Uterine evaluation and gestation diagnosis in owl monkey (Aotus azarai infulatus) using the B mode ultrasound

Background Gynecological and obstetrical ultrasonography has become an indispensable tool in the routine management, health evaluation and research on captive non-human primates.Methods Ultrasound was used to evaluate the uterus and estimate the gestation of owl monkeys. Twelve couples were selected, where five were primiparous and seven multiparous females from the National Primate Center reproductive colony, Ananindeua-PA, Brazil. The procedures were carried out using the GE (R) Logiq 100 MP, equipped with a 7.5 MHz linear probe.Results the females showed a simple uterus, of elongated shape, regular outline and homogeneous echogenic texture. In the uterine measurements craniocaudal diameter, dorsoventral diameter and uterine volume (UV), significant differences were identified (P < 0.05) between ultrasound examinations of primiparous and multiparous females. The UV showed a positive correlation with the number of births. The gestational sac and the embryonic echo were visible between 28 and 38 days after mating. Between 48 and 68 days after mating, embryonic death was identified in all the gestations.Conclusions the chemical (use of tranquilizers) and husbandry factors (capture stress) may be related to the prenatal death. The establishing methods of conditioning the female to the ultrasonographic exam may offer a solution to this problem.

Transmission-expansion planning using the DC model and nonlinear-programming technique

The paper presents a constructive heuristic algorithm (CHA) for solving directly the long-term transmission-network-expansion-planning (LTTNEP) problem using the DC model. The LTTNEP is a very complex mixed-integer nonlinear-programming problem and presents a combinatorial growth in the search space. The CHA is used to find a solution for the LTTNEP problem of good quality. A sensitivity index is used in each step of the CHA to add circuits to the system. This sensitivity index is obtained by solving the relaxed problem of LTTNEP, i.e. considering the number of circuits to be added as a continuous variable. The relaxed problem is a large and complex nonlinear-programming problem and was solved through the interior-point method (IPM). Tests were performed using Garver's system, the modified IEEE 24-Bus system and the Southern Brazilian reduced system. The results presented show the good performance of IPM inside the CHA.

A linear optimization approach to the combined production planning model

Two fundamental processes usually arise in the production planning of many industries. The first one consists of deciding how many final products of each type have to be produced in each period of a planning horizon, the well-known lot sizing problem. The other process consists of cutting raw materials in stock in order to produce smaller parts used in the assembly of final products, the well-studied cutting stock problem. In this paper the decision variables of these two problems are dependent of each other in order to obtain a global optimum solution. Setups that are typically present in lot sizing problems are relaxed together with integer frequencies of cutting patterns in the cutting problem. Therefore, a large scale linear optimizations problem arises, which is exactly solved by a column generated technique. It is worth noting that this new combined problem still takes the trade-off between storage costs (for final products and the parts) and trim losses (in the cutting process). We present some sets of computational tests, analyzed over three different scenarios. These results show that, by combining the problems and using an exact method, it is possible to obtain significant gains when compared to the usual industrial practice, which solve them in sequence. (C) 2010 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Evaluation of 316L Stainless Steel Corrosion Resistance in Solution Simulating the Acid Hydrolysis of Biomass

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

An evaluation of ocean color model estimates of marine primary productivity in coastal and pelagic regions across the globe

Nearly half of the earth's photosynthetically fixed carbon derives from the oceans. To determine global and region specific rates, we rely on models that estimate marine net primary productivity (NPP) thus it is essential that these models are evaluated to determine their accuracy. Here we assessed the skill of 21 ocean color models by comparing their estimates of depth-integrated NPP to 1156 in situ C-14 measurements encompassing ten marine regions including the Sargasso Sea, pelagic North Atlantic, coastal Northeast Atlantic, Black Sea, Mediterranean Sea, Arabian Sea, subtropical North Pacific, Ross Sea, West Antarctic Peninsula, and the Antarctic Polar Frontal Zone. Average model skill, as determined by root-mean square difference calculations, was lowest in the Black and Mediterranean Seas, highest in the pelagic North Atlantic and the Antarctic Polar Frontal Zone, and intermediate in the other six regions. The maximum fraction of model skill that may be attributable to uncertainties in both the input variables and in situ NPP measurements was nearly 72%. on average, the simplest depth/wavelength integrated models performed no worse than the more complex depth/wavelength resolved models. Ocean color models were not highly challenged in extreme conditions of surface chlorophyll-a and sea surface temperature, nor in high-nitrate low-chlorophyll waters. Water column depth was the primary influence on ocean color model performance such that average skill was significantly higher at depths greater than 250 m, suggesting that ocean color models are more challenged in Case-2 waters (coastal) than in Case-1 (pelagic) waters. Given that in situ chlorophyll-a data was used as input data, algorithm improvement is required to eliminate the poor performance of ocean color NPP models in Case-2 waters that are close to coastlines. Finally, ocean color chlorophyll-a algorithms are challenged by optically complex Case-2 waters, thus using satellite-derived chlorophyll-a to estimate NPP in coastal areas would likely further reduce the skill of ocean color models.

