THE GROCERY STORES' WAGE DISTRIBUTION: A SEMI-PARAMETRIC ANALYSIS OF THE ROLE OF RETAILING AND LABOR MARKET INSTITUTIONS

How and why has the wage distribution in U.S. grocery stores changed between 1984 and 1994? Unlike other industries in the time period, the important change in the wage distribution is not rising inequality, but the real wages fell across the entire wage distribution. Changes in labor market institutions explain more than half of the change in the wage distribution in grocery stores. Specifically, the decline in the real value of the minimum wage explains little of the decline in the mean real wage but much of the change in the shape of the distribution between 1984 and 1994, and 95 percent of the decline at the lowest 10th percentile. The decline in union coverage in grocery stores and the narrowing of the union-nonunion wage gap explains much of the decline above the 25th percentile. A third institutional change, the use of part-time employees, is not associated with the changes in grocery industry wage outcomes. One might think that the major changes in operation and technologies that occurred during this time period are at least contributing factors, but we find quite the contrary. If average store size, weekly operating hours, and the use of scanning technology had remained at their 1984 levels, the real wage decline would have been even greater than that actually seen, and for the entire wage distribution. Changes in grocery retailing prevented and even greater decline in real wages. Again unlike many other industries, skill-biased technological change does not appear important for grocery industry wage outcomes. The basis of our analysis is a statistical technique which combines nonparametric kernel density estimation with a parametric re-weighting, applied to Current Population Survey data supplemented with secondary data sources on the Grocery industry.Agribusiness, Labor and Human Capital,

Work hour restrictions: impact on neurosurgical resident training at the University of Utah

Journal ArticleResident work hour restrictions imposed by the Accreditation Council for Graduate Medical Education became effective on July 1, 2003. To evaluate the effect of these regulations on resident operative experience, we reviewed and compared the surgical experience of junior and senior neurosurgical residents four years before and one year after the ACGME restrictions were implemented. Resident work hours since May 2003 and operative caseload during the study period were recorded in commercially available data systems. The mean number of hours worked per week by junior and chief residents decreased f r om 104 and 110 hours before the ACGME work hour restrictions to 81 and 84 hours afterward, respectively. During the four academic years before the work hour limitations took effect, the mean number of major cases performed each year was 802.5 for the chief residents and 849.3 for t he junior residents. Following the restrictions, little changed for t he chief residents. However, the junior residents averaged only 467 cases, a 45 percent decrease f r om t he previous years studied. The mean number of cases covered by each junior resident per month decreased by 30.5 percent after the work hour restrictions were instituted, and the mean number of cases covered per post-call junior resident in one month declined 47.8 percent, from 23 to 12. At our institution, the ACGME work hour restrictions have resulted in decreased resident work hours for all residents at t he expense of the operative experience for junior residents. The operative caseload for chief residents has not been affected

Sporadic osteochondroma of the cervical spine

Journal ArticleOsteochondroma is the most common benign tumor of bone, but axial skeleton involvement is uncommon and usually indicates a hereditary cause such as osteochondromatosis (hereditary multiple exostosis). 1 Approximately 7% of hereditary osteochondromas occur along the vertebral column, which is double the rate of vertebral column occurrences among sporadic cases.4 We present a rare pediatric case of a large sporadic osteochondroma arising from the C-3 lamina. A previously healthy 13-year-old girl with no family history of osteochondroma noticed a posterior neck mass that continued to enlarge over the following year. On examination, the mass was readily visible and nontender to palpation. The patient denied clumsiness of the hands or feet, paresthesias, or neck pain. No motor weakness, sensory disturbance, or hyperreflexia was noted. A lateral plain radiograph demonstrated a calcified mass arising dorsally from the posterior elements of the cervical spine between C-2 and C-4 (Fig. 1). Computerized tomography (CT) scans revealed that the mass was arising from the lamina of C-3 with bone remodeling of the C-2 and C-4 laminae (Fig. 2). Magnetic resonance imaging demonstrated a large multilobulated, cystic, and irregularly enhancing mass with calcified components, measuring 5.8 3 5.5 3 8.7 cm and causing mild cord compression at C3?4 (Fig. 2). The differential diagnosis for this rapidly growing spinal bone lesion included osteochondroma, osteoblastoma, osteosarcoma, and chondrosarcoma. The patient underwent a complete resection via a posterior midline cervical incision. At surgery, the tumor appeared lobulated, well-circumscribed, firm, and calcified (Fig. 3). The tumor and the C-3 lamina were removed. The results of a pathological examination were consistent with an osteochondroma. The postoperative CT scan demonstrated a gross-total resection with stable sagittal alignment

