317 research outputs found
Continuous control of autoimmune disease by antigen-dependent polyclonal CD4+CD25+ regulatory T cells in the regional lymph node
This study investigated the unresolved issue of antigen-dependency and antigen-specificity of autoimmune disease suppression by CD4+CD25+ T cells (T regs). Based on autoimmune ovarian disease (AOD) in day 3 thymectomized (d3tx) mice and polyclonal T regs expressing the Thy1.1 marker, we determined: (a) the location of recipient T cell suppression, (b) the distribution of AOD-suppressing T regs, and (c) the relative efficacy of male versus female T regs. Expansion of recipient CD4+ T cells, activation/memory marker expression, and IFN-γ production were inhibited persistently in the ovary-draining LNs but not elsewhere. The cellular changes were reversed upon Thy1.1+ T reg depletion, with emergence of potent pathogenic T cells and severe AOD. Similar changes were detected in the regional LNs during autoimmune dacryoadenitis and autoimmune prostatitis suppression. Although the infused Thy1.1+ T regs proliferated and were disseminated in peripheral lymphoid organs, only those retrieved from ovary-draining LNs adoptively suppressed AOD at a suboptimal cell dose. By depriving d3tx recipients of ovarian antigens, we unmasked the supremacy of ovarian antigen-exposed female over male T regs in AOD suppression. Thus, disease suppression by polyclonal T regs depends on endogenous antigen stimulation; this occurs in a location where potent antigen-specific T regs accumulate and continuously negate pathogenic T cell response
A practical guide to pre-trial simulations for Bayesian adaptive trials using SAS and BUGS
It is often unclear what specific adaptive trial design features lead to an efficient design which is also feasible to implement. Before deciding on a particular design, it is generally advisable to carry out a simulation study to characterise the properties of candidate designs under a range of plausible assumptions. The implementation of such pre-trial simulation studies presents many challenges and requires considerable statistical programming effort and time. Despite the scale and complexity, there is little existing literature to guide the implementation of such projects using commonly available software. This Teacher's Corner article provides a practical step-by-step guide to implementing such simulation studies including how to specify and fit a Bayesian model in WinBUGS or OpenBUGS using SAS, and how results from the Bayesian analysis may be pulled back into SAS and used for adaptation of allocation probabilities before simulating subsequent stages of the trial. The interface between the two software platforms is described in detail along with useful tips and tricks. A key strength of our approach is that the entire exercise can be defined and controlled from within a single SAS program
From Exploration of Classism to Anticlassist Counseling: Implications for Counselors and Counselor Educators
Classism is a recently studied, but historically present, form of oppression. Despite much attention to inclusion of underrepresented clients in counseling literature, there has been little focus on the presence of classism in academic settings. In an effort to close this gap, a study of 202 individuals, aged 18 to 38, was conducted to explore the relationships among perceived classism, ethnicity, and socioeconomic status. Only 4.5% of the participants had never experienced any incidents of classism. African American individuals were more likely to experience interpersonal classism and working class/poor individuals were more likely to experience interpersonal and systemic classism. Recommendations for counselors, specifically, college counselors working with young adult students, facing classism are also discussed
A framework for targeting water, sanitation and hygiene interventions in pastoralist populations in the Afar region of Ethiopia
Globally, many populations face structural and environmental barriers to access safe water, sanitation and hygiene (WASH) services. Among these populations are many of the 200 million pastoralists whose livelihood patterns and extreme environmental settings challenge conventional WASH programming approaches. In this paper, we studied the Afar pastoralists in Ethiopia to identify WASH interventions that can mostly alleviate public health risks, within the population's structural and environmental living constraints. Surveys were carried out with 148 individuals and observational assessments made in 12 households as part of a Pastoralist Community WASH Risk Assessment. The results show that low levels of access to infrastructure are further compounded by risky behaviours related to water containment, storage and transportation. Additional behavioural risk factors were identified related to sanitation, hygiene and animal husbandry. The Pastoralist Community WASH Risk Assessment visually interprets the seriousness of the risks against the difficulty of addressing the problem. The assessment recommends interventions on household behaviours, environmental cleanliness, water storage, treatment and hand hygiene via small-scale educational interventions. The framework provides an approach for assessing risks in other marginal populations that are poorly understood and served through conventional approaches
Urologists’ and general practitioners’ knowledge, beliefs and practice relevant for opportunistic prostate cancer screening: a PRISMA-compliant systematic review
