206 research outputs found
A survey of science reporting in representative American newspapers
Thesis (M.S.)--Boston Universit
Sex, contraception, or abortion? Explaining class gaps in unintended childbearing
There are wide class gaps in unintended childbearing among single women in the United States, resulting from different contraceptive and abortion choices across income groups. In this paper, we use data from the National Survey of Family Growth (NSFG 2011-2013) to estimate how sexual activity, contraceptive use, and abortion use vary across income lines. Though rates of sexual activity are comparable for all women, low-income women are less likely to use contraception and are less likely to have an abortion once pregnant. We use a shift-share analysis to simulate the effect of equalizing, at the rates of affluent women, the use of the contraception and abortion services across income groups. We find that equalizing contraceptive use reduces the ratio of unintended births between affluent and poor women by half, and that equalizing abortion rates reduces the ratio by one-third
The Inheritance of Black Poverty: Technical Paper
This report confirms the stark differences in upward earnings mobility for black men compared to both black women and whites. It also confirms that black women, despite their solid earnings mobility, have very low family income mobility. The report then estimates the impact of racial differences in marriage rates by simulating higher marriage rates among black women: like Race and Economic Opportunity in the United States: An Intergenerational Perspective" by Raj Chetty, Nathaniel Hendren, Maggie Jones, and Sonya Porter, we find no significant effects
CD74-dependent Deregulation of the Tumor Suppressor Scribble in Human Epithelial and Breast Cancer Cells
The γ subunit of the major histocompatibility complex (MHC) class II complex, CD74, is overexpressed in a significant proportion of metastatic breast tumors, but the mechanistic foundation and biologic significance of this phenomenon are not fully understood. Here, we show that when CD74 is overexpressed in human cancer and noncancerous epithelial cells, it interacts and interferes with the function of Scribble, a product of a well-known tumor suppressor gene. Furthermore, using epithelial cell lines expressing CD74 under the control of tetracycline-inducible promoter and quantitative high-resolution mass spectrometry, we demonstrate that, as a result of CD74 overexpression, the phosphorylation pattern of the C-terminal part of Scribble undergoes specific changes. This is accompanied with a translocation of the protein from the sites of cell-to-cell contacts at the plasma membrane to the cytoplasm, which is likely to effectively enhance the motility and invasiveness of the cancer cells. © 2013 Neoplasia Press, Inc. All rights reserved
New Oldowan locality Sare-Abururu (ca. 1.7 Ma) provides evidence of diverse hominin behaviors on the Homa Peninsula, Kenya
The Homa Peninsula, in southwestern Kenya, continues to yield insights into Oldowan hominin landscape behaviors. The Late Pliocene locality of Nyayanga (∼3–2.6 Ma) preserves some of the oldest Oldowan tools. At the Early Pleistocene locality of Kanjera South (∼2 Ma) toolmakers procured a diversity of raw materials from over 10 km away and strategically reduced them in a grassland-dominated ecosystem. Here, we report findings from Sare-Abururu, a younger (∼1.7 Ma) Oldowan locality approximately 12 km southeast of Kanjera South and 18 km east of Nyayanga. Sare-Abururu has yielded 1754 artifacts in relatively undisturbed low-energy silts and sands. Stable isotopic analysis of pedogenic carbonates suggests that hominin activities were carried out in a grassland-dominated setting with similar vegetation structure as documented at Kanjera South. The composition of a nearby paleo-conglomerate indicates that high-quality stone raw materials were locally