241 research outputs found
Thyroid Function and Perchlorate in Drinking Water: An Evaluation among California Newborns, 1998
Perchlorate (ClO(4)(â)) has been detected in groundwater sources in numerous communities in California and other parts of the United States, raising concerns about potential impacts on health. For California communities where ClO(4)(â) was tested in 1997 and 1998, we evaluated the prevalence of primary congenital hypothyroidism (PCH) and high thyroid-stimulating hormone (TSH) levels among the 342,257 California newborns screened in 1998. We compared thyroid function results among newborns from 24 communities with average ClO(4)(â) concentrations in drinking water > 5 ÎŒg/L (n = 50,326) to newborns from 287 communities with average concentrations â€5 ÎŒg/L (n = 291,931). ClO(4)(â) concentrations obtained from the California Drinking Water Program provided source-specific data for estimating weighted average concentrations in community water. Fifteen cases of PCH from communities with average concentration > 5 ÎŒg/L were observed, with 20.4 expected [adjusted prevalence odds ratio (POR) = 0.71; 95% confidence interval (CI), 0.40â1.19]. Although only 36% of all California newborns were screened before 24 hr of age in 1998, nearly 80% of newborns with high TSH were screened before 24 hr of age. Because of the physiologic postnatal surge of TSH, the results for newborns screened before 24 hr were uninformative for assessing an environmental impact. For newborns screened â„24 hr, the adjusted POR for high TSH was 0.73 (95% CI, 0.40â1.23). All adjusted odds ratios (ORs) were controlled for sex, ethnicity, birth weight, and multiple birth status. Using an assessment of ClO(4)(â) in drinking water based on available data, we did not observe an association between estimated average ClO(4)(â) concentrations > 5 ÎŒg/L in drinking water supplies and the prevalence of clinically diagnosed PCH or high TSH concentrations
Mixture models for undiagnosed prevalent disease and interval-censored incident disease: applications to a cohort assembled from electronic health records.
For cost-effectiveness and efficiency, many large-scale general-purpose cohort studies are being assembled within large health-care providers who use electronic health records. Two key features of such data are that incident disease is interval-censored between irregular visits and there can be pre-existing (prevalent) disease. Because prevalent disease is not always immediately diagnosed, some disease diagnosed at later visits are actually undiagnosed prevalent disease. We consider prevalent disease as a point mass at time zero for clinical applications where there is no interest in time of prevalent disease onset. We demonstrate that the naive Kaplan-Meier cumulative risk estimator underestimates risks at early time points and overestimates later risks. We propose a general family of mixture models for undiagnosed prevalent disease and interval-censored incident disease that we call prevalence-incidence models. Parameters for parametric prevalence-incidence models, such as the logistic regression and Weibull survival (logistic-Weibull) model, are estimated by direct likelihood maximization or by EM algorithm. Non-parametric methods are proposed to calculate cumulative risks for cases without covariates. We compare naive Kaplan-Meier, logistic-Weibull, and non-parametric estimates of cumulative risk in the cervical cancer screening program at Kaiser Permanente Northern California. Kaplan-Meier provided poor estimates while the logistic-Weibull model was a close fit to the non-parametric. Our findings support our use of logistic-Weibull models to develop the risk estimates that underlie current US risk-based cervical cancer screening guidelines. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA
Adherence Patterns to Extended Cervical Screening Intervals in Women Undergoing HPV and Cytology Cotesting
Although guidelines have recommended extended interval cervical screening using concurrent human papillomavirus (HPV) and cytology (âcotestingâ) for over a decade, little is known about its adoption into routine care. Using longitudinal medical record data (2003-2015) from Kaiser Permanente Northern California (KPNC), which adopted triennial cotesting in 2003, we examined adherence to extended interval screening. We analyzed predictors of screening intervals among 504,202 women undergoing routine screening, categorizing interval length into early
Estado y agricultura en Mexico : antecedentes e implicaciones de las reformas salinistas
1 archivo PDF (184 pĂĄginas)El 7 de noviembre de 1991, el presidente Salinas de Gortari anunciĂł la reforma del artĂculo 27 de la ConstituciĂłn, al respecto de esta reforma se presentan siete ensayos, cuyos temas son: perspectiva histĂłrica: desde el Cardenismo hasta el Salinismo; la polĂtica neoliberal: regiones y sectores econĂłmicos; la polĂtica neoliberal: sectores Sociales. PALABRAS CLAVE: Enmiendas constitucionales. Tierras comunales. Agriculture and state. Constitutional amendments. Common
Scribble modulates the MAPK/Fra1 pathway to disrupt luminal and ductal integrity and suppress tumour formation in the mammary gland
Polarity coordinates cell movement, differentiation, proliferation and apoptosis to build and maintain complex epithelial tissues such as the mammary gland. Loss of polarity and the deregulation of these processes are critical events in malignant progression but precisely how and at which stage polarity loss impacts on mammary development and tumourigenesis is unclear. Scrib is a core polarity regulator and tumour suppressor gene however to date our understanding of Scrib function in the mammary gland has been limited to cell culture and transplantation studies of cell lines. Utilizing a conditional mouse model of Scrib loss we report for the first time that Scrib is essential for mammary duct morphogenesis, mammary progenitor cell fate and maintenance, and we demonstrate a critical and specific role for Scribble in the control of the early steps of breast cancer progression. In particular, Scrib-deficiency significantly induced Fra1 expression and basal progenitor clonogenicity, which resulted in fully penetrant ductal hyperplasia characterized by high cell turnover, MAPK hyperactivity, frank polarity loss with mixing of apical and basolateral membrane constituents and expansion of atypical luminal cells. We also show for the first time a role for Scribble in mammalian spindle orientation with the onset of mammary hyperplasia being associated with aberrant luminal cell spindle orientation and a failure to apoptose during the final stage of duct tubulogenesis. Restoring MAPK/Fra1 to baseline levels prevented Scrib-hyperplasia, whereas persistent Scrib deficiency induced alveolar hyperplasia and increased the incidence, onset and grade of mammary tumours. These findings, based on a definitive genetic mouse model provide fundamental insights into mammary duct maturation and homeostasis and reveal that Scrib loss activates a MAPK/Fra1 pathway that alters mammary progenitor activity to drive premalignancy and accelerate tumour progression
The optical behaviour of BL Lacertae at its maximum brightness levels: a blend of geometry and energetics
In 2021 BL Lacertae underwent an extraordinary activity phase, which was
intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration.
