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排序方式: 共有113条查询结果,搜索用时 526 毫秒
1.
Despite consumer and regulatory focus on the quality of final food and beverage (F&B) products, little attention is given to the release and management of toxic chemicals by F&B processors. This study develops five plant-level indicators of environmental performance specific to toxic chemicals. Our findings suggest that (i) only few F&B processors invest in toxic chemical prevention activities; (ii) the major toxic chemical management strategy is treatment rather than recycling or energy recovery; (iii) F&B processors, on average, have improved their toxic chemical management rates between 2001 and 2012; and (iv) there is evidence for homogeneous performance across similar producers in the F&B processing industry but there is no evidence for the role of socio-economic characteristics of surrounding communities on the environmental performance of F&B processors. 相似文献
2.
We studied the latent factor structure of the Beck Depression Inventory (BDI) under the light of Multidimensional Item Response Theory models. Under a Bayesian Markov chain Monte Carlo setting, we chose the most adequate model, estimated its parameters and verified its fit to the data. An evaluation of the inventory in terms of the assumed dimensions seems to agree with previous investigations in the factor structure of the BDI present in the literature. Cognitive and somatic‐affective latent traits were identified in the analysis making possible the interpretation of symptom evolution along these dimensions, in terms of probability of their appearance. 相似文献
3.
The present study aimed to devise a parsimonious instrument for evaluating both the quantitative and qualitative aspects of dream experiences and to quantify Chinese people's dream experiences in ways that facilitated cross-cultural comparisons. The Dream Intensity Inventory was developed and administered to 348 Chinese university students. Individual differences in dream recall frequency were observed, with some participants recalling dreams almost every morning whereas others recalled dreams less than once a month. By contrast, the Chinese participants exhibited less diverse dream awareness frequencies. Multiple dreams in a single night and nightmares were found to be prevalent among the Chinese participants. On the other hand, fewer than half of the participants experienced regularly voluntary control over dream activities and consciousness. The factor analyses of the items in the Dream Intensity Inventory resulted in three readily interpreted factors, which were labeled as the "dream quantity," "altered dream episodes," and "dream vividness" subscales, respectively. When compared with men, women participants had higher frequencies of regular dream experiences including dream awareness, nightmares, and multiple dreams, as measured by the dream quantity subscale. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
《Journal of biological education》2012,46(2):76-79
A dice game for teaching the relationship between water availability and water loss in plant growth 相似文献
5.
Julen Astigarraga Enrique Andivia Miguel A. Zavala Antonio Gazol Vernica Cruz‐Alonso Sergio M. Vicente‐Serrano Paloma Ruiz‐Benito 《Global Change Biology》2020,26(9):5063-5076
Climate and forest structure are considered major drivers of forest demography and productivity. However, recent evidence suggests that the relationships between climate and tree growth are generally non‐stationary (i.e. non‐time stable), and it remains uncertain whether the relationships between climate, forest structure, demography and productivity are stationary or are being altered by recent climatic and structural changes. Here we analysed three surveys from the Spanish Forest Inventory covering c. 30 years of information and we applied mixed and structural equation models to assess temporal trends in forest structure (stand density, basal area, tree size and tree size inequality), forest demography (ingrowth, growth and mortality) and above‐ground forest productivity. We also quantified whether the interactive effects of climate and forest structure on forest demography and above‐ground forest productivity were stationary over two consecutive time periods. Since the 1980s, density, basal area and tree size increased in Iberian forests, and tree size inequality decreased. In addition, we observed reductions in ingrowth and growth, and increases in mortality. Initial forest structure and water availability mainly modulated the temporal trends in forest structure and demography. The magnitude and direction of the interactive effects of climate and forest structure on forest demography changed over the two time periods analysed indicating non‐stationary relationships between climate, forest structure and demography. Above‐ground forest productivity increased due to a positive balance between ingrowth, growth and mortality. Despite increasing productivity over time, we observed an aggravation of the negative effects of climate change and increased competition on forest demography, reducing ingrowth and growth, and increasing mortality. Interestingly, our results suggest that the negative effects of climate change on forest demography could be ameliorated through forest management, which has profound implications for forest adaptation to climate change. 相似文献
6.
