922 resultados para Key Agreement, Password Authentication, Three-party
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Digital models are an alternative for carrying out analyses and devising treatment plans in orthodontics. The objective of this study was to evaluate the accuracy and the reproducibility of measurements of tooth sizes, interdental distances and analyses of occlusion using plaster models and their digital images. Thirty pairs of plaster models were chosen at random, and the digital images of each plaster model were obtained using a laser scanner (3Shape R-700, 3Shape A/S). With the plaster models, the measurements were taken using a caliper (Mitutoyo Digimatic(®), Mitutoyo (UK) Ltd) and the MicroScribe (MS) 3DX (Immersion, San Jose, Calif). For the digital images, the measurement tools used were those from the O3d software (Widialabs, Brazil). The data obtained were compared statistically using the Dahlberg formula, analysis of variance and the Tukey test (p < 0.05). The majority of the measurements, obtained using the caliper and O3d were identical, and both were significantly different from those obtained using the MS. Intra-examiner agreement was lowest when using the MS. The results demonstrated that the accuracy and reproducibility of the tooth measurements and analyses from the plaster models using the caliper and from the digital models using O3d software were identical.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. It includes two aspects: key distribution and key revocation. Many key management protocols have been specifically designed for wireless sensor networks. However, most of the key management protocols focus on the establishment of the required keys or the removal of the compromised keys. The design of these key management protocols does not consider the support of higher level security applications. When the applications are integrated later in sensor networks, new mechanisms must be designed. In this paper, we propose a security framework, uKeying, for wireless sensor networks. This framework can be easily extended to support many security applications. It includes three components: a security mechanism to provide secrecy for communications in sensor networks, an efficient session key distribution scheme, and a centralized key revocation scheme. The proposed framework does not depend on a specific key distribution scheme and can be used to support many security applications, such as secure group communications. Our analysis shows that the framework is secure, efficient, and extensible. The simulation and results also reveal for the first time that a centralized key revocation scheme can also attain a high efficiency.
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Establishing a conservation tree planting can be a challenge in semiarid regions like western Nebraska, where annual precipitation of 20 inches or less is the norm. Tree planting failure commonly occurs as a result of poor site preparation coupled with inadequate weed and grass control the first three to five years after planting. Effective site preparation begins the year before planting. The results help young trees survive and grow in several ways. This NebGuide explains when and how to do site preparation for conservation tree planting in Western Nebraska.
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Objectives: Limbal stem cells (LSC) are self-renewing, highly proliferative cells in vitro, which express a set of specific markers and in vivo have the capacity to reconstruct the entire corneal epithelium in cases of ocular surface injury. Currently, LSC transplantation is a commonly used procedure in patients with either uni- or bilateral total limbal stem cells deficiency (TLSCD). Although LSC transplantation holds great promise for patients, several problems need to be overcome. In order to find an alternative source of cells that can partially substitute LSC in cornea epithelium reconstruction, we aimed at investigating whether human immature dental pulp stem cells (hIDPSC) would present similar key characteristics as LSC and whether they could be used for corneal surface reconstruction in a rabbit TLSCD model. Materials: We used hIDPSC, which co-express mesenchymal and embryonic stem cell markers and present the capacity to differentiate into derivative cells of the three germinal layers. TLSCD was induced by chemical burn in one eye of rabbits. After 30 days, the opaque tissue formed was removed by superficial keratectomy. Experimental group received undifferentiated hIDPSC, while control group only received amniotic membrane (AM). Both groups were sacrificed after 3 months. Results and conclusions: We have demonstrated, using immunohistochemistry and reverse transcription-polymerase chain reaction, that hIDPSCs express markers in common with LSC, such as ABCG2, integrin beta 1, vimentin, p63, connexin 43 and cytokeratins 3/12. They were also capable of reconstructing the eye surface after induction of unilateral TLSCD in rabbits, as shown by morphological and immunohistochemical analysis using human-specific antibodies against limbal and corneal epithelium. Our data suggest that hIDPSCs share similar characteristics with LSC and might be used as a potential alternative source of cells for corneal reconstruction.
