Micro scale modeling grain boundary damage under creep conditions

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Efeitos de reguladores de crescimento na frutificação do morangueiro cultivar «Monte alegre»

Estudou-se em Piracicaba (SP), os efeitos da aplicação de reguladores de crescimento em morangueiro cultivar "Monte Alegre". Efetuou-se a pulverização de SADH 5000 ppm, CCC 2000 ppm e GA 550 ppm; sendo que realizaram-se ainda três aplicações de IAA 10 ppm e GA 10 ppm, além do tratamento controle. Verificou-se que apesar do GA 550 ppm, SADH e GCC reduzirem a produção, três aplicações de IAA 10 ppm ou GA 10 ppm promoveram uma tendência de aumento na produtividade do morangueiro. Notou-se que os reguladores de crescimento não alteraram o número de frutos; sendo que o tratamento com GA 550 ppm promoveu redução no peso médio dos frutos da cultivar "Monte Alegre". Aplicação de GA 550 ppm causou aumento no número de frutos na terceira e quarta semanas de colheita, reduzindo progressivamente nas semanas subseqüentes. Observou-se que aplicações de GA 10 ppm ou IAA 10 ppm promoveram aumento no comprimento dos pedúnculos, facilitando a colheita'.

Efeito de reguladores de crescimento sobre os teores de ácido ascórbico e carboidratos solúveis de morango (Fragaria hybridus)

Foram feitas aplicações dos seguintes reguladores de crescimento em morango (Fragarm hybridus): SADH a 5000 ppm, CCC a 2000 ppm, ATA a 10 ppm (3 aplicações), ácido giberélico a 10 ppm (3 aplicações) e 550 ppm. Análises de peso seco, ácido ascórbico e carboidratos solúveis dos frutos foram efetuadas a fim de se estudar o efeito desses reguladores de crescimento. Não foram detectadas diferenças significativas entre os diversas tratamentos e o controle. O peso seco variou de 7,62 a 9,53%. O conteúdo de ácido ascórbico variou de 35,88 a 71,81 mg/100 g de peso fresco. Os teores médios de carboidratos solúveis, expresso em g/100 g peso fresco, foram: totais (5,58), sacarose (1,01), glucose (1,63) e frutose (1,54).

Deformationsanalyse von Betonschalenelementen

Die vorliegende Masterarbeit beschäftigte sich mit der photogrammetrischen und der laserbasierten Objekterfassung von Betonschalenelementen. Das Ziel hierbei war, zu überprüfen, ob eine Erfassung von Deformationen in Bezug auf die jeweilig angewendeten Verfahren der Stereophotogrammetrie und des terrestrischen Laserscanning möglich sind. Hierzu wurden Daten, basierend auf zwei unterschiedlichen Versuchsanordnungen (ein statischer und ein dynamischer Belastungsprozess) aufgenommen, weiterverarbeitet und analysiert. Die Analyse und Vergleich der aufgenommenen Daten zeigt, dass die grundlegende Art und Weise der Deformation mit beiden Aufnahmeverfahren erfasst werden konnte, sich jedoch erhebliche Unterschiede in der Datenqualität darstellten.

Liberação de magnésio estrutural da vermiculita por dissolução ácida

Estudou-se a liberação de magnésio estrutural da vermiculita procedente de Paulistânia, Estado de Piauí. O material foi triturado e peneirado para obter duas frações de 0,50 a l,15mm e de < 0,10mm. Cada fração de vermiculita foi dividida em três partes. As duas partes foram aquecidas num forno mufla às temperaturas de 550 e 950°C, respectivamente, durante uma hora. As vermiculitas, assim preparadas, foram tratadas com ácido sulfúrico conc. e ácido fosfórico conc. para avaliar a eficiência dos ácidos na liberação de magnésio. Em seguida, estudou-se a liberação de magnésio em função da quantidade de ácido sulfúrico e a necessidade de carbonato de cálcio para neutralizar a acidez residual do produto. Não houve diferença entre o ácido sulfúrico e o ácido fosfórico quanto a extração de magnésio da vermiculita. A granulometria e o aquecimento não influiram na liberação de magnésio pelos ácidos. A adição de ácido sulfúrico à vermiculita em quantidades iguais liberou mais que 80% de magnésio. A quantidade de carbonato de cálcio necessária para neutralizar a acidez residual do produto foi aproximadamente a metade do peso da vermiculita.

