258 research outputs found
Ecotoxicological assessment of juvenile northern pike inhabiting lakes downstream of a uranium mill
Previous studies on fishes exposed to effluent from the Key Lake uranium mill in northern Saskatchewan have demonstrated elevated lipids in young-of-the-year pike (Esox lucius), deformities in larval pike and decreased survival of fathead minnows (Pimephales promelas). The objectives of this thesis were to evaluate possible factors that could be contributing to altered bioenergetics of juvenile northern pike inhabiting lakes receiving effluent from the Key Lake operation and to examine the effects of effluent exposure on biomarkers of oxidative stress and histopathology of target organs. Although glycogen and triglycerides stores were significantly greater in pike from exposure lakes compared to the reference, triglycerides stores of juvenile pike prey items showed no overall differences among lakes. Measures of parasitism, however, were negatively correlated with pike bioenergetics thereby reflecting a possible energetic cost of parasitism on reference lake fish. The degree of infection by intestinal parasites and gill monogeneans was greatest in reference pike and intermediate in low exposure pike, whereas high exposure pike harboured no parasites. Arsenic, nickel and selenium are elevated in lakes downstream of the Key Lake mill and have been shown to be associated with increased reactive oxygen species (ROS) in biological systems causing oxidative stress. The potential for oxidative stress was assessed in pike liver and kidney using several biomarkers. Overall, the concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione did not differ significantly among exposure and reference pike. The activity of glutathione peroxidase was greater in high exposure than reference liver whereas, contrary to predictions, lipid peroxidation was greater in reference than exposure pike tissues. Histopathological evaluations revealed greater kidney and gill pathology in reference lake pike, whereas for liver, hepatocyte morphology differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, uranium) were significantly elevated in exposure pike. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that metals are bioaccumulating in tissue.
Overall, the results from this thesis suggest that the health and condition of juvenile northern pike living downstream of the Key Lake uranium mill may not be compromised by effluent exposure
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Rejection, acceptance and the spectrum between: understanding male attitudes and experiences towards conflict-related sexual violence in eastern Democratic Republic of Congo
Background: Female survivors of sexual violence in conflict experience not only physical and psychological sequelae from the event itself, but often many negative social outcomes, such as rejection and ostracisation from their families and community. Male relatives â whether husbands, fathers, brothers â play a key role in determining how the family and community respond to a survivor of sexual violence. Understanding these perspectives could help improve services for survivors of sexual violence, as well as their families and communities. Methods: This study draws on qualitative data gathered from focus groups of 68 men in the eastern region of Democratic Republic of Congo. Men were asked about their experiences as relatives of women who had experienced sexual violence. Results: Two dominant themes arose throughout the focus groups: factors driving rejection and pathways to acceptance. Factors driving rejection included: fear of sexually transmitted infections, social stigma directed toward the husbands themselves, and an understanding of marriage and fidelity that is incompatible with rape. Men also touched on their own trauma, including struggling with witnessing a rape that took place in public, or caring for a survivor with a child from rape. They noted that the economic burden of medical treatment for survivors was a salient factor in the decision to reject. Pathways to acceptance included factors such as the love of their spouse or relative, survivorsâ potential to give continued financial contribution to the family, the need to keep the family together to care for children in the home, and pressure from people of importance in the community. Conclusion: This study provides unique insight into how male relatives respond to close family members who have experienced sexual violence. This is particularly critical since the reaction of a male relative after rape can be the most pivotal factor in promoting or impeding recovery for a survivor. These results emphasise the importance of services that focus not only on the survivor of violence herself, but also on key family members that can ideally help support her recovery. Electronic supplementary material The online version of this article (10.1186/s12905-017-0479-7) contains supplementary material, which is available to authorized users
An Intervention for Sensory Difficulties in Children with Autism: A Randomized Trial.
