Oblique Shocks As The Origin Of Radio To Gamma-ray Variability In AGN

The `shock in jet' model for cm-waveband blazar variability is revisited, allowing for arbitrary shock orientation with respect to the jet flow direction, and both random and ordered magnetic field. It is shown that oblique shocks can explain events with swings in polarization position angle much less than the 90 deg. associated with transverse structures, while retaining the general characteristics of outbursts, including spectral behavior and level of peak percentage polarization. Models dominated by a force-free, minimum energy magnetic field configuration (essentially helical) display a shallow rise in percentage polarization and frequency dependent swing in polarization position angle not in agreement with the results of single-dish monitoring observations, implying that the field is predominantly random in the quiescent state. Outbursts well-explained by the `shock in jet' model are present during gamma-ray flaring in several sources, supporting the idea that shock events are responsible for activity from the radio to gamma-ray bands.Comment: 19 pages, 8 figures, accepted for publication in Ap

Analysing the Transverse Structure of the Relativistic Jets of AGN

This paper describes a method of fitting total intensity and polarization profiles in VLBI images of astrophysical jets to profiles predicted by a theoretical model. As an example, the method is used to fit profiles of the jet in the Active Galactic Nucleus Mrk501 with profiles predicted by a model in which a cylindrical jet of synchrotron plasma is threaded by a magnetic field with helical and disordered components. This fitting yields model Stokes Q profiles that agree with the observed profiles to within the 1-2 \sigma uncertainties; the I model and observed profiles are overall not in such good agreement, with the model I profiles being generally more symmetrical than the observed profiles. Consistent fitting results are obtained for profiles derived from 6cm VLBI images at two distances from the core, and also for profiles obtained for different wavelengths at a single location in the VLBI jet. The most striking success of the model is its ability to reproduce the spine-sheath polarization structure observed across the jet. Using the derived viewing angle in the jet rest frame, \delta' approximately 83 degrees, together with a superluminal speed reported in the literature, \beta apparent = 3.3, yields a solution for the viewing angle and velocity of the jet in the observer's frame \delta degrees and \beta approximately 0.96. Although these results for Mrk501 must be considered tentative, the combined analysis of polarization profiles and apparent component speeds holds promise as a means of further elucidating the magnetic field structures and other parameters of parsec-scale AGN jets

Trust and Distrust Scale Development: Operationalization and Instrument Validation

Trust and distrust have been studied at great length by researchers in the field of information systems and various other fields over the past few decades without reaching consensus on conceptualization and measurement. The goal of this study was to determine if individual trust and distrust are separate constructs or opposite ends of the same continuum. To this end, based on theoretical rationale, an aggregation of extant, validated trust and distrust instruments combined with newly created trust and distrust items were used as input into a rigorous Q-sorting procedure. The Q-sorting process led to the first contribution of this research: a determination that individual trust and distrust are separate and distinct variables and should be measured individually. An empirical field test was then distributed to test the effects of trust and distrust on a downstream variable within the nomological network of trust and distrust, willingness to transact. Over 100 undergraduate students, who are considered to be digital natives, responded to the survey. Through exploratory and confirmatory analyses, the list of 38 items from the Q-sort was narrowed to a parsimonious set of 20 items, exhibiting content, construct, convergent, and discriminant validity. The creation of a list of items to measure individual trust and distrust is the second major contribution of this research. Post-hoc analyses showed significant main effects of trust and distrust, in the theorized directions, on willingness to transact. Additional post-hoc analysis based on quadrant membership, as described by Lewicki et al. (1998), and IT artifact, yielded too few results to make interpretations. Further, since this study made no hypotheses a priori, the post-hoc analyses should be interpreted with caution. Path analysis should be re-examined in future studies with theoretically developed hypotheses. Finally, since exploratory and confirmatory analyses were performed on the same data set, the results should be re-evaluated in the context of a larger, more diverse sample, to further add to the body of knowledge surrounding individual trust and distrust

Confirmation of the existence of coherent orientations of quasar polarization vectors on cosmological scales

In order to verify the existence of coherent orientations of quasars polarization vectors on very large scales, we have obtained new polarization measurements for a sample of quasars located in a given region of the three-dimensional Universe where the range of polarization position angles was predicted in advance. For this new sample, the hypothesis of uniform distribution of polarization position angles may be rejected at the 1.8% significance level on the basis of a simple binomial test. This result provides an independent confirmation of the existence of alignments of quasar polarization vectors on very large scales. In total, out of 29 polarized quasars located in this region of the sky, 25 have their polarization vectors coherently oriented. This alignment occurs at redshifts 1-2 suggesting the presence of correlations in objects or fields on Gpc scales. More global statistical tests applied to the whole sample of polarized quasars distributed all over the sky confirm that polarization vectors are coherently oriented in a few groups of 20-30 quasars. Some constraints on the phenomenon are also derived. Considering more particularly the quasars in the selected region of the sky, we found that their polarization vectors are roughly parallel to the plane of the Local Supercluster. But the polarization vectors of objects along the same line of sight at lower redshifts are not accordingly aligned. We also found that the known correlations between quasar intrinsic properties and polarization are not destroyed by the alignment effect. Several possible mechanisms are discussed, but the interpretation of this orientation effect remains puzzling.Comment: Accepted for publication in Astronomy & Astrophysic

