1,232 research outputs found

    Pruritus is a common feature in sheep infected with the BSE agent.

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    BACKGROUND: The variability in the clinical or pathological presentation of transmissible spongiform encephalopathies (TSEs) in sheep, such as scrapie and bovine spongiform encephalopathy (BSE), has been attributed to prion protein genotype, strain, breed, clinical duration, dose, route and type of inoculum and the age at infection. The study aimed to describe the clinical signs in sheep infected with the BSE agent throughout its clinical course to determine whether the clinical signs were as variable as described for classical scrapie in sheep. The clinical signs were compared to BSE-negative sheep to assess if disease-specific clinical markers exist. RESULTS: Forty-seven (34%) of 139 sheep, which comprised 123 challenged sheep and 16 undosed controls, were positive for BSE. Affected sheep belonged to five different breeds and three different genotypes (ARQ/ARQ, VRQ/VRQ and AHQ/AHQ). None of the controls or BSE exposed sheep with ARR alleles were positive. Pruritus was present in 41 (87%) BSE positive sheep; the remaining six were judged to be pre-clinically infected. Testing of the response to scratching along the dorsum of a sheep proved to be a good indicator of clinical disease with a test sensitivity of 85% and specificity of 98% and usually coincided with weight loss. Clinical signs that were displayed significantly earlier in BSE positive cases compared to negative cases were behavioural changes, pruritic behaviour, a positive scratch test, alopecia, skin lesions, teeth grinding, tremor, ataxia, loss of weight and loss of body condition. The frequency and severity of each specific clinical sign usually increased with the progression of disease over a period of 16-20 weeks. CONCLUSION: Our results suggest that BSE in sheep presents with relatively uniform clinical signs, with pruritus of increased severity and abnormalities in behaviour or movement as the disease progressed. Based on the studied sheep, these clinical features appear to be independent of breed, affected genotype, dose, route of inoculation and whether BSE was passed into sheep from cattle or from other sheep, suggesting that the clinical phenotype of BSE is influenced by the TSE strain more than by other factors. The clinical phenotype of BSE in the genotypes and breed studied was indistinguishable from that described for classical scrapie cases

    Key agreement protocols for distributed secure multicast over the ring Ep(m)

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    Protocols for authenticated key exchange allow parties within an insecure network to establish a common session key which can then be used to secure their future communication. In this paper we introduce a protocol for distributed key agreement over a noncommutative ring with a large number of noninvertible elements. This protocol uses polynomials with coefficients in the center of the ring. We also present the necessary steps for recalculating the shared secret key when a new user joins the system, or when a user leaves the system.The work of the first author was partially supported by Spanish grant MTM2011-24858 of the Ministerio de Economía y Competitividad of the Gobierno de España. The work of the second author was partially supported by the grant FQM 0211 of the Junta de Andalucía

    Novedades y notas taxonómicas en especies de Senecio de la Patagonia, Argentina

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    405-415A new species and three new varieties of the genus Senecio L. sect. Senecio, are described. The new species, S. pichineuquensis Tortosa and Adr. Bartoli, included in the series Xerosenecio (Cabrera) Cabrera and S. E. Freire, has a geographic distribution in the south of Mendoza and north of Neuquén Provinces. It is characterized by ligneous rigid stems with long internodes, linear, rigid leaves, few-flowered discoid yellow heads grouped in dense corymbs, and narrowly cylindrical involucre. A key is provided for its differentiation from the allied species. A variety of this species with cream-color heads, S. pichineuquensis var. albus Tortosa and Adr. Bartoli, is described. The other two new varieties, S. bracteolatus Hook. et Arn. var. luteous Tortosa and Adr. Bartoli and S. varvarcensis Cabrera var. pinnatus Tortosa and Adr. Bartoli, belong also to the series Xerosenecio, and are apparently endemic to the north of Neuquén Province. The variety luteous of S. bracteolatus differs from the typical variety by its gold yellow florets, higher narrowly cylindrical involucre, and lower number of phyllaries and flowers, whereas the variety pinnatus of S. varvarcensis may be distinguished from the typical variety by its pinnate leaves (vs. entire leaves in var. varvarcensis). Two other species of Senecio that inhabit in Patagonia are included in the synonymy of different species: S. subdiscoideus Sch. Bip. ex Wedd. of the series Metazanthi (Meyen) Cabrera et S. E. Freire, as synonym of S. kingii Hook. f., and S. bipontinii Wedd. of the series Chilenses DC. ex M. G. López, A. F. Wulff and Xifreda subseries Caespitosi (O. Hoffm.) Cabrera et S. E. Freire as synonym of S. crithmoides Hook. et Arn. S. crithmoides, S. iberidifolius Phil., and S. purpuratus Phil. are lectotipified

