Figure 3. 13 C‐based metabolic ﬂux and transcriptomic analyses of centralcarbonmetabolism of the hydroxy acid‐producing strains under batch fermentation conditions with 10 g L −1 initial glucose concentrations. Crabtree‐negative S. cerevisiae strains (TAM—STtam_2803) producing diﬀerent hydroxy acids: lactate (STlac_7031), malate (STmal_5413), and 3HP (SThpdh_2779 and SThibadh_2780) were analyzed for their relative ﬂux distributions and the diﬀerential expression of the genes involved in each reaction. Bar charts next to each reaction show the relative ﬂux values for each strain calculated from a genome‐scale model constrained with data from 13 C‐MFA (normalized over glucose uptake rate). Underneath each graph are heat map plots for the relative transcript levels. Beside each heat map plots are the name of the associated gene. AC, acetate; ACALD, acetaldehyde; ACoAmit, acetyl‐CoA (mitochondrial); AKG, α‐ ketoglutarate; CIT, citrate; DHAP, dihydroxy‐acetone‐phosphate; 13DPG, 1,3‐diphosphateglycerate; E4P, erythrose‐4‐phosphate; EtOH, ethanol; F6P, fructose‐6‐ phosphate; FDP, fructose‐1,6‐diphosphate; FUM, fumarate; GLC, glucose; GLYC, glycerol; GLYC3P, glycerol‐3‐phosphate; G3P, glyceraldehyde‐3‐phosphate; G6P, glucose‐6‐phosphate; ICIT, isocitrate; MAL, malate; OAA, oxaloacetate; PEP, phosphoenolpyruvate; 2PG, 2‐phosphoglycerate; 3PG, 3‐phosphoglycerate; 6PGC, 6‐phospho‐ D ‐gluconate; 6PGL, D ‐6‐phospho‐glucono‐δ‐lactone; PYRcyt, pyruvate (cytosolic); PYRmit, pyruvate (mitochondrial); RU5P, ribulose‐5‐
Eukaryotic cells are able to tune their complex metabolism through compartmentation. This involves confining reactions to designated compartments and controlling the access of metabolites through specific transporters. Mitochondria play an important part in the organization of the eukaryotic cell metabolism (Wahrheit et al., 2011). They work as the powerhouse of the cell, being responsible for the TCA cycle, oxidative phosphorylation and other essential reactions in the centralcarbonmetabolism. Furthermore, mitochondria play a key role in the signaling processes leading to apoptosis (Kroemer et al., 2007). Mitochondrial dysfunctions are associated with the aging process and with a wide range of human diseases (Calvo et al., 2006; Duchen, 2004; Lemasters, 2007; Moreno-Sanchez et al., 2014; Nassir and Ibdah, 2014; Raimundo et al., 2011; Thiele et al., 2005). Metabolite traffic between cytosol and mitochondria is mediated by carriers. These carriers, excellently reviewed by Palmieri (Palmieri, 2013), have important roles in physiological and pathological processes (Gutierrez-Aguilar and Baines, 2013). Studies related to mitochondrial function and metabolism have been so far focused on isolated features, like respiration and the respiratory chain (Frezza et al., 2007; Kuznetsov et al., 2008) or on the function of single mitochondrial transporters. Even after the advent of the systems biology era, the studies focused on the mitochondrial metabolic network as a whole remain scarce (Balaban, 2006). So far, the most complex studies related to mitochondrial metabolism used enzyme kinetics, but their results are limited by insufficient knowledge about regulation and parameter values (Smith and Robinson, 2011; Wu et al., 2007). Studying the mitochondrial metabolism in whole cells is complicated by the overlapping with other cellular reactions and by the limited accessibility of the mitochondria. Selective permeabilization using digitonin (Kuznetsov et al., 2008) is a simple and efficient way to access mitochondria while maintaining their functionality (Bahnemann et al., 2014).
S. solfataricus relies on the branched ED pathway (DeRosa et al., 1984; Schönheit et al., 1995; Ahmed et al., 2005), which is promiscuous for glucose and galactose, for carbohydrate catabolism and only gluconeogenesis seems to proceed via the anabolic EMP pathway. Glucose is completely oxidised to CO2 via an oxidative CAC with O2 as terminal electron acceptor. In S. solfataricus the expression pattern of growth on yeast extract and tryptone (YT) was compared to growth on glucose. Strikingly, the results of the expression analyses of the centralcarbonmetabolism of S. solfataricus on transcriptomic level revealed not a strong regulation of the respective genes and pathways (Snijders et al., 2006). Only in consideration of available proteomic data, the GAPN (SSO3194) turned out to be induced under growth on glucose, furthermore the enzyme is allosterically regulated (Ahmed, 2006), whereas the PGK (SSO0527) as well as the PEPS (SSO0883) are suggested to be induced in YT grown cells and therefore, represent true anabolic enzymes (Snijders et al., 2006).
