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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Dental Calculus: Combining Current Methods in the Study of Diet and Mouth Use Activities Among Neolithic and Early Bronze Age Hunter-Gatherers of the Cis-Baikal, Siberia

2015 June 1900 (has links)
The utility of dental calculus as a proxy for diet and mouth use is explored for the Middle Holocene Cis-Baikal region of Central Siberia based on two methods: a macroscopic analysis of severity and a microscopic analysis of particles within deposits. The study area was inhabited by two culturally and biologically distinct cultures, the Early Neolithic (EN) Kitoi culture (8,000 to 7,000/6,800 cal B.P.) and the Late Neolithic-Early Bronze Age (LN-EBA) Isakovo-Serovo-Glaskovo (ISG) cultural complex (6,000/5,800 to 4,000 cal B.P.), separated by a period of cultural transition marked by a cessation in formal cemetery use. Data were collected from four cemetery sites, two dating to the EN and two dating to the LN-EBA. Nonparametric testing of calculus severity revealed that, for adult males and juveniles, lakeshore populations displayed greater affinity to each other than to their contemporaneous cultural counterpart populations living along riverine systems in the Angara River Valley. Trends within the EN cemetery Shamanka II contrasted to the other cemetery populations, with noticeably larger deposits in anterior quadrants and significant sexual distinctions. The proportion of protein to carbohydrates consumed is known to influence calculus formation, but both cultural groups lived on a diet based predominately on meat sources so dietary ratios alone do not adequately explain the differences distinguished. A complex multifactorial model involving microregional differences in resources/environment, foraging patterns, individual variation, and dental wear patterns provides at least a partial explanation for the results observed. A wide range of particles were recovered during the microscopic analysis of calculus, albeit in low concentrations. The low starch grain counts were consistent with a diet based predominately on meats but still provide some of the first direct evidence for plant consumption in the Cis-Baikal, including possible plant processing by cooking or grinding based on damage evident on the grains. Other particles recovered may provide evidence of mouth use activities or palaeoenvironmental influences. Together, the two components of this analysis offer strong evidence that dental calculus is a useful tool for reconstructing hunter-gatherer lifeways but also highlight the limitations of conducting this type of research on previously excavated and potentially contaminated material.
292

Analysis of a lithic assemblage from the multi-component habitation site Gorelyi Les, Siberia

Kurzybov, Petr Unknown Date
No description available.
293

Quantum-chemical Study Of Geometrical And Electronic Structures Of Aromatic Five-membered Heterocyclic Oligomers In The Ground And Lowest Singlet Excited States

Oksuz, Nevin 01 September 2004 (has links) (PDF)
The nature of the ground state and the first (lowest) singlet excited state geometrical conformations and electronic transitions in the aromatic five-membered heterocyclic oligomers &ndash / oligothiophenes (nT), oligofurans (nF), and oligopyrroles (nP)- containing up to six monomer units (total of 18 molecules) were explored using several computational methodologies. Geometry optimizations were carried out at Austin Model 1 (AM1), Restricted Hartree-Fock (RHF/6-31G*), and Density Functional Theory (DFT, B3LYP/6-31G*) levels for the ground-state conformations of these structurally well-defined heterocyclic oligomers. The Configuration Interaction Singles (CIS) method with the 6-31G* basis set was chosen in computation of the optimal geometry of the lowest singlet excited state. Lowest singlet excitation S1&szlig / S0 energies were calculated using the Zerner&rsquo / s Intermediate Neglect of Differential Overlap for Spectroscopy (ZINDO/S), CIS (CIS/6-31G*), and Time-Dependent DFT (TDDFT/6-31G* and TDDFT/6-31+G*) methods. In computation of the emission S1&agrave / S0 energies, we have employed all methods above except ZINDO/S. In investigation of geometries of the ground and lowest singlet excited state, we compared the bond length alternation (BLA) parameters, Dri in the conjugated backbone of the oligomers. Saturation of the geometrical parameters at the center of oligomers was observed after a certain chain length. Among all methodologies used in computation of excitation (S1&szlig / S0) and emission (S1&agrave / S0) energies, TDDFT results showed the best agreement with experimental data. Fits of computed and experimental excitation energies to an exponential function using the least squares method enabled us to predict Effective Conjugation Length (ECL) values. We obtained the ECLs of 17 (17), 16 (15), and 14 (13) monomer units for polythiophene (PTh), polyfuran (PFu), and polypyrrole (PPr), which have very good agreement with the results obtained from the fits of experimental data (the values in parentheses).
294

