633 research outputs found
On the Chopping Block: Examining the Fairness of Observational Data of Teacher Effectiveness
Since the No Child Left Behind legislation, the assessment of teacher effectiveness (TE) for accountability purposes has been at the forefront of educational policy. Prominent among both already-existing and newly developed measures is the Classroom Assessment Scoring System (CLASS; Pianta, La Paro, & Hamre, 2008). The CLASS is used currently in over 40 states across the country (Teachstone, 2013; Office of Head Start, 2014) to make high-stakes decisions for teachers, including compensation, promotion, and termination. For this reason, it is important that measures like the CLASS are evaluated by research. Our research hypothesizes that if measures like the CLASS can be reliably used for high-stakes outcomes, then scores for individual teachers should remain stable over time, and particularly so within units of thematically related lessons. We used a single-subject design, reflective of the real-world uses of TE scores, to assess score stability for two kindergarten teachers purposively selected from a larger database. Stability ranges were created around mean scores and then visually examined. Significant variability was found between lessons for both teachers, particularly in the instructional support domain of the CLASS. We conclude that single observations are likely not sufficient to reliably evaluate teachers’ instructional effectiveness. Further research should investigate: (1) if similar variability is found with a larger number of teachers when observed for longer periods of time; (2) if this instability is found when using other TE measures; (3) the factors that contribute to observed instability; and (4) the number of teacher observations needed to obtain accurate views of teachers’ effectiveness patterns
Combined QM/MM Study of Thyroid and Steroid Hormone Analogue Interactions with αvβ3 Integrin
Recent biochemical studies have identified a cell surface receptor for thyroid and steroid hormones that bind near the arginine-glycine-aspartate (RGD) recognition site on the heterodimeric αvβ3 integrin. To further characterize the intermolecular interactions for a series of hormone analogues, combined quantum mechanical and molecular mechanical (QM/MM) methods were used to calculate their interaction energies. All calculations were performed in the presence of either calcium (Ca2+) or magnesium (Mg2+) ions. These data reveal that 3,5′-triiodothyronine (T3) and 3,5,3′,5′-tetraiodothyroacetic acid (T4ac) bound in two different modes, occupying two alternate sites, one of which is along the Arg side chain of the RGD cyclic peptide site. These orientations differ from those of the other ligands whose alternate binding modes placed the ligands deeper within the RGD binding pocket. These observations are consistent with biological data that indicate the presence of two discrete binding sites that control distinct downstream signal transduction pathways for T3
Validity of the Bottle Buoyancy Model for Body Fat Determination
International Journal of Exercise Science 10(1): 87-96, 2017. We investigated a modification of the bottle buoyancy (BB) method in comparison to single frequency, bioelectric impedance analysis (BIA) as a valid noninvasive method of percent body fat (%BF) determination. Twenty-eight participants (15 men, 13 women), in counterbalanced-order, completed the BB, BIA, and computerized hydrostatic densitometry (HD) methods. We elected to modify the BB method using a 12.15 L container with participants hugging the container in an upright position. Consistency measures of intraclass correlation coefficient (ICC), typical error (TE), coefficient of variation (CV) and total error of measurement (TEM) are reported. Our modification of the BB resulted in less “bobbing” than described in the previous method, and took ~5 to 15 min per participant to complete. Group values (%BF) did not differ (p \u3e 0.05) for BB (20.7 ± 6.6), BIA (21.0 ± 9.7), and HD (20.2 ± 7.2). Strong measurement agreement was observed between BB and HD (ICC: 0.95, TE: 1.80 %BF, CV: 10.7%, TEM: 1.77 %BF). Agreement between BIA and HD (ICC: 0.85, TE: 3.35 %BF, CV: 19.6%, TEM: 3.29 %BF) was lower than BB. Our modification of the BB method resulted in similar measurement consistency with the originating method. The BB method appears to represent a valid surrogate measure of %BF, superior to that observed with BIA
Hit and run versus long-term activation of PARP-1 by its different domains fine-tunes nuclear processes.
