Elements of metacommunity structure of diatoms and macroinvertebrates within stream networks differing in environmental heterogeneity

Aim Idealized metacommunity structures (i.e. checkerboard, random, quasi-structures, nested, Clementsian, Gleasonian and evenly spaced) have recently gained increasing attention, but their relationships with environmental heterogeneity and how they vary with organism groups remain poorly understood. Here, we tested two main hypotheses: (a) gradient-driven patterns (Clementsian and Gleasonian) occur frequently in heterogeneous environments and (b) small organisms (here, diatoms) are more likely to exhibit gradient-driven patterns than large organisms (here, macroinvertebrates). Location Streams in three regions in China. Taxon Diatoms and macroinvertebrates. Methods The stream diatom and macroinvertebrate data, as well as the environmental data collected from the same set of sites were used to examine the idealized metacommunity structures via the elements of the metacommunity structure (EMS; coherence, turnover and boundary clumping) analysis in three regions. We extended the traditional EMS approach by ordering sites along known environmental gradients. Results We found that Clementsian structure with high degrees of coherence and turnover, and significantly positive clumping was typically observed in the high-heterogeneity regions, whereas randomness was prevalent in the low-heterogeneity region. Macroinvertebrates exhibited clearer Clementsian structures compared with diatoms, while diatoms showed more randomness compared with macroinvertebrates, indicating a stronger role of environmental filtering for macroinvertebrates than diatoms. In most cases, the results of the more novel EMS approach differed from the results of the traditional EMS technique. Main conclusions Our results suggested that the occurrence of different metacommunity structures may be related with the degree of regional environmental heterogeneity. However, diatom metacommunities were more random than those of macroinvertebrate, and such an unexpected result may result from different dispersal abilities between the two organism groups. In addition, we found that the novel EMS approach increased power in discerning metacommunity structure in comparison to the traditional EMS technique.peerReviewe

Evaluation of Muscat types and clones for the local market

Ten European clones and selections of 'Muscat blanc' were investigated about their variability in genetic and enological behavior. The SSR profile of about 120 loci allowed to differentiate most of them. Nevertheless the differences within the variety are rare and do not reflect the heterogeneity of  observed variability. One of the clones (B41/5) represents an earlier ripening type where the overall quality was independent from sugar content. A 27-1 clone was one of the clones with steady high rating concerning wine quality. An interesting alternative for early ripening areas could be the late ripening 'Goldmuskateller' due to the higher stability against Botrytis. One of the samples was not true to type and represented this cultivar

Bowen-York Tensors

There is derived, for a conformally flat three-space, a family of linear second-order partial differential operators which send vectors into tracefree, symmetric two-tensors. These maps, which are parametrized by conformal Killing vectors on the three-space, are such that the divergence of the resulting tensor field depends only on the divergence of the original vector field. In particular these maps send source-free electric fields into TT-tensors. Moreover, if the original vector field is the Coulomb field on $\mathbb{R}^3\backslash \lbrace0\rbrace$, the resulting tensor fields on $\mathbb{R}^3\backslash \lbrace0\rbrace$ are nothing but the family of TT-tensors originally written down by Bowen and York.Comment: 12 pages, Contribution to CQG Special Issue "A Spacetime Safari: Essays in Honour of Vincent Moncrief

Garside and quadratic normalisation: a survey

Starting from the seminal example of the greedy normal norm in braid monoids, we analyse the mechanism of the normal form in a Garside monoid and explain how it extends to the more general framework of Garside families. Extending the viewpoint even more, we then consider general quadratic normalisation procedures and characterise Garside normalisation among them.Comment: 30 page

Stalking influenza by vaccination with pre-fusion headless HA mini-stem.

Inaccuracies in prediction of circulating viral strain genotypes and the possibility of novel reassortants causing a pandemic outbreak necessitate the development of an anti-influenza vaccine with increased breadth of protection and potential for rapid production and deployment. The hemagglutinin (HA) stem is a promising target for universal influenza vaccine as stem-specific antibodies have the potential to be broadly cross-reactive towards different HA subtypes. Here, we report the design of a bacterially expressed polypeptide that mimics a H5 HA stem by protein minimization to focus the antibody response towards the HA stem. The HA mini-stem folds as a trimer mimicking the HA prefusion conformation. It is resistant to thermal/chemical stress, and it binds to conformation-specific, HA stem-directed broadly neutralizing antibodies with high affinity. Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. Passive transfer of immune serum demonstrates the protection is mediated by stem-specific antibodies. Furthermore, antibodies indudced by these HA stems have broad HA reactivity, yet they do not have antibody-dependent enhancement activity

