PfAP2-EXP2, an Essential Transcription Factor for the Intraerythrocytic Development of Plasmodium falciparum

Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.

Effects of Barrier Stiffness on Debris Flow Dynamic Impact—II: Numerical Simulation

The destructive and impactful forces of debris flow commonly causes local damage to engineering structures. The effect of a deformable barrier on the impact dynamics is important in engineering design. In this study, a flow–structure coupled with Smoothed Particle Hydrodynamics model was presented to investigate the effects of barrier stiffness on the debris impact. A comparison of the results of physical tests and simulation results revealed that the proposed smoothed particle hydrodynamics model effectively reproduces the flow kinematics and time history of the impact force. Even slight deflections of the deformable barrier lead to obvious attenuation of the peak impact pressure. Additionally, deformable barriers with lower stiffness tend to deform more downstream upon loading, shifting the deposited sand toward the active failure mode and generating less static earth pressure. When the debris flow has a higher frontal velocity, the impact force on the barrier is dominated by the dynamic component and there is an appreciable effect of the stiffness of the deformable barrier on load attenuation.

Flexural Strength Evaluation of Multi-Cell Composite L-Shaped Concrete-Filled Steel Tubular Beams

Concrete-filled steel tubular (CFST) members have been widely used in industrial structures and high-rise residential buildings. The multi-cell composite L-shaped concrete-filled steel tubular (ML-CFST) cross-section, as an innovative, special-shaped structural arrangement, may solve the issue of normal CFST members protruding from walls and result in more usable interior space. Currently, no design rules are available for the application of ML-CFST members. One of the primary objectives of the present study is to develop recommendations in line with the unified theory to evaluate the bending moment resistance of ML-CFST beams. According to the unified theory, the bending moment resistance of an ML-CFST beam is related to the compressive strength (fsc) and the flexural strength index (γm) of a composite section, in which the accuracy of γm and fsc are affected by a confinement effect factor (ξ). Nevertheless, the original expression of ξ is not suitable for ML-CFST sections, since the appreciable effect of the irregular shape on confinement is neglected. Considering the cross-sectional geometry and boundary conditions of the cells, an equivalent shape factor to modify the confinement effect was proposed in this study through dividing the infill concrete into highly confined areas and less confined areas. An adequate formula to calculate the fsc and an approximate expression of γm for the ML-CFST sections was then developed. Furthermore, four-point bending tests on eight specimens were carried out to investigate the flexural performance of the ML-CFST beams. Lastly, the proposed formulas were assessed against experimental and numerical results. The comparisons show that the proposed unified theory-based approach produced accurate and generally conservative results for the ML-CFST beams studied.

Evaluation of adherence of patients with atrial fibrillation to anticoagulant therapy at the outpatient stage of treatment

Despite clinical guidelines for the treatment of atrial fibrillation (AF) patient adherence to oral anticoagulants (OACs) in routine clinical practice remains low. Assessing the factors affecting adherence to the OACs regimen and developing strategies for its improvement is important. Aim. To assess the adherence of patients with AF to the prescribed anticoagulant therapy at the outpatient stage of treatment. Methodology. The object of the study was 165 patients with nonvalvular AF undergoing treatment in a specialized cardiology department or receiving outpatient treatment in a specialized cardiological dispensary in Saratov from February 2018 to December 2019. After 3, 6, 12 months, a telephone contact with the patients was carried out, a specially designed questionnaire was filled out, in which the anticoagulant therapy received by AF patients was reflected, the Morisky-Green questionnaire was filled out, the answers of patients about the reasons for skipping or stopping the administration of the OACs were recorded. Results. After 3 months. 16.6 % of AF patients replaced the OACs intake with antiplatelet agents, 16 % refused antithrombotic therapy; 43.1 % of AF patients were adherent to OACs. After 6 months. antiplatelet agents were taken by 24.5 % patients (p<0.05), 11.9 % completely stopped taking antithrombotic drugs; 30.8 % of patients were adherent to OACs (p<0.05). After 12 29,5 % patients replaced OACs treatment with antiplatelet agents, 7.6 % patients did not take any antithrombotic drugs; 31.8 % of AF patients were adherent to OACs. The most common reasons for a decrease in the adherence to OACs therapy were the cost of drugs, lack of understanding of the value of OACs administration in AF, and the lack of appreciable effect of OACs administration. Conclusion. At the outpatient stage of treatment, there was an insufficient level of adherence of AFpatients to OACs treatment.

