200 research outputs found
Does the bonding rule break down in AsSe glass?
The local coordination numbers of AsSe glass were determined by a
combination of anomalous x-ray scattering experiments, reverse Monte Carlo
calculations, and {\it ab initio} molecular dynamics simulations. The
well-known `8- bonding rule' proposed by Mott breaks down around the As
atoms, exceeding the rule by 7--26%. An experimental prediction based on
mean-field theory agrees with the present experimental and theoretical results.
The fourfold coordinated As atoms likely form As-As wrong bond chains rather
than ethan-like configurations, which is identified as the origin for the
breakdown of the `8- bonding rule'.Comment: 6 pages, 6figures, 1table, submitted to Europhysics Letter
Decay Properties of Bh and Db Produced in the Cm + Na Reaction
Decay properties of an isotope Bh and its daughter nucleus Db
produced by the Cm(Na, 5\textit{n}) reaction were studied by
using a gas-filled recoil separator coupled with a position-sensitive
semiconductor detector. Bh was clearly identified from the correlation
of the known nuclide, Db. The obtained decay properties of Bh
and Db are consistent with those observed in the 113 chain,
which provided further confirmation of the discovery of 113.Comment: Accepted for publication in J. Phys. Soc. JPN., to be published in
Vol.78 No.
Effect of Low Versus High-Heeled Footwear on Spinopelvic Alignment at Different Phases of Menstrual Cycle in Young Adult Women: A Biopsychosocial Perspective
High-heeled shoes adversely affect spinal curvature, increase the risk of low back pain, and disturb the normal gait pattern. The purpose of this study was to examine, from a biopsychosocial point of view, the combined effect of wearing two different heel heights and of hormonal oscillation throughout different phases of the menstrual cycle on spinopelvic alignment. Notably, 70 females with an average age of 20.42 ± 1.51 years participated in this study, wearing each female two different heel heights as follows: low (2.5 cm) and high (7 cm). Spinopelvic alignment was evaluated by rasterstereography formetric 3D analysis during early follicular, ovulatory, and mid-luteal phases of the menstrual cycle. Statistical analysis showed that there was no significant difference (p > 0.05) on spinopelvic alignment [kyphotic angle (KA), trunk inclination (TI), and pelvic inclination] between wearing low- or high-heeled shoes during early follicular, ovulatory, and mid-luteal phases of the menstrual cycle. Considering that high-heeled shoes are traditionally associated with femininity, body image, beauty, and charm, this research has important biopsychosocial implications that should be explored in detail in future studies
Decay modes of 250No
The Fragment Mass Analyzer at the ATLAS facility has been used to
unambiguously identify the mass number associated with different decay modes of
the nobelium isotopes produced via 204Pb(48Ca,xn)(252-x)No reactions.
Isotopically pure (>99.7%) 204Pb targets were used to reduce background from
more favored reactions on heavier lead isotopes. Two spontaneous fission
half-lives (t_1/2 = 3.7+1.1-0.8 us and 43+22-15 us) were deduced from a total
of 158 fission events. Both decays originate from 250No rather than from
neighboring isotopes as previously suggested. The longer activity most likely
corresponds to a K-isomer in this nucleus. No conclusive evidence for an alpha
branch was observed, resulting in upper limits of 2.1% for the shorter lifetime
and 3.4% for the longer activity.Comment: RevTex4, 10 pages, 5 figures, submitted to PR
New Features in the Computational Infrastructure for Nuclear Astrophysics
A Computational Infrastructure for Nuclear Astrophysics has been developed to streamline the inclusion of the latest nuclear physics data in astrophysics simulations. The infrastructure consists of a platform-independent suite of computer codes that are freely available online at http://nucastrodata.org. The newest features of, and future plans for, this software suite are given. © Copyright owned by the author(s)
Pressure dependence of the static structure of liquid GeTe based on ab initio
We have investigated the pressure dependence of the static structure of liquid GeTe based on ab initio molecular dynamics simulations. The pressure range is between ambient pressure and 250 GPa, and their temperatures between 1000 K and 4000 K, which keep the liquid state. In this study, we found two transition stages caused by the compression. At the first stage, below 12 GPa, atomic distances elongate and Peierls-type distortion is dissolved with increasing pressure. At the second stage, above 12 GPa, atomic distances shorten and the electronic states shows metallic
Impact of helminth infection during pregnancy on cognitive and motor functions of one-year-old children
Objective
To determine the effect of helminth infection during pregnancy on the cognitive and motor functions of one-year-old children.
Methods
Six hundred and thirty five singletons born to pregnant women enrolled before 29 weeks of gestation in a trial comparing two intermittent preventive treatments for malaria were assessed for cognitive and motor functions using the Mullen Scales of Early Learning, in the TOVI study, at twelve months of age in the district of Allada in Benin. Stool samples of pregnant women were collected at recruitment, second antenatal care (ANC) visit (at least one month after recruitment) and just before delivery, and were tested for helminths using the Kato-Katz technique. All pregnant women were administered a total of 600 mg of mebendazole (100 mg two times daily for 3 days) to be taken after the first ANC visit. The intake was not directly observed.
Results
Prevalence of helminth infection was 11.5%, 7.5% and 3.0% at first ANC visit, second ANC visit and at delivery, respectively. Children of mothers who were infected with hookworms at the first ANC visit had 4.9 (95% CI: 1.3â8.6) lower mean gross motor scores compared to those whose mothers were not infected with hookworms at the first ANC visit, in the adjusted model. Helminth infection at least once during pregnancy was associated with infant cognitive and gross motor functions after adjusting for maternal education, gravidity, child sex, family possessions, and quality of the home stimulation.
Conclusion
Helminth infection during pregnancy is associated with poor cognitive and gross motor outcomes in infants. Measures to prevent helminth infection during pregnancy should be reinforced
First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph
The masses of 246Es, 251Fm, and the transfermium nuclei 249â252Md and 254No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N=152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of 246Es and 249,250,252Md were measured for the first time. Using the masses of 249,250Md as anchor points for α decay chains, the masses of heavier nuclei, up to 261Bh and 266Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter ÎŽ2n derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr
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