Environmental Impacts of Products: A Detailed Review of Studies

Environmental effects of economic activities are ultimately driven by consumption, via impacts of the production, use, and waste management phases of products and services ultimately consumed. Integrated product policy (IPP) addressing the life‐cycle impacts of products forms an innovative new generation of environmental policy. Yet this policy requires insight into the final consumption expenditures and related products that have the greatest life‐cycle environmental impacts. This review article brings together the conclusions of 11 studies that analyze the life‐cycle impacts of total societal consumption and the relative importance of different final consumption categories. This review addresses in general studies that were included in the project Environmental Impacts of Products (EIPRO) of the European Union (EU), which form the basis of this special issue. Unlike most studies done in the past 25 years on similar topics, the studies reviewed here covered a broad set of environmental impacts beyond just energy use or carbon dioxide (CO₂) emissions. The studies differed greatly in basic approach (extrapolating LCA data to impacts of consumption categories versus approaches based on environmentally extended input‐output (EEIO) tables), geographical region, disaggregation of final demand, data inventory used, and method of impact assessment. Nevertheless, across all studies a limited number of priorities emerged. The three main priorities, housing, transport, and food, are responsible for 70% of the environmental impacts in most categories, although covering only 55% of the final expenditure in the 25 countries that currently make up the EU. At a more detailed level, priorities are car and most probably air travel within transport, meat and dairy within food, and building structures, heating, and (electrical) energy‐using products within housing. Expenditures on clothing, communication, health care, and education are considerably less important. Given the very different approaches followed in each of the sources reviewed, this result hence must be regarded as extremely robust. Recommendations are given to harmonize and improve the methodological approaches of such analyses, for instance, with regard to modeling of imports, inclusion of capital goods, and making an explicit distinction between household and government expenditure.     

The Soluble Periplasmic Domains of Escherichia coli Cell Division Proteins FtsQ/FtsB/FtsL Form a Trimeric Complex with Submicromolar Affinity

Cell division in Escherichia coli involves a set of essential proteins that assembles at midcell to form the so-called divisome. The divisome regulates the invagination of the inner membrane, cell wall synthesis, and inward growth of the outer membrane. One of the divisome proteins, FtsQ, plays a central but enigmatic role in cell division. This protein associates with FtsB and FtsL, which, like FtsQ, are bitopic inner membrane proteins with a large periplasmic domain (denoted FtsQ_p, FtsB_p, and FtsL_p) that is indispensable for the function of each protein. Considering the vital nature and accessible location of the FtsQBL complex, it is an attractive target for protein-protein interaction inhibitors intended to block bacterial cell division. In this study, we expressed FtsQ_p, FtsB_p, and FtsL_p individually and in combination. Upon co-expression, FtsQ_p was co-purified with FtsB_p and FtsL_p from E. coli extracts as a stable trimeric complex. FtsB_p was also shown to interact with FtsQ_p in the absence of FtsL_p albeit with lower affinity. Interactions were mapped at the C terminus of the respective domains by site-specific cross-linking. The binding affinity and 1:1:1 stoichiometry of the FtsQ_pB_pL_p complex and the FtsQ_pB_p subcomplex were determined in complementary surface plasmon resonance, analytical ultracentrifugation, and native mass spectrometry experiments.     

A challenging insight on the structural unit 1 of molluscan Rapana venosa hemocyanin

Hemocyanins of mollusks are high molecular mass glycoproteins with a complex quaternary structure which still remains to be defined in detail for most of its species as far as number, spatial distribution and interactions of their structural units is concerned. In the present study, we isolated the functional units of the structural subunit RvH1 of Rapana venosa hemocyanin, combining enzymatic and non-enzymatic methods. Our results suggest that Hc's carbohydrate moieties play a basic role in the organization of the structural units, resulting from post-translational polymerization of the 50 kDa functional units and involving sugar moieties that link between them.     

