746 research outputs found

    Asymptotically Safe Standard Model via Vector-Like Fermions

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    We construct asymptotically safe extensions of the Standard Model by adding gauged vector-like fermions. Using large number-of-flavour techniques we argue that all gauge couplings, including the hypercharge and, under certain conditions, the Higgs coupling can achieve an interacting ultraviolet fixed point.Comment: 5 pages, 3 figures, typos fixe

    Exploring the Strategic Alignment of Performing Arts and Computing: Creating and Delivering Multimedia Performing Arts Content, Part II

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    Our Exploring the Strategic Alignment of Performing Arts and Computing initiative aims to develop an interdisciplinary Seidenberg-Performing arts curriculum that will integrate into the performing arts program an expansion of exposure to information technology skills and expertise relevant to creating and delivering computer mediated content. During spring and fall terms 2010 we successfully launched the interdisciplinary course Creating with Web 2.0. The fall 2010 offering includes majors from Finance, Marketing, Accounting, Computer Science, Information Systems and Performing Arts. The first offering enrolled 13 students from Marketing, Finance, Information Systems, Computer Science, Communications and Film. During spring and fall 2011 we will further develop the initial course by creating and including more sophisticated Performing to create content and to focus more attention towards recruiting Performing Arts majors. The concept of creating interactive content as an interdisciplinary curriculum offering has been shown to succeed through our first two offerings of the course. In this segment of the project we will focus much more on Performing Arts individuals and creating more sophisticated content during the Performing Arts classes, and then integrating this content into a living web presence for the Performing Artists and for students from other majors who may also enter the class

    Effect of mid-line or low-line milking systems on lipolysis and milk composition in dairy goats

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    [EN] Two experiments were carried out to investigate how milking in mid-line (ML) affects the lipolysis level and milk composition in goat livestock, in comparison with low-line (LL) milking. The first experiment took place, in triplicate, on an experimental farm. For each replicate, a crossover design (62 goats, two treatments, ML and LL, in two periods each lasting 4 days) was used. Milk samples were taken daily at 0 and 24 h after milking. In the first experimental replicate, some enzymatic coagulation cheeses were made, which were assessed by a panel of tasters at 50 and 100 days of maturation. In the second experiment, the lipolysis level and composition of tank milk from 55 commercial dairy goat farms (25 ML and 30 LL) were analysed, in milk samples taken in three different weeks. The results of the first experiment showed that ML milking increased free fatty acid (FFA) concentration in raw goat's milk significantly (0.71 v. 0.40 mmol/l, respectively). However, in the milk samples taken from commercial farms the FFA concentration remained unaffected by the milking pipeline height (0.59 v. 0.58 mmol/l for ML and LL, respectively). No significant differences were found in the milk composition, nor in the sensory characteristics in the cured cheeses, which suggests that factors other than the milkline height are able to influence the level of lipolysis under commercial conditions. Therefore, ML milking should not be discouraged, provided that the correct functioning and management of the milking operation and milk storage on the farm is guaranteed.Beltrán Martínez, MC.; Manzur Cruz, A.; Rodríguez Garcia, M.; Díaz Sánchez, JR.; Peris Ribera, CJ. (2018). Effect of mid-line or low-line milking systems on lipolysis and milk composition in dairy goats. Journal of Agricultural Science. 156(8):848-854. https://doi.org/10.1017/S0021859618000771S848854156

    The conditional benefits of cannibalism for wood frog tadpoles (lithobates sylvaticus)

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    Wood frog tadpoles have an incredible ability to rapidly adapt to changing conditions, and when population densities become high tadpoles often become cannibalistic. Cannibalism potentially represents an ideal diet by composition, and should be beneficial to the growth and development of cannibalistic individuals. To test the relative efficacy of cannibalism to growth and development we conducted multiple feeding experiments. Results indicate that cannibalism represents a better alternative to starvation and provides some benefit to development and survival of tadpoles over low quality diets. However, cannibalism can be detrimental to tadpole growth and/or develop­ment relative to diets of similar protein content. Additionally, tadpoles raised individually appear to initially avoid consuming the cannibalistic diet, and may continue to do so until they face the risk of starvation. Conversely, when tadpoles were raised in groups providing them with compe­tition, they immediately fed upon the cannibal diet. Our results suggest that competition, rather than dietary quality is likely the driving force behind cannibalistic behaviour unless tadpoles oth­erwise face the risk of starvation

    Can translocated native fishes retain their trophic niche when confronted with a resident invasive?

