282 research outputs found
Pollinator attractors: petaloidy and petal epidermal cell shape in close relatives of snapdragon
The diversity of angiosperms in floral form and development has been an area of interest for biologists. A multitude of studies investigating the evolution of flowering plants have attempted to determine why angiosperms are so diverse. One possible major contributor to flower form diversity is pollinator pressure. The interactions between flowers and their pollinators have important ecological and evolutionary consequences, with co-evolution often occuring. Many studies have looked at suites of floral traits that affect pollinator visitation, which have been coined pollination syndromes (Fenster et al., 2004). These traits include but are not limited to, flower color, flower orientation, landing platforms, and nectar guides. With the increase in genetic tools, and the utilization of model species such as Antirrhinum majus(Plantaginaceae) and Arabidopsis thaliana (Brassicaeae), many studies are looking at the geneitc architecture of floral traits. Studies have determined the genetic blueprint for floral oragn identity, as well as in traits asociated with pollination syndromes including flower color and symmetry. Using members of the Antirrhineae tribe (Plantaginaceae) makes it easier to effectively use the resources from A. majus, or snapdragon. Chapter 1 investigates the applicability of the sliding boundary model for petaloid sepal formation in Rhodochiton atrosanguineum, a close relative of snapdragon. We were interested in determing if the petaloid sepals of R. atrosanguineum had true petal identity, or were merely just colorful sepals. Chapter 2 focuses on possible petal function, and not merely petal identity. Conical cells are found on roughly 80% of angiosperms (Kay et al., 1981) and are thought to be a marker for petal identity. However, conical cells are thought to be absent mostly in hummingbird pollinated flowers, though no studies have looked at this in depth (Christensen and Hansen, 1998). For this chapter, we investigated possible correlated evolution between petal epidermal cell shape and pollination system
Genomic Resources for Erysimum spp. (Brassicaceae): Transcriptome and Chloroplast Genomes
Funding was provided by the Spanish Ministry of Science and Competitiveness (CGL2016-79950-R; CGL2017-86626-C22-P), including FEDER funds. This research was also funded by the Consejeria de Economia, Conocimiento, Empresas y Universidad, and European Regional Development Fund (ERDF), ref. SOMM17/6109/UGR and A-RNM-505-UGR18. COM was supported by the Ministry of Economy and Competitiveness (BES-2014-069022).We are grateful to Modesto Berbel Cascales and José M. Gómez
for their help in sampling and DNA/RNA extractions.Erysimum (Brassicaceae) is a genus of more than 200 species (Al-Shehbaz, 2012). It is widely distributed in the Northern Hemisphere and has been the focus of active research in ecology, evolution, and genetics (Gómez and Perfectti, 2010; Gómez, 2012; Valverde et al., 2016). Despite long-standing interest in Erysimum, its taxonomy has yet to be properly established, partly due to a complex and reticulated evolutionary history that renders phylogenetic reconstructions highly challenging (Ancev, 2006; Marhold and Lihová, 2006; Abdelaziz et al., 2014; Gomez et al., 2014; Moazzeni et al., 2014; Züst et al., 2020).
The Baetic Mountains (South-Eastern Iberia) are among the most critical glacial refugia in Europe. The waxing and waning of plant populations following climatic fluctuations have likely complicated the distribution and genetic variation of extant diversity in this region. Isolation and posterior secondary contact between taxa may have favored hybridization and introgression (Médail and Diadema, 2009). The Erysimum species that inhabit these mountains have been a particularly fruitful system for plant evolutionary ecology [e.g., Gómez et al., 2006, 2008; Gómez and Perfectti, 2010; Gómez, 2012; Valverde et al., 2016]. However, the relationships among these species remain unresolved, hampering comparative and evolutionary studies. Genome duplications, incomplete lineage sorting, and hybridization have compromised the phylogenetic reconstructions within Erysimum (Marhold and Lihová, 2006; Osuna-Mascaró, 2020). Additionally, clarifying this group's complex evolution requires extensive genomic resources, which are currently being produced but are mostly lacking.
