Material characterization and process development for indium-arsenide / indium-gallium-antimonide channel, high electron mobility transistors for low power, high speed applications

Efforts to push the performance of transistors for millimeter-wave and microwave applications have borne fruit through device size scaling and the use of novel material systems. III-V semiconductors and their alloys hold a distinct advantage over silicon because they have much higher electron mobility which is a prerequisite for high frequency operation. InGaAs/InP pseudomorphic heterojunction bipolar transistors (HBTs) have demonstrated fT of 765 GHz at room temperature and InP based high electron mobility transistors (HEMTs) have demonstrated fMax of 1.2 THz. The 6.1 A lattice family of InAs, GaSb, AlSb covers a wide variety of band gaps and is an attractive future material system for high speed device development. Extremely high electron mobilities ~ 30,000 cm^2 V^-1s^-1 have been achieved in modulation doped InAs-AlSb structures. The work described in this thesis involves material characterization and process development for HEMT fabrication on this material system.

Characterization of nanoparticle mediated laser transfection by femtosecond laser pulses for applications in molecular medicine

Background: In molecular medicine, the manipulation of cells is prerequisite to evaluate genes as therapeutic targets or to transfect cells to develop cell therapeutic strategies. To achieve these purposes it is essential that given transfection techniques are capable of handling high cell numbers in reasonable time spans. To fulfill this demand, an alternative nanoparticle mediated laser transfection method is presented herein. The fs-laser excitation of cell-adhered gold nanoparticles evokes localized membrane permeabilization and enables an inflow of extracellular molecules into cells. Results: The parameters for an efficient and gentle cell manipulation are evaluated in detail. Efficiencies of 90% with a cell viability of 93% were achieved for siRNA transfection. The proof for a molecular medical approach is demonstrated by highly efficient knock down of the oncogene HMGA2 in a rapidly proliferating prostate carcinoma in vitro model using siRNA. Additionally, investigations concerning the initial perforation mechanism are conducted. Next to theoretical simulations, the laser induced effects are experimentally investigated by spectrometric and microscopic analysis. The results indicate that near field effects are the initial mechanism of membrane permeabilization. Conclusion: This methodical approach combined with an automated setup, allows a high throughput targeting of several 100,000 cells within seconds, providing an excellent tool for in vitro applications in molecular medicine. NIR fs lasers are characterized by specific advantages when compared to lasers employing longer (ps/ns) pulses in the visible regime. The NIR fs pulses generate low thermal impact while allowing high penetration depths into tissue. Therefore fs lasers could be used for prospective in vivo applications.

Uncertainties in projecting climate-change impacts in marine ecosystems

Projections of the impacts of climate change on marine ecosystems are a key prerequisite for the planning of adaptation strategies, yet they are inevitably associated with uncertainty. Identifying, quantifying, and communicating this uncertainty is key to both evaluating the risk associated with a projection and building confidence in its robustness. We review how uncertainties in such projections are handled in marine science. We employ an approach developed in climate modelling by breaking uncertainty down into (i) structural (model) uncertainty, (ii) initialization and internal variability uncertainty, (iii) parametric uncertainty, and (iv) scenario uncertainty. For each uncertainty type, we then examine the current state-of-the-art in assessing and quantifying its relative importance. We consider whether the marine scientific community has addressed these types of uncertainty sufficiently and highlight the opportunities and challenges associated with doing a better job. We find that even within a relatively small field such as marine science, there are substantial differences between subdisciplines in the degree of attention given to each type of uncertainty. We find that initialization uncertainty is rarely treated explicitly and reducing this type of uncertainty may deliver gains on the seasonal-to-decadal time-scale. We conclude that all parts of marine science could benefit from a greater exchange of ideas, particularly concerning such a universal problem such as the treatment of uncertainty. Finally, marine science should strive to reach the point where scenario uncertainty is the dominant uncertainty in our projections.