IS supported service work: a case study of global certification

Berntsen, Kirsti Elisabeth January 2011 (has links)
The thesis approaches the issue of IS support for service work, understood as distributed knowledge work taking place as a negotiation between diverse interests. It is based on an ethnographically inspired, longitudinal case study of certification auditing according to a formal generic standard. A handful of certification auditors are followed closely, periodically and comprehensively over three years. Observations are combined with interviews of subjects and colleagues, added by exploration of other material. The practices of company ‘W’ is placed within a larger historical and institutional context. Research literature and theory is explored in four chapters from Social studies of science (STS), Computer supported cooperative work (CSCW), Information systems (IS), Information infrastructures (II) and Management literature. The aim is to identify basic characteristics of service work, its opportunities and challenges, from both the company’s and workers’ perspective. Main topics are Decision Making as negotiated sensemaking, contextual rationality and judgement; Sharing of understanding and meaning as ongoing practiced articulation work aiming for trust and an equifinal level of accord that will ‘find and allow common action’; Perseverance in a capable role that will allow calibration of distributed knowledge is vital for auditors. Common Information Spaces (CIS) is used as a framework to explore the heterogeneous circumstances of identity work in work practices; Predictability in production is sought through various strategies of standardization. Approaches to avoid and counter the inherent side-effects of standardization are described. The empirical results of the research project are presented and analysed in four chapters that look at the issue of i) being an accomplished service worker and ii) practicing service work. Both issues are addressed from a local, individual perspective, and from an organizational perspective in terms of the continuation of quality production. The thesis closes with a Conclusion of organized and standardized service work as displaying Practical drift, in response to the research question RQ0. How is IS supported distributed service work negotiated?, followed by implications for IS research and practice. The empirical case displays the role of information systems (IS) support in distributed service work - as part of a larger assembly of standardization measures, a broad-spectrum approach, displaying practical drift in its effect. The service work of certification auditing is characterized by ongoing negotiation of partly contradictory interests. It is heterogeneously standardized through material, rational/immaterial and social/organizational measures, many in place long before the advent of advanced IS. Traditionally, there are release mechanisms that, on the auditors’ discretion, alleviate the inappropriate effects of standardization. With new harmonising efforts the scope of this personal latitude needs to change, but when first implemented the IS along with new procedures start off as too tight. However, over time adaptations are made, making the overall process self regulatory with feedback mechanisms. On the whole, the thesis aims to contribute to the literature on information infrastructures, on knowledge work in general, and CSCW by drawing on insights from this specific collaborative work in controversial settings. The case provides practical insights for resilient systemizing of knowledge based global service work practices.
295

