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The recent divergence of Orchard (Icterus spurius spurius) and Fuertes's Orioles (I. s. fuertesi) makes them an ideal system for investigating species boundaries. Orchard and Fuertes's Orioles differ in several respects. They have distinct breeding ranges Fuertes's Orioles breed in eastern coastal Mexico, whereas Orchard Orioles breed throughout eastern and central North America--and differ in plumage coloration, with adult male Orchard Orioles appearing 'chestnut' and Fuertes's Orioles 'ochre.' However, no detailed quantitative color analyses have been conducted. To characterize these differences we quantitatively measured plumage color using reflectance spectrometry. The colored plumages of adult male Orchard and Fuertes's Orioles have unique spectral characteristics, with no color overlap between them. Combined with life history differences and previous molecular studies, these findings support the classification of Orchard and Fuertes's Orioles as separate species. Additionally, this study demonstrates the utility of quantitative color measurement as a tool for examining species boundaries. Key words: Fuertes's Oriole, Icterus spurius fuertesi, Icterus spurius spurius, Orchard Oriole, plumage coloration, reflectance spectrometry, species boundaries. La reciente divergencia de Icterus spurius spurius e I. s. fuertesi hace de ellos un sistema ideal para investigar los limites de las especies, ya que ambos taxones difieren en varios aspectos. Por un lado, tienen diferentes areas de reproduccion. I. s. fuertesi se reproduce en la costa este mexicana del Golfo de Mexico (Tamaulipas a Veracruz), mientras que I. s. spurius se reproduce por casi todo el este y centro de Norteamerica. Tambien difieren en la coloracion del plumaje. Los machos adultos de I. s. spurius generalmente presentan color castano, mientras que los machos de I. s. fuertesi son ocres. Sin embargo, no se habian realizado analisis cuantitativos de la coloracion. Para caracterizar estas diferencias, usamos espectrometria de reflectancia para medir cuantitativamente el color del plumaje. Encontramos que los plumajes coloreados de los machos adultos de I. s. spurius e I. s. fuertesi tienen caracteristicas de espectro propias, sin superposicion de color entre los taxones. En conjunto con las diferencias en la historia de vida y en los estudios moleculares previos, estas conclusiones apoyan la clasificacion de I. spurius e I. fuertesi como especies distintas. Ademas, esta investigacion demuestra la utilidad de las medidas cuantitativas del color como una herramienta para examinar las fronteras de las especies.

Carotenoid-based colors appear to play a significant signaling role in many animal taxa but not enough is known about the evolutionary changes in caratenoid coloration. A phylogenetic perspective used to examine carotenoid color changes within New World orioles revealed subtle changes among closely related taxa and the use of spectral data provided a better understanding of how elaborate animal colors evolve.

Background Isolated repair of the regurgitant bicuspid aortic valve (BAV) has yielded suboptimal durability, with annular dilatation being important risk factor for recurrent aortic regurgitation. We hypothesized that adding a suture annuloplasty (SA) should lead to improved repair stability. Methods Between July 1999 and September 2014, 268 patients (mean age, 41 ± 13 years, 249 male) underwent isolated BAV repair. From January 2009 to September 2014, 164 consecutive patients (study group) underwent SA using either braided polyester (n = 37) or expanded polytetrafluorethylene (PTFE) (n = 127). Patients who underwent surgery prior to January 2009 served as controls (n = 104). All patients were followed (98.9% complete, 1 week to 181 months). Results Annular size was larger in the study group ( p < 0.001) and age was lower ( p < 0.001). There were no differences between the groups regarding other clinical data. Hospital mortality was 0.7% (n = 2), 10-year survival was 94.2%. Thirty-six patients required valve-related reoperations (8 days to 94 months postoperatively; controls = 32, study = 4). Complications related to SA (ventricular septal defect, interference with coronary artery) occurred in 6 (3.7%) patients, in 4 (10.8%) patients with polyester SA and in 2 (1.6%) patients with PTFE. In the control group freedom from reoperation at 5 and 10 years was 73.2% and 63.7%, respectively. With SA, 5-year stability was significantly improved to 92.6% ( p = 0.0006); it was 96.7% for PTFE versus 83.5% for polyester SA ( p = 0.0132). Conclusions Annular dilatation is a risk factor for failure after repair of regurgitant BAV. Its elimination through the use of SA significantly improves repair stability. With PTFE as material for SA optimal repair stability and minimal local complications are achieved. [ABSTRACT FROM AUTHOR]