Centralcarbonmetabolism and virulence factor synthesis are tightly linked in S. aureus and controlled by several transcription factors [ 3 ]. Notably, CcpA is the only transcription factor known to enhance infectivity of S. aureus [ 6 , 24 , 25 ], while other regulators such as CcpE, CodY, and RpiRc are thought to attenuate rather than to promote infectivity of this bacterium in mice [ 33 , 44 – 47 ]. We show here that HPr contributes positively to infectivity of S. aureus in mice, presumably by affecting centralcarbonmetabolism and virulence factor synthesis in a CcpA-dependent and -independent manner. These effects are likely mediated through changes in sugar transport and carbon metabolization that alter biofilm formation [ 24 ]. It is also possible that HPr in S. aureus acts like the HPr homolog of E. coli to modulate quorum sensing by interacting with autoinducer-2 (AI-2) modifying factors [ 48 ]. Given the importance of HPr on biofilm formation and virulence in S. aureus, this phosphocarrier protein could be a promising drug target for the development of novel anti-staphylococcal compounds.
From the discussion above, it seems that the new ISO certification procedure would be the most accurate and easiest to implement. In this context, experiences from existing and previous border procedures for food products could be highly relevant for an ISO carbon footprint system.
Along with the practical obstacles of implementing and operating firm-targeted carbon tariffs come several legal and political hindrances. Böhringer et al. (2012b) discuss these issues in more detail. The main legal challenge is to comply with the World Trade Organisation (WTO) law. Discrimination of equal goods based on their production methods is not legal. Though it may be legal to take action based on environmental considerations, the rules are strict. Allowing exporters to affect their tariff rate by adjusting their carbon input could be more acceptable than rigid average tariff rates. On the other hand, comprehensive documentation requirements can be regarded as non-tariff trade barriers.
It should be noted that our implementation of tariffs in the model still keeps the assumption that firms within each industry and region have homogenous technologies. This simplifying assumption
significantly reduces the necessary data input of the already comprehensive and detailed model. However, this comes at some loss in real-world heterogeneity. Even before introducing carbon tariffs emission intensities will likely vary across firms within the same sector. Carbon tariffs could, thus, lead to sorting where the least emission-intensive firms export to the regulating region, while the most emission-intensive firms supply to the other regions. Although the least emission-intensive firms may still find it profitable to reduce emissions further when tariffs are firm-targeted rather than region- specific, our model setting will probably overestimate the difference. This is also the case when we consider emissions from electricity generation. Instead of reducing emission intensities in some plants, the reality could be that the exporters switch to electricity plants with relatively low emissions. Thus, the options could be more discrete than our modelling implicitly assumes and, again, the firm- targeting will have smaller impacts compared to a setting where agents are representative.
The greenhouse gas carbon dioxide (CO 2 ) can be converted into
value-added products by carbon capture and utilization (CCU). 1 CCU aims at reducing the use of fossil resources and emissions of greenhouse gases (GHG). 2–4 Importantly, CCU is a potential key enabler for deep de-fossilization of industries that currently rely on fossil feedstocks not only for energy but also a source of carbon, such as the chemical industry. 5 Available analyses suggest that CCU could utilize CO 2 up to the gigatonne scale. 6
Abstract Carbon storage in soils is sensitive to changing climatic conditions, potentially increasing C fluxes from soils to the atmosphere. This study provides an assessment of recent climate variability (1951–2000) and potential future (2001–2055) climate change impacts on soil C storage for croplands in the German part of the Elbe River basin. Results indicate that recently (1991–2000) croplands are a net source of carbon (net annual flux of 10.8 g C m -2 year -1 to the atmosphere). The recent temperature trend for the years 1951–2000 (+0.8 K in summer and +1.4 K in winter mean temperature) alone have already caused a significant net flux of 1.8 g C m -2 year -1 to the atmosphere. Future climate change (2001–2055) derived from regionalised meteorological properties driven by the IPCC-SRES A1 scenario results in an increased net C flux of an additional 4 g C m -2 year -1 in comparison to the reference period (1951–2000). Uncertainties attached to C flux results are estimated with a standard error of 6%. Besides climate-induced alteration of net C fluxes, considerable impacts on groundwater recharge (−45.7%), river flow (−43.2%) and crop yield (−11% to −15% as a basin-wide average for different cereals) were obtained. Recent past and expected temperature changes within the Elbe basin predominantly contribute to the increase of net C fluxes to the atmosphere. However, decreased crop growth (crop yields) and decreased expected water availability counteract even higher net C losses as soil C turnover is reduced through less C input (less crop growth) and drier soil conditions (decrease in water availability). Based on this study, present-day and potential future development of net C fluxes, water components and crop yields were quantified. This allows integrated assessment of different ecosystem services (C storage, water availability and crop yield) under climate change in river basins.
