Sectoral Trends and Driving Forces of Global Energy Use and Greenhouse Gas Emissions

Disaggregation of sectoral energy use and greenhouse gas emissions trends reveals striking differences between sectors and regions of the world. Understanding key driving forces in the energy end-use sectors provides insights for development of projections of future greenhouse gas emissions. This paper examines global and regional historical trends in energy use and carbon emissions in the industrial, buildings, transport, and agriculture sectors. Activity and economic drivers as well as trends in energy and carbon intensity are evaluated. We show that macro-economic indicators, such as GDP, are insufficient for comprehending trends and driving forces at the sectoral level. These indicators need to be supplemented with sector-specific information for a more complete understanding of future energy use and greenhouse gas emissions.     

Age-related decline in metabolic competence of small and medium-sized synaptic mitochondria

A computer-assisted morphometric investigation of cytochrome oxidase (COX) activity, selectively evidenced by preferential diaminobenzidine cytochemistry, has been carried out on synaptic mitochondria in the cerebellar cortex of adult and old rats. The ratio (R) of the area of the cytochemical precipitate (CPA) to the overall area of each mitochondrion (MA) was calculated. R refers to the fraction of the inner mitochondrial membrane actively involved in cellular respiration, thus its quantitative estimation constitutes a reliable index of the mitochondrial metabolic competence (MMC). In adult rats a significant negative correlation between MA and R values was found, while in old animals there was just a positive trend. Paired-quartile comparisons of R values showed a significant age-related decrease in small and medium-sized mitochondria, whereas the lowest and not significant age-related reduction was found in oversized organelles. A paired decrease in number and increase in size is reported to be a general trend for mitochondria during aging, but oversized organelles, according to their low R value, constitute a scanty, though functional, compensating reaction. Thus, the present findings support the argument that the currently reported age-related cellular metabolic decay appears to rely both on the decline in MMC of the small and medium-sized mitochondria, and on their specific reduction in number. This novel result is of biological relevance since it is largely the small and medium-sized mitochondria that are required for the provision of adequate amounts of ATP for actual cellular performance, while the significantly enlarged organelles are thought to represent an intermediate ultrastructural feature in mitochondrial genesis and/or remodelling.     

Singlet molecular oxygen—mediated photooxidation of monochloro and mononitrophenols. A kinetic study

A kinetic and mechanistic study on the aerobic dye sensitized photooxidation of the mono—nitro and chlorophenols was carried out. A singlet molecular oxygen mechanism operates in the photooxidation. Solvent and substituent effects, suggest the intermediacy of a complex with partial charge transfer character, as has been postulated for other phenols.

Chemical (reactive) and physical interactions of the substrates with singlet molecular oxygen were discriminated. Quantum yields for photooxidation (higher for the chlorophenols) range from 3 × 10^‐2 to 2 × 10^‐3, as measured by substrate or oxygen consumption. These values indicate the viability of a singlet molecular oxygen photooxidation as a way for the degradation of nitro and chlorophenol environmental contaminants.     

Heavy Metals in Macroalgae of Havana's Northern Littoral,Cuba

Copper, iron, lead, manganese, and zinc contents were determined in various phyla of macroalgae typical of the rocky mesolittoral zone of Cuba and widely distributed in the Caribbean Region. the samples were collected in different zones along the shores of Havana City which are more or less influenced by anthropogenic activities. Differences in metal contents were observed due to seasonal variations and differences between sampling sites. of the analyzed species, only one brown alga, Padina vickersiae is considered as a suitable candidate for the monitoring of metal contamination.     

All clear? Meerkats attend to contextual information in close calls to coordinate vigilance

Socio-demographic factors, such as group size and their effect on predation vulnerability, have, in addition to intrinsic factors, dominated as explanations when attempting to understand animal vigilance behaviour. It is generally assumed that animals evaluate these external factors visually; however, many socially foraging species adopt a foraging technique that directly compromises the visual system. In these instances, such species may instead rely more on the acoustical medium to assess their relative risk and guide their subsequent anti-predator behaviour. We addressed this question in the socially foraging meerkat (Suricata suricatta). Meerkats forage with their head down, but at the same time frequently produce close calls (‘Foraging’ close calls). Close calls are also produced just after an individual has briefly scanned the surrounding environment for predators (‘Guarding’ close calls). Here, we firstly show that these Guarding and Foraging close call variants are in fact acoustically distinct and secondly subjects are less vigilant (in terms of frequency and time) when exposed to Guarding close call playbacks than when they hear Foraging close calls. We argue that this is the first evidence for socially foraging animals using the information encoded within calls, the main adaptive function of which is unrelated to immediate predator encounters, to coordinate their vigilance behaviour. In addition, these results provide new insights into the potential cognitive mechanisms underlying anti-predator behaviour and suggest meerkats may be capable of signalling to group members the ‘absence’ of predatory threat. If we are to fully understand the complexities underlying the coordination of animal anti-predator behaviour, we encourage future studies to take these additional auditory and cognitive dimensions into account.     