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    Diet interactions between native and non-native fishes may influence the establishment of native species within their historical range (i.e., reintroduction). Therefore, we illustrated the food web structure of and followed the transition of the federally endangered humpback chub Gila cypha into a novel food web following translocation and determined the potential for a non-native species, rainbow trout Oncorhynchus mykiss, to influence translocation success. Humpback chub and rainbow trout used resources high in the food web and assimilated similar proportions of native fishes, suggesting non-native rainbow trout may occupy an ecological role similar to humpback chub. Subsequently, humpback chub may be well suited to colonise tributaries because of their ability to consume resources high in the food web. Additionally, diet partitioning may occur between all members of the fish community as indicated by separation in trophic niche space and little trophic overlap; although all species, particularly bluehead sucker Catostomus discobolus, used a broad range of food resources. Rainbow trout stomach content analysis corroborated stable isotope analysis and suggested rainbow trout diet consisted of aquatic and terrestrial macroinvertebrates, while larger rainbow trout (\u3e120 mm total length) consumed a greater proportion of fish (incidence of piscivory = 5.3%). Trophic interactions may reveal an underutilized niche space or biotic resistance to the establishment of translocated native fishes. Continued translocation of humpback chub into tributaries appears to be one option for conservation. However, successful establishment of humpback chub may depend on continued removal of non-native trout, increasing availability of diet sources at higher trophic levels

    SOLIS PRAIA HOTEL ITAPEMA: os desafios na contratação de mão de obra

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    O Solis Praia Hotel Itapema, localizado na região central da cidade de Itapema, conta com aproximadamente 6.000 m2 de área construída, 85 apartamentos e total estrutura física e administrativa, para um estabelecimento de categoria superior. Situado no litoral Norte Catarinense, sofre com o problema da falta de mão de obra em determinadas épocas do ano, por estar numa região turística de alta sazonalidade. Junto com esta temática, outros fatores como a alta rotatividade no setor, a concorrência com outros estabelecimentos de serviços e a falta de capacitação também contribuem para agravar esta situação. A contratação temporária de um grande número de funcionários torna difícil a manutenção de um padrão de qualidade no atendimento ao hóspede, tendo em vista esta falta capacitação da mão de obra e o pouco tempo para ambientação e treinamento destas pessoas. Contudo o objetivo principal deste estudo é analisar estes fatores, verificando como cada um deles interfere no produto Solis, permitindo ao hotel atrair pessoas comprometidas, incentivar aqueles que lá estão e, assim, garantir a sua permanência neste mercado competitivo

    Adaptation as a potential response to sea-level rise: a genetic basis for salinity tolerance in populations of a coastal marsh fish

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    Relative sea-level rise is resulting in the intrusion of saline waters into marshes historically dominated by fresh water. Saltwater intrusions can potentially affect resident marsh species, especially when storm-related tidal surges cause rapid changes in salinity. We examined the role of historical salinity exposure on the survival of Gambusia affinis from two locations in coastal Louisiana. At each location, we sampled fish populations from fresh, intermediate and brackish marshes. Individuals were then exposed to a salinity of 25‰ and survival time was measured. We found that fish from brackish and intermediate marshes had an increased tolerance to salinity stress relative to fish from freshwater environments. We then tested the descendents of fish from the fresh and brackish marshes, reared for two generation in fresh water, to determine if there was a genetic basis for differential survival. We found that descendents of individuals from brackish marshes showed elevated survivals relative to the descendents of fish with no historical exposure to salinity. The most reasonable mechanism to account for the differences in survival relative to historical exposure is genetic adaptation, suggesting that natural selection may play a role in the responses of resident marsh fishes to future increases in salinity

    Moving towards public policy-ready science: philosophical insights on the social-ecological systems perspective for conservation science

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    The social-ecological systems (SES) perspective stems from the need to rethink the ways humans relate to the environment, given the evidence that conventional conservation and management approaches are often ineffective in dealing with complex socio-environmental problems. The SES approach conceives non-scientific and scientific knowledge as equally necessary in the process of management and public policy formation. Thus, the adoption of the SES approach must also serve to make better decisions about what kind of science and technology would be ‘public policy-ready’ (as well as also ‘policy-relevant’); that is, a science oriented and conceived to provide concrete solutions to societal needs and demands. Here we review and reinterpret the SES perspective as a real paradigm change for conservation science. Under the lenses of philosophy, we try to untangle some weak points of the SES approach in order to advance to a conservation science closer to the process of science-based public policy creation and to enhance the intertwining with other types of knowledge. In this sense, we discuss how co-production of knowledge and decision-making process under the SES perspective are a huge step forward towards fulfilling the need to bring increasingly closer the spheres of science and policy, narrowing its interface.Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Torchio, Gabriela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentin

    Survival of Migrating Salmon Smolts in Large Rivers With and Without Dams

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    The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST) array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT) tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River

    Spatio-temporal patterns of fish assemblages in a large regulated alluvial river

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    1. The River Durance, the last alpine tributary of the River Rhone, is a large, braided alluvial hydrosystem. Following large-scale regulation, flow downstream of the Serre-Poncon dam has been maintained at 1⁄40th of previous annual mean discharge. To assess the effects of historical disturbances, fish assemblages and habitat use were analysed during five summers in a representative reach of the middle Durance. 2. Habitat availability and use were assessed with a multi-scale approach including the variables water depth, current velocity, roughness height of substratum, amount of woody debris and lateral⁄longitudinal location. Eighteen fish species were sampled by electrofishing in 289 habitat sample units. 3. Partial least square (PLS) regression showed that taxa were mainly distributed according to relationships between their total length and water depth⁄velocity variables. Fish assemblage composition was also related to roughness height as well as distance from the bank or to the nearest large woody debris. However, PLS regression revealed no significant differences in habitat selection between two periods of varying hydromorphological stability. 4. Fish distribution patterns and density were related to proximity to the bank and cover, indicating that local scale variables need to be considered in conservation and restoration programmes
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