, photographic estimates from different schools, passes, and camera formats were compared and were found to be quite precise with a standard deviation of approximately 60/0 of school size. Photographic estimates were also compared with estimates made by aerial observers. Most observers tended to underestimate school size, particularly for large schools. The variability among observers was high, indicating that observers should be individually calibrated. SPANISH: Se examinó la exactitud y la precisión de las estimaciones de la magnitud de los cardúmenes de delfines basadas en el cálculo de las fotografías aéreas, usando los datos obtenidos en los últimos reconocimientos aéreos y de los barcos. En 1979, durante un crucero de investigación en un cerquero atunero, se encontró que estas estimaciones eran acertadas; se fotografiaron los cardúmenes de delfines desde un helicóptero del barco, cercados con la red y luego se contaron a medida que se libraban los delfines de la red. Una comparación de las estimaciones fotográficas con estos cálculos indicó que la relación era bastante aproximada y no hubo indicación que se diferenció significativamente de la razón 1:1. Durante un estudio aéreo en 1980, se compararon las estimaciones fotográficas de diferentes del cardúmenes, en los pases y los formatos de las cámaras y se encontró que eran bastante precisos, con una desviación normal de cerca del 60/0 de la magnitud cardumen. Se compararon también las estimaciones fotográficas con las estimaciones realizadas por los observadores aéreos. La mayoría de los observadores tienden a subestimar la magnitud de los cardúmenes, especialmente los cardúmenes grandes. La variabilidad entre los observadores fue elevada, lo que indica que se deben calibrar individualmente los datos de observadores. (PDF contains 39 pages.)

The nutritional status of pre-school children, Kainji Lake communities, Nigeria: a baseline survey

This survey was carried out to provide the Kainji Lake Fisheries Promotion Project (KLFPP), whose overall goal is the improvement of the standard of living of fishing communities around Kainji Lake, Nigeria, and an increase in the availability of fish to consumers, with nutritional status baseline data for long-term monitoring and evaluation of the overall project goal. In a cross-sectional survey, baseline anthropometric data was collected from 768 children, aged 3-60 months in 389 fisherfolk households around the southern sector of Kainji Lake, Nigeria. In addition, data was collected on the nutritional status and fertility of the mothers, vaccination coverage of children and child survival indicators. For control purposes, 576 children and 292 mothers from non-fishing households around Kainji Lake were likewise covered by the survey. A standardised questionnaire was used to collect relevant information, while anthropometric measurements were made using appropriate equipment. Data compilation and analysis was carried out with DATAEASE registered and EPI-INFO registered software, using NCHS reference data for the analysis of anthropometric measurements. The prevalence of stunted children in fishing households was high at 40%, while the prevalence of wasted and underweight children was likewise high at 10% and 29% respectively. Children from non-fishing households had a marginally lower prevalence of stunting, wasting and underweight with 37%, 7% and 25 % respectively, although these differences were not statistically significant. Considering the fact that the survey was carried out during a period of relative food abundance, the prevalence of wasting and underweight children is likely to be much higher during periods of food shortage. The prevalence of stunting, wasting and underweight was relatively high for children aged 3 to 23 months, suggesting an increased risk of malnutrition during this period, most likely associated with inadequate weaning practices. The prevalence of malnourishment amongst women of child-bearing age was relatively high, irrespective of occupation of the household, with an average of 11% undernourished and 6% wasted. Vaccination coverage was very low while infant and child mortality were extremely high with about 1 in 5 children dying before their fifth birthday. Based on the ethical obligation to maximise the potential benefits of the survey, recommendations for activities to improve community nutrition and health were made for communication to relevant authorities. (PDF contains 52 pages)

The nutritional status of pre-school children, Kainji Lake communities, Nigeria: a follow-up survey

