Isocaloric substitution of carbohydrates with protein: the association with weight change and mortality among patients with type 2 diabetes
Campmans-Kuijpers, M.J.E. ; Sluijs, I. van der; Sluik, D. - \ 2015
Cardiovascular Diabetology 14 (2015). - ISSN 1475-2840 - 10 p.
randomized controlled-trial - glycemic load values - dietary-protein - european countries - physical-activity - body-weight - index - nutrition - cancer - fat
Background: The health impact of dietary replacement of carbohydrates with protein for patients with type 2 diabetes is still debated. This study aimed to investigate the association between dietary substitution of carbohydrates with (animal and plant) protein and 5-year weight change, and all-cause and cardiovascular (CVD) mortality risk in patients with type 2 diabetes. Methods: The study included 6,107 diabetes patients from 15 European cohorts. Patients with type 1 diabetes were excluded. At recruitment, validated country-specific food-frequency questionnaires were used to estimate dietary intake. Multivariable adjusted linear regression was used to examine the associations between dietary carbohydrate substitution with protein and 5-year weight change, and Cox regression to estimate hazard ratios (HRs) for (CVD) mortality. Results: Annual weight loss of patients with type 2 diabetes was 0.17 (SD 1.24) kg. After a mean follow-up of 9.2 (SD 2.3)y, 787 (13%) participants had died, of which 266 (4%) deaths were due to CVD. Substitution of 10 gram dietary carbohydrate with total (ß = 187 [75;299]g) and animal (ß = 196 [137;254]g) protein was associated with mean 5-year weight gain. Substitution for plant protein was not significantly associated with weight change (ß = 82 [-421;584]g). Substitution with plant protein was associated with lower all-cause mortality risk (HR = 0.79 [0.64;0.97]), whereas substitution with total or animal protein was not associated with (CVD) mortality risk. Conclusions: In diabetes patients, substitution with plant protein was beneficial with respect to weight change and all-cause mortality as opposed to substitution with animal protein. Therefore, future research is needed whether dietary guidelines should not actively promote substitution of carbohydrates by total protein, but rather focus on substitution of carbohydrates with plant protein.
Implications of Climate Change for Rural Tourism in the Nordic Region
Nicholls, S. ; Amelung, B. - \ 2015
Scandinavian Journal of Hospitality and Tourism 15 (2015)1-2. - ISSN 1502-2250 - p. 48 - 72.
vulnerability - weather - index - variability - perspective - businesses - resources
In many rural regions, including those of the Nordic region, a former dependence on primary activities such as fishing, forestry, mining and/or agriculture has been superseded in recent decades by increasing involvement in the tourism sector. The purpose of this paper is to explore the potential implications of climate change for non-winter rural tourism in the Nordic region. Using the Tourism Climatic Index as an analytical tool, the paper highlights the range of potential conditions for outdoor tourism activity for three future time periods (the 2020s, 2050s and 2080s) under two scenarios of climate change (B1A and A1F). Findings suggest the possibility of substantially longer periods of desirable climatic conditions in future decades, particularly in the southern and eastern portions of the region. Implications of the findings are discussed in the context of the adaptive capacity of various tourism actors (tourists, providers and government) and in light of the particular vulnerabilities and assets of rural communities. The need for an integrated and multilevel approach that recognises the importance of the efficient coordination and integration of resources, products and services across multiple actor boundaries and levels is stressed.
