UPRRP College of Natural Sciences

About: UPRRP College of Natural Sciences is a based out in . It is known for research contribution in the topics: Apoptosis & Population. The organization has 9323 authors who have published 11826 publications receiving 284172 citations.

The impact of future sea-level rise on the European Shelf tides

Abstract: This paper investigates the effect of future sea-level rise (SLR) on the tides of the northwest European Continental Shelf. The European shelf tide is dominated by semidiurnal constituents. This study therefore focuses primarily on the changes in the M2 tidal constituent and the spring and neap tidal conditions. The validated operational Dutch Continental Shelf Model is run for the present day sea-level as well as 2 and 10 m SLR scenarios. The M2 tidal amplitude responds to SLR in a spatially non-uniform manner, with substantial amplitude increases and decreases in both scenarios. The M2 tidal response is non-linear between 2 and 10 m with respect to SLR, particularly in the North Sea. Under the 2 m SLR scenario the M2 constituent is particularly responsive in the resonant areas of the Bristol Channel and Gulf of St. Malo (with large amplitude decreases) and in the southeastern German Bight and Dutch Wadden Sea (with large amplitude increases). Changes in the spring tide are generally greater still than those in the M2 or neap tides. With 2 m SLR the spring tidal range increases up to 35 cm at Cuxhaven and decreases up to −49 cm at St. Malo. Additionally the changes in the shallow water tides are larger than expected. With SLR the depth, wave speed and wave length (tidal resonance characteristics) are increased causing changes in near resonant areas. In expansive shallow areas SLR causes reduced energy dissipation by bottom friction. Combined these mechanisms result in the migration of the amphidromes and complex patterns of non-linear change in the tide with SLR. Despite the significant uncertainty associated with the rate of SLR over the next century, substantial alterations to tidal characteristics can be expected under a high end SLR scenario. Contrary to existing studies this paper highlights the importance of considering the modification of the tides by future SLR. These substantial future changes in the tides could have wide reaching implications; including for example, correctly calculating design level requirements for flood defences, the availability of tidal renewable energy and dredging requirements.

Methods for Detection of Aflatoxins in Agricultural Food Crops

Abstract: Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus. These fungal species are contaminants of foodstuff as well as feeds and are responsible for aflatoxin contamination of these agro products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds. Determination of aflatoxins concentration in food stuff and feeds is thus very important. However, due to their low concentration in foods and feedstuff, analytical methods for detection and quantification of aflatoxins have to be specific, sensitive, and simple to carry out. Several methods including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectroscopy, enzyme-linked immune-sorbent assay (ELISA), and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods. Each of these methods has advantages and limitations in aflatoxins analysis. This review critically examines each of the methods used for detection of aflatoxins in foodstuff, highlighting the advantages and limitations of each method. Finally, a way forward for overcoming such obstacles is suggested.

Melatonin Stimulates the SIRT1/Nrf2 Signaling Pathway Counteracting Lipopolysaccharide (LPS)-Induced Oxidative Stress to Rescue Postnatal Rat Brain.

Abstract: SummaryAims Lipopolysaccharide (LPS) induces oxidative stress and neuroinflammation both in vivo and in vitro. Here, we provided the first detailed description of the mechanism of melatonin neuroprotection against LPS-induced oxidative stress, acute neuroinflammation, and neurodegeneration in the hippocampal dentate gyrus (DG) region of the postnatal day 7 (PND7) rat brain. Methods The neuroprotective effects of melatonin against LPS-induced neurotoxicity were analyzed using multiple research techniques, including Western blotting, immunofluorescence, and enzyme-linked immunosorbent assays (ELISAs) in PND7 rat brain homogenates and BV2 cell lysates in vitro. We also used EX527 to inhibit silent information regulator transcript-1 (SIRT1). Results A single intraperitoneal (i.p) injection of LPS to PND7 rats significantly induced glial cell activation, acute neuroinflammation, reactive oxygen species (ROS) production and apoptotic neurodegeneration in hippocampal DG region after 4 h. However, the coadministration of melatonin significantly inhibited both LPS-induced acute neuroinflammation and apoptotic neurodegeneration and improved synaptic dysfunction in the hippocampal DG region of PND7 rats. Most importantly, melatonin stimulated the SIRT1/Nrf2 (nuclear factor-erythroid 2-related factor 2) signaling pathway to reduce LPS-induced ROS generation. The beneficial effects of melatonin were further confirmed in LPS-stimulated BV2 microglia cell lines in vitro using EX527 as an inhibitor of SIRT1. LPS-induced oxidative stress, Nrf2 inhibition, and neuroinflammation are SIRT1-dependent in BV2 microglia cell lines. Conclusion These results demonstrated that melatonin treatment rescued the hippocampal DG region of PND7 rat brains against LPS-induced oxidative stress damage, acute neuroinflammation, and apoptotic neurodegeneration via SIRT1/Nrf2 signaling pathway activation.

Light Higgsino Dark Matter

Abstract: We reinvestigate the question of whether a light Higgsino-like neutralino is a viable dark matter candidate. To this end we compute the dominant one-loop corrections to the masses of the Higgsino-like states in the minimal supersymmetric standard model (MSSM), due to loops involving heavy quarks and their superpartners. We also calculate analogous corrections to the couplings of Higgsino-like neutralinos to Z and Higgs bosons. In the region of parameter space leading to high Higgsino purity of the lightest neutralino, these corrections can change the expected relic density by up to a factor of 5 in either direction. We conclude that for favorable choices of soft supersymmetry-breaking parameters, a state with more than 99{percent} Higgsino purity could indeed form all cold dark matter in the Universe. In some cases these corrections can also increase the expected cross section for LSP scattering off spinless nuclei by up to two orders of magnitude, or reduce it to zero. {copyright} {ital 1997} {ital The American Physical Society}