499 research outputs found
Bryophytes of Uganda : 2., new and interesting records
51 hepatics and 46 mosses are reported new to Uganda, including one moss new to Africa, one hepatic and two mosses new to mainland Africa, and 2 hepatics that are otherwise known only from their type collection
Evidencing a place for the hippocampus within the core scene processing network
Functional neuroimaging studies have identified several âcoreâ brain regions that are preferentially activated by scene stimuli, namely posterior parahippocampal gyrus (PHG), retrosplenial cortex (RSC), and transverse occipital sulcus (TOS). The hippocampus (HC), too, is thought to play a key role in scene processing, although no study has yet investigated scene-sensitivity in the HC relative to these other âcoreâ regions. Here, we characterised the frequency and consistency of individual scene-preferential responses within these regions by analysing a large dataset (n = 51) in which participants performed a one-back working memory task for scenes, objects, and scrambled objects. An unbiased approach was adopted by applying independently-defined anatomical ROIs to individual-level functional data across different voxel-wise thresholds and spatial filters. It was found that the majority of subjects had preferential scene clusters in PHG (max = 100% of participants), RSC (max = 76%), and TOS (max = 94%). A comparable number of individuals also possessed significant scene-related clusters within their individually defined HC ROIs (max = 88%), evidencing a HC contribution to scene processing. While probabilistic overlap maps of individual clusters showed that overlap âpeaksâ were close to those identified in group-level analyses (particularly for TOS and HC), inter-individual consistency varied across regions and statistical thresholds. The inter-regional and inter-individual variability revealed by these analyses has implications for how scene-sensitive cortex is localised and interrogated in functional neuroimaging studies, particularly in medial temporal lobe regions, such as the H
APOE-Δ4 selectively modulates posteromedial cortex activity during scene perception and short- term memory in young healthy adults OPEN
Apolipoprotein E (APOE) Δ4 is a major genetic risk factor for Alzheimer's disease (AD), yet the mechanisms by which APOE-Δ4 influences early-life brain function, and hence, in turn, risk for later-life AD, are poorly understood. Here, we report a novel, and selective, pattern of functional brain activity alteration in healthy young adult human APOE-Δ4 carriers. Our findings suggest that APOE-Δ4 may influence vulnerability to poorer later life cognitive health via its effect on posteromedial cortex (PMC), a hub region within a brain network involved in spatial processing, and necessary for episodic memory. In two neuroimaging tasks, APOE-Δ4 carriers showed an inability to effectively modulate PMC during scene, but not face and object, working memory and perception. This striking pattern overlaps both functionally and topographically, with the earliest cognitive deficits seen in clinical AD, as well as reported alterations in the default network in amyloid-positive individuals at increased risk of AD. Some of the earliest and most consistent metabolic changes in Alzheimer's disease (AD) are evident in posteromedial cortex (PMC), which comprises posterior cingulate, precuneus and retrosplenial cortice
APOE-Δ4 selectively modulates posteromedial cortex activity during scene perception and short-term memory in young healthy adults
Apolipoprotein E (APOE) Δ4 is a major genetic risk factor for Alzheimerâs disease (AD), yet the mechanisms by which APOE-Δ4 influences early-life brain function, and hence, in turn, risk for later-life AD, are poorly understood. Here, we report a novel, and selective, pattern of functional brain activity alteration in healthy young adult human APOE-Δ4 carriers. Our findings suggest that APOE-Δ4 may influence vulnerability to poorer later life cognitive health via its effect on posteromedial cortex (PMC), a hub region within a brain network involved in spatial processing, and necessary for episodic memory. In two neuroimaging tasks, APOE-Δ4 carriers showed an inability to effectively modulate PMC during scene, but not face and object, working memory and perception. This striking pattern overlaps both functionally and topographically, with the earliest cognitive deficits seen in clinical AD, as well as reported alterations in the default network in amyloid-positive individuals at increased risk of AD
Birth Related Wounds: Risk, Prevention and Management of Complications after Vaginal and Caesarean Section Birth
Application of photogrammetry to generate quantitative geobody data in ephemeral fluvial systems
Outcrop studies are often used as analogues to subsurface sedimentary reservoirs, with photogrammetry representing a useful technique to obtain quantitative geometrical data of sedimentary architectures. Digital photogrammetry techniques were used to study fluvial sediments of the Lower Jurassic Kayenta Formation of the western USA, and model-extracted statistics for channel and sheetflood elements, relevant to reservoir modelling, were compared to 1D and 2D datasets from the same outcrops. Results suggest that the 1D/2D data significantly underestimated element dimensions and ranges in ephemeral-fluvial systems. Consequently, this study demonstrates the value of photogrammetric techniques for obtaining statistically relevant and more accurate reservoir modelling input data from outcrop
Severe childhood malaria syndromes defined by plasma proteome profiles
BACKGROUND
Cerebral malaria (CM) and severe malarial anemia (SMA) are the most serious life-threatening clinical syndromes of Plasmodium falciparum infection in childhood. Therefore it is important to understand the pathology underlying the development of CM and SMA, as opposed to uncomplicated malaria (UM). Different host responses to infection are likely to be reflected in plasma proteome-patterns that associate with clinical status and therefore provide indicators of the pathogenesis of these syndromes.
