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Strict Protocol (strict + protocol)

Distribution by Scientific Domains

Earth and Environmental Science	50%

Selected Abstracts

Functional traits of woody plants: correspondence of species rankings between field adults and laboratory-grown seedlings?

JOURNAL OF VEGETATION SCIENCE, Issue 3 2003
J.H.C. Cornelissen
Castroviejo et al. (1986,2000); Stace (1991) Abstract. Research into interspecific variation in functional traits is important for our understanding of trade-offs in plant design and function, for plant functional type classifications and for understanding ecosystem responses to shifts in species composition. Interspecific rankings of functional traits are a function of, among other factors, ontogenetic or allometric development and environmental effects on phenotypes. For woody plants, which attain large size and long lives, these factors might have strong effects on interspecific trait rankings. This paper is the first to test and compare the correspondence of interspecific rankings between laboratory grown seedlings and field grown adult plants for a wide range of functional leaf and stem traits. It employs data for 90 diverse woody and semiwoody species in a temperate British and a (sub)Mediterranean Spanish flora, all collected according to a strict protocol. For 12 out of 14 leaf and stem traits we found significant correlations between the species ranking in laboratory seedlings and field adults. For leaf size and maximum stem vessel diameter > 50 % of variation in field adults was explained by that in laboratory seedlings. Two important determinants of plant and ecosystem functioning, specific leaf area and leaf N content, had only 27 to 36 and 17 to 31 % of variation, respectively, in field adults explained by laboratory seedlings, owing to subsets of species with particular ecologies deviating from the general trend. In contrast, interspecific rankings for the same traits were strongly correlated between populations of field adults on different geological substrata. Extrapolation of interspecific trait rankings from laboratory seedlings to adult plants in the field, or vice versa, should be done with great caution. [source]

Introduction of early medical abortion in New Zealand: An audit of the first 67 cases

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2005
Carol SHAND
Abstract Background:, In New Zealand, mifepristone became available in 2001, but because of uncertainty about the law, the first 67 cases were carried out under a very strict protocol. Once the prostaglandin had been administered it was necessary that the woman remain in the unit until the products of conception (POC) had been passed and, if this had not occurred within 8 h, she underwent suction curettage. Aims:, To demonstrate that an early medical termination of pregnancy (EMTOP) service could be offered as a safe option for women, despite the constraints of the law. Methods:, An audit of patient notes was carried out on the first 67 patients undergoing an EMTOP at the Level J Unit (LJU), Wellington Hospital. Data collected included age, ethnicity, parity, previous abortions, gestational age, length of time between the administration of mifepristone and misoprostol, length of time after administration of misoprostol to the completion of abortion, whether a fetal sac was seen, analgesia required, extent of heavy bleeding and any adverse effects. Patient characteristics were compared with those of the 3052 women who underwent surgical termination during the same time period. Data were analysed using EpiInfo 2000 (Centers for Disease Control and Prevention, Atlanta, GA) and Chi square tests for significance. Results:, Successful completion of EMTOP occurred in 63 of 67 cases (94%). Only four cases (6%) required completion by suction curettage and this was performed for legal and financial reasons, rather than for medical reasons. Clinical events requiring management, mainly bleeding problems, occurred in 11 patients (16%). Conclusions:, EMTOP with mifepristone and misoprostol was successfully introduced and the experience provides useful data for others contemplating a similar service. [source]

Spatial analysis of oblique photo-point images for quantifying spatio-temporal changes in plant communities

APPLIED VEGETATION SCIENCE, Issue 2 2010
P. Michel
Abstract Question: Can spatial analytical techniques be used to extract quantitative measurements of vegetation communities from ground-based permanent photo-point images? Location: Mount Aspiring National Park, south-western South Island, New Zealand. Methods: Sets of ground-based photographs representing two contrasting vegetation types were selected to test two spatial analytical techniques. In the grid technique, a grid was superimposed onto the photographs and the frequency of species presence in each grid-square was calculated to estimate species abundance/cover over the defined area. In the object-oriented technique, the photographs were segmented into meaningful objects, based on the colour of the pixels and the textural patterns of the images, and the area occupied by an object in the image was used to derive species abundance/cover over the area. Results: Both techniques allow quick and easy classification of digital elements into ecologically relevant categories of vegetation components. The grid technique appeared more robust, being quick and efficient, accommodating all image types and providing presence/absence matrices for multivariate analysis. Fewer classes were identified using the object-oriented technique, in particular for the forest interior site and for small individual plants such as Astelia spp. Conclusions: Both techniques showed potential for the objective quantitative analysis of long-term vegetation monitoring of cover and changes of several component species, using repeat ground-based photographs more specifically for grassland habitats. However, both rely to various degrees on manual classification. Corrective factors and strict protocols for taking the photographs are necessary to account for variation in view angles and to compute values more representative of absolute species abundance. [source]

Are Statistical Contributions to Medicine Undervalued?

BIOMETRICS, Issue 1 2003
Norman E. Breslow
Summary. Econometricians Daniel McFadden and James Heckman won the 2000 Nobel Prize in economics for their work on discrete choice models and selection bias. Statisticians and epidemiologists have made similar contributions to medicine with their work on case-control studies, analysis of incomplete data, and causal inference. In spite of repeated nominations of such eminent figures as Bradford Hill and Richard Doll, however, the Nobel Prize in physiology and medicine has never been awarded for work in biostatistics or epidemiology. (The "exception who proves the rule" is Ronald Ross, who, in 1902, won the second medical Nobel for his discovery that the mosquito was the vector for malaria. Ross then went on to develop the mathematics of epidemic theory,which he considered his most important scientific contribution,and applied his insights to malaria control programs.) The low esteem accorded epidemiology and biostatistics in some medical circles, and increasingly among the public, correlates highly with the contradictory results from observational studies that are displayed so prominently in the lay press. In spite of its demonstrated efficacy in saving lives, the "black box" approach of risk factor epidemiology is not well respected. To correct these unfortunate perceptions, statisticians would do well to follow more closely their own teachings: conduct larger, fewer studies designed to test specific hypotheses, follow strict protocols for study design and analysis, better integrate statistical findings with those from the laboratory, and exercise greater caution in promoting apparently positive results. [source]