Receptors and Other Signaling Proteins Required for Serotonin Control of Locomotion in Caenorhabditis elegans

A better understanding of the molecular mechanisms of signaling by the neurotransmitter serotonin is required to assess the hypothesis that defects in serotonin signaling underlie depression in humans. Caenorhabditis elegans uses serotonin as a neurotransmitter to regulate locomotion, providing a genetic system to analyze serotonin signaling. From large-scale genetic screens we identified 36 mutants of C. elegans in which serotonin fails to have its normal effect of slowing locomotion, and we molecularly identified eight genes affected by 19 of the mutations. Two of the genes encode the serotonin-gated ion channel MOD-1 and the G-protein-coupled serotonin receptor SER-4. mod-1 is expressed in the neurons and muscles that directly control locomotion, while ser-4 is expressed in an almost entirely non-overlapping set of sensory and interneurons. The cells expressing the two receptors are largely not direct postsynaptic targets of serotonergic neurons. We analyzed animals lacking or overexpressing the receptors in various combinations using several assays for serotonin response. We found that the two receptors act in parallel to affect locomotion. Our results show that serotonin functions as an extrasynaptic signal that independently activates multiple receptors at a distance from its release sites and identify at least six additional proteins that appear to act with serotonin receptors to mediate serotonin response.National Institutes of Health (U.S.) (Grant GM24663

Dirac Sea Effects on Superfluidity in Nuclear Matter

We study two kinds of Dirac sea effects on the $^1S_0$ pairing gap in nuclear matter based on the relativistic Hartree approximation to quantum hadrodynamics and the Gor'kov formalism. We show that the vacuum fluctuation effect on the nucleon effective mass is more important than the direct coupling between the Fermi sea and the Dirac sea due to the pairing interaction. The effects of the high-momentum cutoff are also discussed.Comment: 11 pages, 3 eps figures included, uses REVTeX (with \tightenlines

Microscopic Derivation of Non-Markovian Thermalization of a Brownian Particle

In this paper, the first microscopic approach to the Brownian motion is developed in the case where the mass density of the suspending bath is of the same order of magnitude as that of the Brownian (B) particle. Starting from an extended Boltzmann equation, which describes correctly the interaction with the fluid, we derive systematicaly via the multiple time-scale analysis a reduced equation controlling the thermalization of the B particle, i.e. the relaxation towards the Maxwell distribution in velocity space. In contradistinction to the Fokker-Planck equation, the derived new evolution equation is non-local both in time and in velocity space, owing to correlated recollision events between the fluid and particle B. In the long-time limit, it describes a non-markovian generalized Ornstein-Uhlenbeck process. However, in spite of this complex dynamical behaviour, the Stokes-Einstein law relating the friction and diffusion coefficients is shown to remain valid. A microscopic expression for the friction coefficient is derived, which acquires the form of the Stokes law in the limit where the mean-free in the gas is small compared to the radius of particle B.Comment: 28 pages, no figure, submitted to Journal of Statistical Physic

Powers of Romance: The Liminal Challenges of Managing Organizational Intimacy

© The Author(s) 2014 Problematic organizational relationships have recently been at the core of highly visible media coverage. Most analyses of sexual relations in organizations have been, however, simplistic and unidimensional, and have placed insufficient systematic emphasis on the role of governmentality in the social construction of organizational romance. In this article, we proceed in two theoretical steps. First, we elaborate a typology of organizational romance that covers different manifestations of this nuanced process. We think of these as organizational strategies of governmentality. Second, we elaborate and identify liminal cases that fall into the interstices of the four predominant ways of managing sexual relationships in organizations. We think of these as vases of liquid love and life that evade the border controls of regulation by governmentality. Finally, we relate these issues to debates about the nature of the civilizational process and suggest hypotheses for future research

Reciprocal Damon-Eshbach-type spin wave excitation in a magnonic crystal due to tunable magnetic symmetry

