100 research outputs found
Summer warming explains widespread but not uniform greening in the Arctic tundra biome
Arctic warming can influence tundra ecosystem function with consequences for climate feedbacks, wildlife and human communities. Yet ecological change across the Arctic tundra biome remains poorly quantified due to field measurement limitations and reliance on coarse-resolution satellite data. Here, we assess decadal changes in Arctic tundra greenness using time series from the 30 m resolution Landsat satellites. From 1985 to 2016 tundra greenness increased (greening) at ~37.3% of sampling sites and decreased (browning) at ~4.7% of sampling sites. Greening occurred most often at warm sampling sites with increased summer air temperature, soil temperature, and soil moisture, while browning occurred most often at cold sampling sites that cooled and dried. Tundra greenness was positively correlated with graminoid, shrub, and ecosystem productivity measured at field sites. Our results support the hypothesis that summer warming stimulated plant productivity across much, but not all, of the Arctic tundra biome during recent decades
Smoke and Mirrors: U.K. Newspaper Representations of Intimate Partner Domestic Violence
This is a pre-copyedited, author-produced pdf of an article accepted for publication in Violence Against Women following peer review. The final, definitive version of this paper has been published in Violence Against Women, Vol 23 (1): 114-139, first published April 2016 by SAGE Publishing, and is available on line at doi: 10.1177/1077801216634468. All rights reserved.News media are in a position to project certain perspectives on domestic violence while marginalizing others, which has implications for public understanding and policy development. This study applies discourse analysis to articles on domestic violence in two U.K. national daily newspapers published in 2001-2002 and 2011-2012 to evaluate evidence of change over a 10-year time span. The research examines how discourses of domestic violence are constructed through newspaper representations of victims, predominantly women, and perpetrators, predominantly men. Although one of the newspapers adopts a respectful position toward women, the textual and visual techniques adopted by the other reveal a tendency for blaming the victim and sexualizing violence related to perceptions of “deserving” or “undeserving” women victims.Peer reviewe
Global plant trait relationships extend to the climatic extremes of the tundra biome
The majority of variation in six traits critical to the growth, survival and reproduction of plant species is thought to be organised along just two dimensions, corresponding to strategies of plant size and resource acquisition. However, it is unknown whether global plant trait relationships extend to climatic extremes, and if these interspecific relationships are confounded by trait variation within species. We test whether trait relationships extend to the cold extremes of life on Earth using the largest database of tundra plant traits yet compiled. We show that tundra plants demonstrate remarkably similar resource economic traits, but not size traits, compared to global distributions, and exhibit the same two dimensions of trait variation. Three quarters of trait variation occurs among species, mirroring global estimates of interspecific trait variation. Plant trait relationships are thus generalizable to the edge of global trait-space, informing prediction of plant community change in a warming world.Peer reviewe
Traditional plant functional groups explain variation in economic but not size-related traits across the tundra biome
Aim Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits. Location Tundra biome. Time period Data collected between 1964 and 2016. Major taxa studied 295 tundra vascular plant species. Methods We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits. Results Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression. Main conclusions Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling.Peer reviewe
Do physician outcome judgments and judgment biases contribute to inappropriate use of treatments? Study protocol
<p>Abstract</p> <p>Background</p> <p>There are many examples of physicians using treatments inappropriately, despite clear evidence about the circumstances under which the benefits of such treatments outweigh their harms. When such over- or under- use of treatments occurs for common diseases, the burden to the healthcare system and risks to patients can be substantial. We propose that a major contributor to inappropriate treatment may be how clinicians judge the likelihood of important treatment outcomes, and how these judgments influence their treatment decisions. The current study will examine the role of judged outcome probabilities and other cognitive factors in the context of two clinical treatment decisions: 1) prescription of antibiotics for sore throat, where we hypothesize overestimation of benefit and underestimation of harm leads to over-prescription of antibiotics; and 2) initiation of anticoagulation for patients with atrial fibrillation (AF), where we hypothesize that underestimation of benefit and overestimation of harm leads to under-prescription of warfarin.</p> <p>Methods</p> <p>For each of the two conditions, we will administer surveys of two types (Type 1 and Type 2) to different samples of Canadian physicians. The primary goal of the Type 1 survey is to assess physicians' perceived outcome probabilities (both good and bad outcomes) for the target treatment. Type 1 surveys will assess judged outcome probabilities in the context of a representative patient, and include questions about how physicians currently treat such cases, the recollection of rare or vivid outcomes, as well as practice and demographic details. The primary goal of the Type 2 surveys is to measure the specific factors that drive individual clinical judgments and treatment decisions, using a 'clinical judgment analysis' or 'lens modeling' approach. This survey will manipulate eight clinical variables across a series of sixteen realistic case vignettes. Based on the survey responses, we will be able to identify which variables have the greatest effect on physician judgments, and whether judgments are affected by inappropriate cues or incorrect weighting of appropriate cues. We will send antibiotics surveys to family physicians (300 per survey), and warfarin surveys to both family physicians and internal medicine specialists (300 per group per survey), for a total of 1,800 physicians. Each Type 1 survey will be two to four pages in length and take about fifteen minutes to complete, while each Type 2 survey will be eight to ten pages in length and take about thirty minutes to complete.</p> <p>Discussion</p> <p>This work will provide insight into the extent to which clinicians' judgments about the likelihood of important treatment outcomes explain inappropriate treatment decisions. This work will also provide information necessary for the development of an individualized feedback tool designed to improve treatment decisions. The techniques developed here have the potential to be applicable to a wide range of clinical areas where inappropriate utilization stems from biased judgments.</p
