3,180 research outputs found
Evaluasi Kinerja Sistem Rangka Pemikul Momen Khusus Sni 2847-2013 Pada Struktur Dengan Gempa Dominan
Dalam mendesain bangunan, Indonesia memiliki peraturan-peraturan yaitu SNI 03-2847-2013 dan SNI 1726-2012. Pada penelitian sebelumnya, didapatkan masalah pada bangunan yang telah didesain sesuai dengan SNI 03-2847-2002, namun tidak dapat bertahan ketika diuji dengan gempa rencana SNI 1726-2012, dan kegagalan pada struktur tersebut diperkirakan akibat beban gempa dominan. Penelitian ini bertujuan untuk mengevaluasi kembali peraturan tersebut, khususnya pada struktur dengan gempa dominan. Bangunan 3-lantai, diasumsikan sebagai ruko, pada penelitian sebelumnya merupakan bangunan dasar yang akan dimodifikasi menjadi beberapa varian dan akan digunakan sebagai studi kasus. Kinerja bangunan diuji dengan analisis Time History nonlinier. Hasil penelitian ini menunjukkan gempa dominan bukan merupakan penyebab utama kegagalan bangunan
Dynamic critical behavior of the Chayes-Machta-Swendsen-Wang algorithm
We study the dynamic critical behavior of the Chayes-Machta dynamics for the
Fortuin-Kasteleyn random-cluster model, which generalizes the Swendsen-Wang
dynamics for the q-state Potts model to noninteger q, in two and three spatial
dimensions, by Monte Carlo simulation. We show that the Li-Sokal bound z \ge
\alpha/\nu is close to but probably not sharp in d=2, and is far from sharp in
d=3, for all q. The conjecture z \ge \beta/\nu is false (for some values of q)
in both d=2 and d=3.Comment: Revtex4, 4 pages including 4 figure
Peanut Allergen Threshold Study (PATS): Novel single-dose oral food challenge study to validate eliciting doses in children with peanut allergy
Background: Eliciting doses (EDs) of allergenic foods can be defined by the distribution of threshold doses for subjects within a specific population. The ED05 is the dose that elicits a reaction in 5% of allergic subjects. The predicted ED05 for peanut is 1.5 mg of peanut protein (6 mg of whole peanut). Objective: We sought to validate the predicted peanut ED05 (1.5 mg) with a novel single-dose challenge. Methods: Consecutive eligible children with peanut allergy in 3 centers were prospectively invited to participate, irrespective of previous reaction severity. Predetermined criteria for objective reactions were used to identify ED05 single-dose reactors. Results: Five hundred eighteen children (mean age, 6.8 years) were eligible. No significant demographic or clinical differences were identified between 381 (74%) participants and 137 (26%) nonparticipants or between subjects recruited at each center. Three hundred seventy-eight children (206 male) completed the study. Almost half the group reported ignoring precautionary allergen labeling. Two hundred forty-five (65%) children experienced no reaction to the single dose of peanut. Sixty-seven (18%) children reported a subjective reaction without objective findings. Fifty-eight (15%) children experienced signs of a mild and transient nature that did not meet the predetermined criteria. Only 8 (2.1%; 95% CI, 0.6%-3.4%) subjects met the predetermined criteria for an objective and likely related event. No child experienced more than a mild reaction, 4 of the 8 received oral antihistamines only, and none received epinephrine. Food allergy–related quality of life improved from baseline to 1 month after challenge regardless of outcome (η2 = 0.2, P < .0001). Peanut skin prick test responses and peanut- and Ara h 2–specific IgE levels were not associated with objective reactivity to peanut ED05. Conclusion: A single administration of 1.5 mg of peanut protein elicited objective reactions in fewer than the predicted 5% of patients with peanut allergy. The novel single-dose oral food challenge appears clinically safe and patient acceptable, regardless of the outcome. It identifies the most highly dose-sensitive population with food allergy not otherwise identifiable by using routinely available peanut skin prick test responses or specific IgE levels, but this single-dose approach has not yet been validated for risk assessment of individual patients
Genetic association of CDC2 with cerebrospinal fluid tau in Alzheimer's disease
We have recently reported that a polymorphism in the cell division cycle (CDC2) gene, designated Ex6 + 7I/D, is associated with Alzheimer's disease (AD). The CDC2 gene is located on chromosome 10q21.1 close to the marker D10S1225 linked to AD. Active cdc2 accumulates in neurons containing neurofibrillary tangles (NFT), a process that can precede the formation of NFT. Therefore, CDC2 is a promising candidate susceptibility gene for AD. We investigated the possible effects of the CDC2 polymorphism on cerebrospinal fluid (CSF) biomarkers in AD patients. CDC2 genotypes were evaluated in relation to CSF protein levels of total tau, phospho-tau and beta-amyloid (1-42) in AD patients and control individuals, and in relation to the amount of senile plaques and NFT in the frontal cortex and in the hippocampus in patients with autopsy-proven AD and controls. The CDC2 Ex6 + 7I allele was associated with a gene dose-dependent increase of CSF total tau levels (F-2,F- 626 = 7.0, p = 0.001) and the homozygous CDC2Ex6 +7II genotype was significantly more frequent among AD patients compared to controls (p = 0.006, OR = 1.57, 95% CI 1.13-2.17). Our results provide further evidence for an involvement of cdc2 in the pathogenesis of AD. Copyright (C) 2005 S. Karger AG, Basel
Role of the Subunits Interactions in the Conformational Transitions in Adult Human Hemoglobin: an Explicit Solvent Molecular Dynamics Study
Hemoglobin exhibits allosteric structural changes upon ligand binding due to
the dynamic interactions between the ligand binding sites, the amino acids
residues and some other solutes present under physiological conditions. In the
present study, the dynamical and quaternary structural changes occurring in two
unligated (deoxy-) T structures, and two fully ligated (oxy-) R, R2 structures
of adult human hemoglobin were investigated with molecular dynamics. It is
shown that, in the sub-microsecond time scale, there is no marked difference in
the global dynamics of the amino acids residues in both the oxy- and the deoxy-
forms of the individual structures. In addition, the R, R2 are relatively
stable and do not present quaternary conformational changes within the time
scale of our simulations while the T structure is dynamically more flexible and
exhibited the T\rightarrow R quaternary conformational transition, which is
propagated by the relative rotation of the residues at the {\alpha}1{\beta}2
and {\alpha}2{\beta}1 interface.Comment: Reprinted (adapted) with permission from J. Phys. Chem. B
DOI:10.1021/jp3022908. Copyright (2012) American Chemical Societ
The Science Case for an Extended Spitzer Mission
Although the final observations of the Spitzer Warm Mission are currently
scheduled for March 2019, it can continue operations through the end of the
decade with no loss of photometric precision. As we will show, there is a
strong science case for extending the current Warm Mission to December 2020.
