On the local structure of Dirac manifolds

We give a local normal form for Dirac structures. As a consequence, we show that the dimensions of the pre-symplectic leaves of a Dirac manifold have the same parity. We also show that, given a point $m$ of a Dirac manifold $M$, there is a well-defined transverse Poisson structure to the pre-symplectic leaf $P$ through $m$. Finally, we describe the neighborhood of a pre-symplectic leaf in terms of geometric data. This description agrees with that given by Vorobjev for the Poisson caseComment: minor correction

Stability of higher order singular points of Poisson manifolds and Lie algebroids

We study the stability of singular points for smooth Poisson structures as well as general Lie algebroids. We give sufficient conditions for stability lying on the first (not necessarily linear) approximation of the given Poisson structure or Lie algebroid at a singular point. The main tools used here are the classical Lichnerowicz-Poisson cohomology and the deformation cohomology for Lie algebroids recently introduced by Crainic and Moerdijk. We also provide several examples of stable singular points of order $k \geq 1$ for Poisson structures and Lie algebroids. Finally, we apply our results to pre-symplectic leaves of Dirac manifolds.Comment: corrected typo

MARKET STRUCTURE AND SPATIAL PRICE DYNAMICS

A method was developed with time series models to test hypotheses about the relationship between market structure and spatial price dynamics. Long-run dynamic multipliers measuring the magnitude of lagged adjustments for spatial milled rice prices were calculated from the time series model and used as the dependent variable in a regression model that included a number of factors expected to influence price determination. Results show that price adjustments were slower as regional submarket concentration increased and were faster in the regions with a higher market share. Arkansas, the state with the largest market share, was consistently a price leaderDemand and Price Analysis, Industrial Organization,

Students’ Perceptions about Successfully Transitioning to Postsecondary Institutions

Through the auspices of federal legislation, students with disabilities are gaining access to higher education. Still for many students with disabilities, the paramount barriers facing them in their transition to postsecondary education are overwhelming. This paper reports the findings of a qualitative study of 59 postsecondary students with disabilities on factors students perceived to inhibit or contribute to their successful transition into college. The study examines support services and access to reasonable accommodations available to students with disabilities. Students reported the major barriers to accessing college and succeeding in college were societal attitudes, lack of preparation, and financial constraints. The students also identified self-determination and families as necessary supports that propelled their transition into postsecondary education. Recommendations and suggestions for teachers, students, and families are presented by the study’s participants to support students’ with disabilities access and retention in postsecondary institutions

Intérêt des laits fermentés chez l'enfant diarrhéique malnutri

L'objectif de cette étude était de comparer, chez des enfants diarrhéiques malnutris, l'effet thérapeutique d'un yaourt manufacturé à flore vivante et d'un lait fermenté enrichi préparé de façon artisanale (soow). De novembre 1988 à juillet 1989, 50 enfants non sevrés présentant une diarrhée aigüe associée à une malnutrition (indice poids/taille < 80 % des références NCHS) ont été admis dans l'étude; la répartition entre les groupes (soow contre yaourt) a été faite par tirage au sort et les deux groupes étaient comparables pour la réhabilitation nutritionnelle de ces enfants; le gain de poids moyen a été de 16 g/kg/j et le protocole n'a jamais dû être interrompu du fait d'une aggravation de la diarrhée ou d'une perte de poids. Sur le plan biologique, les résultats confirment l'intérêt du dosage de la transthyrétine associé à celui des protéines inflammatoires pour l'évaluation et le suivi du déficit nutritionnel. L'ensemble de ces résultats suggère que la réalimentation précoce à l'aide de laits fermentés enrichis, associée à la réhydratation orale, apparaît comme bénéfique en cas de diarrhée aiguë associée à une malnutrition. (Résumé d'auteur

Diversity of microbial eukaryotes along the West Antarctic Peninsula in austral spring

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Grattepanche, J.-D., Jeffrey, W., Gast, R., & Sanders, R. Diversity of microbial eukaryotes along the West Antarctic Peninsula in austral spring. Frontiers in Microbiology, 13, (2022): 844856, https://doi.org/10.3389/fmicb.2022.844856.During a cruise from October to November 2019, along the West Antarctic Peninsula, between 64.32 and 68.37°S, we assessed the diversity and composition of the active microbial eukaryotic community within three size fractions: micro- (> 20 μm), nano- (20–5 μm), and pico-size fractions (5–0.2 μm). The communities and the environmental parameters displayed latitudinal gradients, and we observed a strong similarity in the microbial eukaryotic communities as well as the environmental parameters between the sub-surface and the deep chlorophyll maximum (DCM) depths. Chlorophyll concentrations were low, and the mixed layer was shallow for most of the 17 stations sampled. The richness of the microplankton was higher in Marguerite Bay (our southernmost stations), compared to more northern stations, while the diversity for the nano- and pico-plankton was relatively stable across latitude. The microplankton communities were dominated by autotrophs, mostly diatoms, while mixotrophs (phototrophs-consuming bacteria and kleptoplastidic ciliates, mostly alveolates, and cryptophytes) were the most abundant and active members of the nano- and picoplankton communities. While phototrophy was the dominant trophic mode, heterotrophy (mixotrophy, phagotrophy, and parasitism) tended to increase southward. The samples from Marguerite Bay showed a distinct community with a high diversity of nanoplankton predators, including spirotrich ciliates, and dinoflagellates, while cryptophytes were observed elsewhere. Some lineages were significantly related—either positively or negatively—to ice coverage (e.g., positive for Pelagophyceae, negative for Spirotrichea) and temperature (e.g., positive for Cryptophyceae, negative for Spirotrichea). This suggests that climate changes will have a strong impact on the microbial eukaryotic community.This work was supported by the National Science Foundation (Grant Nos. ANT 1744767 to RS, ANT 1744663 to RG, and ANT 1744638 to WJ). This research was based, in part, upon sequencing conducted using the Rhode Island Genomics and Sequencing Center, which was supported in part by the National Science Foundation (MRI Grant No. DBI-0215393 and EPSCoR Grant Nos. 0554548 and EPS-1004057), the US Department of Agriculture (Grant Nos. 2002-34438-12688 and 2003-34438-13111), and the University of Rhode Island. This research includes calculations carried out on Temple University HPC resources supported in part by the National Science Foundation through major research instrumentation (Grant No. 1625061) and by the US Army Research Laboratory under (Contract No. W911NF-16-2-0189)