Prophage insertions in Escherichia coli O157:H7 mlrA contribute to the low expression of curli fimbriae and biofilm observed in many clinical isolates. Varying levels of CsgD-dependent curli/biofilm expression are restored to strains bearing prophage insertions in mlrA by mutation of regulatory genes affecting csgD. Our previous study identified strong biofilm- and curli-producing variants in O157:H7 cultures that had lost the mlrA-imbedded prophage characteristic of the parent population, suggesting prophage excision as a mechanism for restoring biofilm properties. In this study, we compared genomic, transcriptomic and phenotypic properties of parent strain PA20 (stx1, stx2) and its prophage-cured variant, 20R2R (stx2), and confirmed the mechanism underlying the differences in biofilm formation. [ABSTRACT FROM AUTHOR]

Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane Grus americana (Gruiformes, Gruidae), which is one of only two North American crane species. It is a large, long-lived bird in which UV sensitivity might be reduced by chromatic aberration and entrance of UV radiation into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate whether the ocular media (i.e. the lens and cornea) absorb UV radiation. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, whereas the cone visual pigment λmax values were determined to be 404 nm (SWS1 ), 450 nm (SWS2), 499 nm (RH2) and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cut-off wavelength (λcut) values similarly fell within ranges recorded in other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type) and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system; however, as a consequence of the αmax of the SWS1 visual pigment (404 nm), it might also have some UV sensitivity. [ABSTRACT FROM AUTHOR]

This study reports on the use of a fibrinogen-derived peptide for the specific targeting and delivery of vancomycin to S taphylococcus epidermidis biofilms. One method by which S. epidermidis initially adheres to biomaterials uses the plasma protein fibrinogen as an intermediary, where the S. epidermidis surface protein SdrG binds to a short amino acid sequence near the amino terminus of the Bβ chain of fibrinogen. We mimicked this binding interaction and demonstrated the use of a synthetic fibrinogen-based β6-20 peptide to target and deliver vancomycin to S. epidermidis in vitro. The β6-20 peptide was synthesized and labeled with a Nanogold probe, and its targeting capabilities were examined through the use of scanning electron microscopy. The Nanogold component was then replaced by vancomycin, utilizing a flexible, variable length poly(ethylene glycol) linker between the peptide and antibiotic to create the targeted vancomycin products, β6-20-PEG x-VAN. Initial binding to surface adherent S. epidermidis was increased in a concentration-dependent manner relative to vancomycin for all equivalent concentrations ≥4 μg/mL, with targeted vancomycin content up to 22.9 times that of vancomycin alone. Retention of the targeted antibiotics was measured after an additional 24-h incubation period, revealing levels 1.3 times that of vancomycin. The results demonstrate the improved targeting and retention of vancomycin within a biofilm due to the incorporation of a specific targeting motif. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2517-2525, 2012. [ABSTRACT FROM AUTHOR]

This study reports the use of a targeted cationic peptide with the ability to disrupt Staphylococcus epidermidis biofilm formation. Complications due to nosocomial infections of implanted medical devices pose a significant health risk to patients, with Staphylococcus epidermidis often implicated in the case of blood-contacting biomaterials. S. epidermidis virulence relies mainly on its ability to form a biofilm, the main component of which is polysaccharide intercellular adhesin (PIA). We utilized the synthetic β6-20 peptide, known to specifically bind S. epidermidis, in order to deliver a cationic polylysine peptide (G3K6) to the bacterial surface and disrupt the charge-charge interactions needed for PIA retention and biofilm stability. The effects of the β6-20-G3K6 peptide on biofilm formation were assessed using optical density, fluorescently labeled wheat germ agglutinin, nucleic acid stain (SYTO 9), and a metabolic assay (XTT, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2 H-tetrazolium-5-carboxanilide inner salt). Biofilms formed in the presence of β6-20-G3K6 peptide (100 μ M) resulted in a 37.9% reduction in PIA content and a 17.5% reduction of adherent bacteria relative to biofilms grown in the absence of peptide. These studies demonstrate the targeting ability of the β6-20 peptide towards biomaterial-adherent S. epidermidis, and highlight the potential for disrupting the early stages of biofilm formation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012. [ABSTRACT FROM AUTHOR]

