Effects of the GnRH antagonist acyline on the testis of the domestic cat (Felis catus)

The aim of this study was to describe the effects of a single dose of the gonadotrophin releasing hormone (GnRH) antagonist acyline on testicular characteristics of the domestic cat. Twelve mature cats were orchidectomised unilaterally (right testis) on Day -7 (n=7) or Day 15 (n=5). On Day 0, 330 μg/kg acyline was administered s.c. to all the animals. Left orchidectomy was carried out on Day 15 (n=2), Day 30 (n=4) and Day 60 (n=6). Sperm were recovered from the epididymis and the testes were evaluated grossly, histologically and immunohistochemically. Significant differences (P<0.05) were found between days for epididymal sperm motility, vigor, abnormal morphology, germinal epithelium height, spermatocytes, spermatids, spermatozoa, lumen and cellular debris. Conversely, no significant differences were found for gross testicular and tubular characteristics, spermatogonia, Sertoli and Leydig cells and intertubular compartments. It was concluded that a single dose of acyline reversibly impaired spermiogenesis, spermatocytogenesis and sperm motility for 2 weeks.     

Meta-analysis of the relationship between ractopamine and dietary lysine levels on carcass characteristics in pigs

A meta-analysis was carried out to evaluate the relationship between ractopamine and dietary lysine levels on carcass characteristics in pigs. The database was composed by 29 articles published in international journals from 1990 to 2007, totalizing 155 treatments and 3786 pigs. Average inclusion of ractopamine was 15.3 ppm (ranging from 0 to 30 ppm) and daily average intake of ractopamine was 24.9 mg. Ractopamine addition increased (P < 0.05) hot carcass weight in 4%, loin area in 12% and lean meat content in 4%. Pigs supplemented with ractopamine presented decrease (P < 0.05) of 8% in backfat thickness at the tenth rib, 3% in backfat thickness at the last rib and 5% in mean backfat thickness. Each increase in 1 mg of ractopamine intake represented a reduction of 0.3 mm in tenth-rib (Y = 29.61-0.308 RAC + 0.025 RAC², R² = 0.81, RAC: ractopamine intake expressed in mg) and 0.5 mm at last-rib backfat thickness (Y = 30.52 + 0.519 RAC-0.0054 RAC², R² = 0.94). The use of ractopamine affected (P > 0.05) neither carcass length and dressing, nor meat marbling and color. Loin area was positively correlated (r = 0.27, P < 0.05) and mean backfat thickness was negatively correlated (r = − 0.27, P < 0.05) to dietary lysine concentration. Pigs supplemented with ractopamine whose daily intake of lysine per unit of metabolic weight was more than 195 mg presented (P < 0.05) loin area 4% higher and backfat thickness 10% lower than other animals. Supplemented pigs that received diets with lysine content superior to their calculated amino acid requirement presented weight gain 14% higher, lean meat content 17% higher, leaf fat 34% lower and loin area 6% higher when compared to other supplemented animals. Ractopamine increases lean meat content and reduces backfat thickness in carcass, however, the interaction between additive and nutritional components must be considered in diet formulation.     

Toxicity of Benzalkonium Chloride on Monoalgal Cultures and Natural Assemblages of Marine Phytoplankton

The current widespread use of benzalkonium chloride (BAC) in different cleaning and disinfecting products led us to investigate its potential toxic effect on phytoplankton. To this aim, different physiological variables were monitored to detect toxicity of four ecologically relevant concentrations of BAC (15–200 μg l^?1) on batch cultures of the microalgae Isochrysis galbana and Chaetoceros gracilis, and on a coastal phytoplankton assemblage. Fluorescence variables measured by fast repetition rate fluorometry, specifically variable fluorescence (F _v), were the most suitable to be used as endpoint among all the variables recorded (biomass, growth rate, size structure, and species composition). Calculated effective concentrations from F _v data provided evidences of higher sensitivity in the natural assemblage at short exposure times (natural assemblage—EC₅₀ [24 h]?=?36.4 μg l^?1 vs. monoalgae—EC₅₀ [24 h]?>?120 μg l^?1). Despite these differences, standard monoalgal laboratory toxicity tests provided comparable estimates of safe concentrations for microalgae in the environment. Assessed EC₁₀ fall within the range of BAC concentrations reported in the literature for different effluents.

