The terms of trade for commodities since the mid-19th century

This paper shows that there was an improvement in the barter terms of trade for non-fuel commodities vs. manufactures in the late 19th and early 20th centuries, followed by significant deterioration over the rest of the 20th century. However, the decline over most of the 20th century was neither continuous nor was it distributed evenly among different commodity groups. The far-reaching changes that the world economy underwent around 1920 and again around 1979 led to a stepwise deterioration which, over the long term, was reflected in roughly a halving of real commodity prices. Tropical agriculture fared the worst, whereas minerals had the best performance, with non-tropical agriculture in an intermediate situation. The increase experienced in the first decade of the 21st century may be the beginning of a long-term upward trend, but it is too soon to tell.Este ensayo muestra que hubo una mejoría en los términos de intercambio de trueque de los productos básicos a fines del siglo XIX y comienzos del XX, seguido por un deterioro significativo en el resto del siglo XX. Sin embargo, el deterioro durante la mayor parte del siglo XX no fue continuo ni se distribuyó en forma homogénea en diferentes grupos de productos. Los cambios de largo alcance que experimentó la economía mundial en torno a 1920 y nuevamente a 1979 se reflejaron en una caída escalonada, que a largo plazo redujo los precios reales de productos básicos aproximadamente a la mitad. La agricultura tropical experimento´ el peor desempeño y la minería el mejor, con la agricultura no tropical en una situación intermedia. El incremento de los precios que se experimento´ en la primera década del siglo XXI puede ser el inicio de una nueva fase de alza de larga duración, pero es demasiado temprano para saberlo

The Influence of Backrest Inclination on Buttock Pressure

Objective To assess the effects of backrest inclination of a wheelchair on buttock pressures in spinal cord injured (SCI) patients and normal subjects. Method The participants were 22 healthy subjects and 22 SCI patients. Buttock pressures of the participants were measured by a Tekscan® pressure sensing mat and software while they were sitting in a reclining wheelchair. Buttock pressures were recorded for 90°, 100°, 110°, 120° and 130° seat-to-back angles at the ischial tuberosity (IT)and sacrococcygeal (SC) areas. Recordings were made at each angle over four seconds at a sampling rate of 10 Hz. Results The side-to-side buttock pressure differences in the IT area for the SCI patients was signifi cantly greater than for the normal subjects. There was no signifi cant diff erence between the SCI patients and the normal subjects in the buttock pressure change pattern of the IT area. Significant increases in pressure on the SC area were found as backrest inclination angle was changed to 90o, 100o and 110° in the normal subjects, but no signifi cant diff erences were found in the SCI patients. Conclusion Most of the SCI patients have freeform posture in wheelchairs, and this leads to an uneven distribution of buttock pressure. In the SCI patients, the peak pressure in the IT area reduced as the backrest angle was increased, but peak pressure at the SC area remained relatively unchanged. To reduce buttock pressure and prevent pressure ulcers and enhance ulcer healing, it can be helpful for tetraplegic patients, to have wheelchair seat-to-back angles above 120°

Effect of multi-planar CT image reformatting on surgeon diagnostic performance for localizing thoracolumbar disc extrusions in dogs

Accurate pre-operative localization and removal of disc material are important for minimizing morbidity in dogs with thoracolumbar disc extrusions. Computed tomography (CT) is an established technique for localizing disc extrusions in dogs, however the effect of multi-planar reformatting (MPR) on surgeon diagnostic performance has not been previously described. The purpose of this study was to test the effect of MPR CT on surgeon diagnostic accuracy, certainty and agreement for localizing thoracolumbar disc extrusions in dogs. Two veterinary surgeons and one veterinary neurologist who were unaware of surgical findings independently reviewed randomized sets of two-dimensional (2D) and MPR CT images from 111 dogs with confirmed thoracolumbar disc extrusions. For each set of images, readers recorded their localizations for extruded disc material and their diagnostic certainty. For MPR images, readers also recorded views they considered most helpful. Diagnostic accuracy estimates, mean diagnostic certainty scores and inter-observer agreement were compared using surgery as the gold standard. Frequencies were compared for MPR views rated most helpful. Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader. Mean diagnostic certainty scores were significantly greater for MPR images in two readers. The change in agreement between 2D and MPR images differed from zero for all analyses (site, side, number affected) among all three readers. Multi-planar views rated most helpful with the highest frequency were oblique transverse and curved dorsal planar MPR views. Findings from this study indicate that multi-planar CT can improve surgeon diagnostic performance for localizing canine thoracolumbar disc extrusions

