15,041 research outputs found
Updated users' guide for TAWFIVE with multigrid
A program for the Transonic Analysis of a Wing and Fuselage with Interacted Viscous Effects (TAWFIVE) was improved by the incorporation of multigrid and a method to specify lift coefficient rather than angle-of-attack. A finite volume full potential multigrid method is used to model the outer inviscid flow field. First order viscous effects are modeled by a 3-D integral boundary layer method. Both turbulent and laminar boundary layers are treated. Wake thickness effects are modeled using a 2-D strip method. A brief discussion of the engineering aspects of the program is given. The input, output, and use of the program are covered in detail. Sample results are given showing the effects of boundary layer corrections and the capability of the lift specification method
Chandra Observation of the Interaction of the Radio Source and Cooling Core in Abell 2063
We present the results of a Chandra observation of the cooling core cluster
Abell 2063. Spectral analysis shows that there is cool gas (2 keV) associated
with the cluster core, which is more than a factor of 2 cooler than the outer
cluster gas (4.1 keV). There also is spectral evidence for a weak cooling flow,
Mdot ~ 20 Msun/yr. The cluster exhibits a complex structure in the center that
consists of several bright knots of emission, a depression in the emission to
the north of the center of the cluster, and a shell of emission surrounding it.
The depression in the X-ray emission is coincident with the position of the
north-eastern radio lobe of the radio source associated with the
cluster-central galaxy. The shell surrounding this region appears to be hotter,
which may be the result of a shock that has been driven into the gas by the
radio source. The power output of the radio source appears to be sufficient to
offset the cooling flow, and heating of the gas through shocks is a possible
explanation of how the energy transfer is established.Comment: Astrophysical Jounal, in press, 26 page with 9 figures, some in
color. Uses AASTEX late
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Development of outbred CD1 mouse colonies with distinct standardized gut microbiota profiles for use in complex microbiota targeted studies.
Studies indicate that the gut microbiota (GM) can significantly influence both local and systemic host physiologic processes. With rising concern for optimization of experimental reproducibility and translatability, it is essential to consider the GM in study design. However, GM profiles can vary between rodent producers making consistency between models challenging. To circumvent this, we developed outbred CD1 mouse colonies with stable, complex GM profiles that can be used as donors for a variety of GM transfer techniques including rederivation, co-housing, cross-foster, and fecal microbiota transfer (FMT). CD1 embryos were surgically transferred into CD1 or C57BL/6 surrogate dams that varied by GM composition and complexity to establish four separate mouse colonies harboring GM profiles representative of contemporary mouse producers. Using targeted 16S rRNA amplicon sequencing, subsequent female offspring were found to have similar GM profiles to surrogate dams. Furthermore, breeding colonies of CD1 mice with distinct GM profiles were maintained for nine generations, demonstrating GM stability within these colonies. To confirm GM stability, we shipped cohorts of these four colonies to collaborating institutions and found no significant variation in GM composition. These mice are an invaluable experimental resource that can be used to investigate GM effects on mouse model phenotype
A novel ingestion strategy for sodium bicarbonate supplementation in a delayed-release form: a randomised crossover study in trained males
Background: Sodium bicarbonate (NaHCO3) is a well-established nutritional ergogenic aid, though gastrointestinal (GI) distress is a common side-effect. Delayed-release NaHCO3 may alleviate GI symptoms and enhance bicarbonate bioavailability following oral ingestion, although this has yet to be confirmed. Methods: In a randomised crossover design, pharmacokinetic responses and acid-base status were compared following two forms of NaHCO3, as were GI symptoms. Twelve trained healthy males (mean ± SD: age 25.8 ± 4.5 y; maximal oxygen uptake ("V" ̇O2max) 58.9 ± 10.9 mL∙kg∙min–1; height 1.8 ± 0.1 m; body mass 82.3 ± 11.1 kg; fat-free mass 72.3 ± 10.0 kg) underwent a control (CON) condition and two experimental conditions: 300 mg∙kg–1 body mass NaHCO3 ingested as an aqueous solution (SOL) and encased in delayed-release capsules (CAP). Blood bicarbonate concentration, pH and base excess (BE) were measured in all conditions over 180 min, as were subjective GI symptom scores. Results: Incidences of GI symptoms and overall severity were significantly lower (mean difference = 45.1%, P < 0.0005 and 47.5%, P < 0.0005 for incidences and severity, respectively) with the CAP than with the SOL. Symptoms displayed increases at 40 to 80 min post-ingestion with the SOL that were negated with CAP (P < 0.05). Time to reach peak bicarbonate concentration, pH and BE were significantly longer with CAP than with the SOL. Conclusions: In summary, CAP can mitigate GI symptoms induced with SOL and should be ingested earlier to induce similar acid-base changes. Furthermore, CAP may be more ergogenic in those who experience severe GI distress with SOL, although this warrants further investigation
Giving Mom a Break: The Impact of Higher EITC Payments on Maternal Health
The 1993 expansions of the Earned Income Tax Credit created the first meaningful separation in the benefit level for families based on the number of children, with families containing two or more children now receiving substantially more in benefits. If income is protective of health, we should see improvements over time in the health for mothers eligible for the EITC with two or more children compared to those with only one child. Using data from the Behavioral Risk Factors Surveillance Survey, we find in difference-in-difference models that for low-educated mothers of two or more children, the number of days with poor mental health and the fraction reporting excellent or very good health improved relative to the mothers with only one child. Using data from the National Health Examination and Nutrition Survey, we find evidence that the probability of having risky levels of biomarkers fell for these same low-educated women impacted more by the 1993 expansions, especially biomarkers that indicate inflammation.
