1,706 research outputs found
An Analysis of the Status of Undergraduate Transportation Management Education in the United States
This paper examines 170 of the non-engineering undergraduate degrees in the fields of supply chain management, logistics, and transportation, including joint majors, present within universities in the United States. The curriculum for each degree was evaluated to determine the extent to which the students were taught transportation and related courses. Each university’s website was also examined to catalog additional best practices in education, such as required internships, used to support teaching transportation outside of formal classroom instruction
New statistical method identifes cytokines that distinguish stool microbiomes
Regressing an outcome or dependent variable onto a set of input or independent variables allows the analyst to measure associations between the two so that changes in the outcome can be described by and predicted by changes in the inputs. While there are many ways of doing this in classical statistics, where the dependent variable has certain properties (e.g., a scalar, survival time, count), little progress on regression where the dependent variable are microbiome taxa counts has been made that do not impose extremely strict conditions on the data. In this paper, we propose and apply a new regression model combining the Dirichlet-multinomial distribution with recursive partitioning providing a fully non-parametric regression model. This model, called DM-RPart, is applied to cytokine data and microbiome taxa count data and is applicable to any microbiome taxa count/metadata, is automatically fit, and intuitively interpretable. This is a model which can be applied to any microbiome or other compositional data and software (R package HMP) available through the R CRAN website
Association between Participation in Outpatient Cardiac Rehabilitation and Self-Reported Receipt of Lifestyle Advice from a Healthcare Provider: Results of a Population-Based Cross-Sectional Survey
We test the hypothesis that the odds of self-reported receipt of lifestyle advice from a health care provider will be lower among outpatient cardiac rehabilitation (OCR) nonattendees and nonreferred patients compared to OCR attendees. Logistic regression was used to analyse cross-sectional data provided by 65% (4971/7678) of patients aged 20 to 84 years discharged from public hospitals with a diagnosis indicating eligibility for OCR between 2002 and 2007. Among respondents, 71% (3518) and 55% (2724) recalled advice regarding physical activity and diet, respectively, while 88% (592/674) of smokers recalled quit advice. OCR attendance was low: 36% (1764) of respondents reported attending OCR, 11% (552) did not attend following referral, and 45% (2217) did not recall being invited. The odds of recalling advice regarding physical activity and diet were significantly lower among OCR nonattendees compared to attendees (OR 0.34, 95% CI 0.21, 0.56 and OR 0.33, 95% CI 0.25, 0.44, resp.) and among nonreferred respondents compared to OCR attendees (OR 0.10, 95% CI 0.07, 0.15 and OR 0.17, 95% CI 0.14, 0.22, resp.). Patients hospitalised for coronary heart disease should be referred to OCR or a suitable alternative to improve recall of lifestyle advice that will reduce the risk of further coronary events
Association between Participation in Outpatient Cardiac Rehabilitation and Self-Reported Receipt of Lifestyle Advice from a Healthcare Provider: Results of a Population-Based Cross-Sectional Survey
We test the hypothesis that the odds of self-reported receipt of lifestyle advice from a health care provider will be lower among outpatient cardiac rehabilitation (OCR) nonattendees and nonreferred patients compared to OCR attendees. Logistic regression was used to analyse cross-sectional data provided by 65% (4971/7678) of patients aged 20 to 84 years discharged from public hospitals with a diagnosis indicating eligibility for OCR between 2002 and 2007. Among respondents, 71% (3518) and 55% (2724) recalled advice regarding physical activity and diet, respectively, while 88% (592/674) of smokers recalled quit advice. OCR attendance was low: 36% (1764) of respondents reported attending OCR, 11% (552) did not attend following referral, and 45% (2217) did not recall being invited. The odds of recalling advice regarding physical activity and diet were significantly lower among OCR nonattendees compared to attendees (OR 0.34, 95% CI 0.21, 0.56 and OR 0.33, 95% CI 0.25, 0.44, resp.) and among nonreferred respondents compared to OCR attendees (OR 0.10, 95% CI 0.07, 0.15 and OR 0.17, 95% CI 0.14, 0.22, resp.). Patients hospitalised for coronary heart disease should be referred to OCR or a suitable alternative to improve recall of lifestyle advice that will reduce the risk of further coronary events
Ser364 of connexin43 and the upregulation of gap junction assembly by cAMP
The assembly of gap junctions (GJs) is a process coordinated by growth factors, kinases, and other signaling molecules. GJ assembly can be enhanced via the elevation of cAMP and subsequent stimulation of connexon trafficking to the plasma membrane. To study the positive regulation of GJ assembly, fibroblasts derived from connexin (Cx)43 knockout (KO) and wild-type (WT) mice were transfected with WT Cx43 (WTCx43) or mutant Cx43. GJ assembly between untransfected WT fibroblasts or stably transfected WTCx43/KO fibroblasts was increased two- to fivefold by 8Br-cAMP, and this increase could be blocked by inhibition of cAMP-dependent protein kinase (PKA) or truncation of the Cx43 COOH terminus (CT). Although serine 364 (S364) of the Cx43 CT was determined to be a major site of phosphorylation, the molar ratio of Cx43 phosphorylation was not increased by 8Br-cAMP. Importantly, GJ assembly between either S364ECx43/KO or S364ECx43/WT fibroblasts was stimulated by 8Br-cAMP, but that between S364ACx43/KO or S364PCx43/KO fibroblasts was not stimulated, indicating that phosphorylation or a negative charge at S364 is required for enhancement of GJ assembly by cAMP. Furthermore, GJ assembly between S364ACx43/WT fibroblasts could be stimulated by 8Br-cAMP, but could not be between S364PCx43/WT fibroblasts. Thus, S364PCx43 interferes with enhanced GJ assembly when coexpressed with WTCx43
