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

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

Failure of -carnitine to protect mice against ammonia toxicity

Recent reports indicate that intraperitoneal administration of -carnitine protects mice from ammonia toxicity. We found that mice injected with -carnitine and subsequently challenged with ammonium acetate succumb as readily as mice injected with saline and the ammonium acetate. Mice pretreated with -carnitine exhibited higher levels of liver ammonia than the saline-pretreated control mice. The ammonia and urea levels in serum and brains were similar in two groups. Our findings are in contrast to those reported previously and therefore warrants further investigation before -carnitine can be considered as a drug to alleviate hyperammonemia in humans.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27412/1/0000446.pd

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

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