    Tipificación en Grindelia (Astereae, Asteraceae)

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    107-109Nomenclatural problems still pending due to lack of information during the revision of the genus Grindelia for South America in 1999 are resolved. Lectotypification for five names is provided

    Livestock trade network: potential for disease transmission and implications for risk-based surveillance on the island of Mayotte

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    The island of Mayotte is a department of France, an outermost region of the European Union located in the Indian Ocean between Madagascar and the coast of Eastern Africa. Due to its close connection to the African mainland and neighbouring islands, the island is under constant threat of introduction of infectious diseases of both human and animal origin. Here, using social network analysis and mathematical modelling, we assessed potential implications of livestock movements between communes in Mayotte for risk-based surveillance. Our analyses showed that communes in the central region of Mayotte acted as a hub in the livestock movement network. The majority of livestock movements occurred between communes in the central region and from communes in the central region to those in the outer region. Also, communes in the central region were more likely to be infected earlier than those in the outer region when the spread of an exotic infectious disease was simulated on the livestock movement network. The findings of this study, therefore, suggest that communes in the central region would play a major role in the spread of infectious diseases via livestock movements, which needs to be considered in the design of risk-based surveillance systems in Mayotte

    Tipificación en Grindelia (Astereae, Asteraceae)

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    107-109Nomenclatural problems still pending due to lack of information during the revision of the genus Grindelia for South America in 1999 are resolved. Lectotypification for five names is provided

    Are white storks addicted to junk food? Impacts of landfill use on the movement and behaviour of resident white storks (Ciconia ciconia) from a partially migratory population

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    Background: The migratory patterns of animals are changing in response to global environmental change with many species forming resident populations in areas where they were once migratory. The white stork (Ciconia ciconia) was wholly migratory in Europe but recently guaranteed, year-round food from landfill sites has facilitated the establishment of resident populations in Iberia. In this study 17 resident white storks were fitted with GPS/GSM data loggers (including accelerometer) and tracked for 9.1 ± 3.7 months to quantify the extent and consistency of landfill attendance by individuals during the non-breeding and breeding seasons and to assess the influence of landfill use on daily distances travelled, percentage of GPS fixes spent foraging and non-landfill foraging ranges. Results: Resident white storks used landfill more during non-breeding (20.1 % ± 2.3 of foraging GPS fixes) than during breeding (14.9 % ± 2.2). Landfill attendance declined with increasing distance between nest and landfill in both seasons. During non-breeding a large percentage of GPS fixes occurred on the nest throughout the day (27 % ± 3.0 of fixes) in the majority of tagged storks. This study provides first confirmation of year-round nest use by resident white storks. The percentage of GPS fixes on the nest was not influenced by the distance between nest and the landfill site. Storks travelled up to 48.2 km to visit landfills during non-breeding and a maximum of 28.1 km during breeding, notably further than previous estimates. Storks nesting close to landfill sites used landfill more and had smaller foraging ranges in non-landfill habitat indicating higher reliance on landfill. The majority of non-landfill foraging occurred around the nest and long distance trips were made specifically to visit landfill. Conclusions: The continuous availability of food resources on landfill has facilitated year-round nest use in white storks and is influencing their home ranges and movement behaviour. White storks rely on landfill sites for foraging especially during the non-breeding season when other food resources are scarcer and this artificial food supplementation probably facilitated the establishment of resident populations. The closure of landfills, as required by EU Landfill Directives, will likely cause dramatic impacts on white stork populations

