Transforming rooftops into productive urban spaces in the Mediterranean : an LCA comparison of agri-urban production and photovoltaic energy generation

Unidad de excelencia María de Maeztu MdM-2015-0552A key strategy towards sustainable urban development is designing cities for increased circular metabolism. The transformation of areas underused, such as urban rooftops, into productive spaces is being increasingly implemented as a result of associated multiple benefits. Rooftop greenhouses (RTGs) are an interesting option for exploiting urban rooftops with direct exposure to sunlight, reducing food miles and creating new agricultural spaces, while building-applied solar photovoltaic (BAPV) panels provide clean energy and reduce greenhouse gas emissions. However, a proper assessment of environmental costs and benefits related to both systems is vital for a successful implementation. By means of Life Cycle Assessment (LCA) method, modelled in the professional software SimaPro, this paper aims at comparing the environmental performance of different productive uses of rooftops under Mediterranean climatic conditions. The results showed that both systems are favourable and contribute to decreasing the environmental impacts thanks to the production of resources on-site. BAPV system shows the highest avoided burdens in comparison with RTG: for instance, the impacts generated by BAPV on climate change and fossil depletion categories, corresponding to - 430 kg CO₂ eq/m² and - 110 kg oil eq/m² respectively (versus - 22 kg CO₂ eq/m² and - 4.7 kg oil eq/m² in the RTG system), are around 20 times lower than RTG. Furthermore, a sensitivity analysis was performed through different scenarios, based on reductions or substitution of the most sensitive input flows, thus providing some useful tools for improved environmental performances. Attention to additional energy and material efficiency, in favour of the more environmentally sustainable choice, should remain a main point of investigation

Targeting Mitochondria by SS-31 Ameliorates the Whole Body Energy Status in Cancer- and Chemotherapy-Induced Cachexia

Cachexia is a complex metabolic syndrome frequently occurring in cancer patients and exacerbated by chemotherapy. In skeletal muscle of cancer hosts, reduced oxidative capacity and low intracellular ATP resulting from abnormal mitochondrial function were described. : The present study aimed at evaluating the ability of the mitochondria-targeted compound SS-31 to counteract muscle wasting and altered metabolism in C26-bearing (C26) mice either receiving chemotherapy (OXFU: oxaliplatin plus 5-fluorouracil) or not. : Mitochondrial dysfunction in C26-bearing (C26) mice associated with alterations of cardiolipin fatty acid chains. Selectively targeting cardiolipin with SS-31 partially counteracted body wasting and prevented the reduction of glycolytic myofiber area. SS-31 prompted muscle mitochondrial succinate dehydrogenase (SDH) activity and rescued intracellular ATP levels, although it was unable to counteract mitochondrial protein loss. Progressively increased dosing of SS-31 to C26 OXFU mice showed transient (21 days) beneficial effects on body and muscle weight loss before the onset of a refractory end-stage condition (28 days). At day 21, SS-31 prevented mitochondrial loss and abnormal autophagy/mitophagy. Skeletal muscle, liver and plasma metabolomes were analyzed, showing marked energy and protein metabolism alterations in tumor hosts. SS-31 partially modulated skeletal muscle and liver metabolome, likely reflecting an improved systemic energy homeostasis. : The results suggest that targeting mitochondrial function may be as important as targeting protein anabolism/catabolism for the prevention of cancer cachexia. With this in mind, prospective multi-modal therapies including SS-31 are warranted

Targeting mitochondria by ss-31 ameliorates the whole body energy status in cancer-and chemotherapy-induced cachexia

Objective: Cachexia is a complex metabolic syndrome frequently occurring in cancer patients and exacerbated by chemotherapy. In skeletal muscle of cancer hosts, reduced oxidative ca-pacity and low intracellular ATP resulting from abnormal mitochondrial function were described. Methods: The present study aimed at evaluating the ability of the mitochondria-targeted compound SS-31 to counteract muscle wasting and altered metabolism in C26-bearing (C26) mice either receiv-ing chemotherapy (OXFU: oxaliplatin plus 5-fluorouracil) or not. Results: Mitochondrial dysfunction in C26-bearing (C26) mice associated with alterations of cardiolipin fatty acid chains. Selectively targeting cardiolipin with SS-31 partially counteracted body wasting and prevented the reduction of glycolytic myofiber area. SS-31 prompted muscle mitochondrial succinate dehydrogenase (SDH) activity and rescued intracellular ATP levels, although it was unable to counteract mitochondrial protein loss. Progressively increased dosing of SS-31 to C26 OXFU mice showed transient (21 days) beneficial effects on body and muscle weight loss before the onset of a refractory end-stage condi-tion (28 days). At day 21, SS-31 prevented mitochondrial loss and abnormal autophagy/mitophagy. Skeletal muscle, liver and plasma metabolomes were analyzed, showing marked energy and protein metabolism alterations in tumor hosts. SS-31 partially modulated skeletal muscle and liver metab-olome, likely reflecting an improved systemic energy homeostasis. Conclusions: The results suggest that targeting mitochondrial function may be as important as targeting protein anabolism/catabo-lism for the prevention of cancer cachexia. With this in mind, prospective multi-modal therapies including SS-31 are warranted

