2,061 research outputs found
No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses
Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed
Retrospective Analysis of Monkeypox Infection
Tests have been developed and optimized for serologic differentiation between monkeypox- and vaccinia-induced immunity
Impaired regeneration in LGMD2A supported by increased Pax7 positive satellite cell content and muscle specific microRNA dysregulation
Introduction—Recent in vitro studies suggest that CAPN3 deficiency leads initially to accelerated myofiber formation followed by depletion of satellite cells (SC). In normal muscle, upregulation of miR-1 and miR-206 facilitates transition from proliferating SCs to differentiating myogenic progenitors.
Methods—We examined the histopathological stages, Pax7 SC content, and muscle specific microRNA expression in biopsy specimens from well-characterized LGMD 2A patients to gain insight into disease pathogenesis.
Results—Three distinct stages of pathological changes were identified that represented the continuum of the dystrophic process from prominent inflammation with necrosis and regeneration to prominent fibrosis, which correlated with age and disease duration. Pax7-positive SCs were highest in fibrotic group and correlated with down-regulation of miR-1, miR-133a, and miR-206.
Conclusions—These observations, and other published reports, are consistent with microRNA dysregulation leading to inability of Pax7-positive SCs to transit from proliferation to differentiation. This results in impaired regeneration and fibrosis.This work was supported by NIH NIAMS U54 AR050733-05, Jesse’s Journey, and the muscular Dystrophy Associatio
Validation of a risk prediction model for Barrett’s esophagus in an Australian population
Creative Commons License: This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Background: Esophageal adenocarcinoma is a disease that has a high mortality rate, the only known precursor being Barrett’s esophagus (BE). While screening for BE is not cost-effective at the population level, targeted screening might be beneficial. We have developed a risk prediction model to identify people with BE, and here we present the external validation of this model.
Materials and methods: A cohort study was undertaken to validate a risk prediction model for BE. Individuals with endoscopy and histopathology proven BE completed a questionnaire containing variables previously identified as risk factors for this condition. Their responses were combined with data from a population sample for analysis. Risk scores were derived for each participant. Overall performance of the risk prediction model in terms of calibration and discrimination was assessed.
Results: Scores from 95 individuals with BE and 636 individuals from the general population were analyzed. The Brier score was 0.118, suggesting reasonable overall performance. The area under the receiver operating characteristic was 0.83 (95% CI 0.78–0.87). The Hosmer–Lemeshow statistic was p=0.14. Minimizing false positives and false negatives, the model achieved a sensitivity of 74% and a specificity of 73%.
Conclusion: This study has validated a risk prediction model for BE that has a higher sensitivity than previous models
Fertility, Living Arrangements, Care and Mobility
There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century – demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed
A survey of the high order multiplicity of nearby solar-type binary stars with Robo-AO
We conducted a survey of nearby binary systems composed of main sequence
stars of spectral types F and G in order to improve our understanding of the
hierarchical nature of multiple star systems. Using Robo-AO, the first robotic
adaptive optics instrument, we collected high angular resolution images with
deep and well-defined detection limits in the SDSS band. A total of 695
components belonging to 595 systems were observed. We prioritized observations
of faint secondary components with separations over to quantify the
still poorly constrained frequency of their sub-systems. Of the 214 secondaries
observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO.
The selection-corrected frequency of secondary sub-systems with periods from
to days is 0.120.03, the same as the frequency of such
companions to the primary. Half of the secondary pairs belong to quadruple
systems where the primary is also a close pair, showing that the presence of
sub-systems in both components of the outer binary is correlated. The
relatively large abundance of 2+2 quadruple systems is a new finding, and will
require more exploration of the formation mechanism of multiple star systems.