We present the WEBT optical data in the BVRI bands acquired at 36 observatories
around the world. In mid 2021 the source showed its historical maximum, with R
= 11.14. The light curves display many episodes of intraday variability, whose
amplitude increases with source brightness, in agreement with a geometrical
interpretation of the long-term flux behaviour. This is also supported by the
long-term spectral variability, with an almost achromatic trend with
brightness. In contrast, short-term variations are found to be strongly
chromatic and are ascribed to energetic processes in the jet. We also analyse
the optical polarimetric behaviour, finding evidence of a strong correlation
between the intrinsic fast variations in flux density and those in polarisation
degree, with a time delay of about 13 h. This suggests a common physical
origin. The overall behaviour of the source can be interpreted as the result of
two mechanisms: variability on time scales greater than several days is likely
produced by orientation effects, while either shock waves propagating in the
jet, or magnetic reconnection, possibly induced by kink instabilities in the
jet, can explain variability on shorter time scales. The latter scenario could
also account for the appearance of quasi-periodic oscillations, with periods
from a few days to a few hours, during outbursts, when the jet is more closely
aligned with our line of sight and the time scales are shortened by
relativistic effects.Comment: 15 pages, 16 figures, submitted to MNRA
Inhibition of dipeptidyl peptidase IV and xanthine oxidase by amino acids and dipeptides
peer-reviewedXanthine oxidase (XO) and dipeptidyl peptidase IV (DPP-IV) inhibition by amino acids and dipeptides was studied. Trp and Trp-containing dipeptides (Arg-Trp, Trp-Val, Val-Trp, Lys-Trp and Ile-Trp) inhibited XO. Three amino acids (Met, Leu and Trp) and eight dipeptides (Phe-Leu, Trp-Val, His-Leu, Glu-Lys, Ala-Leu, Val-Ala, Ser-Leu and Gly-Leu) inhibited DPP-IV. Trp and Trp-Val were multifunctional inhibitors of XO and DPP-IV. Lineweaver and Burk analysis showed that Trp was a non-competitive inhibitor of XO and a competitive inhibitor of DPP-IV. Molecular docking with Autodock Vina was used to better understand the interaction of the peptides with the active site of the enzyme. Because of the non-competitive inhibition observed, docking of Trp-Val to the secondary binding sites of XO and DPP-IV is required. Trp-Val was predicted to be intestinally neutral (between 25% and 75% peptide remaining after 60 min simulated intestinal digestion). These results are of significance for the reduction of reactive oxygen species (ROS) and the increase of the half-life of incretins by food-derived peptides. (C) 2013 Elsevier Ltd. All rights reserved.ACCEPTEDpeer-reviewe
The values of liberteÌ, eÌgaliteÌ, fraterniteÌ fifty years on: why the 'free speech' debate makes it even less likely that Mai '68 could happen in Britain now than it was then
In May 1968 there was a strong sense of left-wing camaraderie that drew many French university students into collaboration with the workersâ unions to rise up against de Gaulleâs government. It is highly unlikely that British campuses could be gripped by these values of solidarity and shared agency in a common cause: what can that tell us about Britain? In Britain there are assumptions on the part of many young adults that we are free, equal and fraternal. The parallel digital world that they inhabit so comfortably appears to encourage and facilitate consumer behaviour and freedom of expression: it seems possible to buy and write online almost exactly what you like without consequences. Yet against a backdrop of crass populist discourse there are urgent issues regarding ethical behaviour: online and offline use of language is sharply racialised and gendered. People of colour and women of all ages are frequently attacked. Hate speech is poorly controlled and legal restraints are lagging behind the global digital empires. In addition, on campus the British government is intervening much more than ever before, which makes some students less free, less equal and less fraternal than others. Free speech is being constrained. Populism is on the rise, framed by political alienation. Finally, precarity affects the young in their responses to university: is it worth incurring the debt of high fees? The philosophy of Ricoeur and Lorey show how to interrogate dominant discourses and attempt a better world
- âŠ