217 research outputs found

    To see ourselves as others see usā€: On the implications of reflected appraisals for ethnic identity and discrimination

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    This study examined how immigrants' feelings of ethnic identity align with their . The results showed that both generations generally felt that they were regarded by both Chinese and Anglo Canadians as more Chinese than they felt themselves but indicated few discrepancies between self-and reflected appraisals of Canadian identity. Reflected appraisals were associated with the experience of personal discrimination only in the second-generation group. The discussion emphasizes the importance of a situational perspective on ethnic identity and underscores important differences between generational groups in their experience of identity and discrimination. Emigrating from one's home country and entering a new, unfamiliar one, entails adapting in many ways, including changing patterns of identificatio

    Influence of Sex/Gender and Race on Responses to Raltegravir Combined With Tenofovir-Emtricitabine in Treatment-Naive Human Immunodeficiency Virus-1 Infected Patients: Pooled Analyses of the STARTMRK and QDMRK Studies.

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    BACKGROUND: Antiretroviral therapy in human immunodeficiency virus (HIV)-infected women and blacks merits particular scrutiny because these groups have been underrepresented in clinical trials. METHODS: To document the effects of raltegravir across sex and racial lines, we conducted a pooled subgroup analysis of the efficacy and safety of raltegravir 400 mg BID plus tenofovir-emtricitabine by sex (women vs men) and self-identified race (black vs non-black) using phase 3 studies in treatment-naive patients. RESULTS: Study participants included 42 black women, 102 non-black women, 48 black men, and 477 non-black men. Clade B infections were less common in women (43.8%) than men (84.6%) and in blacks (45.6%) than non-blacks (80.5%). Baseline CD4 counts were ā‰¤200 cells/ĀµL in 52.2% of blacks and 31.6% of non-blacks. Black men had the largest proportion of patients with baseline CD4 counts/ĀµL and the highest nontreatment-related discontinuation rate among the 4 sex-by-race subgroups. Human immunodeficiency virus-ribonucleic acid levels/mL were achieved at week 48 in 92.7% (95% confidence interval [CI], 80.1-98.5) of black women, 93.6% (95% CI, 86.6-97.6) of non-black women, 82.9% (95% CI, 67.9-92.8) of black men, and 91.4% (95% CI, 88.4-93.8) of non-black men. Serious clinical adverse events were reported in 9.0% of women versus 8.8% of men and in 11.1% of blacks versus 8.5% of non-blacks. CONCLUSIONS: In this post hoc analysis of patients with previously untreated HIV-1 infection receiving raltegravir plus tenofovir-emtricitabine, generally comparable results were achieved across sex and racial subgroups. However, black men had a lower response rate than either black women or non-black men, partially attributable to lower baseline CD4 counts and higher discontinuation rates

    Assessing environmental controls on the distribution of long-chain alkenones in the Canadian Prairies

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    Long-chain alkenones (LCAs) have been used for decades to reconstruct quantitative sea-surface temperature records, but they also have a great potential for paleotemperature reconstructions in lacustrine settings. Here, we investigated how the presence and abundance of LCAs in surface sediments from 106 lakes varied with environmental conditions in lakes of the northern Great Plains (Canadian Prairies) in southern Saskatchewan, Canada. Consistent with preliminary research, we found LCAs in 55% of surveyed lakes, with mean concentrations of 143ā€ÆĪ¼g/g dry sediment, but very high concentrations (up to 2.3ā€Æmg/g dry sediment) in 7% of lakes. Statistical analyses indicate that salinity and stratification play key roles in determining LCA presence and abundance supporting previous research in Spain and the northern Great Plains, USA. Overall, the alkenone unsaturation index (U37K) was not correlated significantly with average summer water temperature, probably because the timing of maximum LCA production occurs during the spring season. We conclude that improved seasonal sampling is required within the study lakes to better identify the timing and habitat of haptophyte production, and allow development of environmental temperature reconstruction tools

    Impacts of forestry planting on primary production in upland lakes from north-west Ireland

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    Planted forests are increasing in many upland regions world-wide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). 210Pb dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (Ī“13C) and nitrogen (Ī“15N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to six-fold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (Ī²-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilisation and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance

