Detection and phylogenetic characterization of astroviruses in insectivorous bats from Central‐Southern Italy

In recent years, bats have been found to harbour many viruses, raising several questions about their role as reservoirs and potential disseminators of zoonotic viruses. We investigated the presence of six virus families in bats in three regions of Central‐Southern Italy. Astroviruses were identified in seven of 13 bat species. Sequence analysis revealed marked genetic heterogeneity among the astroviruses identified, with nucleotide identity ranging between 60.26% and 87.62%. Astrovirus diversity was not associated with the bat species, the geographic areas or the bat colony, suggesting the circulation of several astrovirus strains in Italian ecosystems. Genetic diversification and interspecies transmission appear common in bat astroviruses and could provide, potentially, the bases for transmission to humans and other mammals. Yet overemphasizing this risk might have detrimental consequences for bat conservation and preservation of the important ecosystem services bats provide.     

Effect of EGF on expression and localization of maturation‐promoting factor,mitogen‐activated protein kinase,p34cdc2 and cyclin B during different culture periods on in vitro maturation of canine oocytes

This study aimed to investigate the localization of MPF, MAPK, p34^cdc2 and cyclin B1 proteins, before and after treatment with EGF during different moments of oocyte maturation. The ovaries obtained from 350 domestic dogs were aseptically isolated, immersed in physiological solution and transported at 4°C. In the laboratory, the ovaries were sectioned for the release of cumulus–oocyte complexes. Cumulus–oocyte complexes were selected and divided into treatment groups with and without EGF and cultured for 24, 48 and 72 hr. Immunofluorescence was used for the detection and the localization of MAPK, MPF, p34^cdc2 and cyclin B1 proteins. We observed that the expression and localization of MPF, MAPK, p34^cdc2 and cyclin B1 proteins are associated with meiosis resumption and cell cycle progression, and that EGF influences cell signalling pathways by promoting alterations in the localization of these proteins, improving the acquisition of oocyte competence. This is the first report of the localization of crucial proteins for meiosis progression in domestic dogs and identification of the expression and localization of proteins for cell cycle progression performed in this study represented a step of great importance to elucidate the mechanisms involved in the meiosis block in domestic dogs, allowing the advance in this research area.     

Sustainable water treatment in aquaculture – photolysis and photodynamic therapy for the inactivation of Vibrio species

Species of the genus Vibrio have been recognized as one of the most significant pathogens in aquaculture farming, causing mass mortality of farmed stocks. Photodynamic Antimicrobial Chemotherapy (PACT) with singlet oxygen (¹O₂) has been identified as a powerful and sustainable water treatment method for pathogen eradication. In this study, the efficiencies of photolytic and photodynamic disinfection protocols were studied with two Vibrio species, Vibrio parahaemolyticus and Vibrio owensii. The selected microorganisms were successfully cultivated in marine broth and irradiations were performed with ~10⁸ bacteria mL^?1. Treated samples were monitored for bacterial regrowth for up to 7 days. Photolysis experiments were initially conducted with UV‐A, UV‐B for up to 2 h and visible (VIS) light for up to 24 h. Of these, only irradiation with UV‐B light for at least 45 min was efficient in controlling Vibrio. Irradiations with VIS light were subsequently repeated under PACT conditions in dose?response experiments with two water‐soluble porphyrins, [T₄(MePy)P] and [TPPS₄]. Disinfections of samples were successful for both porphyrin types at minimum concentrations of 10 μM and 24 h of irradiation.     

Chromomycin A2 Induces Autophagy in Melanoma Cells

The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region of Brazil. The cytotoxic activity of chromomycin A2 was evaluated across a panel of human tumor cell lines, which found IC₅₀ values in the nM-range for exposures of 48 and 72 h. MALME-3M, a metastatic melanoma cell line, showed the highest sensitivity to chromomycin A2 after 48h incubation, and was chosen as a model to investigate this potent cytotoxic effect. Treatment with chromomycin A2 at 30 nM reduced cell proliferation, but had no significant effect upon cell viability. Additionally, chromomycin A2 induced accumulation of cells in G₀/G₁ phase of the cell cycle, with consequent reduction of S and G₂/M and unbalanced expression of cyclins. Chromomycin A2 treated cells depicted several cellular fragments resembling autophagosomes and increased expression of proteins LC3-A and LC3-B. Moreover, exposure to chromomycin A2 also induced the appearance of acidic vacuolar organelles in treated cells. These features combined are suggestive of the induction of autophagy promoted by chromomycin A2, a feature not previously described for chromomycins.     

