The quality of political information

The article conceptualizes the quality of political information and shows how the concept can be used for empirical research. I distinguish three aspects of quality (intelligibility, relevance, validity) and use them to judge the constituent foundations of political information, that is component claims (statements of alleged facts) and connection claims (argumentative statements created by causally linking two component claims). The resulting conceptual map thus entails six manifestations of information quality (component claimintelligibility, connection claim intelligibility, component claimrelevance, connection claim relevance, component claim validity, and connection claim validity). I explain how the conceptual map can be used to make sense of the eclectic variety of existing research, and how it can advance new empirical research, as a guide for determining variation in information quality, as a conceptual template for the analysis of different types of political messages and their common quality deficiencies, and as a generator of new research questions and theoretical expectations

A plesiosaur containing an ichthyosaur embryo as stomach contents from the Sundance Formation of the Bighorn Basin, Wyoming

Herein we report the discovery of an ichthyosaur embryo from the Upper Member of the Sundance Formation (Oxfordian) of the Bighorn Basin, Wyoming. The specimen is the first known ichthyosaur embryo from the Upper Jurassic, and is the first Jurassic ichthyosaur embryo from North America. The embryo was discovered in close association with the abdomen of an articulated partial plesiosaur skeleton, and several lines of evidence support the interpretation of the embryo as plesiosaur stomach contents. The small size and extremely poor ossification of the embryo indicate that the animal was probably not a neonate. Although the taxonomic affinities of the fossil are unknown, the large ichthyosaurian (sensu stricto) Opthalmosaurus natans is the only known ichthyosaur from the Sundance Formation, and the embryo may belong to that taxon

High Incidence of Hemiarthroplasty for Shoulder Osteoarthritis Among Recently Graduated Orthopaedic Surgeons

BACKGROUND: Primary glenohumeral osteoarthritis is a common indication for shoulder arthroplasty. Historically, both total shoulder arthroplasty (TSA) and hemi-shoulder arthroplasty (HSA) have been used to treat primary glenohumeral osteoarthritis. The choice between procedures is a topic of debate, with HSA proponents arguing that it is less invasive, faster, less expensive, and technically less demanding, with quality of life outcomes equivalent to those of TSA. More recent evidence suggests TSA is superior in terms of pain relief, function, ROM, strength, and patient satisfaction. We therefore investigated the practice of recently graduated orthopaedic surgeons pertaining to the surgical treatment of this disease. QUESTIONS/PURPOSES: We hypothesized that (1) recently graduated, board eligible, orthopaedic surgeons with fellowship training in shoulder surgery are more likely to perform TSA than surgeons without this training; (2) younger patients are more likely to receive HSA than TSA; (3) patient sex affects the choice of surgery; (4) US geographic region affects practice patterns; and (5) complication rates for HSA and TSA are not different. METHODS: We queried the American Board of Orthopaedic Surgery's database to identify practice patterns of orthopaedic surgeons taking their board examination. We identified 771 patients with primary glenohumeral osteoarthritis treated with TSA or HSA from 2006 to 2011. The rates of TSA and HSA were compared based on the treating surgeon's fellowship training, patient age and sex, US geographic region, and reported surgical complications. RESULTS: Surgeons with fellowship training in shoulder surgery were more likely (86% versus 72%; OR 2.32; 95% CI, 1.56-3.45, p<0.001) than surgeons without this training to perform TSA rather than HSA. The mean age for patients receiving HSA was not different from that for patients receiving TSA (66 versus 68, years, p=0.057). Men were more likely to receive HSA than TSA when compared to women (RR 1.54; 95% CI, 1.19-2.00, p=0.0012). The proportions of TSA and HSA were similar regardless of US geographic region (Midwest HSA 21%, TSA 79%; Northeast HSA 25%, TSA 75%; Northwest HSA 16%, TSA 84%; South HSA 27%, TSA 73%; Southeast HSA 24%, TSA 76%; Southwest HSA 23%, TSA 77%; overall p=0.708). The overall complication rates were not different with the numbers available: 8.4% (15/179) for HSA and 8.1% (48/592) for TSA (p=0.7555). CONCLUSIONS: The findings of this study are at odds with the recommendations in the current clinical practice guidelines for the treatment of glenohumeral osteoarthritis published by the American Academy of Orthopaedic Surgeons. These guidelines favor using TSA over HSA in the treatment of shoulder arthritis. Further investigation is needed to clarify if these practice patterns are isolated to recently graduated board eligible orthopaedic surgeons or if the use of HSA continues with orthopaedic surgeons applying for recertification. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence

