Some examples of the behaviour of conformal geodesics

With the aid of concrete examples, we consider the question of whether, in the presence of conformal curvature, a conformal geodesic can become trapped in smaller and smaller sets, or phrased informally: are spirals possible? We do not arrive at a definitive answer, but we are able to find situations where this behaviour is ruled out, including a reduction of the conformal-geodesic equations to quadratures in a specific non-conformally flat metric.Comment: 19 pages; to appear in Jour.Geom.Phy

Using Bis and Bas Sensitivity to Predict Psychopathology, Emotion Regulation and Well-Being

Gray\u27s (1982) Reinforcement Sensitivity Theory proposes that two major systems in the brain - the behavioral inhibition system and the behavioral activation system - contribute to affective states, behavior and personality. Carver and White\u27s (1994) BIS/BAS scales attempt to measure three aspects of BAS sensitivity: Reward Responsiveness, Fun Seeking and Drive. While widely used, the validity of these scales is unclear. The current study employs structural equation modeling to test the BIS/BAS scales\u27 ability to predict psychopathology, use of emotion regulation strategies and psychological well-being. As BAS sensitivity is thought to have a broad influence on these variables, the BAS subscales that predict these variables may be better measures of BAS sensitivity. While past researchers have looked at these relationships, none of them have done so in a single, multivariate model. Additionally, extraversion has been suggested as directly reflecting BAS sensitivity (Pickering & Smillie, 2008). A second model was also tested that includes extraversion as a predictor, along with the BAS subscales. If extraversion predicts the chosen variables better than the BAS subscales, it may imply that extraversion is a better measure of BAS sensitivity. When included in the same model, Reward Responsiveness predicted all of the outcome variables significantly, while Drive only predicted Externalizing, and Fun Seeking did not significantly predict any of the outcome variables. This may suggest that Reward Responsiveness is a more central component of BAS sensitivity than either Drive or Fun Seeking. When extraversion was added to the model, it predicted the chosen outcome variables largely independently of Reward Responsiveness. This may imply that Extraversion and Reward Responsiveness are largely independent constructs

Investigating the Functional Connectivity of the Bed Nucleus of the Stria Terminalis During Conditions of Threat and Safety Using High Resolution 7 Tesla FMRI

An influential model of the extended amygdala defines fear as the immediate response to phasic threat and anxiety as the prolonged response to unpredictable or sustained threat (Davis, Walker, Miles & Grillon, 2010). This model proposes that in response to unpredictable threat, the centromedial amygdala (CeA) activates the bed nucleus of the stria terminalis (BNST), which coordinates the anxiety response, and, in turn, inhibits the CeA. Connectivity between the BNST and both the basolateral amygdala (BLA) and hippocampus may also play an important role in the coordination of the anxiety response (Davis et al., 2010; Herman et al., 2003; Zhu, Umegaki, Suzuki, Miura & Iguchi, 2001). However, there is a dearth of human research investigating whether state anxiety is accompanied by increased connectivity between the BNST and CeA, BLA and hippocampus. To test whether sustained threat elicits increases connectivity between the BNST and these areas, I monitored participants’ resting brain activity via high resolution 7 tesla fMRI during two five minute resting state scans, one while under threat of unpredictable shock and one while safe. I predicted that each of these areas would exhibit greater connectivity with the BNST during periods of threat vs. safety. To test whether BNST connectivity during periods of threat is altered in anxiety prone individuals, I collected self-reported behavioral inhibition. I predicted that greater behavioral inhibition would predict increased connectivity during periods of threat (vs. safety) between the BNST and the CeA, BLA and hippocampus. I also tested whether connectivity in these areas changes over time following the onset of threat by examining connectivity for three time windows, corresponding roughly to the first, second and fifth minute following threat onset. I predicted positive threat vs. safe BNST-CeA connectivity during the first time window, negative threat vs. safe BNST-CeA connectivity during the second time window, and no difference in BNST-CeA connectivity during the final time window. I found a marginally significant trend toward greater BNST-BLA connectivity during threat vs. safety. I found no evidence for increased BNST-hippocampus connectivity during threat, or that BNST connectivity with either the BLA or hippocampus is modulated by behavioral inhibition. Threat condition, behavioral inhibition, and time window interacted to affect BNST-CeA connectivity, although a lack of significant follow-up tests makes interpreting this interaction challenging. Further research is needed to characterize how individual differences alter the time course of BNST-CeA connectivity during conditions of threat and safety, and the conditions under which threat may elicit BNST connectivity with the hippocampus and BLA

A Pilot Study of Increasing Nonpurposeful Movement Breaks at Work as a Means of Reducing Prolonged Sitting

There is a plethora of workplace physical activity interventions designed to increase purposeful movement, yet few are designed to alleviate prolonged occupational sitting time. A pilot study was conducted to test the feasibility of a workplace e-health intervention based on a passive approach to increase nonpurposeful movement as a means of reducing sitting time. The study was trialled in a professional workplace with forty-six participants (33 females and 13 males) for a period of twenty-six weeks. Participants in the first thirteen weeks received a passive prompt every 45 minutes on their computer screen reminding them to stand and engage in nonpurposeful activity throughout their workday. After thirteen weeks, the prompt was disabled, and participants were then free to voluntary engage the software. Results demonstrated that when employees were exposed to a passive prompt, as opposed to an active prompt, they were five times more likely to fully adhere to completing a movement break every hour of the workday. Based on this pilot study, we suggest that the notion that people are willing to participate in a coercive workplace e-health intervention is promising, and there is a need for further investigation

Registration of N614, A3N615, N616, and N617 Shattercane Genetic Stocks with Cytoplasmic or Nuclear Male Sterility and Juicy or Dry Midribs

