Visible Ring Research Articles

Morpho-phylogenetic evidence reveals Pseudobionectria phoenicis gen. et sp. nov. (Bionectriaceae) from a mangrove habitat

A bionectriaceous ascomycete was collected from palm rachides in a mangrove habitat. Multi-gene phylogenetic analyses indicated this fungus belongs within the Bionectriaceae, forming a sister lineage to Septofusidium herbarum and distinct from other known genera. In this study, we proposed the new genus Pseudobionectria to accommodate the novel species P. phoenicis. Pseudobionectria is distinguished from other genera in Bionectriaceae by its superficial, globose, brownish-orange ascomata with a black crown that is flattened on the top and hyphal appendages that merge with the subiculum below. The asci are unitunicate, lacking a visible apical ring, and the ascospores are 1-septate, oblong-ellipsoidal to fusiform, hyaline, and exhibit spinose ornamentation. The establishment of this new genus is supported by morphological and phylogenetic evidence. Additionally, this paper provides a synopsis of the genera within Bionectriaceae, including information on the type species, morphological characteristics, lifestyles, molecular data and key publications.

Visible light-driven dearomative ring expansion of (aza)arenes to access dihydrofuran-based polycyclic compounds.

The dearomative expansion of aromatic rings has long been pursued by chemists due to its potential to provide tractable approaches for synthesizing valuable non-aromatic molecules. To circumvent the conventional use of hazardous and unstable diazo compounds, photochemical synthesis has recently emerged as a promising platform. However, protocols that can effectively handle both arenes and azaarenes remain scarce. Herein, we introduce a generic strategy that efficiently converts β-(aza)aryl-β-substituted enones into biologically significant cycloheptatriene derivatives, including their aza-variants. This method allows for the easy modulation of diverse functional groups on the product and demonstrates a wide substrate scope, evidenced by its excellent tolerance to various drug motifs and good compatibility with five-membered azaarenes undergoing ring expansion. Moreover, DFT calculations of plausible mechanisms have motivated the implementation of an important cascade diradical recombination strategy for 1,3-dienones, thus facilitating the synthesis of valuable 2-oxabicyclo[3.1.0]hex-3-ene derivatives.

Visible light-mediated ring opening and cyclization of aryl cyclopropanes: efficient synthesis of pyrrolo[1,2-a]quinoxalin-4(5H)-ones with antineoplastic activity

This study describes an efficient and green approach for the synthesis of potentially bioactive pyrrolo[1,2-a]quinoxalin-4(5H)-ones with appreciable functional group tolerance and a wide substrate scope.

Air plasma ablation/erosion test for 4D C/C composites used in the throat of solid rocket motor

A small-scale plasma ablation facility was employed to test the four-directional carbon/carbon (4D C/C) composites under high enthalpy multi-phase jet condition for ablation/erosion performance evaluation with the ablation flow field studied via computational fluid dynamics (CFD). The various ablation rates, ablation behavior and microstructure of the C/C specimens were investigated. The overall mass ablation rate was 0.05715 g·s−1 with 0.05550 mm·s−1and 0.01794 mm·s−1 axial linear ablation rate of inner and outer walls. In the radial direction, the linear ablation rates were 0.07794 and 0.00517 mm·s−1 for the inner and external diameter respectively. Ablation changes the inner wall of the annular specimen into an inverted horn shape, while the edge near the jet becomes rounded corners after the plasma procedure. The interface between the axial carbon rod and the matrix has visible ring fractures. Alumina particles are lodged in cracks and holes as a result of multiphase flow scouring. The regression rate of the composites can be considerably accelerated by particle erosion and the existence of inherent defects. The specimen ablation of top surface and inner wall is attributed to the coupling of the heterogeneous reaction and multiphase erosion. On the back wall of specimen, the regression is mainly caused by thermochemical ablation.

