Detection of extended-spectrum beta-lactamases. The reliability of methods for susceptibility testing as used in Denmark

The susceptibility testing methods used in Denmark were evaluated with respect to their ability to detect cephalosporin resistance with cefuroxime as indicator, especially resistance caused by extended-spectrum beta-lactamases (ESBLs). Two methods for determination of minimal inhibitory concentration (MIC), three agar diffusion methods, a disc approximation test and the ESBL-Etest were used against a panel of strains producing well-known beta-lactamases. The tablet diffusion test (Rosco Neo Sensitabs) as the most used in Denmark had the lowest detection rate of cefuroxime resistance among ESBL-producing strains. The prediffusion method, which is only used at one laboratory, was the most reliable method for such detection. The MIC methods were in good agreement, but the detection rate for resistance due to ESBLs was low and depended on the antibiotics used. The disc approximation test and the ESBL-Etest both resulted in an acceptable ESBL detection rate. The latter tests discriminated between isolates producing the frequent chromosome-mediated and the in Denmark probably very rare ESBL-mediated cephalosporin resistance. For the evaluation of susceptibility tests such strains require special attention.     

Citalopram in premenstrual dysphoria: is intermittent treatment during luteal phases more effective than continuous medication throughout the menstrual cycle?

This article describes a barrier-free burn center that is accessible to persons with disabilities and that complies with Title III of the Americans with Disabilities Act. The burn center has 3 separate components: patient rooms, patient support facilities, and staff support facilities. Thirteen rooms are used to care for 16 patients. Two of the 13 rooms are accessible to people with disabilities. These 2 rooms have wide doors that permit a wheelchair to pass through, and they have enough clear floor space for a wheelchair to make a 180 degrees turn. The rooms have a sink that is accessible from a wheelchair. The bathrooms have large, clear floor spaces that allow for the turning of a wheelchair, elevated toilets, grab bars, and showers that permit wheelchair access. Special wheelchairs that provide easier shower and commode access are available. The patient support services feature a large hydrotherapy room that contains a table-shower system that allows a person in a wheelchair to gain access to both sides of the shower table. A tub room has been constructed to provide compact patient bathing and hydromassage, and it is also accessible to people in wheelchairs. The staff support services include a locker room that has a shower accessible to people with disabilities so that staff members with mobility disorders can work in the burn center. Grade II braille writing marks all of the signs that designate the permanent rooms and spacing in the burn center and in the contiguous common use areas. The common use area has a restroom accessible to people with disabilities and a waiting room with a telephone communications system for people with mobility disorders or mobility impairment.     

Percolation of meltwater through a snowpack

The hydraulics of meltwater percolation through a snowpack is analyzed in some detail. An implicit numerical model is used for determining the meltwater movement. The effect of freezing fronts of the free liquid water in the snowpack is evaluated. It is shown that even after a moderately cold night, it takes several hours of snowmelt before the snowpack again reaches its irreducible liquid content. The meltwater flux front moves very slowly down through the depth, where the liquid water has been refrozen during a preceding night. The time delay between the initiation of snowmelt at the surface and the start of run-off at the base of the snowpack is shown to be determined from a simple continuity reasoning. Finally, a comparison between theory and field measurements is made.     

Influence of Metallurgical Conditions on the Lining Wear in the Kaldo Process

The influence of different metallurgical conditions on the lining wear in the Kaldo process when refining high phosphorus iron has been systematically investigated revealing the following main featuresThe lining is protected by a lime-saturated layer of slag during the main part of the first blowing period.The lining wear starts in connection with the melting of this protective layer which occurs at the end of the first period. After that, the wear rate increases rapidly.The rapid increase of the lining wear is caused by direct combustion in a strongly oxidizing atmosphere of liquid iron which has been dragged up on the lining surface.By decreasing the oxygen activity in the furnace atmosphere at the end of the oxygen-blowing period the wear can be decreased considerably. In practice this has been solved by directing the oxygen jet with high impulse steeply into the bath during this period of the blowing. In this way the lining life in Domnarvet’s 30 ton Kaldo furnace has been increased by about 75% without reducing the steel yield. Blowing time and consumption of oxygen have at the same time decreased by about 10%.     

Effect of zinc on the movement pattern of the minnow, Phoxinus phoxinus L.

A shoal of 30 minnows, Phoxinus phoxinus L., developed hyperactivity as a response to a gradually increased zinc concentration. This behaviour was followed by a period when the fish displayed hypoactivity. Besides the quantitative alterations in activity there were also changes in the distribution between diurnal and nocturnal activity.     

Forward and Reverse Converters and Moduli Set Selection in Signed-Digit?Residue?Number?Systems

This paper presents an investigation into using a combination of two alternative digital number representations; the residue number system (RNS) and the signed-digit (SD) number representation in digital arithmetic circuits. The combined number system is called RNS/SD for short. Since the performance of RNS/SD arithmetic circuits depends on the choice of the moduli set (a set of pairwise prime numbers), the purpose of this work is to compare RNS/SD number systems based on different sets. Five specific moduli sets of different lengths are selected. Moduli-set-specific forward and reverse RNS/SD converters are introduced for each of these sets. A generic conversion technique for moduli sets consisting of any number of elements is also presented. Finite impulse response (FIR) filters are used as reference designs in order to evaluate the performance of RNS/SD processing. The designs are evaluated with respect to delay and circuit area in a commercial 0.13 μm CMOS process. For the case of FIR filters it is shown that generic moduli sets with five or six moduli results in designs with the best area × delay products.

Design of fan-out kinoforms in the entire scalar diffraction regime with an optimal-rotation-angle method

An algorithm for the design of diffractive optical phase elements (kinoforms) that give rise to fan-out (i.e., spot) patterns was developed and tested. The algorithm is based on the Helmholtz-Kirchhoff rigorous scalar diffraction integral for the evaluation of the electric field behind the kinoform. The optimization of the kinoform phase modulation is performed with an efficient optimal-rotation-angle method. The algorithm permits any spatial configuration of the locations of the desired spots. For example, the spots (all or some) can be located at large angles to the optical axis (nonparaxial case) or they can be located in the near near field of the kinoform, i.e., where the Fresnel approximation is no longer valid. Two examples of fabricated kinoforms designed with this algorithm are presented.