Impoundments affect fish reproduction regardless of reproductive strategy

Major changes to local river habitats, after impoundment, are expected to restrict the reproductive activity of fishes with migratory strategies, although the changes are not expected to have relevant effects on fishes with other strategies. The reproductive activity of fishes with different reproductive strategies was evaluated along a longitudinal gradient before, and after, the formation of a reservoir on the Tocantins River (Tocantins State, Brazil). Samples were collected at six sites distributed along 80‐km stretch of the reservoir (R1 to R6 in the upstream–downstream direction) before and after the impoundment. The highest mean values of the reproductive activity index (RAI), considering all species in the river phase, were recorded for the intermediate segments (R4). The reproductive activity was classified as intense at the two sites located further upstream (R2 and R1). The highest mean RAI value after impoundment was observed for the site further upstream (R1). The reproductive activity was classified as intense, however, at every site, except for R6. Regardless of the reproductive strategy, mean RAI values were higher in this phase at site R1, particularly for long‐distance migratory species (LDM). The most lacustrine area (R6) was only relevant for the group of species with parental care. For non‐long‐distance migratory species, without parental care, the reproductive activity was intense at every site, except for R6. Overall, after the impoundment, the fish species tended to seek more lotic environments to spawn, including the riverine zone of the reservoir and side tributaries, regardless of the reproductive strategy. The results of this study provide evidence that impoundments affect the reproduction of the fish, independent of the reproductive strategy, although the intensity of the effect is different for each group.     

Control of an anaerobic digester through normal form of fold bifurcation

Nonlinear dynamics is ubiquitous in engineering systems. As some parameters are varied bifurcations arise in the state variables. Generically, when one parameter changes, Hopf and fold bifurcations are found. Other ones can also be present due to special systems characteristics, such as symmetries. Knowing in advance the significant bifurcation scenario, a novel approach to control can be considered. We compute the normal form corresponding to such a bifurcation and we take this model as the nominal model of the plant. Then we design a nonlinear control which takes advantage of the precise bifurcation scenario. This general method is applied, in this paper, to an anaerobic digester. We will control the process with an adaptive controller.Specifically, we want to compare with the case that the nominal plant is considered as a linear model, such as it is typical in adaptive control techniques. Our proposed method has more benefits in signal control effort, faster convergence rate and low error.This paper shows how the combination of appropriated nonlinear dynamic techniques such as bifurcations and normal forms, and nonlinear control, can give rise to an improvement of the traditional methodology.     

Identification of a Novel Moth Sex Pheromone Component from <Emphasis Type="Italic">Chilecomadia valdiviana</Emphasis>

Chilecomadia valdiviana (Philippi) (Lepidoptera: Cossidae) is an insect native to Chile. The larval stages feed on the wood of economically important fruit tree species such as apple, pear, olive, cherry, and avocado, and also on eucalyptus. This causes weakening and, in case of severe infestation, death of the tree. We report identification of the sex pheromone produced by females of this species. Hexane extracts of the abdominal glands of virgin females were analyzed by gas chromatography (GC) with electroantennographic detection, GC coupled with mass spectrometry, and GC coupled to infrared spectroscopy. The major pheromone component was identified as (7Z,10Z)-7,10-hexadecadienal (Z7,Z10–16:Ald), and minor components present in the extracts were (Z)-7-hexadecenal and (Z)-9-hexadecenal, hexadecanal, and (9Z,12Z)-9,12-octadecadienal. Structural assignments were carried out by comparison of analytical data of the natural products and their dimethyl disulfide adducts with those of authentic reference samples. In field tests, traps baited with Z7,Z10–16:Ald captured significantly more males than control traps.     

Two-Dimensional Numerical Simulation of the Hydro-Sedimentary Phenomena in Lake Taabo, Côte d’Ivoire

In Côte d’Ivoire, most of the reservoirs built to improve water supply, electricity, agriculture and cattle no longer work because of silt deposits and euthrophication. This study aims at modeling the hydro-sedimentary functioning of Lake Taabo in order to understand the sedimentation phenomena taking place. In this survey, 204 water samples and 31 bottom sediment samples were taken, during different hydrological seasons, to estimate suspended sediment concentrations and characterize the bottom sediments of Lake Taabo. The study showed that suspended solid variations are related to hydrological seasons. During dry seasons, the lake is lightly loaded; the average concentration is 7.89 mg/L. At the other end of the scale, during rainy seasons, suspended sediment concentrations increase and the average concentration is around 16.30 mg/L. The bottom of the reservoir mostly consists of mud. Sands are found near the islands and the dam. Sand size varies from medium grain to coarse. The average grain size is 451.48 μm. The hydro-sedimentary environment of Lake Taabo was simulated by a transport model, coupled with a hydrodynamic model. The various simulation scenarios indicated that Lake Taabo is subject to 20 to 60 mm of annual deposits. The greater thicknesses were observed near the spillway and the power intake.     