Braggoriton--Excitation in Photonic Crystal Infiltrated with Polarizable Medium

Light propagation in a photonic crystal infiltrated with polarizable molecules is considered. We demonstrate that the interplay between the spatial dispersion caused by Bragg diffraction and polaritonic frequency dispersion gives rise to novel propagating excitations, or braggoritons, with intragap frequencies. We derive the braggoriton dispersion relation and show that it is governed by two parameters, namely, the strength of light-matter interaction and detuning between the Bragg frequency and that of the infiltrated molecules. We also study defect-induced states when the photonic band gap is divided into two subgaps by the braggoritonic branches and find that each defect creates two intragap localized states inside each subgap.Comment: LaTeX, 8 pages, 5 figure

An Investigation of Longwall Gob Gas Behavior and Control Methods

The National Institute for Occupational Safety and Health (NIOSH) has initiated the use of a tracer gas in field studies to characterize geologic and mining factors influencing the migration of longwall gob gas. Three studies have been conducted using sulfur hexafluoride (SF6) at a coal mine in the Northern Appalachian Basin operating in the Pittsburgh Coalbed. Eight underground tracer gas releases and one gob gas venthole release are summarized. The results indicate that the gas flow in the bleeder network and in the interior regions of longwall panel gobs do not strongly interact and that the negative pressure provided by gob gas venthole exhausters is very significant in maintaining this behavior. The data also show that ventilation practices employed in a large multi-panel gob area are functioning in accordance with the intent of the engineering design, a fact which would be difficult to evaluate using conventional mine ventilation measurement methods

Factors Associated with Correct and Consistent Insecticide Treated Curtain Use in Iquitos, Peru.

Dengue is an arthropod-borne virus of great public health importance, and control of its mosquito vectors is currently the only available method for prevention. Previous research has suggested that insecticide treated curtains (ITCs) can lower dengue vector infestations in houses. This observational study investigated individual and household-level socio-demographic factors associated with correct and consistent use of ITCs in Iquitos, Peru. A baseline knowledge, attitudes, and practices (KAP) survey was administered to 1,333 study participants, and ITCs were then distributed to 593 households as part of a cluster-randomized trial. Follow up KAP surveys and ITC-monitoring checklists were conducted at 9, 18, and 27 months post-ITC distribution. At 9 months post-distribution, almost 70% of ITCs were hanging properly (e.g. hanging fully extended or tied up), particularly those hung on walls compared to other locations. Proper ITC hanging dropped at 18 months to 45.7%. The odds of hanging ITCs correctly and consistently were significantly greater among those participants who were housewives, knew three or more correct symptoms of dengue and at least one correct treatment for dengue, knew a relative or close friend who had had dengue, had children sleeping under a mosquito net, or perceived a change in the amount of mosquitoes in the home. Additionally, the odds of recommending ITCs in the future were significantly greater among those who perceived a change in the amount of mosquitoes in the home (e.g. perceived the ITCs to be effective). Despite various challenges associated with the sustained effectiveness of the selected ITCs, almost half of the ITCs were still hanging at 18 months, suggesting a feasible vector control strategy for sustained community use

Universal subgap optical conductivity in quasi-one-dimensional Peierls systems

Quasi-one-dimensional Peierls systems with quantum and thermal lattice fluctuations can be modeled by a Dirac-type equation with a Gaussian-correlated off-diagonal disorder. A powerful new method gives the exact disorder-averaged Green function used to compute the optical conductivity. The strong subgap tail of the conductivity has a universal scaling form. The frequency and temperature dependence of the calculated spectrum agrees with experiments on KCP(Br) and trans-polyacetylene.Comment: 11 pages (+ 3 figures), LATEX (REVTEX 3.0

A Functional Signature Ontology (FUSION) screen detects an AMPK inhibitor with selective toxicity toward human colon tumor cells

AMPK is a serine threonine kinase composed of a heterotrimer of a catalytic, kinase-containing α and regulatory β and γ subunits. Here we show that individual AMPK subunit expression and requirement for survival varies across colon cancer cell lines. While AMPKα1 expression is relatively consistent across colon cancer cell lines, AMPKα1 depletion does not induce cell death. Conversely, AMPKα2 is expressed at variable levels in colon cancer cells. In high expressing SW480 and moderate expressing HCT116 colon cancer cells, siRNA-mediated depletion induces cell death. These data suggest that AMPK kinase inhibition may be a useful component of future therapeutic strategies. We used Functional Signature Ontology (FUSION) to screen a natural product library to identify compounds that were inhibitors of AMPK to test its potential for detecting small molecules with preferential toxicity toward human colon tumor cells. FUSION identified 5′-hydroxy-staurosporine, which competitively inhibits AMPK. Human colon cancer cell lines are notably more sensitive to 5′-hydroxy-staurosporine than are non-transformed human colon epithelial cells. This study serves as proof-of-concept for unbiased FUSION-based detection of small molecule inhibitors of therapeutic targets and highlights its potential to identify novel compounds for cancer therapy development