554 research outputs found

    Exploiting Rateless Codes in Cloud Storage Systems

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    Variation of genetic and behavioural traits in the sandhopper Talitrus saltator (Crustacea Amphipoda) along a dynamic sand beach

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    In an attempt to unravel the possible relationships among coastal stability, genetic variability and orientation behaviour in the sandhopper Talitrus saltator, we have screened four subpopulations of this species. Sandhoppers along 3 km of a dynamic sand beach were studied for orientation performance (i.e. adherence to the seaward theoretical escape direction (TED)) and sequence variation for a fragment of the mitochondrial (mt) gene encoding for the cytochrome oxidase Subunit I (COI). The sampling sites differed in the stability of the shoreline (from severely eroded to accreting). Analysis of molecular variance (AMOVA) revealed significant subdivisions among the four locations. The subpopulation sampled at the most eroded point showed no haplotype diversity and had the highest scatter in orientation. Genetic diversity increased with decreasing erosion. Orientation performances were best where the beach is in dynamic equilibrium, and were progressively more scattered at the accreting points. Multiple linear regression analyses demonstrated that the variables and factors that affected orientation significantly were daytime, global solar radiation, sex of individuals and haplotype diversity. Environmental factors are likely to influence sandhopper behaviour on a short and medium time scale (i.e. from single individual life span to a few generations). The data also suggest that temporal stability of the shoreline has a positive effect on the genetic variability of the resident sandhopper populations

    Efficient recovery of whole cell proteins in Oenococcus oeni - a comparison of different extraction protocols for high-throughput malolactic starter applications

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    In this study, we compared different total protein extraction protocols to achieve highly efficient isolation and purification of total proteins for the specific protein profiling of Oenococcus oeni. The sodium dodecyl sulfatepolyacrylamide gel electrophoresis patterns obtained for the different extraction protocols revealed not only a qualitative similar protein pattern but also quantitative variations with different intensity bands depending on the extraction method used. The selected extraction method added with sonication proved to work extremely well and efficiently and was able to obtain a high resolution 2- D electrophoresis (2-DE) map. Prominent spots were successfully identified by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry and corresponded to 76 different proteins involved in the main metabolic pathways. The approach allowed to achieve a protein profiling specific for O. oeni from Aglianico wine with numerous characterized protein products corresponding to many different O. oeni genes and associated with main cellular pathways. Further investigations of the 2-DE protein expression profile will provide useful and interesting information on the molecular mechanisms at the protein level responsible for growth and survival of O. oeni in wine

    Synergistic effects of cryolipolysis and shock waves for noninvasive body contouring

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    Excess body fat, localized adiposity, and cellulite represent important social problems. To date, techniques using radiofrequencies, cavitation and noncavitation ultrasound, and carbon dioxide have been studied as treatments for noninvasive body contouring. Ice-Shock Lipolysis is a new noninvasive procedure for reducing subcutaneous fat volume and fibrous cellulite in areas that normally would be treated by liposuction. It uses a combination of acoustic waves and cryolipolysis. Shock waves, used normally in the treatment of renal calculi and musculoskeletal disorders, are focused on the collagen structure of cellulite-afflicted skin. When used on the skin and underlying fat, they cause a remodeling of the collagen fibers, improving the orange-peel appearance typical of the condition. Cryolipolysis, on the other hand, is a noninvasive method used for the localized destruction of subcutaneous adipocytes, with no effects on lipid or liver marker levels in the bloodstream. The combination of the two procedures causes the programmed death and slow resorption of destroyed adipocytes. METHODS: In this study, 50 patients with localized fat and cellulite were treated with a selective protocol for the simultaneous use of two transducers: a Freezing Probe for localized fatty tissue and a Shock Probe for fibrous cellulite. RESULTS: The procedure significantly reduced the circumference in the treated areas, significantly diminishing fat thickness. The mean reduction in fat thickness after treatments was 3.02 cm. Circumference was reduced by a mean of 4.45 cm. Weight was unchanged during the treatment, and no adverse effects were observed. Histologic and immunohistochemical analysis confirmed a gradual reduction of fat tissue by programmed cell death. Moreover, the reduction in fat thickness was accompanied by a significant improvement in microcirculation, and thus, the cellulite. The safety of the method also has been highlighted because it is accompanied by no significant increase in serum liver enzymes or serum lipids. CONCLUSION: The study aimed to observe the effects of the new technique in the treatment of localized fat associated with cellulite in order to assess adipose tissue alterations, cellular apoptosis, and levels of serum lipid or liver markers. The findings show that the action of Ice-Shock Lipolysis is a safe, effective, and well-tolerated noninvasive procedure for body contouring. In particular, the authors believe that this could be an ideal alternative to liposuction for patients who require only small or moderate amounts of adipose tissue and cellulite removal or are not suitable candidates for surgical approaches to body contouring

