A predator prey model with age structure

A general predator-prey model is considered in which the predator population is assumed to have an age structure which significantly affects its fecundity. The model equations are derived from the general McKendrick equations for age structured populations. The existence, stability and destabilization of equilibria are studied as they depend on the prey's natural carrying capacity and the maturation periodm of the predator. The main result of the paper is that for a broad class of maturation functions positive equilibria are either unstable for smallm or are destabilized asm decreases to zero. This is in contrast to the usual rule of thumb that increasing (not decreasing) delays in growth rate responses cause instabilities.Research supported by National Science Foundation Grant No. MCS-7901307-01Research supported by National Scholarship for Study Abroad No. EDN/S-59/80 from the government of India     

Prediction of stenosis behaviour in artery by neural network and multiple linear regressions

Biomechanics and Modeling in Mechanobiology - Blood flow analysis in the artery is a paramount study in the field of arterial stenosis evaluation. Studies conducted so far have reported the...     

Plant growth-promoting Bacillus sp. strain SDA-4 confers Cd tolerance by physio-biochemical improvements,better nutrient acquisition and diminished Cd uptake in Spinacia oleracea L.

Cadmium (Cd) is highly toxic metal for plant metabolic processes even in low concentration due to its longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of a Cd-tolerant phytobeneficial bacterial strain Bacillus sp. SDA-4, isolated, characterized and identified from Chakera wastewater reservoir, Faisalabad, Pakistan, together with spinach (as a test plant) under different Cd regimes. Spinach plants were grown with and without Bacillus sp. SDA-4 inoculation in pots filled with 0, 5 or 10 mg kg⁻¹ CdCl₂-spiked soil. Without Bacillus sp. SDA-4 inoculation, spinach plants exhibited reduction in biomass accumulation, antioxidative enzymes and nutrient retention. However, plants inoculated with Bacillus sp. SDA-4 revealed significantly augmented growth, biomass accumulation and efficiency of antioxidative machinery with concomitant reduction in proline and MDA contents under Cd stress. Furthermore, application of Bacillus sp. SDA-4 assisted the Cd-stressed plants to sustain optimal levels of essential nutrients (N, P, K, Ca and Mg). It was inferred that the characterized Cd-tolerant PGPR strain, Bacillus sp. SDA-4 has a potential to reduce Cd uptake and lipid peroxidation which in turn maintained the optimum balance of nutrients and augmented the growth of Cd-stressed spinach. Analysis of bioconcentration factor (BCF) and translocation factor (TF) revealed that Bacillus sp. SDA-4 inoculation with spinach sequestered Cd in rhizospheric zone. Research outcomes are important for understanding morpho-physio-biochemical attributes of spinach-Bacillus sp. SDA-4 synergy which might provide efficient strategies to decrease Cd retention in edible plants and/or bioremediation of Cd polluted soil colloids.     

Changes in Phyto-Chemical Status upon Viral Infections in Plant: A Critical Review

Most damaging plant diseases have been caused by viruses in the entire world. In tropical and subtropical areas, the damage caused by plant virus leads to great economic and agricultural losses. Single stranded DNA viruses (geminiviruses) are the most perilous pathogens which are responsible for major diseases in agronomic and horticultural crops. Significantly begomoviruses and mastreviruses are the biggest genus of plant infecting viruses, transmitted though Bemisia tabaci and members of Cicadellidae respectively. Plants possesses some naturally existing chemicals term as phyto-chemicals which perform important functions in the plant. Some antioxidant enzymes are used by plants for self-defense upon foreign invasion of infection. This review explains the present perceptive of influence of viral infections on phyto-chemicals, oxidative enzymes and biochemical changes occurring in the plant. Viral infection mediated phyto-chemical changes in plants mainly includes: up and down regulation of photosynthetic pigment, increase in the concentration of phenolic compounds, elevation of starch content in the leaf and up & down regulation of anti-oxidative enzymes including (GPX) guaiacol peroxidase, (PPO) polyphenol oxidase, (APX) ascorbate peroxidase, (SOD) superoxide dismutase and (CTA) catalase. These changes lead to initiation of hypersensitive response, by thicken of the leaf lamina, lignification under the leaf surface, blocking to stomatal openings, systematic cell death, generation of reactive oxidative species (ROS), activation of pathogen mediated resistance pathways i.e., production of salicylic acid and jasmonic acid. Collectively all the physiological changes in the plant due to viral infection supports the activation of defense mechanism of the plant to combat against viral infection by limiting virus in specific area, followed with the production of barriers for pathogen, accumulation of starch in the leaf and excess production of (ROS). These strategies used by the plant to prevent the spread of virus in whole plant and to minimize the risk of severe yield loss.     

Molybdenum supply increases root system growth of winter wheat by enhancing nitric oxide accumulation and expression of NRT genes

Plant and Soil - Success in agronomic biofortification of maize and wheat is highly variable. This study aimed to elucidate the differences in uptake and translocation of foliar-applied zinc (Zn)...     

Screening of Synthetic Isoxazolone Derivative Role in Alzheimer’s Disease: Computational and Pharmacological Approach

Neurochemical Research - Alzheimer's disease (AD) is age-dependent neurological disorder with progressive loss of cognition and memory. This multifactorial disease is characterized by...     

Multifaceted Role of Salicylic Acid in Combating Cold Stress in Plants: A Review

Plants face different types of stresses, including biotic and abiotic stresses. Among various abiotic stress, low-temperature stress alters various morphological, cytological, physiological, and other biochemical processes in plants. To thrive in such condition’s plants must adopt some strategy. Out of various strategies, the approach of using plant growth regulators (PGRs) gained a prominent role in the alleviation of multiple stresses. Salicylic acid, application triggers tolerance to both biotic and abiotic stresses via regulation of various morpho-physiological, cytological, and biochemical attributes. SA is shown to alleviate and regulate the various cold-induced changes. Both endogenous and exogenously applied SA show an imperative role in the alleviation of cold-induced changes by activating multiple signaling pathways like ABA-dependent or independent pathway, Ca²⁺ signaling pathway, mitogen-activated protein kinase (MAPKs) pathway, reactive oxygen species (ROS), and reactive nitrogen species (RNS) pathways. Activation of these pathways leads to the amelioration of the cold-induced changes by increasing production of antioxidants, osmolytes, HSPs and other cold-responsive proteins like LEA, dehydrins, AFPs, PR proteins, and various other proteins. This review describes the tolerance of cold stress by SA in plants through the involvement of different stress signaling pathways.

     

Microscale grooves regulate maturation development of hPSC-CMs by the transient receptor potential channels (TRP channels)

The use of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is limited in drug discovery and cardiac disease mechanism studies due to cell immaturity. Micro-scaled grooves can promote the maturation of cardiomyocytes by aligning them in order, but the mechanism of cardiomyocytes alignment has not been studied. From the level of calcium activity, gene expression and cell morphology, we verified that the W20H5 grooves can effectively promote the maturation of cardiomyocytes. The transient receptor potential channels (TRP channels) also play an important role in the maturation and development of cardiomyocytes. These findings support the engineered hPSC-CMs as a powerful model to study cardiac disease mechanism and partly mimic the myocardial morphological development. The important role of the TRP channels in the maturation and development of myocardium is first revealed.     

Correction to: In Silico Evaluation of Food Derived Bioactive Peptides as Inhibitors of Angiotensin Converting Enzyme (ACE)

International Journal of Peptide Research and Therapeutics - The original version of the article unfortunately contained a typo in co-author name.