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Assessing within-species variation in response to drought is crucial for predicting species' responses to climate change and informing restoration and conservation efforts, yet experimental data are lacking for the vast majority of tropical tree species. We assessed intraspecific variation in response to water availability across a strong rainfall gradient for 16 tropical tree species using reciprocal transplant and common garden field experiments, along with measurements of gene flow and key functional traits linked to drought resistance. Although drought resistance varies widely among species in these forests, we found little evidence for within-species variation in drought resistance. For the majority of functional traits measured, we detected no significant intraspecific variation. The few traits that did vary significantly between drier and wetter origins of the same species all showed relationships opposite to expectations based on drought stress. Furthermore, seedlings of the same species originating from drier and wetter sites performed equally well under drought conditions in the common garden experiment and at the driest transplant site. However, contrary to expectation, wetter-origin seedlings survived better than drier-origin seedlings under wetter conditions in both the reciprocal transplant and common garden experiment, potentially due to lower insect herbivory. Our study provides the most comprehensive picture to date of intraspecific variation in tropical tree species' responses to water availability. Our findings suggest that while drought plays an important role in shaping species composition across moist tropical forests, its influence on within-species variation is limited.
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Sequías , Lluvia , Árboles , Clima Tropical , Árboles/fisiología , Cambio Climático , Agua/metabolismo , Plantones/genética , Plantones/fisiología , Especificidad de la Especie , Bosques , Flujo Génico , Resistencia a la SequíaRESUMEN
PREMISE: Reconciling the use of taxonomy to partition morphological variation and describe genetic divergence within and among closely related species is a persistent challenge in phylogenetics. We reconstructed phylogenetic relationships among Cedrela odorata (Meliaceae) and five closely allied species to test the genetic basis for the current model of species delimitation in this economically valuable and threatened genus. METHODS: We prepared a nuclear species tree with the program SNPhylo and 16,000 single-nucleotide polymorphisms from 168 Cedrela specimens. Based on clades present and ancestral patterns ADMIXTURE, we designed nine species delimitation models and compared each model to current taxonomy with Bayes factor delimitation. Timing of major lineage divergences was estimated with the program SNAPP. RESULTS: The resulting analysis revealed that modern C. odorata evolved from two genetically distinct ancestral sources. All species delimitation models tested better fit the data than the model representing current taxonomic delimitation. Models with the greatest marginal likelihoods separated Mesoamerican C. odorata and South American C. odorata into two species and lumped C. angustifolia and C. montana as a single species. We estimated that Cedrela diversified in South America within the last 19 million years following one or more dispersal events from Mesoamerican lineages. CONCLUSIONS: Our analyses show that the present taxonomic understanding within the genus obscures divergent lineages in C. odorata due in part to morphological differentiation and taxonomic distinctions that are not predictably associated with genetic divergence. A more accurate application of taxonomy to C. odorata and related species may aid in its conservation, management, and restoration efforts.
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Cedrela , Cedrela/genética , Cedrela/anatomía & histología , Filogenia , Teorema de Bayes , Especificidad de la Especie , América del SurRESUMEN
The fall armyworm (Spodoptera frugiperda) is a highly polyphagous lepidopteran pest of relevant food and fiber staple crops. In the Americas, transgenic corn and cotton producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have controlled and reduced the damage caused by S. frugiperda. However, cases of field-evolved S. frugiperda resistance to Bt corn producing the Cry1F insecticidal protein have been documented in North and South America. When characterized, field resistance to Cry1F is linked to insertions and mutations resulting in a modified or truncated ABC transporter subfamily C2 (SfABCC2) protein that serves as Cry1F receptor in susceptible S. frugiperda. In this work, we present detection of a large genomic deletion (~ 8 kb) affecting the SfABCC2 and an ABC transporter gene subfamily 3 -like gene (SfABCC3) as linked to resistance to Cry1F corn in a S. frugiperda strain from Florida (FL39). Monitoring for this genomic deletion using a discriminatory PCR reaction in field-collected S. frugiperda moths detected individuals carrying this allele in Florida, but not in surrounding states. This is the first report of a large genomic deletion being involved in resistance to a Bt insecticidal protein.
