Effect of excess boron on growth, membrane stability, and functional groups of tomato seedlings

With the scarcity of good quality water, plants like tomatoes will be more susceptible to excess boron (EB) in Mediterranean regions. The effects of EB on the growth, free, semi-bound, and bound boron (B) concentrations, and macromolecules of the Solanum lycopersicum L. cultivar Castle Rock, were investigated in this study. Seedlings were exposed to four levels of EB using boric acid. The results manifested that EB inhibited tomato growth, total water content, and photosynthetic pigments. EB harmed the membrane stability, as seen by increased potassium (K) leakage, UV absorbance metabolites, and electrolyte conductivity (EC) in leaf disc solution. EB raised concentrations of free, semi-bound, and bound forms of B in seedlings. Fourier transform infrared spectroscopy (FTIR) data revealed that EB induced uneven wax deposition, altered the shape of cell walls, and lowered cellulose synthesis in seedlings. EB affected the amide I and amide II indicating damage to the protein pools. These results provide new insights into understanding the specific effects of EB on the functional groups of different macromolecules of tomato seedlings

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Dynamic Study of a Delayed Fractional-Order SEIR Epidemic Model with General Incidence and Treatment Functions

This study examines the global features of the SEIR epidemic model in its fractional-order version with time delay. General functions are considered to govern the infection transmission rate, and the rate at which diseased individuals are removed from the infected class. First, we form the proposed model in the Caputo case and perform fundamental mathematical analysis of the model solutions, such as checking for non-negativity and boundedness. The basic reproduction number R0 is then provided after computing the equilibrium points. Following that, sufficient criteria for the global stability of each equilibrium are checked using the relevant Lyapunov functions. It is shown that the characteristics of these general functions, along with the basic reproduction number R0, impact the model’s global features. Finally, a numerical simulation is presented to show the viability and effectiveness of the derived analytical conclusions. According to the results, the system’s enhanced dynamic behavior and larger stability regions in equilibria demonstrate the influence of incorporating the time delay and fractional-order

Phyto-remedial of excessive copper and evaluation of its impact on the metabolic activity of Zea mays

Maize is diagnosed as a heavy metal (HM) accumulator, while the tolerance mechanism is not sufficiently known. A hydroponic experiment was performed to test the ability of maize plants to tolerate and accumulate Cu. Excess copper treatments (ECu; 5 and 10 μM CuSO4) considerably reduced plant growth, photosynthetic pigments, ascorbate peroxidase (APX), and guaiacol peroxidase (POD) activity. However, ECu significantly enhanced catalase (CAT) activity. ECu treatments reduced the leaf membrane integrity as indicated by increasing malondialdehyde (MDA) content in leaves. Proline and phenolic contents were considerably increased in maize organelles by ECu toxicity. ECu treatments considerably stimulated free amino acid (FAA) accumulation, total-soluble proteins (TSPs), and K in shoots, whereas these parameters did not change in the roots. Applications of CuSO4 did not affect the accumulation of total soluble sugars (TSSs) in shoots, while this accumulation enhanced in roots. CuSO4 treatments significantly increased the Cu concentration and uptake but decreased the Cu translocation factor (TF) and bioaccumulation factor (BF). Structural components such as cell wall components, proteins, lipids, and sugars were affected by ECu stress, as shown by infrared spectroscopy (FT-IR) analysis. These results give a new insight into the strategy, which maize can use to treat the Cu-polluted environment as Cu accumulates within seedling tissues and the seedling can protect itself from ECu stress

Global Stability of a Delayed Fractional-Order SEI Epidemic Model with Logistic Growth

In this paper, we investigate the qualitative behavior of a fractional-order susceptible-exposed-infected (SEI) model with logistic growth and time delay. In the proposed epidemic model, we assumed that the susceptible individuals grow logistically and introduced time delay in latent infected individuals equation. The basic reproduction number R0 is derived using next generation matrix to study the dynamics of the disease free and endemic equilibrium points of the system. Based on the characteristic equations and conditions of the stability of fractional-order differential systems, local stability of the two equilibrium points is discussed. Furthermore, a suitable Lyapunov function is proposed to investigate the global stability of equilibrium points. The results demonstrated that the fractional-order derivatives enriched the dynamical behavior of the epidemic system. Moreover, in the fractional-order case, the stability region of the equilibrium points increased. The theoretical results are verified by numerical simulations

An Efficient Synthesis of Novel Bioactive Thiazolyl-Phthalazinediones under Ultrasound Irradiation