A re-examination of the Ghrelin and Ghrelin receptor genes

Seim, Inge January 2009 (has links)
The last few years have seen dramatic advances in genomics, including the discovery of a large number of non-coding and antisense transcripts. This has revolutionised our understanding of multifaceted transcript structures found within gene loci and their roles in the regulation of development, neurogenesis and other complex processes. The recent and continuing surge of knowledge has prompted researchers to reassess and further dissect gene loci. The ghrelin gene (GHRL) gives rise to preproghrelin, which in turn produces ghrelin, a 28 amino acid peptide hormone that acts via the ghrelin receptor (growth hormone secretagogue receptor/GHSR 1a). Ghrelin has many important physiological and pathophysiological roles, including the stimulation of growth hormone (GH) release, appetite regulation, and cancer development. A truncated receptor splice variant, GHSR 1b, does not bind ghrelin, but dimerises with GHSR 1a, and may act as a dominant negative receptor. The gene products of ghrelin and its receptor are frequently overexpressed in human cancer While it is well known that the ghrelin axis (ghrelin and its receptor) plays a range of important functional roles, little is known about the molecular structure and regulation of the ghrelin gene (GHRL) and ghrelin receptor gene (GHSR). This thesis reports the re-annotation of the ghrelin gene, discovery of alternative 5’ exons and transcription start sites, as well as the description of a number of novel splice variants, including isoforms with a putative signal peptide. We also describe the discovery and characterisation of a ghrelin antisense gene (GHRLOS), and the discovery and expression of a ghrelin receptor (growth hormone secretagogue receptor/GHSR) antisense gene (GHSR-OS). We have identified numerous ghrelin-derived transcripts, including variants with extended 5' untranslated regions and putative secreted obestatin and C-ghrelin transcripts. These transcripts initiate from novel first exons, exon -1, exon 0 and a 5' extended 1, with multiple transcription start sites. We used comparative genomics to identify, and RT-PCR to experimentally verify, that the proximal exon 0 and 5' extended exon 1 are transcribed in the mouse ghrelin gene, which suggests the mouse and human proximal first exon architecture is conserved. We have identified numerous novel antisense transcripts in the ghrelin locus. A candidate non-coding endogenous natural antisense gene (GHRLOS) was cloned and demonstrates very low expression levels in the stomach and high levels in the thymus, testis and brain - all major tissues of non-coding RNA expression. Next, we examined if transcription occurs in the antisense orientation to the ghrelin receptor gene, GHSR. A novel gene (GHSR-OS) on the opposite strand of intron 1 of the GHSR gene was identified and characterised using strand-specific RT-PCR and rapid amplification of cDNA ends (RACE). GHSR-OS is differentially expressed and a candidate non-coding RNA gene. In summary, this study has characterised the ghrelin and ghrelin receptor loci and demonstrated natural antisense transcripts to ghrelin and its receptor. Our preliminary work shows that the ghrelin axis generates a broad and complex transcriptional repertoire. This study provides the basis for detailed functional studies of the the ghrelin and GHSR loci and future studies will be needed to further unravel the function, diagnostic and therapeutic potential of the ghrelin axis.
296

An experimental and genomic approach to the regulation of alternative pre-mRNA splicing in Drosophila rnp-4f

Fetherson, Rebecca A. January 2005 (has links)
Thesis (M.S.)--Miami University, Dept. of Zoology, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], ix, 75 p. : ill. Includes bibliographical references (p. 69-75).
297

