Why Are There Revisions to the Jobs Numbers?

At the beginning of each month, the Bureau of Labor Statistics (BLS) reports the change in payroll employment for the previous month. This estimate of jobs gained or lost over the month is closely watched by policymakers and those who work in financial markets and the media. When the estimate is revised in subsequent months, however, data users sometimes perceive a very different picture of the job market than what was initially reported. Data users frequently ask why the number was revised. The short answer is, the revised estimate includes additional information that was not available at the time of the initial release— information that makes the revised estimate more accurate. This BEYOND THE NUMBERS article explains the data collection process that BLS conducts every month to produce the estimate of U.S. employment. The article also should help clarify why BLS releases revisions to the initial estimate so that users will understand the change, if any, in the data

Risk factors in gastric cancer

STATE OF THE ART: Gastric cancer (GC) is still a major health problem worldwide due to its frequency, poor prognosis and limited treatment options. At present prevention is likely to be the most effective means of reducing the incidence and mortality from this disease. The most important etiological factors implicated in gastric carcinogenesis are diet and Helicobacter pylori (H. pylori) infection. High intake of salted, pickled or smoked foods, as well as dried fish and meat and refined carbohydrates significantly increased the risk of developing GC while fibers, fresh vegetables and fruit were found to be inversely associated with GC risk. Epidemiological investigations (retrospective, case-control and prospective) and several meta-analyses have demonstrated that concurrent or previous H. pylori infection is associated with an increased risk of GC in respect to uninfected people. H. pylori colonizes gastric mucosa where it induces a complex inflammatory and immune reaction that on time leads to a severe mucosal damage i.e., atrophy, intestinal metaplasia (IM) and dysplasia. The risk of GC is closely related to the grade and extension of gastric atrophy, IM and dysplasia. PERSPECTIVES AND CONCLUSIONS: Today a plausible program for GC prevention means: (1) a correct dietary habit since childhood increasing vegetables and fruit intake, (2) a decrease of H. pylori spread improving family and community sanitation and hygiene, (3) a search and treat H. pylori strategy in offspring of GC, (4) a search and treat H. pylori strategy in patients with chronic atrophic gastritis and intestinal metaplasia (IM), (5) a careful endoscopic and histologic follow-up if precancerous lesions persist irrespective of H. pylori eradication

Linear And Nonlinear Arabesques: A Study Of Closed Chains Of Negative 2-Element Circuits

In this paper we consider a family of dynamical systems that we call "arabesques", defined as closed chains of 2-element negative circuits. An $n$-dimensional arabesque system has $n$ 2-element circuits, but in addition, it displays by construction, two $n$-element circuits which are both positive vs one positive and one negative, depending on the parity (even or odd) of the dimension $n$. In view of the absence of diagonal terms in their Jacobian matrices, all these dynamical systems are conservative and consequently, they can not possess any attractor. First, we analyze a linear variant of them which we call "arabesque 0" or for short "A0". For increasing dimensions, the trajectories are increasingly complex open tori. Next, we inserted a single cubic nonlinearity that does not affect the signs of its circuits (that we call "arabesque 1" or for short "A1"). These systems have three steady states, whatever the dimension is, in agreement with the order of the nonlinearity. All three are unstable, as there can not be any attractor in their state-space. The 3D variant (that we call for short "A1\_3D") has been analyzed in some detail and found to display a complex mixed set of quasi-periodic and chaotic trajectories. Inserting $n$ cubic nonlinearities (one per equation) in the same way as above, we generate systems "A2\_$n$D". A2\_3D behaves essentially as A1\_3D, in agreement with the fact that the signs of the circuits remain identical. A2\_4D, as well as other arabesque systems with even dimension, has two positive $n$-circuits and nine steady states. Finally, we investigate and compare the complex dynamics of this family of systems in terms of their symmetries.Comment: 22 pages, 12 figures, accepted for publication at Int. J. Bif. Chao

Remediation of soil and groundwater by vacuum-enhanced recovery.

A literature review and case study of Vacuum Enhanced Recovery (VER) technology, also known as bioslurping, is presented in this project paper. The literature review was conducted to investigate historic and current VER design and pilot study practices. The case study presents the field activities and results of an actual VER pilot study conducted at an operating retail petroleum facility. The results of the pilot study were used to assess the feasibility of VER technology to remediate hydrocarbon impacted soil and groundwater and to design a full scale VER system for the site. The pilot study results indicated a high level of contaminant mass removal from the subsurface and a large zone of groundwater influence. Consequently, VER was deemed an acceptable remediation technology for the case site. The full scale system was designed to draw 8.60 am3/min (300 acfm) of air and 57 Lpm of water from the subsurface at an operating vacuum of 457 mm Hg. (18 in. Hg). The system employed a 30 hp oil-sealed liquid vacuum pump attached to eight individually plumbed extraction wells. An initial mass removal rate of 1,430 kg/day of total petroleum hydrocarbons was estimated. VER is a relatively new subject in the field of remediation engineering. Additional research should focus on methods to limit the uncertainty in design due to site-specific heterogeneities, less onerous methods of applying numerical modeling to simulate multiphase flow in the subsurface, and additional case studies to improve pilot study protocol and VER system design.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .N37. Source: Masters Abstracts International, Volume: 39-02, page: 0552. Adviser: Stan Reitsma. Thesis (M.A.Sc.)--University of Windsor (Canada), 2000