Management of COVID-19: current status and future prospects

COVID-19, a highly transmissible pandemic disease, is affecting millions of lives around the world. Severely infected patients show acute respiratory distress symptoms. Sustainable management strategies are required to save lives of the infected people and further preventing spread of the virus. Diagnosis, treatment, and vaccination development initiatives are already exhibited from the scientific community to fight against this virus. In this review, we primarily discuss the management strategies including prevention of spread, prophylaxis, vaccinations, and treatment for COVID-19. Further, analysis of vaccine development status and performance are also briefly discussed. Global socioeconomic impact of COVID-19 is also analyzed as part of this review.     

Geographical Pattern and Environmental Correlates of Regional-Scale General Flowering in Peninsular Malaysia

In South-East Asian dipterocarp forests, many trees synchronize their reproduction at the community level, but irregularly, in a phenomenon known as general flowering (GF). Several proximate cues have been proposed as triggers for the synchronization of Southeast Asian GF, but the debate continues, as many studies have not considered geographical variation in climate and flora. We hypothesized that the spatial pattern of GF forests is explained by previously proposed climatic cues if there are common cues for GF among regions. During the study, GF episodes occurred every year, but the spatial occurrence varied considerably from just a few forests to the whole of Peninsular Malaysia. In 2001, 2002 and 2005, minor and major GF occurred widely throughout Peninsular Malaysia (GF2001, GF2002, and GF2005), and the geographical patterns of GF varied between the episodes. In the three regional-scale GF episodes, most major events occurred in regions where prolonged drought (PD) had been recorded prior, and significant associations between GF scores and PD were found in GF2001 and GF2002. However, the frequency of PD was higher than that of GF throughout the peninsula. In contrast, low temperature (LT) was observed during the study period only before GF2002 and GF2005, but there was no clear spatial relationship between GF and LT in the regional-scale episodes. There was also no evidence that last GF condition influenced the magnitude of GF. Thus, our results suggest that PD would be essential to trigger regional-scale GF in the peninsula, but also that PD does not fully explain the spatial and temporal patterns of GF. The coarse relationships between GF and the proposed climatic cues may be due to the geographical variation in proximate cues for GF, and the climatic and floristic geographical variations should be considered to understand the proximate factors of GF.     

Plant community composition and attributes reveal conservation implications for newly created grassland on capped landfill sites

Biodiversity conservation through restoring degraded habitats or creating new habitats is advocated in the UK Biodiversity Action Plan. Restored grasslands on capped landfill sites are semi-natural habitats that could potentially support a wide range of plant communities. However, it is unknown whether these re-created habitats represent a significant resource in terms of biodiversity conservation. The UK National Vegetation Classification (NVC) was used to study these communities on nine restored capped landfill sites together with paired reference sites in the East Midlands region of the UK during 2007. Plant species data were collected by random quadrats along two 100 m transects from each site. The effects of restoration were investigated by examining plant attributes and Ellenberg indicators on restored landfill sites in comparison to paired reference sites. A total of 170 plant species were found from both sets of sites. There were no significant differences for most of the plant attributes between restored landfill sites and reference sites, though reference sites had significantly higher mean frequencies of native plants, nationally decreasing species and perennial species. In total 26 broad NVC community types were identified of which more than 70% fell within mesotrophic grassland (MG). The diversity of NVC communities confirms that underlying environmental factors such as soil fertility are important, dictating the type of plant communities that exist. It is recommended that management of these capped landfill sites should be targeted towards specific NVC community types to meet conservation targets.     

