A new approach to evaluating the well-being of police.

Background: There is a growing body of evidence that links employee well-being to organizational performance. Although police forces are under increasing pressure to improve efficiency and productivity, the evaluation of well-being in law enforcement is mostly restricted to self-report stress questionnaires that are based on questionable construction methodologies. No instrument to specifically determine the well-being of police force employees currently exists.

Patients may respond differently to paper and electronic versions of the same questionnaires.

Aim: To adapt the Asthma Quality of Life Questionnaire (AQLQ(S)), the Asthma Control Questionnaire (ACQ) and the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ(S)) for a personal digital assistant (Palm TX) and to examine the validity of the electronic versions by comparing them with the original paper versions.

Methods: 84 adults with asthma and 32 with rhinitis were randomised to complete either the paper or the electronic version first. After 2h, they completed the other version.

Development and validation of an electronic version of the Rhinoconjunctivitis Quality of Life Questionnaire.

Background: As clinicians and pharmaceutical companies move from paper versions of health status questionnaires to electronic versions, it cannot be assumed that adaptations to other media will produce valid data.

Aims: The aims of this study were to (1) adapt the Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ(S); standardized version], for the Palm Treo 650, (2) test the device for ease and accuracy of understanding and (3) examine the validity of the electronic version by comparing it with the original paper version of the RQLQ(S).

Methods: Seventy adults with current rhinoconjunctivitis symptoms completed the electronic and paper versions of the RQLQ(S).

Genetic clues to the origin of the apple.

Molecular genetic markers complement archaeological, breeding and geographical investigations of the origins, history and domestication of plants. With increasing access to wild apples from Central Asia, along with the use of molecular genetic markers capable of distinguishing between species, and explicit methods of phylogeny reconstruction, it is now possible to test hypotheses about the origin of the domesticated apple. Analyses of nuclear rDNA and chloroplast DNA (cpDNA) sequences indicate that the domesticated apple is most closely related to series Malus species.

A freeze-fracture study of mesophyll cell membranes in the embryonic Phaseolus leaf, in the dry seed and during the initial stages of germination.

Using rapid-freezing and freeze-fracturing techniques, we have examined cellular organisation within mesophyll cells in primary leaves of Phaseolus, in the dry seed and over a period of 48 hr from the onset of germination. The rapidly-frozen, unetched image reveals a dynamic cytoplasm with membrane shape and role able to change and fluctuate with the increase in cell metabolism. The ER in this tissue is highly mobile, becoming progressively associated with protein and lipid bodies, then plastids, mitochondria and nuclei as cytoplasmic requirements change.

The plasma membrane of young Chara internodal cells revealed by rapid freezing.

Young elongating internodal cells of Chara globularis var. capillacea (Thuill.) Zanev.

Low and high voltage electron microscopy of mitosis and cytokinesis in maize roots.

The structure and distribution of cytoplasmic membranes during mitosis and cytokinesis in maize root tip meristematic cells was investigated by low and high voltage electron microscopy. The electron opacity of the nuclear envelope and endoplasmic reticulum (ER) was enhanced by staining the tissue in a mixture of zinc iodide and osmium tetroxide. Thin sections show the nuclear envelope to disassemble at prophase and become indistinguishable from the surrounding ER and polar aggregations of ER.

The fine structure and development of the trabeculae and the trabecular ring in Selaginella kraussiana.

In the shoot apex of Selaginella kraussiana A. Br., air spaces develop between the endodermal cells, isolating the two steles from the cortex.

The effect of caffeine, different fixation regimes and low temperature on microtubules in the cells of higher plants : Evidence for diversity in their response to chemical and physical treatments.

Caffeine, (1:3:7-tri-methyl-xanthine), either as a prefixation treatment or included with glutaralde-hyde as the primary fixative, destroys or disorganises the microtubules associated with the formation of secondary walls in fibres from the flowering stem of the grass Lolium temulentum L. There is no observable effect of caffeine treatment on the microtubules associated with primary wall formation in collenchyma and young fibres from L. temulentum or in root cap cells of Zea mays L.

Graniferous tracheary elements in the haustorium of the santalaceae.

Haustoria of santalaceous root parasites examined have unusual tracheary elements containing granules within their lumina. Benson (1910) thought the granules were starch and that the cells also contained an enucleate protoplast. She believed the cells combined the functions of phloem and xylem conduits and so named them "phloeotracheides" (sic).

The perception of gravity by a plant.

Ever since geotropism was first studied in plants, attempts have been made to create model systems which might simulate the perception by a plant of a gravitational change. The most resilient of these models, the so-called statolith theory, has now enjoyed a run of over 75 years and demonstrates its viability by reappearing in many different forms. It has shown its value by anticipating the now well understood graviperception mechanism in the Chara rhizoid and this will be described.

Some features of secretory systems in plants.

Recent work on secretion in plants is reviewed, with emphasis on the anatomy and physiology of root cap cells in higher plants, the stalked glands of Drosera capensis, and the secretory mechanism of Dionaea muscipula. Cells of the root cap of higher plants switch from a geo-perceptive role to one of mucilage secretion at maturation. Features of this process, the role of the Golgi and the pathway for mucilage distribution are reviewed.

An excitable membrane in the stalked glands of Drosera capensis L.

Shortly after feeding the surface of the gland of Drosera capensis L. with whole milk or other protein sources the plasmalemma adjacent to the tracheid becomes highly modified. No vesicle is seen to approach the membrane from within the cytoplasm, but the surface of the membrane grows and evaginates outwards forming a small protruding papilla or bleb about 50-100 nm across.

Directional secretion by the Golgi bodies in maize root cells.

In the root caps of many plant species, the outer few layers of cells secrete a polysaccharide mucus. This mucus probably derives from the breakdown of the starch in the amyloplasts. Is then fed through the Golgi bodies and, in vesicular form, reaches and is discharged through the plasmamembrane.

The distribution and redistribution of endoplasmic reticulum (ER) in geoperceptive cells.

Within the root cap in maize the cells believed to be responsible for the perception of gravity possess a rough-surfaced ER system with a distinctive pattern of distribution. The ER is found normally parallel to the nuclear membrane and to the walls, and symmetrically distributed. It can be disturbed from its parallel position by moving the root to any horizontal orientation, but it is not displaced by inverting the root into the 180° vertical position.

The fine structure of the cells that perceive gravity in the root tip of maize.

Within the root cap, in maize, the cells believed to be responsible for the perception all possess large well-developed amyloplasts. They also have normal mitochondria and Golgi bodies, normal rough-surfaced ER with a very striking pattern of distribution, few free ribosomes, walls with an abnormal reticulate encrusting material, irregularly distributed plasmodesmata and an as yet unidentified fine quadruple membranous system. All of these features are discussed in relation to the role of the cells in perception.

The distribution of plasmodesmata in the root tip of maize.

The distribution of plasmodesmata in different regions of the root apex of Zea mays has been analysed from electron micrographs. There are many more plasmodesmata traversing transverse walls than across longitudinal walls in all the regions studied. When the number of plasmodesmata per unit cell volume is calculated, cells in non-dividing tissue have a considerably lower value than cells in dividing tissue.