METHODS AND FINDINGS
Plasma and comprehensive clinical data for discovery and validation cohorts were obtained as part of a prospective case-control study of severe childhood malaria at the main tertiary hospital of the city of Ibadan, an urban and densely populated holoendemic malaria area in Nigeria. A total of 946 children participated in this study. Plasma was subjected to high-throughput proteomic profiling. Statistical pattern-recognition methods were used to find proteome-patterns that defined disease groups. Plasma proteome-patterns accurately distinguished children with CM and with SMA from those with UM, and from healthy or severely ill malaria-negative children.
CONCLUSIONS
We report that an accurate definition of the major childhood malaria syndromes can be achieved using plasma proteome-patterns. Our proteomic data can be exploited to understand the pathogenesis of the different childhood severe malaria syndromes
Psychology and poverty reduction: a global special Issue
A âglobal special issueâ on poverty brought together 9 international psychology journals during 2010 through 2013. The purpose was to highlight psychologyâs contribution toward the Millennium Development Goals (MDGs). These goals are rooted in the âcapabilities approachâ and highlight the importance of fostering environments that support 3 core domains: health, basic education, and income. Here, we analyze what the global special issue contributed. As a whole the global special issue provided an account of âhowâ psychology engages with poverty and poverty reduction. First, the global special issue, more than other research on poverty, was focused on lower- and middle-income settings. Second, while the content of the articles could be coded into 3 specific domains (health/well-being, education/development, and society/work), the vast majority of the articles straddled more than 1 category. Third, the contents of the global special issue could be organized in terms of the type of contribution: that is, practicality, theory, description, and advocacy. We highlight the importance of addressing wider situational and sociopolitical structures that constrain capability and potential, without losing sight of the person. Psychology might (a) concentrate resources on finding out what actually works to enable poverty reduction; and (b) apply what we know to ensure that research on poverty reduction is more informative and compelling to community stakeholders, organizations, and policymakers. Such an âimplementation scienceâ could advance poverty reduction and human development. (PsycINFO Database Record (c) 2014 APA, all rights reserved
QUANTIFYING THE EFFECTIVENESS OF ACTIVE MITIGATION ON TRANSPORTATION CORRIDORS
ABSTRACT: Numerous efforts have been made to quantify avalanche risk in transportation corridors (Schaerer 198
Neurochemical correlates of scene processing in the precuneus/posterior cingulate cortex: A multimodal fMRI and 1H-MRS study
Precuneus/posterior cingulate cortex (PCu/PCC) are key components of a midline network, activated during rest but also in tasks that involve construction of scene or situation models. Despite growing interest in PCu/PCC functional alterations in disease and disease risk, the underlying neurochemical modulators of PCu/PCC's taskâevoked activity are largely unstudied. Here, a multimodal imaging approach was applied to investigate whether interindividual differences in PCu/PCC fMRI activity, elicited during perceptual discrimination of scene stimuli, were correlated with local brain metabolite levels, measured during restingâstate 1HâMRS. Forty healthy young adult participants completed an fMRI perceptual oddâoneâout task for scenes, objects and faces. 1HâMRS metabolites Nâacetylâaspartate (tNAA), glutamate (Glx) and Îłâaminoâbutyric acid (GABA+) were quantified via PRESS and MEGAâPRESS scans in a PCu/PCC voxel and an occipital (OCC) control voxel. Whole brain fMRI revealed a cluster in right dorsal PCu/PCC that showed a greater BOLD response to scenes versus faces and objects. When extracted from an independently defined PCu/PCC region of interest, scene activity (vs. faces and objects and also vs. baseline) was positively correlated with PCu/PCC, but not OCC, tNAA. A voxelâwise regression analysis restricted to the PCu/PCC 1HâMRS voxel area identified a significant PCu/PCC cluster, confirming the positive correlation between sceneârelated BOLD activity and PCu/PCC tNAA. There were no correlations between PCu/PCC activity and Glx or GABA+ levels. These results demonstrate, for the first time, that scene activity in PCu/PCC is linked to local tNAA levels, identifying a neurochemical influence on interindividual differences in the taskâdriven activity of a key brain hub
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