1,815 research outputs found
New constructions for covering designs
A {\em covering design}, or {\em covering}, is a family of
-subsets, called blocks, chosen from a -set, such that each -subset is
contained in at least one of the blocks. The number of blocks is the covering's
{\em size}, and the minimum size of such a covering is denoted by .
This paper gives three new methods for constructing good coverings: a greedy
algorithm similar to Conway and Sloane's algorithm for lexicographic
codes~\cite{lex}, and two methods that synthesize new coverings from
preexisting ones. Using these new methods, together with results in the
literature, we build tables of upper bounds on for , , and .
The Classroom Observation Schedule to Measure Intentional Communication (COSMIC): An observational measure of the intentional communication of children with autism in an unstructured classroom setting
The Classroom Observation Schedule to Measure Intentional Communication (COSMIC) was devised to provide ecologically valid outcome measures for a communication-focused intervention trial. Ninety-one children with autism spectrum disorder aged 6 years 10 months (SD 16 months) were videoed during their everyday snack, teaching and free play activities. Inter-rater reliability was high and relevant items showed significant associations with comparable items from concurrent Autism Diagnostic Observation Schedule – Generic (Lord et al., 2000) assessments. In a subsample of 28 children initial differences in rates of initiations, initiated speech/vocalisation and commenting were predictive of language and communication competence 15 months later. Results suggest that the use of observational measures of intentional communication in natural settings is a valuable assessment strategy for research and clinical practice
Hydration Water Dynamics and Instigation of Protein Structural Relaxation
The molecular mechanism of the solvent motion that is required to instigate
the protein structural relaxation above a critical hydration level or
transition temperature has yet to be determined. In this work we use
quasi-elastic neutron scattering (QENS) and molecular dynamics simulation to
investigate hydration water dynamics near a greatly simplified protein surface.
We consider the hydration water dynamics near the completely deuterated
N-acetyl-leucine-methylamide (NALMA) solute, a hydrophobic amino acid side
chain attached to a polar blocked polypeptide backbone, as a function of
concentration between 0.5M-2.0M, under ambient conditions. In this
Communication, we focus our results of hydration dynamics near a model protein
surface on the issue of how enzymatic activity is restored once a critical
hydration level is reached, and provide a hypothesis for the molecular
mechanism of the solvent motion that is required to trigger protein structural
relaxation when above the hydration transition.Comment: 2 pages, 2 figures, Communicatio
Landscape of Desire: Identity and Nature in Utah\u27s Canyon Country
Landscape of Desire powerfully documents and celebrates a place and the evolutions that occur when human beings are intimately connected to their surroundings. Greg Gordon accomplishes this with a tapestry of writing that interweaves land use history, natural history, experiential education, and personal reflection. He tracks the geomorphology of southern Utah as well as the creatures and plants his student group encounters, the history lessons (planned and unplanned), the trials and joys of gathering so many individuals into a cohesive will, and his own personal epiphanies, restraints, insights, and disillusionments.https://digitalcommons.usu.edu/usupress_pubs/1141/thumbnail.jp
Asymptotically optimal covering designs
A (v,k,t) covering design, or covering, is a family of k-subsets, called
blocks, chosen from a v-set, such that each t-subset is contained in at least
one of the blocks. The number of blocks is the covering's size}, and the
minimum size of such a covering is denoted by C(v,k,t). It is easy to see that
a covering must contain at least (v choose t)/(k choose t) blocks, and in 1985
R\"odl [European J. Combin. 5 (1985), 69-78] proved a long-standing conjecture
of Erd\H{o}s and Hanani [Publ. Math. Debrecen 10 (1963), 10-13] that for fixed
k and t, coverings of size (v choose t)/(k choose t) (1+o(1)) exist (as v \to
\infty).
An earlier paper by the first three authors [J. Combin. Des. 3 (1995),
269-284] gave new methods for constructing good coverings, and gave tables of
upper bounds on C(v,k,t) for small v, k, and t. The present paper shows that
two of those constructions are asymptotically optimal: For fixed k and t, the
size of the coverings constructed matches R\"odl's bound. The paper also makes
the o(1) error bound explicit, and gives some evidence for a much stronger
bound
The SHOC2 phosphatase complex as a therapeutic target for ERK pathway inhibition in RAS-driven tumors
Targeted inhibition of the ERK-MAPK pathway, upregulated in the majority of human cancers, has been hindered in the clinic by drug resistance and on-target toxicity. The MRAS-SHOC2-PP1 complex plays a key, but underexplored role in RAF-ERK pathway activation, by dephosphorylating a critical inhibitory site on RAF-kinases. In this body of work we present a preferential requirement for the SHOC2-phosphatase complex, specifically for Receptor Tyrosine Kinase (RTK), and anchorage-independent (tumorigenic) growth stimulated ERK-activation. We highlight that this context-dependent signalling bias has functional consequences in RAS-mutant cells, by specifically inhibiting anchorage-independent, but not 2D-adhered cell growth. Strikingly we show in vivo that SHOC2 deletion suppresses tumour initiation in KRAS-driven lung cancer models, and significantly extends overall survival. Additionally, SHOC2 inhibition selectively sensitizes KRAS- and EGFR-mutant Non-small cell lung carcinoma (NSCLC) cells to MEK inhibitors. Mechanistically we show this is because SHOC2 is required for feedback-induced RAF dimerization, and as such combined MEK inhibition and SHOC2 suppression leads to more potent and sustained ERK-pathway repression, driving a BIM-dependent apoptosis. Crucially, systemic SHOC2 ablation in adult mice is relatively well tolerated compared with other, core, ERK-pathway signalling nodes. These results present a rationale for the generation of SHOC2 targeted therapies, both as a monotherapy, and to widen the therapeutic index of MEK inhibitors
Match loads of university rugby union players between the 2016 and 2018 Varsity Cup competitions
Background: Rugby union is a popular and continuously growing sport globally. With the advance of technology, practices have been implemented to quantify the match running demands of rugby union players. The aim of this study was to analyse the match loads of rugby union players between the 2016 and 2018 Varsity Cup competitions.
Methods: The sample consisted of 562 match observations of male university rugby union players competing in the Varsity Cup tournaments.
Results: The backline players ran significantly longer total distances (5105 m; p = 0.001; ES = 0.49); have greater high- speed running (496 m; p = 0.001; ES = 1.03), very high-speed running (260 m; p = 0.001; ES = 1.50) and sprint distances (117 m; p = 0.001; ES = 1.32) than forward players. Backline players also accumulated a high number of metres per minute (238 ± 94; p = 0.001; ES = 0.46), total Player Load (488 ± 203; p = 0.001; ES = 0.31), RHIE (9 ± 8; p = 0.001; ES = 0.75) and number of accelerations (4 ± 5; p = 0.001; ES = 0.49).
Conclusion: These findings may assist coaches to develop player position specific training programmes to meet the physical demands of rugby.
Keywords: rugby union, match loads, physical demands, positio
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