The effect of breed,sex, and drug concentration on the pharmacokinetic profile of ivermectin in cattle

Ivermectin (IVM) is one of the most widely used antiparasitic drugs worldwide and has become the drug of choice for anthelmintic and tick treatment in beef cattle production. It is known that pharmacokinetic parameters are fundamental to the rational use of a drug and food safety and these parameters are influenced by different factors. The aim of this study was to evaluate the pharmacokinetic profile of IVM in Bos indicus, Bos taurus, and crossbreed cattle (B. indicus × B. taurus) kept under same field conditions and the possible impacts of sex and IVM formulation (1% and 3.15%). It was observed that IVM concentration was significantly affected by breed. The plasma concentrations of IVM, AUC, C_max, and t_1/2β were significantly higher in B. indicus compared to B. taurus. Crossbreed animals showed an intermediate profile between European and Indian cattle. No alteration in pharmacokinetics parameters was detected when comparing different gender. Concerning the pharmacokinetic data of IVM formulation, it was verified that T_max, AUC, and t_1/2β were higher in 3.15% IVM animals than those from 1% IVM formulation. The results clearly indicated that the IVM plasma concentrations in B. indicus were higher than that in B. taurus.     

Biogenic amines occurrence in wine. Amino acid decarboxylase and proteolytic activities expression by Oenococcus oeni

This work deals with the study of the proteolytic and amino acid decarboxylase activities of selected Oenococcus oeni isolates and the effect of yeast autolysis on biogenic amines production in wine. A total of 220 isolates of O. oeni were tested for decarboxylase and proteolytic activity. Only six isolates showed both activities, but only after a period of adaptation in a growth medium containing wine. The results reported on this paper show that proteolytic activity was dependent on medium composition and bacterial growth phase. It can be assumed that the ability of O. oeni to use wine peptides and to produce biogenic amines is not a constant characteristic of this species, and enzymatic system expression appears to be closely dependent on nutritional and energetical composition of the medium. It also seems to be strain dependent and not widespread among this bacterial community.     

Maquiladora Employment Dynamics in Nuevo Laredo

ABSTRACT The Nuevo Laredo maquiladora sector has grown enormously during the last two decades. The short‐term time series characteristics of this portion of the regional economy are analyzed in an attempt to quantify the trends underlying this remarkable performance. Parameter estimation is accomplished via linear transfer function (LTF) analysis. Data are drawn from the January 1990–December 2000 sample period. Empirical results indicate that real wage rates, maquiladora plants, U.S. industrial activity, and the real exchange rate of the peso play significant roles in determining month‐to‐month fluctuations in maquiladora employment. Furthermore, sub‐sample forecast simulation exercises are conducted as an additional means for verifying model reliability. Empirical results indicate that the forecasts generated with the LTF model are less accurate than those associated with a simple random walk procedure for twelve separate step‐length periods.     

Acute cortisol responses of lambs castrated and docked using rubber rings with or without a castration clamp

Objective To measure the plasma cortisol response in lambs castrated and docked by three different methods (ring castration and tail docking, ring and clamp castration and tail docking; ring and clamp castration and ring tail docking) for 4 h after treatment.
Design A physiological study with controls.
Procedure A rubber ring was applied to the scrotum. Then the castration clamp was placed, distal to the ring, on each spermatic cord such that there was no overlap of the crush lines.
Results There were no differences in the cortisol secretion of the lambs castrated and tail docked by the ring only and by the ring plus castration clamp methods. Using the castration clamp in addition to the ring on the tail had no effect on cortisol secretion.
Conclusions Using the castration clamp did not appear to reduce the cortisol response to ring castration and docking, as demonstrated elsewhere, because the areas of uncrushed tissue between the two castration clamp crush lines allowed nociception from ischemic scrotal tissue to be transmitted cranially via undamaged nerve fibers.     

Evidence of soft-mode quantum phase transitions in electron double layers

Inelastic light scattering by low-energy spin-excitations reveals three distinct configurations of spin of electron double layers in gallium arsenide quantum wells at even-integer quantum Hall states. The transformations among these spin states appear as quantum phase transitions driven by the interplay between Coulomb interactions and Zeeman splittings. One of the transformations correlates with the emergence of a spin-flip intersubband excitation at vanishingly low energy and provides direct evidence of a link between quantum phase transitions and soft collective excitations in a two-dimensional electron system.     

Biodiversity assessment and conservation strategies

The efficient representation of all species in conservation planning is problematic. Often, species distribution is assessed by dividing the land into a grid; complementary sets of grids, in which each taxon is represented at least once, are then sought. To determine if this approach provides useful surrogate information, species and higher taxon data for South African plants and animals were analyzed. Complementary species sets did not coincide and overlapped little with higher taxon sets. Survey extent and taxonomic knowledge did not affect this overlap. Thus, the assumptions of surrogacy, on which so much conservation planning is based, are not supported.     