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Extant Doras are newly diagnosed among Doradidae by the unique combination of maxillary barbels long and fimbriate; mesethmoid with anterior lateral margins converging towards narrow tip; single anterior cranial fontanel contained largely within frontals and anteriorly by mesethmoid (posterior cranial fontanel occluded); anterior nuchal plate wide, pentaganol or roughly hexagonal, sharing distinct lateral suture with epioccipital and isolating supraoccipital from middle nuchal plate; nuchal foramina absent; coracoid process short, posterior tip falling well short of that of postcleithral process; dentary with acicular teeth; and skin immediately ventral to postcleithral process perforated with conspicuous pores. One fossil species, dagger D. dioneae, and two nominal extant species, D. carinatus and D. micropoeus, are recognized as valid and the latter two redescribed. Three additional extant species, D. phlyzakion, D. higuchii and D. zuanoni, are newly described from the middle Amazon and tributaries, lower Amazon tributaries and rio Araguaia (Tocantins drainage), respectively. Doras phlyzakion and D. zuanoni form a monophyletic group that is found in lowland, lentic habitats, and is characterized by multiple conspicuous pores in skin on breast and abdomen, a trait unique among doradids and rare if not unique among all catfishes. The remaining extant species, D. carinatus, D. higuchii and D. micropoeus, with uncertain relationships, are found in upland, lotic habitats. The occurrence of D. carinatus in the Orinoco basin suggests a historical link between right-bank tributaries of the lower Orinoco (e.g., Caroni) draining the western Guiana Shield and more eastern rivers (e.g., Cuyuni-Essequibo) that drain the Shield directly into the Atlantic Ocean. A key to extant species is provided, a neotype is designated for Silurtis carinatus Linnaeus 1766, and Mormyropsis Miranda Ribeiro, 1911, is placed in the synonymy of Doras Lacepede, 1803.
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Generic characters of Irundisaua Martins & Galileo, 2005 are expanded (antennal formula, width of prosternal process inferior or equal to the diameter of procoxa, protibia enlarged and flattened) and two species are transferred from Acanthoderes Audinet-Serville, 1835: I. forsteri (Tippmann, 1960) comb. nov from Peru and Brazil (Amazonas) and I. ucayalensis (Tippmann,1960) comb. nov from Ecuador, Peru and Brazil (Amazonas).Three new genera are described: (1) Catuana gen. nov., type species, C. spinicornis (Tippmann, 1960) comb. nov, characterized by the mesosternal tubercle; (2) Mundeu gen. nov, type species, M. maculicollis (Bates, 1861) comb. nov, with rounded sides of protorax and expanded protibiae; (3) Urangaua gen. nov, with eyes divided and finelly granulated, length of antenomeres III-IV subequal to V-XI; the genus is proposed of two species: U. analis Melzer, 1935 comb. nov, type species, and U. subanalis (Zajciw,1964) comb. nov. A key to the species of Urangaua is added.
