Diversity of Lactifluus (Basidiomycota, Russulales) in West Africa: 5 new species described and some considerations regarding their distribution and ecology

The genus Lactifluus is one of the common ectomycorrhizal fungal taxa in tropical African forest ecosystems. Recent morphological and anatomical mycological studies based on specimens we sampled from 2007 to 2013 in West African forest ecosystems, including dry, dense, riparian forests and woodlands, enable to assess the diversity and the occurrence of Lactifluus species in the Guineo-Sudanian domain. A total of 51 ITS rDNA sequences generated from our samples were aligned against tropical African and worldwide Lactifluus sequences available in GenBank. A Maximum Likelihood phylogenetic tree was inferred from 113 sequences. The phylogenetic placement of the species, combined with our morpho-anatomical data, supported the description of five new species distributed among Lactifluus species. Our data further confirm that the species richness of the genus Lactifluus is high and partly unexplored in the Guineo-Sudanian domain, and confirmed that, in both the Guineo-Sudanian and the Congo-Zambezian domain many common species occur. Patterns of occurrence of the recorded Lactifluus species from Guineo-Sudanian ecozones are also highlighted

The maternal chromosome set is the target of the T-DNA in the in planta transformation of Arabidopsis thaliana.

In planta transformation methods are now commonly used to transform Arabidopsis thaliana by Agrobacterium tumefaciens. The origin of transformants obtained by these methods has been studied by inoculating different floral stages and examining gametophytic expression of an introduced beta-glucuronidase marker gene encoding GUS. We observed that transformation can still occur after treating flowers where embryo sacs have reached the stage of the third division. No GUS expression was observed in embryo sacs or pollen of plants infiltrated with an Agrobacterium strain bearing a GUS gene under the control of a gametophyte-specific promoter. To identify the genetic target we used an insertion mutant in which a gene essential for male gametophytic development has been disrupted by a T-DNA bearing a Basta resistance gene (B(R)). In this mutant the B(R) marker is transferred to the progeny only by the female gametes. This mutant was retransformed with a hygromycin resistance marker and doubly resistant plants were selected. The study of 193 progeny of these transformants revealed 25 plants in which the two resistance markers were linked in coupling and only one plant where they were linked in repulsion. These results point to the chromosome set of the female gametophyte as the main target for the T-DNA

A mathematical and exploratory data analysis of malaria disease transmission through blood transfusion

Malaria is a mosquito-borne disease spread by an infected vector (infected female Anopheles mosquito) or through transfusion of plasmodium-infected blood to susceptible individuals. The disease burden has resulted in high global mortality, particularly among children under the age of five. Many intervention responses have been implemented to control malaria disease transmission, including blood screening, Long-Lasting Insecticide Bed Nets (LLIN), treatment with an anti-malaria drug, spraying chemicals/pesticides on mosquito breeding sites, and indoor residual spray, among others. As a result, the SIR (Susceptible—Infected—Recovered) model was developed to study the impact of various malaria control and mitigation strategies. The associated basic reproduction number and stability theory is used to investigate the stability analysis of the model equilibrium points. By constructing an appropriate Lyapunov function, the global stability of the malaria-free equilibrium is investigated. By determining the direction of bifurcation, the implicit function theorem is used to investigate the stability of the model endemic equilibrium. The model is fitted to malaria data from Benue State, Nigeria, using R and MATLAB. Estimates of parameters were made. Following that, an optimal control model is developed and analyzed using Pontryaging\u27s Maximum Principle. The malaria-free equilibrium point is locally and globally stable if the basic reproduction number (R0) and the blood transfusion reproduction number (Rα) are both less or equal to unity. The study of the sensitive parameters of the model revealed that the transmission rate of malaria from mosquito-to-human (βmh), transmission rate from humans-to-mosquito (βhm), blood transfusion reproduction number (Rα) and recruitment rate of mosquitoes (bm) are all sensitive parameters capable of increasing the basic reproduction number (R0) thereby increasing the risk in spreading malaria disease. The result of the optimal control shows that five possible controls are effective in reducing the transmission of malaria. The study recommended the combination of five controls, followed by the combination of four and three controls is effective in mitigating malaria transmission. The result of the optimal simulation also revealed that for communities or areas where resources are scarce, the combination of Long Lasting Insecticide Treated Bednets (u2), Treatment (u3), and Indoor insecticide spray (u5) is recommended. Numerical simulations are performed to validate the model\u27s analytical results

Within‐session reproducibility of forced oscillometry

BACKGROUND: The forced oscillation technique (FOT) provides detailed information about the mechanics of the respiratory system, while requiring minimal co-operation by the patient. FOT may be abnormal in subjects with normal spirometry and appears to be more closely related to airway symptoms. It is, therefore, attractive in epidemiological studies, where a large number of different examinations are made in each subjects in a short period of time. Current technical standards recommend the mean of three consecutive measurements to be used, but there is limited information regarding within-session variability of FOT measurements.OBJECTIVE: The purpose of this study was to examine the within-session variability in FOT measurements in a large, population-based sample.METHODS: We performed three consecutive FOT measurements in 700 subjects using the impulse oscillometry system. The first measurement was compared to the mean of three measurements for resistance at 5 and 20 Hz (R5 and R20, respectively), R5-R20, reactance at 5 Hz (X5) and resonant frequency (fres ).RESULTS: The differences between the first and the mean of three measurements (median, interquartile range) were minimal, for example 0.002, -0.008 to 0.014 kPa L-1 s for R5 and -0.001, -0.008 to 0.005 kPa L-1 s for X5. Findings were numerically similar for men and women as well as for subjects with and without airflow obstruction at spirometry.CONCLUSIONS: We conclude that, whereas in clinical situations, three FOT measurements are to be preferred, a single measurement may suffice in epidemiological studies

Lactarius megalopterus, a new angiocarpous species from a tropical rainforest in Central Africa, shows adaptations to endozoochorous spore dispersal

ISSN:1617-416XISSN:1861-895