On the dynamics of vortex modes within magnetic islands

Recent work investigating the interaction of magnetic islands with micro-turbulence has uncovered the striking observation of large scale vortex modes forming within the island structure [W.A. Hornsby {\it et al.}, Phys. Plasmas {\bf 17} 092301 (2010)]. These electrostatic vortices are found to be the size of the island and are oscillatory. It is this oscillatory behaviour and the presence of turbulence that leads us to believe that the dynamics are related to the Geodesic Acoustic Mode (GAM), and it is this link that is investigated in this paper. Here we derive an equation for the GAM in the MHD limit, in the presence of a magnetic island modified three-dimensional axisymmetric geometry. The eigenvalues and eigenfunctions are calculated numerically and then utilised to analyse the dynamics of oscillatory large-scale electrostatic potential structures seen in both linear and non-linear gyro-kinetic simulations

Crystal Symmetry Lowering in Chiral Multiferroic Ba3_3TaFe3_3Si2_2O14_{14} observed by X-Ray Magnetic Scattering

Chiral multiferroic langasites have attracted attention due to their doubly-chiral magnetic ground state within an enantiomorphic crystal. We report on a detailed resonant soft X-ray diffraction study of the multiferroic Ba$_3$TaFe$_3$Si$_2$O$_{14}$ at the Fe $L_{2,3}$ and oxygen $K$ edges. Below $T_N$ ($\approx27K$) we observe the satellite reflections $(0,0,\tau)$, $(0,0,2\tau)$, $(0,0,3\tau)$ and $(0,0,1-3\tau)$ where $\tau \approx 0.140 \pm 0.001$. The dependence of the scattering intensity on X-ray polarization and azimuthal angle indicate that the odd harmonics are dominated by the out-of-plane ($\mathbf{\hat{c}}$-axis) magnetic dipole while the $(0,0,2\tau)$ originates from the electron density distortions accompanying magnetic order. We observe dissimilar energy dependences of the diffraction intensity of the purely magnetic odd-harmonic satellites at the Fe $L_3$ edge. Utilizing first-principles calculations, we show that this is a consequence of the loss of threefold crystal symmetry in the multiferroic phase

An Integrative framework of buyer-supplier negative relationship quality and dysfunctional interfirm conflict

Purpose: Problems of relationship quality and interfirm conflict in business to business settings are serious concerns that need to be addressed. Thus, the authors have engaged in an extensive review to promote an understanding of these complex issues. This paper develops an integrated framework for analyzing wide-ranging relations between individual representatives and patterns of interfirm incompatibility for managerial control. Methodology/Approach: The review involves numerous sources that include articles and monographs. A theoretical framework is constructed to integrate fragmented empirical data. In particular, social identity and commitment-trust theories are mobilized for this framework. Findings: The review of studies has a substantial consistency with the theoretical framework. The paper outlines a causal chain from interpersonal agent dissimilarities to dysfunctional buyer-supplier relations, culminating in interfirm pathological conflict. Moderating factors in the causal chain are: agent identity differentiation (for interpersonal dissimilarity), supplier relations mismanagement (for buyer-supplier relationship quality), and interfirm opportunism (for interfirm pathological conflict). Buyer-supplier interfirm incompatibility mediates the causal link between interpersonal dissimilarity and buyer-supplier relationship quality. Identity differentiation, the validation of one’s self-image, is introduced as a process that determines buyer-supplier agent interpersonal dissimilarity judgments. This framework employs a contextual perspective. It describes interactions between observations of micro-level phenomena of interpersonal dissimilarities and macro-level models of interfirm fit. From a managerial perspective, interpersonal relations between individual buyer and supplier agents may be further strengthened by such strategies as expanding the scope of the interpersonal relationship, relaxation of role responsibilities, and volunteering business-related contact referrals. Originality/Value: A new theoretical framework has been devised to predict and explain relationship quality and interfirm pathological conflict in the B to B context. The framework contributes to the value of the knowledge base by serving as a means for building new diagnostic tools for assessment of interfirm behavioral issues affecting exchanges. New concepts are introduced to enhance current literature on B to B marketing. The framework provides concrete indicators that operationally define ideas and enable or improve measurement for empirical modeling

Endocrine disruption in aquatic systems: up-scaling research to address ecological consequences

Endocrine-disrupting chemicals (EDCs) can alter biological function in organisms at environmentally relevant concentrations and are a significant threat to aquatic biodiversity, but there is little understanding of exposure consequences for populations, communities and ecosystems. The pervasive nature of EDCs within aquatic environments and their multiple sub-lethal effects make assessments of their impact especially important but also highly challenging. Herein, we review the data on EDC effects in aquatic systems focusing on studies assessing populations and ecosystems, and including how biotic and abiotic processes may affect, and be affected by, responses to EDCs. Recent research indicates a significant influence of behavioural responses (e.g. enhancing feeding rates), transgenerational effects and trophic cascades in the ecological consequences of EDC exposure. In addition, interactions between EDCs and other chemical, physical and biological factors generate uncertainty in our understanding of the ecological effects of EDCs within aquatic ecosystems. We illustrate how effect thresholds for EDCs generated from individual-based experimental bioassays of the types commonly applied using chemical test guidelines [e.g. Organisation for Economic Co-operation and Development (OECD)] may not necessarily reflect the hazards associated with endocrine disruption. We argue that improved risk assessment for EDCs in aquatic ecosystems urgently requires more ecologically oriented research as well as field-based assessments at population-, community- and food-web levels

