Estimating Indigenous Australian employment in the private sector

Impetus for attempting to delineate 'real' private sector employment derived from concerns regarding the shortcomings of data on this issue identified by the review of the Aboriginal Employment Development Policy (AEDP). In seeking to address these concerns, private sector employment is defined here as consisting of activities that do not depend primarily on government funding for their existence. Using census data, two methods are employed to estimate change in the number of Indigenous people employed in this redefined private sector in 1986 and 1991. The first, a residual approach, uses a mix of census statistics and administrative data sets. The second is based on judicious scrutiny of detailed industry tables from the census cross-classified by private sector employment. Revised statistical limits of Indigenous employment in the private sector are produced with intercensal growth substantially deflated. This paper considers the determinants of employment income for Indigenous Australians compared with non-Indigenous Australians. Ordinary Least Square (OLS) regression techniques are applied to 1991 Census data to consider the question: does the lower income of these Indigenous people reflect differences in their factor endowments (like education) rewarded in the labour market, or are they rewarded differently for the same set of endowments than are non-Indigenous Australians. The results show that the main source of lower incomes for Indigenous Australians was their smaller endowment of human capital characteristics. The paper concludes with a discussion of the policy implications of these results

Strengthening the Ecosystem of Capacity-Building Service Providers: A Case for Why It Matters

Nonprofits frequently find it challenging to find providers best suited to meet their capacity-building needs. This can be especially true when looking for providers to strengthen racial equity capacity. Many nonprofits lack the time, networks, or expertise to identify what’s available and vet various options for cost, relevance, and quality. When the Kresge Foundation designed a program to build leadership capacity through a racial equity lens among its grantees, it wanted to strengthen the marketplace of offerings as well. Kresge’s Fostering Urban Equitable Leadership program sought to build leadership capacity and add value for grantees by offering a curated menu of services from a range of providers. The program also has an explicit goal of helping strengthen participating service providers’ own capacity, which it does by providing grant support and opportunities for peer learning and collaboration. This article explores why more foundations should invest in the capacity of nonprofit capacity builders. It draws on reflections and lessons learned from the program and perspectives from service providers. Foundations have a unique role to play in strengthening the ecosystem of capacitybuilding service providers. The article offers recommendations for how to do so in ways that have the potential to stimulate new thinking about collaborative opportunities, reduce overlap in services, and expand the quality of offerings throughout the field

Analytic moduli spaces of simple sheaves on families of integral curves

We prove the existence of fine moduli spaces of simple coherent sheaves on families of irreducible curves. Our proof is based on the existence of a universal upper bound of the Castelnuovo-Mumford regularity of such sheaves, which we provide.Comment: typos corrected, final version, to appear in Mathematischen Nachrichte

Solvable Theory of a Strange Metal at the Breakdown of a Heavy Fermi Liquid

We introduce an effective theory for quantum critical points in heavy fermion systems involving a change in carrier density without symmetry breaking. The new theory captures a strong coupling metallic fixed point, leading to robust marginal Fermi liquid transport phenomenology, within a controlled large $N$ limit. This is contrasted with the conventional so-called "slave boson" theory of the Kondo breakdown, where the large $N$ limit describes a weak coupling fixed point and non-trivial transport behavior may only be obtained through uncontrolled $1/N$ corrections. We compute the weak field Hall coefficient within the effective model as the system is tuned across the transition. We find that between the two plateaus, reflecting the different carrier densities in the two Fermi liquid phases, the Hall coefficient can develop a peak in the critical crossover regime, consistent with recent experimental findings. In the regime of strong damping of emergent bosonic excitations, the critical point also displays a near-universal "Planckian" transport lifetime, $\tau_{\mathrm{tr}}\sim\hbar/(k_BT)$.Comment: 20 pages, 10 figures, Supplement include

Terminal digit preference biases polyp size measurements at endoscopy, computed tomographic colonography and histopathology

BACKGROUND AND STUDY AIMS: Terminal digit preference bias for "pleasing" numbers has been described in many areas of medicine. The aim of this study was to determine whether endoscopists, radiologists, and pathologists exhibit such bias when measuring colorectal polyp diameters. METHODS: Colorectal polyp diameters measured at endoscopy, computed tomographic colonography (CTC), and histopathology were collated from a colorectal cancer screening program and two parallel multicenter randomized trials. Smoothing models were fitted to the data to estimate the expected number of polyps at 1-mm increments, assuming no systematic measurement bias. The difference between the expected and observed numbers of polyps was calculated for each terminal digit using statistical modeling. The impact of measurement bias on per-patient detection rates of polyps ≥ 10 mm was estimated for each modality. RESULTS: A total of 92 124 individual polyps were measured by endoscopy (91 670 screening and 454 from trials), 2385 polyps were measured by CTC (1664 screening, 721 trials), and 79 272 were measured by histopathology (78 783 screening, 489 trials). Clustering of polyp diameter measurements at 5-mm intervals was demonstrated for all modalities, both in the screening program and the trials. The statistical models estimated that per-patient detection rates of polyps ≥ 10 mm were over-inflated by 2.4 % for endoscopy, 3.1 % for CTC, and 3.3 % for histopathology in the screening program, with similar trends in the randomized trials. CONCLUSION: Endoscopists, radiologists, and pathologists all exhibit terminal digit preference when measuring colorectal polyps. This will bias trial data, referral rates for further testing, adenoma surveillance regimens, and comparisons between tests