The effects of functional fiber on postprandial glycemia, energy intake, satiety, palatability and gastrointestinal wellbeing: a randomized crossover trial
Yuan, J.Y.F. ; Smeele, R.J.M. ; Harington, K.D. ; Loon, F.M. van; Wanders, A.J. ; Venn, B.J. - \ 2014
Nutrition Journal 13 (2014). - ISSN 1475-2891
type-2 diabetes-mellitus - desk-top guide - dietary fiber - digestive tolerance - insulin - foods - metaanalysis - glucose - index
Background: Fiber intakes in developed countries are generally below those recommended by relevant authorities. Given that many people consume fiber-depleted refined-grain products, adding functional fiber will help to increase fiber intakes. The objective of the study was to determine metabolic and sensory effects of adding fiber to bread. Methods: A double-blind pair of randomized crossover trials with a two-week washout in which two fiber-containing breads were compared with control bread. The functional fiber (fruit fiber and FibreMax (TM)) was added to yield 10 g fiber per serve (two slices). Eighty participants (n = 37 fruit fiber and n = 43 FibreMax (TM)) consumed one serve of bread (fiber or control) followed three hours later by a pasta meal consumed ad libitum. Outcome measures included glycemia, satiety, palatability, gastrointestinal wellbeing, visual appeal and subsequent energy intake of the pasta meal. Multivariate regression was undertaken to test for differences between treatment and control for blood glucose, satiety, and cumulative energy intake. Satiety responses were also compared by splitting the data into an immediate response after eating (0-30 min) and a return to hunger analysis (30-180 min). A Wilcoxon sign rank test was used for the first component (0-30 min) and Wilcoxon matched-pairs signed-rank test for the second component (30-180 min). Between treatment differences for gastrointestinal wellbeing were tested using Pearson's chi-square test or Fisher's exact test. Results: Consumption of the fruit fiber bread reduced postprandial glycemia by 35% (95% CI 13 to 51; P = 0.004) and cumulative energy intake by 368 kJ (95% CI 163 to 531; P = 0.001). There was little influence on satiety and the bread was rated as having poor taste and smell whilst generating feelings of nausea in some participants. FibreMax (TM) enriched bread reduced glycemia by 43% (95% CI 17 to 61; P = 0.004) without influence on energy intake or satiety. Apart from a lower visual appeal, the FibreMax (TM) bread was palatable. Neither bread caused gastrointestinal discomfort related to flatulence or bloating. Conclusions: Enriching bread with 10 g of functional fiber per serve is feasible although reformulation is needed to create not only an acceptable bread, but a desirable product.
Diversity of crop development traits and nitrogen use efficiency among potato cultivars grown under contrasting nitrogen regimes
Ospina Nieto, C.A. ; Lammerts Van Bueren, E. ; Allefs, J.J.H.M. ; Engel, B. ; Putten, P.E.L. van der; Linden, C.G. van der; Struik, P.C. - \ 2014
Euphytica 199 (2014)1-2. - ISSN 0014-2336 - p. 13 - 29.
solanum-tuberosum l. - yield response - root-system - dry-matter - nitrate - fertilization - management - quality - index - plant
Potato (Solanum tuberosum L.) requires abundant nitrogen (N) to perform well and has low nitrogen use efficiency (NUE). We assessed phenotypic variation among 189 potato cultivars for NUE and the association between NUE and ecophysiological variables describing canopy development (CDv), under high and low N input. In 2009 and 2010, 189 cultivars were grown with N supply (soil N + fertiliser N) of 75 or 180 kg N/ha at Bant, the Netherlands. CDv was assessed weekly as the percentage of soil covered by green potato leaves (%SC). Data were analysed using a model that described CDv as a function of thermal time, based on the Beta function and estimates of cardinal temperatures. Nitrogen significantly affected model-derived, biologically relevant, curve-fit parameters for each cultivar. The t 1 (i.e., thermal time required to reach maximum soil cover (Vx)) was higher at low than at high N. Other parameters were higher at high than at low N, especially Vx and the period over which it was maintained. Nitrogen also affected tuber dry matter yield, tuber size and weight distributions, N content and N uptake but not tuber dry matter percentage. The total area under the %SC curve was highly correlated with yield in both years. Cultivars performing well under high N also performed well under low N. There was large variation in NUE component traits among cultivars; maturity type partially explained this variation. Variables of the CDv model captured this variation, N effects on light interception and its correlation with yield.
