Localization of QTL for cold tolerance at the germination stage of rice (Oryza sativa L.) using recombinant inbred lines

The cold tolerance of germinating direct-sown rice (Oryza sativa L.) has an increased rate of emergence, which ensures vigorous seedling growth. Research on QTL localization for cold tolerance at the germination stage can assist in molecular marker-assisted selection and enhance breeding efficiency. In this study, 94 populations of recombinant self-incompatible lines from Heigu and Ha 9366 were selected to investigate germination rates at low temperatures. It was found that two QTL loci (qLTG-3 and qLTG-12) were located at different germination times on chromosomes 3 and 12, respectively. The two QTLs at three different germination times, located using QTL, accounted for 21.3–25.9% of the phenotypic variation. Moreover, a reciprocal effect was detected between the two QTLs. The double QTLs increased the germination rate by 22–27% in this population. Additionally, qLTG-12 improved cold tolerance at the seedling stage. The results of this study might provide the materials and molecular markers for future molecular marker-assisted breeding for cold tolerance at the germination stage.

Approach to the 4/3 law for turbulent pipe and channel flows examined through a reformulated scale-by-scale energy budget

In this study, we propose a scale-by-scale (SBS) energy budget equation for flows with homogeneity in at least one direction. This SBS budget represents a modified form of the equation first proposed by Danaila et al. (J. Fluid Mech., vol. 430, 2001, pp. 87–109) for the channel centreline – the primary difference is that, here, we consider the role of pressure along with the errors associated with the isotropic approximations of the interscale divergence and Laplacian of the squared velocity increment. The term encompassing the effects of mean shear is also characterised such that the present analysis can be extended straightforwardly to locations away from the centreline. We show, based on a detailed analysis of previously published channel flow direct numerical simulations and pipe flow experiments near the centreline, how several terms in the present SBS budget equation (including the third-order velocity structure function) behave with increasing Reynolds number. The behaviour of these terms is shown to imply a rate of emergence and subsequent growth of the 4/3 law scale subrange at the channel centreline and pipe axis. The analysis also suggests that the peak magnitude of the third-order velocity structure function occurs at a scale that is fixed in proportion to the Taylor microscale at sufficiently high Reynolds number.

Ameliorative Potential of Chlorogenic Acid on Rotenone-Induced Neurotoxicity in Drosophila Melanogaster Model

Chlorogenic acid (CA), abundantly found in green coffee beans, is a phenolic compound with antioxidant and anti-inflammatory properties amongst others. Exposure to rotenone, a natural pesticide, induces Parkinsonism (a type of neurodegeneration) through the induction of mitochondria dysfunction and oxidative stress. Phytochemicals with antioxidant properties may be promising in attenuating this condition. In this research, the ameliorative role of CA on rotenone-induced toxicity in Drosophila melanogaster was evaluated. Drosophila melanogaster (Harwich strain, 1- 3 days old) was used. 6 groups of five vials each with 50 flies/vial were exposed to CA (0; control (2% ethanol), 7.5, 15, 30, 45 and 60 mg/kg diet) for 28 days in the longevity analysis. A 28-day survival assay was carried out with rotenone (0, 250 and 500 μM). CA (30 mg/kg diet) was selected to evaluate its ameliorative potential on rotenone. For the study, the flies were divided into four groups of five vials each and exposed to CA and rotenone; Group A- control (2% ethanol), Group B- CA only, Group C- rotenone only and Group D- CA (30 mg/kg diet)+ rotenone (500 μM)for 7 days. Thereafter, the homogenate was evaluated for oxidative stress status, rate of emergence, negative geotaxis and acetyl cholinesterase activity. CA (30 mg/kg diet) extended the lifespan of flies by 21.4%. Also, CA ameliorated rotenone-induced perturbation in catalase, glutathione-S-transferase and acetyl cholinesterase activities, total thiol and glutathione levels, and behavioral deficit (p < 0.05). CA may have ameliorative effect against rotenone-induced toxicity and Parkinsonism.

Intensity and frequency of extreme novel epidemics

Observational knowledge of the epidemic intensity, defined as the number of deaths divided by global population and epidemic duration, and of the rate of emergence of infectious disease outbreaks is necessary to test theory and models and to inform public health risk assessment by quantifying the probability of extreme pandemics such as COVID-19. Despite its significance, assembling and analyzing a comprehensive global historical record spanning a variety of diseases remains an unexplored task. A global dataset of historical epidemics from 1600 to present is here compiled and examined using novel statistical methods to estimate the yearly probability of occurrence of extreme epidemics. Historical observations covering four orders of magnitude of epidemic intensity follow a common probability distribution with a slowly decaying power-law tail (generalized Pareto distribution, asymptotic exponent = −0.71). The yearly number of epidemics varies ninefold and shows systematic trends. Yearly occurrence probabilities of extreme epidemics, Py, vary widely: Py of an event with the intensity of the “Spanish influenza” (1918 to 1920) varies between 0.27 and 1.9% from 1600 to present, while its mean recurrence time today is 400 y (95% CI: 332 to 489 y). The slow decay of probability with epidemic intensity implies that extreme epidemics are relatively likely, a property previously undetected due to short observational records and stationary analysis methods. Using recent estimates of the rate of increase in disease emergence from zoonotic reservoirs associated with environmental change, we estimate that the yearly probability of occurrence of extreme epidemics can increase up to threefold in the coming decades.