Novel 2-thiazolylphthalazine derivatives were efficiently synthesized under ultrasound irradiation, resulting in high yields and short reaction times after optimization of the reaction conditions. All prepared compounds were fully characterized using spectroscopic methods. They were screened for their antimicrobial activity against Gram-positive and Gram-negative bacteria as well as for antifungal activity. The antimicrobial activity profile of the tested compounds showed some promising results. The potent activity of compounds 4d, 7b (117% zone inhibition) and 7c (105% zone inhibition) against Salmonella sp., exceeding that of the reference drug Gentamycin is particularly noteworthy. In general, the newly synthesized thiazolylphthalazine derivatives showed higher antimicrobial activity against the tested Gram-negative bacteria than against Gram-positive bacteria and fungi

Development of a hybrid LSTM with chimp optimization algorithm for the pressure ventilator prediction

Abstract The utilization of mechanical ventilation is of utmost importance in the management of individuals afflicted with severe pulmonary conditions. During periods of a pandemic, it becomes imperative to build ventilators that possess the capability to autonomously adapt parameters over the course of treatment. In order to fulfil this requirement, a research investigation was undertaken with the aim of forecasting the magnitude of pressure applied on the patient by the ventilator. The aforementioned forecast was derived from a comprehensive analysis of many variables, including the ventilator's characteristics and the patient's medical state. This analysis was conducted utilizing a sophisticated computational model referred to as Long Short-Term Memory (LSTM). To enhance the predictive accuracy of the LSTM model, the researchers utilized the Chimp Optimization method (ChoA) method. The integration of LSTM and ChoA led to the development of the LSTM-ChoA model, which successfully tackled the issue of hyperparameter selection for the LSTM model. The experimental results revealed that the LSTM-ChoA model exhibited superior performance compared to alternative optimization algorithms, namely whale grey wolf optimizer (GWO), optimization algorithm (WOA), and particle swarm optimization (PSO). Additionally, the LSTM-ChoA model outperformed regression models, including K-nearest neighbor (KNN) Regressor, Random and Forest (RF) Regressor, and Support Vector Machine (SVM) Regressor, in accurately predicting ventilator pressure. The findings indicate that the suggested predictive model, LSTM-ChoA, demonstrates a reduced mean square error (MSE) value. Specifically, when comparing ChoA with GWO, the MSE fell by around 14.8%. Furthermore, when comparing ChoA with PSO and WOA, the MSE decreased by approximately 60%. Additionally, the analysis of variance (ANOVA) findings revealed that the p-value for the LSTM-ChoA model was 0.000, which is less than the predetermined significance level of 0.05. This indicates that the results of the LSTM-ChoA model are statistically significant

Reproductive studies on the carpet clam Paphia textile (Paratapes textilis) (Gmelin 1791) (Family: Veneridae): a guide of aquaculture management along the Egyptian coasts of the Red Sea and Suez Canal

Abstract Background Most aquatic biota's reproductive biology and life cycle are essential to the sustainable management and development of coastal ecosystems and aquaculture. The bivalve Paphia textile (Gmelin 1791), also known as Paratapes textilis, has an economic value in Indo-Pacific waters, including the Red Sea and the Suez Canal lakes, the Egyptian coasts. However, P. textile suffers from extensive fishing and exploitation. Aim The present work aims to study the Paphia textile's reproductive cycle on the Egyptian coasts of the Red Sea for the first time. It helps to manage and develop the coastal ecosystems and aquaculture. Methodology Samples were collected monthly from two saline lakes in the Suez Gulf from December 2019 to November 2020. As part of the comprehensive research study, sex ratio, condition index, sexuality, histological analysis of gonads, shell size, and gonad index were used to investigate the reproductive cycle. Results The results reveal a male-biased sex ratio, possibly due to anthropogenic stressors. The Paphia textile is dioecious. No hermaphrodite cases were observed in the studied specimens. The condition index in winter and spring indicates periods dominated by mature individuals. Five reproductive maturity stages were assigned for both P. textile males and females. Due to the simultaneous development of several developmental stages monthly throughout the sampling year, warm water may be responsible for non-sequential gametogenic cycles. As measured environmental parameters correlate with maturity stages, temperature, salinity, and chlorophyll a play important role in gonad growth. The size at first sexual maturity at which 50% of the Paphia textile population reached maturity ranged from 28.60 to 31.50 mm for females, and between 31.70 and 34.10 mm for males. As the gonad index increases during the ripe stages, this index decreases during the resting, spawning, and spent phases. Conclusions The findings suggest the most suitable temperature for aquaculture spawning is between 20 °C and 30 °C in subtropical waters. Fishing should generally be prohibited at sizes less than 28.60 mm for better management and sustainability of this valuable aquatic resource on the Egyptian coasts of the Red Sea

Additional file 2 of Reproductive studies on the carpet clam Paphia textile (Paratapes textilis) (Gmelin 1791) (Family: Veneridae): a guide of aquaculture management along the Egyptian coasts of the Red Sea and Suez Canal

Additional file 2: Appendix 2. Schematic representation of the carpet clam P. textile shell measurements: SL: Shell length; SH: Shell height; SI: Shell inflation. (SL= 45 mm), published in Farghaley et al., 2022