Quantification of antibiotic use on dairy farms in Pennsylvania

Antibiotic use data are critical for drawing conclusions about the epidemiological connections between antibiotic use in farms animals, antibiotic resistance, animal health, and human health. The goal of this study was to quantitatively and qualitatively characterize antibiotic use on dairy farms in Pennsylvania, the state with second largest number of dairy farms nationally. A survey was sent to 10% of the 6,580 dairy farms registered in Pennsylvania and completed by 235 producers (response rate of 36%). Data on antibiotic use in the previous month and in the previous 6 mo were collected based on farmer self-report, using either recall or treatment records. Two metrics were used to quantify antibiotic consumption: animal-defined daily doses (ADD) and days of therapy (DOT), a metric used in human medicine for purposes of antimicrobial stewardship. Across all farms, 24,444 ADD and 19,029 DOT were reported, representing treatment incidences of 4.2 ADD/1,000 animal-days and 3.3 DOT/1,000 animal-days. These rates were generally lower than those found in other states and countries. The main indication for antibiotic use was mastitis, and first-generation cephalosporins were the most commonly used class of antibiotic for all indications, followed by penicillins and third-generation cephalosporins. Trends in use were similar for ADD and DOT, but the numbers of recorded DOT and associated treatment incidences were generally lower than the number of ADD and associated treatment incidences. Rates of treatment were significantly associated with herd size. This study is the first to quantify antibiotic use on dairy farms in Pennsylvania and the first to use the DOT metric in a dairy setting.     

Survival of Listeria monocytogenes in a simulated dynamic gastrointestinal model during storage of inoculated bologna and salami slices in vacuum packages

Listeria monocytogenes counts were determined during storage (82 days, 4 degrees C) in vacuum packages of inoculated bologna and salami slices and after exposure to a simulated dynamic model of the stomach and small intestine. Variables controlled in the model included gastric emptying and gastrointestinal fluid secretion rates, gradual gastric acidification, and intestinal pH maintenance. L. monocytogenes populations increased on bologna and decreased on salami, reaching 8.7 and 1.4 log CFU/g, respectively, on day 82. Inactivation rates (IR) during gastric exposure of bologna and salami ranged from 0.079 (day 14) to 0.158 (day 57) log CFU/g/min and from 0.013 (day 42) to 0.051 (day 1) log CFU/g/min, respectively. On corresponding days, gastric IR for cells on salami were lower than on bologna, suggesting potential protective effects of the former product. However, it is also possible that the low initial L. monocytogenes levels reached with storage of salami (< or = 2.5 log CFU/g after day 27) may have resulted in slower reductions than in the high levels on bologna. Gradual decline of gastric pH allowed survival in the gastric compartment during the initial stages, which resulted in a large fraction of the cells being delivered into the intestinal compartment. Intestinal IR ranged from 0.003 to 0.048 (bologna) and from 0.002 to 0.056 (salami) log CFU/g/min throughout storage. Although findings indicated potential effects of salami against gastric killing of L. monocytogenes, any effects of the food matrix per se on the gastrointestinal survival of the pathogen were overwhelmed by the high and low contamination levels reached on bologna and salami, respectively, during storage.     

Design for excess capability to handle uncertain product requirements in a developing world setting

Products designed for the developing world often go unused or underused by the intended customers. One cause of this problem is uncertainty regarding the actual requirements of customers in the developing world. This can result when designers, with experience in technologically advanced countries, apply their own value structure to the products they design. Because of the designers’ lack of experience in the culture and environment of the developing world, the actual requirements are only partially known to them. This problem can be mitigated by (i) optimizing product flexibility and adaptability to react to uncertain requirements, and (ii) reducing the most critical uncertainties. The flexibility of a product to adapt to new or changing requirements has been shown to extend the service life of large complex engineered systems (e.g., aircraft carriers, aircraft, communication systems, and space craft). These systems must remain in service for extended periods of time, even though the environments and requirements may change dramatically. Applying these proven techniques to products designed for the developing world can alleviate the problem of uncertain requirements. This paper presents and demonstrates a technique aimed at improving the success of developing world engineering projects. Flexibility and adaptability minimize the impact of uncertainties, and are enabled by numerically optimized amounts of designed-in excess. A sensitivity analysis performed on the system model helps the designer prioritize the set of uncertain requirements and parameters for refinement. The technique is demonstrated in the design of a cookstove intended for use in the developing world.     

The politics of co-design in ICT for sustainable development

ABSTRACT

In this paper, we discuss an approach to co-design in ICT for sustainable development. We first set out to consider sustainable development as incorporate a concern for resilience, adaptability, and autonomy. We then draw on an ongoing participatory design project to illustrate how co-design projects can be configured, along with the political choices that this entails, to support such development.     

