The moment index of minima (II)

The moment index of a nonnegative random variable X has the property that the moment index of the minimum of two independent r.v.s X and Y is greater than or equal to the sum of the moment indices of X and Y. We characterize conditions under which equality holds for a given r.v. X and every independent nonnegative r.v. Y, and discuss extensions to related r.v.s and their distributions

Estimating the Cost of Cervical Cancer Screening in Five Developing Countries

Background: Cost-effectiveness analyses (CEAs) can provide useful information to policymakers concerned with the broad allocation of resources as well as to local decision makers choosing between different options for reducing the burden from a single disease. For the latter, it is important to use country-specific data when possible and to represent cost differences between countries that might make one strategy more or less attractive than another strategy locally. As part of a CEA of cervical cancer screening in five developing countries, we supplemented limited primary cost data by developing other estimation techniques for direct medical and non-medical costs associated with alternative screening approaches using one of three initial screening tests: simple visual screening, HPV DNA testing, and cervical cytology. Here, we report estimation methods and results for three cost areas in which data were lacking. Methods: To supplement direct medical costs, including staff, supplies, and equipment depreciation using country-specific data, we used alternative techniques to quantify cervical cytology and HPV DNA laboratory sample processing costs. We used a detailed quantity and price approach whose face validity was compared to an adaptation of a US laboratory estimation methodology. This methodology was also used to project annual sample processing capacities for each laboratory type. The cost of sample transport from the clinic to the laboratory was estimated using spatial models. A plausible range of the cost of patient time spent seeking and receiving screening was estimated using only formal sector employment and wages as well as using both formal and informal sector participation and country-specific minimum wages. Data sources included primary data from country-specific studies, international databases, international prices, and expert opinion. Costs were standardized to year 2000 international dollars using inflation adjustment and purchasing power parity. Results: Cervical cytology laboratory processing costs were I$1.57–3.37 using the quantity and price method compared to I$1.58–3.02 from the face validation method. HPV DNA processing costs were I$6.07–6.59. Rural laboratory transport costs for cytology were I$0.12–0.64 and I$0.14–0.74 for HPV DNA laboratories. Under assumptions of lower resource efficiency, these estimates increased to I$0.42–0.83 and I$0.54–1.06. Estimates of the value of an hour of patient time using only formal sector participation were I$0.07–4.16, increasing to I$0.30–4.80 when informal and unpaid labor was also included. The value of patient time for traveling, waiting, and attending a screening visit was I$0.68–17.74. With the total cost of screening for cytology and HPV DNA testing ranging from I$4.85–40.54 and I$11.30–48.77 respectively, the cost of the laboratory transport, processing, and patient time accounted for 26–66% and 33–65% of the total costs. From a payer perspective, laboratory transport and processing accounted for 18–48% and 25–60% of total direct medical costs of I$4.11–19.96 and I$10.57–28.18 respectively. Conclusion: Cost estimates of laboratory processing, sample transport, and patient time account for a significant proportion of total cervical cancer screening costs in five developing countries and provide important inputs for CEAs of alternative screening modalities

Assessment and Improvement of the Efficiency of Nitrogen Use on Commercial Dairy Farms

Dairy farming systems have a low efficiency of converting nitrogen (N) into milk protein, due to the many transfers which occur in the production process. Losses of N from the system can be detrimental to the environment and represent wasted inputs. At SAC, in a systems research project, management changes achieved increases in nitrogen efficiency (milk N output/ N inputs) (NE) from 23 to 34% in a grass-clover based system (GC), and 13 to 21% in a purchased fertiliser based system (GN) (Leach & Roberts, 2002). Nitrogen surplus (NS = N inputs - N output in sold produce) was reduced from 184 to 90 kg N/ha in GC and from 369 to 258 kg N/ha in GN. This work was then incorporated into a participatory research project, to obtain data on N balances in commercial dairy systems and investigate the effects of suggesting management changes to improve NE

DSTP-AN: A Distributed System for Transaction Processing Based on Data Resource Migration in ATM Networks

The dynamic migration of data resources has become a strong tool for transaction processing in broadband networks such as ATM. In this paper, a distributed system that takes advantage of data resource migration for transaction processing in ATM networks has been proposed. The proposed system provides mechanisms to select the transaction processing method, to migrate data resources in a way that reduces the time delay and message traffic in locating and accessing them. The first mechanism selects one of the two transaction processing methods: the traditional method that uses two phase commit protocol and other new method based on data resource migration. The second mechanism attempts to improve performance by making each site follow a local policy for directing requests to locate and access data resources as well as migrating them through the system. For this, a new scheme that focuses on reducing the time delay and message traffic needed to access the migratory data resources is proposed. The performance of the proposed scheme has also been evaluated and compared with one of the existing schemes by a simulation study under different system parameters such as frequency of access to the data resources, frequency of data resource migrations, scale of network, etc

Online Enlightenment: A Phidget Notification System for Online Status

This paper describes a physical device that presents online presence information in a semi-public space. The device uses a map metaphor to represent a set of connected labs, showing online instant messenger status for members of the community. Device users can combine information from the device with information from the physical environment to identify unfamiliar lab members, determine human-to-human interaction strategies, and plan meetings. The paper reports on design decisions that were considered in creating the device, supplying rationale for decisions that were made. In particular, we focus on how people integrate physical information from the world and virtual information from this (and similar) devices in the environment, reflecting on ways in which this type of device can improve communication and enhance community. We describe four envisioned usage scenarios for the device, with early feedback from people who work in the space and whose information is displayed on the device