Price competition under cost uncertainty: A laboratory analysis

We study the relation between the number of firms and price-cost margins under price competition with uncertainty about competitors' costs. We present results of an experiment in which two, three and four identical firms repeatedly interact in this environment. In line with the theoretical prediction, market prices decrease with the number of firms, but on average stay above marginal costs. Pricing is less aggressive in duopolies than in triopolies and tetrapolies. However, independently from the number of firms, pricing is more aggressive than in the theoretical equilibrium. Both the absolute and the relative surpluses increase with the number of firms. Total surplus is close to the equilibrium level, since enhanced consumer surplus through lower prices is counteracted by occasional displacements of the most efficient firm in production.

Estudo da potencialidade de populações de Biomphalaria straminea do Estado de Minas Gerais, como hospedeiras do Schistosoma mansoni

Caramujos de Biomphalaria straminea, descendentes de exemplares coletados em nove municípios do Estado de Minas Gerais, foram infectados experimentalmente com três cepas de Schistosoma mansoni: "LE", procedente de Belo Horizonte (MG); "SJ", procedente de São José dos Campos (SP) e "AL" procedente do Nordeste (AL). As taxas de infeção variaram de 0,0 a 24,0% com a cepa "LE"; de 0,0 a 16% com a cepa "SJ" e de 2,0 a 9,0% com a cepa "AL". Os índices de infecção experimental obtidos foram semelhantes aos registrados por outros autores, para B. straminea dessa região. Comparou-se o número de cercárias de cepa "LE", eliminadas por oito exemplares de B. straminea de Baldim e oito Biomphalaria glabrata do controle, após 30 minutos de exposição à luz. O número de cercárias eliminadas por B. straminea foi de 4.550, aproximadamente cinco vezes menor que o de B. glabrata, 22.679. Discute-se a potencialidade desses moluscos como hospedeiros do S. mansoni nessa região.

Effects of stress on economic decision-making: Evidence from laboratory experiments

The ways in which preferences respond to the varying stress of economic environments is a key question for behavioral economics and public policy. We conducted a laboratory experiment to investigate the effects of stress on financial decision making among individuals aged 50 and older. Using the cold pressor task as a physiological stressor, and a series of intelligence tests as cognitive stressors, we find that stress increases subjective discounting rates, has no effect on the degree of risk-aversion, and substantially lowers the effort individuals make to learn about financial decisions.

Silicone moulding for pressure sore debridement.

The radicality of wound debridement is an important feature of the surgical treatment of pressure sores. Several methods such as injection of methylene blue or hydrogen peroxide have been proposed to facilitate and optimise the surgical debridement technique, but none of them proved to be sufficient. We present an innovative modification of the pseudo-tumour technique consisting in the injection of fluid silicone. Vulcanisation of the silicone leads to pressure-sore moulding, permitting a more radical and sterile excision. In a series of 10 paraplegic patients presenting with ischial pressure sores, silicone moulding was used to facilitate debridement. Radical en bloc debridement was achieved in all patients. After a minimal follow-up of 2 years, no complications and recurrences occurred. A three-dimensional (3D) analysis of the silicone prints objectified the pyramidal shape of ischial pressure sores. Our study showed that complete resection without capsular lesion can be easily achieved. Further, it allows the surgeon to analyse the shape and size of the resected defect, which might be helpful to select the appropriate defect coverage technique.

Bacillus subtilis contains two small c-type cytochromes with homologous heme domains but different types of membrane anchors.

We demonstrate that the cccB gene, identified in the Bacillus subtilis genome sequence project, is the structural gene for a 10-kDa membrane-bound cytochrome c(551) lipoprotein described for the first time in B. subtilis. Apparently, CccB corresponds to cytochrome c(551) of the thermophilic bacterium Bacillus PS3. The heme domain of B. subtilis cytochrome c(551) is very similar to that of cytochrome c(550), a protein encoded by the cccA gene and anchored to the membrane by a single transmembrane polypeptide segment. Thus, B. subtilis contains two small, very similar, c-type cytochromes with different types of membrane anchors. The cccB gene is cotranscribed with the yvjA gene, and transcription is repressed by glucose. Mutants deleted for cccB or yvjA-cccB show no apparent growth, sporulation, or germination defect. YvjA is not required for the synthesis of cytochrome c(551), and its function remains unknown.

Population pharmacokinetic modelling and evaluation of different dosage regimens for darunavir and ritonavir in HIV-infected individuals.

