The Swift Gamma-Ray Burst Mission Gehrels, N; Chincarini, G; Giommi, P ...
The Astrophysical journal,
08/2004, Letnik:
611, Številka:
2
Journal Article
Recenzirano
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The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is a first-of-its-kind autonomous rapid-slewing satellite for transient ...astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more than 100 bursts yr super(-1) and performing detailed X-ray and UV/optical afterglow observations spanning timescales from 1 minute to several days after the burst. The objectives are to (1) determine the origin of GRBs, (2) classify GRBs and search for new types, (3) study the interaction of the ultrarelativistic outflows of GRBs with their surrounding medium, and (4) use GRBs to study the early universe out to z > 10. The mission is being developed by a NASA-led international collaboration. It will carry three instruments: a new-generation wide-field gamma-ray (15-150 keV) detector that will detect bursts, calculate 1arcmin-4arcmin positions, and trigger autonomous spacecraft slews; a narrow-field X-ray telescope that will give 5arc sec positions and perform spectroscopy in the 0.2-10 keV band; and a narrow-field UV/optical telescope that will operate in the 170-600 nm band and provide 0!!3 positions and optical finding charts. Redshift determinations will be made for most bursts. In addition to the primary GRB science, the mission will perform a hard X-ray survey to a sensitivity of approx1 mcrab (approx2 x 10 super(-11) ergs cm super(-2) s super(-1) in the 15-150 keV band), more than an order of magnitude better than HEAO 1 A-4. A flexible data and operations system will allow rapid follow-up observations of all types of high-energy transients, with rapid data downlink and uplink available through the NASA TDRSS system. Swift transient data will be rapidly distributed to the astronomical community, and all interested observers are encouraged to participate in follow- up measurements. A Guest Investigator program for the mission will provide funding for community involvement. Innovations from the Swift program applicable to the future include (1) a large-area gamma-ray detector using the new CdZnTe detectors, (2) an autonomous rapid-slewing spacecraft, (3) a multiwavelength payload combining optical, X-ray, and gamma-ray instruments, (4) an observing program coordinated with other ground-based and space-based observatories, and (5) immediate multiwavelength data flow to the community. The mission is currently funded for 2 yr of operations, and the spacecraft will have a lifetime to orbital decay of approx8 yr.
The X‐ray crystal structure of the proform of human matrix metalloproteinase MMP9 has been solved to 2.5 Å resolution. The construct includes the prodomain, the catalytic domain and three FnII ...(fibronectin type II) domains. The prodomain is inserted into the active‐site cleft, blocking access to the catalytic zinc. Comparison with the crystal structure of the most closely related MMP, MMP2, indicates that the conformations of residues in the active‐site cleft and in the cysteine‐switch peptide of the prodomain are highly conserved and that design of MMP9‐specific inhibitors will be challenging. In common with MMP2, the MMP9 S1′ inhibitor‐binding pocket is large compared with that of other MMPs. One small point of difference in the S1′ binding pockets of MMP9 and MMP2 may provide an opportunity to explore the design of specific inhibitors. The side chain of Arg424 in MMP9 is angled slightly away from the S1′ pocket when compared with the corresponding residue in MMP2, Thr424. The secondary structure of the FnII domains is conserved between the two closely related MMPs, although the second FnII domain makes no contact with the catalytic domain in MMP9, while the same domain in MMP2 has a substantial area of interaction with the catalytic domain.
Abstract In this paper we develop a lattice-based computational model focused on bone resorption by osteoclasts in a single cortical basic multicellular unit (BMU). Our model takes into account the ...interaction of osteoclasts with the bone matrix, the interaction of osteoclasts with each other, the generation of osteoclasts from a growing blood vessel, and the renewal of osteoclast nuclei by cell fusion. All these features are shown to strongly influence the geometrical properties of the developing resorption cavity including its size, shape and progression rate, and are also shown to influence the distribution, resorption pattern and trajectories of individual osteoclasts within the BMU. We demonstrate that for certain parameter combinations, resorption cavity shapes can be recovered from the computational model that closely resemble resorption cavity shapes observed from microCT imaging of human cortical bone.
New Frontiers for Organismal Biology Kültz, Dietmar; Clayton, David F; Robinson, Gene E ...
