Discrimination of red porgy Pagrus pagrus (Sparidae) potential stocks in the south-western Atlantic by otolith shape analysis

Otolith shape analysis is a powerful method for fish stock identification. We compared the otolith shape of Pagrus pagrus (Linnaeus 1758) along with its distribution in four south-western Atlantic regions where it is commercially fished: Rio de Janeiro, Rio Grande do Sul in southern Brazil, the Argentine-Uruguayan Common Fishing Zone (UA) and the Argentinian Exclusive Fishing Zone (AR). Otolith shapes were compared by Elliptical Fourier and Wavelet coefficients among specimens in a size range with similar otoliths, morphometric parameters and ages. Four potential stocks were identified: one in the AR, a second along the UA which included specimens from southern Brazil with well-marked opaque bands in its otoliths (MRS), the third in southern Brazil with faint or absent opaque bands in its otoliths (FRS) and the fourth along Rio de Janeiro. The difference in the otolith shape among regions followed differences reported using other stock identification techniques. The similarity between otoliths from UA and MRS (ANOVA-like, P > 0.01) can be explained by seasonal short-range migrations. Otoliths shape differences between MRS and FRS (ANOVA-like, P < 0.01) suggest that P. pagrus does not form a homogeneous group in southern Brazil.     

Decline of Eulia ministrana (Lepidoptera: Tortricidae) in polluted habitats is not accompanied by phenotypic stress responses

Environmental pollution is currently identified as one of the major drivers of rapid decline of insect populations, and this finding has revitalized interest in insect responses to pollution. We tested the hypothesis that the pollution-induced decline of insect populations can be predicted from phenotypic stress responses expressed as morphological differences between populations inhabiting polluted and unpolluted sites. We explored populations of the brassy tortrix Eulia ministrana in subarctic forests along an environmental disturbance gradient created by long-lasting severe impacts of aerial emissions of the copper–nickel smelter in Monchegorsk, northwestern Russia. We used pheromone traps to measure the population densities of this leafrolling moth and to collect specimens for assessment of three morphological stress indices: size, forewing melanization, and fluctuating asymmetry in wing venation. Wing length of E. ministrana increased by 10%, and neither forewing melanization nor fluctuating asymmetry changed from the unpolluted forest to the heavily polluted industrial barren. However, the population density of E. ministrana decreased 5 to 10 fold in the same pollution gradient. Thus, none of the studied potential morphological stress indicators signaled vulnerability of E. ministrana to environmental pollution and/or to pollution-induced environmental disturbance. We conclude that insect populations can decline without any visible signs of stress. The use of morphological proxies of insect fitness to predict the consequences of human impact on insect populations is therefore risky until causal relationships between these proxies and insect abundance are deciphered.     

Dammarane triterpenes targeting α-synuclein: biological activity and evaluation of binding sites by molecular docking

Parkinson''s disease (PD) is a neurodegenerative disorder that affects adult people whose treatment is palliative. Thus, we decided to test three dammarane triterpenes 1, 1a, 1b, and we determined that 1 and 1a inhibit β-aggregation through thioflavine T rather than 1b. Since compound 1 was most active, we determined the interaction between α-synuclein and 1 at 50 µM (Kd) through microscale thermophoresis. Also, we observed differences in height and diameter of aggregates, and α-synuclein remains unfolded in the presence of 1. Also, aggregates treated with 1 do not provoke neurites'' retraction in N2a cells previously induced by retinoic acid. Finally, we studied the potential sites of interaction between 1 with α-synuclein fibrils using molecular modelling. Docking experiments suggest that 1 preferably interact with the site 2 of α-synuclein through hydrogen bonds with residues Y39 and T44.     

Loss of Key Riparian Plant Species Impacts Stream Ecosystem Functioning

Ecosystems - Leaf litter of alder (Alnus glutinosa) is a key resource to detrital stream food webs. Due to its high quality and palatability, it is readily colonised by microorganisms and consumed...     

Impact of manipulation of glycerol/diol dehydratase activity on intestinal microbiota ecology and metabolism

Glycerol/diol dehydratases (GDH) are enzymes that catalyse the production of propionate from 1,2-propanediol, and acrolein from glycerol. Acrolein reacts with dietary carcinogenic heterocyclic amines (HCA), reducing HCA mutagenicity, but is itself also an antimicrobial agent and toxicant. Gut microbial GDH activity has been suggested as an endogenous acrolein source; however, there is limited information on the potential of the intestinal microbiota to have GDH activity, and what impact it can have on the intestinal ecosystem and host health. We hypothesized that GDH activity of gut microbiota is determined by the abundance and distribution of GDH-active taxa and can be enhanced by supplementation of the GDH active Anaerobutyricum hallii, and tested this hypothesis combining quantitative profiling of gdh, model batch fermentations, microbiota manipulation, and kinetic modelling of acrolein formation. Our results suggest that GDH activity is a common trait of intestinal microbiota shared by a few taxa, which was dependent on overall gdh abundance. Anaerobutyricum hallii was identified as a key taxon in GDH metabolism, and its supplementation increased the rate of GDH activity and acrolein release, which enhanced the transformation of HCA and reduced fermentation activity. The findings of this first systematic study on acrolein release by intestinal microbiota indicate that dietary and microbial modulation might impact GDH activity, which may influence host health.     

