194 research outputs found
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Sediment delivery to headwater stream channels following road construction and timber harvest in the Blue Mountains, Oregon
Many studies have focused on improving our understanding of the effects of timber harvesting activities on soil, water, and fisheries resources. Much of this work has led to the development and widespread use has often resulted in model applications that are outside the bounds in which the models were developed. There is currently no adequate method for predicting the quantity of sediment delivered to first and second order channels following road construction and harvesting in areas of ash-influenced soils in the Blue Mountains of eastern Oregon. The objectives of this study were: (1) to determine the amount and rate of sediment delivery to ephemeral (first and second order) stream channels following road construction and logging, and (2) to evaluate the WWSED sediment yield predictions. A variety of methods were employed to accomplish these objectives, including: in-channel and on-slope sediment trapping for quantity and rate determination, physical characterization of the area contributing flow and sediment, physical characterization of the soil samples themselves, and statistical analysis for extrapolation of results. No statistically significant relationships between the quantity of sediment yielded versus either inherent or management disturbance factors could be concluded from this data set. While there appears to be no significant relationship between inherent or management induced disturbance factors and sediment yield, there has been a two-fold increase in sediment yield when comparing 1993 to 1991 sediment yields, a ten-fold increase in sediment yield when comparing 1993 to 1992 sediment yields. The R-Squared values for 1993 sediment yield versus inherent values were considerably higher than 1991 or 1992 values. It can be concluded that while there was an increase in annual sediment yield in the Syrup Creek Study Area, there is no statistically significant relationship between this increase and inherent or management factors. This may be due, in part, to the limited data set with only three years of observations. It is likely that there are other inherent and management factors which would help explain the variation in sediment yields. Results indicate that the WWSED Model has drastically over estimated the sediment yield from this area. From this, we can conclude that the variability of natural systems is far more complex than can be simplified into a prediction model. Several additional years of measurement are necessary. The WWSED model predicts sediment yield for a seven year period. At a minimum, measurements should continue for an additional four years and preferably longer. In addition, it is recommended that a pumping sampler be installed at the mouth of the study area to quantify total suspended load yielding the watershed. This may assist additional years of sampling and provide a more robust data set in which to evaluate the WWSED model
Editorial Perspective: Speaking up for developmental language disorder - the top 10 priorities for research
Developmental language disorder (DLD) is one of the most common neurodevelopmental conditions, yet is chronically underserved, with far fewer children receiving clinical services than expected from prevalence estimates, and very little research attention relative to other neurodevelopmental conditions of similar prevalence and severity. This editorial describes a research priority-setting exercise undertaken by the Royal College of Speech and Language Therapists, which aims to redress this imbalance. From consultations with researchers, practitioners and individuals with lived experience, 10 research priorities emerge. Our goal is to share these priorities with the wider research community, to raise awareness and encourage research collaboration to improve outcomes for young people with DLD
Scattering of long wavelengths into thin silicon photovoltaic films by plasmonic silver nanoparticles
Nanoparticles and nanostructures with plasmonic resonances are currently being employed to enhance the efficiency of solar cells. Ag stripe arrays have been shown theoretically to enhance the short-circuit current of thin silicon layers. Monolayers of Ag nanoparticles with diameter d < 300 nm have shown strong plasmonic resonances when coated in thin polymer layers with thicknesses < d. We study experimentally the diffuse vs. specular scattering from monolayer arrays of Ag nanoparticles (spheres and prisms with diameters in the range 50 â 300 nm) coated onto the front side of thin (100 nm < t < 500 nm) silicon films deposited on glass and flexible polymer substrates, the latter originating in a roll-to-roll manufacturing process. Ag nanoparticles are held in place and aggregation is prevented with a polymer overcoat. We observe interesting wavelength shifts between maxima in specular and diffuse scattering that depend on particle size and shape, indicating that the nanoparticles substantially modify the scattering into the thin silicon film.United States. Air Force (United States. Army. Natick Soldier Research Development and Engineering Center Contract FA8721-05-C-0002)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract W911NF-07-D0004
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Diffusion kurtosis MRI as a predictive biomarker of response to neoadjuvant chemotherapy in high grade serous ovarian cancer
