Logic functions, devices, and circuits based on parametric nonlinear processes

Second-harmonic generation and parametric down-conversion processes have been studied as the basis of all-optical logic gates. All possibilities that are obtainable with both the low and high conversion efficiencies of such processes have been analyzed here. XOR and AND gates are also experimentally proven by using 1-ps pulses at 800 nm within a beta-BaB(2)O(4) crystal, reaching conversion efficiencies of as high as 80%. Based on these phenomena, complex algebraic operations are proposed for performing several different logic functionalities particularly concerning network switching and arithmetic calculation

Quinta dos Vinhais. Circunstâncias (s), diálogo, projecto

Partilho aqui uma experiência pessoal. Um caminho que atravessa um projecto.A narração que apresento tem como objecto de estudo a Quinta dos Vinhais, em Rebordelo, no distrito de Amarante. Trata-se de um aglomerado de habitações vernaculares que pertence ao Ricardo e à Francisca, um casal que, numa certa fase das suas vidas, decidiu abandonar a cidade mudando para o campo.Necessita-se de um projecto de reabilitação e ampliação do conjunto edificado com o objectivo de criar as circunstâncias para que o lugar se transforme numa comunidade autosuficiente, dedicada à actividade rural.Convida-se o leitor a percorrer os momentos mais significativos do projecto, na tentativa de o aproximar ao enredo de acontecimentos que envolveu os protagonistas desta aventura, ajudando a compreendê-lo na sua totalidade.Numa apresentação que experimenta um formato pouco convencional, reconstróise uma sequência (crono)lógica dos eventos que condicionaram o trabalho, fragmentada em fascículos que não impedem ao leitor, aliberdade de subvertê-la, tornando a narrativa única, individual.Marca-se um momento fundamental de transição entre a aprendizagem académica e a profissão, encarando um projecto que abrange uma realidade mais complexa, condicionada por vontades externas que enriquecem e reforçam as soluções adoptadas. O projecto carrega-se de um sentido mais humano. No fundo... para que serve a Arquitectura?Abrem-se aqui as portas para o caminho. Boa viagem.I'm sharing here a personal experience. A path across a project.The story that I'm presenting develops around "Quinta dos Vinhais", a farm in Rebordelo, district of Amarante. It is a cluster of vernacular dwellings belonging to Ricardo and Francisca, a couple who, at a certain moment of their lives, decided to leave the city moving to the countryside.The need for a rehabilitation and extension of the building complex asks for a project, with the aim of creating the circumstances to turn the place into a self-sufficient community, dedicated to rural activity.The reader is invited on a journey through the most significant moments of the project, an attempt of approaching him to the events that involved the protagonists of this adventure, in order to understand it more deeply.In a presentation that experiments an unconventional format, a (chrono)logical sequence of the events that conditioned the work is reconstructed, but fragmented into several booklets, which gives the reader the freedom to subvert it, making the narrative unique, individual.A moment of transition between the academic world and the profession is materialized here, by facing a project which covers a more complex reality, conditioned by external wills that enrich and reinforce the adopted solutions, a project that drives through a certain humanism. In that way... what is the purpose of Architecture?The doors to the path are open. Have a good journey

Application of Scenedesmus obliquus in the Treatment of a Real Wastewater

In the present study, the microalga Scenedesmus obliquus CCAP 276/38 has been applied in the treatment of a real wastewater (RWW) derived from an anaerobic digestion process of corn silage and livestock wastewater. The liquid phase of the digestate showed a low viscosity value and a high content of ammonia up to 3 g/L. In a preliminary phase, the experimental tests were carried out in Erlenmeyer flasks in order to identify the optimal RWW concentration and, in particular, its influence on biomass growth and productivity. The tests were carried out at 20°C at an artificial dark/light cycles of 12 hours. Three different concentrations were tested: 1, 2 and 3% of RWW in water, in the presence of sodium bicarbonate (NaHCO3, 50 mM) as inorganic carbon source. The obtained results showed that S. obliquus was able to grow in all the tested RWW concentrations even if a higher growth rate and biomass production were observed in the cultures containing 1% RWW. In order to test the influence of N/P ratio on microalgal growth, two different salts, KNO3 (0,2 g/L) and K2HPO4 (0,02 g/L), were added to the medium containing 1% RWW (N/P = 84.4), to correct the N/P value. The biomass growth rate increased in the medium with the lower N/P value (N/P = 27.9). The microalgal production process was scaled-up in a stirred tank photobioreactor (working volume 5 L), in the same temperature and illumination conditions using a medium with the composition optimized in flask tests. The culture was carried out for 124 hours, fed-batch addition of RWW (1%) was done during the fermentation in order to replace the carbon source. The results (growth rate, biomass dry weight and productivity) were compared with those obtained in presence of a synthetic medium with sodium bicarbonate 50 mM as carbon source. The work clearly demonstrated the capability of S. obliquus CCAP 276/38to grow in alkaline wastewater and the possibility to employ this species in the treatment of effluents containing high ammonia concentratio

A methodology to assess the intrinsic discriminative ability of a distance function and its interplay with clustering algorithms for microarray data analysis