Lack of effect of adenosine on the function of rodent osteoblasts and osteoclasts in vitro

Extracellular ATP, signalling through P2 receptors, exerts well-documented effects on bone cells, inhibiting mineral deposition by osteoblasts and stimulating the formation and resorptive activity of osteoclasts. The aims of this study were to determine the potential osteotropic effects of adenosine, the hydrolysis product of ATP, on primary bone cells in vitro. We determined the effect of exogenous adenosine on (1) the growth, alkaline phosphatase (TNAP) activity and bone-forming ability of osteoblasts derived from the calvariae of neonatal rats and mice and the marrow of juvenile rats and (2) the formation and resorptive activity of osteoclasts from juvenile mouse marrow. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed marked differences in the expression of P1 receptors in osteoblasts from different sources. Whilst mRNA for the A1 and A2B receptors was expressed by all primary osteoblasts, A2A receptor expression was limited to rat bone marrow and mouse calvarial osteoblasts and the A3 receptor to rat bone marrow osteoblasts. We found that adenosine had no detectable effects on cell growth, TNAP activity or bone formation by rodent osteoblasts in vitro. The analogue 2-chloroadenosine, which is hydrolysed more slowly than adenosine, had no effects on rat or mouse calvarial osteoblasts but increased TNAP activity and bone formation by rat bone marrow osteoblasts by 30–50 % at a concentration of 1 μM. Osteoclasts were found to express the A2A, A2B and A3 receptors; however, neither adenosine (≤100 μM) nor 2-chloroadenosine (≤10 μM) had any effect on the formation or resorptive activity of mouse osteoclasts in vitro. These results suggest that adenosine, unlike ATP, is not a major signalling molecule in the bone

Connexin channels and phospholipids: association and modulation

<p>Abstract</p> <p>Background</p> <p>For membrane proteins, lipids provide a structural framework and means to modulate function. Paired connexin hemichannels form the intercellular channels that compose gap junction plaques while unpaired hemichannels have regulated functions in non-junctional plasma membrane. The importance of interactions between connexin channels and phospholipids is poorly understood.</p> <p>Results</p> <p>Endogenous phospholipids most tightly associated with purified connexin26 or connexin32 hemichannels or with junctional plaques in cell membranes, those likely to have structural and/or modulatory effects, were identified by tandem electrospray ionization-mass spectrometry using class-specific interpretative methods. Phospholipids were characterized by headgroup class, charge, glycerol-alkyl chain linkage and by acyl chain length and saturation. The results indicate that specific endogenous phospholipids are uniquely associated with either connexin26 or connexin32 channels, and some phospholipids are associated with both. Functional effects of the major phospholipid classes on connexin channel activity were assessed by molecular permeability of hemichannels reconstituted into liposomes. Changes to phospholipid composition(s) of the liposome membrane altered the activity of connexin channels in a manner reflecting changes to the surface charge/potential of the membrane and, secondarily, to cholesterol content. Together, the data show that connexin26 and connexin32 channels have a preference for tight association with unique anionic phospholipids, and that these, independent of headgroup, have a positive effect on the activity of both connexin26 and connexin32 channels. Additionally, the data suggest that the likely in vivo phospholipid modulators of connexin channel structure-function that are connexin isoform-specific are found in the cytoplasmic leaflet. A modulatory role for phospholipids that promote negative curvature is also inferred.</p> <p>Conclusion</p> <p>This study is the first to identify (endogenous) phospholipids that tightly associate with connexin channels. The finding that specific phospholipids are associated with different connexin isoforms suggests connexin-specific regulatory and/or structural interactions with lipid membranes. The results are interpreted in light of connexin channel function and cell biology, as informed by current knowledge of lipid-protein interactions and membrane biophysics. The intimate involvement of distinct phospholipids with different connexins contributes to channel structure and/or function, as well as plaque integrity, and to modulation of connexin channels by lipophilic agents.</p

Efficiency and sustainability indicators for papermaking from virgin pulpâ\u80\u94An emergy-based case study

