DECAL: A Reconfigurable Monolithic Active Pixel Sensor for Tracking and Calorimetry in a 180 nm Image Sensor Process.

In this paper, we describe DECAL, a prototype Monolithic Active Pixel Sensor (MAPS) device designed to demonstrate the feasibility of both digital calorimetry and reconfigurability in ASICs for particle physics. The goal of this architecture is to help reduce the development and manufacturing costs of detectors for future colliders by developing a chip that can operate both as a digital silicon calorimeter and a tracking chip. The prototype sensor consists of a matrix of 64 × 64 55 µm pixels, and provides a readout at 40 MHz of the number of particles which have struck the matrix in the preceding 25 ns. It can be configured to report this as a total sum across the sensor (equivalent to the pad of an analogue calorimeter) or the sum per column (equivalent to a traditional strip detector). The design and operation of the sensor are described, and the results of chip characterisation are reported and compared to simulations.

Socioeconomic factors influencing the failure to measure the blood pressure of children during clinical examinations.

The authors measured the percentage of children aged 6 through 17 whose blood pressure (BP) was not measured during recent nonemergency clinical examination and assessed the relative importance of health, ability-to-pay, language, and race-ethnic factors in determining whether BP was measured. Using a pooled dataset from the Medical Expenditure Panel Survey (MEPS) for 2006 and 2007, the authors calculated the percentage of children whose BP was not measured using a sample of children aged 6 through 17 and constructed a logistic regression model to estimate the relative importance of health, economic, and social factors in the examiner's decision to measure BP. A total of 28.9% of children did not have their BP measured. Within this unmeasured group, 31% had a family history of hypertension, 9% had a family history of diabetes, and 5% had a body mass index ≥32 kg/m2 . The logistic regression model of examiners' decisions indicates that social and economic factors strongly compete with health factors in determining which children not to measure. While examiners place many children at risk for hypertension in the measured pool, they also place many at-risk children in the unmeasured pool for economic and social reasons.

Flexible lipid bilayers in implicit solvent.

A minimalist simulation model for lipid bilayers is presented. Each lipid is represented by a flexible chain of beads in implicit solvent. The hydrophobic effect is mimicked through an intermolecular pair potential localized at the "water"/hydrocarbon tail interface. This potential guarantees realistic interfacial tensions for lipids in a bilayer geometry. Lipids self-assemble into bilayer structures that display fluidity and elastic properties consistent with experimental model membrane systems. Varying molecular flexibility allows for tuning of elastic moduli and area per molecule over a range of values seen in experimental systems.

Fatal injuries to teenage construction workers in the US.

BACKGROUND: The construction industry is second only to agriculture in the annual number of fatal injuries in workers less than 18 years of age. We examined fatal injury reports for youth and adult workers to determine risk factors for injury and applicability of existing child labor regulations. METHODS: The US Occupational Safety & Health Administration (OSHA) investigation data for fatal work injuries from 1984 through 1998 were reviewed with respect to type of event, employer characteristics, and apparent violations of existing child labor laws under the Fair Labor Standards Act (FLSA). We also examined whether the employer met exemption criteria for federal enforcement of child labor or OSHA regulations. RESULTS: The fatality rate for teenage construction workers age 19 and younger was 12.1 per 100,000 per year, slightly less than for adult workers. Teenage workers who were fatally injured were more likely than adults to have been employed at non-union construction firms (odds ratio (OR) = 4.96, P < 0.05), firms with fewer than 11 employees (OR = 1.72, P < 0.05), and their employers were more likely to have been cited by OSHA for safety violations (OR = 1.66, P < 0.05) than for firms which were investigated because of a fatality in an adult worker. Fatalities in teenagers were more likely to occur in special construction trades such as roofing. Among fatalities in workers less than 18 years of age, approximately one-half (49%) of the 76 fatal injuries were in apparent violation of existing child labor regulations. We estimated that in 41 of the 76 cases (54%) the employer's gross annual income exceeded the $500,000 threshold for federal enforcement of child labor laws. Only 28 of 76 cases (37%) were at construction firms with 11 or more employees, which are subject to routine OSHA inspections. CONCLUSIONS: Fatal injuries in teenage construction workers differed from those in adults in that they were more likely to be at small, non-union firms of which a substantial proportion were exempt from federal enforcement of child labor laws and from routine OSHA inspections. Safety programs for young construction workers should include small, non-union construction firms and those in special construction trades such as roofing. We did not identify specific areas for new regulation but the number of fatalities reviewed was small.

Impact of the OSHA trench and excavation standard on fatal injury in the construction industry.

In 1989 the US Occupational Safety & Health Administration revised the excavation and trenching standard. We examined fatal injuries from trench cave-in in the construction industry for five year periods before and after the revision in the 47 US states for which data were available for both periods. There was a 2-fold decline in the rate of fatal injury after revision of the standard, which substantially exceeded the decline in other causes of fatal injury in the construction industry during the same period. The decline was somewhat greater in large business firms but was evident in construction firms of all size classes. The fatality rate from trench cave-in in union construction workers was approximately half that of nonunion workers, but we were unable to determine whether this was best explained by union status, employment of union workers at larger construction firms, or both. This study provides evidence for the effectiveness of OSHA regulation in preventing fatal work injury.