Simulation of Diffusive Transport of Radionuclides in the Soil of a Radioactive Waste Disposal Site

The diffusive transport of ¹³⁷Cs, ⁹⁰Sr, and ⁶⁰Co in the clay of a radioactive waste disposal site at PINSTECH was studied to assess the safety of the underlying permeable zone against the release of these radionuclides from buried waste containers in the clay. Diffusion coefficients of these radionuclides were estimated by reservoir to sediment diffusion method via their stable counterparts in a laboratory experiment. A curve-fitting procedure was applied on the measured concentration-time profiles of the reservoir using the one-dimensional solute transport equation with a nonlinear least squares technique. Distribution coefficients were determined in laboratory batch experiments. Diffusive transport simulations were performed with the estimated values of diffusion coefficients and distribution coefficients using the one-dimensional solute transport equation describing Fickian diffusion, equilibrium adsorption, and radioactive decay. The transport simulation results showed that ¹³⁷Cs, ⁹⁰Sr, and ⁶⁰Co will transport distances of 4.33, 3.77, and 1.51 meters, respectively, in the clay before their activity concentrations will drop to clearance levels set by the International Atomic Energy Agency (IAEA), below which the waste is treated as non-radioactive. This showed that concentrations more than clearance levels will not be able to transport to the permeable zone at a minimum depth of seven meters from the ground surface if the waste containers are disposed in a trench below which a clay layer with a thickness of 4.33 meters or more exists.     

Physiological homeostasis for ecological success of Typha (Typha domingensis Pers.) populations in saline soils

The natural capacity of plants to endure salt stress is largely regulated by multifaceted structural and physio-biochemical modulations. Salt toxicity endurance mechanism of six ecotypes of Typha domingensis Pers. was evaluated by analyzing photosynthesis, ionic homeostasis, and stomatal physiology under different levels of salinity (0, 100, 200 and 300 mM NaCl). Typha populations were collected across different areas of Punjab, an eastern province in Pakistan. All studied attributes among ecotypes presented differential changes as compared to control. Different salt treatments not only affected gas exchange attributes but also shown significant modifications in stomatal anatomical changes. As compared to control, net photosynthetic rate, transpiration rate, total chlorophyll contents and carotenoids were increased by 111%, 64%, 103% and 171% respectively, in Sahianwala ecotype among all other ecotypes. Similarly, maximum water use efficiency (WUE), sub stomatal CO₂ concentration, sodium (Na⁺) and chloride (Cl⁻) contents were observed in Sahianwala (191%, 93%, 168%, 158%) and Knotti (162%, 75%, 146%, 182%) respectively, as compared to the others ecotypes. Adaxial and abaxial stomatal areas remained stable in Sahianwala and Knotti. The highest abaxial stomatal density was observed in Gatwala ecotype (42 mm²) and maximum adaxial stomatal density was recorded in Sahianwala ecotype (43 mm²) at 300 mM NaCl salinity. The current study showed that Typha ecotypes responded varyingly to salinity in terms of photosynthesis attributes to avoid damages due to salinity. Overall, differential photosynthetic activity, WUE, and changes in stomatal attributes of Sahianwala and Knotti ecotypes contributed more prominently in tolerating salinity stress. Therefore, Typha domingensis is a potential species to be used to rehabilitate salt affected lands for agriculture and aquatic habitat.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-00963-x.     

Unfolded protein response regulates P53 expression in the pulmonary endothelium

Lung endothelial barrier dysfunction leads to severe pathologies, including the lethal Acute Respiratory Distress Syndrome. P53 has been associated with anti‐inflammatory activities. The current study employs a variety of unfolded protein response (UPR) activators and inhibitors to investigate the regulation of P53 by UPR in lung cells. The bovine cells that were exposed to the UPR inductors brefeldin A, dithiothreitol, and thapsigargin; demonstrated elevated expression levels of P53 compared to the vehicle‐treated cells. On the contrary, the UPR inhibitors N‐acetyl cysteine, kifunensine, and ATP‐competitive IRE1α kinase‐inhibiting RNase attenuator; produced the opposite effects. The outcomes of the present study reveal a positive regulation between UPR and P53. Since it has been shown that a mild induction of the unfolded protein response opposes inflammation, we suggest that P53 is involved in those protective activities in the lung.     

Proteome‐wide B and T cell epitope repertoires in outer membrane proteins of Mycobacterium avium subsp. paratuberculosis have vaccine and diagnostic relevance: a holistic approach

Mycobacterium avium subsp. paratuberculosis (MAP) is an etiological agent of chronic inflammation of the intestine among ruminants and humans. Currently, there are no effective vaccines and sensitive diagnostic tests available for its control and detection. For this, it is of paramount importance to identify the MAP antigens, which may be immunologically recognized by the host immune system. To address this challenge, we performed identification of the immunogenic epitopes in the MAP outer membrane proteins (OMPs). We have previously identified 57 MAP proteins as OMPs [Rana A, Rub A, Akhter Y. 2014. Molecular BioSystems, 10:2329–2337] and have evaluated them for the epitope selection and analysis employing a computational approach. Thirty‐five MAP OMPs are reported with nine‐mer peptides showing high binding affinity to major histocompatibility complex (MHC) class I molecules and 28 MAP OMPs with 15‐mer peptides of high binding affinity for MHC class II molecules. The presence of MHC binding epitopes indicates the potential cell‐mediated immune response inducing capacity of these MAP OMPs in infected host. To further investigate the humoral response inducing properties of OMPs of MAP, we report potential B cell epitopes based on the sequences of peptide antigens and their molecular structures. We also report 10 proteins having epitopes for both B and T cells representing potential candidates which may invoke both humoral and cellular immune responses in the host. These findings will greatly accelerate and expedite the formulation of effective and cost‐efficient vaccines and diagnostic tests against MAP infection. Copyright © 2015 John Wiley & Sons, Ltd.