248 research outputs found
Single-Proton Removal Reaction Study of 16B
The low-lying level structure of the unbound system B has been
investigated via single-proton removal from a 35 MeV/nucleon C beam. The
coincident detection of the beam velocity B fragment and neutron allowed
the relative energy of the in-flight decay of B to be reconstructed. The
resulting spectrum exhibited a narrow peak some 85 keV above threshold. It is
argued that this feature corresponds to a very narrow (100 keV)
resonance, or an unresolved multiplet, with a dominant + configuration which decays by d-wave neutron
emission.Comment: 16 pages, 5 figures, 1 table, submitted to Phys. Lett.
Quaternary development of resilient reefs on the subsiding kimberley continental margin, Northwest Australia
The Kimberley region in remote northwest Australia has poorly known reef systems of two types; coastal fringing reefs and atoll-like shelf-edge reefs. As a major geomorphic feature (from 12ºS to 18ºS) situated along a subsiding continental margin, the shelf edge reefs are in a tropical realm with warm temperatures, relatively low salinity, clear low nutrient waters lacking sediment input, and Indo-West Pacific corals of moderate diversity. Seismic architecture of the Rowley Shoals reveals that differential pre-Holocene subsidence and relative elevation of the pre-Holocene substrate have controlled lagoon sediment infill and reef morphology, forming an evolutionary series reflecting differential accommodation in three otherwise similar reef systems.The Holocene core described for North Scott Reef confirms previous seismic interpretations, and provides a rare ocean-facing reef record. It demonstrates that the Indo-Pacific reef growth phase (RG111) developed during moderate rates of sea level rise of 10 mm/year from 11 to about 7-6.5 ka BP until sea level stabilization, filling the available 27 m of pre-Holocene accommodation. Despite the medium to high hydrodynamic energy imposed by the 4m tides, swell waves and cyclones the reef-building communities represent relatively low-wave energy settings due to their southeast facing and protection afforded by the proximity of the South Reef platform. This study demonstrates the resilience of reefs on the subsiding margin whilst linking Holocene reef morphology to the relative amount of pre-Holocene subsidence
Resolving the ancestry of Austronesian-speaking populations
There are two very different interpretations of the prehistory of Island Southeast Asia (ISEA), with genetic evidence invoked in support of both. The “out-of-Taiwan” model proposes a major Late Holocene expansion of Neolithic Austronesian speakers from Taiwan. An alternative, proposing that Late Glacial/postglacial sea-level rises triggered largely autochthonous dispersals, accounts for some otherwise enigmatic genetic patterns, but fails to explain the Austronesian language dispersal. Combining mitochondrial DNA (mtDNA), Y-chromosome and genome-wide data, we performed the most comprehensive analysis of the region to date, obtaining highly consistent results across all three systems and allowing us to reconcile the models. We infer a primarily common ancestry for Taiwan/ISEA populations established before the Neolithic, but also detected clear signals of two minor Late Holocene migrations, probably representing Neolithic input from both Mainland Southeast Asia and South China, via Taiwan. This latter may therefore have mediated the Austronesian language dispersal, implying small-scale migration and language shift rather than large-scale expansion
Surgical Mask to Prevent Influenza Transmission in Households: A Cluster Randomized Trial
Facemasks and respirators have been stockpiled during pandemic preparedness. However, data on their effectiveness for limiting transmission are scarce. We evaluated the effectiveness of facemask use by index cases for limiting influenza transmission by large droplets produced during coughing in households.A cluster randomized intervention trial was conducted in France during the 2008-2009 influenza season. Households were recruited during a medical visit of a household member with a positive rapid influenza A test and symptoms lasting less than 48 hours. Households were randomized either to the mask or control group for 7 days. In the intervention arm, the index case had to wear a surgical mask from the medical visit and for a period of 5 days. The trial was initially intended to include 372 households but was prematurely interrupted after the inclusion of 105 households (306 contacts) following the advice of an independent steering committee. We used generalized estimating equations to test the association between the intervention and the proportion of household contacts who developed an influenza-like illness during the 7 days following the inclusion. Influenza-like illness was reported in 24/148 (16.2%) of the contacts in the intervention arm and in 25/158 (15.8%) of the contacts in the control arm and the difference between arms was 0.40% (95%CI: -10% to 11%, P = 1.00). We observed a good adherence to the intervention. In various sensitivity analyses, we did not identify any trend in the results suggesting effectiveness of facemasks.This study should be interpreted with caution since the lack of statistical power prevents us to draw formal conclusion regarding effectiveness of facemasks in the context of a seasonal epidemic.clinicaltrials.gov NCT00774774
Non local microscopic potentials for calculation of scattering observables of nucleons on deformed nuclei
Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago
Past sea-level records provide invaluable information about the response of ice sheets to climate forcing. Some such records suggest that the last deglaciation was punctuated by a dramatic period of sea-level rise, of about 20 metres, in less than 500 years. Controversy about the amplitude and timing of this meltwater pulse (MWP-1A) has, however, led to uncertainty about the source of the melt water and its temporal and causal relationships with the abrupt climate changes of the deglaciation. Here we show that MWP-1A started no earlier than 14,650 years ago and ended before 14,310 years ago, making it coeval with the Bolling warming. Our results, based on corals drilled offshore from Tahiti during Integrated Ocean Drilling Project Expedition 310, reveal that the increase in sea level at Tahiti was between 12 and 22 metres, with a most probable value between 14 and 18 metres, establishing a significant meltwater contribution from the Southern Hemisphere. This implies that the rate of eustatic sea-level rise exceeded 40 millimetres per year during MWP-1A
