Naval Vessel Traffic Services

Vessel traffic services (VTSs) ensure the safe and efficient handling of traffic on busy waterways like the English Channel and the approaches to New York. This technique, wherein electronic sensors and communication systems are used to manage traffic actively, can also be used in maritime security operations (MSOs) to enhance safety in areas with risks related to asymmetric threats.1 Nowadays a limited form of VTS is deployed for MSO situated in international waters. These services, provided by naval cooperation and guidance for shipping (NCAGS) organizations, are focused on building maritime domain awareness (MDA) and providing naval-related safety information to merchant shipping

Finite temperature molecular dynamics study of unstable stacking fault free energies in silicon

We calculate the free energies of unstable stacking fault (USF) configurations on the glide and shuffle slip planes in silicon as a function of temperature, using the recently developed Environment Dependent Interatomic Potential (EDIP). We employ the molecular dynamics (MD) adiabatic switching method with appropriate periodic boundary conditions and restrictions to atomic motion that guarantee stability and include volume relaxation of the USF configurations perpendicular to the slip plane. Our MD results using the EDIP model agree fairly well with earlier first-principles estimates for the transition from shuffle to glide plane dominance as a function of temperature. We use these results to make contact to brittle-ductile transition models.Comment: 6 pages revtex, 4 figs, 16 refs, to appear in Phys. Rev.

Aan de wieg van het waterschap : inventarisatie van dijken, kaden en watergangen in het Gelders rivierengebied : ontwerphandreikingen voor wateropgaven

De studie geeft een inventarisatie van ontginningspatronen van het rivierengebied. Deze patronen reflecteren de geschiedenis van de bewoners én de geschiedenis van het Waterschap. Dijken, kaden en weteringen vormden in tijden van weleer de begrenzing van de dorpspolders. De dorpspolders zijn de voorlopers van de waterschappen. Deze studie van een landschapsarchitect, landschapshistoricus en bodemkundige vertelt een verhaal. Een verhaal over de geschiedenis hoe dit gebied bewoonbaar en bewerkbaar wer

A systematic review and critical appraisal of quality indicators to assess optimal palliative care for older people with dementia

© The Author(s) 2019Background: A challenge for commissioners and providers of end-of-life care in dementia is to translate recommendations for good or effective care into quality indicators that inform service development and evaluation. Aim: To identify and critically evaluate quality indicators for end-of-life care in dementia. Results: We found 8657 references, after de-duplication. In all, 19 publications describing 10 new and 3 updated sets of indicators were included in this review. Ultimately, 246 individual indicators were identified as being relevant to dementia end-of-life care and mapped against EAPC guidelines. Conclusions: We systematically derived and assessed a set of quality indicators using a robust framework that provides clear definitions of aspects of palliative care, which are dementia specific, and strengthens the theoretical underpinning of new complex interventions in end-of-life care in dementia.Peer reviewedFinal Published versio