Stability of dietary patterns assessed with reduced rank regression; the Zutphen Elderly Study
Jankovic, N. ; Streppel, M.T. ; Kampman, E. ; Groot, C.P.G.M. de; Boshuizen, H.C. ; Soedamah-Muthu, S.S. ; Kromhout, D. ; Feskens, E.J.M. - \ 2014
Nutrition Journal 13 (2014). - ISSN 1475-2891
coronary-heart-disease - nutrient intake - swedish women - risk-factors - food - mortality - cancer - reproducibility - index - men
Background Reduced rank regression (RRR) combines exploratory analysis with a-priori knowledge by including risk factors in the model. Dietary patterns, derived from RRR analysis, can be interpreted by the chosen risk factor profile and give an indication of positive or adverse health effects for a specific disease. Our aim was to assess the stability of dietary patterns derived by RRR over time. Methods We used data from 467 men, aged 64–85 years, participating in the 1985 and 1990 examination rounds of the Zutphen Elderly Study. Backwards regression on risk factors and food groups was applied prior to the RRR analysis to exclude food groups with low predictability (from 36 to 19 food groups) for the chosen risk factor profile. For the final RRR analysis, dietary intake data from 19 food groups as predictor variables and 6 established risk factors for cardiovascular diseases (body mass index, systolic and diastolic blood pressure, high density lipoprotein and total cholesterol levels, and uric acid) were used. Results Three RRR dietary patterns were derived for both examination years: a “(low in) cereal fibre pattern”, an “alcohol pattern” and an “inconsistent pattern”. The “(low in) cereal fibre pattern” was most stable over time, with a correlation coefficient of 0.47 (95% CI: 0.38-0.53) between 1985 and 1990 measurements. Conclusion Dietary patterns as measured by RRR, after backwards regression, are reasonably stable over a period of five years. Thus, RRR appears to be an attractive method to measure long-term dietary exposure for nutritional epidemiological studies, with one dietary measurement at baseline.
Assessing vegetation change using vegetation-plot databases: a risky business
Chytry, M. ; Tichý, L. ; Hennekens, S.M. ; Schaminee, J.H.J. - \ 2014
Applied Vegetation Science 17 (2014)1. - ISSN 1402-2001 - p. 32 - 41.
long-term changes - plant-communities - phytosociological databases - species richness - grassland - forests - netherlands - drivers - decades - index
Aim Data from vegetation plots can be used for the assessment of past vegetation change in three ways: (1) comparison of old and new records from permanent plots established for vegetation monitoring; (2) revisiting historical phytosociological plots and subsequent comparison of old and new records; (3) comparison of large sets of old and new phytosociological records from the same area but different plots. Option (3) would be the cheapest in regions where large vegetation-plot databases are available, but there is a risk of incorrect results due to a spatial mismatch of old and new plots. Here we assess the accuracy of such analyses. Methods We used three data sets of permanent plots from Czech mountain bogs and Dutch oak forests and heathlands to quantify vegetation change. We selected subsets to simulate analyses based on (1) data from permanent plots or revisited phytosociological plots, i.e. containing old and new records from the same plots, (2) vegetation-plot databases with old and new records from different, randomly selected sites, and (3) vegetation-plot databases with old and new records from different but close sites. We repeated each subset selection 1000 times and analysed vegetation change in each of the three data sets and each variant of subset selection using permutational multivariate analysis of variance. Results For data sets with no actual vegetation change, analyses of some subsets simulating vegetation-plot databases incorrectly suggested significant changes. For a data set with real change, a change was detected in analyses of simulated vegetation-plot databases, but in several cases it had a different direction or magnitude to the real change. Conclusions The assessment of vegetation change using vegetation-plot databases should be either avoided or interpreted with extreme caution because of the risk of incorrect results. Analyses such as these may be used to propose hypotheses about past vegetation change, but their results should not be considered valid unless confirmed using more reliable data. In many contexts, re-visitation studies of historical phytosociological plots may be the best strategy to assess past vegetation change, while new networks of carefully stratified permanent plots are preferable for monitoring future change.
