Introduction to the Special Issue of Plants on "Advances in Plant Reproductive Ecology and Conservation Biology".

Plant reproductive ecology explores aspects of the biology and ecology of plants ranging from breeding systems, plant-pollinator interactions, seed germination, floral traits, and much more [...].

The Conservation Genetics of Iris lacustris (Dwarf Lake Iris), a Great Lakes Endemic.

Iris lacustris, a northern Great Lakes endemic, is a rare species known from 165 occurrences across Lakes Michigan and Huron in the United States and Canada. Due to multiple factors, including habitat loss, lack of seed dispersal, patterns of reproduction, and forest succession, the species is threatened. Early population genetic studies using isozymes and allozymes recovered no to limited genetic variation within the species. To better explore genetic variation across the geographic range of I. lacustris and to identify units for conservation, we used tunable Genotyping-by-Sequencing (tGBS) with 171 individuals across 24 populations from Michigan and Wisconsin, and because the species is polyploid, we filtered the single nucleotide polymorphism (SNP) matrices using polyRAD to recognize diploid and tetraploid loci. Based on multiple population genetic approaches, we resolved three to four population clusters that are geographically structured across the range of the species. The species migrated from west to east across its geographic range, and minimal genetic exchange has occurred among populations. Four units for conservation are recognized, but nine adaptive units were identified, providing evidence for local adaptation across the geographic range of the species. Population genetic analyses with all, diploid, and tetraploid loci recovered similar results, which suggests that methods may be robust to variation in ploidy level.

Parsing a plethora of pollen: the role of pollen size and shape in the evolution of Boraginaceae.

Pollen, the microgametophyte of seed plants, has an important role in plant reproduction and, therefore, evolution. Pollen is variable in, for example, size, shape, aperture number; these features are particularly diverse in some plant taxa and can be diagnostic. In one family, Boraginaceae, the range of pollen diversity suggests the potential utility of this family as a model for integrative studies of pollen development, evolution and molecular biology. In the present study, a comprehensive survey of the diversity and evolution of pollen from 538 species belonging to 72 genera was made using data from the literature and additional scanning electron microscopy examination. Shifts in diversification rates and the evolution of various quantitative characters were detected, and the results revealed remarkable differences in size, shape and number of apertures. The pollen of one subfamily, Boraginoideae, is larger than that in Cynoglossoideae. The diversity of pollen shapes and aperture numbers in one tribe, Lithospermeae, is greater than that in the other tribes. Ancestral pollen for the family was resolved as small, prolate grains that bear three apertures and are iso-aperturate. Of all the tribes, the greatest number of changes in pollen size and aperture number were observed in Lithospermeae and Boragineae, and the number of apertures was found to be stable throughout all tribes of Cynoglossoideae. In addition, the present study showed that diversification of Boraginaceae cannot be assigned to a single factor, such as pollen size, and the increased rate of diversification for species-rich groups (e.g. Cynoglossum) is not correlated with pollen size or shape evolution. The palynological data and patterns of character evolution presented in the study provide better resolution of the roles of geographical and ecological factors in the diversity and evolution of pollen grains of Boraginaceae, and provide suggestions for future palynological research across the family.

Phylogenomics, floral evolution, and biogeography of Lithospermum L. (Boraginaceae).

Lithospermum (Boraginaceae), a geographically cosmopolitan medium-sized genus, includes diverse floral morphology, with variation in corolla size and shape and in breeding system. Over the past decade, multiple studies have examined the evolutionary history of Lithospermum, with most utilizing DNA regions from the plastid genome and/or the nuclear ribosomal internal transcribed spacer. These studies have, in general, not resulted in well-resolved and well-supported phylogenies. In the present study, 298 nuclear DNA regions, amplified via target sequence capture, were utilized for phylogenetic reconstruction for Lithospermum and relatives in Boraginaceae, and patterns of floral evolution, species diversification, and biogeography were examined. Based on multiple phylogenetic methods, Lithospermum is resolved as monophyletic, and the New World species of the genus are also monophyletic. While minimal phylogenetic incongruence is resolved within the nuclear genome, incongruence between the nuclear and plastid genomes is recovered. This is likely due to incomplete lineage sorting during early diversification of the genus in the Americas approximately 7.8 million years ago. At least four shifts to longer corollas are identified throughout Lithospermum, and this may be due to selection for hummingbird-pollinated flowers, particularly for species in Mexico and the southwestern United States. In the New World, one clade of species of the genus diversified primarily across the United States and Canada, and another radiated throughout the mountains of Mexico.

