Assessment of the ideal ratios of digestible essential amino acids for pacu,Piaractus mesopotamicus,juveniles by the amino acid deletion method

The present study aimed to determine the ideal ratios of digestible essential amino acids (EAAs) for pacu (Piaractus mesopotamicus) juveniles by the amino acid (AA) deletion method. A completely randomized design which consisted of 11 treatments and three replicates each was used. The treatments included a control diet (CD) containing 55% of nonpurified natural ingredients and 45% of purified synthetic amino acids and ingredients, and other ten isonitrogenous and isoenergetic EAA limiting diets (LDs), each being deficient in 44.4 ± 0.02% of the respective EAA. Pacu juveniles with initial average body weight of 6.22 ± 0.09 g were distributed among 33 fiber glass tanks. Fish were fed with semipurified and extruded diets for 113 days two times a day until apparent satiation. The ideal ratio of each dietary EAA was calculated on the basis of the relationship between body N retention and amount of EAA deleted from the respective EAA LD. Based on the AA deletion method, the ideal ratios of digestible EAAs for pacu juveniles, relative to lysine requirement of 100% were estimated as: methionine 14.6%, threonine 35.0%, tryptophan 6.6%, arginine 62.8%, histidine 13.6%, isoleucine 26.3%, leucine 43.7%, phenylalanine 27.2%, and valine 35.8%.     

Alternative Potash Fertilizer Source for Millet Crop

Millet is a grass that responds to potassium fertilization and Alfa 01 and Alfa 02 are potential sources of this nutrient. Thus, the aim of this study was to evaluate the potential of as potassium sources by measuring accumulation of this nutrient in millet. The crop was grown in Ustoxic Quartzipsamment (RQo) soil. The experiment was set up in randomized blocks with three repetitions. The treatments consisting of three sources (KCl, Alfa 02, Alfa 01), two rates (200 and 400 kg ha^?1 K₂O) and with no K fertilization (control). Potassium chloride was used as the standard to which the other sources of potassium were compared. Two consecutive crops of millet were grown in the same pots. The first crop received potassium source application but not the second. At the end of experiment, shoot dry matter production, shoot potassium concentration, shoot accumulated potassium, soil potassium and relative agronomic efficiency were determined. The relative agronomic efficiency, calculated from crops, was 100% for KCl, was 84% for Alfa 02 and was 11% for Alfa 01. In the shoot dry matter production and accumulated potassium only Alfa 01 was not statistically different of control. Millet absorbed potassium from the Alfa 02 source in both the first and second crops.     

A survey of antimicrobial-resistant Escherichia coli prevalence in wild mammals in Japan using antimicrobial-containing media

The emergence and spread of antimicrobial-resistant bacteria and resistance genes pose serious human and animal health concerns. Therefore, to control antimicrobial-resistant bacteria in the environment, the status of antimicrobial resistance of Escherichia coli in a variety of wild mammals and their prevalence were examined using antimicrobial-containing media. In total, 750 isolates were obtained from 274/366 (74.9%) wild mammals, and antimicrobial-resistant E. coli was detected in 37/750 isolates (4.9%) from 7 animal species (26/366 [7.1%] individuals). Using antimicrobial-containing media, 14 cefotaxime (CTX)- and 35 nalidixic acid-resistant isolates were obtained from 5 (1.4%) and 17 (4.6%) individuals, respectively. CTX-resistant isolates carried bla_CTX-M-27, bla_CTX-M-55, bla_CTX-M-1, and bla_CMY-2, with multiple resistance genes. Fluoroquinolone-resistant isolates had multiple mutations in the quinolone-resistance determining regions of gyrA and parC or qnrB19. Most resistant isolates exhibited resistance to multiple antimicrobials. The prevalence of antimicrobial-resistant bacteria observed in wild mammals was low; however, it is essential to elucidate the causative factors related to the low prevalence and transmission route of antimicrobial-resistant bacteria/resistance genes released from human activities to wild animals and prevent an increase in their frequency.     

Involvement of ATP‐sensitive K+ channels in the peripheral antinociceptive effect induced by ketamine

ObjectiveTo investigate the contribution of K⁺ channels on peripheral antinociception induced by ketamine.Study designProspective experimental study.Animals110 male Wistar rats weighing 160–200 g.MethodsThe paw pressure required to elicit limb flexion was designated as the nociceptive threshold. Hyperalgesia was induced by intraplantar injection of prostaglandin E₂. All drugs were administered locally into the right hind paw of rats. Ketamine was administered into the right hind paw 2 hours and 55 minutes after local injection of PGE₂. Tetraethylammonium was administered 30 minutes prior to ketamine and the other K⁺ channel blockers, glibenclamide, dequalinium and paxilline, were administered 5 minutes prior to ketamine.ResultsProstaglandin E₂ (2 μg per paw) induced hyperalgesia. Ketamine (10, 20, 40 and 80 μg per paw) elicited a local peripheral antinociceptive effect that was antagonized by a specific blocker of ATP‐sensitive K⁺ channels, glibenclamide (20, 40 and 80 μg per paw). In another experiment, the non‐selective voltage‐dependent K⁺ channel blocker tetraethylammonium (30 μg per paw) and small and large conductance blockers of Ca²⁺‐activated K⁺ channels, dequalinium (50 μg per paw) and paxilline (20 μg per paw), were ineffective at blocking the effect of a local ketamine injection.Conclusions and clinical relevanceAnalysis of these results provides evidence that ketamine, may in part, induce peripheral antinociceptive effects by ATP‐sensitive K⁺ channel pathway activation.     

