Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Environ Monit Assess ; 195(11): 1306, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37828295

RESUMEN

Particulate matter (PM) is a critical air pollutant, responsible for an array of ailments leading to premature mortality worldwide. Nature-based solutions for mitigation of PM and especially role of forests in mitigating PM from an ecosystem perspective are less explored. Forests provide a natural pollution abatement strategy by providing a surface area for the deposition of PM. Depending on their structure and composition, forests have varying capacities for PM adsorption, which is again less explored. Hence, in the present study, we evaluate the removal capacity of PM by the forest-type groups of India. Deposition flux and total PM removal across sixteen forest types were estimated based on the 2019 dataset of PM using Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) data. Externality values and PM removal costs by industrial equipment were used for associating an economic value to the air pollution abatement service by forests. The total PM2.5 removal by forests in 2019 was estimated to be 1361.28 tons and PM10 was estimated to be 303,658.27 tons. Deposition of PM was found to be high in littoral and swamp forests, tropical semi-evergreen forests, tropical moist deciduous forests, and sub-tropical pine forests. Tropical dry deciduous forests had the highest net weight % removal of PM with 39% removal for PM2.5 and 39% removal for PM10. The air pollution abatement service by forests for PM removal was 188 M US dollars (USD) with externality-based removal service by forests of 2009 M USD. The net PM removed by all forests of India was estimated to be approximately worth ₹ 470-648 Crore (59-81 million dollars) for PM2.5 and worth ₹56,746-1,22,617 Crore (7093-15,327 million dollars) for PM10 based on valuation using value transfer method. The study concludes that forests can be a significant contributor to PM reduction at a global level. Especially for India's National Clean Air Programme and further research and policy considerations, the findings would be extremely useful.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Material Particulado/análisis , Ecosistema , Estudios Retrospectivos , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Bosques , Contaminación del Aire/análisis , India
2.
Am J Bot ; 108(3): 411-422, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33792046

RESUMEN

PREMISE: Climate change is having major impacts on alpine and arctic regions, and inter-annual variations in temperature are likely to increase. How increased climate variability will impact plant reproduction is unclear. METHODS: In a 4-year study on fruit production by an alpine plant community in northern Sweden, we applied three warming regimes: (1) a static level of warming with open-top chambers (OTC), (2) press warming, a yearly stepwise increase in warming, and (3) pulse warming, a single-year pulse event of higher warming. We analyzed the relationship between fruit production and monthly temperatures during the budding period, fruiting period, and whole fruit production period and the effect of winter and summer precipitation on fruit production. RESULTS: Year and treatment had a significant effect on total fruit production by evergreen shrubs, Cassiope tetragona, and Dryas octopetala, with large variations between treatments and years. Year, but not treatment, had a significant effect on deciduous shrubs and graminoids, both of which increased fruit production over the 4 years, while forbs were negatively affected by the press warming, but not by year. Fruit production was influenced by ambient temperature during the previous-year budding period, current-year fruiting period, and whole fruit production period. Minimum and average temperatures were more important than maximum temperature. In general, fruit production was negatively correlated with increased precipitation. CONCLUSIONS: These results indicate that predicted increased climate variability and increased precipitation due to climate change may affect plant reproductive output and long-term community dynamics in alpine meadow communities.


Asunto(s)
Frutas , Pradera , Regiones Árticas , Cambio Climático , Suecia , Temperatura
3.
Nanotechnology ; 32(38)2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34082410

RESUMEN

Self-powered photodetectors have grown as inevitable members of the optoelectronic device family. However, it is still challenging to achieve self-powered photodetection with good responsivity in the visible spectrum region. Herein, we report solution-processable poly(3-hexylthiophene) (P3HT)-molybdenum disulfide (MoS2) organic-inorganic hybrid material, which can be used as the active layer in self-powered photodetectors. The morphological and structural properties of the synthesized P3HT-MoS2hybrid material has been discussed using atomic force microscopy and transmission electron microscopy, respectively. The hybrid material loaded with 1 wt% MoS2has shown an enhancement in the self-assembly of polymer in the form of fibrillar formation and excellent structural features in terms ofπ-conjugation. The self-powered photodetectors have been fabricated in indium tin oxide (ITO) coated glass/P3HT-MoS2/Al configuration. The merit of P3HT-MoS2hybrid photodetectors is measured under the illumination of 470, 530, and 627 nm light in ambient conditions. P3HT-MoS2photodetectors show significantly higher responsivity and detectivity. The photo responsivity and detectivity in P3HT-MoS2devices are found to be 271.2 mA W-1and 4.4 × 1010jones at zero bias, respectively, for 470 nm light with the optical power density of 74.1µW cm-2. Furthermore, the photocurrent switching behaviour at periodic illuminations of 1 Hz has also been examined for P3HT-MoS2self-powered photodetectors.

