Pretransitional Optical Activity In Chiral Smectic Liquid Crystals

Pretransitional optical activity measurements in smectic liquid crystals of both law and high chirality are reported. In the low chirality sample, p-(n-(decyloxybenzylidene)-p-amino-(2-methylbutyl)cin-namate (DOBAMBC), the results indicate that the optical activity in both the isotropic phase just above the smectic A phase and in the smectic A phase just above the smectic C* phase can be explained in terms of a Landau-deGennes free energy with no coupling between the chiral modes. In the high chirality sample, 1-methylheptyl 4′-[(4″-tetradecyloxyphenyl)propioloyloxy]biphenyl-4-carboxylate (14P|M7), the data in the isotropic phase above the recently discovered smectic A* phase cannot be explained in this way, even when coupling between the chiral modes is considered. Whether this is due to some feature of the smectic A* phase or is simply the result of strong coupling between the orientational and positional order parameters is a question which remains unanswered

The role of ADA inclusive policies in the recruiting of applicants with Autism Spectrum Disorders

Autism spectrum disorders (ASD) are a set of neurodevelopmental disorders characterized by deficits in social interactions and interpersonal communication, repetitive behaviors, and narrow focus or interests. The severity of ASD is variable, but the symptoms span the entire lifespan of the individuals with ASD and few effective treatments for these symptoms have been identified. Each year in the United States, there are approximately 50,000 people with ASD who turn 18 years old in the United States (Shattuck et al., 2012). Where most 18 year olds are likely to go out and get a job, the employment prospect of individuals with ASD is not very bright. High school graduates with autism are underemployed when compared to their peers and less employed than high school graduates with other developmental or intellectual disorders (Roux, Shattuck, Rast, & Anderson, 2017). Despite this, some reports suggest that gainful employment can benefit individuals with ASD by providing them with desirable social interactions (Hendricks, 2010), and it is the focus of many service providers for individuals with ASD (Migliore et al., 2014). Like most adults, individuals with ASD benefit from the social status that comes with having a job and the degree of financial independence that employment affords them (Gerhardt & Lainer, 2011). Research has also found that employment is associated with an increase in personal dignity, improved self-esteem, increased adaptive abilities, better mental health, and improved cognitive performance for individuals with ASD (Hurlbutt & Chalmers 2004; Mawhood & Howlin 1999; Stephens et al. 2005). The principle means for addressing the underemployment and unemployment for individuals with ASD is to assist them with gaining the skills and training needed to apply for and get a job. Yet even with these efforts, the employment prospects of individuals with ASD has not significantly improved (Bennett & Dukes 2013; Taylor & Seltzer 2011). The present study will investigate the role that organizational communications about hiring and employment policies regarding the Americans with Disabilities Act may have on the potential recruitment of those with ASD as well as the degree to which potential applicants who do not have ASD view these inclusive statements as favorable

Aerobic glycolysis is required for spatial memory acquisition but not memory retrieval in mice

The consolidation of newly formed memories and their retrieval are energetically demanding processes. Aerobic glycolysis (AG), also known as the Warburg effect, consists of the production of lactate from glucose in the presence of oxygen. The astrocyte neuron lactate shuttle hypothesis posits that astrocytes process glucose by AG to generate lactate, which is used as a fuel source within neurons to maintain synaptic activity. Studies in mice have demonstrated that lactate transport between astrocytes and neurons is required for long-term memory formation, yet the role of lactate production in memory acquisition and retrieval has not previously been explored. Here, we examined the effect of dichloroacetate (DCA), a chemical inhibitor of lactate production, on spatial learning and memory in mice using the Morris water maze (MWM). In vivo hyperpolarized 13 C-pyruvate magnetic resonance spectroscopy revealed decreased conversion of pyruvate to lactate in the mouse brain following DCA administration, concomitant with a reduction in the phosphorylation of pyruvate dehydrogenase. DCA exposure before each training session in the MWM impaired learning, which subsequently resulted in impaired memory during the probe trial. In contrast, mice that underwent training without DCA exposure, but received a single DCA injection before the probe trial exhibited normal memory. Our findings indicate that AG plays a key role during memory acquisition but is less important for the retrieval of established memories. Thus, the activation of AG may be important for learning-dependent synaptic plasticity rather than the activation of signaling cascades required for memory retrieval

Separation of v-Src-induced mitogenesis and morphological transformation by inhibition of AP-1

v-Src activity results in both morphological transformation and reentry of quiescent chick embryo fibroblasts (CEF) into cell cycle. We have previously used temperature-sensitive v-Src mutants to show that enhanced activity of cellular AP-1 in the first few hours after activation of v-Src invariably precedes the biological consequences. Here we have investigated whether the early activation of AP-1 is essential for any or all of the v-Src responses by using a mutant c-Fos that comprises the leucine zipper and a disrupted basic region. Expression of the c-Fos mutant partially reduced cellular AP-1 activity in exponentially growing cells. However, in CEF that had been made quiescent by serum deprivation, v-Src-induced stimulation of AP-1 DNA binding activity was substantially reduced. In addition, quiescent CEF stably transfected with this mutant show an impaired mitogenic response to v-Src, indicating that the AP-1 stimulation is a necessary prerequisite for cell-cycle reentry. The ability of v-Src to morphologically transform quiescent CEF was not impaired by the inhibition of AP-1 stimulation, indicating that the mitogenic and morphological consequences of v-Src have distinguishable biochemical mediators. Focal adhesion kinase, a recently identified determinant of cell morphology, undergoes a gel mobility shift, characteristic of its hyperphosphorylated state, in response to v-Src activation in cells expressing the inhibitory AP-1 protein. This provides further evidence that the pathways that regulate morphological transformation are independent of AP-1

Instability and Spatiotemporal Dynamics of Alternans in Paced Cardiac Tissue

We derive an equation that governs the spatiotemporal dynamics of small amplitude alternans in paced cardiac tissue. We show that a pattern-forming linear instability leads to the spontaneous formation of stationary or traveling waves whose nodes divide the tissue into regions with opposite phase of oscillation of action potential duration. This instability is important because it creates dynamically an heterogeneous electrical substrate for inducing fibrillation if the tissue size exceeds a fraction of the pattern wavelength. We compute this wavelength analytically as a function of three basic length scales characterizing dispersion and inter-cellular electrical coupling.Comment: 4 pages, 3 figures, submitted to PR

Community professionals' management of client care : a mixed-methods systematic review

This is the final draft, after peer-review, of a manuscript published in Journal of Health Services Research & Policy. The definitive version, detailed above, is available online at www.rsmjournals.com.Peer reviewedPostprin