Insights into the individual evolutionary origins of Yersinia virulence factor effector proteins.

Pathogenic Yersinia bacteria, including Y. pseudotubuclosis Y. enterocolitica, and Y. pestis, contain the mosaic plasmid pYV that encodes for, among other things, a number of proteinaceous virulence factors. While the evolutionary histories of many of the biovars and strains of pathogenic Yersinia species are well documented, the origins of many of the individual virulence factors have not been comprehensively examined. Here, the evolutionary origins of the genes coding for a set of Yersinia outer protein (Yop) virulence factors were investigated through phylogenetic reconstruction and subsequence analysis. It was found that many of these genes had only a few sequenced homologs and none of the resolved phylogenies recovered the same relationships as was resolved from chromosomal analyses. Many of the evolutionary relationships differ greatly among genes on the plasmid, and variation is also found across different domains of the same gene, which provides evidence of the mosaic nature of the plasmid as well as multiple genes on the plasmid. This mosaic aspect also relates to patterns of selection, which vary among the studied domains.

Morphological Analysis of Size and Shape (MASS): An integrative software program for morphometric analyses of leaves.

PREMISE: Morphometric analysis is a common approach for comparing and categorizing botanical samples; however, completing a suite of analyses using existing tools may require a multi-stage, multi-program process. To facilitate streamlined analysis within a single program, Morphological Analysis of Size and Shape (MASS) for leaves was developed. Its utility is demonstrated using exemplar leaf samples from Acer saccharum, Malus domestica, and Lithospermum. METHODS: Exemplar samples were obtained from across a single tree (Acer saccharum), three trees in the same species (Malus domestica), and online, digitized herbarium specimens (Lithospermum). MASS was used to complete simple geometric measurements of samples, such as length and area, as well as geometric morphological analyses including elliptical Fourier and Procrustes analyses. Principal component analysis (PCA) of data was also completed within the same program. RESULTS: MASS is capable of making desired measurements and analyzing traditional morphometric data as well as landmark and outline data. DISCUSSION: Using MASS, differences were observed among leaves of the three studied taxa, but only in Malus domestica were differences statistically significant or correlated with other morphological features. In the future, MASS could be applied for analysis of other two-dimensional organs and structures. MASS is available for download at https://github.com/gillianlynnryan/MASS.

How to build distylous flowers: comparative floral development and evolution of distylous species across the angiosperms.

PREMISE: Distyly, a plant breeding system characterized by two floral morphs that have reciprocal positioning of anthers and stigmas, is known from at least 27 angiosperm families, making it an excellent example of convergent evolution. The various manners in which patterns of floral development produce the distinct anther and stigma heights in each morph remain largely unexplored from developmental and evolutionary perspectives. METHODS: In 15 species representing at least 12 origins of distyly, heights and lengths of floral organs in each morph throughout development were examined using light microscopy. Patterns of floral organ development were determined and compared among species. Family-level phylogenies of distylous species and relatives were reconstructed, and patterns of ancestral herkogamy were resolved. RESULTS: Differences in floral development between morphs resulted in 12 patterns leading to the anther and stigma positions characterizing distyly. Distylous species evolved from ancestors with different types of herkogamy, with approach herkogamy and lack of herkogamy resolved most frequently. CONCLUSIONS: Seven of the 12 patterns of floral development are known from only one species, with three other patterns described among pairs of close relatives. The most common pattern of floral development, described from at least seven genera, involves for anther heights, distinct intermorph growth rates and for stigma heights, growth rates that differ between morphs only during later development. This pattern is common among subclass Lamiidae, suggesting canalized development within the taxon. Among distylous species, the same type of ancestral herkogamy can give rise to different patterns of floral development.

Do medical students studying in the United Kingdom have an adequate factual knowledge of basic life support?