4.
J Environ Manage ; 298: 113470, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34365182

RESUMEN

Indigenous agroforestry systems are important reservoirs of biodiversity, and ecosystem services with a potential contribution for conservation of biodiversity while sustaining the livelihood of the rural populace. Pineapple (Ananas comosus) agroforestry systems (PAFS) form an essential constituent of the rural landscape in the Indian Eastern Himalayas and other parts of Asia. The traditional PAFS management in southern Assam is unique in that it involves shifting cultivation transitioning from native forests to a PAFS. Scarcity of information on the functioning and services in terms of species diversity and carbon storage potential in the traditional PAFS has restricted the opportunities for consideration under the nature-based solutions of climate action including REDD+. Therefore, the present study assessed the tree diversity and ecosystem carbon storage in a chronosequence from swidden agriculture through different phases of PAFS establishment. The result demonstrated that basal area in the PAFS increased with age. The most dominant species in the native forests was Palaquium polyanthum, while agricultural land use and PAFS aged <5, 11-15 and > 15 years old were dominated by Gmelina arborea, Albizia procera, Areca catechu and Hevea brasiliensis, respectively. The highest value of Shannon-Wiener diversity index (H) was recorded in native forests (2.71), and lowest in 5-10 years old PAFS. The ecosystem carbon storage declined from 261.43 Mg ha-1 in native forests to 181.07 Mg ha-1 in <5-years old PAFS. In <5 years old PAFS, the ecosystem carbon storage was 30 % lower than the native forest; while at >15 years it was merely 5 % less than the native forests. The traditional PAFS maintains a steady ecosystem carbon stock while reducing land use related carbon emission and providing additional co-benefits to the communities. Therefore, the traditional PAFS constitute a good opportunity for REDD+.


Asunto(s)
Carbono , Árboles , Biodiversidad , Conservación de los Recursos Naturales , Ecosistema , Bosques
5.
Langmuir ; 33(47): 13572-13580, 2017 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-29099604

RESUMEN

Two-dimensional (2D) inorganic layered materials when embedded in organic polymer matrix exhibit exotic properties that are grabbing contemporary attention for various applications. Here, nanosheet morphology of molybdenum disufide (MoS2) synthesized via one-pot facile hydrothermal reaction are exfoliated in benign aqueous medium in the presence of indole to obtain a stable dispersion. These exfoliated nanosheets then act as host to template the controlled polymerization of indole. The preassembled MoS2-polyindole (MoS2-PIn) nanostructures are reorganized at the air-water interface using the Langmuir method to facilitate maximum interfacial interaction between nanosheet and polymer. This report emphasizes large area, homogeneous dispersion of uniform-sized MoS2 nanosheets (40-60 nm diameter) in the PIn matrix and the formation of stable and uniform film via the Langmuir-Schaefer (LS) method. These self-assembled, MoS2 decorated PIn LS films are characterized using atomic force microscopy (AFM) and transmission electron microscopy (TEM). The fabricated LS films in sandwiched structure Al/MoS2-PIn/ITO as the Schottky diode portrayed remarkable enhancements in charge transport properties. Our study illustrates the potential of the MoS2-PIn LS film in electronic applications and opens a new dimension for uniform dispersion of 2D materials in other polymers via the Langmuir method for device fabrication and enhancement of electrical properties.