over time. In other words, as the world economy gets more and more integrated via trade, carbon tariffs can gain a more prominent role than asserted by previous analysis.
Our assessment of carbon tariffs however, shows that the increase in carbon trade over time does not go along with an increase in the effectiveness of carbon tariffs to reduce carbon leakage and decrease global costs of emission abatement. The major change over time is that the burden shifting potential of carbon tariffs from abating industrialized OECD regions to developing Non-OECD countries increases markedly due to enforced terms-of-trade effects. The main reasoning behind these insights is that along with the increase in imports of carbon from Non-OECD to OECD there is a strong increase in trade in embodied carbon between Non-OECD countries. In addition, the carbon intensity of OECD regions declined over time such that CO 2 prices must be higher to effect an identical relative emission reduction over
water under visible-light irradiation. Interestingly, Antonietti and coworkers have demonstrated that highly condensed and crystalline carbon nitrides tend to be less active photocatalysts than ‘defect-containing’ (more hydrogen, less crystallinity) carbon nitrides.  Therefore, it is instructive to synthesize different forms of ‘defect-containing’ carbon nitrides and investigate their photoactivity to see how the activity relates to these structures. Although most research focuses on melon-type materials (one-dimensional, heptazine-based carbon nitrides) due to its rather low band gap (2.7 eV),  fewer researchers investigate the photoactivity of the less condensed carbon nitride materials which undergo less condensation than melon but are, on average, more condensed than melem. Herein we have chosen to synthesize these melem oligomers in an open system at relatively low temperatures in order to prevent good crystallization and check whether we can obtain forms of less condensed melon-type materials. Melem and melon are well studied carbon nitride materials. Melem (2,5,8-triamino-tri-s-triazine) C 6 N 7 (NH 2 ) 3 can be obtained by thermal treatment of simpler, less condensed C-N-H compounds
public and financial markets. This explains why most of the carbon intensive companies seem not to be affected by increasing carbon prices with respect to their credit risk in the early period. Hence, the awareness of carbon risk seems to increase with time, which also holds for the contract’s maturity. Concentrating on the five years maturity regression results we find that most of the heavy emitters suffer from carbon risk and the less carbon intensive panels benefit from increasing EUA futures prices. We conclude that carbon risk is a longer-term phenomenon. From a policy perspective this seems reasonable, be- cause carbon risk incorporates policy risk. However, policy decisions and implementations rather face time horizons of years than months. A main reason for this is the security of investment. Thus, companies should be able to plan their investments assuming regulatory stability. In Germany and the European Union emission reduction targets are well com- municated and the regulatory rules within an EU ETS trading periods are transparent. Nevertheless, the somewhat sudden implementation of a driving ban in German cities, such as Essen, Frankfurt, Stuttgart and Berlin, for diesel vehicles with Euro4 or Euro5 engines signals an increase in policy uncertainty. This could lead to an increase in carbon risk perception, because regulatory stability is weakened. This explains the explanatory power of the five years maturity regression results.
Human exposure to formaldehyde can occur by inhalation, ingestion or entry through the skin (de Groot et al., 2009; Dhareshwar and Stella, 2008; NTP, 2010). One pertinent question is whether exogenous formaldehyde can pose a big threat to the CNS by entering the blood and ultimately reaching the brain on crossing the BBB. Some studies have shown that formaldehyde inhalation does not substantially increase the level of formaldehyde in blood over the homeostatic value (Franks, 2005; Heck et al., 1985; Heck et al., 1982) and the brain (Heck et al., 1982). This is not surprising since the formaldehyde- oxidizing enzymes ADH3 and ALDH2 are ubiquitously expressed in all tissues (Alnouti and Klaassen, 2008; Nishimura and Naito, 2006). Also, since the homeostatic concentration of formaldehyde in the blood is about 0.1 mM (Heck and Casanova, 2004; Heck et al., 1985), the body would have to be exposed to high doses of formaldehyde in order to exert cerebral damage after escaping its metabolism, predominantly in the liver. Indeed, exposure to formaldehyde has been reported to cause neurotoxicity in humans as well as animals and depends on the dose and duration of formaldehyde exposure (Kilburn et al., 1985a; Kilburn et al., 1985b; Kilburn et al., 1989; Songur et al., 2010; Songur et al., 2008). Nevertheless, individuals carrying functional polymorphisms in the promoter of ADH3 or genetic polymorphisms in ALDH2 which are suggested to be associated with reduced formaldehyde-oxidizing capacity (Hedberg et al., 2001; Wang et al., 2002) may be more vulnerable to neural damage by exogenous formaldehyde even at low doses.
