Exact Solution for Bulk-Edge Coupling in the Non-Abelian ν=5/2\nu=5/2 Quantum Hall Interferometer

It has been predicted that the phase sensitive part of the current through a non-abelian $\nu = 5/2$ quantum Hall Fabry-Perot interferometer will depend on the number of localized charged $e/4$ quasiparticles (QPs) inside the interferometer cell. In the limit where all QPs are far from the edge, the leading contribution to the interference current is predicted to be absent if the number of enclosed QPs is odd and present otherwise, as a consequence of the non-abelian QP statistics. The situation is more complicated, however, if a localized QP is close enough to the boundary so that it can exchange a Majorana fermion with the edge via a tunneling process. Here, we derive an exact solution for the dependence of the interference current on the coupling strength for this tunneling process, and confirm a previous prediction that for sufficiently strong coupling, the localized QP is effectively incorporated in the edge and no longer affects the interference pattern. We confirm that the dimensionless coupling strength can be tuned by the source-drain voltage, and we find that not only does the magnitude of the even-odd effect change with the strength of bulk-edge coupling, but in addition, there is a universal shift in the interference phase as a function of coupling strength. Some implications for experiments are discussed at the end.Comment: 12 pages, 3 figure

Muscarinic and purinergic signalling within the bladder

The aim of this thesis is to improve our understanding of muscarinic and purinergic neurotransmission within the urinary bladder both within the detrusor muscle and the urothelium as both sites are therapeutic targets. The M2 receptor is the most populous muscarinic receptor in the detrusor muscle however its role is unclear, as detrusor contractility has been demonstrated to be mediated principally by the M3 receptor. The role of the M2 muscarinic receptor in guinea pig and human detrusor contractility was examined through organ bath experiments. Significant M2 modulation of contractility in patients with neuropathic overactivity and overactive bladder symptoms was demonstrated through inhibition of agonist dose response curves and electrical field stimulation with the selective M2 inhibitor methoctramine. Furthermore cAMP elevation through the adenylate cyclase activator forskolin produced an identical and non-additive inhibition to that achieved through methoctramine suggesting that cAMP inhibition is an important mechanism of M2 activation in the detrusor. Detrusor contractility was further assessed through an isolated cell technique and this demonstrated further evidence of M2 mediated contraction of the detrusor indicating that the site of action of M2 agonism is directly within the detrusor cells. Ussing chamber experiments to examine the effect of the exogenous addition of neurotransmitters on the electrical properties of the urothelium were carried out. These demonstrated that cholinergic agonists had no effect but ATP resulted in an increased negativity of the basolateral surface of the urothelium only when added to the luminal but not the basolateral surface. As ATP release from the urothelium has been found to be associated with inflammation and the sensory nerves are adjacent to the basolateral surface, we believe this represents a sensory mechanism whereby a luminal inflammatory signal is transduced electrically across the urothelium to activate the sensory nerves

Color Capable Sub-Pixel Resolving Optofluidic Microscope and Its Application to Blood Cell Imaging for Malaria Diagnosis

Miniaturization of imaging systems can significantly benefit clinical diagnosis in challenging environments, where access to physicians and good equipment can be limited. Sub-pixel resolving optofluidic microscope (SROFM) offers high-resolution imaging in the form of an on-chip device, with the combination of microfluidics and inexpensive CMOS image sensors. In this work, we report on the implementation of color SROFM prototypes with a demonstrated optical resolution of 0.66 µm at their highest acuity. We applied the prototypes to perform color imaging of red blood cells (RBCs) infected with Plasmodium falciparum, a particularly harmful type of malaria parasites and one of the major causes of death in the developing world

Laparoscopic diagnostic peritoneal lavage (L-DPL): A method for evaluation of penetrating abdominal stab wounds

