Structural and functional studies of a high activity NiFeSe Hydrogenase

Theawareness that fossil fuels exist in limited quantities has stimulated research into energy production from renewable sources. Future energy sources! should! be! plentiful! with! negligible! impact! on! the! environment.! Hydrogen!has!the!potential!to!satisfy!these!requirements.!Nevertheless,!current! methods! of! H2! production! rely! on! nonOrenewable! resources.! Biological! H2! production! from! sunlight! or! biomass! is! an! appealing! alternative! to! current! production!methods.!!(...)

Functional genomic analysis of heat stress in Vitis vinifera

Grapevine (Vitis vinifera) is one of most agro-economically important fruit crops worldwide, with a special relevance in Portugal where over 300 varieties are used for wine production. Due to global warming, temperature stress is currently a serious issue affecting crop production especially in temperate climates. Mobile genetic elements such as retrotransposons have been shown to be involved in environmental stress induced genetic and epigenetic modifications. In this study, sequences related to Grapevine Retrotransposon 1 (Gret1) were utilized to determine heat induced genomic and transcriptomic modifications in Touriga Nacional, a traditional Portuguese grapevine variety. For this purpose, growing canes were treated to 42 oC for four hours and leaf genomic DNA and RNA was utilized for various techniques to observe possible genomic alterations and variation in transcription levels of coding and non-coding sequences between non-treated plants and treated plants immediately after heat stress (HS-0 h) or after a 24 hour recovery period (HS-24 h). Heat stress was found to induce a significant decrease in Gret1 related sequences in HS-24 h leaves, indicating an effect of heat stress on genomic structure. In order to identify putative heat induced DNA modifications, genome wide approaches such as Amplified Fragment Length Polymorphism were utilized. This resulted in the identification of a polymorphic DNA fragment in HS-0 h and HS-24 h leaves whose sequence mapped to a genomic region flanking a house keeping gene (NADH) that is represented in multiple copies in the Vitis vinifera genome. Heat stress was also found to affect the transcript levels of various non-coding and gene coding sequences. Accordingly, quantitative real time PCR results established that Gret1 related sequences are up regulated immediately after heat stress whereas the level of transcript of genes involved in identification and repair of double strand breaks are significantly down regulated in HS-0 h plants. Taken together, the results of this work demonstrated heat stress affects both genomic integrity and transcription levels.

Functional characterization and directed engineering of redox proteins for a rational improvement of Bioelectrochemical systems

In recent years, new methods of clean and environmentally friendly energy production have been the focus of intense research efforts. Microbial fuel cells (MFCs) are devices that utilize naturally occurring microorganisms that feed on organic matter, like waste water, while producing electrical energy. The natural habitats of bacteria thriving in microbial fuel cells are usually marine and freshwater sediments. These microorganisms are called dissimilatory metal reducing bacteria (DMRB), but in addition to metals like iron and manganese, they can use organic compounds like DMSO or TMAO, radionuclides and electrodes as terminal electron acceptors in their metabolic pathways.(...)

Functional MRI of stimulus interference on auditory processing in normal listeners and tinnitus patients

We are constantly immersed in stimuli. Upon reaching our senses, stimuli are processed within various brain systems along various pathways into the brain, and eventually turned into a percept. However, there are percepts that do not result from responses to external source stimuli. A particular case of this situation is the auditory percept known as tinnitus. Tinnitus can be seen as a task-irrelevant auditory percept, commonly reported to interfere with normal daily tasks. This is known from reports made by tinnitus sufferers that refer to their phantom percept as distracting, and that it diverts their focus from the task-relevant stimuli.(...)

Effects of an exercise program on the functional capacity of patients with chronic Chagas' heart disease, evaluated by cardiopulmonary testing

INTRODUCTION: Despite all efforts to restrict its transmission, Chagas' disease remains a severe public health problem in Latin America, affecting 8-12 million individuals. Chronic Chagas' heart disease, the chief factor in the high mortality rate associated with the illness, affects more than half a million Brazilians. Its evolution may result in severe heart failure associated with loss of functional capacity and quality of life, with important social and medical/labor consequences. Many studies have shown the beneficial effect of regular exercise on cardiac patients, but few of them have focused on chronic Chagas' heart disease. METHODS: This study evaluated the effects of an exercise program on the functional capacity of patients with chronic Chagas' disease who were treated in outpatient clinics at the Evandro Chagas Institute of Clinical Research and the National Institute of Cardiology, Rio de Janeiro, Brazil. The exercises were performed 3 times a week for 1 h (30 min of aerobic activity and 30 min of resistance exercises and extension) over 6 months in 2010. Functional capacity was evaluated by comparing the direct measurement of the O2 uptake volume (VO2) obtained by a cardiopulmonary exercise test before and after the program (p < 0.05). RESULTS: Eighteen patients (13 females) were followed, with minimum and maximum ages of 30 and 72 years, respectively. We observed an average increase of VO2peak > 10% (p = 0.01949). CONCLUSIONS: The results suggest a statistically significant improvement in functional capacity with regular exercise of the right intensity.

Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease

INTRODUCTION: Exclusive or associated lesions in various structures of the autonomic nervous system occur in the chronic forms of Chagas disease. In the indeterminate form, the lesions are absent or mild, whereas in the exclusive or combined heart and digestive disease forms, they are often more pronounced. Depending on their severity these lesions can result mainly in cardiac parasympathetic dysfunction but also in sympathetic dysfunction of variable degrees. Despite the key autonomic effect on cardiovascular functioning, the pathophysiological and clinical significance of the cardiac autonomic dysfunction in Chagas disease remains unknown. METHODS: Review of data on the cardiac autonomic dysfunction in Chagas disease and their potential consequences, and considerations supporting the possible relationship between this disturbance and general or cardiovascular clinical and functional adverse outcomes. RESULTS: We hypothesise that possible consequences that cardiac dysautonomia might variably occasion or predispose in Chagas disease include: transient or sustained arrhythmias, sudden cardiac death, adverse overall and cardiovascular prognosis with enhanced morbidity and mortality, an inability of the cardiovascular system to adjust to functional demands and/or respond to internal or external stimuli by adjusting heart rate and other hemodynamic variables, and immunomodulatory and cognitive disturbances. CONCLUSIONS: Impaired cardiac autonomic modulation in Chagas disease might not be a mere epiphenomenon without significance. Indirect evidences point for a likely important role of this alteration as a primary predisposing or triggering cause or mediator favouring the development of subtle or evident secondary cardiovascular functional disturbances and clinical consequences, and influencing adverse outcomes.

One-year cardiac morphological and functional evolution following permanent pacemaker implantation in right ventricular septal position in chagasic patients

INTRODUCTION: The septal position is an alternative site for cardiac pacing (CP) that is potentially less harmful to cardiac function. METHODS: Patients with Chagas disease without heart failure submitted to permanent pacemaker (PP) implantation at the Clinics Hospital of the Triângulo Mineiro Federal University (UFTM), were selected from February 2009 to February 2010. The parameters analyzed were ventricular remodeling, the degree of electromechanical dyssynchrony (DEM), exercise time and VO2 max during exercise testing (ET) and functional class (NYHA). Echocardiography was performed 24 to 48h following implantation and after one year follow-up. The patients were submitted to ET one month postprocedure and at the end of one year. RESULTS: Thirty patients were included. Patient mean age was 59±13 years-old. Indication for PP implantation was complete atrioventricular (AV) block in 22 (73.3%) patients and 2nd degree AV block in the other eight (26.7%). All patients were in NYHA I and no changes occurred in the ET parameters. No variations were detected in echocardiographic remodeling measurements. Intraventricular dyssynchrony was observed in 46.6% of cases and interventricular dyssynchrony in 33.3% of patients after one year. CONCLUSIONS: The findings of this work suggest that there is not significant morphological and functional cardiac change following pacemaker implantation in septal position in chagasic patients with normal left ventricular function after one year follow-up. Thus, patients may remain asymptomatic, presenting maintenance of functional capacity and no left ventricular remodeling.

Hybrid capture II and PapilloCheck® tests for detection of anal high-risk human papillomavirus

Introduction This study evaluated the level of concordance between hybrid capture II (HCII) and PapilloCheck® for the detection of high-risk human papillomavirus (HPV) in anal samples. Methods Anal cell samples collected from 42 human immunodeficiency virus (HIV)+ patients were analyzed. Results Considering only the 13 high-risk HPV types that are detectable by both tests, HCII was positive for 52.3% of the samples, and PapilloCheck® was positive for 52.3%. The level of concordance was 80.9% (Kappa = 0.61). Conclusions Good concordance was observed between the tests for the detection of high-risk HPV.

