718 research outputs found
Bubble transport by electro-magnetophoretic forces at anode bottom of aluminium cells
Electrically conducting and nonconducting particles and bubbles experience additional forcing in a liquid which carries electric current. These so called electro-magnetophoretic forces are well known in metallurgical applications, like metal purification in vacuum-arc remelting, electro-slag processes, impurity removal or
concentration change in special castings. However, the effect of electro-magnetophoretic forces has never been considered for aluminium cells where the gas bubbles evolving in the liquid electrolyte are surrounded by an electric current and significant magnetic fields. We present models to estimate the effect of electric current flow in the vicinity of the bubbles and the additional
pressure distribution resulting from the magnetic forces in the surrounding liquid electrolyte. According to the estimates, this force becomes important for bubbles exceeding 2 mm in size, and could be sufficient to overcome the typical drag force associated with electrolyte flow thereby opposing motion of the bubble along the base of the anode when it is inclined at a slight angle. The effect
could explain certain features of the anode effect onset.
Mathematical models and numerical results are presented and a further implementation in the general MHD code for the aluminium cell design is discussed
Probing the IGM/Galaxy Connection IV: The LCO/WFCCD Galaxy Survey of 20 Fields Surrounding UV Bright Quasars
We publish the survey for galaxies in 20 fields containing ultraviolet bright
quasars (with z_em 0.1 to 0.5) that can be used to study the association
between galaxies and absorption systems from the low-z intergalactic medium
(IGM). The survey is magnitude limited (R~19.5 mag) and highly complete out to
10' from the quasar in each field. It was designed to detect dwarf galaxies (L
~ 0.1 L*) at an impact parameter rho 1Mpc (z=0.1) from a quasar. The complete
sample (all 20 fields) includes R-band photometry for 84718 sources and
confirmed redshifts for 2800 sources. This includes 1198 galaxies with 0.005 <
z < (z_em - 0.01) at a median redshift of 0.18, which may associated with IGM
absorption lines. All of the imaging was acquired with cameras on the Swope 40"
telescope and the spectra were obtained via slitmask observations using the
WFCCD spectrograph on the Dupont 100" telescope at Las Campanas Observatory
(LCO). This paper describes the data reduction, imaging analysis, photometry,
and spectral analysis of the survey. We tabulate the principal measurements for
all sources in each field and provide the spectroscopic dataset online.Comment: Accepted to the Astrophysical Journal Supplements; 20 pages, only 6
figures shown in this version. See
http://www.ucolick.org/~xavier/WFCCDOVI/index.html for a full-length
manuscript and other supportive materia
Probing the IGM/Galaxy Connection V: On the Origin of Lya and OVI Absorption at z<0.2
We analyze the association of galaxies to Lya and OVI absorption, the most
commonly detected transitions in the low-z intergalactic medium (IGM), in the
fields of 14 quasars with z_em = 0.06-0.57. Confirming previous studies, we
observe a high covering fraction for Lya absorption to impact parameter rho =
300kpc: 33/37 of our L>0.01L* galaxies show Lya equivalent width W_Lya>50mA.
Galaxies of all luminosity L>0.01L* and spectral type are surrounded by a
diffuse and ionized circumgalactic medium (CGM), whose baryonic mass is
estimated at ~10^(10.5 +/- 0.3) Msun for a constant N_H. The virialized halos
and extended CGM of present-day galaxies are responsible for most strong Lya
absorbers (W_Lya > 300mA) but cannot reproduce the majority of observed lines
in the Lya forest. We conclude that the majority of Lya absorption with
W_Lya=30-300mA occurs in the cosmic web predicted by cosmological simulations
and estimate a characteristic width for these filaments of ~400kpc. Regarding
OVI, we observe a near unity covering fraction to rho=200kpc for L>0.1L*
galaxies and to rho = 300kpc for sub-L* (0.1 L*<L<L*) galaxies. Similar to our
Lya results, stronger OVI systems (W_OVI > 70mA) arise in the virialized halos
of L>0.1L* galaxies. Unlike Lya, the weaker OVI systems (W_OVI~30mA) arise in
the extended CGM of sub-L* galaxies. The majority of OVI gas observed in the
low-z IGM is associated with a diffuse medium surrounding individual galaxies
with L~0.3L*, and rarely originates in the so-called warm-hot IGM (WHIM)
predicted by cosmological simulations.Comment: Submitted to the Astrophysical Journal; 26 pages, 9 figures. See
http://www.ucolick.org/~xavier/WFCCDOVI/index.html for mor
Chlamydia trachomatis Infection in Minority Adolescent Women: A Public Health Challenge
Chlamydia trachomatis is the most common bacterial sexually-transmitted infection in the United States. This disease disproportionately affects adolescent minority women, and untreated infection can lead to lasting reproductive tract morbidity. Recommendations for primary prevention include patient counseling to decrease risky behavior and increase barrier protection use; secondary prevention recommendations include screening and treatment of affected individuals and their sexual partners, barrier contraception use, as well as counseling to decrease behaviors that lead to re-infection. Despite these strategies, both incidence and prevalence of Chlamydia have continued to escalate in this population. Interventions to decrease chlamydial infection should encompass all facets of primary and secondary prevention as well as address the fundamental barrier to prevention – lack of perception of risk in this young age group
