Prats M.,Rovira i Virgili University |
Prats M.,Hospital Universitari Of Tarragona Joan Xxiii |
Font R.,Rovira i Virgili University |
Garcia C.,Rovira i Virgili University |
And 3 more authors.
BMC Nephrology | Year: 2013
Background: Some parenteral iron therapies have been found to be associated with hypophosphatemia. The mechanism of the decrease in serum phosphate is unknown. The aim of this study is to examine the effect of IV ferric carboxymaltose(FCM) on phosphate metabolism and FGF23 levels in patients with chronic kidney disease(CKD). Methods. This is a post-hoc analysis of a prospective study carried out in 47 non-dialysis CKD patients with iron-deficiency anaemia who received a single 1000 mg injection of FCM. Markers of mineral metabolism (calcium, phosphate, 1,25-dihydroxyvitamin D, PTH and FGF23[c-terminal]) were measured prior to FCM administration and at week 3 and week 12 after FCM administration. Based on the measured levels of serum phosphate at week 3, patiens were classified as hypophosphatemic or non-hypophosphatemic. Results: Serum phosphate levels decreased significantly three weeks after FCM administration and remained at lower levels at week 12 (4.24 ± 0.84 vs 3.69 ± 1.10 vs 3.83 ± 0.68 mg/dL, respectively, p < 0.0001. Serum calcium, PTH and 1,25-dihydroxyvitamin D did not change over the course of the study. Serum FGF23 decreased significantly from 442(44.9-4079.2) at baseline to 340(68.5-2603.3) at week 3 and 191.6(51.3-2465.9) RU/mL at week 12, p < 0.0001. Twelve patients were non-hypophosphatemic and 35 hypophosphatemic. FGF23 levels decreased in both groups, whereas no changes were documented in any of the other mineral parameters. Conclusions: In non-dialysis CKD patients, FCM induces reduction in serum phosphate levels that persists for three months. FCM causes a significant decrease in FGF23 levels without changes to other bone metabolism parameters. © 2013 Prats et al.; licensee BioMed Central Ltd.
Ruiz-Peinado R.,Sistemas de Gestion |
Ruiz-Peinado R.,Sustainable Forest Management Research Institute |
Moreno G.,University of Extremadura |
Juarez E.,University of Extremadura |
And 4 more authors.
Journal of Arid Environments | Year: 2013
Shrubs play an important role in water-limited agro-silvo-pastoral systems by providing shelter and forage for livestock, for erosion control, to maintain biodiversity, diversifying the landscape, and above all, facilitating the regeneration of trees. Furthermore, the carbon sink capacity of shrubs could also help to mitigate the effects of climate change since they constitute a high proportion of total plant biomass. The contribution of two common extensive native shrub species (Cistus ladanifer L. and Retama sphaerocarpa (L.) Boiss.) to the carbon pool of Iberian dehesas (Mediterranean agro-silvo-pastoral systems) is analyzed through biomass models developed at both individual (biovolume depending) and community level (height and cover depending).The total amount of carbon stored in these shrubs, including above- and belowground biomass, ranges from 1.8 to 11.2 Mg C ha-1 (mean 6.8 Mg C ha-1) for communities of C. ladanifer and from 2.6 to 8.6 Mg C ha-1 (mean 4.5 Mg C ha-1) for R. sphaerocarpa. These quantities account for over 20-30% of the total plant biomass in the system. The potential for carbon sequestration of these shrubs in the studied system ranges 0.10-1.32 Mg C ha-1 year-1 and 0.25-1.25 Mg C ha-1 year-1 for the C. ladanifer and R. sphaerocarpa communities' respectively. © 2012 Elsevier Ltd.