Comparative metabolomics reveals that Agaricus bisporus fairy ring modulates the growth of alpine meadow plant on the Qinghai-Tibet Plateau

The fairy ring is an ecological phenomenon that consists of a visible green ring composed of mushroom fruiting bodies and a green plant stimulating zone. Agaricus bisporus fairy ring stimulates the growth of alpine meadow plants on the Qinghai-Tibet Plateau, however, the underlying eco-physiological and molecular mechanisms still unclear. Here, using physiological and metabolomic analyses, we showed that A. bisporus fairy ring improves leaf growth of alpine meadow plant by modulating plant metabolism. A. bisporus fairy ring induces the accumulation of a set of amino acids in Kobresia humilis (one of the main plant species of alpine meadow), such as glutamine, asparagine, tryptophan and proline, etc., and thereby modulating nitrogen metabolism, plant growth and stress responses. A. bisporus fairy ring also affects sugar accumulation and carbon metabolism pathways in K. humilis plants. Furthermore, A. bisporus fairy ring alters the metabolite accumulation in soil. Increased accumulation of several organic acids and lipids in soil is beneficial to promote nutrient element uptake in plants and regulate microorganisms growth and propagation in soil. Taken together, our results indicated A. bisporus fairy ring affects alpine meadow plant growth by modulating carbon/nitrogen metabolism, stress responses, nutrient uptake and interaction between soil microorganisms and alpine meadow plants.

Comparing automatically generated and manually measured tree-ring transects of growth trends with Hawaiian sandalwood as an example species

Tree-ring measurements are a primary quantitative tool used in numerous scientific disciplines. Some species, however, exhibit morphological complexities leading to significant uncertainty in these measurements. Hawaiian Sandalwood (Santalum paniculatum) stems, for example, often develop asymmetric growth features that hinder tree-ring measurements. These features include faint-ring boundaries and wedging rings which disappear in portions of the cross-section. In this work we a use a novel two-dimensional transect methodology and our own open-source software, svg-dendro, to analyze particularly difficult cross-sections. Our method accomplishes this by first tracing all rings by hand and automatically generating a user-specified number of transects. On average, these traced measurements had more sensitivity to tree-ring variability without losing important equivalencies with the traditional binocular stereomicroscope technique (e.g., radii, skewness) as indicated by greater mean variance for ring number, mean tree-ring width, and standard deviation. All S. paniculatum samples had ring wedging, where certain sides of the stem had many locally absent tree rings but to different intensities. The new technique allows us to analyze the shift from complete rings with little to no wedging to rings with more wedging starting between the 19th and 40th ring, where deep stem lobes begin forming. The new method also reveals the difficulty in measuring these trees, as the wedging creates multiple lobes with different visible ring counts. This research suggests that this two-dimensional methodology would be best applied to non-circular trees with fewer incomplete rings, supporting the importance of species and population selection. Overall, we have developed an efficient and flexible means to measure otherwise unmeasurable growth features in tree samples through representing tree-ring boundaries as curves and developing software to sort and map transects.

Growth of Stegophiura nodosa (Echinodermata, Ophiuroidea) in the Pechora Sea

AbstractThe brittle star Stegophiura nodosa is one of the most abundant ophiuroid species living in Arctic seas and serves as a food resource for demersal fish. The study of autecological and biological patterns of S. nodosa is important for understanding the species reaction to environmental change. The growth features and growth rate of this brittle star from the Pechora Sea were estimated using the Gompertz equation as the basic mathematical model and compared with Bertalanffy equation parameters. Individual age was evaluated by counting the ring-shaped growth marks in the calcite structure of the animal's vertebral ossicle, where each visible ring was considered to be an annual growth mark. The calculations indicated: the theoretical limiting radius of the brittle star's ossicle (R∞) averages 318 ± 18 μm, and the exponential deceleration of the specific growth rate (g) is found to be 0.46 ± 0.02. The initial hidden growth marks were found to vary from 1–3, and the maximum lifespan of S. nodosa in the Pechora Sea (SE of the Barents Sea) is evaluated to be 9–10 years.

