Magnetic screening properties of an incompressible chiral fluid

We study the possible penetration of a static magnetic field in an idealized sample of many layers supporting a two dimensional charged chiral quantum fluid, to see whether there is a kind of Meissner effect. This is a non standard problem since the quantum fluid is incompressible having a gap in its spectrum. We find that the system shows an intermediate behaviour between superconducting and non-superconducting fluids, the magnetic field being screened or not depending on its orientation relative to the layers.Comment: 20 pages, plain tex, SISSA 50/94/E

Effective Theory of a Chiral Superfluid

We consider an effective Lagrangian describing a fluid living on two-di\-men\-sio\-nal planes. The fluid self-interacts through a Chern-Simons vector potential, whose field strength is proportional to the density fluctuation. This effective Lagrangian can be related to the Anyon mean field, but can also be considered more generally to describe a universality class of superfluids and, when charged, of superconductors. We study the relevant physical properties, including the spectrum, the chirality features appearing in the polarization of scattered EM waves, and the peculiar response under a magnetic field, i.e. a peculiar kind of anisotropic Meissner effect.Comment: 36 pages, plain Tex. (minor changes for clarifying definitions on pages 4,5,6

1994-95 Advisory Council On Social Security Technical Panel on Trends and Issues in Retirement Saving Final Report

The charge of the Technical Panel on Trends and Issues in Retirement Savings (TIRS) was to assist the 1994-95 [Social Security] Advisory Council with respect to its charge to analyze the relative roles of the public and private sectors in the provision of retirement income, particularly how underlying policies of public and private programs, including relevant tax laws, affect retirement decisions and the economic status of the elderly

Modifiable arousal in ADHD and its etiological association with fluctuating reaction times

BACKGROUND: Cognitive theories of attention-deficit/hyperactivity disorder (ADHD) propose that high within-subject fluctuations of cognitive performance in ADHD, particularly reaction time (RT) variability (RTV), may reflect arousal dysregulation. Yet, direct evidence of arousal dysregulation and how it may account for fluctuating reaction times in ADHD is limited. We used skin conductance (SC) as a measure of peripheral arousal and aimed to investigate its phenotypic and familial association with RTV in a large sample of ADHD and control sibling pairs. METHODS: 292 adolescents and young adults, consisting of 73 participants with ADHD and their 75 siblings, as well as 72 controls and their 72 siblings, completed the baseline (slow, unrewarded) and fast-incentive conditions of a RT task, whilst SC was simultaneously recorded. RESULTS: A significant group by condition interaction emerged for SC level (SCL). Participants with ADHD had decreased SCL, compared to controls, in the baseline but not fast-incentive condition. Baseline SCL was negatively associated with RTV and multivariate model fitting demonstrated that the covariance of SCL with RTV, and of SCL with ADHD, was mostly explained by shared familial effects. CPNCLUSIONS: ADHD is associated with decreased, but modifiable, tonic peripheral arousal. A shared familial etiology underlies the relationship between arousal and RTV, and between arousal and ADHD. Given the malleability of SCL, if our findings are replicated, it warrants further exploration as a potential treatment target for ADHD

Essays on transforming security and development in an unequal world

These two papers add further dimensions to the discussions in IDS Bulletin 40.2 (March 2009) on ‘Transforming Security and Development in an Unequal World’ edited by Robin Luckham, Niagalé Bagayoko, Lucia Dammert, Claudio Fuentes and Michael Solis. Like the contributions to the latter, they were first discussed at the founding Colloquium of the Global Consortium for Security Transformation held at Kandalama, Sri Lanka in September 2007. Niagalé Bagayoko’s paper on ‘State, Non-State and Multilateral Logics of Action in Post-Conflict Environments’ considers the complexities of Northern policymaking and their impacts in post-conflict countries. It thus differs from but complements IDS Bulletin 40.2, which focuses mostly on security and development from a Southern perspective. She argues that a number of different policy logics are at work in the security, development, humanitarian and media etc domains, which are sometimes coordinated – but often in tension with – each other. Her approach thus differs from that of certain critical voices in the NGO and academic worlds, which hold that there is a danger that Northern security priorities might ‘securitise’ the humanitarian and development agendas, particularly in post-conflict environments. While these dangers are real, nevertheless one should not stereotype all international actors as ‘Northern’ or as promoting Northern security (e.g. anti-terrorist) agendas. It is instead more fruitful to view such actors as diverse players with conflicting interests that operate according to different policy logics. Lyndsay McLean Hilker’s paper on ‘Why Identity Politics Matters for Security and What Follows for Research and Policy’ spells out a general framework for analysis of identity-based violent conflict, drawing upon empirical examples, including Rwanda, where she has focused her own research. It is unique in its focus on the implications of analysis and research on identity politics for development policy. She contends that identity politics matter both to the persistence of insecurity and to the achievement of greater security. Evidence from multiple contexts demonstrates that identity provides an effective basis for group mobilisation into collective action – both violent and non-violent in nature. If we are to work to combat insecurity at the local as well as the global level, we need to look in more depth at the processes leading to violence in the name of identity in specific contexts, and explore the types of interventions that can prevent and respond to such violence. It is especially important to understand under what circumstances identity politics can be exercised in ways that are inclusive and empowering rather than exclusionary or violent. Keywords: security; conflict; ethnicity; identities; post-conflict reconstruction; humanitarianism; peace-building

Topological phase-fluctuations, amplitude fluctuations, and criticality in extreme type-II superconductors

