287 research outputs found
Trees on K-12 School Campuses in Virginia
Trees and saplings growing on K-12 school campuses were investigated in 105 school districts across Virginia. There were 2812 trees (\u3e12.5 cm stem diameter at 1.4 m above ground level) inventoried across all campuses. The mean and median campus tree population was 27 and 18, respectively. Loblolly pine (Pinus taeda L.) was the most abundant species, accounting for 11% of all inventoried trees. Red maple (Acer rubrum L.) was the most frequently inventoried species, present on 44% of the campuses. Sapling (trees with 2.5-12.5 cm stem diameter at 1.4 m above ground level) populations were similar to tree populations. The mean and median campus sapling population was 23 and 13, respectively. Flowering dogwood (Cornus florida L.) and red maple were the most abundant sapling species, each accounting for about 10% of all inventoried saplings. Flowering dogwood, red maple, Bradford pear (Pyrus calleryana Decne. ‘Bradford’), willow oak (Quercus phellos L. ), and ornamental cherry (Prunus spp. ) were the most frequently inventoried sapling species, each present on more than 25% of the campuses. Across all campuses, species diversity was relatively low: less than 10 species accounted for over 50% of the inventoried trees and saplings. Prominent Virginia natives, in particular Carya and Quercus species, were under represented in the inventory
Using Online Digital Tools and Video to Support International Problem-Based Learning
The goal of this study is to examine how to facilitate cross-cultural groups in problem-based learning (PBL) using online digital tools and videos. The PBL consisted of two video-based cases used to trigger student-learning issues about giving bad news to HIV-positive patients. Mixed groups of medical students from Canada and Hong Kong worked with facilitators from each country along with an expert facilitator. The study used AdobeConnect to support the international model through synchronous video interaction and shared applications. This study examines strategies and challenges in facilitating PBL across distance and cultures. Discourse was analyzed using both an inductive and deductive approach where the later used the Community of Inquiry coding scheme. The international context provides a way to facilitate multiple perspectives about how to communicate bad news to patients from different cultural backgrounds. In addition, we present the results of an exploratory analysis of pre and post tests using a standardized patient that demonstrate that the students’ pattern of communication showed qualitative change. Several conjectures were developed for future research
An initial event in insect innate immune response: structural and biological studies of interactions between β-1,3-glucan and the N-terminal domain of β-1,3-glucan recognition protein
In response to invading microorganisms, insect β-1,3-glucan recognition protein (βGRP), a soluble receptor in the hemolymph, binds to the surfaces of bacteria and fungi and activates serine protease cascades that promote destruction of pathogens by means of melanization or expression of antimicrobial peptides. Here we report on the NMR solution structure of the N-terminal domain of βGRP (N-βGRP) from Indian meal moth (Plodia interpunctella), which is sufficient to activate the prophenoloxidase (proPO) pathway resulting in melanin formation. NMR and isothermal calorimetric titrations of N-βGRP with laminarihexaose, a glucose hexamer containing β-1,3 links, suggest a weak binding of the ligand. However, addition of laminarin, a glucose polysaccharide (~ 6 kDa) containing β-1,3 and β-1,6 links that activates the proPO pathway, to N-βGRP results in the loss of NMR cross-peaks from the backbone 15N-1H groups of the protein, suggesting the formation of a large complex. Analytical ultra centrifugation (AUC) studies of formation of N-βGRP:laminarin complex show that ligand-binding induces sel-fassociation of the protein:carbohydrate complex into a macro structure, likely containing six protein and three laminarin molecules (~ 102 kDa). The macro complex is quite stable, as it does not undergo dissociation upon dilution to sub-micromolar concentrations. The structural model thus derived from the present studies for N-βGRP:laminarin complex in solution differs from the one in which a single N-βGRP molecule has been proposed to bind to a triple helical form of laminarin on the basis of an X-ray crystallographic structure of N-βGRP:laminarihexaose complex [Kanagawa, M., Satoh, T., Ikeda, A., Adachi, Y., Ohno, N., and Yamaguchi, Y. (2011) J. Biol. Chem. 286, 29158-29165]. AUC studies and phenoloxidase activation measurements carried out with the designed mutants of N-βGRP indicate that electrostatic interactions involving Asp45, Arg54, and Asp68 between the ligand-bound protein molecules contribute in part to the stability of N-βGRP:laminarin macro complex and that a decreased stability is accompanied by a reduced activation of the proPO pathway. Increased β-1,6 branching in laminarin also results in destabilization of the macro complex. These novel findings suggest that ligand-induced self-association of βGRP:β-1,3-glucan complex may form a platform on a microbial surface for recruitment of downstream proteases, as a means of amplification of the initial signal of pathogen recognition for the activation of the proPO pathway
Helping the Working Poor: Employer- vs. Employee-Based Subsidies
In the United States and Europe there has been renewed interest in subsidizing firms that employ disadvantaged workers as a means of addressing poverty and other social problems. In contrast, the prevailing practice is largely to provide social welfare benefits directly to individuals. Which approach is better? We re-examine the relative merits of employee- versus employer-based labor market subsidies and conclude there are good reasons to continue to rely on the direct, employee-based approach. In practice, low-wage workers are seldom either low-skill or low-income workers. Furthermore, workers who might quality for a firm-based subsidy are reluctant to so identify themselves for fear of being stigmatized or labeled as needy. Thus, employer-based subsidy programs have lower participation rates and correspondingly higher per capita expenditures than employee-based subsidy programs
Contextual-value approach to the generalized measurement of observables
We present a detailed motivation for and definition of the contextual values
of an observable, which were introduced by Dressel et al. [Phys. Rev. Lett. 104
240401 (2010)]. The theory of contextual values extends the well-established