BACKGROUND: Healthcare professionals have a duty to maintain basic life support (BLS) skills. This study aims to evaluate medical students' factual knowledge of BLS and the training they receive. METHODS: A cross-sectional, closed-response questionnaire was distributed to the first- and fourth-year students studying at institutions in the United Kingdom. The paper questionnaire sought to quantify respondent's previous BLS training, factual knowledge of the BLS algorithm using five multiple choice questions (MCQs), and valuate their desire for further BLS training. Students received 1 point for each correctly identified answer to the 5 MCQ's. RESULTS: A total of 3,732 complete responses were received from 21 medical schools. Eighty percent (n=2,999) of students completed a BLS course as part of their undergraduate medical studies. There was a significant difference (P<0.001) in the percentage of the fourth-year students selecting the correct answer in all the MCQ's compared to the first-year students except in identifying the correct depth of compressions required during CPR (P=0.095). Overall 10.3% (95% CI 9.9% to 10.7%) of respondents correctly identified the answer to 5 MCQ's on BLS 9% of the first-year students (n=194) and 12% of the fourth-year students (n=190). On an institutional level the proportion of students answering all MCQ's correctly ranged from 2% to 54% at different universities. Eighty-one percent of students (n=3,031) wished for more BLS training in their curriculum. CONCLUSION: Factual knowledge of BLS is poor among medical students in the UK. There is a disparity in standards of knowledge across institutions and respondents indicating that they would like more training.

Functional outcomes and quality of life after total laryngectomy with noncircumferential radial forearm free tissue transfer.

BACKGROUND: The purpose of this study was to compare long-term functional and quality of life (QOL) outcomes after total laryngectomy with primary closure and those who underwent reconstruction with noncircumferential radial free forearm tissue transfer (RFFTT). METHODS: Sixty-seven patients were identified by chart review and underwent long-term follow-up using QOL surveys and standardized interviews. RESULTS: The RFFTT group had significantly higher rates of chemotherapy, gastric tube (G-tube) at surgery, and postoperative stricture. At follow-up, most patients (88%) had a tracheoesophageal prosthesis (TEP) and were using it as their primary communication method. Diet and swallowing outcomes were comparable and no one had a G-tube. Device life and TEP complications did not differ significantly. Only voice-related QOL differed significantly between the RFFTT group and those who had undergone total laryngectomy without adjuvant treatment. CONCLUSION: Despite more extensive treatment, the reconstructed group achieved comparable outcomes to those who had undergone total laryngectomy with adjuvant treatment.

Phylogeographic History of Atraphaxis Plants in Arid Northern China and the Origin of A. bracteata in the Loess Plateau.

In China, species of Atraphaxis (Polygonaceae) primarily inhabit arid zones across temperate steppe and desert regions. The complex geologic history (e.g., expansion of deserts) and extreme climate shifts of the region appear to have played an important role in shaping the phylogeography of Atraphaxis. The present study focuses on species-level phylogeographic patterns of Atraphaxis in China, with the goal of determining the impact of past environmental changes, in northern China, on the evolutionary history of the genus. Five hundred and sixty-four individuals distributed among 71 populations of 11 species of Atraphaxis from across the geographic range of the genus were studied using sequence data from two plastid spacers, psbK-psbI and psbB-psbH. The results demonstrate that most chloroplast haplotypes are species-specific, except for some present among widespread species. The phylogeny of Atraphaxis was well structured, and molecular dating analyses suggest that the main divergence events occurred during the late Pliocene and Pleistocene (5.73-0.03 million years ago). The statistical dispersal-vicariance analysis (S-DIVA) results provide evidence that phylogeographic patterns for the genus were characterized by both vicariance events and regional dispersal. The presented data suggest that the rapid expansion of deserts and climatic changes in northern China during the late Pliocene and Pleistocene have driven the diversification and spread of Atraphaxis in the region. The expansion of the Tengger Desert provided appropriate conditions for the origin of A. bracteata. Additionally, a contact zone in the north of the Hexi Corridor was identified as having played a significant role as a migratory route for species in adjacent areas.

Management of Carotid Blowout from Radiation Necrosis.

Although the incidence of carotid blowout has decreased with the advent of better reconstructive techniques, it remains a real risk after major head and neck surgery, especially in an irradiated field. A systematic, multidisciplinary approach incorporating appropriate history and physical examination, adequate resuscitation, diagnostic computed tomography, and diagnostic and therapeutic angiography can manage most of these patients in a safe and effective manner. Surgery has a limited role in acute management, although surgical techniques are useful both for prevention of this problem and for wound management after carotid blowout.

De novo Sequencing and Comparative Transcriptomics of Floral Development of the Distylous Species Lithospermum multiflorum.

