The family Nymphaeaceae includes most of the diversity among the ANA-grade angiosperms. Among the species of this family, floral structures and pollination strategies are quite varied. The genus ...Victoria, as well as subgenera Lotos and Hydrocallis in Nymphaea, presents night-blooming, scented flowers pollinated by scarab beetles. Such similar pollination strategies have led to macromorphological similarities among the flowers of these species, which could be interpreted as homologies or convergences based on different phylogenetic hypotheses about the relationships of these groups. We employed SEM of floral epidermis for seven species of the Nymphaeaceae with contrasting pollination biology to identify the main characters of the floral organs and the potential homologous nature of the structures involved in pollinator attraction. Moreover, we used TEM to observe ultrastructure of papillate-conical epidermis in the stamen of Victoria cruziana. We then tested the phylogenetic or ecological distribution of these traits using both consensus network approaches and ancestral state reconstruction on fixed phylogenies. Our results show that the night-blooming flowers present different specializations in their epidermis, with Victoria cruziana presenting the most elaborate floral anatomy. We also identify for the first time the presence of conical-papillate cells in the order Nymphaeales. The epidermal characters tend to reflect phylogenetic relationships more than convergence due to pollinator selection. These results point to an independent and parallel evolution of scarab pollination in Nymphaeaceae, and show the promise of floral anatomy as a phylogenetic marker. Moreover, they indicate a degree of sophistication in the anatomical basis of cantharophilous flowers in the Nymphaeales that diverges from the most simplistic views of floral evolution in the angiosperms. This article is protected by copyright. All rights reserved.
The amyloid is a natural self-assembled peptide material comparable in specific stiffness to spider silk and steel. Throughout the literature there are many studies of the nanometer-sized amyloid ...fibril; however, peptide mixtures are capable of self-assembling beyond the nanometer scale into micrometer-sized fibers. Here, atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to observe the self-assembly of the peptide mixtures in solution for 20 days and the fibers upon drying. Beyond the nanometer scale, self-assembling fibers differentiate into two morphologies, cylindrical or rectangular cross-section, depending on peptide properties. Microscopic observations delineate a four stage self-assembly mechanism: (1) protofibril (2–4 nm high and 15–30 nm wide) formation; (2) protofibril aggregation into fibrils 6–10 nm high and 60–120 nm wide; (3) fibril aggregation into large fibrils and morphological differentiation where large fibrils begin to resemble the final fiber morphology of cylinders (WG peptides) or tapes (Gd:My peptides). WG large fibrils are 50 nm high and 480 nm wide and Gd:My large fibrils are 10 nm high and 150 nm wide; (4) micrometer-sized fiber formation upon drying at 480 h resulting in 18.0 μm diameter cylindrical fibers (WG peptides) and 14.0 μm wide and 6.0 μm thick flat tapes (Gd:My peptides). Evolution of the large fiber morphology can be rationalized on the basis of the peptide properties.
Abstract
We present an analysis of the Hubble diagram for 12 normal Type Ia supernovae (SNe Ia) observed in the near-infrared (NIR) J and H bands. We select SNe exclusively from the redshift range ...0.03 < z < 0.09 to reduce uncertainties coming from peculiar velocities while remaining in a cosmologically well-understood region. All of the SNe in our sample exhibit no spectral or B-band light-curve peculiarities and lie in the B-band stretch range of 0.8-1.15. Our results suggest that SNe Ia observed in the NIR are the best known standard candles. We fit previously determined NIR light-curve templates to new high-precision data to derive peak magnitudes and to determine the scatter about the Hubble line. Photometry of the 12 SNe is presented in the natural system. Using a standard cosmology of (H
0, Ωm, ΩΛ) = (70, 0.27, 0.73), we find a median J-band absolute magnitude of M
J
= −18.39 with a scatter of σ
J
= 0.116 and a median H-band absolute magnitude of M
H
= −18.36 with a scatter of σ
H
= 0.085. The scatter in the H band is the smallest yet measured. We search for correlations between residuals in the J- and H-band Hubble diagrams and SN properties, such as SN colour, B-band stretch and the projected distance from the centre of the host galaxy. The only significant correlation is between the J-band Hubble residual and the J − H pseudo-colour. We also examine how the scatter changes when fewer points in the NIR are used to constrain the light curve. With a single point in the H band taken anywhere from 10 d before to 15 d after B-band maximum light and a prior on the date of H-band maximum set from the date of B-band maximum, we find that we can measure distances to an accuracy of 6 per cent. The precision of SNe Ia in the NIR provides new opportunities for precision measurements of both the expansion history of the universe and peculiar velocities of nearby galaxies.
