Lineage dynamics in growing biofilms: Spatial patterns of standing vs. de novo diversity

Microbial biofilms show high phenotypic and genetic diversity, yet the mechanisms underlying diversity generation and maintenance remain unclear. Here, we investigate how spatial patterns of growth activity within a biofilm lead to spatial patterns of genetic diversity. Using individual-based computer simulations, we show that the active layer of growing cells at the biofilm interface controls the distribution of lineages within the biofilm, and therefore the patterns of standing and de novo diversity. Comparing biofilms of equal size, those with a thick active layer retain more standing diversity, while de novo diversity is more evenly distributed within the biofilm. In contrast, equal-sized biofilms with a thin active layer retain less standing diversity, and their de novo diversity is concentrated at the top of the biofilm, and in fewer lineages. In the context of antimicrobial resistance, biofilms with a thin active layer may be more prone to generate lineages with multiple resistance mutations, and to seed new resistant biofilms via sloughing of resistant cells from the upper layers. Our study reveals fundamental “baseline” mechanisms underlying the patterning of diversity within biofilms

Recombinant factorVIII Fc fusion protein for the prevention and treatment of bleeding in children with severe hemophilia A

This work was supported by funding from Biogen, including funding for the editorial and writing support in the the development of this paper

Kinetics of Surface Enrichment: A Molecular Dynamics Study

We use molecular dynamics (MD) to study the kinetics of surface enrichment (SE) in a stable homogeneous mixture (AB), placed in contact with a surface which preferentially attracts A. The SE profiles show a characteristic double-exponential behavior with two length scales: \xi_-, which rapidly saturates to its equilibrium value, and \xi_+, which diverges as a power-law with time (\xi_+ \sim t^\theta). We find that hydrodynamic effects result in a crossover of the growth exponent from \theta \simeq 0.5 to \theta \simeq 1.0. There is also a corresponding crossover in the growth dynamics of the SE-layer thickness.Comment: 20 pages, 6 figures, Published in J. Chem. Phys. (Research Highlights

Racial differences in neurocognitive outcomes post-stroke: The impact of healthcare variables

AbstractObjectives:The present study examined differences in neurocognitive outcomes among non-Hispanic Black and White stroke survivors using the NIH Toolbox-Cognition Battery (NIHTB-CB), and investigated the roles of healthcare variables in explaining racial differences in neurocognitive outcomes post-stroke.Methods:One-hundred seventy adults (91 Black; 79 White), who participated in a multisite study were included (age:M=56.4;SD=12.6; education:M=13.7;SD=2.5; 50% male; years post-stroke: 1–18; stroke type: 72% ischemic, 28% hemorrhagic). Neurocognitive function was assessed with the NIHTB-CB, using demographically corrected norms. Participants completed measures of socio-demographic characteristics, health literacy, and healthcare use and access. Stroke severity was assessed with the Modified Rankin Scale.Results:An independent samplesttest indicated Blacks showed more neurocognitive impairment (NIHTB-CB Fluid Composite T-score:M=37.63;SD=11.67) than Whites (Fluid T-score:M=42.59,SD=11.54;p=.006). This difference remained significant after adjusting for reading level (NIHTB-CB Oral Reading), and when stratified by stroke severity. Blacks also scored lower on health literacy, reported differences in insurance type, and reported decreased confidence in the doctors treating them. Multivariable models adjusting for reading level and injury severity showed that health literacy and insurance type were statistically significant predictors of the Fluid cognitive composite (p&lt;.001 andp=.02, respectively) and significantly mediated racial differences on neurocognitive impairment.Conclusions:We replicated prior work showing that Blacks are at increased risk for poorer neurocognitive outcomes post-stroke than Whites. Health literacy and insurance type might be important modifiable factors influencing these differences. (JINS, 2017,23, 640–652)</jats:p

Carbon Monoxide in type II supernovae

Infrared spectra of two type II supernovae 6 months after explosion are presented. The spectra exhibit a strong similarity to the observations of SN 1987A and other type II SNe at comparable epochs. The continuum can be fitted with a cool black body and the hydrogen lines have emissivities that are approximately those of a Case B recombination spectrum. The data extend far enough into the thermal region to detect emission by the first overtone of carbon monoxide. The molecular emission is modeled and compared with that in the spectra of SN 1987A. It is found that the flux in the CO first overtone is comparable to that found in SN 1987A. We argue that Carbon Monoxide forms in the ejecta of all type II SNe during the first year after explosion.Comment: 6 pages, 6 figures, accepted for publications in A&