Soil organic matter and nutrient accumulation in areas under intensive management and swine manure application

Purpose

Land use change and soil management are frequently associated to land degradation and soil organic matter (SOM) losses in tropical regions. In Brazil, in order to avoid this process, different management strategies have been applied, such as no-tillage and agricultural disposal of swine manure (SM). This study was carried out to evaluate the quantity and quality of SOM, as well as the occurrence of nutrient accumulation in soils of areas under contrasting management systems that have received consecutive applications of SM over the last decades in Brazil.

Materials and methods

Five land uses were sampled: native vegetation (NV), pasture with SM application (PA + SM), no-tillage with SM application (NT + SM), no-tillage (NT), and conventional tillage with SM application (CT + SM). Soil organic carbon (SOC), N, labile C, C management index (CMI), P, Ca²⁺, Mg²⁺, K⁺, Al³⁺, Fe, Zn, Mn, Cu, and H + Al were quantified.

Results and discussion

Except for PA + SM, the agricultural land uses caused decreases in SOC contents comparing to NV. PA + SM showed the highest C stocks, 138.9?±?3.4 Mg ha^?1 down to 0.4 m. The application of SM can be associated to the greater C stocks in PA + SM, NT + SM, and CT + SM and to the higher N contents in all land uses under this practice. Land uses which receive higher rates of swine manure application (PA + SM and CT + SM) have shown CMI greater than 100. However, this practice is associated to the accumulation of P, Cu, Na, and Zn in these soils.

Conclusions

The SM application is associated to improvement on C stocks and SOM quality in area under pasture, no-tillage, and conventional tillage in Paraná State, Brazil. However, this practice is the main driver of nutrient accumulation in these areas.

     

Characterization of atypical Enteropathogenic Escherichia coli (aEPEC) isolated from dogs

Enteropathogenic Escherichia coli (EPEC), an important human pathogen has the ability to form attaching and effacing lesions on the intestinal epithelium and has been isolated from a wide range of species. Two EPEC subgroups are recognized: typical (tEPEC) and atypical (aEPEC) strains, differing by the presence of EAF plasmid and bundle-forming pilus (BFP) in typical strains and their absence in atypical strains. This study searched the presence of EPEC strains in 101 fecal samples of diarrheic (n=65) and non-diarrheic (n=36) dogs from two cities in Rio de Janeiro State, Brazil. The isolates were evaluated for the presence of eae, tir, espA, espB and bfpA genes, EAF plasmid, and for the insertion site of the LEE locus. Cell-adherence assays, fluorescent actin staining (FAS) test, hemolysin production and serotyping were also performed. Twenty eight aEPEC isolates were recovered from 48 eae-positive fecal samples, 24 from diarrheic animals and 4 from non-diarrheic ones. PCR showed that most isolates was positive for β or γ intimin, and for β or α subtypes of tir, espA and espB. Six isolates showed a selC insertion of locus LEE. Only two isolates from the same diarrheic animal harbored the bfpA gene, and none presented the EAF plasmid. Most isolates was FAS-positive and showed a localized adherence-like (LAL) in a 6h HeLa cell-adherence assay. A wide diversity of serotypes was detected including O4:H16 and O51:H40, previously described in human disease. The phenotypic and genotypic markers of aEPEC isolated from diarrheic and non-diarrheic dogs were similar to those found in isolates recovered from human disease.     

Geometric approach to evaluate the energy/protein balance in tambaqui (Colossoma macropomum): Can fish ensure nutritional intake targets by postingestion signals?

The aim of this study was to investigate the ability of tambaqui (Colossoma macropomum) to balance the energy (E) and protein (P) ratio by encapsulated diets (without sensory properties). Thirty fish (71.37 ± 2.58 g) were distributed in six 250‐litre tanks. Protein (P), carbohydrate (C) and fat (F) were encapsulated separately to ensure the same sensory properties of each macronutrient. Diets varied in terms of macronutrients to allow the maximal/minimal possibility of ingesting each nutrient following a geometric approach. P, C and F capsules were provided for 40 days (phase 1). After this procedure, fish were subjected to fixed low and poor protein challenges (200 g/kg), and freely to C + F, to evaluate whether they maintained a given intake target (phase 2). As a result, tambaqui showed an intake target at 300 g/kg of crude protein and 16.74 MJ per kg. Give the possibility of freely feeding protein, fish regulated their feed intake and showed a constant E/P ratio pattern (5.024‐5.861 MJ/kg). When protein was restricted and fixed at 200 g/kg, fish maintained similar feed consumption until the end of phase 1, probably to keep a minimal protein amount according to their nutritional requirements.