When focusing on the luciferase activities in the course of growth, it was noticed that luminescence showed specific characteristics in most of the analyzed test strains: after inoculation, luminescence started from a basis level until the mid-exponential growth phase, which was usually after 6 h of cultivation. Maximal luciferase activity seemed to be due to the promoter employed and the carbon source the test strain was grown on. However, all luminescence courses had in common that, after reaching the maximum level, luciferase activity decreased drastically and after 24 h of growth, luminescence levels always were even below the basis level at the beginning. Regarding the decay of luminescence after the 6 h time point, it was remarkable that the half-life of the luciferase usually averaged between 3.5 h and 4.5 h. Thus, the question arose, whether these values displayed the actual half-life of the luciferase in living cells or whether the luciferase protein is subject to active protein degradation mechanisms in C. glutamicum. In order to answer this question, C. glutamicum ∆atlR (pET2_luxABfre_prbtT) was grown in minimal medium containing 1% (w/v) glucose and after 2 h of cultivation, different amounts of spectinomycin were added to the cultures in order to prevent protein biosynthesis. Subsequently, growth and luminescence of the cultures were monitored over a period of 10 h. In Fig. 32A, growth and luciferase activities of cultures with 400 µg and 800 µg spectinomycin/ml are shown, the time point of antibiotic additions is marked as t = 0 h. As a control luminescence and growth of C. glutamicum ∆atlR (pET2_luxABfre_prbtT) without spectinomycin addition is given in Fig. 32B. From the decay of luminescence shown in Fig. 32A, a half-life of around 8 h was calculated for the luciferase protein after shut off of the protein biosynthesis. In contrast, the control culture without antibiotic (Fig. 32B) displayed a distinct faster decrease of luciferase activities after the mid- exponential maximum. This result indicated that there might be an active degradation of proteins after the mid-exponential growth phase in C. glutamicum. An active degradation obviously is prevented by addition of spectinomycin as synthesis of proteases is blocked by
Institute of Statics and Dynamics in Aerospace Structures, University of Stuttgart, Pfaffenwaldring 27, D- 70550 Stuttgart
SUMMARY: The major process for manufacturing carbon/carbon composites is the carboni-
zation of carbon fibre reinforced plastics (CFRP). In this process, the shrinkage of the matrix is hindered by the fibres and leads to a high amount of cracks resulting in a microscopic open porosity. To control this process, it is necessary to gain knowledge about its essential parame- ters, in which the crack microstructure plays an important role. Micrographs (SEM) revealed that the cracks can be distinguished in three different types: fibre-matrix debonding, segmenta- tion cracks and micro-delaminations. Fibre-matrix bonding determines which crack type domi- nates the structure of the final carbon/carbon composite. The evolution of the cracks during pyrolysis (temperature, sequence and importance of the crack types) was investigated by means of acoustic emission and microscopy in combination with a heating stage. By comparing these results with those of thermogravimetric analysis and dilatometer experiments, the devel- opment of the cracks can be explained.
M arine brown macroalgae including Macrocystis integrifolia, Nereocystis luetkeana, Lessoniop- sis littoralis, Laminaria saccharina, Fucus serratus and some further representatives of the Laminariales and Fucales (Phaeophyta) have been investigated w ith respect to their remarkably high potential for /?-carboxylation o f phosphoenolpyruvate supplem enting photosynthetic C 0 2 fixation. K inetic tracer studies indicate th at 14C-labelling o f C 4 acids such as aspartate and malate is not restricted to dark periods, b u t also occurs during photosynthesis. Rates o f carbon fixation into C4 compounds are approxim ately equal in the light and in the dark. D istribution of 14C between C 1 and C4 atoms o f aspartate suggests carbon flow from early occurring photosynthates such as 3-phosphoglycerate to C 4 com pounds including aspartate and malate. In brown macro algae dark carbon fixation via /?-carboxylation o f phosphoenolpyruvate is therefore assumed to be quantitatively and qualitatively integrated into photosynthetic C 0 2 assimilation thus yielding appreciable 14C-labelling of C4 dicarboxylic acids. T he underlying reactions and conversions are basically different from C4 photosynthesis and should preferably be term ed as C 4 metabolism .