6.
J Oral Implantol ; 40 Spec No: 347-55, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25020216

RESUMEN

This investigation was carried out to study the effect of a novel process of surface modification, surface nanostructuring by ultrasonic shot peening, on osteoblast proliferation and corrosion behavior of commercially pure titanium (c p-Ti) in simulated body fluid. A mechanically polished disc of c p-Ti was subjected to ultrasonic shot peening with stainless steel balls to create nanostructure at the surface. A nanostructure (<20 nm) with inhomogeneous distribution was revealed by atomic force and scanning electron microscopy. There was an increase of approximately 10% in cell proliferation, but there was drastic fall in corrosion resistance. Corrosion rate was increased by 327% in the shot peened condition. In order to examine the role of residual stresses associated with the shot peened surface on these aspects, a part of the shot peened specimen was annealed at 400°C for 1 hour. A marked influence of annealing treatment was observed on surface structure, cell proliferation, and corrosion resistance. Surface nanostructure was much more prominent, with increased number density and sharper grain boundaries; cell proliferation was enhanced to approximately 50% and corrosion rate was reduced by 86.2% and 41% as compared with that of the shot peened and the as received conditions, respectively. The highly significant improvement in cell proliferation, resulting from annealing of the shot peened specimen, was attributed to increased volume fraction of stabilized nanostructure, stress recovery, and crystallization of the oxide film. Increase in corrosion resistance from annealing of shot peened material was related to more effective passivation. Thus, the surface of c p-Ti, modified by this novel process, possessed a unique quality of enhancing cell proliferation as well as the corrosion resistance and could be highly effective in reducing treatment time of patients adopting dental and orthopedic implants of titanium and its alloys.


Asunto(s)
Materiales Dentales/química , Nanoestructuras/química , Osteoblastos/fisiología , Titanio/química , Ultrasonido/métodos , Adhesión Celular/fisiología , Técnicas de Cultivo de Célula , Línea Celular , Proliferación Celular , Colorantes , Corrosión , Cristalización , Pulido Dental/métodos , Calor , Humanos , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Nitritos/análisis , Óxidos/química , Potenciometría , Acero Inoxidable/química , Estrés Mecánico , Propiedades de Superficie , Sales de Tetrazolio , Tiazoles , Factores de Tiempo
7.
Sci Total Environ ; 919: 170681, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38325486

RESUMEN

Plant functional attributes are subjected to environmental adjustments, which lead to modulations in forest processes under environmental changes. However, a comprehensive assessment of the relationships between plant traits and carbon stock remains subtle. The present study attempted to accomplish the gap of knowledge by examining the linkages between forest carbon with plant traits within the Banj Oak forest in the Garhwal Himalaya. Twelve individuals from three major species in the Banj Oak forest were randomly selected for trait measurements, and soil samples were collected randomly across the area for evaluation of soil nutrients and carbon. Forest biomass and soil carbon were estimated following standard protocols. A Structural Equation Model (SEM) was applied to establish the relationship between above ground carbon (AGC) and soil organic carbon (SOC) with leaf and stem traits, and soil nutrients. Stem traits were tree height and tree diameter; whereas leaf morphological traits were leaf area, specific leaf area, leaf dry matter content; leaf physiological traits were photosynthesis rate, stomatal conductance, and transpiration rate; and leaf biochemical traits were leaf carbon concentration, leaf nitrogen concentration, and leaf phosphorus concentration. Soil nutrients were available nitrogen, available phosphorus, and exchangeable potassium. Based on SEM results, AGC of the forest was positively correlated with stem traits and leaf physiological traits, while negatively correlated with leaf morphological traits. SOC was positively correlated with soil nutrients and leaf biochemical traits, whereas negatively correlated with stem traits. These findings may support for precise quantification of forest carbon and modeling of forest carbon stocks besides providing inputs to forest managers for devising effective forest management strategies.


Asunto(s)
Carbono , Quercus , Humanos , Secuestro de Carbono , Himalayas , Suelo/química , Bosques , Árboles/fisiología , Nitrógeno/análisis , Fósforo , Hojas de la Planta/química
8.
Heliyon ; 10(2): e24133, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38293486

RESUMEN

Smallholders and pastoralists are particularly vulnerable to the impacts of climate change due to their high reliance on socio-ecological systems for their livelihood. Building their resilience to these adverse effects of climate change is crucial for mitigating their vulnerabilities, especially in remote and fragile ecosystems. This study aims to assess the climate change livelihood resilience of smallholders and pastoralists in the Indian Himalayas. We build a livelihood resilience index, using the three dimensions of resilience, namely assimilative capacity, autopoiesis and cognitive ability, and weighed using entropy-TOPSIS approach The dimensions of resilience was estimated through indicators by a household survey of 289 randomly selected respondents across the three districts of Garhwal Himalayas. The results showed that the livelihood resilience of smallholders was greater than pastoralists. Among pastoralists, settlement brought positive changes to their livelihood, opening the gateway to access basic facilities. Key findings of the study indicate that public policy should focus towards information accessibility, encouraging environmental awareness and conservation, promoting social inclusion and cooperatives, and fostering grass root organization structures like forest-level organisation through informality to strengthen the resilience of communities to climate change.

