3,873 research outputs found
A road map for interoperable language resource metadata
LRs remain expensive to create and thus rare relative to demand across languages and technology types. The accidental re-creation of an LR that already exists is a nearly unforgiveable waste of scarce resources that is unfortunately not so easy to avoid. The number of catalogs the HLT researcher must search, with their different formats, make it possible to overlook an existing resource. This paper sketches the sources of this problem and outlines a proposal to rectify along with a new vision of LR cataloging that will to facilitates the documentation and exploitation of a much wider range of LRs than previously considered
Multigene analyses identify the three earliest lineages of extant flowering plants
AbstractFlowering plants (angiosperms) are by far the largest, most diverse, and most important group of land plants, with over 250,000 species and a dominating presence in most terrestrial ecosystems. Understanding the origin and early diversification of angiosperms has posed a long-standing botanical challenge [1]. Numerous morphological and molecular systematic studies have attempted to reconstruct the early history of this group, including identifying the root of the angiosperm tree. There is considerable disagreement among these studies, with various groups of putatively basal angiosperms from the subclass Magnoliidae having been placed at the root of the angiosperm tree (reviewed in [2–4]). We investigated the early evolution of angiosperms by conducting combined phylogenetic analyses of five genes that represent all three plant genomes from a broad sampling of angiosperms. Amborella, a monotypic, vesselless dioecious shrub from New Caledonia, was clearly identified as the first branch of angiosperm evolution, followed by the Nymphaeales (water lilies), and then a clade of woody vines comprising Schisandraceae and Austrobaileyaceae. These findings are remarkably congruent with those from several concurrent molecular studies [5–7] and have important implications for whether or not the first angiosperms were woody and contained vessels, for interpreting the evolution of other key characteristics of basal angiosperms, and for understanding the timing and pattern of angiosperm origin and diversification
Urinary Levoglucosan as a Biomarker for Wood Smoke: Results of Human Exposure Studies
Urinary levoglucosan was investigated as a potential biomarker for wood smoke exposure in two different controlled experimental settings. Nine subjects were exposed to smoke from a campfire in a controlled setting and four were exposed to smoke from an older model wood stove. All subjects were asked to provide urine samples before and after exposure, and to wear personal PM2.5 monitors during the exposure. Urinary levoglucosan measurements from both studies showed no consistent response to the smoke exposure. A third experiment was conducted to assess the contribution of dietary factors to urinary levoglucosan levels. Nine subjects were asked to consume caramel and provide urine samples before and after consumption. Urinary levoglucosan levels increased within 2 hours of caramel consumption and returned to pre-exposure levels within 24 hours. These studies suggest that diet is a major factor in determining urinary levoglucosan levels and recent dietary history needs to be taken into account for future work involving levoglucosan as a biomarker of wood smoke exposure
Effects of leas and mecury on the blood proteome of children
Heavy metal exposure in children has been associated with a variety of physiological and neurological problems. The goal of this study was to utilize proteomics to enhance the understanding of biochemical interactions responsible for the health problems related to lead and mercury exposure at concentrations well below CDC guidelines. Blood plasma and serum samples from 34 children were depleted of their most abundant proteins using antibody-based affinity columns and analyzed using two different methods, LC-MS/MS and 2-D electrophoresis coupled with MALDI-TOF/MS and tandem mass spectrometry. Apolipoprotein E demonstrated an inverse significant association with lead concentrations (average being one microgram/deciliter) as deduced from LC-MS/MS and 2-D electrophoresis and confirmed by Western blot analysis. This coincides with prior findings that Apolipoprotein E genotype moderates neurobehavioral effects in individuals exposed to lead. Fifteen other proteins were identified by LC-MS/MS as proteins of interest exhibiting expressional differences in the presence of environmental lead and mercury. Brooks Gump is currently at Syracuse University
The atp6 Coding Region Has Been Disrupted and a Novel Reading Frame Generated in the Mitochondrial Genome of Cytoplasmic Male-sterile Radish"