The European Registered Toxicologist (ERT): Current status and prospects for advancement

Following its inception in 1994, the certification of European Registered Toxicologists (ERT) by EUROTOX has been recognized as ensuring professional competence as well as scientific integrity and credibility. Criteria and procedures for registration are contained in the ERT "Guidelines for Registration 2012". The register of ERT currently has over 1900 members. In order to continue the harmonisation of requirements and processes between national registering bodies as a prerequisite for official recognition of the ERT title as a standard, and to take account of recent developments in toxicology, an update of the ERT Guidelines has been prepared in a series of workshops by the EUROTOX subcommittees for education and registration, in consultation with representatives of national toxicology societies and registers. The update includes details of topics and learning outcomes for theoretical training, and how these can be assessed. The importance of continuing professional development as the cornerstone of re-registration is emphasised. To help with the process of harmonisation, it is necessary to collate and share best practices of registration conditions and procedures across Europe. Importantly, this information can also be used to audit compliance with the EUROTOX standards. As recognition of professionals in toxicology, including specialist qualifications, is becoming more important than ever, we believe that this can best be achieved based on the steps for harmonisation outlined here together with the proposed new Guidelines.

O efeito da reprovação na motivação dos alunos

O mundo mudou muito e o modelo escolar existente, que vem desde o século XVIII, manifesta dificuldades de adaptação ao novo mundo. As dificuldades de ensino e aprendizagem também são muito mais vastas do que as do passado, num ensino obrigatório e massificado, e a capacidade de captação da atenção que a escola antes produzia, é hoje mais difícil de obter. A motivação, sem a qual não há aprendizagem, revela a dificuldade da educação escolar em lidar com a realidade atual. Dentro de um referencial teórico sustentado, importa analisar e interpretar o modo como decorre a aprendizagem e o modelo de avaliação do terceiro ciclo do ensino básico, bem como investigar os fatores que influenciam a motivação dos alunos. Para atingir os objetivos do estudo optou-se por uma abordagem metodológica qualitativa, recorrendo à realização de entrevistas semiestruturadas aos vários intervenientes educativos e à análise de documentos, numa escola selecionada para o efeito. Constatou-se, através dos dados obtidos, que a reprovação tem um impacto extremamente significativo no desempenho escolar dos alunos, e que se umas vezes provoca um efeito pedagógico, noutras tem o efeito exatamente inverso. Este trabalho consiste num estudo de caso sobre o efeito que a reprovação provoca na motivação dos alunos que ficam retidos e tem como intuito encontrar estratégias para aumentar a motivação desses mesmos alunos.

Identification of superior reference genes for data normalisation of expression studies via quantitative PCR in hybrid roses (Rosa hybrida)

Background: Gene expression studies are a prerequisite for understanding the biological function of genes. Because of its high sensitivity and easy use, quantitative PCR (qPCR) has become the gold standard for gene expression quantification. To normalise qPCR measurements between samples, the most prominent technique is the use of stably expressed endogenous control genes, the so called reference genes. However, recent studies show there is no universal reference gene for all biological questions. Roses are important ornamental plants for which there has been no evaluation of useful reference genes for gene expression studies. Results: We used three different algorithms (BestKeeper, geNorm and NormFinder) to validate the expression stability of nine candidate reference genes in different rose tissues from three different genotypes of Rosa hybrida and in leaves treated with various stress factors. The candidate genes comprised the classical "housekeeping genes" (Actin, EF-1α, GAPDH, Tubulin and Ubiquitin), and genes showing stable expression in studies in Arabidopsis (PP2A, SAND, TIP and UBC). The programs identified no single gene that showed stable expression under all of the conditions tested, and the individual rankings of the genes differed between the algorithms. Nevertheless the new candidate genes, specifically, PP2A and UBC, were ranked higher as compared to the other traditional reference genes. In general, Tubulin showed the most variable expression and should be avoided as a reference gene. Conclusions: Reference genes evaluated as suitable in experiments with Arabidopsis thaliana were stably expressed in roses under various experimental conditions. In most cases, these genes outperformed conventional reference genes, such as EF1-α and Tubulin. We identified PP2A, SAND and UBC as suitable reference genes, which in different combinations may be used for normalisation in expression analyses via qPCR for different rose tissues and stress treatments. However, the vast genetic variation found within the genus Rosa, including differences in ploidy levels, might also influence expression stability of reference genes, so that future research should also consider different genotypes and ploidy levels.