theory of generalized state measurements by bridging the gap between partial
state collapse and the observables that represent physically relevant
information about the system. To emphasize the general utility of the concept,
we first construct the full theory of contextual values within an operational
formulation of classical probability theory, paying special attention to
observable construction, detector coupling, generalized measurement, and
measurement disturbance. We then extend the results to quantum probability
theory built as a superstructure on the classical theory, pointing out both the
classical correspondences to and the full quantum generalizations of both
L\"uder's rule and the Aharonov-Bergmann-Lebowitz rule in the process. We find
in both cases that the contextual values of a system observable form a
generalized spectrum that is associated with the independent outcomes of a
partially correlated and generally ambiguous detector; the eigenvalues are a
special case when the detector is perfectly correlated and unambiguous. To
illustrate the approach, we apply the technique to both a classical example of
marble color detection and a quantum example of polarization detection. For the
quantum example we detail two devices: Fresnel reflection from a glass
coverslip, and continuous beam displacement from a calcite crystal. We also
analyze the three-box paradox to demonstrate that no negative probabilities are
necessary in its analysis. Finally, we provide a derivation of the quantum weak
value as a limit point of a pre- and postselected conditioned average and
provide sufficient conditions for the derivation to hold.Comment: 36 pages, 5 figures, published versio
High-intensity interval training, but not continuous training, reverses right ventricular hypertrophy and dysfunction in a rat model of pulmonary hypertension
Exercise is beneficial in pulmonary arterial hypertension (PAH), although studies to date indicate little effect on the elevated pulmonary pressures or maladaptive right ventricle (RV) hypertrophy associated with the disease. For chronic left ventricle failure, high-intensity interval training (HIIT) promotes greater endothelial stimulation and superior benefit than customary continuous exercise training (CExT); however, HIIT has not been tested for PAH. Therefore, here we investigated acute and chronic responses to HIIT vs. CExT in a rat model of monocrotaline (MCT)-induced mild PAH. Six weeks of treadmill training (5 times/wk) were performed, as either 30 min HIIT or 60 min low-intensity CExT. To characterize acute hemodynamic responses to the two approaches, novel recordings of simultaneous pulmonary and systemic pressures during running were obtained at pre- and 2, 4, 6, and 8 wk post-MCT using long-term implantable telemetry. MCT-induced decrement in maximal aerobic capacity was ameliorated by both HIIT and CExT, with less pronounced pulmonary vascular remodeling and no increase in RV inflammation or apoptosis observed. Most importantly, only HIIT lowered RV systolic pressure, RV hypertrophy, and total pulmonary resistance, and prompted higher cardiac index that was complemented by a RV increase in the positive inotrope apelin and reduced fibrosis. HIIT prompted a markedly pulsatile pulmonary pressure during running and was associated with greater lung endothelial nitric oxide synthase after 6 wk. We conclude that HIIT may be superior to CExT for improving hemodynamics and maladaptive RV hypertrophy in PAH. HIIT’s superior outcomes may be explained by more favorable pulmonary vascular endothelial adaptation to the pulsatile HIIT stimulus
A cellular trafficking signal in the SIV envelope protein cytoplasmic domain is strongly selected for in pathogenic infection
The HIV/SIV envelope glycoprotein (Env) cytoplasmic domain contains a highly conserved Tyr-based trafficking signal that mediates both clathrin-dependent endocytosis and polarized sorting. Despite extensive analysis, the role of these functions in viral infection and pathogenesis is unclear. An SIV molecular clone (SIVmac239) in which this signal is inactivated by deletion of Gly-720 and Tyr-721 (SIVmac239ΔGY), replicates acutely to high levels in pigtail macaques (PTM) but is rapidly controlled. However, we previously reported that rhesus macaques and PTM can progress to AIDS following SIVmac239ΔGY infection in association with novel amino acid changes in the Env cytoplasmic domain. These included an R722G flanking the ΔGY deletion and a nine nucleotide deletion encoding amino acids 734–736 (ΔQTH) that overlaps the rev and tat open reading frames. We show that molecular clones containing these mutations reconstitute signals for both endocytosis and polarized sorting. In one PTM, a novel genotype was selected that generated a new signal for polarized sorting but not endocytosis. This genotype, together with the ΔGY mutation, was conserved in association with high viral loads for several months when introduced into naïve PTMs. For the first time, our findings reveal strong selection pressure for Env endocytosis and particularly for polarized sorting during pathogenic SIV infection in vivo
American Head and Neck Society Endocrine Section clinical consensus statement: North American quality statements and evidence‐based multidisciplinary workflow algorithms for the evaluation and management of thyroid nodules
BackgroundCare for patients with thyroid nodules is complex and multidisciplinary, and research demonstrates variation in care. The objective was to develop clinical guidelines and quality metrics to reduce unwarranted variation and improve quality.MethodsMultidisciplinary expert consensus and modified Delphi approach. Source documents were workflow algorithms from Kaiser Permanente Northern California and Cancer Care of Ontario based on the 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer.ResultsA consensus‐based, unified preoperative, perioperative, and postoperative workflow was developed for North American use. Twenty‐one panelists achieved consensus on 16 statements about workflow‐embedded process and outcomes metrics addressing safety, access, appropriateness, efficiency, effectiveness, and patient centeredness of care.ConclusionA panel of Canadian and United States experts achieved consensus on workflows and quality metric statements to help reduce unwarranted variation in care, improving overall quality of care for patients diagnosed with thyroid nodules.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148340/1/hed25526_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148340/2/hed25526.pd
- …