4,920 research outputs found
A preliminary assessment of age at death determination using the nuclear weapons testing 14C activity of dentine and enamel
Calibration (using CALIBomb) of radiocarbon measurements made on the enamel of human teeth from people
born during the nuclear era typically produce 2 possible age ranges that potentially reflect the period of tooth formation. These
ranges correspond to periods before and after the 1963 atmospheric 14C maximum. Further measurements made on the
collagen component of the combined dentine and cementum from the roots of the same teeth enable the appropriate age range
to be selected. Using this range and the formation times for individual teeth, we estimated the year of birth of the individuals
and compared these to the known dates of birth. The results were relatively accurate and confirmed those of a previous study
by another research group. The present study demonstrates that it is possible to produce a good estimate of the year of birth
from a single tooth
Quasi-variational coupled-cluster theory: Performance of perturbative treatments of connected triple excitations
Quasi-variational coupled-cluster methods are applied to a selection of diatomic molecules. The potential energy curves, spectroscopic constants, and size consistency errors are calculated and compared to those obtained from both single- and multi-reference methods. The effects of connected triple excitations are introduced with either the standard perturbative (T) formulation, or in the renormalised form, and its symmetrised approximation. It is found that the renormalised ansatz is significantly superior to the standard formulation when describing bond breaking and that in most circumstances, the computationally simpler symmetrisation gives nearly identical results
New challenges in studying nutrition-disease interactions in the developing world.
Latest estimates indicate that nutritional deficiencies account for 3 million child deaths each year in less-developed countries. Targeted nutritional interventions could therefore save millions of lives. However, such interventions require careful optimization to maximize benefit and avoid harm. Progress toward designing effective life-saving interventions is currently hampered by some serious gaps in our understanding of nutrient metabolism in humans. In this Personal Perspective, we highlight some of these gaps and make some proposals as to how improved research methods and technologies can be brought to bear on the problems of undernourished children in the developing world
Stigma in Male Depression and Suicide: A Canadian Sex Comparison Study
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Stigma in men’s depression and suicide can restrict help-seeking, reduce treatment compliance and deter individuals from confiding in friends and family. In this article we report sex comparison findings from a national survey of English-speaking adult Canadians about stigmatized beliefs concerning male depression and suicide. Among respondents without direct experience of depression or suicide (n = 541) more than a third endorsed the view that men with depression are unpredictable. Overall, a greater proportion of males endorsed stigmatizing views about male depression compared to female respondents. A greater proportion of female respondents endorsed items indicating that men who suicide are disconnected, lost and lonely. Male and female respondents with direct personal experience of depression or suicide (n = 360) strongly endorsed stigmatizing attitudes toward themselves and a greater proportion of male respondents indicated that they would be embarrassed about seeking help for depression
VISIT-TS: A multimedia tool for population studies on tic disorder
Population-based assessment of Tourette syndrome (TS) and other tic disorders produces a paradox. On one hand, ideally diagnosis of tic disorders requires expert observation. In fact, diagnostic criteria for TS explicitly require expert assessment of tics for a definite diagnosis. On the other hand, large-scale population surveys with expert assessment of every subject are impracticable. True, several published studies have successfully used expert assessment to find tic prevalence in a representative population (e.g. all students in a school district). However, extending these studies to larger populations is daunting. We created a multimedia tool to demonstrate tics to a lay audience, discuss their defining and common attributes, and address features that differentiate tics from other movements and vocalizations. A first version was modified to improve clarity and to include a more diverse group in terms of age and ethnicity. The result is a tool intended for epidemiological research. It may also provide additional benefits, such as more representative minority recruitment for other TS studies and increased community awareness of TS
Poor Potential Coverage for 7-Valent Pneumococcal Conjugate Vaccine, Malawi
