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Measures Alone (measure + alone)
Selected AbstractsThe impact of lianas on 10 years of tree growth and mortality on Barro Colorado Island, PanamaJOURNAL OF ECOLOGY, Issue 4 2010Laura L. Ingwell Summary 1. Lianas compete intensely with trees, but few studies have examined long-term effects of liana infestation on tree growth and mortality. We quantified the effects of lianas in tree crowns (n = 2907) and rooted within 2 m of trees (n = 1086) on growth and mortality of 30 tree species from 1995 to 2005 on Barro Colorado Island (BCI), Panama, documented liana infestation in tree crowns in 1996 and 2007 to determine the dynamics of liana infestation, and quantified liana infestation in the crowns of 3231 additional canopy trees (d.b.h. ,20 cm) in 2007 to compare with the same metric determined by previous studies in 1967 and 1980. 2. Severe liana infestation increased tree mortality: 21% of liana-free trees in 1996 had died by 2007, whereas 42% of trees with more than 75% of the crown infested by lianas in 1996 had died by 2007. 3. Liana infestation of tree crowns significantly reduced tree growth, particularly on sun-exposed trees. The proximity of rooted lianas significantly reduced the growth of shaded trees. 4. Liana infestation was dynamic: 10.9% of trees with severe liana infestation in their crowns in 1996 had shed all of their lianas by 2007 and 5.3% of trees with no lianas in their crown in 1996 had severe liana infestation in 2007. 5. Liana infestation was common: lianas were present in 53% of trees of the 30 focal species. Including lianas rooted within 2 m of the tree increased this percentage to 78%. Using both above- and below-ground measures may provide a better estimate of liana competition than either measure alone. 6. Liana infestation is increasing on BCI. Lianas were present in the crowns of 73.6% of canopy trees (d.b.h. ,20 cm). Liana canopy infestation was 57% higher than in 1980 and 65% higher than in 1967, which is consistent with reported increases in liana abundance, biomass, and leaf and flower production. 7.,Synthesis. We used one of the largest studies ever conducted on lianas to confirm the negative effects of lianas on tree growth and survival over 10 years. Liana infestation of trees was widespread, dynamic and increasing on BCI. [source] Temporal reliability of psychological assessments for patients in a special hospital with severe personality disorder: a preliminary noteCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2005Professor P. Tyrer Background The new programme for assessing those with dangerous and severe personality disorder relies heavily on psychological assessments of personality disorder and risk. Methods The temporal reliability of assessments of psychopathy (PCL-R), risk (HCR-20) and personality was assessed using the International Personality Disorder Examination (IPDE) in 15 randomly selected male prisoners in a high secure hospital carried out at intervals varying between a mean of nine and 19 months after initial assessments by a variety of assessors. Results Using the intra-class correlation coefficient the agreement varied between0.57 (HCR-20), 0.58 (PCL-R) and 0.38-0.70 for IPDE personality disorders, with the best agreement for antisocial personality disorder (0.70). Comment These levels of agreement are consistent with other recent work on temporal reliability of personality instruments but are a little too low for confidence in these measures alone in the assessment process. Copyright © 2005 Whurr Publishers Ltd. [source] Multiple causality in developmental disorders: methodological implications from computational modellingDEVELOPMENTAL SCIENCE, Issue 5 2003Michael S.C. Thomas When developmental disorders are defined on the basis of behavioural impairments alone, there is a risk that individuals with different underlying cognitive deficits will be grouped together on the basis that they happen to share a certain impairment. This phenomenon is labelled multiple causality. In contrast, a developmental disorder generated by a single underlying cognitive deficit may nevertheless show variable patterns of impairments due to individual differences. Connectionist computational models of development are used to investigate whether there may be ways to distinguish disorder groups with a single underlying cause (homogeneous disorder groups) from disorder groups with multiple underlying causes (heterogeneous disorder groups) on the basis of behavioural measures alone. A heuristic is proposed to assess the underlying causal homogeneity of the disorder group based on the variability of different behavioural measures from the target domain. Heterogeneous disorder groups are likely to show smaller variability on the measure used to define the disorder than on subsequent behavioural measures, while homogeneous groups should show approximately equivalent variability. Homogeneous disorder groups should show reductions in the variability of behavioural measures over time, while heterogeneous groups may not. It is demonstrated how these predictions arise from computational assumptions, and their use is illustrated with reference to behavioural data on naming skills from two developmental disorder groups, Williams syndrome and children with Word Finding Difficulties. [source] The further development of ionoregulatory measures as biomarkers of sensitivity and effect in fish speciesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2002S. J. Croke Abstract Extensive season-by-season sampling was used to establish the normal range of whole-body Na+ and Cl, and Na+ uptake in healthy populations of two fish species, rainbow trout, Oncorhynchus mykiss, and fathead minnow, Pimephales promelas, of known differences in sensitivity to ionoregulatory toxicants (low pH, trace metals). These data together with responses of both species to six different ionoregulatory challenge tests of increasing severity (mild handling, exposure to low Ca2+ water, epinephrine injection, net-confinement stress, exposure to copper, and osmotic shock) were evaluated for their potential as biomarkers of sensitivity and of effect of ionoregulatory toxicants. There were no obvious biomarkers of sensitivity in the ion measures themselves, but four of the six challenges (exposure to low Ca2+ water, epinephrine injection, exposure to copper, and osmotic shock) produced a significantly