9.
Sci Total Environ ; 912: 169197, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38101647

RESUMEN

Land use change, anthropogenic exploitation and climate change have impacted the flow of services in the Himalayan region. The dominant land uses in the region including natural forest, degraded forest, rubber (Hevea brasiliensis) plantations, Areca catechu plantations, Areca agroforestry and Piper agroforestry were considered for the study. A progressive shift in land use was defined as the conversion and restoration of a less productive system like degraded land to plantations or agroforestry systems. A land use shift was considered retrogressive when it entails the establishment of plantations after clearing natural forests or anthropogenic disturbance of natural forests resulting in forest degradation. The objectives of the current study were to estimate changes in soil properties, stand structure, tree biomass, fine root production and carbon storage following a progressive and retrogressive shift in land usage. The aboveground biomass (105.9 Mg ha-1) was highest in the natural forest, followed by Areca agroforestry (100.2 Mg ha-1) and least in the degraded forest (55.3 Mg ha-1). The aboveground biomass carbon (47.1 Mg ha-1) of Areca agroforestry was comparable with that of natural forest (51.3 Mg ha-1). The highest proportion of passive carbon concentrations was observed under Areca agroforestry, whereas the lowest (4.13 g kg-1) was found under Areca plantations in the 0-25 cm soil depth. With the progressive shift in land use from degraded forest to agroforestry, SOC stocks increased by 27.6 % and 3 % under Piper and Areca agroforests, respectively. SOC stocks decreased by 8.5 % with a shift in land use from natural forests to Areca plantations. The production of fine roots was maximum in the Areca agroforest (13.2 Mg ha-1) and lowest under rubber plantations (4.2 Mg ha-1). The results show that progressive shifts from degraded forest to agroforestry can considerably increase carbon stocks, plant species diversity and multifunctionality than shifts to monoculture plantations thereby supporting improved biodiversity and mitigation of climate change.


Asunto(s)
Agricultura , Ecosistema , Goma , Bosques , Suelo/química , Carbono/química , Verduras
10.
Environ Sci Pollut Res Int ; 30(55): 116860-116875, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36795200

RESUMEN

Mountains are one of the most ecological functional areas and provide wide range of ecosystem services (ESs) to the adjoining people. However, the mountainous ESs are highly vulnerable due to land use and land cover (LULC) change and climate change. Therefore, evaluations of the nexus between ESs and mountainous communities are essentially required for policy purpose. This study aims to assess ESs by analyzing LULC focusing in three ecosystems (forest, agriculture, and home garden) from urban and peri-urban areas for last 3 decades, applying participatory and geospatial approaches for a mountainous city in Eastern Himalayan Region (EHR), India. The findings showed that a substantial loss in ESs has occurred during the period. Moreover, there were substantial variations of ecosystem importance and dependency between urban and peri-urban areas with highest importance of provisioning ESs in peri-urban areas and cultural ESs in urban areas. Moreover, among the three ecosystems, forests were strongly supporting the peri-urban areas communities. The result demonstrated that the communities are highly dependent on various ESs for their livelihoods, but the changes of LULC had substantial impact on the loss of ESs. Therefore, implementation of effective land uses planning strategies and measures for ecological security and livelihood sustainability is to be managed with people participation in mountainous areas.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Humanos , Bosques , Ciudades , India
11.
Heliyon ; 9(6): e16563, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37274646

