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Search Results: 1 - 10 of 182879 matches for " Fernando F Costa "
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Characterization of Angiotensin-Converting Enzyme before and after Cryopreservation of Gir Semen  [PDF]
Fernando H. G. Furtado, Fábio J. C. Faria, Elisvania F. Santos, Ricardo G. Almeida, Deiler S. Costa
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.105049
Abstract: The aim of this study was to characterize the angiotensin-converting enzyme (ACE) in Gir semen before and after cryopreservation. The ejaculate of five sexually mature bulls was used. After collection, one 1-mL aliquot of fresh semen was analyzed immediately, and the rest of the semen was cryopreserved in liquid nitrogen for subsequent analysis. Freshly collected semen and thawed cryopreserved semen were centrifuged twice with Tyrode’s albumin lactate pyruvate medium (TALP) to remove plasma and extender, respectively. Samples were then subjected to western blotting, immunocytochemistry, and enzymatic activity techniques. At least one 100 kDa band was observed in every bull analyzed using western blotting with an anti-ACE monoclonal antibody, and band intensity decreased by 70% (p < 0.05) after cryopreservation. Immunocytochemistry showed periacrosomal ACE localization, and the area stained by the fluorescent antibody significantly decreased (p < 0.05) after cryopreservation. Enzyme activity was evaluated using FAPGG substrate hydrolysis, which was significantly lower (p < 0.05) in cryopreserved semen than in fresh semen. Therefore, the process of cryopreservation decreases ACE band intensity and enzyme activity in Gir bull semen, and reduces the stained area in immunocytochemistry.
Characterization of Testicular Angiotensin-Converting Enzyme before and after Semen Cryopreservation and in the Acrosome Reaction of Spermatozoids of Nelore Bulls  [PDF]
Ricardo G. Almeida, Fabio J. C. Faria, Fernando H. G. Furtado, Elisvania F. Santos, Deiler S. Costa
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.104041
Abstract: The aim of this study was to characterize the testicular isoform of angio-tensin-converting enzyme (tACE) before and after semen cryopreservation, and in the acrosome reaction of sperm from Nelore bulls in vitro. Ejaculates of 10 sexually mature Nelore bulls were used. After semen was collected, 1.0 mL of the ejaculate was used for the analysis and the rest was subjected to cryopreservation. Fresh semen before freezing, and frozen/thawed semen were centrifuged twice and the pellet was resuspended intyrode’s albumin lactate pyruvate (TALP). Thereafter, 100 μL aliquots containing 100 × 106 spermatozoa were prepared. Aliquots of samples were used for western blot analysis, subjected to capacitation, and thereafter, acrosome reaction assays were performed in vitro. With the help of an anti-ACE monoclonal antibody, a 100 kDa protein band was identified in the spermatozoa of Nelore bulls. Cryopreservation reduced the intensity of the protein bands obtained by western blot assay to less than half of that observed prior to freezing (P < 0.05). Inhibition of ACE by captopril (10 μM), decreased the percentage of capacitated spermatozoa with a positive acrosome reaction (P < 0.05), indicating the involvement of ACE in these processes. It is concluded that tACE can be found in the spermatozoa of Nelore bulls, and cryopreservation process decreases the intensity of bands of this enzyme; and that the inactivation of tACE reduces the capacity of spermatozoa to undergo the acrosome reaction.
Genética das doen?as hematológicas: as hemoglobinopatias hereditárias
Sonati, Maria de Fátima;Costa, Fernando Ferreira;
Jornal de Pediatria , 2008, DOI: 10.1590/S0021-75572008000500007
Abstract: objective: to summarize recently published data on the pathophysiology, diagnosis and treatment of sickle cell diseases and β-thalassemias, the most relevant hereditary hemoglobinopathies in the global population. sources: searches were run on the medline and scielo databases, limited to the period from 2003 to may 2008, using the terms hereditary hemoglobinopathies, sickle cell diseases and β-thalassemia. two books and two chapters were also included. summary of the findings: more than 2,000 articles were identified; those providing the most important information and broadest views were selected. conclusions: morbidity and mortality rates from sickle cell diseases and β-thalassemia are still very high and represent an important challenge. increased understanding of pathophysiological aspects has lead to significant improvements in treatment and prevention of these diseases.
Accounting choices in Brazil: identifying the characteristics of publicly traded companies that opted to maintain versus derecognise deferred assets
Lorencini, Fernando Drago;Costa, Fábio Moraes da;
Revista Contabilidade & Finan?as , 2012, DOI: 10.1590/S1519-70772012000100004
Abstract: the issuance of brazilian law 11.638/2007 is a critical step in the convergence of the brazilian generally accepted accounting principles (gaaps) towards international financial reporting standards. after the law was implemented and later modified by provisional executive order 449/2008 (converted into law 11.941/2009), certain accounting choices were allowed during the transition period. the brazilian gaaps allowed for restructuring costs and costs related to opening a new facility to be recognised as assets. as a transitional provision, companies were allowed to choose between maintaining or eliminating these values. in this paper, we attempted to identify which company characteristics were associated with this accounting choice. the final sample consisted of brazilian companies listed on the bm & fbovespa, and a logistic regression identified two characteristics. participation in one of the three different corporate governance levels of the bm & fbovespa was associated with the choice to derecognise the deferred assets, while companies decided to maintain the deferred asset if it was relatively large. the empirical evidence reported here contributes to the literature by explaining the manner in which a set of firm characteristics is related to a firm's accounting choices.