Spatially explicit analysis of land use change : a case study for Ecuador

Introduction and objectivesWithin agricultural research increasing attention is paid to the integrated study of agro-ecosystems in order to address issues related to sustainable food production at the eco-regional level. This has been stimulated by the awareness that the world-wide demand for food will continue to increase while at the same there is high pressure on natural resources needed for food production, such as suitable soils and available water. Human-driven land use change is also relevant for global change because of its influence on greenhouse gas emissions, water and energy balances, and biodiversity.These issues have confronted research with substantive methodological challenges, such as the integration of biophysical and socio-economic disciplines over various spatio-temporal scales, and the development of modelling approaches for the exploration of future changes in land use and their effects.The general objective of this thesis is the analysis of spatial variation and temporal dynamics of agricultural land use systems in order to quantitatively assess the interaction between land use and the natural resource base. This is addressed through three derived objectives. Firstly, the spatial analysis of land use systems with the aim to detect the main biophysical and socio-economic drivers of actual land use at different spatial scales. Secondly, the spatially explicit modelling of near-future land use change dynamics, taking into account the multi-scale structure of actual land use and its drivers. Thirdly, the quantification of possible effects of future land use change on the natural resource base and agricultural production.The study areaThe study area is the South-American country of Ecuador. Agriculture is important in Ecuador, both for the production of subsistence crops as well as export crops. The country is characterised by a high agro-ecological diversity. A wide variety of climate and soil conditions exist and land use is diverse, with respect to the crops that are grown as well as the technology levels that are used. Agricultural land use is dynamic due to resource degradation, changes in demand for agricultural products, migration, export and import developments, economic developments and sector policies. A number of land use developments are causing serious threats to the natural resource base.Statistical multi-scale analysis of actual land use systemsLand use in Ecuador was investigated for the year 1991 by means of statistical analysis with the purpose of deriving quantitative estimates of the relative areas of land use types on the basis of biogeophysical, socio-economic and infrastructural conditions (Chapter 2). The smallest spatial units of investigation were 5 by 5 minute (9.25 x 9.25 km) cells of a geographical grid covering the whole country. Through aggregation of these cells, a total of six artificial aggregation levels was obtained with the aim of analysing spatial scale dependence of land use structure. For all aggregation levels independent multiple regression models were constructed for the estimation of areas within cells of permanent crops, temporary crops, grassland and natural vegetation.The variables used in the regression models were selected from a set of potential land use drivers or their proxies. A spatial stratification was applied by dividing the country into three main eco-regions. The results showed that at higher aggregation levels, the independent variables explained more of the variance in areas of land use types. In most cases, biogeophysical, socio-economic as well as infrastructural variables were important for the explanation of land use. The variables included in the models and their relative importance varied between land use types and eco-regions. Also within one eco-region the model variables varied with aggregation level. The results demonstrated spatial scale dependence of land use drivers.Spatially explicit modelling of land use change dynamicsA spatially explicit multi-scale land use change model was explained and demonstrated in Chapter 3. Important inputs for the model were the results of the multi-scale system analysis of Chapter 2. The model consists of two main modules: the demand module and the allocation module. Changes in the national demand for agricultural commodities are estimated with the demand module. The sub-national changes in land use following changes in demand are calculated in a multi-scale allocation module. The finest resolution for which changes were calculated for Ecuador, were the 5 by 5 minute cells. The allocation module takes into account the non-linear complexities of land use systems by dealing with competition between land use types and interconnectivity of landscape elements. Phenomena that operate over large distances like the influence of urban centres, the proximity to infrastructure and migration fluxes are addressed.The allocation of land use changes was validated by modelling backwards from the year 1991 to the year 1974, a year for which an independent data set was available. The validation results showed a rather good agreement with actual land use data at the level of administrative units called cantons. A hypothetical future base-line scenario of increasing demands for agricultural commodities was used to demonstrate how dynamics of land use are modelled. The results indicated "hot-spots", areas with potentially highly dynamic land use change where impacts of land use change on the natural resource base can be expected.Nutrient balances as indicators of sustainabilityUsing a nutrient balance model, inputs and outputs of nitrogen, phosphorus and potassium were estimated for each cell for the main land use types for the year 1991 (Chapter 4). Inputs considered were mineral fertiliser, organic fertiliser, atmospheric deposition, biological N-fixation and sedimentation; outputs considered were harvested product, removed crop residues, leaching, gaseous losses and erosion. The outcomes for cells were aggregated to sub-national and national level.In general, the estimates showed a depletion of the soil nutrient stock in Ecuadorian agro-ecosystems. Nationally, for temporary crops there was mainly a deficit of nitrogen (42 kg ha -1yr -1), while for permanent crops both nitrogen and potassium balances were clearly negative (40 and 25 kg ha -1yr -1, respectively). For grassland overall, losses are smaller. Erosion is a major cause of nitrogen loss but leaching and denitrification also contribute significantly. In permanent crops relatively large amounts of potassium leave the agro-ecosystem through harvested products, due to high potassium concentrations in these products and high yields.At sub-national scale, nutrient depletion under current land use is more severe in the Andean region than the coastal region, mainly as a result of higher erosion losses. The Amazon region is still largely unexploited but this study suggests that the current conversion of forest to agricultural land may cause serious nutrient balance problems at a local level.Exploration through scenariosThe land use change model for Ecuador was used for the dynamic and spatially explicit exploration of near future agricultural land use changes (Chapter 5). A number of plausible scenarios were formulated for the period until the year 2010. At the national level, different developments in national food demand were defined on the basis of assumptions for population growth, consumption patterns and export developments. At the sub-national level the protection of nature parks and land use restrictions due to land degradation were evaluated with respect to their possible spatial impacts on the land use change dynamics within the country. Under the assumptions of the demand scenarios, the area agricultural land expanded significantly, resulting in more use of land in existing agricultural areas and frontier-type expansion into rather undisturbed natural areas. The patterns of change depended on the increase in demand, competition between land use types, changes in the drivers of land use, and the area of land that was excluded from agricultural use.Soil fertility impacts were considered by linking the results of the nutrient balances calculated in Chapter 4 with the results of the land use change model. The results indicated potential negative effects of land use changes on the soil nutrient balance. It was argued that quantification of land use dynamics at the landscape level can support research and policy aimed at understanding the drivers of land use change and the behaviour of complex agro-ecosystems under changing conditions at different spatial scales. This way, issues dealing with sustainable food production and the management of the natural resource base can be addressed in a more integrated and quantitative manner.Spatial and temporal characterisation of Andean potato production systemsChapter 6 described how a statistical analysis of the spatial structure of cropping systems can be combined with the land use change model in order to characterise a specific cropping system. The method was applied for potato production systems in the Ecuadorian Andes. The variation of areas and yields of potato was analysed on the basis of the data for the grid-cells. The results showed a large spatial variability in conditions of potato production systems. The combinations of biophysical and socio-economic variables that best explained the spatial structure of potato areas as well as their yields depended on the geographic area analysed. The whole Andean region was analysed, as well as the provinces Carchi and Chimborazo. Output of the land use change model was used to evaluate the position of potato production systems within the general dynamics of the main land use types. In this way, areas were located where pressure on potato production systems is probable, due to expansion of other agricultural land uses in response to increasing national food demands. Especially competition with grasslands is expected in the near future.When potato-growing areas are pushed into marginal areas, this is likely to have negative consequences for potato productivity. With the results a typology can be given of production systems in relation to their environment. Such information can be used to direct agro-ecological research at specific interactions between environment and crop management.ConclusionsA multi-scale system analysis demonstrated scale dependence of Ecuadorian land use.The results of the multi-scale system analysis could be integrated in a spatially explicit, dynamic, land use change model.Scenarios studies with the model allowed for the exploration of possible future land use changes.The quantitative, spatially explicit, information on land use changes generated by the model offers possibilities for the assessment of the effects of land use change on sustainability of food production, biodiversity and global climate change.Priorities in further methodology development are linkage with geophysical landscape processes and a better incorporation of crop specific management.</UL