Ετήσια ενεργειακή απόδοση πλαισίων λεπτού φιλμ και ισοδύναμη μοντελοποίηση

Τσόλκας, Γεώργιος 16 June 2011 (has links)
Σκοπός αυτής της διπλωματικής εργασίας είναι να εμβαθύνουμε στη λειτουργία των φωτοβολταϊκών πλαισίων λεπτού φίλμ (και συγκεκριμένα των πλαισίων άμορφου πυριτίου - a-Si - και CIS) και μέσα από τα αριθμητικά δεδομένα, να αποφανθούμε πώς η λειτουργία σε πραγματικές συνθήκες μπορεί να επηρεάσει την παραγόμενη ισχύ τους. Στα πλαίσια αυτά, πραγματοποιήθηκαν πειραματικές μετρήσεις, στο χώρο της ταράτσας του κτιρίου του τμήματος των Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών, με φωτοβολταϊκά πλαίσια άμορφου πυριτίου και CIS ισχύος αιχμής 32 και 75 W αντίστοιχα. Οι μετρήσεις πραγματοποιούνταν μια φορά την εβδομάδα κατά τη διάρκεια ενός ημερολογιακού έτους (Μάιος 2009-Απρίλιος 2010) υπό διάφορες συνθήκες ακτινοβολίας και θερμοκρασίας και για αρκετές γωνίες κλίσης, με σκοπό να αποκτήσουμε μια ολοκληρωμένη εικόνα της ενεργειακής τους συμπεριφοράς. Οι μετρήσεις πραγματοποιήθηκαν με τη βοήθεια του μηχανήματος PVPM 2540C το οποίο αποτυπώνει τη χαρακτηριστική ρεύματος-τάσης του προς μέτρηση πλαισίου για μια χρονική στιγμή (σε χρόνο δυο δευτερολέπτων περίπου), ενώ επιπλέον σημειώναμε την ακτινοβολία, τη θερμοκρασία του περιβάλλοντος, καθώς και την κλίση τοποθέτησής τους. Επίσης μελετούσαμε πώς επηρεάζει τη χαρακτηριστική καμπύλη I-V, και κατά συνέπεια την απόδοση, τυχόν σκίαση από παρακείμενο αντικείμενο. Ο προσανατολισμός των πλαισίων ήταν πάντα προς το Νότο, ώστε να έχουμε περισσότερες ώρες ηλιοφάνειας, διότι η Ελλάδα είναι χώρα του βόρειου ημισφαιρίου. Κατά την επεξεργασία των μετρήσεων καταλήξαμε στην βέλτιστη κλίση τοποθέτησης των πλαισίων ανά εποχή καθώς και σε μία βέλτιστη κλίση τοποθέτησης για όλο τo χρόνο για την περιοχή της Πάτρας. Επιπλέον, υπολογίσαμε με τη μέγιστη δυνατή ακρίβεια την ετήσια ενεργειακή απόδοση του κάθε πλαισίου για όλο το έτος και συγκρίναμε τα παραγόμενα αποτελέσματα. Τέλος, με τη βοήθεια του προγράμματος PV*Sol, κάναμε μια μοντελοποίηση του χρησιμοποιούμενου συστήματος για να συγκρίνουμε μ’ αυτή τα πειραματικά μας αποτελέσματα. / The aim of this diploma thesis is to understand deeply the operation of thin-film (specifically amorphous silicon and CIS ) modules and through the numerical data of measurements and calculations, to make a conclusion considering how the operation in real conditions can influence their produced power. Measurements of current and voltage have been realized on the roof of the building of the department of Electrical and Computer Engineering using an amorphous silicon and a CIS photovoltaic module of 32 and 75 W peak power respectively. The measurements took place once a week during one a year (May 2009-April 2010) and our goal was to obtain measurements under various conditions of radiation and temperature and for some tilt angles so that we acquire enough knowledge on their energy behaviour. The measurements were taken by the “pve PVPM 2540C“ device, which plots the characteristic curve of current and voltage of a module (in space of two seconds) and we also noted down the radiation, the ambient temperature, as well as the tilt angle of the modules. Moreover, we have tested how a possible natural shading from an adjacent object influences the characteristic I-V curve, and as a result the efficiency of the module. The orientation of the module was always South, in order to gain more hours of sunlight, as Greece is a country of the northern hemisphere. While processing the measurements, we found the optimal tilt angle of the modules per season as well as per year for Patras area. Moreover, we tried to calculate with the maximum possible accuracy, the annual energy yield by the two different types of modules and compare the results. Finally, by using the computer modelling system “PV*sol”, we tried to simulate our photovoltaic system, in order to compare the measured results to the experimental.
298

