Prevalence of Cytauxzoon felis (Protista: Apicomplexa) in Feral Cats in Russellville Arkansas

Abstract Cytauxzoon felis (C. felis) is a protozoan hemoparasite of domestic and wild felids. Transmitted by ixodid ticks, the sylvatic reservoir for this organism in North America is the bobcat (Lynx rufus) in which the infection is apparently self-limiting. In domestic cats (Felis catus), C. felis causes a highly fatal disease with a distribution that covers much of the central, southcentral and southeastern U.S. and parallels that of the primary vector, the lone star tick (Amblyomma americanum). Interestingly, there appears to be an increased survival rate in domestic cats in the geographic area of the Ozark Plateau. In this study, convenience blood samples from apparently healthy feral cats were microscopically evaluated for the presence of C. felis merozoites. Positive samples were submitted for PCR confirmation by a commercial laboratory. Results indicated a prevalence of 13% (4/32) in this population. Understanding the prevalence of C. felis infection in feral cats is central to evaluating their potential role as a reservoir for the disease and may also further our understanding about the variable pathogenicity of this organism

Medicare Advantage Special Needs Plans for Dual Eligibles: A Primer

Identifies the key issues behind the goal of a new plan for people eligible for both Medicare and Medicaid -- to offer the full array of Medicare, Medicaid, and supplemental benefits through a single plan -- and outlines progress thus far

Walking builds community cohesion: Survey of two New Hampshire communities looks at social capital and walkability

This brief reports the results of a survey conducted in 2009 of approximately 2,000 households in Portsmouth and Manchester, New Hampshire, to examine the connection between walkability and social capital. Authors Shannon Rogers, Kevin Gardner, and Cynthia Carlson report that higher levels of social capital are found in areas that are perceived to be more walkable, as measured by the number of places people can walk to in their community. In addition, walkability is influenced by concerns of safety, access, time, and health and by physical characteristics such as proximity, scale, and aesthetics. Given the link between walkability and greater social capital, and in turn the link between social capital and numerous positive outcomes, refitting communities with greater walkability can have short- and longer-term payoffs. The authors conclude that more walkable communities are healthier communities, and as the research in the brief shows, residents in them are more connected to one another not only by sidewalks but also through the social networks and social capital they form when they live in communities that encourage gathering and meeting face-to-face

Directed evolution of Vibrio fischeri LuxR for increased sensitivity to a broad spectrum of acyl-homoserine lactones

LuxR-type transcriptional regulators play key roles in quorum-sensing systems that employ acyl-homoserine lactones (acyl-HSLs) as signal molecules. These proteins mediate quorum control by changing their interactions with RNA polymerase and DNA in response to binding their cognate acyl-HSL. The evolutionarily related LuxR-type proteins exhibit considerable diversity in primary sequence and in their response to acyl-HSLs having acyl groups of differing length and composition. Little is known about which residues determine acyl-HSL specificity, and less about the evolutionary time scales required to forge new ones. To begin to examine such issues, we have focused on the LuxR protein from Vibrio fischeri, which activates gene transcription in response to binding its cognate quorum signal, 3-oxohexanoyl-homoserine lactone (3OC6HSL). Libraries of luxR mutants were screened for variants exhibiting increased gene activation in response to octanoyl-HSL (C8HSL), with which wild-type LuxR interacts only weakly. Eight LuxR variants were identified that showed a 100-fold increase in sensitivity to C8HSL; these variants also displayed increased sensitivities to pentanoyl-HSL and tetradecanoyl-HSL, while maintaining a wild-type or greater response to 3OC6HSL. The most sensitive variants activated gene transcription as strongly with C8HSL as the wild type did with 3OC6HSL. With one exception, the amino acid residues involved were restricted to the N-terminal, 'signal-binding' domain of LuxR. These residue positions differed from critical positions previously identified via 'loss-of-function' mutagenesis. We have demonstrated that acyl-HSL-dependent quorum-sensing systems can evolve rapidly to respond to new acyl-HSLs, suggesting that there may be an evolutionary advantage to maintaining such plasticity

Reactive point processes: A new approach to predicting power failures in underground electrical systems

Reactive point processes (RPPs) are a new statistical model designed for predicting discrete events in time based on past history. RPPs were developed to handle an important problem within the domain of electrical grid reliability: short-term prediction of electrical grid failures ("manhole events"), including outages, fires, explosions and smoking manholes, which can cause threats to public safety and reliability of electrical service in cities. RPPs incorporate self-exciting, self-regulating and saturating components. The self-excitement occurs as a result of a past event, which causes a temporary rise in vulner ability to future events. The self-regulation occurs as a result of an external inspection which temporarily lowers vulnerability to future events. RPPs can saturate when too many events or inspections occur close together, which ensures that the probability of an event stays within a realistic range. Two of the operational challenges for power companies are (i) making continuous-time failure predictions, and (ii) cost/benefit analysis for decision making and proactive maintenance. RPPs are naturally suited for handling both of these challenges. We use the model to predict power-grid failures in Manhattan over a short-term horizon, and to provide a cost/benefit analysis of different proactive maintenance programs.Comment: Published at http://dx.doi.org/10.1214/14-AOAS789 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Simplicity of algebras associated to \'etale groupoids

We prove that the C*-algebra of a second-countable, \'etale, amenable groupoid is simple if and only if the groupoid is topologically principal and minimal. We also show that if G has totally disconnected unit space, then the associated complex *-algebra introduced by Steinberg is simple if and only if the interior of the isotropy subgroupoid of G is equal to the unit space and G is minimal.Comment: The introduction has been updated and minor changes have been made throughout. To appear in Semigroup Foru

Adenosine to inosine editing by ADAR2 requires formation of a ternary complex on the GluR-B R/G site

RNA editing by members of the ADAR (adenosine deaminase that acts on RNA) enzyme family involves hydrolytic deamination of adenosine to inosine within the context of a double-stranded pre-mRNA substrate. Editing of the human GluR-B transcript is catalyzed by, the enzyme ADAR2 at the Q/R and R/G sites. We have established a minimal RNA substrate for editing based on the RIG site and have characterized the interaction of ADAR2 with this RNA by gel shift, kinetic, and cross-linking analyses. Gel shift analysis revealed that two complexes are formed on the RNA as protein concentration is increased; the ADAR monomers can be crosslinked to one another in an RNA-dependent fashion. We performed a detailed kinetic study of the editing reaction; the data from this study are consistent with a reaction scheme in which formation of an ADAR2.RNA ternary complex is required for efficient RNA editing and in which formation of this complex is rate determining. These observations suggest that RNA adenosine deaminases function as homodimers on their RNA substrates and may partially explain regulation of RNA editing in these systems