The expression of cone opsin genes is a primary determinant of the characteristics of colour vision. Interspecific variation in opsin expression is common in African cichlids. It is correlated with foraging among cichlids from Lake Malawi, and with ambient light environment among cichlids from Lake Victoria. In this study, we tested whether gene expression varied within species such that it might be important in contributing to divergence. We hypothesized that light attenuation with depth would be correlated with predictable changes in gene expression in Lake Malawi, and that this variation would tune visual sensitivities to match the ambient light environment. We observed significant differences in cone opsin expression in three different comparisons among populations of the same species. Higher LWS expression was found in shallow versus deep Copadichromis eucinostomus. In Metriaclima zebra, individuals from Zimbawe Rock expressed significantly more SWS2B than those from Thumbi West Island, although these locales have similar ambient light environments. Finally, Tropheops gracilior from deeper water had significantly more variation in expression than their shallow counterparts. These results support that gene expression varies significantly between populations of the same species. Surprisingly, these results could not be explained by predicted visual performance as models predicted that differential expression patterns did not confer sensitivity advantages at different depths. This suggested that expression variation did not confer a local sensitivity advantage. Therefore, our findings were contrary to a primary requirement of the sensory bias hypothesis. As such, other explanations for intraspecific gene expression variation need to be tested. [ABSTRACT FROM AUTHOR]

Phenotypic evolution may occur either through alterations to the structure of protein-coding genes or their expression. Evidence for which of these two mechanisms more commonly contribute to the evolution of a phenotype can be garnered from examples of parallel and convergent evolution. The visual system of East African cichlid fishes is an excellent system with which to address this question. Cichlid fishes from Lakes Malawi (LM) and Victoria together exhibit three diverse palettes of coexpressed opsins and several important protein-coding mutations that both shift spectral sensitivity. Here we assess both opsin expression and protein-coding diversity among cichlids from a third rift lake, Lake Tanganyika (LT). We found that Tanganyikan cichlids exhibit three palettes of coexpressed opsins that largely overlap the short-, middle-, and long-wavelength–sensitive palettes of LM cichlids. Bayesian phenotypic clustering and ancestral state reconstructions both support the parallel evolution of the short- and middle-wavelength palettes among cichlids from LT and LM. In each case, these transitions occurred from different ancestors that expressed the same long-wavelength palette. We also identified similar but distinct patterns of correlated evolution between opsin expression, diet, and lens transmittance among cichlids from LT and LM as well. In contrast to regulatory changes, we identified few functional or potentially functional mutations in the protein-coding sequences of three variable opsins, with the possible exception of the SWS1 (ultraviolet) opsin. These results underscore the important contribution that gene regulation can make to rapid phenotypic evolution and adaptation. [ABSTRACT FROM PUBLISHER]

Sensory systems play crucial roles in survival and reproduction. Therefore, sensory plasticity has important evolutionary implications. In this study, we examined retinal plasticity in five species of cichlid fish from Lake Malawi. We compared the cone opsin expression profiles of wild-caught fish to lab-reared F1 that had been raised in a UV minus, reduced intensity light environment. All of the opsin genes that were expressed in wild-caught fish were also expressed in lab-reared individuals. However, we found statistically significant differences in relative opsin expression among all five species. The most consistent difference was in the SWS2B (violet) opsin, which was always expressed at higher levels in lab-reared individuals. Estimates of visual pigment quantum catch suggest that this change in expression would increase retinal sensitivity in the light environment of the lab. We also found that the magnitude of plasticity varied across species. These findings have important implications for understanding the genetic regulation of opsin expression and raise many interesting questions about how the cichlid visual system develops. They also suggest that sensory plasticity may have facilitated the ecological diversification of cichlids in Lake Malawi. [ABSTRACT FROM AUTHOR]

A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest- and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short-and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity. [ABSTRACT FROM AUTHOR]

Several recent studies have found instances of cryptic sexual dichromatism within avian taxa. Although this dichromatism has been found in plumage produced through a variety of proximate mechanisms, little is known about how dichromatism varies across these types of plumage within a single species. We used a reflectance spectrometer to measure colour within the Green-backed Tit Parus monticolus, a species which displays multiple types of pigment and structural colours. We found significant differences in spectral measurements corresponding to hue, chroma, and brightness between male and female carotenoid, melanin, structural white, grey and structural blue plumage. The only plumage that did not appear to show sexual dichromatism was the olive plumage of the back. These findings suggest that the mechanism(s) producing cryptic dichromatism in the Green-backed Tit are non-specific and act across multiple types of plumage, rather than within a single type, such as carotenoid-based or structurally produced. [ABSTRACT FROM AUTHOR]

The article discusses the endoscopic surgery using the GERDX device to an obese patient.

