Ground-state Properties of a Supersolid in RPA

We investigate the newly discovered supersolid phase by solving in random-phase approximation the anisotropic Heisenberg model of the hard-core boson ${}^4$He lattice at zero temperature. We include nearest and next-nearest neighbor interactions and calculate exactly all pair correlation functions in a cumulant decoupling scheme. We demonstrate the importance of vacancies and interstitials in the formation of the supersolid phase. The supersolid phase is characterised by strong quantum fluctuations which are taken into account rigorously. Furthermore we confirm that the superfluid to supersolid transition is triggered by a collapsing roton minimum however is stable against spontaneously induced superflow, i.e. vortex creation.Comment: 10 pages, 8 figure

Regulation of wingless-type MMTV integration site family (WNT) signalling in pancreatic islets from wild-type and obese mice

Aims/hypothesis: TCF7L2 is a type 2 diabetes susceptibility gene and downstream effector of canonical wingless-type MMTV integration site family (WNT) signalling. However, it is unknown whether this pathway is active in adult pancreatic islets in vivo, and whether it is regulated in obesity. Methods: We analysed activation of endogenous WNT signalling in the endocrine pancreas from wild-type and obese mice (ob/ob) using a reporter transgene (Topgal). Regulation of WNT signalling was compared using gene chip experiments from isolated pancreatic islets. Activation of canonical WNT signalling in pancreatic islets and the mouse beta cell line MIN6 was measured using immunoblotting for cytosolic β-catenin. Results: Endogenous canonical WNT signalling was absent in the adult endocrine pancreas in both wild-type and obese mice. We identified WNT4 as an abundant WNT signalling molecule in adult pancreatic islets that is induced in two different insulin-resistant mouse models. Increased expression of WNT4 inhibited canonical WNT signalling in pancreatic islets and MIN6 cells. Conclusions/interpretation: Canonical WNT signalling is not active in adult beta cells in vivo. WNT4 provides a potential mechanism for suppression of canonical WNT signalling in obese mic

Behavior of self-propelled acetone droplets in a Leidenfrost state on liquid substrates

It is demonstrated that non-coalescent droplets of acetone can be formed on liquid substrates. The fluid flows around and in an acetone droplet hovering on water are recorded to shed light on the mechanisms which might lead to non-coalescence. For sufficiently low impact velocities, droplets undergo a damped oscillation on the surface of the liquid substrate but at higher velocities clean bounce-off occurs. Comparisons of experimentally observed static configurations of floating droplets to predictions from a theoretical model for a small non-wetting rigid sphere resting on a liquid substrate are made and a tentative strategy for determining the thickness of the vapor layer under a small droplet on a liquid is proposed. This strategy is based on the notion of effective surface tension. The droplets show self-propulsion in straight line trajectories in a manner which can be ascribed to a Marangoni effect. Surprisingly, self-propelled droplets can become immersed beneath the undisturbed water surface. This phenomenon is reasoned to be drag-inducing and might provide a basis for refining observations in previous work

Hydrogeology, geology & engineering aspects of surficial materials on the Lake Michigan shore in Illinois

Other titles: Geologic, Hydrogeologic, and engineering aspects of surficial materials on the Lake Michigan shore in IllinoisOpe

Lymph node and peri-lymph node stroma : phenotype and interaction with T-cells

Indiana University-Purdue University Indianapolis (IUPUI)The non-hematopoietic, stationary stromal cells located inside and surrounding skin-draining lymph nodes play a key role in regulating immune responses. We studied distinct populations of lymph node stromal cells from both human subjects and animal models in order to describe their phenotype and function. In the mouse model, we studied two distinct populations: an endothelial cell population expressing Ly51 and MHC-II, and an epithelial cell population expressing the epithelial adhesion molecule EpCAM. Analysis of intra-nodal and extra-nodal lymph node (CD45-) stromal cells through flow cytometry and qPCR provides a general phenotypic profile of the distinct populations. My research focused on the EpCAM+ epithelial cell population located in the fat pad surrounding the skin draining lymph nodes. The EpCAM+ population has been characterized by surface marker phenotype, anatomic location, and gene expression profile. This population demonstrates the ability to inhibit the activation and proliferation of both CD4 and CD8 T cells. This population may play a role in suppressing overactive inflammation and auto-reactive T cells that escaped thymic deletion. The other major arm of my project consisted of identifying a novel endothelial cell population in human lymph nodes. Freshly resected lymph nodes were processed into single cell suspensions and selected for non-hematopoietic CD45- stromal cells. The unique endothelial population expressing CD34 HLA-DR was then characterized and analyzed for anatomic position, surface marker expression, and gene profiles. Overall, these studies emphasize the importance of stationary lymph node stromal cells to our functioning immune systems, and may have clinical relevance to autoimmune diseases, inflammation, and bone marrow transplantation

