Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-09-21T20:27:56Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Cristina Guedes Pereira.pdf: 566009 bytes, checksum: cec844f5b58d53ff422c894a91e933cf (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-24T18:56:47Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Cristina Guedes Pereira.pdf: 566009 bytes, checksum: cec844f5b58d53ff422c894a91e933cf (MD5) / Made available in DSpace on 2018-09-24T18:56:47Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Cristina Guedes Pereira.pdf: 566009 bytes, checksum: cec844f5b58d53ff422c894a91e933cf (MD5) Previous issue date: 2017-08-02 / CAPES / In this dissertation, we focus on the issue of performing likelihood ratio testing inferences in unit gamma regressions. Our interest lies in testing inferences that are accurate and reliable in small samples. The unit gamma regression model was proposed by Mousa et al. (2016) based on the unit gamma distribution introduced by Grassia (1977). Closed form expressions for the score vector and for Fisher’s information matrix were obtained by Mousa et al. (2016). The model is useful for dealing with doubly limited continuous dependent variables (DLCDV), such as proportions, indices and rates, being an alternative to the beta regression model, which has been widely used in the literature. We derive a small sample adjustment to the likelihood ration ratio test statistic in the class of unit gamma regressions using the approach proposed by Skovgaard (2001). The numerical evidence we present show that the two corrected tests we propose outperform the standard likelihood ratio test in small samples. A real data example is presented. / O foco da presente dissertação reside na realização de testes de hipóteses em regressões gama unitária. O teste da razão de verossimilhanças pode ser consideravelmente impreciso em pequenas amostras. Nosso interesse reside na obtenção de testes que sejam precisos e confiáveis quando o tamanho da amostra é pequeno. A distribuição gama unitária foi proposta por Grassia (1977) e serviu de base para o modelo de regressão gama unitário introduzido por Mousa et al. (2016). O modelo sugerido é útil para modelar variáveis dependentes contínuas duplamente limitadas (VDCDL), como proporções, índices e taxas, sendo uma alternativa ao modelo de regressão beta, que tem sido amplamente utilizado na literatura. Nós derivamos uma correção para a estatística da razão de verossimilhanças nessa classe de modelo utilizando o enfoque desenvolvido por Skovgaard (2001). Com base em tal correção, apresentamos duas estatísticas de teste corrigidas. A evidência numérica que nós apresentamos indica que os testes corrigidos conduzem a inferências mais precisas do que aquelas obtidas com o teste da razão de verossimilhanças padrão em pequenas amostras. Aplicamos os resultados a um conjunto real de dados.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-09-21T20:16:54Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vinícius Teodoro Scher.pdf: 902853 bytes, checksum: 8ce4def07864471ce7717ce6d128d086 (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-24T20:48:15Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vinícius Teodoro Scher.pdf: 902853 bytes, checksum: 8ce4def07864471ce7717ce6d128d086 (MD5) / Made available in DSpace on 2018-09-24T20:48:15Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vinícius Teodoro Scher.pdf: 902853 bytes, checksum: 8ce4def07864471ce7717ce6d128d086 (MD5) Previous issue date: 2017-08-02 / CAPES / The class of beta autoregressive moving average (bARMA) models is useful for modeling time series data that assume values in the standard unit interval, such as rates and proportions. This thesis is composed of two main and independent chapters. In the first part, we consider portmanteau testing inference in the class of bARMA models. To that end, we use tests that have been developed for Gaussian models, such as the Ljung and Box, Monti, Dufour and Roy, Kwan and Sim, and Lin and McLeod tests. We also consider bootstrap variants of the Ljung and Box, Monti, Dufour and Roy, and Kwan and Sim tests. Moreover, we propose two new test statistics which, like the Monti statistic, are based on residual partial autocorrelations. Additionally, we present and discuss results from Monte Carlo simulations and an empirical application. The second part of the thesis focuses on the recursive nature of bARMA loglikelihood derivatives under moving average dynamics. We provide closed form expressions for the relevant derivatives by considering errors in the predictor scale. / A classe de modelos beta autorregressivos de médias móveis (bARMA) é útil para modelar dados que assumem valores no intervalo unitário padrão, como taxas e proporções. A presente dissertação tem como tema tal classe de models e é composta por dois capítulos principais e independentes. Na primeira parte, consideramos inferências baseadas em testes portmanteau na classe de modelos bARMA. Para tanto, utilizamos testes que foram desenvolvidos para modelos gaussianos, como os testes de Ljung e Box, Monti, Dufour e Roy, Kwan e Sim, e Lin e McLeod. Também consideramos variantes bootstrap dos testes de Ljung e Box, Monti, Dufour e Roy and Kwan e Sim. Adicionalmente, propomos duas novas estatísticas de testes que, tal qual a estatística de Monti, são baseadas em autocorrelações parciais dos resíduos. Apresentamos e discutimos resultados de simulações de Monte Carlo e uma aplicação empírica. A segunda parte da dissertação aborda a natureza recursiva das derivadas da função de log-verossimilhança bARMA sob dinâmica de médias móveis. Nós fornecemos expressões em forma fechada para as derivadas relevantes considerando erros na escala do preditor.

