The Effects of Mobile Phone Radiofrequency Radiation on Cochlear Stria Marginal Cells in Sprague–Dawley Rats

To investigate the possible mechanisms for biological effects of 1,800 MHz mobile radiofrequency radiation (RFR), the radiation-specific absorption rate was applied at 2 and 4 W/kg, and the exposure mode was 5 min on and 10 min off (conversation mode). Exposure time was 24 h short-term exposure. Following exposure, to detect cell DNA damage, cell apoptosis, and reactive oxygen species (ROS) generation, the Comet assay test, flow cytometry, DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) staining, and a fluorescent probe were used, respectively. Our experiments revealed that mobile phone RFR did not cause DNA damage in marginal cells, and the rate of cell apoptosis did not increase (P > 0.05). However, the production of ROS in the 4 W/kg exposure group was greater than that in the control group (P < 0.05). In conclusion, these results suggest that mobile phone energy was insufficient to cause cell DNA damage and cell apoptosis following short-term exposure, but the cumulative effect of mobile phone radiation still requires further confirmation. Activation of the ROS system plays a significant role in the biological effects of RFR. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.     

Tetrahydroindolocarbazoles (THICZs) as new class of urokinase (uPA) inhibitors: Synthesis,anticancer evaluation,DNA-damage determination,and molecular modelling study

Tetrahydroindolocarbazoles (THICZs) with versatile substituents, have been designed, synthesized, structure characterized, then investigated for their in-vitro anticancer screening, urokinase inhibition (uPA) evaluated, DNA-damage determination was further explored. Compounds 5, 8, 10 and 17 displayed the most promising antitumor activities against the breast cancer cell line as compared to the standard drug, doxorubicin with IC₅₀ = 5.24 ± 0.37, 4.00 ± 0.52, 7.20 ± 0.90 and 9.60 ± 1.10 µg/ml (versus 3.30 ± 0.48 µg/ml for doxorubicin). Compounds 5, 8, 10 and 17 represents the most significant uPA inhibitors of our study with IC₅₀ of 3.80, 2.70. 4.75, 10.80 (ng/ml) respectively. The expression levels of CDKN2A gene were decreased in 8, 10 and 17 cell lines as compared to those in positive control samples. Cell lines treated with 5, 8, 10 and 17 clearly observed a high score of damaged DNA cells. A deeper examination revealed that our hetroaromatics showed an extensive hydrogen bonding interactions that is required in the S pocket which is important for activity Arg 217, Gly 219, Gly 216, Lys 143 and Ser 190. So we present THICZs as promising uPA inhibitors expected as significant promise for further development as anti-invasiveness drugs.     

Near-Complete Structure and Model of Tel1ATM from Chaetomium thermophilum Reveals a Robust Autoinhibited ATP State

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Oxygen and Reperfusion Damage: an Overview

Reperfusion of the ischaemic myocardium is associated with a number of oxygen dependent processes which can damage cells. The role of oxidants in mediating reperfusion damage will be discussed.     

Is the Sacred ibis a real threat to biodiversity? Long-term study of its diet in non-native areas compared to native areas

This paper presents the results of a 14-year study about the diet of the Sacred ibis in its main introduction area in France and its impact on native bird species, and compares the data to literature from its native area. During an initial period (1993–2004), the diet was essentially composed of invertebrates such as common aquatic insects (correlated with flooding) or Eristalis larvae picked from the mud (a vacant food niche in France), while scraps of meat taken from rubbish dumps were minor. These traditional preys taken from the same ecosystems as in its native area did not result in an exponential increase of the number of breeding Sacred ibises. Invasive Red swamp crayfish recently replaced other foods in its diet with a resulting sharp increase in breeding pair numbers (R² = 0.48). As in other parts of the world, vertebrates constituted very accidental preys, and no bird species were really threatened by such predation. Conversely, the Sacred ibis can have a positive effect as a predator of invasive crayfish. Adding the species to the DAISIE list of the 100 most invasive alien species in Europe therefore appears debatable.     