Isolation and serological survey of Salmonella in pigs in Japan

A total of 267 fecal and serum samples collected from individual pigs reared on a Salmonella-positive farm were subjected to bacteriological and serological examinations of Salmonella. Salmonella was isolated from 47 pigs (17.6%) and prevalence of antibody to lipopolysaccharide (LPS) of S. Typhimurium, which was partly common to S. O4, 12: d: -, was observed in 90 pigs (33.7%). Salmonella was isolated from 26 (28.9%) of 90 antibody-positive pigs and 21 (11.9%) of 177 antibody-negative pigs. Twenty-one of 36 pigs (58.3%) positive for S. O4, 12: d: -, five of 10 pigs (50.0%) positive for S. Havana, and none for S. Anatum had antibodies. Thus, seropositive rates were higher than isolation-positive rates, and antibody prevalence was associated with serovars of the isolates. Then, we analyzed antibody prevalence among pigs on Japanese pig farms. The antibodies to LPS of S. Typhimurium were found in 195 of 1,498 pigs (13.0%) and in at least one serum sample on 35 of 52 farms (67.3%). Our results indicate that Salmonella does not seem to be so prevalent in pigs though it is widely prevalent among pig farms.     

过量表达星星草(Puccinellia tenuiflora)液泡型H~+-ATP酶c亚基基因提高转基因酵母的耐盐性

植物液泡型H+-ATP酶(V-ATPase)在次级转运与应对多种逆境胁迫中具有重要作用。本研究克隆并解析了能够生长在盐碱地上的野生星星草V-ATPase c亚基基因(Put VHA-c)的功能。本研究利用荧光蛋白(GFP)标记结合内涵体染色的方法研究了Put VHA-c蛋白在酵母细胞中的定位,并利用转基因酵母分析了Put VHA-c基因在盐胁迫中的作用。共定位实验显示Put VHA-c-GFP融合蛋白主要定位在酵母细胞的内涵体上。Northern杂交和实时定量PCR显示在星星草悬浮细胞中Put VHA-c基因的表达能够被盐胁迫所诱导。研究结果结合过表达Put VHA-c的转基因酵母具有更高的耐盐性的发现,说明Put VHA-c基因参与着盐胁迫的应答。     

Identification of RFLP markers linked with heading date and its heterosis in hexaploid wheat

Recombinant inbred lines (RILs) from a cross between hexaploid wheat (T. aestivum cv. Chinese Spring (CS) and T. spelta (Sp)) were used for RFLP analysis of heading date and heterosis. Fourteen RFLP markers linking with heading date were identified; two were localized on chromosome 1A, one on 2A, three on 2B, one on 2D, four on 5A, two on 7A and one unlinked but reported to be on group 2. All of these markers may be attributable to genes for earliness per se. However, the markers in the chromosomes of 1A and 7A are new to this study. RILs were crossed with (tim)-CS, the alloplasmic CS with T. timopheevi cytoplasm, and the heterosis from earlier-parent and mid-parents were calculated for the F₁s to examine the heterotic effect toward earliness on heading date. Five and two RFLP markers were associated with heterosis from the earlier-parent and mid-parents, respectively. They were distributed on the chromosomes of homoeologous groups 1 and 2. This revised version was published online in July 2006 with corrections to the Cover Date.     

An experimental assessment of landscape configuration effects on frog and toad abundance and diversity in tropical agro-savannah landscapes of southeastern Brazil

Amphibians are an imperiled group of vertebrate animals that typically have biphasic life histories involving a shift from aquatic larval habitats to terrestrial adult habitats. Habitat loss is the greatest threat to amphibians and the importance of the spatial configuration of terrestrial and breeding habitats upon the landscape in determining amphibian persistence is poorly known. The information gap is particularly acute in tropical landscapes that simultaneously host the greatest and most imperiled amphibian fauna on Earth. We installed 125 artificial ponds at different distances from forest fragments embedded in an agricultural matrix in southeastern Brazil. Constructed ponds attracted 13 anuran species; ponds at the forest fragment-matrix transition hosted a greater abundance and higher species richness of frogs and toads than those installed either far from or well within forest fragments. Forest fragments larger than 70 ha in agricultural areas harbored more individuals than smaller fragments. Our results indicate that landscape configuration has an important influence on frog and toad distribution and abundance in tropical agricultural landscapes and we suggest guidelines for maintaining favorable configurations of aquatic and terrestrial habitats for conserving this rich and imperiled species suite.