Organellar phylogenomics at the epidendroid orchid base, with a focus on the mycoheterotrophic Wullschlaegelia.

BACKGROUND AND AIMS: Heterotrophic plants have long been a challenge for systematists, exemplified by the base of the orchid subfamily Epidendroideae, which contains numerous mycoheterotrophic species. METHODS: Here we address the utility of organellar genomes in resolving relationships at the epidendroid base, specifically employing models of heterotachy, or lineage-specific rate variation over time. We further conduct comparative analyses of plastid genome evolution in heterotrophs and structural variation in matK. KEY RESULTS: We present the first complete plastid genomes (plastomes) of Wullschlaegelia, the sole genus of the tribe Wullschlaegelieae, revealing a highly reduced genome of 37 kilobases, which retains a fraction of the genes present in related autotrophs. Plastid phylogenomic analyses recovered a strongly supported clade composed exclusively of mycoheterotrophic species with long branches. We further analyzed mitochondrial gene sets, which recovered similar relationships to those in other studies using nuclear data, but the placement of Wullschlaegelia remains uncertain. We conducted comparative plastome analyses among Wullschlaegelia and other heterotrophic orchids, revealing a suite of correlated substitutional and structural changes relative to autotrophic species. Lastly, we investigated evolutionary and structural variation in matK, which is retained in Wullschlaegelia and a few other 'late stage' heterotrophs and found evidence for structural conservation despite rapid substitution rates in both Wullschlaegelia and the leafless Gastrodia. CONCLUSIONS: Our analyses reveal the limits of what the plastid genome can tell us on orchid relationships in this part of the tree, even when applying parameter-rich heterotachy models. Our study underscores the need for increased taxon sampling across all three genomes at the epidendroid base, and illustrates the need for further research on addressing heterotachy in phylogenomic analyses.

Photochemistry of Ru(II) Triazole Complexes with 6-Membered Chelate Ligands: Detection and Reactivity of Ligand-Loss Intermediates.

Photochemical ligand release from metal complexes may be exploited in the development of novel photoactivated chemotherapy agents for the treatment of cancer and other diseases. Highly intriguing photochemical behavior is reported for two ruthenium(II) complexes bearing conformationally flexible 1,2,3-triazole-based ligands incorporating a methylene spacer to form 6-membered chelate rings. [Ru(bpy)2(pictz)]2+ (1) and [Ru(bpy)2(btzm)]2+ (2) (bpy = 2,2'-bipyridyl; pictz = 1-(picolyl)-4-phenyl-1,2,3-triazole; btzm = bis(4-phenyl-1,2,3-triazol-4-yl)methane) exhibit coordination by the triazole ring through the less basic N2 atom as a consequence of chelation and readily undergo photochemical release of the pictz and btzm ligands (ϕ = 0.079 and 0.091, respectively) in acetonitrile solution to form cis-[Ru(bpy)2(NCMe)2]2+ (3) in both cases. Ligand-loss intermediates of the form [Ru(bpy)2(κ1-pictz or κ1-btzm)(NCCD3)]2+ are detected by 1H NMR spectroscopy and mass spectrometry. Photolysis of 1 yields three ligand-loss intermediates with monodentate pictz ligands, two of which form through simple decoordination of either the pyridine or triazole donor with subsequent solvent coordination (4-tz(N2) and 4-py, respectively). The third intermediate, shown to be able to form photochemically directly from 1, arises through linkage isomerism in which the monodentate pictz ligand is coordinated by the triazole N3 atom (4-tz(N3)) with a comparable ligand-loss intermediate with an N3-bound κ1-btzm ligand also observed for 2.

Visible-Light Switching of Metallosupramolecular Assemblies.

A photoswitchable ligand and palladium(II) ions form a dynamic mixture of self-assembled metallosupramolecular structures. The photoswitching ligand is an ortho-fluoroazobenzene with appended pyridyl groups. Combining the E-isomer with palladium(II) salts affords a double-walled triangle with composition [Pd3 L6 ]6+ and a distorted tetrahedron [Pd4 L8 ]8+ (1 : 2 ratio at 298 K). Irradiation with 410 nm light generates a photostationary state with approximately 80 % of the E-isomer of the ligand and results in the selective disassembly of the tetrahedron, the more thermodynamically stable structure, and the formation of the triangle, the more kinetically inert product. The triangle is then slowly transformed back into the tetrahedron over 2 days at 333 K. The Z-isomer of the ligand does not form any well-defined structures and has a thermal half-life of 25 days at 298 K. This approach shows how a thermodynamically preferred self-assembled structure can be reversibly pumped to a kinetic trap by small perturbations of the isomer distribution using non-destructive visible light.

