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1.
Agron Sustain Dev ; 43(6): 75, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37969112

RESUMO

Early energy analyses of agriculture revealed that behind higher labor and land productivity of industrial farming, there was a decrease in energy returns on energy (EROI) invested, in comparison to more traditional organic agricultural systems. Studies on recent trends show that efficiency gains in production and use of inputs have again somewhat improved energy returns. However, most of these agricultural energy studies have focused only on external inputs at the crop level, concealing the important role of internal biomass flows that livestock and forestry recirculate within agroecosystems. Here, we synthesize the results of 82 farm systems in North America and Europe from 1830 to 2012 that for the first time show the changing energy profiles of agroecosystems, including livestock and forestry, with a multi-EROI approach that accounts for the energy returns on external inputs, on internal biomass reuses, and on all inputs invested. With this historical circular bioeconomic approach, we found a general trend towards much lower external returns, little or no increases in internal returns, and almost no improvement in total returns. This "energy trap" was driven by shifts towards a growing dependence of crop production on fossil-fueled external inputs, much more intensive livestock production based on feed grains, less forestry, and a structural disintegration of agroecosystem components by increasingly linear industrial farm managements. We conclude that overcoming the energy trap requires nature-based solutions to reduce current dependence on fossil-fueled external industrial inputs and increase the circularity and complexity of agroecosystems to provide healthier diets with less animal products. Supplementary Information: The online version contains supplementary material available at 10.1007/s13593-023-00925-5.

2.
Reg Environ Change ; 18(4): 1089-1101, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31258413

RESUMO

Energy efficiency in biomass production is a major challenge for a future transition to sustainable food and energy provision. This study uses methodologically consistent data on agroecosystem energy flows and different metrics of energetic efficiency from seven regional case studies in North America (USA and Canada) and Europe (Spain and Austria) to investigate energy transitions in Western agroecosystems from the late nineteenth to the late twentieth centuries. We quantify indicators such as external final energy return on investment (EFEROI, i.e., final produce per unit of external energy input), internal final EROI (IFEROI, final produce per unit of biomass reused locally), and final EROI (FEROI, final produce per unit of total inputs consumed). The transition is characterized by increasing final produce accompanied by increasing external energy inputs and stable local biomass reused. External inputs did not replace internal biomass reinvestments, but added to them. The results were declining EFEROI, stable or increasing IFEROI, and diverging trends in FEROI. The factors shaping agroecosystem energy profiles changed in the course of the transition: Under advanced organic and frontier agriculture of the late nineteenth and early twentieth centuries, population density and biogeographic conditions explained both agroecosystem productivity and energy inputs. In industrialized agroecosystems, biogeographic conditions and specific socio-economic factors influenced trends towards increased agroecosystem specialization. The share of livestock products in a region's final produce was the most important factor determining energy returns on investment.

3.
Psicothema ; 20(4): 596-602, 2008 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-18940056

RESUMO

The main objective of the present study is to analyse the role of cynicism as a coping strategy in the process of burnout, considering gender as a key variable in this process. The sample comprised 555 teachers from Spanish primary and secondary schools. A two-wave panel study was carried out: data were gathered during the first term and again during the third and last term of the academic year. Several t-tests for independent samples and moderated hierarchical regression analysis were carried out. Results showed that women have a higher level of exhaustion than men, whereas men have a higher level of cynicism than women. Furthermore, cynicism has a direct and positive effect on exhaustion for women. In the case of men, cynicism is not an effective coping strategy but it has some buffering effect on exhaustion. Thus, a high level of cynicism seems to lead to a lower increase of exhaustion. Results, contributions, and limitations of the present study are discussed.


Assuntos
Adaptação Psicológica , Personalidade , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
4.
Res Q Exerc Sport ; 73(3): 257-70, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12230332

RESUMO

We evaluated the cross-cultural generalizability of the factor structure for the Physical Self-Description Questionnaire (PSDQ) using confirmatory factor analysis. The factor structure was reasonably invariant over large samples of responses by Australian, Spanish, and Turkish students. Consistent with a priori predictions, the factor structures based on Australian and Spanish high school students were somewhat more similar to each other than to those based on Turkish university students, but these differences were small. Psychometric, theoretical cross-cultural, and practical considerations support the PSDQ's usefulness in a variety of research and applied settings. The study also provides a model for comparing psychometric properties based on responses to original and translated versions of sport psychology measures.


Assuntos
Autoimagem , Esportes , Inquéritos e Questionários , Adolescente , Austrália , Criança , Comparação Transcultural , Análise Fatorial , Feminino , Humanos , Masculino , Psicometria , Espanha , Turquia
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