Binding of the Bacillus subtilis LexA protein to the SOS operator
The Bacillus subtilis LexA protein represses the SOS response to DNA damage by binding as a dimer to the consensus operator sequence 5′-CGAACN(4)GTTCG-3′. To characterize the requirements for LexA binding to SOS operators, we determined the operator bases needed for site-specific binding as well as the LexA amino acids required for operator recognition. Using mobility shift assays to determine equilibrium constants for B.subtilis LexA binding to recA operator mutants, we found that several single base substitutions within the 14 bp recA operator sequence destabilized binding enough to abolish site-specific binding. Our results show that the AT base pairs at the third and fourth positions from the 5′ end of a 7 bp half-site are essential and that the preferred binding site for a LexA dimer is 5′-CGAACATATGTTCG-3′. Binding studies with LexA mutants, in which the solvent accessible amino acid residues in the putative DNA binding domain were mutated, indicate that Arg-49 and His-46 are essential for binding and that Lys-53 and Ala-48 are also involved in operator recognition. Guided by our mutational analyses as well as hydroxyl radical footprinting studies of the dinC and recA operators we docked a computer model of B.subtilis LexA on the preferred operator sequence in silico. Our model suggests that binding by a LexA dimer involves bending of the DNA helix within the internal 4 bp of the operator
The role of decompressive craniectomy in limited resource environments
Decompressive craniectomy (DC) is a neurosurgical procedure useful to prevent and
manage the impact of high intracranial pressure (ICP) that leads to brain herniation and
brain’s tissue ischemia. In well-resourced environment this procedure has been proposed
as a last tier therapy when ICP is not controlled by medical therapies in the management
of different neurosurgical emergencies like traumatic brain injury (TBI), stroke, infectious
diseases, hydrocephalus, tumors, etc. The purpose of this narrative review is to discuss
the role of DC in areas of low neurosurgical and neurocritical care resources. We
performed a literature review with a specific search strategy in web repositories and
some local and regional journals from Low and Middle-Income Countries (LMICs). The
most common publications include case reports, case series and observational studies
describing the benefits of the procedure on different pathologies but with several types
of biases due to the absence of robust studies or clinical registries analysis in these kinds
of environments
New statistical method identifies cytokines that distinguish stool microbiomes.
Regressing an outcome or dependent variable onto a set of input or independent variables allows the analyst to measure associations between the two so that changes in the outcome can be described by and predicted by changes in the inputs. While there are many ways of doing this in classical statistics, where the dependent variable has certain properties (e.g., a scalar, survival time, count), little progress on regression where the dependent variable are microbiome taxa counts has been made that do not impose extremely strict conditions on the data. In this paper, we propose and apply a new regression model combining the Dirichlet-multinomial distribution with recursive partitioning providing a fully non-parametric regression model. This model, called DM-RPart, is applied to cytokine data and microbiome taxa count data and is applicable to any microbiome taxa count/metadata, is automatically fit, and intuitively interpretable. This is a model which can be applied to any microbiome or other compositional data and software (R package HMP) available through the R CRAN website
Rapid Quenching of Galaxies at Cosmic Noon
The existence of massive quiescent galaxies at high redshift seems to require
rapid quenching, but it is unclear whether all quiescent galaxies have gone
through this phase and what physical mechanisms are involved. To study rapid
quenching, we use rest-frame colors to select 12 young quiescent galaxies at . From spectral energy distribution fitting, we find that they all
experienced intense starbursts prior to rapid quenching. We confirm this with
deep Magellan/FIRE spectroscopic observations for a subset of seven galaxies.
Broad emission lines are detected for two galaxies and are most likely caused
by AGN activity. The other five galaxies do not show any emission features,
suggesting that gas has already been removed or depleted. Most of the rapidly
quenched galaxies are more compact than normal quiescent galaxies, providing
evidence for a central starburst in the recent past. We estimate an average
transition time of for the rapid quenching phase. Approximately
of quiescent galaxies at have gone through rapid quenching; this
fraction increases to at . We identify analogs in the TNG100
simulation and find that rapid quenching for these galaxies is driven by AGN,
and for half of the cases, gas-rich major mergers seem to trigger the
starburst. We conclude that these massive quiescent galaxies are not just
rapidly quenched but also rapidly formed through a major starburst. We
speculate that mergers drive gas inflow towards the central regions and grow
supermassive black holes, leading to rapid quenching by AGN feedback.Comment: Submitted to ApJ. Comments are welcom
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