Antibiotic Resistance Genes in Minnesota Soil Bacteria from Areas of High and Low Ferric Iron

Naturally-occurring antibiotic resistance genes in soil bacteria represent a potentially important reservoir of genes that could contribute to antibiotic resistance of human pathogens. It has been reported that over 40 genes in bacterial genomes are controlled by concentrations of ferric iron. We examined the effect of soil metal content on the level of resistance to two antibiotics, ampicillin (Amp) and tetracycline (Tet), and the presence of multiple genes that code for efflux pump-mediated resistance. These pumps act to export toxins (e.g. heavy metals and antibiotics, perhaps). Because of this, growth in heavy metal-contaminated soils might select for antibiotic resistance. Ninety-six soil samples were collected over the course of two summers from areas of Minnesota with known high and low ferric iron, as reported by the US Dept. of Interior. Samples were plated on LB plates with either 10 mg/500mL Tet or 50 mg/500mL Amp. Tet resistance was the same in high and low iron soils (p = 0.63, sd = 0.02). Amp resistance was higher in samples from high iron soils only in 2015’s data (2015 p =0.002; 2016 p = 0.75, sd = 38.1). Distribution of resistance was, however, significant for Tet between iron concentrations (p \u3c 0.001). Additionally, total DNA was extracted and PCRs with gel electrophoresis was used to determine the prevalence of 14 different efflux genes (acrB,D,F; emrB,E; mdfA; tehA; yhiV; mexF,Y; tetC,H,B,D) common to soil bacteria. In 2015, five of the eight genes studied were seen in high iron soil, while only one gene was detected in low iron soil. In 2016, four of six genes were found in samples from both soils. Ferric iron levels in the soils tested were not significantly correlated with Tet or Amp resistance levels in soil bacteria in 2016, but were correlated in 2015’s data (Amp only). It is possible that other heavy metals play a more important role in selecting for antibiotic resistance than iron

Russia's Tactical Nuclear Weapons

Report for Defense Research Agency, Swedish Ministry of DefenseThis is the first part in a series of two on Russia's tactical nuclear weapons (TNW). In this report we provide some background information on Russian TNW and discuss policy issues. Russia's nuclear force structure, including what is openly known about its TNW developments since 1991, is addressed. In particular, the three documents on foreign policy, national security (blueprint), and military doctrine, published in 2000, are analysed with regard to their TNW guidelines. Based on a review of the threats currently facing Russia and how they affect Russia's TNW requirements, we conclude with a section on the implications for Russia"s neighbours and strategic partners. We conclude that Russia is likely to maintain a sizeable fraction of its present TNW arsenal for the foreseeable future as a cost-effective and vital defence component. The main reasons for this conclusion are related to Russian concerns about a future potentially expansionist NATO and, to some extent, China. On the other hand, Russia's problems along its southern front and in Central Asia, while of significant magnitude, are believed to have little, if any, impact on its future reliance on TNW. An exception would be if nuclear proliferation were to occur in the Middle East region combined with rising anti- Russian sentiments among Moslems in the area. Charles L. Thornton is a doctoral candidate at the University of Maryland, where he is a graduate research fellow in the School of Public Affair"s Center for International and Security Studies at Maryland

Studies in the Geochronology and Geochemistry of the Transantarctic Mountains

This is the third annual progress report submitted by Institute of Polar Studies researchers to the National Science Foundation (Grant No. GA-898X) on the geochronology and geochemistry of rocks from the Transantarctic Mountains, Antarctica. The results reported in this report are preliminary in nature.National Science Foundation Grant GA-898

Renal colic and childbirth pain: female experience versus male perception

Renal colic is often described by patients as the worst pain ever experienced.1 Pain during childbirth is also similarly described.2 To date, no study has comparatively evaluated the pain of renal colic to that of childbirth in female patients who have experienced both. Furthermore, no such study has evaluated the perception that men with renal colic have with respect to the pain experienced during childbirth. Here we present our cross-sectional observational study to address these questions. The primary objectives of our study were to answer these questions and highlight the severity of renal colic which is not always faced and treated aggressively

An “orientation sphere” visualization for examining animal head movements

Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, head‐mounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head “movement” is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (“environmental framing”).We propose a new approach to visualize the data of such head‐mounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by “longitude” position and head pitch by “latitude” on this “orientation sphere” (O‐sphere).We construct the O‐sphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific heading‐independent head rotation, and propose the derivation of O‐sphere‐metrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.Visualizations of the O‐sphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in free‐ranging animals