•Glycerol thermal processing enhances saccharification of biomass.•Higher crystallinity not correlated with saccharification efficiency.•Lignin removal did not positively impact enzyme digestibility ...of pretreated biomass.•Removal of xylan significantly enhanced rate of conversion.
Biomass was heated (200–240°C) in the presence of glycerol, for 4–12min, under shear to disrupt the native cell wall architecture. The impact of this method, named glycerol thermal processing (GTP), on saccharification efficiency of the hardwood Liquidambar styraciflua, and a control cellulose sample was studied as a function of treatment severity. Furthermore, the enzymatic conversion of samples with varying compositions was studied after extraction of the structural polymers. Interestingly, the sweet gum processed materials crystallinity index increased by 10% of the initial value. The experiments revealed that the residual lignin was not a barrier to limiting the digestibility of cellulose after pretreatment yielding up to 70% glucose based on the starting wood material. Further xylan removal greatly improved the cellulose hydrolysis rate, converting nearly 70% of the cellulose into glucose within 24h, and reaching 78% of ultimate glucan digestibility after 72h.
Background Although synthetic mesh is associated with superior anatomic outcomes for the repair of pelvic organ prolapse, the benefits of mesh have been questioned because of the relatively high ...complication rates. To date, the mechanisms that result in such complications are poorly understood, yet the textile characteristics of mesh products are believed to play an important role. Interestingly, the pore diameter of synthetic mesh has been shown to impact the host response after hernia repair greatly, and such findings have served as design criteria for prolapse meshes, with larger pores viewed as more favorable. Although pore size and porosity are well-characterized before implantation, the changes in these textile properties after implantation are unclear; the application of mechanical forces has the potential to greatly alter pore geometries in vivo. Understanding the impact of mechanical loading on the textile properties of mesh is essential for the development of more effective devices for prolapse repair. Objective The objective of this study was to determine the effect of tensile loading and pore orientation on mesh porosity and pore dimensions. Study Design In this study, the porosity and pore diameter of 4 currently available prolapse meshes were examined in response to uniaxial tensile loads of 0.1, 5, and 10 N while mimicking clinical loading conditions. The textile properties were compared with those observed for the unloaded mesh. Meshes included Gynemesh PS (Ethicon, Somerville, NJ), UltraPro (Artisyn; Ethicon), Restorelle (Coloplast, Minneapolis, MN), and Alyte Y-mesh (Bard, Covington, GA). In addition to the various pore geometries, 3 orientations of Restorelle (0-, 5-, 45-degree offset) and 2 orientations of UltraPro (0-, 90-degree offset) were examined. Results In response to uniaxial loading, both porosity and pore diameter dramatically decreased for most mesh products. The application of 5 N led to reductions in porosity for nearly all groups, with values decreasing by as much as 87% ( P < .05). On loading to 10 N of force, nearly all mesh products that were tested were found to have porosities that approached 0% and 0 pores with diameters >1 mm. Conclusion In this study, it was shown that the pore size of current prolapse meshes dramatically decreases in response to mechanical loading. These findings suggest that prolapse meshes, which are more likely to experience tensile forces in vivo relative to hernia repair meshes, have pores that are unfavorable for tissue integration after surgical tensioning and/or loading in urogynecologic surgeries. Such decreases in pore geometry support the hypothesis that regional increases in the concentration of mesh leads to an enhanced local foreign body response. Although pore deformation in transvaginal meshes requires further characterization, the findings presented here provide a mechanical understanding that can be used to recognize potential areas of concern for complex mesh geometries. Understanding mesh mechanics in response to surgical and in vivo loading conditions may provide improved design criteria for mesh and a refinement of surgical techniques, ultimately leading to better patient outcomes.
