A simple,rapid, and sensitive DNA assay procedure

A simple and rapid assay for quantitative determinations of DNA in crude homogenates is described. The method is based on the enhancement of fluorescence seen when bisbenzimidazole (Hoechst 33258) binds to DNA. Crude homogenates in which chromatin has been dissociated with high salt buffer can be assayed directly and reliably in a few minutes. The dissociation of chromatin is critical to accurate determinations of DNA in biological materials using this method. The assay can detect as little as 10 ng of DNA with rather unsophisticated instrumentation.     

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

Carbon dots have been recognized as one of the most promising candidates for the oxygen reduction reaction (ORR) in alkaline media. However, the desired ORR performance in metal–air batteries is often limited by the moderate electrocatalytic activity and the lack of a method to realize good dispersion. To address these issues, herein a biomass‐deriving method is reported to achieve the in situ phosphorus doping (P‐doping) of carbon dots and their simultaneous decoration onto graphene matrix. The resultant product, namely P‐doped carbon dot/graphene (P‐CD/G) nanocomposites, can reach an ultrahigh P‐doping level for carbon nanomaterials. The P‐CD/G nanocomposites are found to exhibit excellent ORR activity, which is highly comparable to the commercial Pt/C catalysts. When used as the cathode materials for a primary liquid Al–air battery, the device shows an impressive power density of 157.3 mW cm^?2 (comparing to 151.5 mW cm^?2 of a similar Pt/C battery). Finally, an all‐solid‐state flexible Al–air battery is designed and fabricated based on our new nanocomposites. The device exhibits a stable discharge voltage of ≈1.2 V upon different bending states. This study introduces a unique biomass‐derived material system to replace the noble metal catalysts for future portable and wearable electronic devices.     

Diagrammatic scale for severity evaluation of the Eremanthus erythropappus–Puccinia velata pathosystem

Candeia (Eremanthus erythropappus (DC.) MacLeish), a native forest species from South America, has garnered commercial interest due to its production of essential oil that contains alpha-bisabolol. This compound is widely used in the pharmaceutical and cosmetics industry, with approximately 80% of Brazilian production being exported. Since candeia rust (Puccinia velata) has only been reported in Brazil, little is known about its epidemiology and control. There is no methodology to quantify rust severity in candeia, justifying the elaboration and validation of a diagrammatic scale containing eight levels of disease severity based on leaf area coverage (0.25%, 0.5%, 1%, 2%, 4%, 8%, 16% and 32%). In a natural sampling of disease in the field, 95% of the leaves showed severity below 16%, with the remaining 5% showing severities between 16% and 32% of leaf area. Validation of the proposed diagrammatic scale was performed by assessing the results from 10 inexperienced evaluators, performing evaluations of three leaves with different severity levels. The evaluations were performed at 7-day intervals; in the first instance, severity values were assigned without the diagrammatic scale, and for the second attempt, the scale proposed in this study was used. The accuracy and precision of the severity estimates produced by each evaluator compared to the real severity was analysed by linear regression and by Lin's statistics. The reproducibility of the estimates was evaluated by analysing the coefficient of determination of linear regressions by pairs of evaluators. The scale provided adequate levels of accuracy, precision, repeatability and reproducibility, indicating the proposed scale was a suitable method for quantifying the severity of candeia rust.     

Antifeedant Activity of <i>Caesalpinia coriaria</i> Essential Oil Against <i>Incisitermes marginipennis</i> (Latreille)

This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis (Latreille). Plant deterrent agents act as repellents or antifeedants to prevent wood decay and increase its useful life. The potential of the tree Caesalpinia coriaria (Fabaceae) as a biological source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities. The gas chromatography-mass spectrometry analysis of the leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were determined. Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood termite. Unlike the leaf essential oil, geraniol did not exhibit a repellency effect. An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of −7.5 Kcal/mol. Geraniol interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol (negative control) interacted with tryptophan 83 located adjacent to the active site. These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite. However, they are an important natural control alternative.     

New conservation opportunities: Using citizen science in monitoring non-native species in Neotropical region

The combination of highly equipped smartphones, with the increased use of social media, has offered a wide database. Given this, citizen science can be used to record and monitor non-native fish fauna, target new samples and collaborate with monitoring occurrences in new areas. We aimed to demonstrate the efficiency of social media in citizen science as a tool to cooperate with monitoring studies of non-native species. Consequently, we determined the occurrence points of S. brasiliensis in the Iguaçu River basin, indicating sites of greatest occurrence and analyzing the impact of the invasion on the native fauna of the basin. Files and information available on the YouTube^® and Facebook^® media platforms were used as data, was carried out from April 2019 to April 2020. The results were 40 records, 22 videos obtained from Youtube, and seven videos and 11 photos from Facebook, the oldest record was from April 2013, while the largest number of posts was in 2016. Fish records available from online platforms can reveal the occurrence and progressive dispersion of species, in the context of biological invasions, these tools can be of great value in studies that aim to follow the progress of introduced species, contributing by helping to direct new sampling programs and corroborating the occurrence of species in new areas in conjunction with standard monitoring programs. Based on citizen science records, it was possible to update the range of occurrence of the non-native S. brasiliensis in the Iguaçu River basin, cooperating with scientific knowledge. Innovative monitoring and control measures are necessary to deal with invasive species, with citizen science proving to be competent for determining the occurrence of species and showing promise in the entire field of ichthyology.     