Publicly Available and Validated DNA Reference Sequences Are Critical to Fungal Identification and Global Plant Protection Efforts: A Use-Case in Colletotrichum.

Publicly available and validated DNA reference sequences useful for phylogeny estimation and identification of fungal pathogens are an increasingly important resource in the efforts of plant protection organizations to facilitate safe international trade of agricultural commodities. Colletotrichum species are among the most frequently encountered and regulated plant pathogens at U.S. ports-of-entry. The RefSeq Targeted Loci (RTL) project at NCBI (BioProject no. PRJNA177353) contains a database of curated fungal internal transcribed spacer (ITS) sequences that interact extensively with NCBI Taxonomy, resulting in verified name-strain-sequence type associations for >12,000 species. We present a publicly available dataset of verified and curated name-type strain-sequence associations for all available Colletotrichum species. This includes an updated GenBank Taxonomy for 238 species associated with up to 11 protein coding loci and an updated RTL ITS dataset for 226 species. We demonstrate that several marker loci are well suited for phylogenetic inference and identification. We improve understanding of phylogenetic relationships among verified species, verify or improve phylogenetic circumscriptions of 14 species complexes, and reveal that determining relationships among these major clades will require additional data. We present detailed comparisons between phylogenetic and similarity-based approaches to species identification, revealing complex patterns among single marker loci that often lead to misidentification when based on single-locus similarity approaches. We also demonstrate that species-level identification is elusive for a subset of samples regardless of analytical approach, which may be explained by novel species diversity in our dataset and incomplete lineage sorting and lack of accumulated synapomorphies at these loci.

Unprecedented Parallel Photosynthetic Losses in a Heterotrophic Orchid Genus.

Heterotrophic plants are evolutionary experiments in genomic, morphological, and physiological change. Yet, genomic sampling gaps exist among independently derived heterotrophic lineages, leaving unanswered questions about the process of genome modification. Here, we have sequenced complete plastid genomes for all species of the leafless orchid genus Hexalectris, including multiple individuals for most, and leafy relatives Basiphyllaea and Bletia. Our objectives are to determine the number of independent losses of photosynthesis and to test hypotheses on the process of genome degradation as a result of relaxed selection. We demonstrate four to five independent losses of photosynthesis in Hexalectris based on degradation of the photosynthetic apparatus, with all but two species displaying evidence of losses, and variation in gene loss extending below the species level. Degradation in the atp complex is advanced in Hexalectris warnockii, whereas only minimal degradation (i.e., physical loss) has occurred among some "housekeeping" genes. We find genomic rearrangements, shifts in Inverted Repeat boundaries including complete loss in one accession of H. arizonica, and correlations among substitutional and genomic attributes. Our unprecedented finding of multiple, independent transitions to a fully mycoheterotrophic lifestyle in a single genus reveals that the number of such transitions among land plants is likely underestimated. This study underscores the importance of dense taxon sampling, which is highly informative for advancing models of genome evolution in heterotrophs. Mycoheterotrophs such as Hexalectris provide forward-genetic opportunities to study the consequences of radical genome evolution beyond what is possible with mutational studies in model organisms alone.

Visible-Light Photoswitching by Azobenzazoles.

Three visible-light responsive photoswitches are reported, azobis(1-methyl-benzimidazole) (1), azobis(benzoxazole) (2) and azobis(benzothiazole) (3). Photostationary distributions are obtained upon irradiation with visible light comprising approximately 80 % of the thermally unstable isomer, with thermal half-lives up to 8 min and are mostly invariant to solvent. On protonation, compound 1H+ has absorption extending beyond 600 nm, allowing switching with yellow light, and a thermal half-life just under 5 minutes. The two isomers have significantly different pKa values, offering potential as a pH switch. The absorption spectra of 2 and 3 are insensitive to acid, although changes in the thermal half-life of 3 indicate more basic intermediates that significantly influence the thermal barrier to isomerization. These findings are supported by high-level ab initio calculations, which validate that protonation occurs on the ring nitrogen and that the Z isomer is more basic in all cases.