RESUMEN

Phenology, an important ecological attribute, deals with the development of vegetative and reproductive parts of trees called "phenophases", which are important determinants of primary productivity and sensitive to climate change. The present study recorded various phenophases of major tree species (i.e., Quercus leucotrichophora, Rhododendron arboreum, and Myrica esculenta) as per the two-digit numerical system of Biologische Bundesanstalt, Bundessortenamt, Chemische Industrie (BBCH) scale. A total of 72 individual trees, twenty-four from each species, distributed between 1400 and 1980 m. a.s.l elevations were tagged and measured fortnightly for two consecutive years (2019-2021) in the moist temperate forest of Western Himalaya and compared with earlier existing records. Various phenophases were correlated with climatic factors along with duration and thermal time for each phenological growth stage. We found 24 growth stages for Q. leucotrichophora and M. esculenta and 28 for R. arboreum distributed across seven principal growth stages (e.g. bud development, 0; leaf development, 1; shoot development, 3; inflorescence development, 5; flower development, 6; fruit development, 7; and fruit maturation, 8) of trees as per BBCH scale. Maximum growing degree was 748.87 and 627.95 days recorded for R. arboreum and M. esculenta during leaf development, and 796.17 days for Q. leucotrichophora during fruit development. Flower emergence was observed pre, during, and post-emergence of new leaves for R. arboreum, M. esculenta, and Q. leucotrichophora, respectively, which varied at spatial scale with previous findings. Longevity of fruit development to ripening took 17, 4, and 2 months, respectively in Q. leucotrichophora, R. arboreum and M. esculenta. Duration of leaf initiation and flowering was positively correlated with climatic variables, whereas, the reverse was observed for fruiting in the studied tree species. The study concludes that the variations in phenophases of the three species were strongly influenced by climatic variations, especially minimum temperature. The result of the present study would be important in enabling us to formulate efficient forest management strategies by understanding the short-term adaptation of the climate-sensitive important tree species in the western Himalaya.

12.
Environ Sci Pollut Res Int ; 29(42): 63692-63708, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35461418

RESUMEN

The flows of ecosystem services (ESs) from ecological patches (EPs) are being severely challenged due to global change. However, the evaluation of nexus between tribal society and ecological units with focus of tribal livelihood was not a subject of enquiry until recent past. Present study hypothesized that the different EPs has differential nexus in terms of delivery of ESs in Barind region, Eastern India. Dependency and prominence of l livelihood on ESs was evaluated through developing ES dependency index (ESDI) and ecosystem services prominence index (ESPI). Five sub-components (comprising 25 indicators) and ten dominant provisioning ecosystem services (PES) were considered to develop ESDI and ESPI respectively. The seasonal variations of availability of ESs from EPs were also assessed-based five-point Likert scale. The findings of the study showed that (i) the households were highly dependent on PES for their livelihood strategies; (ii) agricultural crops (main foods), housing materials, fuel woods, water, livestock, and medical plants were the dominant ESs; (iii) forests, agricultural lands, water bodies, and homesteads were the main EPs from which ESs were collected; (iv) there was positive correlation between ESDI and ESPI. Moreover, there was substantial variation on dependency of ESs across villages was observed and seasonal variation in ESs was noted in terms of availability and dependency with maximum contribution during the monsoon season. The result clearly suggests that there is a strong nexus between livelihood strategies and ESs in the region. Therefore, diversification of livelihood strategies must be integrated with ESs for human well-being (HWB) as well as environmental sustainability.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Productos Agrícolas , Bosques , Humanos , Agua
13.
Environ Sci Pollut Res Int ; 29(41): 61561-61578, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34355327

RESUMEN

The well-being of the human society cannot be ensured and sustainable unless the flow of Ecosystem Services (ESs) would be matching with their consistent demand. The consistent flow of ESs required sustainable management of ecological resources of the ecosystem. The management of ecosystem can be ensured with variety of approaches. Integration of indigenous ecological knowledge (IEK) in management prescription with the view that IEK-based extraction of ESs ensures removal of resources from the ecosystem within the limit thereby ensuring the sustainability of ecosystem. The present study is an evaluation to understand the nexus between ESs and IEK for sustainable environmental management. The focus of the study was a tribal dominated socio-ecological patch of Barind Region of Malda district, Eastern India. The assessment of ESs and IEK was based on the data collected from the randomly selected tribal households following the pre-tested questionnaire containing questions on ESs as per millennium ecosystem assessment. The data were analyzed following social preference approach, and statistical tests (Kruskal-Wallis and Mann-Whitney). General linear model (GLM) has also been used to examine the impact of socio-demographic attributes on the perceived valuation of ESs. The results revealed that the provisioning ESs (such as water, fuel wood, medical plants) were most preferred followed by cultural and regulating ESs by tribal. Differential importance of ESs was observed among tribal and accounted by gender, education as well as age of the tribe. A gap between the actual accessibility and evaluation of ESs by the tribal communities was also apparent. The socio-demographic attributes have an immense impact on the valuation of ESs and also governed based on the IEK. Various types of indigenous ecological belief systems were closely linked with conservation of ecosystem and sustainable supply of ESs. The present study can contribute to understand socio-ecological nexus with the lens of IEK in tribal dominated ecological landscapes for improved ecosystem and environmental management besides ensuring sustainability of flow of ESs.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Conservación de los Recursos Naturales/métodos , Humanos , India , Plantas
14.
Environ Sci Pollut Res Int ; 29(57): 85904-85921, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34331647

