Global function approach in structural analysis: Basic approach, numerical results

The structural response to a given environment is described by the differential equations of motion of deformable bodies. Analytic solutions of such problems for a reasonably large class of structural configurations are not within the realm of the possible. Consequently, the mathematical problem is recast into a numerical problem for solution on the computer. New technology in the space and energy fields led to a growing demand for accurate analysis which at times cannot be met due to the limits set by available budgets for computer time. In response to this need for more efficient numerical analysis, the possibilities of reducing the number of freedoms in the system through a revival of the global function approach were explored

Teores de ácidos graxos voláteis e acido láctico das silagens de girassol (Helianthus annuus L.) tratadas com aditivos em seis diferentes épocas de abertura.

O objetivo deste trabalho foi avaliar os teores de acidos organicos das silagens de tres genotipos de girassol (M734, Rumbosol 91 e variedade V2000) enriquecida com os seguintes aditivos 0,5% de ureia (U); 0,5% de carbonato de calcio (CC); 0,5% de ureia mais 0,5 de carbonato de calcio (U*CC); inoculante bacteriano (IB) comercial. Também foi ensilado material original sem aditivos que serviu como silagem testemunha (T), sendo utilizados 180 silos de laboratorio de PVC, os quais foram abertos nos dias: um, tres, cinco, sete, 28 e 56 dias. Foram determinados os teores dos acidos lactico, acetico, propionico e butirico por cromatografia gasosas. As silagens com aditivos tiveram a concentracao de acido lactico diminuida significativamente no intervalo para o dia 56 e, com excecao do M734, foram menores que a silagem T, chegando a não ser detectado acido lactico nas silagens do Rumbosol 91 tratados com U, CC, e UCC. Somente as silagens com U*CC foram consistentes em alterar os teores de acido butirico no dia 56 para todos os genotipos (3,62%; 2,73% e 1,69% para o V2000, Rumbosol 91 e M734, respectivamente). O uso do CC elevou a concentracao de acido propionico para 1,39% no ultimo dia de abertura no Rumbosol 91. Sua associacao com ureia resultou em aumento do teor de acido propionico nas silagens do V2000 (0,84%) e do Rumbosol 91 (1,32%). Os aditivos utilizados neste experimentos nao promoveram melhores quanto aos teores dos acidos organicos analisados nas silagens de girassol

Teores de matéria seca, proteína bruta, carboidratos solúveis e extrato etéreo das silagens de tres genótipos de girassol (Helianthus annuus L.) com aditivos em sete diferentes épocas de abertura.

O objetivo deste experimento foi avaliar os teores de materia seca (MS), proteína bruta (PB), carboidratos soluveis (CHO) e extrato etereo (EE) das silagens de tres genotipos: M 734, Rumbosol 91 e a variedade V2000, enriquecidas com ureia (U), carbonato de calcio (CC), ureia mais carbonato de calcio (U*CC); e inoculante bacteriano (IB), sendo tambem ensilado material original sem aditivo que serviu como silagem testemunha (T). Foram utilizados silos de laboratorio de PVC, abertos com um, tres, cinco, sete, 14, 28 e 56 dias de ensilados. As silagens de genotipos M734 foram as que apresentaram os maiores teores de MS comparadas as silagens do Rumbosol 91 e este maior que o V2000. A adicao somente de U resultou em silagens com teores de PB superiores as silagens T e foram semelhantes entre si nos diferentes dias de abertura. Os teores de CHO soluveis variaram de 0,03% a 3,86%, sendo que as silagens T e com aditivos do genotipo M734 apresentaram no dia de abertura um teores significativamente superiores ao Rumbosol 91 e ao V2000. O IB nao promoveu uma rapida queda nos teores de CHO soluveis como esperado. os teores de EE foram estatisticamente superiores para os genotipos V2000 e M734 em relacao ao Rumbosol 91 e nao apresentaram diferenca com a utilizacao dos aditivos. Concluindo, as silagens de girassol avaliadas apresentaram baixos teores de MS e apenas o uso de ureia promoveu alteracoes aumentando o teor de proteina bruta das silagens dentro dos parametros avaliados

Teores de fibra em detergente neutro, fibra em ditergente ácido, lignina e digestibilidade in vitro da matéria seca das silagens de três genótipos de girassol (Helianthus annuus L.) com aditivos em sete diferentes épocas de abertura.

