Plasma instabilities in meteor trails:linear theory

Ablation of micrometeoroids between 70 and 130 km altitude in the atmosphere creates plasma columns with densities exceeding the ambient ionospheric electron density by many orders of magnitude. Density gradients at the edges of these trails can create ambipolar electric fields with amplitudes in excess of 100 mV/m. These fields combine with diamagnetic drifts to drive electrons at speeds exceeding 2 km/s. The fields and gradients also initiate Farley-Buneman and gradient-drift instabilities. These create field-aligned plasma density irregularities which evolve into turbulent structures detectable by radars with a large power-aperture product, such as those found at Jicamarca, Arecibo, and Kwajalein. This paper presents a theory of meteor trail instabilities using both fluid and kinetic methods. In particular, it discusses the origin of the driving electric field, the resulting electron drifts, and the linear plasma instabilities of meteor trails. It shows that though the ambipolar electric field changes amplitude and even direction as a function of altitude, the electrons always drift in the positive ∇n × B direction, where n is the density and B the geomagnetic field. The linear stability analysis predicts that instabilities develop within a limited range of altitudes with the following observational consequences: (1) nonspecular meteor trail echoes will be field-aligned; (2) nonspecular echoes will return from a limited range of altitudes compared with the range over which the head echo reflection indicates the presence of plasma columns; and (3) anomalous cross-field diffusion will occur only within this limited altitude range with consequences for calculating diffusion rates and temperatures with both specular and nonspecular radars

Quantum noise in laser-interferometer gravitational-wave detectors with a heterodyne readout scheme

We analyze and discuss the quantum noise in signal-recycled laser interferometer gravitational-wave detectors, such as Advanced LIGO, using a heterodyne readout scheme and taking into account the optomechanical dynamics. Contrary to homodyne detection, a heterodyne readout scheme can simultaneously measure more than one quadrature of the output field, providing an additional way of optimizing the interferometer sensitivity, but at the price of additional noise. Our analysis provides the framework needed to evaluate whether a homodyne or heterodyne readout scheme is more optimal for second generation interferometers from an astrophysical point of view. As a more theoretical outcome of our analysis, we show that as a consequence of the Heisenberg uncertainty principle the heterodyne scheme cannot convert conventional interferometers into (broadband) quantum non-demolition interferometers.Comment: 16 pages, 8 figure

Understanding The Hobbit: the cross-national and cross-linguistic reception of a global media product in Belgium, France and the Netherlands

The Hobbit franchise, as many global media products, reaches audiences worldwide. Audience members apparently consume a uniform media product. But do they? The World Hobbit Project offers a new and exciting opportunity to explore differences and similarities, for it provides us with audiences' understandings of the trilogy across languages and nationalities. In this paper we conduct a statistical analysis on differences and similarities in understandings of The Hobbit trilogy between Belgium, the Netherlands, and France – both in what audiences do and do not feel The Hobbit films to be. Analyzing this particular region in Europe provides an extraordinary opportunity, for The World Hobbit project allows us to compare on the language level (the Dutch and French-speaking Belgian regions with respectively the Netherlands and France), as well as on the level of national identities (comparing the three countries amongst each other). In doing so, we are able to further understand what informs geographical and linguistic differences in the consumption of a uniform media product. As such, this paper touches upon cultural hegemony, cross-border flows of fiction, language and cultural proximity

Multifactorial profiling of epigenetic landscapes at single-cell resolution using MulTI-Tag

Chromatin profiling at locus resolution uncovers gene regulatory features that define cell types and developmental trajectories, but it remains challenging to map and compare different chromatin-associated proteins in the same sample. Here we describe Multiple Target Identification by Tagmentation (MulTI-Tag), an antibody barcoding approach for profiling multiple chromatin features simultaneously in single cells. We optimized MulTI-Tag to retain high sensitivity and specificity, and we demonstrate detection of up to three histone modifications in the same cell: H3K27me3, H3K4me1/2 and H3K36me3. We apply MulTI-Tag to resolve distinct cell types and developmental trajectories; to distinguish unique, coordinated patterns of active and repressive element regulatory usage associated with differentiation outcomes; and to uncover associations between histone marks. Multifactorial epigenetic profiling holds promise for comprehensively characterizing cell-specific gene regulatory landscapes in development and disease