Dating of sediments in the Biscay bay: Implication for pollution chronology

Important historical informations on the temporal changes of anthropogenic pollution in marine environment can be assessed using sediment analysis. Dating is a crucial prerequisite to reconstruct pollution events, to calculate fluxes, and thus to allow comparison between different sites. This work presents estimates of accumulation rates of sediments in the Bay of Biscay. Fives cores were collected during RIKEAU 2002 cruise on board o/v Thalia in order to study temporal changes in PAH and organohalogens compounds content of sediment. We compare chronostratigraphic estimates on cores derived from the natural radionuclide 210Pb in excess with estimates from the known times of introduction of the artificial radionuclide 137Cs to the environment. 210Pb, 226Ra and 137Cs were measured directly by non-destructive gamma spectrometry using a well type γ-detector. Total 210Pb and 226Ra activities vary from 30 to 150 mBq g-1, and 20 to 36 mBq g-1 respectively; 137Cs presents lower levels (< 5 mBq g-1). Profiles of 210Pb in three cores present a well mixed layer, from 2-3 to 10 cm, in the uppermost sediments, followed by an exponential decrease of activities, suitable for the determination of sedimentation rates. Under constant flux and sedimentation rate assumptions, vertical accretion rates derived from 210Pb present a large range from nearly 0.1 cm yr-1 up to almost 0.3 cm yr-1. Differences are mainly due to relative position of studied cores regarding the muddy patch. Although the moderate level of 137Cs limits the accuracy of this dating method, profiles of 137Cs with depth strengthen mean rates derived from 210Pb data. The implication of this dating on pollutant inputs in sediments of the Bay of Biscay is briefly discussed.

Uma abordagem dirigida a modelo para a geração de casos de teste baseada na detecção de cenários implícitos

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2015.

LiDom builder: Automatising the construction of multilingual domain modules

136 p.

Polymer microspheres: synthesis, characterisation and post-functionalisation by olefin metathesis

Porous polymer particles are used in an extraordinarily wide range of advanced and everyday applications, from combinatorial chemistry, solid-phase organic synthesis and polymer-supported reagents, to environmental analyses and the purification of drinking water. The installation and exploitation of functional chemical handles on the particles is often a prerequisite for their successful exploitation, irrespective of the application and the porous nature of the particles. New methodology for the chemical modification of macroreticular polymers is the primary focus of the work presented in this thesis. Porous polymer microspheres decorated with a diverse range of functional groups were synthesised by the post-polymerisation chemical modification of beaded polymers via olefin cross metathesis. The polymer microspheres were prepared by the precipitation polymerisation of divinylbenzene in porogenic (pore-forming) solvents; the olefin cross-metathesis (CM) functionalisation reactions exploited the pendent (polymer-bound) vinyl groups that were not consumed by polymerisation. Olefin CM reactions involving the pendent vinyl groups were performed in dichloromethane using second-generation Grubbs catalyst (Grubbs II), and a wide range of coupling partners used. The results obtained indicate that high quality, porous polymer microspheres synthesised by precipitation polymerisation in near-θ solvents can be functionalised by olefin CM under very mild conditions to install a diverse range of chemical functionalities into a common polydivinylbenzene precursor. Gel-type polymer microspheres were prepared by the precipitation copolymerisation reaction of divinylbenzene and allyl methacrylate in neat acetonitrile. The unreacted pendent vinyl groups that were not consumed by polymerisation were subjected to internal and external olefin metathesis-based hypercrosslinking reactions. Internal hypercrosslinking was carried out by using ring-closing metathesis (RCM) reactions in toluene using Grubbs II catalyst. Under these conditions, hypercrosslinked (HXL) polymers with specific surface areas around 500 m2g-1 were synthesised. External hypercrosslinking was attempted by using CM/RCM in the presence of a multivinyl coupling partner in toluene using second-generation Hoveyda-Grubbs catalyst. The results obtained indicate that no HXL polymers were obtained. However, during the development of this methodology, a new type of polymerisation was discovered with tetraallylorthosilicate as monomer.

