Limit Cycles for a Class of Continuous and Discontinuous Cubic Polynomial Differential Systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Limit cycles of cubic polynomial differential systems with rational first integrals of degree 2

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Short-term cycles of feed deprivation and refeeding promote full compensatory growth in the Amazon fish matrinxa (Brycon amazonicus)

Developing nutritional strategies that can reduce production costs for the fish industry without affecting productive performance is paramount to make the activity sustainable. We investigated if short-term cycles of feed deprivation and refeeding elicit compensatory growth in matrinxa (Brycon amazonicus) juveniles, using three feeding protocols for 60 days (Phase 1): two levels of deprivation (feed deprivation for two days and refeeding for three - D2R3, or four days - D2R4) and a control level (daily feeding). Following, all fish groups were fed daily at satiation for 15 days (Phase 2). At Phase 1, matrinxa achieved full compensatory growth in both deprivation levels by increasing feed intake and feed efficiency. Overall, deprived fish consumed 40% (D2R3) and 36% (D2R4) less feed than fish fed daily. In Phase 2, growth was similar for all fish. Feed intake increased in both deprived fish, but feed efficiency did not differ among groups and was lower than in Phase 1, indicating a reduced efficiency in feed utilization when food was freely available. We propose that intermittent cycles of feeding represent an effective means to reduce production costs. (C) 2014 Elsevier B.V. All rights reserved.

Physiological Response to Dolops carvalhoi (Crustacea: Branchiura) Infection by Pacu, Piaractus mesopotamicus, Subjected to Short Cycles of Food Restriction and Refeeding

Feeding strategies that reduce feed and promote compensatory growth could be an interesting tool to reduce costs in the fish production. However, fish health must be monitored to evaluate if their physiological response to adverse conditions, such as parasite infection, does not become compromised. A 12-wk growth trial was conducted to determine the physiological responses of pacu, Piaractus mesopotamicus, that were subjected to different fasting/refeeding cycles and infected with the Dolops carvalhoi. The schemes were: (i) control group fish (FD), (ii) food-restricted and controlled refeeding group (FR/Rc), and (iii) food-restricted and refeeding to satiation group (FR/Rs). After 84 d, the fish were exposed to D. carvalhoi for 30 h. The fish subjected to food restriction did not exhibit compensatory growth. Cortisol levels decreased in all groups within 30 h after infection. Glucose levels increased 6 h after the D. carvalhoi in the FR/Rs and 30 h after infection in the FD. In all of the fish groups, the hematocrit values were reduced after infection, and it was associated with a reduction in the mean corpuscular volume and erythrocytes. At 30 h after infection, the number of erythroblasts increased. The use of the feeding schemes does not indicate a failure of the pacu physiological responses.

Lê Cycles and Milnor Classes of Compact Hypersurfaces

We determine the relation amongst the global Lê cycles and the Milnor classes of analytic hypersurfaces defined by a section of a very ample line bundle over a compact complex manifold. The key point is finding appropriate expressions for the global Lê cycles and for the Milnor classes in terms of polar varieties. Our starting points are an interpretation of the Lê cycles given by T. Gaffney and R. Gassler, a formula by A. Parusinski and P. Pragacz for the Milnor classes via McPherson’s functor, and a conjecture of J.-P. Brasselet, that we prove, stating that Milnor classes can be expressed in terms of polar varieties. We then use the work by R. Piegne for Mather classes, by J. Schürmann and M. Tibăr for MacPherson’s classes for constructible functions, and by D. Massey for an extension of the local Lê cycles for constructible sheaves.

Effect of thermal and mechanical cycles on the hardness and roughness of artificial teeth

In this study the effects of thermal and mechanical cycles on the hardness and roughness of artificial teeth were evaluated. Materials and Methods:Specimens were prepared and stored in distilled water at 37ºC for 48 hours (n=10).The hardness and roughness readings were made in the following time intervals, according to each group:G1: after specimen storage in distilled water at 37°C for 48 hours; G2: after 600.000 constant mechanical cycles; G3: after 1.200.000 constant mechanical cycles; G4: after 2.500 thermalcycling baths, alternated between hot water (55°C) and cold water (5°C) and G5: after 5.000 thermalcycling baths, alternated between hot water (55°C) and cold water (5°C). After cycling and storage procedures, the specimens of each group were submittedto surface roughness and hardness readouts. Statistical evaluation was performed by three-way analysis of variance, complemented by the Tukey multiple comparisons of means test. The level of significance adopted was 5%. There was no significant difference between G1, G4 and G5 as regards mean roughness of different brands of artificial teeth. Groups G2 and G3 showed higher mean roughness values, and generally equivalent values in all time intervals, except for Trilux (G3> G2). Significant differences in hardness values were observed in different brands of artificial teeth, and differences in values after thermal and mechanical cycling. In conclusion, our findings suggest that thermal cyclingdid not change the roughness of the artificial teeth tested, but after the mechanical cycling the roughness values increased. Thermal and mechanical cycling influenced the hardness of the artificial teeth tested.

