Security Proof for Quantum Key Distribution Using Qudit Systems

We provide security bounds against coherent attacks for two families of quantum key distribution protocols that use $d$-dimensional quantum systems. In the asymptotic regime, both the secret key rate for fixed noise and the robustness to noise increase with $d$. The finite-key corrections are found to be almost insensitive to $d\lesssim 20$.Comment: 5 pages, 1 figure, version 3 corrects equations (9) and (11), and slightly modifies the figure to reflect the change to equation (11

Molecular and morphological phylogeny of Saccocirridae (Annelida) reveals two cosmopolitan clades with specific habitat preferences

Saccocirrids are tiny, slender annelids inhabiting the interstices among coarse sand sediments in shallow waters. The 22 nominal species can be grouped into two morphological groups "papillocercus"and "krusadensis", based on the absence/presence of a pharyngeal bulbus muscle, absence/presence of ventral ciliary patterns, bilateral/unilateral gonad arrangement and chaetal differences. We present herein the first phylogenetic analyses of Saccocirridae based on four molecular markers and 34 morphological characters, employing maximum likelihood and Bayesian methods. All analyses confirmed the monophyly of each morphological group with high nodal support. As a consequence and based on several apomorphic characters, a new genus, Pharyngocirrus gen. nov., is erected for the "krusadensis"clade. Remarkably, the habitat preferences and trophic guilds are also shown to differ between the two genera, yet show strong consistency within each group. Geographic distribution analyses underscore the family preference for subtropical areas, but reject the previously proposed restriction of Pharyngocirrus gen. nov. to the Indo-Pacific. The finding of two morphologically diverging, cosmopolitan sister clades with different habitat preferences suggest an early ecological diversification of the family, conserved during the later evolution, speciation processes and dispersal of the family75202218CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP140611/2008-82012/08581-0; 2013/04358-7Det Frie Forskningsrad (DFF); Carlsberg Foundation; Reserva de la Biosfera (Government of Lanzarote

Prolonged Aβ treatment leads to impairment in the ability of primary cortical neurons to maintain K+ and Ca2+ homeostasis

<p>Abstract</p> <p>Background</p> <p>Alzheimer's disease (AD) is a progressive neurodegenerative disease, characterised by the formation of insoluble amyloidogenic plaques and neurofibrillary tangles. Beta amyloid (Aβ) peptide is one of the main constituents in Aβ plaques, and is thought to be a primary causative agent in AD. Neurons are likely to be exposed to chronic, sublethal doses of Aβ over an extended time during the pathogenesis of AD, however most studies published to date using <it>in vitro </it>models have focussed on acute studies. To experimentally model the progressive pathogenesis of AD, we exposed primary cortical neurons daily to 1 μM of Aβ_1-40over 7 days and compared their survival with age-similar untreated cells. We also investigated whether chronic Aβ exposure affects neuronal susceptibility to the subsequent acute excitotoxicity induced by 10 μM glutamate and assessed how Ca²⁺and K⁺homeostasis were affected by either treatment.</p> <p>Results</p> <p>We show that continuous exposure to 1 μM Aβ_1-40for seven days decreased survival of cultured cortical neurons by 20%. This decrease in survival correlated with increased K⁺efflux from the cells. One day treatment with 1 μM Aβ followed by glutamate led to a substantially higher K⁺efflux than in the age-similar untreated control. This difference further increased with the duration of the treatment. K⁺efflux also remained higher in Aβ treated cells 20 min after glutamate application leading to 2.8-fold higher total K⁺effluxed from the cells compared to controls. Ca²⁺uptake was significantly higher only after prolonged Aβ treatment with 2.5-fold increase in total Ca²⁺uptake over 20 min post glutamate application after six days of Aβ treatment or longer (P < 0.05).</p> <p>Conclusions</p> <p>Our data suggest that long term exposure to Aβ is detrimental because it reduces the ability of cortical neurons to maintain K⁺and Ca²⁺homeostasis in response to glutamate challenge, a response that might underlie the early symptoms of AD. The observed inability to maintain K⁺homeostasis might furthermore be useful in future studies as an early indicator of pathological changes in response to Aβ.</p