The fast development of high-throughput sequencing technologies has led to a rapid increase in genomic and transcriptomic for many plant species (Dong et al., 2004; Duvick et al., 2007; Sundell et al., 2015; Boyles et al., 2019). However, obtaining complete genome sequencing remains a challenge with large, repetitive-DNA enriched genomes. Transcriptome sequencing is comparatively more accessible, providing a relatively cheap and fast method to obtain large amounts of functional genomic data (Timme et al., 2012; Yang and Smith, 2013; Wickett et al., 2014; Léveillé-Bourret et al., 2017). Accordingly, global initiatives such as the 1,000 plants (1KP) project have generated transcriptomic resources for over 1,000 plant species (Matasci et al., 2014; Leebens-Mack et al., 2019). In addition, the use of RNA-Seq could be useful in obtaining complete chloroplast genomes in a reliable and accessible way, making possible the use of complete molecules in phylogenomic analyses (Smith, 2013; Osuna-Mascaró et al., 2018; Morales-Briones et al., 2021).
Here, we report the annotation of 18 floral transcriptomes assembled de novo from total RNA-Seq libraries and nine chloroplast genomes from seven Erysimum species inhabiting the Baetic Mountains. The chloroplast genomes were assembled from total RNA-Seq data following a previously-validated reference assemble approach (Osuna-Mascaró et al., 2018). The data presented here represent reliable genomic resources for transcriptomic, proteomic, and phylotranscriptomic studies. These data contribute to the ecological and genetic resources available for Brassicaceae in general and the genus Erysimum in particular, being the only genomic resources for these species coming from flower buds.Spanish Ministry of Science and Competitiveness
CGL2016-79950-R
CGL2017-86626-C22-PEuropean CommissionConsejeria de Economia, Conocimiento, Empresas y UniversidadEuropean Commission
SOMM17/6109/UGR
A-RNM-505-UGR18Ministry of Economy and Competitiveness
BES-2014-06902
Measuring hidden phenotype:Quantifying the shape of barley seeds using the Euler characteristic transform
Shape plays a fundamental role in biology. Traditional phenotypic analysis methods measure some features but fail to measure the information embedded in shape comprehensively. To extract, compare and analyse this information embedded in a robust and concise way, we turn to topological data analysis (TDA), specifically the Euler characteristic transform. TDA measures shape comprehensively using mathematical representations based on algebraic topology features. To study its use, we compute both traditional and topological shape descriptors to quantify the morphology of 3121 barley seeds scanned with X-ray computed tomography (CT) technology at 127 μm resolution. The Euler characteristic transform measures shape by analysing topological features of an object at thresholds across a number of directional axes. A Kruskal-Wallis analysis of the information encoded by the topological signature reveals that the Euler characteristic transform picks up successfully the shape of the crease and bottom of the seeds. Moreover, while traditional shape descriptors can cluster the seeds based on their accession, topological shape descriptors can cluster them further based on their panicle. We then successfully train a support vector machine to classify 28 different accessions of barley based exclusively on the shape of their grains. We observe that combining both traditional and topological descriptors classifies barley seeds better than using just traditional descriptors alone. This improvement suggests that TDA is thus a powerful complement to traditional morphometrics to comprehensively describe a multitude of 'hidden' shape nuances which are otherwise not detected.</p
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nQuack: An R package for predicting ploidal level from sequence data using site-based heterozygosity
Premise: Traditional methods of ploidal-level estimation are tedious; using DNA sequence data for cytotype estimation is an ideal alternative. Multiple statistical approaches to leverage sequence data for ploidy inference based on site-based heterozygosity have been developed. However, these approaches may require high-coverage sequence data, use inappropriate probability distributions, or have additional statistical shortcomings that limit inference abilities. We introduce nQuack, an open-source R package that addresses the main shortcomings of current methods. Methods and Results: nQuack performs model selection for improved ploidy predictions. Here, we implement expectation maximization algorithms with normal, beta, and beta-binomial distributions. Using extensive computer simulations that account for variability in sequencing depth, as well as real data sets, we demonstrate the utility and limitations of nQuack. Conclusions: Inferring ploidy based on site-based heterozygosity alone is difficult. Even though nQuack is more accurate than similar methods, we suggest caution when relying on any site-based heterozygosity method to infer ploidy.</p
Better Pumps: Reliable Handpump Infrastructure
