Polar Expansion Research Articles

Plasma membrane and cytoplasmic compartmentalization: a dynamic structural framework required for pollen tube tip growth.

Rapid, unidirectional pollen tube tip growth is essential for fertilization and is widely employed as a model of polar cell expansion, a process crucial for plant morphogenesis. Different proteins and lipids with key functions in the control of polar cell expansion are associated with distinct domains of the plasma membrane (PM) at the pollen tube tip. These domains need to be dynamically maintained during tip growth, which depends on massive secretory and endocytic membrane trafficking. Very little is currently known about the molecular and cellular mechanisms responsible for the compartmentalization of the pollen tube PM. To provide a reliable structural framework for the further characterization of these mechanisms, an integrated quantitative map was compiled of the relative positions in normally growing Nicotiana tabacum (tobacco) pollen tubes of PM domains 1) enriched in key signaling proteins or lipids, 2) displaying high membrane order, or 3) in contact with cytoplasmic structures playing important roles in apical membrane trafficking. Previously identified secretory and endocytic PM domains were also included into this map. Internalization of regulatory proteins or lipids associated with PM regions overlapping with the lateral endocytic domain was assessed based on brefeldin A (BFA) treatment. These analyses revealed remarkable aspects of the structural organization of tobacco pollen tube tips, which 1) enhance our understanding of cellular and regulatory processes underlying tip growth, and 2) highlight important areas of future research.

A novel EZH1/2 dual inhibitor inhibits GCB DLBCL through cell cycle regulation and M2 tumor-associated macrophage polarization

The incidence of germinal center B-cell-like type diffuse large B-cell lymphoma (GCB DLBCL) is steadily increasing, with a known hereditary component. Although some molecular mechanisms in GCB DLBCL have been elucidated, understanding remains incomplete, limiting the effectiveness of targeted therapies. In GCB DLBCL patients, abnormally high expression of zeste homologs 2 (EZH2) is noted, and the compensatory effect of EZH1 following EZH2 inhibition contributes to poor prognosis. This highlights the potential of dual targeting of EZH1/2 as a promising strategy. In this study, we developed a novel inhibitor, EZH-1-P2, targeting EZH1/2, and evaluated its anti-tumor effects on DLBCL cells. Mechanistically, inhibition of EZH1/2 affects the epigenetic regulation of gene expression related to p53, impacting cell cycle progression and GCB DLBCL cell growth. Additionally, while EZH1/2 inhibition impacts NOTCH signaling, the precise mechanism by which it affects M2-type tumor-associated macrophage (M2-TAM) polarization and germinal center expansion requires further investigation. Our research introduces EZH-1-P2 as a novel inhibitor with potential as a candidate for GCB DLBCL therapy, although further studies are needed to fully elucidate its mechanisms.

Refined analysis of Ω−Ω¯+ polarization in electron-positron annihilation process

We investigate the production of spin-3/2 hyperon pairs, Ω−Ω¯+, in electron-positron annihilation within the helicity formalism. A refined selection of helicity basis matrices is proposed to relate polarization expansion coefficients and spin density matrix elements and to illuminate their inherent physical interpretations and symmetrical properties. With a novel parametrization scheme of helicity amplitudes, we perform an analysis of polarization correlation coefficients for double-tag Ω−Ω¯+ pairs. We present three sets of expressions to describe the decay of Ω− hyperons, and further address the existing tension in the measurements of its decay parameters, particularly ϕΩ. The method and the framework developed in this paper can also be applied to studies of the production and decay mechanisms of other spin-3/2 particles. Published by the American Physical Society 2024