Ανάλυση και εξομοίωση φωτοβολταϊκών πλαισίων λεπτών φιλμ

Κοσκινάς, Αθανάσιος 04 October 2011 (has links)
Σκοπός της παρούσας διπλωματικής εργασίας είναι μέσα από την πειραματική διαδικασία και την επεξεργασία των αποτελεσμάτων να μελετηθούν τα φωτοβολταϊκά πλαίσια τεχνολογίας λεπτών φιλμ (Thin Films Photovoltaics-TFPV) που υπάρχουν διαθέσιμα στο εργαστήριο Ασύρματης Τηλεπικοινωνίας του Πανεπιστημίου Πατρών στο Τμήμα Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών και να εξαχθούν συμπεράσματα που θα οδηγήσουν στην κατανόηση της λειτουργίας τους. Η ανάλυσή τους θα διευκρινίσει την λειτουργία τους και σε πραγματικές εφαρμογές. Επιπλέον θα γίνει προσπάθεια πειραματικής εξομοίωσης συνθηκών δοκιμής στους 25οC υπό ηλιακή ακτινοβολία 1000 W/m2 τονίζοντας ότι οι κατασκευαστικές πληροφορίες σε αυτές τις συνθήκες είναι ενδεικτικές και δεν εκφράζουν την συμπεριφορά των πλαισίων σε πραγματικές συνθήκες λειτουργίας. Επίσης θα παρουσιαστεί η επίδραση της τοπικής σκίασης και της αύξησης της προσπίπτουσας ακτινοβολίας σε μέρος ή και σε ολόκληρο το πλαίσιο που προκαλείται από ανάκλαση με τη βοήθεια κατόπτρου. Ειδικότερα παρουσιάζεται η κατάσταση της ενεργειακής πραγματικότητας σήμερα, οι προβληματισμοί για το περιβάλλον, η στροφή στις Ανανεώσιμες Πηγές Ενέργειας και η σημαντικότητα της ενσωμάτωσης φωτοβολταϊκών στα κτήρια. Επίσης παρουσιάζεται η θεωρία της ηλιακής ενέργειας και των φωτοβολταϊκών συστημάτων με τα πλεονεκτήματα και μειονεκτήματά τους. Στην συνέχεια γίνεται αναφορά στη συνδεσιμότητα των φωτοβολταϊκών με την ΔΕΗ και στις ενεργειακές ανάγκες που μπορούν να καλύψουν σε μια κτηριακή εγκατάσταση. Αναλύονται τεχνικές λεπτομέρειες και χαρακτηριστικά μεγέθη των φωτοβολταϊκών στοιχείων καθώς και η εξέλιξη της φωτοβολταϊκής τεχνολογίας ξεκινώντας από το πυρίτιο και καταλήγοντας στα Λεπτά Φιλμ και σε ακόμα νεότερες τεχνολογίες. Στη συνέχεια γίνεται ανάλυση της τεχνολογίας των λεπτών φιλμ προσανατολισμένη στην ενσωμάτωση τους σαν δομικά υλικά σε κατασκευές (BIPV-Building Integrated Photovoltaics).Στην πειραματική διαδικασία επεξηγείται η λογική που ακολουθήθηκε, η πειραματική διάταξη και τα όργανα που χρησιμοποιήθηκαν. Μελετώνται επίσης οι φωτοβολταϊκές παράμετροι και αναλύονται τα πειραματικά δεδομένα. Η ανάλυση γίνεται ως προς την ακτινοβολία, την θερμοκρασία και την εποχή του έτους. Τέλος, τα αποτελέσματα της ανάλυσης, (μέσο ένος προγράμματος στην γλώσσα προγραμματισμού C++), δημιουργούν μια βάση δεδομένων προσπελάσιμη από τον χρήστη για την πρόβλεψη και εξομοίωση των πειραματικών αποτελεσμάτων σε οποιοδήποτε συνδυασμό θερμοκρασίας και ακτινοβολίας. / The purpose of this diploma thesis is to study thin film photovoltaic panels that are available in the wireless communication laboratory in the University of Patras in the department of Electrical and Computer Engineering. Through the experimental process and processing its results our goal was to extract the conclusions that would lead us to a better understanding of their function. Their analysis will determine their usability in real outdoor PV systems. A simulation of the standard test conditions that are set in 250C temperature and 1000 W/m2 radiation is made, pointing out that this information is unable to indicate the actual function of the panels in outdoor conditions. The effects of partial shadowing and increased radiation with mirror system are also presented. More specifically, the energy reality, thoughts about the environment, the global turn towards the renewable energy sources and the significance of photovoltaic integration in buildings (BIPV- Building Integrated Photovoltaics) are mentioned. The theory of solar energy and photovoltaic technology including its advantages and disadvantages is analyzed. Grid-connected PV systems, their contribution in energy production in buildings and the potential of wide application of BIPV is presented. The advantages of thin film as BIPV materials are also mentioned. The experimental parameters, the logics followed in the set up process and the instruments used are part of the complete analysis of thin film parameters in relation to radiation, temperature and time of the year that the measurements occurred. Finally with a C++, a simulation program was created to predict the behavior of the thin film panels in outdoor conditions.
299

Isolamento, investigação química e avaliação do potencial antibiótico, antibiofilme e anti-trichomonas vaginalis de fungos associados a organismos marinhos da costa sul do Brasil / Isolation, chemical investigation and evaluation of antibiotic, antibiofilm and anti-Trichomonas vaginalisactivities of fungi associated to marine organisms from south brazilian coast

