2,358 research outputs found
Rotamer-Restricted Fluorogenicity Of The Bis-Arsenical ReAsH
Fluorogenic dyes such as FlAsH and ReAsH are used widely to localize, monitor, and characterize proteins and their assemblies in live cells. These bis-arsenical dyes can become fluorescent when bound to a protein containing four proximal Cys thiols—a tetracysteine (Cys4) motif. Yet the mechanism by which bis-arsenicals become fluorescent upon binding a Cys4 motif is unknown, and this nescience limits more widespread application of this tool. Here we probe the origins of ReAsH fluorogenicity using both computation and experiment. Our results support a model in which ReAsH fluorescence depends on the relative orientation of the aryl chromophore and the appended arsenic chelate: the fluorescence is rotamer-restricted. Our results do not support a model in which fluorogenicity arises from the relief of ring strain. The calculations identify those As–aryl rotamers that support fluorescence and those that do not and correlate well with prior experiments. The rotamer-restricted model we propose is supported further by biophysical studies: the excited-state fluorescence lifetime of a complex between ReAsH and a protein bearing a high-affinity Cys4 motif is longer than that of ReAsH-EDT2, and the fluorescence intensity of ReAsH-EDT2 increases in solvents of increasing viscosity. By providing a higher resolution view of the structural basis for fluorogenicity, these results provide a clear strategy for the design of more selective bis-arsenicals and better-optimized protein targets, with a concomitant improvement in the ability to characterize previously invisible protein conformational changes and assemblies in live cells
Effect of time at temperature on wild poliovirus titers in stool specimens
AbstractBackgroundThe effect of transport temperature on the viability of poliovirus in stool specimens from paralyzed cases has not been tested. Quality assurance of programmatic indicators will be necessary in the final phase of polio eradication.ObjectiveTo estimate the effect of time at elevated temperatures on wild poliovirus titers in stool specimens.MethodsWe exposed aliquots of pooled wild poliovirus type 1 specimens to elevated temperatures (27°C, 31°C, and 35°C) for varying time periods up to 14 days. We determined the virus titer of these aliquots and created decay curves at each temperature to estimate the relationship between time at temperature and virus titer.ResultsWe found significantly different slopes of decay at each temperature. The negative slopes increased as the temperature increased.ConclusionsWhile poliovirus in stool remains relatively stable at moderately elevated temperature, transport at higher temperatures could impact sample integrity and virus isolation results
Female Adolescent Athletes’ Experiences of Body Dissatisfaction Across Individual and Team Sports
There is an abundance of research explaining the physical and psychological benefits of sport and exercise. Some research suggests sport and exercise may act as a protective factor against body dissatisfaction for adolescent females (Fernández-Bustos et al., 2019; Soulliard et al. 2019). However, it is unclear if adolescent females’ experiences in specific sport settings contribute to perceptions about their bodies. Therefore, this study investigated body perception and its sociocultural influences in adolescent females in team sports versus adolescent females in individual sports. Three focus groups of team sport athletes and two focus groups of individual sport athletes, ages 14-16 years, were conducted. The following four core themes were identified around influences and messaging in sport related to the athletes’ bodies: relationships among teammates and coaches, self-concept, functionality, and social influence. Based on these themes, the findings indicate adolescent female athletes may view sport as a helpful tool to reduce or counteract body dissatisfaction, particularly in team sport athletes. However, sport may not entirely reduce the negative impact from normative and potentially harmful messages surrounding body weight and image, both of which are pervasive in society, the media, and relationships with influential individuals, such as friends, family, and coaches
Nurses\u27 Alumnae Association Bulletin - Volume 6 Number 9
Remember the Relief Fund
Welcome! Miss Childs
Financial Report
Calendar of Coming Events
Lest You Forget!