Biosorptive removal of chromium by husk of Lathyrus sativus: Evaluation of the binding mechanism,kinetic and equilibrium study

The adsorption of tri‐ and hexavalent chromium by the husk of Lathyrus sativus (HLS), which is an agro‐waste has been investigated to find a potential solution to environmental pollution. The pH‐dependent adsorption process finds the optimum values for trivalent and hexavalent chromium ions at about pH 5.0 and pH 2.0, respectively. The process is very fast initially and attains an equilibrium within 90 min following pseudo second‐order rate kinetics. Equilibrium adsorption data can best elucidated by the Langmuir–Freundlich dual model (r² = 0.998) in comparison with other isotherm models examined indicating that both physi‐ and chemisorption are components of the binding mechanism of chromium ions on HLS. The results show that one gram of HLS can adsorb 24.6 mg Cr³⁺ and 44.5 mg Cr⁶⁺. Fourier transform infrared data and functional group modification experiments indicate that –NH₂, ‐COOH, ‐OH, ‐PO₄^3? groups of the biomass interact chemically with the chromium ions. SEM‐energy dispersive X‐ray analysis and X‐ray diffraction spectrum analysis were used to further assess the morphological changes and the mechanisms of chromium ion interaction with HLS. The analysis signified that the biosorption process involved surface morphological changes, complexation and an ion exchange mechanism. The amorphous nature of HLS facilitating metal biosorption was indicated by the X‐ray diffraction analysis.     

Characteristics of Symmetric Surface Plasmon Polariton Mode in Glass–Metal–Glass Waveguide

The propagation characteristics of symmetric surface plasmon polariton mode in a glass–metal–glass waveguide are presented. Gallium lanthanum sulfide has been taken as the glass and silver (Ag) has been used as the metal. The analysis has been done both numerically and analytically. A two-dimensional finite-difference time-domain-based simulation model has been developed in order to analyze the propagation characteristics numerically. The obtained results using numerical and analytical methods have been compared and a very good agreement has been found.     

Reproductive Organ and Vascular Specific Promoter of the Rice Plasma Membrane Ca2+ATPase Mediates Environmental Stress Responses in Plants

Background

Plasma membrane Ca²⁺ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca²⁺) from the cell, hence regulating Ca²⁺ level within cells. Though plant Ca²⁺ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied.

Results

The 1478 bp promoter sequence of rice plasma membrane Ca²⁺ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca²⁺ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The −1478 to −886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for −1210 and −886 bp flanking region. The −1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The −1210 and −886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the −886 bp and −519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs.

Conclusions

The rice plasma membrane Ca²⁺ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible nature of this promoter could grant wide applicability in plant biotechnology.     

Health-Related Financial Catastrophe,Inequality and Chronic Illness in Bangladesh

Background

Bangladesh has a high proportion of households incurring catastrophic health expenditure, and very limited risk sharing mechanisms. Identifying determinants of out-of-pocket (OOP) payments and catastrophic health expenditure may reveal opportunities to reduce costs and protect households from financial risk.

Objective

This study investigates the determinants of high healthcare expenditure and healthcare- related financial catastrophe.

Methods

A cross-sectional household survey was conducted in Rajshahi city, Bangladesh, in 2011. Catastrophic health expenditure was estimated separately based on capacity to pay and proportion of non-food expenditure. Determinants of OOP payments and financial catastrophe were estimated using double hurdle and Poisson regression models respectively.

Results

On average households spent 11% of their total budgets on health, half the residents spent 7% of the monthly per capita consumption expenditure for one illness, and nearly 9% of households faced financial catastrophe. The poorest households spent less on health but had a four times higher risk of catastrophe than the richest households. The risk of financial catastrophe and the level of OOP payments were higher for users of inpatient, outpatient public and private facilities respectively compared to using self-medication or traditional healers. Other determinants of OOP payments and catastrophic expenses were economic status, presence of chronic illness in the household, and illness among children and adults.

Conclusion

Households that received inpatient or outpatient private care experienced the highest burden of health expenditure. The poorest members of the community also face large, often catastrophic expenses. Chronic illness management is crucial to reducing the total burden of disease in a household and its associated increased risk of level of OOP payments and catastrophic expenses. Households can only be protected from these situations by reducing the health system''s dependency on OOP payments and providing more financial risk protection.     

