301 research outputs found

    A Cross Comparison of Spatiotemporally Enhanced Springtime Phenological Measurements From Satellites and Ground in a Northern U.S. Mixed Forest

    Get PDF
    Cross comparison of satellite-derived land surface phenology (LSP) and ground measurements is useful to ensure the relevance of detected seasonal vegetation change to the underlying biophysical processes. While standard 16-day and 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index (VI)-based springtime LSP has been evaluated in previous studies, it remains unclear whether LSP with enhanced temporal and spatial resolutions can capture additional details of ground phenology. In this paper, we compared LSP derived from 500-m daily MODIS and 30-m MODIS-Landsat fused VI data with landscape phenology (LP) in a northern U.S. mixed forest. LP was previously developed from intensively observed deciduous and coniferous tree phenology using an upscaling approach. Results showed that daily MODIS-based LSP consistently estimated greenup onset dates at the study area (625 m × 625 m) level with 4.48 days of mean absolute error (MAE), slightly better than that of using 16-day standard VI (4.63 days MAE). For the observed study areas, the time series with increased number of observations confirmed that post-bud burst deciduous tree phenology contributes the most to vegetation reflectance change. Moreover, fused VI time series demonstrated closer correspondences with LP at the community level (0.1-20 ha) than using MODIS alone at the study area level (390 ha). The fused LSP captured greenup onset dates for respective forest communities of varied sizes and compositions with four days of the overall MAE. This study supports further use of spatiotemporally enhanced LSP for more precise phenological monitoring

    Effective Interventions to Reduce the Increase In Elective Cesarean Sections In Low Risk Women

    Get PDF
    According to the Annals of Family Medicine, the amount of babies born via cesarean section has increased from 4.5% in 1965 to 26.1% in 2002 and nearly 40% of all cesarean sections are repeats. After an extensive literature review, results showed that patients need to be educated about the risks and benefits of vaginal delivery and cesarean delivery. It was also found that there needs to be policy changes to decrease the amount of cesarean sections done and increase the labor and delivery support without using interventions. Further study should be focused on morbidity and mortality very low birth weight neonates for women with previous cesarean sections that accounts for unplanned VBAC deliveries.https://scholar.dominican.edu/ug-student-posters/1035/thumbnail.jp

    Markers of T-cell senescence and physical frailty: insights from Singapore Longitudinal Ageing Studies

    Get PDF
    10.1038/npjamd.2015.5npj Aging and Mechanisms of Disease1500

    The Physical Properties of High-Mass Star-Forming Clumps: A Systematic Comparison of Molecular Tracers

    Full text link
    We present observations of HCO+ and H^13CO+, N2H+, HCS+, HCN and HN^13C, SO and ^34SO, CCH, SO_2, and CH_3OH-E towards a sample of 27 high-mass clumps coincident with water maser emission. All transitions are observed with or convolved to nearly identical resolution (30"), allowing for inter-comparison of the clump properties derived from the mapped transitions. We find N2H+ emission is spatially differentiated compared to the dust and the other molecules towards a few very luminous cores (10 of 27) and the N2H+ integrated intensity does not correlate well with dust continuum flux. We calculate the effective excitation density, n_eff, the density required to excite a 1 K line in T_kin=20 K gas for each molecular tracer. The intensity of molecular tracers with larger effective excitation densities (n_eff > 10^5 cm^-3) appear to correlate more strongly with the submillimeter dust continuum intensity. The median sizes of the clumps are anti-correlated with the n_eff of the tracers (which span more than three orders of magnitude). Virial mass is not correlated with n_eff, especially where the lines are optically thick as the linewidths may be broadened significantly by non-virial motions. The median mass surface density and median volume density of the clumps is correlated with n_eff indicating the importance of understanding the excitation conditions of the molecular tracer when deriving the average properties of an ensemble of cores.Comment: 75 pages, 38 figure

    Systemic and metabolic signature of sarcopenia in community-dwelling older adults

    Get PDF
    Background Evidence suggests the pivotal contribution of nutrition as a modifiable risk factor for sarcopenia. The present cross-sectional study characterized the nutritional and metabolic profile of sarcopenia through an extensive exploration of a wide array of blood biomarkers related to muscle protein metabolism and transcriptomic signatures in community-dwelling elderly adults. Methods Among 189 older individuals with a mean age of 73.2 years, sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia criteria based on appendicular lean mass measured by dual-energy X-ray absorptiometry scan, muscle strength, and gait speed. Nutritional status was evaluated using the mini-nutritional assessment (MNA). In addition, we assessed specific blood biomarkers of nutritional status (plasma essential amino acids [EAAs], vitamins), nicotine-derived metabolites, and an extensive microarray analysis from peripheral blood mononuclear cells. Results Malnutrition defined by low MNA score was independently associated with sarcopenia (p < .001). Sarcopenic elderly showed lower body mass index and leptin and higher adiponectin and high-density lipoproteins. Levels of EAAs including lysine, methionine, phenylalanine, threonine, as well as branched-chain AAs and choline, were inversely associated with sarcopenia. Furthermore, nicotine metabolites (cotinine and trans-3′-hydroxycotine) and vitamin B6 status were linked to one or more clinical and functional measures of sarcopenia. Differentially expressed genes and ingenuity pathway analysis supported the association of nutrition with sarcopenia. Conclusions Herein, the characterization of a nutritional and metabolic signature of sarcopenia provides a firm basis and potential identification of specific targets and directions for the nutritional approach to the prevention and treatment of sarcopenia in aging populations

    Effects of choral singing versus health education on cognitive decline and aging: a randomized controlled trial.

