Improved electrode gives high-quality biological recordings

To obtain high quality waveforms from a subject engaged in physical activity, an improved electrode assembly has been devised. This consists of a cup containing an electrically conductive paste and a silver electrode. The paste maintains contact between the skin and the plate

Electrode for biological recording

Electrochemically reversible silver-silver chloride electrode for detecting bioelectric potential differences generated by human muscles and organ

Policy-induced Internal Migration: An Empirical Investigation of the Canadian Case

We investigate the influence of public policy on interprovincial migration in Canada using new aggregated migration data for 1974-1996, the longest period studied so far. We consider the consequences of regional variation in a variety of policies, and also investigate the effects of certain extraordinary events in Quebec and in the Atlantic provinces. The results indicate that while the changing bias in the unemployment insurance system may have induced some people to move to the relatively high unemployment Atlantic region, the resulting flows are likely too small to have altered regional unemployment rates. In contrast, political events in Quebec in the 1970's and the closing of the cod fishery in 1992 appear to be associated with large changes in migration patterns.migration, regional disparity, public policy, unemployment insurance, conditional logit, taxation data

What do we Know about the Relationship between Regionalized Aspects of the Unemployment Insurance System and Internal Migration in Canada?

The purpose of this paper is to critically review the past four decades of empirical research on the relationship between internal migration and regional variation in the generosity of Canada’s unemployment insurance system. It has long been argued that because the Canadian insurance system is more generous towards people who live in relatively disadvantaged regions, it retards the out-migration that is part of the market process, thereby slowing economic development and contributing to the persistence of regional inequality in earned incomes. The survey shows, however, that there is no evidence in the empirical literature that regional variation in the generosity of the insurance system has altered internal migration patterns in Canada in a substantial manner.regional variation in unemployment insurance generosity, internal migration, interprovincial migration, earned income, comprehensive income differentials, index of insurance generosity, labour market attachment, conditional logit model

Assessment of quality indicators among nurse practitioners performing upper endoscopy.

Background and study aims Limited international data have shown that non-physicians can safely perform upper endoscopy, but no such study has been performed in the United States. Our aim was to assess the quality of outpatient upper endoscopies performed by nurse practitioners (NPs).Patients and methods Retrospective chart review of upper endoscopies performed by 3 NPs between 2010 and 2013 was performed. Comparisons among all NPs performing upper endoscopy and assessment of individual NP performance over time with respect to quality indicators were performed.Results Three NPs performed 333 upper endoscopies (distribution of 166, 44, and 123, respectively). Of the cases, 98.2 %s were successfully completed to the second portion of the duodenum. In most cases, photo-documentation of required anatomical landmarks was performed: GE junction (84.2 %), GE junction in retroflexed view (84.2 %), antrum (82.1 %) and duodenum (80.9 %). Photo-documentation improved with increasing experience. NPs appropriately performed biopsies for specific medical conditions: 10/11 (90.9 %) gastric ulcers were biopsied and 63/66 (95.5) of patients with iron deficiency had duodenal biopsies performed for celiac disease. A physician endoscopist was required during the procedure 22.5 % of the time. Important parameters such as documenting informed consent (100 %) and documenting a discharge plan (99.4 %) in the procedure reports were overwhelming present. There was a single adverse event during the study period.Conclusion In the first US study of NPs performing upper endoscopy, they were able to perform high-quality and safe upper endoscopies. These findings support incorporation of non-physicians alongside physicians to help meet the growing demand for endoscopic services across the United States

Can aggregate quarry silt lagoons provide resources for wading birds?

Wading birds have declined across Europe as the intensification of lowland agriculture has resulted in the loss and degradation of wetland areas. Lowland aggregate extraction sites that incorporate areas of fine, waste sediments deposited in silt lagoons have the potential to be restored for wader conservation. We set out to determine the potential value of silt lagoons to wading birds by comparing the water quality, sediment profiles, aquatic invertebrate abundance and diversity (prey availability) and wader site use at five sites representing various stages of active aggregate extraction and restoration for conservation purposes. Wader counts were conducted monthly over a twelve month period using replicated scan samples, and the invertebrate communities studied during the breeding and autumn migration season (June–September). Water quality variables were similar between sites, but sediments from active quarries were dominated by moderately sorted fine sands in comparison to the coarser sediment profiles of restored areas. June and September there was no significant difference in invertebrate diversity between sites, however richness was significantly lower on quarry sites and total abundance a factor of ten higher at restored sites than on silt lagoons, with the dominant taxa similar across all sites. Waders used all sites; albeit at lower abundance and richness on silt lagoons and two species were recorded breeding on active silting sites. We conclude that the fine, uniform sediments of modern silt lagoons limited invertebrate diversity and abundance, diminishing the value of silt lagoons to waders. Simple low-cost intervention measures increasing substrate heterogeneity and creating temporary ponds could increase invertebrate richness and abundance, and enhance the conservation potential of these sites

