2,461 research outputs found
Embedding auxetic properties in designing active-bending gridshells
Advancements in computational tools are offering designers the possibility to change their relationship with materials. The exploration ofauxetic metamaterials, specifically engineered to obtain properties beyond those found in nature, is the promising field examined in this paper. The aim is to define tools and methods in order to design auxetics, and use them tocreate efficient active-bending structures. By programming their geometry through several parameters, it is possible to finely control curvature and structural resistance. The paper describes an original investigation into the process of programming such structures through the use of combined computational tools
Energy conversion in turbulent weakly-collisional plasmas: Eulerian Hybrid Vlasov-Maxwell simulations
Kinetic simulations based on the Eulerian Hybrid Vlasov-Maxwell (HVM)
formalism permit the examination of plasma turbulence with useful resolution of
the proton velocity distribution function (VDF). The HVM model is employed here
to study the balance of energy, focusing on channels of conversion that lead to
proton kinetic effects, including growth of internal energy and temperature
anisotropies. We show that this Eulerian simulation approach, which is almost
noise-free, is able to provide an accurate energy balance for protons. The
results demonstrate explicitly that the recovered temperature growth is
directly related to the role of the pressure-strain interaction. Furthermore,
analysis of local spatial correlations indicates that the pressure-strain
interaction is qualitatively associated with strong-current, high-vorticity
structures, although other local terms -- such as the heat flux -- weaken the
correlation. These numerical capabilities based on the Eulerian approach will
enable deeper study of transfer and conversion channels in weakly collisional
Vlasov plasmas.Comment: Accepted for publication on Physics of Plasma
Health screenings administered during the domestic medical examination of refugees and other eligible immigrants in nine US states, 2014-2016: A cross-sectional analysis.
BACKGROUND: Refugees and other select visa holders are recommended to receive a domestic medical examination within 90 days after arrival to the United States. Limited data have been published on the coverage of screenings offered during this examination across multiple resettlement states, preventing evaluation of this voluntary program\u27s potential impact on postarrival refugee health. This analysis sought to calculate and compare screening proportions among refugees and other eligible populations to assess the domestic medical examination\u27s impact on screening coverage resulting from this examination.
METHODS AND FINDINGS: We conducted a cross-sectional analysis to summarize and compare domestic medical examination data from January 2014 to December 2016 from persons receiving a domestic medical examination in seven states (California, Colorado, Minnesota, New York, Kentucky, Illinois, and Texas); one county (Marion County, Indiana); and one academic medical center in Philadelphia, Pennsylvania. We analyzed screening coverage by sex, age, nationality, and country of last residence of persons and compared the proportions of persons receiving recommended screenings by those characteristics. We received data on disease screenings for 105,541 individuals who received a domestic medical examination; 47% were female and 51.5% were between the ages of 18 and 44. The proportions of people undergoing screening tests for infectious diseases were high, including for tuberculosis (91.6% screened), hepatitis B (95.8% screened), and human immunodeficiency virus (HIV; 80.3% screened). Screening rates for other health conditions were lower, including mental health (36.8% screened). The main limitation of our analysis was reliance on data that were collected primarily for programmatic rather than surveillance purposes.
CONCLUSIONS: In this analysis, we observed high rates of screening coverage for tuberculosis, hepatitis B, and HIV during the domestic medical examination and lower screening coverage for mental health. This analysis provided evidence that the domestic medical examination is an opportunity to ensure newly arrived refugees and other eligible populations receive recommended health screenings and are connected to the US healthcare system. We also identified knowledge gaps on how screenings are conducted for some conditions, notably mental health, identifying directions for future research
Health of Special Immigrant Visa holders from Iraq and Afghanistan after arrival into the United States using Domestic Medical Examination data, 2014-2016: A cross-sectional analysis.
BACKGROUND: Since 2008, the United States has issued between 2,000 and 19,000 Special Immigrant Visas (SIV) annually, with the majority issued to applicants from Iraq and Afghanistan. SIV holders (SIVH) are applicants who were employed by, or on behalf of, the US government or the US military. There is limited information about health conditions in SIV populations to help guide US clinicians caring for SIVH. Thus, we sought to describe health characteristics of recently arrived SIVH from Iraq and Afghanistan who were seen for domestic medical examinations.