Diastereoselective Control of Tetraphenylethene Reactivity by Metal Template Self-Assembly.

The reaction of 4,4',4'',4'''-(ethene-1,1,2,2-tetrayl)tetraaniline with 2-pyridinecarboxaldehyde and iron(II) chloride resulted, after aqueous workup, in the diastereoselective formation of an [Fe2 L3 ]4+ triple-stranded helicate structure, irrespective of the stoichiometry employed. The helicate structure was characterized in solution by multinuclear NMR spectroscopy, and in the solid state by single-crystal X-ray crystallography. The reaction of iron(II) tetrafluoroborate or iron(II) bistriflimide with the tetraaniline and 2-pyridinecarboxaldehyde allowed the formation of an [Fe8 L6 ]16+ cube when the appropriate stoichiometry was used, but these structures were unstable with respect to hydrolysis. The pendant amine groups on the helicate can be functionalized by reaction with acid chlorides or anhydrides, and the resulting functionalized tetraphenylethene (TPE) units were isolated by the reaction of the helicate with tris(2-aminoethyl)amine. The emission properties of the TPE units were studied in THF/water mixtures, and they were found by dynamic light scattering to self-assemble into large (av. diameter 250 nm) structures.

Excited States of Triphenylamine-Substituted 2-Pyridyl-1,2,3-triazole Complexes.

A new 2-pyridyl-1,2,3-triazole (pytri) ligand, TPA-pytri, substituted with a triphenylamine (TPA) donor group on the 5 position of the pyridyl unit was synthesized and characterized. Dichloroplatinum(II), bis(phenylacetylide)platinum(II), bromotricarbonylrhenium(I), and bis(bipyridyl)ruthenium(II) complexes of this ligand were synthesized and compared to complexes of pytri ligands without the TPA substituent. The complexes of unsubstituted pytri ligands show metal-to-ligand charge-transfer (MLCT) absorption bands involving the pytri ligand in the near-UV region. These transitions are complemented by intraligand charge-transfer (ILCT) bands in the TPA-pytri complexes, resulting in greatly improved visible absorption (λmax = 421 nm and ϵ = 19800 M-1 cm-1 for [Pt(TPA-pytri)Cl2]). The resonance Raman enhancement patterns allow for assignment of these absorption bands. The [Re(TPA-pytri)(CO)3Br] and [Pt(TPA-pytri)(CCPh)2] complexes were examined with time-resolved infrared spectroscopy. Shifts in the C≡C and C≡O stretching bands revealed that the complexes form states with increased electron density about their metal centers. [Pt(TPA-pytri)Cl2] is unusual in that it is emissive despite the presence of deactivating d-d states, which prevents emission from the unsubstituted pytri complex.

Comparison of inverse and regular 2-pyridyl-1,2,3-triazole "click" complexes: structures, stability, electrochemical, and photophysical properties.

Two inverse 2-pyridyl-1,2,3-triazole "click" ligands, 2-(4-phenyl-1H-1,2,3-triazol-1-yl)pyridine and 2-(4-benzyl-1H-1,2,3-triazol-1-yl)pyridine, and their palladium(II), platinum(II), rhenium(I), and ruthenium(II) complexes have been synthesized in good to excellent yields. The properties of these inverse "click" complexes have been compared to the isomeric regular compounds using a variety of techniques. X-ray crystallographic analysis shows that the regular and inverse complexes are structurally very similar. However, the chemical and physical properties of the isomers are quite different. Ligand exchange studies and density functional theory (DFT) calculations indicate that metal complexes of the regular 2-(1-R-1H-1,2,3-triazol-4-yl)pyridine (R = phenyl, benzyl) ligands are more stable than those formed with the inverse 2-(4-R-1H-1,2,3-triazol-1-yl)pyridine (R = phenyl, benzyl) "click" chelators. Additionally, the bis-2,2'-bipyridine (bpy) ruthenium(II) complexes of the "click" chelators have been shown to have short excited state lifetimes, which in the inverse triazole case, resulted in ejection of the 2-pyridyl-1,2,3-triazole ligand from the complex. Under identical conditions, the isomeric regular 2-pyridyl-1,2,3-triazole ruthenium(II) bpy complexes are photochemically inert. The absorption spectra of the inverse rhenium(I) and platinum(II) complexes are red-shifted compared to the regular compounds. It is shown that conjugation between the substituent group R and triazolyl unit has a negligible effect on the photophysical properties of the complexes. The inverse rhenium(I) complexes have large Stokes shifts, long metal-to-ligand charge transfer (MLCT) excited state lifetimes, and respectable quantum yields which are relatively solvent insensitive.