Approximately 90 million people in Africa lack access to safe drinking water, despite having water infrastructure installed in their community. The India Mark II and the Afridev handpumps are among the most widely used handpumps in the world. Sadly, studies show that approximately 30% of these handpumps are non-operational due to failures of the bearings, seals, head flange, and other common components. The Better Pumps team of the Collaboratory provides engineering support for partners who are working to improve handpump sustainability. We partnered with Tony Beers and AlignedWorks to validate a bearing test methodology for the India Mark II handpump. By modifying the loading conditions in our handpump test machine, we were able to replicate failures observed by AlignedWorks in a field trial of their bearing design. We partnered with Matt Schwiebert and Living Water International to test new seal designs for the India Mark II and Afridev handpumps and to measure head flange deflections in the India Mark II handpump. Seal performance data collected by the team was used to validate a new design in advance of field trials by Living Water International. Head flange deflection data was collected for partner benchmarking of their computational analysis. Test methodologies and results are reported.https://mosaic.messiah.edu/engr2021/1000/thumbnail.jp
Reactive mercury in the troposphere: Model formation and results for Florida, the northeastern United States, and the Atlantic Ocean
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95402/1/jgrd13669.pd
Molecular phylogeography and species distribution modelling evidence of 'oceanic' adaptation for Actinidia eriantha with a refugium along the oceanic-continental gradient in a biodiversity hotspot.
BACKGROUND: Refugia is considered to be critical for maintaining biodiversity; while discerning the type and pattern of refugia is pivotal for our understanding of evolutionary processes in the context of conservation. Interglacial and glacial refugia have been studied throughout subtropical China. However, studies on refugia along the oceanic-continental gradient have largely been ignored. We used a liana Actinidia eriantha, which occurs across the eastern moist evergreen broad-leaved forests of subtropical China, as a case study to test hypotheses of refugia along the oceanic-continental gradient and 'oceanic' adaptation. RESULTS: The phylogeographic pattern of A. eriantha was explored using a combination of three cpDNA markers and 38 nuclear microsatellite loci, Species distribution modelling and dispersal corridors analysis. Our data showed intermediate levels of genetic diversity [haplotype diversity (hT) = 0.498; unbiased expected heterozygosity (UHE) = 0.510] both at the species and population level. Microsatellite loci revealed five clusters largely corresponding to geographic regions. Coalescent time of cpDNA lineages was dated to the middle Pliocene (ca. 4.03 Ma). Both geographic distance and climate difference have important roles for intraspecific divergence of the species. The Zhejiang-Fujian Hilly Region was demonstrated to be a refugium along the oceanic-continental gradient of the species and fit the 'refugia in refugia' pattern. Species distribution modelling analysis indicated that Precipitation of Coldest Quarter (importance of 44%), Temperature Seasonality (29%) and Mean Temperature of Wettest Quarter (25%) contributed the most to model development. By checking the isolines in the three climate layers, we found that A. eriantha prefer higher precipitation during the coldest quarter, lower seasonal temperature difference and lower mean temperature during the wettest quarter, which correspond to 'oceanic' adaptation. Actinidia eriantha expanded to its western distribution range along the dispersal corridor repeatedly during the glacial periods. CONCLUSIONS: Overall, our results provide integrated evidence demonstrating that the Zhejiang-Fujian Hilly Region is a refugium along the oceanic-continental gradient of Actinidia eriantha in subtropical China and that speciation is attributed to 'oceanic' adaptation. This study gives a deeper understanding of the refugia in subtropical China and will contribute to the conservation and utilization of kiwifruit wild resources in the context of climate change
Toward optimal implementation of cancer prevention and control programs in public health: A study protocol on mis-implementation
Abstract Background Much of the cancer burden in the USA is preventable, through application of existing knowledge. State-level funders and public health practitioners are in ideal positions to affect programs and policies related to cancer control. Mis-implementation refers to ending effective programs and policies prematurely or continuing ineffective ones. Greater attention to mis-implementation should lead to use of effective interventions and more efficient expenditure of resources, which in the long term, will lead to more positive cancer outcomes. Methods This is a three-phase study that takes a comprehensive approach, leading to the elucidation of tactics for addressing mis-implementation. Phase 1: We assess the extent to which mis-implementation is occurring among state