β-1,3-glucanases são enzimas encontradas em muitos organismos, como fungos, bactéria e plantas. Suas funções incluem remodelamento de parede celular, defesa e digestão. É um alvo interessante para o controle populacional de insetos-praga, porque é ausente em vertebrados. Em insetos, é encontrada no intestino de muitas ordens diferentes, e hidrolizam β-1,3 ou β-1,3(4)-glucanas ingeridas, mas pouco se sabe sobre as propriedades e a função dessas enzimas. Nós estudamos três espécies de insetos, de três ordens diferentes. Spodoptera frugiperda (Lepidoptera), Tenebrio molitor (Coleoptera) e Abracris flavolineata (Orthoptera) são insetos herbívoros e pestes de plantações, mas suas beta-1,3-glucanases diferem significativamente. A β- 1,3-glucanase de S. frugiperda (SLAM) foi purificada do intestino médio da larva. Ela apresenta uma massa molecular de 37,5 kDa, um pH ótimo alcalino de 9,0, é ativa contra β-1,3-glucana (laminarina), mas é incapaz de hidrolizar β-1,3-1,6-glucana de levedura ou outros polisacarídeos. SLAM é não-processiva (0,4), e não é inibida por altas concentrações de substrato. Diferente de outras β-1,3-glucanases digestivas de insetos, SLAM é incapaz de lisar células de Saccharomyces cerevisae. O cDNA correspondente à SLAM foi clonado e sequenciado, demonstrando que a proteína pertence à família 16 das Glicosídeo-Hidrolases. A modelagem tridimensional de SLAM, feito com base em homologia de sequência, sugere que o resíduo E228 possa afetar a ionização dos resíduos catalíticos, causando o deslocamento do pH ótimo da enzima. Anti-corpos específicos para SLAM foram produzidos, e estes reagem com uma única proteína oriunda do intestino médio da larva, responsável pela atividade β-1,3- glucanásica majoritária. A imunocitolocalização de SLAM demonstra que a enzima é encontrada em vesículas secretórias e no glicocálix das células colunares, e portanto não é originária de simbiontes. Nós clonamos e sequenciamos o cDNA correspondente à β-1,3-glucanase majoritária presente no intestino médio da larva de T. molitor (TLAM). Ela pertence à família 16 das Glicosídeo-Hidrolases e está relacionada com proteínas ligantes de β -glucanas, da mesma forma que a enzima de S. frugiperda. A modelagem tridimensional por homologia de sequência permitiu identificar alguns resíduos de amino-ácidos (E174, E179, H204, Y304, R127 e R2181) no sítio ativo da enzima, que podem ser importantes para a atividade de TLAM. A β-1,3-glucanase digestiva do gafanhoto Abracris flavolineata (Orthoptera) é diferente das enzimas já estudadas em insetos. Ela apresenta uma estratégia catalítica processiva, liberando glicose como maior parte dos produtos, e é inibida por altas concentrações de substrato. Para estudar as bases estruturais desse mecanismo, nós procuramos obter a sequência de cDNA correspondente à enzima já caracterizada. O alinhamento múltiplo das β-1,3- glucanases de insetos e proteínas ligantes de beta-glucanas indicou que uma duplicação gênica da enzima do ancestral comum de moluscos e artrópodes. Uma cópia originou as beta-1,3-glucanase de insetos, perdendo uma região N-Terminal com cerca de 100 pares de bases, enquanto a outra cópia originou as proteínas ligantes de beta-glucana, perdendo os resíduos catalíticos. / β-1,3-glucanases are widespread enzymes, found in all major groups of invertebrates, fungi, bacteria and plants. Since this enzyme is absent in vertebrates, it constitutes an interesting target for control of insect pests population. Its functions range from cell wall remodeling, defense and digestion. In insects, it is found in the gut of many different orders, hydrolyzing β-1,3 or β-1,3(4)-glucanas, but little is known about the properties and function of these enzymes. We studied three insect species each pertaining to a different order. Spodoptera frugiperda (Lepidoptera), Tenebrio molitor (Coleoptera) and Abracris flavolineata are herbivores and crops pests, but their β-1,3- glucanases differ significantly. S. frugiperda β -1,3-glucanase (SLAM) was purified from the larval midgut. It has a molecular mass of 37.5 kDa, an alkaline optimum pH of 9.0, is active against β-1,3-glucan (laminarin), but cannot hydrolyze yeast β-1,3-1,6-glucan or other polysaccharides. The enzyme is an endoglucanase with low processivity (0.4), and is not inhibited by high concentrations of substrate. In contrast to other digestive β-1,3- glucanases from insects, SLAM is unable to lyse Saccharomyces cerevisae cells. The cDNA encoding SLAM was cloned and sequenced, showing that the protein belongs to glycosyl