580 research outputs found
O, Ne, Mg, and Fe abundances in hot X-ray emitting halos of galaxy clusters, groups, and giant early-type galaxies with XMM-Newton RGS spectroscopy
Chemical elements in the hot medium permeating early-type galaxies, groups,
and clusters make them an excellent laboratory for studying metal enrichment
and cycling processes in the largest scales of the Universe. Here, we report
the XMM-Newton RGS analysis of 14 early-type galaxies, including the well-known
brightest cluster galaxies of Perseus, for instance. The spatial distribution
of the O/Fe, Ne/Fe, and Mg/Fe ratios is generally flat at the central 60
arcsecond regions of each object, irrespective of whether or not a central Fe
abundance drop has been reported. Common profiles between noble gas and normal
metal suggest that the dust depletion process does not work predominantly in
these systems. Therefore, observed abundance drops are possibly attributed to
other origins, like systematics in the atomic codes. Giant systems of high gas
mass-to-luminosity ratio tend to hold a hot gas ( 2 keV) yielding the
solar N/Fe, O/Fe, Ne/Fe, Mg/Fe, and Ni/Fe ratios. Contrarily, light systems at
a subkiloelectronvolt temperature regime, including isolated or group-centered
galaxies, generally exhibit super-solar N/Fe, Ni/Fe, Ne/O, and Mg/O ratios. We
find that the latest supernova nucleosynthesis models fail to reproduce such a
super-solar abundance pattern. Possible systematic uncertainties contributing
to these high abundance ratios of cool objects are also discussed in tandem
with the crucial role of future X-ray missions.Comment: submitted to Ap
EFFECTS OF DIFFERENT TYPES OF AUDITORY INPUT ON INCIDENTAL VOCABULARY LEARNING BY L2 JAPANESE SPEAKERS
Research on advanced L2 adult learners and viable classroom instruction for them has become increasingly important along with increasing global connections. This study investigated the effects of different kinds of spoken input modification on listening comprehension and incidental vocabulary learning by 106 advanced Chinese speakers of Japanese in Japan. The participants were randomly assigned to four types of input (genuine, simplified, elaborated, modified elaborated) used in four short academic talks by Japanese professionals. Each talk contained eight low-frequency nouns, each appearing three times. Learning outcomes were assessed using three different measures: form-recognition, meaning recognition with contextual information, and meaning recognition via L2 definitions. Participants responded to three types of comprehension questions (replication, synthesis, inference) while listening to the talks. Scores from an online proficiency test and two working memory (WM) tasks served as moderator variables.Results showed that elaborated input was the most effective of the four types for both comprehension and incidental vocabulary learning. Results also showed that modified elaborated input, a novel input modification type that contained the same elaboration but with shorter sentences, was more effective when higher WM was available. In contrast, elaborated input was least influenced by WM capacities. Regarding the relationships between input modification and type of comprehension questions, modified elaborated input had a marginally significant effect on replication items. For synthesis and inference items, statistically significant effects for input type were not found, contradicting previous results in the literature. Proficiency showed significant effects on all tests, whereas WM showed interaction effects with simplified and modified elaborated input.
In light of these findings, the study concludes that (a) elaborated input is more beneficial for advanced L2 learners than genuine input regardless of WM, (b) modified elaborated input with short sentences requires WM, (c) input elaboration is more effective than input enhancement for incidental vocabulary learning for both form and meaning recognition, and (d) enhanced incidental vocabulary conditions using greater input elaboration are likely to provide L2 learners with better input and opportunities to learn more lexical items incidentally
Multiscale expansion of the lattice potential KdV equation on functions of infinite slow-varyness order
We present a discrete multiscale expansion of the lattice potential
Korteweg-de Vries (lpKdV) equation on functions of infinite order of
slow-varyness. To do so we introduce a formal expansion of the shift operator
on many lattices holding at all orders. The lowest secularity condition from
the expansion of the lpKdV equation gives a nonlinear lattice equation,
depending on shifts of all orders, of the form of the nonlinear Schr\"odinger
(NLS) equationComment: 9 pages, submitted to Journ. Phys.