Refreshing the role of open water surfaces on mitigating the maximum urban heat island effect
Steeneveld, G.J. ; Koopmans, S. ; Heusinkveld, B.G. ; Theeuwes, N.E. - \ 2014
Landscape and Urban Planning 121 (2014). - ISSN 0169-2046 - p. 92 - 96.
land-use - temperature - comfort - strategies - index - uk
During warm summer episodes citizens in urban areas are subject to reduced human thermal comfort and negative health effects. To mitigate these adverse effects, land use planners and urban designers have used the evaporative power of water bodies as a tool to limit the urban heat island effect (UHI) and undesirable human thermal comfort. Based on weather observations by Dutch hobby meteorologists and a station network in Rotterdam (Netherlands), we show that water bodies increase rather than decrease the 95 percentile of the daily maximum UHI. The high heat capacity of water suppresses the diurnal and annual cycle over water, and water temperatures remain relatively high after evening and season transitions. This is reflected to the 2 m temperature above and in the surround of the water body, and in a relatively high UHI. Our result has consequences for the daily practice in urban design concerning microclimate effects.
Estimating crop-specific evapotranspiration using remote-sensing imagery at various spatial resolutions for improving crop growth modelling
Sepulcre-Canto, G. ; Gellens-Meulenberghs, F. ; Arboleda, A. ; Duveiller, G. ; Wit, A.J.W. de; Eerens, H. ; Djaby, B. ; Defourny, P. - \ 2013
International Journal of Remote Sensing 34 (2013)9-10. - ISSN 0143-1161 - p. 3274 - 3288.
soil-moisture - index - china
By governing water transfer between vegetation and atmosphere, evapotranspiration (ET) can have a strong influence on crop yields. An estimation of ET from remote sensing is proposed by the EUMETSAT ‘Satellite Application Facility’ (SAF) on Land Surface Analysis (LSA). This ET product is obtained operationally every 30 min using a simplified SVAT scheme that uses, as input, a combination of remotely sensed data and atmospheric model outputs. The standard operational mode uses other LSA-SAF products coming from SEVIRI imagery (the albedo, the downwelling surface shortwave flux, and the downwelling surface longwave flux), meteorological data, and the ECOCLIMAP database to identify and characterize the land cover. With the overall objective of adapting this ET product to crop growth monitoring necessities, this study focused first on improving the ET product by integrating crop-specific information from high and medium spatial resolution remote-sensing data. A Landsat (30 m)-based crop type classification is used to identify areas where the target crop, winter wheat, is located and where crop-specific Moderate Resolution Imaging Spectroradiometer (MODIS) (250 m) time series of green area index (GAI) can be extracted. The SVAT model was run for 1 year (2007) over a study area covering Belgium and part of France using this supplementary information. Results were compared to those obtained using the standard operational mode. ET results were also compared with ground truth data measured in an eddy covariance station. Furthermore, transpiration and potential transpiration maps were retrieved and compared with those produced using the Crop Growth Monitoring System (CGMS), which is run operationally by the European Commission's Joint Research Centre to produce in-season forecast of major European crops. The potential of using ET obtained from remote sensing to improve crop growth modelling in such a framework is studied and discussed. Finally, the use of the ET product is also explored by integrating it in a simpler modelling approach based on light-use efficiency. The Carnegie–Ames–Stanford Approach (CASA) agroecosystem model was therefore applied to obtain net primary production, dry matter productivity, and crop yield using only LSA-SAF products. The values of yield were compared with those obtained using CGMS, and the dry matter productivity values with those produced at the Flemish Institute for Technological Research (VITO). Results showed the potential of using this simplified remote-sensing method for crop monitoring
Assessment of the influence of amylose-LPC complexation on the extent of wheat starch digestibility by size-exclusion chromatography
Ahmadi-Abhari, S. ; Woortman, A.J.J. ; Hamer, R.J. ; Loos, K. - \ 2013
Food Chemistry 141 (2013)4. - ISSN 0308-8146 - p. 4318 - 4323.