Streptococcus pneumoniae infections can be prevented by using new conjugate vaccines, but these vaccines have limited serogroup coverage. We report the first serogrouping data from carried and invasive isolates obtained from children and adults in Malawi. The 7-valent vaccine would cover 41% of invasive isolates from children and 25% from adults. A 9-valent vaccine, including types 1 and 5, would cover 66% of invasive isolates from children and 55% from adults
The Kondo Box: A Magnetic Impurity in an Ultrasmall Metallic Grain
We study the Kondo effect generated by a single magnetic impurity embedded in
an ultrasmall metallic grain, to be called a ``Kondo box''. We find that the
Kondo resonance is strongly affected when the mean level spacing in the grain
becomes larger than the Kondo temperature, in a way that depends on the parity
of the number of electrons on the grain. We show that the single-electron
tunneling conductance through such a grain features Kondo-induced Fano-type
resonances of measurable size, with an anomalous dependence on temperature and
level spacing.Comment: 4 Latex pages, 4 figures, submitted to Phys. Rev. Let
Impact of educational attainment on the association between social class at birth and multimorbidity in middle age in the Aberdeen Children of the 1950s cohort study
Objective
Multimorbidity (the co-existence of two or more health conditions) is increasingly prevalent. No long-term cohort study has examined the impact of contemporaneously measured birth social class and educational attainment upon adult self-reported multimorbidity. We investigated the impact of educational attainment on the relationship between social class at birth and adult self-reported multimorbidity in the Aberdeen Children of the 1950s (ACONF) cohort.
Methods
A prospective cohort study using the ACONF cohort. ACONF included 12,150 individuals born in Aberdeen, Scotland 1950-1956. In 2001, 7,184 (64%) responded to a questionnaire providing information including self-reported morbidity and educational attainment. The exposure was father’s social class at birth from birth records and the outcome was self-reported multimorbidity. Logistic regression assessed the association between social class and multimorbidity with adjustment for gender, then by educational attainment and finally by childhood cognition and secondary school type. Odds ratios (ORs) and 95% confidence intervals were presented.
Results
Of 7,184 individuals (mean age 48, 52% female), 5.4% reported multimorbidity. Birth social class was associated with adult multimorbidity. For example the OR of multimorbidity adjusted by gender was 0.62 (95% CI 0.39-1.00) in the highest social class group (I/II) in relation to the reference group (III (manual)) and was 1.85 (95% CI 1.19-2.88) in the lowest social class group. This was partially attenuated in all social class categories by educational attainment, for example the OR was 0.74 (95% CI 0.45-1.21) in group I/II following adjustment.
Conclusion
Lower social class at birth was associated with developing multimorbidity in middle age. This was partially mediated by educational attainment and future research should consider identifying the other explanatory variables. The results are relevant to researchers and to those aiming to reduce the impact of multimorbidity
Defining and measuring multimorbidity: a systematic review of systematic reviews
Background
Multimorbidity, the coexistence of multiple health conditions, is a growing public health challenge. Research and intervention development are hampered by the lack of consensus regarding defining and measuring multimorbidity. The aim of this systematic review was to pool the findings of systematic reviews examining definitions and measures of multimorbidity.
Methods
Medline, Embase, PubMed and Cochrane were searched from database inception to February 2017. Two authors independently screened titles, abstracts and full texts and extracted data from the included papers. Disagreements were resolved with a third author. Reviews were quality assessed.
Results
Of six reviews, two focussed on definitions and four on measures. Multimorbidity was commonly defined as the presence of multiple diseases or conditions, often with a cut-off of two or more. One review developed a holistic definition including biopsychosocial and somatic factors as well as disease. Reviews recommended using measures validated for the outcome of interest. Disease counts are an alternative if no validated measure exists.
Conclusions
To enable comparison between studies and settings, researchers and practitioners should be explicit about their choice of definition and measure. Using a cut-off of two or more conditions as part of the definition is widely adopted. Measure selection should be based on tools validated for the outcome being considered. Where there is no validated measure, or where multiple outcomes or populations are being considered, disease counts are appropriate
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