Tritrichomonas foetus damages bovine oocytes in vitro

Tritrichomonas foetus is an extracellular parasite of the urogenital tract in cattle. It causes infertility and abortion, but there is no documented information on the susceptibility of bovine oocytes to the parasite, except by one article that claimed no effects of T. foetus on oocytes or embryos. The aim of the present study was to study the effects provoked by T. foetus when in interaction with bovine oocytes. Oocytes were obtained from cow ovaries and divided into two groups: (1) one group contained cumulus cells, whereas (2) a second group was denuded from these cells. Light microscopy, video microscopy and scanning electron microscopy (SEM) revealed that exposure of oocytes to T. foetus caused rapid adhesion of the trichomonads to cumulus cells and to the zona pellucida (ZP). Motile parasites were observed for 12 h. The ZP was completely damaged, and the parasites were able to infiltrate beneath the ZP and reached the oocytes directly when the oocytes were denuded of the cumulus cells. Both the oocytes and the cumulus cells exhibited morphological characteristics compatible with apoptosis after interaction with T. foetus, such as chromatin condensation, the presence of several cytoplasmic vacuoles, with intact cellular membranes and organelles. The results from this study demonstrate that when a large number of T. foetus interacts with oocytes in vitro damage and apoptosis are provoked in the cow's reproductive cells. The behavior of this parasite as one of the causes of cattle infertility is discussed.     

Laparoscopic ovariectomy in dogs: comparison between laparoendoscopic single-site and three-portal access

This study was conducted to evaluate the feasibility and therapeutic safety of laparoendoscopic single-site ovariectomy (LESS-OVE) and 3-portal laparoscopic ovariectomy (Lap-OVE) in dogs. Ten female mixed breed dogs were included in the study. Dogs were divided into group 1 (LESS-OVE; n = 5) and group 2 (Lap-OVE; n = 5). All procedures were performed by laparoscopic-skilled surgeons, and the anesthetic protocol was the same for all patients. In both groups, the ovarian vascular pedicle and ligaments were transected using a bipolar vessel sealer/divider device. The mean total surgical time was slightly longer in LESS-OVE (36.6 ± 3.5 min) than Lap-OVE (32.0 ± 3.0 min); however, the differences were not significant. Perioperative complications were not reported in any group. Both laparoscopic techniques were shown to be equally feasible and safe for patients. However, surgeons found LESS-OVE to require more skill than Lap-OVE. Therefore, additional studies should be conducted to evaluate this novel approach in clinical veterinary practice, and a proper laparoscopic training program for veterinary surgeons should be developed.     

Sourcing Rhizobium leguminosarum biovar viciae strains from Mediterranean centres of origin to optimize nitrogen fixation in forage legumes grown on acid soils

Over the last three decades, farming systems in Europe and Australia have seen a decline in legume plantings, leading to reduced soil carbon and fertility, and an increase in plant disease, reliance on industrial nitrogen fertilizer and herbicides. In Australia, one reason for this decline has been the movement towards sowing crops and forages into dry soil, before the opening rains, as a consequence of climate variability. This practice predicates against the survival of rhizobial inoculants, and hence generates uncertainty about legume performance. The research reported here was initiated to improve the robustness of a specific forage legume/rhizobia symbiosis to increase nitrogen fixation in low pH, infertile soils. Rhizobial strains (Rhizobium leguminosarum biovar viciae) from Pisum sativum L. were sourced from acid soils in southern Italy and southern Australia. Strains were evaluated for N fixation on the forage legumes P. sativum, Vicia sativa and Vicia villosa, then for survival and persistence in acid soils (pH_Ca 4.6). Fourteen of the strains produced a higher percentage of nitrogen derived from the atmosphere (%Ndfa) compared to commercial comparator strain SU303 (<78%). Twenty‐two strains survived sufficiently into the second season to form more nodules than SU303, which only achieved 3% of plants nodulated. Elite strains WSM4643 and WSM4645 produced six times more nodulated plants than SU303 and had significantly higher saprophytic competence in acid soil. These strains have the ability to optimize symbiotic associations with field peas and vetch in soils with low fertility, carbon and pH that are restrictive to the current commercial strain SU303.     

