Liming as an ameliorator of copper toxicity in black oat (Avena strigosa Schreb.)

This study aimed to assess the effect of liming as an ameliorator of copper (Cu) toxicity in black oats (Avena strigosa Schreb.) grown in soil with a sandy texture. The treatments were soil supplementation with increasing doses of lime (0.0, 0.5 and 1.0 g kg^?1) and two of Cu (0 and 50 mg kg^?1). Pre-germinated black oat seeds were sown for 30 days in the soil, subsequently, the plant height, root and shoot dry mass and concentration of total chlorophyll, chlorophylls a and b, carotenoids and total soluble carbohydrates and starch were analyzed. The dose of 50 mg kg^?1 soil Cu caused a toxic effect on black oat plant growth and development, affected the internal distribution of nutrients, decreased the leaf chlorophyll concentration and increased the leaf concentration of total soluble carbohydrates and starch. Increasing lime doses ameliorated the toxic effects of Cu.     

Performance of beef heifers supplemented with sodium lasalocid

This study was conducted on 78 13-month-old crossbred beef heifers that weighed 215 kg in Southern Rio Grande do Sul (RS) State, Brazil. We evaluated the performance of beef heifers that were reared in a pasture system that received a mineral supplement energy-type protein with added sodium lasalocid (LAS). The heifers were randomly and uniformly divided into 2 groups, with 39 animals in each group. One group of animals received a mineral supplement energy-type protein without sodium lasalocid (CON), and the other group received a mineral supplement energy-type protein with added LAS. The mean feed intake, the body weight (BW), the average daily gain (ADG), the body condition score (BCS), and ovarian cyclicity were recorded, and economic parameters were calculated. No differences in supplement intake were observed between the groups, which ensures adequate intake of the other components of the mineral mixture, which are part of the nutritional requirements for the production process. Similarly, no difference in the ADG was observed between treatments. We observed that the heifers in the LAS group had a higher BW gain (51 kg) that the CON heifers (40 kg; P?<?0.05). In addition, LAS-supplemented heifers had a higher BCS (3.53) than CON heifers (3.38) at the end of the experiment (P?<?0.05). The heifers supplemented with LAS had a higher profitability than the CON heifers, even with the higher cost of the supplement containing LAS; this effect was due to the higher live BW at the end of the study. We concluded that the administration of a mineral supplement energy-type protein with added LAS has beneficial effects on beef heifers in terms of production and economic feasibility.     

Sheep fed with banana leaf hay reduce ruminal protozoa population

A ciliate protozoa suppression can reduce methane production increasing the energy efficiency utilization by ruminants. The physicochemical characteristics of rumen fluid and the profile of the rumen protozoa populations were evaluated for sheep fed banana leaf hay in replacement of the Cynodon dactylon cv. vaqueiro hay. A total of 30 male sheep were raised in intensive system during 15 days of adaptation and 63 days of experimental period. The animals were distributed in a completely randomized design that included six replicates of five treatments with replacement levels (0, 25, 50, 75, and 100%) of the grass vaquero for the banana leaf hay. Samples of fluid were collected directly from the rumen with sterile catheters. Color, odor, viscosity, and the methylene blue reduction potential (MBRP) were evaluated and pH estimated using a digital potentiometer. After decimal dilutions, counts of genus protozoa were performed in Sedgewick Rafter chambers. The averages of pH, MBRP, color, odor, and viscosity were not influenced by the inclusion of the banana leaf hay. However, the total number of protozoa and Entodinium spp. population significantly decreased at 75 and 100% inclusions of banana leaf hay as roughage.     

"Time sweet time": circadian characterization of galectin-1 null mice

Background  

Recent evidence suggests a two-way interaction between the immune and circadian systems. Circadian control of immune factors, as well as the effect of immunological variables on circadian rhythms, might be key elements in both physiological and pathological responses to the environment. Among these relevant factors, galectin-1 is a member of a family of evolutionarily-conserved glycan-binding proteins with both extracellular and intracellular effects, playing important roles in immune cell processes and inflammatory responses. Many of these actions have been studied through the use of mice with a null mutation in the galectin-1 (Lgals1) gene. To further analyze the role of endogenous galectin-1 in vivo, we aimed to characterize the circadian behavior of galectin-1 null (Lgals1 ^-/-) mice.     

