Agricultural biomass as provisioning ecosystem service: quantification of energy flows

Agro-ecosystems supply provisioning, regulating and cultural services to human society. This study focuses on the agro-ecosystem provisioning services regarding the production of agricultural biomass. These services strongly respond to the socio-economic demands of human beings, and are characterised by an injection of energy in the ecosystems production cycle which is often exceeding the ecological capacity of the ecosystem, i.e. the overall ability of the ecosystem to produce goods and services linked to its bio-physical structure and processes that take place during the agricultural production. Agricultural production is identified as ecosystem service in widely recognised ecosystem service frameworks, but currently there is no clear agreement within the scientific and policy communities on how the ecological-socio-economic flow linked to this provisioning service should be assessed, beyond a mere accounting of yields. This study attempts to provide a new insight to this issue by proposing an approach based on the energy budget, which takes into consideration the energy needed by the ecosystem to supply the service. The approach is based on the concepts of Energy Return on Investment (EROI) and Net Energy Balance (NEB), and considers different bio-physical structures and processes of agroecosystems. The work is structured in three parts: the first aims at estimating inputs (machinery, seeds, fertilizers, irrigation, labour) in energy terms; the second at estimating biomass output in energy terms; the third to compare actual agricultural production with three reference scenarios encompassing a range of human input (no input – low input –high input scenarios). Results show that in general terms cereal and grassland systems have the largest energy gains (both in terms of EROI and NEB). Such systems are characterised by a lower economic value of their output compared to other producing systems such as fruits, which have lower energy gains but a higher embodied energy, which is recognized in the market as valuable. Comparison of actual production systems with the high input scenario confirms that current production in Europe is already highly intensive, and that increasing the energy input would not improve the efficiency of the conversion of such additional energy into biomass. Overall, the proposed approach seems a useful tool to identify which are the factors in the agricultural production process that could be modified to improve the energy efficiency in agricultural systems and the sustainability of their production. This study can be considered as a first step in the assessment of the total energy balance of the agro-ecosystem. In fact it deals with the quantification of energy regarding human inputs and the corresponding output and further analysis should address crucial issues such as the quality of the energy and the embodied energy in the plant production, which will help to better understand the complexity of the agro-ecosystems

Ret receptor tyrosine kinase sustains proliferation and tissue maturation in intestinal epithelia.

Expression of the Ret receptor tyrosine kinase is a defining feature of enteric neurons. Its importance is underscored by the effects of its mutation in Hirschsprung disease, leading to absence of gut innervation and severe gastrointestinal symptoms. We report a new and physiologically significant site of Ret expression in the intestine: the intestinal epithelium. Experiments in Drosophila indicate that Ret is expressed both by enteric neurons and adult intestinal epithelial progenitors, which require Ret to sustain their proliferation. Mechanistically, Ret is engaged in a positive feedback loop with Wnt/Wingless signalling, modulated by Src and Fak kinases. We find that Ret is also expressed by the developing intestinal epithelium of mice, where its expression is maintained into the adult stage in a subset of enteroendocrine/enterochromaffin cells. Mouse organoid experiments point to an intrinsic role for Ret in promoting epithelial maturation and regulating Wnt signalling. Our findings reveal evolutionary conservation of the positive Ret/Wnt signalling feedback in both developmental and homoeostatic contexts. They also suggest an epithelial contribution to Ret loss-of-function disorders such as Hirschsprung disease

Ret receptor tyrosine kinase sustains proliferation and tissue maturation in intestinal epithelia

Expression of the Ret receptor tyrosine kinase is a defining feature of enteric neurons. Its importance is underscored by the effects of its mutation in Hirschsprung disease, leading to absence of gut innervation and severe gastrointestinal symptoms. We report a new and physiologically significant site of Ret expression in the intestine: the intestinal epithelium. Experiments in Drosophila indicate that Ret is expressed both by enteric neurons and adult intestinal epithelial progenitors, which require Ret to sustain their proliferation. Mechanistically, Ret is engaged in a positive feedback loop with Wnt/Wingless signalling, modulated by Src and Fak kinases. We find that Ret is also expressed by the developing intestinal epithelium of mice, where its expression is maintained into the adult stage in a subset of enteroendocrine/enterochromaffin cells. Mouse organoid experiments point to an intrinsic role for Ret in promoting epithelial maturation and regulating Wnt signalling. Our findings reveal evolutionary conservation of the positive Ret/Wnt signalling feedback in both developmental and homeostatic contexts. They also suggest an epithelial contribution to Ret loss-of-function disorders such as Hirschsprung disease.Peer reviewe

Ex Ante Impact Assessment of Policies Affecting Land Use, Part A: Analytical Framework

Contemporary policy making calls for scientific support to anticipate the possible consequences of optional policy decisions on sustainable development. This paper presents an analytical framework for ex ante assessment of economic, social, and environmental impacts of policy driven land use changes that can be used as an aid to policy making. The tasks were to (1) link policy scenarios with land use change simulations, (2) link land use change simulations with environmental, social, and economic impacts through indicators, and (3) valuate the impacts in the context of sustainable development. The outcome was a basis for dialogue at the science-policy interface in the process of developing new policies on the European level that impact on land and land use. The analytical approach provides a logical thread for ex ante impact assessment within the context of sustainable development, land use multifunctionality, and land use change and it provides a thorough discussion of achievements and open challenges related to the framework. It concludes with considerations on the potential for using evidence based ex ante assessments in the process of policy development. The paper is complemented by a B-paper providing exemplary results from two applications of the framework: a financial reform scenario of the Common Agricultural Policy of the European Union, and a bioenergy policy scenario for the case of Poland (Helming et al. 2011)

Differences in consumer decision-making styles among selected south-east European countries

Fast changes in retailing and complex consumer decision-making processes have increased the need for additional investigation of differences and similarities in consumer decision-making styles (CDMS) in various countries. This paper tests the reliability and validity of Sproles and Kendall’s Consumer Style Inventory (CSI) instrument, identifies and compares CDMS in Croatia, Bosnia and Herzegovina and Macedonia (FYR). Data obtained from surveys conducted among university students in observed countries (n = 1.206) were analysed by using exploratory and confirmatory factor analyses and the analysis of variance (ANOVA). The results provided support for six factors, which means that the original US eight-model cannot be fully applied in this region. Croatian consumers are the least brand-conscious and novelty-fashion conscious. Macedonian consumers are the most quality-conscious, brand-conscious, novelty-fashion conscious, recreational shopping conscious and brand-loyal, while Bosnian consumers are the most confused by overchoice. The traits of price consciousness and impulsiveness were not tested because of lack of reliability among items. The paper provides guidelines for marketers on how to position and more effectively advertise their products and services in analysed countries

Structural aspects and physiological consequences of APP/APLP trans-dimerization

The amyloid precursor protein (APP) is one of the key proteins in Alzheimer’s disease (AD), as it is the precursor of amyloid β (Aβ) peptides accumulating in amyloid plaques. The processing of APP and the pathogenic features of especially Aβ oligomers have been analyzed in detail. Remarkably, there is accumulating evidence from cell biological and structural studies suggesting that APP and its mammalian homologs, the amyloid precursor-like proteins (APLP1 and APLP2), participate under physiological conditions via trans-cellular dimerization in synaptogenesis. This offers the possibility that loss of synapses in AD might be partially explained by dysfunction of APP/APLPs cell adhesion properties. In this review, structural characteristics of APP trans-cellular interaction will be placed critically in context with its putative physiological functions focusing on cell adhesion and synaptogenesis