Lattice perturbation theory for gluonic and fermionic actions

We calculate the two loop Landau mean links and the one loop renormalisation of the anisotropy for Wilson and improved SU(3) gauge actions, using twisted boundary conditions as a gauge invariant infrared regulator. We show these accurately describe simulated results, and outline a method for generating Feynman rules for general lattice field theories, in a form suitable for efficient numerical calculation of perturbative loop diagrams.Comment: 6 pages of LaTeX. Two posters at Lattice2002(improve) combine

Aplicação de altas pressões em chouriço de peru sem aditivos - segurança alimentar

As tecnologias emergentes de conservação dos alimentos têm como objetivo a segurança microbiológica, preservando a qualidade nutricional e sensorial ao longo do armazenamento. As altas pressões hidrostáticas são um método de conservação, alternativo aos processos térmicos existentes mais agressivos. O objetivo deste trabalho foi avaliar a aplicação de altas pressões em chouriço de peru produzido sem adição de aditivos numa unidade fabril e submetido a altas pressões (600MPa durante 8 min). As amostras foram armazenadas a 4 °C. Analisadas no dia da aplicação do tratamento e após 2 e 4 meses. Os parâmetros microbiológicos, designadamente contagens de bactérias lácticas mesófilas, bolores e leveduras, bactérias coliformes, Clostridium perfringens, estafilococos coagulase positivos, Escherichia coli ß-glucuronidase positiva, mesófilos, psicrotróficos, e pesquisa de Listeria monocytogenes, e de Salmonella spp., foram analisados recorrendo às metodologias definidas segundo as normas internacionais. Na pesquisa de patogénicos todas as amostras analisadas apresentaram um resultado de ausência em 25 g de produto. As contagens de Escherichia coli, bolores e leveduras, bactérias coliformes, Clostridium perfringens, e estafilococos coagulase positivos revelaram-se inferiores a 10 UFC g-1. As amostras submetidas a altas pressões hidrostáticas obtiveram contagens de bactérias lácticas mesófilas, mesófilos e psicrotróficos inferiores às contagens das amostras sem tratamento, desde o dia da aplicação do tratamento, com uma redução de 2 log. Perante os resultados obtidos, o fabrico de chouriço de peru sem aditivos e com aplicação de altas pressões hidrostáticas surge como um método de conservação do produto.N/

Efeito da aplicação de altas pressões em chouriço de frango sem aditivos

A procura de produtos com carne de aves e sem aditivos é cada vez mais acentuada por parte dos consumidores. As indústrias alimentares tentam corresponder a estas exigências com o desenvolvimento de produtos isentos de aditivos mas garantindo a segurança alimentar. As altas pressões são uma alternativa interessante face aos métodos tradicionais de conservação de alimentos, uma vez que permitem aumentar a segurança microbiológica. O objetivo deste trabalho foi estudar o efeito das altas pressões em chouriço de frango sem adição de aditivos, produzido numa unidade industrial. Após o tratamento (600MPa por 8 min) as amostras foram armazenadas a 4 °C. O controlo microbiológico foi realizado no dia 0, 2 e 4 meses de conservação. Efetuaram-se contagens de bactérias lácticas mesófilas, bolores e leveduras, bactérias coliformes, Clostridium perfringens, estafilococos coagulase positivos, Escherichia coli ß-glucuronidase positiva, mesófilos, e psicrotróficos, e pesquisas de Listeria monocytogenes, Salmonella spp., segundo as normas internacionais. Os resultados apontam a ausência de Salmonella spp. e de Listeria monocytogenes em 25 g de produto. As contagens de Escherichia coli, bolores e leveduras, bactérias coliformes, Clostridium perfringens, e estafilococos coagulase positivos foram inferiores a 10 UFC g-1 em todas as amostras. As análises microbiológicas revelaram que as amostras com tratamento obtiveram contagens de bactérias lácticas mesófilas, mesófilos e psicrotróficos inferiores às contagens das amostras sem tratamento, com uma redução de 2 log. Esta redução poderá estar associada ao efeito das altas pressões ao nível da estrutura e integridade funcional da membrana citoplasmática dos microrganismos. Em suma, as altas pressões são uma técnica de grande interesse na indústria alimentar.info:eu-repo/semantics/publishedVersio

