Computing Economic Equilibria through Nonsmooth Optimization

In the first section the problem of nonsmooth optimization is described in general terms, setting the precise hypothesis in mathematical language. Section 2 describes the principles of an example which arises in the context of the linkage of national models of food and agriculture. The general methodology is presented in Section 3, where the algorithm of solution is outlined. Section 4 reports on an extensive set of numerical experiments, both on problems known in the literature, and on the example of Section 2. Finally the paper concludes with some remarks about improvements of the algorithm, which motivate further research on the subject

Simulating the Socio-Economic and Biogeophysical Driving Forces of Land-Use and Land-Cover Change: The IIASA Land-Use Change Model

In 1995, a new project Modeling Land-Use and Land-Cover Changes in Europe and Northern Asia (LUC) was established at IIASA with the objective of analyzing the spatial characteristics, temporal dynamics, and environmental consequences of land-use and land-cover changes that have occurred in Europe and Northern Asia over the period 1900 to 1990 as a result of a range of socio-economic and biogeophysical driving forces. The analysis will then be used to project plausible future changes in land use and land cover for the period 1990 to 2050 under different assumptions of future demographic, economic, technological, social and political development. The study region, Europe and Northern Asia, has been selected because of its diversity in social, economic and political organization, the rapid changes in recent history, and the significant implications for current and future land-use and land-cover change. Land-cover change is driven by a multitude of processes. Natural processes, such as vegetation dynamics, involve alterations in cover due to natural changes in climate and soils. However, changes of land cover driven by anthropogenic forcing are currently the most important and most rapid of all changes (Turner et al. 1990). Therefore, any sound effort to project the future state of land cover must consider the determinants of human requirements and activities, e.g., demand for land-based products such as food, fiber and fuel, or use of land for recreation. In the past, major land-cover conversions have occurred as a consequence of deforestation to convert land for crop and livestock production; removal of wood for fuel and timber; conversion of wetlands to agricultural and other uses; conversion of land for habitation, infrastructure and industry; and conversion of land for mineral extraction (Turner et al. 1993). These human-induced conversions of land cover, particularly during the past two centuries, have resulted in a net release of CO2 to the atmosphere, changes in the characteristics of land surfaces (e.g., albedo and roughness), and decreased biodiversity. More subtle processes, termed land-cover modifications, affect the character of the land cover without changing its overall classification. For instance, land-cover degradation through erosion, overgrazing, desertification, salinization and acidification, is currently considered a major environmental problem. Although the effects of land-cover modifications may be small at local scales, their aggregate impact may be considerable. For example, use of fertilizers locally has no significance for atmospheric concentrations of greenhouse gases. However, when practiced frequently in many locations, nitrogen fertilizer can make a significant contribution to emissions of nitrous oxide (N2O) globally. The implementation of a comprehensive land-use change model poses a number of methodological challenges. These include the complexity of the issues involved and the large number of interacting agents and factors; the nonlinear interactions between prices, the supply of and the demand for land-based commodities and resources; the importance of intertemporal aspects; the intricacy of biogeophysical feedbacks; and the essential role of uncertainty in the overall evaluation of strategies. The interaction mechanisms between biophysical cycles and economic processes have mainly been studied in dynamic simulation models that follow recursive chains of causation, where the past and present events determine what will happen tomorrow. Not surprisingly, many of these studies have led to dramatic predictions, basically because the agents whose behavior is described within the model are themselves assumed to be unable to predict at all. By contrast, in micro-economics it is usually assumed that agents do have the capacity to make informed predictions and to plan so as to avoid the probability of disaster in the future. However, even full information and rationality of individual choice are not always sufficient to avoid disaster. The coordination mechanisms that prevail among economic agents often tend to be of decisive importance. The aim of this paper is to summarize the LUC project approach and to extend our earlier writings on modeling of land-use and land-cover change dynamics. We discuss the adequacy and applicability of welfare analysis as a conceptual framework for the LUC project at IIASA. We recognize from the outset the complexity of socio-economic and environmental driving forces and the fundamental uncertainties involved in their spatial and temporal interactions (and outcomes). Unlike physical particles, economic agents have the ability to anticipate, and they possess the freedom to change their behavior. This inherent unpredictability, in particular the multiplicity of possible outcomes, calls for a normative approach, and for comparative policy analysis rather than exact prediction. Therefore, we adopt an approach that enables the explicit representation of various policy measures, thus providing a means to search for "better futures", i.e., for trajectories of future development that may alleviate environmental stresses while improving human welfare