Simple Summary: The planning treatment volume (PTV) during internal mammary irradiation (IMNI) regularly overlaps with lung tissue and is often in close proximity to the heart. Thus, exclusion of lung tissue from the PTV is a potential technique to spare the organs at risk (OARs) during adjuvant breast cancer irradiation. Using an innovative dose recalculation and accumulation algorithm, we evaluated the safety of exclusion of lung tissue from the PTV. According to our data, exclusion of lung tissue from the PTV to spare the OARs leads to significant dose reduction in the target volume and can, therefore, not be recommended. The current study aims to determine whether exclusion of lung tissue from planning treatment volume (PTV) is a valid organ at risk (OAR)-sparing technique during internal mammary irradiation (IMNI). Twenty patients with left-sided breast cancer undergoing adjuvant radiotherapy including IMNI after mastectomy or lumpectomy with daily ConeBeam CT (CBCT; median n = 28) were enrolled in the current study. The daily dose distribution of the patients was estimated by recalculating treatment plans on CBCT-scans based on a standard PTV (PTV margin: 5mm-STD) and a modified PTV, which excluded overlapping lung tissue (ExLung). Using 3D-deformable dose accumulation, the dose coverage in the target volume was estimated in dependence of the PTV-margins. The estimated delivered dose in the IMN-CTV was significantly lower for the ExLung PTV compared to the STD PTV: ExLung: V95%: 76.6 ± 22.9%; V90%: 89.6 ± 13.2%, STD: V95%: 95.6 ± 7.4%; V90%: 99.1 ± 2.7%. Daily CBCT imaging cannot sufficiently compensate the anatomic changes and intrafraction movement throughout the treatment. Therefore, to ensure adequate delivery of the prescribed dose to the IMN-CTV, exclusion of lung tissue from the PTV to spare the OARs is not recommended. [ABSTRACT FROM AUTHOR]

This paper deals with the Tikhonov regularization for nonlinear ill-posed operator equations in Hilbert scales with oversmoothing penalties. One focus is on the application of the discrepancy principle for choosing the regularization parameter and its consequences. Numerical case studies are performed in order to complement analytical results concerning the oversmoothing situation. For example, case studies are presented for exact solutions of Hölder type smoothness with a low Hölder exponent. Moreover, the regularization parameter choice using the discrepancy principle, for which rate results are proven in the oversmoothing case in in reference (Hofmann, B.; Mathé, P. Inverse Probl. 2018, 34, 015007) is compared to Hölder type a priori choices. On the other hand, well-known analytical results on the existence and convergence of regularized solutions are summarized and partially augmented. In particular, a sketch for a novel proof to derive Hölder convergence rates in the case of oversmoothing penalties is given, extending ideas from in reference (Hofmann, B.; Plato, R. ETNA. 2020, 93). [ABSTRACT FROM AUTHOR]

The biofilm life style helps bacteria resist oxidative stress, desiccation, antibiotic treatment, and starvation. Biofilm formation involves a complex regulatory gene network controlled by various environmental signals. It was previously shown that prophage insertions in mlrA and heterogeneous mutations in rpoS constituted major obstacles limiting biofilm formation and the expression of extracellular curli fibers in strains of Escherichia coli serotype O157:H7. The purpose of this study was to test strains from other important serotypes of Shiga toxin-producing E. coli (STEC) (O26, O45, O103, O111, O113, O121, and O145) for similar regulatory restrictions. In a small but diverse collection of biofilm-forming and non-forming strains, mlrA prophage insertions were identified in only 4 of the 19 strains (serotypes O103, O113, and O145). Only the STEC O103 and O113 strains could be complemented by a trans-copy of mlrA to restore curli production and Congo red (CR) dye affinity. RpoS mutations were found in 5 strains (4 serotypes), each with low CR affinity, and the defects were moderately restored by a wild-type copy of rpoS in 2 of the 3 strains attempted. Fourteen strains in this study showed no or weak biofilm formation, of which 9 could be explained by prophage insertions or rpoS mutations. However, each of the remaining five biofilm-deficient strains, as well as the two O145 strains that could not be complemented by mlrA, showed complete or nearly complete lack of motility. This study indicates that mlrA prophage insertions and rpoS mutations do limit biofilm and curli expression in the non-serotype O157:H7 STEC but prophage insertions may not be as common as in serotype O157:H7 strains. The results also suggest that lack of motility provides a third major factor limiting biofilm formation in the non-O157:H7 STEC. Understanding biofilm regulatory mechanisms will prove beneficial in reducing pathogen survival and enhancing food safety. [ABSTRACT FROM AUTHOR]