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Bacillus thuringiensis , Insecticidas , Transportadoras de Casetes de Unión a ATP/genética , Animales , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Endotoxinas/genética , Florida , Genómica , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacología , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Plantas Modificadas Genéticamente/genética , Spodoptera/metabolismo , Zea mays/genética , Zea mays/metabolismoRESUMEN
Forest conversion and habitat loss are major threats to biological diversity. Forest regeneration can mitigate the negative effects of old-growth forest loss on species diversity, but less is known about the extent to which forest loss reduces genetic diversity in remnant populations and whether secondary forests play a role in the maintenance of genetic diversity. We quantified genetic diversity in a tropical hummingbird-pollinated understorey herb, Heliconia tortuosa, across a landscape mosaic of primary and secondary forest regrowth. Using microsatellite genotypes from >850 adult and juvenile plants within 33 forest patches and extensive bird surveys, we examined the effect of contemporary and historical landscape features including forest age (primary vs. secondary forest), stand isolation and pollinator assemblages on genetic diversity and levels of inbreeding in H. tortuosa. We found that inbreeding was up to three times higher in secondary forest, and this effect was amplified with reductions in primary forest in the surrounding landscape through reduced observed heterozygosity in isolated fragments. Inbreeding in forest patches was negatively correlated with the local frequency of specialist long-distance foraging traplining hummingbirds. Traplining hummingbirds therefore appear to facilitate mating among unrelated plants-an inference we tested using empirically parameterized simulations. Higher levels of inbreeding in H. tortuosa are therefore associated with reduced functional diversity of hummingbirds in secondary forests and forest patches isolated from primary forests. Our findings suggest a cryptic consequence of primary forest loss and secondary forest regeneration through the disruption of mutualistic interactions resulting in the erosion of genetic diversity in a common understorey plant.
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Heliconiaceae , Animales , Aves/genética , Ecosistema , Bosques , Heliconiaceae/genética , Endogamia , Plantas , Árboles/genéticaRESUMEN
Identifying key traits that can serve as proxies for species drought resistance is crucial for predicting and mitigating the effects of climate change in diverse plant communities. Turgor loss point (πtlp ) is a recently emerged trait that has been linked to species distributions across gradients of water availability. However, a direct relationship between πtlp and species ability to survive drought has yet to be established for woody species. Using a manipulative field experiment to quantify species drought resistance (i.e., their survival response to drought), combined with measurements of πtlp for 16 tree species, we show a negative relationship between πtlp and seedling drought resistance. Using long-term forest plot data, we also show that πtlp predicts seedling survival responses to a severe El Niño-related drought, although additional factors are clearly also important. Our study demonstrates that species with lower πtlp exhibit higher survival under both experimental and natural drought. These results provide a missing cornerstone in the assessment of the traits underlying drought resistance in woody species and strengthen πtlp as a proxy for evaluating which species will lose or win under projections of exacerbating drought regimes.
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Sequías , Árboles , Hojas de la Planta/fisiología , Plantones , Árboles/fisiología , Clima Tropical , AguaRESUMEN
Elevational and latitudinal gradients in species diversity may be mediated by biotic interactions that cause density-dependent effects of conspecifics on survival or growth to differ from effects of heterospecifics (i.e. conspecific density dependence), but limited evidence exists to support this. We tested the hypothesis that conspecific density dependence varies with elevation using over 40 years of data on tree survival and growth from 23 old-growth temperate forest stands across a 1,000-m elevation gradient. We found that conspecific-density-dependent effects on survival of small-to-intermediate-sized focal trees were negative in lower elevation, higher diversity forest stands typically characterised by warmer temperatures and greater relative humidity. Conspecific-density-dependent effects on survival were less negative in higher elevation stands and ridges than in lower elevation stands and valley bottoms for small-to-intermediate-sized trees, but were neutral for larger trees across elevations. Conspecific-density-dependent effects on growth were negative across all tree size classes and elevations. These findings reveal fundamental differences in biotic interactions that may contribute to relationships between species diversity, elevation and climate.