Exposure of bovine sperm to pro-oxidants impairs the developmental competence of the embryo after the first cleavage

The present study describes the effects of exposure of bovine sperm to mild and more intense ROS generating conditions. The membrane integrity of the incubated sperm was assessed and the incubated sperm were used for IVF after which the percentages of cleavage and blastocyst formation were determined for a period up to 9 days. The incubated sperm samples showed increased levels of molecular oxidation in the plasma membrane, the mitochondria, the cytosol and to a lesser extent in the sperm's DNA. The sperm membrane integrity as well as the first cleavage rates obtained with sperm from mild ROS generating conditions (100 microM H2O2) were not different from sperm incubated without pro-oxidants. However, exposure of sperm to more severe oxidative stress (500 mM H2O2 or a combination of 100 microM ascorbic acid, 20 microM FeSO4 and 500 microM H2O2) led to plasma membrane oxidation, reduced percentages of cleaved embryos and a reduction in the percentages of cleaved embryos that developed to the blastocyst stage. From these results, we conclude that the impact of oxidative stress to sperm becomes primarily manifest after the first cleavage of the formed zygote. Importantly, the level of lipid peroxidation in the sperm plasma membrane significantly correlates with blastocyst formation when the corresponding sperm is used for in vitro fertilization of oocytes.     

Molecular mechanisms of pathogenicity: how do pathogenic microorganisms develop cross-kingdom host jumps?

It is common knowledge that pathogenic viruses can change hosts, with avian influenza, the HIV, and the causal agent of variant Creutzfeldt-Jacob encephalitis as well-known examples. Less well known, however, is that host jumps also occur with more complex pathogenic microorganisms such as bacteria and fungi. In extreme cases, these host jumps even cross kingdom of life barriers. A number of requirements need to be met to enable a microorganism to cross such kingdom barriers. Potential cross-kingdom pathogenic microorganisms must be able to come into close and frequent contact with potential hosts, and must be able to overcome or evade host defences. Reproduction on, in, or near the new host will ensure the transmission or release of successful genotypes. An unexpectedly high number of cross-kingdom host shifts of bacterial and fungal pathogens are described in the literature. Interestingly, the molecular mechanisms underlying these shifts show commonalities. The evolution of pathogenicity towards novel hosts may be based on traits that were originally developed to ensure survival in the microorganism's original habitat, including former hosts.     

Reconciling ecogeographical rules: rainfall and temperature predict global colour variation in the largest bird radiation

Ecogeographical rules that associate climate with organismal form and function can reveal patterns of climatic adaptation. Two rules link animal coloration with climate: Gloger's rule (darker coloration where wet and warm), and Bogert's rule (darker coloration where cold). Whereas Gloger's rule was proposed for endotherms, and Bogert's rule for ectotherms, both rules may apply more broadly, despite their seemingly opposing effects. Here, we test this contradiction on a global scale across passerine birds. Consistent with Gloger's rule, birds were darker in wetter areas and, following Bogert's rule, lighter where warm, although birds became lighter again at very low temperatures. Rainfall and temperature had antagonistic or additive effects depending on their pattern of covariation, and this predicted whether birds followed the rules. We integrate both rules into a general framework to explain heterogeneity in climatic effects on coloration, which has implications to understand patterns of diversification, climatic adaptation and climate change impacts.     

