191 research outputs found
Kinematical and chemical vertical structure of the Galactic thick disk II. A lack of dark matter in the solar neighborhood
We estimated the dynamical surface mass density Sigma at the solar position
between Z=1.5 and 4 kpc from the Galactic plane, as inferred from the
kinematics of thick disk stars. The formulation is exact within the limit of
validity of a few basic assumptions. The resulting trend of Sigma(Z) matches
the expectations of visible mass alone, and no dark component is required to
account for the observations. We extrapolate a dark matter (DM) density in the
solar neighborhood of 0+-1 mM_sun pc^-3, and all the current models of a
spherical DM halo are excluded at a confidence level higher than 4sigma. A
detailed analysis reveals that a small amount of DM is allowed in the volume
under study by the change of some input parameter or hypothesis, but not enough
to match the expectations of the models, except under an exotic combination of
non-standard assumptions. Identical results are obtained when repeating the
calculation with kinematical measurements available in the literature. We
demonstrate that a DM halo would be detected by our method, and therefore the
results have no straightforward interpretation. Only the presence of a highly
prolate (flattening q>2) DM halo can be reconciled with the observations, but
this is highly unlikely in LambdaCDM models. The results challenge the current
understanding of the spatial distribution and nature of the Galactic DM. In
particular, our results may indicate that any direct DM detection experiment is
doomed to fail, if the local density of the target particles is negligible.Comment: Accepted for publication in the Astrophysical Journa
Survival and health status of DOTS tuberculosis patients in rural Lao PDR
<p>Abstract</p> <p>Background</p> <p>Contact tracing of tuberculosis (TB) patients is rarely performed in low-income countries. Our objective was to assess the outcome of and compliance with directly observed treatment (DOTS) of TB patients over a 3 year period in rural Lao PDR.</p> <p>Methods</p> <p>We performed a retrospective cohort study in which we enrolled TB patients who started DOTS treatment at Attapeu Provincial Hospital. We traced, through hospital records, all patients in their residential village. We conducted a standardized questionnaire with all TB patients and performed physical and anthropometric examinations as well as evaluations of compliance through counting of treatment pills at home and at the health facilities.</p> <p>Results</p> <p>Of 172 enrolled TB patients (sex ratio female/male: 0.52, mean age: 46.9 years ± 16.9), 26 (15.1%) died. These had a lower weight at the start (34.6 <it>vs</it>. 40.8 kg, p < 0.001) and were less compliant (91.6% <it>vs</it>. 19.2%, p < 0.001) than survivors. Low compliance was associated with poor accessibility to health care (p = 0.01) and symptomatic improvement (p = 0.02). Survivors had persistently poor health status. They were underweight (54.7%), and still had clinical symptoms (53.5%), including dyspnoea (28.8%) and haemoptysis (9.5%).</p> <p>Conclusion</p> <p>Our study suggests a lower rate of survival than expected from official statistics. Additionally, it showed that follow-up of TB patients is feasible although the patients lived in very remote area of Laos. Follow-up should be strengthened as it can improve patient compliance, and allow contact tracing, detection of new cases and collection of accurate treatment outcome information.</p
Risk of latent tuberculosis infection in children living in households with tuberculosis patients: a cross sectional survey in remote northern Lao People's Democratic Republic
ABSTRACT: BACKGROUND: Tuberculosis is highly prevalent in Laos (289 per 100,000). We evaluated the risk of latent tuberculosis infection (LTBI) among children (0-15 years) living with tuberculosis patients in rural northern Laos. METHODS: In a cross sectional survey of 30 randomly selected villages, 72 tuberculosis patients were traced and their 317 contacts (148 were children) investigated using a questionnaire, a tuberculin skin tests (positive: <= 10mm), a 3-day sputum examination for acid-fast bacilli (AFB), and chest radiography. RESULTS: None of the 148 contact-children received prophylaxis, one had cervical tuberculosis; the risk for LTBI was 31.0%. Awareness of the infectiousness of tuberculosis was low among patients (31%) and their contacts (31%), and risky behavior was common. After multivariate logistic analysis, increased LTBI was found in children with contact with sputum positive adults (OR: 3.3, 95% CI: 1.4-7.7), patients highly positive sputum prior to treatment (AFB <2+; OR: 4.7, 95% CI: 1.7-12.3), and living in ethnic minorities (OR: 5.4, 95% CI: 2.2-13.6). CONCLUSION: The study supports the importance of contact tracing in remote settings with high TB prevalence. Suggestions to improve the children's detection rate, the use of existing guidelines, chemoprophylaxis of contact-children and the available interventions in Laos are discussed. Improving education and awareness of the infectiousness of TB in patients is urgently needed to reduce TB transmissio
The availability of novelty sweets within the high school fringe
Background Reducing sugar consumption is a primary focus of current global public health policy. Achieving 5% of total energy from free sugars will be difficult acknowledging the concentration of free sugars in sugar sweetened beverages, confectionery and as hidden sugars in many savoury items. The expansion of the novelty sweet market in the UK has significant implications for children and young adults as they contribute to dental caries, dental erosion and obesity.