Bad apples in bad barrels revisited: Cognitive moral development, just world beliefs, rewards, and ethical decision-making

In this study, we test the interactive effect on ethical decision-making of (1) personal characteristics, and (2) personal expectancies based on perceptions of organizational rewards and punishments. Personal characteristics studied were cognitive moral development and belief in a just world. Using an in-basket simulation, we found that exposure to reward system information influenced managers' outcome expectancies. Further, outcome expectancies and belief in a just world interacted with managers' cognitive moral development to influence managers' ethical decision-making. In particular, low-cognitive moral development managers who expected that their organization condoned unethical behavior made less ethical decisions while high cognitive moral development managers became more ethical in this environment. Low cognitive moral development managers also behaved less ethically when their belief in a just world was high

Macroinvertebrate communities in streams with contrasting water sources in the Japanese Alps

Alpine streams are typically fed from a range of water sources including glacial meltwater, snowmelt, groundwater flow, and surface rainfall runoff. These contributions are projected to shift with climate change, particularly in the Japanese Alps where snow is expected to decrease, but rainfall events increase. The overarching aim of the study was to understand the key variables driving macroinvertebrate community composition in groundwater and snowmelt-fed streams (n = 6) in the Kamikochi region of the northern Japanese Alps (April–December 2017). Macroinvertebrate abundance, species richness, and diversity were not significantly different between the two stream types. Community structure, however, was different between groundwater and snowmelt-fed streams with macroinvertebrate taxa specialized for the environmental conditions present in each system. Temporal variation in the abundance, species richness, and diversity of macroinvertebrate communities was also significantly different between groundwater and snowmelt streams over the study period, with snowmelt streams exhibiting far higher levels of variation. Two snowmelt streams considered perennial proved to be intermittent with periodic drying of the streambed, but the macroinvertebrates in these systems rebounded rapidly after flows resumed with no reduction in taxonomic diversity. These same streams, nevertheless, showed a major reduction in diversity and abundance following periods of high flow, indicating floods rather than periodic drying was a major driver of community structure. This conclusion was also supported from functional analyses, which showed that the more variable snowmelt streams were characterized by taxa with resistant, rather than resilient, life-history traits. The findings demonstrate the potential for significant turnover in species composition with changing environmental conditions in Japanese alpine stream systems, with groundwater-fed streams potentially more resilient to future changes in comparison to snowmelt-fed streams

Heterogeneity of Human Gingival Fibroblasts in Tobaccostimulated Collagen Degradation

poster abstractMatrix metalloproteinases (MMPs) are a large family of zinc-dependent endopeptidases and their activity is modulated by tissue inhibitors of metalloproteinases (TIMPs). Smoking is a risk factor for periodontal disease. Cigarette smoke condensate (CSC) is the particulate matter of cigarette smoke. Human gingival fibroblasts (HGFs) are one of major cellular components in periodontal tissue. CSC can increase collagen degradation of HGFs by enhancing and altering the localization of MMPs. Previous clinical studies also showed that some smoking people even with very high dental plaque index still had good periodontal status and did not develop periodontal disease. Objectives: The aim of this study was to investigate the heterogeneity of HGFs to CSC-stimulated collagen degradation and to start examining its mechanisms. Methods: Eleven HGF cell lines were established from healthy gingival tissue from patients undergoing crown-lengthening surgery. HGFs were seeded as single colony (75,000 cells/well) in 6-well Type I collagen coated plates and exposed to 100 µg/ml CSC (Murty Pharmaceuticals, Lexington, KY) diluted in serum-free media with/without a MMPs inhibitor (GM6001, 100 nM, Chemicon, Temecla, CA) for 3 days. HGFs were seeded with serum free media alone as controls. The mRNA levels of multiple MMPs/TIMPs were measured by reverse transcriptionpolymerase chain reaction. Results: CSC increased collagen degradation in 7 HGF cell lines (CSC-susceptible HGFs), but not in 4 HGF cell lines (CSC-unsusceptible HGFs). GM6001 inhibited CSC-stimulated collagen degradation in all of CSC-susceptible HGFs. The mRNA levels of MMP-1, MMP-2, MMP-3, MMP-14, TIMP-1, and TIMP-2 increased 2.5, 1.3, 3.9, 2.0, 1.6, and 1.3 fold, respectively, in the CSC-susceptible HGFs. However, expression of MMPs/TIMPs basically didn’t change in the CSC-unsusceptible HGFs, except for MMP-3 which increased 1.4 fold. Conclusions: Heterogeneity of HGFs existed in regard to the CSC-stimulated collagen degradation and the altered expression of the MMPs/TIMPs may be responsible for this heterogeneity. This project was supported by the IUPUI Tobacco Cessation and Biobehavioral Center

Development of a 16S Reference Library for eDNA Metabarcoding the Freshwater Fishes of Western Ecuador.

This project examines the use of the 16S locus to amplify neotropical freshwater fishes native to Western Ecuador in a newly created 16S reference library for DNA barcoding and eDNA metabarcoding applications. Among the orders Characiformes, Siluriformes, Cichliformes, Gobiiformes, Cryprinodontiformes, Gymnotiformes, and Perciformes, a compendium of 105 specimens were sequenced, with 43 representing new 16S sequences previously unavailable on Genbank