Benthic habitat mapping for living resources

Much of the development activity in Chesapeake Bay involves modification to subtidal bottoms. . .

Fast and robust single particle reconstruction in 3D fluorescence microscopy

Single particle reconstruction has recently emerged in 3D fluorescence microscopy as a powerful technique to improve the axial resolution and the degree of fluorescent labeling. It is based on the reconstruction of an average volume of a biological particle from the acquisition multiple views with unknown poses. Current methods are limited either by template bias, restriction to 2D data, high computational cost or a lack of robustness to low fluorescent labeling. In this work, we propose a single particle reconstruction method dedicated to convolutional models in 3D fluorescence microscopy that overcome these issues. We address the joint reconstruction and estimation of the poses of the particles, which translates into a challenging non-convex optimization problem. Our approach is based on a multilevel reformulation of this problem, and the development of efficient optimization techniques at each level. We demonstrate on synthetic data that our method outperforms the standard approaches in terms of resolution and reconstruction error, while achieving a low computational cost. We also perform successful reconstruction on real datasets of centrioles to show the potential of our method in concrete applications

The Texas National Estuarine Research Reserve : site nomination and application for predesignation assistance : October 15, 2003

site nomination and applicationThis document describes the process and outcome of the work to nominate a site within the Texas coastal zone for the of the National Estuarine Research Reserve System (NERRS). The NERRS program is administered by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), as authorized under Section 315 of the Coastal Zone Management Act of 1972. The overall mission of this program is to promote stewardship of the nations estuaries through science and education using a system of protected areas. Although national in scope, individual sites are state owned and managed with oversight and coordination provided by NOAA. The selection of a candidate Texas National Estuarine Research Reserve (NERR) site was initiated by the University of Texas Marine Science Institute (UTMSI). The University of Texas at Austin sought the assistance of the Texas General Land Office (GLO) to coordinate the site selection process and prepare the site nomination package. The site selection process was accomplished through the work of two standing committees, tasked with identifying, evaluating, and selecting a candidate site, as well as developing appropriate local, state, federal, and private partnerships that will ultimately define the NERR. The Site Selection Committee (SSC) provided overall guidance to the process and the Site Evaluation Subcommittee (SES) provided technical guidance in evaluating sites. Membership in both committees included individuals from state and federal agencies, state, federal and local public officials (state officers and legislators), academic institutions, private groups (e.g., private industry and environmental groups), and the general public. The process also included a public hearing to solicit comment and input from local residents and landowners in Rockport, Texas. The proposed Texas NERR site was selected from a group of 65 sites, within the Western Gulf of Mexico biogeographical subregion of the Louisianian Biogeographic Region, that represent key estuarine areas within the state's coastal zone. The proposed site (236,641 acres) consists of a combination of approximately 166,131 acres of state-owned coastal habitat, including estuarine intertidal marsh and shallow open-water bottoms and approximately 66,718 acres of estuarine marsh and non-tidal coastal plain habitat that is part of the Aransas and Matagorda Island National Wildlife Refuge. The site also encompasses the Buccaneer Ranch Cove Preserve (279 acres), a 257 acre parcel under conservation by The Nature Conservancy (Johnson Ranch), and a 3,256 acre private parcel (Fennessey Ranch) bordered on three sides by the Mission River that is proposed by the owner as a conservation area. The entire proposed site includes a diverse suite of estuarine and non-estuarine habitats (many of high quality) that form an intact coastal watershed. The site also includes a number of archaeological sites (i.e., indian middens) and supports significant faunal and floral components. The site is relatively rural with limited industrial and community impacts. Upon acceptance of the Texas NERR nomination by NOAA, UTMSI will proceed with development of drafts of an Environmental Impact Statement and Management Plan for the site. It is anticipated that appropriate management agreements will be developed during this phase of site designation to address the educational, research and management objectives of the NERR. The overall goals, objectives, and policies of the Texas NERR will be scoped during the Environmental Impact Statement process and addressed in the Management Plan. Landholding partnerships in the Texas NERR are anticipated to include: USFWS (federal), GLO, TxDOT, TPWD, Coastal Bend Land Trust, The Nature Conservancy, and the Fennessey Ranch. Local administrative partnerships in the Texas NERR are anticipated to include: Aransas County, and the City of RockportNational Oceanic and Atmospheric Administration United States. Office of Ocean and Coastal Resource ManagementMarine Scienc

Slc2a10 knock-out mice deficient in ascorbic acid synthesis recapitulate aspects of arterial tortuosity syndrome and display mitochondrial respiration defects

Arterial tortuosity syndrome (ATS) is a recessively inherited connective tissue disorder, mainly characterized by tortuosity and aneurysm formation of the major arteries. ATS is caused by loss-of-function mutations in SLC2A10, encoding the facilitative glucose transporter GLUT10. Former studies implicated GLUT10 in the transport of dehydroascorbic acid, the oxidized form of ascorbic acid (AA). Mouse models carrying homozygous Slc2a10 missense mutations did not recapitulate the human phenotype. Since mice, in contrast to humans, are able to intracellularly synthesize AA, we generated a novel ATS mouse model, deficient for Slc2a10 as well as Gulo, which encodes for L-gulonolactone oxidase, an enzyme catalyzing the final step in AA biosynthesis in mouse. Gulo;Slc2a10 double knock-out mice showed mild phenotypic anomalies, which were absent in single knock-out controls. While Gulo;Slc2a10 double knock-out mice did not fully phenocopy human ATS, histological and immunocytochemical analysis revealed compromised extracellular matrix formation. Transforming growth factor beta signaling remained unaltered, while mitochondrial function was compromised in smooth muscle cells derived from Gulo;Slc2a10 double knock-out mice. Altogether, our data add evidence that ATS is an ascorbate compartmentalization disorder, but additional factors underlying the observed phenotype in humans remain to be determined