Ni/HZSM-5 catalyst preparation by deposition-precipitation. Part 2. Catalytic hydrodeoxygenation reactions of lignin model compounds in organic and aqueous systems

Nickel metal supported on HZSM-5 (zeolite) is a promising catalyst for lignin depolymerization. In this work, the ability of catalysts prepared via deposition-precipitation (DP) to perform hydrodeoxygenation (HDO) on two lignin model compounds in organic and aqueous solvents was evaluated; guaiacol in dodecane and 2-phenoxy-1-phenylethanol (PPE) in aqueous solutions. All Ni/HZSM-5 catalysts were capable of guaiacol HDO into cyclohexane at 523 K. The role of the HZSM-5 acid sites was confirmed by comparison with Ni/SiO2 (inert support) which exhibited incomplete deoxygenation of guaiacol due to the inability to perform the cyclohexanol dehydration step. The catalyst prepared with 15 wt% Ni, a DP time of 16 h, and a calcination temperature of 673 K (Ni(15)/HZSM-5 DP16_Cal673), performed the guaiacol conversion with the greatest selectivity towards HDO products, with an intrinsic rate ratio (HDO rate to conversion rate) of 0.31, and 90% selectivity to cyclohexane. Catalytic activity and selectivity of Ni/HZSM-5 (15 wt%) in aqueous environments (water and 0.1 M NaOH solution) was confirmed using PPE reactions at 523 K. After 30 min reaction time in water, Ni/HZSM-5 exhibited ~100% conversion of PPE, and good yield of the desired products; ethylbenzene and phenol (~35% and 23% of initial carbon, respectively). Ni/HZSM-5 in NaOH solution resulted in significantly higher ring saturation compared to the Ni/HZSM-5 in water or the NaOH solution control

Representation of the Community Earth System Model (CESM1) CAM4-chem within the Chemistry-Climate Model Initiative (CCMI)

The Community Earth System Model (CESM1) CAM4-chem has been used to perform the Chemistry Climate Model Initiative (CCMI) reference and sensitivity simulations. In this model, the Community Atmospheric Model version 4 (CAM4) is fully coupled to tropospheric and stratospheric chemistry. Details and specifics of each configuration, including new developments and improvements are described. CESM1 CAM4-chem is a low-top model that reaches up to approximately 40km and uses a horizontal resolution of 1.9° latitude and 2.5° longitude. For the specified dynamics experiments, the model is nudged to Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. We summarize the performance of the three reference simulations suggested by CCMI, with a focus on the last 15 years of the simulation when most observations are available. Comparisons with selected data sets are employed to demonstrate the general performance of the model. We highlight new data sets that are suited for multi-model evaluation studies. Most important improvements of the model are the treatment of stratospheric aerosols and the corresponding adjustments for radiation and optics, the updated chemistry scheme including improved polar chemistry and stratospheric dynamics and improved dry deposition rates. These updates lead to a very good representation of tropospheric ozone within 20% of values from available observations for most regions. In particular, the trend and magnitude of surface ozone is much improved compared to earlier versions of the model. Furthermore, stratospheric column ozone of the Southern Hemisphere in winter and spring is reasonably well represented. All experiments still underestimate CO most significantly in Northern Hemisphere spring and show a significant underestimation of hydrocarbons based on surface observations

Do primordial Lithium abundances imply there's no Dark Energy?

