Uniqueness for the inverse fixed angle scattering problem

We present a uniqueness result in dimensions $2$ and $3$ for the inverse fixed angle scattering problem associated to the Schr\"odinger operator $-\Delta+q$, where $q$ is a small real valued potential with compact support in the Sobolev space $W^{\beta,2}$ with $\beta>0.$ This result improves the known result, due to Stefanov, in the sense that almost no regularity is required for the potential. The uniqueness result still holds in dimension $4$, but for more regular potentials in $W^{\beta,2}$ with $\beta>2/3$

Light‐Emitting Diodes: Progress in Plant Micropropagation

In commercial micropropagation laboratories, the light source is one of the most important factors controlling plant morphogenesis and metabolism of plant cells and tissue and organ cultures. Lamp manufacturers have begun to rate lamps specifically for plant needs. The traditional light source used for in vitro propagation is fluorescent lamps (FLs). However, power consumption in FL use is expensive and produces a wide range of wavelengths (350–750 nm) unnecessary for plant development. Light‐emitting diodes (LEDs) have recently emerged as an alternative for commercial micropropagation. The flexibility of matching LED wavelengths to plant photoreceptors may provide more optimal production, influencing plant morphology and chlorophyll content. Although previous reports have confirmed physiological effects of LED light quality on morphogenesis and growth of several plantlets in vitro, these study results showed that LED light is more suitable for plant morphogenesis and growth than FLs. However, the responses vary according to plant species. This chapter describes the applications and benefits of LED lamps on chlorophyll in plant micropropagation. Two study cases are exposed, Anthurium (Anthurium andreanum) and moth orchids (Phalaenopsisis sp.), both species with economic importance as ornamental plants, where LEDs have a positive effect on in vitro development and chlorophyll content

Developing a set of strategies, in Portugal, to monitor and prevent damages in animal housing, due to hot climate conditions

In Portugal, animal production (mainly meat and milk) represents 32% of the Agriculture Domestic Product and, in some regions, its socio-economic importance is quite relevant. Located in Southwestern Europe, Portugal has a mediterranean climate: Winter is cold and wet. Summer is hot and dry particularly in Alentejo and northeastern regions. Significantly high temperatures combined with dry air (or even wet air) may bring about serious problems or damage to livestock and losses to the farmer. In Portugal, it is estimated that 20% of the annual losses in animal production are due to adverse climatic factors or deficient regulation in indoor climatization of animal housing. The situation is most problematic in summer when very high temperatures occur. According to the HWDI (Heat Wave Duration Index) since 2000, in Portugal three heat waves have occurred, with temperatures over 40 degrees C. Generally, in all regions, these periods of very high temperatures are combined with dry air (low relative humidity). In most cases, the buildings are not suitable for animal housing under high temperatures. They lack appropriate equipment to control indoor environmental conditions. To minimize the effects of these adverse climatic situations on animal production, in Portugal, we intend to carry out a work project to tackle this problem. For that purpose, we intend to develop a set of strategies aiming at: - collecting information about animal breeding and animal housing; - identifying the climatic factors that affect livestock, in all portuguese regions; - evaluating the effects of the climatic factors on animal production, in different regions; - studying strategies and methods to help farmers cope with the problem; - establishing a web page to spread information; To carry out this work we have to organize a multidisciplinary team in order to embrace all different fields of interest related to this problem

Strategies to minimize effects of hot climate conditions on livestock in Portugal. A regional approach

In Portugal, animal production is of major significance, both economically and socially. Livestock are especially important to those regions in which agriculture is the main economic activity. Situated in Southwestern Europe, Portugal has a Mediterranean climate with hot and dry Summer. Livestock farmers have to deal with high temperatures and with their effects on animal production. In most cases, breeders are not prepared to handle animals under high temperatures; they lack facilities and/or knowledge about this problem. We have begun work with the aim of developing strategies to monitor and prevent harm to animals (housed or raised outdoors) during the summer months. We need to identify the Portuguese regions most seriously affected by this problem, as well as where and for how long high temperatures occur most frequently. Both individual days with very high temperatures and heat waves are becoming more and more common in Portugal. The past four summers have been among the hottest ever registered. Since 2003, eight heat waves have occurred. We chose two locations in Portugal's Northeast to carry out a preliminary study in order to evaluate the occurrence of hot climate conditions in recent years; to develop methods of obtaining that data; and to learn how climatic factors (mainly temperature) evolve over the course of the summer. We can conclude that in this region livestock are commonly exposed to high temperatures for long periods. It becomes clear that it is necessary to develop strategies to protect animals from the effects of such conditions

Monitorização, prevenção, comunicação e resolução dos riscos climáticos no sector pecuário. Estabelecimento de estratégias de implementação de um serviço de alerta e de combate ao problema