Leviers proposés par le travail en groupe pour l'apprentissage : retour d'expérience

International audienceAfin de favoriser l’apprentissage en profondeur lors d’un enseignement dispensé à des étudiants en formation d’ingénierie, un dispositif pédagogique mettant l’accent sur le transfert des connaissances a été mis en place. Une explication à l’oral d’un travail personnel y a notamment été mise en œuvre. L’apport de cette explication pour l’apprentissage a été questionné via des observations directes et des, entretiens semi-directifs. Il apparaît tout d’abord que cette séquence pédagogique ne soutient pas de façon significative l’apprentissage. Il apparaît également que 80% des séquences citées comme participant à l’apprentissage relèvent du travail de groupe. Le lien entre le travail en groupe et l’apprentissage a été questionné auprès des étudiants ayant suivi l’enseignement. Les interactions continues au cours de ce travail et une distribution du travail horizontale, encouragées par des compte rendus réguliers, semblent favoriser l’apprentissage. Au contraire l’interaction avec l’enseignant lors du travail personnel ne semble pas nécessaire

Two New Techniques for Evaluating Connectivity of Septic Fields to Great Lake Watersheds and Embayments

Pictometry Oblique Imagery was successfully used to map septic fields in Oak Orchard watershed. Analysis of the imagery proved to be efficient for finding leach fields, and between 66 to 81% of the septic fields previously mapped by the Genesee Orleans County Department of Health, were identified. The remainder were not identified because of canopy cover, or were either septic systems without leach fields, the septic field postdated the imagery, or were not visible. Consequently under ideal conditions (septic systems with leach fields and no canopy or shadows) the method should be able to identify over 80% of the systems. Imagery taken during the transition from dormant to growing season proved best for identifying leach fields. One example of a plume from a short circuited system was recorded. A total of 1277 septic fields were mapped in the watershed. Spatial distribution was heterogenous, with dense sites of septic fields concentrated along residential road corridors. Approximately 4.2% of the leach fields were located less than 100 feet of a tributary. This is below the minimum separation distance of a leach field to a waterbody that is required by the NYS Department of Health code. The average distance of a leach field to a tributary is 327 meters with 50% of the leach fields occurring within 240 meters of mapped tributaries. Maps of important septic field “hotspots” were developed for watershed stakeholders and include tributaries along Batavia-Elba Townline Rd., Marsh Creek, and tributaries near the intersections of Alleghany and Lockport Rds, Judge Rd and Knowlesville Rd., and Lockport and Albion Rd. Considerable numbers of septic fields occur along Lake Alice in the main stem of the river, however this stretch is probably diluted by water input from the Erie Canal at the Glendale Dam. In a second set of experiments, a new DNA-based groundwater tracer was introduced to two septic systems to see if it could be used to trace individual septic systems. The tracer was not discovered in one site, however, a breakthrough curve was obtained in the second site 31 days after being introduced into the toilet. This tracer passed through at least 200 meters of groundwater flowpath and 1 km of stream. The results of these experiments suggest that frequent, systematic sampling and careful lab protocols to identify the signal to noise threshold of the procedure are critical to the success of the technique. In summary we suggest that Pictometry Oblique Imagery can be used to map septic fields in a watershed and that the DNA Tracer technique may be successful in some septic systems. Further research needs to be conducted to improve the success of the latter

Effects of alpha-linolenic acid vs. docosahexaenoic acid supply on the distribution of fatty acids among the rat cardiac subcellular membranes after a short- or long-term dietary exposure

Previous work showed that the functional cardiac effect of dietary alpha-linolenic acid (ALA) in rats requires a long feeding period (6 months), although a docosahexaenoic (DHA) acid-supply affects cardiac adrenergic response after 2 months. However, the total cardiac membrane n-3 polyunsaturated fatty acid (PUFA) composition remained unchanged after 2 months. This delay could be due to a specific reorganization of the different subcellular membrane PUFA profiles. This study was designed to investigate the evolution between 2 and 6 months of diet duration of the fatty acid profile in sarcolemmal (SL), mitochondrial (MI), nuclear (NU) and sarcoplasmic reticulum (SR) membrane fractions. Male Wistar rats were randomly assigned to 3 dietary groups (n = 10/diet/period), either n-3 PUFA-free diet (CTL), or ALA or DHA-rich diets. After 2 or 6 months, the subcellular cardiac membrane fractions were separated by differential centrifugations and sucrose gradients. Each membrane profile was analysed by gas chromatography (GC) after lipid extraction. As expected the n-3 PUFA-rich diets incorporated n-3 PUFA instead of n-6 PUFA in all the subcellular fractions, which also exhibited individual specificities. The diet duration increased SFA and decreased PUFA in SL, whereas NU remained constant. The SR and MI enriched in n-3 PUFA exhibited a decreased DHA level with ageing in the DHA and CTL groups. Conversely, the n-3 PUFA level remained unchanged in the ALA group, due to a significant increase in docosapentaenoic acid (DPA). N-3 PUFA rich diets lead to a better PUFA profile in all the fractions and significantly prevent the profile modifications induced by ageing. With the ALA diet the n-3 PUFA content, particularly in SR and SL kept increasing between 2 and 6 months, which may partly account for the delay to achieve the modification of adrenergic response