2,511 research outputs found
Environmental Law: A Reevaluation of Federal Pre-Emption and the Commerce Clause
This Comment addresses how the concern of state and local governments to regain control over environmental regulation has resulted in a marked increase in conflicts with the commerce and supremacy clauses of the Constitution. Various tests have been used by the courts to determine violations of these Constitutional provisions where environmental objectives are sought through local laws. In the field of environmental litigation, traditional tests are constantly challenged to meet the changing moral climate of the nation. This Comment weighs the desire of local legislatures for more responsive environmental regulation against the federal goal of uniform regulation and unrestrained interstate commerce, concluding that the court must decide on a policy of pre-emption in order for the nation to know whether environmental reform will be spearheaded from the states or the federal government
Whole-body heat stress and exercise stimulate the appearance of platelet microvesicles in plasma with limited influence of vascular shear stress
Intense, large muscle mass exercise increases circulating microvesicles, but our understanding of microvesicle dynamics and mechanisms inducing their release remains limited. However, increased vascular shear stress is generally thought to be involved. Here, we manipulated exercise-independent and exercise-dependent shear stress using systemic heat stress with localized single-leg cooling (low shear) followed by single-leg knee extensor exercise with the cooled or heated leg (Study 1, n = 8) and whole-body passive heat stress followed by cycling (Study 2, n = 8). We quantified femoral artery shear rates (SRs) and arterial and venous platelet microvesicles (PMV-CD41+) and endothelial microvesicles (EMV-CD62E+). In Study 1, mild passive heat stress while one leg remained cooled did not affect [microvesicle] (P ≥ 0.05). Single-leg knee extensor exercise increased active leg SRs by ~12-fold and increased arterial and venous [PMVs] by two- to threefold, even in the nonexercising contralateral leg (P < 0.05). In Study 2, moderate whole-body passive heat stress increased arterial [PMV] compared with baseline (mean±SE, from 19.9 ± 1.5 to 35.5 ± 5.4 PMV.μL-1.103, P < 0.05), and cycling with heat stress increased [PMV] further in the venous circulation (from 27.5 ± 2.2 at baseline to 57.5 ± 7.2 PMV.μL-1.103 during cycling with heat stress, P < 0.05), with a tendency for increased appearance of PMV across exercising limbs. Taken together, these findings demonstrate that whole-body heat stress may increase arterial [PMV], and intense exercise engaging either large or small muscle mass promote PMV formation locally and systemically, with no influence upon [EMV]. Local shear stress, however, does not appear to be the major stimulus modulating PMV formation in healthy humans
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Beyond First/Last Mile Active Transportation - BikeShare@UH
Bike sharing is a new green transportation solution that has been developed and adopted at various cities around the world. In this paper, we present the process and results of the design and prototypes that a group of undergraduate students developed for a BikeShare@UH program during Summer 2017. After presenting the detailed results of four project teams focusing on customer discovery, bike share station (BSS) location identification, cloud-based mobile computing platform for user engagement and bike share program operation and management, smart lock, and alternative energy source based on PV panel. With the phase one implementation at the University planned in Spring 2018, we anticipate gathering real time data and feedback to improve the system.Cockrell School of Engineerin
República del Perú: Evaluación de la gobernabilidad política
Como en la mayoría de los Estados democráticos actuales, en el Perú el sistema político ha evolucionado de estructuras de gobierno caracterizadas por la concentración del poder político y la relativa exclusión de la mayoría de la población del proceso decisorio, a sistemas más inclusivos que tienden a agregar de manera más efectiva los intereses de las mayorías como consecuencia de una mayor competición entre los actores políticos. La conjugación de factores geográficos, culturales, sociales, económicos propios de la historia y evolución política peruana hicieron que en los comienzos de su vida republicana ostentara un grado importante de concentración de poder y bajos niveles de competición política. La existencia de controles leves y apenas formales sobre el Poder Ejecutivo, y un tipo de contienda política caracterizada por el faccionalismo, hizo que los distintos grupos que competían por influencia lo hicieran para promover agendas particulares en detrimento del interés general. Desde los años sesenta ha habido procesos de transformación política. Sin embargo, el aumento de la participación y de la diversidad de opciones políticas no ha bastado para desarrollar un tejido jurídicoinstitucional que conduzca a la eliminación de las desigualdades históricas y a la promoción del desarrollo económico y social sostenible. Esta incapacidad del sistema político peruano tuvo y tiene sus raíces en el carácter faccional de la competición política (Gráfico 1), el cual se ha traducido en una excesiva concentración del poder político que se expresa en un centralismo exacerbado, la concentración de la toma de decisiones en la presidencia, la ineficacia de los mecanismos de rendición de cuentas en el ámbito político, social y judicial, y en las marcadas desigualdades sociales.Perú, Poder Ejecutivo, Estado democrático
Mid-IR Luminosities and UV/Optical Star Formation Rates at z<1.4
UV continuum and mid-IR emission constitute two widely used star formation
indicators at intermediate and high redshifts. We study 2430 galaxies with
z<1.4 in the Extended Groth Strip with MIPS 24 mic observations from FIDEL,
spectroscopy from DEEP2, and UV, optical, and near-IR photometry from AEGIS.
