469 research outputs found

    Modern pollen-vegetation relationships along a steep temperature gradient in the Tropical Andes of Ecuador

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    This is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this record.The characterization of modern pollen rain assemblages along environmental gradients is an essential prerequisite for reliable interpretations of fossil pollen records. In this study, we identify pollen-vegetation relationships using modern pollen rain assemblages in moss polsters (n = 13) and lake sediment surface samples (n = 11) along a steep temperature gradient of 7°C (3100–4200 m above sea level) on the western Andean Cordillera, Ecuador. The pollen rain is correlated to vascular plant abundance data recorded in vegetation relevées (n = 13). Results show that pollen spectra from both moss polsters and sediment surface samples reflect changes in species composition along the temperature gradient, despite overrepresentation of upper montane forest taxa in the latter. Estimated pollen transport distance for a lake (Laguna Llaviucu) situated in a steep upper montane forest valley is 1–2 km, while a lake (Laguna Pallcacocha) in the páramo captures pollen input from a distance of up to 10–40 km. Weinmannia spp., Podocarpus spp., and Hedyosmum sp. are indicators of local upper montane forest vegetation, while Phlegmariurus spp. and Plantago spp. are indicators for local páramo vegetation.Earth and Life Science council (ALW) of the Netherlands Organisation of Scientific Researc

    Brief Communication Gaze-Centered Updating of Visual Space in Human Parietal Cortex

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    Single-unit recordings have identified a region in the posterior parietal cortex (PPC) of the monkey that represents and updates visual space in a gaze-centered frame. Here, using event-related functional magnetic resonance imaging, we identified an analogous bilateral region in the human PPC that shows contralateral topography for memory-guided eye movements and arm movements. Furthermore, when eye movements reversed the remembered horizontal target location relative to the gaze fixation point, this PPC region exchanged activity across the two cortical lobules. This shows that the human PPC dynamically updates the spatial goals for action in a gaze-centered frame

    Effects of Dementia-Care Mapping on Residents and Staff of Care Homes:A Pragmatic Cluster-Randomised Controlled Trial

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    BACKGROUND: The effectiveness of dementia-care mapping (DCM) for institutionalised people with dementia has been demonstrated in an explanatory cluster-randomised controlled trial (cRCT) with two DCM researchers carrying out the DCM intervention. In order to be able to inform daily practice, we studied DCM effectiveness in a pragmatic cRCT involving a wide range of care homes with trained nursing staff carrying out the intervention. METHODS: Dementia special care units were randomly assigned to DCM or usual care. Nurses from the intervention care homes received DCM training and conducted the 4-months DCM-intervention twice during the study. The primary outcome was agitation, measured with the Cohen-Mansfield agitation inventory (CMAI). The secondary outcomes included residents’ neuropsychiatric symptoms (NPSs) and quality of life, and staff stress and job satisfaction. The nursing staff made all measurements at baseline and two follow-ups at 4-month intervals. We used linear mixed-effect models to test treatment and time effects. RESULTS: 34 units from 11 care homes, including 434 residents and 382 nursing staff members, were randomly assigned. Ten nurses from the intervention units completed the basic and advanced DCM training. Intention-to-treat analysis showed no statistically significant effect on the CMAI (mean difference between groups 2·4, 95% CI −2·7 to 7·6; p = 0·34). More NPSs were reported in the intervention group than in usual care (p = 0·02). Intervention staff reported fewer negative and more positive emotional reactions during work (p = 0·02). There were no other significant effects. CONCLUSIONS: Our pragmatic findings did not confirm the effect on the primary outcome of agitation in the explanatory study. Perhaps the variability of the extent of implementation of DCM may explain the lack of effect. TRIAL REGISTRATION: Dutch Trials Registry NTR2314

    Smart Phone, Smart Science: How the Use of Smartphones Can Revolutionize Research in Cognitive Science

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    Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific “instrument” that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science

    Drusen of the iris: in advanced malignant choroidal melanoma

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    Drusen were found in the iris between the layers of the pigment epithelium and the dilator muscle in an eye of a 52 year old patient that contained a large malignant choroidal melanoma. The significance of this unusual observation in comparison to the common drusen of Bruch's membrane of the choroid is discussed. In einem Auge einer 52jährigen Patientin, das wegen eines Melanoms der Aderhaut enukleiert werden mußte, fanden sich Drusen der Regenbogenhaut, die zwischen dem Pigmentepithel und dem Dilatator-Muskel lagen. Die Bedeutung dieser Drusen im Vergleich zu den Drusen der Aderhaut wird erörtert.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47368/1/417_2004_Article_BF00506637.pd

    The Effect of Sugar-Free Versus Sugar-Sweetened Beverages on Satiety, Liking and Wanting: An 18 Month Randomized Double-Blind Trial in Children

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    BACKGROUND: Substituting sugar-free for sugar-sweetened beverages reduces weight gain. A possible explanation is that sugar-containing and sugar-free beverages cause the same degree of satiety. However, this has not been tested in long-term trials. METHODS: We randomized 203 children aged 7-11 years to receive 250 mL per day of an artificially sweetened sugar-free beverage or a similarly looking and tasting sugar-sweetened beverage. We measured satiety on a 5-point scale by questionnaire at 0, 6, 12 and 18 months. We calculated the change in satiety from before intake to 1 minute after intake and 15 minutes after intake. We then calculated the odds ratio that satiety increased by 1 point in the sugar-group versus the sugar-free group. We also investigated how much the children liked and wanted the beverages. RESULTS: 146 children or 72% completed the study. We found no statistically significant difference in satiety between the sugar-free and sugar-sweetened group; the adjusted odds ratio for a 1 point increase in satiety in the sugar group versus the sugar-free group was 0.77 at 1 minute (95% confidence interval, 0.46 to 1.29), and 1.44 at 15 minutes after intake (95% CI, 0.86 to 2.40). The sugar-group liked and wanted their beverage slightly more than the sugar-free group, adjusted odds ratio 1.63 (95% CI 1.05 to 2.54) and 1.65 (95% CI 1.07 to 2.55), respectively. CONCLUSIONS: Sugar-sweetened and sugar-free beverages produced similar satiety. Therefore when children are given sugar-free instead of sugar-containing drinks they might not make up the missing calories from other sources. This may explain our previous observation that children in the sugar-free group accumulated less body fat than those in the sugar group.<br /
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