Condes S.,Technical University of Madrid |
Del Rio M.,Sistemas de Gestion |
Del Rio M.,Sustainable Forest Management Research Institute |
Sterba H.,University of Natural Resources and Life Sciences, Vienna
Forest Ecology and Management | Year: 2013
Despite the increasing relevance of mixed stands due to their potential benefits; little information is available with regard to the effect of mixtures on yield in forest systems. Hence, it is necessary to study inter-specific relationships, and the resulting yield in mixed stands, which may vary with stand development, site or stand density, etc. In Spain, the province of Navarra is considered one of the biodiversity reservoirs; however, mixed forests occupy only a small area, probably as a consequence of management plans, in which there is an excessive focus on the productivity aspect, favoring the presence of pure stands of the most marketable species. The aim of this paper is to study how growth efficiencies of beech (Fagus sylvatica) and pine (Pinus sylvestris) are modified by the admixture of the other species and to determine whether stand density modifies interspecific relationships and to what extent. Two models were fitted from Spanish National Forest Inventory data, for P. sylvestris and F. sylvatica respectively, which relate the growth efficiency of the species, i.e. the volume increment of the species divided by the species proportion by area, with dominant height, quadratic mean diameter, stocking degree, and the species proportions by area of each species. Growth efficiency of pine increased with the admixture of beech, decreasing this positive effect when stocking degree increased. However, the positive effect of pine admixture on beech growth was greater at higher stocking degrees. Growth efficiency of beech was also dependent on stand dominant height, resulting in a net negative mixing effect when stand dominant heights and stocking degrees were simultaneously low. There is a relatively large range of species proportions and stocking degrees which results in transgressive overyielding: higher volume increments in mixed stands than that of the most productive pure pine stands. We concluded that stocking degree is a key factor in between-species interactions, being the effects of mixing not always greater at higher stand densities, but it depends on species composition. © 2012 Elsevier B.V.
Alberdi I.,Sistemas de Gestion |
Canellas I.,Sistemas de Gestion |
Condes S.,Technical University of Madrid
Forest Systems | Year: 2014
Aim of study: In this study, a methodology has been designed to assess biodiversity in the frame of the Spanish National Forest Inventory with the aim of evaluating the conservation status of Spanish forests and their future evolution. This methodology takes into account the different national and international initiatives together with the different types and characteristics of forests in Spain. Area of study: Álava province (Basque country, Spain). Material and methods: To analyse the contribution of each of the different indices to the biodiversity assessment, a statistical analysis using PCA multivariate techniques was performed for structure, composition and dead wood indicators. Main results: The selected biodiversity indicators (based on field measurements) are presented along with an analysis of the results from four representative forest types in Álava by way of an example of the potential of this methodology. Research highlights: The statistical analysis revealed the important information contribution of Mingling index to the composition indicators. Regarding the structure indicators, it is remarkable the interest of using standard deviations and skewness of height and diameter as indicators. Finally it is interesting to point out the interest of assessing dead saplings since they provide additional information and their volume is a particularly useful parameter for analyzing the success of regeneration.
Nunez A.,Sistemas de Gestion |
Chi C.,Oregon State University
International Journal for Equity in Health | Year: 2013
One of the most extensive Chilean health care reforms occurred in July 2005, when the Regime of Explicit Health Guarantees (AUGE) became effective. This reform guarantees coverage for a specific set of health conditions. Thus, the purpose of this study is to provide timely evidence for policy makers to understand the current distribution and equity of health care utilization in Chile.The authors analyzed secondary data from the National Socioeconomic Survey (CASEN) for the years 1992-2009 and the 2006 Satisfaction and Out-of-Pocket Payment Survey to assess equity in health care utilization using two different approaches. First, we used a two-part model to estimate factors associated with the utilization of health care. Second, we decomposed income-related inequalities in medical care use into contributions of need and non-need factors and estimated a horizontal inequity index.Findings of this empirical study include evidence of inequities in the Chilean health care system that are beneficial to the better-off. We also identified some key factors, including education and health care payment, which affect the utilization of health care services. Results of this study could help researchers and policy makers identify targets for improving equity in health care utilization and strengthening availability of health care services accordingly. © 2013 Núñez and Chi; licensee BioMed Central Ltd.
Ruiz-Peinado R.,Sistemas de Gestion |
Ruiz-Peinado R.,University of Valladolid |
Montero G.,Sistemas de Gestion |
Montero G.,University of Valladolid |
And 2 more authors.