High Voltage Apparatus for Nuclear Physics

The design and performance of a transformer-rectifier voltage quadrupling installation for potentials up to 600 KV will be described

Monitoring SO2 emission at the Soufriere Hills Volcano: implications for changes in erruptive conditions

FLWINinfo:eu-repo/semantics/publishe

Detection of Anisotropies in the Gravitational-Wave Stochastic Background

By correlating the signals from a pair of gravitational-wave detectors, one can undertake sensitive searches for a stochastic background of gravitational radiation. If the stochastic background is anisotropic, then this correlated signal varies harmonically with the earth's rotation. We calculate how the harmonics of this varying signal are related to the multipole moments which characterize the anisotropy, and give a formula for the signal-to-noise ratio of a given harmonic. The specific case of the two LIGO (Laser Interferometric Gravitational Observatory) detectors, which will begin operation around the year 2000, is analyzed in detail. We consider two possible examples of anisotropy. If the gravitational-wave stochastic background contains a dipole intensity anisotropy whose origin (like that of the Cosmic Background Radiation) is motion of our local system, then that anisotropy will be observable by the advanced LIGO detector (with 90% confidence in one year of observation) if \Omega_{gw} > 5.3 \times 10^{-8} h_{100}^{-2}. We also study the signal produced by stochastic sources distributed in the same way as the luminous matter in the galactic disk, and in the same way as the galactic halo. The anisotropy due to sources distributed as the galactic disk or as the galactic halo will be observable by the advanced LIGO detector (with 90% confidence in one year of observation) if \Omega_{gw} > 1.8 \times 10^{-10} h_{100}^{-2} or \Omega_{gw} > 6.7 \times 10^{-8} h_{100}^{-2}, respectively.Comment: 25 pages, Latex with RevTeX and epsfig, now includes S/N ratio calculations, expected response from anisotropy due to local motion & sources in galax

IMPACT OF SEX ON MACROVASCULAR ENDOTHELIAL FUNCTION DURING PROLONGED SITTING WITH A MILD HYPERCAPNIC ENVIRONEMNT

IMPACT OF SEX ON MACROVASCULAR ENDOTHELIAL FUNCTION DURING PROLONGED SITTING WITH A MILD HYPERCAPNIC ENVIORNMENT Andres Benitez-Albiter1, Michael F. Allen1, Elizabeth J. Pekas1, Cody P. Anderson1, and Song-Young Park1 1 - School of Health & Kinesiology University of Nebraska Omaha, Omaha, NE Introduction: Prolonged sitting (PS), defined as sitting for 2+ hours at a time[SYP1] , has been identified as an independent risk factor for cardiovascular disease. It has been well-documented that an acute PS bout can impair macro- and microvascular dysfunction in healthy young individuals. Recently, we reported that PS in mild hypercapnic environments (elevated CO2 concentrations equivalent to crowded areas such as offices or auditoriums) can further exacerbate these impairments in healthy young adults, and these impairments can be partially prevented by intermittent bouts of passive and active leg movements. Office workers are one of the largest sectors of the US workforce, and have been reported to be frequently exposed to PS with mild hypercapnic environments. Therefore, there is a need of study to examine if our previous findings can be seen in office workers. Additionally, it is crucial to investigate if there is any differential contribution of biological sex on these findings. The purpose of this study was to examine the impact of active and passive muscular contraction on macrovascular endothelial function during PS with mild-hypercapnic environment in middle-aged office workers, and further compare potential differences between sex. Methods: Healthy office workers (n=13, 6 males and 7 females, 39±4, 41±9, respectively) participated in three experimental visits and consisted of 2.5 h of prolonged sitting in a mild-hypercapnic environment (CO2 = 1500 ppm): control (CON, no movement), passive (PASS, passive limb movement), and active (ACT, active limb movement). Brachial artery and popliteal artery endothelial function were measured pre- and post-sitting for all visits using flow-mediated dilation (FMD). Results: Following 2.5 h of sitting, ACT showed greater popliteal artery FMD compared to CON. Additionally, females exhibited a significant reduction in popliteal artery FMD in the CON but was preserved in males after PS. No changes in Brachial artery FMD after PS, and no sex difference was found. Conclusion: PS significantly reduces leg vascular function in middle-aged office workers. Additionally, females showed greater reduction in leg vascular function compared to males. We conclude that uninterrupted prolonged sitting may induce a greater impairment on leg vascular function in females, indicating that this population may be at a greater risk compared to males. Additionally, intermittent bouts of active movement required to preserve leg vascular function during bouts of PS