Pedro Cardoso Sérgio S. Henriques Clara Gaspar Luis C. Crespo Rui Carvalho Jesper B. Schmidt Pedro Sousa Tamás Szűts 《Journal of Insect Conservation》2009,13(1):45-55
Intensive fieldwork has been undertaken in Portugal in order to develop a standardized and optimized sampling protocol for
Mediterranean spiders. The present study had the objectives of testing the use of semi-quantitative sampling for obtaining
an exhaustive species richness assessment of spiders and testing the effects of day, time of day, collector and sampling method
on the collected species richness and composition of a Mediterranean scrubland. The collecting summed 224 samples corresponding
to one person-hour of effective fieldwork each. In total, 115 species were captured, of which 110 were recorded inside a delimited
one-hectare plot, corresponding to more than 70% of the about 160 estimated species. Although no estimator reached the asymptote,
the Michaelis-Menten curve behaviour indicates that the estimated richness should be accurate. Most different sampling approaches
(day, time of day, collector and sampling method) were found to influence richness, abundance or composition of the samples
to some extent, although sampling method had the strongest influence whereas “collector” showed no effect at all. The results
support the idea that the only variables that need to be controlled in similar protocols are the sampling methods and the
time of day when each method is executed. We conclude that populations in structurally simple habitats present narrower peaks
of adult abundance, which implies higher percentages of juveniles in samples. Finally, results also indicate that habitats
with a relatively simple structure like scrublands may require as much sampling effort, in order to reach similar proportions
of captured species in relation to the estimated richness, as habitats that are much more complex. 相似文献
7.
8.
JOHN M. TIRPAK D. TODD JONES-FARRAND FRANK R. THOMPSON III DANIEL J. TWEDT CHARLES K. BAXTER JANE A. FITZGERALD WILLIAM B. UIHLEIN III 《The Journal of wildlife management》2009,73(8):1307-1315
ABSTRACT Emerging methods in habitat and wildlife population modeling promise new horizons in conservation but only if these methods provide robust population-habitat linkages. We used Breeding Bird Survey (BBS) data to verify and validate newly developed habitat suitability index (HSI) models for 40 priority landbird species in the Central Hardwoods and West Gulf Coastal Plain/Ouachitas Bird Conservation Regions. We considered a species’ HSI model verified if there was a significant rank correlation between mean predicted HSI score and mean observed BBS abundance across the 88 ecological subsections within these Bird Conservation Regions. When we included all subsections, correlations verified 37 models. Models for 3 species were unverified. Rank correlations for an additional 5 species were not significant when analyses included only subsections with BBS abundance >0. To validate models, we developed generalized linear models with mean observed BBS abundance as the response variable and mean HSI score and Bird Conservation Region as predictor variables. We considered verified models validated if the overall model was an improvement over an intercept-only null model and the coefficient on the HSI variable in the model was >0. Validation provided a more rigorous assessment of model performance than verification, and models for 12 species that we verified failed validation. Species whose models failed validation were either poorly sampled by BBS protocols or associated with woodland and shrubland habitats embedded within predominantly open landscapes. We validated models for 25 species. Habitat specialists and species reaching their highest densities in predominantly forested landscapes were more likely to have validated models. In their current form, validated models are useful for conservation planning of priority landbirds and offer both insight into limiting factors at ecoregional scales and a framework for monitoring priority landbird populations from readily available national data sets. 相似文献
9.
10.
Nay Chi Htun Koichi Miyaki Chenxi Zhao Masaaki Muramatsu Noriko Sato 《Biochemical and biophysical research communications》2014
Higher cognitive performance, maintenance of mental health and psychological well-being require adequate prefrontal cortex (PFC) function. “Inverted U-shaped” dopamine model indicates optimal PFC dopamine level is important to attain its function while high or low levels have adverse effects. Catechol-O-methyltransferase (COMT) and methylenetetrahydrofolate reductase (MTHFR) may be involved in this complex non-linear PFC dopamine regulation. We addressed whether genetic variation reflecting COMT and MTHFR activities can explain the inter-individual mental health differences in healthy Japanese men (n = 188). The mental health was measured by Mental Health Inventory (MHI)-5 score. The rs4633–rs4818–rs4680 haplotypes were used to represent the multilevel COMT activities, while for MTHFR, the functional single polymorphism, rs1801133 (C677T), was used. We examined the effectiveness of haplotype-based association analysis of COMT on mental health together with studying its interaction with MTHFR-C677T. As a result, the relation between activity-ranked COMT genotype and MHI-5 score showed a tendency to fit into an “inverted U-shaped” quadratic curve (P = 0.054). This curvilinear correlation was significant in the subjects with MTHFR-CC (P < 0.001), but not with MTHFR T-allele carriers (P = 0.793). Our pilot study implies a potential influence of COMT and MTHFR genotypic combination on normal variation of mental health. 相似文献