Cluster Production in Quark-Hadron Phase Transition

The problem of cluster formation and growth in first-order quark-hadron phase transition in heavy-ion collisions is considered. Behaving as Brownian particles, the clusters carry out random walks and can encounter one another, leading to coalescence and breakup. A simulation of the process in cellular automaton suggests the possibility of a scaling distribution in the cluster sizes. The experimental determination of the cluster-size distribution is urged as a means to find a clear signature of phase transition.Comment: 12 pages + 1 figure. Report # OITS-517. To be published in Phys. Rev. Lett. 71, xxx (1994

Microbial lysate upregulates host oxytocin

Neuropeptide hormone oxytocin has roles in social bonding, energy metabolism, and wound healing contributing to good physical, mental and social health. It was previously shown that feeding of a human commensal microbe Lactobacillus reuteri (L. reuteri) is sufficient to up-regulate endogenous oxytocin levels and improve wound healing capacity in mice. Here we show that oral L. reuteri-induced skin wound repair benefits extend to human subjects. Further, dietary supplementation with a sterile lysate of this microbe alone is sufficient to boost systemic oxytocin levels and improve wound repair capacity. Oxytocin-producing cells were found to be increased in the caudal paraventricular nucleus [PVN] of the hypothalamus after feeding of a sterile lysed preparation of L. reuteri, coincident with lowered blood levels of stress hormone corticosterone and more rapid epidermal closure, in mouse models. We conclude that microbe viability is not essential for regulating host oxytocin levels. The results suggest that a peptide or metabolite produced by bacteria may modulate host oxytocin secretion for potential public or personalized health goals.Published versio

Interpersonal influence among public health leaders in the United States Department of Health and Human Services

Background. In public health, interpersonal influence has been identified as an important factor in the spread of health information, and in understanding and changing health behaviors. However, little is known about influence in public health leadership. Influence is important in leadership settings, where public health professionals contribute to national policy and practice agendas. Drawing on social theory and recent advances in statistical network modeling, we examined influence in a network of tobacco control leaders at the United States Department of Health and Human Services (DHHS). Design and Methods. Fifty-four tobacco control leaders across all 11 agencies in the DHHS were identified; 49 (91%) responded to a web-based survey. Participants were asked about communication with other tobacco control leaders, who influenced their work, and general job characteristics. Exponential random graph modeling was used to develop a network model of influence accounting for characteristics of individuals, their relationships, and global network structures. Results. Higher job ranks, more experience in tobacco control, and more time devoted to tobacco control each week increased the likelihood of influence nomination, as did more frequent communication between network members. Being in the same agency and working the same number of hours per week were positively associated with mutual influence nominations. Controlling for these characteristics, the network also exhibited patterns associated with influential clusters of network members. Conclusions. Findings from this unique study provide a perspective on influence within a government agency that both helps to understand decision-making and also can serve to inform organizational efforts that allow for more effective structuring of leadership

Muscle strength and gait speed rather than lean mass are better indicators for poor cognitive function in older men

We aimed to examine muscle strength, function and mass in relation to cognition in older men. This cross-sectional data-set included 292 men aged &ge;60 yr. Handgrip strength (kg) was measured by dynamometry, gait speed by 4-metre walk (m/s) and appendicular lean mass (kg) by dual-energy x-ray absorptiometry. Cognition was assessed across four domains: psychomotor function, attention, visual learning and working memory. Composite scores for overall cognition were calculated. Bivariate analyses indicated that handgrip strength and gait speed were positively associated with cognitive function. After accounting for confounders, positive associations between individual muscle (or physical) measures and cognitive performance were sustained for handgrip strength and psychomotor function, gait speed and psychomotor function, gait speed and attention, handgrip strength and overall cognition, and gait speed and overall cognition. In multivariable models, handgrip strength and gait speed independently predicted psychomotor function and overall cognition. No associations were detected between lean mass and cognition after adjusting for confounders. Thus, low muscle strength and slower gait speed, rather than low lean mass, were associated with poor cognition in older men