Categorized confounders and type-I error

Abstract: The loss of signal associated with categorizing a continuous variable is well known, and previous studies have demonstrated that this can lead to an inflation of Type-I error when the categorized variable is a confounder in a regression analysis estimating the effect of an exposure on an outcome. However, it is not known how the Type-I error may vary under different circumstances, including logistic versus linear regression, different distributions of the confounder, and different categorization methods. Here we analytically quantified the effect of categorization, and then performed a series of 9600 Monte Carlo simulations to estimate the Type-I error inflation associated with categorization of a confounder under different regression scenarios. We show that Type-I error is unacceptably high (>10% in most scenarios, and often 100%). The only exception was when the variable categorized was a continuous mixture proxy for a genuinely dichotomous latent variable, where both the continuous proxy and the categorized variable are error-ridden proxies for the dichotomous latent variable. As expected, error inflation was also higher with larger sample size, fewer categories, and stronger associations between the confounder and the exposure or outcome. We provide online tools that can help researchers estimate the potential error inflation and understand how serious a problem this is

The effects of laryngeal mask airway passage simulation training on the acquisition of undergraduate clinical skills: a randomised controlled trial

Background\ud Effective use of the laryngeal mask airway (LMA) requires learning proper insertion technique in normal patients undergoing routine surgical procedures. However, there is a move towards simulation training for learning practical clinical skills, such as LMA placement. The evidence linking different amounts of mannequin simulation training to the undergraduate clinical skill of LMA placement in real patients is limited. The purpose of this study was to compare the effectiveness in vivo of two LMA placement simulation courses of different durations. \ud \ud Methods\ud Medical students (n = 126) enrolled in a randomised controlled trial. Seventy-eight of these students completed the trial. The control group (n = 38) received brief mannequin training while the intervention group (n = 40) received additional more intensive mannequin training as part of which they repeated LMA insertion until they were proficient. The anaesthetists supervising LMA placements in real patients rated the participants' performance on assessment forms. Participants completed a self-assessment questionnaire. \ud \ud Results\ud Additional mannequin training was not associated with improved performance (37% of intervention participants received an overall placement rating of > 3/5 on their first patient compared to 48% of the control group, $X^2$ = 0.81, p = 0.37). The agreement between the participants and their instructors in terms of LMA placement success rates was poor to fair. Participants reported that mannequins were poor at mimicking reality. \ud \ud Conclusions\ud The results suggest that the value of extended mannequin simulation training in the case of LMA placement is limited. Educators considering simulation for the training of practical skills should reflect on the extent to which the in vitro simulation mimics the skill required and the degree of difficulty of the procedure. \ud \u

Cognitive consequences of perceiving social exclusion

Although a great deal is now known about how people mentally represent individuals and groups, less attention has been paid to the question of how interpersonal relationships are represented in memory. Drawing on principles of categorization, this paper reports an investigation into how we mentally represent the relationships of others. In three experiments, evidence for assimilation effects following social exclusion (and subsequent categorization) is found. Experiment 1 uses a judgment paradigm to demonstrate that social exclusion influences the perception of interpersonal closeness. Experiments 2 and 3 employ a memory confusion paradigm to establish that representations of relationship partners are assimilated following the exclusion of a third party. © 2008 Elsevier Inc. All rights reserved

Towards a framework for analysis of eye-tracking studies in the three dimensional environment: a study of visual search by experienced readers of endoluminal CT colonography.

Objective: Eye tracking in three dimensions is novel, but established descriptors derived from two-dimensional (2D) studies are not transferable. We aimed to develop metrics suitable for statistical comparison of eye-tracking data obtained from readers of three-dimensional (3D) “virtual” medical imaging, using CT colonography (CTC) as a typical example. Methods: Ten experienced radiologists were eye tracked while observing eight 3D endoluminal CTC videos. Sub-sequently, we developed metrics that described their visual search patterns based on concepts derived from 2D gaze studies. Statistical methods were developed to allow analysis of the metrics. Results: Eye tracking was possible for all readers. Visual dwell on the moving region of interest (ROI) was defined as pursuit of the moving object across multiple frames. Using this concept of pursuit, five categories of metrics were defined that allowed characterization of reader gaze behaviour. These were time to first pursuit, identi-fication and assessment time, pursuit duration, ROI size and pursuit frequency. Additional subcategories allowed us to further characterize visual search between readers in the test population. Conclusion: We propose metrics for the characterization of visual search of 3D moving medical images. These metrics can be used to compare readers’ visual search patterns and provide a reproducible framework for the analysis of gaze tracking in the 3D environment. Advances in knowledge: This article describes a novel set of metrics that can be used to describe gaze behaviour when eye tracking readers during interpretation of 3D medical images. These metrics build on those established for 2D eye tracking and are applicable to increasingly common 3D medical image displays

Effects of hippocampal damage on reward threshold and response rate during self-stimulation of the ventral tegmental area in the rat

The main purpose of this study was to explore the role of the hippocampus in motivated behavior. Rats with bilateral excitotoxic lesions of the hippocampus and controls were trained to lever press for electrical stimulation of the ventral tegmental area. Rate intensity functions were generated from an ascending and descending series of current intensities. Lesion-induced changes in sensitivity to reward were distinguished from enhancements in motor output by calculating reward thresholds and maximal response rates from the rate-intensity functions. Rats with hippocampal damage showed lower reward thresholds and higher maximal response rates than controls. These results provide further evidence of hippocampal modulation of the nucleus accumbens, suggesting that lesions of this structure enhance sensitivity to reward and increase motor output