Comparative Elimination of Begomoviruses in Cassava Meristems and Axillary Buds

Aim: The production of healthy cuttings from a local cassava cultivar for cassava mosaic control. Study design: The study was carried out at the In Vitro Culture Laboratory using the techniques of thermotherapy and culture of tissues and explants in a specific medium. Place and duration: The study was carried out at the Laboratory of Biological and Agronomic Sciences for Development at the University of Bangui, Central African Republic from December 2017 to June 2018. Methodology: A variety of cassava called six-month very susceptible to mosaic was used for this work. The cuttings used were infected by Cassava Mosaic Begomoviruses (CMBs) with high severity. It were subcultured in a room under the heat of 37 ° C to 40 ° C for two weeks. Explants and meristems were taken from the stems and the apices, respectively. These collected materials were treated and seeded on appropriate culture media. After the plants produced in vitro were acclimatized and the leaves were removed to check their phytosanitary state by the PCR technique. Results: The rate of emergence of the acclimatized plants and the expression of the disease on the microplants were evaluated. The results show that 75% of the weaned vitro plants recovered under acclimatization. In addition, the acclimatized plants left growing in the greenhouse for four months remained asymptomatic. Molecular analysis by PCR showed that begomoviruses were not detected on meristem samples unlike samples from stem fragments. Conclusion: The combination of thermotherapy technique associated with the culture of meristems constitutes an effective means useful for the sanitation of infected plant material.

Field Assessment of Some Agronomic Traits of Four Groundnuts (Arachis hypogaea L.) Varieties from the Germplasm of Gimbi Research Station

Aim: To evaluate under agro-environmental conditions of Gimbi research station, some agronomic traits of four groundnut varieties from germplasm of PNL. Study Design: This study was conducted using a randomized complete block design with four treatments repeated three times. Place and Duration of the Study: The study was conducted in Gimbi research station between October 2019 and January 2020 (i.e. 4 months). Methodology: Trial was conducted using four treatments with three replications. Data collected concerned percentage of seedlings emerged, number of days between sowing and flowering 50%, dry pod weight, weight of unsorted seed, weight of sorted seeds, percentage of good seeds, shelling percentage, average weight of 1,000 seeds and grain yield per hectare. All data were submitted to analysis of variance at 5% probability level. Results: The rate of seedlings emerged recorded on each groundnut variety was overall less than 50%. All varieties flowered 32 days after sowing. The highest average weight of dry pods (410.8g) was noted on A1408, while the lowest value of dry pod weight (310.6g) was observed on JL24. The highest weight of unsorted seeds (360.9g) was recorded on A1408, while the lowest value (260.7g) was observed on JL24. Variety A1408 presented the highest weight of stored seeds (350.5g), while the lowest value (250.8g) was noted on variety JL24. The highest percentage of good seeds (97.3) was obtained on A1408, while variety Sivi presented the lowest percentage of good seeds (93.2). The highest shelling percentage of groundnut pods (87.6) was obtained on A1408, while the lowest shelling percentage (83.5) was noted on JL24. The lowest weight of 1,000 seeds was noted on Sivi variety (484.6g), and the highest value was recorded on A1408 (522.6g). The highest grain yield (912.9Kg.ha-1) was obtained on variety A1408, while the lowest grain yield was noted on JL24 (690Kg.ha-1). Conclusion: Seeds of all varieties presented a very low rate of emergence (less than 50%). Variety A1408 was more productive than other varieties, and variety JL24 used as control should be regarded as having degenerated.

The Emergence, Persistence, and Dissemination of Antimicrobial-Resistant Bacteria in Environmental Hajj Settings and Implications for Public Health

The emergence of antimicrobial resistance is causing the loss of what was once considered the miracle cure. The transmission of antimicrobial resistance during mass gathering is a potential threat in addition to other infectious diseases. Here, we review the English language literature on the rate and the acquisition of antimicrobial resistance during the Hajj. There is a variable incidence of methicillin-resistant Staphylococcus aureus, Escherichia coli, and Enterobacteriaceae. There had been no report of multi-drug-resistant Mycobacterium tuberculosis. Continued surveillance of antimicrobial resistance coupled with public health measures are needed to decrease the rate of emergence of resistance.