greater effect in the more sensitive of the two species, fathead minnow. Based on the responses of both species, this article makes a number of recommendations for the application of ion measures alone and in combination with challenge tests to the assessment of chronic effects in populations experiencing sublethal ionoregulatory stress. [source] Assessment of the benefits of user involvement in health research from the Warwick Diabetes Care Research User Group: a qualitative case studyHEALTH EXPECTATIONS, Issue 3 2007Antje Lindenmeyer PhD Abstract Objective, To assess the benefits of involving health-care users in diabetes research. Design and participants, For this qualitative case study, semi-structured interviews were conducted with researchers who had worked extensively with the group. During regular meetings of the Research User Group, members discussed their views of the group's effectiveness as part of the meeting's agenda. Interviews and discussions were transcribed, coded using N-Vivo software and analysed using constant comparative methods. Results, Involvement of users in research was generally seen as contributing to effective and meaningful research. However, the group should not be considered to be representative of the patient population or participants of future trials. An important contributor to the group's success was its longstanding nature, enabling users to gain more insight into research and form constructive working relationships with researchers. The user-led nature of the group asserted itself, especially, in the language used during group meetings. A partial shift of power from researchers to users was generally acknowledged. Users' main contribution was their practical expertise in living with diabetes, but their involvement also helped researchers to remain connected to the ,real world' in which research would be applied. While the group's work fulfilled established principles of consumer involvement in research, important contributions relying on personal interaction between users and researchers were hard to evaluate by process measures alone. Conclusions, We demonstrated the feasibility, acceptability and effectiveness of this longstanding, experienced, lay-led research advisory group. Its impact on research stems from the continuing interaction between researchers and users, and the general ethos of learning from each other in an on-going process. Both process measures and qualitative interviews with stakeholders are needed to evaluate the contributions of service users to health research. [source] Wetlands with controlled drainage and sub-irrigation systems,modelling of the water balanceHYDROLOGICAL PROCESSES, Issue 14 2007Ottfried Dietrich Abstract Over the past centuries, the agricultural use of wetlands in Central Europe has required interference with the natural wetland water balance. Often this has consisted of drainage measures alone. In low-precipitation areas, it has also involved the operation of combined drainage and sub-irrigation systems. Model studies conducted as part of planning processes, or with a view to finding out the impact of changing climate conditions on the water balance of wetlands, must take these facts into account. For this reason, a water balance model has been devised for wetlands whose water balance is governed by water resources management systems. It is based on the WBalMo model system. Special modules were integrated into WBalMo to calculate the water balance of wetland areas (WABI module) and to regulate inflow partitioning within the wetland (REGINF module). When calculating the water balance, the WABI module takes into account precipitation and potential evapotranspiration, groundwater levels below surface, soil types, land-use classes, inflows via the running water system, and data for target water levels. It provides actual evapotranspiration, discharge into the running water system, and groundwater levels in the area. The example of the Spreewald, a major wetland area in north-eastern Germany, was used to design and test the WBalMo Spreewald model. The comparison of measured and calculated water balance parameters of the wetland area confirms the suitability of the model for water balance studies in wetlands with complex water resources management systems. The results reveal the strong influence of water management on the water balance of such areas. The model system has proved to be excellently suited for planning and carrying out water management measures aimed at the sustainable development of wetlands. Furthermore, scenario analyses can be used to assess the impact of global change on the water balance of wetlands. Copyright © 2006 John Wiley & Sons, Ltd. [source] In situ methods of measurement,an important line of evidence in the environmental risk frameworkINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 2 2007Jim Wharfe Abstract A tiered framework provides a structured approach to assess and manage risk and underpins much of the legislation concerning chemicals and environmental management. Management decisions regarding appropriate controls can have high cost implications to the regulated community. The risk framework provides an evidence-based approach to reduce uncertainty in decision making. Traditional assessment is heavily dependent on laboratory-generated toxicity test data and estimations of exposure and effect. Despite many well documented demonstrations of in situ methodologies, they are rarely used by regulators to help improve assessment or to validate risk. Emerging legislation puts greater emphasis on environmental outcomes and represents a significant shift from the reliance on chemical measures alone toward biological responses that improve assessment and demonstrate ecological benefit. Diagnostic methods, that could include in situ-based measures, will help assess and manage environments failing to achieve good status and it is likely that a weight of evidence approach will be needed to help inform management decisions. The potential application of such measures in the risk framework is reviewed in the context of current and emerging legislation concerning chemicals. Effect measures on the basis of in situ methods provide an alternative line of evidence and can help reduce uncertainty in decision making. Criteria are presented to help select appropriate methods in a multiple-line, weight of evidence approach. [source] | ||||||||||||||||