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1.
PLoS One ; 8(7): e69176, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23894426

RESUMEN

Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise.


Asunto(s)
Ejercicio Físico/fisiología , Autoimagen , Niño , Salud Ambiental , Ejercicio Físico/psicología , Femenino , Humanos , Masculino , Aptitud Física/fisiología , Aptitud Física/psicología
2.
Appl Environ Microbiol ; 70(5): 2692-701, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15128520

RESUMEN

The composition of the active microbial (bacterial and fungal) soil community in an arable wheat field subjected to different management practices was examined at five times during a 1-year period. Field sections were fertilized either at good agricultural practice (GAP) levels or at reduced levels (0.5x GAP) and were inoculated with vesicular arbuscular mycorrhizae (VAM) at the same time. Field subsections were treated either with or without pesticides. Changes in the active microbial communities were investigated by denaturing gradient gel electrophoresis analysis of reverse transcription-PCR-amplified 16S and 18S rRNA. Microbial community structure was primarily determined by season, and the seasonal trends were similar for the fungal and bacterial components. Between-sample microbial heterogeneity decreased under a mature crop in the summer but increased following harvesting and plowing. Although similar overall trends were seen for the two microbial components, sample variability was greater for the fungal community than for the bacterial community. The greatest management effects were due to GAP fertilization, which caused increases in the bacterial numbers in the total and culturable communities. Microbial biomass similarly increased. GAP fertilization also caused large shifts in both the active bacterial community structure and the active fungal community structure and additionally resulted in a decrease in the heterogeneity of the active bacterial community. Pesticide addition did not significantly affect bacterial numbers or heterogeneity, but it led to major shifts in the active soil bacterial community structure. PCR primers specific for Glomales 25S rRNA genes were used to monitor the VAM population following inoculation. Glomales were detected initially only in VAM-inoculated field sections but were subsequently detected in noninoculated field sections as the season progressed. After plowing, the level of Glomales was reduced in noninoculated field sections but remained high in VAM-inoculated field sections. Inoculation of VAM correlated with elevated soil phosphate and carbon levels.


Asunto(s)
Agricultura , Bacterias/crecimiento & desarrollo , Fertilizantes , Hongos/crecimiento & desarrollo , Plaguicidas/farmacología , Microbiología del Suelo , Triticum , Bacterias/genética , Bacterias/aislamiento & purificación , Recuento de Colonia Microbiana , ADN Ribosómico/análisis , Ecosistema , Electroforesis/métodos , Hongos/genética , Hongos/aislamiento & purificación , ARN Ribosómico 16S/genética , ARN Ribosómico 18S/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
3.
Appl Environ Microbiol ; 69(3): 1800-9, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12620873

RESUMEN

Degradation of agricultural land and the resulting loss of soil biodiversity and productivity are of great concern. Land-use management practices can be used to ameliorate such degradation. The soil bacterial communities at three separate arable farms in eastern England, with different farm management practices, were investigated by using a polyphasic approach combining traditional soil analyses, physiological analysis, and nucleic acid profiling. Organic farming did not necessarily result in elevated organic matter levels; instead, a strong association with increased nitrate availability was apparent. Ordination of the physiological (BIOLOG) data separated the soil bacterial communities into two clusters, determined by soil type. Denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphism analyses of 16S ribosomal DNA identified three bacterial communities largely on the basis of soil type but with discrimination for pea cropping. Five fields from geographically distinct soils, with different cropping regimens, produced highly similar profiles. The active communities (16S rRNA) were further discriminated by farm location and, to some degree, by land-use practices. The results of this investigation indicated that soil type was the key factor determining bacterial community composition in these arable soils. Leguminous crops on particular soil types had a positive effect upon organic matter levels and resulted in small changes in the active bacterial population. The active population was therefore more indicative of short-term management changes.


Asunto(s)
Agricultura , Bacterias/clasificación , Bacterias/metabolismo , Ecosistema , Microbiología del Suelo , Suelo/análisis , Bacterias/genética , Bacterias/crecimiento & desarrollo , Técnicas de Tipificación Bacteriana , Conservación de los Recursos Naturales , ADN Ribosómico/análisis , Electroforesis/métodos , Fabaceae/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , ARN Ribosómico 16S/genética
4.
Environ Sci Technol ; 37(2): 201-8, 2003 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-12564888

RESUMEN

Eutrophication has many known consequences, but there are few data on the environmental and health costs. We developed a new framework of cost categories that assess both social and ecological damage costs and policy response costs. These findings indicate the severe effects of nutrient enrichment and eutrophication on many sectors of the economy. We estimate the damage costs of freshwater eutrophication in England and Wales to be $105-160 million yr(-1) (pound 75.0-114.3 m). The policy response costs are a measure of how much is being spent to address this damage, and these amount to $77 million yr(-1) pound 54.8 m). The damage costs are dominated by seven items each with costs of $15 million yr(-1) or more: reduced value of waterfront dwellings, drinking water treatment costs for nitrogen removal, reduced recreational and amenity value of water bodies, drinking water treatment costs for removal of algal toxins and decomposition products, reduced value of nonpolluted atmosphere, negative ecological effects on biota, and net economic losses from the tourist industry. In common with other environmental problems, it would represent net value (or cost reduction) if damage was prevented at source. A variety of effective economic, regulatory, and administrative policy instruments are available for internalizing these costs.


Asunto(s)
Ecología , Eutrofización , Modelos Teóricos , Purificación del Agua/economía , Abastecimiento de Agua , Costos y Análisis de Costo , Inglaterra , Eucariontes , Humanos , Nitrógeno/aislamiento & purificación , Recreación , Gales , Purificación del Agua/métodos
5.
Santa Cruz; DPID;Universidad NUR;IIED; 1997. 267 p. ilus.
Monografía en Español | LIBOCS, LIBOSP | ID: biblio-1333369

Asunto(s)
Aprendizaje
6.
Santa Cruz de la Sierra; . ilus, tab.(Metodologías participativas).
Monografía en Español | LILACS-Express | LIBOCS, LIBOPI | ID: biblio-1296275
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