     

Field performance of a liquid formulation of Azospirillum brasilense on dryland wheat productivity

The beneficial effects of inoculating with Azospirillum brasilense on crop productivity have been widely described, but extensive use in typical agricultural field environments is scarcely documented. The objective of this study was to quantify the productivity of wheat (Triticum aestivum L.) whose seed was inoculated with a liquid formulation containing Azospirillum brasilense INTA Az-39 strain under typical dryland farming conditions. The study was performed in the 2002–2006 growing seasons, evaluating inoculated and non-inoculated seed at 297 experimental locations in the Pampas region of Argentina. The inoculated crops exhibited more vigorous vegetative growth, with both greater shoot and root dry matter accumulation (12.9 and 22.0%, respectively). The inoculation increased the number of harvested grains by 6.1%, and grain yield by 260 kg ha^?1 (8.0%). Positive responses were determined in about 70% of the sites, depending mostly on the attainable yield and independently of fertilization and other crop and soil management practices. In general, more response to inoculation was observed in the absence of major crop growth limitations, suggesting the complementary contribution of the Azospirillum brasilense treatment to more efficiently developing higher yielding wheat.     

Agromorphological genetic diversity of Spanish traditional melons

The variability of 62 Spanish landraces (and two hybrids used as reference) was described by analysing 39 morphological traits and eight SSR makers. Results showed that 81% of the examined genetic pool belonged to the inodorus type. Spanish traditional melons presented fruits from flattened and globular shapes to elliptical. Rind colour varied from pale green, almost white and yellow to dark green and almost black. Rind texture varied from smooth to intensely wrinkled. Spanish landraces also had larger fruits (average fruit weight ~2.6 kg) and longer vegetative cycles (117 days to maturity) compared to landraces from other geographical origins. Farmers seem to have focused on selection towards large fruits, which usually requires the longest production cycles. Fruit colour, size and shape seemed to have been determinant in varietal selection. Hierarchical clustering resulted in two main groups (climacteric and non-climacteric). The largest group was composed of 60 accessions of non-climacteric types, which includes the most demanded by national markets, ‘Piel de Sapo’, which fruits were characterized by an ovate or elliptical shape, a green rind, big spots and stains distributed over the whole fruit, a rounded blossom end shape and a very pointed stem end shape. The study demonstrates that the Spanish genetic pool is much more diverse. Wide variability was found in a geographical area with vast historical importance in melon farming. These evaluations has allowed the identification of several uniform groups of non-climacteric cultivars (‘Piel de Sapo’, ‘Mochuelo’, ‘Tendral’, Yellow/White, Winter and Black groups) and a set of highly variable climacteric ones. However, many accessions with singular properties remain unclassified, demonstrating the morphological variability of the studied collection. Melons in Spain have wide variability together with a vast historical importance on farms. Some fruit types, or at least some morphological characters reflected by painters during centuries, have reached the present. The present study confirmed the need to preserve these irreplaceable genetic resources and continue their study and evaluation for valuable traits which could enhance farmer’s opportunities for entering new markets.     

Probability of surface fire spread in Brazilian rainforest fuels from outdoor experimental measurements

This paper describes the development of a logistic model to predict the probability of surface fire spread in Brazilian rainforest fuels from outdoor experimental measurements. Surface fires spread over litter composed mostly of dead leaves and twigs. There were 72 individual outdoor experiments in eighteen sites. The fire propagated in 49% of the experiments. In each experiment, the litter height, litter temperature, unburned litter mass, wet and dry litter mass, soil temperature, wet and dry soil mass, ambient wind velocity, ambient air temperature, ambient air relative humidity and duration of fire spread were measured. Using these data, the rate of fire spread, litter bulk density, litter and soil moisture content, litter load and litter residue fraction were determined. For the sake of analysis, experimental results were classified into two groups: one for which the fire propagated and the other one for which the fire self-extinguished. Analyses of a logistic regression model showed that the relevant parameters for fire propagation are litter height and litter moisture content. Concerning the probability of successful fire propagation, the model showed a true positive rate of 71% and a true negative rate of 84%. The outdoor experiments also served to gather data to improve the understanding of surface fires and to provide input data for future computer simulations.     

