Sexual Dimorphism of Staminate- and Pistillate-Phase Flowers of Saponaria officinalis (Bouncing Bet) Affects Pollinator Behavior and Seed Set

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals

Severe course of Lyme neuroborreliosis in an HIV-1 positive patient; case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Lyme Neuroborreliosis (LNB) in a human immunodeficiency virus (HIV) positive patient is a rare co-infection and has only been reported four times in literature. No case of an HIV patient with a meningoencephalitis due to LNB in combination with HIV has been described to date.</p> <p>Case presentation</p> <p>A 51 year old woman previously diagnosed with HIV presented with an atypical and severe LNB. Diagnosis was made evident by several microbiological techniques. Biochemical and microbiological recovery during treatment was rapid, however after treatment the patient suffered from severe and persistent sequelae.</p> <p>Conclusions</p> <p>A clinician should consider LNB when being confronted with an HIV patient with focal encephalitis, without any history of Lyme disease or tick bites, in an endemic area. Rapid diagnosis and treatment is necessary in order to minimize severe sequelae.</p

Estimating the burden of disease attributable to four selected environmental risk factors in South Africa

The first South African National Burden of Disease study quantified the underlying causes of premature mortality and morbidity experienced in South Africa in the year 2000. This was followed by a Comparative Risk Assessment to estimate the contributions of 17 selected risk factors to burden of disease in South Africa. This paper describes the health impact of exposure to four selected environmental risk factors: unsafe water, sanitation and hygiene; indoor air pollution from household use of solid fuels; urban outdoor air pollution and lead exposure.The study followed World Health Organization comparative risk assessment methodology. Population-attributable fractions were calculated and applied to revised burden of disease estimates (deaths and disability adjusted life years, [DALYs]) from the South African Burden of Disease study to obtain the attributable burden for each selected risk factor. The burden attributable to the joint effect of the four environmental risk factors was also estimated taking into account competing risks and common pathways. Monte Carlo simulation-modeling techniques were used to quantify sampling, uncertainty.Almost 24 000 deaths were attributable to the joint effect of these four environmental risk factors, accounting for 4.6% (95% uncertainty interval 3.8-5.3%) of all deaths in South Africa in 2000. Overall the burden due to these environmental risks was equivalent to 3.7% (95% uncertainty interval 3.4-4.0%) of the total disease burden for South Africa, with unsafe water sanitation and hygiene the main contributor to joint burden. The joint attributable burden was especially high in children under 5 years of age, accounting for 10.8% of total deaths in this age group and 9.7% of burden of disease.This study highlights the public health impact of exposure to environmental risks and the significant burden of preventable disease attributable to exposure to these four major environmental risk factors in South Africa. Evidence-based policies and programs must be developed and implemented to address these risk factors at individual, household, and community levels

Sexual Dimorphism of Staminate- and Pistillate-Phase Flowers of Saponaria officinalis (Bouncing Bet) Affects Pollinator Behavior and Seed Set

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals

Homogeneous hydrogenations of nitriles catalyzed by rhenium complexes

Rhenium(I) nitrosyl complexes bearing large bite angle diphosphines efficiently catalyze the hydrogenation of nitriles to the corresponding symmetrical secondary amines

Rhenium Nitrosyl complexes bearing large-bite-angle diphosphines

A series of ReBr(2)(MeCN)(NO)(P boolean AND P)] complexes (P boolean AND P = 1,1'-bis(diphenylphosphino)ferrocene (dppfc) (1a), 1,1'-bis(diisopropylphosphino)ferrocene (diprpfc) (1b), 2,2'-bis(diphenylphosphino)diphenyl ether (dpephos) (1c), 10,11-dihydro-4,5-bis(diphenylphosphino)dibenzob,f]oxepine (homoxantphos) (1d), 4,6-bis(diphenylphosphino)-10,10-dimethylphenoxasilin (Sixantphos) (1e)) were prepared with diphosphines varying in the P-Re-P bite angles. 1a,c-e were obtained from the reaction of ReBr5(NO)]NEt(4)](2) with an an excess of the respective diphosphine in MeCN or MeCN/THF mixtures at elevated temperatures. Compound 1b was obtained by an alternative route, cleaving the dinuclear {ReBr(mu(2)-Br)(NO)(diprpfc)1}(2)] unit (2b) with MeCN. 2b was prepared from the reaction of ReBr(5)(NO)]NEt(4)](2) with diprpfc in EtOH. The reaction of 1a-d with HSiEt(3) gave the seven-coordinate ReBr(H)(2)(SiEt(3))(NO)(P boolean AND P)] compounds 4a-d, of which 4a,c,d are only stable in solution in the presence of HSiEt(3). The SiMe(3) (4f) and SiCl(3) (4g) derivatives of 4b were also prepared by applying the reaction of lb with HSiMe(3) and HSiCl(3). 1a,c,e, 2b, and 4f,g were structurally characterized. For 1c,e, 2b, and 4f,g NO/Br disorder was observed, which originates from the presence of two isomeric forms in the crystals of the respective compounds. For lc,d fast interconversion of these isomers could be observed in their (31)P{(1)H} NMR spectra at room temperature

