227 research outputs found
Executive Education: Can it Be Too Good?
A successful business school must serve two communities: the research community on one hand; and the business community on the other. However, despite the spectacular growth of business education over the last four or five decades, there has been growing criticism of the relevance of much business school activity: The academic-practitioner divide has emerged and largely refuses to close. To bridge the gap b-schools must serve both communities concurrently. Executive education is identified as being a critical strategy in the repertoire of b-school deans through which to do so. The aim of this paper is to discuss the construct of executive education, and to challenge some of the dominant logics that executive education is simply education for executives. Executive education is reported as being distinctive from most content focused education – the tangible material that most universities teach.
The successful design and delivery of a suite of non-credit executive education courses, with a focus on corporate and institutional governance, is presented. Their underpinning pedagogy, based on developing a critically reflective practitioner, is discussed. Executive education courses are found to be distinctive on the basis that responsibility for learning, and the direction of the journey being taken, rests largely with the participants themselves. The adverse reaction to a six month long not-for-credit short course, offered in-house annually for four years is then briefly described. Observations are shared as to the source of this reaction. The means of avoiding similar adversity towards effective executive education in the future is then identified
Assessment of Slip Severity Among Different Age Groups
A laboratory study utilizing new techniques for assessing slip severity was conducted to investigate the process of inadvertent slips and falls among different age groups. Forty-two subjects from three age groups (young adults, middle-aged, and the elderly) walked on a rectangular track at a self-determined pace. Without the subjects’ awareness, a slippery floor surface was placed on the track over a force-measuring platform. The results indicated that elderly adults’ friction demand (RCOF) was not significantly different from the young and middle-aged adults. The older adults, however, fell more often than the other age groups. Fall recovery threshold (FRT) measures indicated that younger adults were able to recover from a slip (thus preventing a fall) with higher sliding speeds and longer slip distances than older adults. Additionally, older adults’ adjusted friction utilization (AFU) on the slippery floor surface was not adjusted within the dynamic friction requirements, resulting in more falls. Based on the age-related differences observed, it appears that fall-related accidents among older adults are due more to factors influencing compensation of a slip rather than gait characteristics influencing slip initiation
Hypercube matrix computation task
A major objective of the Hypercube Matrix Computation effort at the Jet Propulsion Laboratory (JPL) is to investigate the applicability of a parallel computing architecture to the solution of large-scale electromagnetic scattering problems. Three scattering analysis codes are being implemented and assessed on a JPL/California Institute of Technology (Caltech) Mark 3 Hypercube. The codes, which utilize different underlying algorithms, give a means of evaluating the general applicability of this parallel architecture. The three analysis codes being implemented are a frequency domain method of moments code, a time domain finite difference code, and a frequency domain finite elements code. These analysis capabilities are being integrated into an electromagnetics interactive analysis workstation which can serve as a design tool for the construction of antennas and other radiating or scattering structures. The first two years of work on the Hypercube Matrix Computation effort is summarized. It includes both new developments and results as well as work previously reported in the Hypercube Matrix Computation Task: Final Report for 1986 to 1987 (JPL Publication 87-18)
A stratigraphic investigation of the Celtic Sea megaridges based on seismic and core data from the Irish-UK sectors
The Celtic Sea contains the world's largest continental shelf sediment ridges. These megaridges were initially interpreted as tidal features formed during post-glacial marine transgression, but glacigenic sediments have been recovered from their flanks. We examine the stratigraphy of the megaridges using new decimetric-resolution geophysical data correlated to sediment cores to test hypothetical tidal vs glacial modes of formation. The megaridges comprise three main units, 1) a superficial fining-upward drape that extends across the shelf above an unconformity. Underlying this drape is 2), the Melville Formation (MFm) which comprises the upper bulk of the megaridges, sometimes displaying dipping internal acoustic reflections and consisting of medium to coarse sand and shell fragments; characteristics consistent with either a tidal or glacifluvial origin. The MFm unconformably overlies 3), the Upper Little Sole Formation (ULSFm), previously interpreted to be of late Pliocene to early Pleistocene age, but here shown to correlate to Late Pleistocene glacigenic sediments forming a precursor topography. The superficial drape is interpreted as a product of prolonged wave energy as tidal currents diminished during the final stages of post-glacial marine transgression. We argue that the stratigraphy constrains the age of the MFm to between 24.3 and 14 ka BP, based on published dates, coeval with deglaciation and a modelled period of megatidal conditions during post-glacial marine transgression. Stratigraphically and sedimentologically, the megaridges could represent preserved glacifluvial features, but we suggest that they comprise post-glacial tidal deposits (MFm) mantling a partially-eroded glacial topography (ULSFm). The observed stratigraphy suggests that ice extended to the continental shelf-edge
LASSO: Large Adaptive optics Survey for Substellar Objects using the new SAPHIRA detector on Robo-AO
We report on initial results from the largest infrared AO direct imaging
survey searching for wide orbit (>100 AU) massive exoplanets and brown dwarfs
as companions around young nearby stars using Robo-AO at the 2.1-m telescope on
Kitt Peak, Arizona. The occurrence rates of these rare substellar companions
are critical to furthering our understanding of the origin of planetary-mass
