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Activity pacing (AP) is a concept that is central to many chronic pain theories and treatments, yet there remains confusion regarding its definition and effects.To review the current knowledge concerning AP and integrate this knowledge in a manner that allows for a clear definition and useful directions for future research.A narrative review of the major theoretical approaches to AP and of the empirical evidence regarding the effects of AP interventions, followed by an integrative discussion.The concept of AP is derived from 2 main traditions: operant and energy conservation. Although there are common elements across these traditions, significant conceptual and practical differences exist, which has led to confusion. Little empirical evidence exists concerning the efficacy of AP as a treatment for chronic pain.Future research on AP should be based on a clear theoretical foundation, consider the context in which the AP behavior occurs and the type of pacing problem ("underactivity" vs. "overactivity"), and should examine the impact of AP treatment on multiple clinical outcomes. We provide a provisional definition of AP and specific recommendations that we believe will move the field forward.

AbstractBluetongue (BT) is a commonly cited example of a disease with a distribution believed to have recently expanded in response to global warming. The BT virus is transmitted to ruminants by biting midges of the genus Culicoides, and it has been hypothesized that the emergence of BT in Mediterranean Europe during the last two decades is a consequence of the recent colonization of the region by Culicoides imicola and linked to climate change. To better understand the mechanism responsible for the northward spread of BT, we tested the hypothesis of a recent colonization of Italy by C. imicola, by obtaining samples from more than 60 localities across Italy, Corsica, Southern France, and Northern Africa (the hypothesized source point for the recent invasion of C. imicola), and by genotyping them with 10 newly identified microsatellite loci. The patterns of genetic variation within and among the sampled populations were characterized and used in a rigorous approximate Bayesian computation framework to compare three competing historical hypotheses related to the arrival and establishment of C. imicola in Italy. The hypothesis of an ancient presence of the insect vector was strongly favoured by this analysis, with an associated P ≥ 99%, suggesting that causes other than the northward range expansion of C. imicola may have supported the emergence of BT in southern Europe. Overall, this study illustrates the potential of molecular genetic markers for exploring the assumed link between climate change and the spread of diseases.

AbstractThe possible effects on cognitive processes of external electric fields, such as those generated by power line pillars and household appliances are of increasing public concern. They are difficult to study experimentally, and the relatively scarce and contradictory evidence make it difficult to clearly assess these effects. In this study, we investigate how, why and to what extent external perturbations of the intrinsic neuronal activity, such as those that can be caused by generation, transmission and use of electrical energy can affect neuronal activity during cognitive processes. For this purpose, we used a morphologically and biophysically realistic three‐dimensional model of CA1 pyramidal neurons. The simulation findings suggest that an electric field oscillating at power lines frequency, and environmentally measured strength, can significantly alter both the average firing rate and temporal spike distribution properties of a hippocampal CA1 pyramidal neuron. This effect strongly depends on the specific and instantaneous relative spatial location of the neuron with respect to the field, and on the synaptic input properties. The model makes experimentally testable predictions on the possible functional consequences for normal hippocampal functions such as object recognition and spatial navigation. The results suggest that, although EF effects on cognitive processes may be difficult to occur in everyday life, their functional consequences deserve some consideration, especially when they constitute a systematic presence in living environments.

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.

Elevated environmental carbon dioxide (pCO2) levels have been found to cause organ damage in the early life stages of different commercial fish species, including Atlantic cod (Gadus morhua). To illuminate the underlying mechanisms causing pathologies in the intestines, the kidney, the pancreas and the liver in response to elevated pCO2, we examined related gene expression patterns in Atlantic cod reared for two months under three different pCO2 regimes: 380 μatm (control), 1800 μatm (medium) and 4200 μatm (high). We extracted RNA from whole fish sampled during the larval (32 dph) and early juvenile stage (46 dph) for relative expression analysis of 18 different genes related to essential metabolic pathways. At 32 dph, larvae subjected to the medium treatment displayed an up-regulation of genes mainly associated with fatty acid and glycogen synthesis (GYS2, 6PGL, ACoA, CPTA1, FAS and PPAR1b). Larvae exposed to the high pCO2 treatment upregulated fewer but similar genes (6PGL, ACoA and PPAR1b,). These data suggest stress-induced alterations in the lipid and fatty acid metabolism and a disrupted lipid homeostasis in larvae, providing a mechanistic link to the findings of lipid droplet overload in the liver and organ pathologies. At 46 dph, no significant differences in gene expression were detected, confirming a higher resilience of juveniles in comparison to larvae when exposed to elevated pCO2 up to 4200 μatm.

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.

Various spinal cord stimulation (SCS) modes are used in the treatment of chronic neuropathic pain disorders. Conventional (Con) and Burst-SCS are hypothesized to exert analgesic effects through different stimulation-induced mechanisms. Preclinical electrophysiological findings suggest that stimulation intensity is correlated with the effectiveness of Burst-SCS. Therefore, we aimed to investigate the relation between amplitude (charge per second) and behavioral effects in a rat model of chronic neuropathic pain, for both Conventional Spinal Cord Stimulation (Con-SCS) and biphasic Burst-SCS.Animals (n = 12 rats) received a unilateral partial sciatic nerve ligation, after which they were implanted with quadripolar electrodes in the epidural space at thoracic level 13. Mechanical hypersensitivity was assessed using paw withdrawal thresholds (WTs) to von Frey monofilaments, at various SCS intensities (amplitudes) and multiple time points during 60 minutes of stimulation and 30 minutes post stimulation.Increasing amplitude was shown to improve the efficacy of Con-SCS, whereas the efficacy of Burst-SCS showed a non-monotonic relation with amplitude. Con-SCS at 66% MT (n = 5) and Burst-SCS at 50% MT (n = 6) were found to be equally effective in normalizing mechanical hypersensitivity. However, in the assessed time period Burst-SCS required significantly more mean charge per second to do so (p < 0.01). When applied at comparable mean charge per second, Con-SCS resulted in a superior behavioral outcome (p < 0.01), compared with Burst-SCS.Biphasic Burst-SCS requires significantly more mean charge per second in order to achieve similar pain relief, as compared with Con-SCS, in an experimental model of chronic neuropathic pain.

Genetic studies are ideal platforms for assessing the extent of genetic diversity, inferring the genetic architecture, and evaluating complex trait interrelations for cell wall compositional and bioconversion traits relevant to bioenergy applications. Through the characterization of a forage maize doubled haploid (DH) population, we indicate the substantial degree of highly heritable (h2 > ~65 %) diversity in cell wall composition and bioconversion potential available within this important agronomic species. In addition to variation in lignin content, extensive genotypic diversity was found for the concentration and composition of hemicelluloses, the latter found to exert an influence on the recalcitrance of maize cell walls. Our results also demonstrate that forage maize harbors considerable variation for the release of cell wall glucose following pretreatment and enzymatic saccharification. In fact, the extent of variability observed for bioconversion efficiency (nearly 30 % between population extremes) greatly exceeded ranges reported in previous studies. In our population, a total of 52 quantitative trait loci (QTL) were detected for biomass compositional and bioconversion characters across 8 chromosomes. Noteworthy, from eight QTL related to bioconversion properties, five were previously unidentified and warrant further investigation. Ultimately, our results substantiate forage maize germplasm as a valid genetic resource for advancing cell wall degradability traits in bioenergy maize-breeding programs. However, since useful variation for cell wall traits is defined by QTL with “minor” effects (R2 = ~10 %), cultivar development for bio-based applications will rely on advanced marker-assisted selection procedures centered on detecting and increasing the frequency of favorable QTL alleles in elite flint and dent germplasm.