Plumage colour in nestling blue tits: sexual dichromatism,condition dependence and genetic effects

Sexual-selection theory assumes that there are costs associated with ornamental plumage coloration. While pigment-based ornaments have repeatedly been shown to be condition dependent, this has been more difficult to demonstrate for structural colours. We present evidence for condition dependence of both types of plumage colour in nestling blue tits (Parus caeruleus). Using reflectance spectrometry, we show that blue tit nestlings are sexually dichromatic, with males having more chromatic (more 'saturated') and ultraviolet (UV)-shifted tail coloration and more chromatic yellow breast coloration. The sexual dimorphism in nestling tail coloration is qualitatively similar to that of chick-feeding adults from the same population. By contrast, the breast plumage of adult birds is not sexually dichromatic in terms of chroma. In nestlings, the chroma of both tail and breast feathers is positively associated with condition (body mass on day 14). The UV/blue hue of the tail feathers is influenced by paternally inherited genes, as indicated by a maternal half-sibling comparison. We conclude that the expression of both carotenoid-based and structural coloration seems to be condition dependent in blue tit nestlings, and that there are additional genetic effects on the hue of the UV/blue tail feathers. The signalling or other functions of sexual dichromatism in nestlings remain obscure. Our study shows that nestling blue tits are suitable model organisms for the study of ontogenetic costs and heritability of both carotenoid-based and structural colour in birds.     

Convergent evolution of gigantism in the flora of an isolated archipelago

Animals often evolve conspicuous differences in body size after colonising isolated islands. However, far less is known about repeated patterns in the evolution of plant size on islands. We tested for convergent evolution of leaf area, seed size and plant stature in the flora of the Chatham Islands (i.e. Rēkohu), which are located 700 km off the east coast of New Zealand. First, we measured leaf area, seed size and plant stature from populations of 22 plant taxa on the Chatham Islands. These data were then compared to analogous measurements from their sister taxa on the mainland to test for evidence of island gigantism, and whether size changes differ between leaves, seeds and stature. Second, we collated data from the literature to test whether size changes in endemic taxa differed among plant growth forms or were correlated with divergence times. Results showed that all three plant traits tended to increase in size on the Chatham Islands. However, field data showed that size increases tended to be more consistent in seeds and leaves than in stature. Data from the literature indicated that size increases also differed among growth forms. Herbaceous species showed the strongest evidence of gigantism, followed by woody plants, while graminoids showed a weak trend towards dwarfism. Insular size increases in seeds and leaves were also positively related to divergence times, indicating that taxa which have resided on the Chatham Islands for longer periods show stronger evidence of gigantism than taxa which arrived more recently. Overall results illustrate that gigantism is a hallmark of the Chatham Island flora, providing a remarkable example of convergent evolution.     

Impact of land‐use change to Jatropha bioenergy plantations on biomass and soil carbon stocks: a field study in Mali

Small‐scale Jatropha cultivation and biodiesel production have the potential of contributing to local development, energy security, and greenhouse gas (GHG) mitigation. In recent years however, the GHG mitigation potential of biofuel crops is heavily disputed due to the occurrence of a carbon debt, caused by CO₂ emissions from biomass and soil after land‐use change (LUC). Most published carbon footprint studies of Jatropha report modeled results based on a very limited database. In particular, little empirical data exist on the effects of Jatropha on biomass and soil C stocks. In this study, we used field data to quantify these C pools in three land uses in Mali, that is, Jatropha plantations, annual cropland, and fallow land, to estimate both the Jatropha C debt and its C sequestration potential. Four‐year‐old Jatropha plantations hold on average 2.3 Mg C ha^?1 in their above‐ and belowground woody biomass, which is considerably lower compared to results from other regions. This can be explained by the adverse growing conditions and poor local management. No significant soil organic carbon (SOC) sequestration could be demonstrated after 4 years of cultivation. While the conversion of cropland to Jatropha does not entail significant C losses, the replacement of fallow land results in an average C debt of 34.7 Mg C ha^?1, mainly caused by biomass removal (73%). Retaining native savannah woodland trees on the field during LUC and improved crop management focusing on SOC conservation can play an important role in reducing Jatropha's C debt. Although planting Jatropha on degraded, carbon‐poor cropland results in a limited C debt, the low biomass production, and seed yield attained on these lands reduce Jatropha's potential to sequester C and replace fossil fuels. Therefore, future research should mainly focus on increasing Jatropha's crop productivity in these degraded lands.