Expressão gênica e potencial de desenvolvimento in vitro dos complexos cúmulos-oócitos ovinos tratados com roscovitina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito do ácido linoleico e catalese sobre o desenvolvimento e criotolerãncia de embriões bovinos produzidos in vitro na ausência de soro e baixa tensão de oxigênio: Mônica Ferreira Accorsi. -

Pós-graduação em Ciência Animal - FMVA

Análise in vitro da proliferação celular e produção de mediadores inflamatórios por células da conjuntiva estimuladas por materiais utilizados na confecção de próteses oculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Meiotic arrest of sheep oocytes using roscovitine under different medium compositions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Back-to-back correlations in finite expanding systems

Back-to-Back Correlations (BBC) of particle-antiparticle pairs are predicted to appear if hot and dense hadronic matter is formed in high energy nucleus-nucleus collisions. The BBC are related to in-medium mass-modification and squeezing of the quanta involved. Although the suppression of finite emission times were already known, the effects of finite system sizes and of collective phenomena had not been studied yet. Thus, for testing the survival and magnitude of the effect in more realistic situations, we study the BBC when mass-modification occurs in a finite sized, thermalized medium, considering a non-relativistically expanding fireball with finite emission time, and evaluating the width of the back-to-back correlation function. We show that the BBC signal indeed survives the expansion and flow effects, with sufficient magnitude to be observed at RHIC.

Estratégias para minimização do estresse oxidativo em sistemas de produção in vitro de embriões bovinos destinados à vitrificação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Application of Mossbauer spectroscopy to the study of corrosion resistance in NaCl solution of plasma nitrided AISI 316L stainless steel

Corrosion research in steels is one of the areas in which Mossbauer spectroscopy has become a required analytical technique, since it is a powerful tool for both identifying and quantifying distinctive phases (which contain Fe) with accuracy. In this manuscript, this technique was used to the study of corrosion resistance of plasma nitrided AISI 316L samples in the presence of chloride anions. Plasma nitriding has been carried out using dc glow-discharge, nitriding treatments, in medium of 80 vol.% H-2 and 20 vol.% N-2, at 673 K, and at different time intervals: 2, 4, and 7 h. Treated samples were characterized by means of phase composition and morphological analysis, and electrochemical tests in NaCl aerated solution in order to investigate the influence of treatment time on the microstructure and the corrosion resistance, proved by conversion electron Mossbauer spectroscopy (CEMS), glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM) and potentiodynamic polarization. A modified layer of about 8 gin was observed for all the nitrided samples, independently of the nitriding time. A metastable phase, S phase or gamma(N), was produced. It seems to be correlated with gamma`-Fe-4 N phase. If the gamma(N) fraction decreases, the gamma` fraction increases. The gamma(N) magnetic nature was analyzed. When the nitriding time increases, the results indicate that there is a significant reduction in the relative fraction of the magnetic gamma(N) (in) phase. In contrast, the paramagnetic gamma(N) (p) phase increases. The GAXRD analysis confirms the Mossbauer results, and it also indicates CrN traces for the sample nitrided for 7 h. Corrosion results demonstrate that time in the plasma nitriding treatment plays an important role for the corrosion resistance. The sample treated for 4 h showed the best result of corrosion resistance. It seems that the epsilon/gamma` fraction ratio plays an important role in thin corrosion resistance since this sample shows the maximum value for this ratio. (c) 2008 Published by Elsevier B.V.

