Changes in synaptic transmission and protein expression in the brains of adult offspring after prenatal inhibition of the kynurenine pathway

During early brain development, N-methyl-d-aspartate (NMDA) receptors are involved in cell migration, neuritogenesis, axon guidance and synapse formation, but the mechanisms which regulate NMDA receptor density and function remain unclear. The kynurenine pathway of tryptophan metabolism includes an agonist (quinolinic acid) and an antagonist (kynurenic acid) at NMDA receptors and we have previously shown that inhibition of the pathway using the kynurenine-3-monoxygenase inhibitor Ro61-8048 in late gestation produces rapid changes in protein expression in the embryos and effects on synaptic transmission lasting until postnatal day 21 (P21). The present study sought to determine whether any of these effects are maintained into adulthood. After prenatal injections of Ro61-8048 the litter was allowed to develop to P60 when some offspring were euthanized and the brains removed for examination. Analysis of protein expression by Western blotting revealed significantly reduced expression of the GluN2A subunit (32%) and the morphogenetic protein sonic hedgehog (31%), with a 29% increase in the expression of doublecortin, a protein associated with neurogenesis. No changes were seen in mRNA abundance using quantitative real-time polymerase chain reaction. Neuronal excitability was normal in the CA1 region of hippocampal slices but paired-pulse stimulation revealed less inhibition at short interpulse intervals. The amount of long-term potentiation was decreased by 49% in treated pups and recovery after low-frequency stimulation was delayed. The results not only strengthen the view that basal, constitutive kynurenine metabolism is involved in normal brain development, but also show that changes induced prenatally can affect the brains of adult offspring and those changes are quite different from those seen previously at weaning (P21). Those changes may be mediated by altered expression of NMDAR subunits and sonic hedgehog

Global perspectives on observing ocean boundary current systems

Ocean boundary current systems are key components of the climate system, are home to highly productive ecosystems, and have numerous societal impacts. Establishment of a global network of boundary current observing systems is a critical part of ongoing development of the Global Ocean Observing System. The characteristics of boundary current systems are reviewed, focusing on scientific and societal motivations for sustained observing. Techniques currently used to observe boundary current systems are reviewed, followed by a census of the current state of boundary current observing systems globally. Next steps in the development of boundary current observing systems are considered, leading to several specific recommendations

Thermodynamic analysis of algal biocrude production

Although algal biofuels possess great potential, profitable production is quite challenging. Much of this challenge is rooted in the thermodynamic constraints associated with producing fuels with high energy, low entropy, and high exergy from dispersed materials. In this study, a preliminary thermodynamic analysis is presented that calculates the energy, entropy, and exergy of the intermediate products for algal biocrude production. These values are also used in an initial attempt to characterize the thermodynamic efficiency of that system. The production pathway is simplified by assuming ideal solutions throughout. Results for the energy and exergy efficiencies, and the first-order energy and exergy return on investment, of the system are given. The summary finding is that the first-order energy return on investment in the best case considered could be as high as 520, as compared to 1.7 × 10?3 in the experimental unit under development. While this analysis shows that significant improvement may be possible, the ultimate thermodynamic efficiency of algal biofuels likely lies closer to the moderate case examined here, which yielded a first-order energy return on investment of 10. For perspective, the first-order energy return on investment for oil and gas production has been estimated in the literature to be ?35.Center for Electromechanic

Progression of lipid profile and cell structure in a research-scale production pathway for algal biocrude

Although there has been a large research effort associated with individual parts of various algal biofuel production pathways, few studies have tracked changes in product composition throughout an integrated biofuel production process. This study uses microscopy and chromatography to analyze the progression of lipid profile and cell structure of algal cells throughout a research-scale production pathway for biocrude. For the specific processing methods used in this pathway, it is shown that TAG content decreased, while DAG and FFA content increased during processing. The changes in the lipid content corresponded to cell degradation that was observed by SEM and TEM throughout processing. These results demonstrate the dynamic nature of lipid composition in an algal culture used for biofuel production and emphasize the need to monitor changes in lipid profile, as those changes can directly impact biofuel productivity.Center for Electromechanic

Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

Worldwide, algal biofuel research and development efforts have focused on increasing the competitiveness of algal biofuels by increasing the energy and financial return on investments, reducing water intensity and resource requirements, and increasing algal productivity. In this study, analyses are presented in each of these areas—costs, resource needs, and productivity—for two cases: (1) an Experimental Case, using mostly measured data for a lab-scale system, and (2) a theorized Highly Productive Case that represents an optimized commercial-scale production system, albeit one that relies on full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein concludes that the energy and financial return on investments are less than 1, the water intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption (e.g., nitrogen). The analysis and presentation of results highlight critical areas for advancement and innovation that must occur for sustainable and profitable algal biofuel production can occur at a scale that yields significant petroleum displacement. To this end, targets for energy consumption, production cost, water consumption, and nutrient consumption are presented that would promote sustainable algal biofuel production. Furthermore, this work demonstrates a procedure and method by which subsequent advances in technology and biotechnology can be framed to track progress.Center for Electromechanic

Cohort Contributions to Race- and Gender-Specific Trends in the Incidence of Hepatocellular Carcinoma in the USA

Introduction: Increasing incidence of lifelong obesity and associated nonalcoholic steatohepatitis in younger birth cohorts may have contributed to growing incidence of hepatocellular carcinoma (HCC) in the USA. Yet, the contribution of cohort effects to trends in HCC incidence is unclear. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) program 1973�2013, race- and gender-specific trends in HCC incidence in the USA were decomposed using age-period-cohort (APC) modeling. Results: Among SEER registry sites included in the analysis, there were 25,532 cases of HCC diagnosed including 15,867 (62) White males, 3541 (14) Black males, 5009 (20) White females, and 1115 (4) Black females. HCC incidence increases across periods, especially among men. Underlying this increase, APC models found significant cohort effects among White men, White women, and Black men, with rapid growth in HCC risk among cohorts born after 1940. A similar cohort trend among Black women did not reach statistical significance when compared to an age-period model. Conclusions: Cohort-specific trends have significantly contributed to increasing HCC incidence in recent decades. The rapid increase in HCC risk among younger cohorts suggests that the incidence of HCC will continue increasing in the near future. © 2017, Société Internationale de Chirurgie

Cohort Contributions to Race- and Gender-Specific Trends in the Incidence of Hepatocellular Carcinoma in the USA

Introduction: Increasing incidence of lifelong obesity and associated nonalcoholic steatohepatitis in younger birth cohorts may have contributed to growing incidence of hepatocellular carcinoma (HCC) in the USA. Yet, the contribution of cohort effects to trends in HCC incidence is unclear. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) program 1973�2013, race- and gender-specific trends in HCC incidence in the USA were decomposed using age-period-cohort (APC) modeling. Results: Among SEER registry sites included in the analysis, there were 25,532 cases of HCC diagnosed including 15,867 (62) White males, 3541 (14) Black males, 5009 (20) White females, and 1115 (4) Black females. HCC incidence increases across periods, especially among men. Underlying this increase, APC models found significant cohort effects among White men, White women, and Black men, with rapid growth in HCC risk among cohorts born after 1940. A similar cohort trend among Black women did not reach statistical significance when compared to an age-period model. Conclusions: Cohort-specific trends have significantly contributed to increasing HCC incidence in recent decades. The rapid increase in HCC risk among younger cohorts suggests that the incidence of HCC will continue increasing in the near future. © 2017, Société Internationale de Chirurgie

Apprendre du passé pour prédire le futur : réponses des poissons migrateurs amphihalins européens au changement climatique

International audienceClimate change can have an effect on species distributions. The 1900 distribution and potential future distribution of diadromous fish in Europe, North Africa, and the Middle East were explored using generalized additive models (GAMs) and selected habitat characteristics of 196 basins. Robust presenceabsence models were built for 20 of the 28 diadromous species in the study area using longitude, annual temperature, drainage surface area, annual precipitation, and source elevation as explanatory variables. Inspection of the relationship between each variable and species presenceabsence revealed that the GAMs were generally interpretable and plausible. Given the predicted rise in annual temperature in climate models ranging between 18C and 78C by 2100, the fish species were classified according to those losing suitable basins, those gaining suitable basins, and those showing little or no change. It was found that the climate envelopes based on temperature and precipitation for diadromous species would, in general, be shifted farther northeastwards by 2100, and these shifting ranges were comparable with those assessed in other studies. The uncertain future of some species was highlighted, and it was concluded that conservation policy and management plans will need to be revised in the face of climate change