Risk factors to incidental leptospirosis and its role on the reproduction of ewes and goats of Espírito Santo state,Brazil

Ovine and caprine stockbreeding have been gaining attention in developing countries as an attractive investment. On these animals, infectious diseases of the reproductive tract, such as leptospirosis, can compromise the production leading to economic losses. The present study aimed to determine the risk factors associated with incidental leptospirosis and its influence on the reproductive parameters of ewes and goats of Espírito Santo state, Brazil. A total of 737 animals distributed on 24 herds/flocks were studied, and an overall prevalence of 10.9 % seroreactive animals was observed. Serogroup Icterohaemorrhagiae was the most frequent in goats (97.0 %) as well as in ewes (78.3 %). Regarding risk factors related to leptospirosis, the presence of waterholes and the semi-intensive breeding system were the most important associated to seroreactivity. Besides, there was an observed association between seroreactivity and reproductive failures (P?<?0.05). Moreover, seroreactive ewes (relative risk (RR)?=?1.3) and goats (RR?=?1.9) presented more chances to have abortions than seronegative animals. Furthermore, seroreactive ewes presented 11.6 more chances of having premature births when compared to the seronegative ones. It can be concluded that Leptospira infection, mainly those caused incidental strains (such as Icterohaemorrhagiae serogroup), is a significant factor to reduce the productivity of small ruminants’ herds/flocks in the studied region, and environmental measures must be considered on control programs.

     

Critical loads for nitrogen deposition on forest ecosystems

Critical loads for N deposition are derived from an ecosystem's anion and cation balance assuming that the processes determining ecosystem stability are soil acidification and nitrate leaching. Depending on the deposition of S, the parent soil material, and the site quality critical N deposition rates will range between 20 to 200 mmol m^?2 yr^?1 (3 to 14 kg ha^?1 yr^?1) on silicate soils and reach 20 to 390 mmol m^?2 yr^?1 (3 to 48 kg ha^?1) on calcareous soils.     

Postprandial glycemia, insulinemia, and satiety responses in healthy subjects after whole grain rye bread made from different rye varieties. 1

Rye products typically induce low insulin responses and appear to facilitate glucose regulation. The objective of this study was to investigate differences in postprandial glucose, insulin, and satiety responses between breads made from five rye varieties. Breads made from whole grain rye (Amilo, Rekrut, Dankowski Zlote, Nikita, and Haute Loire Pop) or a white wheat bread (WWB) were tested in a randomized cross-over design in 14 healthy subjects (50 g available starch). Metabolic responses were also related to the composition of dietary fiber and bioactive compounds in the breads and to the rate of in vitro starch hydrolysis. The Amilo and Rekrut rye breads induced significantly lower insulin indices (II) than WWB. Low early postprandial glucose and insulin responses (tAUC 0-60 min) were related to higher amounts of caffeic, ferulic, sinapic, and vanillic acids in the rye breads, indicating that the phenolic acids in rye may influence glycemic regulation. All rye breads induced significantly higher subjective feelings of fullness compared to WWB. A low II was related to a higher feeling of fullness and a lower desire to eat in the late postprandial phase (180 min). The data indicate that some rye varieties may be more insulin-saving than others, possibly due to differences in dietary fiber, rate of starch hydrolysis, and bioactive components such as phenolic acids.     

Response of Thawed Epidi dymal Red Deer Spermatozoa to Increasing Concentrations of Hydrogen Peroxide,and Importance of Individual Male Variability

Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H₂O₂) levels on red deer spermatozoa after cryopreservation, and the role of male‐to‐male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 μm H₂O₂ for 2 h at 37°C. Intracellular reactive oxygen species (H₂DCFDA‐CM) increased with H₂O₂ concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 μm . Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 μm H₂O₂ and above. In a second experiment, samples from seven males were submitted to 0 and 200 μm H₂O₂ for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H₂O₂ presence. We found that the kinematic parameters reflected male‐to‐male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H₂O₂ or after incubation with H₂O₂. Red deer spermatozoa are relatively resilient to H₂O₂ after thawing, but it seems to be a great male‐to‐male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols.     