Oxylipin Diversity in the Diatom Family Leptocylindraceae Reveals DHA Derivatives in Marine Diatoms

Marine planktonic organisms, such as diatoms, are prospective sources of novel bioactive metabolites. Oxygenated derivatives of fatty acids, generally referred to as oxylipins, in diatoms comprise a highly diverse and complex family of secondary metabolites. These molecules have recently been implicated in several biological processes including intra- and inter-cellular signaling as well as in defense against biotic stressors and grazers. Here, we analyze the production and diversity of C₂₀ and C₂₂ non-volatile oxylipins in five species of the family Leptocylindraceae, which constitute a basal clade in the diatom phylogeny. We report the presence of species-specific lipoxygenase activity and oxylipin patterns, providing the first demonstration of enzymatic production of docosahexaenoic acid derivatives in marine diatoms. The differences observed in lipoxygenase pathways among the species investigated broadly reflected the relationships observed with phylogenetic markers, thus providing functional support to the taxonomic diversity of the individual species.     

Ambient Levels and Sources of Lower Carbonyls at Montelibretti, Rome (Italy)

Concentration levels of 11 lower carbonyls were studied at Montelibretti, a semi-rural area near Rome, Italy, over July–September 2005 and February 2006. In both periods the most abundant carbonyls were acetone and formaldehyde, followed by methylglyoxal, acetaldehyde and hexanal. Monthly variation was apparent with maximum values observed in July, when levels at least a factor two higher compared to the successive months were observed. In summer all carbonyls except acetone were reasonably well correlated among themselves and with ozone. In addition very high formaldehyde/benzene concentration ratios were measured in the summer months compared to February. These findings indicated that photochemical reactions should be the major source of carbonyls in summer. Ranking of carbonyls respect to ozone production potential emphasized the predominance of formaldehyde and methylglyoxal, followed at a distance by glyoxal and acetaldehyde.     

Structure-activity relationships of derivatives of fusapyrone, an antifungal metabolite of Fusarium semitectum

Fusapyrone (1) and deoxyfusapyrone (2) are two 3-substituted-4-hydroxy-6-alkyl-2-pyrones isolated from Fusarium semitectum that have considerable antifungal activity against molds. Because of their low zootoxicity and selective action they are potentially utilizable along with biocontrol yeasts for control of postharvest crop diseases. Seven derivatives of 1 (3 and 5-10) and one derivative of 2 (4) were obtained by chemical modifications of the glycosyl residue, the 2-pyrone ring, the aliphatic chain, or a combination thereof, and a structure-activity correlation study was carried out with regard to their zootoxicity and antifungal activity. Derivatives 7-10, as well as 1, were slightly zootoxic in Artemia salina (brine shrimp) bioassays, whereas pentaacetylation of 1 into 3, 5, and 6 resulted in a strong increase in toxicity. Compound 4, the tetraacetyl derivative of 2, was as toxic as 2. Because the structural changes of 1 that resulted in an increase of biological activity in A. salina bioassay were those that affected mainly the water solubility of the molecule, it appears that toxicity is related to hydrophobicity. Compounds 1 and 2 showed strong antifungal activity toward Botrytis cinerea, Aspergillus parasiticus, and Penicilliun brevi-compactum (minimum inhibitory concentration at 24 h = 0.78-6.25 microg/mL). Among derivatives 3-10, only compounds 7, 9, and 10 retained some activity, limited to B. cinerea and at high concentration (25-50 microg/mL). None of the compounds 1-10 inhibited the growth of the biocontrol yeasts Pichia guilliermondii and Rhodotorula glutinis at the highest concentration tested (50 microg/mL).     

Combined and single effects of elevated CO2 and temperatures on rice bakanae disease under controlled conditions in phytotrons

Bakanae disease, caused by Fusarium fujikuroi, was investigated under different CO₂ and temperature environments in order to simulate climate changes in the F. fujikuroi–rice pathosystem. F. fujikuroi-infected plants were grown under six phytotron conditions: low (18/22 °C night/day), medium (22/26 °C), and high (26/30 °C) temperature, at either ambient (450 ppm) or elevated (850 ppm) CO₂ concentrations. Bakanae disease index (DI), seedling death incidence, fungal DNA quantity, and chlorophyll and carbohydrate contents varied significantly in infected plants as a consequence of changes in both CO₂ and temperature. Plant height and dry weight were only influenced by single factors (temperature for height, and temperature or CO₂ for dry weight), and not by the CO₂ × temperature interaction. Medium and high temperatures (irrespective of the CO₂ level) increased the DI significantly (range from 67.5% to 95.8%) compared to low temperatures (range from 45.8% to 47.5%). Under elevated CO₂ levels, noticeable differences in the expression of four rice defence-related genes and fungal DNA quantity were observed between those plants grown at higher temperatures and those at lower temperatures. Overall, combined and single effects of elevated CO₂ and high temperatures seem to be favourable for bakanae disease development in the Mediterranean basin.     