Objective To identify the most available types of novelty sweets within the high school fringe in Cardiff, UK and to assess their price range and where and how they were displayed in shops.
Subjects and methods Shops within a ten minute walking distance around five purposively selected high schools in the Cardiff aea representing different levels of deprivation were visited. Shops in Cardiff city centre and three supermarkets were also visited to identify the most commonly available novelty sweets.
Results The ten most popular novelty sweets identified in these scoping visits were (in descending order): Brain Licker, Push Pop, Juicy Drop, Lickedy Lips, Big Baby Pop, Vimto candy spray, Toxic Waste, Tango candy spray, Brain Blasterz Bitz and Mega Mouth candy spray. Novelty sweets were located on low shelves which were accessible to all age-groups in 73% (14 out of 19) of the shops. Novelty sweets were displayed in the checkout area in 37% (seven out of 19) shops. The price of the top ten novelty sweets ranged from 39p to £1.
Conclusion A wide range of acidic and sugary novelty sweets were easily accessible and priced within pocket money range. Those personnel involved in delivering dental and wider health education or health promotion need to be aware of recent developments in children's confectionery. The potential effects of these novelty sweets on both general and dental health require further investigation
COPA syndrome in an Icelandic family caused by a recurrent missense mutation in COPA
Background: Rare missense mutations in the gene encoding coatomer subunit alpha (COPA) have recently been
shown to cause autoimmune interstitial lung, joint and kidney disease, also known as COPA syndrome, under a
dominant mode of inheritance.
Case presentation: Here we describe an Icelandic family with three affected individuals over two generations with
a rare clinical presentation of lung and joint disease and a histological diagnosis of follicular bronchiolitis. We performed
whole-genome sequencing (WGS) of the three affected as well as three unaffected members of the family, and searched
for rare genotypes associated with disease using 30,067 sequenced Icelanders as a reference population. We assessed all
coding and splicing variants, prioritizing variants in genes known to cause interstitial lung disease. We detected a
heterozygous missense mutation, p.Glu241Lys, in the COPA gene, private to the affected family members. The
mutation occurred de novo in the paternal germline of the index case and was absent from 30,067 Icelandic
genomes and 141,353 individuals from the genome Aggregation Database (gnomAD). The mutation occurs
within the conserved and functionally important WD40 domain of the COPA protein.
Conclusions: This is the second report of the p.Glu241Lys mutation in COPA, indicating the recurrent nature of the
mutation. The mutation was reported to co-segregate with COPA syndrome in a large family from the USA with five
affected members, and classified as pathogenic. The two separate occurrences of the p.Glu241Lys mutation in cases and
its absence from a large number of sequenced genomes confirms its role in the pathogenesis of the COPA syndrome.