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Ecosistema , Árboles , Biodiversidad , Clima , BosquesRESUMEN
As extreme climate events are predicted to become more frequent because of global climate change, understanding their impacts on natural systems is crucial. Tropical forests are vulnerable to droughts associated with extreme El Niño events. However, little is known about how tropical seedling communities respond to El Niño-related droughts, even though patterns of seedling survival shape future forest structure and diversity. Using long-term data from eight tropical moist forests spanning a rainfall gradient in central Panama, we show that community-wide seedling mortality increased by 11% during the extreme 2015-16 El Niño, with mortality increasing most in drought-sensitive species and in wetter forests. These results indicate that severe El Niño-related droughts influence understory dynamics in tropical forests, with effects varying both within and across sites. Our findings suggest that predicted increases in the frequency of extreme El Niño events will alter tropical plant communities through their effects on early life stages.
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El Niño Oscilación del Sur , Árboles , Sequías , Bosques , Estaciones del Año , Plantones , Clima TropicalRESUMEN
Species identification can be challenging for biologists, healthcare practitioners and members of the general public. Snakes are no exception, and the potential medical consequences of venomous snake misidentification can be significant. Here, we collected data on identification of 100 snake species by building a week-long online citizen science challenge which attracted more than 1000 participants from around the world. We show that a large community including both professional herpetologists and skilled avocational snake enthusiasts with the potential to quickly (less than 2 min) and accurately (69-90%; see text) identify snakes is active online around the clock, but that only a small fraction of community members are proficient at identifying snakes to the species level, even when provided with the snake's geographical origin. Nevertheless, participants showed great enthusiasm and engagement, and our study provides evidence that innovative citizen science/crowdsourcing approaches can play significant roles in training and building capacity. Although identification by an expert familiar with the local snake fauna will always be the gold standard, we suggest that healthcare workers, clinicians, epidemiologists and other parties interested in snakebite could become more connected to these communities, and that professional herpetologists and skilled avocational snake enthusiasts could organize ways to help connect medical professionals to crowdsourcing platforms. Involving skilled avocational snake enthusiasts in decision making could build the capacity of healthcare workers to identify snakes more quickly, specifically and accurately, and ultimately improve snakebite treatment data and outcomes.
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As part of an insect resistance management plan to preserve Bt transgenic technology, annual monitoring of target pests is mandated to detect susceptibility changes to Bt toxins. Currently Helicoverpa zea (Boddie) monitoring involves investigating unexpected injury in Bt crop fields and collecting larvae from non-Bt host plants for laboratory diet bioassays to determine mortality responses to diagnostic concentrations of Bt toxins. To date, this monitoring approach has not detected any significant change from the known range of baseline susceptibility to Bt toxins, yet practical field-evolved resistance in H. zea populations and numerous occurrences of unexpected injury occur in Bt crops. In this study, we implemented a network of 73 sentinel sweet corn trials, spanning 16 U.S. states and 4 Canadian provinces, for monitoring changes in H. zea susceptibility to Cry and Vip3A toxins by measuring differences in ear damage and larval infestations between isogenic pairs of non-Bt and Bt hybrids over three years. This approach can monitor susceptibility changes and regional differences in other ear-feeding lepidopteran pests. Temporal changes in the field efficacy of each toxin were evidenced by comparing our current results with earlier published studies, including baseline data for each Bt trait when first commercialized. Changes in amount of ear damage showed significant increases in H. zea resistance to Cry toxins and possibly lower susceptibility to Vip3a. Our findings demonstrate that the sentinel plot approach as an in-field screen can effectively monitor phenotypic resistance and document field-evolved resistance in target pest populations, improving resistance monitoring for Bt crops.
