Effect of Biochar Amendment and Ageing on Adsorption and Degradation of Two Herbicides

Biochar amendment can alter soil properties, for instance, the ability to adsorb and degrade different chemicals. However, ageing of the biochar, due to processes occurring in the soil over time, can influence such biochar-mediated effects. This study examined how biochar affected adsorption and degradation of two herbicides, glyphosate (N-(phosphonomethyl)-glycine) and diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in soil and how these effects were modulated by ageing of the biochar. One sandy and one clayey soil that had been freshly amended with a wood-based biochar (0, 1, 10, 20 and 30% w/w) were studied. An ageing experiment, in which the soil-biochar mixtures were aged for 3.5 months in the laboratory, was also performed. Adsorption and degradation were studied in these soil and soil-biochar mixtures, and compared to results from a soil historically enriched with charcoal. Biochar amendment increased the pH in both soils and increased the water-holding capacity of the sandy soil. Adsorption of diuron was enhanced by biochar amendment in both soils, while glyphosate adsorption was decreased in the sandy soil. Ageing of soil-biochar mixtures decreased adsorption of both herbicides in comparison with freshly biochar-amended soil. Herbicide degradation rates were not consistently affected by biochar amendment or ageing in any of the soils. However, glyphosate half-lives correlated with the Freundlich Kf values in the clayey soil, indicating that degradation was limited by availability there.     

Genetic analysis of Anisakis typica (Nematoda: Anisakidae) from cetaceans of the northeast coast of Brazil: new data on its definitive hosts

Prevalence and seasonal variations of helminth infections and their association with morbidity parameters were studied in traditionally reared Cambodian cattle. Four villages in two provinces of West Cambodia were visited on monthly intervals over a period of 11 months, during which 2391 animals were faecal and blood sampled for parasitological and haematological examinations. The body condition score (BCS), faecal consistency (diarrhoea score, DS), colour of the ocular conjunctivae (FAMACHA(?)) and packed cell volume were determined for each individual animal. The overall proportion of samples that was positive for gastrointestinal nematodes was 52%, 44% and 37% in calves (from 1 to 6 months), young animals (6 to 24 months) and adults (over 24 months), respectively, while geometric mean faecal egg counts (FECs) for each of these age categories were 125, 66 and 15 eggs per gram, respectively. Six genera of strongyles were found in the faecal cultures, i.e. in descending order of occurrence, Cooperia, Oesophagostomum, Haemonchus, Trichostrongylus, Mecistocirrus and Bunostomum. The prevalences of Fasciola and Paramphistomum, estimated by coprological examination, varied between 5-20% and 45-95%, respectively. Logistic mixed models were used to investigate associations of morbidity markers with the presence of parasite infection. A low BCS was associated with gastrointestinal nematode and liver fluke infections, and soft faecal consistency with Paramphistomum infections. However, other factors such as nutritional deficiencies and intercurrent diseases are likely to enhance the effects of parasites and should therefore be considered when using these morbidity parameters as indicators of parasitism.     

METHOD OF SEMEN COLLECTION AND ARTIFICIAL INSEMINATION IN SNAKES

This study focuses on the method for sperm extraction and artificial insemination in snakes. Ten adult healthy snakes (4.6) were included in the study (Pantherophis guttatus 1.3; Hydrodynastes gigas 1.1; Corallus hortulanus 1.1; and Sanzinia madagascariesis 1.1). Massage of the ventral aspect of the caudal third of the male snake body for 2 to 3 minutes was performed successfully for the semen collection. Both female and male P. guttatus and H. gigas were placed in brumation, with the female snakes being assessed for ovarian activity after emerging from dormancy. Only females showing ultrasonographic evidence of vitellogenic follicles were included in the study. S. madagascariensis and C. hortulanus were maintained at the same temperature through the year, and the ovarian activity was assessed ultrasonographically prior to artificially inseminating the animal. With the aid of a rigid endoscope, fresh semen was delivered through the cloaca and into the females’ oviducts using a catheter connected to the syringe. The technique failed in female S. madagascariensis and H. gigas. Two female P. guttatus laid eggs 2 months after artificial insemination, with hatchlings emerging following 2 months of development within the eggs. The third female corn snake did not lay an egg. The female C. hortulans produced eggs 4 months after insemination. The manual massage method of sperm collection in male snakes and endoscopy-assisted insemination in female snakes may be useful for conservation programs.     

