A Systematic Uncertainty Analysis of an Evaluative Fate and Exposure Model

Multimedia fate and exposure models are widely used to regulate the release of toxic chemicals, to set cleanup standards for contaminated sites, and to evaluate emissions in life-cycle assessment. CalTOX, one of these models, is used to calculate the potential dose, an outcome that is combined with the toxicity of the chemical to determine the Human Toxicity Potential (HTP), used to aggregate and compare emissions. The comprehensive assessment of the uncertainty in the potential dose calculation in this article serves to provide the information necessary to evaluate the reliability of decisions based on the HTP A framework for uncertainty analysis in multimedia risk assessment is proposed and evaluated with four types of uncertainty. Parameter uncertainty is assessed through Monte Carlo analysis. The variability in landscape parameters is assessed through a comparison of potential dose calculations for different regions in the United States. Decision rule uncertainty is explored through a comparison of the HTP values under open and closed system boundaries. Model uncertainty is evaluated through two case studies, one using alternative formulations for calculating the plant concentration and the other testing the steady state assumption for wet deposition. This investigation shows that steady state conditions for the removal of chemicals from the atmosphere are not appropriate and result in an underestimate of the potential dose for 25% of the 336 chemicals evaluated.     

The television archive: A source for the sociological study of culture

In this essay the George Foster Peabody Collection and the WSB Atlanta Television News Archive are described. A discussion of the form, structure and content of the collections reveal that each are ideally suited to visual sociological investigation. In all, the textual body of visual imagery found in the Peabody collection is an important source for the study of culture. The collection offers access to fifty years of award winning audio and video recordings, spanning news, documentary, international, entertainment, public service and childrens program submissions, the WSB collection contains a rich array of materials that service to elaborate on a cultural and historic framework of the new and old south. Hard news stories along with documentaries reveal a variety of public and social rituals of historic importance, the WSB and Peabody collections can be accessed to fulfil a number of scholarly endeavors. Visual sociologists, anthropologists and communication scholars are encouraged to further explore the use of these two electronic media archives.     

Replacement of semi-natural cover with artificial substrates in urban parks causes a decline of house sparrows Passer domesticus in Mediterranean towns

Urban Ecosystems - Many European towns and cities have undergone reurbanisation processes in recent decades. However, their effects on urban biodiversity have been poorly studied. Currently...     

创业精神在中国

大型国有企业或外资企业在经济发展中所取得的成就往往受到广泛关注，而由国际著名战略咨询公司摩立特集团和国务院发展研究中心近期公布的一项调查显示，中小型创业企业的增长活力和动力也不可忽视。     

A Lean transportation approach for improving emergency medical operations

Abstract

This paper extends the approach of Lean transportation to improve the performance of emergency medical processes (EMP) by adapting its main concepts into the main characteristics of the EMP environment. The paper is based on an inductive theory-building process initiated from a case study in the field of emergency medical services. The development of the suggested performance improvement approach triggered from an exhaustive analysis of a process involved and an exploratory review of the existing improvement approaches available. The process of concern can be described as a specialized transportation process, where human lives are at risk. Its characteristics led to a natural application of Lean transportation. The results include, a novel approach for improving the agility and efficient EMS processes. This is validated with an application for improving ambulance response times and turnaround times of the Red Cross operations located in Monterrey, Mexico. The approach proved to be an integrated scheme for identifying waste opportunities at a systems level. This characteristic is important to let operations management prioritize improvement efforts in a limited budget situation. This work suggests the application of the emerging Lean transportation approach for increasing the agility performance of EMS processes.     

Kidnap risks and migration: evidence from Colombia

Using a unique data set from the major Colombian cities collected between 2000–2003 and with information on more than 12,000 households, this paper studies the relationship between the kidnap risk a household faces with its migration decisions. We find evidence that exposure to such risk induces households to react sending some of their members to an international destination but not necessarily to a domestic one. Estimates are robust to the inclusion of several household characteristics usual in the migration literature, other crime risks, reported feelings of insecurity of the household, and an alternative measure of kidnap risk.