hydrolase family 16 as other insect glucanases and glucan-binding proteins. SLAM homology modeling suggests that E228 may affect the ionization of the catalytic residues, thus displacing the enzyme pH optimum. SLAM antiserum reacts with a single protein in the insect midgut. Immunocytolocalization reveals the presence of the enzyme in secretory vesicles and glycocalyx from columnar cells. We cloned and sequenced the cDNA of T. molitor β-1,3-glucanase. It belongs to glycoside hydrolase family 16, and is related to other insect glucanases and glucan-binding proteins. Sequence analysis and homology modeling allowed the identification of some residues (E174, E179, H204, Y304, R127 and R181) at the active site of the enzyme, which may be important for TLAM activity. The grasshopper A. flavolineata has a β-1,3-glucanase with a processive catalytic strategy. To study the structural basis of this property, we aimed to obtain its encoding sequence to better understand this catalytic mechanism. Multiple sequence alignment of insects β-1,3-glucanases and β-glucan-binding protein indicates that the β- 1,3-glucanase gene duplicated in the ancestor of mollusks and arthropods. One copy originated the insect β-1,3-glucanases after losing a 100 bp N-terminal portion and the arthropode β-glucan-binding proteins by the loss of the catalytic residues.

Foram purificadas através de uma combinação de cromatografias as duas &#946;- glicosidases digestivas (Mr 47.000 e 50.000 - denominadas &#946;47 e &#946;50, respectivamente) encontradas na larva de S. frugiperda. Experimentos de competição entre substratos e modificação química mostraram que a &#946;47 possui dois sítios ativos. Um desses sítios denominado aril&$946;glicosidase apresenta um subsítio -1 que liga galactose mais eficientemente do enquanto ,que o subsítio +1 prefere pequenos grupos hidrofóbicos cíclicos. O segundo sítio, denominado celobiase, possui um subsítio -1 que prefere glicose. Já a região de ligação do aglicone apresenta 4 subsítios, que ligam glicose com afinidade decrescente à medida que afastam-se do ponto de clivagem do substrato. O cDNA que codifica a &#946;50 foi clonado e sequenciado. Alinhamentos de sequência de aminoácidos, experimentos de competição entre substratos e inibição mostraram que esta enzima possui apenas um sítio ativo. O subsítio -1, cuja especificidade é controlada por uma rede de pontes de hidrogênio, foi estudado comparando-se os parâmetros cinéticos (Kcat e KcaUKm) para a hidrólise de NP&#946;glicosídeos. A região de posicionamento do aglicone, uma fenda hidrofóbica composta de 3 subsítios, foi caracterizada utilizando-se alquil &#946;-glucosídeos e oligocelodextrinas como inibidores. O alinhamento da sequência de aminoácidos da &#946;50 com outras glicosil hidrolases sugeriu quais aminoácidos participariam da ligação do substrato e que o GlU187 (doador de prótons - pKa = 7,5) e o GIU399 (nucleófilo - pKa = 4,5) estão diretamente envolvidos na catálise. Além disso, a Arg97 e a Tyr331 participam indiretamente modulando o pKa do GIU399. r . / Two digestive &#946;-glycosidases (MW 47,000 and 50,000, named &#946;gly47 and &#946;gly50, respectively) whose are found in the S. frugiperda larvae were purified by a combination of chromatographic steps. Substrate competition experiments and chemical modification data showed that &#946;gly47 has two active sites. One of them was called aryl &#946;-glycosidase and presents a -1 subsite that prefers galactose while the +1 subsite binds small cyclic hydrophobic groups. The other active site was called cellobiase and presents 4 subsites that bind glucose residues weaker as they get far from the cleavage point. The cDNA that codes the &#946;gly50 was cloned and sequenced. Amino acid sequence alignment, substrate competition experiments and inhibitions proved that this enzyme has just one active site. The -1 subsite specificity is controlled by a hydrogen bond network as it was showed comparing the kinetic parameters (Kcat and KcatlKm) for some NP&#946;glycosides hydrolysis. The aglycone binding region, a hydrophobic cleft, was studied with alkyl &#946;-glucosides and oligocellodextrins as competitive inhibitors. Amino acid sequence alignment between the &#946;gly50 and other glycosil hydrolases showed the amino acids responsible for the substrate binding and that the GIU<SUB.187 (proton donor - pKa = 7.5) and GIU399 (nucleophile - pKa = 4.5) are directly involved in the catalysis. Beside this, Arg97 and Tyr331 participate indirectly in the catalysis, modulating the nucleophile pKa