cancer control programs in public health. This initial phase will involve a survey of 800 practitioners representing all states. The programs represented will span the full continuum of cancer control, from primary prevention to survivorship. Phase 2: Using data from phase 1 to identify organizations in which mis-implementation is particularly high or low, the team will conduct eight comparative case studies to get a richer understanding of mis-implementation and to understand contextual differences. These case studies will highlight lessons learned about mis-implementation and identify hypothesized drivers. Phase 3: Agent-based modeling will be used to identify dynamic interactions between individual capacity, organizational capacity, use of evidence, funding, and external factors driving mis-implementation. The team will then translate and disseminate findings from phases 1 to 3 to practitioners and practice-related stakeholders to support the reduction of mis-implementation. Discussion This study is innovative and significant because it will (1) be the first to refine and further develop reliable and valid measures of mis-implementation of public health programs; (2) bring together a strong, transdisciplinary team with significant expertise in practice-based research; (3) use agent-based modeling to address cancer control implementation; and (4) use a participatory, evidence-based, stakeholder-driven approach that will identify key leverage points for addressing mis-implementation among state public health programs. This research is expected to provide replicable computational simulation models that can identify leverage points and public health system dynamics to reduce mis-implementation in cancer control and may be of interest to other health areas
Molecular Phylogeography and Ecological Niche Modeling of Sibbaldia procumbens s.l. (Rosaceae)
The phylogeographical analysis and ecological niche modeling (ENM) of the widely distributed Northern Hemisphere Sibbaldia procumbens s.l. can help evaluate how tectonic motion and climate change helped shape the current distribution patterns of this species. Three chloroplast regions (the atpI-atpH and trnL-trnF intergenic spacers and the trnL intron) were obtained from 332 (156 from present study and 176 from the previous study) individuals of S. procumbens s.l. An unrooted haplotype network was constructed using the software NETWORK, while BEAST was used to estimate the divergence times among haplotypes. ENM was performed by MAXENT to explore the historical dynamic distribution of S. procumbens s.l. The haplotype distribution demonstrates significant phylogeographical structure (NST > GST; P < 0.01). The best partitioning of genetic diversity by SAMOVA produced three groups, while the time to the most recent common ancestor of all haplotypes was estimated to originate during the Miocene, with most of the haplotype diversity having occurred during the Quaternary. The MAXENT analysis showed S. procumbens s.l. had a wider distribution range during the last glacial maximum and a narrower distribution range during the last interglacial, with predictions into the future showing the distribution range of S. procumbens s.l. shrinking
Is plasma vitamin C an appropriate biomarker of vitamin C intake? A systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>As the primary source of dietary vitamin C is fruit and to some extent vegetables, the plasma level of vitamin C has been considered a good surrogate or predictor of vitamin C intake by fruit and vegetable consumption. The purpose of this systematic review was to investigate the relationship between dietary vitamin C intakes measured by different dietary methods and plasma levels of vitamin C.</p> <p>Method</p> <p>We searched the literature up to May 2006 through the OVID interface: MEDLINE (from 1960) and EMBASE (from 1988). We also reviewed the reference lists in the articles, reviews, and textbooks retrieved. A total of 26 studies were selected and their results were combined using meta-analytic techniques with random-effect model approach.</p> <p>Results</p> <p>The overall result of this study showed a positive correlation coefficient between Food Frequency Questionnaire (FFQ) and biomarker (<it>r </it>= 0.35 for "both" genders, 0.39 for females, and 0.46 for males). Also the correlation between Dietary Recalls (DR)/diary and biomarker was 0.46 for "both" genders, 0.44 for females, and 0.36 for males. An overall correlation of 0.39 was found when using the weight record method. Adjusting for energy intake improved the observed correlation for FFQ from 0.31 to 0.41. In addition, we compared the correlation for smokers and non-smokers for both genders (FFQ: for non-smoker <it>r </it>= 0.45, adjusted for smoking <it>r </it>= 0.33).</p> <p>Conclusion</p> <p>Our findings show that FFQ and DR/diary have a moderate relationship with plasma vitamin C. The correlation may be affected/influenced by the presence of external factors such as vitamin bioavailability, absorption condition, stress and food processing and storage time, or by error in reporting vitamin C intake.</p
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