디지털 전환에 따른 근로의 권리 실현 방안

Digital transformation has emerged as a hot topic around the world, attracting attention as an opportunity to overcome various crises and discover new growth engines. This paper examines the impact and problems of digital transformation in realizing Right to Work and suggests normative responses.
 Digital transformation may increase unemployment and lead to job polarization and subsequent expansion of income inequality and poverty. Additionally, as the number of unstable workers increases, blind spots in protection of labor laws and social insurance may increase. In addition, as work flexibility increases, the risk of work-life balance, health, and privacy being violated may increase. Furthermore, as recruitment and personnel management using intelligent information technology expands, problems such as trans- parency, fairness, and the possibility of infringement on personal information and privacy may arise.
 The normative response to these problems is to maintain the principle that digital transformation is ultimately for the benefit of humans and must contribute to the guarantee of basic rights, while keeping in mind the harmony of autonomy and regulation, strengthening transparency, and securing social integration.
 Above all, policies are needed to revitalize industrial dynamics to promote employment. The introduction of basic income may be considered, but sufficient prior review and social consensus must be obtained. In addition, we must be able to adapt to various new problems in the work area that arise due to digital transformation by expanding the scope of application of labor-related laws and including new disciplinary content. First, the requirements for recognizing worker status must be newly established and a social security system that can cover all unemployed individuals must be established. Next, in response to problems that may arise as digital work and full-time work becomes possible, the right to disconnect is needed to be specified and the paradigm of the occupational safety and health legislation must be changed. Furthermore, it is necessary to respond to situations where recruitment and personnel management using intelligent information technology are widely used. Measures are needed to establish minimum standards for data use and ensure transparency while being careful not to excessively restrict the possibility of data use or infringe on autonomy by imposing excessive regulations.

A 3-dimentinal CFD model for simulation of an O2/N2 separation process using an industrial PIHF membrane module for N2 enrichment

In this research, simulation of an O2/N2 membrane separation process for N2 enrichment using an industrial polyimide hollow fiber (PIHF) membrane module was performed based on finite element method. A 3-dimensional (3D) model was used to simulate the mass transfer, convection and diffusion phenomenon in the membrane module. In order to validate the model, the simulation results were compared with the industrial process data, and good agreement was observed. The effects of feed molar flow rate, feed pressure, and molar flow rate of sweep gas stream on the N2 enrichment percentage were investigated. As discovered, the N2 enrichment percentage is improved by enhancing the feed pressure and sweep gas flow rate, while an increase in feed flow rate promotes a diminish in percentage of N2 enrichment. Besides the operational parameters, the influence of flow patterns (co-current and counter-current) and fiber length on the N2 enrichment in lumen side and gas molecules distribution in the membrane side of PIHF membrane module was investigated respectively. As the fiber length increased, the N2 enrichment percentage augments for both patterns due to membrane surface area increment in the PIHF membrane module, which the percentage of N2 enrichment in the countercurrent pattern was higher than co-current. Moreover, Concentration Polarization Index (CPI) was investigated to show the degree of polarization expansion along the PIHF membrane. The effect of feed molar flow rate on the concentration polarization index was investigated, which showed that concentration polarization phenomenon is reduced when feed molar flow rate enhances.

The Fine-scale Structure of Polar Coronal Holes

Coronal holes are thought to be composed of relatively broad columnar structures known as plumes. Here, we demonstrate that the plumes (and interplumes) in polar coronal holes are composed of fine-scale filamentary structure, with average scales of 2″–10″. The fine structure is the off-limb analog of the previously found “plumelets” of Uritsky et al. The off-limb observations enable an examination of the fine structure without the influence of the underlying atmosphere along the line of sight. Hence, we show that the fine-scale structure is present at least until the edge of the field of view of the Solar Dynamics Observatory. The fine structure is found to have spatial distribution that follows a k −1 power law perpendicular to the inferred magnetic field direction. For a small sample of the fine structure, the cross-sectional profiles are measured as a function of height. In some cases, the measurements indicate that the fine structure expands super-radially, consistent with existing models of polar field expansion and the expansion of the plumes. We discuss the implications of the presence of the fine structure with respect to understanding wave propagation in the coronal holes and their contribution to powering the solar wind.

Identifying imprints of externally derived dust and halogens in the sedimentary record of an Iberian alpine lake for the past ∼13,500 years – Lake Peixão, Serra da Estrela (Central Portugal)

