654 research outputs found
Beyond Finger-Pointing and Test Scores
This report examines high-stakes interventions in low-performing schools in six cities in Cross City Campaign's network
Recommended from our members
The Impact of Including Teacher and School Characteristics on Predicting Value-Added Score Estimates
Value-added models (VAMs) have become widely used in evaluating teacher accountability. The use of these models for high-stakes decisions making has been very controversial due to lack of consistency in classifying teachers as high performing or low performing. There is an abundance of research on the impact of various student level covariates on teacher value-added scores; however, less is known about the impact of teacher-level and school-level covariates. This study uses hierarchical linear modeling to examine the impact of including teacher characteristics, school characteristics, and student demographics aggregated at the school level on elementary mathematics and reading teacher value-added scores. Data for this study was collected from a large school district in north Texas. This study found that across all VAMs fitted, 32% of mathematics teachers and 37% of reading teachers changed quintile ranking for their value-added score at least once across all VAMs, while 55% and 65% of schools changed their quintile ranking of value-added scores based on mathematics and reading achievement, respectively. The results show that failing to control for aggregated student demographics has a large impact on both teacher level and school level value-added scores. Policymakers and administrators using VAM estimates in high-stakes decision-making should include teacher- and school-level covariates in their VAMs
Blending and Spending: Financial Influences Impacting Childfree Stepmothersā Relationship Satisfaction
There exists a need to better understand how monetary factors impact the partnerships of childfree stepmothers in blended families. The present study examines the correlation of couplesā shared financial values and congruence in financial management behaviors with relationship satisfaction among these stepmothers. Participants included 104 childfree stepmothers in blended families. Findings indicated that perceived shared financial values positively predicted relationship satisfaction. In addition, while financial behavior congruence between stepmothers and their partners did predict relationship satisfaction, it did so through a weaker inverse association. Contrary to expectations, financial behavior congruence did not mediate the association between shared financial values and relationship satisfaction. These results reflect the complex role of financial factors in the well-being of childfree stepmothers within blended families and the need for nuanced psychological and financial support tailored to this oft-overlooked group of women
For common community phylogenetic analyses, go ahead and use synthesis phylogenies
Should we build our own phylogenetic trees based on gene sequence data, or can we simply use available synthesis phylogenies? This is a fundamental question that any study involving a phylogenetic framework must face at the beginning of the project. Building a phylogeny from gene sequence data (purposeābuilt phylogeny) requires more effort, expertise, and cost than subsetting an already available phylogeny (synthesisābased phylogeny). However, we still lack a comparison of how these two approaches to building phylogenetic trees influence common community phylogenetic analyses such as comparing community phylogenetic diversity and estimating trait phylogenetic signal. Here, we generated three purposeābuilt phylogenies and their corresponding synthesisābased trees (two from Phylomatic and one from the Open Tree of Life, OTL). We simulated 1,000 communities and 12,000 continuous traits along each purposeābuilt phylogeny. We then compared the effects of different trees on estimates of phylogenetic diversity (alpha and beta) and phylogenetic signal (Pagelās Ī» and Blombergās K). Synthesisābased phylogenies generally yielded higher estimates of phylogenetic diversity when compared to purposeābuilt phylogenies. However, resulting measures of phylogenetic diversity from both types of phylogenies were highly correlated (Spearmanās ĻĀ >Ā 0.8 in most cases). Mean pairwise distance (both alpha and beta) is the index that is most robust to the differences in tree construction that we tested. Measures of phylogenetic diversity based on the OTL showed the highest correlation with measures based on the purposeābuilt phylogenies. Trait phylogenetic signal estimated with synthesisābased phylogenies, especially from the OTL, was also highly correlated with estimates of Blombergās K or close to Pagelās Ī» from purposeābuilt phylogenies when traits were simulated under Brownian motion. For commonly employed community phylogenetic analyses, our results justify taking advantage of recently developed and continuously improving synthesis trees, especially the Open Tree of Life.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151322/1/ecy2788_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151322/2/ecy2788.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151322/3/ecy2788-sup-0001-AppendixS1.pd
Macrosystems ecology: Understanding ecological patterns and processes at continental scales
Macrosystems ecology is the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales. This emerging subdiscipline addresses ecological questions and environmental problems at these broad scales. Here, we describe this new field, show how it relates to modern ecological study, and highlight opportunities that stem from taking a macrosystems perspective. We present a hierarchical framework for investigating macrosystems at any level of ecological organization and in relation to broader and finer scales. Building on well-established theory and concepts from other subdisciplines of ecology, we identify feedbacks, linkages among distant regions, and interactions that cross scales of space and time as the most likely sources of unexpected and novel behaviors in macrosystems. We present three examples that highlight the importance of this multiscaled systems perspective for understanding the ecology of regions to continents
Parallel-plate Flow Chamber and Continuous Flow Circuit to Evaluate Endothelial Progenitor Cells under Laminar Flow Shear Stress
The overall goal of this method is to describe a technique to subject adherent cells to laminar flow conditions and evaluate their response to well quantifiable fluid shear stresses1.