Economic Design of X Control Charts for Monitoring a First Order Autoregressive Process
Antonio F. B. Costa,Fernando Antonio Elias Claro
Brazilian Journal of Operations & Production Management , 2010,
Abstract: In this paper we deal with the economic design of an X control chart used to monitor a quality characteristic whose observations fit to a first order autoregressive model. The Duncan cost model is used to select the control chart parameters, namely the sample size (n), the sampling interval (h) and the control limit coefficient (k), that lead to the optimal monitoring cost. We found that the autocorrelation has an adverse effect on the chart’s power, on the false alarm risk and on the cost. It also increases n and h and decreases k. To counteract this undesired effect we considered setting up the subgroups using non-sequential observations. It is shown that this sampling strategy significantly reduces the monitoring cost.
Resistência de genótipos de algodoeiro a Anthonomus grandis Boh., Frankliniella sp. e Aphis gossypii Glover
Morales, Lauro;Cena, Pedro;Mendes Neto, Fernando P.;Costa, Servilio F.;Oliveira, Fernando T. de;
Anais da Sociedade Entomológica do Brasil , 1997, DOI: 10.1590/S0301-80591997000100013
Abstract: resistance to boll weevil anthonomus grandis, frankliniella sp. and aphis gossypii on five genotypes of cotton (gossypium hirsutum) was evaluated. four evaluations for boll weevil were conducted observing punctured buds. resistance to thrips and greenbug was evaluated 32 days after emergence, observing dead or damaged plants. first evaluation showed 4.6 % attacked buds in sicot 3 and 48.1 % in iac-20; 130 days after emergence, buds of all genotypes were equally damaged. oklahoma red showed only 3.0 % of dead or damaged plants due to thrips and greenbug attack, while iac-20 presented 21.0 % of damaged plants.
Diagnosis of hepatitis C virus in Brazilian blood donors using a reverse transcriptase nested polymerase chain reaction: comparison with enzyme immunoassay and recombinant protein immunoblot assay
GON?ALES, Neiva S. L.;COSTA, Fernando F.;VASSALLO, José;GON?ALES JR., Fernando L.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2000, DOI: 10.1590/S0036-46652000000500005
Abstract: screening blood donations for anti-hcv antibodies and alanine aminotransferase (alt) serum levels generally prevents the transmission of hepatitis c virus (hcv) by transfusion. the aim of the present study was to evaluate the efficiency of the enzyme immunoassay (eia) screening policy in identifying potentially infectious blood donors capable to transmit hepatitis c through blood transfusion. we have used a reverse transcriptase (rt)-nested polymerase chain reaction (pcr) to investigate the presence of hcv-rna in blood donors. the prevalence of hcv-rna positive individuals was compared with the recombinant immunoblot assay (riba-2) results in order to assess the usefulness of both tests as confirmatory assays. both tests results were also compared with the eia-2 od/c ratio (optical densities of the samples divided by the cut off value). alt results were expressed as the alt quotient (qalt), calculated dividing the alt value of the samples by the maximum normal value (53ui/l) for the method. donors (n=178) were divided into five groups according to their eia anti-hcv status and qalt: group a (eia33, alt<1), group b (eia33, alt>1), group c (1£eia<3, alt<1), group d (1£eia<3, alt>1) and group e (eia£0.7). hcv sequences were detected by rt-nested pcr, using primers for the most conserved region of viral genome. riba-2 was applied to the same samples. in group a (n=6), all samples were positive by rt-nested pcr and riba-2. among 124 samples in group b, 120 (96.8%) were riba-2 positive and 4 (3.2%) were riba-2 indeterminate but were seropositive for antigen c22.3. in group b, 109 (87.9%) of the riba-2 positive samples were also rt-nested pcr positive, as well as were all riba-2 indeterminate samples. in group c, all samples (n=9) were rt-nested pcr negative: 4 (44.4%) were also riba-2 negative, 4 (44.4%) were riba-2 positive and 1 (11.1%) was riba-2 indeterminate. hcv-rna was detected by rt-nested pcr in 3 (37.5%) out of 8 samples in group d. only one of them was also rib
Diagnosis of hepatitis C virus in Brazilian blood donors using a reverse transcriptase nested polymerase chain reaction: comparison with enzyme immunoassay and recombinant protein immunoblot assay
GON?ALES Neiva S. L.,COSTA Fernando F.,VASSALLO José,GON?ALES JR. Fernando L.