Bound state solution of the grassmannian nonlinear sigma model with fermions

We construct the S-matrix for bound state (gauge-invariant) scattering for nonlinear sigma models defined on the manifold SU(n) S(U(p)⊗U(n-p)) with fermions. It is not possible to compute gauge non-singlet matrix elements. In the present language, constraints from higher conservation laws determine the bound state solution. An alternative derivation is also presented. © 1988.

Exact solution for a three-dimensional three-body problem with harmonic interactions

The three-dimensional three-body problem with non-equal masses interacting through pairwise harmonic forces of non-equal strengths is analysed. It is shown that the Jacobi coordinates per se do not decouple this problem but lead to the problem of two coupled three-dimensional harmonic oscillators which becomes exactly soluble through the use of an additional coordinate set.

Renormalization of the ladder light-front Bethe-Salpeter equation in the Yukawa model

The reduction of the two-fermion Bethe-Salpeter equation in the framework of light-front dynamics is studied for the Yukawa model. It yields auxiliary three-dimensional quantities for the transition matrix and the bound state. The arising effective interaction can be perturbatively expanded in powers of the coupling constant gs allowing a defined number of boson exchanges; it is divergent and needs renormalization; it also includes the instantaneous term of the Dirac propagator. One possible solution of the renormalization problem of the boson exchanges is shown to be provided by expanding the effective interaction beyond single boson exchange. The effective interaction in ladder approximation up to order g4 s is discussed in detail. It is shown that the effective interaction naturally yields the box counterterm required to be introduced ad hoc previously. The covariant results of the Bethe-Salpeter equation can be recovered from the corresponding auxiliary three-dimensional quantities.

On the regular-geometric-figure solution to the N-body problem

The regular-geometric-figure solution to the N-body problem is presented in a very simple way. The Newtonian formalism is used without resorting to a more involved rotating coordinate system. Those configurations occur for other kinds of interactions beyond the gravitational ones for some special values of the parameters of the forces. For the harmonic oscillator, in particular, it is shown that the N-body problem is reduced to N one-body problems.

A new solution to the optimal power flow problem

A new approach to solving the Optimal Power Flow problem is described, making use of some recent findings, especially in the area of primal-dual methods for complex programming. In this approach, equality constraints are handled by Newton's method inequality constraints for voltage and transformer taps by the logarithmic barrier method and the other inequality constraints by the augmented Lagrangian method. Numerical test results are presented, showing the effective performance of this algorithm. © 2001 IEEE.

The monosodium glutamate (MSG) obese rat as a model for the study of exercise in obesity

Obesity is an increasing problem in several countries, leading to health problems. Physical exercise, in turn, can be used effectively by itself or in combination with dietary restriction to trigger weight loss. The present study was designed to evaluate the effects of aerobic exercise training on lipid profile of obese male Wistar rats in order to verify if this model may be of value for the study of exercise in obesity. Obesity was induced by MSG administration (4mg/g, each other day, from birth to 14 days old) After 14 from drug administration, the rats were separated into two groups: MSG-S (sedentary) and MSG-T (exercise trained). Exercise training consisted in 1h/day, 5 days/week, with an overload of 5% bw, for 10 weeks. Rats of the same age and strain, receiving saline at birth, were used as control (C), and subdivided into two groups: C-S and C-T. At the end of the experimental period, MSG-T and C-T rats showed similar blood lactate and muscle glycogen responses to exercise training and acute exercise. MSG-S rats showed significantly higher carcass fat, serum triacylglycerol, serum insulin and liver total fat than C-S rats. On the other hand, MSG-T rats had lower carcass fat, serum triacylglycerol and liver total fat than MSG-S rats. There were no statistical differences in food intake and serum free fatty acids among the groups studied. These data indicate that this model may be of value for the study of exercise effects on tissue and circulating lipid profile in obesity.