METHODS AND FINDINGS: This cross-sectional analysis included data from Iraqi and Afghan SIVH who received a domestic medical examination from January 2014 to December 2016. Data were gathered from state refugee health programs in seven states (California, Colorado, Illinois, Kentucky, Minnesota, New York, and Texas), one county, and one academic medical center and included 6,124 adults and 4,814 children. Data were collected for communicable diseases commonly screened for during the exam, including tuberculosis (TB), hepatitis B, hepatitis C, malaria, strongyloidiasis, schistosomiasis, other intestinal parasites, syphilis, gonorrhea, chlamydia, and human immunodeficiency virus, as well as elevated blood lead levels (EBLL). We investigated the frequency and proportion of diseases and whether there were any differences in selected disease prevalence in SIVH from Iraq compared to SIVH from Afghanistan. A majority of SIV adults were male (Iraqi 54.0%, Afghan 58.6%) and aged 18-44 (Iraqi 86.0%, Afghan 97.7%). More SIV children were male (Iraqi 56.2%, Afghan 52.2%) and aged 6-17 (Iraqi 50.2%, Afghan 40.7%). The average age of adults was 29.7 years, and the average age for children was 5.6 years. Among SIV adults, 14.4% were diagnosed with latent tuberculosis infection (LTBI), 63.5% were susceptible to hepatitis B virus (HBV) infection, and 31.0% had at least one intestinal parasite. Afghan adults were more likely to have LTBI (prevalence ratio [PR]: 2.0; 95% confidence interval [CI] 1.5-2.7) and to be infected with HBV (PR: 4.6; 95% CI 3.6-6.0) than Iraqi adults. Among SIV children, 26.7% were susceptible to HBV infection, 22.1% had at least one intestinal parasite, and 50.1% had EBLL (≥5 mcg/dL). Afghan children were more likely to have a pathogenic intestinal parasite (PR: 2.7; 95% CI 2.4-3.2) and EBLL (PR: 2.0; 95% CI 1.5-2.5) than Iraqi children. Limitations of the analysis included lack of uniform health screening data collection across all nine sites and possible misclassification by clinicians of Iraqi and Afghan SIVH as Iraqi and Afghan refugees, respectively.
CONCLUSION: In this analysis, we observed that 14% of SIV adults had LTBI, 27% of SIVH had at least one intestinal parasite, and about half of SIV children had EBLL. Most adults were susceptible to HBV. In general, prevalence of infection was higher for most conditions among Afghan SIVH compared to Iraqi SIVH. The Centers for Disease Control and Prevention (CDC) Guidelines for the US Domestic Medical Examination for Newly Arriving Refugees can assist state public health departments and clinicians in the care of SIVH during the domestic medical examination. Future analyses can explore other aspects of health among resettled SIV populations, including noncommunicable diseases and vaccination coverage
Activation of Serine One-Carbon Metabolism by Calcineurin A beta 1 Reduces Myocardial Hypertrophy and Improves Ventricular Function
Background In response to pressure overload, the heart develops ventricular hypertrophy that progressively decompensates and leads to heart failure. This pathological hypertrophy is mediated, among others, by the phosphatase calcineurin and is characterized by metabolic changes that impair energy production by mitochondria. Objectives The authors aimed to determine the role of the calcineurin splicing variant CnAβ1 in the context of cardiac hypertrophy and its mechanism of action. Methods Transgenic mice overexpressing CnAβ1 specifically in cardiomyocytes and mice lacking the unique C-terminal domain in CnAβ1 (CnAβ1Δi12 mice) were used. Pressure overload hypertrophy was induced by transaortic constriction. Cardiac function was measured by echocardiography. Mice were characterized using various molecular analyses. Results In contrast to other calcineurin isoforms, the authors show here that cardiac-specific overexpression of CnAβ1 in transgenic mice reduces cardiac hypertrophy and improves cardiac function. This effect is mediated by activation of serine and one-carbon metabolism, and the production of antioxidant mediators that prevent mitochondrial protein oxidation and preserve ATP production. The induction of enzymes involved in this metabolic pathway by CnAβ1 is dependent on mTOR activity. Inhibition of serine and one-carbon metabolism blocks the beneficial effects of CnAβ1. CnAβ1Δi12 mice show increased cardiac hypertrophy and declined contractility. Conclusions The metabolic reprogramming induced by CnAβ1 redefines the role of calcineurin in the heart and shows for the first time that activation of the serine and one-carbon pathway has beneficial effects on cardiac hypertrophy and function, paving the way for new therapeutic approaches
On an iteratively reweighted linesearch based algorithm for nonconvex composite optimization