Characterization of Lasiodiplodia theobromae (Pat.) Griffon & Maubl causing stem canker on Teak (Tectona grandis L.) in Ecuador

Teak is a very important tropical timber in Ecuador. In 2017, teak samples displaying stem canker symptoms were collected in two provinces of Ecuador. From 11 symptomatic trees, 11 isolates resembling a species of Lasiodiplodia were obtained. All isolates obtained induced stem canker on teak plants after artificial inoculation, confirming them as the cause of the observed canker symptoms. Bayesian inference with concatenated sequences of complete ITS and partial TEF-α and β-TUB gene sequences from two representative isolates clustered teak isolates with other sequences of Lasiodiplodia theobromae available in Genbank. This is the first report of L. theobromae causing stem canker on teak plants in Ecuador.     

Comparison of 15N natural abundance and difference methods for estimating N2 fixation of soybeans grown in a tropical soil

Abstract

A study was carried out to compare the difference or N-yield method with the ¹⁵N natural abundance method for the estimation of the fractional contribution of biological N₂ fixation in the different plant parts of nodulating and non-nodulating isolines of soybeans. The results indicated that the δ¹⁵N values of most plant parts of soybeans were significantly lower (p<0.05) in the nodulating than in the non-nodulating isoline. However, in the case of the root+nodule component, the δ¹⁵N value was higher in the nodulating than in the non-nodulating isoline possibly due to isotopic discrimination of ¹⁵N over ¹⁴N which may have occurred in the nodules. Inoculation of soybeans with the Bradyrhizobium japonicum strain CB 1809 increased significantly (p<0.05) the δ¹⁵N value of the root+nodule component implying that the effectiveness of the soybean-rhizobium symbiosis had increased by inoculation.

Percentage of plant N derived from atmospheric N₂ fixation (%Ndfa) estimated by the ¹⁵N natural abundance method was highly correlated (r=0.762, p<0.01) with that by the difference or N-yield method and the differences between the two methods were not statistically significant. The agreement between the two methods was closer at maturity than at the early reproductive stage.

The %Ndfa obtained by the difference method ranged from 48.4 to 92.6% whereas the %Ndfa obtained by the ¹⁵N natural abundance method ranged from 43.2 to 92.4% in the different plant parts. Based on the ¹⁵N natural abundance method, approximately 15% of the N in pod, shoot, grain, and shell was derived from the soil but in the case of stover, this fraction was about 55%.     

Operational Effectiveness of Centralized Nursery for Small-Scale Forestry in San Carlos City, Negros Occidental, the Philippines: Lessons Learned in Seedling Production for Commercial Energy Crop Plantations

One way to maximize potential income of smallholder tree farmers is to ensure high quality of planting material. In San Carlos City, Negros Occidental, the Philippines, great importance is placed on seedling quality because Energy Crop Plantations (ECPs) managed under a Short-Rotation Coppice (SRC) system will involve a single planting for several three-year coppices. High seedling quality requires superior seed provenances and seedling propagation methods. Throughout the establishment of the nursery facility, and the propagation of planting stock, data collection, reporting and database systems have been designed to capture relevant costs and technical information. Training has been provided to nursery personnel and labourers to enable them to operate the nursery and produce high quality seedlings. This paper reports a practical operational evaluation of all materials and procedures followed in nursery establishment and seedling production. Economies of scale in nursery operation are achieved at a production level of at least 90,000 seedlings per planting season of three months in the year. The production cost is estimated at PhP 3.57/seedling, excluding the cost of the nursery infrastructure and overheads. Cost comparison with decentralized or contracted nurseries shows little variation at a total cost of PhP 4.12/seedling. However, with these alternative nursery arrangements there is high risk of producing low quality seedlings by possible reduction of inputs and skipping quality enhancement procedures to reduce production cost.     

Health evaluation of a radiocollared population of free-ranging Baird's tapirs (Tapirus bairdii) in Costa Rica.

The health of a population of free-ranging tapirs (Tapirus bairdii) inhabiting Corcovado National Park, Costa Rica, was assessed as part of an ongoing ecologic study. Nineteen tapirs were immobilized between March 1997 and February 2000, and samples of blood, skin biopsies, and ectoparasites were collected. Ticks were identified as Amblyomma oblongoguttatum or A. coelebs. Hematology and serum biochemistry results suggest statistically significant differences between free-ranging and captive populations that should be interpreted with caution in view of inherent environmental differences between the two populations. Five of 17 animals tested positive for Leptospira bratislava, and 12 individuals tested positive for Venezuelan equine encephalitis. One of nine skin biopsies examined was abnormal and diagnosed as leukoderma. This report represents the first health assessment of a free-ranging population of tapirs.