Odor supported place cell model and goal navigation in rodents

Experiments with rodents demonstrate that visual cues play an important role in the control of hippocampal place cells and spatial navigation. Nevertheless, rats may also rely on auditory, olfactory and somatosensory stimuli for orientation. It is also known that rats can track odors or self-generated scent marks to find a food source. Here we model odor supported place cells by using a simple feed-forward network and analyze the impact of olfactory cues on place cell formation and spatial navigation. The obtained place cells are used to solve a goal navigation task by a novel mechanism based on self-marking by odor patches combined with a Q-learning algorithm. We also analyze the impact of place cell remapping on goal directed behavior when switching between two environments. We emphasize the importance of olfactory cues in place cell formation and show that the utility of environmental and self-generated olfactory cues, together with a mixed navigation strategy, improves goal directed navigation

Introductory Life Science Mathematics and Quantitative Neuroscience Courses

We describe two sets of courses designed to enhance the mathematical, statistical, and computational training of life science undergraduates at Emory College. The first course is an introductory sequence in differential and integral calculus, modeling with differential equations, probability, and inferential statistics. The second is an upper-division course in computational neuroscience. We provide a description of each course, detailed syllabi, examples of content, and a brief discussion of the main issues encountered in developing and offering the courses

A calibration method for broad-bandwidth cavity enhanced absorption spectroscopy performed with supercontinuum radiation

An efficient calibration method has been developed for broad-bandwidth cavity enhanced absorption spectroscopy. The calibration is performed using phase shift cavity ring-down spectroscopy, which is conveniently implemented through use of an acousto-optic tunable filter (AOTF). The AOTF permits a narrowband portion of the SC spectrum to be scanned over the full high-reflectivity bandwidth of the cavity mirrors. After calibration the AOTF is switched off and broad-bandwidth CEAS can be performed with the same light source without any loss of alignment to the set-up. We demonstrate the merits of the method by probing transitions of oxygen molecules O-2 and collisional pairs of oxygen molecules (O-2)(2) in the visible spectral range

Engaging with issues of emotionality in mathematics teacher education for social justice

This article focuses on the relationship between social justice, emotionality and mathematics teaching in the context of the education of prospective teachers of mathematics. A relational approach to social justice calls for giving attention to enacting socially-just relationships in mathematics classrooms. Emotionality and social justice in teaching mathematics variously intersect, interrelate or interweave. An intervention, usng creative action methods, with a cohort of prospective teachers addressing these issues is described to illustrate the connection between emotionality and social justice in the context of mathematics teacher education. Creative action methods involve a variety of dramatic, interactive and experiential tools that can promote personal and group engagement and embodied reflection. The intervention aimed to engage the prospective teachers with some key issues for social justice in mathematics education through dialogue about the emotionality of teaching and learning mathematics. Some of the possibilities and limits of using such methods are considered

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

Modules for Prolog Revisited

Module systems are an essential feature of programming languages as they facilitate the re-use of existing code and the development of general purpose libraries. Unfortunately, there has been no consensual module system for Prolog, hence no strong development of libraries, in sharp contrast to what exists in Java for instance. One difficulty comes from the call predicate which interferes with the protection of the code, an essential task of a module system. By distinguishing the called module code protection from the calling module code protection, we review the existing syntactic module systems for Prolog. We show that no module system ensures both forms of code protection, with the noticeable exceptions of Ciao-Prolog and XSB. We then present a formal module system for logic programs with calls and closures, define its operational semantics and formally prove the code protection property. Interestingly, we also provide an equivalent logical semantics of modular logic programs without calls nor closures, which shows how they can be translated into constraint logic programs over a simple module constraint system