Nonlinear dynamo in a short Taylor-Couette setup

It is numerically demonstrated by means of a magnetohydrodynamics code that a short Taylor-Couette setup with a body force can sustain dynamo action. The magnetic threshold is comparable to what is usually obtained in spherical geometries. The linear dynamo is characterized by a rotating equatorial dipole. The nonlinear regime is characterized by fluctuating kinetic and magnetic energies and a tilted dipole whose axial component exhibits aperiodic reversals during the time evolution. These numerical evidences of dynamo action in a short Taylor-Couette setup may be useful for developing an experimental device

Euler configurations and quasi-polynomial systems

In the Newtonian 3-body problem, for any choice of the three masses, there are exactly three Euler configurations (also known as the three Euler points). In Helmholtz' problem of 3 point vortices in the plane, there are at most three collinear relative equilibria. The "at most three" part is common to both statements, but the respective arguments for it are usually so different that one could think of a casual coincidence. By proving a statement on a quasi-polynomial system, we show that the "at most three" holds in a general context which includes both cases. We indicate some hard conjectures about the configurations of relative equilibrium and suggest they could be attacked within the quasi-polynomial framework.Comment: 21 pages, 6 figure

Metastatic Renal Cell Carcinoma Rapidly Progressive to Sunitinib: What to Do Next?

Background: From 10% to 26% of patients with metastatic renal cell carcinoma (mRCC) experience rapidly progressive disease (PD) on treatment with sunitinib. Objective: To investigate the benefit of subsequent treatment with another tyrosine kinase inhibitor (TKI) or a mammalian target of rapamycin (mTOR) inhibitor in such primary refractory patients. Design, setting, and participants: A total of 150 mRCC patients with rapidly PD on first- line sunitinib (within two cycles, n = 93, or four cycles, n = 57) were identified: median age 59 yr; nephrectomy 86%; histological subtypes: clear cell (77.8%), papillary (14%), and sarco- matoid features (18%); according to the Memorial Sloan-Kettering Cancer Center and French classifications: good risk (11% and 7%, respectively), intermediate (68% and 63%, respectively), and poor (21% and 29%, respectively). Outcome measurements and statistical analysis: Data were retrospectively collected by a questionnaire from 19 European oncology centers between March 2005 and March 2011. Pro- gression-free survival (PFS) and overall survival (OS) were calculated (Kaplan-Meier method). Results and limitations: Median OS from the start of first-line treatment was 7.4 mo. Second-line treatment was administered to 86 (57%) patients (44 mTOR inhibitors: 23 ever- olimus and 21 temsirolimus; 39 TKIs alone or in combination; three chemotherapy). Second- line PFS was not significantly different between TKIs and mTOR inhibitors (2.0 vs 0.9 mo; p = 0.536). Median OS from the start of second-line treatment was 5.0 mo for mTOR inhibitors and 6.6 mo for TKIs (p = 0.15). Conclusions: Treatment with further TKIs or mTOR inhibitors for mRCC patients primarily refractory to first-line sunitinib in the observed time period achieved very minimal benefit, suggesting avoiding TKI rechallenge and possibly preferring alternative strategies, such as immune checkpoint inhibitors, after PD to a treatment line including a TKI in this setting. Patient summary: The present work collected data about 150 patients affected by meta- static renal cell carcinoma, who received one of the current standard of care as first-line treatment, namely, the antiangiogenic drug sunitinib, and experienced rapid worsening of the disease. We investigated and described the subsequent outcome of such patients treated with two different types of drug, administered as second-line therapy, to better understand the best strategy to adopt for patients who got no benefit from sunitinib and to describe the current therapeutic approach in such cases

A comment on Scott's “Black Polygamous Family Formation”

This brief article takes a critical look at Joseph W. Scott's article “Black Polygamous Family Formation.” While Scott's research is seen as helpful, several problems in his treatment of plural mating and marriage arrangements among Black Americans are discussed. Major conceptual problems are created by Scott's use (or misuse) of the concept “polygyny.” Significant methodological problems are also posed by his sampling approach, operationalization of concepts, and analytic strategies. Studies such as Scott's are of optimal value when their exploratory nature, and consequent limitation, are clearly acknowledged.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44661/1/10834_2005_Article_BF01082935.pd

Antifouling activity of novel polyisoprene-based coatings made from photocurable natural rubber derived oligomers