Sick leave among home-care personnel: a longitudinal study of risk factors

BACKGROUND: Sick leave due to neck, shoulder and back disorders (NSBD) is higher among health-care workers, especially nursing aides/assistant nurses, compared with employees in other occupations. More information is needed about predictors of sick leave among health care workers. The aim of the study was to assess whether self-reported factors related to health, work and leisure time could predict: 1) future certified sick leave due to any cause, in nursing aides/assistant nurses (Study group I) and 2) future self-reported sick leave due to NSBD in nursing aides/assistant nurses (Study group II). METHODS: Study group I, comprised 443 female nursing aides/assistant nurses, not on sick leave at baseline when a questionnaire was completed. Data on certified sick leave were collected after 18 months. Study group II comprised 274 of the women, who at baseline reported no sick leave during the preceding year due to NSBD and who participated at the 18 month follow-up. Data on sick leave due to NSBD were collected from the questionnaire at 18 months. The associations between future sick leave and factors related to health, work and leisure time were tested by logistic regression analyses. RESULTS: Health-related factors such as previous low back disorders (OR: 1.89; 95% CI 1.20–2.97) and previous sick leave (OR 6.40; 95%CI 3.97–10.31), were associated with a higher risk of future sick leave due to any cause. Factors related to health, work and leisure time, i.e. previous low back disorders (OR: 4.45; 95% CI 1.27–15.77) previous sick leave, not due to NSBD (OR 3.30; 95%CI 1.33–8.17), high strain work (OR 2.34; 95%CI 1.05–5.23) and high perceived physical exertion in domestic work (OR 2.56; 95%CI 1.12–5.86) were associated with a higher risk of future sick leave due to NSBD. In the final analyses, previous low back disorders and previous sick leave remained significant in both study groups. CONCLUSION: The results suggest a focus on previous low back disorders and previous sick leave for the design of early prevention programmes aiming at reducing future sick leave due to any cause, as well as due to NSBD, among nursing aides/assistant nurses. A multifactorial approach may be of importance in the early prevention of sick leave due to NSBD

Effectiveness of a Multidisciplinary Occupational Training Program for Chronic Low Back Pain

Objective: To evaluate the effectiveness of a 12-wk multidisciplinary occupational training program for patients with chronic low back pain and to identify prognostic factors for treatment success. Design: A total of 51 participants were evaluated at baseline, at discharge, and at 1 yr after conclusion of the program. The evaluation included a physical examination and assessment of functional disability, psychological factors, and coping styles. The main target of the program is full work resumption. The central outcome measures therefore are three variables on return to work. Results: Analysis of variance for repeated measures revealed significant beneficial changes during the program for all measures except for several coping-style variables. The acquired level of maximum oxygen uptake, trunk flexibility, functional disability, and catastrophizing were maintained at 1-yr follow-up. At 1-yr follow-up, >60% of the participants had fully returned to work, which is an increase of >40% compared with baseline. Regression analyses showed that sex, age, the baseline values of reinterpretation of pain sensations, and functional disability and changes in trunk flexibility scores during the program are important prognostic factors for complete return to work. Conclusions: Based on the current findings, the program seems to be efficacious in the short term. Future attention must be directed toward maintaining these results, although work resumption rates improved considerably 1 yr after conclusion of the program