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Bacillus thuringiensis , Mariposas Nocturnas , Animales , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Canadá , Endotoxinas , Proteínas Hemolisinas/genética , Resistencia a los Insecticidas , Control Biológico de Vectores , Plantas Modificadas Genéticamente/genética , Zea mays/genéticaRESUMEN
A number of soybean varieties traditionally bred for resistance to various soybean arthropod pests have been identified as resistant to Megacopta cribraria (F.) (Hemiptera: Plataspidae). However, the mechanisms of host-plant resistance (HPR) in this system are not understood. The goal of this study was to identify the mechanisms of resistance by examining the role of plant volatile organic compounds (VOCs) and free amino acids (FAAs) among 16 soybean varieties. Choice and no-choice cage experiments identified several soybean varieties that demonstrated antixenosis as well as antibiosis. However, resistance varied over time in certain soybean varieties, such as N02-7002 and PI567352B. Mean nymph number from choice experiments had positive correlations with the FAAs asparagine, tryptophan, alanine, phenylanaline, and serine; negative correlation with leucine and threonine. Four plant volatiles, hexanal, 2-pentylfuran, beta-cyclocitral, and cis-9-hexadecenal, were positively correlated with subsequent nymph development, whereas n-hexadecenoic acid was negatively correlated with nymph number only, in adult choice cage experiments. This study contributes to understanding the mechanisms of HPR through associations with plant VOCs and FAAs in relation to M. cribraria development and provides useful knowledge for developing soybean varieties for M. cribraria management.
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Fabaceae , Hemípteros , Heterópteros , Compuestos Orgánicos Volátiles , Animales , Ninfa , Glycine maxRESUMEN
In Northeastern China, the intensive cropping system and increased use of chemical fertilizer has caused severe problems in terms of sustainable agricultural development. Therefore, to improve agricultural sustainability and crop productivity the farming system needs to be modified in the region. A pot experiment was conducted to evaluate the effect of maize-alfalfa intercropping on the physiological characteristics, nitrogen (N) uptake and yield of the maize crops in northeast China in 2017-2018. The study findings showed that intercropping under N fertilization progressively improved the physio-agronomic indices of the maize crop as compared to mono-cropping. The grain yield, 100 seed weight and biomass dry matter of maize crop improved in intercropping when it was practiced with N fertilizer. Furthermore, intercropping with N fertilization increased the chlorophyll content of the maize crop at bell-mouthed, silking, filing and mature stages by 19%, 44%, 12%, and 9% in 2017 and by 23%, 43%, 15%, and 11% in 2018, respectively, as compared with the monocropping system. Unlike monocropping, intercropping with N fertilization increased the photosynthesis rate (14% and 15%), stomatal conductance (74% and 98%) and transpiration rate (74% and 75%) in 2017 and 2018, respectively. However, intercropping reduced intercellular CO2 (Ci ). Moreover, intercropping with N fertilization increased the maize N content of grain and leaves as well as total N uptake by 49%, 31% and 93% in 2017 and 53%, 34% and 132%, respectively, in 2018 as compared to monocropping. In conclusion, our results suggest that maize-alfalfa intercropping with optimal N fertilization provides a practical method for improving growth, yield and N accumulation in the maize crop.
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Producción de Cultivos , Medicago sativa , Nitrógeno , Zea mays , China , Producción de Cultivos/métodos , Fertilizantes , Medicago sativa/crecimiento & desarrollo , Medicago sativa/metabolismo , Nitrógeno/metabolismo , Zea mays/crecimiento & desarrollo , Zea mays/metabolismoRESUMEN
The sugarcane aphid, Melanaphis sacchari Zehntner, is an economically damaging pest of sorghum, Sorghum bicolor (L.), across the southern United States. Field experiments investigated impacts of sorghum cultivar, nitrogen fertilization, and insecticides on M. sacchari infestations and sorghum yields in Louisiana and South Carolina in 2017 and 2018. In South Carolina, M. sacchari densities in unprotected plots peaked on 30-31 July of both years before declining by early- to mid-August. In Louisiana, infestations peaked on 26 and 12 July for 2017 and 2018, respectively, and declined by mid-August. Nitrogen fertilization influenced M. sacchari densities in Louisiana in 2018 with the highest-level infestations recorded from plots that received high N rates. Densities of M. sacchari on susceptible sorghum cultivar, DKS 38-88, were 1.5- to 2.3-fold greater than on DKS 37-07 in both years in Louisiana and in 2018 in South Carolina. Nitrogen fertilization was associated with improved sorghum yields in Louisiana experiments. Sorghum yields across experiments were 2- to 4-fold greater in plots protected with multiple insecticide applications than in unprotected plots. Yield from plots with insecticides sprayed once at currently used action thresholds differed from unprotected plots only in the 2018 Louisiana experiment. Results from these experiments indicate insecticidal protection of susceptible sorghum cultivars remains critical throughout much of the southern United States. Further research is needed to develop integrated management programs that incorporate fertilization manipulation, cultivar resistance, and insecticidal control.
