A genetic case study. Engineering biotechnologies for practicalapplication to livestock will speed technology transfer to breedingcompanies

Animal improvement first became organized during the 18th and 19th centuries through the efforts of individual enthusiasts culminating in the formation of Breed Societies. In the first half of the 20th century, Mendelian theory was combined with new developments in statistics to produce the science of Quantitative Genetics, the field of genetics dealing with the inheritance of quantitative characters influenced by many genes. This produced the theoretical framework for modern day breeding     

Poly(N-acryloyl-l-prolyl morpholine): a g.p.c. packing exhibiting novel temperature dependence in solute distribution coefficients

The synthesis of poly(N-acryloyl-l-prolyl morpholine), a new bead packing for the g.p.c. of small molecules, is described. Characteristic g.p.c. behaviour and high column efficiencies were observed in water and benzyl alcohol. Novel, reversible temperature variations in solute Wheaton and Bauman distribution coefficients were observed. This effect, which is most marked in water, is caused by thermo-reversible changes in network pore size distribution in the bead packing.     

Applying SVMs and weight-based factor analysis to unsupervised adaptation for speaker verification

This paper presents an extended study on the implementation of support vector machine (SVM) based speaker verification in systems that employ continuous progressive model adaptation using the weight-based factor analysis model. The weight-based factor analysis model compensates for session variations in unsupervised scenarios by incorporating trial confidence measures in the general statistics used in the inter-session variability modelling process. Employing weight-based factor analysis in Gaussian mixture models (GMMs) was recently found to provide significant performance gains to unsupervised classification. Further improvements in performance were found through the integration of SVM-based classification in the system by means of GMM supervectors.This study focuses particularly on the way in which a client is represented in the SVM kernel space using single and multiple target supervectors. Experimental results indicate that training client SVMs using a single target supervector maximises performance while exhibiting a certain robustness to the inclusion of impostor training data in the model. Furthermore, the inclusion of low-scoring target trials in the adaptation process is investigated where they were found to significantly aid performance.     

Synthesis and characterization of poly(acryloyl morpholine) xerogel networks suitable for the gel permeation chromatography of small molecules

The synthesis and characterization of a crosslinked poly(acryloyl morpholine) network, Enzacryl® Gel KO, calculated to be effective as a matrix for the g.p.c. of small molecules, is described. Chromatographic performance was evaluated in water, chloroform, dimethylformamide and pyridine. Characteristic g.p.c. behaviour was observed for all standards tested although ‘additional exclusion’ was observed in the case of aliphatic hydrocarbons in the three organic solvents and with aromatic hydrocarbons in chloroform and pyridine. Similar molecular weight fractionation ranges were obtained for poly(ethylene glycols) in the four solvents investigated the molecular weight exclusion limit being less than 1500.     

Polite web-based intelligent tutors: Can they improve learning in classrooms?

Should an intelligent software tutor be polite, in an effort to motivate and cajole students to learn, or should it use more direct language? If it should be polite, under what conditions? In a series of studies in different contexts (e.g., lab versus classroom) with a variety of students (e.g., low prior knowledge versus high prior knowledge), the politeness effect was investigated in the context of web-based intelligent tutoring systems, software that runs on the Internet and employs artificial intelligence and learning science techniques to help students learn. The goal was to pinpoint the appropriate conditions for having the web-based tutors provide polite feedback and hints (e.g., “Let’s convert the units of the first item”) versus direct feedback and hints (e.g., “Convert the units of the first item now”). In the study presented in this paper, 132 high school students in a classroom setting, grouped as low and high prior knowledge learners according to a pre-intervention knowledge questionnaire, did not benefit more from polite feedback and hints than direct feedback and hints on either an immediate or delayed posttest, both of which contained near transfer and conceptual test items. Of particular interest and contrary to an earlier lab study, low prior knowledge students did not benefit more from using the polite version of a tutor. On the other hand, a politeness effect was observed for the students who made the most errors during the intervention, a different proxy for low prior knowledge, hinting that even in a classroom setting, politeness may be beneficial for more needy students. This article presents and discusses these results, as well as discussing the politeness effect more generally, its theoretical underpinnings, and future directions.     

A politeness effect in learning with web-based intelligent tutors

College students learned to solve chemistry stoichiometry problems with a web-based intelligent tutor that provided hints and feedback, using either polite or direct language. There was a pattern in which students with low prior knowledge of chemistry performed better on subsequent problem-solving tests if they learned from the polite tutor rather than the direct tutor (d=.78 on an immediate test, d=.51 on a delayed test), whereas students with high prior knowledge showed the reverse trend (d=?.47 for an immediate test; d=?.13 for a delayed test). These results point to a boundary condition for the politeness principle—the idea that people learn more deeply when words are in polite style. At least for low-knowledge learners, the results are consistent with social agency theory—the idea that social cues, such as politeness, can prime learners to accept a web-based tutor as a social partner and therefore try harder to make sense of the tutor’s messages.     

Heterogeneous reactions of glyoxal on particulate matter: identification of acetals and sulfate esters

Reactive uptake of glyoxal onto particulate matter has been studied in laboratory experiments in a 2 m3 Teflon reaction chamber. Inorganic seed particles of different composition were utilized, including (NH4)2SO4, (NH4)2SO4/ H2SO4, NaNO3, and simulated sea salt, while the relative humidity and acid concentration were varied. The organic composition of the growing particles was measured in situ with an aerosol mass spectrometer, providing particle mass spectra as a means of product identification. Aerosol physical characteristics were also measured with a differential mobility analyzer and condensation nucleus counter. Regardless of seed composition, particle growth was rapid and continuous over the course of several hours. Identification of several mass fragments greater than the glyoxal monomer suggested that heterogeneous reactionsto form glyoxal adducts of lowvolatility had occurred. Temporal analysis of the mass fragments was consistent with a proposed acid-catalyzed mechanism whereby glyoxal is first hydrated, followed by self-reaction to form cyclic acetal structures. Increased relative humidity slowed the formation of higher order oligomers, also consistent with the proposed mechanism. The relative contribution of various oligomers to the overall organic composition was strongly dependent on the relative humidity and hence the particulate water concentration. A mild acid catalysis was also observed upon increasing the acidity of the seed particles. Specific mass fragments were found that could only arise from sulfate esters and were not present on the non-sulfur-containing seed particles. This first evidence of the formation of organic sulfates in particles is presented together with a proposed mechanism and molecular structure. These results suggest that the formation of these products of glyoxal uptake can contribute significantly to secondary organic aerosol.     

Intradimensional and extradimensional shifts in spatial learning.

Animals trained on 2 discriminations learn the 2nd rapidly if the relevant stimuli are from the same dimension as the 1st (an intradimensional or ID shift) but slowly if the relevant stimuli for the 2 problems are from different dimensions (an extradimensional or ED shift). Four experiments examined ID and ED shifts in spatial learning. Rats trained on 2 spatial problems learned the 2nd more rapidly than rats whose 1st problem had been nonspatial. But this difference between ID and ED shifts depended on the spatial relationship between rewarded (S+) and unrewarded (S-) alternatives in the 2 spatial problems. The results imply that rats trained on a spatial discrimination do not learn to attend to all spatial landmarks but only to those that serve to differentiate S+ and S-. (PsycINFO Database Record (c) 2010 APA, all rights reserved)