Assessment of uncertainties in a long range atmospheric transport model: Methodology, application and implications in a UK context.

Acid deposition models are inherently simplified representations of real world behaviour and their performance is best evaluated by comparison with observations. National and international acid rain policy assessments handle observed and modelled deposition fields in different ways. Here, both the observed and modelled deposition fields are seen as uncertain and the Generalised Likelihood Uncertainty Estimation (GLUE) framework is used to choose acceptable sets of model input parameters that minimise the differences between them. These acceptable sets of model parameters are then used to estimate deposition budgets to the UK and to provide a probabilistic treatment of excess deposition over environmental quality standards (critical loads).

Biopsy versus resection for malignant glioma.

BACKGROUND: Patients with isolated supratentorial brain tumours, presumed to be primary on imaging, have two surgical management options - biopsy or resection. Surgical opinions appear to be equally divided when considering the relative risks and benefits of these two procedures. OBJECTIVES: To estimate the clinical effectiveness of radical surgical resection compared to simple biopsy in patients with malignant glioma. SEARCH STRATEGY: Electronic database searches of COCHRANE CONTROLLED TRIALS REGISTER (including the Cochrane Cancer Network Specialised Register of Trials), MEDLINE, CANCERLIT, EMBASE, BIOSIS and SCIENCE CITATION INDEX. Hand searching the references of all identified studies; hand searching the Journal of Neuro-Oncology over the previous 10 years, including all conference abstracts; personal communication. SELECTION CRITERIA: Randomised and clinical controlled trials were included if they compared biopsy to resection, or looked at effect of extent of resection on survival, time to progression or quality of life, for malignant glioma patients of all ages. DATA COLLECTION AND ANALYSIS: Studies were to be identified, critically appraised and data extracted by the author (SEM). Ideally hazard ratios for overall survival were to be calculated along with the estimates of odds ratios from the percentage survival at one and two years. For dichotomous data, Peto odds ratios (OR) with 95% confidence intervals (CI) were hoped to have been estimated. Normal continuous data were to have been summated using the weighted mean difference (WMD). MAIN RESULTS: The electronic database search yielded 2100 citations. Of these, two articles were identified for possible inclusion, however both were excluded. The hand search and personal communication were similarly unproductive. No studies were included in the review and no data was synthesised. REVIEWER'S CONCLUSIONS: Given that no qualifying studies were identified and because this is an important issue, both in terms of patient risk and benefit and health economics, the authors feels it important to conduct a randomised controlled trial in this subject.

Climate change as the dominant control on glacial-interglacial variations in C3 and C4 plant abundance.

Although C4 plant expansions have been recognized in the late Miocene, identification of the underlying causes is complicated by the uncertainties associated with estimates of ancient precipitation, temperature, and partial pressure of atmospheric carbon dioxide (PCO2). Here we report the carbon isotopic compositions of leaf wax n-alkanes in lake sediment cores from two sites in Mesoamerica that have experienced contrasting moisture variations since the last glacial maximum. Opposite isotopic trends obtained from these two sites indicate that regional climate exerts a strong control on the relative abundance of C3 and C4 plants and that in the absence of favorable moisture and temperature conditions, low PCO2 alone is insufficient to drive an expansion of C4 plants.

Biopsy versus resection for malignant glioma.

BACKGROUND: Patients with isolated supratentorial brain tumours, presumed to be primary on imaging, have two surgical management options - biopsy or resection. Surgical opinions appear to be equally divided when considering the relative risks and benefits of these two procedures. OBJECTIVES: To estimate the clinical effectiveness of radical surgical resection compared to simple biopsy in patients with malignant glioma. SEARCH STRATEGY: Electronic database searches of COCHRANE CONTROLLED TRIALS REGISTER (including the Cochrane Cancer Network Specialised Register of Trials), MEDLINE, CANCERLIT, EMBASE, BIOSIS and SCIENCE CITATION INDEX. Hand searching the references of all identified studies; hand searching the Journal of Neuro-Oncology over the previous 10 years, including all conference abstracts; personal communication. SELECTION CRITERIA: Randomised and clinical controlled trials were included if they compared biopsy to resection, or looked at effect of extent of resection on survival, time to progression or quality of life, for malignant glioma patients of all ages. DATA COLLECTION AND ANALYSIS: Studies were to be identified, critically appraised and data extracted by the author (SEM). For dichotomous data, Peto odds ratios (OR) with 95% confidence intervals (CI) were hoped to have been estimated. Normal continuous data were to have been summated using the weighted mean difference (WMD). MAIN RESULTS: The electronic database search yielded 2100 citations. Of these, two articles were identified for possible inclusion, however both were excluded. The hand search and personal communication were similarly unproductive. No studies were included in the review and no data was synthesised. REVIEWER'S CONCLUSIONS: Given that no qualifying studies were identified and because this is an important issue, both in terms of patient risk and benefit and health economics, the author feels it important to conduct a randomised controlled trial in this subject.

Students' preferences for collaborative learning processes.

Collaborative learning processes facilitate problem solving for nurses practicing in multidisciplinary settings. The purpose of this research was to compare preferences of "nontraditional"- and "traditional-aged" students for instructional methods for Associate Degree nursing education. First- and second-year nursing students from nine randomly selected community college programs in North Carolina voluntarily completed the Student Orientations Survey (Morstain, 1976). The survey assessed instructional preferences regarding the purpose of obtaining an associate degree (achievement or imaging), the process (assignments or independent study), and the desired degree of collaboration with faculty (assessment and collaborative interaction). By ANCOVA, first-year students and those recently out of high school were more achievement oriented. First-year students preferred structured assignments and assessment. Older students were inquiry oriented. Second-year students preferred independent study. Second-year students and those aged 18 to 22 years preferred collaborative interaction learning. Ethnic and gender preferences were identified for inquiry and interaction learning.

Behaviorism to humanism: the case for philosophical transformations in nursing education.

Collaborative learning processes and problem-based learning methods facilitate critical thinking capabilities for nurses practicing in multidisciplinary settings. Nursing education, as well as that of other healthcare providers, traditionally has been based on behaviorist educational theory. Massive economic and cultural shifts, and the nationwide movement toward community-based healthcare environments will mandate broad changes for structuring the philosophical framework for nursing education. Humanistic collaborative learning methods are proposed to meet the needs of preparing the next century of nursing care professionals.

On the arid margin: the relationship between climate, humans and the environment. A review of evidence from the highlands of central Mexico.

There has long been speculation as to the relationship between climate, humans and the environment. Until recently, however, it has proved difficult to establish the degree to which these factors are interlinked. Here we draw on evidence that has recently emerged from a series of investigations in central México to evaluate the long-term human impact on the environment and to establish the impact that late Holocene changes in the climate have had on the indigenous populations that lived on the arid frontier of Mesoamerica. Data from these studies indicate that: 1) the indigenous peoples of central México had a significant and often detrimental impact on the landscape, causing widespread land degradation; 2) The onset of anthropogenic accelerated erosion coincided with the introduction of sedentary agriculture in this region; 3) Fluctuations in the climate of central México over the last 4,000 years have had a significant impact on the subsistence strategies of the population which extended its territory into the northern arid lands during wetter periods, but rapidly abandoned these areas when the climate became drier.