Abstract: This study assessed the feasibility of using diffusion kurtosis imaging (DKI) as a measure of tissue heterogeneity and proliferation to predict the response of high grade serous ovarian cancer (HGSOC) to neoadjuvant chemotherapy (NACT). Seventeen patients with HGSOC were imaged at 3 T and had biopsy samples taken prior to any treatment. The patients were divided into two groups: responders and non-responders based on Response Evaluation Criteria In Solid Tumours (RECIST) criteria. The following imaging metrics were calculated: apparent diffusion coefficient (ADC), apparent diffusion (Dapp) and apparent kurtosis (Kapp). Tumour cellularity and proliferation were quantified using histology and Ki-67 immunohistochemistry. Mean Kapp before therapy was higher in responders compared to non-responders: 0.69 ± 0.13 versus 0.51 ± 0.11 respectively, P = 0.02. Tumour cellularity correlated positively with Kapp (rho = 0.50, P = 0.04) and negatively with both ADC (rho = â0.72, P = 0.001) and Dapp (rho = â0.80, P < 0.001). Ki-67 expression correlated with Kapp (rho = 0.53, P = 0.03) but not with ADC or Dapp. In conclusion, Kapp was found to be a potential predictive biomarker of NACT response in HGSOC, which suggests that DKI is a promising clinical tool for use oncology and radiology that should be evaluated further in future larger studies
Vitamins and minerals for women: recent programs and intervention trials
Women's nutrition has received little attention in nutrition programming, even though clinical trials and intervention trials have suggested that dietary improvement or supplementation with several nutrients may improve their health, especially in low-income settings, the main focus of this paper. Most attention so far has focused on how improvements in maternal nutrition can improve health outcomes for infants and young children. Adequate vitamin D and calcium nutrition throughout life may reduce the risk of osteoporosis, and calcium supplementation during pregnancy may reduce preeclampsia and low birth weight. To reduce neural tube defects, additional folic acid and possibly vitamin B12 need to be provided to non-deficient women before they know they are pregnant. This is best achieved by fortifying a staple food. It is unclear whether maternal vitamin A supplementation will lead to improved health outcomes for mother or child. Iron, iodine and zinc supplementation are widely needed for deficient women. Multimicronutrient supplementation (MMS) in place of the more common iron-folate supplements given in pregnancy in low-income countries may slightly increase birth weight, but its impact on neonatal mortality and other outcomes is unclear. More sustainable alternative approaches deserve greater research attention
Polygamy slows down population divergence in shorebirds.
Sexual selection may act as a promotor of speciation since divergent mate choice and competition for mates can rapidly lead to reproductive isolation. Alternatively, sexual selection may also retard speciation since polygamous individuals can access additional mates by increased breeding dispersal. High breeding dispersal should hence increase gene flow and reduce diversification in polygamous species. Here we test how polygamy predicts diversification in shorebirds using genetic differentiation and subspecies richness as proxies for population divergence. Examining microsatellite data from 79 populations in ten plover species (Genus: Charadrius) we found that polygamous species display significantly less genetic structure and weaker isolation-by-distance effects than monogamous species. Consistent with this result, a comparative analysis including 136 shorebird species showed significantly fewer subspecies for polygamous than for monogamous species. By contrast, migratory behaviour neither predicted genetic differentiation nor subspecies richness. Taken together, our results suggest that dispersal associated with polygamy may facilitate gene flow and limit population divergence. Therefore, intense sexual selection, as occurs in polygamous species, may act as a brake rather than an engine of speciation in shorebirds. We discuss alternative explanations for these results and call for further studies to understand the relationships between sexual selection, dispersal and diversification. This article is protected by copyright. All rights reserved
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Near-Surface Engineered Environmental Barrier Integrity
The INEEL Environmental Systems Research and Analysis (ESRA) program has launched a new R&D project on Near-Surface Engineered Environmental Barrier Integrity to increase knowledge and capabilities for using engineering and ecological components to improve the integrity of near-surface barriers used to confine contaminants from the public and the environment. The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions and enable improved solutions for future cleanup decisions. The research is planned to (a) improve the knowledge of degradation mechanisms (weathering, biological, geological, chemical, radiological, and catastrophic) in times shorter than service life, (b) improve modeling of barrier degradation dynamics, (c) develop sensor systems to identify degradation prior to failure, and (d) provide a better basis for developing and testing of new barrier systems to increase reliability and reduce the risk of failure. Our project combines selected exploratory studies (benchtop and field scale), coupled effects accelerated aging testing and the meso-scale, testing of new monitoring concepts, and modeling of dynamic systems. The performance of evapo- transpiration, capillary, and grout-based barriers will be examined
Reimagining Development 3.0 for a Changing Planet
This working paper argues we need to reimagine development tactics to fashion Development 3.0, to match what business analysts now call World 3.0, a global system characterized by high turbulence and new threats. It begins by contrasting our former classification of countries spatially into First, Second and Third worlds with a new division of development epochs in sequence since the end of World War II. World 1.0 emphasized industrialization, urbanization, and modernization, lasting from 1945 to 1980. World 2.0 emphasized global trade, and a shift to private actors doing the work of development, from 1980 to the early 2000s. World 3.0 can be seen as superceding globalization by concern with emergent threats. World 1.0 privileged state actions to accelerate ânation buildingâ within former colonies, whereas World 2.0 privileged private capital and free trade as engines for economic growth. Now, following wars, disasters, and the near meltdown of the global financial system in 2007/08, we enter World 3.0 as depicted by Ghemawat and others.
