55 research outputs found
TEMPORAL EFFECTS OF MECHANICAL TREATMENT ON WINTER MOOSE BROWSE IN SOUTH-CENTRAL ALASKA
Sites containing winter browse species utilized by moose on the Copper River Delta of south-central Alaska were mechanically treated (hydraulic-axed) to counteract possible earthquake-related increases in less-preferred forage species, and to measure treatment effects on biomass, height, nutritional quality (crude protein, lignin, and tannin), utilization, and snow burial on preferred (willow [Salix spp.]) and less-preferred forage species (sweetgale [Myrica gale], cottonwood [Populus trichocarpa], and alder [Alnus viridis sinuata]) within 3 winter scenarios (mild, moderate, and severe). Sites were treated in 4 winters (1990–1992, 2008, 2010, and 2012) within 5 stand types in 20 sites varying from 0.9–63.4 ha. We found few significant differences in biomass, height, nutritional quality, utilization, and snow burial relative to controls. However, our ability to detect differences may have been limited by sample size (n = 1–9), as visual comparison suggests hydraulic-axing may be an effective method for increasing willow biomass while reducing alder biomass without influencing nutritional quality. However, because treated willows were shorter than untreated willows, treatment may result in less preferred forage for moose in severe winters with deep snow. Our results have implications for habitat management of moose but further research is needed to determine incremental and long-term effects of treatment on willow growth and productivity
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Agave salmiana Plant Communities in Central Mexico as Affected by Commercial Use
Agave salmiana is a native plant species harvested for the commercial production of mezcal (Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha⁻¹) in the short-use areas and less (892 plants ha⁻¹) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha⁻¹) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).Keywords: nopalera, magueyera, shrub replacement, mezcal, Opunti
Project Themyscira
Currently, both governments and private corporations are developing lunar exploration projects for scientific research and spaceflight operations. However, a viable plan for a lunar base is yet to be developed. The goal of Project Themyscira is to design a self-sufficient, sustainable lunar base capable of supporting five crew members for a period of six months. The feasibility study is two-fold. It will test the effectiveness and efficiency of the life-support systems to accomplish the mission, as well as evaluate its financial and logistic feasibility. In order to study the required systems to support human life, the team conducted an extensive literature survey on previous designs for human settlements in space and their limitations. This assessment yielded a series of constraints for oxygen production, atmospheric modeling, energy production, water treatment, and thermal regulation. Preliminary findings show that while some of the necessary support systems have the technology required to provide the necessary outputs, the logistics to set up the lunar base are not financially feasible. Nonetheless, artificial atmosphere models, artificial photosynthesis and radiation-protected photovoltaic cells are some of the existing technologies that would allow the lunar base to sustain human life. Consequently, optimizing the technologies so that they can be taken to space in smaller dimensions could result in logistical feasibility. The team will focus on developing testing methods to optimize the systems necessary to sustain the lunar base
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Predicting foundation bunchgrass species abundances: model-assisted decision-making in protected-area sagebrush steppe
Foundation species are structurally dominant members of ecological communities that can stabilize ecological processes and influence resilience to disturbance and resistance to invasion. Being common, they are often overlooked for conservation but are increasingly threatened from land use change, biological invasions, and over‐exploitation. The pattern of foundation species abundances over space and time may be used to guide decision‐making, particularly in protected areas for which they are iconic. We used ordinal logistic regression to identify the important environmental influences on the abundance patterns of bluebunch wheatgrass (Pseudoroegneria spicata), Thurber's needlegrass (Achnatherum thurberianum), and Sandberg bluegrass (Poa secunda) in protected‐area sagebrush steppe. We then predicted bunchgrass abundances along gradients of topography, disturbance, and invasive annual grass abundance. We used model