This survey was carried out to provide the Kainji Lake Fisheries Promotion Project (KLFPP), whose overall goal is the improvement of the standard of living of fishing communities around Kainji Lake, Nigeria, managing the fisheries on a sustainable basis, with follow-up data for long-term monitoring and evaluation of the overall project goal. A similar survey, conducted in 1996, provided the baseline against which data from the current survey was evaluated. In a cross-sectional survey, anthropometric data was collected from 576 children aged 3-60 months in 282 fisherfolk households around the southern sector of Kainji Lake, Nigeria. In addition, data was collected on the nutritional status and fertility of the mothers, vaccination coverage of children and child survival indicators. For control purposes, 374 children and 181 mothers from non-fishing households around Kainji Lake were likewise covered by the survey. A standardised questionnaire was used to collect relevant data, while anthropometric measurements were made using appropriate equipment. Data compilation and analysis was carried out with a specially designed Microsoft Access application, using NCHS reference data for the analysis of anthropometric measurements. Statistical significance testing was done using EPI-INFO" software. The results of the follow-up survey indicate a slight increase in the percentage of stunted pre-school children in fishing households around Kainji Lake, from 40% in 1996 to 41% in 1999. This increase is however not statistically significant (p= 0.704). Over the same period, the percentage of stunted children in non-fishing households increased from 37% to 39% (p= 0.540), which is also not statistically significant. Likewise, there were no statistically significant differences between the 1996 and 1999 results for the prevalence of either wasted or underweight children in fishing households. The same applies to children from non-fishing households. In addition, vaccination coverage remains very low while infant and child mortality rates continue to be extremely high with about 1 in 5 children dying before their fifth birthday. There has been no perceptible and lasting improvement in the standard of living of fishing households over the course of the second project phase as indicated by the persistently high prevalence of stunting. The situation is the same for the control group, indicating that for the region as a whole, a number of factors beyond the immediate influence of the project continue to negatively impact on the standard of living. The results also show that the project activities have not had any negative long-term effect on the nutritional status of the beneficiaries. (PDF contains 44 pages)

Conselhos escolares nas escolas municipais de Duque de Caxias:tensões e perspectivas

A pesquisa objetivou investigar a formação dos conselheiros escolares nas Escolas Municipais de Duque de Caxias a partir da adesão do Município ao Programa Nacional de Fortalecimento dos Conselhos Escolares, coordenado pela Secretaria de Educação Básica do Ministério da Educação. Como o exame das ações do Programa e a identificação das mesmas no referido município perpassam pelos níveis macro, meso e micro do sistema educacional, a metodologia constituiu-se de pesquisa bibliográfica, análise de documentos, construção e retrospectiva histórica em torno do princípio da gestão democrática e dos conselhos escolares; de entrevistas no MEC, na Secretaria Municipal de Educação, com os diretores de duas escolas da rede de ensino e grupo focal com o Conselho Escolar, além da observação nas escolas. Tendo como base o princípio da democracia e a construção da prática democrática nas escolas, por meio da gestão, percebem-se os conselhos escolares como segmentos representativos, tanto da possibilidade de transformação como de manutenção dos processos que envolvem a transparência, a autonomia e a participação da comunidade escolar na gestão das escolas. A verificação das ações de um Programa governamental em escala nacional, envolvendo a colaboração entre os entes federados, permite desmistificar o distanciamento entre as esferas dos sistemas de ensino neste processo que envolve a capacitação dos conselheiros escolares. A pesquisa revelou que, embora o Município de Duque de Caxias tenha aderido ao Programa, ainda não promoveu ações no sentido de formação de seus Conselheiros Escolares. Não obstante, uma das escolas observadas no estudo promove uma dinâmica articulada, em seu funcionamento, no que se refere à participação da comunidade escolar e local na gestão da escola

Sentidos e significados sobre o choro das crianças nas creches públicas do Município de Juiz de Fora/MG