Genes controlling the morphological, micromorphological, and physiological components of the breeding system distyly have been hypothesized, but many of the genes have not been investigated throughout development of the two floral morphs. To this end, the present study is an examination of comparative transcriptomes from three stages of development for the floral organs of the morphs of Lithospermum multiflorum. Transcriptomes of flowers of the two morphs, from various stages of development, were sequenced using an Illumina HiSeq 2000. The floral transcriptome of L. multiflorum was assembled, and differential gene expression (DE) was identified between morphs, throughout development. Additionally, Gene Ontology (GO) terms for DE genes were determined. Fewer genes were DE early in development compared to later in development, with more genes highly expressed in the gynoecium of the SS morph and the corolla and androecium of the LS morph. A reciprocal pattern was observed later in development, and many more genes were DE during this latter stage. During early development, DE genes appear to be involved in growth and floral development, and during later development, DE genes seem to affect physiological functions. Interestingly, many genes involved in response to stress were identified as DE between morphs.

Vector potential and population dynamics for Amblyomma inornatum.

We studied the natural life cycle of Amblyomma inornatum and its vector potential in South Texas. This tick is distributed throughout South Texas and most of Central America. A. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the Tamaulipan Biotic Province in South Texas. The life cycle of A. inornatum in South Texas showed a clear seasonal pattern consistent with one generation per year. Nymphs emerged in the spring with a peak in February through May. Adults emerged in the summer with a peak in July through September. Detection of A. inornatum larvae was negatively correlated with saturation deficit and positively correlated with rain in the previous few months. Adult activity was positively correlated with temperature and rain in the previous five weeks. Using PCR we detected the presence of species related to Candidatus Borrelia lonestari, Borrelia burgdorferi, Rickettsia species (Candidatus Rickettsia amblyommii), Ehrlichia chaffeensis, and another Ehrlichia related to Ehrlichia ewingii. Finally we sequenced the mitochondrial 16S rRNA genes and found that A. inornatum is most closely related to Amblyomma parvum. This is the first report of the life cycle, vector potential and phylogeny of A. inornatum.

A phylogenetic analysis of morphological and molecular characters of Boraginaceae: evolutionary relationships, taxonomy, and patterns of character evolution.

The angiosperm family Boraginaceae includes ca. 1600 species distributed among ca. 110 genera. Some floral features are constant within the family, but many vegetative, floral, pollen, and nutlet traits vary. Utilizing 224 species of Boraginaceae and related taxa, five matrices were constructed with various combinations of morphological characters, three chloroplast DNA regions, and one nuclear ribosomal DNA region. Phylogenetic analyses were conducted for these matrices, and patterns of character evolution were examined. Boraginaceae is resolved as monophyletic, with Wellstedia as its sister. Codon is sister to Boraginaceae + Wellstedia. Although most of the investigated morphological characters have a low consistency index, particular character states are synapomorphies for large clades in each of the tribes of the family. In Boraginaceae, the breeding system heterostyly evolved at least 12 times, which is the largest number of origins resolved in any family; therefore Boraginaceae can serve as a model for the evolution and development of heterostyly. Nutlet ornamentation is most diverse in Cynoglosseae and Trichodesmeae, while pollen and floral features are most variable in Boragineae and Lithospermeae. Phylogenetic relationships and patterns of character evolution identified in the present study set the stage for future work creating an updated taxonomic system of Boraginaceae.

Subjective and objective parameters of the adult female voice after cricotracheal resection and dilation.

OBJECTIVES: We compared the voice outcomes after cricotracheal resection (CTR) and airway dilation in adult women. METHODS: We performed long-term comprehensive voice assessments in 23 adult women treated for laryngotracheal stenosis, including acoustic and perceptual measurements of voice, videostroboscopy, the Voice Handicap Index, and an open-ended subjective questionnaire. RESULTS: Voice measures were abnormal in both groups. Objective pitch and loudness measurements were significantly more impaired after CTR than after dilation. Perceptual ratings of voice were worse after CTR than after dilation, particularly with regard to breathiness, pitch, and loudness. The CTR group was more likely to report a voice disorder, reported significantly more voice symptoms, and had higher voice handicap scores. Videostroboscopy was frequently abnormal in both groups, with more evidence of vocal hyperfunction after CTR. Self-ratings of breathing and swallowing were generally high in both groups, but voice satisfaction was rated lower after CTR. CONCLUSIONS: Voice was more significantly negatively impacted by CTR than by dilation. Surprisingly, many individuals in both groups reported improvements--a finding that possibly highlights the impact of laryngotracheal stenosis on airflow and vocal function before surgery. The importance of patient selection and preoperative counseling is emphasized, along with the potential need for voice therapy.