Aerobic training prevents cardiometabolic changes triggered by myocardial infarction in ovariectomized rats

This study aimed to evaluate the impact of aerobic training (AT) on autonomic, cardiometabolic, ubiquitin‐proteasome activity, and inflammatory changes evoked by myocardial infarction (MI) in ovariectomized rats. Female Wistar rats were ovariectomized and divided into four groups: sedentary + sham (SS), sedentary + MI (SI), AT + sham surgery (TS), AT + MI (TI). AT was performed on a treadmill for 8 weeks before MI. Infarcted rats previously subjected to AT presented improved physical capacity, increased interleukin‐10, and decreased pro‐inflammatory cytokines. Metabolomic analysis identified and quantified 62 metabolites, 9 were considered significant by the Vip Score. SS, SI, and TS groups presented distinct metabolic profiles; however, TI could not be distinguished from the SS group. MI dramatically increased levels of dimethylamine, and AT prevented this response. Our findings suggest that AT may be useful in preventing the negative changes in functional, inflammatory, and metabolic parameters related to MI in ovariectomized rats.     

Digestive capacities allow the Mexican long-nosed bat (Leptonycteris nivalis) to live in cold environments

Digestive capabilities of nectar-feeding vertebrates to assimilate sugars affect their ability to acquire and store energy and could determine the minimal temperatures at which these animals can survive. Here, we described the sugar digestive capability of Leptonycteris nivalis and related it with its capacity to live in cold environments. We measured the enzymatic activity, food intake rate and changes in body mass of bats feeding at four different sucrose concentrations (from 5 to 35% wt./vol.). Additionally, we used a mathematical model to predict food intake and compared it with the food intake of bats. L. nivalis was able to obtain ~ 111.3 kJ of energy regardless of the sugar concentration of their food. Also, bats gained ~ 2.57 g of mass during the experimental trials and this gain was independent of sugar concentration. The affinity (1 / K_m) of sucrase (EC 3.2.1.48) was one order of magnitude higher relative to that reported for its sister species Leptonycteris yerbabuenae (0.250 and 0.0189 mmol^? 1 L, respectively), allowing this species to have a higher energy intake rate. We propose that the high ability to acquire energy conferred L. nivalis the faculty to invade cold environments, avoiding in this way the ecological competition with its sympatric species L. yerbabuenae.     

Lipid and protein oxidation in hepatic homogenates and cell membranes exposed to bile acids

Cholestasis occurs in a variety of hepatic diseases and causes damage due to accumulation of bile acids in the liver. The aim was to investigate the effect of several bile acids, i.e. chenodeoxycholic, taurochenodeoxycholic, deoxycholic, taurodeoxycholic, ursodeoxycholic, lithocholic and taurolithocholic (TLC), in inducing oxidative damage. Hepatic tissue of male Sprague-Dawley rats was incubated with or without 1 mM of each bile acid, with or without 0.1 mM FeCl₃ and 0.1 mM ascorbic acid for the purpose of generating free radicals. Several bile acids increased lipid and protein oxidation, with TLC being the most pro-oxidative (657% and 175% in homogenates and 350% and 311% in membranes, respectively). TLC also enhanced iron-induced oxidative stress to lipids (21% in homogenates and 29% in membranes) and to proteins (74% in membranes). This enhancement was dose- and time-dependent and was reduced by melatonin. These results suggest that bile acids differentially mediate hepatic oxidative stress and may be involved in the physiopathology of cholestasis.     

Comparison of insecticidal paint and deltamethrin against Triatoma infestans (Hemiptera: Reduviidae) feeding and mortality in simulated natural conditions

The vector of Chagas disease, Triatoma infestans, is largely controlled by the household application of pyrethroid insecticides. Because effective, large‐scale insecticide application is costly and necessitates numerous trained personnel, alternative control techniques are badly needed. We compared the residual effect of organophosphate‐based insecticidal paint (Inesfly 5A IGR? (I5A)) to standard deltamethrin, and a negative control, against T. infestans in a simulated natural environment. We evaluated mortality, knockdown, and ability to take a blood meal among 5^th instar nymphs. I5A paint caused significantly greater mortality at time points up to nine months compared to deltamethrin (Fisher's Exact Test, p < 0.01 in all instances). A year following application, mortality among nymphs in the I5A was similar to those in the deltamethrin (χ2 = 0.76, df=1, p < 0.76). At months 0 and 1 after application, fewer nymphs exposed to deltamethrin took a blood meal compared to insects exposed to paint (Fisher's Exact Tests, p < 0.01 and p < 0.01, respectively). Insecticidal paint may provide an easily‐applied means of protection against vectors of Chagas disease.     

Three new species of Fufius Simon, 1888 (Araneae,Cyrtaucheniidae) from Brazil with the redescription of Fufius funebris Vellard, 1924 and description of the female of Fufius lucasae Guadanucci & Indicatti, 2004

The mygalomorph neotropical genus Fufius Simon, 1888 comprises ten species, distributed from Guatemala in Central America to southeastern Brazil, in South America. Most of the species were described from northern South America, in the Amazonian region. Only F. funebris Vellard, 1924 and F. lucasae Guadanucci & Indicatti, 2004 are known from regions more to the south of the continent. Herein we describe three new Brazilian species, Fufius minusculus sp. n. and F. jalapensis sp. n. from the state of Tocantins, and F. candango sp. n. from Distrito Federal. The female of F. lucasae is described for first time and the male and female of F. funebris are redescribed based on specimens collected at the type locality.