194 research outputs found
sj-docx-1-wso-10.1177_17474930221137019 – Supplemental material for The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis
No full textSupplemental material, sj-docx-1-wso-10.1177_17474930221137019 for The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis by Bonnie Yin Ka Lam, Yuan Cai, Rufus Akinyemi, Geert Jan Biessels, Hilde van den Brink, Christopher Chen, Chin Wai Cheung, King Ngai Chow, Henry Kwun Hang Chung, Marco Duering, Siu Ting Fu, Deborah Gustafson, Saima Hilal, Vincent Ming Ho Hui, Rajesh Kalaria, SangYun Kim, Maggie Li Man Lam, Frank Erik de Leeuw, Ami Sin Man Li, Hugh Stephen Markus, Anna Marseglia, Huijing Zheng, John O’Brien, Leonardo Pantoni, Perminder Singh Sachdev, Eric E Smith, Joanna Wardlaw and Vincent Chung Tong Mok in International Journal of Stroke</p
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Cognitive leisure activities, but not watching TV, for future brain benefits
No full textIs the incidence of dementia declining?
No full textAction on preventative health could lower the risk of dementia for future generations, argues this report.
Executive summary
The world-wide projections of the prevalence of dementia in the coming decades have been a source of great concern to health systems and societies around the world. The World Alzheimer Report 2010 estimated that there were 36 million people with dementia in 2010, with an expected doubling every 20 years to nearly 115 million in 2050. These sobering figures are based on assumptions that the age-adjusted prevalence of dementia would remain constant and the population would continue to age at the current rate.
The assumption that the incidence of dementia will remain stable is now being put into question. There is emerging evidence to suggest that the incidence of dementia in older individuals may be declining. It appears that this change may be recent and has possibly occurred only in the last one to two decades. It may also be restricted so far to high income countries, although data from low and middle income countries are lacking.
The reasons for this change are not understood, but education, more stimulating environments and better control of vascular risk factors may have contributed. The data are still preliminary and more studies are needed to establish the extent of this change and understand its causes. It should be noted that the decline is not large enough to offset the increase in prevalence of dementia due to the ageing of the population and therefore investment and efforts to develop better treatments and care for people with dementia need to continue.
The fact that dementia rates are malleable is an encouraging finding but the reduction cannot be taken for granted as gains in population health can easily be lost if societies do not remain vigilant and continually proactive. These preliminary findings provide a strong argument for large scale Government investment in dementia-prevention strategies, which should start from early life
NDVI Based Assessment of Land Cover Changes Using Remote Sensing and GIS (A case study of Srinagar district, Kashmir)
No full textNormalized Difference Vegetation Index (NDVI) is an index of greenness or photosynthetic activity in a plant. It is a technique of obtaining various features based upon their spectral signature such as vegetation index, land cover classification, urban areas and remaining areas presented in the image. The NDVI differencing method using Landsat thematic mapping images and Landsat oli was implemented to assess the chane in vegetation cover from 2001to 2017. In the present study, Landsat TM images of 2001 and landsat 8 of 2017 were used to extract NDVI values. The NDVI values calculated from the satellite image of the year 2001 ranges from 0.62 to -0.41 and that of the year 2017 shows a significant change across the whole region and its value ranges from 0.53 to -0.10 based upon their spectral signature .This technique is also used for the mapping of changes in land use and land cover. NDVI method is applied according to its characteristic like vegetation at different NDVI threshold values such as -0.1, -0.09, 0.14, 0.06, 0.28, 0.35, and 0.5. The NDVI values were initially computed using the Natural Breaks (Jenks) method to classify NDVI map. Results confirmed that the area without vegetation, such as water bodies, as well as built up areas and barren lands, increased from 35 % in 2001 to 39.67 % in 2017.Key words: Normalized Difference Vegetation Index,land use/landcover, spectral signature
NDVI Based assessment of land cover changes using remote sensing and GIS-(A case study of Srinagar district, Kashmir)