Análise da emergência e desenvolvimento inicial de plântulas de Handroanthus roseo-albus (Ridl.) Mattos e Handroanthus serratifolius (Vahl) S.O.Grose sobre diferentes tipos de substratos

<p class="Normal1"><span class="fontstyle0">The formation of quality forest seedlings has a direct relationship with the substrates that will be used; the germination of seeds and the formation of the root system and the aerial part are associated with the particular characteristics of each substrate. Therefore, the study aimed to evaluate the influence of different substrates on the formation of ipê-branco and ipê-amarelo seedlings. The experimental design adopted was completely random, with the treatments distributed in a 2 x 5 factorial arrangement (2 species and 5 substrates), with 4 replications. We used the following components to compose the substrates: carbonized rice husks (CAC), fresh rice husks (CA), autoclaved for two hours at 120 °C, commercial substrate (SC) Bioflora, washed sand (AL), and bovine manure (EB). The study was arranged in five treatments: treatment 1 - CAC, treatment 2 - CA, treatment 3 - SC, treatment 4 - AL and treatment 5 - EB. The following morphological characteristics have been evaluated: Collection diameter, height of the seedlings and the Dickson Quality Index (DQI) of the seedlings, which was obtained through the variables: weight of total dry matter (TWMW), weight of dry matter of the aerial part (TWMW), weight of dry matter of the root (RWMW), H and DC. The emergence speed and the emergence percentage index were lower for both species in the treatment containing 100% in natura rice husk. The commercial substrate Bioflora, enabled good performance in the emergence of both species, obtaining satisfactory results in terms of the percentage rate of emergence and a higher speed of emergence between treatments. The bovine manure substrate obtained superior results in the initial development for both Handroanthus serratifolius (Vahl) S.O.Grose and Handroanthus roseo-albus (Ridl.) Mattos.</span><br /><br /></p>

THE EVALUATION OF USER`S REPRESENTATION OF PERSONAL COMPUTER

Relevance. The increasing complexity of technical devices used by humans and the high rate of emergence of new devices and their functions lead to the emergence of various practices and habits of working with them. It is possible to see a specific representation of what a personal computer (PC) consists of and how it works for each of these practices. This representation has developed in the process of working with a PC as its mental model. However, the task of reconstructing these models and comparing different respondents with each other according to the specifics of their understanding of the PC does not have the necessary methodological support. It is necessary to get representations of PC in a comparable form to effectively compare the different people`s/group`s representations of PC with each other and study their mental models, preserving the qualitative specifics of these “images of PC”. The purpose of this work is to empirically approbate the technology of reconstructing the representations of PC users about the computer itself as a multidimensional psychological space of descriptions of its work. Methods. Methods of group interviews and card sorting were used to collect descriptions of “how PC works”, multidimensional scaling methods were used to reconstruct representations of PC among groups of study participants. Results. We have reconstructed and described the representations about the work of the PC of three groups of users — schoolchildren (N = 22), programmers (N = 22) and ordinary adults without special education (N = 21) as multidimen-sional spaces of descriptions of the work of the PC. We identified the bases of classification of PC operation descriptions for each group of users and develop a technology for analyzing the results of studying their representations about PC as latent characteristics that form the basis of classification of PC operation descriptions.

Etude de l’effet rémanent de Mavi MNPV dans un champ de niébé

Le niébé est l’une des légumineuses alimentaires la plus importante dans toutes les régions de l’Afrique Sub-saharienne. L’objectif de ce travail était d’étudier l’effet rémanent de Mavi Multinucléo polyhedrovirus (Mavi MNPV) après la récolte du niébé au champ. Le champ a été traité 5 fois au biopesticide Mavi MNPV à la fréquence de sept jours. Deux semaines après la récolte, deux plants ainsi que les graines de chaque traitement sur chaque unité parcellaire ayant reçu les traitements de Mavi MNPV de 107, 108 et 109 virions/ml ont été collectés et amenés au laboratoire avec le substrat de développement de la plante (sable). Aucune des formulations issues des substrats sable, racines, feuilles, tiges et graines n’a affecté la mortalité des larves L2 et L3 de Maruca vitrata et aucune différence significative n’a été observée entre les traitements et le témoin. Quels que soient les traitements, le taux d’émergence des adultes est élevé ; ce qui signifie que la variation de la concentration de Mavi MNPV ne conditionne pas sa présence dans le sol, les tiges, les feuilles, les racines et les graines. Le biopesticide Mavi MNPV n’est pas persistant dans la nature.Mots clés : Niébé, Mavi MNPV, Maruca vitrata, Effet rémanent English Title: Study of the residual effect of Mavi MNPV in a cowpea field Cowpea is one of the most important food legumes in all regions of Sub-Saharan Africa. The objective of this research work was to study the persistence effect of Mavi Multinucleus polyhedrovirus (Mavi MNPV) after field harvest of the cowpea. The field was treated 5 times with Mavi MNPV biopesticide at seven days. Two weeks after harvest, two plants as well as the seeds from each treatment on each plot unit that received Mavi MNPV treatments of 107, 108 and 109 virions / ml were removed and brought to the laboratory with the plant development substrate (sand). None of the formulations from sand, root, leaf, stem and seed substrates did not affect the mortality of L2 and L3 larvae of Maruca vitrata and no significant difference was observed between treatments and control. Regardless of the treatments, the rate of emergence of adults is high; this means that the variation in the concentration of Mavi MNPV does not condition its presence in soil, stems, leaves, roots and seeds. Mavi MNPV biopesticide is not persistent in nature.Keywords: Cowpea, Mavi MNPV, Maruca vitrata, Residual effect.