2,397 research outputs found
Impact of screening on cervical cancer incidence: A population-based case-control study in the United States.
Cervical cancer is widely preventable through screening, but little is known about the duration of protection offered by a negative screen in North America. A case-control study was conducted with records from population-based registries in New Mexico. Cases were women diagnosed with cervical cancer in 2006-2016, obtained from the Tumor Registry. Five controls per case from the New Mexico HPV Pap Registry were matched to cases by sex, age and place of residence. Dates and results of all cervical screening and diagnostic tests since 2006 were identified from the pap registry. We estimated the odds ratio of nonlocalized (Stage II+) and localized (Stage I) cervical cancer associated with attending screening in the 3 years prior to case-diagnosis compared to women not screened in 5 years. Of 876 cases, 527 were aged 25-64 years with ≥3 years of potential screening data. Only 38% of cases and 61% of controls attended screening in a 3-year period. Women screened in the 3 years prior to diagnosis had 83% lower risk of nonlocalized cancer (odds ratio [OR] = 0.17, 95% CI: 0.12-0.24) and 48% lower odds of localized cancer (OR = 0.52, 95% CI: 0.38-0.72), compared to women not screened in the 5 years prior to diagnosis. Women remained at low risk of nonlocalized cancer for 3.5-5 years after a negative screen compared to women with no negative screens in the 5 years prior to diagnosis. Routine cervical screening is effective at preventing localized and nonlocalized cervical cancers; 3 yearly screening prevents 83% of nonlocalized cancers, with no additional benefit of more frequent screening. Increasing screening coverage remains essential to further reduce cervical cancer incidence.This work was supported by the US National Cancer Institute (NCI) U54CA164336 to CMW (CMW, CLW, MR) with subcontracts to Texas A & M University, College Station, Texas (YJM, DWG) and to University of Alabama at Birmingham (ICS) and by the US National Institute of Allergy and Infectious Diseases U19AI113187 to CMW with subcontract to Queen Mary University of London (QMUL) (JC, PDS). This project was also supported by Contract HHSN261201800014I, Task Order HHSN26100001 from the National Cancer Institute (CLW). In addition, support was received from Cancer Research UK programme grants C8161/A1689 to PDS (RL, CM) and C569/A16891 to JC, from NCI P30CA118100 (to CL Willman) (YJM) and the Ford Foundation (YJM)
High-throughput UHPLC/MS/MS-based metabolic profiling using a vacuum jacketed column
In UHPLC, frictional heating from the eluent flowing through the column at pressures of ca. 10–15 Kpsi causes radial diffusion via temperature differences between the center of the column and its walls. Longitudinal dispersion also occurs due to temperature gradients between the inlet and outlet. These effects cause band broadening but can be mitigated via a combination of vacuum jacketed stainless steel tubing, reduced column end nut mass, and a constant temperature in the column from heating the inlet fitting. Here, vacuum jacketed column (VJC) technology, employing a novel column housing located on the source of the mass spectrometer and minimized tubing from the column outlet to the electrospray probe, was applied to profiling metabolites in urine. For a 75 s reversed-phase gradient separation, the average peak widths for endogenous compounds in urine were 1.2 and 0.6 s for conventional LC/MS and VJC systems, respectively. The peak tailing factor was reduced from 1.25 to 1.13 when using the VJC system compared to conventional UHPLC, and the peak capacity increased from 65 to 120, with a 25% increase in features detected in urine. The increased resolving power of the VJC system reduced co-elution, simplifying MS and MS/MS spectra, providing a more confident metabolite identification. The increased LC performance also gave more intense MS peaks, with a 10–120% increase in response, improving the quality of the MS data and detection limits. Reducing the LC gradient duration to 37 s gave peak widths of ca. 0.4 s and a peak capacity of 84
Complex circular subsidence structures in tephra deposited on large blocks of ice: Varða tuff cone, Öræfajökull, Iceland
Several broadly circular structures up to 16 m in diameter, into which higher strata have sagged and locally collapsed, are present in a tephra outcrop on southwest Öræfajökull, southern Iceland. The tephra was sourced in a nearby basaltic tuff cone at Varða. The structures have not previously been described in tuff cones, and they probably formed by the melting out of large buried blocks of ice emplaced during a preceding jökulhlaup that may have been triggered by a subglacial eruption within the Öræfajökull ice cap. They are named ice-melt subsidence structures, and they are analogous to kettle holes that are commonly found in proglacial sandurs and some lahars sourced in ice-clad volcanoes. The internal structure is better exposed in the Varða examples because of an absence of fluvial infilling and reworking, and erosion of the outcrop to reveal the deeper geometry. The ice-melt subsidence structures at Varða are a proxy for buried ice. They are the only known evidence for a subglacial eruption and associated jökulhlaup that created the ice blocks. The recognition of such structures elsewhere will be useful in reconstructing more complete regional volcanic histories as well as for identifying ice-proximal settings during palaeoenvironmental investigations
Building development and roads: implications for the distribution of stone curlews across the Brecks
Background: Substantial new housing and infrastructure development planned within England has the potential to conflict with the nature conservation interests of protected sites. The Breckland area of eastern England (the Brecks) is designated as a Special Protection Area for a number of bird species, including the stone curlew (for which it holds more than 60% of the UK total population). We explore the effect of buildings and roads on the spatial distribution of stone curlew nests across the Brecks in order to inform strategic development plans to avoid adverse effects on such European protected sites. Methodology: Using data across all years (and subsets of years) over the period 1988 – 2006 but restricted to habitat areas of arable land with suitable soils, we assessed nest density in relation to the distances to nearest settlements and to major roads. Measures of the local density of nearby buildings, roads and traffic levels were assessed using normal kernel distance-weighting functions. Quasi-Poisson generalised linear mixed models allowing for spatial auto-correlation were fitted. Results: Significantly lower densities of stone curlew nests were found at distances up to 1500m from settlements, and distances up to 1000m or more from major (trunk) roads. The best fitting models involved optimally distance-weighted variables for the extent of nearby buildings and the trunk road traffic levels. Significance : The results and predictions from this study of past data suggests there is cause for concern that future housing development and associated road infrastructure within the Breckland area could have negative impacts on the nesting stone curlew population. Given the strict legal protection afforded to the SPA the planning and conservation bodies have subsequently agreed precautionary restrictions on building development within the distances identified and used the modelling predictions to agree mitigation measures for proposed trunk road developments