RESUMEN

Urban water management is a growing concern in India's rapidly urbanizing cities. Population growth and climatic variability are exuberating the impact on surface and underground water supply. Understanding the causes and the extent of water vulnerability is required for developing effective strategies for water insecurities. This study attempts to assess the water vulnerability across different wards of a touristic city of Himalaya-Nainital using IPCC approach considering the three dimensions: exposure, sensitivity, and adaptive capacity. Seven indicators, mostly spatial, i.e. edaphic (aspect, elevation) and climatic (land surface temperature) besides some water infrastructural (distance to water distribution) and population, were considered for development of vulnerability index using Analytical Hierarchy Process for assigning weights. These indicators were simple to extract and easy to obtain and mostly available from secondary sources and were capable to account the variability at micro-level. Moreover, the current adaptation mechanisms for water security were also derived through conducting surveys by randomly selecting households across the wards. Staff House and Harinagar wards were the most vulnerable. The survey results that the adaptation mechanism should be managed at individual and organization level. Policy measures such as optimum use of water, grey water recycling, spring rejuvenation, rain water harvesting, and leakage proof infrastructure with intervention of new technologies, may be adopted and implemented for reducing the water vulnerability in the city along with the public participation. The appropriate measures for water vulnerability would further provide support for improving the facilities to the tourists in the city thereby improved economic opportunities to the locals.


Asunto(s)
Cambio Climático , Agua , Humanos , Ciudades , Abastecimiento de Agua , Crecimiento Demográfico
15.
Sci Total Environ ; 836: 155450, 2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-35490820

RESUMEN

Alpine and polar regions are predicted to be among the most vulnerable to changes in temperature, precipitation, and nutrient availability. We carried out a seven-year factorial experiment with warming and nutrient addition in two alpine vegetation communities. We analyzed the relationship between fruit production and monthly mean, maximum, and min temperatures during the fall of the pre-fruiting year, the fruiting summer, and the whole fruit production period, and measured the effects of precipitation and growing and thawing degree days (GDD & TDD) on fruit production. Nutrient addition (heath: 27.88 ± 3.19 fold change at the end of the experiment; meadow: 18.02 ± 4.07) and combined nutrient addition and warming (heath: 20.63 ± 29.34 fold change at the end of the experiment; meadow: 18.21 ± 16.28) increased total fruit production and fruit production of graminoids. Fruit production of evergreen and deciduous shrubs fluctuated among the treatments and years in both the heath and meadow. Pre-maximum temperatures had a negative effect on fruit production in both communities, while current year maximum temperatures had a positive impact on fruit production in the meadow. Pre-minimum, pre-mean, current mean, total minimum, and total mean temperatures were all positively correlated with fruit production in the meadow. The current year and total precipitation had a negative effect on the fruit production of deciduous shrubs in the heath. GDD had a positive effect on fruit production in both communities, while TDD only impacted fruit production in the meadow. Increased nutrient availability increased fruit production over time in the high alpine plant communities, while experimental warming had either no effect or a negative effect. Deciduous shrubs were the most sensitive to climate parameters in both communities, and the meadow was more sensitive than the heath. The difference in importance of TDD for fruit production may be due to differences in snow cover in the two communities.


Asunto(s)
Ecosistema , Pradera , Cambio Climático , Frutas , Nutrientes , Temperatura
16.
Br J Ophthalmol ; 106(3): 409-414, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-33334818