Predictors of stable return-to-work in non-acute, non-specific spinal pain: low total prior sick-listing, high self prediction and young age. A two-year prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Non-specific spinal pain (NSP), comprising back and/or neck pain, is one of the leading disorders in long-term sick-listing. During 2000-2004, 125 Swedish primary-care patients with non-acute NSP, full-time sick-listed 6 weeks-2 years, were included in a randomized controlled trial to compare a cognitive-behavioural programme with traditional primary care. This prospective cohort study is a re-assessment of the data from the randomized trial with the 2 treatment groups considered as a single cohort. The aim was to investigate which baseline variables predict a stable return-to-work during a 2-year period after baseline: objective variables from function tests, socioeconomic, subjective and/or treatment variables. Stable return-to-work was a return-to-work lasting for at least 1 month from the start of follow-up.</p> <p>Methods</p> <p><it>Stable return-to-work </it>was the outcome variable, the above-mentioned factors were the predictive variables in multiple-logistic regression models, one per follow-up at 6, 12, 18 and 24 months after baseline. The factors from univariate analyzes with a <it>p</it>-value of at most .10 were included. The non-significant variables were excluded stepwise to yield models comprising only significant factors (<it>p </it>< .05). As the comparatively few cases made it risky to associate certain predictors with certain time-points, we finally considered the predictors which were represented in at least 3 follow-ups. They are presented with odds ratios (OR) and 95% confidence intervals.</p> <p>Results</p> <p>Three variables qualified, all of them represented in 3 follow-ups: <it>Low total prior sick-listing </it>(including all diagnoses) was the strongest predictor in 2 follow-ups, 18 and 24 months, OR 4.8 [1.9-12.3] and 3.8 [1.6-8.7] respectively, <it>High self prediction </it>(the patients' own belief in return-to-work) was the strongest at 12 months, OR 5.2 [1.5-17.5] and <it>Young age </it>(max 44 years) the second strongest at 18 months, OR 3.5 [1.3-9.1].</p> <p>Conclusions</p> <p>In primary-care patients with non-acute NSP, the strong predictors of stable return-to-work were 2 socioeconomic variables, <it>Low total prior sick-listing </it>and <it>Young age</it>, and 1 subjective variable, <it>High self-prediction</it>. Objective variables from function tests and treatment variables were non-predictors. Except for <it>Young age</it>, the predictors have previously been insufficiently studied, and so our study should widen knowledge within clinical practice.</p> <p>Trial registration</p> <p>Trial registration number for the original trial NCT00488735.</p

Two Types of Planning in Neighborhoods

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68338/2/10.1177_0739456X8400300209.pd

Benefiting Business: The Fragmented Federal Response to American Deindustrialization

The widespread manufacturing job loss that resulted from late 20th century American deindustrialization has had particularly devastating consequences for former U.S. industrial workers and communities. While other countries responded with a range of policies to assist economically distressed communities and workers, the U.S. response was far less robust. This dissertation asks, why was the U.S. federal policy response so limited in addressing deindustrialization, what characterized the limited form certain policies took, and what were the consequences of these actions? I argue that the response is best understood as a limited and fragmented policy response that addressed piecemeal consequences of industrial decline. Using comparative historical analysis, I argue that the demise of the more comprehensive National Industrial Recovery Act in 1935 left a “negative policy legacy” that prompted policymakers between 1961 and 1988 to experiment with policies that focused on discrete consequences of deindustrialization. The expiration of the Area Redevelopment Act (1961) in 1964 additionally foreclosed future opportunities for more holistic measures. In the wake of these failed programs, distinct policies such as the Worker Adjustment and Retraining Notification Act (WARN), Trade Adjustment Assistance (TAA), and enterprise zone legislation, emerged and subsequently developed separately from one another. To conduct an analysis of how these policies developed over time, I use congressional testimony and presidential archives. I theorize that each policy thread developed through processes of gradual institutional change that reflected business’s influence to varying degrees. I argue first that notification policies like WARN were significantly delayed and limited as a result of business mobilization through American national institutions. Secondly, I argue that while TAA originally served as a compensatory policy for displaced workers, its institutional tie to trade policy and presidential “fast-track” authority allowed for shifting institutional authority and policy layering that exacerbated jobs losses and the need for compensatory assistance. Finally, I argue that redevelopment policy – recast as enterprise zone legislation – developed through policy conversion, allowing for the proliferation of business tax benefits as opposed to targeted community development. Though originally intended to help workers and communities, these discrete policies institutionally evolved to benefit business more than their intended targets