Literature review--efficacy of various disinfectants against Legionella in water systems

There have been reported outbreaks of Legionnaires' disease at hospitals and industrial facilities, which prompted the development of various preventive measures. For example, Ford has been developing and implementing such a measure at its facilities worldwide to provide technical guidance for controlling Legionella in water systems. One of the key issues for implementing the measure is the selection of a disinfectant(s) and optimum conditions for its use. Therefore, available publications on various disinfectants and disinfection processes used for the inactivation of Legionella bacteria were reviewed. Two disinfection methods were reviewed: chemical and thermal. For chemical methods, disinfectants used were metal ions (copper and silver), oxidizing agents (halogen containing compounds [chlorine, bromine, iodine, chlorine dioxide, chloramines, and halogenated hydantoins], ozone, and hydrogen peroxide), non-oxidizing agents (heterocyclic ketones, guanidines, thiocarbamates, aldehydes, amines, thiocyanates, organo-tin compounds, halogenated amides, and halogenated glycols), and UV light. In general, oxidizing disinfectants were found to be more effective than non-oxidizing ones. Among oxidizing agents, chlorine is known to be effective and widely used. Among non-oxidizing agents, 2,2-dibromo-3-nitropropionamide appears to be the most effective followed by glutaraldehyde. Isothiazolin (known as Kathon), polyhexamethylene biguanide, and 2-bromo-2-nitropropionamide (known as Bronopol) were found to be less effective than glutaraldehyde. Thermal disinfection is effective at > 60 degrees C (140 degrees F).     

Roles of subsidiary managers in multinational corporations: The effect of dual organizational identification

Abstract and Key Results

Optical detection of ion-channel-induced proton transport in supported phospholipid bilayers

The integration of ion-channel transport functions with responses derived from nanostructured and nanoporous silica mesophase materials is demonstrated. Patterned thin-film mesophases consisting of alternating hydrophilic nanoporous regions and hydrophobic nanostructured regions allow for spatially localized proton transport via selective dimerization of gramicidin in lipid bilayers formed on the hydrophilic regions. The adjoining hydrophobic mesostructure doped with a pH sensitive dye reports the transport. The ease of integrating functional membranes and reporters through the use of patterned mesophases should enable high throughput studies of membrane transport.     

Highly Active and Diastereoselective N,O‐ and N,N‐Yttrium Complexes for Intramolecular Hydroamination

The intramolecular hydroamination of aminoalkynes and unactivated aminoalkenes catalyzed by yttrium N,O‐ and N,N‐complexes has been investigated. The N,N‐yttrium complexes are highly active, catalyzing the conversion of a wide range of terminal aminoalkenes at room temperature, and internal aminoalkenes at elevated temperature, to yield pyrrolidine and piperidine products in high yields. A high diastereoselectivity of up to 23:1 is observed at 0 °C with 1‐methyl‐4‐pentenylamine as substrate.     

A predictive model for the effect of temperature and predrying treatments in reducing Listeria monocytogenes populations during drying of beef jerky

The objective of this study was to model the effect of drying temperatures (52, 57, and 63 degrees C) and predrying treatments on the inactivation of Listeria monocytogenes on beef jerky. Before drying, beef slices were inoculated with a 10-strain composite of L. monocytogenes and then treated with the following: (i) nothing (C), (ii) traditional marinade (M), or (iii) dipping in 5% acetic acid solution for 10 min, followed by M (AM). In addition, sequential stresses (exposure to 10% NaCl, followed by an adjustment of the pH to 5.0 and, subsequently, a water bath at 45 degrees C) were applied to the inocula before beef contamination and drying at 63 degrees C. Surviving L. monocytogenes were determined on tryptic soy agar plus 0.6% yeast extract (TSAYE) and on PALCAM agar at 0, 2, 4, 6, 8, and 10 h during drying. Data were modeled by a linear regression (treatment AM) and a logistic-based equation capable of fitting biphasic inactivation curves without initial shoulder (treatments C and M). The total log reductions expressed as the CFU per square centimeter of L. monocytogenes (3.9 to 5.1) for the samples treated with M (3.5 to 5.4) when compared with C were similar, whereas AM-treated samples had higher (6.1 to 6.8) reductions. All survival curves were characterized by an initial rapid decrease in populations within the first 2 h, which was followed by a secondary death phase at a lower rate. No significant (P > or = 0.05) differences in inactivation were observed due to drying temperatures in the range (52 to 63 degrees C) tested. Inactivation differences between recovered counts of stressed and unstressed cells were significant (P < 0.05) in PALCAM but not in TSAYE. The acidified predrying treatment (AM) had higher pathogen inactivation during drying than other treatments, regardless of drying temperature. The models developed may be useful in designing effective drying processes for beef jerky.