No full textNormalized Difference Vegetation Index (NDVI) is an index of greenness or photosynthetic activity in a plant. It is a technique of obtaining various features based upon their spectral signatures such as vegetation index, land cover classification, urban areas and remaining areas presented in the image. In the present study, the NDVI differencing method using Landsat 7 ETM+ images and Landsat OLI were implemented to assess the change in vegetation cover from 2001 to 2017 using the Natural Breaks (Jenks) method. NDVI values calculated from the satellite image of the year 2001 range from 0.62 to -0.41and that of the year 2017 ranges from 0.53 to -0.10based upon their spectral signature. The NDVI method is applied according to its characteristics like vegetation at different NDVI threshold values such as -0.1, -0.09, 0.14, 0.06, 0.28, 0.35, and 0.5. Afterwards, a Difference NDVI map between 2001 and 2017 is generated to identify negatively or positively values of land cover changes. Results confirmed that the area without vegetation, such as water bodies, built-up areas and as well as barren lands, increased from 35 % in 2001 to 39.67 % in 2017. The densely vegetated area decreased from 8.62 % to 2.15 % indicating the need to develop new policies in the city to protect vegetation areas during economic and urban development in the city of Srinagar.El Índice de Vegetación de Diferencia Normalizada (NDVI) es un índice de actividad verde o fotosintética en una planta. Es una técnica para obtener varias características en función de sus firmas espectrales, como el índice de vegetación, la clasificación de la cobertura del suelo, las áreas urbanas y las áreas restantes que se presentan en la imagen. En el presente estudio, se implementó el método de diferenciación NDVI utilizando imágenes de mapeo temático Landsat y Landsat OLI para evaluar el cambio en la cubierta vegetal de 2001 a 2017 utilizando el método Natural Breaks (Jenks). Valores NDVI calculados a partir de la imagen de satélite de los rangos del año 2001 de 0.62 a -0.41 y el del año 2017 varía de 0.53 a -0.10 en función de su firma espectral. El método NDVI se aplica de acuerdo con sus características como la vegetación en diferentes valores umbral de NDVI, como -0.1, -0.09, 0.14, 0.06, 0.28, 0.35 y 0.5 Luego, se genera un mapa de NDVI de diferencia entre 2001 y 2017 para negativa o positivamente Identificar los valores de los cambios en la cobertura del suelo. Los resultados confirmaron que el área sin vegetación, como cuerpos de agua, así como áreas urbanizadas y tierras áridas, aumentó de 35% en 2001 a 39.67% en 2017. El área densamente vegetada disminuyó de 8.62% a 2.15% indicando la necesidad desarrollar nuevas políticas en la ciudad para proteger las áreas de vegetación durante el desarrollo económico y urbano en la ciudad de Srinagar
Estimación De La Temperatura De La Superficie Terrestre De La Ciudad De Srinagar, India Utilizando Datos De Landsat 8
No full textLand surface tempreature (LST) is a critical parameter for the study of biosphere, cryosphere and climate change.. Thermal infrared remote sensing data can be used to measure Land Surface Temperature (LST). It will measure the energy exiting the Earth's surface and record the apparent temperature of the surface. It is now possible to measure LST due to the advent of satellite imagery and digital image processing applications. The LST for Srinagar city was calculated using the Split Window algorithm (SW) and Landsat-8 (Path-149 and Row-36) Thermal Infrared Sensor (TIRS) data with a resolution of 100m. . Emissivity was calculated using the Normalized Differential Vegetation Index (NDVI) proportion of vegetation methodology, with bands 4 and 5 (30 m resolution) from the Operational Land Imager (OLI). Surface temperatures were found to be higher in central regions and lower in heavily vegetated areas. The LST derived using the SW algorithm was more efficient and precise since it used both OLI and TIRS bandsLa temperatura de la superficie terrestre (LST) es un parámetro crítico para el estudio de la biosfera, la criosfera y el cambio climático. Los datos de teledetección infrarroja térmica se pueden utilizar para medir la temperatura de la superficie terrestre (LST). Medirá la energía que sale de la superficie de la Tierra y registrará la temperatura aparente de la superficie. Ahora es posible medir LST debido a la llegada de imágenes de satélite y aplicaciones de procesamiento de imágenes digitales. El LST para la ciudad de Srinagar se calculó utilizando el algoritmo de ventana dividida (SW) y los datos del sensor infrarrojo térmico (TIRS) Landsat-8 (Path-149 y Row-36) con una resolución de 100 m. . La emisividad se calculó utilizando la metodología de proporción de vegetación del NDVI, con las bandas 4 y 5 (resolución de 30 m) del Operational Land Imager (OLI). Se encontró que las temperaturas de la superficie eran más altas en las regiones centrales y más bajas en las áreas densamente vegetadas. El LST derivado usando el algoritmo SW fue más eficiente y preciso ya que usó bandas OLI y TIRS