Obstetrical and neonatal outcomes among women infected with hepatitis C and their infants.

OBJECTIVES: (1) To describe obstetrical and neonatal outcomes among a cohort of hepatitis C virus (HCV) infected women, comparing HCV RNA positive to HCV RNA negative women; (2) to characterize virologic and hepatic parameters associated with HCV infection during pregnancy; and (3) to describe the rate of HCV vertical transmission. METHODS: We prospectively enrolled 145 HCV-positive pregnant women across British Columbia between 2000 and 2003. Participating women were monitored during pregnancy and their infants were followed to assess them for HCV infection. Maternal HCV RNA was assessed close to delivery. RESULTS: Seventy percent of women reported injection drug use as their primary risk factor for HCV acquisition. Observed rates of intrauterine fetal death, preterm delivery, small for gestational age, and low birth weight infants were 3.4%, 17.9%, 11.3%, and 12.5%, respectively, without a significant association with maternal HCV RNA status. The rate of cholestasis was 5.6% in the HCV RNA-positive group (6/108) and 2.8% in the HCV RNA-negative group (1/37) (P = 0.496). Serum alanine aminotransferase levels decreased significantly through pregnancy, and were significantly higher in HCV RNA-positive women than in HCV RNA-negative women after controlling for cholestasis, co-infections, and alcohol consumption. Among the HCV RNA-positive women, the median FIB-4 score was 0.67 (IQR 0.56 to 0.76) in the first trimester, 0.74 (IQR 0.52 to 1.18) in the second trimester, and 0.89 (IQR 0.52 to 1.09) in the third trimester (P = 0.02). The median HCV viral load at delivery was 424 561 IU/mL. The vertical transmission rate was 4.7% in HCV RNA-positive women, with no cases in HCV RNA-negative women. CONCLUSION: Because of the high rates of poor obstetrical outcomes found in this prospective cohort, population-level screening for HCV in pregnancy should be considered.

Objectifs : 1) Décrire les issues obstétricales et néonatales au sein d'une cohorte de femmes infectées par le virus de l'hépatite C (VHC), en comparant des femmes séropositives pour l'ARN du VHC à des femmes séronégatives pour l'ARN du VHC; 2) caractériser les paramètres virologiques et hépatiques associés à l'infection par le VHC pendant la grossesse; et 3) décrire le taux de transmission verticale du VHC. Méthodes : Nous avons sollicité, de manière prospective, la participation de 145 femmes enceintes séropositives pour le VHC provenant des quatre coins de la Colombie-Britannique, entre 2000 et 2003. Les participantes ont fait l'objet d'un suivi pendant la grossesse, tandis que leurs nouveau-nés ont été suivis afin de déterminer la présence ou non d'une infection par le VHC. La présence d'ARN du VHC chez la mère a été évaluée peu avant l'accouchement. Résultats : Soixante-dix pour cent des femmes ont indiqué que la consommation de drogues par injection constituait leur principal facteur de risque d'acquisition du VHC. Les taux constatés de mort fœtale intra-utérine, d'accouchement préterme, d'hypotrophie fœtale et de faible poids à la naissance étaient, respectivement, de 3,4 %, de 17,9 %, de 11,3 % et de 12,5 %, sans association significative avec le statut maternel quant à l'ARN du VHC. Le taux de cholestase était de 5,6 % chez les femmes séropositives pour l'ARN du VHC (6/108) et de 2,8 % chez les femmes séronégatives pour l'ARN du VHC (1/37) (P = 0,496). Les taux sériques d'alanine aminotransférase ont diminué considérablement tout au long de la grossesse et étaient nettement plus élevés chez les femmes séropositives pour l'ARN du VHC que chez les femmes séronégatives pour l'ARN du VHC, à la suite de la neutralisation des effets de la cholestase, des co-infections et de la consommation d'alcool. Chez les femmes séropositives pour l'ARN du VHC, le score FIB-4 médian était de 0,67 (IIQ 0,56 - 0,76) pendant le premier trimestre, de 0,74 (IIQ 0,52 - 1,18) pendant le deuxième trimestre et de 0,89 (IIQ 0,52 - 1,09) pendant le troisième trimestre (P = 0,02). La charge virale médiane en ce qui concerne le VHC au moment de l'accouchement était de 424 561 UI/ml. Le taux de transmission verticale était de 4,7 % chez les femmes séropositives pour l'ARN du VHC; aucun cas n'a été recensé chez les femmes séronégatives pour l'ARN du VHC. Conclusion : Compte tenu des taux élevés de piètres issues obstétricales qui sont constatés au sein de cette cohorte prospective, la mise en œuvre d'un dépistage populationnel du VHC pendant la grossesse devrait être envisagée.

