Distinguishing the “Truly National” From the “Truly Local”: Customary Allocation, Commercial Activity, and Collective Action

This Essay makes two claims about different methods of defining the expanse and limits of the Commerce Clause. My first claim is that approaches that privilege traditional subjects of state regulation are unworkable and undesirable. These approaches are unworkable in light of the frequency with which the federal government and the states regulate the same subject matter in our world of largely overlapping federal and state legislative jurisdiction. The approaches are undesirable because the question of customary allocation is unrelated to the principal reason why Congress possesses the power to regulate interstate commerce: solving collective action problems involving multiple states. These problems are evident in the way that some federal judges invoked regulatory custom in litigation over the constitutionality of the minimum coverage provision in the Patient Protection and Affordable Care Act. The areas of health insurance and health care are not of exclusive state concern, and it is impossible to lose—or to win—a competition requiring skillful lawyers or judges to describe them as more state than federal, or more federal than state. Nor is it most important what the answer is. More promising are the approaches that view congressional authority as turning on either commercial activity or collective action problems facing the states. My second claim is that these two approaches have advantages and disadvantages, and that the choice between them exemplifies the more general tension between applying rules and applying their background justifications. I have previously defended a collective action approach to Article I, Section 8. My primary purpose in this Essay is to clarify the jurisprudential stakes in adopting one method or the other and to identify the problems that advocates of each approach must address

A Rapid Dynamical Monte Carlo Algorithm for Glassy Systems

In this paper we present a dynamical Monte Carlo algorithm which is applicable to systems satisfying a clustering condition: during the dynamical evolution the system is mostly trapped in deep local minima (as happens in glasses, pinning problems etc.). We compare the algorithm to the usual Monte Carlo algorithm, using as an example the Bernasconi model. In this model, a straightforward implementation of the algorithm gives an improvement of several orders of magnitude in computational speed with respect to a recent, already very efficient, implementation of the algorithm of Bortz, Kalos and Lebowitz.Comment: RevTex 7 pages + 4 figures (uuencoded) appended; LPS preprin

Critical phenomenon of the order-disorder transition in incompressible active fluids

We study incompressible systems of motile particles with alignment interactions. Unlike their compressible counterparts, in which the order-disorder (i.e., moving to static) transition, tuned by either noise or number density, is discontinuous, in incompressible systems this transition can be continuous, and belongs to a new universality class. We calculate the critical exponents to $\mathcal{O}(\epsilon )$ in an $\epsilon =4-d$ expansion, and derive two exact scaling relations. This is the first analytic treatment of a phase transition in a new universality class in an active system

Upper bound limit analysis of slope stability using rigid finite elements and nonlinear programming

In this paper, the development and application of a new upper bound limit method for two- and three-dimensional (2D and 3D) slope stability problems is presented. Rigid finite elements are used to construct a kinematically admissible velocity field. Kinematically admissible velocity discontinuities are permitted to occur at all inter-element boundaries. The proposed method formulates the slope stability problem as an optimization problem based on the upper bound theorem. The objective function for determination of the minimum value of the factor of safety has a number of unknowns that are subject to a set of linear and nonlinear equality constraints as well as linear inequality constraints. The objective function and constrain equations are derived from an energy-work balance equation, the Mohr-Coulomb failure (yield) criterion, an associated flow rule, and a number of boundary conditions. The objective function with constraints leads to a standard nonlinear programming problem, which can be solved by a sequential quadratic algorithm. A computer program has been developed for finding the factor of safety of a slope, which makes the present method simple to implement. Four typical 2D and 3D slope stability problems are selected from the literature and are analysed using the present method. The results of the present limit analysis are compared with those produced by other approaches reported in the literature.published_or_final_versio

Rule of law and the international diffusion of E-commerce

A conceptual model of various factors that could explain the differences among countries in the adoption of e-commerce is presented. Firms' technology adoption decisions and output growth depend upon the efficiency of the capital markets, which diversify the risks of adopting new technologies and thus encourage early adoption of e-commerce. Countries with an active direct marketing industry experience higher levels of e-commerce activities because companies do not need to educate customers about the nature of the remote purchases. The development of e-commerce may be slow in countries without strong and effectively enforced commercial laws, despite having the necessary conditions to accelerate e-commerce

The determinants of health related quality of life of patients on maintenance haemodialysis at Kenyatta National Hospital, Kenya

Background: Health related quality of life (HRQOL) is increasingly being recognised as a primary outcome measure in the treatment of end stage renal disease. In addition to being an important surrogate marker of quality of care in patients on maintenance haemodialysis, HRQOL measures have being shown to be robust predictors of mortality and morbidity.Objective: To determine the health related quality of life and its determinants in patients on maintenance haemodialysis at the Kenyatta National Hospital.Design: A cross-sectional descriptive study.Setting: Renal unit, Kenyatta National HospitalSubjects: Adult patients with end stage renal disease on maintenance haemodialysis.Results: The mean physical composite summary and mental composite summary scores were 39.09±9.49 and 41.87±10.56 respectively. The burden of kidney disease sub-scale, symptom and problems sub-scale and effect of kidney disease on daily life sub-scale scores were 16.15±21.83, 73.46±18.06 and 67.63±23.45 respectively. No significant correlations were found between the health-related quality of life scores, socio-demographic and clinical factors assessed.Conclusion: The health-related quality of life of patients on maintenance haemodialysis is reduced. The physical quality of life is more affected than the mental quality of life. No independent determinants of health-related quality of life were identified

