127 research outputs found
Product-Carbon-Footprint von Lebensmitteln in Ăsterreich: biologisch und konventionell im Vergleich
The aim of this broad conceived study was to analyse greenhouse gas emissions (GHGE) of more than 130 foodstuffs from two organic agricultural production methods (Organic premium brand and Organic EU-standard) as compared to conventional farming in Austria. The system boundaries of the life-cycle study ranged from agriculture and its upstream supply chain to the retailer, including changes in soil organic carbon (humus) and land use change. In conclusion, all organic products in both organic methods showed lower GHGE per hectare but also per kg of foodstuff than comparable, conventional products. Therefore, the product carbon footprint (PCF) of organic products was lower throughout the implemented study. Organic dairy products resulted in 10 to 21 % lower CO2-eq per kg of product than conventional foodstuffs, organic wheat bread showed 22 to 25 %, bread products 34 to 42% and organic vegetables 10 to 35 % lower CO2-eq per kg of product. Furthermore, this detailed calculation throughout the whole value chain pointed out âhot spotsâ of CO2-eq-emissions for producers and retailers with existing GHG reducing potentials
Food systems in a zero-deforestation world: Dietary change is more important than intensification for climate targets in 2050
Global food systems contribute to climate change, the transgression of planetary boundaries and deforestation. An improved understanding of the environmental impacts of different food system futures is crucial for forging strategies to sustainably nourish a growing world population. We here quantify the greenhouse gas (GHG) emissions of global food system scenarios within a biophysically feasible âoption spaceâ in 2050 comprising all scenarios in which biomass supply â calculated as function of agricultural area and yields â is sufficient to cover biomass demand â derived from human diets and the feed demand of livestock. We assessed the biophysical feasibility of 520 scenarios in a hypothetical no-deforestation world.
For all feasible scenarios, we calculate (in) direct GHG emissions related to agriculture. We also include (possibly negative) GHG emissions from land-use change, including changes in soil organic carbon (SOC) and carbon sinks from vegetation regrowth on land spared from food production. We identify 313 of 520 scenarios as feasible. Agricultural GHG emissions (excluding land use change) of feasible scenarios range from 1.7 to 12.5 Gt CO2e yrâ1. When including changes in SOC and vegetation regrowth on spare land, the range is between â10.7 and 12.5 Gt CO2e yrâ1. Our results show that diets are the main determinant of GHG emissions, with highest GHG emissions found for scenarios including high meat demand, especially if focused on ruminant meat and milk, and lowest emissions for scenarios with vegan diets. Contrary to frequent claims, our results indicate that diets and the composition and quantity of livestock feed, not crop yields, are the strongest determinants of GHG emissions from food-systems when existing forests are to be protected
EXIOBASE 3: Developing a time series of detailed environmentally extended multi-regional input-output tables
Environmentally extended multiregional input-output (EE MRIO) tables have emerged as a key framework to provide a comprehensive description of the global economy and analyze its effects on the environment. Of the available EE MRIO databases, EXIOBASE stands out as a database compatible with the System of Environmental-Economic Accounting (SEEA) with a high sectorial detail matched with multiple social and environmental satellite accounts. In this paper, we present the latest developments realized with EXIOBASE 3âa time series
of EE MRIO tables ranging from 1995 to 2011 for 44 countries (28 EU member plus 16 major economies) and five rest of the world regions. EXIOBASE 3 builds upon the previous versions of EXIOBASE by using rectangular supply-use tables (SUTs) in a 163 industry by 200 products classification as the main building blocks. In order to capture structural changes, economic developments, as repor ted by national statistical agencies, were imposed on the available, disaggregated SUTs from EXIOBASE 2. These initial estimates were further refined by incorporating detailed data on energy, agricultural production, resource extraction, and bilateral trade. EXIOBASE 3 inherits the high level of environmental stressor detail from its precursor, with further improvement in the level of detail for resource extraction. To account for the expansion of the European Union (EU), EXIOBASE 3 was developed with the full EU28 country set (including the new member state Croatia). EXIOBASE 3 provides a unique tool for analyzing the dynamics of environmental pressures of economic activities over time
Hypoxia induced downregulation of hepcidin is mediated by platelet derived growth factor BB
OBJECTIVE:
Hypoxia affects body iron homeostasis; however, the underlying mechanisms are incompletely understood.
DESIGN:
Using a standardised hypoxia chamber, 23 healthy volunteers were subjected to hypoxic conditions, equivalent to an altitude of 5600 m, for 6 h. Subsequent experiments were performed in C57BL/6 mice, CREB-H knockout mice, primary hepatocytes and HepG2 cells.
RESULTS:
Exposure of subjects to hypoxia resulted in a significant decrease of serum levels of the master regulator of iron homeostasis hepcidin and elevated concentrations of platelet derived growth factor (PDGF)-BB. Using correlation analysis, we identified PDGF-BB to be associated with hypoxia mediated hepcidin repression in humans. We then exposed mice to hypoxia using a standardised chamber and observed downregulation of hepatic hepcidin mRNA expression that was paralleled by elevated serum PDGF-BB protein concentrations and higher serum iron levels as compared with mice housed under normoxic conditions. PDGF-BB treatment in vitro and in vivo resulted in suppression of both steady state and BMP6 inducible hepcidin expression. Mechanistically, PDGF-BB inhibits hepcidin transcription by downregulating the protein expression of the transcription factors CREB and CREB-H, and pharmacological blockade or genetic ablation of these pathways abrogated the effects of PDGF-BB toward hepcidin expression.