BackgroundRecent guidelines on opportunistic prostate cancer screening conclude that the decision to screen with prostate-specific antigen should be made by each patient individually together with the clinician. However, there is evidence of a lack of clinicians’ awareness of prostate cancer screening. This study sought to assess the recent evidence of clinicians’ knowledge, beliefs, and practice regarding opportunistic prostate cancer screening comparing urologists and generals practitioners.MethodsA systematic search was conducted in 3 online databases: MEDLINE, Web of Science and EMBASE (from January 1, 2015, to January 9th, 2023). Studies that explored clinicians’ knowledge, beliefs, and practices regarding opportunistic prostate cancer screening were included. Studies were assessed for quality reporting according to the Strengthening the Reporting of Observational studies in Epidemiology guidelines.ResultsA total of 14 studies met the inclusion criteria: ten studies included primary care health professionals, three studies included urologists, and one study included both. Studies involving general practitioners showed a generally low level of awareness of the recommended uses of the test, and urologists showed a greater knowledge of clinical practice guidelines. General practitioners’ opinion of prostate-specific antigen was generally unfavourable in contrast to urologists’ who were more likely to be proactive in ordering the test. Less than half of the included studies evaluated shared-decision making in practice and 50% of clinicians surveyed implemented it.ConclusionGeneral practitioners had less knowledge of prostate cancer risk factors and clinical practice guidelines in the use of PSA than urologists, which makes them less likely to follow available recommendations. A need to carry out education interventions with trusted resources based on the available evidence and the current guidelines was identified
Development and Validation of the Microbiology for Health Sciences Concept Inventory
Identifying misconceptions in student learning is a valuable practice for evaluating student learning gains and directing educational interventions. By accurately identifying students’ knowledge and misconceptions about microbiology concepts, instructors can design effective classroom practices centered on student understanding. Following the development of ASM’s Curriculum Guidelines in 2012, we developed a concept inventory, the Microbiology for Health Sciences Concept Inventory (MHSCI), that measures learning gains and identifies student misconceptions in health sciences microbiology classrooms. The 23-question MHSCI was delivered to a wide variety of students at multiple institution types. Psychometric analysis identified that the MHSCI instrument is both discriminatory and reliable in measuring student learning gains. The MHSCI results correlated with course outcomes, showing the value of using the instrument alongside course level assessments to measure student learning. The MHSCI is a reliable and efficient way to measure student learning in microbiology and can be used both as a faculty development tool and an effective student assessment tool
Ultraviolet Spectroscopy of Asteroid (4) Vesta
We report a comprehensive review of the UV-visible spectrum and rotational
lightcurve of Vesta combining new observations by Hubble Space Telescope and
Swift Gamma-ray Burst Observatory with archival International Ultraviolet
Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm are
derived by carefully comparing these observations from various instruments at
different times and observing geometries. Vesta has a rotationally averaged
geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673
nm, and 0.30 at 950 nm. The linear spectral slope as measured between 240 and
320 nm in the ultraviolet displays a sharp minimum near a sub-Earth longitude
of 20^{\circ}, and maximum in the eastern hemisphere. This is consistent with
the longitudinal distribution of the spectral slope in the visible wavelength.
The photometric uncertainty in the ultraviolet is ~20%, and in the visible
wavelengths it is better than 10%. The amplitude of Vesta's rotational
lightcurves is ~10% throughout the range of wavelengths we observed, but is
smaller at 950 nm (~6%) near the 1-\mum band center. Contrary to earlier
reports, we found no evidence for any difference between the phasing of the
ultraviolet and visible/near-infrared lightcurves with respect to sub-Earth
longitude. Vesta's average spectrum between 220 and 950 nm can well be
described by measured reflectance spectra of fine particle howardite-like
materials of basaltic achondrite meteorites. Combining this with the in-phase
behavior of the ultraviolet, visible, and near-infrared lightcurves, and the
spectral slopes with respect to the rotational phase, we conclude that there is
no global ultraviolet/visible reversal on Vesta. Consequently, this implies a
lack of global space weathering on Vesta, as previously inferred from
visible-near-infrared data.Comment: 44 pages, 5 figures, 1 tabl
Non-thermal emission processes in massive binaries
In this paper, I present a general discussion of several astrophysical
processes likely to play a role in the production of non-thermal emission in
massive stars, with emphasis on massive binaries. Even though the discussion
will start in the radio domain where the non-thermal emission was first
detected, the census of physical processes involved in the non-thermal emission
from massive stars shows that many spectral domains are concerned, from the
radio to the very high energies.
First, the theoretical aspects of the non-thermal emission from early-type
stars will be addressed. The main topics that will be discussed are
respectively the physics of individual stellar winds and their interaction in
binary systems, the acceleration of relativistic electrons, the magnetic field
of massive stars, and finally the non-thermal emission processes relevant to
the case of massive stars. Second, this general qualitative discussion will be
followed by a more quantitative one, devoted to the most probable scenario
where non-thermal radio emitters are massive binaries. I will show how several
stellar, wind and orbital parameters can be combined in order to make some
semi-quantitative predictions on the high-energy counterpart to the non-thermal
emission detected in the radio domain.
These theoretical considerations will be followed by a census of results
obtained so far, and related to this topic... (see paper for full abstract)Comment: 47 pages, 5 postscript figures, accepted for publication in Astronomy
and Astrophysics Review. Astronomy and Astrophysics Review, in pres
- …