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Background Numerous daily activities require simultaneous application of motor and cognitive skills (dual-tasking). The execution of such tasks is especially difficult for the elderly and for people with (neuro-) degenerative disorders. Training of physical and cognitive abilities helps prevent or slow down the age-related decline of cognition. The aim of this review is to summarise and assess the role of combined physical-and-cognitive-training characteristics in improving cognitive performance and to propose an effective training scheme within the frame of a suitable experimental design. Methods A systematic electronic literature search was conducted in selected databases. The following criteria were compulsory for inclusion in the study: 1. A (Randomized) Controlled Trial (RCT or CT) design; 2. Implementation of combined physical and cognitive training, either simultaneously (dual task) or subsequently - at least one hour per weekly over four weeks or more; 3. Cognitive outcomes as a study’s endpoint. Results Twenty articles met the inclusion criteria. It appears that either simultaneous or subsequently combined physical and cognitive training is more successful compared to single physical or single cognitive exercise. Training characteristics like length, frequency, duration, intensity and level of task difficulty seem to determine cognitive performance. However, the articles show that cognitive improvement seems to remain somewhat confined to trained cognitive functions rather than generalising to other cognitive or daily-living skills. Conclusion Due to methodological heterogeneity among studies, results need to be treated with caution. We critically discuss the role of training characteristics and propose a potentially effective training intervention within an appropriate experimental design.

The light reactions of photosynthesis store energy in the form of an electrochemical gradient of protons, or proton motive force (pmf), comprised of electrical (Δψ) and osmotic (ΔpH) components. Both components can drive the synthesis of ATP at the chloroplast ATP synthase, but the ΔpH component also plays a key role in regulating photosynthesis, down-regulating the efficiency of light capture by photosynthetic antennae via the q(E) mechanism, and governing electron transfer at the cytochrome b(6)f complex. Differential partitioning of pmf into ΔpH and Δψ has been observed under environmental stresses and proposed as a mechanism for fine-tuning photosynthetic regulation, but the mechanism of this tuning is unknown. We show here that putrescine can alter the partitioning of pmf both in vivo (in Arabidopsis mutant lines and in Nicotiana wild type) and in vitro, suggesting that the endogenous titer of weak bases such as putrescine represents an unrecognized mechanism for regulating photosynthetic responses to the environment.

Hydrogen is a highly promising energy source with important social and economic implications. The ability of green algae to produce photosynthetic hydrogen under anaerobic conditions has been known for years. However, until today the yield of production has been very low, limiting an industrial scale use. In the present paper, 73 years after the first report on H(2)-production from green algae, we present a combinational biological system where the biodegradation procedure of one meta-substituted dichlorophenol (m-dcp) is the key element for maintaining continuous and high rate H(2)-production (>100 times higher than previously reported) in chloroplasts and mitochondria of the green alga Scenedesmus obliquus. In particular, we report that reduced m-dcps (biodegradation intermediates) mimic endogenous electron and proton carriers in chloroplasts and mitochondria, inhibit Photosystem II (PSII) activity (and therefore O(2) production) and enhance Photosystem I (PSI) and hydrogenase activity. In addition, we show that there are some indications for hydrogen production from sources other than chloroplasts in Scenedesmus obliquus. The regulation of these multistage and highly evolved redox pathways leads to high yields of hydrogen production and paves the way for an efficient application to industrial scale use, utilizing simple energy sources and one meta-substituted dichlorophenol as regulating elements.

The growth of the biological nuclear magnetic resonance (NMR) field and the development of new experimental technology have mandated the revision and enlargement of the NMR-STAR ontology used to represent experiments, spectral and derived data, and supporting metadata. We present here a brief description of the NMR-STAR ontology and software tools for manipulating NMR-STAR data files, editing the files, extracting selected data, and creating data visualizations. Detailed information on these is accessible from the links provided.

Polyamines (PAs) are low molecular weight amines that occur in every living organism. The three main PAs (putrescine, spermidine, and spermine) are involved in several important biochemical processes covered in recent reviews. As rule of thumb, increase of the cellular titer of PAs in plants is related to cell growth and cell tolerance to abiotic and biotic stress. In the present contribution, we describe recent findings from plant bioenergetics that bring to light a previously unrecognized dynamic behavior of the PA pool. Traditionally, PAs are described by many authors as organic polycations, when in fact they are bases that can be found in a charged or uncharged form. Although uncharged forms represent less than 0.1% of the total pool, we propose that their physiological role could be crucial in chemiosmosis. This process describes the formation of a PA gradient across membranes within seconds and is difficult to be tested in vivo in plants due to the relatively small molecular weight of PAs and the speed of the process. We tested the hypothesis that PAs act as permeable buffers in intact leaves by using recent advances in vivo probing. We found that an increase of PAs increases the electric component (Δψ) and decreases the ΔpH component of the proton motive force. These findings reveal an important modulation of the energy production process and photoprotection of the chloroplast by PAs. We explain in detail the theory behind PA pumping and ion trapping in acidic compartments (such as the lumen in chloroplasts) and how this regulatory process could improve either the photochemical efficiency of the photosynthetic apparatus and increase the synthesis of ATP or fine tune antenna regulation and make the plant more tolerant to stress.