Coccidioidomycosis seasonality in California: a longitudinal surveillance study of the climate determinants and spatiotemporal variability of seasonal dynamics, 2000–2021
BackgroundCoccidioidomycosis, an emerging fungal disease in the western USA, exhibits seasonal patterns that are poorly understood, including periods of strong cyclicity, aseasonal intervals, and variation in seasonal timing that have been minimally characterized, and unexplained as to their causal factors. Coccidioidomycosis incidence has increased markedly in recent years, and our limited understanding of intra- and inter-annual seasonality has hindered the identification of important drivers of disease transmission, including climate conditions. In this study, we aim to characterize coccidioidomycosis seasonality in endemic regions of California and to estimate the relationship between drought conditions and coccidioidomycosis seasonal periodicity and timing.MethodsWe analysed data on all reported incident cases of coccidioidomycosis in California from 2000 to 2021 to characterize seasonal patterns in incidence, and conducted wavelet analyses to assess the dominant periodicity, power, and timing of incidence for 17 counties with consistently high incidence rates. We assessed associations between seasonality parameters and measures of drought in California using a distributed lag nonlinear modelling framework.FindingsAll counties exhibited annual cyclicity in incidence (i.e., a dominant wavelet periodicity of 12 months), but there was considerable heterogeneity in seasonal strength and timing across regions and years. On average, 12-month periodicity was most pronounced in the Southern San Joaquin Valley and Central Coast. Further, the annual seasonal cycles in the Southern San Joaquin Valley and the Southern Inland regions occurred earlier than those in coastal and northern counties, yet the timing of annual cycles became more aligned among counties by the end of the study period. Drought conditions were associated with a strong attenuation of the annual seasonal cycle, and seasonal peaks became more pronounced in the 1-2 years after a drought ended.InterpretationWe conclude that drought conditions do not increase the risk of coccidioidomycosis onset uniformly across the year, but instead promote increased risk concentrated within a specific calendar period (September to December). The findings have important implications for public health preparedness, and for how future shifts in seasonal climate patterns and extreme events may impact spatial and temporal coccidioidomycosis risk.FundingNational Institutes of Health
Evidence for Cold Accretion: Primitive Gas Flowing onto a Galaxy at z~0.274
We present UV and optical observations from the Cosmic Origins Spectrograph
on the Hubble Space Telescope and Keck of a z= 0.27395 Lyman limit system (LLS)
seen in absorption against the QSO PG1630+377. We detect H I absorption with
log N(HI)=17.06\pm0.05 as well as Mg II, C III, Si III, and O VI in this
system. The column densities are readily explained if this is a multi-phase
system, with the intermediate and low ions arising in a very low metallicity
([Mg/ H] =-1.71 \pm 0.06) photoionized gas. We identify via Keck spectroscopy
and Large Binocular Telescope imaging a 0.3 L_* star-forming galaxy projected
37 kpc from the QSO at nearly identical redshift (z=0.27406, \Delta v = -26
\kms) with near solar metallicity ([O/ H]=-0.20 \pm 0.15). The presence of very
low metallicity gas in the proximity of a near-solar metallicity, sub-L_*
galaxy strongly suggests that the LLS probes gas infalling onto the galaxy. A
search of the literature reveals that such low metallicity LLSs are not
uncommon. We found that 50% (4/8) of the well-studied z < 1 LLSs have
metallicities similar to the present system and show sub-L_* galaxies with rho
< 100 kpc in those fields where redshifts have been surveyed. We argue that the
properties of these primitive LLSs and their host galaxies are consistent with
those of cold mode accretion streams seen in galaxy simulations.Comment: Accepted for publication in the Astrophysical Journa
The information needs of people living with ankylosing spondylitis: a questionnaire survey
<p>BACKGROUND:Today, health care is patient-centred with patients more involved in medical decision making and taking an active role in managing their disease. It is important that patients are appropriately informed about their condition and that their health care needs are met. We examine the information utilisation, sources and needs of people with ankylosing spondylitis (AS).</p>
<p>METHODS: Participants in an existing AS cohort study were asked to complete a postal or online questionnaire containing closed and open-ended questions, regarding their information access and needs. Participants were stratified by age and descriptive statistics were performed using STATA 11, while thematic analysis was performed on open-ended question narratives. Qualitative data was handled in Microsoft Access and explored for emerging themes and patterns of experiences.</p>