Bioscience,
06/2013, Letnik:
63, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Understanding how complex organisms function as integrated units that constantly interact with their environment is a long-standing challenge in biology. To address this challenge, organismal biology ...reveals general organizing principles of physiological systems and behavior—in particular, in complex multicellular animals. Organismal biology also focuses on the role of individual variability in the evolutionary maintenance of diversity. To broadly advance these frontiers, cross-compatibility of experimental designs, methodological approaches, and data interpretation pipelines represents a key prerequisite. It is now possible to rapidly and systematically analyze complete genomes to elucidate genetic variation associated with traits and conditions that define individuals, populations, and species. However, genetic variation alone does not explain the varied individual physiology and behavior of complex organisms. We propose that such emergent properties of complex organisms can best be explained through a renewed emphasis on the context and life-history dependence of individual phenotypes to complement genetic data.
Abstract
Introduction
Evidence-based cessation methods including nicotine replacement therapy (NRT), non-NRT medications, quitlines, and behavioral treatments are underutilized by smokers attempting ...to quit. Although a number of studies have demonstrated a relationship between state-level tobacco policies (eg, taxation, appropriations) and cessation, whether such state-level factors influence likelihood of using an evidence-based treatment is unclear. Accordingly, the aims of the present study were: (1) to describe evidence-based cessation method utilization by state and (2) to examine the effect of state-level factors on cessation method utilization above and beyond individual-level predictors.
Methods
Data were utilized from the 2010–2011 Tobacco Use Supplement to the Current Population Survey (TUS-CPS). Participants included 9232 smokers who reported a past-year quit attempt. Data on 11 state-level predictors were collated from national datasets. Analyses were based on: (1) descriptive characterization of quit method usage, (2) logistic regression models to determine state-level factors as predictors of quit method utilization, controlling for individual-level predictors, (3) cluster analyses grouping states with similar state-level factors, and (4) examination of cluster as a predictor of cessation method.
Results
Tobacco control appropriations significantly predicted NRT, quitline, and behavioral treatment utilization. Additional state-level factors that demonstrated significant relationships included Medicaid coverage of non-NRT medications and behavioral treatment, tobacco tax rate, smoking prevalence, and percentage of population uninsured. State clustering significantly predicted quit method across all four methods.
Conclusions
State-level factors influence the likelihood of residents utilizing evidence-based quit methods. Results are discussed in terms of implications for tobacco policy at the state level.
Implications
Results from the present study highlight state tobacco control appropriations as a robust predictor of evidence-based cessation method utilization. Other significant state-level predictors of evidence-based cessation method utilization included Medicaid coverage of non-NRT medications and behavioral treatment, tobacco tax rate, smoking prevalence, and percentage of population uninsured. Moreover, state-level predictors clustered together to significantly predict evidence-based cessation method utilization. Thus, increasing tobacco control appropriations, extending health insurance coverage, maximizing revenue from tobacco taxation and tobacco settlements, and ultimately decreasing smoking prevalence are important targets for individual states to promote utilization of evidence-based cessation methods.
Abstract Prospective analysis was performed of self-reported and biochemically confirmed tobacco use in 50 head and neck cancer patients during treatment. With 93.5% compliance to complete weekly ...self-report and biochemical confirmatory tests, 29.4% of smokers required biochemical assessment for identification. Accuracy increased by 14.9% with weekly vs. baseline self-reported assessments. Data confirm that head and neck cancer patients misrepresent true tobacco use during treatment.
The author reflects on the early entry of clinical and counseling psychology into the general medical hospital setting in the 1950s and 1960s. Drawing largely from his 3½ decades as a Department of ...Veterans Affairs psychologist (mainly in the areas of tuberculosis and endstage renal disease), he describes problems and contributions associated with psychology's entry into this new arena. These involved not only providing direct patient services at the bedside; just as much, they involved clarifying psychological health concepts, the training of patients and their families in taking the most active roles in their own treatment, and the professional relationships between psychologists and their new colleagues in the medical and surgical wards.
1. The effect of dietary fibre digestion in the human gut on its ability to alter bowel habit and impair mineral absorption has been investigated using the technique of metablic balance. 2. Five ...healthy male students were studied for 9 weeks under controlled dietary conditions and during the last 6 weeks they took 36 g pectin/d. Bowel habit, transit through the gut, faecal fibre excretion, calcium balance and faecal composition were measured. 3. During the control period only 15% of the dietary fibre ingested was excreted in the stools and when pectin was added to the diet there was no increase in fibre excretion. Stool frequency and mean transit time were unchanged by pectin but stool wet weight increased by 33% and faecal excretion increased (%) for fatty acids 80, nitrogen 47, total dry matter 28 and bile acids 35. Ca balance remained unchanged. 4. It may be concluded from these results that dietary fibre is largely metabolized in the human gut and dietary pectin completely so. This could explain its lack of effect on bowel habit and Ca balance. Other changes in the faeces may be related to an increase in bacterial mass.
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