    Friendship prediction and homophily in social media

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    International audienceSocial media have attracted considerable attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and topical components of social media has been only partially explored. Here, we study the presence of homophily in three systems that combine tagging social media with online social networks. We find a substantial level of topical similarity among users who are close to each other in the social network. We introduce a null model that preserves user activity while removing local correlations, allowing us to disentangle the actual local similarity between users from statistical effects due to the assortative mixing of user activity and centrality in the social network. This analysis suggests that users with similar interests are more likely to be friends, and therefore topical similarity measures among users based solely on their annotation metadata should be predictive of social links. We test this hypothesis on several datasets, confirming that social networks constructed from topical similarity capture actual friendship accurately. When combined with topological features, topical similarity achieves a link prediction accuracy of about 92%

    Volcanic hazard assessment at the Campi Flegrei caldera

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    Previous and new results from probabilistic approaches based on available volcanological data from real eruptions of Campi Flegrei, are assembled in a comprehensive assessment of volcanic hazards at the Campi Flegrei caldera, in order to compare the volcanic hazards related to the different types of events. Hazard maps based on a very wide set of numerical simulations, produced using field and laboratory data as input parameters relative to the whole range of fallout and pyroclastic-flow events and their relative occurrence, are presented. The results allow us to quantitatively evaluate and compare the hazard related to pyroclastic fallout and density currents (PDCs) in the Campi Flegrei area and its surroundings, including the city of Naples. Due to the dominant wind directions, the hazard from fallout mostly affects the area east of the caldera, and the caldera itself, with the level of probability and expected thickness decreasing with distance from the caldera and outside the eastern sectors. The hazard from PDCs decrease roughly radially with distance from the caldera centre and is strongly controlled by the topographic relief, which produces an effective barrier to propagation of PDCs to the east and northeast, areas which include metropolitan Naples. The main result is that the metropolitan area of Naples would be directly exposed to both fallout and PDCs. Moreover, the level of probability for critical tephra accumulation by fallout is relatively high, even for moderate-scale events, while, due to the presence of topographic barriers, the hazard from PDCs is only moderate and mostly associated with the largest events

    Microscopic Calculation of the Constitutive Relations

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    Homogenization theory is used to calculate the macroscopic dielectric constant from the quantum microscopic dielectric function in a periodic medium. The method can be used to calculate any macroscopic constitutive relation, but it is illustrated here for the case of electrodynamics of matter. The so-called cell problem of homogenization theory is solved and an explicit expression is given for the macroscopic dielectric constant in a form akin to the Clausius-Mossotti or Lorentz-Lorenz relation. The validity of this expression is checked by showing that the macroscopic dielectric constant is causal and has the expected symmetry properties, and that the average of the microscopic energy density is the macroscopic one. Finally, the general expression is applied to Bloch eigenstates. Finally, the corresponding many-body problem is briefly discussed.Comment: 14 pages, 2 figure

    Instructions to Authors

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    C.J.V. was supported by a scholarship of the German National Academic Foundation.Social manipulation represents an important aspect of human social interactions, including cooperative ones. Yet, little is known about social manipulation of conspecifics in nonhuman great apes. We investigated how orang-utan, Pongo abelii, mothers used their offspring as a means to access food in competitive and cooperative test situations. In the competitive situations, only the offspring could retrieve high-value food rewards. Here, orang-utan mothers often stole the food from their offspring and even coerced them into retrieving it to begin with, by moving the offspring to the test site, guiding their arms and bodies towards the food, and even reorienting their hands so that they would grab the food. However, modifying the task constraints so that mothers were now required to cooperate with their offspring to obtain the food changed the mothers' behaviour completely. Suddenly, mothers cooperated with their offspring by handing them tools that only their offspring could use to activate a mechanism delivering food for both of them. We conclude that orang-utans, like humans, are able to flexibly use conspecifics as a social tool and that this kind of social tool use supports their ability to cooperate.PostprintPeer reviewe

    Application of Vis/Nir spectroscopy to establish peach ripening as affected by rootstock

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    The objective of this paper was to monitor peach ripeness of “Chimarrita” and “Maciel” cultivars, grafted on different rootstocks, using the pulp firmness parameter, as an indicator of harvest time through equipment based on Vis/Nir spectroscopy. The orchard was installed in 2005, has a "V" conduction system with spacing of 5.0 x 1.5 m, and the cultivars are grafted on seven rootstocks: “Capdeboscq”, “Flordaguard”, “Nemaguard”, “Okinawa”, “Tsukuba”, “Umezeiro” and “Viamão”. After harvesting, the fruits were evaluated by the NIR CASE spectrophotometer, establishing categories of pulp firmness, between 40N and 60N for fruits consumed in a long term and <40N for immediate consumption. The analyzed rootstocks alter the peach ripeness of the “Chimarrita” and “Maciel” cultivars. The “Umezeiro” rootstock anticipates harvest for the “Chimarrita” cultivar. The “Nemaguard”/ “Maciel” combination provides fruits with a superior harvest period than the other ones evaluated. The Vis/Nir Spectroscopy is a useful tool to monitor the harvest of “Chimarrita” and “Maciel” cultivars
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