A novel geomatics method for assessing the Haughton impact structure

AbstractTerrestrial impact structures are typically modified by erosion, burial, and tectonic deformation. Their systematic morphologies are typically reconstructed through a combination of geological and topographic mapping, satellite imagery, and geophysical surveys. This study applies a novel geomatics approach to assessment of the morphology of the extensively studied Haughton impact structure (HIS), Devon Island, Nunavut, in order to test its potential to improve the accuracy and quality of future impact structure reconstruction. This new methodology integrates HIS lithological data, in the form of digitized geologic mapping, with a digital elevation model, within diametrically opposed, wedge‐shaped couplets, and plots these data as pseudo cross sections that capitalize on the radial symmetry of the impact structure. The pseudo cross sections provide an accurate reconstruction of the near‐surface stratigraphic sequences and terraces in the faulted annulus of the modified crater rim. The resultant pseudo cross sections support current interpretations regarding the 10–12 km diameter of the transient cavity, and successfully reproduce the visible outer ring and intermediate uplifted zone within the central basin. Observed positions of vertical offsets suggest that the extent of impact deformation extends beyond the current estimates of the apparent crater rim to radial distances of between 14 and 15 km. Finally, the new geomatics approach provides an improved determination of the spatial, stratigraphic, and temporal relationships among the Haughton Formation lake sediments, allochthonous crater‐fill impactites, and uplifted target rocks, and indicates that there was a not‐insignificant time gap between the formation of the impact structure and the deposition of the sediments.

Explantation of the CyPass implant in acase series of patients with corneal decompensation

In microinvasive glaucoma surgery (MIGS) the CyPass microstent (Alcon Inc.) was implanted in the suprachoroidal space to increase the uveoscleral outflow, thereby lowering the intraocular pressure. Due to the excessive loss of corneal endothelial cells, the implant was withdrawn from the global market in August 2018. Aloss of corneal endothelial cells was observed in 6patients (8eyes in total) with early to moderate primary open-angle glaucoma 3years after CyPass implantation. One eye developed abullous keratopathy. In all patients an implant migration in the anterior chamber compared to the original postoperative position was detected, with more than one ring of the CyPass implant being visible in the anterior chamber. In all eight cases the CyPass implant was removed. The local therapy with cortisone eye drops in combination with a5% sodium chloride solution did not improve chronic corneal edema in one patient. Therefore, aDescemet membrane endothelial keratoplasty (DMEK) was performed with postoperative improvement of visual acuity. In patients with more than one visible ring of the CyPass implant in the anterior chamber and subsequent localized loss of corneal endothelial cells, CyPass trimming or removal is recommended to avoid the progression of generalized corneal endothelial cell reduction and the onset of refractory, chronic corneal edema.

The place of total testosterone in the etiology of pilonidal sinus disease

Aim: There are lots of factors accused in the etiology of SPSD. One of those factors is hypertrichosis. Hypertrichosis is increased by high levels of testosterone. In our clinical practices, we observe the secondary effects of high testosterone levels in those with SPSD. Hence, we intended to analyze the correlation between testosterone and SPSD.Material and Methods: The first 200 patients who applied to General Surgery Clinic at Malatya State Hospital and were diagnosed with SPDS, were included in the study after being informed of our research and signing the informed consent form. The total testosterone (TT) levels of the patients were measured and recorded along with their demographic data. Also, a control group was formed of male and female patients without SPSD having the same demographic characteristics, whose TT levels were also subsequently recorded. The data from control and study groups were then compared and analyzed.Results: Of the 200 patients included in the study, 43 (21.5%) were female and 157 (78.5%) were male. Their overall mean age was 24.13±7.04 years and the median age was 22 years (min:14- max:50). The male-to-female ratio was 3.65. The rate of females and males who had high levels of TT was significantly higher than that of the control group (p0.001). Conclusion: We recommend measuring serum TT levels of patients who apply to hospital for SPSD. SPSD might be the first visible ring of the chain of diseases characterized by high levels of TT.

Visible light-induced palladium-catalyzed ring opening β-H elimination and addition of cyclobutanone oxime esters.

A palladium catalyst under visible light irradiation activates cyclobutanone oxime ester through single electron transfer to induce radical ring opening to generate hybrid cyanoalkyl Pd(i) radical species. Hybrid cyanoalkyl Pd(i) radical species can undergo either β-H elimination to deliver (E)-4-arylbut-3-enenitrile or undergo radical addition with silyl enol ether and enamide to generate δ-cyano ketones. A dual ligand system composed of two phosphine ligands is essential for the high reactivity.

Using gaze behavior to parcellate the explicit and implicit contributions to visuomotor learning.