The genetic ghost of an invasion past: colonization and extinction revealed by historical hybridization in Senecio.

Hybridization is an important evolutionary factor in the diversification of many plant and animal species. Of particular interest is that historical hybridization resulting in the origin of new species or introgressants has occurred between species now geographically separated by great distances. Here, we report that Senecio massaicus, a tetraploid species native to Morocco and the Canary Islands, contains genetic material of two distinct, geographically separated lineages: a Mediterranean lineage and a mainly southern African lineage. A time-calibrated internal transcribed spacer phylogeny indicates that the hybridization event took place up to 6.18 Ma. Because the southern African lineage has never been recorded from Morocco or the Canary Islands, we hypothesize that it reached this area in the distant past, but never became permanently established. Interestingly, the southern African lineage includes S. inaequidens, a highly invasive species that has recently become widespread throughout Europe and was introduced at the end of the 19th century as a 'wool alien'. Our results suggest that this more recent invasion of Europe by S. inaequidens represents the second arrival of this lineage into the region.

Improving the quality of family meeting documentation in the ICU at the end of life.

Objective: Improve documentation quality of end-of-life family meetings in a tertiary intensive care unit (ICU). Design: Before-and-after interventional quality improvement project between October 2018 and February 2020 utilising an electronic pro-forma record. Setting: Australian, University affiliated, mixed medical-surgical 22 bed adult ICU. Participants: Patients who were admitted to the ICU for active management and subsequently died during that ICU admission. We enrolled 50 patients who died before and 50 patients after the introduction of the electronic family meeting pro-forma record. Intervention: Through collaboration with ICU medical and nursing staff, End-of-life Special Interest Group and Clinical Documentation Committee we developed the ICU Family Meeting Discussion Note as an electronic pro-forma record with multiple key fields of entry. Main outcome measures: Patient records were examined for the presence of documented details around patient's admission, family meetings and specific elements surrounding the patient's death. Results: The introduction of a pro-forma record markedly improved the quality of documentation of end-of-life care related family meetings. Documentation increased in recording hospital admission date/time (6% vs 84%), meeting location (14% vs 70%), the reason patients were absent from the meeting (34% vs 72%), the Medical Treatment Decision Maker (MTDM) (10% vs 44%), the patient's resuscitation status (22% vs 54%), and treatment options discussed (78% vs 94%) (p ⩽ 0.005 for all). Conclusion: Introducing an electronic pro-forma record to facilitate family meeting documentation increased the frequency of important recorded information. Further studies are required to assess whether documentation quality improvements are sustainable and whether they affect patient- or relative-centred outcomes.

Mycorrhizal specificity in the fully mycoheterotrophic Hexalectris Raf. (Orchidaceae: Epidendroideae).

