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The Antarctic Peninsula is one of the regions to be most affected by increase in sea surface temperatures (SSTs) mediated by Global Climate Change; indeed, most negative predictions imply an up to 6 °C increment by the end of the XXI century. Temperature is one of the most important factors mediating diversity and distribution of macroalgae, although there is still no consensus as to the likely effects of higher SSTs, especially for polar seaweeds. Some available information suggests that potential strategies to withstand future increases in SSTs will be founded upon the glutathione-ascorbate cycle and the induction of chaperone-functioning heat shock proteins (HSPs); however, their eventual role, even for general stress responses, is unclear. The intertidal green, brown and red macroalgae species Monostroma hariotii, Adenocystis utricularis and Pyropia endiviifolia, respectively, from King George Island, Antarctic Peninsula, were exposed to 2 °C (control) and 8 °C (climate change scenario) for up to 5 days (d). Photosynthetic activity (αETR and ETRmax, and EkETR), photoinhibition (Fv/Fm) and photoprotection processes (αNPQ, NPQmax, and EkNPQ) provided no evidence of negative ecophysiological effects. There were moderate increases in H2O2 production and levels of lipid peroxidation with temperature, results supported by stable levels of total glutathione and ascorbate pools, with mostly higher levels of reduced ascorbate and glutathione than oxidized forms in all species. Transcripts of P. endiviifolia indicated a general upregulation of all antioxidant enzymes and HSPs genes studied under warmer temperature, although with different levels of activation with time. This pioneering investigation exploring different levels of biological organization, suggested that Antarctic intertidal macroalgae may be able to withstand future rise in SSTs, probably slightly altering their latitudinal distribution and/or range of thermal tolerance, by exhibiting robust glutathione-ascorbate production and recycling, as well as the induction of associated antioxidant enzymatic machinery and the syntheses of HSPs.

An ultracapacitor (UCap) based on carbon xerogel electrodes and sodium sulfate electrolyte was investigated in the voltage range between 0 and 1.8 V. Notwithstanding the high value of maximum voltage (1.8 V) the UCap exhibited excellent stability during 20000 of cycling test. Moreover, the achievement of this high voltage made possible to obtain high value of specific energy. The stability was possible because the potential limits of electrode-electrolyte decomposition at positive and negative electrodes were never achieved. This is because an asymmetric UCap with different amounts of carbon xerogel in the electrodes was used. The UCap with the carbon xerogel of BET specific surface area of 3100 m(2) g(-1) demonstrated a specific energy of 17.5 Wh kg(-1) and a specific capacitance of 156 F g(-1) and, retained 91% of initial capacitance after 20000 cycles of duration test. (C) 2012 Elsevier B.V. All rights reserved.

In order to apply the EU Water Framework Directive for temporary streams, it is important to quantify the space–time development of different aquatic states. We report on research on the development of aquatic states for temporary streams in the Evrotas basin, Greece. The SIMGRO regional hydrological model was used in a GIS framework to generate flow time series for the Evrotas River and all major tributaries. Five flow phases were distinguished: flood conditions, riffles, connected pools, isolated pools and dry bed conditions. Thresholds based on local hydraulic characteristics were identified per stream reach and flow phase, enabling the frequency of flow phases per month and the average frequencies for all streams to be derived. Three historical scenarios within the 20th century, marking periods of major changes in water management, were investigated. Additionally, a climate scenario for the 2050s was analysed. Simulations revealed that low flows are now much lower, mainly because more groundwater is abstracted for irrigation. The consequence is that stretches of the river fall dry during several months, causing the ecological status to deteriorate.

