Heavy Quarkonium in a weakly-coupled quark-gluon plasma below the melting temperature

We calculate the heavy quarkonium energy levels and decay widths in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> T >> m alpha_s^2 >> m_D (m being the heavy-quark mass), at order m alpha_s^5. We first sequentially integrate out the scales m, m alpha_s and T, and, next, we carry out the calculations in the resulting effective theory using techniques of integration by regions. A collinear region is identified, which contributes at this order. We also discuss the implications of our results concerning heavy quarkonium suppression in heavy ion collisions.Comment: 25 pages, 2 figure

Sparse Coding Predicts Optic Flow Specificities of Zebrafish Pretectal Neurons

Zebrafish pretectal neurons exhibit specificities for large-field optic flow patterns associated with rotatory or translatory body motion. We investigate the hypothesis that these specificities reflect the input statistics of natural optic flow. Realistic motion sequences were generated using computer graphics simulating self-motion in an underwater scene. Local retinal motion was estimated with a motion detector and encoded in four populations of directionally tuned retinal ganglion cells, represented as two signed input variables. This activity was then used as input into one of two learning networks: a sparse coding network (competitive learning) and backpropagation network (supervised learning). Both simulations develop specificities for optic flow which are comparable to those found in a neurophysiological study (Kubo et al. 2014), and relative frequencies of the various neuronal responses are best modeled by the sparse coding approach. We conclude that the optic flow neurons in the zebrafish pretectum do reflect the optic flow statistics. The predicted vectorial receptive fields show typical optic flow fields but also "Gabor" and dipole-shaped patterns that likely reflect difference fields needed for reconstruction by linear superposition.Comment: Published Conference Paper from ICANN 2018, Rhode

Norovirus Infection and Disease in an Ecuadorian Birth Cohort: Association of Certain Norovirus Genotypes With Host FUT2 Secretor Status.

BACKGROUND: Although norovirus is the most common cause of gastroenteritis, there are few data on the community incidence of infection/disease or the patterns of acquired immunity or innate resistance to norovirus. METHODS: We followed a community-based birth cohort of 194 children in Ecuador with the aim to estimate (1) the incidence of norovirus gastroenteritis from birth to age 3 years, (2) the protective effect of norovirus infection against subsequent infection/disease, and (3) the association of infection and disease with FUT2 secretor status. RESULTS: Over the 3-year period, we detected a mean of 2.26 diarrheal episodes per child (range, 0-12 episodes). Norovirus was detected in 260 samples (18%) but was not found more frequently in diarrheal samples (79 of 438 [18%]), compared with diarrhea-free samples (181 of 1016 [18%]; P = .919). A total of 66% of children had at least 1 norovirus infection during the first 3 years of life, and 40% of children had 2 infections. Previous norovirus infections were not associated with the risk of subsequent infection. All genogroup II, genotype 4 (GII.4) infections were among secretor-positive children (P < .001), but higher rates of non-GII.4 infections were found in secretor-negative children (relative risk, 0.56; P = .029). CONCLUSIONS: GII.4 infections were uniquely detected in secretor-positive children, while non-GII.4 infections were more often found in secretor-negative children

NLStradamus: a simple Hidden Markov Model for nuclear localization signal prediction

<p>Abstract</p> <p>Background</p> <p>Nuclear localization signals (NLSs) are stretches of residues within a protein that are important for the regulated nuclear import of the protein. Of the many import pathways that exist in yeast, the best characterized is termed the 'classical' NLS pathway. The classical NLS contains specific patterns of basic residues and computational methods have been designed to predict the location of these motifs on proteins. The consensus sequences, or patterns, for the other import pathways are less well-understood.</p> <p>Results</p> <p>In this paper, we present an analysis of characterized NLSs in yeast, and find, despite the large number of nuclear import pathways, that NLSs seem to show similar patterns of amino acid residues. We test current prediction methods and observe a low true positive rate. We therefore suggest an approach using hidden Markov models (HMMs) to predict novel NLSs in proteins. We show that our method is able to consistently find 37% of the NLSs with a low false positive rate and that our method retains its true positive rate outside of the yeast data set used for the training parameters.</p> <p>Conclusion</p> <p>Our implementation of this model, NLStradamus, is made available at: <url>http://www.moseslab.csb.utoronto.ca/NLStradamus/</url></p

Angular Spectrum Analysis Applied to Undercladding Flaws and Dipole Probes

An important class of subsurface cracks occur in nuclear power plant pressure vessels. These pressure vessels, normally made of carbon steel, are protected by a layer of weld material applied directly onto the surface, leaving a highly inhomogeneoue cladding with a rough surface and a very irregular interface. Subsurface cracks originate at the interface between the carbon steel walls of the pressure vessel and the protective cladding layer. The propagation is initially into the carbon steel and eventually into the cladding, and needs to be detected before reaching the surface (Fig. 1). The inhomogeneity of the cladding material and the irregular surfaces pose serious difficulties for ultrasonic detection. These difficulties are less critical for eddy current testing due to the fact that the layered structure of the cladding has more variation in its elastic properties than its electrical conductivity

Effet de l’inoculation avec des spores de champignon ectomycorhizien du genre Scleroderma sur la croissance et la nutrition des plants de Afzelia africana Sm. en pépinière