Assessing temporal variation of primary and ecosystem production in two Mediterranean forests using a modified 3-PG model

Context

Forest ecosystem carbon uptake is heavily affected by increasing drought in the Mediterranean region.

Aims

The objectives of this study were to assess the capacity of a modified 3-PG model to capture temporal variation in gross primary productivity (GPP), and ecosystem net carbon uptake (NEE) in two Mediterranean forest types.

Methods

The model was upgraded from a monthly (3-PG) to a daily time step (3-PG_day), and a soil water balance routine was included to better represent soil water availability. The model was evaluated against seasonal GPP and NEE dynamics from eddy covariance measurements.

Results

Simulated and measured soil water content values were congruent throughout the study period for both forest types. 3-PG_day effectively described the following: GPP and NEE seasonal patterns; the transition of forest ecosystems from carbon sink to carbon source; however, the model overestimated diurnal ecosystem respiration values and failed to predict ecosystem respiration peaks.

Conclusions

The model served as a rather effective tool to represent seasonal variation in gross primary productivity, and ecosystem net carbon uptake under Mediterranean drought-prone conditions. However, its semi-empirical nature and the simplicity inherent in the original model formulation are obstacles preventing the model working well for short-term daily predictions.     

Dogs' features strongly affect people's feelings and behavior toward them

Dogs are a strong appeal for people. The aim of this research was to assess whether different dog features affect people's feelings and behavior toward them. Three puppies (1 Labrador retriever, 1 golden retriever, and 1 Border collie), 7 average adult dogs (3 small, 2 medium, and 2 large), and 2 adult pit bulls (1 black and 1 brown) were involved. They were on the leash with handlers (12 girls) who were instructed to maintain a neutral posture of waiting. People who passed in front of the dog–handler couple were videorecorded and then interviewed through an 8-item questionnaire. Most passersby (81.7%) noticed the dog. Tenderness was higher for the puppies (64.9%) in comparison to the average adult dogs (35.4%) and pit bulls (10.8%) (χ² = 100.442; P = 0.000). Pit bulls left more passersby indifferent (36.3%), followed by the medium-sized dogs (26.5%) and then the small dogs (19.2%) (χ² = 37.268; P = 0.000). Fear was more common at the sight of a pit bull (10.8%), especially when compared with a puppy (2.3%) or a small dog (0.7%) (χ² = 17.723; P = 0.001). More respondents desired to interact with puppies (49.1%) than with pit bulls (22.5%; χ² = 11.133; P = 0.000), and they actually related with young dogs (20.5%) more than with the pit bulls (4.9%). A high statistical difference can be observed for the behavior of participants toward the different categories of dogs (χ² = 43.519; P = 0.000) and their handlers (χ² = 23.854; P = 0.000). In detail, passersby showed more interest toward puppies and interacted more with puppies and large dogs, and their handlers, compared with dogs showing different features.Some factors related to passersby could affect the dog catalysis effect. Women interacted with the handlers more than men did (12.1% vs. 7.3%; χ² = 3.980; P = 0.046), but no difference was observed for the number of interactions with dogs.Passersby handling a dog were more predisposed to interact with the experimental dog (45.6% vs. 7.5%; χ² = 139.606; P = 0.000) and his or her handler (43.5% vs. 5.7%; χ² = 64,526; P = 0.000). Data suggest that puppies and pit bulls are at the 2 extremes of the dog appeal–people axis, with average dogs in the middle.     

Diphenylamine residues in apples caused by contamination in fruit storage facilities

The potential of fruit storage facilities that are contaminated with the widely used chemical antioxidant diphenylamine to cross-contaminate untreated apples (Malus × domestica Borkh.) was studied. A new sample preparation method identified the storage room paint, contaminated from past treatments, as the major source of cross-contamination in the analyzed facilities. Diphenylamine amounts of up to 917 g were found in a single storage room and were shown to correlate with the extent of cross-contamination on stored apples. Our data support a diffusion-based mechanism where the wall paint releases the antioxidant to the storage room atmosphere even years after the last treatment. Given the extent of cross-contamination found in our model experiments and under commercial storage conditions, we deduce a significant risk of exceeding the potentially upcoming maximum residue level of 0.01 mg kg(-1) on stored fruit in contaminated rooms even years after the last diphenylamine treatment.