8,209 research outputs found
Individual and collective identification in contemporary forensics
It has long been understood that individual and collective identification are inexorably intertwined. This convergence is not limited to genetics. This paper discusses the convergence of individual and collective identification in a comparative analysis of three other forensic areas: fingerprint analysis, microscopic hair comparison, and microbiome forensics. In all three case studies, we see purportedly individualizing technologies reverting, in a sense, to collective identification. Presumably, this has much to do with the perceived utility of collective identification. When knowing precisely who is the donor of a trace is not possible, or not useful, then knowing that the donor is ‘white,’ or ‘black,’ or ‘Middle Eastern’ begins to seem somehow useful. In each case, we also see that these collective identifications are ultimately founded on crude and broad, seemingly ‘commonsensical’ or ‘social,’ racial categories. These categories, meanwhile, are based on a less-than-fully-transparent combination of self-identification or official ascription. These suspect data are then transformed into seemingly persuasive scientific claims about the genetic attributes of this or that ‘race,’ ‘ethnicity,’ or ‘ancestry.’ Through this comparison the paper will explore how the individual and the collective are ‘done’ differently and similarly in different forensic disciplines
Reducing the use of inhaled corticosteroids in mild-moderate COPD: an observational study in east London
Inhaled corticosteroids (ICS) are often prescribed for worsening breathlessness, exacerbation frequency or lung function in chronic obstructive pulmonary disease (COPD). In mild-moderate disease and infrequent exacerbations, treatment risks may outweigh benefits and ICS may be withdrawn safely under supervision. A systematic ICS deprescribing programme for patients with mild-moderate COPD was introduced in an east London Clinical Commissioning Group (CCG) in April 2017. Primary care patient record analysis found that prescribing fell from 34.9% (n = 701) in the 18 months pre-intervention to 26.9% (n = 538) by the second year of implementation, decreasing 0.84% per quarter post intervention (p = 0.006, linear regression). The relative decrease was greater than the comparison CCG (23.0% vs. 9.9%). Only South Asian ethnicity was associated with increased cessation (odds ratio 1.48, confidence interval (CI) 1.09-2.01), p = 0.013, logistic regression). Patient outcome data were not collected. A primary care-led programme comprising local education, financial incentivisation and consultant support led to a significant decrease in ICS prescribing
Perceptions of school-based alcohol education by educational and health stakeholders: “Education as usual” compared to a randomised controlled trial
The present study sought the views of stakeholders, including school leaders and statutory stakeholders, on the content and evaluation of a classroom-based alcohol education intervention in a Randomised Controlled Trial in Scotland and Northern Ireland. Purposive sampling was used to ensure that schools from both the Intervention and Control groups were equally represented, and to ensure that similar numbers and grades of stakeholders in both countries were represented. A total of 27 participants (Male = 13 (48%); Female = 14 (52%)) engaged in a semi-structured interview prior to the end of the trial. Results suggest that: schools generally design their own alcohol education programmes; that intervention schools thought highly of the particular intervention tested; and that both groups engaged meaningfully in the research. The threshold for acceptance of the intervention was lower than the successful outcome of the trial. More pragmatic considerations were considered equally important. From the point of view of the statutory stakeholders, funding of an intervention depends on a successful outcome evaluation, but that “success” may mean a positive impact on at-risk groups, and not necessarily at a universal level. School-based participants also focussed on ease of delivery and user friendliness as key determinants of programme utilisation
In vitro and in vivo modification of Neisseria gonorrhoeae lipooligosaccharide epitope structure by sialylation.