<p>RESULTS: Despite 73% of respondents having internet access, only 49% used the internet to access information regarding AS. Even then, this was only infrequently. Only 50% of respondents reported accessing written information about AS, which was obtained mainly in specialist clinics. Women were more likely than men to access information (63% (women) 46% (men)) regardless of the source, while younger patients were more likely to use online sources. The main source of non-written information was the rheumatologist. Overall, the respondents felt there was sufficient information available, but there was a perception that the tone was often too negative. The majority (95%) of people would like to receive a regular newsletter about AS, containing positive practical and local information. Suggestions were also made for more information about AS to be made available to non-specialist medical professionals and the general public.</p>
<p>CONCLUSIONS: There appears to be sufficient information available for people with AS in the UK and this is mostly accessed by younger AS patients. Many patients, particularly men, choose not to access AS information and concerns were raised about its negative tone. Patients still rely on written and verbal information from their specialists. Future initiatives should focus on the delivery of more positive information, targeting younger participants in particular and increasing the awareness in the general population and wider non-specialist medical community.</p>
Transcriptome response to heat stress in a chicken hepatocellular carcinoma cell line
Heat stress triggers an evolutionarily conserved set of responses in cells. The transcriptome responds to hyperthermia by altering expression of genes to adapt the cell or organism to survive the heat challenge. RNA-seq technology allows rapid identification of environmentally responsive genes on a large scale. In this study, we have used RNA-seq to identify heat stress responsive genes in the chicken male white leghorn hepatocellular (LMH) cell line. The transcripts of 812 genes were responsive to heat stress (p \u3c 0.01) with 235 genes upregulated and 577 downregulated following 2.5 h of heat stress. Among the upregulated were genes whose products function as chaperones, along with genes affecting collagen synthesis and deposition, transcription factors, chromatin remodelers, and genes modulating the WNT and TGF-beta pathways. Predominant among the downregulated genes were ones that affect DNA replication and repair along with chromosomal segregation. Many of the genes identified in this study have not been previously implicated in the heat stress response. These data extend our understanding of the transcriptome response to heat stress with many of the identified biological processes and pathways likely to function in adapting cells and organisms to hyperthermic stress. Furthermore, this study should provide important insight to future efforts attempting to improve species abilities to withstand heat stress through genome-wide association studies and breeding
Educating novice practitioners to detect elder financial abuse: A randomised controlled trial
© 2014 Harries et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.This article has been made available through the Brunel Open Access Publishing Fund.Background - Health and social care professionals are well positioned to identify and intervene in cases of elder financial abuse. An evidence-based educational intervention was developed to advance practitioners’ decision-making in this domain. The objective was to test the effectiveness of a decision-training educational intervention on novices’ ability to detect elder financial abuse. The research was funded by an E.S.R.C. grant reference RES-189-25-0334.
Methods - A parallel-group, randomised controlled trial was conducted using a judgement analysis approach. Each participant used the World Wide Web to judge case sets at pre-test and post-test. The intervention group was provided with training after pre-test testing, whereas the control group were purely given instructions to continue with the task. 154 pre-registration health and social care practitioners were randomly allocated to intervention (n78) or control (n76). The intervention comprised of written and graphical descriptions of an expert consensus standard explaining how case information should be used to identify elder financial abuse. Participants’ ratings of certainty of abuse occurring (detection) were correlated with the experts’ ratings of the same cases at both stages of testing.
Results - At pre-test, no differences were found between control and intervention on rating capacity. Comparison of mean scores for the control and intervention group at pre-test compared to immediate post-test, showed a statistically significant result. The intervention was shown to have had a positive moderate effect; at immediate post-test, the intervention group’s ratings had become more similar to those of the experts, whereas the control’s capacity did not improve. The results of this study indicate that the decision-training intervention had a positive effect on detection ability.
Conclusions - This freely available, web-based decision-training aid is an effective evidence-based educational resource. Health and social care professionals can use the resource to enhance their ability to detect elder financial abuse. It has been embedded in a web resource at http://www.elderfinancialabuse.co.uk.ESR
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