Mycoheterotrophic species have abandoned an autotrophic lifestyle and obtain carbon exclusively from mycorrhizal fungi. Although these species have evolved independently in many plant families, such events have occurred most often in the Orchidaceae, resulting in the highest concentration of these species in the tracheophytes. Studies of mycoheterotrophic species' mycobionts have generally revealed extreme levels of mycorrhizal specialization, suggesting that this system is ideal for studying the evolution of mycorrhizal associations. However, these studies have often investigated single or few, often unrelated, species without consideration of their phylogenetic relationships. Herein, we present the first investigation of the mycorrhizal associates of all species of a well-characterized orchid genus comprised exclusively of mycoheterotrophic species. With the employment of molecular phylogenetic methods, we identify the fungal associates of each of nine Hexalectris species from 134 individuals and 42 populations. We report that Hexalectris warnockii associates exclusively with members of the Thelephoraceae, H. brevicaulis and H. grandiflora associate with members of the Russulaceae and Sebacinaceae subgroup A, while each member of the H. spicata species complex associates primarily with unique sets of Sebacinaceae subgroup A clades. These results are consistent with other studies of mycorrhizal specificity within mycoheterotrophic plants in that they suggest strong selection within divergent lineages for unique associations with narrow clades of mycorrhizal fungi. Our results also suggest that mycorrhizal associations are a rapidly evolving characteristic in the H. spicata complex.

Draft genome sequence of the basidiomycetous fungus Tinctoporellus epimiltinus strain RS1.

Members of the genus Tinctoporellus, which belong to the wood-degrading basidiomycetes, possess the ability to synthesize an array of industrially potent enzymes and metabolites. Here, we present the draft genome sequence of the species Tinctoporellus epimiltinus strain RS1, which is the first to represent its genus. The genome was sequenced using Illumina's 2 × 150 bp paired-end Nextera protocol. The draft genome assembly was 46.2 Mb in size consisting of 13,791 protein coding genes. Identification of carbohydrate active enzymes and laccases from the data may be useful in order to harness the metabolic potentials of the fungi. The data can be accessed at ENA under the accession number FTLJ00000000.

Plastid Genome Degradation in the Endangered, Mycoheterotrophic, North American Orchid Hexalectris warnockii.

Heterotrophic plants provide evolutionarily independent, natural experiments in the genomic consequences of radically altered nutritional regimes. Here, we have sequenced and annotated the plastid genome of the endangered mycoheterotrophic orchid Hexalectris warnockii. This orchid bears a plastid genome that is ∼80% the total length of the leafy, photosynthetic Phalaenopsis, and contains just over half the number of putatively functional genes of the latter. The plastid genome of H. warnockii bears pseudogenes and has experienced losses of genes encoding proteins directly (e.g., psa/psb, rbcL) and indirectly involved in photosynthesis (atp genes), suggesting it has progressed beyond the initial stages of plastome degradation, based on previous models of plastid genome evolution. Several dispersed and tandem repeats were detected, that are potentially useful as conservation genetic markers. In addition, a 29-kb inversion and a significant contraction of the inverted repeat boundaries are observed in this plastome. The Hexalectris warnockii plastid genome adds to a growing body of data useful in refining evolutionary models in parasites, and provides a resource for conservation studies in these endangered orchids.

Structure-function relationships of donor-acceptor Stenhouse adduct photochromic switches.

The first in-depth, systematic study of the photoswitching properties of Donor-Acceptor Stenhouse Adducts (DASAs) is reported. Barbituric acid derived DASAs functionalised with 14 different amines ranging from dimethylamine to 4-methoxy-N-methylaniline were structurally characterised in solution using 1H and 13C NMR spectroscopy and, in eight cases, in the solid state by single crystal X-ray diffraction. The distribution of coloured and colourless isomers in the dark, their photostationary states under irradiation, apparent thermal half-lives, and fatigue resistance are systematically compared. A simple kinetic model is used to characterise photoswitching behaviour and reveals that minor structural modifications can significantly improve the photoswitching properties of DASA photochromes. These modifications result in excellent photoswitching properties for '1st generation' DASAs in chloroform, including exceptional fatigue resistance, opening the door for these photochromic molecules to find widespread applications.

Cloud fraction at the ARM SGP site: reducing uncertainty with self-organizing maps.

