27 research outputs found
Various Approaches for Predicting Land Cover in Mountain Areas
Using former maps, geographers intend to study the evolution of the land
cover in order to have a prospective approach on the future landscape;
predictions of the future land cover, by the use of older maps and
environmental variables, are usually done through the GIS (Geographic
Information System). We propose here to confront this classical geographical
approach with statistical approaches: a linear parametric model (polychotomous
regression modeling) and a nonparametric one (multilayer perceptron). These
methodologies have been tested on two real areas on which the land cover is
known at various dates; this allows us to emphasize the benefit of these two
statistical approaches compared to GIS and to discuss the way GIS could be
improved by the use of statistical models.Comment: 14 pages; Classifications: Information Theory; Probability Theory &
Applications; Statistical Computing; Statistical Theory & Method
Evaluating the spatial uncertainty of future land abandonment in a mountain valley (Vicdessos, Pyrenees-France) : insights form model parameterization and experiments
International audienceEuropean mountains are particularly sensitive to climatic disruptions and land use changes. The latter leads to high rates of natural reforestation over the last 50 years. Faced with the challenge of predicting possible impacts on ecosystem services, LUCC models offer new opportunities for land managers to adapt or mitigate their strategies. Assessing the spatial uncertainty of future LUCC is crucial for the defintion of sustainable land use strategies. However, the sources of uncertainty may differ, including the input parameters, the model itself, and the wide range of possible futures. The aim of this paper is to propose a method to assess the probability of occurrence of future LUCC that combines the inherent uncertainty of model parameterization and the ensemble uncertainty of the future based scenarios. For this purpose, we used the Land Change Modeler tool to simulate future LUCC on a study site located in the Pyrenees Mountains (France) and 2 scenarios illustratins 2 land use strategies. The model was parameterized with the same driving factors used for its calibration. The defintion of static vs. dynamic and quantitative vs. qualitative (discretized) driving factors, and their combination resulted in 4 parameterizations. The combination of model outcomes produced maps of spatial uncertainty of future LUCC. This work involves literature to future-based LUCC studies. It goes beyond the uncertainty of simulation models by integrating the unceertainty of the future to provide maps to help decision makers and land managers
Efficacy of different 8 h time-restricted eating schedules on visceral adipose tissue and cardiometabolic health: A study protocol
Background and aims: To investigate the efficacy and feasibility of three different 8 h
time-restricted eating (TRE) schedules (i.e., early, late, and self-selected) compared to each other
and to a usual-care (UC) intervention on visceral adipose tissue (VAT) and cardiometabolic health
in men and women.
Methods and results: Anticipated 208 adults (50% women) aged 30e60 years, with overweight/
obesity (25 BMI<40 kg/m2
) and with mild metabolic impairments will be recruited for this
parallel-group, multicenter randomized controlled trial. Participants will be randomly allocated
(1:1:1:1) to one of four groups for 12 weeks: UC, early TRE, late TRE or self-selected TRE. The UC
group will maintain their habitual eating window and receive, as well as the TRE groups, healthy
lifestyle education for weight management. The early TRE group will start eating not later than
10:00, and the late TRE group not before 13:00. The self-selected TRE group will select an 8 h
eating window before the intervention and maintain it over the intervention. The primary
outcome is changes in VAT, whereas secondary outcomes include body composition and cardio metabolic risk factors.
