The proeutectoid cementite transformation in steels

A comprehensive, critical, and up to date review is presented for the proeutectoid cementite transformation in steels. It is believed that many of the new findings, features, and concepts presented here for this classic phase transformation in steels serve as a model which may be more broadly applicable to test against many other phase transformations systems as well. There were a number of early investigations of cementite morphology, and this review considers those early results in light of many newer studies that provide critical new insight into cementite morphologies in both two and three dimensions. A number of different orientation relationships (ORs) between proeutectoid cementite and the austenite matrix from which it forms have been reported in the literature, in some cases leading to confusion, and they are critically evaluated here, as are the habit plane, growth direction, and interfacial structure of various morphologies of proeutectoid cementite. Quantitative experimental and theoretical investigations of the growth kinetics of the proeutectoid cementite transformation are considered next, and the nucleation site of proeutectoid cementite in austenite is also discussed in some detail. This review considers all of these issues in a critical way in which differences, commonalities, important features, and redundancies are sorted out, in order to present a unified picture that will add some clarity to this subject. The different features and issues of this transformation that are considered in detail throughout this review are finally brought together in a comprehensive way in the last major section of this paper on ‘Formation mechanism(s) of proeutectoid cementite’, in order to provide a complete, modern view of the formation of proeutectoid cementite from austenite. To the best knowledge of the present authors, before this review a thorough assessment of this classic phase transformation in steels had not been undertaken since 1962, when Professor Hubert I. Aaronson covered this topic in a section of the book entitled ‘The Decomposition of Austenite by Diffusional Processes’. In large part due to a number of ground breaking new findings on the proeutectoid cementite transformation since then (particularly in the last decade), it is very timely for a new review on this topic

Deaf white cats

A Quick guide on deaf white cats: domestic cats that are completely white with blue eyes that have no functional hearing, proving a natural model for human congenital deafness

Deaf white cats

A Quick guide on deaf white cats: domestic cats that are completely white with blue eyes that have no functional hearing, proving a natural model for human congenital deafness

Externally imposed electric field enhances plant root tip regeneration

In plants, shoot and root regeneration can be induced in the distinctive conditions of tissue culture (in vitro), but is also observed in intact individuals (in planta) recovering from tissue damage. Roots, for example, can regenerate their fully excised meristems in planta, even in mutants with impaired apical stem cell niches. Unfortunately, to date a comprehensive understanding of regeneration in plants is still missing. Here, we provide evidence that an imposed electric field can perturb apical root regeneration in Arabidopsis. Crucially, we explored both spatial and temporal competences of the stump to respond to electrical stimulation, respectively by varying the position of the cut and the time interval between excision and stimulation. Our data indicate that a brief pulse of an electric field parallel to the root is sufficient to increase by up to two-fold the probability of its regeneration, and to perturb the local distribution of the hormone auxin, as well as cell division regulation. Remarkably, the orientation of the root towards the anode or the cathode is shown to play a role

Learning Spaces: Youth, Literacy and New Media in Remote Indigenous Australia

“This work offers us the rare opportunity to step inside innovative uses of technologies, mergers of global technologies into local knowledge, and community advocacy of local history and ideology…The young people who move through these pages are motivated and proud of having had the opportunities that make possible their linking together of historical knowledge and contemporary means of communication and performance. The means illustrated here have enabled them to develop skills that will help them move into the future as adults engaged with the health and life of their own communities, connected to their language and culture as their way of being in the world of the local so as to know the world of the global.” Professor Shirley Brice Heath Stanford University, US

Neurocognitive factors in sensory restoration of early deafness: a connectome model

Progress in biomedical technology (cochlear, vestibular, and retinal implants) has led to remarkable success in neurosensory restoration, particularly in the auditory system. However, outcomes vary considerably, even after accounting for comorbidity-for example, after cochlear implantation, some deaf children develop spoken language skills approaching those of their hearing peers, whereas other children fail to do so. Here, we review evidence that auditory deprivation has widespread effects on brain development, affecting the capacity to process information beyond the auditory system. After sensory loss and deafness, the brain's effective connectivity is altered within the auditory system, between sensory systems, and between the auditory system and centres serving higher order neurocognitive functions. As a result, congenital sensory loss could be thought of as a connectome disease, with interindividual variability in the brain's adaptation to sensory loss underpinning much of the observed variation in outcome of cochlear implantation. Different executive functions, sequential processing, and concept formation are at particular risk in deaf children. A battery of clinical tests can allow early identification of neurocognitive risk factors. Intervention strategies that address these impairments with a personalised approach, taking interindividual variations into account, will further improve outcomes

Origins of thalamic and cortical projections to the posterior auditory field in congenitally deaf cats.

Crossmodal plasticity takes place following sensory loss, such that areas that normally process the missing modality are reorganized to provide compensatory function in the remaining sensory systems. For example, congenitally deaf cats outperform normal hearing animals on localization of visual stimuli presented in the periphery, and this advantage has been shown to be mediated by the posterior auditory field (PAF). In order to determine the nature of the anatomical differences that underlie this phenomenon, we injected a retrograde tracer into PAF of congenitally deaf animals and quantified the thalamic and cortical projections to this field. The pattern of projections from areas throughout the brain was determined to be qualitatively similar to that previously demonstrated in normal hearing animals, but with twice as many projections arising from non-auditory cortical areas. In addition, small ectopic projections were observed from a number of fields in visual cortex, including areas 19, 20a, 20b, and 21b, and area 7 of parietal cortex. These areas did not show projections to PAF in cats deafened ototoxically near the onset of hearing, and provide a possible mechanism for crossmodal reorganization of PAF. These, along with the possible contributions of other mechanisms, are considered

Searching for the effect of multiple uncontrolled interventions in BRMS

We search for the effects of 8 different (uncontrolled) interventions (1intervention per school) on the sub-concepts of learner’s (4th to 8th grade)motivation, self-regulation, and ICT competency data over the past threeyears. Data marking for intervention (yes/no), ICT competence of teachersand the presence of specially trained teachers are added to the formulas.Assessment of ICT competency in 3rd grade can be used as prior. Smoothsillustrate if the (motivation or self-regulation) concepts grow over timegrouped by intervention, school or grade. Grades are nested within schoolsand data is grouped by student. Are we missing anything