Comparison of estimated energy intake in children using a Web-based Dietary Assessment Software with accelerometer-estimated energy expenditure in children

Background: The OPUS (Optimal well-being, development and health for Danish children through a healthy New Nordic Diet) project carried out a school meal study to assess the impact of a New Nordic Diet (NND). The random controlled trial involved 834 children aged 8–11 in nine local authority schools in Denmark. Dietary assessment was carried out using a program known as WebDASC (Web-based Dietary Assessment Software for Children) to collect data from the children. Objective: To compare the energy intake (EI) of schoolchildren aged 8–11 estimated using the WebDASC system against the total energy expenditure (TEE) as derived from accelerometers worn by the children during the same period. A second objective was to evaluate the WebDASC's usability. Design: Eighty-one schoolchildren took part in what was the pilot study for the OPUS project, and they recorded their total diet using WebDASC and wore an accelerometer for two periods of seven consecutive days: at baseline, when they ate their usual packed lunches and at intervention when they were served the NND. EI was estimated using WebDASC, and TEE was calculated from accelerometer-derived activity energy expenditure, basal metabolic rate, and diet-induced thermogenesis. WebDASC's usability was assessed using a questionnaire. Parents could help their children record their diet and answer the questionnaire. Results: Evaluated against TEE as derived from the accelerometers worn at the same time, the WebDASC performed just as well as other traditional methods of collecting dietary data and proved both effective and acceptable with children aged 8–11, even with perhaps less familiar foods of the NND. Conclusions: WebDASC is a useful method that provided a reasonably accurate measure of EI at group level when compared to TEE derived from accelerometer-determined physical activity in children. WebDASC will benefit future research in this area

Direct demonstration of ATP-dependent release of SecA from a translocating preprotein by surface plasmon resonance

Translocase mediates the transport of preproteins across the inner membrane of Escherichia coli. SecA binds with high affinity to the membrane-embedded protein-conducting SecYEG complex and serves as both a receptor for secretory proteins and as an ATP-driven molecular motor. Cycles of ATP binding and hydrolysis by SecA drive the progressive movement of the preprotein across the membrane. Surface plasmon resonance allows an online monitoring of protein interactions. Here we report on the kinetic analysis of the interaction between SecA and the membrane-embedded SecYEG complex. Immobilization of membrane vesicles containing overproduced SecYEG on the Biacore Pioneer L1 chip allows the detection of high affinity SecA binding to the SecYEG complex and online monitoring of the translocation of the secretory protein proOmpA. SecA binds tightly to the SecYEG . proOmpA complex and is released only upon ATP hydrolysis. The results provide direct evidence for a model in which SecA cycles at the SecYEG complex during translocation.</p

Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement.

Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut).Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist.When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health

Combined 1H-Detected solid-state NMR spectroscopy and electron cryotomography to study membrane proteins across resolutions in native environments

Membrane proteins remain challenging targets for structural biology, despite much effort, as their native environment is heterogeneous and complex. Most methods rely on detergents to extract membrane proteins from their native environment, but this removal can significantly alter the structure and function of these proteins. Here, we overcome these challenges with a hybrid method to study membrane proteins in their native membranes, combining high-resolution solid-state nuclear magnetic resonance spectroscopy and electron cryotomography using the same sample. Our method allows the structure and function of membrane proteins to be studied in their native environments, across different spatial and temporal resolutions, and the combination is more powerful than each technique individually. We use the method to demonstrate that the bacterial membrane protein YidC adopts a different conformation in native membranes and that substrate binding to YidC in these native membranes differs from purified and reconstituted system