After growth of gonococci in the presence of cytidine monophospho-N-acetyl-neuraminic acid (CMP-NANA), their 4.5-kD lipooligosaccharide (LOS) component was increased by approximately 400 daltons, whereas the LOS of strains lacking the 4.5-kD component were unaffected. Expression of mAb-defined epitopes on the 4.5-kD component was decreased on LOS of strains grown in CMP-NANA, and treatment of the LOS with neuraminidase reversed this affect. Gonococci incubated with human PMNs also had decreased expression of the 4.5-kD+ epitopes. A detergent extract of gonococci incorporated radiolabeled NANA in the LOS, suggesting the presence of a sialyltransferase in gonococci. Exogenous sialyltransferases also could use LOS as an acceptor
Immobilization of antibacterial dihydropyrrol-2-ones on functional polymer supports to prevent bacterial infections in vivo
Antibiotic-resistant Staphylococcus aureus is of great concern, as it causes a wide range of life-threatening infections. The current study demonstrates that dihydropyrrolone (DHP)-coated polyacrylamide substrates are effective in reducing the number of culturable clinical isolates of S. aureus in vitro in a dose-dependent manner and are able to reduce the pathogenic potential of staphylococcal infection in a subcutaneous infection model. Covalently bound DHPs therefore show great potential for use as an antimicrobial strategy in device-related applications. Copyright © 2012, American Society for Microbiology. All Rights Reserved
Chromium isotopes in marine hydrothermal sediments
Hydrothermal chromium (Cr) cycling contributes to marine Cr inventories and their Cr isotopic composition, yet Cr isotope effects associated with this cycling remain poorly documented. Here we determine the distribution, isotopic composition, and diagenetic mobility of Cr in hydrothermal sediments from the distal flank of the South East Pacific Rise (SEPR, DSDP-site 598). We find that Cr is primarily associated with the metalliferous iron (oxyhydr) oxide and detrital components of the sediment (0.4–3.6 mg kg⁻¹), whereas Cr concentrations are much lower in the dominant carbonate phase (80% Cr from the sediment relative to Fe. We propose this loss is tied to oxidation of authigenic Cr(III) to Cr(VI) followed by diagenetic remobilization and efflux from the sediment pile. The bulk δ⁵³Cr composition of the SEPR sediments is isotopically light (−0.24 to −0.57 ± 0.05‰) and the authigenic δ⁵³Cr is as light as −1.2 ± 0.2‰, and we argue that this light Cr isotopic composition results from the partial reduction of oxic seawater-bearing Cr(VI) by reduced hydrothermal vent fluids enriched in Fe(II)aq. Diagenetic oxidation of the reactive Cr pool by Mn-oxides and loss of Cr(VI) from the sediment may further deplete the sediment in ⁵³Cr during diagenesis. The δ⁵³Cr composition of the detrital Cr fraction of the sediment (average δ⁵³Cr composition = −0.05 ± 0.04‰) falls within the igneous silicate earth (ISE) range, revealing that detrital Cr delivered to this region of the Pacific ocean is unfractionated, and has carried a relatively constant δ⁵³Cr composition over the last 5.7 million years. Together our results show that light δ⁵³Cr compositions in hydrothermal sediments are imparted through a combination of processes previously overlooked in the marine Cr biogeochemical cycle, and that the δ⁵³Cr composition of such sediments may provide a rich source of information on paleo-marine redox conditions
Prevalence and Predictors of Vitamin D Insufficiency in Children: A Great Britain Population Based Study
Objectives
To evaluate the prevalence and predictors of vitamin D insufficiency (VDI) in children In Great Britain.
Design
A nationally representative cross-sectional study survey of children (1102) aged 4–18 years (999 white, 570 male) living in private households (January 1997–1998). Interventions provided information about dietary habits, physical activity, socio-demographics, and blood sample. Outcome measures were vitamin D insufficiency (<50 nmol/L).
Results
Vitamin D levels (mean = 62.1 nmol/L, 95%CI 60.4–63.7) were insufficient in 35%, and decreased with age in both sexes (p<0.001). Young People living between 53–59 degrees latitude had lower levels (compared with 50–53 degrees, p = 0.045). Dietary intake and gender had no effect on vitamin D status. A logistic regression model showed increased risk of VDI in the following: adolescents (14–18 years old), odds ratio (OR) = 3.6 (95%CI 1.8–7.2) compared with younger children (4–8 years); non white children (OR = 37 [95%CI 15–90]); blood levels taken December-May (OR = 6.5 [95%CI 4.3–10.1]); on income support (OR = 2.2 [95%CI 1.3–3.9]); not taking vitamin D supplementation (OR = 3.7 [95%CI 1.4–9.8]); being overweight (OR 1.6 [95%CI 1.0–2.5]); <1/2 hour outdoor exercise/day/week (OR = 1.5 [95%CI 1.0–2.3]); watched >2.5 hours of TV/day/week (OR = 1.6[95%CI 1.0–2.4]).
Conclusion
We confirm a previously under-recognised risk of VDI in adolescents. The marked higher risk for VDI in non-white children suggests they should be targeted in any preventative strategies. The association of higher risk of VDI among children who exercised less outdoors, watched more TV and were overweight highlights potentially modifiable risk factors. Clearer guidelines and an increased awareness especially in adolescents are needed, as there are no recommendations for vitamin D supplementation in older children
Transportability without positivity: a synthesis of statistical and simulation modeling
When estimating an effect of an action with a randomized or observational
study, that study is often not a random sample of the desired target
population. Instead, estimates from that study can be transported to the target
population. However, transportability methods generally rely on a positivity
assumption, such that all relevant covariate patterns in the target population
are also observed in the study sample. Strict eligibility criteria,
particularly in the context of randomized trials, may lead to violations of
this assumption. Two common approaches to address positivity violations are
restricting the target population and restricting the relevant covariate set.