We also targeted close binaries with periods less than 100~yr, searching for
their distant tertiary components, and discovered 17 certain and 2 potential
new triples. In a sub-sample of 241 close binaries, 71 have additional outer
companions. The overall frequency of tertiary components is not enhanced,
compared to all (non-binary) targets, but in the range of outer periods from
to days (separations on the order of 500~AU), the frequency
of tertiary components is 0.160.03, exceeding by almost a factor of two
the frequency of similar systems among all targets (0.09)
First discoveries of z similar to 6 quasars with the Kilo-Degree Survey and VISTA Kilo-Degree Infrared Galaxy survey
This work is financially supported by the Netherlands Research School for Astronomy (NOVA) and Target. Target is supported by Samenwerkingsverband Noord Nederland, European fund for regional development, Dutch Ministry of economic affairs, Pieken in de Delta, Provinces of Groningen and Drenthe
Phase Ib study of CP-868,596, a PDGFR inhibitor, combined with docetaxel with or without axitinib, a VEGFR inhibitor
BACKGROUND: Tumoural interstitial hypertension, possibly modulated by platelet-derived and vascular endothelial growth factor receptors (PDGFR and VEGFR), may mediate resistance to chemotherapy. METHODS: Forty-eight patients with advanced solid tumours received oral PDGFR inhibitor CP-868,596 (60-100 mg twice daily (BID)) and docetaxel (75-100 mg m⁻²), or CP-868,596 (60 mg BID), docetaxel (75 mg m⁻²), and VEGFR inhibitor axitinib (5 mg BID). RESULTS: The CP-868,596/docetaxel was escalated as above. The CP-868,596/docetaxel/axitinib was not dose escalated because of increased incidence of mucositis-like adverse events (AEs) with concurrent neutropenia relative to that expected for docetaxel. All tested regimens were tolerable, including 100 mg BID CP-868,596 (recommended phase II dose) plus 100 mg m⁻² docetaxel (maximum approved dose). Most treatment-emergent AEs were mild-moderate and reversible, commonly including nausea, diarrhoea, vomiting, constipation, fatigue, and anaemia (CP-868,596/docetaxel), and hypertension, lethargy, diarrhoea, and fatigue (CP-868,596/docetaxel/axitnib). Pharmacokinetics were unaffected by co-administration. Twenty-one patients achieved stable disease, including all seven evaluable on CP-868,596/docetaxel/axitinib. All nine CP-868,596/docetaxel/axitinib patients received therapy for a median of six (range, 3-16) cycles. CONCLUSIONS: The CP-868,596/docetaxel was well tolerated, but increased efficacy was not observed. Addition of axitinib delivered greater benefits than expected in the number of patients achieving prolonged stable disease with a moderate increase in AEs
An instrument to determine the technological literacy levels of upper secondary school students
In this article, an instrument for assessing upper secondary school students’
levels of technological literacy is presented. The items making up the instrument emerged
from a previous study that employed a phenomenographic research approach to explore
students’ conceptions of technology in terms of their understanding of the nature of
technology and their interaction with technological artefacts. The instrument was validated
through administration to 1,245 students on completion of their 12 years of formal
schooling. A factor analysis was conducted on the data and Cronbach alpha reliability coefficients
determined. The results show that a five-dimension factor structure (namely,
artefact, process, direction/instruction, tinkering, and engagement) strongly supported the
dimensions as developed during the original phenomenographic study. The Cronbach
alpha reliability co-efficient of each dimension was satisfactory. Based on these findings,
the instrument has been shown to be valid and reliable and can be used with confidence
A review of the opportunities and challenges for using remote sensing for management of surface-canopy forming kelps
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cavanaugh, K. C., Bell, T., Costa, M., Eddy, N. E., Gendall, L., Gleason, M. G., Hessing-Lewis, M., Martone, R., McPherson, M., Pontier, O., Reshitnyk, L., Beas-Luna, R., Carr, M., Caselle, J. E., Cavanaugh, K. C., Miller, R. F., Hamilton, S., Heady, W. N., Hirsh, H. K., Hohman R., Lee L. C., Lorda J., Ray J., Reed D. C., Saccomanno V. R., Schroeder, S. B. A review of the opportunities and challenges for using remote sensing for management of surface-canopy forming kelps. Frontiers in Marine Science, 8, (2021): 753531, https://doi.org/10.3389/fmars.2021.753531.Surface-canopy forming kelps provide the foundation for ecosystems that are ecologically, culturally, and economically important. However, these kelp forests are naturally dynamic systems that are also threatened by a range of global and local pressures. As a result, there is a need for tools that enable managers to reliably track changes in their distribution, abundance, and health in a timely manner. Remote sensing data availability has increased dramatically in recent years and this data represents a valuable tool for monitoring surface-canopy forming kelps. However, the choice of remote sensing data and analytic approach must be properly matched to management objectives and tailored to the physical and biological characteristics of the region of interest. This review identifies remote sensing datasets and analyses best suited to address different management needs and environmental settings using case studies from the west coast of North America. We highlight the importance of integrating different datasets and approaches to facilitate comparisons across regions and promote coordination of management strategies.Funding was provided by the Nature Conservancy (Grant No. 02042019-5719), the U.S. National Science Foundation (Grant No. OCE 1831937), and the U.S. Department of Energy ARPA-E (Grant No. DE-AR0000922)
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