Spitzer has already made major impacts in the fields of exoplanets (including
microlensing events), characterizing near Earth objects, enhancing our
knowledge of nearby stars and brown dwarfs, understanding the properties and
structure of our Milky Way galaxy, and deep wide-field extragalactic surveys to
study galaxy birth and evolution. By extending Spitzer through 2020, it can
continue to make ground-breaking discoveries in those fields, and provide
crucial support to the NASA flagship missions JWST and WFIRST, as well as the
upcoming TESS mission, and it will complement ground-based observations by LSST
and the new large telescopes of the next decade. This scientific program
addresses NASA's Science Mission Directive's objectives in astrophysics, which
include discovering how the universe works, exploring how it began and evolved,
and searching for life on planets around other stars.Comment: 75 pages. See page 3 for Table of Contents and page 4 for Executive
Summar
Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Diverse outcomes of binary-disk interactions
Circumstellar disks do not evolve in isolation, as about half of solar-type
stars were born in binary or multiple systems. Resolving disks in binary
systems provides the opportunity to examine the influence of stellar companions
on the outcomes of planet formation. We aim to investigate and compare disks in
stellar multiple systems with near-infrared scattered-light imaging as part of
the Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS)
program. We used polarimetric differential imaging with SPHERE/IRDIS at the VLT
to search for scattered light from the circumstellar disks in three multiple
systems, CHX 22, S CrA, and HP Cha. We performed astrometric and orbit analyses
for the stellar companions using archival HST, VLT/NACO, and SPHERE data.
Combined with the age and orbital constraints, the observed disk structures
provide insights into the evolutionary history and the impact of the stellar
companions. The small grains in CHX 22 form a tail-like structure surrounding
the close binary, which likely results from a close encounter and capture of a
cloudlet. S CrA shows intricate structures (tentative ringed and spiral
features) in the circumprimary disk as a possible consequence of perturbations
by companions. The circumsecondary disk is truncated and connected to the
primary disk via a streamer, suggesting tidal interactions. In HP Cha, the
primary disk is less disturbed and features a tenuous streamer, through which
the material flows towards the companions. The comparison of the three systems
spans a wide range of binary separation (50 - 500 au) and illustrates the
decreasing influence on disk structures with the distance of companions. This
agrees with the statistical analysis of exoplanet population in binaries, that
planet formation is likely obstructed around close binary systems, while it is
not suppressed in wide binaries.Comment: 19 pages, 6 figures, accpeted for publication in A&
Beyond Simple AGN Unification with Chandra-observed 3CRR Sources at 0.5 < z < 1
Low-frequency radio selection finds radio-bright galaxies regardless of the
amount of obscuration by gas and dust. We report \chandra\ observations of a
complete 178~MHz-selected, and so orientation unbiased, sample of 44
3CRR sources. The sample is comprised of quasars and narrow-line radio galaxies
(NLRGs) with similar radio luminosities, and the radio structure serves as both
an age and an orientation indicator. Consistent with Unification, intrinsic
obscuration (measured by \nh, X-ray hardness ratio, and X-ray luminosity)
generally increases with inclination. However, the sample includes a population
not seen in high- 3CRR sources: NLRGs viewed at intermediate inclination
angles with \nh~~cm. Multiwavelength analysis suggests these
objects have lower than typical NLRGs at similar orientation.
Thus both orientation and are important, and a
"radiation-regulated Unification" provides a better explanation of the sample's
observed properties. In comparison with the 3CRR sample at , our
lower-redshift sample shows a higher fraction of Compton-thin NLRGs (45\% vs.\
29\%) but similar Compton-thick fraction (20\%), implying a larger covering
factor of Compton-thin material at intermediate viewing angles and so a more
"puffed-up" torus atmosphere. We posit that this is due to a range of extending to lower values in this sample. In contrast, at high redshifts
the narrower range and high values allowed orientation (and so
simple Unification) to dominate the sample's observed properties
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Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.
We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition
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