companions on wide orbits. The observing efficiency of Robo-AO allows us to
conduct a survey an order of magnitude larger than previously possible. We
commissioned a low-noise high-speed SAPHIRA near-infrared camera to conduct
this survey and report on its sensitivity, performance, and data reduction
process.Comment: 10 pages, 7 figures, SPIE conference proceeding
Cryptococcus gattii in North American Pacific Northwest: whole-population genome analysis provides insights into species evolution and dispersal
The emergence of distinct populations of Cryptococcus gattii in the temperate North American Pacific Northwest (PNW) was surprising, as this species was previously thought to be confined to tropical and semitropical regions. Beyond a new habitat niche, the dominant emergent population displayed increased virulence and caused primary pulmonary disease, as opposed to the predominantly neurologic disease seen previously elsewhere. Whole-genome sequencing was performed on 118 C. gattii isolates, including the PNW subtypes and the global diversity of molecular type VGII, to better ascertain the natural source and genomic adaptations leading to the emergence of infection in the PNW. Overall, the VGII population was highly diverse, demonstrating large numbers of mutational and recombinational events; however, the three dominant subtypes from the PNW were of low diversity and were completely clonal. Although strains of VGII were found on at least five continents, all genetic subpopulations were represented or were most closely related to strains from South America. The phylogenetic data are consistent with multiple dispersal events from South America to North America and elsewhere. Numerous gene content differences were identified between the emergent clones and other VGII lineages, including genes potentially related to habitat adaptation, virulence, and pathology. Evidence was also found for possible gene introgression from Cryptococcus neoformans var. grubii that is rarely seen in global C. gattii but that was present in all PNW populations. These findings provide greater understanding of C. gattii evolution in North America and support extensive evolution in, and dispersal from, South America. Importance: Cryptococcus gattii emerged in the temperate North American Pacific Northwest (PNW) in the late 1990s. Beyond a new environmental niche, these emergent populations displayed increased virulence and resulted in a different pattern of clinical disease. In particular, severe pulmonary infections predominated in contrast to presentation with neurologic disease as seen previously elsewhere. We employed population-level whole-genome sequencing and analysis to explore the genetic relationships and gene content of the PNW C. gattii populations. We provide evidence that the PNW strains originated from South America and identified numerous genes potentially related to habitat adaptation, virulence expression, and clinical presentation. Characterization of these genetic features may lead to improved diagnostics and therapies for such fungal infections. The data indicate that there were multiple recent introductions of C. gattii into the PNW. Public health vigilance is warranted for emergence in regions where C. gattii is not thought to be endemic
Effects of Aging on the Biomechanics of Slips and Falls
Although much has been learned in recent decades about the deterioration of muscular strength, gait adaptations, and sensory degradation among older adults, little is known about how these intrinsic changes affect biomechanical parameters associated with slip-induced fall accidents. In general, the objective of this laboratory study was to investigate the process of initiation, detection, and recovery of inadvertent slips and falls. We examined the initiation of and recovery from foot slips among three age groups utilizing biomechanical parameters, muscle strength, and sensory measurements. Forty-two young, middle-age, and older participants walked around a walking track at a comfortable pace. Slippery floor surfaces were placed on the track over force platforms at random intervals without the participants’ awareness. Results indicated that younger participants slipped as often as the older participants, suggesting that the likelihood of slip initiation is similar across all age groups; however, older individuals’ recovery process was much slower and less effective. The ability to successfully recover from a slip (thus preventing a fall) is believed to be affected by lower extremity muscle strength and sensory degradation among older individuals. Results from this research can help pinpoint possible intervention strategies for improving dynamic equilibrium among older adults
Mutations in RAB39B Cause X-Linked Intellectual Disability and Early-Onset Parkinson Disease with alpha-Synuclein Pathology
Advances in understanding the etiology of Parkinson disease have been driven by the identification of causative mutations in families. Genetic analysis of an Australian family with three males displaying clinical features of early-onset parkinsonism and intellectual disability identified a approximately 45 kb deletion resulting in the complete loss of RAB39B. We subsequently identified a missense mutation (c.503C>A [p.Thr168Lys]) in RAB39B in an unrelated Wisconsin kindred affected by a similar clinical phenotype. In silico and in vitro studies demonstrated that the mutation destabilized the protein, consistent with loss of function. In vitro small-hairpin-RNA-mediated knockdown of Rab39b resulted in a reduction in the density of alpha-synuclein immunoreactive puncta in dendritic processes of cultured neurons. In addition, in multiple cell models, we demonstrated that knockdown of Rab39b was associated with reduced steady-state levels of alpha-synuclein. Post mortem studies demonstrated that loss of RAB39B resulted in pathologically confirmed Parkinson disease. There was extensive dopaminergic neuron loss in the substantia nigra and widespread classic Lewy body pathology. Additional pathological features included cortical Lewy bodies, brain iron accumulation, tau immunoreactivity, and axonal spheroids. Overall, we have shown that loss-of-function mutations in RAB39B cause intellectual disability and pathologically confirmed early-onset Parkinson disease. The loss of RAB39B results in dysregulation of alpha-synuclein homeostasis and a spectrum of neuropathological features that implicate RAB39B in the pathogenesis of Parkinson disease and potentially other neurodegenerative disorders
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