Estimating Heterogeneity in the Benefits of Medical Treatment Intensity
Federal and state laws passed in the late 1990 increased considerably postpartum stays for newborns. Using all births in California over the 1995-2001 period, 2SLS estimates suggest that for the average newborn impacted by the law, increased treatment intensity had modest and statistically insignificant (p-value>0.05) impacts on readmission probabilities. Allowing the treatment effect to vary by pre-existing conditions or the pre-law propensity score of being discharged early, two objective measures of medical need, demonstrates that the law had large and statistically significant impacts for those with the greatest likelihood of a readmission. These results demonstrate heterogeneity in the returns to greater treatment intensity, and the returns to the average and marginal patient vary considerably.
Three-dimensional rotational averages in radiation-molecule interactions: an irreducible cartesian tensor formulation
Site-specific Tn7 transposition into the human genome
The bacterial transposon, Tn7, inserts into a single site in the Escherichia coli chromosome termed attTn7 via the sequence-specific DNA binding of the target selector protein, TnsD. The target DNA sequence required for Tn7 transposition is located within the C-terminus of the glucosamine synthetase (glmS) gene, which is an essential, highly conserved gene found ubiquitously from bacteria to humans. Here, we show that Tn7 can transpose in vitro adjacent to two potential targets in the human genome: the gfpt-1 and gfpt-2 sequences, the human analogs of glmS. The frequency of transposition adjacent to the human gfpt-1 target is comparable with the E.coli glmS target; the human gfpt-2 target shows reduced transposition. The binding of TnsD to these sequences mirrors the transposition activity. In contrast to the human gfpt sequences, Tn7 does not transpose adjacent to the gfa-1 sequence, the glmS analog in Saccharomyces cerevisiae. We also report that a nucleosome core particle assembled on the human gfpt-1 sequence reduces Tn7 transposition by likely impairing the accessibility of target DNA to the Tns proteins. We discuss the implications of these findings for the potential use of Tn7 as a site-specific DNA delivery agent for gene therapy
Automated data analysis of unstructured grey literature in health research: A mapping review
\ua9 2023 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. The amount of grey literature and ‘softer’ intelligence from social media or websites is vast. Given the long lead-times of producing high-quality peer-reviewed health information, this is causing a demand for new ways to provide prompt input for secondary research. To our knowledge, this is the first review of automated data extraction methods or tools for health-related grey literature and soft data, with a focus on (semi)automating horizon scans, health technology assessments (HTA), evidence maps, or other literature reviews. We searched six databases to cover both health- and computer-science literature. After deduplication, 10% of the search results were screened by two reviewers, the remainder was single-screened up to an estimated 95% sensitivity; screening was stopped early after screening an additional 1000 results with no new includes. All full texts were retrieved, screened, and extracted by a single reviewer and 10% were checked in duplicate. We included 84 papers covering automation for health-related social media, internet fora, news, patents, government agencies and charities, or trial registers. From each paper, we extracted data about important functionalities for users of the tool or method; information about the level of support and reliability; and about practical challenges and research gaps. Poor availability of code, data, and usable tools leads to low transparency regarding performance and duplication of work. Financial implications, scalability, integration into downstream workflows, and meaningful evaluations should be carefully planned before starting to develop a tool, given the vast amounts of data and opportunities those tools offer to expedite research
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