Mediation of cognitive function improvements by strength gains after resistance training in older adults with mild cognitive impairment: outcomes of the study of mental and resistance training
No full textObjectives: To determine whether improvements in aerobic capacity (VO₂peak) and strength after progressive resistance training (PRT) mediate improvements in cognitive function. Design: Randomized, double-blind, double-sham, controlled trial. Setting: University research facility. Participants: Community-dwelling older adults (aged ≥55) with mild cognitive impairment (MCI) (N = 100). Intervention: PRT and cognitive training (CT), 2 to 3 days per week for 6 months. Measurements Alzheimer's Disease Assessment Scale–cognitive subscale (ADAS-Cog); global, executive, and memory domains; peak strength (1 repetition maximum); and VO₂peak. Results: PRT increased upper (standardized mean difference (SMD) = 0.69, 95% confidence interval = 0.47, 0.91), lower (SMD = 0.94, 95% CI = 0.69–1.20) and whole-body (SMD = 0.84, 95% CI = 0.62–1.05) strength and percentage change in VO₂peak (8.0%, 95% CI = 2.2–13.8) significantly more than sham exercise. Higher strength scores, but not greater VO2peak, were significantly associated with improvements in cognition (P < .05). Greater lower body strength significantly mediated the effect of PRT on ADAS-Cog improvements (indirect effect: β = −0.64, 95% CI = −1.38 to −0.004; direct effect: β = −0.37, 95% CI = −1.51–0.78) and global domain (indirect effect: β = 0.12, 95% CI = 0.02–0.22; direct effect: β = −0.003, 95% CI = −0.17–0.16) but not for executive domain (indirect effect: β = 0.11, 95% CI = −0.04–0.26; direct effect: β = 0.03, 95% CI = −0.17–0.23). Conclusion: High-intensity PRT results in significant improvements in cognitive function, muscle strength, and aerobic capacity in older adults with MCI. Strength gains, but not aerobic capacity changes, mediate the cognitive benefits of PRT. Future investigations are warranted to determine the physiological mechanisms linking strength gains and cognitive benefits.Yorgi Mavros, Nicola Gates, Guy C. Wilson, Nidhi Jain, Jacinda Meiklejohn, Henry Brodaty, Wei Wen, Nalin Singh, Bernhard T. Baune, Chao Suo, Michael K. Baker, Nasim Foroughi, Yi Wang, Perminder S. Sachdev, Michael Valenzuela and Maria A. Fiatarone Sing
Geriatric psychiatry: is the jury still out on the cognitive effects of homocysteine and one-carbon metabolism?
No full textPurpose of review: This review considers the evidence for the contribution of hyperhomocysteinemia to cognitive impairment, the dementias and Parkinson's disease, focusing on published literature from April 2002 to April 2003. Recent findings: Homocysteine is a sulphur-containing amino acid that is involved in cycles related to one-carbon metabolism within the body, and elevations in its level can result from multiple aspects of these cycles. Elevated homocysteine impairs methylation, crucial to DNA synthesis and repair, is toxic to the vascular system, is cytotoxic and is directly neurotoxic. These effects interact with ageing-related pathology and toxins to augment neurodegenerative processes. Controversies remain in the ascertainment of homocysteine levels and in the salience of its contribution to cognitive impairment, the dementias and Parkinson's disease. However, cross-sectional studies generally agree homocysteine levels greater than 14 μmol/l are associated with increased risk of cognitive impairment. Hyperhomocysteinemia is associated with an increased risk of cognitive impairment after stroke, and is a contributory factor to the cognitive deficits of vascular dementia and AD. Elevated homocysteine levels have been demonstrated in L-dopa treated Parkinson's disease patients in associated with vascular risk. Hyperhomocysteinemia is also associated with increased brain atrophy in healthy elderly. Summary: There is an increasingly solid case for the association between hyperhomocysteinemia, as a marker of disturbed one-carbon metabolism, and cognitive impairment. The findings from preliminary investigations of vitamin supplementation to lower homocysteine in candidate conditions such as stroke and dementia are encouraging, but evidence is needed from large randomized controlled trials before supplementation can be advocated
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