Poly(ADP-ribose) polymerase 1 (PARP-1) is a multidomain multifunctional nuclear enzyme involved in the regulation of the chromatin structure and transcription. PARP-1 consists of three functional domains: the N-terminal DNA-binding domain (DBD) containing three zinc fingers, the automodification domain (A), and the C-terminal domain, which includes the protein interacting WGR domain (W) and the catalytic (Cat) subdomain responsible for the poly(ADP ribosyl)ating reaction. The mechanisms coordinating the functions of these domains and determining the positioning of PARP-1 in chromatin remain unknown. Using multiple deletional isoforms of PARP-1, lacking one or another of its three domains, as well as consisting of only one of those domains, we demonstrate that different functions of PARP-1 are coordinated by interactions among these domains and their targets. Interaction between the DBD and damaged DNA leads to a short-term binding and activation of PARP-1. This hit and run activation of PARP-1 initiates the DNA repair pathway at a specific point. The long-term chromatin loosening required to sustain transcription takes place when the C-terminal domain of PARP-1 binds to chromatin by interacting with histone H4 in the nucleosome. This long-term activation of PARP-1 results in a continuous accumulation of pADPr, which maintains chromatin in the loosened state around a certain locus so that the transcription machinery has continuous access to DNA. Cooperation between the DBD and C-terminal domain occurs in response to heat shock (HS), allowing PARP-1 to scan chromatin for specific binding sites
Observation of Quantum Effects in sub Kelvin Cold Reactions
There has been a long-standing quest to observe chemical reactions at low
temperatures where reaction rates and pathways are governed by quantum
mechanical effects. So far this field of Quantum Chemistry has been dominated
by theory. The difficulty has been to realize in the laboratory low enough
collisional velocities between neutral reactants, so that the quantum wave
nature could be observed. We report here the first realization of merged
neutral supersonic beams, and the observation of clear quantum effects in the
resulting reactions. We observe orbiting resonances in the Penning ionization
reaction of argon and molecular hydrogen with metastable helium leading to a
sharp increase in the absolute reaction rate in the energy range corresponding
to a few degrees kelvin down to 10 mK. Our method is widely applicable to many
canonical chemical reactions, and will enable a breakthrough in the
experimental study of Quantum Chemistry
Diazoxide-responsive hyperinsulinemic hypoglycemia caused by HNF4A gene mutations
Objective: The phenotype associated with heterozygous HNF4A gene mutations has recently been extended to include diazoxide responsive neonatal hypoglycemia in addition to maturity-onset diabetes of the young (MODY). To date, mutation screening has been limited to patients with a family history consistent with MODY. In this study, we investigated the prevalence of HNF4A mutations in a large cohort of patients with diazoxide responsive hyperinsulinemic hypoglycemia (HH).
Subjects and methods: We sequenced the ABCC8, KCNJ11, GCK, GLUD1, and/or HNF4A genes in 220 patients with HH responsive to diazoxide. The order of genetic testing was dependent upon the clinical phenotype.
Results: A genetic diagnosis was possible for 59/220 (27%) patients. KATP channel mutations were most common (15%) followed by GLUD1 mutations causing hyperinsulinism with hyperammonemia (5.9%), and HNF4A mutations (5%). Seven of the 11 probands with a heterozygous HNF4A mutation did not have a parent affected with diabetes, and four de novo mutations were confirmed. These patients were diagnosed with HI within the first week of life (median age 1 day), and they had increased birth weight (median +2.4 SDS). The duration of diazoxide treatment ranged from 3 months to ongoing at 8 years.
Conclusions: In this large series, HNF4A mutations are the third most common cause of diazoxide responsive HH. We recommend that HNF4A sequencing is considered in all patients with diazoxide responsive HH diagnosed in the first week of life irrespective of a family history of diabetes, once KATP channel mutations have been excluded
Utilizing Weightlifting for Cycling Performance
Abstract available in the 9th Annual Coaches and Sport Science College
- …