Diagnosis of vibriosis in the era of genomics: lessons from invertebrates

Global changes linked to increases in temperature and ocean acidification, but also to more direct anthropogenic influences such as aquaculture, have caused a worldwide increase in the reports of Vibrio-associated illnesses affecting humans and also animals such as shrimp and molluscs. Investigation of the emergence of Vibrio pathogenesis events requires the analysis of microbial evolution at the gene, genome and population levels, in order to identify genomic modifications linked to increased virulence, resistance and/or prevalence, or to recent host shift. From a more applied point of view, the elucidation of virulence mechanisms is a prerequisite to devising prophylactic methods to fight infectious agents. In comparison with human pathogens, fairly little is known about the requirements for virulence in vibrios pathogenic to animals. However, the advent of genome sequencing, especially next-generation technologies,the possibility of genetically manipulating most of the Vibrio strains, and the recent availability of standardised animals for experimental infections have now compensated for the considerable delay in advancement of the knowledge of non-model pathogens such as Vibrio and have led to new scientific questions.

Structural Basis for Clonal Diversity of the Public T Cell Response to Dominant Epitopes from Cytomegalovirus and Influenza

A diverse T cell receptor (TCR) repertoire is a prerequisite for effective viral clearance. However, knowledge of human TCR repertoire to defined viral antigens is limited. Recent advances in high-throughput sequencing (HTS) and single-cell sorting have revolutionized the study of human TCR repertoires to different types of viruses. In collaboration with the laboratory of Dr. Nan-ping Weng (National Institute on Aging, NIH), we applied unique molecular identifier (UMI)-labelled HTS, single-cell paired TCR analysis, surface plasmon resonance, and X-ray crystallography to exhaustively interrogate CD8+ TCR repertoires specific for cytomegalovirus (CMV) and influenza A (Flu) in HLA-A2+ humans. Our two CMV-specific TCR-pMHC structures and two Flu-specific TCR-pMHC structures provide a plausible explanation for the much higher diversity of CMV-specific than Flu-specific TCR repertoires in humans. Our comprehensive biochemical and structural portrait of two different anti-viral T cell responses may contribute to the future development of predictors of immunity or disease at the individual level.

O papel do auxiliar de desenvolvimento infantil da Secretaria de Educação do Recife : das normativas do cargo a prática profissional

O presente trabalho tem como temática: O papel do Auxiliar de Desenvolvimento Infantil da Secretaria de Educação do Recife: das normativas do cargo a prática profissional. Este profissional desenvolve suas funções dentro das creches e centros de educação infantil da Secretaria de Educação do Recife, trabalhando com crianças de 0 a 3 anos. O objetivo deste estudo é identificar as relações entre o pré-requisito exigido para o cargo, as atribuições conferidas à função e a prática profissional do Auxiliar de Desenvolvimento Infantil, tomando para análise o último concurso realizado em 2014. A partir dessa configuração e para entender de fato o papel do Auxiliar de Desenvolvimento Infantil, pontuando a sua função como pedagógica ou não, considerando que se atribui como pré-requisito para o provimento do cargo a exigência de formação no Ensino Médio. O estudo parte da revisão de literatura sobre a concepção de infância, criança e educação passando pelas contribuições teóricas de vários autores, sobretudo os que abordam as questões da infância e da educação infantil de maneira contextualizada. Procedeu-se também a abordagem da evolução do perfil profissional daqueles que atuam na Educação Infantil no Brasil, pois, ao longo dos anos, estes profissionais vêm passando por transformações e exigências em relação a sua atuação, sobretudo em decorrência das mudanças de concepção de infância, de criança e de educação. A metodologia é qualitativa e como instrumento de coleta de dados utilizou-se questionários e entrevista. Os sujeitos da pesquisa são os Auxiliares de Desenvolvimento Infantil, os professores de Educação Infantil e a Divisão de Educação Infantil da Secretaria de Educação do Recife. Os resultados apontaram que o trabalho desenvolvido pelos ADIs dentro das instituições de educação infantil é pedagógico. Estes profissionais realizam atividades educativas e desta forma, pode-se dizer, que esta função exige que o profissional tenha conhecimentos pedagógicos para exercê-la. Finalmente, este estudo poderá contribuir para que a Secretaria de Educação do Recife redirecione a política pública de Educação Infantil no que se refere aos pré-requisitos de formação dos profissionais concursados para o trabalho nas instituições de educação infantil, exigindo a formação mínima no Normal Médio (Magistério) para a função de Auxiliar de Desenvolvimento Infantil, entendendo que esta função exige que o profissional tenha conhecimentos pedagógicos para atuar junto às crianças de 0 a 3 anos.