Successful motor performance relies on our ability to adapt to changes in the environment by learning novel mappings between motor commands and sensory outcomes. Such adaptation is thought to involve two distinct mechanisms: an implicit, error-based component linked to slow learning and an explicit, strategic component linked to fast learning and savings (i.e., faster relearning). Because behavior, at any given moment, is the resultant combination of these two processes, it has remained a challenge to parcellate their relative contributions to performance. The explicit component to visuomotor rotation (VMR) learning has recently been measured by having participants verbally report their aiming strategy used to counteract the rotation. However, this procedure has been shown to magnify the explicit component. Here we tested whether task-specific eye movements, a natural component of reach planning, but poorly studied in motor learning tasks, can provide a direct readout of the state of the explicit component during VMR learning. We show, by placing targets on a visible ring and including a delay between target presentation and reach onset, that individual differences in gaze patterns during sensorimotor learning are linked to participants' rates of learning and their expression of savings. Specifically, we find that participants who, during reach planning, naturally fixate an aimpoint rotated away from the target location, show faster initial adaptation and readaptation 24 h later. Our results demonstrate that gaze behavior cannot only uniquely identify individuals who implement cognitive strategies during learning but also how their implementation is linked to differences in learning. NEW & NOTEWORTHY Although it is increasingly well appreciated that sensorimotor learning is driven by two separate components, an error-based process and a strategic process, it has remained a challenge to identify their relative contributions to performance. Here we demonstrate that task-specific eye movements provide a direct read-out of explicit strategies during sensorimotor learning in the presence of visual landmarks. We further show that individual differences in gaze behavior are linked to learning rate and savings.

Visible light photoredox-catalyzed difluoromethylation and ring expansion of 1-(1-arylvinyl)cyclobutanols

A visible light photoredox-catalyzed difluoromethylation and ring expansion via 1,2-carbon migration of 1-(1-arylvinyl)cyclobutanol derivatives has been developed. This approach offers a facile way to prepare difluoromethyl-substituted cyclopentanone derivatives.

Evaluation of the Fracture Toughness of Titanium Nitride Hardening Coatings According to Kinetic Indentation and Acoustic Emission Parameters

The possibility of the effective use of the kinetic indentation method in combination with the acoustic emission method for evaluating the fracture toughness of titanium nitride hardening coatings is shown. It is established that the occurrence of the first jog on the loading line of the kinetic indentation diagram in “load–indentor displacement–time” coordinates is due to the formation of the first crack in the coating and practically coincides in time with the occurrence of the acoustic emission impulse with an increased energy value. This permits a more accurate and substantiated determination of the critical load, indentation depth of the indentor, and hardness at which the first visible ring crack forms around the impression on the coating surface.

Anisotropic total variation minimization approach in in-line phase-contrast tomography and its application to correction of ring artifacts**Project supported by the National Natural Science Foundation of China (Grant Nos. 61671004, 61271012, 81371549, 81671683, and 11501415), the Natural Science Foundation of Tianjin City, China (Grant No. 16JCYBJC28600), the WBE Liver Fibrosis Foundation of China (Grant No. CFHPC20131033), the Instrument Developing Project of

In-line phase-contrast computed tomography (IL-PC-CT) imaging is a new physical and biochemical imaging method. IL-PC-CT has advantages compared to absorption CT when imaging soft tissues. In practical applications, ring artifacts which will reduce the image quality are commonly encountered in IL-PC-CT, and numerous correction methods exist to either pre-process the sinogram or post-process the reconstructed image. In this study, we develop an IL-PC-CT reconstruction method based on anisotropic total variation (TV) minimization. Using this method, the ring artifacts are corrected during the reconstruction process. This method is compared with two methods: a sinogram preprocessing correction technique based on wavelet-FFT filter and a reconstruction method based on isotropic TV. The correction results show that the proposed method can reduce visible ring artifacts while preserving the liver section details for real liver section synchrotron data.

