Characterization of the novel ene reductase Ppo-Er1 from paenibacillus polymyxa

Ene reductases enable the asymmetric hydrogenation of activated alkenes allowing the manufacture of valuable chiral products. The enzymes complement existing metal- and organocatalytic approaches for the stereoselective reduction of activated C=C double bonds, and efforts to expand the biocatalytic toolbox with additional ene reductases are of high academic and industrial interest. Here, we present the characterization of a novel ene reductase from Paenibacillus polymyxa, named Ppo-Er1, belonging to the recently identified subgroup III of the old yellow enzyme family. The determination of substrate scope, solvent stability, temperature, and pH range of Ppo-Er1 is one of the first examples of a detailed biophysical characterization of a subgroup III enzyme. Notably, Ppo-Er1 possesses a wide temperature optimum (Topt: 20–45 °C) and retains high conversion rates of at least 70% even at 10 °C reaction temperature making it an interesting biocatalyst for the conversion of temperature-labile substrates. When assaying a set of different organic solvents to determine Ppo-Er1′s solvent tolerance, the ene reductase exhibited good performance in up to 40% cyclohexane as well as 20 vol% DMSO and ethanol. In summary, Ppo-Er1 exhibited activity for thirteen out of the nineteen investigated compounds, for ten of which Michaelis–Menten kinetics could be determined. The enzyme exhibited the highest specificity constant for maleimide with a kcat/KM value of 287 mM−1 s−1. In addition, Ppo-Er1 proved to be highly enantioselective for selected substrates with measured enantiomeric excess values of 92% or higher for 2-methyl-2-cyclohexenone, citral, and carvone

Evolutionary psychology: the emperor’s new paradigm

For some evolutionary psychology is merely a field of inquiry, but for others it is a robust paradigm involving specific theories about the nature and evolution of the human mind. Proponents of this paradigm claim to have made several important discoveries regarding the evolved architecture of the mind. Highly publicized discoveries include a cheater-detection module, a psychological sex difference in jealousy, and motivational mechanisms underlying parental love and its lapses, which purportedly result in child maltreatment. In this article, I argue that the empirical evidence for these ‘discoveries’ is inconclusive, at best. I suggest that, as the reigning paradigm in evolutionary psychology has produced questionable results, the evolutionary study of human psychology is still in need of a guiding paradigm

Physics: The Polar Pattern Predictor

Several models of the dynamo that generates the magnetic field of the earth are based on the assumption of a convective flow in the liquid portion of the earth\u27s outer core that possesses non-vanishing helicity (Busse, 1978; Moffatt, 1978). Helicity is a measure of the strength of flow and its twist: the helicity density is the scalar product of the velocity of the flow and its vorticity. The vorticity is the curl of the velocity and thus gives a measure of the twist around the direction of motion. A laboratory model, the polar pattern predictor, that demonstrates several qualitative flow features, including helicity expected to be associated with the flow of the geodynamo, is exhibited here. Busse (1975 and 1976) performed quasilinear calculations to indicate the probable form of convective motion in the earth\u27s interior that might be associated with the geodynamo. Busse and Carrigan (1976) actually modeled the flow in a rotating annulus and established the presence of the cylindrical convective rolls. These rolls are the dominant feature in the circulation outside a cylinder inscribing the solid inner core. However, such flows do not have net helicity, and secondorder effects, such as Ekrnan suction, are required to give secondary flows capable of dynamo action (Busse, 1970, 1973, and 1976; Moffatt , 1978:313-318)

Evolutionary Psychology, Meet Developmental Neurobiology: Against Promiscuous Modularity

This revised version was published online in July 2006 with corrections to the Cover Date.Evolutionary psychologists claim that the mind contains “hundreds or thousands” of “genetically specified” modules, which are evolutionary adaptations for their cognitive functions. We argue that, while the adult human mind/brain typically contains a degree of modularization, its “modules” are neither genetically specified nor evolutionary adaptations. Rather, they result from the brain's developmental plasticity, which allows environmental task demands a large role in shaping the brain's information-processing structures. The brain's developmental plasticity is our fundamental psychological adaptation, and the “modules” that result from it are adaptive responses to local conditions, not past evolutionary environments. If different individuals share common environments, however, they may develop similar “modules,” and this process can mimic the development of genetically specified modules in the evolutionary psychologist's sense

Quantum correlations in position, momentum, and intermediate bases for a full optical field of view

We report an eight-element, linear-array, single-photon detector that uses multiple fibers of differing lengths coupled to a single detector, the timing information from which reveals the position in which the photon was measured. Using two such arrays and two detectors we measure the correlations of photons produced by parametric downconversion, without recourse to mechanical scanning. Spatial light modulators acting as variable focal length lenses positioned between the downconversion crystal and the arrays allow us to switch between measurement of position, transverse momentum, or intermediate bases. We observe the product of the variances of the conditional probabilities for position and momentum to be more than an order of magnitude below the classical limit, realizing a full-field demonstration of the Einstein-Podolsky-Rosen paradox. Such, multistate measurement technologies allow access to the higher information content of the photon based upon spatial modes

The Human Virome in Children and its Relationship to Febrile Illness

This study investigates the relationship of viruses to febrile illness in children. Subjects are normal children 2-36 months of age with fever along with normal children of the same age without fever, plus immunocompromised children with fever along with immunocompromised children without fever. Specimens obtained include blood, nasopharyngeal secretions, and feces. Specimens are analyzed using a panel of virus-specific PCR assays and also by high throughput sequencing using 454 and Illumina platforms

