Redressing the balance: Commentary on “Examining motor learning in older adults using analogy instruction” by Tse, Wong, and Masters (2017)

Tse, Wong, and Masters (2017) recently published a study that indicated that analogy instruction may help older adults acquire resilient motor skills that require reduced cognitive processing compared to traditional explicit instruction. Although we do not dispute that analogy learning may prove useful for this population, in this commentary, we contend that there are methodological issues in this research—which are shared with previous studies comparing analogy and explicit instruction—that potentially limit ecological validity, impact the size of detected effects, influence the development and understanding of associated theory, and, as such, constrain resulting recommendations for applied practice. Of particular concern is the comparison of the single-item analogy instruction to the list of nine explicit instructions, which risks conflating the effects of the type of instruction with the volume of instruction. We further argue that the benefits of analogy may be more parsimoniously explained by the instruction’s capability to succinctly convey skill (rather than its potential for limiting reinvestment), but that this capability may only be realised if the to-be-learned analogy is relevant and readily understood by the learner. Finally, we suggest that research in this area must look to incorporate more rigorous methods that compare experimental conditions to representative reference groups that allow us to explore how and when to deploy the myriad instructional tools available to practitioners and learners

Cropping diversity and input use affect weed competition

Non-Peer ReviewedOf the various pests affecting crop growth weeds are among the most visible and potentially the most damaging. Changing markets, higher input costs and technological change are having a profound impact on weed management decisions in Western Canada. While the decision to change management practices can be immediate the long term agronomic consequences of adopting a farm management system are not well understood. One objective of a long term study, established at Scott in 1995, was to investigate the impact of 3 levels of inputs and 3 levels of cropping diversity on in-crop weed competition. Weed biomass used as an indicator of weed competition, was found to be largely a function of input level decisions and the interaction of weed control operations with precipitation timing. Greater weed biomass in an Organic input system could be linked to a limited number of early season tillage operations occurring over a short window of opportunity near the time of seeding. Herbicides applied later in the growing season in the Reduced and High input system effectively delayed weed growth and reduced weed biomass. Weeds in the Organic input system tended to respond to June-July precipitation while weed growth in the Reduced and High input system increased as July precipitation increased. Differences between cropping diversities were less pronounced showing similar weed biomass trends over time

Towards the New AusGeoid Model

Since November 1998, all high-precision GPS users in Australia have adopted the AUSGeoid98 gravimetric geoid model to transform GPS-derived ellipsoidal heights to the Australian Height Datum (AHD) and vice versa. Since AUSGeoid98 was released by Geoscience Australia (http://www.ga.gov.au/nmd/geodesy/ausgeoid/) based on recommendations by the first-named author, several new theories have been formulated and refined datasets have been released, all of which can improve the Australian geoid model. This paper reports our latest implementations of these theories and datasets, which comprise a global geopotential model derived from the GRACE (Gravity Recovery And Climate Experiment) dedicated satellite gravimetry mission, gravimetric terrain corrections from the version-2 DEM-9S 9"x9" digital elevation model, approximately 200,000 additional land gravity observations in Geoscience Australia's database, improved gravity data cleaning methods, refined marine gravity data from multi-mission satellite radar altimetry, a least-squares crossover adjustment of ship-track gravity observations, and new GPS data collected by State and Territory geodetic survey agencies at key tide-gauges, some junction points and other benchmarks of the AHD. The refined gravimetric geoid solution will be fitted to the GPS-AHD data using least-squares collocation so as to deliberately provide a more direct transformation to the AHD that obviates the need to occupy nearby AHD benchmarks during a GPS survey. This pragmatic solution, while not producing a classical equipotential geoid model, does provide a very useful product for GPS users in Australia until the AHD is rigorously redefined. Our results show that the new model will deliver GPS-derived AHD heights with an RMS of less than ~12 cm in an absolute sense over most parts of Australia, which reduces when used in relative mode over shorter GPS baselines. In short, the new model will deliver height results that are commensurate with or better than Australian class LC (third order) geodetic levelling methods. As with AUSGeoid98, this new product will be released and administered by Geoscience Australia based on our recommendations, hopefully towards the end of 2005

Seven naturally variant loci serve as genetic modifiers of Lamc2jeb induced non-Herlitz junctional Epidermolysis Bullosa in mice.