Instrument downtime leads to uncertainty in the monthly and annual record of cloud fraction (CF), making it difficult to perform time series analyses of cloud properties and perform detailed evaluations of model simulations. As cloud occurrence is partially controlled by the large-scale atmospheric environment, this knowledge is used to reduce uncertainties in the instrument record. Synoptic patterns diagnosed from the North American Regional Reanalysis (NARR) during the period 1997-2010 are classified using a competitive neural network known as the self-organizing map (SOM). The classified synoptic states are then compared to the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) instrument record to determine the expected CF. A number of SOMs are tested to understand how the number of classes and the period of classifications impact the relationship between classified states and CFs. Bootstrapping is utilized to quantify the uncertainty of the instrument record when statistical information from the SOM is included. Although all SOMs significantly reduce the uncertainty of the CF record calculated in Kennedy et al. (Theor Appl Climatol 115:91-105, 2014), SOMs with a large number of classes and separated by month are required to produce the lowest uncertainty and best agreement with the annual cycle of CF. This result may be due to a manifestation of seasonally dependent biases in NARR. With use of the SOMs, the average uncertainty in monthly CF is reduced in half from the values calculated in Kennedy et al. (Theor Appl Climatol 115:91-105, 2014).

Patterns and causes of incongruence between plastid and nuclear Senecioneae (Asteraceae) phylogenies.

One of the longstanding questions in phylogenetic systematics is how to address incongruence among phylogenies obtained from multiple markers and how to determine the causes. This study presents a detailed analysis of incongruent patterns between plastid and ITS/ETS phylogenies of Tribe Senecioneae (Asteraceae). This approach revealed widespread and strongly supported incongruence, which complicates conclusions about evolutionary relationships at all taxonomic levels. The patterns of incongruence that were resolved suggest that incomplete lineage sorting (ILS) and/or ancient hybridization are the most likely explanations. These phenomena are, however, extremely difficult to distinguish because they may result in similar phylogenetic patterns. We present a novel approach to evaluate whether ILS can be excluded as an explanation for incongruent patterns. This coalescence-based method uses molecular dating estimates of the duration of the putative ILS events to determine if invoking ILS as an explanation for incongruence would require unrealistically high effective population sizes. For four of the incongruent patterns identified within the Senecioneae, this approach indicates that ILS cannot be invoked to explain the observed incongruence. Alternatively, these patterns are more realistically explained by ancient hybridization events.

Comparison of the classification of obesity by BMI vs. dual-energy X-ray absorptiometry in the Newfoundland population.

Although BMI is the most widely used measure of obesity, debate still exists on how accurately BMI defines obesity. In this study, adiposity status defined by BMI and dual-energy X-ray absorptiometry (DXA) was compared in a large population to evaluate the accuracy of BMI. A total of 1,691 adult volunteers from Newfoundland and Labrador participated in the study. BMI and body fat percentage (%BF) were measured for all subjects following a 12-h fasting period. Subjects were categorized as underweight (UW), normal weight (NW), overweight (OW), or obese (OB) based on BMI and %BF criteria. Differences between the two methods were compared within gender and by age-groups. According to BMI criteria, 1.2% of women were classified as UW, 44.2% as NW, 34.2% as OW, and 20.3% as OB. When women were classified according to %BF criteria, 2.2% were UW, 29.6% were NW, 30.9% were OW, and 37.1% were OB. The overall discrepancy between the two methods for women was substantial at 34.7% (14.6% for NW and 16.8% for OB, P < 0.001). In men, the overall discrepancy was 35.2% between BMI and DXA (17.6% for OW and 13.5% for OB, P < 0.001). Misclassification by BMI was dependent on age, gender, and adiposity status. In conclusion, BMI misclassified adiposity status in approximately one-third of women and men compared with DXA. Caution should be taken when BMI is used in clinical and scientific research as well as clinical practice.

Biomechanics of conidial dispersal in the toxic mold Stachybotrys chartarum.

Conidial dispersal in Stachybotrys chartarum in response to low-velocity airflow was studied using a microflow apparatus. The maximum rate of spore release occurred during the first 5 min of airflow, followed by a dramatic reduction in dispersal that left more than 99% of the conidia attached to their conidiophores. Micromanipulation of undisturbed colonies showed that micronewton (microN) forces were needed to dislodge spore clusters from their supporting conidiophores. Calculations show that airspeeds that normally prevail in the indoor environment disturb colonies with forces that are 1000-fold lower, in the nanonewton (nN) range. Low-velocity airflow does not, therefore, cause sufficient disturbance to disperse a large proportion of the conidia of S. chartarum.