Conclusion: This study will determine whether the timing of the eating window during TRE im pacts its efficacy on VAT, body composition and cardiometabolic risk factors and provide insights
about its feasibilit
Tropical tree growth driven by dry-season climate variability
Interannual variability in the global land carbon sink is strongly related to variations in tropical temperature and rainfall. This association suggests an important role for moisture-driven fluctuations in tropical vegetation productivity, but empirical evidence to quantify the responsible ecological processes is missing. Such evidence can be obtained from tree-ring data that quantify variability in a major vegetation productivity component: woody biomass growth. Here we compile a pantropical tree-ring network to show that annual woody biomass growth increases primarily with dry-season precipitation and decreases with dry-season maximum temperature. The strength of these dry-season climate responses varies among sites, as reflected in four robust and distinct climate response groups of tropical tree growth derived from clustering. Using cluster and regression analyses, we find that dry-season climate responses are amplified in regions that are drier, hotter and more climatically variable. These amplification patterns suggest that projected global warming will probably aggravate drought-induced declines in annual tropical vegetation productivity. Our study reveals a previously underappreciated role of dry-season climate variability in driving the dynamics of tropical vegetation productivity and consequently in influencing the land carbon sink.We acknowledge financial support to the co-authors provided by Agencia Nacional de Promoción Científica y Tecnológica, Argentina (PICT 2014-2797) to M.E.F.; Alberta Mennega Stichting to P.G.; BBVA Foundation to H.A.M. and J.J.C.; Belspo BRAIN project: BR/143/A3/HERBAXYLAREDD to H.B.; Confederação da Agricultura e Pecuária do Brasil - CNA to C.F.; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES, Brazil (PDSE 15011/13-5 to M.A.P.; 88881.135931/2016-01 to C.F.; 88887.199858/2018-00 to G.A.-P.; Finance Code 001 for all Brazilian collaborators); Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq, Brazil (ENV 42 to O.D.; 1009/4785031-2 to G.C.; 311874/2017-7 to J.S.); CONACYT-CB-2016-283134 to J.V.-D.; CONICET to F.A.R.; CUOMO FOUNDATION (IPCC scholarship) to M.M.; Deutsche Forschungsgemeinschaft - DFG (BR 1895/15-1 to A.B.; BR 1895/23-1 to A.B.; BR 1895/29-1 to A.B.; BR 1895/24-1 to M.M.); DGD-RMCA PilotMAB to B.T.; Dirección General de Asuntos del Personal Académico of the UNAM (Mexico) to R.B.; Elsa-Neumann-Scholarship of the Federal State of Berlin to F.S.; EMBRAPA Brazilian Agricultural Research Corporation to C.F.; Equatorian Dirección de Investigación UNL (21-DI-FARNR-2019) to D.P.-C.; São Paulo Research Foundation FAPESP (2009/53951-7 to M.T.-F.; 2012/50457-4 to G.C.; 2018/01847‐0 to P.G.; 2018/24514-7 to J.R.V.A.; 2019/08783-0 to G.M.L.; 2019/27110-7 to C.F.); FAPESP-NERC 18/50080-4 to G.C.; FAPITEC/SE/FUNTEC no. 01/2011 to M.A.P.; Fulbright Fellowship to B.J.E.; German Academic Exchange Service (DAAD) to M.I. and M.R.; German Ministry of Education, Science, Research, and Technology (FRG 0339638) to O.D.; ICRAF through the Forests, Trees, and Agroforestry research programme of the CGIAR to M.M.; Inter-American Institute for Global Change Research (IAI-SGP-CRA 2047) to J.V.-D.; International Foundation for Science (D/5466-1) to M.I.; Lamont Climate Center to B.M.B.; Miquelfonds to P.G.; National Geographic Global Exploration Fund (GEFNE80-13) to I.R.; USA’s National Science Foundation NSF (IBN-9801287 to A.J.L.; GER 9553623 and a postdoctoral fellowship to B.J.E.); NSF P2C2 (AGS-1501321) to A.C.B., D.G.-S. and G.A.-P.; NSF-FAPESP PIRE 2017/50085-3 to M.T.-F., G.C. and G.M.L.; NUFFIC-NICHE programme (HEART project) to B.K., E.M., J.H.S., J.N. and R. Vinya; Peru ‘s CONCYTEC and World Bank (043-2019-FONDECYT-BM-INC.INV.) to J.G.I.; Peru’s Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica (FONDECYT-BM-INC.INV 039-2019) to E.J.R.-R. and M.E.F.; Programa Bosques Andinos - HELVETAS Swiss Intercooperation to M.E.F.; Programa Nacional de Becas y Crédito Educativo - PRONABEC to J.G.I.; Schlumberger Foundation Faculty for the Future to J.N.; Sigma Xi to A.J.L.; Smithsonian Tropical Research Institute to R. Alfaro-Sánchez.; Spanish Ministry of Foreign Affairs AECID (11-CAP2-1730) to H.A.M. and J.J.C.; UK NERC grant NE/K01353X/1 to E.G.Peer reviewe
Interest in intermediate soft-classified maps in land change model validation: suitability versus transition potential
International audienceThis study compares two types of intermediate soft-classified maps. The first type uses land use/cover suitability maps based on a multi-criteria evaluation (MCE). The second type focuses on the transition potential between land use/cover categories based on a multi-layer perceptron (MLP). The concepts and methodological approaches are illustrated in a comparable manner using a Corine data set from the Murcia region (2300 km 2 , Spain) in combination with maps of drivers that were created with two stochastic, discretely operating, commonly used tools (MCE in CA_MARKOV and MLP in Land Change Modeler). The importance of the different approaches and techniques for the obtained results is illustrated by comparing the specific characteristics of both approaches by validating the suitability versus transition potential maps to each other using a Spearman correlation matrix and, between the Corine maps, using classical ROC (receiver operating characteristic) statistics. Then, we propose a new use of ROC statistics to compare these intermediate soft-classified maps with their respective hard-classified maps of the models for each category. The validation of these results can be beneficial in choosing a suitable model and provide a better understanding of the implications of the different modeling steps and the advantages and limitations of the modeling tools
Predicción de la distribución potencial del alcornoque en montes de Málaga mediante modelos de nicho biológico a partir de registros de presencia y variables ambientales in situ y ex situ
XVII Congreso Nacional de Tecnologías de Información Geográfica, Málaga, 29, 30 de junio y 1 de julio 2016.[ES] Los modelos de nicho ecológico analizan el hábitat de una especie a partir de las inferencias estadísticas sobre los registros de presencia (y ausencia) y las variables ambientales explicativas.