Furthering critical institutionalism

This special issue furthers the study of natural resource management from a critical institutional perspective. Critical institutionalism (CI) is a contemporary body of thought that explores how institutions dynamically mediate relationships between people, natural resources and society. It focuses on the complexity of institutions entwined in everyday social life, their historical formation, the interplay between formal and informal, traditional and modern arrangements, and the power relations that animate them. In such perspectives a social justice lens is often used to scrutinise the outcomes of institutional processes. We argue here that critical institutional approaches have potentially much to offer commons scholarship, particularly through the explanatory power of the concept of bricolage for better understanding institutional change. Critical institutional approaches, gathering momentum over the past 15 years or so, have excited considerable interest but the insights generated from different disciplinary perspectives remain insufficiently synthesised. Analyses emphasising complexity can be relatively illegible to policy-makers, a fact which lessens their reach. This special issue therefore aims to synthesise critical institutional ideas and so to lay the foundation for moving beyond the emergent stage to make meaningful academic and policy impact. In bringing together papers here we define and synthesise key themes of critical institutionalism, outline the concept of institutional bricolage and identity some key challenges facing this school of thought

A short screening instrument for poststroke dementia : the R-CAMCOG

BACKGROUND AND PURPOSE: The CAMCOG is a feasible cognitive screening instrument for dementia in patients with a recent stroke. A major disadvantage of the CAMCOG, however, is its lengthy and relatively complex administration for screening purposes. We therefore developed the Rotterdam CAMCOG (R-CAMCOG), based on the original version. Our aim was to reduce the estimated administration time to 15 minutes or less and to retain or perhaps even improve its diagnostic accuracy. METHODS: We analyzed the item scores on the CAMCOG of 300 consecutive stroke patients, after exclusion of patients with a severe aphasia or lowered consciousness level, who were entered in the Rotterdam Stroke Databank. The diagnosis of dementia was made independent of the R-CAMCOG score, on the basis of clinical examination and neuropsychological test results. The R-CAMCOG was constructed in 3 steps. First, items with floor and ceiling effects were removed. Next, subscales with no additional diagnostic value were excluded. Finally, we removed items that did not contribute to the homogeneity of the subscales. The diagnostic accuracy of the R-CAMCOG and the original CAMCOG was determined by means of the area under the receiver operating characteristic (ROC) curve. RESULTS: In the 3 steps, the number of items was reduced from 59 to 25, divided over the subscales orientation, memory (recent, remote, and learning), perception, and abstraction. The subscale orientation did not reach significance in a logistic regression model but was included in the R-CAMCOG because of its high face validity in dementia screening. Internal validation with ROC analysis suggests that the R-CAMCOG and the CAMCOG are equally accurate in screening for poststroke dementia (area under the curve was 0.95 for both tests). CONCLUSIONS: The R-CAMCOG has overcome the disadvantages of the original CAMCOG. It is a promising, short, and easy-to-administer screening instrument for poststroke dementia. It seems to be sufficiently accurate for this purpose, but the test has yet to be validated in a separate, independent study

Temperature effects on dislocation core energies in silicon and germanium

Temperature effects on the energetics of the 90-degree partial dislocation in silicon and germanium are investigated, using non-equilibrium methods to estimate free energies, coupled with Monte Carlo simulations. Atomic interactions are described by Tersoff and EDIP interatomic potentials. Our results indicate that the vibrational entropy has the effect of increasing the difference in free energy between the two possible reconstructions of the 90-degree partial, namely, the single-period and the double-period geometries. This effect further increases the energetic stability of the double-period reconstruction at high temperatures. The results also indicate that anharmonic effects may play an important role in determining the structural properties of these defects in the high-temperature regime.Comment: 8 pages in two-column physical-review format with six figure