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Huanglongbing (HLB) is associated with Candidatus Liberibacter spp., endogenous, sieve tube-restricted bacteria that are transmitted by citrus psyllid insect vectors. Transgenic expression in the phloem of specific genes that might affect Ca. Liberibacter spp. growth and development may be an adequate strategy to improve citrus resistance to HLB. To study specific phloem gene expression in citrus, we developed three different binary vector constructs with expression cassettes bearing the beta-glucuronidase (GUS) reporter gene (uidA) under the control of one of the three different promoters: Citrus phloem protein 2 (CsPP2), Arabidopsis thaliana phloem protein 2 (AtPP2), and Arabidopsis thaliana sucrose transporter 2 (AtSUC2). Transgenic lines of 'Hamlin', 'Pera', and 'Valencia' sweet oranges [Citrus sinensis (L.) Osbeck] were produced via Agrobacterium tumefaciens transformation. The epicotyl segments collected from in vitro germinated seedlings were used as explants. The gene nptII, which confers resistance to the antibiotic kanamycin, was used for selection. The transformation efficiency was expressed as the number of GUS-positive shoots over the total number of explants and varied from 1.54 to 6.08 % among the three cultivars and three constructs studied. Several lines of the three sweet orange cultivars analyzed using PCR and Southern blot analysis were genetically transformed with the three constructs evaluated. The histological GUS activity in the leaves indicates that the uidA gene was preferentially expressed in the phloem, which suggests that the use of the three promoters might be adequate for producing HLB-resistant transgenic sweet oranges. The results reported here conclusively demonstrate the preferential expression of GUS in the phloem driven by two heterologous and one homologous gene promoters. Key message The results reported here conclusively demonstrate the preferential expression of GUS in the phloem driven by two heterologous and one homologous gene promoters.
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In accelerating dark energy models, the estimates of the Hubble constant, Ho, from Sunyaev-Zerdovich effect (SZE) and X-ray surface brightness of galaxy clusters may depend on the matter content (Omega(M)), the curvature (Omega(K)) and the equation of state parameter GO. In this article, by using a sample of 25 angular diameter distances of galaxy clusters described by the elliptical beta model obtained through the SZE/X-ray technique, we constrain Ho in the framework of a general ACDM model (arbitrary curvature) and a flat XCDM model with a constant equation of state parameter omega = p(x)/rho(x). In order to avoid the use of priors in the cosmological parameters, we apply a joint analysis involving the baryon acoustic oscillations (BA()) and the (MB Shift Parameter signature. By taking into account the statistical and systematic errors of the SZE/X-ray technique we obtain for nonflat ACDM model H-0 = 74(-4.0)(+5.0) km s(-1) Mpc(-1) (1 sigma) whereas for a fiat universe with constant equation of state parameter we find H-0 = 72(-4.0)(+5.5) km s(-1) Mpc(-1)(1 sigma). By assuming that galaxy clusters are described by a spherical beta model these results change to H-0 = 6(-7.0)(+8.0) and H-0 = 59(-6.0)(+9.0) km s(-1) Mpc(-1)(1 sigma), respectively. The results from elliptical description are in good agreement with independent studies from the Hubble Space Telescope key project and recent estimates based on the Wilkinson Microwave Anisotropy Probe, thereby suggesting that the combination of these three independent phenomena provides an interesting method to constrain the Bubble constant. As an extra bonus, the adoption of the elliptical description is revealed to be a quite realistic assumption. Finally, by comparing these results with a recent determination for a, flat ACDM model using only the SZE/X-ray technique and BAO, we see that the geometry has a very weak influence on H-0 estimates for this combination of data.
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PURPOSE: To indicate orthographic changes to be used as a basic reference for professionals, researchers, doctors, teachers, students and users, which are directly linked and performing activities in health services in general, aimed at implementing the correct orthography in recovery and production of their scientific studies. METHODS: For data collection, were shown some examples of terminology DeCS (Descriptors in Health Science) analyzed according to the current spelling and compared with the Orthographic Vocabulary of Portuguese Language (VOLP). RESULTS: It was select and listed examples of key words and/or terms related to Health Sciences, which was compared to the respective rules of the Orthographic Agreement of Portuguese Language, and divided into three items: graphical accentuation, the non use of dieresis and exceptions and, the use of hyphen. CONCLUSION: This study show some guidelines for the orthographic alterations of the terms used by scientific community, according the new orthographic rules, contributing for the efficiency in the description of the documents and consequently in their recovery.
