772 research outputs found
Protection and maintenance of permanent pastures
peer reviewedAll farmers receiving direct payments are subject to compulsory cross-compliance which includes standards related to the maintenance and protection of permanent pastures. Questionnaire techniques and spatio-temporal analyses demonstrated that the ratio of permanent pasture area to agricultural land provides a simple tool for monitoring and controlling the protection of permanent pastures at the regional to Member State level. Huge variations in the ratio across Europe were related to the importance of permanent pastures, the interpretation of definitions, sources of information used, differences in calculation, and the presence of protective and/or sensitive zones.
Precautionary or complementary measures are in place in most Member States in order to prevent decreases in the ratio. The implementation of GAEC standards related to permanent pastures overlaps with the standard management requirements, national legislation and current agri-environmental programmes. The study advocates the establishment of a comprehensive geo-information platform consisting of a topologically correct inventory of all permanent pasture parcels in a 1:1 geo-referenced relation between IACS and LPIS; ancillary spatially explicit data such as orthophotos, remote sensing images and other thematic geo-databases; and, geodatabases with parcel information compiled for other monitoring purposes such as those within the framework of the Nitrates Directive or 2nd pillar support
Characterization of methane-seep communities in a deep-sea area designated for oil and natural gas exploitation off Trinidad and Tobago
Exploration of the deep ocean (>200 m) is taking on added importance as human development encroaches. Despite increasing oil and natural gas exploration and exploitation, the deep ocean of Trinidad and Tobago is almost entirely unknown. The only scientific team to image the deep seafloor within the Trinidad and Tobago Exclusive Economic Zone was from IFREMER in the 1980s. That exploration led to the discovery of the El Pilar methane seeps and associated chemosynthetic communities on the accretionary prism to the east of Trinidad and Tobago. In 2014, the E/V Nautilus, in collaboration with local scientists, visited two previously sampled as well as two unexplored areas of the El Pilar site between 998 and 1,629 m depth using remotely operated vehicles. Eighty-three megafaunal morphospecies from extensive chemosynthetic communities surrounding active methane seepage were observed at four sites. These communities were dominated by megafaunal invertebrates including mussels (Bathymodiolus childressi), shrimp (Alvinocaris cf. muricola), Lamellibrachia sp. 2 tubeworms, and Pachycara caribbaeum. Adjacent to areas of active seepage was an ecotone of suspension feeders including Haplosclerida sponges, stylasterids and Neovermilia serpulids on authigenic carbonates. Beyond this were large Bathymodiolus shell middens. Finally there was either a zone of sparse octocorals and other non-chemosynthetic species likely benefiting from the carbonate substratum and enriched production within the seep habitat, or sedimented inactive areas. This paper highlights these ecologically significant areas and increases the knowledge of the biodiversity of the Trinidad and Tobago deep ocean. Because methane seepage and chemosynthetic communities are related to the presence of extractable oil and gas resources, development of best practices for the conservation of biodiversity in Trinidad and Tobago waters within the context of energy extraction is critical. Potential impacts on benthic communities during oil and gas activities will likely be long lasting and include physical disturbance during drilling among others. Recommendations for the stewardship of these widespread habitats include: (1) seeking international cooperation; (2) holding wider stakeholder discussions; (3) adopting stringent environmental regulations; and (4) increasing deep-sea research to gather crucial baseline data in order to conduct appropriate marine spatial planning with the creation of marine protected areas.Copyright © 2017 Amon, Gobin, Van Dover, Levin, Marsh and Raineault. This
is an open-access article distributed under the terms of the Creative Commons
Attribution License (CC BY). The use, distribution or reproduction in other forums
is permitted, provided the original author(s) or licensor are credited and that the
original publication in this journal is cited, in accordance with accepted academic
practice. No use, distribution or reproduction is permitted which does not comply
with these terms
Conventional niche overlap measurements are not effective for assessing interspecific competition
Interspecific competition is notoriously difficult to detect and quantify, especially in species that are wide-ranging or otherwise difficult to track in the wild. Research investigating interspecific competition usually relies on niche overlap measurements despite that this approach alone does not yield rigorous inference. As an illustration, we review published research assessing interspecific competition in mid-sized carnivores in North America (bobcat – Lynx rufus; Canada lynx – Lynx canadensis; coyote – Canis latrans), and report on shortcomings associated with commonly used study designs and types of inference. Niche overlap measurements typically focus on one or two resources (e.g., food, space, habitat), often using non-independent sampling units and inadequate replication. Few studies measure overlap variation through space, time, or resource variability, which is crucial for robust assessment. Niche overlap (or lack thereof) is used as evidence both for and against interspecific competition, reflecting a weak link between competition theory, predicted responses, and observations. Overall, challenges associated with conducting competition research in the field promote over-reliance on simple measurements, flawed study designs and weak inference. Minimally, niche overlap studies should include assessment across multiple niche dimensions and spatial or temporal variation in competitor density or resource availability. Dynamic investigative approaches should include new technologies for tracking inter-individual interactions, study designs that leverage quasi-experiments (e.g., decline in shared resources, biological control of one competitor), and synthetic analyses (e.g., meta-regression). Ultimately, better understanding of competition theory vis-à-vis study design and data needs will promote improved understanding of the role of interspecific competition in nature
Status of the light ion source developments at CEA/Saclay
ACC NIMInternational audienceSILHI (High Intensity Light Ion Source) is an ECR ion source producing high intensity proton ordeuteron beams at 95 keV. It is now installed in the IPHI site building, on the CEA/Saclay center. IPHI is a frontend demonstrator of high power accelerator. The source regularly delivers more than 130 mA protons in CWmode and already produced more than 170 mA deuterons in pulsed mode at nominal energy. The last beamcharacterisations, including emittance measurements, space charge compensation analysis and diagnosticimprovements, will be reported. Taking into account the SILHI experience, new developments are in progress tobuild and test a 5 mA deuteron source working in CW mode. This new source will also operate at 2.45 GHz andpermanent magnets will provide the magnetic configuration. This source, of which the design will be discussed,will have to fit in with the SPIRAL 2 accelerator developed at GANIL to produce Radioactive Ion Beams. TheH- test stand status is briefly presented here and detailed in companion papers.This work is partly supported by the European Commission under contract n°: HPRI-CT-2001-50021
Experimental Legionella longbeachae infection in intratracheally inoculated mice
This study established an experimental model of replicative
Legionella longbeachae
infection in
A/J mice. The animals were infected by intratracheal inoculation of 10
3
–10
9
c.f.u.