En el presente trabajo, nuestro objetivo principal ha sido estimar la distribución potencial del alcornoque en los Montes de Málaga, donde las poblaciones de la especie se encuentran históricamente muy mermadas. Para ello, hemos utilizado una doble estrategia para desarrollar un mapa de distribución potencial del alcornoque en el conjunto de Andalucía y, particularmente, en los Montes de Málaga, utilizando registros de presencia y variables ambientales de toda la región, y registros de presencia y variables ambientales exclusivamente del entorno de los Montes de Málaga, comparando los resultados de las predicciones.
Los resultados mostraron una distribución potencial del alcornoque mucho mayor que la distribución actual, principalmente en el área de los Montes de Málaga. Las precipitaciones y la litología fueron las variables con mayor importancia en la distribución de la especie, y la evapotranspiración potencial en la distribución de las poblaciones locales. Los mapas de distribución generados suponen una efectiva herramienta para el estudio de la distribución de la flora en el marco de una gestión integrada del territorio.[EN] Environmental niche models analyze the habitat of species by using statistical inferences from records of presence (and absence) and explanatory environmental variables.
In this work, our main objective has been to predict the potential distribution area of cork oak in Montes de Malaga (South of Spain), where populations of this species were historically deforested by human activities. To do this, we used a dual strategy to mapping the potential distribution area of cork oak in Andalusia and, mainly, in Montes de Málaga; We used only-presence records and environmental variables of Andalusia and only-presence records and environmental variables of Montes de Malaga, and finally we compared the results of our predictions.
The results showed that our models predicted a potential area distribution of cork oak greater than the current distribution, mainly in Montes de Malaga. The rainfall and the lithology were the most important factors in the distribution of Quercus suber at regional scale, and potential evapotranspiration in the distribution of local populations. The distribution maps generated are an effective tool for the study of the distribution of flora and environmental management.N
In Vitro Anthelmintic Activity of Methanolic Extract from Caesalpinia coriaria J. Willd Fruits against Haemonchus contortus Eggs and Infective Larvae
The aim of this study was to evaluate the in vitro lethal effect of a methanolic extract (ME) from Caesalpinia coriaria fruits against Haemonchus contortus eggs and infective larvae. The anthelmintic activity was assessed using the egg hatching inhibition assay (EHI) and the mortality test. The ME was assessed using five concentrations as follows: 6.15, 3.12, 1.56, and 0.78 mg/mL to eggs and 150, 100, 75, and 50 mg/mL to larvae, respectively. Ivermectin (5 mg/mL) was used as positive control and 4% methanol and distilled water were used as negative controls. The data of ovicidal and larvicidal effect were analyzed with a completely randomized design through ANOVA analysis using the general linear model (GLM) and lethal concentrations (LC50 and LC90) were estimated through a Probit analysis using the SAS program. A clear ME increased concentration dependence effect was observed in the EHI and mortality tests. The highest activity of the methanolic extract was observed at the highest concentration (P < 0.05) to obtain a similar effect to the positive control (ivermectin), with LC50 = 78.38 and 0.00064 mg/mL and LC90 =235.63 and 0.024 mg/mL, respectively, for larvae and eggs. The results indicate that the C. coriaria fruit ME possesses in vitro ovicidal and larvicidal properties (gallotannins: methyl gallate) against H. contortus that needs to be investigated more in vivo for the control of gastroenteric nematodes in ruminants