Volatiles from Marina neglecta: Biocide effect on insect vectors of tropical diseases in Southern Mexico

Preventive measures based in the control of insect vectors are considered as the best choice to decrease the incidence of insect-borne diseases. Herein we report on the volatile content of the leaf essential oils from Marina neglecta, a medicinal plant distributed in the tropical regions of southern Mexico. In order to investigate the chemical variation of the essential oils, a volatile screening was performed during the four seasons of the years 2016–2019. Simultaneously, their biological activity was tested on distinct life stages of Meccus pallidipennis, M. bassolsae, Aedes aegypti and A. albopictus. Essential oils were mainly constituted of β-pinene (>30%) β-caryophyllene (>25%) and germacrene D (>13%). Dorsal-abdomen application of essential oils on triatomines, revealed an efficient LC₅₀ for nymphs of the stages I to III (4 µg/insect), nymphs of the stages IV to V (5–6 µg/insect), and adults (7–8 µg/insect). The LT₅₀ for the stages I to III was between 6 and 8 h, whereas that for the stages IV to V and adults oscillated between 12 and 16 h and 22 to 26 h, respectively. Fumigation experiments performed on nymph V, demonstrated that 300 µg L^?1 air produced 100% mortality after 72 h post-treatment. Among tested volatiles, β-pinene and β-caryophyllene produced a comparable mortality rate (p < 0.01) than that of essential oils in the stages assayed. Essential oils showed strong larvicidal (LC₅₀, 24–36 µg mL^?1) and adulticidal (35–48 µg mL^?1) activities in mosquito species with an LT₅₀ of 4.5 h and 25–35 min, respectively. The evaluation of β-pinene produced a significant mortality rate (p < 0.01) in larvae whereas germacrene D was the most effective volatile (p < 0.01) against adults of both mosquito species. According to our results, β-pinene was the most effective volatile against the four insect species evaluated and its effect was comparable to that of the essential oil.     

Initiation, long-term cryopreservation, and recovery of Abies alba Mill. embryogenic cell lines

Somatic embryogenesis of Abies alba (Mill.) has significant potential to become an effective method for vegetative propagation of this species. To induce somatic embryogenesis in A. alba, the influence of the mother tree, sampling dates, and cold treatment storage of cones were examined. The initiation frequencies ranged from 1.7% to 16.6%. The sampling date and cone storage, but not the mother tree, had a significant effect on the initiation of embryogenic cultures. Storage of embryogenic cell lines was tested through cryopreservation for 6 yr. Four out of 12 cryostored embryogenic cell lines recovered, and the regeneration of cotyledonary embryos was obtained with two cell lines. The ability of embryogenic cell masses to produce somatic embryos and the mean number of cotyledonary embryos were higher when the maturation protocol was based on embryogenic suspensions dispersed on filter paper. The properly developed germinants were obtained only from maturation media where 32 μM abscisic acid was used, being 16.2% when polyethylene glycol (PEG) was not present and 1.8% when supplemented with 10% (w/v) PEG, respectively. The present study provides evidence that it is possible to cryopreserve A. alba embryogenic cultures while maintaining their maturing ability for the lengthy period (6 yr) needed for progeny testing of field-grown trees. Therefore, our findings are important for further studies and advanced breeding work of the species; however, the conversion of germinants into ex vitro conditions still remains a significant challenge.     

cis-Jasmone indirect action on egg parasitoids (Hymenoptera: Scelionidae) and its application in biological control of soybean stink bugs (Hemiptera: Pentatomidae)

In many plants, the secondary metabolite cis-jasmone activates the metabolic pathway that produces volatile organic compounds attractive to natural enemies and, sometimes, repellent to herbivores. Previous studies indicate that the feeding damage caused by the herbivore Euschistus heros or the exogenous application of cis-jasmone in soybean plants induces the release of herbivore-induced plant volatiles (HIPVs) with a similar chemical profile and these compounds can attract the stink bug egg parasitoid Telenomus podisi (Scelionidae). Herein we tested in field conditions the effect of exogenous application of cis-jasmone in soybean plants on the parasitoid and stink bug community and on stink bug egg parasitism. In two areas, one within a soybean and another within a Crotalaria matrix, we randomly distributed 2 m² plots, with soybean plants induced (treatment, n = 5) or not induced by cis-jasmone (control, n = 5) in the field. We sampled the parasitoid community weekly with yellow sticky traps (n = 3/plot) and monitored parasitism with sentinel eggs of E. heros (n = 150/plot). We also monitored the population of stink bugs weekly, by sampling each plot with shake-cloth technique. The abundance of Scelionidae was highest overall and also in treated plots during the first four weeks in the area with a soybean matrix, but decreased thereafter. The richness of parasitoid families was similar between treatment and control plots in the area with a soybean matrix, but higher in control plots in the area with a Crotalaria matrix. Evenness was higher in control plots in the area with soybean matrix, whereas the reverse occurred in the area with a Crotalaria matrix. Results suggest that treatment with cis-jasmone effectively attracted and enhanced the population of scelionid parasitoids, but had no effect on the occurrence and intensity of parasitism and in the number of stink bugs.     

An electromyographic analysis of two handwriting grasp patterns

BackgroundHandwriting is a fundamental skill needed for the development of daily-life activities during lifetime and can be performed using different forms to hold the writing object. In this study, we monitored the sEMG activity of trapezius, biceps brachii, extensor carpi radialis brevis and flexor digitorum superficialis during a handwriting task with two groups of subjects using different grasp patterns.Subjects and methodsTwenty-four university students (thirteen males and eleven females; mean age of 22.04 ± 2.8 years) were included in this study. We randomly invited 12 subjects that used the Dynamic Tripod grasp and 12 subjects that used the Static Tripod grasp.ResultsThe static tripod group showed statistically significant changes in the sEMG activity of trapezium and biceps brachii muscles during handwriting when compared to dynamic tripod group’s subjects. No significant differences were found in extensor carpi radialis brevis and flexor digitorum superficialis activities among the two groups.ConclusionThe findings in this study suggest an increased activity of proximal muscles among subjects using a transitional grasp, indicating potential higher energy expenditure and muscular harm with the maintenance of this motor pattern in handwriting tasks, especially during the progression in academic life.