Dynamic endocrine testing. The Mayo Clinic model

An endocrine testing center (ETC) is a universal requirement for the practice of endocrinology. Modifications of the Mayo Clinic model for an ETC should be applicable to most endocrine practices. Key components of an ETC include a centralized testing area, registered nurse-physician team, detailed testing protocols, and patient education programs.     

MARKOV DECISION PROCESSES WITH UNCERTAIN TRANSITION RATES: SENSITIVITY AND MAX HYPHEN MIN CONTROL

Solution techniques for Markov decision problems rely on exact knowledge of the transition rates, which may be difficult or impossible to obtain. In this paper, we consider Markov decision problems with uncertain transition rates represented as compact sets. We first consider the problem of sensitivity analysis where the aim is to quantify the range of uncertainty of the average per‐unit‐time reward given the range of uncertainty of the transition rates. We then develop solution techniques for the problem of obtaining the max‐min optimal policy, which maximizes the worst‐case average per‐unit‐time reward. In each of these problems, we distinguish between systems that can have their transition rates chosen independently and those where the transition rates depend on each other. Our solution techniques are applicable to Markov decision processes with fixed but unknown transition rates and to those with time‐varying transition rates.     

The discourse of ‘Respect for People’ in UK construction

A competency‐based review of professional quantity surveying is important for service excellence and has continuing relevance in the built environment of the 21^st century. A survey of quantity surveyors in professional practice in South Africa has provided a new perspective on the relative importance of competencies required for current and future quantity surveying services, and revealed notable gaps between the important competencies and current proficiency levels among practitioners. The survey was based on a structured questionnaire reflecting 23 defined competencies, which were derived from the literature and from in‐depth interviews with selected practitioners. The results indicated that technically orientated competencies were rated of highest importance for current services, while management orientated competencies were rated of higher importance for future services. The profession was rated as deploying below average proficiency levels in marketing, advanced financial management, leadership and general management, and project management, although these received high current and future importance ratings. The findings suggest that initial and continuing education and training of professional quantity surveyors should emphasize the development of management‐orientated competencies.     

Lamellar structure of POM spherulites imaged by a two-stage RuO4 staining technique

Ruthenium tetroxide solution was prepared in situ by oxidation of ruthenium compounds at lower oxidation states with an excess of sodium periodate. The solution was able to stain saturated polymer POM in the vapor phase and it remained effective for up to 2 weeks. The melting behavior of POM samples stained for different lengths of time was studied with DSC and the staining process was analyzed. The results indicated that ruthenium tetroxide affected both the amorphous region and the crystals. During the early stage of the staining process, the tetroxide reacted preferentially with the amorphous material near the specimen surface. Much of this affected material was washed away after the rinsing process, thus resulting in an apparent increase in crystallinity. Prolonged staining would cause more crystals to degrade; hence, the crystallinity would drop. A two-step vapor staining technique was developed to improve the contrast between the amorphous and crystalline regions of ultrathin POM sections. The lamellar structure of POM spherulites was revealed and examined under TEM. The results showed that POM spherulites possess a category 2 structure and the thickness of the lamellae is about 7 nm. © 1996 John Wiley & Sons, Inc.     

De novo fatty acid synthesis and fatty acid elongation catalyzed by subcellular fractions from hog and human aorta

De novo synthesis and mitochondrial elongation of fatty acids have been demonstrated in subcellular fractions from hog and human aorta. Microsomal fatty acid elongation has been shown in hog aorta. The activity catalyzing the formation of fatty acids from acetyl and malonyl CoA was associated with a high molecular weight complex in the 6×10⁶g×min supernatant fraction. The principal product was palmitic acid. Some myristic and stearic acids were also formed. One elongation system was associated with protein which sedimented between 4500 g×min and 150,000 g×min. It used acetyl CoA but not malonyl CoA, and NADH was the preferred reducing agent. Radioactivity from acetyl CoA was incorporated into many fatty acids. In hog aorta a second elongation system was found associated with protein which sedimented at 6×10⁶ g×min. It used malonyl CoA preferentially as substrate and either NADH or NADPH as reducing agent.     

Resonance transformer power conditioners

One solution to the problem of high-power transformers is the concept of the resonance transformer, which uses a set of resonant circuits, made up of discrete inductors and capacitors, to achieve a transformerlike voltage gain. A brief overview of the general approach is presented. Because this approach does not require the magnetic core material associated with a conventional transformer, a significant savings in both size and weight can be realized, particularly at higher power levels. Technical issues associated with the conventional transformer, such as coupling of the primary and secondary windings at both high voltages and high frequencies and thermal management of heat generated in the transformer core, are also avoided. Several designs have been generated and tested, including a 20-kHz, 10- to 15-kW average power system. This power supply provides a voltage gain of 50 and weighs less than 45 kg. Additional designs for higher power levels above 1 MW are discussed along with information on expected sizes, weights, and general scaling tendencies     

Convectively driven polymerase chain reaction thermal cycler

We have fabricated a low-cost disposable polymerase chain reaction thermal chamber that uses buoyancy forces to move the sample solution between the different temperatures necessary for amplification. Three-dimensional, unsteady finite element modeling and a simpler 1-D steady-state model are used together with digital particle image velocimetry data to characterize the flow within the device. Biological samples have been amplified using this novel thermal chamber. Time for amplification is less than 30 min. More importantly, an analysis of the energy consumption shows significant improvements over current technology.     

A New Family of Ternary Almost Perfect Nonlinear Mappings

A mapping f(x) from GF(pⁿ) to GF(pⁿ) is differentially k-uniform if k is the maximum number of solutions x isin GF(pⁿ) of f(x+a) - f(x) = b, where a, b isin GF(pⁿ) and a ne 0. A 2-uniform mapping is called almost perfect nonlinear (APN). This correspondence describes new families of ternary APN mappings over GF(3ⁿ), n>3 odd, of the form f(x) = ux^d + x^{d 2} where d₁ = (3^n-1)/2 - 1 and d₂ = 3ⁿ - 2.     

Modelling consumer behavioural intentions towards food with implications for marketing quality low-input and organic food

The paper is based upon a study of European consumers’ behavioural intentions towards food purchase for four food products in six countries. The analytical method employs a structural equation model within the marketing framework of the quality-value-satisfaction-loyalty (QVSL) paradigm. The paper focuses on country-based versions of the model. The sample consists of 5072 regular consumers of the four products and includes consumers of conventional foods, quality low-input foods and organic foods. The model establishes the determinants of behavioural intentions towards foods that consumers purchase regularly. In addition, it provides the facility to examine the potential of quality low-input foods and organic foods. The results reveal the contribution of satisfaction, perceived value and perceived quality to improving behavioural intentions and how these constructs could contribute to the improved effectiveness of marketing conventional, quality low-input and organic foods to existing and potential consumers.