Herpesvirus Infections of the Central Nervous System

There are over 200 herpesvirus species, of which 10 affect humans. Each of these 10 herpesviruses has a unique clinical syndrome, but common to all is their ability to cause infection and pathology in the central nervous system. In this article, we discuss the epidemiology, clinical presentation, diagnostic modalities, treatment, sequelae, and availability of vaccination of each of the following herpesviruses: herpes simplex virus 1 and 2, varicella zoster virus, human cytomegalovirus, human herpesvirus 6A, 6B, and 7, Epstein-Barr virus, human herpesvirus 8, and simian herpesvirus B

Potentiality in Biology

We take the potentialities that are studied in the biological sciences (e.g., totipotency) to be an important subtype of biological dispositions. The goal of this paper is twofold: first, we want to provide a detailed understanding of what biological dispositions are. We claim that two features are essential for dispositions in biology: the importance of the manifestation process and the diversity of conditions that need to be satisfied for the disposition to be manifest. Second, we demonstrate that the concept of a disposition (or potentiality) is a very useful tool for the analysis of the explanatory practice in the biological sciences. On the one hand it allows an in-depth analysis of the nature and diversity of the conditions under which biological systems display specific behaviors. On the other hand the concept of a disposition may serve a unificatory role in the philosophy of the natural sciences since it captures not only the explanatory practice of biology, but of all natural sciences. Towards the end we will briefly come back to the notion of a potentiality in biology

Test Characteristics of Urinary Lipoarabinomannan and Predictors of Mortality among Hospitalized HIV-Infected Tuberculosis Suspects in Tanzania.

Tuberculosis is the most common cause of death among patients with HIV infection living in tuberculosis endemic countries, but many cases are not diagnosed pre-mortem. We assessed the test characteristics of urinary lipoarabinomannan (LAM) and predictors of mortality among HIV-associated tuberculosis suspects in Tanzania. We prospectively enrolled hospitalized HIV-infected patients in Dar es Salaam, with ≥2 weeks of cough or fever, or weight loss. Subjects gave 2 mLs of urine to test for LAM using a commercially available ELISA, ≥2 sputum specimens for concentrated AFB smear and solid media culture, and 40 mLs of blood for culture. Among 212 evaluable subjects, 143 (68%) were female; mean age was 36 years; and the median CD4 count 86 cells/mm(3). 69 subjects (33%) had culture confirmation of tuberculosis and 65 (31%) were LAM positive. For 69 cases of sputum or blood culture-confirmed tuberculosis, LAM sensitivity was 65% and specificity 86% compared to 36% and 98% for sputum smear. LAM test characteristics were not different in patients with bacteremia but showed higher sensitivity and lower specificity with decreasing CD4 cell count. Two month mortality was 64 (53%) of 121 with outcomes available. In multivariate analysis there was significant association of mortality with absence of anti-retroviral therapy (p = 0.004) and a trend toward association with a positive urine LAM (p = 0.16). Among culture-negative patients mortality was 9 (75%) of 12 in LAM positive patients and 27 (38%) of 71 in LAM negative patients (p = 0.02). Urine LAM is more sensitive than sputum smear and has utility for the rapid diagnosis of culture-confirmed tuberculosis in this high-risk population. Mortality data raise the possibility that urine LAM may also be a marker for culture-negative tuberculosis

Quantification of optical pulsed-plane-wave-shaping by chiral sculptured thin films

The durations and average speeds of ultrashort optical pulses transmitted through chiral sculptured thin films (STFs) were calculated using a finite-difference time-domain algorithm. Chiral STFs are a class of nanoengineered materials whose microstructure comprises parallel helicoidal nanowires grown normal to a substrate. The nanowires are $\sim$10-300 nm in diameter and $\sim1-10 \mu$m in length. Durations of transmitted pulses tend to increase with decreasing (free-space) wavelength of the carrier plane wave, while average speeds tend to increase with increasing wavelength. An increase in nonlinearity, as manifested by an intensity-dependent refractive index in the frequency domain, tends to increase durations of transmitted pulses and decrease average speeds. The circular Bragg phenomenon exhibited by a chiral STFs manifests itself in the frequency domain as high reflectivity for normally incident carrier plane waves whose circular polarization state is matched to the structural handedness of the film and whose wavelength falls in a range known as the Bragg regime; films of the opposite structural handedness reflect such plane waves little. This effect tends to distort the shapes of transmitted pulses with respect to the incident pulses, and such shaping can cause sharp changes in some measures of average speed with respect to carrier wavelength. A local maximum in the variation of one measure of the pulse duration with respect to wavelength is noted and attributed to the circular Bragg phenomenon. Several of these effects are explained via frequency-domain arguments. The presented results serve as a foundation for future theoretical and experimental studies of optical pulse propagation through causal, nonlinear, nonhomogeneous, and anisotropic materials.Comment: To appear in Journal of Modern Optic