Na Europa do Sul ou nas regiões mediterrâneas, as temperaturas muito elevadas podem provocar dificuldades e danos na produção animal e aos produtores. Os fenómenos de ondas de calor ou de temperaturas muito elevadas, causam prejuízos avultados e perdas significativas na produção animal. Em Portugal, verificamos que são cada vez mais frequentes a ocorrência de situações com condições climáticas adversas, devidas a períodos de temperaturas elevadas. Verificaram-se, também, diversas ondas de calor, de acordo com o HWDI (Heat Wave Duration Index). Atendendo a estas questões e porque as ondas de calor coincidem com algumas regiões do país onde estão concentradas as actividades de produção animal, estamos a desenvolver um trabalho que pretende estudar e acompanhar estes fenómenos, no intuito de minimizar o seu impacto nas explorações pecuárias. Pretende-se identificar os factores climáticos que, nas diferentes regiões, podem afectar os animais; identificar a diversidade climática em cada região; avaliar os efeitos diferenciados da diversidade climática na produção animal. Para isso, preparou-se um conjunto de medidas e estratégias, envolvendo um trabalho interdisciplinar, para fazer face a este problema. In the South of Europe or mediterranean regions, significant high temperatures combined with dry air (or even wet air) may produce serious problems or damages to livestock and to the farmer. To understand and minimize the effects of this situation in Portugal, we intend to carry out a work project aiming to identify the climatic factors that affect livestock in all portuguese regions; the climatic diversity of the several regions; to evaluate the effects of the climatic factors in livestock; and to develop strategies to face these problems

Synthesis, Characterization and Evaluation of the Cytotoxicity of Ni-Doped Zn(Se,S) Quantum Dots

Quantum dots (QDs) are semiconductor nanocrystals with desirable optical properties for biological applications, such as bioimaging and drug delivery. However, the potential toxicity of these nanostructures in biological systems limits their application. The present work is focused on the synthesis, characterization, and evaluation of the toxicity of water-stable Ni-doped Zn(Se,S) QDs. Also, the study of nondoped nanostructures was included for comparison purposes. Ni-doped nanostructures were produced from zinc chloride and selenide aqueous solutions in presence of 3-mercaptopropionic acid and Ni molar concentration of 0.001 M. In order to evaluate the potential cytoxicity of these doped nanostructures, human pancreatic carcinoma cells (PANC-1) were used as model. The cell viability was monitored in presence of Ni-doped Zn(Se,S) QDs at concentrations ranging from 0 μg/mL to 500 μg/mL and light excited Ni-doped Zn(Se,S) nanostructures were evaluated at 50 μg/mL. Results suggested that Ni-doped Zn(Se,S) nanostructures were completely safe to PANC-1 when concentrations from 0 μg/mL to 500 μg/mL were used, whereas non-doped nanostructures evidenced toxicity at concentrations higher than 200 μg/mL. Also, Ni-doped Zn(Se,S) QDs under light excitation do not evidence toxicity to PANC-1. These findings suggest strongly that Zn(Se,S) nanostructures doped with nickel could be used in a safe manner in light-driving biological applications and drug delivery

Algoritmo mixto mínima entropía-máxima información para la selección de ítems en un test adaptativo informatizado

El objetivo del estudio que presentamos es comparar la eficacia como estrategia de selección de ítems de tres algoritmos diferentes: a) basado en máxima información; b) basado en mínima entropía; y c) mixto mínima entropía en los ítems iniciales y máxima información en el resto; bajo la hipótesis de que el algoritmo mixto, puede dotar al TAI de mayor eficacia. Las simulaciones de procesos TAI se realizaron sobre un banco de 28 ítems de respuesta graduada calibrado según el modelo de Samejima, tomando como respuesta al TAI la respuesta original de los sujetos que fueron utilizados para la calibración. Los resultados iniciales muestran cómo el criterio mixto es más eficaz que cualquiera de los otros dos tomados independientemente. Dicha eficacia se maximiza cuando el algoritmo de mínima entropía se restringe a la selección de los primeros ítems del TAI, ya que con las respuestas a estos primeros ítems la estimación de θ comienza a ser relevante y el algoritmo de máxima información se optimiza.Item selection algorithms in computerized adaptive testing. The aim of this paper is to compare the efficacy of three different item selection algorithms in computerized adaptive testing (CAT). These algorithms are based as follows: the first one is based on Item Information, the second one on Entropy, and the last algorithm is a mixture of the two previous ones. The CAT process was simulated using an emotional adjustment item bank. This item bank contains 28 graded items in six categories, calibrated using Samejima (1969) Graded Response Model. The initial results show that the mixed criterium algorithm performs better than the other ones