Architectural Considerations for a Self-Configuring Routing Scheme for Spontaneous Networks

Decoupling the permanent identifier of a node from the node's topology-dependent address is a promising approach toward completely scalable self-organizing networks. A group of proposals that have adopted such an approach use the same structure to: address nodes, perform routing, and implement location service. In this way, the consistency of the routing protocol relies on the coherent sharing of the addressing space among all nodes in the network. Such proposals use a logical tree-like structure where routes in this space correspond to routes in the physical level. The advantage of tree-like spaces is that it allows for simple address assignment and management. Nevertheless, it has low route selection flexibility, which results in low routing performance and poor resilience to failures. In this paper, we propose to increase the number of paths using incomplete hypercubes. The design of more complex structures, like multi-dimensional Cartesian spaces, improves the resilience and routing performance due to the flexibility in route selection. We present a framework for using hypercubes to implement indirect routing. This framework allows to give a solution adapted to the dynamics of the network, providing a proactive and reactive routing protocols, our major contributions. We show that, contrary to traditional approaches, our proposal supports more dynamic networks and is more robust to node failures

Adaptive Deployment for Pervasive Data Gathering in Connectivity-Challenged Environments

International audienceSome current and future pervasive data driven applications must operate in "extreme" environments where end-to-end connectivity cannot be guaranteed at all times. In fact, it is likely that in these environments partitions are, rather than exceptions, part of the normal network operation. In this paper, we introduce cover, a suite of adaptive strategies to control the trajectory of "infrastructure" nodes, which are deployed to bridge network partitions and thus play a critical role in data delivery. In particular, we focus on applications where end (or target) nodes are mobile and their mobility is unknown. Our goal is then to deploy and manage infrastructure nodes so that application-level requirements such as reliable data delivery and latency are met while still limiting deployment cost and balancing the load among infrastructure nodes. Cover achieves these goals using a localized and adaptive approach to infrastructure management based on the observed mobility of target nodes. To this end, Cover takes advantage of contact opportunities between infrastructure nodes to exchange information about their covered zones, and thus, help monitor targets in a more efficient fashion. Through extensive simulations, we show how Cover's adaptive features yield a fair distribution of targets per infrastructure node based only on limited network knowledge

Opportunistic data collection through delegation

We consider a collection system where collectors move around gathering information generated by data producers. In such a system, data may remain uncollected when the number of collectors is insufficient to cover the whole population of producers. Motivated by the observation that node encounters are sufficient to build a connected relationship graph, we propose to take advantage of the inherent interactions among nodes and transform some producers into delegates. With such an approach, collectors only need to meet delegates that, in turn, are responsible for gathering data from a subset of standard producers. We achieve this goal through two contributions. First, we investigate several delegation strategies based on the relative importance of nodes in their social interactions (i.e., the node centrality). Second, by considering a prediction strategy that estimates the likelihood of two nodes meeting each other, we investigate how the delegation strategies perform on predicted traces. We evaluate the delegation strategies both in terms of coverage and size of the delegation existing real mobility data sets. We observe that delegation strategies that rely on localized information perform as well as the ones that consider a complete view of the topology.Nous considérons un système de collecte où les collectionneurs se déplacent et collectent les informations générées par les producteurs de données. Dans un tel système, les données peuvent ne pas être collectées lorsque le nombre de collectionneurs est insuffisant pour couvrir l'ensemble de la population des producteurs. Motivé par le fait que les rencontres de nœuds sont suffisants pour construire un graphe connecté, nous proposons de profiter des interactions inhérentes entre les nœuds et transformer certains producteurs en délégués. Avec une telle approche, les collectionneurs ont seulement besoin de rencontrer les délégués que, à leur tour, sont responsables de la collecte de données d'un sous-ensemble des producteurs. Nous atteignons cet objectif grâce à deux contributions. Tout d'abord, nous étudions plusieurs stratégies de délégation basée sur l'importance relative des nœuds dans leurs interactions sociales (par exemple, la centralité du nœud). Deuxièmement, en considérant une stratégie de prédiction qui donne les estimations de la probabilité d'une rencontre de deux nœuds, nous étudions les stratégies de délégation avec les traces prédit. Nous évaluons les stratégies de délégation à la fois en termes de couverture et de la taille du groupe de délégation en utilisant des traces de mobilité réelles. Nous n'observons que les stratégies de délégation qui se basent sur des informations localisées fournis aussi des bons résultats comparés aux résultats considérant une vue complète de la topologie

Utilização de diluente alternativo acrescido de frutose visando a criopreservação de sêmen suíno