The impact of epilepsy surgery on sex hormones and the menstrual cycle in female patients

AbstractWe investigated the impact of temporal lobe epilepsy surgery on sex hormones and menstrual cycles. Sixteen female patients with temporal lobe epilepsy were investigated prior to surgery and 3, 6, and 12 months after surgery. The patients received carbamazepine (CBZ) as monotherapy (10 patients ) or in combination with other antiepileptic drugs (six patients ). Antiepileptic drugs were maintained after surgery. During the 1-year follow-up after surgery eight patients (50%) remained completely free of seizures. In another four patients (25%) only rare disabling seizures occurred. There were no significant differences between pre-surgical and post-surgical serum concentrations of testosterone, free testosterone, prolactin, dehydroepiandrosterone sulfate, growth hormone, cortisol and sex hormone binding globulin. There was, however, a significant increase in serum androstenedione concentration 6 months post-surgically (P< 0.02). Documentation of menstrual cycles in addition to laboratory parameters revealed individual post-surgical changes of the menstrual cycle in eight patients . Four patients had a change in menstrual periodicity: two patients with complete seizure control had regular cycles instead of oligomenorrhoea and two patients with incomplete seizure control had oligomenorrhoea instead of regular cycles. These data indicate that at least in some patients with temporal lobe epilepsy surgical treatment influences menstrual periodicity

Offering disinclined people the choice between different screening appointments: a randomised online survey

Objectives: An invitation to cancer screening with a single (fixed) appointment time has been shown to be a more effective way at increasing uptake compared with an invitation with an open (unscheduled) appointment. The present study tested whether offering more than one fixed appointment could further enhance this effect or be detrimental to people’s intention. / Design: Experimental online hypothetical vignette survey. / Methods: 1,908 respondents who stated that they did not intend to participate in Bowel Scope Screening (BSS) were offered either one, two, four or six hypothetical fixed BSS appointments (all of which covered the same time of day to control for individual preferences). / Results: Participants who were given more than one appointment to choose from were less likely to intend to book an appointment despite multiple appointments being perceived as more convenient. / Conclusions: These results suggest that when it comes to offering people appointments for cancer screening, less (choice) is more, at least if alternatives fail to serve an inherent preference

Acceptability of risk-stratified breast screening: Effect of the order of presenting risk and benefit information

OBJECTIVE: To test whether reduced-frequency risk-stratified breast screening would be perceived more favourably by transposing the order of information on benefits and risks. METHODS: After reading vignettes describing non-stratified three-yearly screening and a risk-stratified alternative with five-yearly invitations for women at low risk, 698 women completed an online survey. Participants were allocated at random to information on screening benefits followed by risks, or vice versa, and asked to state preferences for either screening system. Participants also rated perceived magnitude of screening benefits and risks, and breast cancer susceptibility. RESULTS: Binomial logistic regression did not find order effects on preferences (p = 0.533) or perceived benefits of screening (p = 0.780). Perceived screening risks were greater when risks were presented first (p < 0.0005). Greater perceived susceptibility was associated with lower proportions preferring risk-stratified screening (15% vs. 39% in highest and lowest groups; p = 0.002), as were greater perceived screening benefits (e.g. 13% vs. 45% in highest and lowest groups; p < 0.0005). CONCLUSIONS: No information order effect on preferences was observed. Information order did affect screening risk perceptions. Efforts to improve perceptions may need to be more intensive than those tested. Women perceiving themselves as high risk or perceiving greater benefits of screening may be particularly averse to less frequent screening

Buoyant Venus station mission feasibility study for 1972 and 1973 launch opportunities. Volume 3 - Configuration definition. Part 2 - Appendixes Final report

Buoyant Venus station mission study for 1972 - 1973 launch period - backup data including atmospheric models, heat shield requirements, etc

Preliminary measurements of lumbar spine kinematics and stiffness

The purpose of the presented study was the experimental measurement of lumbar spine stiffness and its range of motion. The dependence of torsion moment of lumbar spine segment on deflection of flexion, extension and torsion was observed during experiments. Stiffness of spine segment was determined from measured data. Human lumbar spine was used for verification of the experimental technique. The sample consisted of one lumbar vertebrae composed by five vertebral bodies and four intervertebral discs. All muscles were removed, however all ligaments were preserved. Experiments were ca rried out on the test system MTS 858.2 MiniBionix, where loading by axial force and torsion moment is possible at the same time. Special Modular Bionix Spine Test Fixator, attached to the test system was used for the measurements. Loading was controlled kinematically (gradual turning) by keeping the axial force equal zero. Measurement was timedependent. The results of these experiments are going to be used as input data for creating a model of artificial lumbar spine and new type of artificial disc replacement