Biomass production in experimental grasslands of different species richness during three years of climate warming

in Biogeosciences (2008), 5

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have ... [more ▼]

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have stimulated studies on the response of terrestrial ecosystems to this global change. Experiments have likewise addressed the importance of species numbers for ecosystem functioning. There is, however, little knowledge on the interplay between warming and species richness. During three years, we grew experimental plant communities containing one, three or nine grassland species in 12 sunlit, climate-controlled chambers in Wilrijk, Belgium. Half of these chambers were exposed to ambient air temperatures (unheated), while the other half were warmed by 3 degrees C (heated). Equal amounts of water were added to heated and unheated communities, so that warming would imply drier soils if evapotranspiration was higher. Biomass production was decreased due to warming, both aboveground (-29%) and belowground (-25%), as negative impacts of increased heat and drought stress in summer prevailed. Complementarity effects, likely mostly through both increased aboveground spatial complementarity and facilitative effects of legumes, led to higher shoot and root biomass in multi-species communities, regardless of the induced warming. Surprisingly, warming suppressed productivity the most in 9-species communities, which may be attributed to negative impacts of intense interspecific competition for resources under conditions of high abiotic stress. Our results suggest that warming and the associated soil drying could reduce primary production in many temperate grasslands, and that this will not necessarily be mitigated by efforts to maintain or increase species richness. [less ▲]

Les biomatéraux.

Conference (2002, March 07)

Biomaterials, their potential in medicine and their actual side effects

Conference (2004, November 29)

Biomechanical Properties of Human Pelvic Organs

in Urology (2012), 79(4), 96817-96822

OBJECTIVE: To comparatively define the biomechanical characteristics of the pelvic organs (the vagina, bladder, and rectum), which are crucial for the maintenance of pelvic support. Despite minimal ... [more ▼]

OBJECTIVE: To comparatively define the biomechanical characteristics of the pelvic organs (the vagina, bladder, and rectum), which are crucial for the maintenance of pelvic support. Despite minimal fundamental studies, meshes are increasingly implanted into the vesicovaginal and rectovaginal spaces to replace disrupted native tissues and to treat pelvic organ prolapse. However, the mechanical characteristics of these materials have not yet been compared with those of the “functional unit,” the vagina, bladder, and rectum. METHODS: Samples from 5 fresh female cadavers without prolapse were collected. Uniaxial tension tests under monotonic and cyclic loading were performed and the stress-strain curves obtained. RESULTS: The biomechanical properties of the vaginal, bladder, and rectal tissues differed significantly. We were able to demonstrate a nonlinear relationship between the stress and strain and a visco- hyperelastic behavior with a Mullins effect of damage of the tissues examined. Comparable rigidity was found between the investigated tissues at low strains; however, at large strain levels, marked differences could be observed. The vagina was much more rigid and less extendible than the rectal tissue, which, in turn, was more rigid than the bladder tissue. The anterior and posterior vagina revealed a different stiffness, and the bladder tissue was anisotropic at large strain levels. CONCLUSION: Our results underline the pivotal role of the vaginal tissue for the maintenance of pelvic support. The observed differences with respect to tissue rigidity should have pronounced effects on the physiologic organ function, pointing to the necessity of a differentiated view on using the same prosthetic material for different anatomic locations. [less ▲]

Biomedical application of NMR metabolomics: study of Age-related Macular Degeneration (AMD)

Conference (2012, May 08)

Biomedical image classification with random subwindows and decision trees

in Computer Vision for Biomedical Image Applications (2005)

In this paper, we address a problem of biomedical image classification that involves the automatic classification of x-ray images in 57 predefined classes with large intra-class variability. To achieve ... [more ▼]

In this paper, we address a problem of biomedical image classification that involves the automatic classification of x-ray images in 57 predefined classes with large intra-class variability. To achieve that goal, we apply and slightly adapt a recent generic method for image classification based on ensemble of decision trees and random subwindows. We obtain classification results close to the state of the art on a publicly available database of 10000 x-ray images. We also provide some clues to interpret the classification of each image in terms of subwindow relevance. [less ▲]

Biomedical risk analysis in myocardial infarction

Conference (1983, January)

Biometallurgy for a greener E-wastes recycling

Conference (2010, September 03)

Biometrological assessment of skin protectors against moderate cold threat.

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at ... [more ▼]

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at decreasing heat loss by water evaporation from the skin. Objective : To compare the efficacy of 6 topical formulations enriched or not in rubefacients. The role of the vehicle was also assessed. Methods : A total of 30 trained cyclists tested the products on their forearms. The skin temperature and electrometric values were recorded at baseline following applications of the test products, and after 30 min-bicycle riding in moderately cold and humid outdoor conditions. Results : At baseline, skin temperature was increased by rubefacients dispersed a lipogel and o/w emulsion. This parameter decreased at all test sites after riding, but the values remained higher at the rubefacient-treated sites compared to the control untreated site. The oil and lipogel formulations achieved partial occlusion decreasing the transepidermal water loss. This effect was maintained after exercise without, however, hindering sweating. Conclusion : Among the presently tested formulations, the rubefacient-enriched lipogels appeared to be the most efficient formulations for maintaining skin temperature in the normal range during sport practice in a moderately cold environment. [less ▲]

Biometrology of physical properties of skin in thyroid dysfunction.

in Journal of the European Academy of Dermatology & Venereology (2008), 22(10), 1173-1177

OBJECTIVE: There is ample clinical evidence that skin is responsive to physiopathological levels of circulating thyroid hormones. The aim of the study was to assess some physical changes of the skin in ... [more ▼]

OBJECTIVE: There is ample clinical evidence that skin is responsive to physiopathological levels of circulating thyroid hormones. The aim of the study was to assess some physical changes of the skin in the presence of moderate thyroid dysfunction. SETTING: University Hospital. PATIENTS AND METHODS: A total of 119 adults suffering from hypothyroidism or hyperthyroidism and 60 healthy controls were enrolled in this study. Hormonal dosages (TSH, fT3, fT4) were assessed in the serum. A series of biometrological assessments were also performed on the volar and dorsal aspects of the forearms. These included electrometric assessments (Nova Dermal Phase Meter, Corneometer), evaporimetry (Tewameter)), colorimetry (Mexameter), ultrasound shear wave propagation (Reviscometer) and squamometry X. Correlations were searched between each of the serum hormonal dosages and each of the biometrological parameters. RESULTS: The hormonal changes in the untreated patients with thyroid dysfunction were modest in intensity. A few outlier values with regard to the normal range were found for each biometrological parameter. No correlations were found between fT3 or fT4 and each of the physical parameters. By contrast, significant negative linear correlations were found between thyroid-stimulating hormone (TSH) and skin hydration measured by the Corneometer and the Nova DPM. CONCLUSION: This multipronged exploratory study shows that direct or indirect effects of TSH may influence the stratum corneum hydration. This correlation seemed very sensitive, as no other specific biophysical parameter was significantly correlated with the thyroid hormonal concentrations in the serum. However, our findings do not exclude the possibility of some other skin changes supervening in case of more severe thyroid dysfunction. The mechanism by which TSH alters the stratum corneum hydration is yet unknown. [less ▲]