This study aimed to analyze skimmed milk powder (SMP) and fructose in a new cooling curve to freeze boar semen. A total of 49 semen samples from seven boars were cryopreserved using the new curve with addition of glucose and fructose to the refrigerating diluents: Beltsville Thawing Solution (BTS + G; BTS + F) and Skimmed milk powder (SMP + G; SMP + F), totaling four experimental groups for analysis. To finish the curve, aliquots of semen were packaged in 0.5 ml straws and kept in liquid nitrogen. During the cooling curve, SMP mean spermatic vigor and motility were greater than the BTS (p < 0.05). After thawing, a decrease of spermatic force and motility in both extenders was observed, where the BTS presented spermatic vigor (2.1 ± 0.55) and motility (38 ± 21.8), presenting better results (p < 0.05). There was no statistical difference between sugars added to the BTS and SMP in spermatic force and motility (p > 0.05), although the use of fructose allowed an equalization of motility between the SMP and BTS (p > 0.05). Functionality of membrane was better preserved with the addition of fructose, in both extenders. The rate of sperm viability was significantly higher in extender containing glucose and SMP (71.8 ± 12.5). The percentage of intact acrosome was higher on the treatment containing glucose, independent of the extender (BTS + G: 81.8 ± 7.2, SMP + G: 81.4 ± 14.2). To conclude, the results suggest that the BTS is still the best option to cryopreserve and fructose could be used in boar semen cryopreservation in new cooling curve.O presente trabalho analisou o emprego do leite em pó desnatado (LPD) adicionado de frutose em uma nova curva de resfriamento para criopreservação de sêmen suíno. Um total de 49 ejaculados, de sete varrões foram criopreservados utilizando a nova curva de resfriamento com glicose e frutose adicionada aos diluentes Beltsville Thawing Solution (BTS + D; BTS + F) e Leite em pó desnatado (LPD + D; LPD + F), totalizando quatro grupos experimentais para análises. Ao final da curva, as alíquotas de sêmen foram envasadas em palhetas de 0,5 mL e mantidas em nitrogênio líquido. Durante a curva de resfriamento, a média de vigor e motilidade espermática do LPD foi maior do que do BTS (p < 0.05). Após descongelação, observou-se queda do vigor e motilidade em ambos diluentes, com o BTS apresentando melhores resultados de vigor (2,1 ± 0,55) e de motilidade (38 ± 21,8) (p < 0,05). Entretanto, o uso da frutose permitiu equiparação dos valores da motilidade entre LPD e BTS (p > 0,05). A funcionalidade de membrana foi melhor preservada com adição da frutose, em ambos os diluentes. Os dados de vitalidade espermática foram significativamente maiores no diluente contendo glicose e LPD (71,8 ± 12,5). A porcentagem de acrossomas intactos foi maior no tratamento que continha glicose, independentemente do diluente utilizado (BTS + G: 81,8 ± 7,2, SMP + G: 81,4 ± 14,2). Os resultados obtidos indicaram que o BTS, ainda é a melhor opção de criopreservação e que a frutose pode ser utilizada para criopreservação de sêmen de varrão na nova curva de resfriamento

Performance Analysis of a Privacy-Preserving Frame Sniffer on a Raspberry Pi

International audienceWi-Fi (IEEE 802.11) networks are an abundant data source that may serve different applications such as epidemic tracking and prevention, disaster response, crowdsensing, or ubiquitous urban services. Nevertheless, collecting and exploiting such data brings many privacy liabilities, considering that each transmitted frame has the MAC address (a unique device identifier) of the corresponding personal device, also considered sensitive information. Literature has shown that the MAC randomization performed by manufacturers of phones is not enough to protect devices' identification. Data obfuscation is a promising solution to avoid storing advertised identifiers of devices and prevent attackers from acquiring sensitive data. Obfuscating such identifiers while also being able to differentiate frames sent by different devices poses a significant challenge for frame capturing by low-resource IoT devices in real-time. This paper illustrates the impact of on-the-fly hashing as an obfuscating measure to protect people's privacy. Since no popular off-the-shelf sniffer (using wireshark or tcpdump) allows for on-the-fly hashing, we build upon the scapy library a custommade sniffer capable of hashing the required data needed to protect user privacy. We demonstrate the viability of this privacypreserving IoT sniffer on a Raspberry Pi platform