Scopel, Marina January 2012 (has links)
Fungos isolados de organismos marinhos têm despertado o interesse de pesquisadores no mundo inteiro, por representarem uma fonte diferenciada de metabólitos secundários, devido às condições ambientais as quais esses microrganismos estão sujeitos. Diversas atividades biológicas têm sido relatadas para estas substâncias, principalmente antitumoral, antimicrobiano e antiparasitária. O crescente aumento nos casos de resistência a antibióticos aponta para a necessidade da disponibilidade de novos agentes terapêuticos. Neste contexto, este trabalho objetivou a identificação dos fungos associados a organismos marinhos coletados na Ilha do Arvoredo (SC), visando o isolamento bioguiado de metabólitos de extratos de micélio e meios de cultivo. As atividades antibiótica e antibiofilme frente aos patógenos Staphylococcus epidermidis ATCC 35984 e Pseudomonas aeruginosa ATCC 27853 e anti-Trichomonas vaginalis ATCC 30236 e isolados clínicos, foram investigadas. Todos os fungos isolados foram cultivados por períodos de 7, 14 e 21 dias. Utilizando técnicas moleculares, foram identificados 37 fungos pertencentes ao Filo Ascomycota e um ao Filo Basidiomycota, distribuídos entre 15 diferentes gêneros. O rastreamento de metabólitos quanto à atividade antibiótica foi realizado utilizando a técnica de difusão em agar, obtendo-se 19 amostras com halos de inibição superiores a 10 mm de diâmetro. As atividades antiformação e erradicação de biofilme previamente formado foram avaliadas pelo método de coloração com cristal violeta, e 5% do total de amostras apresentaram inibição de formação e 1% a erradicação de mais de 75% de biofilme de S. epidermidis. Da mesma forma, 5% das amostras foram capazes de inibir ou erradicar entre 51% e 75% biofilmes de P. aeruginosa. Entre os isolados, foram selecionados um fungo pertencente à ordem Sordariales (isolado F22, 14 dias de cultivo) e outro ao gênero Penicillium (isolado F37, 7 dias de cultivo). Os filtrados dos fungos foram particionados com acetato de etila e submetidos à separação cromatográfica, levando à identificação dos compostos mevalonolactona e cis-cyclo(leucyl-tyrosyl) (identificados por técnicas espectroscópicas e espectrométricas), ambos ativos na inibição da formação de biofilme de S. epidermidis ATCC. Mevalonolactona também apresentou atividade frente a isolados clínicos de S. epidermidis revelando, além da atividade antibiofilme, atividade antibiótica em concentração de 0,06 mg/mL. A atividade frente ao parasita T. vaginalis foi avaliada pela técnica de coloração de resazurina e a viabilidade dos trofozoítos caracterizada utilizando trypan blue. Duas amostras dos fungos Hipocrea lixii e Penicillium citrinum mostraram a presença de metabólitos ativos. A inibição do crescimento dos trofozoítos foi observada em 24 horas (MIC=2,5 mg/mL), de acordo com a curva cinética de crescimento. A ausência de hemólise de eritrócitos também foi observada para estas duas amostras. Os resultados obtidos corroboram com os relatos sobre o grande potencial dos fungos marinhos para a descoberta de metabólitos ativos. / Fungi isolated from marine organisms attract the interest of many researchers around the world, since they produce differentiated secondary metabolites due to the environmental conditions to which these organisms are subjected. Several biological activities have been reported for these compounds, mainly as antitumoral, antibacterial and, antiprotozoal. The increasing cases of antimicrobial drug resistance reveal the necessity for the search for new therapeutic agents. In this context, this study aimed to identify the fungi associated with marine organisms collected in the Arvoredo Island (SC/Brazil), in order to isolate bioactive metabolites in extracts of mycelia and broth. The antibiotic and antibiofilm activities against Staphylococcus epidermidis ATCC 35984 and Pseudomonas aeruginosa ATCC 27853 and anti-Trichomonas vaginalis ATCC 30236 and clinical isolates activity were investigated. The isolated fungi from marine organisms were cultured for 7, 14 and 21 days. Using molecular techniques, 36 fungi belonging to the Ascomycota and one to Basidiomycota phyla, were identified, distributed among 15 different genera. Screening for metabolites possessing antibiotic activity was performed using the agar diffusion assay, for which was obtained 19 samples with inhibition halo higher than 10 mm in diameter. The inhibition and eradication of biofilm were performed by cristal violet staining method, and 5% of the total samples showed inhibition and 1% eradication of more than 75% of S. epidermidis biofilm. Moreover, 5% of the samples were able to inhibit and eradicate between 51% and 75% of biofilm formed by P. aeruginosa. Among these samples, one strain belonging to the order Sordariales (isolate F22, 14-days of cultive) and one to the genus Penicillium (isolate F37, 7-days of cultive) were selected. The filtrate was extracted with ethyl acetate and subjected to separation by chromatographic techniques, leading to purified compounds mevalonolactone and cis-cyclo(leucyl-tyrosyl) (identified by spectroscopic and spectrometric techniques), both able to inhibit biofilm formation by S. epidermidis ATCC. Mevalonolactone also showed activity against clinical isolates of S. epidermidis revealing, both antibiofilm and antibiotic activities at 0.06 mg.mL-1. The anti-T. vaginalis assay was carried out using the resazurin staining method andviability of trophozoites were characterized using trypan blue. Two samples of the fungi Hypocrea lixii and Penicillium citrinum showed the presence of active metabolites able to inhibit the trophozoites growth in 24 hours (MIC = 2.5 mg.mL-1), according to the kinetic curve of growth. Absence of hemolysis of erythrocytes was also observed for these two filtrate samples. The results corroborate with the reports of the great potential of marine fungi in the discovery of active metabolites.
300