Occurrence of Methanogenic Archaea in Highly Polluted Sediments of Tropical Santos-So Vicente Estuary (So Paulo, Brazil)

Little is known about the ability of methanogens to grow and produce methane in estuarine environments. In this study, traditional methods for cultivating strictly anaerobic microorganisms were combined with Fluorescence in situ hybridization (FISH) technique to enrich and identify methanogenic Archaea cultures occurring in highly polluted sediments of tropical Santos-So Vicente Estuary (So Paulo, Brazil). Sediment samples were enriched at 30A degrees C under strict anaerobic and halophilic conditions, using a basal medium containing 2% of sodium chloride and amended with glucose, methanol, and sodium salts of acetate, formate and lactate. High methanogenic activity was detected, as evidenced by the biogas containing 11.5 mmol of methane at 20 days of incubation time and methane yield of 0.138-mmol CH(4)/g organic matter/g volatile suspense solids. Cells of methanogenic Archaea were selected by serial dilution in medium amended separately with sodium acetate, sodium formate, or methanol. FISH analysis revealed the presence of Methanobacteriaceae and Methanosarcina sp. cells.

Chorioallantoic and yolk sac placentation in Thrichomys laurentinus (Echimyidae) and the evolution of hystricognath rodents

The evolutionary history of Hystricognathi is associated with major transformations in their placental system. Data so far indicate that key characters are independent from size dimensions in medium to very large species. To better understand the situation in smaller species, we analyzed placental development in a spiny rat, Thrichomys laurentinus. Fourteen individuals ranging from early implantation to near term were investigated by histology, immunohistochemistry, proliferation activity and electron microscopy. Placentation in Thrichomys revealed major parallels to the guinea pig and other hystricognath rodents with respect to the early and invasive implantation, the process of trophoblast invasion, the internal organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta. In contrast to systematically related small-sized species, the placental regionalization in Thrichomys was characterized by a remarkable lobulated structure and associated growing processes. Reverse to former perspectives, these conditions represented ancient character states of hystricognaths. The subplacenta was temporarily supplied by both the maternal and fetal blood systems, a rare condition among hystricognaths. The extraplacental trophoblast originating from the subplacenta was partly proliferative in mid gestation. In conclusion, the presented results indicated that only minor variations occurred in small-sized hystricognath species, independent of their systematic interrelationships. Previous views were supported that placentation in hystricognaths followed an extraordinary stable pattern, although the group had distinct habitats in South America and Africa that were separated 30-40 million years ago. J. Exp. Zool. (Mol. Dev. Evol.) 318:13-25, 2012. (C) 2011 Wiley Periodicals, Inc.

Prevalence of overweight preschool children in public day care centers: a cross-sectional study

CONTEXT AND OBJECTIVE: Brazil is undergoing a period of epidemiological transition associated with demographic and nutritional changes. The prevalence of obesity is also increasing in children and is causing numerous health problems that are becoming public health issues. The aim here was to evaluate the prevalence of overweight among children of two and three years of age. DESIGN AND SETTING: Cross-sectional study in municipal day care centers in Taubate, state of Sao Paulo, Brazil. METHODS: Weight and height measurements were made on 447 preschool children forming a probabilistic randomized sample. Their body mass index (BMI) was calculated. Their nutritional status was classified using the World Health Organization reference cutoff points (2006). Their mean weight, height and BMI were compared according to their age and sex. RESULTS: The mean values for the final sample (n = 447) were as follows: mean age: 38.6 months (+/- 3.5) and Z scores for: weight/height (W/H): 0.50 (+/- 1.22); height/age: -0.03 (+/- 1.07); weight/age (W/A): 0.51 (+/- 1.23); and BMI: 0.51(+/- 1.23). The prevalence of overweight children (BMI > 1 z) was 28.86%, while the prevalence of underweight children (BMI < -2 z) was 0.89%. There were no differences in mean BMI among the two and three-year age groups (P = 0.66). CONCLUSION: A high prevalence of overweight was observed in the sample of two and three-year-old children, with practically no malnutrition, thus showing that a significant nutritional transition may already be occurring, even in medium-sized cities of developing countries.