O objetivo desta tese consistiu em saber se os sentidos compartilhados e os significados construídos sobre o choro das crianças nas creches públicas do município de Juiz de Fora, durante as sessões reflexivas com as coordenadoras/diretoras, produzem espaços de reflexão teórica sobre as práticas capazes de criar uma prática de reflexão. Pelo tipo de problema formulado optei por trabalhar a perspectiva metodológica a partir do paradigma crítico de pesquisa, concretizado na modalidade de pesquisa crítica de colaboração, com enfoque sócio-histórico-cultural. Isto se justifica porque busco compreender o lugar do choro das crianças nas práticas das coordenadoras/diretoras, procurando identificar se a consciência das ações institucionalizadas pode produzir mudanças nas práticas no interior das creches. O corpus discurso da tese constitui-se de 10 sessões reflexivas, cujos dados produzidos foram organizados e analisados a partir da perspectiva teórico-metodológica dos Núcleos de Significação de Aguiar e Ozella (2006). O campo teórico está circunscrito no diálogo entre Vigotski, Bakhtin e Wallon. Isso porque estes autores contribuíram, sobremaneira, para a discussão sobre sentido, significado; linguagem e consciência, zona de desenvolvimento proximal, além do estudo da emoção, em especial, sobre a manifestação do choro da criança no contexto da creche. A arquitetura dos Núcleos de Significação revelou a necessidade de aprofundar questões relacionadas aos diversos olhares para o choro da criança; estratégias para lidar com o choro a partir da visão das coordenadoras/diretoras; o controle/descontrole/não controle do choro; a inter-relação do choro, da creche e da família e, finalmente, a reflexão teórico-prática como possibilidade de reverberação no cotidiano da creche. As análises confirmaram três premissas básicas: a) que a emoção constitui-se como o primeiro recurso de interação com o outro, que antecede a própria representação simbólica e por isso é valioso o aprofundamento deste assunto em cursos de formação; b) quando tornamos a cena vivida mais clara, essa clareza pode trazer elementos para outras possíveis intervenções, para outros possíveis diálogos sobre o choro da criança. A perspectiva de transformação pode acontecer exatamente no diálogo entre o cotidiano, a história e espaços de reflexão; c) que o fundamental, nos contextos de formação, é não focalizar apenas o conteúdo a ser transmitido sem possibilidade de reflexão sobre o próprio contexto a que se destina porque é pelo possível distanciamento e necessário estranhamento das práticas rotineiras, esporadicamente ou quase nunca questionadas, que a reflexão e a crítica se estabelecem.

Noções para persuadir e educar: os discursos médico-higiênicos na formação e ofício do professorado primário (1914-1928)

O projeto de higienização, com efeitos sentidos ainda no século XIX, atravessou as primeiras décadas dos novecentos propondo intervenções cada vez mais incisivas na população brasileira, porém pautadas no princípio da educação higiênica. O pressuposto de que era necessário conscientizar e educar higienicamente a população, ao invés de impor apenas a obediência a medidas legislativas, tornou a escola primária um dos principais escopos das iniciativas em proveito da formação de hábitos sadios. Este olhar sobre a escola primária exigiu do professorado o preparo para lidar com tais desafios. Esta dissertação situa- se no âmbito da proposta de refletir acerca da interferência dos discursos e conhecimentos médico-higiênicos na formação e ofício da docência primária. Para tal efeito, tomamos como algumas das principais fontes os compêndios escolares de higiene, endereçados às escolas normais, bem como os programas da disciplina, produzidos para conduzir o ensino na Escola Normal do Distrito Federal. Tendo em vista que este aparato didático-pedagógico, composto pelos compêndios e pela disciplina de Higiene, manteve forte relação com o que se difundiu acerca do professorado primário a respeito de seu papel na campanha higiênica , também fez parte da perspectiva deste estudo o exame dos discursos proferidos nos congressos médicos e educacionais. Tais discursos nos auxiliaram no sentido de perceber a retórica que requisitava o alargamento do papel do professorado primário, no contexto das primeiras décadas do século XX, impulsionando uma suposta adequação do plano de formação docente às emergências da saúde pública. Ademais, as iniciativas voltadas para o aperfeiçoamento dos professores primários, fora das escolas normais, também se expressaram como discursos destas novas atribuições: tratamos dos cursos de aperfeiçoamento em higiene, promovidos por instituições distintas. Tornava-se necessário disciplinar a infância e suscitar nela novos hábitos. Portanto, os professores primários foram convocados a se constituírem braços direitos dos higienistas.