Natural rubber is a renewable resource with a potential as precursor of a very wide range of novel polymers, including polyisoprene-based surfaces with antifouling (AF) activity. In this work, new ionic and non-ionic coatings were prepared by the photocrosslinking reaction of photosensitive cis-1,4- oligoisoprenes, bearing a variable number of ammonium groups. The photochemical crosslinking was achieved using radical (via acrylate groups) or cationic (via epoxy groups) processes. Surface properties of these coatings were studied by static contact angle measurements and AFM imaging. Assessment of bioactivity demonstrated that most of the resulting coatings showed AF potential against fouling organisms: growth inhibition of marine bacteria (Pseudoalteromonas elyakovii, Shewanella putrefaciens, Cobetia marina, Polaribacter irgensii, Vibrio aestuarianus) and fungi (Halosphaeriopsis mediosetigera, Asteromyces cruciatus, Lulworthia uniseptata, Zalerion sp., Monodictys pelagica); decreased adhesion of microalgae (Navicula jeffreyi, Cylindrotheca closterium, Chlorarachnion globosum, Pleurochrysis roscoffensis, Exanthemachrysis gayraliae, Amphora coffeaeformis); inhibition of attachment and/or germination of spores of Ulva intestinalis. The best AF activity was obtained with the ionic surfaces. These new coatings prepared from precursors obtained from natural rubber are in essence active by contact. As the biocidal functions are fixed covalently to the polymer chain, detectable release of biocidal products in the marine ecosystem is prevented so that a valuable environment-friendly alternative for new AF coatings is hereby proposed

The nuclear receptors of Biomphalaria glabrata and Lottia gigantea: Implications for developing new model organisms

© 2015 Kaur et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNuclear receptors (NRs) are transcription regulators involved in an array of diverse physiological functions including key roles in endocrine and metabolic function. The aim of this study was to identify nuclear receptors in the fully sequenced genome of the gastropod snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni and compare these to known vertebrate NRs, with a view to assessing the snail's potential as a invertebrate model organism for endocrine function, both as a prospective new test organism and to elucidate the fundamental genetic and mechanistic causes of disease. For comparative purposes, the genome of a second gastropod, the owl limpet, Lottia gigantea was also investigated for nuclear receptors. Thirty-nine and thirty-three putative NRs were identified from the B. glabrata and L. gigantea genomes respectively, based on the presence of a conserved DNA-binding domain and/or ligand-binding domain. Nuclear receptor transcript expression was confirmed and sequences were subjected to a comparative phylogenetic analysis, which demonstrated that these molluscs have representatives of all the major NR subfamilies (1-6). Many of the identified NRs are conserved between vertebrates and invertebrates, however differences exist, most notably, the absence of receptors of Group 3C, which includes some of the vertebrate endocrine hormone targets. The mollusc genomes also contain NR homologues that are present in insects and nematodes but not in vertebrates, such as Group 1J (HR48/DAF12/HR96). The identification of many shared receptors between humans and molluscs indicates the potential for molluscs as model organisms; however the absence of several steroid hormone receptors indicates snail endocrine systems are fundamentally different.The National Centre for the Replacement, Refinement and Reduction of Animals in Research, Grant Ref:G0900802 to CSJ, LRN, SJ & EJR [www.nc3rs.org.uk]

G-Quadruplex Visualization in Cells via Antibody and Fluorescence Probe

G-quadruplexes (G4s) are noncanonical nucleic acids structures involved in key regulatory and pathological roles in eukaryotes, prokaryotes, and viruses: the development of specific antibodies and fluorescent probes represent an invaluable tool to understand their biological relevance. We here present three protocols for the visualization of G4s in cells, both uninfected and HSV-1 infected, using a specific antibody and a fluorescent G4 ligand, and the effect of the fluorescent ligand on a G4 binding protein, nucleolin, upon binding of the molecule to the nucleic acids structure

Witnessing loss in the everyday: community buildings in Austerity Britain

This article is concerned with what happens to precarious community buildings in times of austerity. It responds to a landscape of capitalist realism, in which instrumental, economic forms of value are mobilised to justify the closure of ordinary buildings whose survival is not identified as a political priority. We focus on two London cases of a library and an elderly day centre under threat of closure, and trace how grammars of austerity rendered these buildings substitutable. Considering how abstract sociological conceptions of value/s can struggle to break into the embedded common sense of austerity, we explore how ethnographic practices of collaboration and attentiveness can help amplify alternative expressions of the meanings of these buildings for their communities. Enacting a form of ethnographic witnessing, which learns from Wittgenstein, we highlight the creative, vernacular registers and gestures of library users and day centre members, and we show how these were anchored in the buildings themselves. In this way, we supplement noisier, more hyperbolic accounts of the violence of austerity by amplifying quotidian responses, which express how ordinary buildings and the forms of life they sustain, matter