Revista do Instituto de Medicina Tropical de S?o Paulo , 2000,
Abstract: Screening blood donations for anti-HCV antibodies and alanine aminotransferase (ALT) serum levels generally prevents the transmission of hepatitis C virus (HCV) by transfusion. The aim of the present study was to evaluate the efficiency of the enzyme immunoassay (EIA) screening policy in identifying potentially infectious blood donors capable to transmit hepatitis C through blood transfusion. We have used a reverse transcriptase (RT)-nested polymerase chain reaction (PCR) to investigate the presence of HCV-RNA in blood donors. The prevalence of HCV-RNA positive individuals was compared with the recombinant immunoblot assay (RIBA-2) results in order to assess the usefulness of both tests as confirmatory assays. Both tests results were also compared with the EIA-2 OD/C ratio (optical densities of the samples divided by the cut off value). ALT results were expressed as the ALT quotient (qALT), calculated dividing the ALT value of the samples by the maximum normal value (53UI/l) for the method. Donors (n=178) were divided into five groups according to their EIA anti-HCV status and qALT: group A (EIA > or = 3, ALT<1), group B (EIA > or = 3, ALT>1), group C (1<=EIA<3, ALT<1), group D (1<=EIA<3, ALT>1) and group E (EIA<=0.7). HCV sequences were detected by RT-nested PCR, using primers for the most conserved region of viral genome. RIBA-2 was applied to the same samples. In group A (n=6), all samples were positive by RT-nested PCR and RIBA-2. Among 124 samples in group B, 120 (96.8%) were RIBA-2 positive and 4 (3.2%) were RIBA-2 indeterminate but were seropositive for antigen c22.3. In group B, 109 (87.9%) of the RIBA-2 positive samples were also RT-nested PCR positive, as well as were all RIBA-2 indeterminate samples. In group C, all samples (n=9) were RT-nested PCR negative: 4 (44.4%) were also RIBA-2 negative, 4 (44.4%) were RIBA-2 positive and 1 (11.1%) was RIBA-2 indeterminate. HCV-RNA was detected by RT-nested PCR in 3 (37.5%) out of 8 samples in group D. Only one of them was also RIBA-2 positive, all the others were RIBA-2 indeterminate. All of the group E samples (controls) were RT- nested PCR and RIBA-2 negative. Our study suggests a strong relation between anti-HCV EIA-2 ratio > or = 3 and detectable HCV-RNA by RT-nested PCR. We have also noted that blood donors with RIBA-2 indeterminate presented a high degree of detectable HCV-RNA using RT-nested PCR (75%), especially when the c22.3 band was detected.
Aedeagus morphology as a discriminant marker in two closely related Cactophilic species of Drosophila (Diptera; Drosophilidae) in South America
Franco Fernando F.,Prado Pedro R.R.,Sene Fábio M.,Costa Luciano F.
Anais da Academia Brasileira de Ciências , 2006,
Abstract: Drosophila serido and D. antonietae are sibling species belonging to the Drosophila buzzatii cluster. Morphologically, they can only be discriminated by quantitative traits. In this paper we analyze the length and equalized average curvature of four regions of the aedeagus of D. antonietae and D. serido. Specimens of D. serido and D. antonietae were classified correctly 96.74% of the time. Based only on the variable that most contributed to the discrimination of the groups (equalized average curvature of the arch IV of the aedeagus), we observed significant intraspecific morphological divergence in D. serido in relation to the D. antonietae, in agreement with other markers. The high morphological divergence in equalized average curvature of the arch IV of the aedeagus shows that this region evolved faster than others, since the divergence of the two species. The importance of the present study to the understanding of the genetic basis that controls the formation of the aedeagus, in the species of the Drosophila buzzatii cluster, is discussed.
Determinantes macroecon?micos do spread bancário no Brasil: teoria e evidência recente
Oreiro, José Luís da Costa;Paula, Luiz Fernando de;Silva, Guilherme Jonas Costa da;Ono, Fábio Hideki;
Economia Aplicada , 2006, DOI: 10.1590/S1413-80502006000400007
Abstract: due to the successful implementation of the price stabilization programme (real plan), the greater international financial integration and, more recently, the adoption of a floating exchange rate regime, it was expected in brazil a sharp decline of the banking interest spreads converging to the international levels. however, such a reduction did not materialized. indeed, one of the main factors to why the ratio total credit over gdp is still low in brazil is the very high loan interest rates. the paper aims to at analyze the macroeconomic determinants of banking spread in brazil. for this purpose, we make use of a multiple regression analysis with the objective to find what macroeconomic variables are determining, directly or indirectly, the banking spread in the period 1994-2003. the results show that the high volatility of the short-term interest rate (selic) and its level are the main macroeconomic determinants of the banking spread in brazil.
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