    Get PDF
    We conducted a randomized controlled trial to examine choral singing's effect on cognitive decline in aging. Older Singaporeans who were at high risk of future dementia were recruited: 47 were assigned to choral singing intervention (CSI) and 46 were assigned to health education program (HEP). Participants attended weekly one-hour choral singing or weekly one-hour health education for two years. Change in cognitive function was measured by a composite cognitive test score (CCTS) derived from raw scores of neuropsychological tests; biomarkers included brain magnetic resonance imaging, oxidative damage and immunosenescence. The average age of the participants were 70 years and 73/93 (78.5%) were female. The change of CCTS from baseline to 24 months was 0.05 among participants in the CSI group and -0.1 among participants in the HEP group. The between-group difference (0.15, p=0.042) became smaller (0.12, p=0.09) after adjusting for baseline CCTS. No between-group differences on biomarkers were observed. Our data support the role of choral singing in improving cognitive health in aging. The beneficial effect is at least comparable than that of health education in preventing cognitive decline in a community of elderly people. Biological mechanisms underlying the observed efficacy should be further studied

    Metformin monotherapy downregulates diabetes-associated inflammatory status and impacts on mortality

    Get PDF
    Aging is the main risk factor for developing diabetes and other age-related diseases. One of the most common features of age-related comorbidities is the presence of low-grade chronic inflammation. This is also the case of metabolic syndrome and diabetes. At the subclinical level, a pro-inflammatory phenotype was shown to be associated with Type-2 diabetes mellitus (T2DM). This low to mid-grade inflammation is also present in elderly individuals and has been termed inflammaging. Whether inflammation is a component of aging or exclusively associated with age-related diseases in not entirely known. We used clinical data and biological readouts in a group of individuals stratified by age, diabetes status and comorbidities to investigate this aspect. While aging is the main predisposing factor for several diseases there is a concomitant increased level of pro-inflammatory cytokines. DM patients show an increased level of sTNFRll, sICAM-1, and TIMP-1 when compared to Healthy, Non-DM and Pre-DM individuals. These inflammatory molecules are also associated with insulin resistance and metabolic syndrome in Non-DM and pre-DM individuals. We also show that metformin monotherapy was associated with significantly lower levels of inflammatory molecules, like TNF, sTNFRI and sTNFRII, when compared to other monotherapies. Longitudinal follow up indicates a higher proportion of death occurs in individuals taking other monotherapies compared to metformin monotherapy. Together our finding shows that chronic inflammation is present in healthy elderly individuals and exacerbated with diabetes patients. Likewise, metformin could help target age-related chronic inflammation in general, and reduce the predisposition to comorbidities and mortality

    Examining the LLAMA aptitude tests

    Get PDF
    This study assesses the reliability1 of the LLAMA aptitude tests (Meara, 2005). The LLAMA tests were designed as shorter, free, language-neutral tests loosely based on the MLAT tests (Carroll & Sapon, 1959). They contain four sub-components: vocabulary acquisition, sound recognition, sound-symbol correspondence and grammatical inferencing. Granena (2013) and Rogers et al. (2016) provided initial results regarding factors which might influence LLAMA test scores. This paper develops this previous work by examining some of issues raised with a larger cohort and focuses on the following research questions. 1. Are the LLAMA tests language neutral?2. What is the effect of bilingualism on LLAMA test scores?3. What is the effect of age on LLAMA test scores?4. How much variance can background factors account for in the LLAMA test results? Data were collected from 240 participants aged 10–75 for RQ1–3. We found no significant differences in terms of language background (RQ1) but instructed second language learners significantly outperformed monolinguals (RQ2). For RQ3 we found that the younger groups were outperformed by all the other groups. For RQ4, we investigated how much variance in LLAMA test results six individual background factors could explain. We combined data from Rogers et al. (2016) and this study giving 404 participants in total. Using a multiple regression analysis, we found that prior L2 instruction predicted more of the variance (6%) than any other factor. We suggest that when using the LLAMA tests, researchers should consider controlling for language learning experience. This study scrutinises the components of the LLAMA tests with a large set of data. We conclude that the results are robust across a range of individual differences but suggest that different norms may be needed for younger age groups and those who have received prior L2 instruction
    corecore