Pan-cancer deconvolution of tumour composition using DNA methylation
The nature and extent of immune cell infiltration into solid tumours are key determinants of therapeutic response. Here, using a DNA methylation-based approach to tumour cell fraction deconvolution, we report the integrated analysis of tumour composition and genomics across a wide spectrum of solid cancers. Initially studying head and neck squamous cell carcinoma, we identify two distinct tumour subgroups: ‘immune hot’ and ‘immune cold’, which display differing prognosis, mutation burden, cytokine signalling, cytolytic activity and oncogenic driver events. We demonstrate the existence of such tumour subgroups pan-cancer, link clonal-neoantigen burden to cytotoxic T-lymphocyte infiltration, and show that transcriptional signatures of hot tumours are selectively engaged in immunotherapy responders. We also find that treatment-naive hot tumours are markedly enriched for known immune-resistance genomic alterations, potentially explaining the heterogeneity of immunotherapy response and prognosis seen within this group. Finally, we define a catalogue of mediators of active antitumour immunity, deriving candidate biomarkers and potential targets for precision immunotherapy
Tundra Trait Team: A database of plant traits spanning the tundra biome
Abstract
Motivation:
The Tundra Trait Team (TTT) database includes field-based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade-offs, trait–environment relationships and environmental filtering, and trait variation across spatial scales, to validate satellite data, and to inform Earth system model parameters.
Main types of variable contained:
The database contains 91,970 measurements of 18 plant traits. The most frequently measured traits (> 1,000 observations each) include plant height, leaf area, specific leaf area, leaf fresh and dry mass, leaf dry matter content, leaf nitrogen, carbon and phosphorus content, leaf C:N and N:P, seed mass, and stem specific density.
Spatial location and grain:
Measurements were collected in tundra habitats in both the Northern and Southern Hemispheres, including Arctic sites in Alaska, Canada, Greenland, Fennoscandia and Siberia, alpine sites in the European Alps, Colorado Rockies, Caucasus, Ural Mountains, Pyrenees, Australian Alps, and Central Otago Mountains (New Zealand), and sub-Antarctic Marion Island. More than 99% of observations are georeferenced.
Time period and grain:
All data were collected between 1964 and 2018. A small number of sites have repeated trait measurements at two or more time periods.
Major taxa and level of measurement:
Trait measurements were made on 978 terrestrial vascular plant species growing in tundra habitats. Most observations are on individuals (86%), while the remainder represent plot or site means or maximums per species.
Software format:
csv file and GitHub repository with data cleaning scripts in R; contribution to TRY plant trait database (www.try-db.org) to be included in the next version release
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The first 50 years: A review of the Department of Energy domestic safeguards and security program
World War II not only brought the United States rapidly into the nuclear age, but it also brought a new term, {open_quotes}safeguards.{close_quotes} By that time, physical security was an already established activity that dealt with the protection of possessions such as property, vehicles, and other valuables. A secret nuclear project under a stadium at the University of Chicago would add a new dimension to physical security. Similarly, a community known only by its post office box at a location 27 miles from Santa Fe, New Mexico (PO Box 1663) would initiate new programs to protect information and technology while their programs changed the science and warfare around the world. The Manhattan Project and what was to become the Los Alamos Scientific Laboratory (now Los Alamos National Laboratory) would extend the applications of physical security and, soon to be implemented, safeguards to produce important technical advances for the protection, accounting, control, and nonproliferation of fissile nuclear materials. Security for nuclear materials and weapons information began as a foremost consideration with the start of the nuclear programs in the early 1940s. In the 1960s, the Atoms for Peace Program promoted the peaceful use of nuclear energy and made the US a supplier of nuclear materials and peaceful-use nuclear technology to other states. This program also changed the focus on nuclear materials from that of worldwide control to inspection by an independent agency, the proposed International Atomic Energy Agency. At this same time the nuclear weapons states increased from three to five. Other nations worked to obtain a nuclear weapons capability, resulting in increasing concerns about nuclear proliferation
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Safeguards systems analysis research and development and the practice of safeguards at DOE facilities
Los Alamos Safeguards Systems Group personnel interact with Department of Energy (DOE) nuclear materials processing facilities in a number of ways. Among them are training courses, formal technical assistance such as developing information management or data analysis software and informal ad hoc assistance especially in reviewing and commenting on existing facility safeguards technology and procedures. These activities are supported by the DOE Office of Safeguards and Security, DOE Operations Offices, and contractor organizations. Because of the relationships with the Operations Office and facility personnel, the Safeguards Systems Group research and development (R D) staff have developed an understanding of the needs of the entire complex. Improved safeguards are needed in areas such as materials control activities, accountability procedures and techniques, systems analysis and evaluation methods, and material handling procedures. This paper surveys the generic needs for efficient and cost effective enhancements in safeguards technologies and procedures at DOE facilities, identifies areas where existing safeguards R D products are being applied or could be applied, and sets a direction for future systems analysis R D to address practical facility safeguards needs
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