Phylogenies of atpD and recA support the small subunit rRNA-based classification of rhizobia

The current classification of the rhizobia (root-nodule symbionts) assigns them to six genera. It is strongly influenced by the small subunit (16S, SSU) rRNA molecular phylogeny, but such single-gene phylogenies may not reflect the evolution of the genome as a whole. To test this, parts of the atpD and recA genes have been sequenced for 25 type strains within the alpha -Proteobacteria, representing species in Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium, Azorhizobium, Agrobacterium, Phyllobacterium, Mycoplana and Brevundimonas. The current genera Sinorhizobium and Mesorhizobium are well supported by these genes, each forming a distinct phylogenetic clade with unequivocal bootstrap support. There is good support for a Rhizobium clade that includes Agrobacterium tumefaciens, and the very close relationship between Agrobacterium rhizogenes and Rhizobium tropici is confirmed. There is evidence for recombination within the genera Mesorhizobium and Sinorhizobium, but the congruence of the phylogenies at higher levels indicates that the genera are genetically isolated. rRNA provides a reliable distinction between genera, but genetic relationships within a genus may be disturbed by recombination

How Exemplary Educational Leadership Preparation Programs Hone the Interpersonal-Intrapersonal (i2) Skills of Future Leaders

John P. Kotter argues that business schools continue to prepare leaders for 20th century needs, as they typically teach students how to manage an organization, rather than how to lead one. In this article, we explore how Kotter’s assertion applies to educational leadership preparation programs. We examine the ways a purposive sample of exemplary programs structure and implement learning experiences for aspiring educational leaders. Leveraging our findings from these cases and the literature on transformational learning and leadership, we argue that today’s programs should include “powerful learning experiences” that challenge and coach leadership candidates to build the skills and capacities necessary to both manage and lead organizations. If educational leaders are the “driving subsystem” for school improvement efforts, then leadership preparation must move aspiring leaders beyond technical competence and toward the more transformational aspects of leading

Design optimisation of air-fed full pressurised suits

This article is a post-print version of the published article which may be accessed at the link below.The JET machine and associated facilities require significant maintenance and enhancement installation activities in support of the experimental exploitation programme. A proportion of these activities are within radiological and respiratory hazardous environments. As such, breathing air-fed one-piece pressurised suits provide workers with protection from the inhalation of both airborne tritium and beryllium dust. The design of these suits has essentially developed empirically. There is a practical necessity to improve the design to optimise worker performance, protection and thermal comfort. This paper details the complexity of modeling the three-dimensional thermofluid domain between the inner surface of the suit and under garments that includes mass as well as heat transfer, suiting geometry, human metabolism and respiration and effects of limb movements. The methods used include computational fluid dynamics (CFD), theoretical adaptations of mixed-phase turbulent flow, profile scanning of a suit and actuating life size mannequin and data processing of the images and experimental validation trials. The achievements of the current programme and collaborations are presented in the paper and future endeavors are discussed.The author gratefully acknowledges the loan of the articulated mannequin from the Defence Science and Technology Laboratories. This work was funded jointly by EPSRC and by the European Communities under the contract of Association between EURATOM and UKAEA. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work was carried out within the framework of EFDA

Game Theoretical Interactions of Moving Agents

Game theory has been one of the most successful quantitative concepts to describe social interactions, their strategical aspects, and outcomes. Among the payoff matrix quantifying the result of a social interaction, the interaction conditions have been varied, such as the number of repeated interactions, the number of interaction partners, the possibility to punish defective behavior etc. While an extension to spatial interactions has been considered early on such as in the "game of life", recent studies have focussed on effects of the structure of social interaction networks. However, the possibility of individuals to move and, thereby, evade areas with a high level of defection, and to seek areas with a high level of cooperation, has not been fully explored so far. This contribution presents a model combining game theoretical interactions with success-driven motion in space, and studies the consequences that this may have for the degree of cooperation and the spatio-temporal dynamics in the population. It is demonstrated that the combination of game theoretical interactions with motion gives rise to many self-organized behavioral patterns on an aggregate level, which can explain a variety of empirically observed social behaviors

Mutation of the Human Circadian Clock Gene CRY1 in Familial Delayed Sleep Phase Disorder

