Air change rate vs airflow pathway: bioaerosol containment and removal in patient rooms

Recent studies have shown that higher air change rates may have the unintended consequence of creating turbulent airflows that entrain high concentrations of infectious particles within the breathing zone, and possibly, breakdown pressure relationships necessary to contain the spread of infectious particles to other clinical spaces

A translation invariant pure DEA model

YesThis communication complements the DEA model proposed by Lovell and Pastor (1999), by incorporating both positive and negative criteria in the model. As such, we propose a DEA model, known as pure DEA, using a directional distance function approach

An experiment on first-price common-value auctions with asymmetric information structures: The blessed winner

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.In common-value auctions bidders have access to public information, and may also hold private information prior to choosing their bids. The literature has predominately focused on the case in which bidders are ex-ante symmetric and privately informed, and finds that aggressive bidding such that payoffs are negative is common (the winner's curse). In practice, bidders often only have access to public information, and use this information to form (possibly differing) beliefs. In addition, a bidder who is not privately informed may face bidders who are. We examine bidding behavior of both informed and uninformed bidders, and vary the information structure they face. We find that uninformed bidders underbid dramatically and persistently, while informed bidders tend to overbid in the two-bidder case. Our results highlight the importance of correctly modeling the information available to bidders.Financial support from the Department of Economics at Texas A&M University and the BID cluster at the University of Exeter is gratefully acknowledged

Ventilation Rates and Airflow Pathways in Patient Rooms: A Case Study of Bioaerosol Containment and Removal

Most studies on the transmission of infectious airborne disease have focused on patient room air changes per hour (ACH) and how ACH provides pathogen dilution and removal. The logical but mostly unproven premise is that greater air change rates reduce the concentration of infectious particles and thus, the probability of airborne disease transmission. Recently, a growing body of research suggests pathways between pathogenic source (patient) and control (exhaust) may be the dominant environmental factor. While increases in airborne disease transmission have been associated with ventilation rates below 2 ACH, comparatively less data are available to quantify the benefits of higher air change rates in clinical spaces. As a result, a series of tests were conducted in an actual hospital to observe the containment and removal of respirable aerosols (0.5–10 μm) with respect to ventilation rate and directional airflow in a general patient room, and, an airborne infectious isolation room. Higher ventilation rates were not found to be proportionately effective in reducing aerosol concentrations. Specifically, increasing mechanical ventilation from 2.5 to 5.5 ACH reduced aerosol concentrations only 30% on average. However, particle concentrations were more than 40% higher in pathways between the source and exhaust as was the suspension and migration of larger particles (3–10 μm) throughout the patient room(s). Computational analyses were used to validate the experimental results, and, to further quantify the effect of ventilation rate on exhaust and deposition removal in patient rooms as well as other particle transport phenomena

The Influence of National Culture on Effectiveness of Safety Trainings During Postdisaster Reconstruction

Non-English speaking workers constitute a disproportionately high number of workers involved in postdisaster reconstruction. Additionally, the rate of fatality among these workers is higher than the industry average. Research shows this population is more prone to unsafe behaviors in the working environment, conceivably because many of these workers are sent into the field prior to any formalized training. Recent studies show that the native culture of construction workers can impact risk-taking behavior. While numerous researchers have attempted to develop training materials for Hispanic workers, the number of studies that consider the impact of native culture on safety behavior is minimal. To answer this emerging knowledge gap, this paper develops a framework that will help to discern the influence of native culture, as well as other socioeconomic characteristics, on the effectiveness of safety trainings for non-English speaking workers. The formulation of this framework will pave the way for an enhanced understanding of the impact native culture plays on unsafe behaviors within a diverse workforce. Foreseeably, this understanding will play a significant role in developing culturally sensitive training materials in the future

The role of energy productivity in the U.S. agriculture

This paper investigates the role of energy on U.S. agricultural productivity using panel data at the state level for the period 1960-2004. We first provide a historical account of energy use in U.S. agriculture. To do this we rely on the Bennet cost indicator to study how the price and volume components of energy costs have developed over time. We then proceed to analyze the contribution of energy to productivity in U.S. agriculture employing the Bennet-Bowley productivity indicator. An important feature of the Bennet-Bowley indicator is its direct association with the change in (normalized) profits. Thus our study is also able to analyze the link between profitability and productivity in U.S. agriculture. Panel regression estimates indicate that energy prices have a negative effect on profitability in the U.S. agricultural sector. We also find that energy productivity has generally remained below total farm productivity following the 1973-1974 global energy crisis

An economic approach to achievement and improvement indexes

This study proposes a useful alternative to the "aggregate deprivation index" which is used to measure the well-beings of individuals in different countries or geographic locations. Furthermore, we also propose an improvement index which alleviates well known difficulties associated with overtime comparisons of "aggregate deprivation index". While deriving our indexes, we pursued an economic approach to index numbers theory and relied on the assumptions of optimizing behavior. The proposed achievement index has its roots in the theory of quantity indexes whose axiomatic properties are well established. The roots of our improvement index on the other hand, is well grounded in the productivity growth literature. The study also provides a numerical example

Accounting for externalities in the measurement of productivity growth: The Malmquist cost productivity measure

This paper starts with the basic premise: that conventional measures of productivity growth-often used as a measure of corporate performance-which ignore external or social output, are biased. We then construct an alternative productivity growth measure using activity analysis which integrates the externality/social output into a generalized productivity measure reflecting social responsibility. This method is very general and could be applied to gauge corporate social responsibility. We provide an application to US agriculture to demonstrate the approach: We show that conventional measures of productivity are biased upward when production of negative externalities (or bad) outputs is increasing. Conversely, this same measure of productivity is biased downward when externalities in production are decreasing. © 2004 Elsevier B.V. All rights reserved

The development of social preferences

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordThis paper examines how social preferences develop with age. This is done using a range of mini-dictator games from which we classify 665 subjects into a variety of behavioural types. We expand on previous developmental studies of pro-sociality and parochialism by analysing individuals aged 9–67, and by employing a cross country study where participants from Spain interact with participants from different ethnic groups (Arab, East Asian, Black and White) belonging to different countries (Morocco, China, Senegal and Spain). We identify a ‘U-shaped’ relationship between age and egalitarianism that had previously gone unnoticed, and appeared linear. An inverse “U-shaped” relationship is found to be true for altruism. A gender differential is found to emerge in teenage years, with females becoming less altruistic but more egalitarian than males. In contrast to the majority of previous economic studies of the development of social preferences, we report evidence of increased altruism, and decreased egalitarianism and spite expressed towards black individuals from Senegal