Emissions and macroeconomic impacts
Table 3 reports the impacts of unilateral emission regulation in Switzerland and the US on emissions and welfare. The leakage rate is defined as the change in unregulated emissions abroad as a share of the domestic emission reduction. A leakage rate of 50%, for example, means that half of the domestic emission reduction is offset by increases in emissions abroad. Welfare changes are reported in Hicksian equivalent income variation. This measure denotes the amount which is necessary to add to (or subtract from) the business-as-usual income of the household so that she enjoys a utility level equal to the one in the counterfactual policy scenario on the basis of ex-ante relative prices. 9 One difficulty, however, in comparing welfare impacts between REF and TRF is that the amount of global emissions differs between the two regulatory regimes, as the abating country keeps with a fixed 20% reduction target in domestic base-year emissions irrespective of the emissions in the rest of the world. To accommodate a coherent global cost- effectiveness analysis between the REF and TRF scenarios, we would need to keep global carbon emissions constant. In this vein, we implement an additional scenario – denoted TRF* – where we adjust the domestic emission reduction target of the unilateral abating region in the case of carbon tariffs to match the same global emissions as triggered in the REF scenario. 10
Production impacts in EITE industries
We now turn to the impact assessment of unilateral emission pricing on EITE industries where we can build on the insights from the multi-region input-output analysis in Section 3.
Unilateral CO2 emission pricing leads to a cost increase for domestic EITE goods where emission- intensive goods – either in terms of fossil fuels or in terms of other dirty non-energy intermediate goods – represent a significant share of inputs. The cost increase reduces competitiveness vis-à-vis producers from unregulated regions both on the domestic market as well as on international markets. A complementary carbon tariff affects the competitiveness of domestic EITE production differently on the domestic and international markets. In first place, the tariff leads to a further cost increase since the domestic emission price has to be paid additionally on the carbon embodied in imported inputs. Domestic EITE industries then face an even bigger cost disadvantage on international markets than under uniform emission pricing only. In contrast, the tariff levels the playing field in domestic markets, since it effects that the entire embodied carbon of a good has to be paid for – independent of whether it is produced domestically or abroad. In fact, since the EITE industries in Switzerland and the US are “cleaner” from the outset compared to other world regions (see Section 3), unilateral emission pricing complemented with carbon import tariffs may even establish a cost advantage on domestic markets against at least some foreign competitors. 13
Goetz et al. (2009) distinguished three approaches for using remote sensing data to map carbon stocks. In the simplest method, the stratify and multiply (SM) approach, e.g. as used by Mayaux et al. (2004) or Suchenwirth et al. (2012), a single value or a range of values is assigned to each class of land cover, vegetation type, or other site characteristic. This approach is limited due to the range of biomass within any given thematic class and the ambiguities concerning the identification of given types. The second approach, combine and assign (CA), extends the SM approach to a wider range of spatial data to improve classifications (Gibbs et al. 2007). It has the advantage of using finer spatial units of aggregation and weighted data layers, but is limited due to the moot representativeness of class values and difficulties in acquiring consistent information as the study area size increases. The third approach, direct remote sensing (DR), uses machine learning techniques and extends satellite measurements directly to maps, i.e., a classification algorithm is trained to develop an optimized set of rules through iterative repeated data analysis (Breiman 2001) for the estimation of biomass and carbon (Baccini et al. 2012). This approach results in continuous values for biomass based on easily understandable rules, such as those described for the Amazon basin (Saatchi et al. 2007), Russian forests (Houghton et al. 2007), or the African continent (Williams et al. 2007).
Table 2 shows the results of the update provided by Arnone et al. The column numbers correspond to the numbering in Table 1. First we consider the over- all scores (political plus economic autonomy, last two columns). With the exception of Canada (loss of one point) and the US (no change), all countries have improved the degree of overall autonomy of their central banks. The most significant increases occurred in former low-autonomy countries that joined the European Monetary Union (euro area), such as Greece, Italy, Portugal or Spain. It is interest- ing to note that also some non-EMU countries, like Denmark, New Zealand, Switzerland and the UK, were able to markedly improve their scores for cen- tral bank autonomy during the period considered. The European Central Bank (ECB) stands out with the highest (and highest possible) score of 16 points.