Evidence for Pervasive Adaptive Protein Evolution in Wild Mice
The relative contributions of neutral and adaptive substitutions to molecular evolution has been one of the most controversial issues in evolutionary biology for more than 40 years. The analysis of within-species nucleotide polymorphism and between-species divergence data supports a widespread role for adaptive protein evolution in certain taxa. For example, estimates of the proportion of adaptive amino acid substitutions (alpha) are 50% or more in enteric bacteria and Drosophila. In contrast, recent estimates of alpha for hominids have been at most 13%. Here, we estimate alpha for protein sequences of murid rodents based on nucleotide polymorphism data from multiple genes in a population of the house mouse subspecies Mus musculus castaneus, which inhabits the ancestral range of the Mus species complex and nucleotide divergence between M. m. castaneus and M. famulus or the rat. We estimate that 57% of amino acid substitutions in murids have been driven by positive selection. Hominids, therefore, are exceptional in having low apparent levels of adaptive protein evolution. The high frequency of adaptive amino acid substitutions in wild mice is consistent with their large effective population size, leading to effective natural selection at the molecular level. Effective natural selection also manifests itself as a paucity of effectively neutral nonsynonymous mutations in M. m. castaneus compared to humans
Low-Energy Signals from Kinetic Mixing with a Warped Abelian Hidden Sector
We investigate the detailed phenomenology of a light Abelian hidden sector in
the Randall-Sundrum framework. Relative to other works with light hidden
sectors, the main new feature is a tower of hidden Kaluza-Klein vectors that
kinetically mix with the Standard Model photon and Z. We investigate the decay
properties of the hidden sector fields in some detail, and develop an approach
for calculating processes initiated on the ultraviolet brane of a warped space
with large injection momentum relative to the infrared scale. Using these
results, we determine the detailed bounds on the light warped hidden sector
from precision electroweak measurements and low-energy experiments. We find
viable regions of parameter space that lead to significant production rates for
several of the hidden Kaluza-Klein vectors in meson factories and fixed-target
experiments. This offers the possibility of exploring the structure of an extra
spacetime dimension with lower-energy probes.Comment: (1+32) Pages, 13 Figures. v2: JHEP version (minor modifications,
results unchanged
Population genomics of domestic and wild yeasts
The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation
A Randomized Controlled Pilot Study to Evaluate a Technology Platform for the Assisted Living of People with Dementia and their Carers.
The use of telemedicine is becoming increasingly popular in assisting with the home management of People with Dementia (PwD) by offering services to the carers that may enhance their ability to care for their relative for longer. A computerized platform, ALADDIN, was evaluated in its usefulness to reduce carer burden and distress and to improve their quality of life, in an attempt to delay institutionalization of PwD. ALADDIN offers educational material about dementia to carers and provides the opportunity to contact other carers and clinicians. ALADDIN also facilitates remote monitoring of the PwD and their carers by the clinicians to enable speedy delivery of appropriate intervention. The ALADDIN platform was piloted at three European sites, and used by thirty carers of PwD living in the community (platform group). The platform group and a control group of thirty PwD and their carers were assessed at baseline, 3 months, and 6 months. The results showed a significant improvement in the quality of life of the carers in the platform group, with some reduction in carer burden and distress. The platform was useful in monitoring the patients and facilitating contact with other professionals. Access to and use of the ALADDIN platform was rated positively by carers and clinicians. The ALADDIN platform's usefulness and applicability for prolonging the home management of PwD are discussed
Future possibilities in the prevention of breast cancer: Breast cancer prevention trials
The available results from breast cancer chemoprevention trials are reviewed. Four trials using tamoxifen have been performed, of which three have reported efficacy results. A fifth trial using raloxifene has also been reported. The largest tamoxifen trial showed approximately 50% reduction in breast cancer incidence in the short term, but the two smaller trials did not find any reduction. Greater agreement exists for side effects; incidences of thromboembolic disease and endometrial cancers are raised approximately threefold when tamoxifen is used for 5 years. The possible reasons for the discrepancy in breast cancer reduction are explored. A review of trial parameters does not clearly explain this difference, and a meta-analysis indicates that all results are compatible with a 40% reduction in short-term incidence. Several important questions remain regarding the clinical implications of this result, including the effect on mortality, the appropriate risk groups for chemoprevention and the long-term effects on incidence. Continued follow up of these trials is crucial for resolving these issues
Decontamination of 16S rRNA gene amplicon sequence datasets based on bacterial load assessment by qPCR
Identification of unexpected taxa in 16S rRNA surveys of low-density microbiota, diluted mock communities and cultures demonstrated that a variable fraction of sequence reads originated from exogenous DNA. The sources of these contaminants are reagents used in DNA extraction, PCR, and next-generation sequencing library preparation, and human (skin, oral and respiratory) microbiota from the investigators
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