Induced breeding of the South American catfish, Rhamdia sapo (C. & V.)

Pituitary suspensions from the characin, Prochilodus platensis, were injected intraperitoneally into male and female Rhamdia sapo at doses between 0.37 and 6 mg dry weight per kg of body weight. Doses from 0.75 to 6.0 mg/kg effectively induced ovulation. The latent period between injection and ovulation for females held at different temperatures (17 to 27°C) decreased with increasing temperature.Stripping of gametes from both sexes, and dry method fertilization were successful and produced viable eggs. The period between ovulation and stripping for the highest hatching rates decreased from about 9 h at 20°C, to 5 h at 24°C. No viable eggs remained in samples obtained after 15 h at 20°C, or 8 h at 24°C. Hatching percentage and the fraction of deformed fry were negatively correlated (r = ?0.75; P < 0.001).     

Induced breeding of the sabalo,Prochilodus platensis Holmberg

Maturation and ovulation were induced in female Prochilodus platensis with multiple homologous pituitary extract injections (total dose 0.9 to 1.4 hypophysis/kg) or single injections of pituitary extract combined with human chorionic gonadotrophin ((1 hypophysis + 500 I.U.)/kg). One of the females given the latter treatment produced viable eggs. Latency time from injection to ovulation was 9 h (at 28°C). Hatching occurred 12 h after fertilization. Survival after 30 days of rearing was 96%.     

Effects of mechanical stress in under-sized clams, Tapes philippinarum: a laboratory approach

The present study is a first attempt at evaluating the effects of repeated disturbance, such as that caused by mechanical fishing systems, on the target species, Tapes philippinarum, intensively exploited in the Lagoon of Venice (North-East Italy). In particular, in free-access fishing grounds, detrimental effects of dredging may be suffered by under-sized clams, which are disturbed by fishing tools many times throughout their lives before they are collected. Similar mechanical stress conditions are experienced by T. philippinarum in licensed areas, where they are farmed in aquaculture conditions and undergo the harmful impact of hydraulic dredging. To evaluate the effects of short-term mechanical stress, under-sized clams were subjected to experimental shaking in the laboratory, and detrimental effects on their well-being were investigated by applying the biomarker approach. Changes in physiological, biochemical and behavioural responses were evaluated by determining scope for growth, adenylate energy charge, survival in air time, reburrowing time, and shell damage level. Responses highlighted general worsening in clam condition as mechanical stress increased. Among the various measurements, survival in air and reburrowing time appeared particularly suitable as indices, their responsiveness and applicability suggesting their use in assessing mechanical stress due to dredging in field conditions.     

Changes in some constituents of pea seed during commercial canning

Changes in crude protein (CP), non protein nitrogen (NPN), total sulphur (TS) contents, carbon/nitrogen (C/N) and nitrogen/sulphur (N/S) ratios and albumin protein (AP) were studied in four sizes of peas at various stages of the commercial canning process. Of all the parameters considered, NPN, AP, and TS showed the most regular trend to decrease during the commercial canning process. In this paper the use of these three parameters is proposed to obtain a Heat Treatment Index (HTI) applicable to raw, blanched and canned peas, according to the equation: HTI=(NPN×AP)/TS.     

Atom collision-induced resistivity of carbon nanotubes

We report the observation of unusually strong and systematic changes in the electron transport in metallic single-walled carbon nanotubes that are undergoing collisions with inert gas atoms or small molecules. At fixed gas temperature and pressure, changes in the resistance and thermopower of thin films are observed that scale as roughly M(1/3), where M is the mass of the colliding gas species (He, Ar, Ne, Kr, Xe, CH4, and N2). Results of molecular dynamics simulations are also presented that show that the maximum deformation of the tube wall upon collision and the total energy transfer between the colliding atom and the nanotube also exhibit a roughly M(1/3) dependence. It appears that the transient deformation (or dent) in the tube wall may provide a previously unknown scattering mechanism needed to explain the atom collision-induced changes in the electrical transport.