A survey of primary care physician practices in antibiotic prescribing for the treatment of uncomplicated male gonoccocal urethritis
<p>Abstract</p> <p>Background</p> <p>The development of resistance to antimicrobial therapy by <it>Neisseria gonorrhoeae </it>causes on-going problems for individual case management of gonorrhoea. Surveillance data about <it>N. gonorrhoeae </it>have indicated an increase in the incidence of gonorrhoea in France in 2006. As a consequence of the development of antibiotic resistance in <it>N. gonorrhoeae</it>, French guidelines excluded fluoroquinolones as a standard treatment for <it>N. gonorrhoeae</it>. Ceftriaxone became the recommended treatment, associated with azithromycin for <it>Clamydia trachomatis </it>infection. Our aim was to describe the practice patterns of general practitioners (GPs) in managing the antibiotic treatment of patients with symptoms suggestive of uncomplicated male urethritis.</p> <p>Methods</p> <p>We developed a clinical vignette describing a man with typical gonococcal urethritis symptoms to elicit questions about antibiotic treatment. We mailed the electronic questionnaire to a random sample of 1000 French GPs belonging to the <it>Sentinelles </it>Network.</p> <p>Results</p> <p>By the end of the survey period, 350 vignettes were received, yielding a response rate of 35%. Sixty-six GPs (20.2%) prescribed the recommended antibiotics for the simultaneous treatment of <it>N</it>. <it>gonorrhoeae </it>and <it>C. trachomatis </it>infections, while 132 GPs (40.4%) prescribed only non-recommended antibiotics, including ciprofloxacin in 69 cases (21.1%). General practitioners with less than 10 years in practice showed better compliance to guidelines than those with more years in practice (p < 0.05).</p> <p>Conclusions</p> <p>The results suggest a mismatch between the guidelines and the antibiotic treatment of male uncomplicated urethritis by French GPs, mostly among the subgroup of physicians who have been in practice longer. Educational approaches based on practice feedback need to be developed to improve these deficits in the quality of care.</p
Genetic Structure of Human A/H1N1 and A/H3N2 Influenza Virus on Corsica Island: Phylogenetic Analysis and Vaccine Strain Match, 2006–2010
Background: The aim of this study was to analyse the genetic patterns of Hemagglutinin (HA) genes of influenza A strains circulating on Corsica Island during the 2006-2009 epidemic seasons and the 2009-2010 pandemic season. [br/]
Methods: Nasopharyngeal samples from 371 patients with influenza-like illness (ILI) were collected by General Practitioners (GPs) of the Sentinelles Network through a randomised selection routine. [br/]
Results: Phylogenetic analysis of HA revealed that A/H3N2 strains circulating on Corsica were closely related to the WHO recommended vaccine strains in each analyzed season (2006-2007 to 2008-2009). Seasonal Corsican influenza A/H1N1 isolated during the 2007-2008 season had drifted towards the A/Brisbane/59/2007 lineage, the A/H1N1 vaccine strain for the 2008-2009 season. The A/H1N1 2009 (A/H1N1pdm) strains isolated on Corsica Island were characterized by the S220T mutation specific to clade 7 isolates. It should be noted that Corsican isolates formed a separate sub-clade of clade 7 as a consequence of the presence of the fixed substitution D222E. The percentages of the perfect match vaccine efficacy, estimated by using the p(epitope) model, against influenza viruses circulating on Corsica Island varied substantially across the four seasons analyzed, and tend to be highest for A/H1N1 compared with A/H3N2 vaccines, suggesting that cross-immunity seems to be stronger for the H1 HA gene. [br/]
Conclusion: The molecular analysis of the HA gene of influenza viruses that circulated on Corsica Island between 2006-2010 showed for each season the presence of a dominant lineage characterized by at least one fixed mutation. The A/H3N2 and A/H1N1pdm isolates were characterized by multiples fixation at antigenic sites. The fixation of specific mutations at each outbreak could be explained by the combination of a neutral phenomenon and a founder effect, favoring the presence of a dominant lineage in a closed environment such as Corsica Island
Krüppel-Like Factor 6 Expression Changes during Trophoblast Syncytialization and Transactivates ßhCG and PSG Placental Genes
BACKGROUND: Krüppel-like factor-6 (KLF6) is a widely expressed member of the Sp1/KLF family of transcriptional regulators involved in differentiation, cell cycle control and proliferation in several cell systems. Even though the highest expression level of KLF6 has been detected in human and mice placenta, its function in trophoblast physiology is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we explored KLF6 expression and sub-cellular distribution in human trophoblast cells differentiating into the syncytial pathway, and its role in the regulation of genes associated with placental development and pregnancy maintenance. Confocal immunofluorescence microscopy demonstrated that KLF6 is expressed throughout human cytotrophoblast differentiation showing no evident modifications in its nuclear and cytoplasmic localization pattern. KLF6 transcript and protein peaked early during the syncytialization process as determined by qRT-PCR and western blot assays. Overexpression of KLF6 in trophoblast-derived JEG-3 cells showed a preferential nuclear signal correlating with enhanced expression of human β-chorionic gonadotropin (βhCG) and pregnancy-specific glycoprotein (PSG) genes. Moreover, KLF6 transactivated βhCG5, PSG5 and PSG3 gene promoters. Deletion of KLF6 Zn-finger DNA binding domain or mutation of the consensus KLF6 binding site abolished transactivation of the PSG5 promoter. CONCLUSIONS/SIGNIFICANCE: Results are consistent with KLF6 playing a role as transcriptional regulator of relevant genes for placental differentiation and physiology such as βhCG and PSG, in agreement with an early and transient increase of KLF6 expression during trophoblast syncytialization
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