CONCLUSIONS:
Hypoxia decreases hepatic hepcidin expression by a novel regulatory pathway exerted via PDGF-BB, leading to increased availability of circulating iron that can be used for erythropoiesis
Kapitel 5. Mitigation des Klimawandels
Aufgrund der GröĂe der betroffenen LandflĂ€chen, den bei ihrer Nutzung emittierten und sequestrierten Treibhausgasen (THG) und des teilweise ungĂŒnstigen Zustands von Böden in Hinblick auf ihren Gehalt an organisch gebundenem Kohlenstoff (C) kommt der Landnutzung a priori eine wichtige Rolle bei MitigationsbemĂŒhungen zu. Zur Minderung des Klimawandels ist eine Verringerung der atmosphĂ€rischen CO2-Konzentration erforderlich, die durch eine Abnahme der THG-Emissionen und durch Aufnahme und langfristige Speicherung von atmosphĂ€rischem Kohlenstoff in Biomasse und Boden erreicht werden kann (Chenu et al., 2019; Mayer et al., 2018; Paustian et al., 2016; Vos et al., 2018). Der Erhaltung bzw. idealerweise Erhöhung der organischen Substanz des Bodens durch geeignete BodenschutzmaĂnahmen kommt entscheidende Bedeutung zu
Lactoferrin prevents LPS-induced decrease of the iron exporter ferroportin in human monocytes/macrophages.
Iron balance is tightly linked to inflammation and it has been demonstrated that many proteins involved in cellular iron management are up- or down-regulated by inflammatory stimuli, ultimately leading to iron retention in the reticuloendothelial system. Ferroportin is a key player in maintenance of correct iron homeostasis, because it is the only known mammalian cellular iron exporter. In this work we show that incubation of THP-1 monocytes/macrophages with lactoferrin prevents the LPS-induced decrease of ferroportin by reducing secretion of IL-6. © 2014 Springer Science+Business Media New York.Iron balance is tightly linked to inflammation
and it has been demonstrated that many proteins
involved in cellular iron management are up- or downregulated
by inflammatory stimuli, ultimately leading
to iron retention in the reticuloendothelial system.
Ferroportin is a key player in maintenance of correct
iron homeostasis, because it is the only known
mammalian cellular iron exporter. In this work we
show that incubation of THP-1 monocytes/macrophages
with lactoferrin prevents the LPS-induced
decrease of ferroportin by reducing secretion of IL-6
Hepcidin Expression in Iron Overload Diseases Is Variably Modulated by Circulating Factors
Hepcidin is a regulatory hormone that plays a major role in controlling body iron homeostasis. Circulating factors (holotransferrin, cytokines, erythroid regulators) might variably contribute to hepcidin modulation in different pathological conditions. There are few studies analysing the relationship between hepcidin transcript and related protein expression profiles in humans. Our aims were: a. to measure hepcidin expression at either hepatic, serum and urinary level in three paradigmatic iron overload conditions (hemochromatosis, thalassemia and dysmetabolic iron overload syndrome) and in controls; b. to measure mRNA hepcidin expression in two different hepatic cell lines (HepG2 and Huh-7) exposed to patients and controls sera to assess whether circulating factors could influence hepcidin transcription in different pathological conditions. Our findings suggest that hepcidin assays reflect hepatic hepcidin production, but also indicate that correlation is not ideal, likely due to methodological limits and to several post-trascriptional events. In vitro study showed that THAL sera down-regulated, HFE-HH and C-NAFLD sera up-regulated hepcidin synthesis. HAMP mRNA expression in Huh-7 cells exposed to sera form C-Donors, HFE-HH and THAL reproduced, at lower level, the results observed in HepG2, suggesting the important but not critical role of HFE in hepcidin regulation
One Man's Blessing, Another Woman's Curse? Family Factors and the Gender-Earnings Gap of Doctors
Using data from a new longitudinal survey of doctors from Australia, the authors test whether observed large gender-pay gaps among general practitioners (GPs) are the result of women's larger willingness to interrupt their careers. On average, female GPs earn A105,000, and A15,000-A35,000 in comparison to men without children, indicating the presence of a breadwinner effect that exacerbates the gender-earnings gap
On-demand erythrocyte disposal and iron recycling requires transient macrophages in the liver
Iron is an essential component of the erythrocyte protein hemoglobin and is crucial to oxygen transport in vertebrates. In the steady state, erythrocyte production is in equilibrium with erythrocyte removal1. In various pathophysiological conditions, however, erythrocyte life span is severely compromised, which threatens the organism with anemia and iron toxicity2,3. Here we identify an on-demand mechanism that clears erythrocytes and recycles iron. We show that Ly-6Chigh monocytes ingest stressed and senescent erythrocytes, accumulate in the liver via coordinated chemotactic cues, and differentiate to ferroportin 1 (FPN1)-expressing macrophages that can deliver iron to hepatocytes. Monocyte-derived FPN1+ Tim-4neg macrophages are transient, reside alongside embryonically-derived Tim-4high Kupffer cells, and depend on Csf1 and Nrf2. The spleen likewise recruits iron-loaded Ly-6Chigh monocytes, but these do not differentiate into iron-recycling macrophages due to the suppressive action of Csf2. Inhibiting monocyte recruitment to the liver leads to kidney and liver damage. These observations identify the liver as the primary organ supporting rapid erythrocyte removal and iron recycling and uncover a mechanism by which the body adapts to fluctuations in erythrocyte integrity
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