Keywords: COPA syndrome, Lung disease, Arthritis, Immune dysregulation, Case reportPeer Reviewe
Dental erosive wear and salivary flow rate in physically active young adults
Background
Little attention has been directed towards identifying the relationship between physical exercise, dental erosive wear and salivary secretion. The study aimed i) to describe the prevalence and severity of dental erosive wear among a group of physically active young adults, ii) to describe the patterns of dietary consumption and lifestyle among these individuals and iii) to study possible effect of exercise on salivary flow rate.
Methods
Young members (age range 18-32 years) of a fitness-centre were invited to participate in the study. Inclusion criteria were healthy young adults training hard at least twice a week. A non-exercising comparison group was selected from an ongoing study among 18-year-olds. Two hundred and twenty participants accepted an intraoral examination and completed a questionnaire. Seventy of the exercising participants provided saliva samples. The examination was performed at the fitness-centre or at a dental clinic (comparison group), using tested erosive wear system (VEDE). Saliva sampling (unstimulated and stimulated) was performed before and after exercise. Occlusal surfaces of the first molars in both jaws and the labial and palatal surfaces of the upper incisors and canines were selected as index teeth.
Results
Dental erosive wear was registered in 64% of the exercising participants, more often in the older age group, and in 20% of the comparison group. Enamel lesions were most observed in the upper central incisors (33%); dentine lesions in lower first molar (27%). One fourth of the participants had erosive wear into dentine, significantly more in males than in females (p = 0.047). More participants with erosive wear had decreased salivary flow during exercise compared with the non-erosion group (p < 0.01). The stimulated salivary flow rate was in the lower rage (≤ 1 ml/min) among more than one third of the participants, and more erosive lesions were registered than in subjects with higher flow rates (p < 0.01).
Conclusion
The study showed that a high proportion of physically active young adults have erosive lesions and indicate that hard exercise and decreased stimulated salivary flow rate may be associated with such wear
Investigation of the erosive potential of sour novelty sweets
Provides a background about the link between acidic beverages and dental erosion.
Discusses the potential risk of developing dental erosion upon the frequent consumption of novelty sweets.
Provides information which could be used by dental personnel in counselling patients who consume novelty sweets or at risk of developing dental erosion.
Abstract
Background The expansion of the novelty sweets market in the UK has major potential public health implications in children and young adults as they may cause dental erosion.
Objective To investigate the erosive potential of the novelty sweets in term of their physiochemical properties and amount of enamel loss.
Subjects and methods The pH of a variety of novelty sweets was tested in vitro using a pH meter and the neutralisable acidity was assessed by titrating the sweets against 0.1M NaOH. The viscosity of the novelty sweets was measured using a rotational viscometer. The wettability of enamel by each sweet was measured using dynamic contact angle analyser. Enamel loss was assessed using contact profilometry.
Results The pH ranged from 1.8–3.2, the neutralisable acidity ranged from 9–201 ml of 0.1 NaOH. The viscosity of the novelty sweets that come in liquid form ranged from 2–594 mPa s. The surface enamel erosion ranged from 1.95–15.77 μm and from 2.5–17.6 μm with and without immersing in saliva for 1 hour before immersing in acidic solution respectively. The amount of subsurface enamel loss was ranged from 0.75 to 2.3 μm following ultrasonication at 0 min of acidic attack and from 0.23 to 0.85 μm at 60 minutes of acidic attack while immersed in saliva. The contact angle between enamel surface and four sweet was less than the angle formed between the orange juice and the enamel which caused more wettability of enamel.
Conclusion The pH is lower than the critical value for enamel erosion (5.5), high neutralisable acidity and high sugar content strongly suggest that these sweets may cause significant amount of dental erosion clinically. In addition, the degree of wettability of enamel by solution is an important factor to consider in determining the enamel loss caused by acidic solution. Immediate tooth brushing would cause further enamel loss as a result of the mechanical removal of softened enamel. However, it has been suggested that postponing brushing after erosive attack should be reconsidered
- …