On the number of limit cycles in discontinuous piecewise linear differential systems with two pieces separated by a straight line

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

On the Limit Cycles for a Class of Continuous Piecewise Linear Differential Systems with Three Zones

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

Evaluation of silent period on masticatory cycles of different muscles in dentate oral contraceptives users and nonusers

The aim of this study was to evaluate the influence of oral contraceptive use on the silent period (SP) of anterior temporal and masseter muscles during the menstrual cycle. Totally, 28 women on reproductive age were selected including 15 nonusers of any hormone and 13 contraceptive users. All patients were dentate without muscular temporomandibular disorders. Electromyography (SP test) of the anterior temporal and masseter muscles was conducted every week during three consecutive menstrual cycles at 1(st) day of menstruation (P1), 7(th) day (P2), 14(th) day (P3) and 21(st) day (P4). The SP values in the anterior temporal and masseter muscles were measured at both sides. The SP values of the right side (13.49 ms) at P2 were significantly different compared to the left side (12.28 ms). However, there was no significant difference on the interactions among the three factors. It can be concluded that the SP values in healthy women in reproductive age may not be influenced by the menstrual cycle with similar results for both muscles.

Influence of the number of load cycles to obtain the stiffness properties of angico preto (Anadenanthera macrocarpa) wood specie

The tests used to obtain the stiffness properties of wood are made with two loading cycles, as defined by the Brazilian standard ABNT NBR 7190 (Design of Timber Structures). However, the possibility of reducing the number of cycles allows decrease the operating time of the machine, resulting in reduced spending on electricity used during the tests. This research aimed to investigate, with the aid of the analysis of variance (ANOVA), the influence of the use of three load cycles to obtain the modulus of elasticity in compression parallel to grain (Ec0), in tensile parallel to the grain (Et0), in bending (Em) and in compression perpendicular to the grain (Ec90) of Angico Preto (Anadenanthera macrocarpa) wood specie. For the number of cycles and stiffness were manufactured 12 samples, totaling 144 specimens. The results of the ANOVA revealed statistical equivalence between the stiffness properties for both load cycle numbers evaluated, indicating that it is possible to carry out the tests with a single charge cycle, allowing savings in time and energy in the operation of the equipment.

The association between follicular size at time of spontaneous rupture and pregnancy rates in clomiphene citrate treated PCOS patients in coit cycles

Objective: To investigate the follicular size at spontaneous rupture on pregnancy rate in patientswith polycystic ovary syndrome (PCOS) undergoing clomiphene citrate (CC) ovulation.Design: Cross-sectional study.Patients and methods: One hundred and four women with ovulatory cycles after use of CCfollowed by ultrasound to determine the follicle size at the time of rupture, which wassubsequently correlated with the occurrence of pregnancy or not in coit cycles.Results: In the group of follicular rupture at a mean diameter25 mm (n¼54), pregnancy ratewas 35.1% and when follicular rupture occurred at a mean diameter425 mm (n¼50), it was34% (p40.05). When different diameters at follicular rupture were randomly correlated with thepregnancy rate, there was no significant difference.Conclusion: Our data suggest that the occurrence of pregnancy after ovulation induction withCC in women with PCOS is not associated with follicle size at the time of rupture.

Restructured products from tilapia industry by products: the effects of tapioca starch and washing cycles

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

Phenological cycles, thermal time and growth curves of mango fruit cultivars in subtropical conditions

There are many mango cultivars available in different regions. It is about time we analysed their productive behavior in these areas, as well as their phenological performance. This study aimed to evaluate: phenological cycles, thermal time and growth curves of mango fruit cultivars in subtropical conditions. For this study we used the following cultivars: Espada Vermelha, Keitt and Palmer. All the experiments were done at UNESP experimental farm in Sao Manuel (SP), during the agricultural cycle from 2012 to 2013. It was selected 15 branches in each plant, which provided 150 per cultivar. It was determined the number of days of phenological cycles of flowering to fruit ripening, as well as the total number of days to flowering and harvesting. The thermal time was evaluated to each phenological cycle and expressed in accumulation of degree-days. The measurement of the longitudinal diameters (LD) and transverse diameters (TD) of the fruitwere performed in a 12 day’s intervals, from the tenth day after the flowers anthesis, to evaluate the growth curve. Based on the data, it was found that Keitt cultivar requires more days for the fruit to reach physiological maturity and greater accumulation of degree-days to complete its production cycle. The growth curves of the three varieties of fruits have a simple sigmoidal model in function of the days after anthesis.