    Hormonal and emotional responses to competition using a dyadic approach: Basal testosterone predicts emotional state after a defeat

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    The present study analyzes the testosterone (T), cortisol (C) and emotional response in competitive interactions between dyads, as well as the relationship between basal T and the emotional response. Seventy-two men and women (36 dyads) participated in same-sex dyads in a face-to-face laboratory competition, and thirty-two men and women (16 dyads) carried out the same task in a non-competitive condition. Salivary samples (5 ml of saliva, plastic vials) were provided at three time points (baseline, task, and post-task), and subsequently T (pg/ml) and C (nmol/L) concentrations were measured using ELISA method. Participants completed self-reported measures of emotional valence, emotional arousal and perceived dominance by means of the Self-Assessment Manikin (SAM), at three time points (pre-task, task, and post-task). Two-level crossed Multilevel Models (MLM) showed a participants' stability in C (Mean ± SEM: baseline: 3.84 ± 0.28, task: 2.92 ± 0.28 and post-task: 2.62 ± 0.3), emotional valence (pre-task: 4 ± 0.06, task: 3.66 ± 0.1 and post-task: 3.84 ± 0.09), arousal (pre-task: 3.29 ± 0.09, task: 3.83 ± 0.09 and post-task: 3.38 ± 0.1) and dominance (pre-task: 3.28 ± 0.08, task: 3.4 ± 0.1 and post-task: 3.44 ± 0.09) values, which in the case of emotional valence and dominance was modulated by time-point, outcome and sex. Furthermore, analyses revealed that opponents' C, arousal and dominance values at one time-point influenced participants' values at the following time-point modulated by outcome, sex and time-point. Moreover, MLM indicated that in loser men, individuals higher in basal T (126.31 ± 6.4) displayed higher negative emotional valence after the defeat (post-task: 3.6 ± 0.21), while in women basal T (99.78 ± 12.6) was not significantly related to post competition emotional valence. These findings reinforce the importance of studying the relationship between hormonal and psychological changes in dyadic competition, and confirm that men and women differ in their psychophysiological responses to competition

    Elastofibroma Dorsi

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    Se realiza un estudio clínico-patológico de dos casos, mujeres de 57 y 45 años, de "elastofibroma dorsi" intervenidos quirúrgicamente. En una enferma apareció como una tumoracion asintomática y en otra asociada a dolor en el hombro irradiado a miembro superior derecho. Se describen las particularizadas clínicas, las exploraciones complementarias, los hallazgos quirúrgicos y las características histológicas de estos tumores de partes blandas cuyo origen debe referirse a una alteración del tejido fibroelástico. Se confronta nuestra experiencia con los casos anteriormente publicados confirmándose su aparición en mujeres adultas o añosas dedicadas a trabajos manuales rutinarios, que parecen estar implicados en la patogenia del elastofibroma dorsi. En uno de los casos, aunque localizado en el espacio anatómico escápulo-torácico, su situación era supraescapular frente a la típicamente infraescapular del elastofibroma dorsi, y la consideramos la primera observación de la literatura.A clinical-pathological study of two cases of elastofibroma dorsi was carried out. Both patients were female, 57 and 45 years old, and underwent surgical operation. One patients was sympton-free, while the other complained of pain in the shoulder which spread to the upper right arm. The autors describe the clinical details, the diagnostic methods employed, the results of surgery and the histopathological features of these tumours which must have originated in a modification of conective tissue, especially in elastic fibres. We compare our findings with those of previously published cases and can confirm the appearence of these tumours in adults or middle-aged women who carry out rutinary manual work, which seems to be connected with the pathogeny of the elastofibroma dorsi. These are normally found adjacent to the vertebral border of the escapula at its inferior angle, but in one case ot was located in the supra-escapular region and we believe this is the first evidence of this kind in the literature
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