Characterizing entanglement with geometric entanglement witnesses

We show how to detect entangled, bound entangled, and separable bipartite quantum states of arbitrary dimension and mixedness using geometric entanglement witnesses. These witnesses are constructed using properties of the Hilbert-Schmidt geometry and can be shifted along parameterized lines. The involved conditions are simplified using Bloch decompositions of operators and states. As an example we determine the three different types of states for a family of two-qutrit states that is part of the "magic simplex", i.e. the set of Bell-state mixtures of arbitrary dimension.Comment: 19 pages, 4 figures, some typos and notational errors corrected. To be published in J. Phys. A: Math. Theo

Two computable sets of multipartite entanglement measures

We present two sets of computable entanglement measures for multipartite systems where each subsystem can have different degrees of freedom (so-called qudits). One set, called 'separability' measure, reveals which of the subsystems are separable/entangled. For that we have to extend the concept of k-separability for multipartite systems to a novel unambiguous separability concept which we call \gamma_k-separability. The second set of entanglement measures reveals the 'kind' of entanglement, i.e. if it is bipartite, tripartite, ..., n-partite entangled and is denoted as the 'physical' measure. We show how lower bounds on both sets of measures can be obtained by the observation that any entropy may be rewritten via operational expressions known as m-concurrences. Moreover, for different classes of bipartite or multipartite qudit systems we compute the bounds explicitly and discover that they are often tight or equivalent to positive partial transposition (PPT).Comment: 3 figures, 21 page

Influenza virus differentially activates mTORC1 and mTORC2 signaling to maximize late stage replication

<div><p>Influenza A virus usurps host signaling factors to regulate its replication. One example is mTOR, a cellular regulator of protein synthesis, growth and motility. While the role of mTORC1 in viral infection has been studied, the mechanisms that induce mTORC1 activation and the substrates regulated by mTORC1 during influenza virus infection have not been established. In addition, the role of mTORC2 during influenza virus infection remains unknown. Here we show that mTORC2 and PDPK1 differentially phosphorylate AKT upon influenza virus infection. PDPK1-mediated phoshorylation of AKT at a distinct site is required for mTORC1 activation by influenza virus. On the other hand, the viral NS1 protein promotes phosphorylation of AKT at a different site via mTORC2, which is an activity dispensable for mTORC1 stimulation but known to regulate apoptosis. Influenza virus HA protein and down-regulation of the mTORC1 inhibitor REDD1 by the virus M2 protein promote mTORC1 activity. Systematic phosphoproteomics analysis performed in cells lacking the mTORC2 component Rictor in the absence or presence of Torin, an inhibitor of both mTORC1 and mTORC2, revealed mTORC1-dependent substrates regulated during infection. Members of pathways that regulate mTORC1 or are regulated by mTORC1 were identified, including constituents of the translation machinery that once activated can promote translation. mTORC1 activation supports viral protein expression and replication. As mTORC1 activation is optimal midway through the virus life cycle, the observed effects on viral protein expression likely support the late stages of influenza virus replication when infected cells undergo significant stress.</p></div

High Resolution Hybrid Pixel Sensors for the e+e- TESLA Linear Collider Vertex Tracker

In order to fully exploit the physics potential of a future high energy e+e- linear collider, a Vertex Tracker, providing high resolution track reconstruction, is required. Hybrid Silicon pixel sensors are an attractive option, for the sensor technology, due to their read-out speed and radiation hardness, favoured in the high rate environment of the TESLA e+e- linear collider design but have been so far limited by the achievable single point space resolution. In this paper, a conceptual design of the TESLA Vertex Tracker, based on a novel layout of hybrid pixel sensors with interleaved cells to improve their spatial resolution, is presented.Comment: 12 pages, 5 figures, to appear in the Proceedings of the Vertex99 Workshop, Texel (The Netherlands), June 199

Determination of the angle gamma using B -> D* V modes

We propose a method to determine the angle $\gamma=arg(V_{ub})$, using the $B\to D^*V$ ($V=K^*, \rho$) modes. The $D^*$ is considered to decay to $D \pi$. An interference of the $B \to D^{*0}V$ and $B \to \bar {D^{*0}}V$ amplitudes is achieved by looking at a common final state $f$, in the subsequent decays of $D^0/\bar{D^0}$. A detailed analysis of the angular distribution, allows determination, not only of $\gamma$ and $|V_{ub}|$, but also all the hadronic amplitudes and strong phases involved. No prior knowledge of doubly Cabibbo suppressed branching ratios of $D$ are required. Large CP violating asymmetries ($\sim30$ for $\gamma=30^o$) are possible if $\bar{D^0} \to f$ is doubly Cabbibo suppressed, while $D^0 \to f$ is Cabbibo allowed, for decays of $B^+$ or $B^0$.Comment: 12 Pages Revte