How to engage low category users through social media- The case of the make-up sector in Portugal

Purpose: This work project should be inevitably deemed as a practical approach to a marketing problem; “How to engage low category users through the social media – the case of the make-up sector in Portugal”. Design/methodology/approach: Online structured questionnaires and in-depth interviews were used. The questionnaire was answered by 110 women aged from 15 to 45 years old and the interviews were conducted with 14 women of the same age. The interviews provided key insights for the questionnaire formulation. Findings: Women are poorly informed on make-up properties and characteristics, feeling a genuine concern in regard to this subject. Lack of time, occasional usage and skin damage are the main barriers for make-up usage by low category users. Overcoming these aspects pass by demystifying the association of make-up with skin damage and emphasise the functional and emotional benefits of make-up. Further, brands need to create contents more consumer-oriented and ask directly to fans/followers suggestions and other insights. Resort to Portuguese “common” women for greater empathy in campaigns, promote online meetings between followers and make-up professionals on social media; and finally take advantage of the hybrid condition of Facebook, which incorporates multiple forms of content presentation, including videos, the most appealing format of make-up presentation for women. Research limitations/implications: Further studies addressing this topic, by using larger samples and study of specific make-up brands and campaign programs, over social media to reach a solid growth potential of make-up market evidences in Portugal. Originality/ value: Make-up brands are emphasising their interest in linking social media and marketing their promotional mix around social marketing.

Avaliação da sustentabilidade corporativa: estudo das relações híbridas pelo modelo do Hybrid Bottom Line

A presente tese reflete sobre os temas do desenvolvimento sustentável, da sustentabilidade corporativa, da responsabilidade social corporativa e das dimensões do Triple Bottom Line. O principal objetivo do nosso trabalho é contribuir para o conhecimento das relações que se estabelecem nas interseções entre a dimensão económica, social e ambiental da sustentabilidade corporativa, aqui designadas de relações híbridas. Neste sentido, desenvolveu-se um enquadramento teórico que fundamenta o modelo proposto, designado por Hybrid Bottom Line. De acordo com este enquadramento procurou-se conceber uma metodologia que permitisse analisar como é que estas relações de interseção entre economia-ambiente e economia-social se verificam e de que forma os seus resultados podem beneficiar a compreensão, avaliação e melhorias no entendimento da sustentabilidade corporativa, bem como possibilitar uma análise dirigida a fatores recombinantes específicos. Em complemento, foi desenvolvida uma proposta que permite posicionar o esforço desenvolvido pela empresa no âmbito da sustentabilidade e desta forma tipificar as suas ações. Nesta tese a abordagem empírica recaiu na análise dos relatórios de sustentabilidade publicados pelas empresas e baseados nas diretivas de relato propostas pelo Global Reporting Initiative. A amostra para o estudo abrangeu um total de 85 empresas de diferentes dimensões de 36 sectores económicos e representando 36 países de 5 continentes. A análise dos resultados foi feita utilizando diversos métodos de análise de dados (de frequência e de conteúdo) e análises estatísticas (análise de contingência, variância e de correspondências múltiplas) que permitiram observar as relações entre as dimensões do Triple Bottom Line, dando lugar à construção de uma matriz de relações híbridas. Seguidamente foi realizada uma análise longitudinal de uma das empresas da amostra tendo como referência a matriz híbrida obtida, assim como a tipificação da empresa no âmbito da sustentabilidade. Os resultados alcançados nas diferentes fases indicam que o enquadramento teórico que foi utilizado é útil para a análise das interseções entre as dimensões e permite uma avaliação dirigida a fatos ocorridos entre pares dimensionais, bem como projetar análises e posicionamentos futuros. Os resultados obtidos sugerem que a proposta apresentada é útil e deverá ser utilizada e desenvolvida noutros contextos. Esta tese contribui para a ideia de que a responsabilidade corporativa não deve ser só vista e operacionalizada como uma realidade de dimensões segmentadas mas também deve ser observada como um conjunto possível de interações que se manifestam nas interseções das suas diferentes dimensões.

Cellulose-based composites as functional conductive materials for printed electronics

In this work, cellulose-based electro and ionic conductive composites were developed for application in cellulose based printed electronics. Electroconductive inks were successfully formulated for screen-printing using carbon fibers (CFs) and multi-walled carbon nanotubes (MWCNTs) as conductive functional material and cellulose derivatives working as binder. The formulated inks were used to fabricate conductive flexible and disposable electrodes on paper-based substrates. Interesting results were obtained after 10 printing passes and drying at RT of the ink with 10 % wt. of pristine CFs and 3% wt. of carboxymethyl cellulose (CMC), exhibiting a resistivity of 1.03 Ωcm and a resolution of 400 μm. Also, a resistivity of 0.57 Ωcm was obtained for only one printing pass using an ink based on 0.5 % wt. MWCNTs and 3 % wt. CMC. It was also demonstrated that ionic conductive cellulose matrix hydrogel can be used in electrolyte-gated transistors (EGTs). The electrolytes revealed a double layer capacitance of 12.10 μFcm-2 and ionic conductivity of 3.56x10-7 Scm-1. EGTs with a planar configuration, using sputtered GIZO as semiconducting layer, reached an ON/OFF ratio of 3.47x105, a VON of 0.2 V and a charge carrier mobility of 2.32 cm2V-1s-1.