In vitro organogenesis of zucchini squash cv. Caserta

A protocol for the in vitro culture of Cucurbita pepo cv. Caserta was studied, using a cotyledon segment with an attached hypocotyl fragment as an explant. First, to determine the optimal seedling age, explants were collected from 4 to 6-day-old in vitro germinated seedlings and cultured in MS basal medium supplemented with benzylaminopurine (BAP, 4.5 mu M), under a 16-h photoperiod at 27 degrees C. Based on the results obtained, the explants collected from the 4-day-old seedlings were then cultured in MS basal medium supplemented with different concentrations of BAP (0, 1.1, 2.2, 3.3, 4.5, or 5.5 mu M) and incubated under a 16-h photoperiod at 27 degrees C. In vitro organogenesis was most efficient with explants collected from 4-day-old seedlings cultured in medium supplemented with 4.5 mu M of BAP. After 4 weeks of incubation the development of adventitious buds at the cotyledon/hypocotyl junction could be observed. These buds were transferred to elongation and rooting medium and the developed plants were acclimatized to greenhouse conditions. The morphogenic process was characterized using light and scanning electron microscopy analyses to confirm the organogenesis. The results showed that this alternate explant is efficient for in vitro culture of zucchini squash cv. Caserta. The protocol will be further examined for future use in genetic transformation experiments in this species.

Evolution of pi(0) Suppression in Au plus Au Collisions from root s(NN)=39 to 200 GeV

Neutral-pion pi(0) spectra were measured at midrapidity (vertical bar y vertical bar < 0.35) in Au + Au collisions at root s(NN) = 39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1 < p(T) < 10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p + p collisions. The nuclear modification factors (RAA) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T) = 7 GeV/c, R-AA is similar for root sNN = 62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R-AA well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where pi(0) spectra in central Au + Au collisions have the same power as in p + p collisions is approximate to 5 and 7 GeV/c for root sNN = 200 and 62.4 GeV, respectively. For the root sNN = 39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the root sNN = 62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hardscattered partons to higher p(T) as the collision energy decreases.

LC-DAD/ESI-MS/MS study of phenolic compounds in ash (Fraxinus excelsior L. and F. americana L.) heartwood. Effect of toasting intensity at cooperage

The phenolic composition of heartwood extracts from Fraxinus excelsior L. and F. americana L., both before and after toasting in cooperage, was studied using LC-DAD/ESI-MS/MS. Low-molecular weight (LMW) phenolic compounds, secoiridoids, phenylethanoid glycosides, dilignols and oligolignols compounds were detected, and 48 were identified, or tentatively characterized, on the basis of their retention time, UV/Vis and MS spectra, and MS fragmentation patterns. Some LMW phenolic compounds like protocatechuic acid and aldehyde, hydroxytyrosol and tyrosol, were unlike to those for oak wood, while ellagic and gallic acid were not found. The toasting of wood resulted in a progressive increase in lignin degradation products with regard to toasting intensity. The levels of some of these compounds in medium-toasted ash woods were much higher than those normally detected in toasted oak, highlighting vanillin levels, thus a more pronounced vanilla character can be expected when using toasted ash wood in the aging wines. Moreover, in seasoned wood, we found a great variety of phenolic compounds which had not been found in oak wood, especially oleuropein, ligstroside and olivil, along with verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. Toasting mainly provoked their degradation, thus in medium-toasted wood, only four of them were detected. This resulted in a minor differentiation between toasted ash and oak woods. The absence of tannins in ash wood, which are very important in oak wood, is another peculiar characteristic that should be taken into account when considering its use in cooperage. Copyright (C) 2012 John Wiley & Sons, Ltd.