We review thirteen major changes not recognized within World 2.0 or its accompanying Development 2.0 regime. The major changes include the rise of homeless capital, the Conservative counter-revolution of the 1980s, the implosion of the USSR, rise of modern China, emergence of BRIC nations, a pan-urban world, rise of identity politics, reemergence of Africa, shift to non-state warfare, growing threat of climate change, MENA nations experience Arab Spring, digital worlds expand, and velocity increases. They suggest coming turbulence and unexpected outcomes, or âmashupsâ (Ramo).
These changes suggest a different emergent system, becoming World 3.0 which has profound differences from how we view our planetâs political economy (World 2.0).
If so, the paper outlines implications which suggest the time has come to âtake on boardâ our changed planetary circumstances, and thus begin crafting Development 3.0.
âWhere the wild things areâ, introduces metaphors to change the âmeta-narrativesâ used for viewing World 3.0: âherding elephants,â âtaming feral capitalâ, âswimming with tidesâ and âavoiding mashupsâ. They help us realize that long recognized problems (or âelephantsâ) may show unexpected behaviors to pose new threats within World 3.0.
The main argument of the paper then lays out a bakerâs dozen changes needed if we hope to fashion more effective ways to promote development for us all. We must ârebalance societyâ (ala Mintzberg), refashion aid, privilege sustainability, emphasize fair trade, tame feral capital, devise better metrics, include all nations & peoples, seat G-20 not G-8, recognize semi-sovereigns, focus on a pan-urban world, build coalitions in networks, involve women & youth, and rebuild community leadership. All of which assumes we can offset a strong tide towards return to the excesses of World 2.0
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Sodium MRI with 3D-cones as a measure of tumour cellularity in high grade serous ovarian cancer.
The aim of this study was to assess the feasibility of rapid sodium MRI (23Na-MRI) for the imaging of peritoneal cancer deposits in high grade serous ovarian cancer (HGSOC) and to evaluate the relationship of 23Na-MRI with tumour cellularity. 23Na-MRI was performed at 3âT on twelve HGSOC patients using a 3D-cones acquisition technique. Tumour biopsies specimens were collected after imaging and cellularity was measured from histology. Total 23Na-MRI scan time for each patient was approximately 11âmin. At an isotropic resolution of 5.6âmm, signal-to-noise ratios (SNRs) of 82.2 ± 15.3 and 15.1 ± 7.1 (meanâ±âstandard deviation) were achieved for imaging of tumour tissue sodium concentration (TSC) and intracellular weighted sodium concentration (IWS) respectively. Tumour TSC and IWS concentrations were: 56.8â±â19.1âmM and 30.8â±â9.2âmM respectively and skeletal muscle TSC and IWS concentrations were 33.2â±â16.3âmM and 20.5â±â9.9âmM respectively. There were significant sodium concentration differences between cancer and skeletal muscle, Wilcoxon signed-rank test, Pâ<â 0.001 for TSC and Pâ=â 0.01 for IWS imaging. Tumour cellularity displayed a strong negative correlation with TSC, Spearman's rho = -0.92, Pâ<â 0.001, but did not correlate with IWS. This study demonstrates that 23Na-MRI using 3D-cones can rapidly assess sodium concentration in peritoneal deposits of HGSOC and that TSC may serve as a biomarker of tumour cellularity.CRU
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