RESUMEN

OBJECTIVE: To study the uptake of annual diabetic retinopathy screening and study the 5-year trends in the detection of screen-positive diabetic retinopathy and non-diabetes-related eye disease in a cohort of annually screened individuals. DESIGN: Retrospective retinopathy screening attendance and retinopathy grading analysis. SETTING: Community-based retinopathy screening centres for the Diabetic RetinaScreen Programme. PARTICIPANTS: 171 557 were identified by the screening programme to be eligible for annual diabetic retinopathy screening. 120 048 individuals over the age of 12 consented to and attended at least one screening appointment between February 2013 to December 2018. MAIN OUTCOME MEASURES: Detection rate per 100 000 of any retinopathy, screen-positive referrable retinopathy and nondiabetic eye disease. RESULTS: Uptake of screening had reached 67.2% in the fifth round of screening. Detection rate of screen-positive retinopathy reduced from 13 229 to 4237 per 100 000 screened over five rounds. Detection of proliferative disease had reduced from 2898 to 713 per 100 000 screened. Non-diabetic eye disease detection and referral to treatment centres increased almost eightfold from 393 in round 1 to 3225 per 100 000 screened. The majority of individuals referred to treatment centres for ophthalmologist assessment are over the age of 50 years. CONCLUSIONS: Screening programme has seen a reduced detection rate both screen-positive retinopathy referral in Ireland over five rounds of screening. Management of nondiabetic eye diseases poses a significant challenge in improving visual outcomes of people living with diabetes in Ireland.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , Atención a la Salud , Retinopatía Diabética/diagnóstico , Retinopatía Diabética/epidemiología , Humanos , Tamizaje Masivo , Persona de Mediana Edad , Derivación y Consulta , Estudios Retrospectivos
17.
Sci Rep ; 11(1): 23807, 2021 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-34893677

RESUMEN

Leaf functional traits support plant survival and growth in different stress and disturbed conditions and respond according to leaf habit. The present study examined 13 leaf traits (3 morphological, 3 chemical, 5 physiological, and 2 stoichiometry) of nine dominant forest tree species (3 coniferous, 3 deciduous broad-leaved, 3 evergreen broad-leafed) to understand the varied response of leaf habits. The hypothesis was to test if functional traits of the conifers, deciduous and evergreen differ significantly in the temperate forest and to determine the applicability of leaf economic theory i.e., conservative vs. acquisitive resource investment, in the temperate Himalayan region. The attributes of the functional traits i.e., leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf water content (LWC), stomatal conductance (Gs), and transpiration (E) followed the order deciduous > evergreen > coniferous. Leaf carbon and leaf C/N ratio showed the opposite pattern, coniferous > evergreen > deciduous. Chlorophyll (Chl) and photosynthetic rate (A) were highest for evergreen species, followed by deciduous and coniferous species. Also, structural equation modelling determined that morphological factors were negatively related to physiological and positively with chemical factors. Nevertheless, physiological and chemical factors were positively related to each other. The physiological traits were mainly regulated by stomatal conductance (Gs) however the morphological traits were determined by LDMC. Stoichiometry traits, such as leaf C/N, were found to be positively related to leaf carbon, and leaf N/P was found to be positively related to leaf nitrogen. The result of the leaf functional traits relationship would lead to precise prediction for the functionality of the temperate forest ecosystem at the regional scale.


Asunto(s)
Ecosistema , Ambiente , Bosques , Hojas de la Planta/anatomía & histología , Árboles/anatomía & histología , Árboles/fisiología , Biodiversidad , Clima , Modelos Teóricos , Fitoquímicos/análisis , Hojas de la Planta/química , Fenómenos Fisiológicos de las Plantas , Carácter Cuantitativo Heredable
18.
Acta Diabetol ; 58(5): 643-650, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33483856

RESUMEN

AIMS: We aimed to determine the patient and screening-level factors that are associated with non-attendance in the Irish National Diabetic Retinal screening programme (Diabetic RetinaScreen). To accomplish this, we modelled a selection of predictors derived from the historical screening records of patients with diabetes. METHODS: In this cohort study, appointment data from the national diabetic retinopathy screening programme (RetinaScreen) were extracted and augmented using publicly available meteorological and geospatial data. A total of 653,969 appointments from 158,655 patients were included for analysis. Mixed-effects models (univariable and multivariable) were used to estimate the influence of several variables on non-attendance to screening appointments. RESULTS: All variables considered for analysis were statistically significant. Variables of note, with meaningful effect, were age (OR: 1.23 per decade away from 70; 95% CI: [1.22-1.24]), type 2 diabetes (OR: 1.10; 95% CI: [1.06-1.14]) and socio-economic deprivation (OR: 1.12; 95% CI: [1.09-1.16]). A majority (52%) of missed appointments were from patients who had missed three or more appointments. CONCLUSIONS: This study is the first to outline factors that are associated with non-attendance within the Irish national diabetic retinopathy screening service. In particular, when corrected for age and other factors, patients with type 2 diabetes had higher rates of non-attendance. Additionally, this is the first study of any diabetic screening programme to demonstrate that weather may influence attendance. This research provides unique insight to guide the implementation of an optimal and cost-effective intervention strategy to improve attendance.