Attention
Review of the Alumnae Association Meetings
Institutional Staff Nurses\u27 Section
Report of Staff Activities - 1947-1948
Private Duty Section
The White Haven Division
Barton Memorial Division
Remember the Relief Fund
Student Nurses\u27 Activities
Jefferson Scores Again
The Clara Melville Scholarship Fund
Interesting Activities of the Nurses\u27 Home Committee of the Women\u27s Board
Exclusive for Nurses
Changes in the Maternity Division
Gray Lady Musical Therapy Service
Memorial Service Honoring Mrs. Bessie Dobson Altemus
The Blood Donor Center
The Hospital Pharmacy
Medical College News
Remember the Relief Fund
Administrative Staff and Faculty of the School of Nursing
Streptomycin
Changes in the Staff at Jefferson Hospital
Care of the Thoracic Surgical Patient
Miscellaneous Items
Marriages
New Arrivals
Deaths
The Bulletin Committee
Attention, Alumnae
New Addresse
The laurentian record of neoproterozoic glaciation, tectonism, and eukaryotic evolution in Death Vally, California
Neoproterozoic strata in Death Valley, California contain eukaryotic microfossils and glacial deposits that have been used to assess the severity of putative Snowball Earth events and the biological response to extreme environmental change. These successions also contain evidence for syn-sedimentary faulting that has been related to the rifting of Rodinia, and in turn the tectonic context of the onset of Snowball Earth. These interpretations hinge on local geological relationships and both regional and global stratigraphic correlations. Here we present new geological mapping, measured stratigraphic sections, carbon and strontium isotope chemostratigraphy, and micropaleontology from the Neoproterozoic glacial deposits and bounding strata in Death Valley. These new data enable us to refine regional correlations both across Death Valley and throughout Laurentia, and construct a new age model for glaciogenic strata and microfossil assemblages. Particularly, our remapping of the Kingston Peak Formation in the Saddle Peak Hills and near the type locality shows for the first time that glacial deposits of both the Marinoan and Sturtian glaciations can be distinguished in southeastern Death Valley, and that beds containing vase-shaped microfossils are slump blocks derived from the underlying strata. These slump blocks are associated with multiple overlapping unconformities that developed during syn-sedimentary faulting, which is a common feature of Cyrogenian strata along the margin of Laurentia from California to Alaska. With these data, we conclude that all of the microfossils that have been described to date in Neoproterozoic strata of Death Valley predate the glaciations and do not bear on the severity, extent or duration of Neoproterozoic Snowball Earth events
Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up
Objective:
Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD.
Design:
Cross-sectional surveys linked to hospital admissions and death records.
Subjects:
19 329 adults (aged 18–86 years) from a representative sample of the Scottish population.
Measurements:
Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption.
Results:
For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38).
Conclusions:
In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences
Update on neutrino mixing in the early Universe
From the current cosmological observations of CMB and nuclear abundances we
show, with an analytic procedure, that the total effective number of extra
neutrino species . We also describe the possible
signatures of non standard effects that could be revealed in future CMB
observations. This cosmological information is then applied to neutrino mixing
models. Taking into account the recent results from the SNO and SuperKamiokande
experiments, disfavouring pure active to sterile neutrino oscillations, we show
that all 4 neutrino mixing models, both of 2+2 and 3+1 type, lead to a full
thermalization of the sterile neutrino flavor. Moreover such a sterile neutrino
production excludes the possibility of an electron neutrino asymmetry
generation and we conclude that , in
disagreement with the cosmological bound. This result is valid under the
assumption that the initial neutrino asymmetries are small. We suggest the
existence of a second sterile neutrino flavor, with mixing properties such to
generate a large electron neutrino asymmetry, as a possible way out.Comment: 29 pages, 3 figures; to appear on Phys.Rev.D; added discussion (at
page 19) and references; typos correcte
Parameterization Effects in the analysis of AMI Sunyaev-Zel'dovich Observations
Most Sunyaev--Zel'dovich (SZ) and X-ray analyses of galaxy clusters try to
constrain the cluster total mass and/or gas mass using parameterised models and
assumptions of spherical symmetry and hydrostatic equilibrium. By numerically
exploring the probability distributions of the cluster parameters given the
simulated interferometric SZ data in the context of Bayesian methods, and
assuming a beta-model for the electron number density we investigate the
capability of this model and analysis to return the simulated cluster input
quantities via three rameterisations. In parameterisation I we assume that the
T is an input parameter. We find that parameterisation I can hardly constrain
the cluster parameters. We then investigate parameterisations II and III in
which fg(r200) replaces temperature as a main variable. In parameterisation II
we relate M_T(r200) and T assuming hydrostatic equilibrium. We find that
parameterisation II can constrain the cluster physical parameters but the
temperature estimate is biased low. In parameterisation III, the virial theorem
replaces the hydrostatic equilibrium assumption. We find that parameterisation
III results in unbiased estimates of the cluster properties. We generate a
second simulated cluster using a generalised NFW (GNFW) pressure profile and
analyse it with an entropy based model to take into account the temperature
gradient in our analysis and improve the cluster gas density distribution. This
model also constrains the cluster physical parameters and the results show a
radial decline in the gas temperature as expected. The mean cluster total mass
estimates are also within 1 sigma from the simulated cluster true values.
However, we find that for at least interferometric SZ analysis in practice at
the present time, there is no differences in the AMI visibilities between the
two models. This may of course change as the instruments improve.Comment: 19 pages, 13 tables, 24 figure
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