Spatiotemporal Distribution of Black Bear-Human Conflicts in Colorado,USA

Abstract: Management and conservation of large carnivores increasingly includes conflicts with humans. Consequently, a greater understanding of spatiotemporal trends of conflicts is needed to efficiently allocate resources and apply targeted management. Therefore, we examined spatial and temporal distribution of American black bear (Ursus americanus; hereafter, bear)-human conflicts in Colorado, USA, related to 3 conflict types (agriculture operations, human development, and road kills). We used the Getis-Ord G_i* spatial clustering statistic to describe location and assess magnitude of bear-human conflicts in Colorado during 1986–2003 and investigated temporal trends of bear-human conflicts by type. Bear-human conflicts showed distinct spatial clustering by type, and areas of high clustering overlapped conflict types. Clustering for agriculture operations conflicts had the largest overall G_i* value and overlapped counties with high sheep production. Both human development and road-kill conflict clusters were high in areas of high-quality oak (Quercus spp.)—shrub habitat in the central and southern portions of Colorado's Front Range region and near the city of Durango in southwestern Colorado. Bear-human conflicts varied by year and type but overall increased during the 18 years. Summed across years, most conflicts were related to agriculture (32%), followed by road kills (27%) and human development (24%). The greatest proportion of agriculture operations-related conflicts (76%), human development-related conflicts (36%), and road kills (47%) occurred in 1988, 1999, and 2003, respectively. Considering that bear-human conflicts in Colorado increased over time and will likely continue to increase, we suggest wildlife managers improve data collection by obtaining detailed location data, categorizing conflict types uniformly, and applying conflict regulations consistently to strengthen inference of similar analyses. We also suggest that managers target efforts to mitigate damage by focusing on areas with high clustering of conflicts.     

Membrane lipid composition and susceptibility to bile salt damage

Erythrocyte membranes with low sphingomyelin: choline-containing phospholipid ratios haemolyse at low concentrations of the bile salt, glycocholate. Erythrocytes with higher sphingomyelin: choline-containing phospholipid ratios require progessively greater concentrations of the bile salt for lysis.Sublytic concentrations of glycocholate remove phospholipid and acetylcholinesterase from the membranes. Membranes with low sphingomyelin: choline-containing phospholipid ratios lose both particulate (microvesicles of distinct composition) and ‘solubilized’ material, the particulate form predominating. The proportion of particulate material falls with increase of the membrane sphingomyelin: choline-containing phospholipid ratio and those membranes of highest sphingomyelin: choline-containing phospholipid ratio lose material predominantly in ‘solubilized’ form.Sheep erythrocytes treated to increase their content of phosphatidylcholine (and thereby reduce their membrane sphingomyelin: choline-containing phospholipid ratio) become more susceptible to lysis by glycocholate.These observations indicate a correlation between membrane lipid composition and the perturbation of membranes with bile salt; they also point to possible features of membranes capable of surviving exposure to the high bile salt concentrations of the biliary tract.     

Discovery of novel chalcone-dithiocarbamates as ROS-mediated apoptosis inducers by inhibiting catalase

Novel chalcone-dithiocarbamate hybrids were designed, synthesized and evaluated for antiproliferative activity against selected cancer cell lines (MGC803, MCF7, and PC3). Among these analogues, (E)-2-oxo-2-((4-(3-(3,4,5-trimethoxyphenyl)acryloyl)phenyl)amino)ethyl-4-(2-hydroxyethyl)piperazine-1-carbodithioate (12d) showed the best inhibitory activity against PC3 cells (IC₅₀ = 1.05 μM). Cellular mechanism studies elucidated 12d could inhibit colony formation, arrest cell cycle at G2/M phase and induce DNA damage against PC3 cells. Compound 12d also induced mitochondrial apoptosis by caspase activation, MMP decrease, ROS production and catalase (CAT) inhibition. Importantly, 12d inhibited epithelial-mesenchymal transition (EMT) process by regulating EMT-related proteins (E-cadherin, N-cadherin, Vimentin, MMP2, MMP9). These results indicated that 12d is a promising lead compound and deserves further investigation for prevention and treatment of human prostate cancer.     

Land use and climate influences on waterbirds in the Prairie Potholes

Aim We examined the influences of regional climate and land‐use variables on mallard (Anas platyrhynchos), blue‐winged teal (Anas discors), ruddy duck (Oxyura jamaicensis) and pied‐billed grebe (Podilymbus podiceps) abundances to inform conservation planning in the Prairie Pothole Region of the United States. Location The US portion of Bird Conservation Region 11 (US‐BCR11, the Prairie Potholes), which encompasses six states within the United States: Montana, North Dakota, South Dakota, Nebraska, Minnesota and Iowa. Methods We used data from the North American Breeding Bird Survey (NABBS), the National Land Cover Data Set, and the National Climatic Data Center to model the effects of environmental variables on waterbird abundance. We evaluated land‐use covariates at three logarithmically related spatial scales (1000, 10,000 and 100,000 ha), and constructed hierarchical spatial count models a priori using information from published habitat associations. Model fitting was performed using a hierarchical modelling approach within a Bayesian framework. Results Models with the same variables expressed at different scales were often in the best model subset, indicating that the influence of spatial scale was small. Both land‐use and climate variables contributed strongly to predicting waterbird abundance in US‐BCR11. The strongest positive influences on waterbird abundance were the percentage of wetland area across all three spatial scales, herbaceous vegetation and precipitation variables. Other variables that we included in our models did not appear to influence waterbirds in this study. Main conclusions Understanding the relationships of waterbird abundance to climate and land use may allow us to make predictions of future distribution and abundance as environmental factors change. Additionally, results from this study can suggest locations where conservation and management efforts should be focused.