Asunto(s)
Retinopatía Diabética/diagnóstico , Tamizaje Masivo , Pacientes no Presentados/estadística & datos numéricos , Anciano , Estudios de Cohortes , Análisis Costo-Beneficio , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/economía , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/economía , Diabetes Mellitus Tipo 2/epidemiología , Retinopatía Diabética/economía , Retinopatía Diabética/epidemiología , Femenino , Humanos , Masculino , Tamizaje Masivo/economía , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Pacientes no Presentados/economía , Pobreza/estadística & datos numéricos , Factores de Riesgo , Factores Socioeconómicos
19.
Orphanet J Rare Dis ; 16(1): 200, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33952326

RESUMEN

INTRODUCTION: Inherited retinal degenerations (IRD) are rare genetic disorders with > 300 known genetic loci, manifesting variably progressive visual dysfunction. IRDs were historically underserved due to lack of effective interventions. Many novel therapies will require accurate diagnosis (phenotype and genotype), thus an efficient and effective pathway for assessment and management is required. METHODS: Using surveys of existing practice patterns and advice from international experts, an all-Ireland IRD service (Target 5000) was designed. Detailed phenotyping was followed by next generation genetic sequencing in both a research and accredited laboratory. Unresolved pedigrees underwent further studies (whole gene/whole exome/whole genome sequencing). Novel variants were interrogated for pathogenicity (cascade screening, in silico analysis, functional studies). A multidisciplinary team (MDT; ophthalmologists, physicians, geneticists, genetic counsellors) reconciled phenotype with genotype. A bespoke care plan was created for each patient comprising supports, existing interventions, and novel therapies/clinical trials. RESULTS AND DISCUSSION: Prior to Target 5000, a significant cohort of patients were not engaged with healthcare/support services due to lack of effective interventions. Pathogenic or likely pathogenic variants in IRD-associated genes were detected in 62.3%, with 11.6% having variants of unknown significance. The genotyping arm of Target 5000 allowed a 42.73% cost saving over independent testing, plus the value of MDT expertise/processing. Partial funding has transferred from charitable sources to government resources. CONCLUSION: Target 5000 demonstrates efficacious and efficient clinical/genetic diagnosis, while discovering novel IRD-implicated genes/variants and investigating mechanisms of disease and avenues of intervention. This model could be used to develop similar IRD programmes in small/medium-sized nations.


Asunto(s)
Degeneración Retiniana , Distrofias Retinianas , Exoma , Humanos , Irlanda , Mutación , Linaje , Distrofias Retinianas/genética
20.
Environ Technol Innov ; 20: 101164, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32959018

RESUMEN

The deteriorating water quality (WQ) of the sacred north-flowing perennial Indian River, Ganga was a serious concern in recent decades for population adjoining to the river and policy planners. The present evaluation attempts to assess the long-term (1989-2016) physiochemical characteristics of WQ of river Ganga at five upstream locations (Uttarkashi, Tehri, Rudraprayag, Devprayag, and Rishikesh) of Uttarakhand, India using comprehensive pollution index (CPI) and environmetrics (PCA and CA). These methods were used to categorize, summarize expensive datasets, and grouping the similar polluted areas along the river stretches. The WQ of river at all the locations were within the good category and most of the physiochemical parameters were well within their acceptable limit for drinking WQ. Considerably, CPI demonstrated the river WQ was in slight pollution range (CPI: 0.40-1.00) in the year 2007 and 2015 at all the five locations. The positive correlation coefficient (R2 > 0.50) among NO2 + NO3, Ca, Na, B, and K indicates the significant contribution of organic and inorganic salts through runoffs from catchments due to weathering of rocks. PCA confirmed the input source of nutrients in the river from both natural and anthropogenic sources. Moreover, the upstream WQ assessed was found to be good as compared to the severely polluted downstream region. Due to COVID-19 and shutdown in the country, reduction of pollution load in the river was observed due to the rejuvenation capability of river Ganga. This information can assist the environmentalist, policymaker, and water resources planners & managers to prepare strategic planning in advance to maintain the aesthetic and cultural value of Ganga river in future.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA