127 research outputs found
Gipsy 3D: Analysis, Visualization and Vo-Tools
The scientific goals of the AMIGA project are based on the analysis of a
significant amount of spectroscopic 3D data. In order to perform this work we
present an initiative to develop a new VO compliant package, including present
core applications and tasks offered by the Groningen Image Processing System
(GIPSY), and new ones based on use cases elaborated in collaboration with ad-
vanced users. One of the main goals is to provide local interoperability
between GIPSY (visualization and data analysis) and other VO software. The
connectivity with the Virtual Observatory environment will provide general
access to 3D data VO archives and services, maximizing the potential for
scientific discovery.Comment: 2 pages, 1 figure, to appear in the proceedings of the
"Multi-wavelength Astronomy and Virtual Observatory" Workshop held at ESAC
1-3 Dec 200
Increasing aridity threatens the sexual regeneration of Quercus ilex(holm oak) in Mediterranean ecosystems
Knowledge of the recruitment of dominant forest species is a key aspect for forest conservation and the ecosystem services they provide. In this paper, we address how the simultaneous action of climate change and the intensity of land use in the past influence the recruitment of a forest species that depends on the provision of nurse plants to recruit. We compared the number of saplings (up to 15 years old) and juveniles (16 to 50 years old) of Quercus ilex in 17, 5.3 ha plots in the Iberian System (eastern Spain). We used a gradient of past deforestation intensity crossed with two levels of average annual precipitation, one of them at the lower limit of the species'' precipitation niche (semi-arid) and the other at the optimum (sub-humid). We also examined the association between recruits and nurse plants and the effect on this association of plot-scale factors, such as seed abundance (reproductive Q. ilex), microsites (nurse species and soil availability), and large herbivores. The increase in aridity in the last decades has drastically reduced the recruitment of new individuals in the forests of Q. ilex located in the lower limit of their precipitation niche, regardless of the intensity of past deforestation that they suffered. Recruitment in these climatic conditions depends almost exclusively on large trees and shrubs whose abundance may also be limited by aridity. The lack of regeneration questions the future of these populations, as the number of individuals will decrease over time despite the strong resistance of adult trees to disturbance and drought
PIH16 ECONOMIC EVALUATION OF TWO ALTERNATIVE TREATMENTS FOR OVARIAN STIMULATION IN ASSISTED REPRODUCTION
Empleo de la fotografía en la diagnosis de un paisaje de interés cultural, la vega de Granada
La fotografía del paisaje es un instrumento de análisis fundamental para la diagnosis de
los territorios. Todo paisaje cuenta con valores objetivos y otros subjetivos vinculados a su
percepción, entre los que se encuentra los de carácter cultural, que si además cuentan con
valor patrimonial lo hacen merecedor de protección específica por su interés. La fotografía
es una herramienta adecuada para el análisis de los elementos de cualificación patrimonial
del paisaje, del estado de los conflictos que les afectan, y para el descubrimiento de las
oportunidades para su preservación. Las series de fotografías aéreas aportan importantes
datos sobre la evolución de los usos en el territorio, de las zonas límites de contacto y de la
permanencia o desaparición de los elementos de valor en la caracterización cultural. Siendo
necesarias las comprensiones territorial, integral, transversal y escalar de estos paisajes
culturales de interés, en los agrarios que aún conservan su funcionalidad debe considerarse
también su dinámica cambiante. La Vega de Granada es un ejemplo de paisaje agrario de
interés cultural dinámico inmerso en una aglomeración urbana, razón de ser y origen de
la misma, soporte de su sociedad e historia, cuyo valor patrimonial es reivindicado cada
vez con mayor fuerza a la vez que su preservación es más precaria, acosado por el avance
indiscriminado de usos no agrarios que lo han fragmentado y devaluado de manera
significativa en las últimas décadas. En el estudio de este paisaje resulta fundamental desde
el punto de vista metodológico el empleo de fotografías que hacen comprender la evolución
producida, siendo especialmente útil su empleo en la comprensión de los nuevos conflictos
producidos desde el último tercio del siglo XX.The landscape photography is a fundamental tool of analysis in order to diagnose territories.
Every landscape has its objective and subjective values linked to perception. Amongst them, it
is relevant to remember that if the cultural one involves a heritage value, then the landscape
is worth of a specific protection. Thus, the photography is an adequate tool for the analysis
of the heritage elements in the landscape, of the state of the conflicts that affect them and in
order to find the opportunities to its preservation. The series of aerial photographs provide
important information about the evolution of the uses in the territory, their borders of
connection and the continuity or disappearance of the values in the cultural qualification. It
is necessary an approach in a territorial, comprehensive, cross-cutting and pluri-scale way to
these cultural landscapes of interest. In the agrarian ones which still conserve its functionalities,
it must also be considered its dynamic reality. The Vega of Granada is an example of a
dynamic agrarian landscape of cultural interest in the midst of urban agglomerations. This
condition is in its origin, in its raison d’être and in the explanation of its society and its history.