This study evaluated a manualized intervention for sensory difficulties for children with autism, ages 4-8 years, using a randomized trial design. Diagnosis of autism was confirmed using gold standard measures. Results show that the children in the treatment group (n = 17) who received 30 sessions of the occupational therapy intervention scored significantly higher (p = 0.003, d = 1.2) on Goal Attainment Scales (primary outcome), and also scored significantly better on measures of caregiver assistance in self-care (p = 0.008 d = 0.9) and socialization (p = 0.04, d = 0.7) than the Usual Care control group (n = 15). The study shows high rigor in its measurement of treatment fidelity and use of a manualized protocol, and provides support for the use of this intervention for children with autism. Findings are discussed in terms of their implications for practice and future research
Periodontal pathogens are a risk factor of oral cavity squamous cell carcinoma, independent of tobacco and alcohol and human papillomavirus
Over the past decade, there has been a change in the epidemiology of oral cavity squamous cell cancer (OC-SCC). Many new cases of OC-SCC lack the recognized risk factors of smoking, alcohol and human papilloma virus. The aim of this study was to determine if the oral microbiome may be associated with OC-SCC in nonsmoking HPV negative patients. We compared the oral microbiome of HPV-negative nonsmoker OC-SCC(n = 18), premalignant lesions(PML) (n = 8) and normal control patients (n = 12). Their oral microbiome was sampled by oral wash and defined by 16S rRNA gene sequencing. We report that the periodontal pathogens Fusobacterium, Prevotella, Alloprevotella were enriched while commensal Streptococcus depleted in OC-SCC. Based on the four genera plus a marker genus Veillonella for PML, we classified the oral microbiome into two types. Gene/pathway analysis revealed a progressive increase of genes encoding HSP90 and ligands for TLRs 1, 2 and 4 along the controlsâPML â OC-SCC progression sequence. Our findings suggest an association between periodontal pathogens and OC-SCC in non smoking HPV negative patients
Reconstructing Tuberculosis Services after Major Conflict: Experiences and Lessons Learned in East Timor
BACKGROUND: Tuberculosis (TB) is a major public health problem in developing countries. Following the disruption to health services in East Timor due to violent political conflict in 1999, the National Tuberculosis Control Program was established, with a local non-government organisation as the lead agency. Within a few months, the TB program was operational in all districts. METHODS AND FINDINGS: Using the East Timor TB program as a case study, we have examined the enabling factors for the implementation of this type of communicable disease control program in a post-conflict setting. Stakeholder analysis was undertaken, and semi-structured interviews were conducted in 2003 with 24 key local and international stakeholders. Coordination, cooperation, and collaboration were identified as major contributors to the success of the TB program. The existing local structure and experience of the local non-government organisation, the commitment among local personnel and international advisors to establishing an effective program, and the willingness of international advisers and local counterparts to be flexible in their approach were also important factors. This success was achieved despite major impediments, including mass population displacement, lack of infrastructure, and the competing interests of organisations working in the health sector. CONCLUSIONS: Five years after the conflict, the TB program continues to operate in all districts with high notification rates, although the lack of a feeling of ownership by government health workers remains a challenge. Lessons learned in East Timor may be applicable to other post-conflict settings where TB is highly prevalent, and may have relevance to other disease control programs
Spitzer observations of a 24 micron shadow: Bok Globule CB190
We present Spitzer observations of the dark globule CB190 (L771). We observe
a roughly circular 24 micron shadow with a 70 arcsec radius. The extinction
profile of this shadow matches the profile derived from 2MASS photometry at the
outer edges of the globule and reaches a maximum of ~32 visual magnitudes at
the center. The corresponding mass of CB190 is ~10 Msun. Our 12CO and 13CO J =
2-1 data over a 10 arcmin X 10 arcmin region centered on the shadow show a
temperature ~10 K. The thermal continuum indicates a similar temperature for
the dust. The molecular data also show evidence of freezeout onto dust grains.