As neither of these restrictions are ideal, we instead propose a synthesis of
statistical and simulation models to address positivity violations. We propose
corresponding g-computation and inverse probability weighting estimators. The
restriction and synthesis approaches to addressing positivity violations are
contrasted with a simulation experiment and an illustrative example in the
context of sexually transmitted infection testing uptake. In both cases, the
proposed synthesis approach accurately addressed the original research question
when paired with a thoughtfully selected simulation model. Neither of the
restriction approaches were able to accurately address the motivating question.
As public health decisions must often be made with imperfect target population
information, model synthesis is a viable approach given a combination of
empirical data and external information based on the best available knowledge
Growth in ataxia telangiectasia
BACKGROUND: Ataxia telangiectasia (A-T) is a DNA repair disorder that affects multiple body systems. Neurological problems and immunodeficiency are two important features of this disease. At this time, two main severity groups are defined in A-T: classic (the more severe form) and mild. Poor growth is a common problem in classic A-T. An objective of this study was to develop growth references for classic A-T. Another objective was to compare growth patterns in classic A-T and mild A-T with each other and with the general population, using the CDC growth references. A final objective was to examine the effects of chronic infection on height. RESULTS: We found that classic A-T patients were smaller overall, and suffered from height and weight faltering that continued throughout childhood and adolescence. When compared to the CDC growth references, the median heights and weights for both male and female patients eventually fell to or below the 3rd centile on the CDC charts. Height faltering was more pronounced in females. Birthweight was lower in the classic A-T group compared to mild A-T and the general population, whereas birth length was not. Finally, we investigated height and BMI faltering in relation to number of infections and found no association. CONCLUSIONS: Classic A-T appears to affect growth in utero. Although children appear to grow well in very early life, faltering begins early, and is unrelenting
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Dye···TiO2 Interfacial Structure of Dye-Sensitised Solar Cell Working Electrodes Buried under a Solution of I-/I3- Redox Electrolyte
Dye-sensitised solar cells (DSCs) have niche prospects for electricity-generating windows that could equip buildings for energy-sustainable future cities. However, this ‘smart window’ technology is being held back by a lack of understanding in how the dye interacts with its device environment at the molecular level. A better appreciation of the dye⋯TiO2 interfacial structure of the DSC working electrodes would be particularly valuable since associated structure–function relationships could be established; these rules would provide a ‘toolkit’ for the molecular engineering of more suitable DSC dyes via rational design. Previous materials characterisation efforts have been limited to determining this interfacial structure within an environment exposed to air or situated in a solvent medium. This study is the first to reveal the structure of this buried interface within the functional device environment, and represents the first application of in situ neutron reflectometry to DSC research. By incorporating the electrolyte into the structural model of this buried interface, we reveal how lithium cations from the electrolyte constituents influence the dye⋯TiO2 binding configuration of an organic sensitiser, MK-44, via Li+ complexation to the cyanoacrylate group. This dye is the molecular congener of the high-performance MK-2 DSC dye, whose hexa-alkyl chains appear to stabilise it from Li+ complexation. Our in situ neutron reflectometry findings are built up from auxiliary structural models derived from ex situ X-ray reflectometry and corroborated via density functional theory and UV/vis absorption spectroscopy. Significant differences between the in situ and ex situ dye⋯TiO2 interfacial structures are found, highlighting the need to characterise the molecular structure of DSC working electrodes while in a fully assembled device.The authors wish to thank Andrew Nelson and Gerry Triani of ANSTO for their guidance on reflectometry data analysis and TiO2 deposition, respectively. We thank Shogo Mori from Shinshu University, Japan, and Nagatoshi Koumura from the National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, for providing the MK-44 dye material for this work. We also acknowledge ANSTO for a part-funded PhD studentship, and Garry McIntyre therein for overseeing local project support. Neutron beamtime at ANSTO was provided under proposal DB3739. J. M. C. is grateful to the 1851 Royal Commission for the 2014 Design Fellowship, and Argonne National Laboratory where work done was supported by DOE Office of Science, Office of Basic Energy Sciences, under Contract no. DE-AC02-06CH11357. Y. G. thanks the Cambridge Overseas Trust for a PhD scholarship
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