Comparative floral development in Lithospermum (Boraginaceae) and implications for the evolution and development of heterostyly.

PREMISE OF THE STUDY: The evolution and development of floral developmental patterns were investigated in three heterostylous and three homostylous species of Lithospermum to determine whether species that independently acquired the same floral form follow the same pattern of development or different patterns. METHODS: Using light and scanning electron microscopy, we observed developmental patterns in flowers at different stages of maturity. These patterns were compared within individual species, between heterostylous morphs, and among heterostylous and homostylous species. KEY RESULTS: Although heterostyly has been determined by phylogenetic analysis to have originated independently in each of the heterostylous species, flowers of the long-style morph of each species follow similar patterns of gross development, as do those of the short-style morph. In addition, the flowers of each morph develop in a manner similar to those of their respective homostylous, herkogamous relatives. However, the developmental patterns of the stylar epidermal cells differ among these species and between heterostylous and homostylous species. CONCLUSIONS: Floral developmental patterns in homostylous species provide evidence that modification of specific traits, such as patterns of stylar growth, can lead to the evolution of heterostyly. The developmental changes that affect the positions of the stigmas and anthers in each morph likely involve either temporal or spatial modifications of gene function. The floral developmental patterns described here and the occurrence of multiple types of herkogamy within some species of Lithospermum provide evidence that heterostylous species in the genus have originated via distinct evolutionary developmental pathways.

Determining the efficacy and cost-effectiveness of the ActiValve: results of a long-term prospective trial.

OBJECTIVES/HYPOTHESIS: To investigate 1) whether the Provox ActiValve results in increased device-life in individuals with below average device-life, 2) whether it is cost-effective, and 3) whether it has any impact on voice-related quality of life. STUDY DESIGN: Prospective study. METHODS: Individuals who experienced below-average tracheoesophageal prosthesis (TEP) life were studied. RESULTS: Individuals with persistent below-average TEP life were enrolled in the study and underwent periodic re-evaluation. The majority (73%) experienced significant improvement as a result of use of the device. Those who continued to wear the device were followed for an average of 30.45 months (range, 14.70-43.49 months) and wore a total of 31 devices over this time. They demonstrated an average increase in device-life of more than 500%, going from an average of 1.93 months with a traditional indwelling device to 10.30 months with the ActiValve. The majority of individuals found that voicing with the ActiValve was either the same or better than with their previous indwelling TEP. Voice-related quality of life was not significantly different from that of a group of controls. Overall satisfaction with the device was high, and the majority would have chosen the ActiValve in the future. Overall, there were estimated to be cost savings to third-party payers through use of the ActiValve in this population. CONCLUSIONS: The ActiValve is effective in increasing device-life in selected patients who have failed conservative measures. Our protocol for use of the device requires individuals to meet several usage criteria before initial placement and to return for periodic monitoring.

Quantum molecular dynamics simulations of transport properties in liquid and dense-plasma plutonium.

We have calculated the viscosity and self-diffusion coefficients of plutonium in the liquid phase using quantum molecular dynamics (QMD) and in the dense-plasma phase using orbital-free molecular dynamics (OFMD), as well as in the intermediate warm dense matter regime with both methods. Our liquid metal results for viscosity are about 40% lower than measured experimentally, whereas a previous calculation using an empirical interatomic potential (modified embedded-atom method) obtained results 3-4 times larger than the experiment. The QMD and OFMD results agree well at the intermediate temperatures. The calculations in the dense-plasma regime for temperatures from 50 to 5000 eV and densities about 1-5 times ambient are compared with the one-component plasma (OCP) model, using effective charges given by the average-atom code INFERNO. The INFERNO-OCP model results agree with the OFMD to within about a factor of 2, except for the viscosity at temperatures less than about 100 eV, where the disagreement is greater. A Stokes-Einstein relationship of the viscosities and diffusion coefficients is found to hold fairly well separately in both the liquid and dense-plasma regimes.