Modelling landscape management scenarios for equitable and sustainable futures in rural areas based on ecosystem services

Scenario analysis is a useful technique to inform landscape planning of social-ecological systems by modelling future trends in ecosystem service supply and distribution. This is especially critical in floodplain agroecosystems of rural areas, which are at risk of losing riparian forest corridors due to increasing land use conversion for agricultural production and other ecosystem services due to rural abandonment. However, few studies investigating the effects of land management combine social and ecological modelling in scenario analyses. We estimated the supply of 16 ecosystem services under five alternative scenarios along two gradients: agricultural intensification of the floodplain and active ecological restoration of the riparian forest. We used redundancy analyses to detect ecosystem service bundles and interviews to identify societal gains and losses associated with each management scenario. Our results show how land management influences both the supply and distribution of ecosystem services. Scenarios promoting active ecological restoration supplied more services and benefited a larger range of societal sectors than scenarios focused on provisioning services. We also found two consistent bundles across scenarios, one related to less intensive food supply and another one related to outdoor activities. Interestingly, additional services were included in these bundles in the different scenarios, reflecting land management effects. Landscape scale management promoting both the conservation of ecosystem functioning and the sustainable use of provisioning services could supply a more balanced set of ecosystem services and benefit a larger number of societal sectors, contributing to more equitable and sustainable futures in rural areas

Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests

At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical “land management” practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species’ habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species

Plant β-diversity i in human-altered forest ecosystems: the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages

An understanding of spatial patterns of plant species diversity and the factors that drive those patterns is critical for the development of appropriate biodiversity management in forest ecosystems. We studied the spatial organization of plants species in human- modified and managed oak forests (primarily, Quercus faginea) in the Central Pre- Pyrenees, Spain. To test whether plant community assemblages varied non-randomly across the spatial scales, we used multiplicative diversity partitioning based on a nested hierarchical design of three increasingly coarser spatial scales (transect, stand, region). To quantify the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages and identify the determinants of plant diversity patterns, we used canonical ordination. We observed a high contribution of ˟-diversity to total -diversity and found ˟-diversity to be higher and ˞-diversity to be lower than expected by random distributions of individuals at different spatial scales. Results, however, partly depended on the weighting of rare and abundant species. Variables expressing the historical management intensities of the stand such as mean stand age, the abundance of the dominant tree species (Q. faginea), age structure of the stand, and stand size were the main factors that explained the compositional variation in plant communities. The results indicate that (1) the structural, spatial, and topographical characteristics of the forest stands have the greatest effect on diversity patterns, (2) forests in landscapes that have different land use histories are environmentally heterogeneous and, therefore, can experience high levels of compositional differentiation, even at local scales (e.g., within the same stand). Maintaining habitat heterogeneity at multiple spatial scales should be considered in the development of management plans for enhancing plant diversity and related functions in human-altered forest

Ovarian Fibrosarcoma: Clinicopathologic Considerations about the Intraoperative and Post-Surgical Procedures

Primary ovarian fibrosarcomas are very uncommon neoplasms. Since the diagnostic criteria were established in 1981, less than one hundred cases have been reported. This diagnosis can be difficult to establish and other similar appearing mesenchymal processes must be ruled out. In every case this diagnosis is under consideration. Multiple sections of the specimen and immunohistochemical stains will be necessary to support this diagnosis. The difficulty of recognition in frozen section in the majority of the situations implies that the diagnosis should be deferred to the definitive study of the permanent sections with immunohistochemical studies. There exists a histological resemblance between a primary ovarian fibrosarcoma and actively mitotic fibroma. In some cases, it can be impossible to separate exactly these two entities. We report a well-differentiated ovarian fibrosarcoma, with less than 1-2 mitosis ×10 HPF and low-grade cytological atypia, similar to active mitotic fibromas, developing liver metastasis one year later. Despite having distant metastasis, some cases with long survival rates have been reported in patients who received chemotherapy after surgery; so that the adjuvant chemotherapy should be considered, especially in young females