Forest Systems | Year: 2012
To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data.
del Rio M.,Sistemas de Gestion |
del Rio M.,Sustainable Forest Management Research Institute UVa INIA |
Schutze G.,TU Munich |
Pretzsch H.,TU Munich
Plant Biology | Year: 2014
Facilitation, reduced competition or increased competition can arise in mixed stands and become essential to the performance of these stands when compared to pure stands. Facilitation and over-yielding are widely held to prevail on poor sites, whereas neutral interactions or competition, leading to under-yielding of mixed versus pure stands, can occur on fertile sites. While previous studies have focused on the spatial variation of mixing effects, we examine the temporal variation of facilitation and competition and its effect on growth. The study is based on tree ring measurement on cores from increment borings from 559 trees of Norway spruce (Picea abies [L.] Karst.), European beech (Fagus sylvatica [L.]) and sessile oak (Quercus petraea (Matt.) Liebl.) in southern Germany, half of which were in pure stands and half in adjacent mixed stands. Mean basal area growth indices were calculated from tree ring measurements for pure and mixed stands for every species and site. The temporal variation, with positive correlations between species-specific growth indices during periods of low growth and neutral or negative correlations during periods of high growth, is more distinct in mixed than in neighbouring pure stands. We provide evidence that years with low growth trigger over-yielding of trees in mixed as opposed to pure stands, while years with high growth lead to under-yielding. We discuss the relevance of the results in terms of advancing our understanding and modelling of mixed stands, extension of the stress gradient hypothesis, and the performance of mixed versus pure stands in the face of climate change. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.
Martin-Benito D.,Sistemas de Gestion |
Martin-Benito D.,Lamont Doherty Earth Observatory |
Kint V.,Catholic University of Leuven |
del Rio M.,Sistemas de Gestion |
And 2 more authors.
Forest Ecology and Management | Year: 2011
Positive and negative effects of climate change on forest growth have been observed in different parts of the world. However, much is still unknown about how forest structure and productivity might affect climate-growth relationships in the future. We examined the effects of climate, site quality, and competition on tree basal area growth of black pine (Pinus nigra Arn.) between 1964 and 2005 in 21 sites in the Iberian Peninsula. We used a new approach to simultaneously account for climate-growth relationships, inter-annual growth variability, and stand structural changes, by fitting a linear mixed effects model (LMEM) for basal area increments (BAI) using climate data, tree-ring chronologies, and repeated forest inventory data. This approach showed the potential to improve our understanding of climate effects on tree growth and to include climate in empirical forest growth models. We used the LMEM to make projections of BAI growth under two CO2 emission scenarios and two global circulation models (GCM). The main climate drivers for growth were precipitation from previous autumn to summer and winter temperature with a positive effect, and temperature in spring-summer which had a negative effect. Tree response to climate was modulated by stand conditions, tree competition, and productivity. The more productive stands showed greater ability to either maintain or increase growth at warmer spring-summer temperatures under different levels of autumn-summer precipitation. Growth projections showed important regional differences. In general, growth under future climate is predicted to decrease although moderate growth increases might be expected in the northern region for highly and moderately productive stands. © 2011 Elsevier B.V.
Manso R.,Sistemas de Gestion |
Fortin M.,Agro ParisTech |
Calama R.,Sistemas de Gestion |
Pardos M.,Sistemas de Gestion
Forest Ecology and Management | Year: 2013
The direct application of existing models for seed germination may often be inadequate in the context of ecology and forestry germination experiments. This is because basic model assumptions are violated and variables available to forest managers are rarely used. In this paper, we present a method which addresses the aforementioned shortcomings. The approach is illustrated through a case study of Pinus pinea L. Our findings will also shed light on the role of germination in the general failure of natural regeneration in managed forests of this species. The presented technique consists of a mixed regression model based on survival analysis. Climate and stand covariates were tested. Data for fitting the model were gathered from a 5-year germination experiment in a mature, managed P. pinea stand in the Northern Plateau of Spain in which two different stand densities can be found. The model predictions proved to be unbiased and highly accurate when compared with the training data. Germination in P. pinea was controlled through thermal variables at stand level. At microsite level, low densities negatively affected the probability of germination. A time-lag in the response was also detected. Overall, the proposed technique provides a reliable alternative to germination modelling in ecology/forestry studies by using accessible/suitable variables. The P. pinea case study highlights the importance of producing unbiased predictions. In this species, the occurrence and timing of germination suggest a very different regeneration strategy from that understood by forest managers until now, which may explain the high failure rate of natural regeneration in managed stands. In addition, these findings provide valuable information for the management of P. pinea under climate-change conditions. © 2012 Elsevier B.V.