Social media and Internet marketing in residential property management : development of a learning module for FCSPM 275 Marketing and leasing residential properties

Nearly 38 million households, or 33% of the United States population, are renters (National Multi Housing Council [NMHC], 2010). Individuals currently seeking a new apartment home are faced with many ways to find their new home. However, not all property managers or property management companies use the Internet or social media websites to market their properties. Property managers and leasing professionals need to determine if the marketing techniques they use meet the needs of the renters they hope to acquire. The researcher did an extensive literature reviews on numerous topics that include current trends in apartment living, legal issues, Internet marketing, and the use of social media and Internet marketing in residential property management. After the researcher completed the literature review he created a module of learning to be taught in the Ball State University Course "Marketing and Leasing Residential Properties,"� FCSPM 275. This module of learning includes PowerPoint slides, a homework assignment, and a module quiz.Thesis (M.A.)Department of Family and Consumer Science

Low-Bandwidth and Non-Compute Intensive Remote Identification of Microbes from Raw Sequencing Reads

Cheap high-throughput DNA sequencing may soon become routine not only for human genomes but also for practically anything requiring the identification of living organisms from their DNA: tracking of infectious agents, control of food products, bioreactors, or environmental samples. We propose a novel general approach to the analysis of sequencing data in which the reference genome does not have to be specified. Using a distributed architecture we are able to query a remote server for hints about what the reference might be, transferring a relatively small amount of data, and the hints can be used for more computationally-demanding work. Our system consists of a server with known reference DNA indexed, and a client with raw sequencing reads. The client sends a sample of unidentified reads, and in return receives a list of matching references known to the server. Sequences for the references can be retrieved and used for exhaustive computation on the reads, such as alignment. To demonstrate this approach we have implemented a web server, indexing tens of thousands of publicly available genomes and genomic regions from various organisms and returning lists of matching hits from query sequencing reads. We have also implemented two clients, one of them running in a web browser, in order to demonstrate that gigabytes of raw sequencing reads of unknown origin could be identified without the need to transfer a very large volume of data, and on modestly powered computing devices. A web access is available at http://tapir.cbs.dtu.dk. The source code for a python command-line client, a server, and supplementary data is available at http://bit.ly/1aURxkc

The malaria testing and treatment landscape in Kenya: results from a nationally representative survey among the public and private sector in 2016

Abstract Background Since 2004, Kenya’s national malaria treatment guidelines have stipulated artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated malaria, and since 2014, confirmatory diagnosis of malaria in all cases before treatment has been recommended. A number of strategies to support national guidelines have been implemented in the public and private sectors in recent years. A nationally-representative malaria outlet survey, implemented across four epidemiological zones, was conducted between June and August 2016 to provide practical evidence to inform strategies and policies in Kenya towards achieving national malaria control goals. Results A total of 17,852 outlets were screened and 2271 outlets were eligible and interviewed. 78.3% of all screened public health facilities stocked both malaria diagnostic testing and quality-assured ACT (QAACT). Sulfadoxine–pyrimethamine (SP) for intermittent preventive treatment in pregnancy was available in 70% of public health facilities in endemic areas where it is recommended for treatment. SP was rarely found in the public sector outside of the endemic areas (< 0.5%). The anti-malaria stocking private sector had lower levels of QAACT (46.7%) and malaria blood testing (20.8%) availability but accounted for majority of anti-malarial distribution (70.6% of the national market share). More than 40% of anti-malarials were distributed by unregistered pharmacies (37.3%) and general retailers (7.1%). QAACT accounted for 58.2% of the total anti-malarial market share, while market share for non-QAACT was 15.8% and for SP, 24.8%. In endemic areas, 74.9% of anti-malarials distributed were QAACT. Elsewhere, QAACT market share was 49.4% in the endemic-prone areas, 33.2% in seasonal-transmission areas and 37.9% in low-risk areas. Conclusion Although public sector availability of QAACT and malaria diagnosis is relatively high, there is a gap in availability of both testing and treatment that must be addressed. The private sector in Kenya, where the majority of anti-malarials are distributed, is also critical for achieving universal coverage with appropriate malaria case management. There is need for a renewed commitment and effective strategies to ensure access to affordable QAACT and confirmatory testing in the private sector, and should consider how to address malaria case management among informal providers responsible for a substantial proportion of the anti-malarial market share

Cooperative Breeding and Long-Distance Dispersal: A Test Using Vagrant Records

Cooperative breeding is generally associated with increased philopatry and sedentariness, presumably because short-distance dispersal facilitates the maintenance of kin groups. There are, however, few data on long-distance dispersal in cooperative breeders-the variable likely to be important for genetic diversification and speciation. We tested the hypothesis that cooperative breeders are less likely to engage in long-distance dispersal events by comparing records of vagrants outside their normal geographic range for matched pairs (cooperatively vs. non-cooperatively breeding) of North American species of birds. Results failed to support the hypothesis of reduced long-distance dispersal among cooperative breeders. Thus, our results counter the conclusion that the lower rate of speciation among cooperative breeding taxa found in recent analyses is a consequence of reduced vagility