Development and characterization of a distributed measurement system for the evaluation of voltage quality in electric power networks

The research activity carried out during the PhD course in Electrical Engineering belongs to the branch of electric and electronic measurements. The main subject of the present thesis is a distributed measurement system to be installed in Medium Voltage power networks, as well as the method developed to analyze data acquired by the measurement system itself and to monitor power quality. In chapter 2 the increasing interest towards power quality in electrical systems is illustrated, by reporting the international research activity inherent to the problem and the relevant standards and guidelines emitted. The aspect of the quality of voltage provided by utilities and influenced by customers in the various points of a network came out only in recent years, in particular as a consequence of the energy market liberalization. Usually, the concept of quality of the delivered energy has been associated mostly to its continuity. Hence the reliability was the main characteristic to be ensured for power systems. Nowadays, the number and duration of interruptions are the “quality indicators” commonly perceived by most customers; for this reason, a short section is dedicated also to network reliability and its regulation. In this contest it should be noted that although the measurement system developed during the research activity belongs to the field of power quality evaluation systems, the information registered in real time by its remote stations can be used to improve the system reliability too. Given the vast scenario of power quality degrading phenomena that usually can occur in distribution networks, the study has been focused on electromagnetic transients affecting line voltages. The outcome of such a study has been the design and realization of a distributed measurement system which continuously monitor the phase signals in different points of a network, detect the occurrence of transients superposed to the fundamental steady state component and register the time of occurrence of such events. The data set is finally used to locate the source of the transient disturbance propagating along the network lines. Most of the oscillatory transients affecting line voltages are due to faults occurring in any point of the distribution system and have to be seen before protection equipment intervention. An important conclusion is that the method can improve the monitored network reliability, since the knowledge of the location of a fault allows the energy manager to reduce as much as possible both the area of the network to be disconnected for protection purposes and the time spent by technical staff to recover the abnormal condition and/or the damage. The part of the thesis presenting the results of such a study and activity is structured as follows: chapter 3 deals with the propagation of electromagnetic transients in power systems by defining characteristics and causes of the phenomena and briefly reporting the theory and approaches used to study transients propagation. Then the state of the art concerning methods to detect and locate faults in distribution networks is presented. Finally the attention is paid on the particular technique adopted for the same purpose during the thesis, and the methods developed on the basis of such approach. Chapter 4 reports the configuration of the distribution networks on which the fault location method has been applied by means of simulations as well as the results obtained case by case. In this way the performance featured by the location procedure firstly in ideal then in realistic operating conditions are tested. In chapter 5 the measurement system designed to implement the transients detection and fault location method is presented. The hardware belonging to the measurement chain of every acquisition channel in remote stations is described. Then, the global measurement system is characterized by considering the non ideal aspects of each device that can concur to the final combined uncertainty on the estimated position of the fault in the network under test. Finally, such parameter is computed according to the Guide to the Expression of Uncertainty in Measurements, by means of a numeric procedure. In the last chapter a device is described that has been designed and realized during the PhD activity aiming at substituting the commercial capacitive voltage divider belonging to the conditioning block of the measurement chain. Such a study has been carried out aiming at providing an alternative to the used transducer that could feature equivalent performance and lower cost. In this way, the economical impact of the investment associated to the whole measurement system would be significantly reduced, making the method application much more feasible.

Studio del comportamento flesso-torsionale di un telaio in materiale composito per vettura sportiva

Lo studio svolto in merito alle tecniche di produzione di componenti strutturali in materiale composito ha permesso il raggiungimento di una precisa consapevolezza dello stato dell’arte del settore, in particolare in riferimento ai processi attualmente utilizzati per l’industrializzazione in media-grande serie. Con l’obiettivo di sintetizzare i principali vantaggi delle tecnologie suddette e permettere la realizzazione di forme più complesse, si è proceduto all’analisi di fattibilità, attraverso uno studio funzionale e una prima progettazione di una tecnologia di produzione per nastratura automatizzata di componenti strutturali in materiale composito. Si è voluto quindi dimostrare la flessibilità e la consistenza del processo disegnando un telaio nastrato in carbonio, intercambiabile al telaio FSAE 2009 in tubolare d’acciaio (stessi punti di attacco motore, punti di attacco telaietto posteriore, attacchi sospensioni anteriori) e che garantisca un sostanziale vantaggio in termini di peso, a pari rigidezza torsionale. La caratterizzazione di tale telaio è stata eseguita mediante l'utilizzo del calcolo strutturale, validato da prove sperimentali.