predictions to prioritize the landscape for implementation of a management and restoration decision‐support tool. Models were fit to categorical estimates of grass cover obtained from an extensive ground‐based monitoring dataset. We found that remnant stands of abundant wheatgrass and bluegrass were associated with steep north‐facing slopes in higher and more remote portions of the landscape outside of recently burned areas where invasive annual grasses were less abundant. These areas represented only 25% of the landscape and were prioritized for protection efforts. Needlegrass was associated with south‐facing slopes, but in low abundance and in association with invasive cheatgrass (Bromus tectorum). Abundances of all three species were strongly negatively correlated with occurrence of another invasive annual grass, medusahead (Taeniatherum caput‐medusae). The rarity of priority bunchgrass stands underscored the extent of degradation and the need for prioritization. We found no evidence that insularity reduced invasibility; annual grass invasion represents a serious threat to protected‐area bunchgrass communities. Our study area was entirely within the Wyoming big sagebrush ecological zone, understood to have inherently low resilience to disturbance and resistance to weed invasion. However, our study revealed important variation in abundance of the foundation species associated with resilience and resistance along the topographic‐soil moisture gradient within this zone, providing an important foothold for conservation decision‐making in these steppe ecosystems. We found the foundation species focus a parsimonious strategy linking monitoring to decision‐making via biogeographic modeling
Carotid ultrasound is useful for the cardiovascular risk stratification in patients with hidradenitis suppurativa
INTRODUCTION: Hidradenitis suppurativa (HS) is a chronic inflammatory cutaneous disease which has been associated with an increased risk of adverse cardiovascular (CV) outcomes. Adequate stratification of the CV risk is an issue of major importance in patients with HS. To analyze the usefulness of carotid ultrasound (US) assessment for the CV disease risk stratification compared with a traditional score, the Framingham risk score (FRS), in a series of patients with HS.
METHODS:
Cross-sectional study of 60 patients with HS without history of CV events, diabetes mellitus or chronic kidney disease. Information on CV risk factors was collected and the FRS was calculated. Thus, the patients were classified into low, intermediate and high-CV disease risk categories based on FRS. Carotid US was performed in all participants, and the presence of atherosclerotic plaques was considered as a marker of high CV risk.
RESULTS:
HS patients had a mean age of 45.1±10.2 years, and 55% were female. The median FRS was 5.7 (IQR: 3.1-14.7). Twenty-four (40%) of the patients were classified into the low risk group, 28 (46.7%) in the intermediate risk group, and 8 (13.3%) into the FRS-high risk category. Noteworthy, carotid US revealed that about one-third of the patients (17/52; 32.6%) in the FRS-based low and intermediate risk categories had carotid plaques, and, therefore, they were reclassified into a high-risk category.
CONCLUSION:
CV risk in HS patients may be underestimated by using the FRS. Carotid US may be useful to improve the CV risk stratification of patients with HS.This study was funded through an unrestricted grant provided by AbbVie to MGL. AbbVie has not played any role in study design, data collection and analysis, decision to publish or preparation of the manuscript
DNA Barcoding Bromeliaceae: Achievements and Pitfalls
<div><h3>Background</h3><p>DNA barcoding has been successfully established in animals as a tool for organismal identification and taxonomic clarification. Slower nucleotide substitution rates in plant genomes have made the selection of a DNA barcode for land plants a much more difficult task. The Plant Working Group of the Consortium for the Barcode of Life (CBOL) recommended the two-marker combination <em>rbcL</em>/<em>matK</em> as a pragmatic solution to a complex trade-off between universality, sequence quality, discrimination, and cost.