The data are coupled with stellar population models and Bayesian SED fitting to
estimate dust-corrected SFRs. In order to probe the dust heating from stellar
populations of various ages, the derived SFRs were averaged over various
timescales--from 100 Myr for "current" SFR to 1--3 Gyr for long-timescale SFRs.
These SED-based UV/optical SFRs are compared to total infrared luminosities
extrapolated from 24 mic observations. We find that for the blue, actively star
forming galaxies the correlation between the IR luminosity and the UV/optical
SFR shows a decrease in scatter when going from shorter to longer SFR-averaging
timescales. We interpret this as the greater role of intermediate age stellar
populations in heating the dust than what is typically assumed. This holds over
the entire redshift range. Many so-called green valley galaxies are simply
dust-obscured actively star-forming galaxies. However, there exist 24
mic-detected galaxies, some with L>10^11 L_sun, yet with little current star
formation. For them a reasonable amount of dust absorption of stellar light is
sufficient to produce the observed levels of IR. In our sample optical and
X-ray AGNs do not contribute on average more than ~50% to the mid-IR
luminosity, and we see no evidence for a large population of "IR excess"
galaxies (Abridged).Comment: Accepted for publication in ApJ. Content identical to arXiv version
1. No color figure
On Soliton-type Solutions of Equations Associated with N-component Systems
The algebraic geometric approach to -component systems of nonlinear
integrable PDE's is used to obtain and analyze explicit solutions of the
coupled KdV and Dym equations. Detailed analysis of soliton fission, kink to
anti-kink transitions and multi-peaked soliton solutions is carried out.
Transformations are used to connect these solutions to several other equations
that model physical phenomena in fluid dynamics and nonlinear optics.Comment: 43 pages, 16 figure
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Associations of Blood Pressure and Cholesterol Levels During Young Adulthood With Later Cardiovascular Events.
BackgroundBlood pressure (BP) and cholesterol are major modifiable risk factors for cardiovascular disease (CVD), but effects of exposures during young adulthood on later life CVD risk have not been well quantified.ObjectiveThe authors sought to evaluate the independent associations between young adult exposures to risk factors and later life CVD risk, accounting for later life exposures.MethodsThe authors pooled data from 6 U.S. cohorts with observations spanning the life course from young adulthood to later life, and imputed risk factor trajectories for low-density lipoprotein (LDL) and high-density lipoprotein cholesterols, systolic and diastolic BP starting from age 18 years for every participant. Time-weighted average exposures to each risk factor during young (age 18 to 39 years) and later adulthood (age ≥40 years) were calculated and linked to subsequent risks of coronary heart disease (CHD), heart failure (HF), or stroke.ResultsA total of 36,030 participants were included. During a median follow-up of 17 years, there were 4,570 CHD, 5,119 HF, and 2,862 stroke events. When young and later adult risk factors were considered jointly in the model, young adult LDL ≥100 mg/dl (compared with <100 mg/dl) was associated with a 64% increased risk for CHD, independent of later adult exposures. Similarly, young adult SBP ≥130 mm Hg (compared with <120 mm Hg) was associated with a 37% increased risk for HF, and young adult DBP ≥80 mm Hg (compared with <80 mm Hg) was associated with a 21% increased risk.ConclusionsCumulative young adult exposures to elevated systolic BP, diastolic BP and LDL were associated with increased CVD risks in later life, independent of later adult exposures
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Photoreversible interconversion of a phytochrome photosensory module in the crystalline state.
