558 research outputs found

    Research Notes: A spontaneous mutant at the st2 locus

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    In 1971, Detroy Green, Department of Agronomy, Iowa State University, found sterile plants in an F4 single-plant progeny row from a cross of Hark X Harosoy Dt2Dt2. This family segregated 66 fertile to 21 sterile plants. Microspore mother cells of the sterile plants were examined, and a low level of chromosome pairing was observed, indicating that the sterile was either an asynaptic or desynaptic mutant

    Exploring patterns of response across the lifespan: the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) study

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    Abstract Background With declining rates of participation in epidemiological studies there is an important need to attempt to understand what factors might affect response. This study examines the pattern of response at different adult ages within a contemporary cross-sectional population-based cohort, the Cambridge Centre for Ageing and Neuroscience (Cam-CAN). Methods Using logistic regression, we investigated associations between age, gender and Townsend deprivation level for both participants and non-participants. Weighted estimates of the odds ratios with confidence intervals for each demographic characteristic were calculated. Reasons given for refusal were grouped into three broad categories: ‘active’, ‘passive’ and illness preventing interview. Results An association of age and participation was found, with individuals in middle age groups more likely to participate (age group 48–57 OR: 1.8, 95% CI: 1.5–2.2 and age group 58–67 OR: 2.1, 95% CI: 1.7–2.4). Overall, there was no difference in participation between men and women. An association with deprivation was found, with those living in the most deprived areas being the least willing to participate (fifth quintile OR: 0.6, 95% CI: 0.5–0.7). An interaction between age and gender was found whereby younger women and older men were more likely to agree to participate (p = 0.01). Conclusion Our findings highlight some of the factors affecting recruitment into epidemiological studies in the UK and suggest that targeted age-specific recruitment strategies might be needed to increase participation rates in future cohort investigations

    Predicting the Effect of Moisture Content on the Flexural Properties of Southern Pine Dimension Lumber

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    Current procedures for adjusting lumber properties for changes in moisture content are based on trends observed with the mean properties. This study was initiated to develop analytical procedures for adjusting the flexural properties of 2-inch-thick southern pine dimension lumber applicable to all grades and sizes as well as all levels of the cumulative frequency distribution. Equations are derived for adjusting modulus of rupture (MOR), modulus of elasticity (MOE), moment capacity (RS), and flexural stiffness (EI) for changes in moisture content. The best of these equations are significantly more accurate than current procedures for adjusting strength properties (MOR and RS). Because MOE and EI are less affected by changes in moisture content, most of the equations, including the current American Society for Testing and Materials procedure, work well for these properties

    In-flight radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

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    A reflectance-based method was used to provide an analysis of the in-flight radiometric performance of AVIRIS. Field spectral reflectance measurements of the surface and extinction measurements of the atmosphere using solar radiation were used as input to atmospheric radiative transfer calculations. Five separate codes were used in the analysis. Four include multiple scattering, and the computed radiances from these for flight conditions were in good agreement. Code-generated radiances were compared with AVIRIS-predicted radiances based on two laboratory calibrations (pre- and post-season of flight) for a uniform highly reflecting natural dry lake target. For one spectrometer (C), the pre- and post-season calibration factors were found to give identical results, and to be in agreement with the atmospheric models that include multiple scattering. This positive result validates the field and laboratory calibration technique. Results for the other spectrometers (A, B and D) were widely at variance with the models no matter which calibration factors were used. Potential causes of these discrepancies are discussed

    Is late-life dependency increasing or not? A comparison of the Cognitive Function and Ageing Studies (CFAS)

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    Background: Little is known about how dependency levels have changed between generational cohorts of older people. We estimated years lived in different care states at age 65 in 1991 and 2011 and new projections of future demand for care. Methods: Two population-based studies of older people in defined geographical areas conducted two decades apart (the Cognitive Function and Ageing Studies) provided prevalence estimates of dependency in four states: high (24-hour care); medium (daily care); low (less than daily); independent. Years in each dependency state were calculated by Sullivan’s method. To project future demand, the proportions in each dependency state (by age group and sex) were applied to the 2014 England population projections. Findings: Between 1991 and 2011 there were significant increases in years lived from age 65 with low (men:1·7 years, 95%CI 1·0-2·4; women:2·4 years, 95%CI 1·8-3·1) and high dependency (men:0·9 years, 95%CI 0·2-1·7; women:1·3 years, 95%CI 0·5-2·1). The majority of men’s extra years of life were independent (36%) or with low dependency (36%) whilst for women the majority were spent with low dependency (58%), only 5% being independent. There were substantial reductions in the proportions with medium and high dependency who lived in care homes, although, if these dependency and care home proportions remain constant in the future, further population ageing will require an extra 71,000 care home places by 2025. Interpretation: On average older men now spend 2.4 years and women 3.0 years with substantial care needs (medium or high dependency), and most will live in the community. These findings have considerable implications for older people’s families who provide the majority of unpaid care, but the findings also supply valuable new information for governments and care providers planning the resources and funding required for the care of their future ageing populations