BACKGROUND: The management of penetrating abdominal stab wounds has been the subject of continued reappraisal and controversy. In the present study a novel method which combines the use of diagnostic laparoscopy and DPL, termed laparoscopic diagnostic peritoneal lavage (L-DPL) is described METHOD: Five trauma patients with penetrating injuries to the lower chest or abdomen were included. Standard videoscopic equipment is utilized for the laparoscopic trauma evaluation of the injured patient. When no significant injury is detected, the videoscope is withdrawn and 1000 mL of normal saline is infused through the abdominal trochar into the peritoneal cavity, and the effluent fluid studied for RBCs, WBC, amylase debry, bile as it is uced in regular diagnostic peritoneal lavage RESULTS: Laparoscopic peritoneal lavage (L-DPL) was then performed and proved to be negative in all 5 patients. RBC lavage counts above 100,000/mcrl were not considered as a positive lavage result, because the bleeding source was directly observed and controlled laparoscopically. All patients recovered uneventfully and were released within 3 days. This procedure combines the visual advantages of laparoscopy together with the sensitivity and specificty of DPL for the diagnosis of significant penetrating intra-abdominal injury, when the diagnostic strategy of selective consevatism for abdominal stab wounds is adopted. CONCLUSION: A method of laparoscopic diagnostic peritoneal lavage (L-DPL) in hemodynamically stable patients with penetrating lower thoracic or abdominal stab wounds is described. The method is especially applicable for trauma surgeons with only basic experience in laparoscopic technique. This procedure is used to obtain conclusive evidence of significant intra-abdominal injury, confirm peritoneal penetration, control intra-abdominal bleeding, and repair lacerations to the diaphragm and abdominal wall. The combination of laparoscopy and DPL afforded by the L-DPL method adds to the sensitivity and specificity of DPL, and avoids under or over sesitivty, that have limited the use of DPL in the hemodynamically stable trauma patients with suspicious or proven peritoneal penetration

An Empirical Analysis of Noncompetition Clauses and Other Restrictive Postemployment Covenants

Employment contracts for most employees are not publicly available, leaving researchers to speculate on whether they contain post-employment restrictions on employee mobility, and if so, what those provisions look like. Using a large sample of publicly available CEO employment contracts, we are able to examine these noncompetition covenants, including post-employment covenants not to compete (“CNCs†or “noncompetesâ€), non-solicitation agreements (“NSAsâ€), and non-disclosure agreements (“NDAsâ€). What we find confirms some long-held assumptions about restrictive covenants, but also uncovers some surprises. We begin by discussing why employers use restrictive covenants and examining how the courts have treated them. We then analyze an extensive sample of CEO employment contracts drawn from a large random sample of 500 S&P 1500 companies. We find that 80% of these employment contracts contain CNCs, often with a broad geographic scope, and that these generally last only one to two years. Similarly, we find that NSAs routinely appear in these contracts, barring solicitation of the firm’s employees and customers or clients. We demonstrate that NDAs are prevalent and prohibit the CEOs from disclosing unspecified “confidential information.†In addition, we note that there is a strong “California effect,†whereby firms from that state are less likely to put CNCs in employment contracts. Our research also uncovers several previously undocumented trends. First, we see a robust trend in these contracts of more and more restrictive covenants appearing over time and with greatly expanded enforcement rights for the firm. Second, we find clear path dependence for these clauses, with a prior CNC being a convincing predictor of their use in future employment contracts. Third, longer-term contracts are more likely to have CNC clauses than short-term contracts, most probably because the firm has more confidence in making investments in CEOs that are committed to staying for longer periods. We argue that this shows that for some firms the risk of harm from a departing executive may simply be more acute than with other firms

Local Charge of the nu=5/2 Fractional Quantum Hall State

Electrons in two dimensions and strong magnetic fields effectively lose their kinetic energy and display exotic behavior dominated by Coulomb forces. When the ratio of electrons to magnetic flux quanta in the system is near 5/2, the unique correlated phase that emerges is predicted to be gapped with fractionally charged quasiparticles and a ground state degeneracy that grows exponentially as these quasiparticles are introduced. Interestingly, the only way to transform between the many ground states would be to braid the fractional excitations around each other, a property with applications in quantum information processing. Here we present the first observation of localized quasiparticles at nu=5/2, confined to puddles by disorder. Using a local electrometer to compare how quasiparticles at nu=5/2 and nu=7/3 charge these puddles, we are able to extract the ratio of local charges for these states. Averaged over several disorder configurations and samples, we find the ratio to be 4/3, suggesting that the local charges are e/3 at seven thirds and e/4 at five halves, in agreement with theoretical predictions. This confirmation of localized e/4 quasiparticles is necessary for proposed interferometry experiments to test statistics and computational ability of the state at nu=5/2.Comment: 6 pages, 4 figures corrected titl

Screening and breeding for insect resistance in pea, lentil, faba bean and chickpea

Although grain legumes are considered to be particularly susceptible to insect damage, few studies have quantified these losses in farmers’ fields. Insecticides can protect each of the; legumes from pest damage, but plant resistance appears to be an attractive alternative, particularly for developing countries. Large differences in susceptibility to the major insect pests have been detected in the germplasm of each of pea, faba bean, lentil and chickpea, but there are no reports of successful exploitation of genotypes bred for resistance. Methods of screening and breeding for resistance are described, with particular reference to Heliothis armigera on chickpea. The dangers of breeding crops under protected conditions, for subsequent use in farmers’ fields where protection is not afforded, are emphasized