Background: Clustering is one of the most well known activities in scientific investigation and the object of research in many disciplines, ranging from statistics to computer science. Following Handl et al., it can be summarized as a three step process: (1) choice of a distance function; (2) choice of a clustering algorithm; (3) choice of a validation method. Although such a purist approach to clustering is hardly seen in many areas of science, genomic data require that level of attention, if inferences made from cluster analysis have to be of some relevance to biomedical research. Results: A procedure is proposed for the assessment of the discriminative ability of a distance function. That is, the evaluation of the ability of a distance function to capture structure in a dataset. It is based on the introduction of a new external validation index, referred to as Balanced Misclassification Index (BMI, for short) and of a nontrivial modification of the well known Receiver Operating Curve (ROC, for short), which we refer to as Corrected ROC (CROC, for short). The main results are: (a) a quantitative and qualitative method to describe the intrinsic separation ability of a distance; (b) a quantitative method to assess the performance of a clustering algorithm in conjunction with the intrinsic separation ability of a distance function. The proposed procedure is more informative than the ones available in the literature due to the adopted tools. Indeed, the first one allows to map distances and clustering solutions as graphical objects on a plane, and gives information about the bias of the clustering algorithm with respect to a distance. The second tool is a new external validity index which shows similar performances with respect to the state of the art, but with more flexibility, allowing for a broader spectrum of applications. In fact, it allows not only to quantify the merit of each clustering solution but also to quantify the agglomerative or divisive errors due to the algorithm. Conclusions: The new methodology has been used to experimentally study three popular distance functions, namely, Euclidean distance d2, Pearson correlation dr and mutual information dMI. Based on the results of the experiments, we have that the Euclidean and Pearson correlation distances have a good intrinsic discrimination ability. Conversely, the mutual information distance does not seem to offer the same flexibility and versatility as the other two distances. Apparently, that is due to well known problems in its estimation. since it requires that a dataset must have a substantial number of features to be reliable. Nevertheless, taking into account such a fact, together with results presented in Priness et al., one receives an indication that dMI may be superior to the other distances considered in this study only in conjunction with clustering algorithms specifically designed for its use. In addition, it results that K-means, Average Link, and Complete link clustering algorithms are in most cases able to improve the discriminative ability of the distances considered in this study with respect to clustering. The methodology has a range of applicability that goes well beyond microarray data since it is independent of the nature of the input data. The only requirement is that the input data must have the same format of a "feature matrix". In particular it can be used to cluster ChIP-seq data

A motif-independent metric for DNA sequence specificity

<p>Abstract</p> <p>Background</p> <p>Genome-wide mapping of protein-DNA interactions has been widely used to investigate biological functions of the genome. An important question is to what extent such interactions are regulated at the DNA sequence level. However, current investigation is hampered by the lack of computational methods for systematic evaluating sequence specificity.</p> <p>Results</p> <p>We present a simple, unbiased quantitative measure for DNA sequence specificity called the Motif Independent Measure (MIM). By analyzing both simulated and real experimental data, we found that the MIM measure can be used to detect sequence specificity independent of presence of transcription factor (TF) binding motifs. We also found that the level of specificity associated with H3K4me1 target sequences is highly cell-type specific and highest in embryonic stem (ES) cells. We predicted H3K4me1 target sequences by using the N- score model and found that the prediction accuracy is indeed high in ES cells.The software to compute the MIM is freely available at: <url>https://github.com/lucapinello/mim</url>. </p> <p>Conclusions</p> <p>Our method provides a unified framework for quantifying DNA sequence specificity and serves as a guide for development of sequence-based prediction models.</p

Opening study on the development of a new biosensor for metal toxicity based on pseudomonas fluorescens pyoverdine

To date, different kinds of biosensing elements have been used effectively for environmental monitoring. Microbial cells seem to be well-suited for this task: they are cheap, adaptable to variable field conditions and give a measurable response to a broad number of chemicals. Among different pollutants, heavy metals are still a major problem for the environment. A reasonable starting point for the selection of a biorecognition element to develop a biosensor for metals could be that of a microorganism that exhibits good mechanisms to cope with metals. Pseudomonads are characterized by the secretion of siderophores (e.g., pyoverdine), low-molecular weight compounds that chelate Fe3+ during iron starvation. Pyoverdine is easily detected by colorimetric assay, and it is suitable for simple online measurements. In this work, in order to evaluate pyoverdine as a biorecognition element for metal detection, the influence of metal ions (Fe3+, Cu2+, Zn2+), but also of temperature, pH and nutrients, on microbial growth and pyoverdine regulation has been studied in P. fluorescens. Each of these variables has been shown to influence the synthesis of siderophore: for instance, the lower the temperature, the higher the production of pyoverdine. Moreover, the concentration of pyoverdine produced in the presence of metals has been compared with the maximum allowable concentrations indicated in international regulations (e.g., 98/83/EC), and a correlation that could be useful to build a colorimetric biosensor has been observed

Numerical and experimental verification of an inverse-direct approach for load and strain monitoring in aeronautical structures

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Agrochemical Contamination of Honey and Bee Bread Collected in the Piedmont Region, Italy

This study shows the results of a local biomonitoring plan developed by a regional beekeeping association, Aspromiele, in several areas of Piedmont (Italy), in order to understand the status of contamination from pesticides present in the environment and eventually to evaluate their impact on apiculture. Glyphosate was the most abundant chemical found in the bee bread and honey samples. The other pesticides detected at lower concentrations and minor frequency were mandipropamid, tau-fluvalinate, metalaxil and spiroxamine. Even if in the present study the pesticides found in the bee bread and honey were limited to a few molecules, it is important to highlight that the presence of glyphosate could represent a hazard to bees. Honeybees are the main pollinators in agricultural ecosystems, and thus appropriate environmental management could lead to a reduction in the impact of these chemicals on bees and other beneficial insects