Detections of Lyman-break galaxies (LBGs) at high-redshift are affected by gravitational lensing induced by foreground deflectors not only in galaxy clusters, but also in blank fields. We quantify ...the impact of strong magnification in the samples of B
435, V
606, i
775 and z
850 & Y
105 dropouts (4 ≲ z ≲ 8) observed in the eXtreme Deep Field (XDF) and the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields by investigating the proximity of dropouts to foreground objects. We find that ∼6 per cent of bright z ∼ 7 LBGs (
$m_{H_{160}}<26$
) have been strongly lensed (μ > 2) by foreground objects. This fraction decreases from ∼3.5 per cent at z ∼ 6 to ∼1.5 per cent at z ∼ 4. Since the observed fraction of strongly lensed LBGs is a function of the shape of the luminosity function (LF), it can be used to derive Schechter parameters, α and M
⋆, independently from galaxy number counts. Our magnification bias analysis yields Schechter-function parameters in close agreement with those determined from galaxy counts albeit with larger uncertainties. Extrapolation of our analysis to z ≳ 8 suggests that surveys with JWST, WFIRST and Euclid should find excess LBGs at the bright end, over an intrinsic exponential cutoff. Finally, we highlight how the magnification bias measurement near the XDF detection limit can be used to probe the population of galaxies beyond this limit. Preliminary results suggest that the magnification bias at M
UV ∼ −18 is weaker than expected if α ≲ −1.7 extends well below the current detection limits. This could imply a flattening of the LF at M
UV ≳ −16.5. However, selection effects and completeness estimates are difficult to quantify precisely. Thus, we do not rule out a steep LF extending to M
UV ≳ −15.
We demonstrated that confronting mice to the Unpredictable Chronic Mild Stress (UCMS) procedure-a validated model of stress-induced depression-results in behavioural alterations and biochemical ...changes in the kynurenine pathway (KP), suspected to modify the glutamatergic neurotransmission through the imbalance between downstream metabolites such as 3-hydroxykynurenine, quinolinic and kynurenic acids. We showed that daily treatment with the IDO1 inhibitor 1-methyl-D-tryptophan partially rescues UCMS-induced KP alterations as does the antidepressant fluoxetine. More importantly we demonstrated that 1-methyl-D-tryptophan was able to alleviate most of the behavioural changes resulting from UCMS exposure. We also showed that both fluoxetine and 1-methyl-D-tryptophan robustly reduced peripheral levels of proinflammatory cytokines in UCMS mice suggesting that their therapeutic effects might occur through anti-inflammatory processes. KP inhibition might be involved in the positive effects of fluoxetine on mice behaviour and could be a relevant strategy to counteract depressive-like symptoms.
Purpose
Major adult maxillary transverse discrepancies are usually treated with surgically assisted rapid maxillary expansion (SARME), utilizing a combination of surgical and orthodontic techniques. ...Unfortunately, a consensus has not been reached on topics ranging from the best surgical technique that should be performed to the ideal expander type that should be installed. The present study sought to evaluate the efficiency and stability of the maxillary expansion achieved with two types of expanders following the same SARME procedure without pterygomaxillary disjunction (PMD).