Productivity of Cowpea (Vigna unguiculata (L) Walp) genotypes under Varying Population Densities

To investigate the influence of three population densities (88,000, 44,000, and 29,000 plants/ha) on the growth and yield of five cowpea varieties (IT97K-461, IT97K-568-18, IT98K-131-2, IT99K-1060 and IT99K-`245), a field experiment was conducted at Teaching and Research farm of Landmark University. Growth parameters such as germination count, plant height, and number of trifoliate leaves per plant, number of branches per plant, flower production dynamics and dry matter determination were measured, while harvest index, shelling percentage, number of seeds per pod, see weight pods per plant and grain yield were measured at harvest as yield components. Data were subjected to statistical analysis of variance (ANOVA) using SAS Institute. Significant means were separated using Duncans Multiple Range Test at 5% probability level. Results revealed that there were no constant trends in growth parameters response to population density. Plant height and flower production decreased with increased population density, while number of leaves per plant and dry matter increased with increasing population density. There was no appreciable effect of population density on branching. All these parameters were significantly (p≤0.05) affected with variety, while there was no significant (p≤0.05) interaction effect. Most yield components decreased with increasing population density while grain yield however, slightly increased with increasing population density. All yield parameter and grain yield significantly varied with variety, while there were no appreciable interaction effect. In conclusion, a population density of 88,000 plants /ha gives the highest growth and grain yield. While, variety, IT97-568-18 gives the higher growth and grain yield than other varieties studied.

Application of multiphase flow and droplet separation theory in modeling cough droplets contamination range to mitigate COVID-19 transmission: Do not stand too close to me!

On March 11, 2020, the World Health Organization (WHO) declared that COVID-19 is a pandemic, warning the world of a health catastrophe and social, economic, and political disruptions. According to WHO, COVID-19 is transmitted by the transport of respiratory droplets generated by a violent respiratory event such as sneeze and cough directly to susceptible persons, or indirectly through surfaces. The aim of this study is to propose simple physical and mathematical models based on two-phase flow dynamics and droplet separation theory. The proposed mathematical model predicts the contamination range of ejected cough droplets, estimating the safe person-to-person social distance. As a result, the proposed simple model predicted a contamination range of 2.3 m for a male adult. In addition, to understand the behavior of ejected cough droplets, a sensitivity analysis is carried out to investigate the effect on contamination range of cough air flowrate, i.e., body/lung size, droplet size, and droplet drag coefficient. It is found that as the body/lung size decreases, i.e., lower cough flow rate, contamination range decreases, resulting in 1.9 m for an adult female, and 1.4 m for a child. In addition, the model predictions show an appreciable effect of droplet size, and droplet drag coefficient on cough contamination range. In particular, the effect of droplet drag coefficient is of interest, because of its relationship to ambient conditions such as temperature and relative humidity, in which both affect ambient air viscosity, and thus drag coefficient. This is important in investigating the contamination range and person-to-person social-distance as climate changes.

Weighted pseudo asymptotically Bloch periodic solutions to nonlocal Cauchy problems of integrodifferential equations in Banach spaces

This paper is mainly concerned with some new asymptotic properties on mild solutions to a nonlocal Cauchy problem of integrodifferential equation in Banach spaces. Under some well-imposed conditions on the nonlocal Cauchy, the neutral and forced terms, respectively, we establish some existence results for weighted pseudo S-asymptotically (ω, k)-Bloch periodic mild solutions to the referenced equation on R + ${\mathbb{R}}_{+}$ by suitable superposition theorems. The results show that the strict contraction of the nonlocal Cauchy and the neutral terms with the state variable has an appreciable effect on the existence and uniqueness of such a solution compared with the forced term. As an auxiliary result, the existence of weighted pseudo S-asymptotically (ω, k)-Bloch periodic mild solutions is deduced under the sublinear growth condition on the force term with its state variable. The existence of weighted pseudo S-asymptotically ω-antiperiodic mild solution is also obtained as a special example.