The gene atp6, encoding subunit 6 of the mitochondrial Fo-ATPase complex, has been characterized from both the normal (fertile) and Ogura (male-sterile) radish cytoplasms in order to determine if previously identified atp6 transcriptional differences could play a role in cytoplasmic maIe sterility. Normal radish atp6 encodes a 262-amino acid polypeptide that exhibits approximately 80% sequence identity with other plant atp6 polypeptides. A tRNA""' gene is located 150 base pairs 5' to atp6, and the two genes may be co-transcribed. As a result of extensive rearrangement, sequences that comprise the normal atp6 locus are present in three widely separated regions of the Ogura mitochondrial genome. Both 5' and 3' rearrangement breakpoints have been identified and found to be associated with short repeated sequences. The normal and Ogura atp6 loci share a common 987-base pair region containing most of the atp6 coding region and 106 base pairs of the 3'-flanking region. A 105-codon open reading frame is transcribed as the first gene of an Ogura atp6 bicistroaic mRNA. This sequence is not present in normal radish mitochondrial DNA. There are many nucleotide differences in the Ogura atp6 5'-flanking and coding regions that can be expected to eliminate normal translation of atp6. At least two possibilities exist for translation of Ogura atp6, both of which would result in an NHz-terminal amino acid sequence different from that of normal radish
Characterization of radish mitochondrial atpA: influence of nuclear background on transcription of atpA -associated sequences and relationship with male sterility
We have previously shown that the mitochondrial gene atpA , encoding the α subunit of F 1 ATP synthase, is associated with DNA rearrangements and nuclear-specific transcript patterns in the male-sterile cytoplasm of Ogura radish. Here we present a detailed characterization of this gene from both the normal (fertile) and Ogura (male-sterile) cytoplasms of radish to determine if it is involved in Ogura cytoplasmic male sterility. The normal and Ogura radish atpA loci are virtually identical for 3.8 kb, including a 507 codon open reading frame whose product is approximately 92% identical to other plant ATPA polypeptides. Rearrangement breakpoints have been identified 613 bp 5′ and 1663 bp 3′ to the atpA coding region. The 5′ rearrangement breakpoint is located within a repeated sequence that has been associated with other rearrangement events in radish mitochondria. The previously identified transcript difference results from transcription originating upstream of this rearrangement site. Although the presence of this transcript is affected by nuclear background, analyses in several different sterile and fertile nuclear backgrounds indicate that the presence of this transcript is not strictly correlated with male sterility. In addition, normal levels of ATPA polypeptide are present in sterile plants containing the Ogura cytoplasm.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43427/1/11103_2004_Article_BF00016123.pd
Impacts of Red Imported Fire Ants on Northern Bobwhite Nest Survival
Invasive species are a large management issue because of extensive environmental and economic damage. The red imported fire ant (RIFA, Solenopsis invicta) is an invasive species of growing concern in wildlife management in the United States because of its increasing distribution, difficulty to suppress, and aggressive predation on native invertebrates, herpetofauna, birds, and small mammals. Managers of the northern bobwhite (Colinus virginianus) have questioned the direct impact of RIFA on bobwhite nest success, particularly the factors that might influence the level of nest predation. We hypothesized that RIFA predation on northern bobwhite would vary by location and correlate with drier weather conditions. To test our hypothesis we analyzed bobwhite nest data gathered from 3 properties in the southeastern United States. The nest data are part of a larger research effort on bobwhites, collected by Tall Timbers Research Station and the Albany Quail Project using radiotelemetry from 1992 to 2015. Over these 23 years we tracked bobwhites and located nests (n = 3,207) daily to determine nest fate (success or failure) based on field sign and evidence attributed to specific causes of mortality. We used the nest-survival model in Program MARK to estimate nest survival. Average nest survival varied annually for the Albany and Tall Timbers study areas, respectively. The overall effect of RIFAs on nest survival was generally small, with an average annual loss in Albany of 5.13% (range = 0–15.59%) and 2.17% in Tall Timbers (range = 0–5.83%), but in some years was as high as 15.6%. Greater losses occurred late in the breeding season when it was typically drier and the loss rate in general was higher on the drier of the 2 study sites. Despite the relatively small direct impact on nesting success demonstrated, indirect effects of RIFAs on bobwhite populations are poorly understood at present. Quantifying the influence of indirect factors, such as soil type and habitat disturbance, on RIFA abundance and the subsequent impact on bobwhites, will provide additional insight to the ecological interaction with a highly pervasive and expanding invasive species and help inform management options
Baseline patient characteristics associated with response to biologic therapy in patients with psoriatic arthritis enrolled in the Corrona Psoriatic Arthritis/Spondyloarthritis Registry.
Objectives: To compare baseline characteristics between patients with psoriatic arthritis (PsA) who achieved and did not achieve minimal disease activity (MDA) with biologic therapy in the US-based Corrona Psoriatic Arthritis/Spondyloarthritis Registry.
Methods: Patients with PsA aged ≥18 years enrolled between March 2013 and March 2016 who were receiving biologics at enrolment (baseline), not in MDA and had ≥2 follow-up visits were included. Patients were classified as those who remained on their index biologic and achieved MDA at the second follow-up visit (MDA achievers (MDA-A)) and those who did not (MDA non-achievers (MDA-NA)). Demographics, clinical characteristics, patient-reported outcomes and medication history were compared between groups.
