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Enhanced or reduced pCO(2) (partial pressure of CO2) may affect the photosynthetic performance of marine microalgae since changes in pCO(2) can influence the activity of carbon concentrating mechanisms, modulate cellular RuBisCO levels or alter carbon uptake efficiency. In the present study we compared the photophysiology of the Antarctic diatom Chaetoceros brevis at two pCO(2) extremes: 750 ppmv (2x ambient) and 190 ppmv (0.5x ambient) CO2. Cultures were acclimated to four irradiance regimes: two regimes simulating deep or shallow vertical mixing, and two regimes mimicking limiting and saturating stable water column conditions. Then, growth rate, pigmentation, RuBisCO large subunit expression. RuBisCO activity, photosynthesis vs irradiance curves, effective quantum yield of PSII (F-v/F-m), and POC were measured. The four irradiance regimes induced a suite of photophysiological responses, ranging from low light acclimation to efficient photoprotection. Growth was reduced under the low constant and the deep mixing regime, compared to the shallow mixing and the stable saturating regime. Low stable irradiance resulted in higher light harvesting pigment concentrations, lower RuBisCO activity and a lower light saturation point (E-k) compared to the other irradiance regimes. Highest RuBisCO activity as well as P-max levels was measured in the shallow mixing regime, which received the highest total daily light dose. Photoprotection by xanthophyll cycling was observed under all irradiance regimes except the low stable irradiance regime, and xanthophyll cycle pool sizes were higher under the dynamic irradiance regimes. For the fluctuating irradiance regimes. E-v/E-m was hardly affected by previous excess irradiance exposure, suggesting minimal PSII damage. No significant differences between the two pCO(2) levels were found, with respect to growth, pigment content and composition, photosynthesis, photoprotection and RuBisCO activity, for all four irradiance regimes. Thus, within the range tested, pCO(2) does not significantly affect the photophysiological performance of C. brevis. (C) 2011 Elsevier B.V. All rights reserved.

AbstractAimBats are promising candidates for studying morphometric responses to anthropogenic climate or land‐use changes. We assessed whether the cranial size of a common bat (Pipistrellus kuhlii) had changed between 1875 and 2007. We formulated the following hypotheses: (1) if heat loss is an important reaction to climate change, body size will have decreased in response to the increased temperatures, because small bats have a larger surface‐to‐volume ratio and dissipate heat more effectively; (2) if water loss is the main driver, body size will have increased in response to the temperature increase, because larger bats will lose water more slowly through a reduced surface‐to‐volume ratio; (3) the energetic benefits provided by urbanization (food concentration at street lamps, warmer maternity roosts in buildings) will lead to a general body size increase in P. kuhlii; and (4) because street lamps impair moth antipredatory manoeuvres, cranial size may have selectively increased as an adaptive response to handle larger prey (moths) in artificially illuminated sites. Ours is the first study to assess temporal trends in bat body size over more than a century and to relate them to urbanization.LocationMainland Italy.MethodsWe used traditional morphometrics to compare seven variables of skull size in 117 museum specimens (75 female, 42 male).ResultsCranial size increased after 1950, but this change was not paralleled by an increase in body size, measured as forearm length. This selective increase matched a rapid increase in electric public illumination in Italy.Main conclusionsStreet lights are crucial foraging sites for P. kuhlii. The directional change that we found in cranial size might represent microevolutionary adaptive tracking of a sudden shift in food size, making more profitable prey available.

Hemicellulosic oligosaccharides are sugar molecules that contain xylose, mannose, and arabinose in variable concentrations ranging from 3 to 10 molecules. These medium and long chain sugars can be classified as non-digestible carbohydrates, thus playing an important role in gastrointestinal health as prebiotics. Their physiological benefits, primarily stimulation of the proliferation of lactic acid bacteria and bifidobacteria in the colon informs their significance as high value nutraceuticals in the food and pharmaceutical industry. In addition they are well known as useful components of important pharmaceutical products. There are two main ways of producing these sugars from biomass, which include enzymatic and non-enzymatic pretreatments. Each of the two processes has advantages and disadvantages. Enzymatic processes are associated with high costs, higher concentration of monomeric sugars, and low oligosaccharide yields while thermo-chemical processes are usually associated with undesirable byproducts such as furfural and lower oligosaccharide yields. In this paper we discuss the benefits and constraints for optimization of different methods for the production of oligosaccharides from biomass.

Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a tipping point. Whether human activities will trigger such a global event in the near future is uncertain, due to critical knowledge gaps. In particular, we lack understanding of how regime shifts propagate across scales, and whether local or regional tipping points can lead to global transitions. The ongoing disruption of ecosystems and climate, combined with unprecedented breakdown of isolation by human migration and trade, highlights the need to operate within safe planetary boundaries.

Danish district heating systems have good water quality, but continue to suffer from biofouling and biocorrosion. Localisation analyses of bacteria using microautoradiography were performed for one system in order to obtain detailed information for solving these problems. A mass balance showed that 77% of the bacteria were located at surfaces, with 23% in the bulk water, and 9% of the total carbon originated from biomass, while 91% was dissolved in the bulk water. The presence of active bacteria was determined with microautoradiography which showed that biofilms contained 99% and 1% were in the bulk water. A high bacterial functional diversity was observed, with active mesophilic and thermophilic bacteria under aerobic and anaerobic conditions and with potentially corrosive biofilm bacteria present. The study reveals that by applying the activity based approach, the ratio of living and dead bacteria in the biofilm and bulk water in this type of system could be accurately determined. Also, the results emphasise that to minimise biofilm growth and biocorrosion, monitoring should be established focusing on the surfaces, since bulk water parameters do not reflect bacterial activity.

Nutrient-sufficient and nitrate- or sulfate-deprived plants of Brassica oleracea L. were exposed to 4 microl l(-1) NH3 (2.8 mg m(-3)), and effects on biomass production and allocation, N-compounds and root morphology investigated. Nitrate-deprived plants were able to transfer to atmospheric NH3 as nitrogen source, but biomass allocation in favor of the root was not changed by exposure to NH3. NH3 reduced the difference in total root length between nitrate-sufficient and nitrate-deprived plants, and increased the specific root length in the latter. The internal N status, therefore, might be involved in controlling root length in B. oleracea. Root surface area, volume and diameter were unaffected by both nitrate deprivation and NH3 exposure. In sulfate-deprived plants an inhibitory effect of NH3 on root morphological parameters was observed. These plants, therefore, might be more susceptible to atmospheric NH3 than nitrate-deprived plants. The relevance of the present data under field conditions is discussed.

To highlight the satiating background and effects of proteins and their implications for weight management.The satiating effect of protein is the key player in body-weight loss and body-weight maintenance thereafter. Specific high-protein meals or high-protein diets induced satiety require a realistic bandwidth of energy intake, protein concentrations, texture, and timing of assessment of effects. Satiety is nutrient specifically supported by elevated amino acid concentrations, responses of anorexigenic hormones or protein-induced energy expenditure. During long-term high-protein diets sustained satiety, energy expenditure, and sparing fat-free body mass are essential. For effects due to satiety, ad libitum energy intake conditions are necessary. Adverse events related to kidney damage may occur with sulphur-containing amino acids; individuals with obesity, metabolic syndrome and diabetes mellitus II may be susceptible groups.Highly controlled medium-term studies overcoming possible differences due to texture, timing and macronutrient exchange, and assessing satiety, energy expenditure and substrate oxidation at the same time, need to be executed with a realistic bandwidth of different types of proteins in overweight individuals in different energy balances.