Evaluation of toxicity after one-months treatment with Bauhinia forficata decoction in streptozotocin-induced diabetic rats

Background: Previous experiments have shown that a decoction of Bauhinia forficata leaves reduces the changes in carbohydrate and protein metabolism that occur in rats with streptozotocin-induced diabetes. In the present investigation, the serum activities of enzymes known to be reliable toxicity markers were monitored in normal and streptozotocin-diabetic rats to discover whether the use of B. forficata decoction has toxic effects on liver, muscle or pancreas tissue or on renal microcirculation. Methods: An experimental group of normal and streptozotocin-diabetic rats received an aqueous decoction of fresh B. forficata leaves (150 g/L) by mouth for 33 days while a control group of normal and diabetic rats received water for the same length of time. The serum activity of the toxicity markers lactate dehydrogenase, creatine kinase, amylase, angiotensin-converting enzyme and bilirubin were assayed before receiving B. forficata decoction and on day 19 and 33 of treatment. Results: The toxicity markers in normal and diabetic rats were not altered by the diabetes itself nor by treatment with decoction. Whether or not they received B. forficata decoction the normal rats showed a significant increase in serum amylase activity during the experimental period while there was a tendency for the diabetic rats, both treated and untreated with decoction, to have lower serum amylase activities than the normal rats. Conclusions: Administration of an aqueous decoction of B. forficata is a potential treatment for diabetes and does not produce toxic effects measurable with the enzyme markers used in our study. © 2004 Pepato et al; licensee BioMed Central Ltd.

Acellular dermal tissue study: an ultrastructural evaluation of human and porcine derived tissues in a rat model

The purpose of this study was to evaluate the host response of a human and a porcine derived acellular dermal tissue (ADT) implanted in the subcutaneous tissue of a rat model. Two subcutaneous pockets were surgically created along the dorsal midline of 25 rats (5 rats/group). The human ADT was placed superiorly and the porcine ADT, inferiorly. The animals were sacrificed at 07, 15, 30, 60 and 180 postoperative days (PO) and the ADTs and surrounding soft tissues were assessed for ultrastructural evaluation by transmission electron microscopy. The ultrastructural findings were similar in both materials. Normal collagen and elastic fibers bundles were observed during all experimental moments, as well as macrophages presenting cytoplasmic enlargements digesting cellular portions after 15 PO. From 30 until 180 PO, vacuolar structures filled with an amorphous, electron-transparent substance, were present inside and outside the fibroblasts. Both human and porcine ADT showed similar pattern of ultrastructural response when implanted in the subcutaneous tissue of rats. The porcine ADT appears as a good alternative to be used as a biomaterial.

The LQ control problem for Markovian jumps linear systems with horizon defined by stopping times

This paper deals with a stochastic optimal control problem involving discrete-time jump Markov linear systems. The jumps or changes between the system operation modes evolve according to an underlying Markov chain. In the model studied, the problem horizon is defined by a stopping time τ which represents either, the occurrence of a fix number N of failures or repairs (TN), or the occurrence of a crucial failure event (τΔ), after which the system is brought to a halt for maintenance. In addition, an intermediary mixed case for which T represents the minimum between TN and τΔ is also considered. These stopping times coincide with some of the jump times of the Markov state and the information available allows the reconfiguration of the control action at each jump time, in the form of a linear feedback gain. The solution for the linear quadratic problem with complete Markov state observation is presented. The solution is given in terms of recursions of a set of algebraic Riccati equations (ARE) or a coupled set of algebraic Riccati equation (CARE).

An active/reactive predispatch model incorporating ramp rate constraints solved by dual decomposition/lagrangian relaxation

The Predispatch model (PD) calculates a short-term generation policy for power systems. In this work a PD model is proposed that improves two modeling aspects generally neglected in the literature: voltage/reactive power constraints and ramp rate constraints for generating units. Reactive power constraints turn the PD into a non-linear problem and the ramp rate constraints couple the problem dynamically in time domain. The solution of the PD is turned into a harder task when such constraints are introduced. The dual decomposition/ lagrangian relaxation technique is used in the solution approach for handing dynamic constraints. As a result the PD is decomposed into a series of independent Optimal Power Flow (FPO) sub problems, in which the reactive power is represented in detail. The solution of the independent FPO is coordinated by means of Lagrange multipliers, so that dynamic constraints are iteratively satisfied. Comparisons between dispatch policies calculated with and without the representation of ramp rate constraints are performed, using the IEEE 30 bus test system. The results point-out the importance of representing such constraints in the generation dispatch policy. © 2004 IEEE.