Assessment of genetic diversity of zoonotic Brucella spp. recovered from livestock in Egypt using multiple locus VNTR analysis

Brucellosis is endemic in most parts of Egypt, where it is caused mainly by Brucella melitensis biovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominant Brucella species/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17 Brucella spp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat) from four governorates during a period of five years (2002-2007) was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing). Thirteen strains were identified as B. melitensis biovar 3 while all phenotypic and genetic techniques classified the remaining isolates as B. abortus (n = 2) and B. suis biovar 1 (n = 2). MLVA-15 yielded a high discriminatory power (h = 0.801), indicating a high genetic diversity among the B. melitensis strains circulating among domestic ruminants in Egypt. This is the first report of the isolation of B. suis from cattle in Egypt which, coupled with the finding of B. abortus, suggests a potential role of livestock as reservoirs of several zoonotic Brucella species in the region.

Från ensamhet till gemenskap och hur det kommer sig : En studie om faktorer som kan påverka äldre personers väg från ensamhet till gemenskap

Syftet med studien är att öka förståelsen för vilka faktorer som kan leda till och påverka äldre personers deltagande i en social gruppaktivitet riktad till ensamma äldre. Då känslan av ensamheten kan ge stora negativa effekter för den äldre är det viktigt att öka förståelsen och kunskapen om de fenomen och faktorer som påverkar och leder till mer gemenskap och välbefinnande. Studien är en kvalitativ intervjustudie och det insamlade materialet har analyserats genom kvalitativ innehållsanalys med en induktiv ansats. Antonovskys salutogena perspektiv har använts som teoretisk referensram. Sex personer i åldern 75-90 år har deltagit i semistrukturerade intervjuer. Deltagarna ingick i frivilligorganisationen Äldrekontakts sociala gruppaktivitet vilket är riktad till ensamma äldre som söker gemenskap. I resultatet framkom tre olika teman vilket sammanfattar de faktorer som ledde till och påverkade de äldres deltagande i den sociala gruppaktiviteten. De teman som ingår är: förändringsgrunder, förutsättningar och fördelar. Temat förändringsgrunder belyser att motivet för de äldre att delta i aktiviteten grundar sig i en önskan om en ökad gemenskap då relationerna blivit färre och att det hade uppstått en känsla av ensamhet. Vidare framkommer att deltagarnas förhållningssätt riktades mot välbefinnande genom att vara aktiv, att ha en stärkande inställning och att våga exponera sig. Temat förutsättningar beskriver villkor för ett deltagande i aktiviteten. Yttre faktorer var stödet att komma till och från aktiviteten och att det var anspråkslöst att delta. Den inre faktorn var att deltagarna hade tillräckligt med ork så att aktiveten gick att genomföra. Temat fördelar visar på de vinster som uppkom i och med deltagandet i denna gruppaktivitet. Denna aktivitet berikade vardagen genom att det blev ett avbrott i det vardagliga livet och att det fanns något att se fram emot. Deltagarna blev sedda och hörda då det fanns någon att samtala med och något att prata om samt att det skapades nya bekantskaper. En känsla av att bli omhändertagen uppstod vilket uttrycktes genom en tacksamhet att få delta och att det kändes tryggt att medverka i aktiviteten. Resultatet har analyserats genom Antonovskys salutogena perspektiv och tre slutsatser har framtagits. Dessa tre teman har identifierats som en process. Temat förändringsgrunder har visat sig vara en grundförutsättning för resterande process och det har också framkommit att deltagarna har en hög känsla av sammanhang. Denna kunskap kan hjälpa de äldre och de som vill stödja ensamma äldre att ta steget från ensamhet till gemenskap.