Asymptotic Exit Location Distributions in the Stochastic Exit Problem

Consider a two-dimensional continuous-time dynamical system, with an attracting fixed point $S$. If the deterministic dynamics are perturbed by white noise (random perturbations) of strength $\epsilon$, the system state will eventually leave the domain of attraction $\Omega$ of $S$. We analyse the case when, as $\epsilon\to0$, the exit location on the boundary $\partial\Omega$ is increasingly concentrated near a saddle point $H$ of the deterministic dynamics. We show that the asymptotic form of the exit location distribution on $\partial\Omega$ is generically non-Gaussian and asymmetric, and classify the possible limiting distributions. A key role is played by a parameter $\mu$, equal to the ratio $|\lambda_s(H)|/\lambda_u(H)$ of the stable and unstable eigenvalues of the linearized deterministic flow at $H$. If $\mu<1$ then the exit location distribution is generically asymptotic as $\epsilon\to0$ to a Weibull distribution with shape parameter $2/\mu$, on the $O(\epsilon^{\mu/2})$ length scale near $H$. If $\mu>1$ it is generically asymptotic to a distribution on the $O(\epsilon^{1/2})$ length scale, whose moments we compute. The asymmetry of the asymptotic exit location distribution is attributable to the generic presence of a `classically forbidden' region: a wedge-shaped subset of $\Omega$ with $H$ as vertex, which is reached from $S$, in the $\epsilon\to0$ limit, only via `bent' (non-smooth) fluctuational paths that first pass through the vicinity of $H$. We deduce from the presence of this forbidden region that the classical Eyring formula for the small-$\epsilon$ exponential asymptotics of the mean first exit time is generically inapplicable.Comment: This is a 72-page Postscript file, about 600K in length. Hardcopy requests to [email protected] or [email protected]

Reframing Mathematical Futures II Project: Development of a draft learning progression for algebraic reasoning

Curriculum documents make a clear distinction between algebraic skills and algebraic reasoning, where the development of the former is far more readily articulated than the latter. While there are many studies of algebraic reasoning, these are usually topic specific and/or highly contextual. What are the big ideas of algebraic reasoning and is it possible to map their learning trajectory? This paper reports on the preliminary phase of a large national study in Australia which is designed to move beyond the hypothetical and to provide an evidence-based foundation for a learning progression. Using rich assessment tasks designed for middle years students of mathematics, this paper reports on the method of analysis used and some preliminary findings

Developing learning progressions to support mathematical reasoning in the middle years - algebraic reasoning

As part of the Reframing Mathematical Futures II Project on Mathematical Reasoning, algebraic reasoning was identified as one of the three areas to be investigated. This involved developing a hypothetical learning progression for algebra to inform the design of assessment tasks to test the progression. The assessment forms were then sent to trial schools and the data was analysed using Rasch analysis. This paper reports on the analysis of preliminary data received and outlines some implications for teaching

Practical trapped-ion protocols for universal qudit-based quantum computing

The notion of universal quantum computation can be generalized to multi-level qudits, which offer advantages in resource usage and algorithmic efficiencies. Trapped ions, which are pristine and well-controlled quantum systems, offer an ideal platform to develop qudit-based quantum information processing. Previous work has not fully explored the practicality of implementing trapped-ion qudits accounting for known experimental error sources. Here, we describe a universal set of protocols for state preparation, single-qudit gates, a new generalization of the M\o{}lmer-S\o{}rensen gate for two-qudit gates, and a measurement scheme which utilizes shelving to a meta-stable state. We numerically simulate known sources of error from previous trapped ion experiments, and show that there are no fundamental limitations to achieving fidelities above $99\%$ for three-level qudits encoded in $^{137}\mathrm{Ba}^+$ ions. Our methods are extensible to higher-dimensional qudits, and our measurement and single-qudit gate protocols can achieve $99\%$ fidelities for five-level qudits. We identify avenues to further decrease errors in future work. Our results suggest that three-level trapped ion qudits will be a useful technology for quantum information processing