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Áfidos , Fertilizantes , Insecticidas , Sorghum , Animales , Louisiana , Nitrógeno , South CarolinaRESUMEN
INTRODUCTION: Burn wound infections result in delayed healing and increased pain, scarring, sepsis risk and healthcare costs. Clinical decision making about burn wound infection should be supported by evidence syntheses. Validity of evidence from systematic reviews may be reduced if definitions of burn wound infectionvary between trials. This review aimed to determine whether burn wound infectionis defined, and whether there is variation in the indicators used to define burn wound infectionacross studies testing interventions for patients with burns. METHOD: Searches were carried out in four databases (Ovid Medline, Ovid Embase, Cinahl, Cochrane Register of Trials) to identify studies evaluating interventions for patients with burns and reporting a burn wound infection outcome. Pre-defined inclusion and exclusion criteria were systematically applied to select relevant studies. Data were systematically extracted and reported narratively. RESULTS: 2056 studies were identified, of which 72 met the inclusion criteria, comprising 71 unique datasets. 52.1% of studies were randomised controlled trials. Twenty-eight (38.0%) studies reporting a burn wound infection outcome did not report how they had defined it. In the methods of included studies, 59 studies (83.1%) reported that they planned to measure burn wound infection as an outcome. Of these, 44 studies (74.6%) described how they had defined burn wound infection; 6 studies (13.6%) reported use of a previously developed consensus-informed definition of burn wound infection, and 41 studies (69.5%) described the specific indicators used to define it. Studies used between one (11 studies; 26.8%) and nine indicators (2 studies; 4.9%) to define burn wound infection (median = 3, inter-quartile range = 2). The most commonly used indicator was presence of bacteria in the wound (61.0% of studies). Only 13 studies (31.7%) defined burn wound infection using the same indicators as at least one other study. DISCUSSION AND CONCLUSIONS: Within intervention studies reporting burn wound infection outcomes, a definition of this outcome is commonly not provided, or it varies between studies. This will prevent evidence synthesis to identify effective treatments for patients with burn injuries. Since there is no objective method for assessing burn wound infection, expert consensus is needed to agree a minimum set of indicators (Core Indicator Set) reported in all trials reporting burn wound infection as an outcome.
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Quemaduras , Reportes Públicos de Datos en Atención de Salud , Infección de Heridas , Quemaduras/terapia , Toma de Decisiones Clínicas , Consenso , Humanos , Resultado del Tratamiento , Cicatrización de Heridas , Infección de Heridas/epidemiologíaRESUMEN
Megacopta cribraria (F.) (Hemiptera: Plataspidae) is an invasive pest of soybean that has spread across the southeastern United States since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and host plant resistance (HPR) among soybean varieties, although the specific mechanisms of HPR remain unknown. The objectives of this study were, therefore, to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC); and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety 'Camp' was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and should be managed by incorporating integrated pest management tactics, such as HPR, that help conserve natural enemy populations.