Phylogenetic analysis to define feline immunodeficiency virus subtypes in 31 domestic cats in South Africa

Feline immunodeficiency virus (FIV), a lentivirus, is an important pathogen of domestic cats around the world and has many similarities to human immunodeficiency virus (HIV). A characteristic of these lentiviruses is their extensive genetic diversity which has been an obstacle in the development of successful vaccines. Of the FIV genes, the envelope gene is the most variable and sequence differences in a portion of this gene have been used to define 5 FIV subtypes (A, B, C, D and E). In this study, the proviral DNA sequence of the V3-V5 region of the envelope gene was determined in blood samples from 31 FIV positive cats from 4 different regions of South Africa. Phylogenetic analysis demonstrated the presence of both subtypes A and C, with subtype A predominating. These findings contribute to the understanding of the genetic diversity of FI

Observing binary inspiral in gravitational radiation: One interferometer

We investigate the sensitivity of individual LIGO/VIRGO-like interferometers and the precision with which they can determine the characteristics of an inspiralling binary system. Since the two interferometers of the LIGO detector share nearly the same orientation, their joint sensitivity is similar to that of a single, more sensitive interferometer. We express our results for a single interferometer of both initial and advanced LIGO design, and also for the LIGO detector in the limit that its two interferometers share exactly the same orientation. We approximate the evolution of a binary system as driven exclusively by leading order quadrupole gravitational radiation. To assess the sensitivity, we calculate the rate at which sources are expected to be observed, the range to which they are observable, and the precision with which characteristic quantities describing the observed binary system can be determined. Assuming a conservative rate density for coalescing neutron star binary systems we expect that the advanced LIGO detector will observe approximately 69~yr${}^{-1}$ with an amplitude SNR greater than 8. Of these, approximately 7~yr${}^{-1}$ will be from binaries at distances greater than 950~Mpc. We explore the sensitivity of these results to a tunable parameter in the interferometer design (the recycling frequency). The optimum choice of the parameter is dependent on the goal of the observations, e.g., maximizing the rate of detections or maximizing the precision of measurement. We determine the optimum parameter values for these two cases.Comment: 40 pages (plus 7 figures), LaTeX/REVTEX3.0, NU-GR-

Conserve Epitopes of Influenza Virus Induce Innate and Adaptive Immune Responses to Produce Specific Antibody Against M2e Protein

The existing vaccines against influenza are based onthe generation of neutralizing antibody primarilydirected against surface protein, haemagglutinin(HA) and neuraminidase (NA). However, antigenicdrift and occasional shift of these two membraneglycoproteins, HA and NA, make vaccine productioncumbersome and necessitate yearly revision ofthe vaccine seed strains by the World HealthOrganization. For these reasons, many investigatorshave often tried to look at the possibility of generatinga universal vaccine useful against more than oneinfluenza strain. The objective of research was toobtain an alternative antigen as vaccine candidatefor universal flu vaccination, instead of HA and NAcomponents. In this study, we use conserved epitopeM2e which is consist of three major componentsuch as N-terminal M2e2-24 (24 amino acids),transmembrane(59 amino acids) and C-terminal (19amino acids). We design two components of antigen,linier and branched structures. The antigens thenformulated with aluminium hydroxide gel comparedto FCA/IFA adjuvant. These vaccines were testedtheir immunogenicity, and the potency to mature thedendritic cells for stimulating either CD8+ T cell orantibody-mediated immune responses. The antibodytitre and the maturity of dendritic cell indicated bycytokines concentration such as; IFN-ã, IL2 and IL4were measured by ELISA test.The result of researchshowed that the conserved epitope of Me2 2-16 whenincorporated with P25 protein from canine distempervirus (linear structure) in alhydrogel adjuvant hasgreater potential to produce anti-M2e antibodiesthan in Freund adjuvant. Alhydrogel adjuvant hada stronger effect than Freund adjuvant. Alhydrogelalso stimulate the release of IL-2 and IL-4

Increased aerobic capacity reduces susceptibility to acute high‐fat diet‐induced weight gain

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134165/1/oby21564.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134165/2/oby21564_am.pd