Facilitating practice-led co-innovation for the improvement in animal welfare

Using the egg-laying-hen sector as a case study, the European Union-funded ‘Hennovation’ thematic network has been testing mechanisms to enable practice-led innovation through the establishment of 19 innovation networks of farmers and within the laying-hen processing industry, supported by existing science and market-driven actors. These networks were facilitated to proactively search for, share and use new ideas to improve hen welfare, efficiency and sustainability. This article provides insights into the tools used, including a framework for the facilitation of practice-led collaborative innovation processes. This framework was developed through participatory action research to monitor network performance and self-reflection by facilitators. Practice-led innovation processes are network specific and evolve as the actors within the network come together to share common problems, experiment with possible solutions and learn. The participatory and iterative nature of this process leads to uncertainty in process and end results. This raises methodological challenges in the management of such processes and requires a flexible and adaptive management approach focusing on learning and reflection. </jats:p

Nationwide Distributional Determinants For A Wildlife And Human Parasite

Understanding the factors that constrain species distributions is a long-standing goal of ecology, although many studies involve only free-living species. Studies of disease occurrence and spread often require broader knowledge of distributional overlap for free-living and parasitic species, emphasizing the importance of determining the distributional constraints on parasites. Flatworm trematodes in the genus Alaria are a broadly distributed group of parasites with wildlife and human health implications. Using a 10-year survey of 624 ponds across the United States, we evaluated the relative roles of climate, geology, and land cover for Alaria occurrence using species distribution modeling (Maxent). We also conducted a step-wise parameterization of Maxent and a sampling bias control method, which may be useful for improving the functionality of Maxent. From among 26 considered models simulations, we identified the primary Alaria occurrence areas that included western and mid-western US with a low probability of predicted occurrence in the central and southern US. The best-fitting Alaria model (mean test AUC:0.829 ± 0.070 SD; average of 10 ensemble models) is comprised of 9 variables including climate, geology, and land cover. Bootstrapping with 20 replicates was found to be the best Maxent method because it maximized mean test AUC and decreased mean standard deviation. Geology was the most important variable explaining 24% of the variation followed by precipitation in the wettest month (15%) and mean temperature of the driest quarter (14%). Land cover was not a substantial explanation of Alaria occurrence (7%). Geology is likely mediating through its effect on water quality and pH, while climatic variables may affect the composition of Alaria hosts. Our results may help inform predictions of infection risk in wildlife and humans

The chemistry and mode of action of naturally-occurring growth regulators from avena

This thesis is concerned with the nature and function of endogenous chemicals in the maintenance of oat seed dormancy. The prime germination inhibitors within dormant Avena spp. Are characterised and their development pattern during seed maturation and after-ripening established. Their in vitro biological activities as inhibitors of germination and reserve starch degradation are also shown. Abscisic acid (ABA) and a group of saturated, medium-chain length carboxylic acids (MCFA) have been detected in dormant Avena seed. Levels of endogenous fatty acid and ABA were monitored in developing grain of dormant and non-dormant oat species. It is shown that the highest amounts of MCFA are present within dormant seed, these levels decreasing during, or prior to, that period of increasing seed germinability. Reduced amounts of MCFA are associated with non-dormant grain. It is shown that oat seed germination correlates well with V the endogenous level of MCFA, particularly nonanoic acid. It is speculated that volatile fatty acids are lost from dormant wild oat grain during dry storage by a natural physical process involving gradual volatilisation. ABA did not appear to be directly involved with oat seed dormancy. Large variations in ABA content only occurred in hydrated grain of both species, the level increasing markedly during grain filling. As desiccation on the parent plant proceeded the ABA content of seeds rapidly decreased. At harvest the levels of free ABA in common and wild oat were found to be similar, although their germinations were 65% and 0%, respectively. It is shown that ABA is not efficacious as an inhibitor of germination in the common oat. MCFA are detected in the 3 inhibitor mixtures isolated from a wide variety of plant material. It is proposed that they contribute to the inhibitory properties of this complex. Fatty acids in the series pentanoic to undecanoic are tested for their physiological activity in seed germination. MCFA are found to inhibit seed germination and suppress gibberellin-induced amylolysis in barley at concentrations below 10-3M. In general, nonanoic acid is the most effective treatment. At a concentration of about 2 x 10-3M nonanoic acid reduces the germination of non-dormant oat seed by 50%. MCFA-induced inhibition of lettuce seed germination is shown to be similar to natural thermodormancy, being reversed by treatment with red light or applications of cytokinin or gibberellin. It is speculated that MCFA impose their inhibitory action by modifying membrane function and/or enzyme activity within the plant cell

Improving Enzyme Fitness with Machine Learning

The combinatorial composition of proteins has triggered the application of machine learning in enzyme engineering. By predicting how protein sequence encodes function, researchers aim to leverage machine learning models to select a reduced number of optimized sequences for laboratory measurement with the aim to lower costs and shorten timelines of enzyme engineering campaigns. In this review, we will highlight successful algorithm-aided protein engineering examples, including work carried out within the NCCR Catalysis. In this context, we will discuss the underlying computational methods developed to improve enzyme properties such as enantioselectivity, regioselectivity, activity, and stability. Considering the rapid maturing of computational techniques, we expect that their continued application in enzyme engineering campaigns will be key to deliver additional powerful biocatalysts for sustainable chemical synthesis