ADIÇÃO DE ÁCIDO FÍTICO AO DILUENTE BTS NA CONSERVAÇÃO DO SÊMEN DO VARRÃO: AVALIAÇÃO IN VIVO

The maintenance of boar semen under refrigerated conditions has been highlighted as an effective technique for the diffusion of genetic material through artificial insemination programs. In this sense, the addition of several substances, such as antioxidants, to the diluente has been used in the conservation semen from various domestic species. Thus, this study aimed to investigate the action of phytic acid added to the semen extender, conserved under refrigeration by evaluating the fertility results obtained from inseminated swine females. Four boars (Agroceres), which were used for artificial insemination as semen donors, and seventy females were used to compose the lots during the seven weeks of the experiment. The insemination lots were formed with the semen diluted in BTS (35 females) and BTS added with phytic acid at 525μM/100mL (35 females). For results evaluation, the following aspects were considered: 1) fertility rate; 2) farrowing rate; 3) total number of piglets/delivery; 4) number of live birth piglets/delivery. It was observed that the fertility and farrowing rates, as well as the prolificacy of sows inseminated with BTS and BTS added with phytic acid did not differ statistically (p>0.05). The addition of phytic acid to the BTS diluent did not influence the reproductive results of swine. Therefore, further studies must be performed to evaluate the efficacy of different phytic acid concentrations on the fertility and prolificacy of sows.A manutenção do sêmen suíno sob condições de refrigeração tem se destacado como uma técnica eficiente para a difusão do material genético, através dos programas de inseminação artificial. Neste sentido, a adição de várias substâncias, como antioxidantes, ao diluente vem sendo adotada na conservação do sêmen de diversas espécies domésticas. Assim, o objetivo deste estudo foi investigar a ação do ácido fítico adicionado ao diluente do sêmen conservado sob refrigeração, através da avaliação dos resultados de fertilidade de fêmeas suínas inseminadas. Foram utilizados quatro reprodutores (Agroceres) e setenta fêmeas para formação de lotes no decorrer de sete semanas. Os lotes de inseminação foram formados com o sêmen diluído em BTS (35 fêmeas) e BTS adicionado de ácido fítico na concentração de 525µM/100mL (35 fêmeas). Na avaliação dos resultados, considerou-se os seguintes aspectos: 1) taxa de fertilidade; 2) taxa de parição; 3) número total de leitões/parto; 4) número de leitões nascidos vivos/parto. Observou-se que as taxas de fertilidade e parição, assim como a prolificidade das porcas inseminadas com BTS e BTS adicionado de ácido fítico não diferiram estatisticamente (p>0,05). A adição do ácido fítico ao diluente BTS não influenciou os resultados reprodutivos das fêmeas suínas. Dessa forma, estudos futuros devem ser realizados a fim de avaliar a eficácia de diferentes concentrações do ácido fítico sobre a fertilidade e prolificidade de fêmeas suínas

USO DO DMSO A 3% E DIFERENTES CONCENTRAÇÕES DE GLICEROL NA CURVA DE RESFRIAMENTO DO SÊMEN SUÍNO

This study aimed to test the cryoprotectant Dimethylsulfoxide (DMSO-3%) and glycerol, in five concentrations (0.5%, 1%, 3%, 5% and 7%) in a new cooling curve. Seven collections from seven boars (n=49) through the gloved hand technique were made. DMSO (3%) and glycerol were added separately to the freezing diluent. During the analysis of the curve, the lowest mean sperm count was observed at a concentration of 7% glycerol. The concentration of 1% glycerol obtained more sperm motility (72±12.3) but, did not differ in concentrations of 5% glycerol. Higher mean sperm motility and vigor after thawing were observed at 3% glycerol, differing from 0.5% glycerol and 3% DMSO concentrations regarding vigor and other treatments regarding sperm motility. In the osmotic resistance test, 3% glycerol as a freezing agent provided better protection to the spermatic membrane, differing from the   other treatments except for 3% DMSO and 1% glycerol. A higher percentage of living cells was observed in the 5% and 7% glycerol concentration, differing from the other concentrations. The highest percentage of spermatozoa with intact acrosomes was observed when the freezing diluent containing 3% glycerol (73.8±11.9) was used. The results of this study suggested that glycerol is still the best cryoprotective option to be used in cryopreservation processes of swine sperm.Este trabalho teve como objetivo testar o crioprotetor Dimetilsulfóxido (DMSO-3%) e o glicerol, em cinco concentrações (0,5%, 1%, 3%, 5% e 7%) em uma nova curva de resfriamento. Foram feitas sete coletas de sete varrões (n=49) através da técnica da mão enluvada. O DMSO (3%) e o glicerol foram adicionados separadamente ao diluente de congelação. Durante a análise da curva, a menor média de vigor espermático foi observada à concentração de 7% de glicerol. Na concentração de 1% de glicerol obteve-se maior média de motilidade espermática (72±12,3), sem diferença em relação à concentração de 5%. Maiores médias de vigor e motilidade espermática pós-descongelação foram observadas a 3% de glicerol, diferindo das concentrações de 0,5% de glicerol e 3% de DMSO quanto ao vigor e dos demais tratamentos quanto à motilidade espermática. No teste de resistência osmótica o glicerol a 3% como diluente de congelação proporcionou melhor proteção à membrana espermática, diferindo dos demais tratamentos, exceto do DMSO a 3% e glicerol a 1%. Observou-se maior porcentagem de células vivas na concentração de 5% e 7% de glicerol, diferindo das demais concentrações. Já o maior percentual de espermatozoides com acrossomas intactos foi observado quando se utilizou o diluente de congelação contendo glicerol a 3% (73,8±11,9). Os resultados do presente estudo, sugeriram que o glicerol, ainda é a melhor opção de crioprotetor a ser utilizada nos processos de criopreservação do espermatozoide suíno