abundant. Toolmakers at Sare-Abururu produced angular fragments from quartz pebbles, representing a considerable contrast to the strategies used to reduce high quality raw materials at Kanjera South. Although lithic reduction at Sare-Abururu was technologically simple, toolmakers proficiently produced cutting edges, made few mistakes and exhibited a mastery of platform management, demonstrating that expedient technical strategies do not necessarily indicate a lack of skill or suitable raw materials. Lithic procurement and reduction patterns on the Homa Peninsula appear to reflect variation in local resource contexts rather than large-scale evolutionary changes in mobility, energy budget, or toolmaker cognition
An X-ray Spectral Survey of Radio-Loud AGN With ASCA
We present a uniform and systematic analysis of the 0.6-10 keV X-ray spectra
of radio-loud active galactic nuclei (AGN) observed by ASCA. The sample 10
BLRGs, 5 QSRs, 9 NLRGs, and 10 RGs. At soft X-rays, about half of the NLRGs and
all of the RGs exhibit a thermal plasma component, with a bimodal distribution
of temperatures and luminosities, suggesting an origin either in a surrounding
cluster or loose group or in a hot corona. At energies above 2 keV, a hard
power-law component is detected in 90% of cases. The power-law photon indices
and luminosities in BLRGs, QSRs, and NLRGs are similar, consistent with
orientation-based unification schemes. Significant excess cold absorption is
detected in most NLRGs, but also in some BLRGS and QSRs, which was somewhat
unexpected. In contrast to Seyfert galaxies, only one object showss the
signature of a warm absorber. The nuclear X-ray luminosity is correlated with
the luminosity of the [O III] emission line, the FIR emission at 12 microns,
and the lobe radio power at 5 GHz. The Fe K line is detected in 50% of BLRGs,
one QSR, and a handful of NLRGs. This sample also includes 6 Weak Line Radio
Galaxies (WLRGs). Their spectra WLRGs can be generally decomposed into a soft
thermal component with hard absrorbed power-law component, which is
significantly flatter than any other radio-loud AGNs. Their intrinsic
luminosities are two orders of magnitude lower than in other sources of the
sample. An interesting possibility is that WLRGs represent an extreme
population of radio galaxies in which the central black hole is accreting at a
rate well below the Eddington rate.Comment: To appear in the Astrophysical Journal. 72 pages, including many
tables and figures. Fig 1 is separate, in TIFF format. Postscript version of
fig 1 and postscript version of entire preprint can be obtained from
http://www.astro.psu.edu/users/mce/preprint_index.htm
Teacher agency in curriculum making: agents of change and spaces for manoeuvre
In the wake of new forms of curricular policy in many parts of the world, teachers are increasingly required to act as agents of change. And yet, teacher agency is under-theorised and often misconstrued in the educational change literature, wherein agency and change are seen as synonymous and positive. This paper addresses the issue of teacher agency in the context of an empirical study of curriculum making in schooling. Drawing upon the existing literature, we outline an ecological view of agency as an effect. These insights frame the analysis of a set of empirical data, derived from a research project about curriculum-making in a school and further education college in Scotland. Based upon the evidence, we argue that the extent to which teachers are able to achieve agency varies from context to context based upon certain environmental conditions of possibility and constraint, and that an important factor in this lies in the beliefs, values and attributes that teachers mobilise in relation to particular situations
The National Adult Inpatient Survey conducted in the English National Health Service from 2002 to 2009: how have the data been used and what do we know as a result?
