252 research outputs found

    A crustal seismic profile across Sicily

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    A crustal reflection seismic profile, more than 100 km long, was recorded across central Sicily, from the Tyrrhenian shore to the Sicily Channel, to understand the deep structures and the collision mechanisms between Europe and Africa and the subsequent geodynamic evolution. The profile was acquired using explosive sources and 240 active channels recorded by a Sercel 408-XL, 24 bits A/D converter, with a 12 km spread and a 24-fold coverage. The data were processed following a non-conventional procedure in order to preserve the relative amplitudes of the reflections and to better investigate the Sicily deep structures down to the Moho. The main highlighted structures are the dramatic flexure of the Iblean crust, the huge, deeper than expected, trough of Caltanissetta consisting of deep seated thrusts and nappes, and the imbricate thrust system of rigid bodies characterizing the northern Maghrebian chain. We designed an ad hoc acquisition and processing in order to highlight these main geological features in the seismic stacked section. Moreover, the deepest parts of the Caltanissetta trough are imaged for the first time, and its bottom is now fixed at more than 7 s TWT. The giant crustal wedge flexuring the Iblean foreland and the Moho geometries are examinated

    Molecular genotyping of bacillus anthracis strains from Georgia and northeastern part of Turkey

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    Bacillus anthracis is the causal agent of anthrax and has a history of use as a biological weapon. Anthrax cases occur worldwide and the disease is endemic in certain regions. Here we describe a study of the genetic diversity of B. anthracis strains in two endemic areas: The country of Georgia and the Kars region of Turkey. Thirty Turkish isolates and thirty Georgian isolates were subjected to Single Nucleotide Polymorphism (SNP) sub typing, followed by higher-resolution genotyping using 25-loci variable-number tandem repeat analysis (MLVA-25). Canonical SNP typing indicated that Turkish strains belonged to both the A.Br.003 linage and the Australian 94 lineage. In light of a recent analysis that placed the majority of Georgian B. anthracis isolates in one phylogenetic group, we screened the Turkish strains using a previously developed Georgian SNP panel. Minimal diversity was observed among the Kars strains within the Georgian SNP lineage: all 30 of these strains grouped with A.Br.026, ten strains were derived from A.Br.028, and only two isolates belonged to A.Br.029. According to the results of MLVA-25 genotyping, all 30 Turkish strains belong to two clusters. Cluster A is more diverse than cluster B. Our results suggest that B. anthracis strains originating from Georgia and the northeastern part of Turkey are genetically interrelated, which could be explained by the geographic proximity of the countries

    TECHNIQUES FOR REARING AND RELEASING NONMIGRATORY CRANES: LESSONS FROM THE MISSISSIPPI SANDHILL CRANE PROGRAM

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    Captive-reared Mississippi sandhill cranes (Grus canadensis pulla) reared at the Patuxent Wildlife Research Center (patuxent) have been released at the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) since 1981. Of 131 birds released through December 1990, 103 were reared by foster parents. The remaining 28 were experimentally hand-reared in 1989 and 1990. After refining release procedures, parent-reared birds have integrated into the wild flock, many have survived, and some have bred. Releases of hand-reared cranes elsewhere in the 1970\u27s were largely unsuccessful. at least in part due to the lack of a lengthy acclimation period. A new hand-rearing protocol holds promise in producing release-worthy birds. The technique employs some features first used in the 1960\u27s (e.g., a costume for the human caretaker and model crane heads used to train chicks to feed). In the mid-1980\u27s, the following features were added: (1) the costumed caretaker was given a visor and feathers, (2) a taxidermic crane head or a hand puppet was held or suspended from the ceiling for use in stimulating chicks to feed, (3) a taxidermic mount of a brooding crane supplied warmth, (4) a full-sized live crane was maintained in an adjacent pen and in visual contact with neonatal young to provide an imprinting model, and (5) a small group of adult (or subadult) cranes was penned adjacent to the outdoor chick pens to provide socialization models. Recent releases of Mississippi sandhill cranes hand-reared according to this protocol and released in Mississippi have had high first-year survival rates. The now-operational technique holds promise for producing large numbers of release-worthy birds

