Statistical treatment for the wet bias in tree-ring chronologies: a case study from the Interior West,USA

Dendroclimatic research has long assumed a linear relationship between tree-ring increment and climate variables. However, ring width frequently underestimates extremely wet years, a phenomenon we refer to as ‘wet bias’. In this paper, we present statistical evidence for wet bias that is obscured by the assumption of linearity. To improve tree-ring-climate modeling, we take into account wet bias by introducing two modified linear regression models: a linear spline regression (LSR) and a likelihood-based wet bias adjusted linear regression (WBALR), in comparison with a quadratic regression (QR) model. Using gridded precipitation data and tree-ring indices of multiple species from various sites in Utah, both LSR and WBALR show a significant improvement over the linear regression model and out-perform QR in terms of in-sample \({R}^{2}\) and out-of-sample MSE. This further shows that the wet bias emerges from nonlinearity of tree-ring chronologies in reconstructing precipitation. The pattern and extent of wet bias varies by species, by site, and by precipitation regime, making it difficult to generalize the mechanisms behind its cause. However, it is likely that dis-coupling between precipitation amounts (e.g., percent received as rain/snow or percent infiltrating the soil) and its availability to trees (e.g., root zone dynamics), is the primary mechanism driving wet bias.     

Spatial and covariate-varying relationships among dominant tree species in Utah

Environmental and Ecological Statistics - The presence and establishment of a tree species at a particular spatial location is influenced by multiple physiological and environmental filters such as...     

Evaluating the impact of HIA on urban reconstruction decision-making. Who manages whose risks?

Practitioners and academic researchers increasingly look to evaluation of health impact assessment (HIA) to improve its practice, its efficiency and its legitimacy. Evaluation is also used to account to policy-makers, who express doubts that the benefits of HIA justify its costs. Until recently evaluation of HIA focused on instrument design and procedures but now the focus needs to shift to analysis of the interaction of HIA and decision-making. Multiple case studies have been applied to identify the conditions in which HIA produces the desired benefits. These studies used analytical concepts derived from the literature on evaluation, knowledge utilization, science of sociology and knowledge management.This paper describes a case study in which the strategic motives of the decision-makers affected the impact of an HIA. This HIA comprised of a quantitative environmental model ‘City & Environment’ that was used to assess environmental health impacts of an urban reconstruction plan in a Dutch city. The evaluation of the HIA shows that the decision to follow the recommendations of the HIA was part of a damage control strategy. The more HIA goals deviate from the policy problem and the less HIA is embedded in institutional procedures, then the more HIA impact will be subject to strategic decision-making behaviour. Appropriate cognitive and social strategies are needed to avoid ‘negative learning’ in those the HIA seeks to influence.     

A review of prehistoric and early historic mainland salt marsh vegetation in the northern-Netherlands based on the analysis of plant macrofossils

The article presents an overview of archaeobotanical research on artificial dwelling mounds, so-called ‘terps’, in the northern-Netherlands. A total of 40 studies carried out over the past 40 years is evaluated. The vegetation diversity in the area as well as the differences with the present marsh are studied. Seriation, Principal Component Analysis and Sørensen similarity indices are used to assess the diversity of both individual samples and sites. For comparison with the present marshes, an index based on the TMAP vegetation typology was defined. Based on these methods, a selection of the individual samples was analyzed phytosociologically. It is found that all samples represent a mixture of vegetation types, but that the salt marsh species are a constant factor. The variation in the sample composition is not related to their dating, except for some of the latest samples that reflect the earliest endikements. Great similarity to the present marshes is found, but the analysis also testifies of a landscape profoundly disturbed by human activities throughout history.     

A cross-country comparison of pregnant women's decision-making and perspectives when opting for non-invasive prenatal testing in the Netherlands and Belgium

Background

The Netherlands and Belgium have been among the first countries to offer non-invasive prenatal testing (NIPT) as a first-tier screening test. Despite similarities, differences exist in counseling modalities and test uptake. This study explored decision-making and perspectives of pregnant women who opted for NIPT in both countries.

Methods

A questionnaire study was performed among pregnant women in the Netherlands (NL) (n = 587) and Belgium (BE) (n = 444) opting for NIPT, including measures on informed choice, personal and societal perspectives on trisomy 21, 18 and 13 and pregnancy termination.

Results

Differences between Dutch and Belgian women were shown in the level of informed choice (NL: 83% vs. BE: 59%, p < 0.001), intention to terminate the pregnancy in case of confirmed trisomy 21 (NL: 51% vs. BE: 62%, p = 0.003) and trisomy 13/18 (NL: 80% vs. BE: 73%, p = 0.020). More Belgian women considered trisomy 21 a severe condition (NL: 64% vs. BE: 81%, p < 0.001). Belgian women more frequently indicated that they believed parents are judged for having a child with trisomy 21 (BE: 42% vs. NL: 16%, p < 0.001) and were less positive about quality of care and support for children with trisomy 21 (BE: 23% vs. NL: 62%, p < 0.001).

Conclusion

Differences in women's decision-making regarding NIPT and the conditions screened for may be influenced by counseling aspects and country-specific societal and cultural contexts.