A major barrier to defining the structural intermediates that arise during the reversible photointerconversion of phytochromes between their biologically inactive and active states has been the lack of crystals that faithfully undergo this transition within the crystal lattice. Here, we describe a crystalline form of the cyclic GMP phosphodiesterases/adenylyl cyclase/FhlA (GAF) domain from the cyanobacteriochrome PixJ in Thermosynechococcus elongatus assembled with phycocyanobilin that permits reversible photoconversion between the blue light-absorbing Pb and green light-absorbing Pg states, as well as thermal reversion of Pg back to Pb. The X-ray crystallographic structure of Pb matches previous models, including autocatalytic conversion of phycocyanobilin to phycoviolobilin upon binding and its tandem thioether linkage to the GAF domain. Cryocrystallography at 150 K, which compared diffraction data from a single crystal as Pb or after irradiation with blue light, detected photoconversion product(s) based on Fobs - Fobs difference maps that were consistent with rotation of the bonds connecting pyrrole rings C and D. Further spectroscopic analyses showed that phycoviolobilin is susceptible to X-ray radiation damage, especially as Pg, during single-crystal X-ray diffraction analyses, which could complicate fine mapping of the various intermediate states. Fortunately, we found that PixJ crystals are amenable to serial femtosecond crystallography (SFX) analyses using X-ray free-electron lasers (XFELs). As proof of principle, we solved by room temperature SFX the GAF domain structure of Pb to 1.55-Å resolution, which was strongly congruent with synchrotron-based models. Analysis of these crystals by SFX should now enable structural characterization of the early events that drive phytochrome photoconversion
Identification of PKD1L1 Gene Variants in Children with the Biliary Atresia Splenic Malformation Syndrome
Biliary atresia (BA) is the most common cause of end‐stage liver disease in children and the primary indication for pediatric liver transplantation, yet underlying etiologies remain unknown. Approximately 10% of infants affected by BA exhibit various laterality defects (heterotaxy) including splenic abnormalities and complex cardiac malformations — a distinctive subgroup commonly referred to as the biliary atresia splenic malformation (BASM) syndrome. We hypothesized that genetic factors linking laterality features with the etiopathogenesis of BA in BASM patients could be identified through whole exome sequencing (WES) of an affected cohort. DNA specimens from 67 BASM subjects, including 58 patient‐parent trios, from the NIDDK‐supported Childhood Liver Disease Research Network (ChiLDReN) underwent WES. Candidate gene variants derived from a pre‐specified set of 2,016 genes associated with ciliary dysgenesis and/or dysfunction or cholestasis were prioritized according to pathogenicity, population frequency, and mode of inheritance. Five BASM subjects harbored rare and potentially deleterious bi‐allelic variants in polycystin 1‐like 1, PKD1L1, a gene associated with ciliary calcium signaling and embryonic laterality determination in fish, mice and humans. Heterozygous PKD1L1 variants were found in 3 additional subjects. Immunohistochemical analysis of liver from the one BASM subject available revealed decreased PKD1L1 expression in bile duct epithelium when compared to normal livers and livers affected by other non‐cholestatic diseases. Conclusion WES identified bi‐allelic and heterozygous PKD1L1 variants of interest in 8 BASM subjects from the ChiLDReN dataset. The dual roles for PKD1L1 in laterality determination and ciliary function suggest that PKD1L1 is a new, biologically plausible, cholangiocyte‐expressed candidate gene for the BASM syndrome
Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations
Abstract
Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline
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