Identification and characterization of a novel etiological agent of mango malformation disease in Mexico, Fusarium mexicanum sp. nov

The primary objective of this study was to characterize Fusarium spp. associated with the economically devastating mango malformation disease (MMD) in Mexico. In all, 142 Fusarium strains were isolated from symptomatic mango inflorescences and vegetative tissues in eight geographically diverse Mexican states from 2002 through 2007. Initially, all the Mexican isolates were screened for genetic diversity using appolymerase chain reaction and random amplified polymorphic DNA markers and were grouped into seven distinct genotypes. Based on results of these analyses, evolutionary relationships and species limits of the genetically diverse MMD-associated Fusarium spp. were investigated using multilocus DNA sequence data and phylogenetic species recognition. Maximum parsimony analyses of a five-locus data set comprising 5.8 kb of aligned DNA sequence data indicated that at least nine phylogenetically distinct Fusarium spp. within the Gibberella fujikuroi species complex are associated with MMD, including one species within the African clade (Fusarium pseudocircinatum), two species within the Asian clade (F. mangiferae and F. proliferatum), and at least six species within the American clade (F. sterilihyphosum and five undescribed Fusarium spp.). Molecular phylogenetic analyses indicate that a novel genealogically exclusive lineage within the American clade was the predominant MMD associate in Mexico. This new Fusarium sp. caused MMD and could be distinguished from all other known species morphologically by the production of mostly sterile, coiled hyphae which are typically associated with sporodochial conidiophores together with unbranched or sparsely branched aerial conidiophores. Koch's postulates were completed for isolates of the new species on nucellar seedlings of mango cv. Ataulfo. This pathogen is formally described herein as F. mexicanum.     

Effects of feeding frequency on growth,feed efficiency and body composition of juveniles Brazilian sardine,Sardinella brasiliensis (Steindacher 1879)

The Brazilian sardine is the most important fishery resource in Brazil. Their production has declined along the last 30 years due the overfishing, climatic and oceanographic phenomena. This study was carried out to determine the optimal feeding frequency for juvenile Brazilian sardine based on growth, feed efficiency, feed intake and body composition. Six feeding frequencies of one, two, three, four, five and six times a day were evaluated in triplicate tanks for 50 days. Fish with initial mean weight of 3.29 ± 0.56 g were fed daily to apparent satiation. The results showed that fish fed once daily had lower body weight gain, specific growth rate and condition factor (P < 0.05) compared with other treatments. The feed efficiency ratio in fish fed once daily was significantly higher (P < 0.05) than those fed two or more times a day. No significant differences were observed in the coefficient of variation in body weight (P > 0.05) among the treatments. Feed intake was directly proportional to the feeding frequency. Fish fed once daily showed lower hepatosomatic and mesenteric fat indices (P < 0.05) than the other treatments. Neither protein nor ash content of fish were significantly (P > 0.05) affected by feeding frequency. However, the lipid content increased with feeding frequency. The results suggest that the optimal feeding frequency for juvenile Brazilian sardine is at least twice daily.     

Book reviews

Rodents in Agriculture: A Review of Findings in Bangladesh. By H. Posamentier: Sonderpublikation der GTZ No. 176, 1989, 107 pp. ISBN 3–88085–306–1. Price DM 22.00 (approx. £7.50 or US$13.00).

Motivating Farmers for Action: how strategic multimedia campaigns can help; results and experiences of the Bangladesh rat control campaign. By R. Adhikarya and H. Posamentier. Eshborn: Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ), 1987, pp. 209. ISBN 3–88085–289–8.     

Simultaneous Removal of H2S, NH3, and Ethyl Mercaptan in Biotrickling Filters Packed with Poplar Wood and Polyurethane Foam: Impact of pH During Startup and Crossed Effects Evaluation

The present work discusses the startup and operation of different biotrickling filters during the simultaneous removal of NH₃, H₂S, and ethyl mercaptan (EM) for odor control, focusing on (a) the impact of pH control in the stability of the nitrification processes during reactor startup and (b) the crossed effects among selected pollutants and their by-products. Two biotrickling filters were packed with poplar wood chips (R1 and R2A), while a third reactor was packed with polyurethane foam (R2B). R2A and R2B presented a pH control system, whereas R1 did not. Loads of 2?C10?g N?CNH₃ m^?3?h^?1, 5?C16?g S?CH₂S m^?3?h^?1, and 1?C6?g EM m^?3?h^?1 were supplied to the bioreactors. The presence of a pH control loop in R2A and R2B proved to be crucial to avoid long startup periods and bioreactors malfunctioning due to biological activity inhibition. In addition, the impact of the presence of different concentrations of a series of N species (NH ₄ ⁺ , NO ₂ ^? , and NO ₃ ^? ) and S species (SO ₄ ^2? and S^2?) on the performance of the two biotrickling filters was studied by increasing their load to the reactors. Sulfide oxidation proved to be the most resilient process, since it was not affected in any of the experiments, while nitrification and EM removal were severely affected. In particular, the latter was affected by SO ₄ ^2? and NO ₂ ^? , while nitrification was significantly affected by NH ₄ ⁺ . The biotrickling filter packed with polyurethane foam was more sensitive to crossed effects than the biotrickling filter packed with poplar wood chips.