Patterns of daily human activity are controlled by an intrinsic circadian clock that promotes ∼24 hr rhythms in many behavioral and physiological processes. This system is altered in delayed sleep phase disorder (DSPD), a common form of insomnia in which sleep episodes are shifted to later times misaligned with the societal norm. Here, we report a hereditary form of DSPD associated with a dominant coding variation in the core circadian clock gene CRY1, which creates a transcriptional inhibitor with enhanced affinity for circadian activator proteins Clock and Bmal1. This gain-of-function CRY1 variant causes reduced expression of key transcriptional targets and lengthens the period of circadian molecular rhythms, providing a mechanistic link to DSPD symptoms. The allele has a frequency of up to 0.6%, and reverse phenotyping of unrelated families corroborates late and/or fragmented sleep patterns in carriers, suggesting that it affects sleep behavior in a sizeable portion of the human population. © 2017 Elsevier Inc

Thin-Film Metamaterials called Sculptured Thin Films

Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.Comment: to be published in Proc. ICTP School on Metamaterials (Augsut 2009, Sibiu, Romania

Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution of Ices

This report arises from an ongoing program to monitor Neptune's largest moon Triton spectroscopically in the 0.8 to 2.4 micron range using IRTF/SpeX. Our objective is to search for changes on Triton's surface as witnessed by changes in the infrared absorption bands of its surface ices N2, CH4, H2O, CO, and CO2. We have recorded infrared spectra of Triton on 53 nights over the ten apparitions from 2000 through 2009. The data generally confirm our previously reported diurnal spectral variations of the ice absorption bands (Grundy & Young 2004). Nitrogen ice shows a large amplitude variation, with much stronger absorption on Triton's Neptune-facing hemisphere. We present evidence for seasonal evolution of Triton's N2 ice: the 2.15 micron absorption band appears to be diminishing, especially on the Neptune-facing hemisphere. Although it is mostly dissolved in N2 ice, Triton's CH4 ice shows a very different longitudinal variation from the N2 ice, challenging assumptions of how the two ices behave. Unlike Triton's CH4 ice, the CO ice does exhibit longitudinal variation very similar to the N2 ice, implying that CO and N2 condense and sublimate together, maintaining a consistent mixing ratio. Absorptions by H2O and CO2 ices show negligible variation as Triton rotates, implying very uniform and/or high latitude spatial distributions for those two non-volatile ices.Comment: 22 pages, 13 figures, 5 tables, to appear in Icaru

Innovative organotypic in vitro models for safety assessment: aligning with regulatory requirements and understanding models of the heart, skin, and liver as paradigms

The development of improved, innovative models for the detection of toxicity of drugs, chemicals, or chemicals in cosmetics is crucial to efficiently bring new products safely to market in a cost-effective and timely manner. In addition, improvement in models to detect toxicity may reduce the incidence of unexpected post-marketing toxicity and reduce or eliminate the need for animal testing. The safety of novel products of the pharmaceutical, chemical, or cosmetics industry must be assured; therefore, toxicological properties need to be assessed. Accepted methods for gathering the information required by law for approval of substances are often animal methods. To reduce, refine, and replace animal testing, innovative organotypic in vitro models have emerged. Such models appear at different levels of complexity ranging from simpler, self-organized three-dimensional (3D) cell cultures up to more advanced scaffold-based co-cultures consisting of multiple cell types. This review provides an overview of recent developments in the field of toxicity testing with in vitro models for three major organ types: heart, skin, and liver. This review also examines regulatory aspects of such models in Europe and the UK, and summarizes best practices to facilitate the acceptance and appropriate use of advanced in vitro models

Excited Baryons in Lattice QCD

We present first results for the masses of positive and negative parity excited baryons calculated in lattice QCD using an O(a^2)-improved gluon action and a fat-link irrelevant clover (FLIC) fermion action in which only the irrelevant operators are constructed with APE-smeared links. The results are in agreement with earlier calculations of N^* resonances using improved actions and exhibit a clear mass splitting between the nucleon and its chiral partner. An correlation matrix analysis reveals two low-lying J^P=(1/2)^- states with a small mass splitting. The study of different Lambda interpolating fields suggests a similar splitting between the lowest two Lambda1/2^- octet states. However, the empirical mass suppression of the Lambda^*(1405) is not evident in these quenched QCD simulations, suggesting a potentially important role for the meson cloud of the Lambda^*(1405) and/or a need for more exotic interpolating fields.Comment: Correlation matrix analysis performed. Increased to 400 configurations. 22 pages, 13 figures, 15 table