Reconstruction of seasonal precipitation in Hawai'i using high-resolution carbon isotope measurements across tree rings

Determination of carbon isotope (δ13C) values of tree-ring tissue is a well-established method to reconstruct past climate variability at annual resolution, but such records are limited in tropical latitudes due to the lack of well-defined annual growth bands. Recent work has demonstrated the potential for high-resolution, intra-ring δ13C records to help define ring boundaries in tropical environments and provide additional climate information at sub-annual resolution. Here we present a high-resolution, intra-ring carbon isotope (δ13C) record of the Hawaiian endemic species Sophora chrysophylla (also known as “māmane”) in order to assess the ability to extract seasonal climate information from these drought tolerant trees. Tree cores were sampled from high-elevation māmane trees growing on the west side of Mauna Kea, Big Island. Across our entire dataset (1986–2008), we identified a notable decreasing linear trend in the δ13C record of 0.061‰/year that can be attributed to changes in the δ13C value of atmospheric CO2 and pCO2 concentration associated with fossil fuel burning. Correcting for these affects yields a nearly flat δ13C record with a slope of −0.0075‰/year, suggesting no long-term trends in climate across the study period. We observe a quasi-periodic change in the δ13C values [Δ(δ13C)] measured within each ring that averages 1.09±0.50‰ (±1σ, n=23) in amplitude. These variations are interpreted as the intra-annual isotopic signal in tree photosynthesis. The δ13C variability correlates with the visible ring structure of the sample, suggesting the presence of annual growth rings at this tropical high elevation site.We applied these data to a model that relates the Δ(δ13C) value to seasonal changes in precipitation in order to reconstruct annual changes in total summer (May through October) and winter (November through April) precipitation at the site. Across the 23-year record (1986–2008; n=579 δ13C measurements), reconstructed values for the ratio of summer to winter precipitation, total summer precipitation, and total winter precipitation correlate well with rainfall data collected from a nearby weather station (r=0.65, 0.36, and 0.70, respectively). These results support application of this model to reconstruct inter-annual changes in seasonal precipitation from long-term tree-ring chronologies. They also demonstrate the potential of using māmane δ13C for future long-term climate reconstructions.

Letter to the editor: Theileria in loggerhead sea turtles Caretta caretta

The article by Di Santi et al. (2012) titled BHemoparasitization by Theileria in the loggerheads Caretta caretta of the Mediterranean Sea^ describes various stages of what the authors interpret as Theileria organism within erythrocytes and leukocytes of loggerhead sea turtles based on morphologic features of the suspected organism. The identification of an organism that has not been previously documented in reptiles requires its ultrastructural and molecular characterization. For example, Paparini et al. (2012) describe novel Babesia and Theileria genotypes in erythrocytes of marsupials having 0.8–2 μm in diameter intra-erythrocytic inclusions with clearly visible signet ring or dot-like forms containing dark purple nuclear material consistent with a piroplasm. Molecular analysis was used for genotype confirmation and phylogenetic analysis. For reasons provided below, we do not believe that Theileria, or any infectious organism, is present in the images presented in Di Santi et al. (2012). Figure 1c–f by Di Santi et al. (2012) describes schizonts in lymphocytes. However, we believe these to be granules within granulocytes; Fig. 1g is consistent with features of a heterophil with drying or fixation artifact rather than a Theileria schizont. Likewise, inclusions in cells in Fig. 1h–j do not have morphology consistent with schizonts. Figure 1j may be a lysed melanomacrophage, a non-specific finding in blood films of healthy reptiles (Strik et al. 2007). Figures 2 and 3 by Di Santi et al. (2012) have images of erythrocytes that are reported to contain intraerythrocytic rounded, bacilliform, or crescent-shaped parasites. Inclusions were variably described as dividing merozoites, tiny bacilliform parasites, curved trophozoites, and gametocytes. These colorless, refractile, and variably sized Binclusions^ are not consistent with Theileria organisms, but rather appear to be drying or fixation artifacts, which can be observed in erythrocytes and leukocytes of any species, especially in thicker areas of a blood film (Fig. 1 in this correspondence below). Figure 4 a,b by Di Santi et al. are reported to show heterophils phagocytizing parasitized erythrocytes. The morphologic description of erythrophagia in loggerhead turtles has been recently addressed (Stacy and Harvey 2015) in response to another publication by this laboratory (Ruggiero et al. 2013). As stated previously, we disagree that erythrophagia is present in the images in which it is described. The erythrocytes are next to the heterophils but the cell membrane of heterophils does not encircle erythrocytes. The amorphous orange discoloration of the background is consistent with an artifact that may originate from drying, staining (residual stain), or smearing (cytoplasmic contents leaked from damaged heterophils). * Nicole I. Stacy stacyn@ufl.edu

Toward online quantification of tracheal stenosis from videobronchoscopy.