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Glycine max , Heterópteros , Animales , Georgia , North Carolina , Ninfa , South Carolina , TricomasRESUMEN
Abiotic and biotic drivers of co-occurring fungal functional guilds across regional-scale environmental gradients remain poorly understood. We characterized fungal communities using Illumina sequencing from soil cores collected across three Neotropical rainforests in Panama that vary in soil properties and plant community composition. We classified each fungal OTU into different functional guilds, namely plant pathogens, saprotrophs, arbuscular mycorrhizal (AM), or ectomycorrhizal (ECM). We measured soil properties and nutrients within each core and determined the tree community composition and richness around each sampling core. Canonical correspondence analyses showed that soil pH and moisture were shared potential drivers of fungal communities for all guilds. However, partial the Mantel tests showed different strength of responses of fungal guilds to composition of trees and soils. Plant pathogens and saprotrophs were more strongly correlated with soil properties than with tree composition; ECM fungi showed a stronger correlation with tree composition than with soil properties; and AM fungi were correlated with soil properties, but not with trees. In conclusion, we show that co-occurring fungal guilds respond differently to abiotic and biotic environmental factors, depending on their ecological function. This highlights the joint role that abiotic and biotic factors play in determining composition of fungal communities, including those associated with plant hosts.
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Hongos/fisiología , Bosque Lluvioso , Microbiología del Suelo , Suelo/química , Árboles/crecimiento & desarrollo , Micorrizas/fisiología , PanamáRESUMEN
BACKGROUND: Tree species in the genus Cedrela P. Browne are threatened by timber overexploitation across the Neotropics. Genetic identification of processed timber can be used to supplement wood anatomy to assist in the taxonomic and source validation of protected species and populations of Cedrela. However, few genetic resources exist that enable both species and source identification of Cedrela timber products. We developed several 'omic resources including a leaf transcriptome, organelle genome (cpDNA), and diagnostic single nucleotide polymorphisms (SNPs) that may assist the classification of Cedrela specimens to species and geographic origin and enable future research on this widespread Neotropical tree genus. RESULTS: We designed hybridization capture probes to enrich for thousands of genes from both freshly preserved leaf tissue and from herbarium specimens across eight Meliaceae species. We first assembled a draft de novo transcriptome for C. odorata, and then identified putatively low-copy genes. Hybridization probes for 10,001 transcript models successfully enriched 9795 (98%) of these targets, and analysis of target capture efficiency showed that probes worked effectively for five Cedrela species, with each species showing similar mean on-target sequence yield and depth. The probes showed greater enrichment efficiency for Cedrela species relative to the other three distantly related Meliaceae species. We provide a set of candidate SNPs for species identification of four of the Cedrela species included in this analysis, and present draft chloroplast genomes for multiple individuals of eight species from four genera in the Meliaceae. CONCLUSIONS: Deforestation and illegal logging threaten forest biodiversity globally, and wood screening tools offer enforcement agencies new approaches to identify illegally harvested timber. The genomic resources described here provide the foundation required to develop genetic screening methods for Cedrela species identification and source validation. Due to their transferability across the genus and family as well as demonstrated applicability for both fresh leaves and herbarium specimens, the genomic resources described here provide additional tools for studies examining the ecology and evolutionary history of Cedrela and related species in the Meliaceae.
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Cedrela/genética , Perfilación de la Expresión Génica/métodos , Genoma del Cloroplasto/genética , Genómica/métodos , Árboles/genética , Región del Caribe , Cedrela/clasificación , América Central , Geografía , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Meliaceae/clasificación , Meliaceae/genética , Filogenia , Hojas de la Planta/genética , Polimorfismo de Nucleótido Simple , América del Sur , Especificidad de la Especie , Árboles/clasificación , Clima TropicalRESUMEN
Hilsenhoff's family-level index (FBI) combines information about the relative abundances of taxa and their tolerances to pollution. Versions of this index are used extensively in North America to assess water quality. When faced with constraints on time, money, or expertise, bioassessment practitioners have been tempted to calculate a version of the FBI with very coarse (e.g., order-level) taxonomy. Such an approach requires a degree of within-taxon averaging of tolerance values and raises questions about the degree to which accuracy is compromised and bias is introduced. Data from thousands of streams in Ontario (Canada) demonstrated that such tolerance-value averaging produces index scores and associated water-quality classifications that are not equivalent to those calculated with the standard family-level taxonomic precision. Two methods were used in an attempt to correct the order-level FBI scores to equivalence with the family-level index: (1) tolerance scores for the orders included in the calculation were calculated as abundance-weighted means of the scores of their component families, and (2) order-level FBI scores were estimated as predicted values from a polynomial regression of the two versions of the index. The use of abundance-weighted mean tolerance scores greatly improved the accuracy of the order-level index, and the regression-based correction reduced bias by equalizing the distribution of errors across the range of observed FBI values. Nonetheless, equivalence of scores was not demonstrated, and water quality was misclassified in 12 to 80% of cases. Practitioners are discouraged from the practice of tolerance-value averaging and are advised to adhere to the standard family-level FBI.