Foram ensilados tres genotipos de girassol (M 734, Rumbosol 91 e a variedade V2000), sendo a forragem fresca enriquecida com 0,5% de ureia (U); 0,5% de carbonato de calcio (CC); 0,5% de ureia mais 0,5% de carbonato de calcio (U+CC); inoculante bacteriano (IB) comercial. Tambem foi ensilado material original sem aditivo que serviu como silagem testemunha (T). Foram utilizados silos de laboratorio de PVC, abertos com um, tres, cinco, sete, 14, 28 e 56 dias de ensilados, sendo determinados fibra em detergente neutro (FDN), fibra em detergente acido (FDA), lignina e a digestibilidade in vitro da materia seca (DIVMS). As silagens do Rumbosol 91 apresentaram valores estatisticos superiores ao genotipo V2000 e M734 na maioria dos dias de abertura para o FDN, FDA e lignina, sendo que os aditivos não promoveram alteracoes nos constituintes da parede celular. As silagens T apresentaram no dia de abertura 56 valores de 51,0%, 49,1% e 48,9% de DIVMS para o genotipo M734, V2000 e Rumbosol 91, respectivamente, nao havendo diferença entre eles, o mesmo observado para os aditivos utilizados no decorrer do processo fermentativo. Pode-se concluir, que os aditivos utilizados neste experimento nao proporcionaram melhoras nas silagens de girassol quanto aos parametros avaliados

Valores de pH e teores de nitrogênio amoniacal das silagens de três genótipos de girassol (Helianthus annuus L.) com aditivos durante o processo fermentativo.

Silagens de tres genotipos de girassol: M 734, Rumbosol 91 e a variedade V2000, foram enriquecida com 0,5% de ureia (U); 0,5% de carbonato de calcio (CC); 0,5% de ureia mais 0,5% de carbonato de calcio (U+CC); inoculante bacteriano (IB), sendo também ensilado material original sem aditivo que serviu como silagem testemunha (T), visando avaliar os efeitos nos valores de pH e nitrogenio amoniacal (N-NH)(. Foram utilizados silos de laboratório de PVC, abertos nos dias um, tres, cinco, sete, 14, 28 e 56 de ensilados. A adicao de U as silagens acarretou em pH numericamente mais elevado em todas as silagens a partir do terceiro dia de abertura quando comparado a silagem T, porem as diferenças estatisticas observadas nao foram consistentes. Os maiores valores de pH foram verificados nas silagens de girassol tratadas com U+CC (78,8% N-NH3/NT), que estabilizou a producao de nitrogenio amoniacal no decimo quarto dia de abertura com 69,3% N.NH3/NT. A penas a adicao de ureia associada a carbonato de calcio apresentou a mesma resposta para os parametros avaliados nos tres genotipos. Contudo, deve-se ter cautela na recomendacao destes aditivos para silagem de girassol, pois estes altos valores encontrados podem estar relacionados a fermentacao indesejaveis no silo

A Combined Nucleic Acid and Protein Analysis in Friedreich Ataxia: Implications for Diagnosis, Pathogenesis and Clinical Trial Design

BACKGROUND: Friedreich's ataxia (FRDA) is the most common hereditary ataxia among caucasians. The molecular defect in FRDA is the trinucleotide GAA expansion in the first intron of the FXN gene, which encodes frataxin. No studies have yet reported frataxin protein and mRNA levels in a large cohort of FRDA patients, carriers and controls. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled 24 patients with classic FRDA phenotype (cFA), 6 late onset FRDA (LOFA), all homozygous for GAA expansion, 5 pFA cases who harbored the GAA expansion in compound heterozygosis with FXN point mutations (namely, p.I154F, c.482+3delA, p.R165P), 33 healthy expansion carriers, and 29 healthy controls. DNA was genotyped for GAA expansion, mRNA/FXN was quantified in real-time, and frataxin protein was measured using lateral-flow immunoassay in peripheral blood mononuclear cells (PBMCs). Mean residual levels of frataxin, compared to controls, were 35.8%, 65.6%, 33%, and 68.7% in cFA, LOFA, pFA and healthy carriers, respectively. Comparison of both cFA and pFA with controls resulted in 100% sensitivity and specificity, but there was overlap between LOFA, carriers and controls. Frataxin levels correlated inversely with GAA1 and GAA2 expansions, and directly with age at onset. Messenger RNA expression was reduced to 19.4% in cFA, 50.4% in LOFA, 52.7% in pFA, 53.0% in carriers, as compared to controls (p<0.0001). mRNA levels proved to be diagnostic when comparing cFA with controls resulting in 100% sensitivity and specificity. In cFA and LOFA patients mRNA levels correlated directly with protein levels and age at onset, and inversely with GAA1 and GAA2. CONCLUSION/SIGNIFICANCE: We report the first explorative study on combined frataxin and mRNA levels in PBMCs from a cohort of FRDA patients, carriers and healthy individuals. Lateral-flow immunoassay differentiated cFA and pFA patients from controls, whereas determination of mRNA in q-PCR was sensitive and specific only in cFA

Evolutionary conservation and in vitro reconstitution of microsporidian iron–sulfur cluster biosynthesis