laser-light-scattering - lipid complexes - enzyme - index
Amylose forms inclusion complexes with lysophosphatidylcholine (LPC), that decrease the susceptibility of amylose to amylase degradation. This study on the influence of complexation on starch susceptibility to amylase explains the nature of this protective effect. Wheat starch suspensions (9% w/w) containing 0.5–5% LPC were subjected to hydrolysis by porcine pancreatic a-amylase at 37 °C for several digestion times. The digesta were analysed by size-exclusion chromatography (SEC). The molar mass distribution was closely dependent on the digestion time and amount of LPC. This study precisely demonstrates the alteration of the digestion profile of starch on a molecular level, influenced by amylose-LPC complexation; however the effect depends on the digestion time. During 15 and 30 min digestion, inclusion complexes not only protect amylopectin in the initial hydrolysis stage, but also demonstrate lower susceptibility of the molecular amylose complexes to amylase hydrolysis. Digestion for 240 min resulted in a lower oligosaccharide peak concentration, in the presence of a high LPC concentration, which is related to less degradation of complexed amylose fraction.
Influence of lysophosphatidylcholine on the gelation of diluted wheat starch suspensions
Ahmadi-Abhari, S. ; Woortman, A.J.J. ; Hamer, R.J. ; Oudhuis, A.A.C.M. ; Loos, K. - \ 2013
Carbohydrate Polymers 93 (2013)1. - ISSN 0144-8617 - p. 224 - 231.
amylose-lipid complexes - water-content - gelatinization - digestibility - glycerophosphatidylcholine - cultivars - systems - index
Starch is an omnipresent constituent which is used for its nutritional and structuring properties. Recently concerns have been raised since starch is a source of readily available glucose which is tightly correlated with diabetes type II and obesity. For this reason, the possibilities for modulating the digestibility of starch while preserving its functional properties were investigated; therefore the focus of this paper is on starch gelatinization and the effect of lysophosphatidylcholine (LPC) on the structuring properties of wheat starch. The effect of LPC on thermal properties and viscosity behavior of starch suspensions was studied using DSC and RVA, respectively. The influence on granular structure was observed by light microscopy. The RVA profile demonstrated no viscosity increase at high LPC concentrations which proves intact granular structure after gelatinization. LPC in intermediate concentrations resulted in a notable delay of pasting; however the peak and end viscosities were influenced as well. Lower LPC concentrations demonstrated a higher peak viscosity as compared with pure starch suspensions. DSC results imply that inclusion complexes of amylose–LPC might be formed during pasting time. Since the viscosity profiles are changed by LPC addition, swelling power and solubility of starch granules are influenced as well. LPC hinders swelling power and solubility of starch granules which are stimulated by heating.
Factor analysis is more appropriate to identify overall dietary patterns associated with diabetes when compared with treelet transform analysis
Schoenaker, D.A.J.M. ; Dobson, A. ; Soedamah-Muthu, S.S. ; Mishra, G.D. - \ 2013
The Journal of Nutrition 143 (2013)3. - ISSN 0022-3166 - p. 392 - 398.
adaptive multiscale basis - sparse unordered data - womens health - prevention - australia - validity - rotation - cohort - index
Treelet transform (TT) is a proposed alternative to factor analysis for deriving dietary patterns. Before applying this method to nutrition data, further analyses are required to assess its validity in nutritional epidemiology. We aimed to compare dietary patterns from factor analysis and TT and their associations with diabetes incidence. Complete data were available for 7349 women (50-55 y at baseline) from the Australian Longitudinal Study on Women's Health. Exploratory factor analysis and TT were performed to obtain patterns by using dietary data collected from an FFQ. Generalized estimating equations analyses were used to examine associations between dietary patterns and diabetes incidence. Two patterns were identified by both methods: a prudent and a Western dietary pattern. Factor analysis factors are a linear combination of all food items, whereas TT factors also include items with zero loading. The Western pattern identified by factor analysis showed a significant positive association with diabetes [highest quintile: OR = 1.94 (95% CI: 1.25, 3.00); P-trend = 0.001). Both factor analysis and TT involve different assumptions and subjective decisions. TT produces clearly interpretable factors accounting for almost as much variance as factors from factor analysis. However, TT patterns include food items with zero loading and therefore do not represent overall dietary patterns. The different dietary pattern loading structures identified by both methods result in different conclusions regarding the relationship with diabetes. Results from this study indicate that factor analysis might be a more appropriate method for identifying overall dietary patterns associated with diabetes compared with TT.