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Biodiversidad , Monitoreo del Ambiente/métodos , Sesgo , Clasificación , Monitoreo del Ambiente/normas , Ontario , Ríos , Calidad del Agua/normasRESUMEN
BACKGROUND: Skin grafts following deep burns are needed to ensure healing. Grafts that fail and require re-grafting cause significant distress to patients and additional costs for the NHS. Shearing, which leads to graft loss, may be reduced through the use of low-friction bedding. A feasibility study was conducted to assess proof of concept for the use of low-friction bedding for patients with burns. Patient, parent and staff views on the acceptability of this material were explored through semi-structured interviews. METHOD: Patient views were gathered through telephone interviews (n=17; 11 adult patients and 6 parents of child patients). One patient completed the questionnaire in written form because of hearing difficulties. Staff views were gathered at two time points: at the start of the study through open-ended questionnaires (n=20) and at the end of the study through focus group (n=12) and telephone interviews (n=3). Data were analysed using framework analysis. RESULTS: Three themes were identified describing both patient and staff views of the sheets: Slippery feel of the sheets; leaking wounds and sheet changes; and movement and friction. Overall patients' views of the sheets were positive; they were comfortable to use the sheets and experienced reduced pain and itching. However, issues related to the slipperiness were highlighted. Staff views were largely negative because of difficulty in use, lack of absorbency, and increased workload. CONCLUSION: The use of low-friction bedding is acceptable to patients undergoing a skin graft following a burn injury; however, problems related to sliding down the bed and soiling of sheets need addressing. Staff were supportive of the concept of low-friction bedding; however, they reported significant challenges in day-to-day use of sheets. Low-friction bedding presents a promising alternative to standard cotton sheets for patients with burns and those at risk of pressure sores; however, further work is needed to address current challenges in use.
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Actitud del Personal de Salud , Ropa de Cama y Ropa Blanca , Quemaduras/cirugía , Fricción , Aceptación de la Atención de Salud , Trasplante de Piel , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Exudados y Transudados , Estudios de Factibilidad , Femenino , Grupos Focales , Humanos , Lactante , Masculino , Persona de Mediana Edad , Personal de Enfermería en Hospital , Prueba de Estudio Conceptual , Investigación Cualitativa , Carga de Trabajo , Adulto JovenRESUMEN
The objective of this economic study was to evaluate the resource use and cost associated with the management of small area burns, including the additional costs associated with unexpected illness after burn in children of less than five years of age. This study was conducted as a secondary analysis of a multi-centre prospective observational cohort study investigating the physiological response to burns in children. 452 children were included in the economic analysis (median age=1.60years, 61.3% boys, median total burn surface area [TBSA]=1.00%) with a mean length of stay of 0.69 days. Of these children, 21.5% re-presented to medical care with an unexpected illness within fourteen days of injury. The cost of managing a burn of less than 10% TBSA in a child less than five years of age was £785. The additional cost associated with the management of illness after burn was £1381. A generalised linear regression model was used to determine the association between an unexpected illness after burn, presenting child characteristics and NHS cost. Our findings may be of value to those planning economic evaluations of novel technologies in burn care.