OBJECTIVES: Darunavir is a protease inhibitor that is administered with low-dose ritonavir to enhance its bioavailability. It is prescribed at standard dosage regimens of 600/100 mg twice daily in treatment-experienced patients and 800/100 mg once daily in naive patients. A population pharmacokinetic approach was used to characterize the pharmacokinetics of both drugs and their interaction in a cohort of unselected patients and to compare darunavir exposure expected under alternative dosage regimens. METHODS: The study population included 105 HIV-infected individuals who provided darunavir and ritonavir plasma concentrations. Firstly, a population pharmacokinetic analysis for darunavir and ritonavir was conducted, with inclusion of patients' demographic, clinical and genetic characteristics as potential covariates (NONMEM(®)). Then, the interaction between darunavir and ritonavir was studied while incorporating levels of both drugs into different inhibitory models. Finally, model-based simulations were performed to compare trough concentrations (Cmin) between the recommended dosage regimen and alternative combinations of darunavir and ritonavir. RESULTS: A one-compartment model with first-order absorption adequately characterized darunavir and ritonavir pharmacokinetics. The between-subject variability in both compounds was important [coefficient of variation (CV%) 34% and 47% for darunavir and ritonavir clearance, respectively]. Lopinavir and ritonavir exposure (AUC) affected darunavir clearance, while body weight and darunavir AUC influenced ritonavir elimination. None of the tested genetic variants showed any influence on darunavir or ritonavir pharmacokinetics. The simulations predicted darunavir Cmin much higher than the IC50 thresholds for wild-type and protease inhibitor-resistant HIV-1 strains (55 and 550 ng/mL, respectively) under standard dosing in >98% of experienced and naive patients. Alternative regimens of darunavir/ritonavir 1200/100 or 1200/200 mg once daily also had predicted adequate Cmin (>550 ng/mL) in 84% and 93% of patients, respectively. Reduction of darunavir/ritonavir dosage to 600/50 mg twice daily led to a 23% reduction in average Cmin, still with only 3.8% of patients having concentrations below the IC50 for resistant strains. CONCLUSIONS: The important variability in darunavir and ritonavir pharmacokinetics is poorly explained by clinical covariates and genetic influences. In experienced patients, treatment simplification strategies guided by drug level measurements and adherence monitoring could be proposed.

How central and connected am I in my family? Bridging and bonding social capital in family configurations of young adults with psychiatric disorders

AIMS: This article explores the structures of relational resources that individuals with psychiatric disorders get from their family configurations using the concept of social capital. METHODS: The research is based on a sample of 54 individuals with psychiatric disorders and behavioural problems, and a comparison sample of 54 individuals without a clinical record matched to the clinical respondents for age and sex. Standard measures of social capital from social network methods are applied on family configurations of individuals from both samples. Differences are tested by variance analysis. RESULTS: Structures of family resources available to individuals with psychiatric disorders are distinct. Individuals with psychiatric disorders perceive themselves as less central in their family configurations and less connected to their family members. Their significant family members are perceived as less connected with each other. As a whole, their family configurations are smaller and do not include spouses or partners. Therefore bridging and bonding social capitals are not readily available for them. CONCLUSION: As family configurations of individuals with psychiatric disorders provide fewer relational resources than other families, they are not able to deal with social integration of individuals with psychiatric disorders on their own.

Genome-wide association study of recurrent major depressive disorder in two European case-control cohorts.

Major depressive disorder (MDD) is a highly prevalent disorder with substantial heritability. Heritability has been shown to be substantial and higher in the variant of MDD characterized by recurrent episodes of depression. Genetic studies have thus far failed to identify clear and consistent evidence of genetic risk factors for MDD. We conducted a genome-wide association study (GWAS) in two independent datasets. The first GWAS was performed on 1022 recurrent MDD patients and 1000 controls genotyped on the Illumina 550 platform. The second was conducted on 492 recurrent MDD patients and 1052 controls selected from a population-based collection, genotyped on the Affymetrix 5.0 platform. Neither GWAS identified any SNP that achieved GWAS significance. We obtained imputed genotypes at the Illumina loci for the individuals genotyped on the Affymetrix platform, and performed a meta-analysis of the two GWASs for this common set of approximately half a million SNPs. The meta-analysis did not yield genome-wide significant results either. The results from our study suggest that SNPs with substantial odds ratio are unlikely to exist for MDD, at least in our datasets and among the relatively common SNPs genotyped or tagged by the half-million-loci arrays. Meta-analysis of larger datasets is warranted to identify SNPs with smaller effects or with rarer allele frequencies that contribute to the risk of MDD.