Indiana University-Purdue University Indianapolis (IUPUI) / Type 2 diabetes mellitus is a chronic disorder characterized by hyperglycemia, insulin resistance, and insufficient insulin secretion from the pancreatic β cells. To maintain adequate levels of insulin secretion, β cells rely on highly coordinated control of luminal ER Ca2+. Stromal Interaction Molecule 1 (STIM1) is an ER Ca2+ sensor that serves to replenish ER Ca2+ stores in response to depletion by gating plasmalemmal Orai1 channels in a process known as store-operated calcium entry (SOCE). We developed a method for the direct measurement of SOCE in pancreatic β cells and found that deletion of STIM1 in INS-1 cells (STIM1KO) is sufficient to block Ca2+ influx in response to store-depletion. To determine the physiological importance of β cell STIM1, we created mice with pancreatic β cell specific deletion of STIM1 (STIM1Δβ) and placed them on a high fat diet (HFD) with 60% of kilocalories derived from fat. After 8 weeks of HFD, female, but not male, STIM1Δβ mice exhibited increased body weight and fat mass as well as significant glucose intolerance and impaired insulin secretion without observable differences in insulin tolerance. Immunohistochemical analysis revealed a reduction of β cell mass and an increase of α cell mass; ELISA of islet lysates revealed a similar significant reduction in insulin content and increased glucagon content. RNA-sequencing performed on STIM1Δβ islets revealed differentially expressed genes for functions related to apoptosis, lipid metabolism, and epithelial cell differentiation, as well as loss of β cell identity. Proteomics analysis of STIM1KO cells phenocopied the metabolic findings, revealing significantly increased glucagon expression. Analysis of islet RNA-sequencing results showed modulation of pathways related to 17-β estradiol (E2) signaling, with notable downregulation of G-protein coupled estrogen receptor 1 (GPER1) expression. Consistently, treatment of female wild-type islets with pharmacological SOCE inhibitors led to reduced expression GPER1, while STIM1KO cells showed lower mobilization of intracellular cAMP levels in response to GPER agonist treatment. Taken together, these findings identify a novel interaction between SOCE and E2 signaling in the female islet and suggest that loss of STIM1 and impairments in SOCE may contribute to diabetes pathophysiology through loss of β cell identity. / 2022-12-28

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β decay studies of nuclei at the limits of stability are essential in evaluating the physical aspects behind the structural changes, particle configurations and interactions in neutronor proton-rich systems. Isobarically purified beams were used at the Holifeld Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study the β decays of 75Cu and 77Cu. Two different experiments were performed. In the first study, only concernig the decay of 77Cu, the 25-MV tandem accelerated ions were time-tagged using a micro-channel plate detector, passed through a six-segment ion chamber, and implanted on the tape of a moving tape collector. The passage through an ion chamber insured the ion identification by energy loss in the six segments. The Low Energy Radioactive Ion Beam Spectroscopy Station consisting of a universal detector support with four Ge clover detectors, two â detectors and a moving tape collector, was used in the second experiment. Bypassing of the tandem accelerator gave a factor of 10 gain in beam intensity for both 75Cu and 77Cu. These experiments resulted in considerable information on the previously unknown level structure of 75Zn with some 120 γ-ray transitions placed in a level scheme containing 59 levels including two above the neutron separation energy. We have also identified the previously unknown 1/2− isomeric state at 127 keV. A total of 64 γ rays were placed in a level scheme for 77Zn containing 35 excited states including one state above the neutron separation energy, while two γ rays were observed for the βn branch to states in 76Zn. The growth and decay curves of some prominent γ rays indicate a single β-decaying state with a half-life of 480(9) ms. The decay pattern for 77Cu, with observed feeding of 8(3)% to the 7/2+ 77Zng and 6(3)% to the 1/2− 77Znm, in contrast to the large feeding observed for decay of πp3/2 73Cug to 1/2− 73Zng, strongly suggests a πf5/2 ground state for the studied 77Cu activity. Results will be presented and the prospects for future possible studies will also be discussed.