Geospatial Analysis of Rickettsial Species in Arkansas

Rickettsia species are obligate intracellular, arthropod-borne bacteria with a potential to cause multiple diseases including Rocky Mountain spotted fever (RMSF). Fleas, mites, and ticks serve as vectors for Rickettsia, but ticks are the primary vector of interest. RMSF and other rickettsial diseases have continued to gain importance in both human and veterinary medicine as RMSF is the most common tick-borne disease within the United States according to the Lyme and Tick-Borne Disease Research Center. A statewide citizen science project was utilized to determine the prevalence of Spotted Fever Group (SFG) Rickettsia in Arkansas. This project yielded results in 64 of Arkansas’s 75 counties. Results were utilized to determine prevalence in each of the represented counties, and then compiled into a geospatial representation of the data. It was determined that 34.32% of the ticks sampled were carriers of one or more rickettsial species. As the samples were divided by county, multiple counties were shown to have concerningly high exposure risk for SFG Rickettsia. There were six species of ticks represented throughout this study with Amblyomma americanum being the most common. There were also six species of Spotted Fever Group Rickettsia found within the samples. The small portion of ticks that underwent further analysis to determine the specific rickettsial species present, indicated that Rickettsia amblyommatis is likely the most common SFG Rickettsia in Arkansas

Harnessing the social: state, crisis and (big) society

The paper analyses the UK government’s plans to create a social investment market. The Big Society as political economy is understood as a response to three aspects of a multi-faceted, global crisis: a crisis of capital accumulation; a crisis of social reproduction; and, a fiscal crisis of the state. While the neoliberal state is retreating from the sphere of social reproduction, further off-loading the costs of social reproduction onto the unwaged realms of the home and the community, it is simultaneously engaging in efforts to enable this terrain of social reproduction to be harnessed for profit. Key to this process are specific government policies, the creation of new financial institutions and instruments and the introduction of the metric of ‘social value’. Policies ostensibly aimed at resolving the crisis in ways that empower local communities, actually foster further financialisation and a deepening of capitalist disciplinary logics into the social fabric

Daedalus deals with adulthood (review)

A review of Adulthood, Daedalus, Volume 105, no 2, spring 1976

BIOMECHANICAL TESTING OF A COMPLIANT BENCH FOR STEP AEROBICS

INTRODUCTION The purpose of this study was to determine if adding compliance to the bench used in step aerobics routines would decrease the stress on the musculoskeletal system. The stresses are imposed by the shock of the ground reaction forces (external) and due to joint compression caused by muscles attempting to absorb and generate forces (internal). Injury has been related to the amount of force and the rate of force application. Repetitive strain was not a primary consideration in this study. METHODS The present investigation involved four step aerobics instructors and 11 recreational calibre subjects. Each subject performed two types of stepping exercises at a cadence of 120 beats per minute. A compliant bench was constructed with similar dimensions to the traditional rigid bench. The major difference was that the compliant bench had an arched top of plywood that would deform by becoming more flat as it was loaded. The stiffness of the top was about 8 KN*m-l. Two force plates were used to measure the ground and bench reaction forces. The data were sampled at 100 samples per second and ensemble averaged over 15 steps for each subject and each task to obtain a representative record and a measure of the variability. The representative record was analysed for peak forces and each individual step was analysed for the rate of rise of force. The rate of rise of force was processed by filtering out the high frequency noise of the force channel and differentiating the signal with respect to time. EMG of the knee extensors of the right leg was also examined. Four two-way analyses of variance with repeated measures were applied to the peak force and rate of rise of force data. The two factors were the type of bench and state of fatigue. The significance level was chosen to be p < 0.05. RESULTS The step-to-step variability within each subject was quite low. The peak ground reaction forces of the compliant bench were not significantly different for the instructors on each bench and the EMG of the vastus lateralis did not show a significant increase in muscle activity to absorb shock on the rigid bench. The 11 recreational calibre subjects showed a main effect for three of the four analyses. The compliant bench was found to have significantly lower rates of rise of force in both the step and propulsive moves and a lower peak force in the propulsive move. The peak forces were lower in the step move but not enough for statistical significance. There was no main effect for fatigue or interaction between fatigue and bench type. CONCLUSIONS Risk of injury by either high peak force or muscle force was neither increased nor decreased when the instructors used the compliant bench. It appears that professionals are able to provide musculoskeletal shock absorption without significantly increasing the muscle activation when performing on a rigid surface. Recreational athletes, however, were not as capable and would benefit more by exercising on a compliant surface

Characterization of Overwintering Perenniality in Napiergrass: Traditional and Molecular Approaches

Napiergrass (Pennisetum purpureum Schum.) is a tropical grass limited in adaptation to the southern United States, and efforts to expand its area of production as a quality forage crop as well as a high-biomass biofuel crop are needed. Phenotypic selection and screening of napiergrass S1 inbred lines and F1 hybrids for increased winter hardiness (USDA Winter Hardiness Zones 8b to 7b) demonstrated that napiergrass is more winter hardy than expected. Variation in hardiness zone 7b winter weather patterns at Vernon, TX, and Alma, AR, resulted in 40% survival across genotypes and no winter survival, respectively, even though the minimum temperatures at both locations were similar. Winter survival in this species is associated with rhizome development. Therefore, rhizome candidate gene expression assays using quantitative polymerase chain reaction (qPCR), on fall and spring sampled rhizomes for genes associated with overwintering, rhizome development, and rhizome proliferation resulted in two cloned genes, APETELA2 (AP2) and Rare Cold Inducible 1 (RCI1) conferring detectable changes in gene expression patterns. Spring sampled rhizomes showed the greatest fold change (FC), specifically in the zone of cell division across all genotypes. Attempts to transfer genes associated with cold-tolerance from oriental fountaingrass (Pennisetum orientale L.C. Rich.) and buffelgrass [Cenchrus ciliaris (L.) syn Pennisetum ciliare Link] into napiergrass via wide hybridization were not successful because no interspecific hybrids were recovered. Analysis of pollen tube growth and pollen-pistil interactions did not reveal barriers to these hybridizations, but post- fertilization events may be the reason for the failure to recover hybrids and this needs to be investigated