Modified sorting technique to mitigate the collateral mortality of trawled school prawns (Metapenaeus macleayi)

The potential for changes to onboard handling practices in order to improve the fate of juvenile school prawns (Metapenaeus macleayi) discarded during trawling were investigated in two Australian rivers (Clarence and Hunter) by comparing a purpose-built, water-filled sorting tray against a conventional dry tray across various conditions, including the range of typical delays before the start of sorting the catch (2 min vs. 15 min). Juvenile school prawns (n= 5760), caught during 32 and 16 deployments in each river, were caged and sacrificed at four times: immediately (T0), and at 24 (T24), 72 (T72), and 120 (T12 0) hours after having been discarded. In both rivers, most mortalities occurred between T0 and T24 and, after adjusting for control deaths (<12%), were greatest for the 15-min conventional treatment (up to 41% at T120). Mixed-effects logistic models revealed that in addition to the sampling time, method of sorting, and delay in sorting, the weight of the catch, salinity, and percentage cloud cover were significant predictors of mortality. Although trawling caused some mortalities and comparable stress (measured as L -lactate) in all school prawns, use of the water tray lessened the negative impacts of some of the above factors across both the 2-min and 15-min delays in sorting so that the overall discard mortality was reduced by more than a third. When used in conjunction with selective trawls, widespread application of the water tray should help to improve the sustainability of trawling for school prawns.

Impact of Cyberprogram 2.0 on Different Types of School Violence and Aggressiveness

Some antibullying interventions have shown positive outcomes with regard to reducing violence. The aim of the study was to experimentally assess the effects on school violence and aggressiveness of a program to prevent and reduce cyberbullying. The sample was comprised of a randomly selected sample of 176 adolescents (93 experimental, 83 control), aged 13-15 years. The study used a repeated measures pre-posttest design with a control group. Before and after the program, two assessment instruments were administered: the "Cuestionario de Violencia Escolar-Revisado" (CUVE-R [School Violence Questionnaire- Revised]; Alvarez Garcia et al., 2011) and the "Cuestionario de agresividad premeditada e impulsiva" (CAPI-A [Premeditated and Impulsive Aggressiveness Questionnaire]; Andreu, 2010). The intervention consisted of 19 one-hour sessions carried out during the school term. The program contains 25 activities with the following objectives: (1) to identify and conceptualize bullying/cyberbullying; (2) to analyze the consequences of bullying/cyberbullying, promoting participants' capacity to report such actions when they are discovered; (3) to develop coping strategies to prevent and reduce bullying/cyberbullying; and (4) to achieve other transversal goals, such as developing positive variables (empathy, active listening, social skills, constructive conflict resolution, etc.). The pre-posttest ANCOVAs confirmed that the program stimulated a decrease in: (1) diverse types of school violence teachers' violence toward students (ridiculing or publicly humiliating students in front of the class, etc.); students' physical violence (fights, blows, shoves... aimed at the victim, or at his or her property, etc.); students' verbal violence (using offensive language, cruel, embarrassing, or insulting words... toward classmates and teachers); social exclusion (rejection or exclusion of a person or group, etc.), and violence through Information and Communication Technologies (ICT; violent behaviors by means of electronic instruments such as mobile phones and the Internet); and (2) premeditated and impulsive aggressiveness. Pre-posttest MANCOVA revealed differences between conditions with a medium effect size. This work contributes an efficacious intervention tool for the prevention and reduction of peer violence. The conclusions drawn from this study have interesting implications for educational and clinical intervention.