Low‐Voltage Tunable Pseudo‐Differential Transconductor with High Linearity

A novel tunable transconductor is presented. Input transistors operate in the triode region to achieve programmable voltage‐to‐current conversion. These transistors are kept in the triode region by a novel negative feedback loop which features simplicity, low voltage requirements, and high output resistance. A linearity analysis is carried out which demonstrates how the proposed transconductance tuning scheme leads to high linearity in a wide transconductance range. Measurement results for a 0.5 μm CMOS implementation of the transconductor show a transconductance tuning range of more than a decade (15 μA/V to 165 μA/V) and a total harmonic distortion of ?67 dB at 1 MHz for an input of 1 V_pp and a supply voltage of 1.8 V.     

Dietary fatty acid intervention of lactating cows simultaneously affects lipid profiles of meat and milk

BACKGROUND: The present study investigated tissue‐specific responses of muscle and mammary gland to a 10 week intervention of German Holstein cows (n = 18) with three different dietary fat supplements (saturated fat; linseed oil or sunflower oil plus docosahexaenoic acid‐rich algae) by analysing fatty acid profiles and quality parameters of meat and milk. RESULTS: Plant oil/algae intervention affected neither fat content nor quality parameters of meat but decreased fat content and saturated fatty acid amounts of milk. Linseed oil/algae intervention caused significantly higher concentrations of C18:3n‐3 (meat, 1.0 g per 100 g; milk, 1.2 g per 100 g) and C22:6n‐3 (meat, 0.3 g per 100 g; milk, 0.14 g per 100 g). Sunflower oil/algae intervention increased n‐6 fatty acid contents in milk (4.0 g per 100 g) but not in meat. Elevated amounts of C18:1trans isomers and C18:1trans‐11 were found in meat and especially in milk of plant oil/algae‐fed cows. C18:1cis‐9 amounts were found to be increased in milk but decreased in meat after plant oil/algae intervention. CONCLUSION: The present study demonstrated that dietary fatty acid manipulation substantially shifted the fatty acid profiles of milk and to a lesser extent of meat, whereas meat quality traits were not affected. Indications of tissue‐specific responses of mammary gland and muscle were identified. Copyright © 2012 Society of Chemical Industry     

Multi-Classification by Using Tri-Class SVM

The standard form for dealing with multi-class classification problems when bi-classifiers are used is to consider a two-phase (decomposition, reconstruction) training scheme. The most popular decomposition procedures are pairwise coupling (one versus one, 1-v-1), which considers a learning machine for each Pair of classes, and the one-versus-all scheme (one versus all, 1-v-r), which takes into consideration each class versus the remaining classes. In this article a 1-v-1 tri-class Support Vector Machine (SVM) is presented. The expansion of the architecture of this machine into three categories specifically addresses the decomposition problem of how to prevent the loss of information which occurs in the usual 1-v-1 training procedure. The proposed machine, by means of a third class, allows all the information to be incorporated into the remaining training patterns when a multi-class problem is considered in the form of a 1-v-1 decomposition. Three general structures are presented where each improves some features from the precedent structure. In order to deal with multi-classification problems, it is demonstrated that the final machine proposed allows ordinal regression as a form of decomposition procedure. Examples and experimental results are presented which illustrate the performance of the new tri-class SV machine.     

Unified dual for bi-class SVM approaches

SVM theory was originally developed on the basis of a separable binary classification problem, and other approaches have been later introduced. In this paper, we demonstrated that all these approaches admit the same dual problem formulation.     

Survival in stage T2-T3A bladder cancer treated with radical cystectomy

OBJECTIVE: The optimal treatment for patients with localized muscle-infiltrating urothelial carcinoma (Jewett stage B or T2-T3a of the TNM classification, UICC 1992) continues to be a controversy. The present study analyzed the survival rate in patients with stage T2-T3a bladder cancer who had been treated by radical cystectomy. METHODS: The records of 50 patients with T2-T3a NO tumor, submitted to pelvic lymphadenectomy and radical cystoprostatectomy, were reviewed to determine the prognosis in this group of patients. Seventeen patients (34%) received three courses of systemic chemotherapy (CMV) prior to cystectomy. RESULTS: The overall 5-year survival rate was 73%; 76% for those with T2 (n = 30) and 67% for those with T3a (n = 20) (log-rank, p = 0.27). No statistically significant differences were observed for age (less than or over 65 years), tumor growth pattern (papillary or flat), tumor size (less or greater than 5 cms) or treatment (with or without induction CMV). However, patients with G1-2 tumor had a better survival rate (94% at 5 years) than those with G3 tumor (51%), a difference with statistical significance (log-rank, p = 0.047). The Cox regression analysis showed no independent variable of prognostic significance. CONCLUSION: Muscle-infiltrating urothelial carcinoma is highly curable by radical surgery. Some authors believe it is unnecessary to distinguish T2-T3a lesions; therefore a critical review of the TNM classification appears to be warranted. We are unable to distinguish patients with a better prognosis that might benefit from less aggressive therapeutic options. Similarly, the therapeutic benefits of induction chemotherapy prior to cystectomy in patients with stage T2-T3a tumor could not be demonstrated.