Last week, the United States designated nearly 140,000 square miles of the Pacific Ocean northwest of Hawaii as the largest protected marine reserve in the world. This is good news, considering that earlier this year, 4000 delegates left the international Conference of the Parties to the Convention on Biological Diversity (held in March 2006 in Brazil) with mixed feelings. Portrayal of the conference as successful by the Executive Secretary was in stark contrast to the frustration expressed by environmentalist groups about the failure to progress toward creating large marine protected areas. Paradoxically, the fact that the oceans are the patrimony of all nations creates a legislation gap that is the major obstacle to increasing the percent of protected ocean to the 10% targeted by the convention. This obstacle is augmented by a lack of awareness by legislators and the general public about the role, status, and prospects of biological diversity in oceans relative to the land. Until a better understanding of the diversity of and threats to life in the oceans is achieved, there will be no progress in protecting marine biodiversity. The vast richness of marine biodiversity remains to be discovered, particularly in remote habitats such as the deep ocean. There is a widespread misconception that extinction in the ocean is unlikely because of its huge biogeographical ranges and high connectivity of habitat. But recent surveys and molecular analyses of ocean samples have revealed marine invertebrates with biogeographical ranges as small as 4 km. Specialized communities in deep-sea habitats, such as hydrothermal vents and cold seeps, are isolated across thousands of kilometers. Marine diversity is much more extensive and vulnerable than previously thought. Moreover, much of this diversity is microbial and therefore generally unappealing to society. Indeed, more charismatic animals and plants receive most of the conservationists' attention. Scientific research must unveil the importance of ocean life diversity, test for declines in important taxa and ecosystems, elucidate the causes of these declines, and provide remedial options to change these perception biases. ![Figure][1] Although research on biodiversity has increased, these efforts are dominated by studies on land. Between 1987 and 2004, only 9.8% of published research dealt with marine biodiversity. This severe imbalance percolates through international programs. For instance, only about 10% of the First Open Science Conference of the Diversitas Programme (November 2005 in Mexico) that dealt with biodiversity science addressed marine biodiversity. This disproportionally small research effort on marine biodiversity is in sharp contrast to the large genomic diversity in the oceans as compared to that on land. Most branches of the evolutionary tree of life thrive in the oceans, whereas most terrestrial species are contained within only two branches, a result of the extended history of life in the oceans (3500 million years). The genomic richness of the ocean is an untapped resource for biotechnology, pharmacy, and food. The number of marine species brought into aquaculture exceeds, after only 30 years of development, the number of animal species domesticated over 10,000 years of husbandry on land. Realizing these opportunities requires progress to improve our present knowledge about sustainably managing marine resources. The oceans have lost much of their fish biomass and megafauna to hunting, and key coastal habitats are lost globally at rates 2 to 10 times faster than those in tropical forests [also see the Report by Lotze et al. in this issue (p. [1806][2])]. Anthropogenic inputs to the ocean are causing hypoxia and widespread deterioration of water quality, and anthropogenic CO2 emissions are causing ocean acidification, which is emerging as a global threat to calcifying marine organisms. The concept of protected areas that emerged from studies of life on land cannot be readily extrapolated to the ocean. Until last week, the total protected marine area was 10 times smaller than that on land, and most marine protected areas are too small to be effective. Mounting evidence indicates that marine food webs are connected across oceanic scales, but the forces driving these connections are poorly understood. We must improve our understanding of how the global ocean ecosystem works in order to design networks of protected areas that effectively preserve biodiversity. Indeed, as Mora et al. point out in this issue (p. [1750][3]), the present design of some marine protected areas may not be optimal. Further promoting marine biodiversity research requires a larger scientific community and more resources than currently exist. This can be achieved through increased international cooperative efforts and networking. We must do this before we face a future depleted of marine resources. [1]: pending:yes [2]: /lookup/doi/10.1126/science.1128035 [3]: /lookup/doi/10.1126/science.1125295

Modeling electricity storage to address challenges and opportunities of its applications for smart grids requires inter-temporal equalities to keep track of energy content over time. These constraints present crucial modeling elements, which may affect case study results. Hence, correct modeling improves conclusions as to which extent energy storage applications can enhance future electric power systems sustainability, reliability, and efficiency. This paper presents a novel and improved mixedinteger linear problem (MILP) formulation for energy storage of plug-in (hybrid) electric vehicles (PEVs) for reserves in power system models. It is based on insights from the field of System Dynamics, in which complex interactions between different elements are studied by means of feedback loops as well as stocks, flows and co-flows. Generalized to a multi-bus system, this formulation includes improvements in the energy balance and surpasses shortcomings in the way existing literature deals with reserve constraints. Tested on the IEEE 14-bus system with realistic PEV mobility patterns, the deterministic results show significant changes in the scheduling of the units, often referred to as unit commitment (UC) . info:eu-repo/semantics/draft

Abstract The use of night cooling ventilation in addition of phase change materials (PCMs) is a very powerful strategy for reducing the cooling demand of buildings. Nevertheless, there are inherent drawbacks in the way things have been doing so far: (a) The limited area of contact between PCM and the air; (b) the very low convective heat transfer coefficients which prevents the use of significant amounts of PCM and (c) the very low utilization factor of the cool stored due to the large phase shift between the time when cool is stored and time when it is required by the building. In this paper, we present innovative solutions using PCM to overcome the above situation. Compared with existing solutions, innovative solutions proposed, increase the contact area between PCM and air by a factor of approximately 3.6, increase the convective heat transfer coefficient significantly, and improve the utilization factor due to the inclusion of active control systems which allow the cold stored be actually used when required.

In this work, the existence of different crystal field sites for the rare-earth-doped tin dioxide nanopowder and RE-doped SiO2-SnO2 glass-ceramics is investigated. The slightly different crystal field symmetries have been resolved by using site-selective fluorescence line-narrowing spectroscopy. The obtained results show that a variety of optically non equivalent sites exist for the europium ion in the tin dioxide oxide structure associated to different allowed positions of the oxygen vacancies, whereas additional spectral disorder is found in the case of the glass-ceramic matrix. Ultrafast spectroscopy performed on Eu3+-doped tin dioxide nanocrystals shows that host-rare earth energy transfer occurs at a transfer rate of about 1.5×106 s-1. Similar experiments carried out for the Er3+-doped glass-ceramic system also validate the hypothesis that both host and matrix-excited RE emissions are decoupled due to the different origins of the involved physical mechanisms.

Urban environments that are stressful for plant function and growth will become increasingly widespread in future. In this opinion article, we define the concept of 'urban plant physiology', which focuses on plant responses and long term adaptations to urban conditions and on the capacity of urban vegetation to mitigate environmental hazards in urbanized settings such as air and soil pollution. Use of appropriate control treatments would allow for studies in urban environments to be comparable to expensive manipulative experiments. In this opinion article, we propose to couple two approaches, based either on environmental gradients or manipulated gradients, to develop the concept of urban plant physiology for assessing how single or multiple environmental factors affect the key environmental services provided by urban forests.