Our flow chamber design and flow circuit (Fig. 1) contains a transparent viewing region that enables testing of cell adhesion and imaging of cell morphology immediately before flow (Fig. 11A, B), at various time points during flow (Fig. 11C), and after flow (Fig. 11D). These experiments are illustrated with human umbilical cord blood-derived endothelial progenitor cells (EPCs) and porcine EPCs2,3.
This method is also applicable to other adherent cell types, e.g. smooth muscle cells (SMCs) or fibroblasts.
The chamber and all parts of the circuit are easily sterilized with steam autoclaving In contrast to other chambers, e.g. microfluidic chambers, large numbers of cells (> 1 million depending on cell size) can be recovered after the flow experiment under sterile conditions for cell culture or other experiments, e.g. DNA or RNA extraction, or immunohistochemistry (Fig. 11E), or scanning electron microscopy5. The shear stress can be adjusted by varying the flow rate of the perfusate, the fluid viscosity, or the channel height and width. The latter can reduce fluid volume or cell needs while ensuring that one-dimensional flow is maintained. It is not necessary to measure chamber height between experiments, since the chamber height does not depend on the use of gaskets, which greatly increases the ease of multiple experiments. Furthermore, the circuit design easily enables the collection of perfusate samples for analysis and/or quantification of metabolites secreted by cells under fluid shear stress exposure, e.g. nitric oxide (Fig. 12)6
Recommended from our members
Species and Population Specific Gene Expression in Blood Transcriptomes of Marine Turtles
Background: Transcriptomic data has demonstrated utility to advance the study of physiological diversity and organisms\u27 responses to environmental stressors. However, a lack of genomic resources and challenges associated with collecting high-quality RNA can limit its application for many wild populations. Minimally invasive blood sampling combined with de novo transcriptomic approaches has great potential to alleviate these barriers. Here, we advance these goals for marine turtles by generating high quality de novo blood transcriptome assemblies to characterize functional diversity and compare global transcriptional profiles between tissues, species, and foraging aggregations.ResultsWe generated high quality blood transcriptome assemblies for hawksbill (Eretmochelys imbricata), loggerhead (Caretta caretta), green (Chelonia mydas), and leatherback (Dermochelys coriacea) turtles. The functional diversity in assembled blood transcriptomes was comparable to those from more traditionally sampled tissues. A total of 31.3% of orthogroups identified were present in all four species, representing a core set of conserved genes expressed in blood and shared across marine turtle species. We observed strong species-specific expression of these genes, as well as distinct transcriptomic profiles between green turtle foraging aggregations that inhabit areas of greater or lesser anthropogenic disturbance.ConclusionsObtaining global gene expression data through non-lethal, minimally invasive sampling can greatly expand the applications of RNA-sequencing in protected long-lived species such as marine turtles. The distinct differences in gene expression signatures between species and foraging aggregations provide insight into the functional genomics underlying the diversity in this ancient vertebrate lineage. The transcriptomic resources generated here can be used in further studies examining the evolutionary ecology and anthropogenic impacts on marine turtles
Recommended from our members
Checkpoint inhibition of origin firing prevents DNA topological stress.
A universal feature of DNA damage and replication stress in eukaryotes is the activation of a checkpoint-kinase response. In S-phase, the checkpoint inhibits replication initiation, yet the function of this global block to origin firing remains unknown. To establish the physiological roles of this arm of the checkpoint, we analyzed separation of function mutants in the budding yeast Saccharomyces cerevisiae that allow global origin firing upon replication stress, despite an otherwise normal checkpoint response. Using genetic screens, we show that lack of the checkpoint-block to origin firing results in a dependence on pathways required for the resolution of topological problems. Failure to inhibit replication initiation indeed causes increased DNA catenation, resulting in DNA damage and chromosome loss. We further show that such topological stress is not only a consequence of a failed checkpoint response but also occurs in an unperturbed S-phase when too many origins fire simultaneously. Together we reveal that the role of limiting the number of replication initiation events is to prevent DNA topological problems, which may be relevant for the treatment of cancer with both topoisomerase and checkpoint inhibitors
- ā¦