Early Treatment with Methylprednisolone Pulse Therapy Combined with Tonsillectomy for Heavy Proteinuric Henoch-Schönlein Purpura Nephritis in Children
Background: There is no clear consensus as to which patients with Henoch-Schönlein purpura nephritis (HSPN) at risk of a poor outcome should be treated and what therapeutic regimen should be used. Methods: Nine children with heavy proteinuric HSPN received prompt initiation of methylprednisolone pulse therapy (MPT) combined with tonsillectomy in a prospective study. Results: At presentation, the mean values for the patientsâ urine protein excretion (early-morning urinary protein/creatinine ratio), serum IgA, activity index (AI), and chronicity index (CI) were 5.0 ± 5.6 g/g Cr, 135.6 ± 56.5 mg/dl, 4.0 ± 0.7, and 1.7 ± 1.3, respectively. At the second biopsy, conducted approximately 24 months after initiation of therapy, the patientsâ serum albumin had significantly increased (4.4 ± 0.2, p Conclusions: Early treatment with MPT combined with tonsillectomy is effective in ameliorating the histopathological progression and improving the clinical course of children with heavy proteinuric HSPN
Element Stratification in the Middle-Aged Type Ia Supernova Remnant G344.7-0.1
Despite their importance, a detailed understanding of Type Ia supernovae (SNe
Ia) remains elusive. X-ray measurements of the element distributions in
supernova remnants (SNRs) offer important clues for understanding the explosion
and nucleosynthesis mechanisms for SNe Ia. However, it is challenging to
observe the entire ejecta mass in X-rays for young SNRs, because the central
ejecta may not have been heated by the reverse shock yet. Here we present over
200 kilosecond Chandra observations of the Type Ia SNR G344.7-0.1, whose age is
old enough for the reverse shock to have reached the SNR center, providing an
opportunity to investigate the distribution of the entire ejecta mass. We
reveal a clear stratification of heavy elements with a centrally peaked
distribution of the Fe ejecta surrounded by intermediate-mass elements (IMEs:
Si, S, Ar Ca) with an arc-like structure. The centroid energy of the Fe K
emission is marginally lower in the central Fe-rich region than in the outer
IME-rich regions, suggesting that the Fe ejecta were shock-heated more
recently. These results are consistent with the prediction for standard SN Ia
models, where the heavier elements are synthesized in the interior of an
exploding white dwarf. We find, however, that the peak location of the Fe K
emission is slightly offset to the west with respect to the geometric center of
the SNR. This apparent asymmetry is likely due to the inhomogeneous density
distribution of the ambient medium, consistent with our radio observations of
the ambient molecular and neutral gas.Comment: 16 pages, 10 figures, Accepted for publication in Astrophysical
Journa
Predicting the Start of the Aedes albopictus (Diptera: Culicidae) Female Adult Biting Season Using the Spring Temperature in Japan
Aedes albopictus (Skuse) (Diptera: Culicidae) is distributed widely and is common in much of Japan. In Japan, female adults begin to bite in between April and June, except in the southern subtropics where the mosquito has no dormant period. It is difficult to estimate the first Ae. albopictus biting day because it varies annually depending on the location. Over several years, we surveyed the mosquitoes at different locations that covered a range of warmer to cooler areas of Japan. We found an association between the timing of first biting day by Ae. albopictus and spring temperature. In spring months, the strongest correlation was found with mean April temperatures, followed by March. Based on these data, it may, therefore, be possible to apply a simple formula to predict the timing of the first biting day at various geographical locations in Japan. Forecasting maps were created using a simple prediction formula. We found that the first biting day for Ae. albopictus changed depending on early spring temperatures for each year. There was an approximate 20-d difference in first biting day between years with warmer and cooler springs. This prediction model will provide useful insight for planning and practice of Ae. albopictus control programs, targeting larvae and adults, in temperate regions globally.ArticleJournal of Medical Entomology.54(6):1519-1524(2017)journal articl
Broccoli consumption and chronic atrophic gastritis among Japanese males: an epidemiological investigation.
Previous in vitro and animal experiments have shown that sulforaphane, which is abundant in broccoli, inhibits Helicobacter pylori (H. pylori) infection and blocks gastric tumor formation. This suggests that broccoli consumption prevents chronic atrophic gastritis (CAG) introduced by H. pylori infection and, therefore, gastric cancer. For an epidemiological investigation of the relationship between the broccoli consumption and CAG, a cross-sectional study of 438 male employees, aged 39 to 60 years, of a Japanese steel company was conducted. CAG was serologically determined with serum cut-off values set at pepsinogen I < or = 70 ng/ml and a ratio of serum pepsinogen I/pepsinogen II < or = 3.0. Broccoli consumption (weekly frequency) and diet were monitored by using a 31-item food frequency questionnaire. The prevalence of CAG among men who ate broccoli once or more weekly was twice as high as that among men who consumed a negligible amount (P < 0.05). Multiple logistic regression analysis indicated that broccoli consumption once or more weekly significantly increased the risk for CAG (odds ratio, 3.06; 95% confidence interval, 1.12-8.38; P < 0.05), after controlling for age, education, cigarette smoking, and alcohol consumption. The present study failed to show an expected association between frequent broccoli consumption and a low prevalence of CAG.</p
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