Association between High Fat-low Carbohydrate Diet Score and Newly Diagnosed Type 2 Diabetes in Chinese Population
Na, Y. ; Feskens, E.J.M. ; Li, Y.P. ; Zhang, J. ; Fu, P. ; Ma, G.S. ; Yang, X.G. - \ 2012
Biomedical and environmental sciences 25 (2012)4. - ISSN 0895-3988 - p. 373 - 382.
coronary-heart-disease - insulin sensitivity - risk - women - metaanalysis - profile - index - men
Objective To study the association between high fat-low carbohydrate diet score and newly diagnosed type 2 diabetes in Chinese population. Methods Data about 20 717 subjects aged 45-59 years from the cross-sectional 2002 China National Nutrition and Health Survey were analyzed. High fat-low carbohydrate diet was scored according to the energy of carbohydrate, fat, and protein. Results Of the 20 717 subjects, 1 332 were diagnosed with hyperglycemia and 662 were newly diagnosed with type 2 diabetes. Multivariate adjusted analysis showed that the highest score of type 2 diabetes patients was 2.75 (95% CI: 2.09-3.61). The score of type 2 diabetes patients was 1.87 (95% CI: 1.35-2.58) after further adjustment for their socioeconomic status and physical activity. No significant difference was found in the odds ratio after further adjustment for BMI, blood pressure, lipid level, and energy intake. No evidence was observed for the relation between high fat-low carbohydrate-diet score in type 2 diabetes patients due to high family income, less education, physical activity, overweight, hypertension, high TG, or low HDL level. Conclusion High fat-low carbohydrate diets, far different from traditional Chinese diets, are associated with the high incidence of type 2 diabetes in Chinese population.
Observation uncertainty of satellite soil moisture products determined with physically-based modeling
Wanders, N. ; Karssenberg, D. ; Bierkens, M.F.P. ; Parinussa, R. ; Jeu, R. de; Dam, J.C. van; Jong, S. de - \ 2012
Remote Sensing of Environment 127 (2012). - ISSN 0034-4257 - p. 341 - 356.
passive microwave measurements - improving runoff prediction - vegetation optical depth - ers scatterometer - amsr-e - retrieval - assimilation - validation - algorithm - index
Accurate estimates of soil moisture as initial conditions to hydrological models are expected to greatly increase the accuracy of flood and drought predictions. As in-situ soil moisture observations are scarce, satellite-based estimates are a suitable alternative. The validation of remotely sensed soil moisture products is generally hampered by the difference in spatial support of in-situ observations and satellite footprints. Unsaturated zone modeling may serve as a valuable validation tool because it could bridge the gap of different spatial supports. A stochastic, distributed unsaturated zone model (SWAP) was used in which the spatial support was matched to these of the satellite soil moisture retrievals. A comparison between point observations and the SWAP model was performed to enhance understanding of the model and to assure that the SWAP model could be used with confidence for other locations in Spain. A timeseries analysis was performed to compare surface soil moisture from the SWAP model to surface soil moisture retrievals from three different microwave sensors, including AMSR-E, SMOS and ASCAT. Results suggest that temporal dynamics are best captured by AMSR-E and ASCAT resulting in an averaged correlation coefficient of 0.68 and 0.71, respectively. SMOS shows the capability of capturing the long-term trends, however on short timescales the soil moisture signal was not captured as well as by the other sensors, resulting in an averaged correlation coefficient of 0.42. Root mean square errors for the three sensors were found to be very similar (± 0.05 m3m- 3). The satellite uncertainty is spatially correlated and distinct spatial patterns are found over Spain.