Inovação em pequenas e médias empresas: uma análise comparativa entre Brasil e países europeus

Silva, Marcelo Duarte 22 February 2017 (has links)
Pequenas e médias empresas têm grande importância na geração de emprego e renda, o que as qualifica como agentes capazes de impulsionar o crescimento e desenvolvimento econômico. O constante processo de mudança tecnológica tem imposto desafios que, ao menos parcialmente, têm sido enfrentados pelas firmas de pequeno e médio porte. Em resposta a esse processo, esta dissertação tem como referencial teórico a abordagem neoschumpeteriana da tecnologia e da mudança econômica, que propõe o processo inovativo e a “destruição criativa” como centrais ao desenvolvimento da atividade econômica. Considera-se a hipótese de que há relevante discrepância entre os resultados, esforços e atividades inovativas de pequenas, médias e grandes empresas, em países com sistemas nacionais de inovação e estruturas produtivas distintas, como Brasil e países da Comunidade Europeia. O objetivo geral é identificar as particularidades das atividades inovativas em empresas de pequeno porte, assim como comparar as diferenças dos esforços e resultados inovativos entre os países selecionados. Para tanto, é apresentado um conjunto de indicadores formulados a partir de dados extraídos da Pesquisa de Inovação Tecnológica (PINTEC), edições de 2008 e 2011, e da Community Innovation Survey (CIS), edições CIS6 e CIS8. Os resultados indicam que quando comparadas com as grandes firmas, as pequenas e médias empresas têm menor taxa de inovação, concentram seus esforços e gastos inovativos em poucas atividades inovativas, têm maior participação de inovações do tipo processo, além de cooperarem menos e com menor quantidade de parceiros. Esse padrão é verificado com mais intensidade no Brasil e em economias menos avançadas da Comunidade Europeia. Há forte presença de apoio do governo no Brasil, quando comparado com maioria dos demais países selecionados, havendo considerável melhora entre os períodos de análise. Esses resultados apontam para a necessidade de se ampliar políticas públicas com vistas a diminuir tais discrepâncias entre as pequenas e grandes empresas brasileiras. / Small and medium-sized firms have great impact in generating employment and income, which qualifies them as capable agents of boosting economic growth and development. The constant process of technological change presents a challenge that has been faced, at least partially, by small and medium-sized firms. In response to this process, this teses has as theoretical reference to the Neoschumpeterian approach of technology and economic change, which proposes the innovative process and "creative destruction" as central to the development of economic activity. It is considered the hypothesis that there is a significant discrepancy between the results, efforts and innovative activities of small, medium and large firms in countries with different national innovation systems and production structures, such as Brazil and European Community countries. The main issue is to identify the particularities of innovating in small enterprises, as well as compare the differences in innovative efforts and results among selected countries. To that, a set of indicators are formulated from data extracted from the Pesquisa de Inovação Tecnológica (PINTEC), editions of 2008 and 2011, and the Community Innovation Survey (CIS), editions CIS6 and CIS8. The results indicate that compared to large firms, small and medium enterprises have a lower rate of innovation, concentrate their efforts and innovative spending on few innovative activities, have a great participation in process type innovations, and cooperate less and with few partners. This standard is strongly verified in Brazil and in the less advanced economies of the European Community. There is a strong presence of government support in Brazil, when compared to most of the other selected countries, with considerable improvement between the periods of analysis. These results point to the need to expand public policies aimed at reducing such discrepancies between small and large Brazilian companies. / Dissertação (Mestrado)

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