We study the effect of critical fluctuations on the $(B,T)$ phase diagram in extreme type-II superconductors in zero and finite magnetic field using large-scale Monte Carlo simulations on the Ginzburg-Landau model in a frozen gauge approximation. We show that a vortex-loop unbinding gives a correct picture of the zero field superconducting-normal transition even in the presence of amplitude fluctuations, which are far from being critical at $T_c$. We extract critical exponents of the dual model by studying the topological excitations of the original model. From the vortex-loop distribution function we extract the anomalous dimension of the dual field $\eta \simeq -0.18$, and conclude that the charged Ginzburg-Landau model and the neutral 3DXY model belong to different universality classes. We find are two distinct scaling regimes for the vortex-line lattice melting line: a high-field scaling regime and a distinct low-field 3DXY critical scaling regime. We also find indications of an abrupt change in the connectivity of the vortex-tangle in the vortex liquid along a line $T_L \geq T_M$. This is the finite field counter-part of the zero-field vortex-loop blowout. Which at low enough fields appears to coincide with $T_M$. Here, a description of the vortex system only in terms of field induced vortex lines is inadequate at and above the VLL melting temperature.Comment: 30 pages, 14 figure

The Bostrichidae of the Maltese Islands (Coleoptera)

The Bostrichidae of the Maltese Islands are reviewed. Ten species are recorded with certainty from this Archipelago, of which 6 namely, Trogoxylon impressum (Comolli, 1837), Amphicerus bimaculatus (A.G. Olivier, 1790), Heterobostrychus aequalis (Waterhouse, 1884), Sinoxylon unidentatum (Fabricius, 1801), Xyloperthella picea (A.G. Olivier, 1790) and Apate monachus Fabricius, 1775 are recorded for the first time. Two of the mentioned species (H. aequalis and S. unidentatum) are alien and recorded only on the basis of single captures and the possible establishment of these species is discussed. Earlier records of Scobicia pustulata (Fabricius, 1801) from Malta are incorrect and should be attributed to S. chevrieri (A. Villa & J.B. Villa, 1835). A zoogeographical analysis and an updated checklist of the 12 species of Bostrichidae recorded from the Maltese Islands and neighbouring Sicilian islands (Pantelleria, Linosa and Lampedusa) are also provided. Rhizopertha dominica (Fabricius, 1792) form granulipennis Lesne in Beeson & Bhatia, 1937 from Uttarakhand (northern India) was overlooked by almost all subsequent authors. Its history is summarized and the following new synonymy is established: Rhizopertha dominica (Fabricius, 1792) form granulipennis Lesne in Beeson & Bhatia, 1937 = Rhyzopertha dominica (Fabricius, 1792), syn. n. Finally, records of Amphicerus bimaculatus from Azerbaijan, of Bostrichus capucinus (Linnaeus, 1758) from Jordan and Syria, of Scobicia chevrieri from Jordan and Italy, of Xyloperthella picea from Italy, and of Apate monachus from Corsica (France) and Italy, are also provided.peer-reviewe

Kinetic modeling of tumor growth and dissemination in the craniospinal axis: implications for craniospinal irradiation

BACKGROUND: Medulloblastoma and other types of tumors that gain access to the cerebrospinal fluid can spread throughout the craniospinal axis. The purpose of this study was to devise a simple multi-compartment kinetic model using established tumor cell growth and treatment sensitivity parameters to model the complications of this spread as well as the impact of treatment with craniospinal radiotherapy. METHODS: A two-compartment mathematical model was constructed. Rate constants were derived from previously published work and the model used to predict outcomes for various clinical scenarios. RESULTS: The model is simple and with the use of known and estimated clinical parameters is consistent with known clinical outcomes. Treatment outcomes are critically dependent upon the duration of the treatment break and the radiosensitivity of the tumor. Cross-plot analyses serve as an estimate of likelihood of cure as a function of these and other factors. CONCLUSION: The model accurately describes known clinical outcomes for patients with medulloblastoma. It can help guide treatment decisions for radiation oncologists treating patients with this disease. Incorporation of other treatment modalities, such as chemotherapy, that enhance radiation sensitivity and/or reduce tumor burden, are predicted to significantly increase the probability of cure

Uveal Melanoma Treated With Iodine-125 Episcleral Plaque: An Analysis of Dose on Disease Control and Visual Outcomes

In the treatment of uveal melanomas, the optimal prescribed dose to maximize disease control, but minimize radiation-related complications is unknown. Historically our institution has treated uveal melanomas to doses less than 85 Gy to the tumor apex even if the apex was less than 5mm in height. Here, we investigate how tumor control and visual outcomes are affected by the radiation dose at the tumor apex

A treatment applying a biomechanical device to the feet of patients with knee osteoarthritis results in reduced pain and improved function: a prospective controlled study

<p>Abstract</p> <p>Background</p> <p>This study examined the effect of treatment with a novel biomechanical device on the level of pain and function in patients with knee OA.</p> <p>Methods</p> <p>Patients with bilateral knee OA were enrolled to active and control groups. Patients were evaluated at baseline, at 4 weeks and at the 8-week endpoint. A novel biomechanical device was individually calibrated to patients from the active group. Patients from the control group received an identical foot-worn platform without the biomechanical elements. Primary outcomes were the WOMAC Index and ALF assessments.</p> <p>Results</p> <p>There were no baseline differences between the groups. At 8 weeks, the active group showed a mean improvement of 64.8% on the WOMAC pain scale, a mean improvement of 62.7% on the WOMAC function scale, and a mean improvement of 31.4% on the ALF scale. The control group demonstrated no improvement in the above parameters. Significant differences were found between the active and control groups in all the parameters of assessment.</p> <p>Conclusions</p> <p>The biomechanical device and treatment methodology is effective in significantly reducing pain and improving function in knee OA patients.</p> <p>The study is registered at clinicaltrials.gov, identifier NCT00457132, <url>http://www.clinicaltrials.gov/ct/show/NCT00457132?order=1</url></p