Iberian lacustrine sediments are a valuable archive to document environmental changes since the last glacial termination, seen as key for anticipating future climate/environmental changes and their far-reaching implications for generations to come. Herein, multi-proxy-based indicators of a mountain lake record from Serra da Estrela were used to reconstruct atmospheric (in)fluxes and associated climatic/environmental changes over the last ∼13.5 ka. Depositions of long-range transported dust (likely from the Sahara) and halogens (primarily derived from seawater) were higher for the pre-Holocene, particularly in the late Bølling-Allerød–Younger Dryas period, compared to the Holocene. This synchronous increase could be related to a recognized dust-laden atmosphere, along with the combined effect of (i) an earlier proposed effective transport of Sahara dust for higher latitudes during cold periods and (ii) the progressive Polar Front expansion southwards, with the amplification of halogen activation reactions in lower latitudes due to greater closeness to snow/sea ice (halide-laden) surfaces. Additionally, the orographic blocking of Serra da Estrela may have played a critical role in increasing precipitation of Atlantic origin at higher altitudes, with the presence of snow prompting physical and chemical processes involving halogen species. In the Late Holocene, the dust proxy records highlighted two periods of enhanced input to Lake Peixão, the first (∼3.5–2.7 ka BP) after the end of the last African Humid Period and the second, from the 19th century onwards, agreeing with the advent of commercial agriculture, and human contribution to land degradation and dust emission in the Sahara/Sahel region. The oceanic imprints throughout the Holocene matched well with North Atlantic rapid climatic changes that, in turn, coincided with ice-rafted debris or Bond events and other records of increased storminess for the European coasts. Positive parallel peaks in halogens were found in recent times, probably connected to fire extinction by halogenated alkanes and roadway de-icing.

Different niches for stem cells carrying the same oncogenic driver affect pathogenesis and therapy response in myeloproliferative neoplasms

Aging facilitates the expansion of hematopoietic stem cells (HSCs) carrying clonal hematopoiesis-related somatic mutations and the development of myeloid malignancies, such as myeloproliferative neoplasms (MPNs). While cooperating mutations can cause transformation, it is unclear whether distinct bone marrow (BM) HSC-niches can influence the growth and therapy response of HSCs carrying the same oncogenic driver. Here we found different BM niches for HSCs in MPN subtypes. JAK–STAT signaling differentially regulates CDC42-dependent HSC polarity, niche interaction and mutant cell expansion. Asymmetric HSC distribution causes differential BM niche remodeling: sinusoidal dilation in polycythemia vera and endosteal niche expansion in essential thrombocythemia. MPN development accelerates in a prematurely aged BM microenvironment, suggesting that the specialized niche can modulate mutant cell expansion. Finally, dissimilar HSC-niche interactions underpin variable clinical response to JAK inhibitor. Therefore, HSC-niche interactions influence the expansion rate and therapy response of cells carrying the same clonal hematopoiesis oncogenic driver.

3D spheroid-microvasculature-on-a-chip for tumor-endothelium mechanobiology interplay

During the final stage of cancer metastasis, tumor cells embed themselves in distant capillary beds, from where they extravasate and establish secondary tumors. Recent findings underscore the pivotal roles of blood/lymphatic flow and shear stress in this intricate tumor extravasation process. Despite the increasing evidence, there is a dearth of systematic and biomechanical methodologies that accurately mimic intricate 3D microtissue interactions within a controlled hydrodynamic microenvironment. Addressing this gap, we introduce an easy-to-operate 3D spheroid-microvasculature-on-a-chip (SMAC) model. Operating under both static and regulated flow conditions, the SMAC model facilitates the replication of the biomechanical interplay between heterogeneous tumor spheroids and endothelium in a quantitative manner. Serving as an in vitro model for metastasis mechanobiology, our model unveils the phenomena of 3D spheroid-induced endothelial compression and cell-cell junction degradation during tumor migration and expansion. Furthermore, we investigated the influence of shear stress on endothelial orientation, polarization, and tumor spheroid expansion. Collectively, our SMAC model provides a compact, cost-efficient, and adaptable platform for probing the mechanobiology of metastasis.

Fast plug-in capacitors polarity detection with morphology and SVM fusion method in automatic optical inspection system

Defect detection is a critical element in the PCB manufacturing process. Different from surface mount PCB, the components on the plug-in PCB are usually installed manually, resulting in significant errors. We make contributions in the following two aspects: (1) a framework and measurement method of a light source and make a cheap and efficient lighting system; (2) a fusion algorithm based on machine learning and morphology for polarity detection of plug-in capacitors. The capacitor is detected using SVM and fused with the polar coordinate expansion method. The AOI system and the proposed fusion algorithm have been applied to the production line, with an accuracy of \(99.73\%\) and a missed detection rate \(0.12\%\).