We estimate a distance to CB190 of 400 pc using the spectroscopic parallax of a
star associated with the globule. Bonnor-Ebert fits to the density profile, in
conjunction with this distance, yield xi_max = 7.2, indicating that CB190 may
be unstable. The high temperature (56 K) of the best fit Bonnor-Ebert model is
in contradiction with the CO and thermal continuum data, leading to the
conclusion that the thermal pressure is not enough to prevent free-fall
collapse. We also find that the turbulence in the cloud is inadequate to
support it. However, the cloud may be supported by the magnetic field, if this
field is at the average level for dark globules. Since the magnetic field will
eventually leak out through ambipolar diffusion, it is likely that CB190 is
collapsing or in a late pre-collapse stage.Comment: 16 pages, 13 figures, accepted for publication in Ap
A Hand-Powered, Portable, Low-Cost Centrifuge for Diagnosing Anemia in Low-Resource Settings
This report describes the development of a hand-powered centrifuge to determine hematocrit values in low-resource settings. A hand-powered centrifuge was constructed by using a salad spinner. Hematocrit values were measured by using the hand-powered device, and results were compared with those of a benchtop centrifuge. The packed cell volume (PCV) measured with the hand-powered device correlated linearly with results obtained with a benchtop centrifuge (r = 0.986, P < 0.001). The PCVs measured with the hand-powered centrifuge were consistently 1.14 times higher than those measured with the benchtop system. The 14% increase in PCV measured with the hand-powered centrifuge is caused by increased plasma trapped in the cell column. The reader card was adjusted to compensate for trapped plasma. A hand-powered centrifuge and calibrated reader card can be constructed for U.S. $35 and can accurately determine hematocrit values. It is suitable for use in low-resource settings because it is mechanically-powered, inexpensive, and accurate
COVID-19 and mental health in 8 low- and middle-income countries: a prospective cohort study
Background
The Coronavirus Disease 2019 (COVID-19) pandemic and associated mitigation policies created a global economic and health crisis of unprecedented depth and scale, raising the estimated prevalence of depression by more than a quarter in high-income countries. Low- and middle-income countries (LMICs) suffered the negative effects on living standards the most severely. However, the consequences of the pandemic for mental health in LMICs have received less attention. Therefore, this study assesses the association between the COVID-19 crisis and mental health in 8 LMICs.
Methods and findings
We conducted a prospective cohort study to examine the correlation between the COVID-19 pandemic and mental health in 10 populations from 8 LMICs in Asia, Africa, and South America. The analysis included 21,162 individuals (mean age 38.01 years, 64% female) who were interviewed at least once pre- as well as post-pandemic. The total number of survey waves ranged from 2 to 17 (mean 7.1). Our individual-level primary outcome measure was based on validated screening tools for depression and a weighted index of depression questions, dependent on the sample. Sample-specific estimates and 95% confidence intervals (CIs) for the association between COVID-19 periods and mental health were estimated using linear regressions with individual fixed effects, controlling for independent time trends and seasonal variation in mental health where possible. In addition, a regression discontinuity design was used for the samples with multiple surveys conducted just before and after the onset of the pandemic. We aggregated sample-specific coefficients using a random-effects model, distinguishing between estimates for the short (0 to 4 months) and longer term (4+ months). The random-effects aggregation showed that depression symptoms are associated with a increase by 0.29 standard deviations (SDs) (95% CI [â.47, â.11], p-value = 0.002) in the 4 months following the onset of the pandemic. This change was equivalent to moving from the 50th to the 63rd percentile in our median sample. Although aggregate depression is correlated with a decline to 0.21 SD (95% CI [â0.07, â.34], p-value = 0.003) in the period thereafter, the average recovery of 0.07 SD (95% CI [â0.09, .22], p-value = 0.41) was not statistically significant. The observed trends were consistent across countries and robust to alternative specifications. Two limitations of our study are that not all samples are representative of the national population, and the mental health measures differ across samples.
Conclusions
Controlling for seasonality, we documented a large, significant, negative association of the pandemic on mental health, especially during the early months of lockdown. The magnitude is comparable (but opposite) to the effects of cash transfers and multifaceted antipoverty programs on mental health in LMICs. Absent policy interventions, the pandemic could be associated with a lasting legacy of depression, particularly in settings with limited mental health support services, such as in many LMICs. We also demonstrated that mental health fluctuates with agricultural crop cycles, deteriorating during âleanâ, pre-harvest periods and recovering thereafter. Ignoring such seasonal variations in mental health may lead to unreliable inferences about the association between the pandemic and mental health
Color-color Relations for Red Giants in Star Clusters
New Johnson-Cousins UBVRI photometry of giants in globular clusters is
combined with JHK photometry on the CIT system to produce color sequences for
giants from the globular clusters M3, M5, M13, and M92. UBVRI data are also
presented for giants in the metal-rich open cluster NGC 6791. These data fill a
gap in the literature, especially for the R & I bands. We provide the empirical
relations between broad band colors for various [Fe/H] values for metal-poor
giants. The color sequences for U-B and B-V show clear separations for
different [Fe/H] values. We also find weak, though unexpected, metallicity
dependences of V-R, V-I, and J-K colors. H-K is metal-insensitive. The above
colors are plotted as a function of V-K, and a literature (V-K) - T_{eff}
relation is given.Comment: 21 pages, 7 figures; AASTeX 4.0; to appear in the July 1998 edition
of PASP. Revised version; includes discussion on possible effects of
reddening error
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