Nutrient-rich foods in relation to various measures of anthropometry
Streppel, M.T. ; Groot, C.P.G.M. de; Feskens, E.J.M. - \ 2012
Family Practice 29 (2012)Suppl. 1. - ISSN 0263-2136 - p. i36 - i43.
dietary-intake - rotterdam - index - validation - density - obesity - disease
Background. Nutrient quality systems, for example the nutrient-rich foods (NRF) index, measure the nutrient quality of individual foods and may be used to assess the nutrient density of the overall diet. It is not yet known whether the NRF index is helpful in weight management. We hypothesize that a nutrient-dense diet is associated with a lower body weight and waist circumference. Objective. The objective of the present study was to examine the association between the NRF index and various measures of anthropometry. Methods. This study was carried out in a sample of 2044 men and 2925 women, aged =55 years, participating in a community-based prospective cohort study in Rotterdam, The Netherlands. The NRF9.3 algorithms were used to estimate the nutrient density of the subjects’ diets. Linear regression was used to examine the association between the NRF index scores and body mass index (BMI), body weight, waist circumference, wait-to-hip ratio and waist-to-height ratio. Results. Subjects with a high NRF9.3 index score had a lower energy intake (EI) as compared to those with low NRF9.3 index score. However, after adjustment for age, gender and other confounders, the NRF9.3 index score as well as the Nutrient Rich 9 index score were positively associated with BMI, body weight, waist circumference and waist-to-height ratio. Conclusions. Although subjects with a high NRF9.3 index score had a lower EI than those subjects with a low index score, their BMI, body weight, waist circumference and waist-to-height ratio was higher. The association between nutrient quality and body composition is therefore complex
Costing the impact of climate change on tourism in Europe: results of the PESETA project. Climatic Change
Amelung, B. ; Moreno, A. - \ 2012
Climatic Change 112 (2012)1. - ISSN 0165-0009 - p. 83 - 100.
index - model
Climate change might lead to large shifts in tourist flows, with large economic implications. This article simulates the effect of future climate change by the 2080s on outdoor international tourism expenditure within Europe. The assessment is based on the statistical relationship between bed nights and a climate-related index of human comfort, after accounting for other determinants of bed nights such as income and prices. It is concluded that climate change could have significant impacts on the regional distribution of the physical resources supporting tourism in Europe. For example, in summer, Southern Europe could experience climate conditions that are less favourable to tourism than the current climate, while countries in the North could enjoy better conditions. The economic effects of these changes are likely to be sizeable, albeit difficult to assess. Crucially, they are shown to depend on tourists’ temporal flexibility with respect to holiday planning. The greater the prominence of institutional rigidities such as school holidays, the larger the differences between winning and losing regions in terms of economic impact.
A generalized maximum entropy stochastic frontier measuring productivity accounting for spatial dependency
Tonini, A. ; Pede, V. - \ 2011
Entropy 13 (2011)11. - ISSN 1099-4300 - p. 1916 - 1927.
moments estimation - panel-data - inefficiency - index
In this paper, a stochastic frontier model accounting for spatial dependency is developed using generalized maximum entropy estimation. An application is made for measuring total factor productivity in European agriculture. The empirical results show that agricultural productivity growth in Europe is driven by upward movements of technology over time through technological developments. Results are then compared for a situation in which spatial dependency in the technical inefficiency effects is not accounted
Comparison of bioassessment results and costs between preserved and unpreserved macroinvertebrate samples from streams
Keizer-Vlek, H.E. ; Goedhart, P.W. ; Verdonschot, P.F.M. - \ 2011
Environmental Monitoring and Assessment 175 (2011)1-4. - ISSN 0167-6369 - p. 613 - 621.
rapid assessment - benthic macroinvertebrates - macro-invertebrates - statistical power - sorting methods - water-quality - rivers - communities - level - index
The choice to use or not use a preservative before sorting macroinvertebrate samples (i.e., dead specimens vs. living specimens) is based on studies not solely focused on the effects of preservation. Using identical sample processing protocols, we compared preserved and unpreserved samples for the following parameters: (1) the number of taxa and individuals for each major macroinvertebrate group, (2) ecological quality classes calculated with a multimetric index developed for the assessment of small Dutch lowland streams, and (3) costs of sample processing. We collected macroinvertebrate samples from three lowland streams in the Netherlands. At each site, we collected six replicate samples, of which three samples were preserved and three were not. Significantly different numbers of Ephemeroptera individuals and Hydracarina taxa and individuals were collected from preserved samples compared to unpreserved samples. In assessments based on these individual metrics, standardization of sample processing will be required. In streams with Ephemeroptera, the preservation of samples is necessary to optimize the number of Ephemeroptera individuals collected. In streams that contain Hydracarina, the preservation of samples will result in an underestimation of the number of Hydracarina taxa and individuals present. In only one instance there was a difference in ecological quality between preserved and unpreserved samples, indicating that assessing small Dutch lowland streams does not require standardization of sample preservation as part of the sample processing protocol. We detected no significant differences in sample processing costs between preserved and unpreserved samples.