In this paper we propose a new algorithm for solving a class of nonsmooth nonconvex problems, which is obtained by combining the iteratively reweighted scheme with a finite number of forward–backward iterations based on a linesearch procedure. The new method overcomes some limitations of linesearch forward–backward methods, since it can be applied also to minimize functions containing terms that are both nonsmooth and nonconvex. Moreover, the combined scheme can take advantage of acceleration techniques consisting in suitable selection rules for the algorithm parameters. We develop the convergence analysis of the new method within the framework of the Kurdyka– Lojasiewicz property. Finally, we present the results of a numerical experience on microscopy image super resolution, showing that the performances of our method are comparable or superior to those of other algorithms designed for this specific application
GloPID-R report on chikungunya, o\u27nyong-nyong and Mayaro virus, part 5: Entomological aspects
The GloPID-R (Global Research Collaboration for Infectious Disease Preparedness) chikungunya (CHIKV), o\u27nyong-nyong (ONNV) and Mayaro virus (MAYV) Working Group has been established to investigate natural history, epidemiology and clinical aspects of infection by these viruses. Here, we present a report dedicated to entomological aspects of CHIKV, ONNV and MAYV. Recent global expansion of chikungunya virus has been possible because CHIKV established a transmission cycle in urban settings using anthropophilic vectors such as Aedes albopictus and Aedes aegypti. MAYV and ONNV have a more limited geographic distribution, being confined to Africa (ONNV) and central-southern America (MAYV). ONNV is probably maintained through an enzootic cycle that has not been characterized yet, with Anopheles species as main vectors and humans as amplification hosts during epidemics. MAYV is transmitted by Haemagogus species in an enzootic cycle using non-human primates as the main amplification and maintenance hosts, and humans becoming sporadically infected when venturing in or nearby forest habitats. Here, we focused on the transmission cycle and natural vectors that sustain circulation of these viruses in their respective locations. The knowledge of the natural ecology of transmission and the capacity of different vectors to transmit these viruses is crucial to understand CHIKV emergence, and to assess the risk that MAYV and ONNV will expand on wide scale using anthropophilic mosquito species not normally considered primary vectors. Finally, the experts identified knowledge gaps and provided adapted recommendations, in order to address future entomological investigations in the right direction
Characterization of the Interaction between the Cohesin Subunits Rad21 and SA1/2
The cohesin complex is responsible for the fidelity of chromosomal segregation during mitosis. It consists of four core
subunits, namely Rad21/Mcd1/Scc1, Smc1, Smc3, and one of the yeast Scc3 orthologs SA1 or SA2. Sister chromatid cohesion
is generated during DNA replication and maintained until the onset of anaphase. Among the many proposed models of the
cohesin complex, the メcoreメ cohesin subunits Smc1, Smc3, and Rad21 are almost universally displayed as tripartite ring.
However, other than its supportive role in the cohesin ring, little is known about the fourth core subunit SA1/SA2. To gain
deeper insight into the function of SA1/SA2 in the cohesin complex, we have mapped the interactive regions of SA2 and
Rad21 in vitro and ex vivo. Whereas SA2 interacts with Rad21 through a broad region (301ヨ750 aa), Rad21 binds to SA
proteins through two SA-binding motifs on Rad21, namely N-terminal (NT) and middle part (MP) SA-binding motif, located
At 60-81 aa of the N-terminus and 383ヨ392 aa of the MP of Rad21, respectively. The MP SA-binding motif is a 10 amino acid,
a-helical motif. Deletion of these 10 amino acids or mutation of three conserved amino acids (L385, F389, and T390) in this ahelical
motif significantly hinders Rad21 from physically interacting with SA1/2. Besides the MP SA-binding motif, the NT SAbinding
motif is also important for SA1/2 interaction. Although mutations on both SA-binding motifs disrupt Rad21-SA1/2
interaction, they had no apparent effect on the Smc1-Smc3-Rad21 interaction. However, the Rad21-Rad21 dimerization was
reduced by the mutations, indicating potential involvement of the two SA-binding motifs in the formation of the two-ring
handcuff for chromosomal cohesion. Furthermore, mutant Rad21 proteins failed to significantly rescue precocious
chromosome separation caused by depletion of endogenous Rad21 in mitotic cells, further indicating the physiological
significance of the two SA-binding motifs of Rad21
Retinal and choroidal thickness measurements using spectral domain optical coherence tomography in anterior and intermediate uveitis.
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