Production of giant mouse oocyte nucleoli and assessment of their protein content

Compared with advanced developmental stage embryos and somatic cells, fully grown mammalian oocytes contain specific nucleolus-like structures (NPB - nucleolus precursor bodies). It is commonly accepted that they serve as a store of material(s) from which typical nucleoli are gradually formed. Whilst nucleoli from somatic cells can be collected relatively easily for further biochemical analyses, a sufficient number of oocyte nucleoli is very difficult to obtain. We have found that isolated oocytes nucleoli fuse very efficiently when contact is established between them. Thus, well visible giant nucleoli can be obtained, relatively easily handled and then used for further biochemical analyses. With the use of colloidal gold staining, we estimated that a single fully grown mouse oocyte nucleolus contains approximately 1.6 ng of protein. We do believe that this approach will accelerate further research aiming at analyzing the composition of oocyte nucleoli in more detail.     

Bacterial colonisation in the gut of Phlebotomus duboseqi (Diptera: Psychodidae): transtadial passage and the role of female diet

Bacteria isolated from the gut of different developmental stages of Philebotomus duboseqi Neveu-Lcmaire, 1906 belonged almost all to aerobic or facultatively anaerobic gram-negative rods. In females, the highest bacterial counts were observed two days after bloodfeeding; seven days after bloodfeeding the bacterial counts returned to pre-feeding levels. Most isolates were identified phenotypically as Ochrobactrum sp. The distinctiveness and homogeneity of the phenotypic and genotypic characteristics of Ochrobactrum isolates indicated that they belonged to a single strain (designated AK). This strain was acquired by larvae from food and passaged transtadially: it was isolated from the guts of fourth-instar larvae shortly before pupation, from pupae as well from newly emerged females. Most other bacteria found in females were acquired from the sugar solution fed to adults. To determine if the midgut lectin activity may serve as antibacterial agent females were membrane-fed on blood with addition of inhibitory carbohydrates. No significant differences in bacterial infections were found between experimental and control groups and we suppose that the lectin activity has no effect on gram-negative bacteria present in sandfly gut.     

Successful transmission of a retrovirus depends on the commensal microbiota

To establish chronic infections, viruses must develop strategies to evade the host's immune responses. Many retroviruses, including mouse mammary tumor virus (MMTV), are transmitted most efficiently through mucosal surfaces rich in microbiota. We found that MMTV, when ingested by newborn mice, stimulates a state of unresponsiveness toward viral antigens. This process required the intestinal microbiota, as antibiotic-treated mice or germ-free mice did not transmit infectious virus to their offspring. MMTV-bound bacterial lipopolysaccharide triggered Toll-like receptor 4 and subsequent interleukin-6 (IL-6)-dependent induction of the inhibitory cytokine IL-10. Thus, MMTV has evolved to rely on the interaction with the microbiota to induce an immune evasion pathway. Together, these findings reveal the fundamental importance of commensal microbiota in viral infections.     

Analysis of tofu‐related traits by a bench‐scale tofu production method and their relationship with agronomic traits in European soybean

European tofu manufacturers are becoming more and more interested in locally grown soybeans. A prerequisite for the development of European tofu cultivars is to improve our understanding of how the environment and genetics affect soymilk and tofu quality, as well as how quality and agronomic traits are correlated. This study was based on 215 recombinant inbred lines derived from two populations and grown at three locations that were evaluated for tofu traits in a bench‐scale tofu laboratory. The heritabilities of most of the evaluated tofu traits were moderately high with h² > 0.6. We observed significant genotypic variance components, but an even stronger contribution of the location. The network analysis of the evaluated traits was population‐dependent; however, the tofu traits were not associated with any of the agronomic traits. Collectively, our results indicate the potential to improve tofu‐related traits in European soybean. The bench‐scale tofu production method provides a valuable tool to test soybean lines in breeding programmes; however, the method needs to be further improved and automated to minimize errors due to the laboratory staff.     

A comparison of quality parameters of fresh feline ejaculates collected by three different collection techniques

The aim of our study was to compare the quality parameters of fresh feline ejaculates collected by three different techniques—urethral catheterization after medetomidine administration (CT), electroejaculation (EE) and epididymal slicing after orchiectomy (EP). A total of 34 adult male cats (Felis catus) were included in the study. In all male cats, the sperm collection was performed under general anaesthesia by three collection methods in the following order: urethral catheterization, electroejaculation and epididymal slicing. The sperm parameters evaluated were as follows: volume, motility, viability, sperm concentration, total sperm count and morphological examination. The highest quality semen parameters were achieved using EE. The comparison of results of the evaluated sperm quality parameters from EE and EP showed significant differences only in one case—the percentage of head abnormalities and lower percentage of head abnormalities were achieved using EE compared to EP: 8.5% (3.0%–21.0%) versus 10.0% (4.0%–22.0%). Semen collected by CT rendered the lowest quality samples when compared to sperm samples collected by EE and EP, especially with respect to the motility and total sperm count which were significantly lower (p < 0.001). Our study showed that sperm samples collected by EE and EP result in better quality of feline ejaculates compared to collection by CT from sperm samples collected from the same male cats. These results demonstrate the necessity of further research of urethral catheterization as a novel technique of semen collection in male cats.