Les champignons ectomycorhiziens du genre Scleroderma sont des gast&#233;romyc&#232;tes produisant une masse sporale importante pouvant &#234;tre utilis&#233;e comme inoculum. Des plants de Afzelia africana Sm. ont &#233;t&#233; inocul&#233;s en p&#233;pini&#232;re avec diff&#233;rentes doses de spores sur un substrat sableux. Les doses de spores apport&#233;es &#233;taient : 0 (t&#233;moin), 20, 50 et 100 mg de spores pour chacune des deux esp&#232;ces de Scleroderma test&#233;e; Scleroderma dictyosporum Pat. et S. verrucosum (Bull.) Pers. r&#233;colt&#233;es sous diff&#233;rentes plantes h&#244;tes. Les r&#233;sultats obtenus montrent des taux de mycorhization faibles, 21,5 &#224; 26,4% en fonction des doses de spores. Tous les traitements sont significativement diff&#233;rents du t&#233;moin, cependant aucune diff&#233;rence significative entre les diff&#233;rentes doses de spores n&#8217;a &#233;t&#233; observ&#233;e. L&#8217;inoculation n&#8217;a pas am&#233;lior&#233; les param&#232;tres de croissance hormis le diam&#232;tre au collet qui est significativement plus important chez les plants inocul&#233;s avec les doses 50 et 100 mg de S. dictyosporum (Sd50 et Sd100). L&#8217;inoculation a am&#233;lior&#233; la nutrition phosphat&#233;e des plants inocul&#233;s avec la dose Sv20. Ces donn&#233;es sugg&#232;rent que la r&#233;ponse &#224; l&#8217;inoculation est peu d&#233;pendante de la dose de spores apport&#233;e. La texture sableuse du substrat et sa pauvret&#233; en &#233;l&#233;ments min&#233;raux ne semblent pas favorables &#224; l&#8217;optimisation de la mycorhization. Les spores peuvent constituer une source d&#8217;inoculum important, n&#233;anmoins, hormis le substrat pauvre, le faible taux de mycorhization observ&#233; peut &#234;tre du en partie au taux de germination et au d&#233;lai mis pour la germination des spores et donc l&#8217;&#233;tablissement de la symbiose.Mots cl&#233;s : Mycorhization contr&#244;l&#233;e, Doses de spores, Croissance et nutrition des plant

Fast Scalable Construction of (Minimal Perfect Hash) Functions

Recent advances in random linear systems on finite fields have paved the way for the construction of constant-time data structures representing static functions and minimal perfect hash functions using less space with respect to existing techniques. The main obstruction for any practical application of these results is the cubic-time Gaussian elimination required to solve these linear systems: despite they can be made very small, the computation is still too slow to be feasible. In this paper we describe in detail a number of heuristics and programming techniques to speed up the resolution of these systems by several orders of magnitude, making the overall construction competitive with the standard and widely used MWHC technique, which is based on hypergraph peeling. In particular, we introduce broadword programming techniques for fast equation manipulation and a lazy Gaussian elimination algorithm. We also describe a number of technical improvements to the data structure which further reduce space usage and improve lookup speed. Our implementation of these techniques yields a minimal perfect hash function data structure occupying 2.24 bits per element, compared to 2.68 for MWHC-based ones, and a static function data structure which reduces the multiplicative overhead from 1.23 to 1.03

Generalized Integer Partitions, Tilings of Zonotopes and Lattices

In this paper, we study two kinds of combinatorial objects, generalized integer partitions and tilings of two dimensional zonotopes, using dynamical systems and order theory. We show that the sets of partitions ordered with a simple dynamics, have the distributive lattice structure. Likewise, we show that the set of tilings of zonotopes, ordered with a simple and classical dynamics, is the disjoint union of distributive lattices which we describe. We also discuss the special case of linear integer partitions, for which other dynamical systems exist. These results give a better understanding of the behaviour of tilings of zonotopes with flips and dynamical systems involving partitions.Comment: See http://www.liafa.jussieu.fr/~latapy

Public health agencies' use of social media for communication during pandemics: a scoping review of the literature

Public health agencies (PHAs) have increasingly incorporated social media into their communication mix during successive pandemics in the 21st century. However, the quality, timing, and accuracy of their health messages have varied significantly, resulting in mixed outcomes for communication, audience engagement, and pandemic management. This study aimed to identify factors influencing the effectiveness of pandemic-related health messages shared by PHAs on social media and to report their impact on public engagement as documented in the literature. A scoping literature review was conducted following a predefined protocol. An electronic search of 7 relevant databases and 5 grey literature repositories yielded 9,714 papers published between January 2003 and November 2022. Seventy-three papers were deemed eligible and selected for review. The results underscored the insufficiency of social media guidance policies for PHAs. Six themes were identified: message source, message topic, message style, message timing, content credibility and reliability, and message recipient profile. These themes encompassed 20 variables that could inform PHAs' social media public health communication during pandemics. Additionally, the findings revealed potential interconnectedness among the variables, and this study concluded by proposing a conceptual model that expands upon existing theoretical foundations for developing and evaluating pandemic-related health messaging

Field performance of the parasitoid wasp, Trichogrammatoidea armigera (Hymenoptera: Trichogrammatidae) following releases against the millet head miner, Heliocheilus albipunctella (Lepidoptera: Noctuidae) in the Sahel

The effectiveness of the egg parasitoid Trichogrammatoidea armigera Nagaraja (Hymenoptera: Trichogrammatidae) in controlling Heliocheilus albipunctella de Joannis (Lepidoptera: Noctuidae), a major insect pest of pearl millet in the Sahel was assessed during two consecutive years in Niger on-station and on-farm conditions. We found that released T. armigera were able to find and parasitize host eggs within pearl millet fields both onstation and in farmers’ fields. On-station releases of T. armigera led to an average 4.86-fold increase in T. armigera parasitism compared to control fields, where no parasitoids were released. Likewise, on-farm releases of T. armigera led to up to 5.31-fold more egg parasitism by T. armigera in release fields than in control. Our results suggest the effectiveness of T. armigera and lays the groundwork for using T.armigera in augmentative biological control of H. albipunctella in the Sahel