Explaining the well established observation that the expansion rate of the universe is apparently accelerating is one of the defining scientific problems of our age. Within the standard model of cosmology, the repulsive 'dark energy' supposedly responsible has no explanation at a fundamental level, despite many varied attempts. A further important dilemma in the standard model is the Lithium problem, which is the substantial mismatch between the theoretical prediction for 7-Li from Big Bang Nucleosynthesis and the value that we observe today. This observation is one of the very few we have from along our past worldline as opposed to our past lightcone. By releasing the untested assumption that the universe is homogeneous on very large scales, both apparent acceleration and the Lithium problem can be easily accounted for as different aspects of cosmic inhomogeneity, without causing problems for other cosmological phenomena such as the cosmic microwave background. We illustrate this in the context of a void model.Comment: 14 pages, 4 figures. v2: minor rearrangements in the text, comments and references expanded, results unchange

The use of barriers to limit the spread of aquatic invasive animal species: a global review

Aquatic invasive species (AIS) are one of the principal threats to freshwater biodiversity. Exclusion barriers are increasingly being used as a management strategy to control the spread of AIS. However, exclusion barriers can also impact native organisms and their effectiveness is likely to be context dependent. We conducted a quantitative literature review to evaluate the use of barriers to control animal AIS in freshwater ecosystems worldwide. The quantitative aspect of the review was supplemented by case studies that describe some of the challenges, successes, and opportunities for the use of the use of AIS exclusion barriers globally. Barriers have been used since the 1950s to control the spread of AIS, but effort has been increasing since 2005 (80% of studies) and an increasingly diverse range of AIS taxa are now targeted in a wide range of habitat types. The global use of AIS barriers has been concentrated in North America (74% of studies), Australasia (11%), and Europe (10%). Physical barriers (e.g., weirs, exclusion screens, and velocity barriers) have been most widely used (47%), followed by electric (27%) and chemical barriers (12%). Fish were the most targeted taxa (86%), followed by crustaceans (10%), molluscs (3%) and amphibians (1%). Most studies have been moderately successful in limiting the passage of AIS, with 86% of the barriers tested deterring >70% of individuals. However, only 25% of studies evaluated barrier impacts on native species, and development of selective passage is still in its infancy. Most studies have been too short (47% < 1 year, 87% < 5 years) to detect ecological impacts or have failed to use robust before-after-control-impact (BACI) study designs (only 5%). Hence, more effective monitoring is required to assess the long-term effectiveness of exclusion barriers as an AIS management tool. Our global case studies highlight the pressing need for AIS control in many ecoregions, and exclusion barriers have the potential to become an effective tool in some situations. However, the design and operation of exclusion barriers must be refined to deliver selective passage of native fauna, and exclusion barriers should only be used sparingly as part of a wider integrated management strategy

A concerted systems biology analysis of phenol metabolism in Rhodococcus opacus PD630

Rhodococcus opacus PD630 metabolizes aromatic substrates and naturally produces branched-chain lipids, which are advantageous traits for lignin valorization. To provide insights into its lignocellulose hydrolysate utilization, we performed 13C-pathway tracing, 13C-pulse-tracing, transcriptional profiling, biomass composition analysis, and metabolite profiling in conjunction with 13C-metabolic flux analysis (13C-MFA) of phenol metabolism. We found that 1) phenol is metabolized mainly through the ortho–cleavage pathway; 2) phenol utilization requires a highly active TCA cycle; 3) NADPH is generated mainly via NADPH-dependent isocitrate dehydrogenase; 4) active cataplerotic fluxes increase plasticity in the TCA cycle; and 5) gluconeogenesis occurs partially through the reversed Entner–Doudoroff pathway (EDP). We also found that phenol-fed R. opacus PD630 generally has lower sugar phosphate concentrations (e.g., fructose 1,6-bisphosphatase) compared to metabolite pools in 13C-glucose-fed Escherichia coli (set as internal standards), while its TCA metabolites (e.g., malate, succinate, and α-ketoglutarate) accumulate intracellularly with measurable succinate secretion. In addition, we found that phenol utilization was inhibited by benzoate, while catabolite repressions by other tested carbon substrates (e.g., glucose and acetate) were absent in R. opacus PD630. Three adaptively-evolved strains display very different growth rates when fed with phenol as a sole carbon source, but they maintain a conserved flux network. These findings improve our understanding of R. opacus’ metabolism for future lignin valorization