Physiologically based pharmacokinetic modeling of perfluoroalkyl substances in the human body

Currently, there are limited data on the levels of perfluoroalkyl substances other than perfluorooctane sulfonic acid and perfluorooctanoic acid in the human body. Most of this information has been extracted from biological monitoring of plasma while the occurrence of perfluoroalkyl substances in other human tissues is rarely studied. The objective of the present study was to develop a physiologically based pharmacokinetic model to assess the concentration of perfluoroalkyl substances in human tissues, based on an existing model previously validated for perfluorooctane sulfonic acid and perfluorooctanoic acid. Experimental data on concentrations of perfluoroalkyl substances in human tissues from individuals in Tarragona County (Catalonia, Spain) were used to estimate the values of some distribution and elimination parameters needed for the simulation. No significant correlations were found between these parameters and the chain lengths. The model was finally validated for five perfluoroalkyl substances.     

Performance evaluation of two commercial chemiluminescence NOx analysers according to European Standard EN 14211

According to Directive 2008/50/EC, all equipment used for NO(x) fixed measurements must comply with the reference method or equivalent by 11 June 2013. Up to that date, non-type-approved equipment can continue to be used in air monitoring networks and will probably also be used in air pollution studies even after that date. In this context, it is advisable to know how these "old" measuring instruments respond to the requirements of European Standard EN 14211: 2005: Ambient Air Quality--Standard method for the measurement of the concentration of nitrogen dioxide and nitrogen monoxide by chemiluminescence. In this work, we carry out a thorough performance evaluation of two commercial NO(x) analysers, both purchased before 2010, according to the mentioned Standard. Results show that water vapour interference is one of the most important disconformities with this Standard. The expanded uncertainty estimation of both analysers was below the quality objective of the above-mentioned Directive (15%); however, this calculation was performed by applying some modifications to the proposed model of Standard EN 14211. These modifications are also discussed in the paper.     

Genotoxic effects of the herbicide Roundup® in the fish Corydoras paleatus (Jenyns 1842) after short-term, environmentally low concentration exposure

The glyphosate-based herbicide, Roundup^®, is one of the most used pesticides worldwide. In concert with the advent of transgenic crops resistant to glyphosate, the use of this pesticide has led to an increase in agricultural yields. The objective of this study was to evaluate the genotoxic effect that the herbicide Roundup^® (at a concentration of 6.67 μg/L, corresponding to 3.20 μg/L glyphosate) can have on the fish Corydoras paleatus. Treatment groups were exposed for 3, 6, and 9 days, and effects were analyzed using the piscine micronucleus test (PMT) and comet assay. A group subjected to filtered water only was used as a negative control. The PMT did not show differences between the control and exposed groups for any of the treatment times. In contrast, the comet assay showed a high rate of DNA damage in group exposed to Roundup^® for all treatment times, both for blood and hepatic cells. We conclude that for the low concentration used in this research, the herbicide shows potential genotoxic effects. Future research will be important in evaluating the effects of this substance, whose presence in the environment is ever-increasing.     

Encounters between Antarctic limpets, <Emphasis Type="Italic">Nacella concinna</Emphasis>, and predatory sea stars, <Emphasis Type="Italic">Lysasterias</Emphasis> sp., in laboratory and field experiments

Antarctic limpets, Nacella concinna, from the Admiralty Bay (King George Island, South Shetlands) for at least part of the year (austral winter) co-exist with predatory sea stars Lysasterias sp. Our laboratory and field experiments established that the presence of Lysasterias sp. or its odour had considerable influence upon their behaviour. Limpets’ responses, consisting of shell mushrooming, shell rotation and flight, were distinctly different from their reaction to other stimuli, such as food and conspecific odours, or mechanical stimulation. Moreover, a significant impact of sea star presence on limpets’ activity was observed, with limpets fleeing to a distance of 60 cm from the predator. Such reactions allow limpets to lower the incidence of sea star predation, but at the cost of presumptive disrupting of foraging and an additional energy expended for locomotion. A visible difference was noted between two limpet populations, with the rockpool limpets responding only after physical contact with being touched by a sea star, and the subtidal ones responding at a distance of up to 20 cm.