Addressing Grand Challenges in Sustainable Food Transitions:Opportunities Through the Triple Change Strategy

Despite emerging consumer trends and policies promoting sustainable food consumption, the transition towards societal tipping points for sustainable food systems remains protracted due to multifaceted challenges such as consumer misconceptions, value chain inequalities, and policy fragmentation. Addressing these challenges requires a comprehensive approach that considers all actors within the food system. The present paper follows the paradigm set by the Consumers’ Understanding of Eating Sustainably (CUES) Horizon Europe project and introduces CUES’ Triple Change strategy. This strategy highlights Consumer and Cultural Change, Industrial Change, and Policy Change as interconnected dimensions essential for driving behavioral change and ensuring a successful transition to sustainable food systems. By leveraging persuasive communication and interventions for transparency, fostering value chain reform, and advocating for policy transformations, the Triple Change aims to overcome existing barriers and create opportunities to accelerate the shift towards a resilient food system. This paper explores the grand challenges and opportunities within each of these dimensions and offers a holistic framework for academics, stakeholders, and policymakers to contribute to sustainable food transitions.</p

Scar Perception in School-aged Children After Major Surgery in Infancy

Background: The long-term effects of childhood surgery scars on health status, quality of life (QoL), self-esteem, and body image remain uncertain. This study explores these effects in school-aged children. Methods: We conducted a retrospective cohort study involving 454 children (58% boys; 8–17 years) who had undergone surgical correction of anatomical anomalies or neonatal ECMO. Data included patient-reported scar perception and scar-related embarrassment, along with psychological assessment via questionnaires. Results: About 34% of children rated their scars as 'nice-looking', 49% as 'indifferent', and 12% as 'rather ugly'. Most children (91%) never experienced scar-related embarrassment, while frequent embarrassment was reported by 3%. Surgical scar correction was desired by 6% of the 8-year-olds and 19% of the 17-year-olds. Scar perception did not significantly affect health status or QoL. However, negative scar perception was associated with lower self-esteem in girls and a more negative body image in boys. Girls were more likely to report negative scar perception (OR: 1.54, 95%-CI: 1.06–2.24) and scar-related embarrassment (OR: 4.29, 95%-CI: 1.77–10.44). Conclusion: Children who underwent surgery in the neonatal period and subsequently grew up with scars resulting thereof, mostly perceive them either indifferently or positively, with minimal effect on health status and QoL. Nonetheless, some children, particularly girls, experienced negative perceptions of their scars, although scar-related embarrassment was rare. We recommend integrating scar assessment into routine follow-up at ages 12 and 17, and offering appropriate and timely guidance and support to children at risk for negative effects of scars. Level of Evidence: III.</p

Co- and post-translational translocation through the protein-conducting channel:analogous mechanisms at work?

Many proteins are translocated across, or integrated into, membranes. Both functions are fulfilled by the 'translocon/translocase', which contains a membrane-embedded proteinconducting channel (PCC) and associated soluble factors that drive translocation and insertion reactions using nucleotide triphosphates as fuel. This perspective focuses on reinterpreting existing experimental data in light of a recently proposed PCC model comprising a front-to-front dimer of SecY or Sec61 heterotrimeric complexes. In this new framework, we propose (i) a revised model for SRP-SR-mediated docking of the ribosome-nascent polypeptide to the PCC; (ii) that the dynamic interplay between protein substrate, soluble factors and PCC controls the opening and closing of a transmembrane channel across, and/or a lateral gate into, the membrane; and (iii) that co-and post-translational translocation, involving the ribosome and SecA, respectively, not only converge at the PCC but also use analogous mechanisms for coordinating protein translocation