Biomedical subjects

K Upton

Publications and source records attributed to K Upton.

4 recordsLinked to original sources

PubMed1993

An efficient disk based data structure for rapid searching of quantitative two-dimensional gel databases.

Fast access of two-dimensional (2-D) gel quantitative databases is important for rapid searching for protein differences between sets of 2-D gels from an experiment. The GELLAB-II system organizes corresponding spots from the gels in the database into reference or "Rspot" sets. These Rspot numeric names index fixed regions in the paged composite gel database file. This is adequate for an existing database, but has several problems. (i) Building the initial database requires guessing how much disk space to pre-allocate for each corresponding spot (i.e. spots from different gels). If it ever runs out of pre-allocated space during this process, it must expand the size of each corresponding set of spots copying the old database data into the new in-place on the disk. (ii) When adding new gels or editing the database, if a new spot is created, the system may also go into this expansion mode. The time spent and wasted disk space can be appreciable--depending on the size of the database (order of 100 gel database). (iii) Because each set of corresponding spots is the same size, we waste space in most spot sets since they do not require the additional space a few spot sets require which contain additional fragmented spots. We present a new low-level disk object-based structure and algorithm, paged indexed buckets (PIB), which optimizes disk space usage while having similar retrieval speed to the original method.

Algorithms↗

PubMed1993

A fast spot segmentation algorithm for two-dimensional gel electrophoresis analysis.

An important issue in the automation of two-dimensional gel electrophoresis image analysis is the detection and quantification of protein spots. A spot segmentation algorithm must detect, define the extent of, and measure the integrated density of spots under a wide variety of actual gel image conditions. Besides these functions, the algorithm must be memory efficient to be able to process very large gel images and do this in a reasonable amount of computation time on low-cost computers, such as workstations and personal computers. We have developed a fast spot segmentation algorithm, extending the GELLAB-II segmenter, which extracts spots in a single raster scanning pass through the gel image. The performance analysis of the algorithm will be given in the paper as well as a discussion of the algorithm.

Algorithms↗

PubMed1991

Study into the ability of patients with impaired lung function to use breath alcohol testing devices.

A subject who fails to provide an adequate breath sample for a breath alcohol measuring device under the provisions of Road Traffic Act 1988 may be charged with refusing to supply a sample unless the police officer believes the person is genuinely unable to do so. Subjects who are confronted with this situation may approach their general practitioner or chest physician for advice on whether they are medically able to provide adequate breath samples to satisfy the breath testing devices. There is currently no guidance available for medical practitioners concerning respiratory performance or lung function which will impair the use of such breath testing devices. This paper describes experiments with human volunteers suffering from respiratory illnesses and their ability to provide adequate breath samples to satisfy the requirements of the breath alcohol testing devices used in Great Britain. It was found that the most suitable parameters for determining whether a subject was capable of using a breath alcohol testing device were spirometry measurements of Forced Expired Volume in one second (FEV1) and Forced Vital Capacity (FVC). In this study subjects with a FEV1 less than 2.0 litres and a FVC less than 2.6 litres were generally unable to use all the devices.

Adolescent↗

PubMed1991

The effect of salbutamol on breath alcohol testing in asthmatics.

Subjects suffering from asthma can occasionally experience difficulty in providing adequate breath samples for evidential breath alcohol testing devices and may therefore resort to the use of bronchodilators such as salbutamol to improve their respiration. Experiments showed that although salbutamol caused bronchodilation it did not affect breath alcohol levels of asthmatics who have been drinking. The blood:breath alcohol ratios obtained from asthmatics were within the normally recorded range before and after use of salbutamol. We conclude that the use of salbutamol by asthmatics does not affect the reliability of measurements made by evidential breath alcohol testing devices.

Adult↗