USO DE DILUENTES ALTERNATIVOS E DO ÁCIDO FÍTICO ADICIONADO AO SÊMEN SUÍNO CONSERVADO

Antioxidants are used for the preservation of semen from several domestic species. Diante disso, the present study aimed to determine the best diluent for adding different concentrations of phytic acid and verify the effects on boar sperm kept. In the step I, 60 ejaculated and three extenders were used: BTS; LPD and ACP-103®. In the step II, the BTS as best diluent of step I, has received three concentrations of phytic acid: (T1) BTS (control); BTS + 175mM of phytic acid (T2); BTS + 350mM (T3) and BTS + 525mM (T4). Daily analyzes of vigour and motility were performed, and in D0 and D4 hyposmotic and vitality and acrosomal integrity. The T4 on sperm motility was higher (p<0.05) compared to T1. Regarding the percentage of live sperm, no significant difference was found in any of the treatments tested, however, in the case of membrane integrity, T4 in D0 and D4 achieved significantly better results (p<0.05) in comparison with T1. The addition of phytic acid in BTS promoted positive effects in some analyzes, but more studies must be conducted to elucidate the effects of phytic acid on sperm metabolism.Antioxidantes são utilizados na conservação do sêmen de diversas espécies domésticas. Diante disso, o presente estudo teve como objetivo verificar o melhor diluente para adicionar diferentes concentrações de ácido fítico e verificar os efeitos sobre os espermatozoides suínos conservados. Na etapa I, 60 ejaculados e três diluentes foram utilizados: BTS; LPD e ACP-103®. Já na etapa 2, O BTS como melhor diluente da I etapa, foi acrescido de três concentrações de ácido fítico (n=60): (T1) BTS (controle); BTS+175µM de ácido fítico (T2); BTS+350µM (T3); e BTS+525µM (T4). Foram realizadas análises diárias de vigor e motilidade, e em D0 e D4 foram realizados os testes hiposmótico e de vitalidade e integridade acrossomal. A motilidade espermática no T4 foi superior (p<0,05) em relação ao T1. Em relação ao percentual de espermatozoides vivos, não houve diferença significativa em nenhum dos tratamentos testados, porém, tratando-se da integridade da membrana, o T4 em D0 e D4 obteve significativamente melhor resultado (p<0,05) em relação ao T1. A adição do ácido fítico no BTS promoveu efeitos positivos em determinadas análises, porém, mais estudos devem ser conduzidos para elucidação dos efeitos do ácido fítico sobre o metabolismo espermático

Cirurgia bariátrica: a percepção do paciente frente ao impacto físico, psicológico e social

Objetivo: compreender a percepção dos pacientes frente à realização da cirurgia bariátrica, bem como identificar o impacto físico, psicológico e social nos indivíduos após sua realização. Método: Pesquisa de campo, descritiva e exploratória de abordagem qualitativa. Foram entrevistados quinze funcionários de uma empresa particular voltada para o atendimento de saúde, que se submeteram à realização da cirurgia bariátrica. Os dados foram coletados por meio de entrevista semiestruturada e tratados por meio da técnica de análise de conteúdo temática. Resultados: Apesar das dificuldades inerentes ao procedimento, relacionadas à adaptação da dieta e desconfortos; a percepção dos participantes do estudo acerca da realização da cirurgia bariátrica é positiva, tendo em vista a melhora de sua condição física, bem como aumento da autoestima, inserção social e profissional. Destaca-se o apoio da família e acompanhamento pela equipe multidisciplinar como estratégias para o melhor alcance de resultados e superação de dificuldades. Conclusão: Conclui-se que as mudanças que ocorrem no âmbito físico, emocional, pessoal e social dos pacientes que se submetem à cirurgia bariátrica, impactam diretamente em sua qualidade de vida.