A minimum hypothesis explanation for an IMF with a lognormal body and power law tail

We present a minimum hypothesis model for an IMF that resembles a lognormal distribution at low masses but has a distinct power-law tail. Even if the central limit theorem ensures a lognormal distribution of condensation masses at birth, a power-law tail in the distribution arises due to accretion from the ambient cloud, coupled with a non-uniform (exponential) distribution of accretion times.Comment: 2 pages, 1 figure, to appear in IMF@50, eds. E. Corbelli, F. Palla, and H. Zinnecker, Kluwer, Astrophysics and Space Science Librar

Adjudication of Federal Causes of Action in State Court

The first section of this article considers the power of state courts to hear federal cases. Since it is now well established that state courts have the constitutional power to adjudicate federal causes of action if Congress so desires, the significant questions concern the method by which the judiciary is to decipher congressional intent. Although the courts have no difficulty where Congress has explicitly addressed the issue of state court jurisdiction, problems do arise in situations where Congress has remained silent on the question. The first section critically examines the traditional criteria employed by the courts for determining congressional intent in the face of congressional silence and then suggests a substantial alteration in the judiciary\u27s approach to the matter. The second section of the article considers the obligation of state courts to hear federal cases. After first evaluating constitutional questions surrounding such an obligation, this section wilI also examine difficult questions involving congressional intent-specifically, the circumstances under which Congress\u27 silence is intended to permit state courts to avoid hearing federal cases

Periodic boundary conditions for the simulation of 3D domain patterns in tetragonal ferroelectric material

Periodic domain patterns in tetragonal ferroelectrics are explored using a phase field model calibrated for barium titanate. In this context, we discuss the standard periodic boundary condition and introduce the concept of reverse periodic boundary conditions. Both concepts allow the assembly of cubic cells in accordance with mechanical and electrical conditions. However, application of the reverse periodic boundary condition is due to an increased size of the RVE and enforces more complex structures compared to the standard condition. This may be of particular interest for other multiphysics simulations. Additionally, we formulate mechanical side conditions with minimal spherical (hydrostatic) stress, or conditions with controlled average strain. It is found that in sufficiently small periodic cells, only a uniform single domain, or the simplest stripe domains constitute equilibrium states. However, once the periodic cells are of order 20 domain wall widths in size, more complex, 3-dimensional patterns emerge. Some of these patterns are known from prior studies, but we also identify other domain patterns with long, ribbon-like domains threaded through them and some vortex-like structures. Keywords: Periodic boundary conditions; RVE simulation; Tetragonal ferroelectrics; Polarization patterns; Polarization vortex; Multiphysics simulation

Angiotensin blockade for diabetes: Monitor microalbuminuria?

No studies address whether continued screening for microalbuminuria once a patient is taking an angiotensin-converting enzyme (ACE) inhibitor or angiotensin-2 receptor blocker (ARB) improves outcomes. Indirect evidence and expert opinion suggest that it may be beneficial to continue microalbuminuria surveillance to assess response to therapy and monitor disease progression (strength of recommendation: C, based on expert opinion)

Which tests are the most useful for diagnosing PID?

No single test has adequate sensitivity and specificity to reliably identify pelvic inflammatory disease (PID) and thus help to spare women serious sequelae, including infertility (strength of recommendation [SOR]: B, based on systematic reviews of cohort studies and individual cohort studies)

A Significant Population of Candidate New Members of the ρ Ophiuchi Cluster

We present a general method for identifying the pre-main-sequence population of any star-forming region, unbiased with respect to the presence or absence of disks, in contrast to samples selected primarily via their mid-infrared emission from Spitzer surveys. We have applied this technique to a new, deep, wide-field, near-infrared imaging survey of the ρ Ophiuchi cloud core to search for candidate low-mass members. In conjunction with published Spitzer IRAC photometry and least-squares fits of model spectra (COND, DUSTY, NextGen, and blackbody) to the observed spectral energy distributions, we have identified 948 candidate cloud members within our 90% completeness limits of J = 20.0, H = 20.0, and Ks = 18.50. This population represents a factor of ~3 increase in the number of known young stellar objects in the ρ Ophiuchi cloud. A large fraction of the candidate cluster members (81% ± 3%) exhibit infrared excess emission consistent with the presence of disks, thus strengthening the possibility of their being bona fide cloud members. Spectroscopic follow-up will confirm the nature of individual objects, better constrain their parameters, and allow an initial mass function to be derived

Unproceedings of the Fourth .Astronomy Conference (.Astronomy 4), Heidelberg, Germany, July 9-11 2012

The goal of the .Astronomy conference series is to bring together astronomers, educators, developers and others interested in using the Internet as a medium for astronomy. Attendance at the event is limited to approximately 50 participants, and days are split into mornings of scheduled talks, followed by 'unconference' afternoons, where sessions are defined by participants during the course of the event. Participants in unconference sessions are discouraged from formal presentations, with discussion, workshop-style formats or informal practical tutorials encouraged. The conference also designates one day as a 'hack day', in which attendees collaborate in groups on day-long projects for presentation the following morning. These hacks are often a way of concentrating effort, learning new skills, and exploring ideas in a practical fashion. The emphasis on informal, focused interaction makes recording proceedings more difficult than for a normal meeting. While the first .Astronomy conference is preserved formally in a book, more recent iterations are not documented. We therefore, in the spirit of .Astronomy, report 'unproceedings' from .Astronomy 4, which was held in Heidelberg in July 2012.Comment: 11 pages, 1 figure, .Astronomy 4, #dotastr

The Core of the Participatory Budgeting Problem

In participatory budgeting, communities collectively decide on the allocation of public tax dollars for local public projects. In this work, we consider the question of fairly aggregating the preferences of community members to determine an allocation of funds to projects. This problem is different from standard fair resource allocation because of public goods: The allocated goods benefit all users simultaneously. Fairness is crucial in participatory decision making, since generating equitable outcomes is an important goal of these processes. We argue that the classic game theoretic notion of core captures fairness in the setting. To compute the core, we first develop a novel characterization of a public goods market equilibrium called the Lindahl equilibrium, which is always a core solution. We then provide the first (to our knowledge) polynomial time algorithm for computing such an equilibrium for a broad set of utility functions; our algorithm also generalizes (in a non-trivial way) the well-known concept of proportional fairness. We use our theoretical insights to perform experiments on real participatory budgeting voting data. We empirically show that the core can be efficiently computed for utility functions that naturally model our practical setting, and examine the relation of the core with the familiar welfare objective. Finally, we address concerns of incentives and mechanism design by developing a randomized approximately dominant-strategy truthful mechanism building on the exponential mechanism from differential privacy