Properties of 4ΛH Hypernucleus in Three-Cluster Microscopic Models

Within the framework of microscopic three-cluster algebraic models with possible consideration of clustering types (D + n) + Λ, (D + Λ) + n, and (n + Λ) + D, the properties of discrete spectrum states of hypernucleus 4ΛH and continuous spectrum states in the 3H + Λ channel are studied. It is shown that the cluster structure is almost completely determined by the clustering (D + n) + Λ with a rather appreciable effect from the polarization of the binary subsystem (D + n) due to its interaction with the Λ particle.

Thermodynamic Estimation of the Parameters for the C–H–O–N–Me-Systems as Operating Fluid Simulants for New Processes of Powder Thermal Spraying and Spheroidizing

Over the past few years, a group of new processes was developed for high-temperature, including plasma electric arc spraying (at ambient pressure) and spheroidizing of some ceramic and metal powder materials with the use of gaseous hydrocarbons in the heat carriers as well as with feeding of organic additions into a high-temperature jet, in particular, polymeric ones, to control porosity of sprayed metallic functional coatings. The paper considers the possibility to modify such technological processes by introducing solid fuel additions of a polymer type into the operating fluid of an apparatus for gasthermal (plasma or other) treatment, which provides melting of metal or oxide powders. For this, with the help of thermodynamic analysis, the processes have been evaluated at temperatures (300–3000) K for the set of such reacting five component systems as C–H–O–N–Me (at ambient pressure 0.101 MPa) with five variants of Ме – aluminum, titanium, chrome, copper, nickel. This makes it possible to consider these systems as simulants for potential technologies for the treatment of oxide powders (Al2O3, TiO2, Cr2O3) as well as metallic ones (Cu, Ni and their alloys). In order to obtain high exothermic contribution to the heating of powders, the combination “air + polymeric addition (polyethylene) of LDPE grade” was chosen as mixed heat carrier (operating fluid) for the basic version of simulated process. During the analysis of equilibria for the considered multicomponent systems (17 variants), a set of following parameters has been used to characterize the energy intensity of the target powder heating process: the equivalence ratio for reacting mixture and its adiabatic temperature; the energy efficiency of material heating with and without taking into account the effect of fuel addition; specific energy consumption for the powder melting; autothermicity degree of the process during the combined heating (electrothermal heating by the arc of plasma torch and heat flux from the “air + solid fuel additions” mixture) of refractory powders. As a result of the assessment, the preferred (from thermodynamic standpoint) regimes of the considered processes have been found and the possibility to realize an energy-efficient heating of these oxide and metal materials (without oxidation of the latter to CuOx, NiO) with a reduced part of the electric channel of energy transfer, resulted from the carrying out of appreciable effect of the fuel-initiated mechanism of heating in the analyzed C–H–O–N–Mesystems, has been shown in the paper.

Lubrication and stability enhancement by attaching superconducting magnetic force on non-contacting mechanical seals for reusable rocket turbopump

The purpose of this paper is to investigate the lubrication performance and stability improvement of rocket turbopump mechanical seals by attaching superconducting magnetic force. A comprehensive multiphysics numerical model is presented including microscale clearance flow, magnetic field, as well as three degrees of freedom dynamic motion. The Maxwell equation and modified Reynolds equation considering mass-conserving boundary conditions and turbulence flow were solved simultaneously at each time step to obtain the transient response of sealing parameters. Results indicate that the mechanical seal attaching superconducting magnetic force could dramatically improve carrying capacity and lubrication characteristics under heavy loading conditions, and it also has an appreciable effect on dynamic stability. It is worth exploring the application of superconducting magnetic force in reusable rockets and cryogenic equipment combined with its unique advantages.