Purification and characterization of Taq polymerase: A 9-week biochemistry laboratory project for undergraduate students

We have developed a 9-week undergraduate laboratory series focused on the purification and characterization of Thermus aquaticus DNA polymerase (Taq). Our aim was to provide undergraduate biochemistry students with a full-semester continuing project simulating a research-like experience, while having each week\u27s procedure focus on a single learning goal. The laboratory series has been taught for the past 7 years, and survey-based assessment of the effectiveness of the laboratory series was completed during the 2006 and 2007 fall semesters. Statistical analysis of the survey results demonstrate that the laboratory series is very effective in teaching students the theory and practice of protein purification and analysis while also demonstrating positive results in more broad areas of scientific skill and knowledge. Amongst the findings, the largest reported increases in knowledge were related to students\u27 understanding of how patent law relates to laboratory science, a topic of great importance to modern researchers that is readily discussed in relation to Taq polymerase. Overall, this laboratory series proves to be a very effective component in the curricula of undergraduate biology and chemistry majors and may be an appropriate laboratory experience for undergraduates. © 2010 by The International Union of Biochemistry and Molecular Biology

The dependence of intrinsic alignment of galaxies on wavelength using KiDS and GAMA

The outer regions of galaxies are more susceptible to the tidal interactions that lead to intrinsic alignments of galaxies. The resulting alignment signal may therefore depend on the passband if the colours of galaxies vary spatially. To quantify this, we measured the shapes of galaxies with spectroscopic redshifts from the GAMA survey using deep gri imaging data from the KiloDegree Survey. The performance of the moment-based shape measurement algorithm DEIMOS was assessed using dedicated image simulations, which showed that the ellipticities could be determined with an accuracy better than 1% in all bands. Additional tests for potential systematic errors did not reveal any issues. We measure a significant difference of the alignment signal between the g,r and i-band observations. This difference exceeds the amplitude of the linear alignment model on scales below 2 Mpc/h. Separating the sample into central/satellite and red/blue galaxies, we find that that the difference is dominated by red satellite galaxies.Comment: 16 pages, 13 figures, accepted, to appear in A&

Identifying an avid eating profile in childhood: Associations with temperament, feeding practices and food insecurity

This study aimed to identify distinct eating behaviour profiles in young children and examine how other key predictors of children's eating behaviour, including child temperament, the experience of food insecurity, or parental feeding practices, may vary by identified profiles. An online survey was conducted with 995 parents/carers living in England and Wales (N = 995, Mage = 35.4 years, 80% female, 88% White). Participants reported on their child's eating behaviour using the Child Eating Behaviour Questionnaire and completed measures of child temperament, household food security and parental feeding practices. Latent Profile Analysis (LPA) was carried out to identify distinct eating profiles amongst the children (36–72 months, Mage = 48.8 months, 52% female). Four eating profiles emerged from the sample of children: (a) avid eating, (b) avoidant eating, (c) happy eating, and (d) typical eating. Avid eating (21.9% of children) was characterised by higher levels of food responsiveness, enjoyment of food, and emotional over-eating in combination with lower satiety responsiveness, slowness in eating and food fussiness. Children with an avid eating profile were reported to be more surgent and experienced greater food insecurity than all other eating profiles. Parents of children belonging to the avid eating profile showed significantly greater use of food for emotional regulation, varied and balanced food provision, restriction of food for health, and restriction of food for weight feeding practices than the three other eating profiles

Cooperative, Connected and Automated Mobility - impact analysis roadmap

This report consolidates the results of activities where citizens and organisations in 8 European countries co-created use cases and business models for the deployment of autonomous vehicles for passenger and freight transport. We then define methods to assess the systems-wide impact of those use cases and business models, including 1) the rationale for each approach, 2) data to be collected, 3) data collection methods, 4) analysis methods and expected outcomes, and 5) recruitment strategies and ethics considerations. Finally, we define methods for modelling the impacts and integrating them into an impact assessment tool

The adsorption of Cu on the CeO2(110) surface

We report a detailed density functional theory (DFT) study in conjunction with extended X-ray absorption fine structure (EXAFS) experiments on the geometrical and local electronic properties of Cu adatoms and Cu(II) ions in presence of water molecules and of CuO nanoclusters on the CeO2(110) surface. Our study of (CuO)n(=1,2&4) clusters on CeO2(110) shows that based on the Cu–O environment, the geometrical properties of these clusters may vary and their presence may lead to relatively high localization of charge on the exposed surfaces. We find that in the presence of an optimum concentration of water molecules, Cu has a square pyramidal geometry, which agrees well with our experimental findings; we also find that Cu(II) facilitates water adsorption on the CeO2(110) surface. We further show that a critical concentration of water molecules is required for the hydrolysis of water on Cu(OH)2/CeO2(110) and on pristine CeO2(110) surfaces

Tracking extended mucociliary transport activity of individual deposited particles: longitudinal synchrotron X-ray imaging in live mice

To assess potential therapies for respiratory diseases in which mucociliary transit (MCT) is impaired, such as cystic fibrosis and primary ciliary dyskinesia, a novel and non-invasive MCT quantification method has been developed in which the transit rate and behaviour of individual micrometre-sized deposited particles are measured in live mice using synchrotron phase-contrast X-ray imaging. Particle clearance by MCT is known to be a two-phase process that occurs over a period of minutes to days. Previous studies have assessed MCT in the fast-clearance phase, ∼20 min after marker particle dosing. The aim of this study was to non-invasively image changes in particle presence and MCT during the slow-clearance phase, and simultaneously determine whether repeat synchrotron X-ray imaging of mice was feasible over periods of 3, 9 and 25 h. All mice tolerated the repeat imaging procedure with no adverse effects. Quantitative image analysis revealed that the particle MCT rate and the number of particles present in the airway both decreased with time. This study successfully demonstrated for the first time that longitudinal synchrotron X-ray imaging studies are possible in live small animals, provided appropriate animal handling techniques are used and care is taken to reduce the delivered radiation dose.Martin Donnelley, Kaye S. Morgan, Karen K. W. Siu, Andreas Fouras, Nigel R. Farrow, Richard P. Carnibella and David W. Parson

Seed systems smallholder farmers use

Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts

An Experimental and Theoretical Study of the Variation of 4f Hybridization Across the La1-xCexIn3 Series

Crystal structures of a series of La1-xCexIn3 (x = 0.02, 0.2, 0.5, or 0.8) intermetallic compounds have been investigated by both neutron and X-ray diffraction, and their physical properties have been characterized by magnetic susceptibility and specific heat measurements. Our results emphasize atypical atomic displacement parameters (ADP) for the In and the rare-earth sites. Depending on the x value, the In ADP presents either an "ellipsoidal" elongation (La-rich compounds) or a "butterfly-like" distortion (Ce-rich compounds). These deformations have been understood by theoretical techniques based on the band theory and are the result of hybridization between conduction electrons and 4f-electrons.Comment: 7 pages, 8 figure