601 research outputs found
An economic valuation of improved water quality in Opequon watershed
The Opequon watershed is in northern Virginia and the eastern panhandle of West Virginia. In both states, Opequon Creek is classified as impaired due to violation of the bacteria standard and the narrative General Standard. Both states are using Total Maximum Daily Load (TMDL) plans to improve water quality. As part of the TMDL process, a contingent valuation survey was developed which would measure the benefits of improved water quality in Opequon watershed. Five thousand surveys were mailed to households in West Virginia and Virginia. Median willingness-to-pay (WTP) values were estimated from grouped tobit models. For in-state water quality improvements, Virginia households were found to have an annual WTP of {dollar}48 and West Virginia households were found to have an annual WTP of {dollar}32. For out-of-state clean-up, households in both states were found to have a one-time WTP of {dollar}18. Total benefits of improved water quality most likely range between {dollar}3.7 and {dollar}5.1 million
Exploring Extension Involvement in Farm to School Program Activities
The study reported here examined Extension professionals\u27 involvement in farm-to-school program activities. Results of an online survey distributed to eight state Extension systems indicate that on average, Extension professionals are involved with one farm to school program activity, with most supporting school or community garden programs. Results also indicate that Extension professionals are interested in being involved with an average of four farm to school program activities. Results demonstrate that each Extension program area is currently involved and is interested in supporting farm to school through a variety of different activities
Using Variable Interval Reinforcement Schedules to Support Students in the Classroom: An Introduction With Illustrative Examples
When behaviors are reinforced with a variable interval reinforcement schedule, reinforcement is available only after an unknown period of time. These types of reinforcement schedules are most useful for reinforcing slow and steady responding and for differentially reinforcing behaviors that are incompatible with some problematic behaviors. This review helps define variable interval reinforcement schedules, uses the example of a strategy to manage thumb-sucking behavior to illustrate the implementation of these schedules, and describes potential applications in school and clinical settings
The Role of Legal Services in the Antipoverty Program
Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages
The Human Connectome Project 7 Tesla retinotopy dataset: Description and population receptive field analysis
The Human Connectome Project 7 Tesla retinotopy dataset: Description and population receptive field analysis
Enhancing Accountability: ServSafe™ Impact Template Delivers
Generating statewide impact data from Extension programs can be challenging. To streamline reporting, Extension specialists, with the help of county agents and administrators, generated a statewide impact statement for the ServSafe™ program in Virginia. This template includes knowledge gain, behavior change, and economic impact from participants generated from current standardized evaluation methods used by all Extension educators across the state. Providing this template for agents resulted in easier, more consistent yearly reporting for those agents administering the program
Age-Related Changes in MicroRNA Expression and Pharmacogenes in Human Liver
Developmental changes in the liver can significantly impact drug disposition. Due to the emergence of microRNAs (miRNAs) as important regulators of drug disposition gene expression, we studied age-dependent changes in miRNA expression. Expression of 533 miRNAs was measured in 90 human liver tissues (fetal, pediatric [1-17 years], and adult [28-80 years]; n = 30 each). In all, 114 miRNAs were upregulated and 72 were downregulated from fetal to pediatric, and 2 and 3, respectively, from pediatric to adult. Among the developmentally changing miRNAs, 99 miRNA-mRNA interactions were predicted or experimentally validated (e.g., hsa-miR-125b-5p-CYP1A1; hsa-miR-34a-5p-HNF4A). In human liver samples (n = 10 each), analyzed by RNA-sequencing, significant negative correlations were observed between the expression of >1,000 miRNAs and mRNAs of drug disposition and regulatory genes. Our data suggest a mechanism for the marked changes in hepatic gene expression between the fetal and pediatric developmental periods, and support a role for these age-dependent miRNAs in regulating drug disposition
Time-resolved spectroscopy of multi-excitonic decay in an InAs quantum dot
The multi-excitonic decay process in a single InAs quantum dot is studied
through high-resolution time-resolved spectroscopy. A cascaded emission
sequence involving three spectral lines is seen that is described well over a
wide range of pump powers by a simple model. The measured biexcitonic decay
rate is about 1.5 times the single-exciton decay rate. This ratio suggests the
presence of selection rules, as well as a significant effect of the Coulomb
interaction on the biexcitonic wavefunction.Comment: one typo fixe
- …