Concentration of Bioactive Compounds from Elderberry (<Emphasis Type="Italic">Sambucus nigra</Emphasis> L.) Juice by Nanofiltration Membranes

For the first time the chemical profile, physico-chemical parameters, inhibition of carbohydrate hydrolysing enzymes associated with type 2 diabetes, and radical scavenging properties of Sambucus nigra L. (elderberry) juice treated by nanofiltration (NF) were investigated. Three commercial NF membranes with different molecular weight cut-off (MWCO) (400 and 1000 Da) and polymeric material (composite fluoro-polymer and polyethersulphone) were tested. According to HPLC analyses, most part of bioactive compounds were retained by the NF membranes producing a retentate fraction of interest for the production of functional foods. The NP030 membrane, a polyethersulphone membrane with a MWCO of 400 Da, exhibited the highest rejection towards phenolic compounds when compared with the other selected membranes. Accordingly, the produced retentate fractions exhibited the highest radical scavenging activity.     

In silico annotation of five candidate genes associated with pathogenicity in Fusarium circinatum

The Pine Pitch Canker disease caused by the pathogenic fungus Fusarium circinatum is one of the most devastating diseases in pine forests, afforestation and nurseries around the world. Despite the importance of this phytopathogen, only a little is known about the genes that drive the infection traits and the virulence factors. In this work, five candidate genes (i.e. Fcfga1, Fcfgb1, Fcac, Fcrho1 and FcpacC) were in silico annotated using the whole genome of F. circinatum as reference. The similarity of these proposed genes at nucleotide and protein levels with genes previously described in other Fusarium species was > 90% of identity and > 90% query coverage in all cases. In addition, the gene ontology of each candidate gene was also investigated.     

Influence of multiple- and single-species infestations on herbivore-induced cotton volatiles and <Emphasis Type="Italic">Anthonomus grandis</Emphasis> behaviour

Plants interact with multiple organisms throughout their life cycle. As a result, they are commonly attacked by multiple species of herbivores, leading to the induction of plant defence systems. Herbivore-induced plant volatiles (HIPVs) play an important role in the interaction between community members and can be used to manipulate insect pest behaviour, being a valuable tool in integrated pest management strategy. In this study, the interaction of two chewing insects, the boll weevil, Anthonomus grandis, and the fall armyworm, Spodoptera frugiperda, and of one piercing-sucking insect, the Neotropical brown stinkbug, Euschistus heros, was evaluated for the induction of volatile compounds in cotton under single- and multiple-species attacks. As a control, the emissions of undamaged plants were also measured. In addition, the effect of HIPVs on boll weevil behaviour was also assessed. Qualitatively, single- and multiple-species herbivory induced a similar volatile blend. There was, however, a difference in the amount and proportion of compounds emitted. Plants infested with E. heros emitted a blend of volatiles more similar to that of the undamaged control compared to the other herbivore-induced treatments. The plant volatiles emitted due to simultaneous multiple-species herbivory were induced faster than volatiles emitted by sequential herbivory events, indicating different induction mechanisms depending on the attack configuration. In addition, cotton volatiles induced by an individual attack of A. grandis were attractive to conspecifics, as were the volatiles induced by multiple-species herbivory in both simultaneous and sequential attacks. The use of cotton HIPVs, both under multiple- and single-species attack, can be used for the development of alternative methods for semiochemical-based weevil management, e.g., enrichment of aggregation pheromone traps with plant volatiles.