    TECHNIQUES FOR REARING AND RELEASING NONMIGRATORY CRANES: LESSONS FROM THE MISSISSIPPI SANDHILL CRANE PROGRAM

    Get PDF
    Captive-reared Mississippi sandhill cranes (Grus canadensis pulla) reared at the Patuxent Wildlife Research Center (patuxent) have been released at the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) since 1981. Of 131 birds released through December 1990, 103 were reared by foster parents. The remaining 28 were experimentally hand-reared in 1989 and 1990. After refining release procedures, parent-reared birds have integrated into the wild flock, many have survived, and some have bred. Releases of hand-reared cranes elsewhere in the 1970\u27s were largely unsuccessful. at least in part due to the lack of a lengthy acclimation period. A new hand-rearing protocol holds promise in producing release-worthy birds. The technique employs some features first used in the 1960\u27s (e.g., a costume for the human caretaker and model crane heads used to train chicks to feed). In the mid-1980\u27s, the following features were added: (1) the costumed caretaker was given a visor and feathers, (2) a taxidermic crane head or a hand puppet was held or suspended from the ceiling for use in stimulating chicks to feed, (3) a taxidermic mount of a brooding crane supplied warmth, (4) a full-sized live crane was maintained in an adjacent pen and in visual contact with neonatal young to provide an imprinting model, and (5) a small group of adult (or subadult) cranes was penned adjacent to the outdoor chick pens to provide socialization models. Recent releases of Mississippi sandhill cranes hand-reared according to this protocol and released in Mississippi have had high first-year survival rates. The now-operational technique holds promise for producing large numbers of release-worthy birds

    Seismic structure and activity of the north-central Lesser Antilles subduction zone from an integrated approach: similarities with the Tohoku forearc

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    The 300 km long north-central segment of the Lesser Antilles subduction zone, including Martinique and Guadeloupe islands has been the target of a specific approach to the seismic structure and activity by a cluster of active and passive offshore-onshore seismic experiments coordinated within the ¿Thales was right¿ proposal to the European Union action (Laigle et al., Tectonophys., in rev.) The top of the subducting plate can be followed under the wide accretionary wedge by a dense grid of dip- and strike-lines of multichannel reflection seismics. This reveals the hidden updip limit of the contact of the upper plate crustal backstop thrust onto the slab. Two OBS refraction seismic profiles constrained a 26 km large crustal thickness from the volcanic arc throughout the forearc domain (Kopp et al., EPSL, 2011). These new observations imply a three times larger width of the potential interplate seismogenic zone under the marine domain of the Caribbean plate with respect to a regular intra-oceanic subduction zone, in the common assumption that the upper plate Moho contact on the slab is a proxy of its downdip limit. Towards larger depth under the mantle corner, the top of the slab imaged from the conversions of teleseismic body-waves and the locations of earthquakes from the dense temporary array of 80 OBS and land seismometers appears with kinks which increase the dip from 10-20° under the forearc domain, to 60° on the segment from 70 km depth down to under the volcanic arc. There, at 140 km depth just north of Martinique the 2007 M 7.4 earthquake, largest for half a century, was accompanied by an increased seismic activity over the whole depth range, which provides a new focused image thanks to the OBS and land deployments. A double-planed dipping slab seismicity is thus now resolved, as originally discovered in Tohoku ( NE Japan) and since in some other subduction zones. Other types of seismic activity uniquely observed in Tohoku, are resolved now here, such as ¿supraslab¿ earthquakes with normal-faulting focal mechanisms reliably located in the mantle corner and ¿deep flat-thrust¿ earthquakes at 45 km depth on the interplate fault under the Caribbean plate forearc mantle. None such types of seismicity should occur under the paradigm of a regular peridotitic mantle of the upper plate which is serpentinized by the fluids provided from the dehydrating slab beneath, and which is commonly considered as limiting the downward extent of the interplate seismic coupling. If the upper plate here comprised lithospheric segments related to the earlier formation of the Caribbean oceanic plateau by the material advection from a mantle plume, it could then be underlain by a correspondingly modified, heterogeneous mantle, which may impose regions of stick-slip behaviour on the interplate under the mantle corner among stable-gliding areas. The Tohoku 2011 M9 earthquake was unexpected not only in its slip reaching to the trench, but also in its slip reaching far under the mantle corner against the serpentinization decoupling paradigm, and its structural setting may be revisited for resolving corresponding structural heterogeneityPeer Reviewe

    Molecular genotyping of bacillus anthracis strains from Georgia and northeastern part of Turkey

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    Bacillus anthracis is the causal agent of anthrax and has a history of use as a biological weapon. Anthrax cases occur worldwide and the disease is endemic in certain regions. Here we describe a study of the genetic diversity of B. anthracis strains in two endemic areas: The country of Georgia and the Kars region of Turkey. Thirty Turkish isolates and thirty Georgian isolates were subjected to Single Nucleotide Polymorphism (SNP) sub typing, followed by higher-resolution genotyping using 25-loci variable-number tandem repeat analysis (MLVA-25). Canonical SNP typing indicated that Turkish strains belonged to both the A.Br.003 linage and the Australian 94 lineage. In light of a recent analysis that placed the majority of Georgian B. anthracis isolates in one phylogenetic group, we screened the Turkish strains using a previously developed Georgian SNP panel. Minimal diversity was observed among the Kars strains within the Georgian SNP lineage: all 30 of these strains grouped with A.Br.026, ten strains were derived from A.Br.028, and only two isolates belonged to A.Br.029. According to the results of MLVA-25 genotyping, all 30 Turkish strains belong to two clusters. Cluster A is more diverse than cluster B. Our results suggest that B. anthracis strains originating from Georgia and the northeastern part of Turkey are genetically interrelated, which could be explained by the geographic proximity of the countries
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