Methods
Twenty-four patients with a maxillary transverse deficiency were enrolled in the study. All patients underwent the same SARME, and 12 received a bone-anchored (KLS Martin®) and 12 were installed with a tooth-borne (Hyrax®) expander. Dental impressions were collected both preoperatively and 1 year postoperatively. These casts were scanned and the distances between specific interdental and intergingival points were measured and analyzed. Statistical analyses were performed to assess the effects expander type had on the efficiency of the maxillary expansion and long-term stability.
Results
Expansion in the anterior maxillary and premolar regions was found to be similar in both groups. In contrast, the tooth-borne device resulted in a significantly greater expansion in the molar region.
Conclusion
The SARME technique without PMD is highly effective at treating adults with maxillary transverse deficiencies, and the type of expander selected depends on the location of the larger maxillary constriction region of each patient.
The three principal studies dedicated to the natural history of peritoneal carcinomatosis (PC) from colorectal cancer consistently showed median survival ranging between 6 and 8 months. New ...approaches combining cytoreductive surgery and perioperative intraperitoneal chemotherapy suggest improved survival.
A retrospective multicenter study was performed to evaluate the international experience with this combined treatment and to identify the principal prognostic indicators. All patients had cytoreductive surgery and perioperative intraperitoneal chemotherapy (intraperitoneal chemohyperthermia and/or immediate postoperative intraperitoneal chemotherapy). PC from appendiceal origin was excluded.
The study included 506 patients from 28 institutions operated between May 1987 and December 2002. Their median age was 51 years. The median follow-up was 53 months. The morbidity and mortality rates were 22.9% and 4%, respectively. The overall median survival was 19.2 months. Patients in whom cytoreductive surgery was complete had a median survival of 32.4 months, compared with 8.4 months for patients in whom complete cytoreductive surgery was not possible (P <.001). Positive independent prognostic indicators by multivariate analysis were complete cytoreduction, treatment by a second procedure, limited extent of PC, age less than 65 years, and use of adjuvant chemotherapy. The use of neoadjuvant chemotherapy, lymph node involvement, presence of liver metastasis, and poor histologic differentiation were negative independent prognostic indicators.
The therapeutic approach combining cytoreductive surgery with perioperative intraperitoneal chemotherapy achieved long-term survival in a selected group of patients with PC from colorectal origin with acceptable morbidity and mortality. The complete cytoreductive surgery was the most important prognostic indicator.
BACKGROUND AND AIMS: In the sexually deceptive Ophrys genus, species isolation is generally considered ethological and occurs via different, specific pollinators, but there are cases in which Ophrys ...species can share a common pollinator and differ in pollen placement on the body of the insect. In that condition, species are expected to be reproductively isolated through a pre-mating mechanical barrier. Here, the relative contribution of pre- vs. post-mating barriers to gene flow among two Ophrys species that share a common pollinator and can occur in sympatry is studied. METHODS: A natural hybrid zone on Sardinia between O. iricolor and O. incubacea, sharing Andrena morio as pollinator, was investigated by analysing floral traits involved in pollinator attraction as odour extracts both for non-active and active compounds and for labellum morphology. The genetic architecture of the hybrid zone was also estimated with amplified fragment length polymorphism (AFLP) markers, and pollination fitness and seed set of both parental species and their hybrids in the sympatric zone were estimated by controlled crosses. KEY RESULTS: Although hybrids were intermediate between parental species in labellum morphology and non-active odour compounds, both parental species and hybrids produced a similar odour bouquet for active compounds. However, hybrids produced significantly lower fruit and seed set than parental species, and the genetic architecture of the hybrid zone suggests that they were mostly first-generation hybrids. CONCLUSIONS: The two parental species hybridize in sympatry as a consequence of pollinator overlap and weak mechanical isolation, but post-zygotic barriers reduce hybrid frequency and fitness, and prevent extensive introgression. These results highlight a significant contribution of late post-mating barriers, such as chromosomal divergence, for maintaining reproductive isolation, in an orchid group for which pre-mating barriers are often considered predominant.
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