Rhenium in Homogeneous Catalysis: ReBrH(NO)(labile ligand) (large-bite-angle diphosphine)] Complexes as Highly Active Catalysts in Olefin Hydrogenations

The reaction of ReBr(2)(MeCN)(NO)(P boolean AND P)] (P boolean AND P = 1,1'-bisdiphenylphosphinoferrocene (dppfc) (la), 1,1'-bisriiisopropylphosphinopherrocene (diprpfc) (1b), 2,2'-bis(diphenylphosphino)diphenyi ether (dpephos) (1c), 10,11-dihydro-4,5bis(diphenylphosphino)dibenzobf]oxepine (homoxantphos) (1d) and 4,6-bis(diphenylphosphino)-10,10-dimethylphenoxasilin (Sixantphos) (1e)) led in the presence of HSiEt(3) and ethylene to formation of the ethylene hydride complexes ReBrH(eta(2)-C(2)H(4))(NO)(P boolean AND P)] (3a,b,d), the MeCN ethyl complex ReBr(Et)(MeCN)(NO)(dpephos)] (5c) and two ortho-metalated stereoisomers ReBr(eta(2)-C(2)H(4))(NO)(eta(3)-o-C(6)H(4)-Sixantphos)] 8e(up) and 8e(down). The complexes 3a,b,d, and 5c and the isomers of 8e showed high catalytic activity (TOFs ranging from 22 to 4870 h(-1), TONs up to 24000) in the hydrogenation of monosubstituted olefins. For 8e(down) and 8e(up) a remarkable functional group tolerance and catalyst stability were noticed. Kinetic experiments revealed k(obs) to be first order in c(cat) and c(H(2)) and zeroth order in c(olefin). Mechanistic studies and DFT calculations suggest the catalysis to proceed along an Osborn-type catalytic cycle with olefin before H2 addition. The unsaturated key intermediates ReBrH(NO)(P boolean AND P)] (2a-e) could be intercepted with MeCN as ReBrH(MeCN)(NO)(P boolean AND P)] (10a-d) complexes or isolated as dimeric mu(2)-(H)(2) complexes {ReBr(mu(2)-H)(NO)(P boolean AND P)}(2)] (9b and 9e). Variation of the bidentate ligand demonstrated a crucial influence of the (large)-bite-angle on the catalytic performance and reactivity of 3a,b,d, 5c, and 8e

Sexual dimorphism of staminate- and pistillate-phase flowers of Saponaria officinalis (bouncing bet) affects pollinator behavior and seed set.

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals

Pollen limitation.

<p>Seeds produced by emasculated open-pollinated and hand-pollinated flowers and intact hand-pollinated flowers of <i>S. officinalis</i> growing in shaded and sun exposed plots in 2012. Different letters above the bars indicate statistically significant differences (α = 0.05).</p

Possible UV nectar guides in <i>S. officinalis</i>.

<p>Differences in the UV reflectance at proximal and distal ends of petals of <i>S. officinalis</i> in staminate- and pistillate-stage flowers. Boxes represent the median and quartile ranges for each variable. Open circles represent values that lie between 1.5 and 3 box lengths from the end of the box. The average percentage of light reflectance in the UV range was corrected for overall amount of light reflected over the entire spectrum (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093615#s2" target="_blank">Methods</a>).</p