<p>Abstract</p> <p>Background</p> <p>When it was initiated in 2001, England's national patient survey programme was one of the first in the world and has now been widely emulated in other healthcare systems. The aim of the survey programme was to make the National Health Service (NHS) more "patient centred" and more responsive to patient feedback. The national inpatient survey has now been running in England annually since 2002 gathering data from over 600,000 patients. The aim of this study is to investigate how the data have been used and to summarise what has been learned about patients' evaluation of care as a result.</p> <p>Methods</p> <p>Two independent researchers systematically gathered all research that included analyses of the English national adult inpatient survey data. Journals, databases and relevant websites were searched. Publications prior to 2002 were excluded. Articles were also identified following consultation with experts. All documents were then critically appraised by two co-authors both of whom have a background in statistical analysis.</p> <p>Results</p> <p>We found that the majority of the studies identified were reports produced by organisations contracted to gather the data or co-ordinate the data collection and used mainly descriptive statistics. A few articles used the survey data for evidence based reporting or linked the survey to other healthcare data. The patient's socio-demographic characteristics appeared to influence their evaluation of their care but characteristics of the workforce and the. At a national level, the results of the survey have been remarkably stable over time. Only in those areas where there have been co-ordinated government-led campaigns, targets and incentives, have improvements been shown. The main findings of the review are that while the survey data have been used for different purposes they seem to have incited little academic interest.</p> <p>Conclusions</p> <p>The national inpatient survey has been a useful resource for many authors and organisations but the full potential inherent in this large, longitudinal publicly available dataset about patients' experiences has not as yet been fully exploited.</p> <p>This review suggests that the presence of survey results alone is not enough to improve patients' experiences and further research is required to understand whether and how the survey can be best used to improve standards of care in the NHS.</p
A novel member of the let-7 microRNA family is associated with developmental transitions in filarial nematode parasites
Background: Filarial nematodes are important pathogens in the tropics transmitted to humans via the bite of blood sucking arthropod vectors. The molecular mechanisms underpinning survival and differentiation of these parasites following transmission are poorly understood. microRNAs are small non-coding RNA molecules that regulate target mRNAs and we set out to investigate whether they play a role in the infection event.
Results: microRNAs differentially expressed during the early post-infective stages of Brugia pahangi L3 were identified by microarray analysis. One of these, bpa-miR-5364, was selected for further study as it is upregulated ~12-fold at 24 hours post-infection, is specific to clade III nematodes, and is a novel member of the let-7 family, which are known to have key developmental functions in the free-living nematode Caenorhabditis elegans. Predicted mRNA targets of bpa-miR-5364 were identified using bioinformatics and comparative genomics approaches that relied on the conservation of miR-5364 binding sites in the orthologous mRNAs of other filarial nematodes. Finally, we confirmed the interaction between bpa-miR-5364 and three of its predicted targets using a dual luciferase assay.
Conclusions: These data provide new insight into the molecular mechanisms underpinning the transmission of third stage larvae of filarial nematodes from vector to mammal. This study is the first to identify parasitic nematode mRNAs that are verified targets of specific microRNAs and demonstrates that post-transcriptional control of gene expression via stage-specific expression of microRNAs may be important in the success of filarial infection
The Effect of Selenium Supplementation in the Prevention of DNA Damage in White Blood Cells of Hemodialyzed Patients: A Pilot Study
Patients with chronic kidney disease (CKD) have an increased incidence of cancer. It is well known that long periods of hemodialysis (HD) treatment are linked to DNA damage due to oxidative stress. In this study, we examined the effect of selenium (Se) supplementation to CKD patients on HD on the prevention of oxidative DNA damage in white blood cells. Blood samples were drawn from 42 CKD patients on HD (at the beginning of the study and after 1 and 3 months) and from 30 healthy controls. Twenty-two patients were supplemented with 200 μg Se (as Se-rich yeast) per day and 20 with placebo (baker's yeast) for 3 months. Se concentration in plasma and DNA damage in white blood cells expressed as the tail moment, including single-strand breaks (SSB) and oxidative bases lesion in DNA, using formamidopyrimidine glycosylase (FPG), were measured. Se concentration in patients was significantly lower than in healthy subjects (P < 0.0001) and increased significantly after 3 months of Se supplementation (P < 0.0001). Tail moment (SSB) in patients before the study was three times higher than in healthy subjects (P < 0.01). After 3 months of Se supplementation, it decreased significantly (P < 0.01) and was about 16% lower than in healthy subjects. The oxidative bases lesion in DNA (tail moment, FPG) of HD patients at the beginning of the study was significantly higher (P < 0.01) compared with controls, and 3 months after Se supplementation it was 2.6 times lower than in controls (P < 0.01). No changes in tail moment was observed in the placebo group. In conclusion, our study shows that in CKD patients on HD, DNA damage in white blood cells is higher than in healthy controls, and Se supplementation prevents the damage of DNA
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