Cell functional enviromics: applications to Pichia pastoris

The present PhD thesis develops the cell functional enviromics (CFE) method to investigate the relationship between environment and cellular physiology. CFE may be defined as the envirome-wide cellular function reconstruction through the collection and systems-level analysis of dynamic envirome data. Throughout the thesis, CFE is illustrated by two main applications to cultures of a constitutive P. pastoris X33 strain expressing a scFv antibody fragment. The first application addresses the challenge of culture media development. A dataset was built from 26 shake flask experiments, with variations in trace elements concentrations and basal medium dilution based on the standard BSM+PTM1. Protein yield showed high sensitivity to culture medium variations, while biomass was essentially determined by BSM dilution. High scFv yield was associated with high overall metabolic fluxes through central carbon pathways concomitantly with a relative shift of carbon flux from biosynthetic towards energy-generating pathways. CFE identified three cellular functions (growth, energy generation and by-product formation) that together described 98.8% of the variance in observed fluxes. Analyses of how medium factors relate to identified cellular functions showed iron and manganese at concentrations close to PTM1 inhibit overall metabolic activity. The second application addresses bioreactor operation. Pilot 50 L fed-batch cultivations, followed by 1H-NMR exometabolite profiling, allowed the acquisition of data for 21 environmental factors over time. CFE identified five major metabolic pathway groups that are frequently activated by the environment. The resulting functional enviromics map may serve as template for future optimization of media composition and feeding strategies for Pichia pastoris. The present PhD thesis is a step forward towards establishing the foundations of CFE that is still at its infancy. The methods developed herein are a contribution for changing the culture media and process development paradigm towards a holistic and systematic discipline in the future.

Hybrid investment strategy active portfolio management – US stock market

This thesis aims to develop an alternative active managed portfolio strategy based on companies‟ Fundamental and Technical Analysis and analyze its finals results. There is a big distinction between the two approaches and the main objective is to understand if it is possible to take advantage of both. With this in mind a Hybrid investment strategy for the US stock market, due to its dimension and liquidity, which was able to outperform the S&P 500 index, the benchmark, during both Bear and Bull Markets between 2000 and 2015.

Photochemical synthesis and functional transformations of bicyclic vinyl aziridines

Aziridines, a class of organic compounds containing a three membered heterocycle with a nitrogen atom, are extremely valuable molecules in organic and medicinal chemistry. They are frequently used as versatile precursors in the synthesis of natural products, and many biologically active molecules possess the aziridine moiety. The reactivity of aziridines has been studied, for example, in ring-opening reactions with thiols. However, not much interest seems to be given to reactions of aziridines in aqueous media, despite the numberless advantages of using water as solvent in organic chemistry. The nucleophilic ring-opening reaction of aziridines in aqueous media was here explored. Following the Kaplan aziridine synthetic methodology, in which pyridinium salts undergo a photochemical transformation to give bicyclic vinyl aziridines, new aziridines were synthetized. Their nucleophilic ring-opening reaction in water under physiological conditions was investigated and a range of sulphur, nitrogen, carbon and oxygen nucleophiles tested. Thiols, anilines and azide proved to be good nucleophiles to react with the aziridines, giving the ring-opening product in moderate to good yields. The best results were obtained with thiols, more specifically with cysteine-derived nucleophiles. Preliminary results show that these bicyclic vinyl aziridines can modify calcitonin, a peptide containing two cysteine amino acids residues, grating them the potential to be used in bioconjugation as ligands to cysteine-containing proteins, or even as enzyme inhibitors of, for example, cysteine proteases. Additionally, exploratory investigations suggest that the separation of both enantiomers of the bicyclic vinyl aziridine can be performed by taking advantage of an enzymatic methodology for the resolution of racemic secondary alcohols. Both enantiomers would be highly valuable as precursors in the synthesis of enantiomerically pure molecules, as no other method is currently reported for their separation.

Conflict in cross-functional teams

The present study is a qualitative analysis of the tensions that occur in cross-functional teams (CFTs) and the way in which they can affect the teams' accomplishments. The research is focused on a single case, COHTTEC 2005, a program aimed at transforming new technologies into businesses that took place in Lisbon, Portugal, starting March 2005. In this program, participants were organized in cross-functional teams that included researchers and management students. Semi-structured interviews were made to a sample of 17 participants. These interviews were recorded and transcribed. A table was then elaborated based on the primary data provided by the subjects and these data were classified in different categories. A three-stage model of group dynamics is proposed. The major findings of this project point to the role of interpersonal relationships on group outcomes. More specifically, several patterns associated with team malfunction were uncovered, the clearest ones being autocratic decision-making and arrogant behavior from some team members, as well as escalation in relationship conflict. Implications from these results are discussed, both for future research and for practice.