Epidermolysis Bullosa (EB) is a group of rare genetic disorders that compromise the structural integrity of the skin such that blisters and subsequent erosions occur after minor trauma. While primary genetic risk of all subforms of EB adhere to Mendelian patterns of inheritance, their clinical presentations and severities can vary greatly, implying genetic modifiers. The Lamc2jeb mouse model of non-Herlitz junctional EB (JEB-nH) demonstrated that genetic modifiers can contribute substantially to the phenotypic variability of JEB and likely other forms of EB. The innocuous changes in an \u27EB related gene\u27, Col17a1, have shown it to be a dominant modifier of Lamc2jeb. This work identifies six additional Quantitative Trait Loci (QTL) that modify disease in Lamc2jeb/jeb mice. Three QTL include other known \u27EB related genes\u27, with the strongest modifier effect mapping to a region including the epidermal hemi-desmosomal structural gene dystonin (Dst-e/Bpag1-e). Three other QTL map to intervals devoid of known EB-associated genes. Of these, one contains the nuclear receptor coactivator Ppargc1a as its primary candidate and the others contain related genes Pparg and Igf1, suggesting modifier pathways. These results, demonstrating the potent disease modifying effects of normally innocuous genetic variants, greatly expand the landscape of genetic modifiers of EB and therapeutic approaches that may be applied

Proteome profile and functional classification of proteins in Arabidopsis thaliana (Landsberg erecta) mature pollen

Proteome analysis of mature Arabidopsis thaliana (Landsberg erecta ecotype) pollen was conducted using two-dimensional gel electrophoresis and mass spectrometry. A total of 960 spots were resolved on pH 4–7 IPG strips and 110 distinct proteins were identified from 150 spots analyzed. The identified proteins were categorized based on their functional role in the pollen, which included proteins involved in energy regulation, defense-related mechanisms, calcium-binding and signaling, cytoskeletal formation, pollen allergens, glycine-rich proteins (GRPs), and late embryogenesis abundant (LEA) proteins. These proteins potentially play important roles in pollen function at maturity and during subsequent germination and tube growth. Some of the proteins identified were related to known pollen-specific transcripts, while some were similar to proteins found in the seed. In this study, 66 new proteins were identified which were not reported in two other recent studies on Arabidopsis pollen, 17 proteins were common in all three studies, and 35 or 26 proteins reported here had an overlap with one or the other two studies. These differences may be attributed to the methods of protein extraction, spot selection for analysis, and the ecotype used. Together, the three studies provide a broad spectrum of the Arabidopsis pollen proteome

Human antibodies induce arthritis in mice deficient in the low-affinity inhibitory IgG receptor FcγRIIB

Rheumatoid arthritis (RA) is a complex autoimmune disease with a poorly understood pathogenesis. The disease is associated with polyclonal B cell activation and the production of autoantibodies (autoAbs), but there is a longstanding controversy as to whether such Abs contribute to, or are secondary to, the pathogenesis of RA. To address the potential pathogenicity of human RA–associated Abs, we developed a passive transfer model involving mice deficient in the low-affinity inhibitory Fc receptor, FcγRIIB. We report that plasma or serum from patients with active RA can induce inflammation and histological lesions in FcγRIIB−/− mice consistent with arthritis, and that this pathogenic activity is caused by the immunoglobulin G–rich fraction. Our results suggest that humoral autoimmunity can contribute directly to autoimmune arthritis, and that FcγRIIB−/− mice are a promising model to evaluate the arthritogenic potential of human autoAbs

Dystonin modifiers of junctional epidermolysis bullosa and models of epidermolysis bullosa simplex without dystonia musculorum.

The Lamc2jeb junctional epidermolysis bullosa (EB) mouse model has been used to demonstrate that significant genetic modification of EB symptoms is possible, identifying as modifiers Col17a1 and six other quantitative trait loci, several with strong candidate genes including dystonin (Dst/Bpag1). Here, CRISPR/Cas9 was used to alter exon 23 in mouse skin specific isoform Dst-e (Ensembl GRCm38 transcript name Dst-213, transcript ID ENSMUST00000183302.5, protein size 2639AA) and validate a proposed arginine/glutamine difference at amino acid p1226 in B6 versus 129 mice as a modifier of EB. Frame shift deletions (FSD) in mouse Dst-e exon 23 (Dst-eFSD/FSD) were also identified that cause mice carrying wild-type Lamc2 to develop a phenotype similar to human EB simplex without dystonia musculorum. When combined, Dst-eFSD/FSD modifies Lamc2jeb/jeb (FSD+jeb) induced disease in unexpected ways implicating an altered balance between DST-e (BPAG1e) and a rarely reported rodless DST-eS (BPAG1eS) in epithelium as a possible mechanism. Further, FSD+jeb mice with pinnae removed are found to provide a test bed for studying internal epithelium EB disease and treatment without severe skin disease as a limiting factor while also revealing and accelerating significant nasopharynx symptoms present but not previously noted in Lamc2jeb/jeb mice

A re-appraisal of the reliability of the 20 m multi-stage shuttle run test

This is the author's PDF version of an article published in European journal of applied physiology in 2007. The original publication is available at www.springerlink.co