Runoff at the micro-plot and slope scale following wildfire, central Portugal

Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations. Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events

Runoff and erosion at the micro-plot and slope scale in a small burnt catchment, central Portugal

Wildfires can have important impacts on hydrological processes and soil erosion in forest catchments, due to the destruction of vegetation cover and changes to soil properties. However, the processes involved are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, especially in the up-scaling from hillslopes to catchments; in consequence, current models are poorly adapted for burnt forest conditions. The objective of this presentation is to give an overview of the hydrological response and sediment yield from the micro-plot to slope scale, in the first year following a wildfire (2008/2009) that burnt an entire catchment nearby the Colmeal village, central Portugal. The overview will focus on three slopes inside the catchment, with samples including: • Runoff at micro-plot scale (12 bounded plots) and slope scale (12 open plots); • Sediments and Organic Matter loss at micro-plot scale (12 bounded plots) and slope scale (12 open plots plus 3 Sediment fences); • Rainfall and Soil moisture data; • Soil Water Repellency and Ground Cover data. The analysis of the first year following the wildfire clearly shows the complexity of runoff generation and the associated sediment transport in recently burnt areas, with pronounced differences between hillslopes and across spatial scales as well as with marked variations through time. This work was performed in the framework of the EROSFIRE-II project (PTDC/AGR-CFL/70968/2006) which has as overall aim to predict soil erosion risk in recently burnt forest areas, including common post-fire forest management practices; the project focuses on the simultaneous measurement of runoff and soil erosion at multiple spatial scales.The results to be presented in this session are expected to show how sediment is generated, transported and exported in the Colmeal watershed; and contribute to understand and simulate erosion processes in burnt catchments, including for model development and evaluation

Interference effects in above-threshold ionization from diatomic molecules: determining the internuclear separation

We calculate angle-resolved above-threshold ionization spectra for diatomic molecules in linearly polarized laser fields, employing the strong-field approximation. The interference structure resulting from the individual contributions of the different scattering scenarios is discussed in detail, with respect to the dependence on the internuclear distance and molecular orientation. We show that, in general, the contributions from the processes in which the electron is freed at one center and rescatters off the other obscure the interference maxima and minima obtained from single-center processes. However, around the boundary of the energy regions for which rescattering has a classical counterpart, such processes play a negligible role and very clear interference patterns are observed. In such energy regions, one is able to infer the internuclear distance from the energy difference between adjacent interference minima.Comment: 10 pages, 8 figures; discussions slightly modified and an additional figure inserted for clarit

Peri-operative anaphylaxis in Coimbra: the experience of our drug allergy clinic

Background: The incidence of peri-operative anaphylactic reactions ranges from 1:10,000 to 1:20,000. It is crucial to identify the risk factors, the trigger agent and to fi nd adequate alternatives. Aims: To characterise patients with peri-operative anaphylactic reactions. Methods: We performed a retrospective study of patients with suspected adverse peri-operative reactions to anaesthetic drugs, observed in a Drug Allergy Outpatients Clinic from 1994 to 2005. Anaphylaxis was diagnosed based on the clinical history and skin tests to latex, neuromuscular blocking agents (NMBA), hypnotics, opioids and antibiotics. Specifi c IgE to latex was performed in patients with positive skin-prick-tests. Results: We evaluated the clinical charts of 45 patients with adverse peri-operative reactions, 39 of whom were female. Anaphylaxis was diagnosed in 16 patients (35.6%), 15 females, mean age 36.3 years. The remaining patients had non-anaphylactic (28.8%) or not well-characterised reactions (35.6%). In terms of severity, 50% presented grade III and 50% grade IV anaphylaxis. Skin-prick-tests were positive to latex in three patients and negative to all anaesthetic drugs. Intradermal skin tests were positive in 10 out of 16 patients with anaphylactic reactions: 10 to NMBA [atracurium (n = 8), vecuronium (n = 4), suxamethonium (n = 4) and pancuronium (n = 2)], one to fentanyl, one to thiopental and one to cefuroxime. In three cases, the culprit agent was not identifi ed. In four patients, at least one alternative NMBA, with no skin test reactivity, was found. Of these four patients, two underwent further surgical procedures without adverse reactions. Five patients had previously had two or more anaesthetic procedures and four had presented adverse reactions in prior surgeries. Conclusions: In our study the most common causes of anaphylaxis were NMBAs (62.5%) and latex (18.7%), in line with that described in the literature. In 81% of patients with anaphylactic reactions, skin tests were positive to at least one anaesthetic drug or to latex. A high incidence of severe anaphylaxis was found, probably because cases with less severe clinical signs were not referred to our clinic. The results emphasise the need for systematic evaluation of anaphylactic reactions during anaesthesia. This can be achieved by the creation of a specialised Allergo-Anaesthesia Clinic, as has been the case in our Department

Gene flow from transgenic common beans expressing the bar gene.

Gene flow is a common phenomenon even in self-pollinated plant species. With the advent of genetically modified plants this subject has become of the utmost importance due to the need for controlling the spread of transgenes. This study was conducted to determine the occurrence and intensity of outcrossing in transgenic common beans. In order to evaluate the outcross rates, four experiments were conducted in Santo Antonio de Goiás (GO, Brazil) and one in Londrina (PR, Brazil), using transgenic cultivars resistant to the herbicide glufosinate ammonium and their conventional counterparts as recipients of the transgene. Experiments with cv. Olathe pinto and the transgenic line Olathe M1/4 were conducted in a completely randomized design with ten replications for three years in one location, whereas the experiments with cv. Pérola and the transgenic line Pérola M1/4 were conducted at two locations for one year, with the transgenic cultivar surrounded on all sides by the conventional counterpart. The outcross occurred at a negligible rate of 0.00741% in cv. Pérola, while none was observed (0.0%) in cv. Olathe pinto. The frequency of gene flow was cultivar dependent and most of the observed outcross was within 2.5 m from the edge of the pollen source

Manejo de leguminosas em videira - 1a. colheita.

O objetivo do trabalho foi melhorar as características do solo para se obter uma maior produtividade de uva em uma agricultura sustentável