We report spin-wave (SW) propagation in a one-dimensional magnonic crystal (MC) explored by all electrical spectroscopy. The MC consists of a periodic array of 255 nm wide permalloy nanowires with a small edge-to-edge separation of 45 nm. Provoking antiparallel alignment of the magnetization of neighboring nanowires, we unexpectedly find reciprocal excitation of DamonEshbach type SWs. The characteristics are in contrast to ferromagnetic thin films and controlled via, both, the external magnetic field and magnetic states. The observed reciprocal excitation is a metamaterial property for SWs and attributed to the peculiar magnetic symmetry of the artificially tailored magnetic material. The findings offer great perspectives for nanoscale SW interference devices. Spectroscopy performed on periodic arrays of bistable ferromagnetic nanowires has evidenced magnonic crystal (MC) behavior reflecting a man-made band structure for spin waves (SWs). 1,2 Periodic nanowires of identical width have recently been shown to form a special class of artificial crystal offering unprecedented functionality via reprogrammed band structures. Different magnetic states such as ferromagnetic order (FMO) and antiferromagnetic order (AFO) allowed one to redefine the unit cell and periodicity of the lattice in one-andthe-same one-dimensional (1D) MC. 3 At the same time, thin films and magnonic waveguides from yttrium iron garnet and Ni 80 Fe 20 have been shown to exhibit non-reciprocal SW characteristics when Damon-Eshbach-type (DE) spin waves were excited by microwave antenna. 4-8 For DE modes, the wave vector k is perpendicular to the magnetization M. Spin waves travelling in opposite directions had markedly different precessional amplitudes. For MCs, this issue has not yet been addressed in detail 9,10 though reciprocity is of special interest for magneto-photonics 11 and advanced applications, such as reprogrammable filters and logic devices based on SWs. In this paper, we report SWs transmitted through a 1D array of bistable permalloy (Ni 80 Fe 20 ) nanowires [ We explain this behavior considering the distinct magnetic symmetry of the artificial crystal, provoking a metamaterial property not found for the natural material. Our findings ar

On the Quantitative Impact of the Schechter-Valle Theorem

We evaluate the Schechter-Valle (Black Box) theorem quantitatively by considering the most general Lorentz invariant Lagrangian consisting of point-like operators for neutrinoless double beta decay. It is well known that the Black Box operators induce Majorana neutrino masses at four-loop level. This warrants the statement that an observation of neutrinoless double beta decay guarantees the Majorana nature of neutrinos. We calculate these radiatively generated masses and find that they are many orders of magnitude smaller than the observed neutrino masses and splittings. Thus, some lepton number violating New Physics (which may at tree-level not be related to neutrino masses) may induce Black Box operators which can explain an observed rate of neutrinoless double beta decay. Although these operators guarantee finite Majorana neutrino masses, the smallness of the Black Box contributions implies that other neutrino mass terms (Dirac or Majorana) must exist. If neutrino masses have a significant Majorana contribution then this will become the dominant part of the Black Box operator. However, neutrinos might also be predominantly Dirac particles, while other lepton number violating New Physics dominates neutrinoless double beta decay. Translating an observed rate of neutrinoless double beta decay into neutrino masses would then be completely misleading. Although the principal statement of the Schechter-Valle theorem remains valid, we conclude that the Black Box diagram itself generates radiatively only mass terms which are many orders of magnitude too small to explain neutrino masses. Therefore, other operators must give the leading contributions to neutrino masses, which could be of Dirac or Majorana nature.Comment: 18 pages, 4 figures; v2: minor corrections, reference added, matches journal version; v3: typo corrected, physics result and conclusions unchange

A frameshift mutation in NOD2 associated with susceptibility to Crohn's disease

Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract, which is thought to result from the effect of environmental factors in a genetically predisposed host. A gene location in the pericentromeric region of chromosome 16, IBD1, that contributes to susceptibility to Crohn's disease has been established through multiple linkage studies(1-6), but the specific gene(s) has not been identified. NOD2, a gene that encodes a protein with homology to plant disease resistance gene products is located in the peak region of linkage on chromosome 16 (ref. 7). Here we show, by using the transmission disequilibium test and case-control analysis, that a frameshift mutation caused by a cytosine insertion, 3020insC, which is expected to encode a truncated NOD2 protein, is associated with Crohn's disease. Wild-type NOD2 activates nuclear factor NF-kappaB, making it responsive to bacterial lipopolysaccharides; however, this induction was deficient in mutant NOD2. These results implicate NOD2 in susceptibility to Crohn's disease, and suggest a link between an innate immune response to bacterial components and development of disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62856/1/411603a0.pd

The normal state Fermi surface of pristine and Pb-doped Bi2212 from ARPES measurements and its photon energy independence

We address the question as to whether the topology of the normal state Fermi surface of Bi2212 - as seen in angle resolved photoemission - depends on the photon energy used to measure it. High resolution photoemission spectra and Fermi surface maps from pristine and Pb-doped Bi2212 are presented, recorded using both polarised and unpolarised radiation of differing energies. The data show clearly that no main band crosses the Fermi surface along the GMZ direction in reciprocal space, even for a photon energy of 32 eV, thus ruling out the existence of a G-centred, electron-like Fermi surface in this archetypal high Tc superconductor. The true topology of the normal state Fermi surface remains that of hole-like barrels centred at the X,Y points of the Brillouin zone.Comment: 4 pages (revtex), 4 figures (jpg

Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.

Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29)