That is why the heritage value is more every day reclaimed while its preservation is every
time more uncertain because of the indiscriminate progress of the non-agrarian uses which
have significantly fragmented and devaluated the landscape during these last decades. In the
methodology of this landscape study has been essential the use of photographs in order to
understand the evolution, and it has been particularly useful to figure out the new conflicts
originated in the last third of the 20th Century
The success of Quercus ilex plantations in agricultural fields in eastern Spain
Twenty-five years after planting, we measured the survival, growth and reproduction of 153 Quercus ilex plantations promoted by the afforestation programme of the European Union’s Common Agricultural Policy in agricultural fields in the east of the Iberian Peninsula, as a function of climatic aridity and stand characteristics related to water supply and competition among trees for water. Using field sampling, we found that, on average, 80% of the trees in plantations survived, more than 55% had already produced acorns and the tallest tree in each field exceeded 4 m, which are all higher values than those reported for forest plantations of this species in the same area and which represent the overcoming of the limitations imposed by climatic aridity on the natural regeneration of the species. A small proportion of the variation in all success variables was explained by water-related plantation characteristics, such as planting density, drought intensity in the year after planting, and soil permeability. However, climatic aridity only influenced the proportion of reproductive trees, but not the other variables of plantation success. However, most of the variation in planting success variables was linked to who owned the field, which nursery produced the seedlings, and the year of planting. Our results support the idea that the deep soils of agricultural fields counteract the negative effect of climatic aridity on plant performance, but that it is necessary to standardise nursery and planting practices, adapt planting density to the environmental characteristics of the site and provide irrigation supply in the early years to ensure the success of future plantations
Surface modification of starch based blends using potassium permanganate-nitric acid system and its effect on the adherence and proliferation of osteoblastic-like cells
The surface modification of three starch based polymeric biomaterials, using a KMnO4/NHO3 oxidizing system, and the effect of that modification on the osteoblastic cell adhesion has been investigated. The rationale of this work is as follows—starch based polymers have been proposed for use as tissue engineering scaffolds in several publications. It is known that in biodegradable systems it is quite difficult to have both cell adhesion and proliferation. Starch based polymers have shown to perform better than poly-lactic acid based materials but there is still room for improvement. This particular work is aimed at enhancing cell adhesion and proliferation on the surface of several starch based polymer blends that are being proposed as tissue engineering scaffolds.
The surface of the polymeric biomaterials was chemically modified using a KMnO4/HNO3 system. This treatment resulted in more hydrophilic surfaces, which was confirmed by contact angle measurements. The effect of the treatment on the bioactivity of the surface modified biomaterials was also studied. The bioactivity tests, performed in simulated body fluid after biomimetic coating, showed that a dense film of calcium phosphate was formed after 30 days. Finally, human osteoblast-like cells were cultured on unmodified (control) and modified materials in order to observe the effect of the presence of higher numbers of polar groups on the adhesion and proliferation of those cells. Two of the modified polymers presented changes in the adhesion behavior and a significant increase in the proliferation rate kinetics when compared to the unmodified controls.FCT (Portugal) for providing the postdoctoral grant (BPD/8491/2002)
Effect of starch-based biomaterials on the in vitro proliferation and viability of osteoblast-like cells
The cytotoxicity of starch-based polymers was investigated using different methodologies. Poly-L-lactic acid (PLLA) was used as a control for comparison purposes. Extracts of four different starch-based blends (corn starch and ethylene vinyl alcohol (SEVA-C), corn starch and cellulose acetate (SCA), corn starch and polycaprolactone (SPCL) and starch and poly-lactic acid (SPLA70) were prepared in culture medium and their toxicity was analysed. Osteoblast-like cells (SaOs-2) were incubated with the extracts and cell viability was assessed using the MTT test and a lactate dehydrogenase (LDH) assay. In addition DNA and total protein were quantified in order to evaluate cell proliferation. Cells were also cultured in direct contact with the polymers for 3 and 7 days and observed in light and scanning electron microscopy (SEM). LDH and DNA quantification revealed to be the most sensitive tests to assess respectively cell viability and cell proliferation after incubation with starch-based materials and PLLA. SCA was the starch blend with higher cytotoxicity index although similar to PLLA polymer. Cell adhesion tests confirmed the worst performance of the blend of starch with cellulose acetate but also showed that SPCL does not perform as well as it could be expected. All the other materials were shown to present a comparable behaviour in terms of cell adhesion showing slight differences in morphology that seem to disappear for longer culture times.
The results of this study suggest that not only the extract of the materials but also their three-dimensional form has to be biologically tested in order to analyse material-associated parameters that are not possible to consider within the degradation extract. In this study, the majority of the starch-based biomaterials presented very promising results in terms of cytotoxicity, comparable to the currently used biodegradable PLLA which might lead the biocompatibility evaluation of those novel biomaterials to other studies.Fundação para a Ciência e a Tecnologia (FCT
Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa
BACKGROUND: In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. METHODS: This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides. RESULTS: The quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21) and 3.16 ± 3.5 μg/L (n = 13) average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69%) followed by Hex River (46%) and Piketberg (39%). Detections were more frequent in surface water (47%) than in groundwater (32%) and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR) criteria. CONCLUSION: The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa
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