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Redescriptions of Bizarrifrons magus (Nitzsch [in Giebel], 1866), the type species of Bizarrifrons, and B. picturatus Carriker & Diaz-Ungria, 1961 are given based on material from their type hosts. The nymphal instars of these two species are described and illustrated for the first time. Also, three new species are named and described: B. latifrons, from the russet-backed oropendola, Psarocolius angustifrons alfredi (Des Murs, 1856); B. wecksteini, from the Amazonian oropendola, Psarocolius b. bifasciatus (Spix, 1824); and B. quasisymmetricus, from the solitary cacique, Cacicus solitarius (Vieillot, 1816) (Passeriformes: Icteridae). Two species-groups are proposed, and a checklist and a key for the species of Bizarrifrons are also included. Sequences of a portion of the mitochondrial cytochrome oxidase I (COI) and the nuclear elongation factor 1 alpha (EF-1 alpha) genes for two species are given for the first time in this genus.
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Birds are the most diverse and largest group of extant tetrapods. They show marked variability, yet much of this variation is superficial and due to feather and bill color and shape. Under the feathers, the skeleto-muscular system is rather constant throughout the bird group. The adaptation to flight is the explanation for this uniformity. The more obvious morphological adaptations for flight are the wings, but the trunk is always rigid, the tail is short and the neck is flexible, since all these features are correlated with flying behaviour. Unrelated to the exigencies of flight, the legs always have three long bones, and all the birds walk on their toes. This leg structure is a striking plesiomorphic feature that was already present in related dinosaurs. The multi-purpose potential of the legs is the result of the skeletal architecture of a body with three segmented flexed legs. This configuration provides mechanical properties that allow the use of the legs as propulsive, paddling, foraging or grooming tools. It is the association of diverse modes of locomotion-walking, running, hopping, flying and swimming-that have enabled the birds to colonize almost all the environments on Earth.
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Until now, the Neotropical termite genus Cyranotermes was known from three species: C. timuassu Araujo, C. glaber Constantino, and C. caete Cancello. In this paper a new species, Cyranotermes karipuna, n. sp., is described and illustrated from imago, worker, and soldier castes, along with its nest. It is also provided an illustrated identification key to species of Cyranotermes, a map with the occurrence of all species, and the first description of the imago caste of Cyranotermes, based on the first description of the imago of C. timuassu, and the imago of the new species.
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Phospholipases A(2) (PLA(2)) are key enzymes in membrane metabolism. The release of fatty acids and lysophospholipids by PLA(2) activates several intra-cellular second messenger cascades that regulate a wide variety of physiological responses. The aim of the present study is to describe a radioenzymatic assay to determine the activity of three main PLA(2) subtypes in platelets, namely extracellular calcium-dependent PLA(2) (sPLA(2)) and intracellular calcium-dependent (cPLA(2)) and calcium-independent PLA(2) (iPLA(2)). The differentiation of these distinct PLA(2) subtypes was based on the enzyme substrate preference (arachdonic acid or palmitoyl acid) and calcium concentration. Our results indicate that this new assay is feasible, precise and specific to measure the activity of the aforementioned subtypes of PLA(2). Therefore, this protocol can be used to investigate modifications of PLA(2) homeostasis in distinct biological models addressing the pathophysiology of many medical and neuropsychiatric disorders such as schizophrenia and Alzheimer's disease. (C) 2012 Elsevier Ltd. All rights reserved.
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Fifteen species have been placed in Blattisocius Keegan of which only three were previously reported from Brazil. These mites are found in several different habitats and often mentioned as predators of pests of stored food. In this work, specimens of this genus collected from commercial dog food in Brazil were determined as a new species which is here described as Blattisocius everti n. sp. and the closely related Blattisocius keegani Fox, here redescribed. Subsequently, other specimens of Blattisocius deposited in the mite collection of "Departamento de Entomologia e Acarologia of Escola Superior de Agricultura "Luiz de Queiroz", Universidade de Sao Paulo" were examined and identified. Finally, a dichotomous key to separate the world species of Blattisocius was elaborated based on the examination of the specimens at hand and on the descriptions and redescriptions of other species.