The pulp and paper sector is the fourth-largest industrial sector worldwide in terms of energy use, accounting for approximately 6% of the total industrial energy consumption and contributing to 2% of direct carbon dioxide (CO2) emissions produced by industries. The definition of the environmental profile of this industrial sector is crucial, due to the high market demand of paper and the increasing concern for the environmental costs of the whole papermaking process. A sustainability perspective should rely on a wider and holistic viewpoint, properly including all direct and indirect interactions with the environment. To this purpose, the Emergy (spelled with m) Accounting method (EMA) is very appropriate for the evaluation of the efficiency, effectiveness and sustainability of the papermaking process under different perspectives (resource quality, fossil energy and material consumption, environmental and human-driven support). Several studies concerning environmental impacts, eco-efficiency, and cleaner technologies in the pulp and paper sector have already been carried out, but none of them addressed resource quality and resource generation costs from a supply-side point of view. This study aims to fill this gap in the literature by highlighting the direct and indirect contribution in terms of natural capital and ecosystem services to the pulp and paper production process. By means of EMA performance indices, this paper aims to assess the environmental sustainability associated to the production of pulp and paper, so as to identify those process steps that entail the highest environmental costs and require improvements. Three forest management scenarios â\u88\u92 based on Spruce/Pine, Eucalyptus and Poplar production for raw material supply â\u88\u92 were evaluated to assess the sustainability and the efficiency of each species. Moreover, the marginal costs of achieving higher energy and material efficiency are investigated, with a special focus placed on the identification of the effects of energy input flows on additional demand for environmental services. The research results show that the largest supply-side environmental costs are generated by the industrial processing activities, due to high energy, water and chemicals consumption. Only a minor role is played by forestry activities that supply the raw feedstock, although forestry management practices certainly affect both the final productivity and the energy balance, through the amount and use efficiency of the farm inputs. Additionally, among the three forest systems under study, Spruce/Pine forest management displays the most sustainable option for paper production because, basing on the emergy indices, it presents the best sustainable contribution to both the economy and the environment of the investigated region. In conclusion, the application of EMA approach allowed a more comprehensive assessment of forestry and industrial operations, contributing to assist decision makers in implementing the best environmental management of papermaking process

End-of-life treatment of crystalline silicon photovoltaic panels. An emergy-based case study

Although photovoltaic (PV) technology has been projected as one of the most promising candidates to replace conventional fossil based power generation, claims about the potential disadvantages of the PV panels end-of-life (EoL) deserve careful attention in order to fully establish a feasibility and viability baseline and support technological and implementation policies. The current challenge concerning PV technology resides in making them efficient and competitive in comparison with traditional power generation systems, without disregarding the appraisal of EoL impacts. The emergy analysis method proved to be a reliable approach for the evaluation of the efficiency, effectiveness and environmental friendliness of technological processes under a global scale perspective and may likely be applied to the EoL PV investigation as a complement of conventional energy and economic assessments. Therefore, this method was used in this study to evaluate the sustainability of a PV panel recycling process. In addition, this paper aims to explore the implications of methodological assumptions when Emergy Accounting (EMA) tackles waste management systems, in order to address the shortcomings in this field. Results show that the PV panel treatment can generate large environmental benefits not only at the local scale of the process, but also at the larger scale of the industrial manufacture and material recovery, as well as at the even larger scale of the biosphere where resources come from and pollution is released. The comparison between the emergy invested for electricity production via PV and fossil energy sources also including EoL resource and environmental costs, highlights that PV technology is competitive under both energy and environmental points of view. This comparison reveals that the solar technologies imply remarkable emergy savings (1.45E+12 sej/kWh for fossil sources versus 3.57E+11 sej/kWh for crystalline silicon photovoltaic down to 2.31E+11 sej/kWh for cadmium telluride photovoltaic). Results clearly show that PV solar power can be considered a mature technology and can favorably compete with other renewable and non-renewable options for electricity generation. However, efficiency improvements of PV panels thermal recovery are still possible and may lead to further decrease of still too large emergy costs of the treatment process, not to talk of potential recovery alternatives such as chemical treatment for silicon cells and better upstream industrial design

Structural studies on archaeal phytanyl-ether lipids isolated from membranes of extreme halophiles by linear ion-trap multiple-stage tandem mass spectrometry with electrospray ionization

The structures of archaeal glycerophospholipids and glycolipids are unique in that they consist of phytanyl substituents ether linked to the glycerol backbone, imparting stability to the molecules. In this contribution, we described multiple-stage linear ion-trap combined with high resolution mass spectrometry toward structural characterization of this lipid family desorbed as lithiated adduct ions or as the [M-H]- and [M-2H]2- ions by ESI. MSn on various forms of the lithiated adduct ions yielded rich structurally informative ions leading to complete structure identification of this lipid family, including the location of the methyl branches of the phytanyl chain. By contrast, structural information deriving from MSn on the [M-H]- and [M-2H]2- ions is not complete. The fragmentation pathways in an ion-trap, including unusual internal loss of glycerol moiety and internal loss of hexose found for this lipid family were proposed. This mass spectrometric approach provides a simple tool to facilitate confident characterization of this unique lipid famil