</p> <h3>Methodology/Principal Findings</h3><p>It is expected that a system based on any one, or a small number of plastid genes will fail within certain taxonomic groups with low amounts of plastid variation, while performing well in others. We tested the effectiveness of the proposed CBOL Plant Working Group barcoding <em>markers</em> for land plants in identifying 46 bromeliad species, a group rich in endemic species from the endangered Brazilian Atlantic Rainforest. Although we obtained high quality sequences with the suggested primers, species discrimination in our data set was only 43.48%. Addition of a third marker, <em>trnH–psbA</em>, did not show significant improvement. This species identification failure in Bromeliaceaecould also be seen in the analysis of the GenBank's <em>matK</em> data set. Bromeliaceae's sequence divergence was almost three times lower than the observed for Asteraceae and Orchidaceae. This low variation rate also resulted in poorly resolved tree topologies. Among the three Bromeliaceae subfamilies sampled, Tillandsioideae was the only one recovered as a monophyletic group with high bootstrap value (98.6%). Species paraphyly was a common feature in our sampling.</p> <h3>Conclusions/Significance</h3><p>Our results show that although DNA barcoding is an important tool for biodiversity assessment, it tends to fail in taxonomy complicated and recently diverged plant groups, such as Bromeliaceae. Additional research might be needed to develop markers capable to discriminate species in these complex botanical groups.</p> </div
Detection of high cardiovascular risk patients with ankylosing spondylitis based on the assessment of abdominal aortic calcium as compared to carotid ultrasound
ABSTRACT:
Background: This study aimed to determine whether, besides carotid ultrasound (US), a lateral lumbar spine radiography may also help identify ankylosing spondylitis (AS) patients at high risk of cardiovascular (CV) disease.
Methods: A set of 125 AS patients older than 35 years without a history of CV events, diabetes mellitus, or chronic kidney disease was recruited. Carotid US and lateral lumbar spine radiography were performed in all of them. The CV risk was calculated according to the total cholesterol systematic coronary risk evaluation (TC- CORE) algorithm.
Presence of carotid plaques was defined following the Mannheim Carotid Intima-media Thickness and Plaque Consensus. Abdominal aortic calcium (AAC) in a plain radiography was defined as calcific densities visible in an area parallel and anterior to the lumbar spine.
Results: Carotid US showed higher sensitivity than lateral lumbar spine radiography to detect high CV risk in the 54 patients with moderate TC-SCORE (61% versus 38.9%). Using carotid plaques as the gold standard test, a predictive model that included a TC-SCORE >= 5% or the presence of AAC in the lateral lumbar spine radiography in patients with both moderate and low CV risk (< 5%) according to the TC-SCORE yielded a sensitivity of 50.9% with a specificity of 95.7% to identify high/very high CV-risk AS patients. A positive correlation between AAC and carotid plaques was observed (r2 = 0.49, p < 0.001).
Conclusions: A lateral lumbar spine radiography is a useful tool to identify patients with AS at high risk of CV disease
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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Western Land Managers will Need all Available Tools for Adapting to Climate Change, Including Grazing: A Critique of Beschta et al.
In a previous article, Beschta et al. (Environ
Manag 51(2):474–491, 2013) argue that grazing by large
ungulates (both native and domestic) should be eliminated
or greatly reduced on western public lands to reduce
potential climate change impacts. The authors did not
present a balanced synthesis of the scientific literature, and
their publication is more of an opinion article. Their conclusions
do not reflect the complexities associated with
herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a
challenge. Legacy effects of uncontrolled grazing during
the homestead era further complicate analysis of current
grazing impacts. Interactions of climate change and grazing
will depend on the specific situation. For example,
increasing atmospheric CO₂ and temperatures may increase
accumulation of fine fuels (primarily grasses) and thus
increase wildfire risk. Prescribed grazing by livestock is
one of the few management tools available for reducing
fine fuel accumulation. While there are certainly points on
the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal.
Broad scale reduction of domestic and wild herbivores to
help native plant communities cope with climate change
will be unnecessary because over the past 20–50 years land
managers have actively sought to bring populations of
native and domestic herbivores in balance with the potential
of vegetation and soils. To cope with a changing climate,
land managers will need access to all available
vegetation management tools, including grazing.Keywords: Grazing, Riparian areas, Public lands, Climate chang
The 16th Data Release of the Sloan Digital Sky Surveys : First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).Peer reviewe
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