The impact on the extracted low-frequency noise (LFN) parameter values due to LFN variability in CMOS devices is investigated. First, it is demonstrated that the noise level dispersion follows a log normal statistical distribution. Then, based on this feature, it is explained why the mean values from the linear data are different from the mean values (or median values) calculated from the log noise data. Finally, the consequence of this finding in terms of LFN characterisation issues and Monte Carlo LFN variability circuit simulation is discussed.

Transglutaminases function as biological glues in animal cells, plant cells and microbes. In energy producing organelles such as chloroplasts the presence of transglutaminases was recently confirmed. Furthermore, a plastidial transglutaminase has been cloned from maize and the first plants overexpressing tgz are available (Nicotiana tabacum TGZ OE). Our hypothesis is that the overexpression of plastidal transglutaminase will alter photosynthesis via increased polyamination of the antenna of photosystem II. We have used standard analytical tools to separate the antenna from photosystem II in wild type and modified plants, 6 specific antibodies against LHCbs to confirm their presence and sensitive HPLC method to quantify the polyamination level of these proteins. We report that bound spermidine and spermine were significantly increased (∼80%) in overexpressors. Moreover, we used recent advances in in vivo probing to study simultaneously the proton and electron circuit of thylakoids. Under physiological conditions overexpressors show a 3-fold higher sensitivity of the antenna down regulation loop (qE) to the elicitor (luminal protons) which is estimated as the ΔpH component of thylakoidal proton motive force. In addition, photosystem (hyper-PSIIα) with an exceptionally high antenna (large absorption cross section), accumulate in transglutaminase over expressers doubling the rate constant of light energy utilization (Kα) and promoting thylakoid membrane stacking. Polyamination of antenna proteins is a previously unrecognized mechanism for the modulation of the size (antenna absorption cross section) and sensitivity of photosystem II to down regulation. Future research will reveal which peptides and which residues of the antenna are responsible for such effects.

Forest growth is commonly used to explore tree vitality and ability to resist to environmental changes or climatic fluctuations. This paper illustrates and examines how regional climatic conditions can be related to the decline of tree growth, which were found to be more distinct in Ten. (Hungarian oak) and . (European beech) and less pronounced in Matt f. (Bulgarian fir) on three long-term intensive monitoring plots (ICP Forests-Level II) in Greece during the period 1996–2009. Relative basal area increment and volume increment were calculated, expressing tree growth in terms of mean relative annual periodic increment. A decline in the growth of basal area and volume was observed after hot and dry periods, where annual temperatures and precipitation were far from the mean of the analyzed period. This observation was statistically confirmed in oak and beech plots regarding summer precipitation only and are in agreement with the findings of previous studies in Europe. The representativeness of the results at a national scale needs further investigation, although our results provide a good basis for further and more intensive monitoring programs to address various forest management scenarios against the background of potential climatic changes in the Mediterranean area.

Polyamines (PAs) are nitrogenous molecules that are indispensable for cell viability and with an agreed-on role in the modulation of stress responses. Tobacco plants with downregulated SAMDC (AS-SAMDC) exhibit reduced PAs synthesis but normal levels of PA catabolism. We used AS-SAMDC to increase our understanding on the role of PAs in stress responses. Surprisingly, at control conditions AS-SAMDC plants showed increased biomass and altered developmental characteristics, such as increased height and leaf number. On the contrary, during salt stress AS-SAMDC plants showed reduced vigor when compared to the WT. During salt stress, the AS-SAMDC plants although showing compensatory readjustments of the antioxidant machinery and of photosynthetic apparatus, they failed to sustain their vigor. AS-SAMDC sensitivity was accompanied by inability to effectively control H2O2 levels and concentrations of monovalent and divalent cations. In accordance with these findings, we suggest that PAs may regulate the trade-off between growth and tolerance responses.

Plastidial transglutaminase is one of the most promising enzymes in chloroplast bioenergetics due to its link with polyamine pathways and the cross talk with signals such as Ca(2+) and GTP. Here, we show the effect of the increase of transglutaminase activity in Arabidopsis by using genetic transformation techniques. These lines fulfill their biological cycle normally (normal growth in soil, production of viable seeds) and show a relatively mild increase in transglutaminase activity (127%). These overexpressors of transglutaminase (OE TGase) have an extended stroma thylakoid network (71% higher number of PSIIβ centers), similar chlorophyll content (-4%), higher linear electron flow (+13%), and higher threshold of photoprotection activation (∼100%). On the other hand OE TGase showed a reduced maximum photochemistry of PSII (-6.5%), a smaller antenna per photosystem II (-25%), a lower photoprotective \"energization\" quenching or qE (-77% at 490 μmol photons m(-2) s(-1)) due to a higher threshold of qE activation and slightly lower light induced proton motive force (-17%). The role of the polyamines and of the transglutaminase in the regulation of chemiosmosis and photoprotection in chloroplasts is discussed.