L. longbeachae
serogroup 1 (USA clinical isolates D4968, D4969 and D4973). The inocula of 10
9
,10
8
,10
7
and
10
6
c.f.u. of all tested
L. longbeachae
serogroup 1 isolates were lethal for A/J mice. Inoculation
of 10
5
c.f.u.
L. longbeachae
caused death in 90% of the animals within 5 days, whilst inoculation
of 10
4
c.f.u. caused sporadic death of mice. All animals that received 10
3
c.f.u. bacteria developed
acute lower respiratory disease, but were able to clear
Legionella
from the lungs within 3 weeks.
The kinetics of bacterial growth in the lungs was independent of inoculum size and reached a
growth peak about 3 logarithms above the initial inoculum at 72 h after inoculation. The most
prominent histological changes in the lungs were observed at 48–72 h after inoculation in the
form of a focal, neutrophil-dominant, peribronchiolar infiltration. The inflammatory process did not
progress towards the interstitial or alveolar spaces. Immunohistological analyses revealed
L.
longbeachae
serogroup 1 during the early phase of infection near the bronchiolar epithelia and
later co-localized with inflammatory cells. BALB/c and C57BL/6 mice strains were also
susceptible to infection with all
L. longbeachae
serogroup 1 strains tested and very similar
changes were observed in the lungs of infected animals. These results underline the infection
potential of
L. longbeachae
serogroup 1, which is associated with high morbidity and lethality in
mic
Kinetic and paramagnetic NMR investigations of the inhibition of Streptomyces antibioticus tyrosinase
Metals in Catalysis, Biomimetics & Inorganic Material
Source identification and distribution reveals the potential of the geochemical Antarctic sea ice proxy IPSO25
The presence of a di-unsaturated highly branched isoprenoid (HBI) lipid biomarker (diene II) in Southern Ocean sediments has previously been proposed as a proxy measure of palaeo Antarctic sea ice. Here we show that a source of diene II is the sympagic diatom Berkeleya adeliensis Medlin. Furthermore, the propensity for B. adeliensis to flourish in platelet ice is reflected by an offshore downward gradient in diene II concentration in >100 surface sediments from Antarctic coastal and near-coastal environments. Since platelet ice formation is strongly associated with super-cooled freshwater inflow, we further hypothesize that sedimentary diene II provides a potentially sensitive proxy indicator of landfast sea ice influenced by meltwater discharge from nearby glaciers and ice shelves, and re-examination of some previous diene II downcore records supports this hypothesis. The term IPSO25-Ice Proxy for the Southern Ocean with 25 carbon atoms-is proposed as a proxy name for diene II
Disorder-Driven Pretransitional Tweed in Martensitic Transformations
Defying the conventional wisdom regarding first--order transitions, {\it
solid--solid displacive transformations} are often accompanied by pronounced
pretransitional phenomena. Generally, these phenomena are indicative of some
mesoscopic lattice deformation that ``anticipates'' the upcoming phase
transition. Among these precursive effects is the observation of the so-called
``tweed'' pattern in transmission electron microscopy in a wide variety of
materials. We have investigated the tweed deformation in a two dimensional
model system, and found that it arises because the compositional disorder
intrinsic to any alloy conspires with the natural geometric constraints of the
lattice to produce a frustrated, glassy phase. The predicted phase diagram and
glassy behavior have been verified by numerical simulations, and diffraction
patterns of simulated systems are found to compare well with experimental data.
Analytically comparing to alternative models of strain-disorder coupling, we
show that the present model best accounts for experimental observations.Comment: 43 pages in TeX, plus figures. Most figures supplied separately in
uuencoded format. Three other figures available via anonymous ftp
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