Chemical and carbon isotopic evolution of hydrocarbons during prograde metamorphism from 100°C to 550°C: Case study in the Liassic black shale formation of Central Swiss Alps

Hydrocarbon distributions and stable isotope ratios of carbonates (delta(13)C(car), delta(18)O(car)), kerogen (delta(13)C(ker)), extractable organic matter (delta(13)C(EOM)) and individual hydrocarbons of Liassic black shale samples from a prograde metamorphic sequence in the Swiss Alps were used to identify the major organic reactions with increasing metamorphic grade. The studied samples range from the diagenetic zone (< 100 degrees C) to amphibolite facies (similar to 550 degrees C). The samples within the diagenetic zones (< 100 and 150 degrees C) are characterized by the dominance of C-< 20 n-alkanes, suggesting an origin related with marine and/or bacterial inputs. The metamorphic samples (200 to 550 degrees C) have distributions significantly dominated by C-12 and C-13 n-alkanes, C-14, C-16 and C-18 n-alkylcyclopentanes and to a lesser extend C-15, C-17 and C-21 n-alkylcyclohexanes. The progressive C-13-enrichment (up to 3.9 parts per thousand) with metamorphism of the C-> 17 n-alkanes suggests the occurrence of cracking reactions of high molecular weight compounds. The isotopically heavier (up to 5.6 parts per thousand) C-< 17 n-alkanes in metamorphic samples are likely originated by thermal degradation of long-chain homologous with preferential release of isotopically light C-1 and C-2 radicals. The dominance of specific even C-number n-alkylcyclopentanes suggests an origin related to direct cyclization mechanism (without decarboxylation step) of algal or bacterial fatty acids occurring in reducing aqueous metamorphic fluid conditions. The regular increase of the concentrations of n-alkylcycloalkanes vs. C-> 13 n-alkanes with metamorphism suggests progressive thermal release of kerogen-linked fatty acid precursors and degradation of n-alkanes. Changes of the steroid and terpenoid distributions are clearly related to increasing metamorphic temperatures. The absence of 18 alpha(H)-22,29,30-trisnorneohopane (Ts), the occurrence of 17 beta(H)-trisnorhopane, 17 beta(H), 21 alpha(H)-hopanes in the C-29 to C-31 range and 5 alpha(H),14 alpha(H),17 alpha(H)-20R C-27, C-29 steranes in the low diagenetic samples (< 100 degrees C) are characteristic of immature bitumens. The higher thermal stress within the upper diagenetic zone (150 degrees C) is marked by the presence of Ts, the disappearance of 17 beta(H)-trisnorhopane and thermodynamic equilibrium of the 22S/(22S + 22R) homohopane ratios. The increase of the alpha alpha alpha-sterane 20S/(20S + 20R) and 20R beta beta/(beta beta + alpha alpha) ratios (from 0.0 to 0.55 and from 0.0 to 0.40, respectively) in the upper diagenetic zone indicates the occurrence of isomerization reactions already at < 150 degrees C. However, the isomerization at C-20 (R -> S) reaches thermodynamic equilibrium values already at the upper diagenesis (similar to 150 degrees C) whereas the epimerisation at C-14 and C-17 (alpha alpha ->beta beta) arrives to constant values in the lower anchizone (similar to 200 degrees C). The ratios Ts vs. 17 alpha(H)-22,29,30-trisnorneohopane [(Ts/(Ts + Tm)] and 18 alpha(H)-30-norneohopane (C29Ts) vs. 17 alpha(H),21 beta(H)-30-norhopane [C29Ts/(C29Ts + C-29)] increase until the medium anchizone (200 to 250 degrees C) from 0.0 to 0.96 and from 0.0 to 0.44, respectively. An opposite trend owards lower values is observed in the higher metamorphic samples. The occurrence of specific hydrocarbons (e.g., n-alkylcyclopentanes, cadalene, hydrogenated aromatic compounds) in metamorphic samples points to kerogen degradation reactions most probably occurring in the presence of water and under reducing conditions. The changes of hydrocarbon distributions and carbon isotopic compositions of n-alkanes related to metamorphism suggest that the organic geochemistry may help to evaluate the lowest grades of prograde metamorphism. Copyright (c) 2005 Elsevier Ltd.