75 research outputs found

    Virtual Access Points for Vehicular Networks

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    ABSTRACT This paper introduces the concept of Virtual Access Points (VAPs) for wireless Vehicular Ad-hoc Networks (VANETS). This new technique allows data dissemination among vehicles, thus extending the reach of roadside access points to uncovered road areas. Each vehicle that receives a message from an Access Point (AP) stores this message and rebroadcasts it into non covered areas. This extends the network coverage for non time critical messages. The VAP role is transparent to the connected nodes, and designed to avoid interference since each operates on a bounded region outside any AP. The experiments show the presented mechanism of store and forward at specific positions present a gain, in term of all the evaluated parameters

    Adaptation of O157:H7 and non-O157 Escherichia coli strains in orange juice and subsequent resistance to UV-C radiation

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    This study assessed the acid-adaptation of pathogenic and non-pathogenic strains of Escherichia coli in orange juice and the microbial resistance to the subsequent UV-C radiation treatment. Nine Shiga toxin-producing E. coli (STEC) and one strain of a non-pathogenic surrogate E. coli were used in this study. Each E. coli strain was inoculated in orange juice, following pre-exposure during 0, 1, 2, and 3 h at 10 °C. Then, the inoculated juices with the ten different strains separately were exposed to 0 and 2 J/cm2 of UV-C radiation. The D value (i.e., the UV-C dose in J/cm2 required to cause a one-log reduction in the target microorganism) was calculated. Further, the resistance coefficient [RC; i.e., the ratio between the D-values for the control condition (D0h) and each pre-exposure tested time (D1h, D2h, D3h)] were determined. The results indicated that the resistance of E. coli was influenced by the pre-exposure period in the orange juice, with increased resistance to UV-C observed for periods >2 h. Furthermore, the sensitivity of cells to subsequent UV-C treatment was found to be strain-dependent. The results may allow the development of more reliable UV-C radiation processes for orange juice processing aiming the inactivation of pathogenic E. coli.Fil: Oteiza, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Asistencia Técnica a la Industria; ArgentinaFil: Caturla, Magdevis Y. R.. Universidade Estadual de Campinas; BrasilFil: do Prado Silva, Leonardo. Universidade Estadual de Campinas; BrasilFil: Câmara, Antonio A.. Universidade Estadual de Campinas; BrasilFil: Barril, Patricia Angelica. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Asistencia Técnica a la Industria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sant'Ana, Anderson S.. Universidade Estadual de Campinas; BrasilFil: Giannuzzi, Leda. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Zaritzky, Noemi Elisabet. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

    Adipose Tissue-Derived Stem Cell Treatment Prevents Renal Disease Progression

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    Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 x 10(5) ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 x 10(5) ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4. IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. the renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-alpha, KC, RANTES, and IL-1 alpha. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial-mesenchymal transition.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)DECIT/Ministerio do SaudeComplex Fluids INCTUniversidade Federal de São Paulo, Div Nephrol, Escola Paulista Med, Expt & Clin Immunol Lab, BR-04023900 São Paulo, BrazilUniv São Paulo, Dept Pathol, São Paulo, BrazilUniv Fed Triangulo Mineiro, Div Pathol, Uberaba, MG, BrazilUniv São Paulo, Dept Immunol, Lab Transplantat Immunobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Escola Paulista Med, Expt & Clin Immunol Lab, BR-04023900 São Paulo, BrazilFAPESP: 09/13251-6FAPESP: 07/07139-3CNPq: 473844/2009-5Web of Scienc

    Margens cirúrgicas no dermatofibrossarcoma protuberans: relato de caso e revisão da literatura

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    Introduction: Dermatofibrosarcoma protuberans (DFSP) is a rare dermal fibrohistiocytic tumor that affects the skin, accounting for 1% of soft tissue sarcomas and representing less than0.1% of all malignancies. The main characteristic of this type of tumor is a high rate of local recurrence after surgical excision. Deciding the proper surgical margin for complete resection is a challenge. Case report: 24 year-old, shows a reddish vegetative asymptomatic tumor on the left shoulder. She has a positive family history of DFSP in the lower limb. The definitive histopathological report confirmed Dermatofibrossarcoma protuberans. Discussion: The histological feature of the tumor is the presence of tentacle type projections of neoplastic cells in the periphery extending through the subcutaneous tissue to the muscular fascia. Of course, the most important factor for local control is the achievement of free surgical margins. Excision through Mohs micrographic surgery is a great option in regions where wide excision is not desirable, as in the face. The standard margin in most pf the literature is 3 cm resected to the muscular fascia, and it can be reduced to 2 cm in places where the extensive excision impairs the conformation of the site, as in the face.Introdução: O dermatofibrossarcoma protuberante (DFSP) é um tumor fibrohistiocítico de origem dérmica raro, que acomete a pele, representando 1% dos sarcomas de partes moles e menos de 0,1% de todas malignidades. A principal característica deste tipo de tumor é a sua elevada taxa de recidiva local após excisão cirúrgica. Decidir a margem cirúrgica adequada para a ressecção completa é um desafio. Relato de caso: 24 anos, apresenta lesão tumoral vegetante avermelhada no ombro esquerdo, assintomática. Possui história familiar positiva de DFSP em membro inferior. O laudo histopatológico definitivo confirmou Dermatofibrossarcoma protuberans. Discussão: A característica histológica do tumor é a presença de projeções tipo tentáculos de células neoplásicas na periferia que se estendem através do tecido subcutâneo até a fáscia muscular. Certamente, o fator de maior importância para o controle local é a obtenção de margens cirúrgicas livres. A excisão através da cirurgia micrográfica de Mohs é uma ótima opção em regiões onde a excisão ampla não é desejável, como na face. A margem padrão estabelicida em grande parte da literatura é de 3 cm com ressecção até a fáscia muscular, podendo ser diminuida para 2 cm em locais em que a excisão ampla prejudique a conformação do local, como na fac

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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