Results: Of 148 patients with PsA who met the inclusion criteria, 34 (23.0%) and 114 (77.0%) were classified as MDA-A and MDA-NA, respectively. At baseline, most patients (96.6%) were receiving tumour necrosis factor inhibitors, and both groups were similar in age, sex, race, medication history, enthesitis and dactylitis counts, disease duration and comorbidities. Compared with MDA-A, MDA-NA had significantly worse mean tender joint count (7.2 vs 3.4), patient-reported pain (51.2 vs 35.7), patient-reported fatigue (54.1 vs 42.4), physical function (Health Assessment Questionnaire, 1.0 vs 0.6), Bath Ankylosing Disease Activity Index (5.0 vs 3.4) and Bath Ankylosing Spondylitis Functional Index (4.0 vs 2.0) scores (all p\u3c0.05).
Conclusions: Approximately one in four patients achieved MDA with their index biologic at the time of the second follow-up visit. Both groups were similar in several baseline demographic and clinical features; however, patients who did not achieve MDA generally had worse tender joint counts and patient-reported outcomes
Multiple major increases and decreases in mitochondrial substitution rates in the plant family Geraniaceae
Background: Rates of synonymous nucleotide substitutions are, in general, exceptionally low in plant mitochondrial genomes, several times lower than in chloroplast genomes, 10-20 times lower than in plant nuclear genomes, and 50-100 times lower than in many animal mitochondrial genomes. Several cases of moderate variation in mitochondrial substitution rates have been reported in plants, but these mostly involve correlated changes in chloroplast and/or nuclear substitution rates and are therefore thought to reflect whole-organism forces rather than ones impinging directly on the mitochondrial mutation rate. Only a single case of extensive, mitochondrial-specific rate changes has been described, in the angiosperm genus Plantago. Results: We explored a second potential case of highly accelerated mitochondrial sequence evolution in plants. This case was first suggested by relatively poor hybridization of mitochondrial gene probes to DNA of Pelargonium hortorum (the common geranium). We found that all eight mitochondrial genes sequenced from P. hortorum are exceptionally divergent, whereas chloroplast and nuclear divergence is unexceptional in P. hortorum. Two mitochondrial genes were sequenced from a broad range of taxa of variable relatedness to P. hortorum, and absolute rates of mitochondrial synonymous substitutions were calculated on each branch of a phylogenetic tree of these taxa. We infer one major, similar to 10-fold increase in the mitochondrial synonymous substitution rate at the base of the Pelargonium family Geraniaceae, and a subsequent similar to 10-fold rate increase early in the evolution of Pelargonium. We also infer several moderate to major rate decreases following these initial rate increases, such that the mitochondrial substitution rate has returned to normally low levels in many members of the Geraniaceae. Finally, we find unusually little RNA editing of Geraniaceae mitochondrial genes, suggesting high levels of retroprocessing in their history. Conclusion: The existence of major, mitochondrial-specific changes in rates of synonymous substitutions in the Geraniaceae implies major and reversible underlying changes in the mitochondrial mutation rate in this family. Together with the recent report of a similar pattern of rate heterogeneity in Plantago, these findings indicate that the mitochondrial mutation rate is a more plastic character in plants than previously realized. Many molecular factors could be responsible for these dramatic changes in the mitochondrial mutation rate, including nuclear gene mutations affecting the fidelity and efficacy of mitochondrial DNA replication and/or repair and consistent with the lack of RNA editing - exceptionally high levels of mutagenic retroprocessing. That the mitochondrial mutation rate has returned to normally low levels in many Geraniaceae raises the possibility that, akin to the ephemerality of mutator strains in bacteria, selection favors a low mutation rate in plant mitochondria
Heatwave attribution based on reliable operational weather forecasts
The 2021 Pacific Northwest heatwave was so extreme as to challenge conventional statistical and climate-model-based approaches to extreme weather attribution. However, state-of-the-art operational weather prediction systems are demonstrably able to simulate the detailed physics of the heatwave. Here, we leverage these systems to show that human influence on the climate made this event at least 8 [2–50] times more likely. At the current rate of global warming, the likelihood of such an event is doubling every 20 [10–50] years. Given the multi-decade lower-bound return-time implied by the length of the historical record, this rate of change in likelihood is highly relevant for decision makers. Further, forecast-based attribution can synthesise the conditional event-specific storyline and unconditional event-class probabilistic approaches to attribution. If developed as a routine service in forecasting centres, it could provide reliable estimates of human influence on extreme weather risk, which is critical to supporting effective adaptation planning
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