    Synthesis and Evaluation of New Cathepsin D Inhibitors

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    Cathepsin D, a lysosomal aspartic protease, has been suggested to play a role in the metastatic potential of several types of cancer A high activated cathepsin D level in breast tumor tissue has been associated with an increased incidence of relapse and metastasis. High levels of active cathepsin D have also been found in colon cancer, prostate cancer, uterine cancer, and ovarian cancer. Hydroxyethyl isosteres with cyclic tertiary amine have proven to be clinically useful as inhibitors of aspartyl proteases, such as cathepsin D and the HIV1 aspartyl protease. Also cathepsin D has recently been associated with the development of Alzheimer\u27s disease. Specific proteinase inhibitors, useful in investigations of the mechanisms and pathways of intracellular protein degradation, could lead to the development of therapeutic agents for treatment of many types of carcinomas as well as Alzheimer\u27s disease. The design and the synthesis of (hydroxyethyl)amine isostere inhibitors with the cyclic tertiary amines is described. The IC-50 and apparent Ki values for several cathepsin D inhibitors are reported

    Changing non-participation in epidemiological studies of older people: evidence from the Cognitive Function and Ageing Study I and II.

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    BACKGROUND: non-participation in epidemiological studies threatens the generalisability of findings. OBJECTIVE: to investigate the change in non-participation between the Medical Research Council Cognitive Function and Ageing Study (CFAS) I and II. DESIGN: a comparison of two epidemiological studies of older people using identical methods. SETTING: three geographical areas of the United Kingdom. SUBJECTS: older people aged 65 years and over. METHODS: the two studies were conducted approximately two decades apart between 1989 and 1994 (CFAS I) and between 2008 and 2011 (CFAS II). Random samples were drawn from primary care lists. We compared demographic factors associated with non-participation. RESULTS: non-participation in CFAS II was higher than in CFAS I (45.3 versus 18.3%). After adjustment for confounders, in both CFAS I and CFAS II, women were more likely to decline to take part (CFAS I: odds ratio (OR) 1.3 95% confidence interval (CI) 1.2 to 1.4; CFAS II: 1.1 95% CI 1.1 to 1.2). Deprivation was associated with non-participation in both studies (highest versus lowest Townsend deprivation quintile, CFAS I: OR 1.4 95% CI 1.2 to 1.6; CFAS II: 2.0 95% CI 1.8 to 2.2). Age was not associated with non-participation in either study (CFAS I, P = 0.21; CFAS II, P = 0.47). CONCLUSIONS: non-participation in epidemiological studies of older people has increased substantially in the past two decades and public willingness to take part in studies of this kind would appear to be declining. As communities become more diverse and older people have increasing commitments on their time, new ways to engage prospective participants are urgently needed.This work was supported by the Department of Health; the Medical Research Council; The National Institute of Health Research comprehensive research networks in West Anglia and Trent and the dementias and neurodegenerative disease research networks in Newcastle (grant number G9901400, G0601022). F.E.M. is supported by the MRC U105292687. The funders had no role in the design, implementation, analysis or interpretation of the study.This is the final version. It is available from Oxford University Press via http://dx.doi.org/10.1093/ageing/afv10

    Comparing motor-­vehicle crash risk of EU and US vehicles

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    This study examined the hypotheses that vehicles meeting EU safety standards perform similarly to US-­‐regulated vehicles in the US driving environment, and vice versa. The analyses used three statistical approaches to “triangulate” evidence regarding differences in crash and injury risk. Separate analyses assessed crash avoidance technologies, including headlamps and mirrors. The results suggest that when controlling for differences in environment and exposure, vehicles meeting EU standards offer reduced risk of serious injury in frontal/side crashes and have driver-­‐side mirrors that reduce risk in lane-­‐change crashes better, while vehicles meeting US standards provide a lower risk of injury in rollovers and have headlamps that make pedestrians more conspicuous.Alliance of Automobile Manufacturershttp://deepblue.lib.umich.edu/bitstream/2027.42/112977/1/103199.pd

    Identifying People with Acute HIV Infection (AHI) – Demographic Features, Risk Factors, and Use of Health Care among Individuals with AHI in North Carolina

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    Identifying and counseling individuals with Acute HIV Infection (AHI) offers a critical opportunity to avert preventable HIV transmission, however opportunities to recognize these individuals may be missed. We surveyed 32 adults diagnosed with AHI during voluntary HIV testing from 1/1/03 to 2/28/05 in publicly funded testing sites in NC to describe their clinical, social, and behavioral characteristics. Eighty-one percent of participants were men; 59% were African American. Seventy-five percent experienced symptoms consistent with acute retroviral syndrome; although 83% sought medical care for these symptoms, only 15% were appropriately diagnosed at that initial medical visit, suggesting opportunities to diagnose these individuals earlier were missed. Eighty-five percent of the men engaged in sex with men. More than 50% of the participants thought they were infected with HIV by a steady partner. This study yields important information to assist in identifying populations at risk for or infected with AHI and designing both primary and secondary prevention interventions
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