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11.
Spatial heterogeneity in species composition constrains plant community responses to herbivory and fertilisation 下载免费PDF全文
Dorothee Hodapp Elizabeth T. Borer W. Stanley Harpole Eric M. Lind Eric W. Seabloom Peter B. Adler Juan Alberti Carlos A. Arnillas Jonathan D. Bakker Lori Biederman Marc Cadotte Elsa E. Cleland Scott Collins Philip A. Fay Jennifer Firn Nicole Hagenah Yann Hautier Oscar Iribarne Johannes M. H. Knops Rebecca L. McCulley Andrew MacDougall Joslin L. Moore John W. Morgan Brent Mortensen Kimberly J. La Pierre Anita C. Risch Martin Schütz Pablo Peri Carly J. Stevens Justin Wright Helmut Hillebrand 《Ecology letters》2018,21(9):1364-1371
Environmental change can result in substantial shifts in community composition. The associated immigration and extinction events are likely constrained by the spatial distribution of species. Still, studies on environmental change typically quantify biotic responses at single spatial (time series within a single plot) or temporal (spatial beta diversity at single time points) scales, ignoring their potential interdependence. Here, we use data from a global network of grassland experiments to determine how turnover responses to two major forms of environmental change – fertilisation and herbivore loss – are affected by species pool size and spatial compositional heterogeneity. Fertilisation led to higher rates of local extinction, whereas turnover in herbivore exclusion plots was driven by species replacement. Overall, sites with more spatially heterogeneous composition showed significantly higher rates of annual turnover, independent of species pool size and treatment. Taking into account spatial biodiversity aspects will therefore improve our understanding of consequences of global and anthropogenic change on community dynamics. 相似文献
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Study design
A prospective treatment study with a new brace was conducted Objective. To evaluate radiological and subjective clinical results after one year conservative brace treatment with pressure onto lordosis at the thoracolumbar joint in children with scoliosis and kyphosis.Summary of background data
Conservative brace treatment of adolescent scoliosis is not proven to be effective in terms of lasting correction. Conservative treatment in kyphotic deformities may lead to satisfactory correction. None of the brace or casting techniques is based on sagittal forces only applied at the thoracolumbar spine (TLI= thoracolumbar lordotic intervention). Previously we showed in patients with scoliosis after forced lordosis at the thoracolumbar spine a radiological instantaneous reduction in both coronal curves of double major scoliosis.Methods
A consecutive series of 91 children with adolescent scoliosis and kyphosis were treated with a modified symmetric 30 degrees Boston brace to ensure only forced lordosis at the thoracolumbar spine. Scoliosis was defined with a Cobb angle of at least one of the curves [greater than or equal to] 25 degrees and kyphosis with or without a curve <25 degrees in the coronal plane. Standing radiographs were made i) at start, ii) in brace at beginning and iii) after one year treatment without brace.Results
Before treatment start ??in brace?? radiographs showed a strong reduction of the Cobb angles in different curves in kyphosis and scoliosis groups (sagittal n = 5 all p < 0.001, pelvic obliquity p < 0.001). After one year of brace treatment in scoliosis and kyphosis group the measurements on radiographs made without brace revealed an improvement in 3 Cobb angles each.Conclusion
Conservative treatment using thoracolumbar lordotic intervention in scoliotic and kyphotic deformities in adolescence demonstrates a marked improvement after one year also in clinical and postural criteria. An effect not obtained with current brace techniques. 相似文献14.
The breast can be considered conceptually as a cone. This article compares and contrasts short-scar breast reduction techniques with inverted T techniques using the cone model. Four issues are examined-the base of the breast, breast projection, the inframammary fold, and the pedicle. The short-scar techniques focus on reshaping the breast parenchyma, and skin redraping occurs secondarily. Application of this model suggests that these techniques have the advantage of better projection and greater longevity. These techniques seldom give a square shape and are better at dealing with upper pole deficiency. However, the ability of the skin to redrape is the limiting factor; hence, results are less predictable with large-volume breast reductions. The emphasis of this article is on increasing the understanding of the mechanics of breast reduction. It is this factor that will enable appropriate selection of a particular technique. 相似文献
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Role of suppressor T cells in herpes simplex virus-induced immune deviation. 总被引:2,自引:1,他引:1 下载免费PDF全文
Herpes simplex virus type 1 inoculated into the anterior chamber of the mouse eye induces suppression of anti-herpes simplex virus T-cell-mediated delayed hypersensitivity. This suppression is virus-specific, and mediated by splenic T lymphocytes, and it can be adoptively transferred to naive recipients. 相似文献
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Simon van Mourik Aalt DJ van Dijk Maarten de Gee Richard GH Immink Kerstin Kaufmann Gerco C Angenent Roeland CHJ van Ham Jaap Molenaar 《BMC systems biology》2010,4(1):101
Background
The genetic control of floral organ specification is currently being investigated by various approaches, both experimentally and through modeling. Models and simulations have mostly involved boolean or related methods, and so far a quantitative, continuous-time approach has not been explored. 相似文献18.
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R Podstawski DJ Choszcz S Konopka J Klimczak M Starczewski 《Biology of sport / Institute of Sport》2014,31(4):315-321
The aim of the study was to evaluate anthropometric characteristics as determinants of 500 m rowing ergometer performance in physically inactive collegiate females. In this cross-sectional study, which included 196 collegiate females aged 19-23 years not participating in regular physical activities, body mass (BM), body height (BH), length of upper limbs (LA), length of lower limbs (LL), body mass index (BMI), slenderness index (SI), and the Choszcz-Podstawski index (CPI) were measured and a stepwise multiple regression analysis was performed. Participants performed 500 m maximal effort on a Concept II rowing ergometer. BM, BH, LA, LL, and the BMI, SI and CPI indices were found to be statistically significant determinants of 500 m performance. The best results (T) were achieved by females whose BH ranged from 170 to 180 cm, with LA and LL ranging from 75 to 80 cm and 85 to 90 cm, respectively. The best fitting statistical model was identified as: T = 11.6793 LR – 0.1130 LR2 – 0.0589 LN2 + 29.2157 CPI2 + 0.1370 LR·LN - 2.6926 LR·CPI – 211.7796. This study supports a need for additional studies focusing on understanding the importance of anthropometric differences in rowing ergometer performance, which could lead to establishing a better quality reference for evaluation of cardiorespiratory fitness tested using a rowing ergometer in collegiate females. 相似文献