Técnica de control de rápida respuesta dinámica para convertidores DC/DC integrados de alta frecuencia (5MHz)

Una frecuencia de conmutación de 5MHz permite la integración en un chip de un convertidor DC/DC de baja potencia (10W). Aunque a esta frecuencia de conmutación es posible emplear un control modo tensión con un ancho de banda de 1MHz, los efectos parásitos y la robustez del sistema no permiten esa frecuencia de ancho de banda tan elevada. En esta publicación se propone una técnica de control que optimiza la respuesta dinámica de convertidores DC/DC de elevada frecuencia de conmutación. El control propuesto y analizado se basa en el control modo corriente de pico de la corriente del condensador de salida de un convertidor reductor (Buck). El lazo de corriente del condensador de salida proporciona la rápida respuesta dinámica, ya que se comporta como un feed-forward de la corriente por la carga, mientras que el lazo de tensión proporciona regulación y exactitud en régimen permanente. Los resultados experimentales han validado la rápida respuesta dinámica del control frente a escalones de carga

Fast control technique based on peak current mode control of the output capacitor current

The control proposed and analyzed in this paper is based on the peak current mode control of the output capacitor current of a Buck converter. The output capacitor current loop provides fast dynamic response to the control since it behaves as a feed-forward of the load current while the voltage loop provides accurate steady state regulation. A simulation oriented averaged model of the proposed control has been developed to design the external voltage loop. As shown in simulations, with the converter switching at 5 MHz, the proposed control with a voltage loop of 50 kHz bandwidth has the same voltage drop and a similar dynamic response as a 1 MHz bandwidth voltage mode control. The reduction of the bandwidth makes easier the control implementation and integration. Finally, experimental results have been achieved verifying the fast dynamic response of the proposed control under load step

Fast control technique for high frequency (5MHz) DC/DC integrated converter

A switching frequency of 5 MHz allows the integration in a chip of a low power (10W) DC/DC converter. Although this switching frequency would make feasible a voltage mode control with 1MHz bandwidth, the parasitics and robustness don't allow such a high frequency bandwidth. This paper proposes a fast control technique that helps to optimize the dynamic response of high frequency DC/DC converter. The control proposed and analyzed in this paper is based on the peak current mode control of the output capacitor current of a Buck converter. The output capacitor current loop provides fast dynamic response to the control since it behaves as a feed-forward of the load current while the voltage loop provides accurate steady state regulation. Experimental results have validated the fast dynamic response of the proposed control under load steps

Fast control technique for high frequency DC/DC integrated converter based on non-invasive output capacitance current estimation

High switching frequency allows the integration of low power DC/DC converters. Although a high switching frequency would make feasible a voltage mode control with 1MHz bandwidth, parasitic effects and robustness don’t allow such a high bandwidth. This paper proposes a fast control to optimize the dynamic response of high frequency DC/DC converters. The proposed control is based on the peak current mode control of the output capacitor current. The output capacitor current loop provides fast dynamic response while the voltage loop provides accurate steady state regulation. Experimental results have validated the fast dynamic response of the proposed control under load step

V2ic Control: A Novel Control Technique with Very Fast Response under Load and Voltage Steps

High switching frequencies (several MHz) allow the integration of low power DC/DC converters. Although, in theory, a high switching frequency would make possible to implement a conventional voltage mode control with very high bandwidth, in practice, parasitic effects and robustness make very complex to achieve bandwidths higher than 1MHz. This paper proposes a fast control technique to optimize the dynamic response of high switching frequency DC/DC converters. The proposed control is based on two loops. The fast internal loop has information of the output capacitor current and the error voltage, providing fast dynamic response under load and output voltage reference steps, while the slow external voltage loop provides accurate steady state regulation. Experimental results validate the fast dynamic response of the proposed control under load and output voltage reference steps and its suitability for high switching frequencies