Four shattercane [Sorghum bicolor subsp. drummondii (Nees ex Steud.) de Wet ex Davidse] genetic stocks—N614 (Reg. No. GS-652, PI 665684), A3N615 (Reg. No. GS-651, PI 665683), N616 (Reg. No. GS-653, PI 665685), and N617 (Reg. No. GS-654, PI 665686)—with A3 cytoplasmic male sterility or the nuclear male sterility gene ms3 containing either juicy (dd) or dry (DD) culms were developed jointly by the USDA-ARS; the Iowa Agricultural and Home Economics Experiment Station, College of Agriculture and Life Sciences, Iowa State University; and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska. The stocks were released in July 2011. The source material for these genetic stocks was isolated from an archetypical shattercane population found near Lincoln, NE. Release of these genetic stocks makes available shattercane lines with both A3 cytoplasmic male sterility, and ms3 genetic (nuclear) male sterility to facilitate crossing. These genetic stocks also contain juicy (dd) or dry (DD) culms, a visible genetic marker to facilitate screening progeny resulting from crosses. The genetic stocks have immediate application for basic research involving gene flow from cultivated sorghum [Sorghum bicolor (L.) Moench] to shattercane and on the fitness of offspring resulting from such crosses

A model for the fate of carbon dioxide from a simulated carbon storage seep

Offshore geological carbon storage (GCS) is a rapidly developing technology essential for meeting international climate goals. While the likelihood of leakage from a properly planned geological sequestration site is low, assurance that CO stays contained will require robust monitoring programs. While seismic imaging methods are used to monitor the geological reservoir, the ideal method for monitoring the water column above the reservoir depends on the fate and transport of CO. Whether CO is likely to be present as a rising seep of bubbles or dissolved in the water column near the seafloor will determine the appropriate monitoring technology and lead to a better understanding of the environmental impact of a potential leak. In this study, high definition video of a laboratory release of a carbon dioxide bubble seep recorded the size distribution of bubbles as a function of flow rate and orifice diameter. The transport of CO from different bubble size distributions was then modeled using the Texas A&M Oil Spill Calculator modeling suite. Model results show that the most important factor determining the rise height and transport of CO from the simulated leak was the maximum initial bubble size. For a maximum bubble radius of 5 mm, 95% of CO in the simulated seep reached a height of 17.1 m above the seafloor. When the maximum bubble radius was limited to 3 mm, 95% of CO dissolved by 7.8 m above the seafloor. The modeled results were verified during a controlled release of CO in Oslo Fjord.publishedVersio

Phylogeography of the thermophilic Cyanobacterium Mastigocladus Laminosus

We have taken a phylogeographic approach to investigate the demographic and evolutionary processes that have shaped the geographic patterns of genetic diversity for a sample of isolates of the cosmopolitan thermophillic cyanobacterial Mastigocladus laminosus morphotype collected from throughout most of its range. Although M. laminosus is found in thermal areas throughout the world, our observation that populations are typically genetically differentiated on local geographic scales suggests the existence of dispersal barriers, a conclusion corroborated by evidence for genetic isolation by distance. Genealogies inferred using nitrogen metabolism gene sequence data suggest that a significant amount of the extant global diversity of M. laminosus can be traced back to a common ancestor associated with the western North American hot spot currently located below Yellowstone National Park. Estimated intragenic recombination rates are comparable to those of pathogenic bacteria known for their capacity to exchange DNA, indicating that genetic exchange has played an important role in generating novel variation during M. laminosus diversification. Selection has constrained protein changes at loci involved in the assimilation of both dinitrogen and nitrate, suggesting the historic use of both nitrogen sources in this heterocystous cyanobacterium. Lineage-specific differences in thermal performance were also observed

Are Australian pre-service physical education teachers prepared to teach inclusive physical education?

Abstract: Australian pre-service physical education (PE) teachers must be prepared for the reality of teaching in inclusive classrooms. Past studies have indicated that the amount of academic preparedness can affect pre-service PE teachers’ intentions to successfully teach in inclusive settings. The current study measured these intentions in a sample of pre-service PE teachers from two different universities. This modified survey required participants to respond to two separate scenarios: one teaching inclusive PE to a student with attention deficit hyperactivity disorder, and one to a student with autism. All participants completed an adapted PE unit with an embedded practicum of different lengths. Findings indicated that pre-service teachers’ who experienced the larger adapted PE practicum had more favourable intentions towards teaching students with both disabilities compared to the other cohort. Implications of this research to improve Australian PE teacher training are discussed and recommendations are made

Physical Educators’ Efficacy in Utilising Paraprofessionals in an Inclusive Setting

Inclusion of students with disabilities (SwD) in Australian health and physical education (HPE) classes is on the rise. Reasonable adjustment to assist inclusive practice is often accomplished through the use of teaching assistants, or paraprofessionals. While this practice is commonly understood within the classroom, this approach remains obscure in the HPE setting. The purpose of this study was to explore how Australian HPE teachers utilise paraprofessionals when teaching SwD in inclusive environments. HPE teachers (N=14) completed an online questionnaire inquiring how paraprofessionals are being used and the strategies they are using to develop working relationships with paraprofessionals. The HPE teachers in our sample generally had a favourable attitudes towards the paraprofessionals they have worked with, however a lack of appropriate training and HPE curriculum knowledge were highlighted as deficient areas that may have an adverse effect on the overall HPE environment. While the paraprofessionals were recognised as providing a level of support that was generally to the satisfaction of the HPE teachers, the HPE teachers’ consistently provided areas in which the paraprofessional could improve. Strategies to foster this collaborative working relationship were also investigated, and the primary finding dealt with adequate reciprocal communication. With the move toward inclusive practice in Australian public schools this is an area that warrants further investigation so all students can benefit from a healthy and productive HPE