Optimization of Multiple Pathogen Detection Using the TaqMan Array Card: Application for a Population-Based Study of Neonatal Infection

Identification of etiology remains a significant challenge in the diagnosis of infectious diseases, particularly in resource-poor settings. Viral, bacterial, and fungal pathogens, as well as parasites, play a role for many syndromes, and optimizing a single diagnostic system to detect a range of pathogens is challenging. The TaqMan Array Card (TAC) is a multiple-pathogen detection method that has previously been identified as a valuable technique for determining etiology of infections and holds promise for expanded use in clinical microbiology laboratories and surveillance studies. We selected TAC for use in the Aetiology of Neonatal Infection in South Asia (ANISA) study for identifying etiologies of severe disease in neonates in Bangladesh, India, and Pakistan. Here we report optimization of TAC to improve pathogen detection and overcome technical challenges associated with use of this technology in a large-scale surveillance study. Specifically, we increased the number of assay replicates, implemented a more robust RT-qPCR enzyme formulation, and adopted a more efficient method for extraction of total nucleic acid from blood specimens. We also report the development and analytical validation of ten new assays for use in the ANISA study. Based on these data, we revised the study-specific TACs for detection of 22 pathogens in NP/OP swabs and 12 pathogens in blood specimens as well as two control reactions (internal positive control and human nucleic acid control) for each specimen type. The cumulative improvements realized through these optimization studies will benefit ANISA and perhaps other studies utilizing multiple-pathogen detection approaches. These lessons may also contribute to the expansion of TAC technology to the clinical setting.     

Predation of cotton bollworm by green lacewings in the presence of cotton aphid as alternative prey on transgenic Bt and conventional cotton

Experiments were conducted in small arenas and on whole plants to explore the effect of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae), as alternative prey on the predation of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) larvae by green lacewing larvae, Mallada signatus Schneider (Neuroptera: Chrysopidae). Transgenic Bt (Bollgard II^®) and conventional cotton plants were included to explore potential differences in the predator's performance on these cotton types. In small arenas, the presence of 20 aphids reduced predation on H. armigera larvae by 22% (from 5.5 to 3.3 of 10) by a single lacewing larva over a 24‐h period. The presence of H. armigera reduced predation on aphids by ca. 29% (from 16.8 to 11.0 of 20) over 24 h. On whole plants, the presence of alternative prey had no effect on the number of H. armigera larvae or aphids remaining after 3 days. The presence of H. armigera larvae alone, without the predator, caused a 24% reduction in the numbers of aphids on conventional, but not on Bt cotton plants. The combination of Bt cotton and lacewing larvae caused a 96.6% removal of early‐stage H. armigera larvae, a statistically significant increase over the addition of the proportions (91.6%) removed by each factor measured separately, providing evidence of synergism. These studies suggest that the presence of aphids as alternative prey would not necessarily disrupt the predation by green lacewing on larvae of H. armigera, especially on Bt cotton.     

In vitro toxicity and antidiabetic activity of a newly developed polyherbal formulation (MAC-ST/001) in streptozotocin-induced diabetic Wistar rats

The present study was designed to investigate the hypoglycemic effect of an aqueous extract of MAC-ST/001 (a new polyherbal formulation) which was given once daily to rats at different doses. The animals were divided into diabetic and nondiabetic control groups. The duration of each experiment lasted from 1 week to 1 month, and the results were compared with that of the standard hypoglycemic drug glibenclamide (10 mg/kg), which was given once daily. In this study, biochemical and histopathological parameters were studied in streptozotacin (STZ) (single intraperitoneal injection of 55 mg/kg)-induced diabetic rats. The diabetic rats showed a significant (p?<?0.05 and p?<?0.01) decrease in their body weight and serum amylase with marked elevation in blood glucose, serum cholesterol, blood urea nitrogen, creatinine, alkaline phosphatase, and serum transaminases (AST and ALT) after 1 week till the 28th day of diabetes. Cytotoxicity of MAC-ST/001 formulation was also studied on C2C12, 3T3-L1, and HepG2 cells through MTT assay. Histological examination of the liver and pancreas of normal control, diabetic control, and drug-treated rats revealed significant results. Finally, it was concluded that administration of this MAC-ST/001 extract reversed most blood and tissue changes caused by STZ-induced diabetes in rats.