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Biomedical subjects

D W Newman

Publications and source records attributed to D W Newman.

9 recordsLinked to original sources
PubMed2003

From research and development to practice-based evidence: clinical governance initiatives in a service for adults with mild intellectual disability and mental health needs.

BACKGROUND: Practice-based evidence represents the contribution of practitioners who utilize research methodologies to examine the quality of their clinical practice and service provision. METHODS: The present paper describes the evolution of a routine practice-based evidence system (PBES) via four phases of research and development. The four phases are described, as is their relevance to assessment and intervention with regard to the mental health problems of people with mild intellectual disability. Phase four describes the development of a routine PBES. RESULTS: The PBES is capable of profiling the individual mental health needs of service users and examining service effectiveness and quality at an organizational level. CONCLUSIONS: The PBES is discussed according to its current utility and possible directions for future development. The system is presented as an example of clinical governance that could be utilized by multidisciplinary teams to develop and maintain an organizational culture of quality.

Evidence-Based Medicine↗
PubMed1980

Aging and regreening in soybean cotyledons. 1 Ultrastructural changes in plastids and plastoglobuli.

Ultrastructural changes were studied in plastids from mature, partially senescent, senescent, and regreened soybean cotyledons. Tissues were fixed for electron microscopy and also plastoglobuli were isolated from 14-, 16-, and 23-day-old tissues as well as from tissues which had been regreened. In mature tissues, the mesophyll, as compared to the palisade parenchyma, plastids have a poorly developed lamellar system. At the beginning of senescence there occurred an increase in the size of granal stacks and in the size and number of plastoglobuli. At late stages of senescence there is a breakdown of thylakoids. During regreening there is a recovery of the chloroplast fine structure. Plastoglobuli isolated from senescent cotyledons were large and appeared wrinkled when observed with a scanning electron microscope unlike those isolated from mature tissues which were spherical. Chloroplasts in regreened tissues originate either from proplastids or from intermediate stages of slightly senescent plastids.

Chloroplasts↗
PubMed1973

Lipid transformations in greening and senescing leaf tissue.

Analyses were made of chlorophyll a and b and fatty acids (18:3, 18:2, 18:1, 18:0, 16:2, 16:1, and 16:0) of greening and senescing leaf tissue. Those dark-grown tissues given a prior treatment of red, far red, or red followed by far red light showed similar increases in chlorophylls and linolenate (18:3) when exposed to continuous white light. In contrast, green barley (Hordeum vulgare L.) leaves placed in the dark lost chlorophylls and fatty acids, especially 18:3. Senescing cocklebur (Xanthium strumarium L.) leaf tissue showed a decline in chlorophyll and fatty acids, especially again 18:3. Abscisic acid, but not sucrose, accelerated these senescent changes. Radioactive acetate incorporation into the galacto-lipids and phospholipids of senescing cocklebur leaf tissue increased and then the radioactivity of the lipids decreased in senescent tissues.

Journal Article↗
PubMed1971

The effect of red and far red light on the desaturation of Fatty acids in barley leaves.

Barley (Hordeum vulgare) leaf tissue was either (a) exposed to continuous red light or (b) exposed to red, far red, or red followed by far red light. The fatty acid composition and incorporation of acetate-2-(14)C into linolenate were determined. Changes occurred in the fatty acid composition of dark-grown barley leaves regardless of whether the plants were subsequently exposed to red light or whether the tissue remained in the dark. Measurements were also made of the fatty acids of the coleoptile. Red light treatment did not reduce the lag period for the synthesis of linolenate when chlorophyll synthesis was inhibited. It appears that the desaturation process per se in the synthesis of linolenate is not phytochrome-mediated but may appear to be phytochrome mediated if, possibly, galactolipid and chlorophyll syntheses occur concomitantly.

Journal Article↗
PubMed1966

Chloroplast Fatty Acid transformations in nitrogen-deficient and senescent tissues.

The fatty acids of plastids from several types of mineral-deficient and senescent tissues were analyzed. Incorporation of acetate into long-chain fatty acids of leaf tissue and of plastids from nitrogen-deficient and normal plants was determined. In general, the senescent and nitrogen-deficient chloroplasts contained a higher ratio of saturates to unsaturates than did plastids from younger tissues and from tissues grown on a complete nutrient.Nitrogen-deficient leaf tissue and plastids were capable of rapidly incorporating acetate into some of the fatty acids, especially palmitic and oleic acids. However, the comparative rate of acetate incorporation into linolenic acid in nitrogen-deficient chlorophyllous tissue was less than in tissue grown on a complete nutrient. With the addition of UDP-glucose to a reaction mixture containing added cofactors for noncyclic photosynthetic phosphorylation the relative incorporation of acetate into linolenate as compared to palmitate was increased in both the nitrogen-deficient and normal leaf tissue. This would indicate that nitrogen-deficient tissues have the enzymic systems for forming long-chain fatty acids but that the reduced photosynthesis limits the amount of precursors for the formation of lipids, especially galactolipids. However, nothing is known about the rate of fatty acid degradation under these conditions.

Journal Article↗