    Natural climate solutions

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    Our thanks for inputs by L. Almond, A. Baccini, A. Bowman, S. CookPatton, J. Evans, K. Holl, R. Lalasz, A. Nassikas, M. Spalding, M. Wolosin, and expert elicitation respondents. Our thanks for datasets developed by the Hansen lab and the NESCent grasslands working group (C. Lehmann, D. Griffith, T. M. Anderson, D. J. Beerling, W. Bond, E. Denton, E. Edwards, E. Forrestel, D. Fox, W. Hoffmann, R. Hyde, T. Kluyver, L. Mucina, B. Passey, S. Pau, J. Ratnam, N. Salamin, B. Santini, K. Simpson, M. Smith, B. Spriggs, C. Still, C. Strƶmberg, and C. P. Osborne). This study was made possible by funding from the Doris Duke Charitable Foundation. Woodbury was supported in part by USDA-NIFA Project 2011-67003-30205 Data deposition: A global spatial dataset of reforestation opportunities has been deposited on Zenodo (https://zenodo.org/record/883444). This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1710465114/-/DCSupplemental.Peer reviewedPublisher PD

    Cross-sectional and longitudinal voxel-based grey matter asymmetries in Huntington's disease

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    Huntington's disease (HD) is a progressive neurodegenerative disorder that can be genetically confirmed with certainty decades before clinical onset. This allows the investigation of functional and structural changes in HD many years prior to disease onset, which may reveal important mechanistic insights into brain function, structure and organization in general. While regional atrophy is present at early stages of HD, it is still unclear if both hemispheres are equally affected by neurodegeneration and how the extent of asymmetry affects domain-specific functional decline. Here, we used whole-brain voxel-based analysis to investigate cross-sectional and longitudinal hemispheric asymmetries in grey matter (GM) volume in 56 manifest HD (mHD), 83 pre-manifest HD (preHD), and 80 healthy controls (HC). Furthermore, a regression analysis was used to assess the relationship between neuroanatomical asymmetries and decline in motor and cognitive measures across the disease spectrum. The cross-sectional analysis showed striatal leftward-biased GM atrophy in mHD, but not in preHD, relative to HC. Longitudinally, no net 36-month change in GM asymmetries was found in any of the groups. In the regression analysis, HD-related decline in quantitative-motor (Q-Motor) performance was linked to lower GM volume in the left superior parietal cortex. These findings suggest a stronger disease effect targeting the left hemisphere, especially in those with declining motor performance. This effect did not change over a period of three years and may indicate a compensatory role of the right hemisphere in line with recent functional imaging studies

    Novel alkenone-producing strains of genus Isochrysis (Haptophyta) isolated from Canadian saline lakes show temperature sensitivity of alkenones and alkenoates

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    Alkenone-producing species have been recently found in diverse lacustrine environments, albeit with taxonomic information derived indirectly from environmental genomic techniques. In this study, we isolated alkenone-producing algal species from Canadian saline lakes and established unialgal cultures of individual strains to identify their taxonomical and molecular biological characteristics. Water and sediments collected from the lakes were first enriched in artificial seawater medium over a range of salinities (5ā€“40 g/L) to cultivate taxa in vitro. Unialgal cultures of seven haptophyte strains were isolated and categorized in the Isochrysis clade using SSU and LSU rRNA gene analysis. The alkenone distributions within isolated strains were determined to be novel compared with other previously reported alkenone-producing haptophytes. While all strains produced the typical C37 and C38 range of isomers, one strain isolated from Canadian salt lakes also produced novel C41 and C42 alkenones that are temperature sensitive. In addition, we showed that all alkenone unsaturation indices (e.g., UK37 and UK'37) are temperature-dependent in culture experiments, and that alkenoate indices (e.g., UA37, UA38, RIA38 and A37/A38) provide alternative options for temperature calibration based on these new lacustrine algal strains. Importantly, these indices show temperature dependence in culture experiments at temperatures below 10ā€ÆĀ°C, where traditional alkenone proxies were not as sensitive. We hypothesize that this suite of calibrations may be used for reconstructions of past water temperature in a broad range of lakes in the Canadian prairies

    Impacts of forestry planting on primary production in upland lakes from north-west Ireland

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    Planted forests are increasing in many upland regions worldwide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here, the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4ā€“64% of catchment area). 210Pb-dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (Ī“13C) and nitrogen (Ī“15N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to sixfold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39ā€“116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (Ī²-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilization and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance
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