Assessing drought risk and irrigation need in northern Ethiopia
Araya, A. ; Stroosnijder, L. - \ 2011
Agricultural and Forest Meteorology 151 (2011)4. - ISSN 0168-1923 - p. 425 - 436.
barley hordeum-vulgare - rainwater use - dry spells - rainfall - highlands - variability - model - index - conservation - efficiency
Long-term climate data of four stations in the northern Ethiopia were analyzed in combination with information from local farmers and documented materials. From this analysis, a suitable drought-assessing technique was developed and site-specific needs for supplementary irrigation were explored. Results showed that our technique for assessing drought and crop failure corresponded well with farmer observations. The three major causes of crop failure (dry spells, short growing period and “total lack of rain”) which were explicitly listed and ranked by the local farmers were found to match the analyzed data well. The agro-meteorological variables with the most severe consequences were “short growing period” and “total lack of rain”. To prolong the growing period, supplementary irrigation is recommended in the month of September for three of the stations (Maychew, Mekelle and Adigudom) because: (1) rain frequently stops in early September or late August and crops have no other source of water for the rest of the growing period; (2) sufficient surface runoff can be harvested in July and August to be stored in farm ponds and used in September; (3) more cultivable land can be irrigated if supplementary irrigation is scheduled only for the month of September; and (4) giving supplementary irrigation in September can cut yield reduction by over 80% and crop failure by over 50%, except at Alamata. At Alamata, supplementary irrigation must be scheduled for July. The conditions experienced during the famine years of the early 1980s were primarily caused by the continued total rain failure over multiple years. Giving supplementary irrigation in July or September would probably not have mitigated the effects of these droughts, especially at Alamata and Maychew stations
Individual, country, and journal self-citation in soil science
Minasny, B. ; Hartemink, A.E. ; McBratney, A. - \ 2010
Geoderma 155 (2010)3-4. - ISSN 0016-7061 - p. 434 - 438.
impact factor - index
Self-citation is common practice in most sciences but it differs between disciplines, countries and journals. Here we report on self-citation in soil science. We investigated citations in the major soil science journals and conducted an analysis on a country basis and for the subdiscipline of Pedometrics. It was found that the median rate of individual self-citation was 12%, and ranged from 5 to 60% in 31 soil science journals. A high rate Of journal self-citation was accompanied by a high impact factor ranking, but ranking based on the Eigenfactor (TM) revealed a very different ranking compared to the impact factor score ranking. The distribution of country self-citation rate follows a power law, and a logarithmic function was fitted to the data. Taking into account the logarithmic function, China had high Fates of self-citations whereas Egypt, Algeria, Ukraine, and Indonesia have low levels of self-citations. With few exceptions, self-citation rates in soil science are reasonable and comparable to the other biophysical sciences.
Stock Market Efficiency in Thin Trading Markets: The Case of the Vietnamese Stock Market
Dong Loc, T. ; Lanjouw, G. ; Lensink, B.W. - \ 2010
Applied Economics 42 (2010)27. - ISSN 0003-6846 - p. 3519 - 3532.
random-walk hypothesis - hong-kong - exchange - variance - behavior - returns - prices - index - tests
This article reviews developments in the Stock Trading Centre (STC) in Ho Chi Minh City, Vietnam, the main stock market in the country, since its start in 2000. It presents information about developments in the number of stocks traded, trading activity and stock-price developments. This article focuses on the question whether the market is weak-form efficient. An important element of the investigation concerns the possible bias of the results caused by the thin trading that characterizes the STC. Stock-market returns are corrected for this. The main conclusion is that the STC is not efficient in the weak form.