This work was supported by Marie Curie Postdoctoral Fellowships to T.A.W., E. H. and S. L., a European Research Council Advanced Investigator Grant (ERC-2010-AdG-268701) to T.M.E., and a Wellcome Trust Programme Grant (number 045404) to T.M.E. and J.M.L. R.L. acknowledges generous financial support from Deutsche Forschungsgemeinschaft (SFB 593, SFB 987, GRK 1216, LI 415/5), LOEWE program of state Hessen, Max-Planck Gesellschaft, von Behring-Röntgen StiftungMicrosporidians are a diverse group of obligate intracellular parasites that have minimized their genome content and simplified their sub-cellular structures by reductive evolution. Functional studies are limited because we lack reliable genetic tools for their manipulation. Here, we demonstrate that the cristae-deficient mitochondrion (mitosome) of the microsporidian Trachipleistophora hominis is the functional site of iron-sulphur cluster (ISC) assembly, which we suggest is the essential task of this organelle. Cell fractionation, fluorescence imaging and fine-scale immunoelectron microscopy demonstrate that mitosomes contain a complete pathway for [2Fe-2S] cluster biosynthesis that we biochemically reconstituted using purified recombinant mitosomal ISC proteins. Reconstitution proceeded as rapidly and efficiently as observed for yeast or fungal mitochondrial ISC components. Core components of the T. hominis cytosolic iron-sulphur protein assembly (CIA) pathway were also identified including the essential Cfd1-Nbp35 scaffold complex that assembles a [4Fe-4S] cluster as shown by spectroscopic methods in vitro. Phylogenetic analyses reveal that both the ISC and CIA biosynthetic pathways are predominantly bacterial, but their cytosolic and nuclear target Fe/S proteins are mainly archaeal. This mixed evolutionary history of the Fe/S-related proteins and pathways, and their strong conservation among highly reduced parasites, provides additional compelling evidence for the ancient chimeric ancestry of eukaryotes.Publisher PDFPeer reviewe

T2 Values of Posterior Horns of Knee Menisci in Asymptomatic Subjects

[[abstract]]Purpose: The magnetic resonance (MR) T2 value of cartilage is a reliable indicator of tissue properties and therefore may be used as an objective diagnostic tool in early meniscal degeneration. The purpose of this study was to investigate age, gender, location, and zonal differences in MR T2 value of the posterior horns of knee menisci in asymptomatic subjects. Methods: Sixty asymptomatic volunteers (30 men and 30 women) were enrolled and divided into three different age groups: 20–34, 35–49 and 50–70 years. The inclusion criteria were BMI＜30 kg/cm2, normalized Western Ontario and McMaster Universities (WOMAC) pain score of zero, and no evidence of meniscal and ligamentous abnormalities on routine knee MR imaging. The T2 values were measured on images acquired with a T2-weighted fat-suppressed turbo spin-echo sequence at 3T. Results: The mean T2 values in both medial and lateral menisci for the 20–34, 35–49, and 50–70 age groups were 9.94 msec±0.94, 10.73 msec±1.55, and 12.36 msec±2.27, respectively, for women and 9.17 msec±0.74, 9.64 msec±0.67, and 10.95 msec±1.33, respectively, for men. The T2 values were significantly higher in the 50–70 age group than the 20–34 age group (P＜0.001) and in women than in men (P = 0.001, 0.004, and 0.049 for each respective age group). T2 values were significantly higher in medial menisci than in lateral menisci only in women age 50–70 (3.33 msec, P = 0.006) and in the white zone and red/white zone of the 50–70 and 35–49 age groups than that of the 20–34 age group (2.47, 1.02; 2.77, 1.16 msec, respectively, all P＜0.01). Conclusion: The MR T2 values of the posterior meniscal horns increase with increasing age in women and are higher in women than in men. The age-related rise of T2 values appears to be more severe in medial menisci than in lateral menisci. Differences exist in the white zone and red/white zone.[[incitationindex]]SCI[[booktype]]電子

The Presence of the Iron-Sulfur Motif Is Important for the Conformational Stability of the Antiviral Protein, Viperin

Viperin, an antiviral protein, has been shown to contain a CX3CX2C motif, which is conserved in the radical S-adenosyl-methionine (SAM) enzyme family. A triple mutant which replaces these three cysteines with alanines has been shown to have severe deficiency in antiviral activity. Since the crystal structure of Viperin is not available, we have used a combination of computational methods including multi-template homology modeling and molecular dynamics simulation to develop a low-resolution predicted structure. The results show that Viperin is an α -β protein containing iron-sulfur cluster at the center pocket. The calculations suggest that the removal of iron-sulfur cluster would lead to collapse of the protein tertiary structure. To verify these predictions, we have prepared, expressed and purified four mutant proteins. In three mutants individual cysteine residues were replaced by alanine residues while in the fourth all the cysteines were replaced by alanines. Conformational analyses using circular dichroism and steady state fluorescence spectroscopy indicate that the mutant proteins are partially unfolded, conformationally unstable and aggregation prone. The lack of conformational stability of the mutant proteins may have direct relevance to the absence of their antiviral activity