93 research outputs found
Experimental stress during molt suggests the evolution of condition-dependent and condition-independent ornaments in the king penguin
Acknowledgments We thank Emilie Lefol for her help in the field, and two anonymous reviewers for their comments on the manuscript. This research was funded by the French Polar Institute (IPEV– Research Program 119) and the French National Centre for Scientific Research (CNRS- INEE). Field logistic support was provided by Terres Australes et Antarctiques Françaises. Q.S. was funded by a doctoral fellowship from the Ministère Français de l’Education Supérieur et de la Recherche.Peer reviewedPublisher PD
Marine health of the Arabian Gulf: Drivers of pollution and assessment approaches focusing on desalination activities
The Arabian Gulf is one of the most adversely affected marine environments worldwide, which results from combined pollution drivers including climate change, oil and gas activities, and coastal anthropogenic disturbances. Desalination activities are one of the major marine pollution drivers regionally and internationally. Arabian Gulf countries represent a hotspot of desalination activities as they are responsible for nearly 50% of the global desalination capacity. Building desalination plants, up-taking seawater, and discharging untreated brine back into the sea adversely affects the biodiversity of the marine ecosystems. The present review attempted to reveal the potential negative effects of desalination plants on the Gulf's marine environments. We emphasised different conventional and innovative assessment tools used to assess the health of marine environments and evaluate the damage exerted by desalination activity in the Gulf. Finally, we suggested effective management approaches to tackle the issue including the significance of national regulations and regional cooperation
Vaginal microbiota and cytokine levels predict preterm delivery in Asian women
Preterm birth (PTB) is the most common cause of neonatal morbidity and mortality worldwide. Approximately half of PTBs is linked with microbial etiologies, including pathologic changes to the vaginal microbiota, which vary according to ethnicity. Globally more than 50% of PTBs occur in Asia, but studies of the vaginal microbiome and its association with pregnancy outcomes in Asian women are lacking. This study aimed to longitudinally analyzed the vaginal microbiome and cytokine environment of 18 Karen and Burman pregnant women who delivered preterm and 36 matched controls delivering at full term. Using 16S ribosomal RNA gene sequencing we identified a predictive vaginal microbiota signature for PTB that was detectable as early as the first trimester of pregnancy, characterized by higher levels of Prevotella buccalis, and lower levels of Lactobacillus crispatus and Finegoldia, accompanied by decreased levels of cytokines including IFNgamma, IL-4, and TNFalpha. Differences in the vaginal microbial diversity and local vaginal immune environment were associated with greater risk of preterm birth. Our findings highlight new opportunities to predict PTB in Asian women in low-resource settings who are at highest risk of adverse outcomes from unexpected PTB, as well as in Burman/Karen ethnic minority groups in high-resource regions
Local Magnetic Properties of a Monolayer of Mn12 Single Molecule Magnets
The magnetic properties of a monolayer of Mn12 single molecule magnets
grafted onto a Si substrate have been investigated using depth-controlled
-detected nuclear magnetic resonance. A low energy beam of spin
polarized radioactive 8Li was used to probe the local static magnetic field
distribution near the Mn12 monolayer in the Si substrate. The resonance
linewidth varies strongly as a function of implantation depth as a result of
the magnetic dipolar fields generated by the Mn12 electronic magnetic moments.
The temperature dependence of the linewidth indicates that the magnetic
properties of the Mn12 moments in this low dimensional configuration differ
from bulk Mn12.Comment: 6 pages, 4 figure
Observation of slow order parameter fluctuations in superconducting films using beta-detected NMR
We report beta-NMR investigations of polarized 8Li implanted in thin Pb and
Ag/Nb films. At the critical superconducting temperature, we observe a singular
peak in the spin relaxation rate in small longitudinal magnetic fields, which
is attributed to fluctuations in the superconducting order parameter. However,
the peak is more than an order of magnitude larger than the prediction based on
the enhancement of the dynamic electron spin susceptibility by superconducting
fluctuations and reflects the presence of unexpected slow fluctuations.
Furthermore the fluctuations are rapidly suppressed in a small magnetic field,
which may explain why they have not been observed previously with conventional
NMR or NQR.Comment: 5 pages, 2 figure
Giant Vortices Below the Surface of NbSe Detected Using Low Energy -NMR
A low energy radioactive beam of polarized Li has been used to observe
the vortex lattice near the surface of superconducting NbSe. The
inhomogeneous magnetic field distribution associated with the vortex lattice
was measured using depth-resolved -detected NMR. Below one
observes the characteristic lineshape for a triangular vortex lattice which
depends on the magnetic penetration depth and vortex core radius. The size of
the vortex core varies strongly with magnetic field. In particular in a low
field of 10.8 mT the core radius is much larger than the coherence length. The
possible origin of these giant vortices is discussed.Comment: 5 pages, 3 figures. Submitted to Phys. Rev. Let
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