Lack of objective measurement of tracheal obstruction degree has a negative impact on the chosen treatment prone to lead to unnecessary repeated explorations and other scanners. Accurate computation of tracheal stenosis in videobronchoscopy would constitute a breakthrough for this noninvasive technique and a reduction in operation cost for the public health service. Stenosis calculation is based on the comparison of the region delimited by the lumen in an obstructed frame and the region delimited by the first visible ring in a healthy frame. We propose a parametric strategy for the extraction of lumen and tracheal ring regions based on models of their geometry and appearance that guide a deformable model. To ensure a systematic applicability, we present a statistical framework to choose optimal parametric values and a strategy to choose the frames that minimize the impact of scope optical distortion. Our method has been tested in 40 cases covering different stenosed tracheas. Experiments report a non- clinically relevant [Formula: see text] of discrepancy in the calculated stenotic area and a computational time allowing online implementation in the operating room. Our methodology allows reliable measurements of airway narrowing in the operating room. To fully assess its clinical impact, a prospective clinical trial should be done.

Beverage emulsions: Comparison among nanoparticle stabilized emulsion with starch and surfactant stabilized emulsions

Emulsions are widely used in beverages to impart desired appearance and flavor to the products. Ring formation in beverages with emulsions during thermal processing and storage is one of the key challenges. This study was aimed at comparing the relative effectiveness of silica nanoparticle based emulsifiers with surfactant and biopolymer based emulsifier (modified starch) in influencing physical stability of emulsions in a model juice. The stability of emulsions was measured by characterizing changes in emulsion droplet size, zeta potential, UV–vis absorbance and visual evaluation of phase separation or ring formation in both primary emulsions and beverage emulsions as a function of storage time. The influence of thermal processing on stability of emulsions both immediately after processing and upon storage was evaluated. The thermal processing conditions simulated both high temperature short time and low temperature long time pasteurization conditions. The results demonstrate that the mean droplet diameter of primary emulsions stabilized by selected emulsifiers was stable during storage for 21days with and without pasteurization. Based on measurements of mean droplet diameter and visible ring formation, polyoxyethylene sorbitan monolaurate (tween-20) stabilized emulsion was not stable in a model juice and the stability of this emulsion was further reduced with thermal processing. In contrast, starch and silica stabilized emulsions in a model juice did not show significant changes in particle diameter or visible ring formation during storage with and without prior thermal processing, although starch stabilized emulsion did show a decrease in absorbance during storage. Zeta potential measurements in a model juice indicate that the surface properties of emulsions were significantly distinct from those of primary emulsion, indicating interaction of juice components with the emulsion interface influencing the surface charge at the interface. These changes in zeta potential of emulsion droplets did not correlate with reduced stability of the emulsions. Overall, the results demonstrate that nanoparticle stabilized emulsions can improve stability of emulsion in beverages as compared to surfactant and biopolymer stabilized emulsions and provides a comprehensive matrix to evaluate stability of emulsions in beverages.

Evaluation of polymeric nanoparticle formulations by effective imaging and quantitation of cellular uptake for controlled delivery of doxorubicin.

Various polymeric nanoparticles have been extensively engineered for applications in controlled drug release delivery in the last decades. Currently, there is a great demand to develop a strategy to qualitatively and quantitatively evaluate these polymeric nanoparticle formulations for producing innovative delivery systems. In this work, a screening platform is developed using luminescent quantum dots as drug model and imaging label to evaluate nanoparticle formulations incorporating either hydrophilic or hydrophobic drugs and imaging agents. It is validated that there is no influence of the incorporated entities on the cellular uptake profile. The use of quantum dots enables efficient detection and precise quantitation of cellular uptake of particles which occupy 25% of the cell volume. The correlation of quantum dot- and doxorubicin-incorporated nanoparticles is useful to develop an evaluation platform for nanoparticle formulations through imaging and quantitation. This platform is also used to observe the surface properties effect of other polymers such as chitosan and poly(ethylene) glycol on the cellular interaction and uptake. Moreover, quantum dots can be used to study microparticle theranostic delivery formulations by deliberately incorporating as visible ring surrounding the microparticles for their easy identifying and tracing in diagnostic and chemotherapeutic applications.