Storm time polar cap expansion: interplanetary magnetic field clock angle dependence

Abstract. It is well known that the polar cap, delineated by the open–closed field line boundary (OCB), responds to changes in the interplanetary magnetic field (IMF). In general, the boundary moves equatorward when the IMF turns southward and contracts poleward when the IMF turns northward. However, observations of the OCB are spotty and limited in local time, making more detailed studies of its IMF dependence difficult. Here, we simulate five solar storm periods with the coupled model consisting of the Open Geospace General Circulation Model (OpenGGCM) coupled with the Coupled Thermosphere Ionosphere Model (CTIM) and the Rice Convection Model (RCM), i.e., the OpenGGCM-CTIM-RCM, to estimate the location and dynamics of the OCB. For these events, polar cap boundary location observations are also obtained from Defense Meteorological Satellite Program (DMSP) precipitation spectrograms and compared with the model output. There is a large scatter in the DMSP observations and in the model output. Although the model does not predict the OCB with high fidelity for every observation, it does reproduce the general trend as a function of IMF clock angle. On average, the model overestimates the latitude of the open–closed field line boundary by 1.61∘. Additional analysis of the simulated polar cap boundary dynamics across all local times shows that the MLT of the largest polar cap expansion closely correlates with the IMF clock angle, that the strongest correlation occurs when the IMF is southward, that during strong southward IMF the polar cap shifts sunward, and that the polar cap rapidly contracts at all local times when the IMF turns northward.

Down-regulating a fiber-specific KCR like gene GhKCRL1 suppressed fiber elongation through blocking the synthesis of sphingolipids in fiber cell

Cotton is an important natural fiber crop in the world. Cotton fiber cell is an extremely elongated single-cell trichome of seeds. Therefore, the fiber cell is an ideal model for studying plant cell elongation (polar expansion) and secondary wall deposition. Moreover, the two processes determine the quality (length, strength and fineness) of mature cotton fiber. However, the regulatory mechanism of fiber elongation remains unclear. Ligon lintless-1 ( Li-1 ) mutant is a fiber elongation mutant and a good material to study fiber elongation. In the present study, through analyzing the different expression genes in 10-DPA (day post anthesis) fiber cell of Li-1 mutant and its wild type (TM-1), we found a KCR (3-Ketoacyl-Coenzyme A Reductase) like gene, GhKCRL1 , was strikingly down-regulated in Li-1 mutant. GhKCRL1 shared low sequence identity with the 17 beta-hydroxysteroid dehydrogenase 12 of animal and the reported GhKCR1, GhKCR2, and GhKCR3 of upland cotton. GhKCRL1 was specifically expressed in fiber cells and its expression level peaked in 10-DPA fiber cells. GhKCRL1 is located in the endoplasmic reticulum . Down-regulating the expression of GhKCRL1 suppressed fiber elongation and significantly shortened mature fiber length. The sphingolipids contained VLCFA and LCFA strikingly declined in RNAi fiber cells. Consistently, the expression levels of most genes involved in sphingolipid biosynthesis and very long chain fatty acid (VLCFA) biosynthesis decreased in GhKCRL1 down-regulated cotton fibers. And the exogenous application of VLCFA (C24 FA) could rescue the elongation of GhKCRL1 down-regulated fiber cells. Taken together, the results revealed that the fiber-specific GhKCRL1 play some roles in cotton fiber elongation by regulating sphingolipid biosynthesis. Pattern diagram of the GhKCRL regulating fiber elongation. • GhKCRL1 is a novel KCR gene in upland cotton. • GhKCRL1 specifically expressed in fibers cells. • Down-regulating GhKCRL1 expression suppressed fiber cell elongation. • Down-regulating GhKCRL1 blocking the synthesis of sphingolipids in fiber cell.

Class III Peroxidases PRX01, PRX44, and PRX73 Control Root Hair Growth in Arabidopsis thaliana.

Root hair cells are important sensors of soil conditions. They grow towards and absorb water-soluble nutrients. This fast and oscillatory growth is mediated by continuous remodeling of the cell wall. Root hair cell walls contain polysaccharides and hydroxyproline-rich glycoproteins, including extensins (EXTs). Class-III peroxidases (PRXs) are secreted into the apoplastic space and are thought to trigger either cell wall loosening or polymerization of cell wall components, such as Tyr-mediated assembly of EXT networks (EXT-PRXs). The precise role of these EXT-PRXs is unknown. Using genetic, biochemical, and modeling approaches, we identified and characterized three root-hair-specific putative EXT-PRXs, PRX01, PRX44, and PRX73. prx01,44,73 triple mutation and PRX44 and PRX73 overexpression had opposite effects on root hair growth, peroxidase activity, and ROS production, with a clear impact on cell wall thickness. We use an EXT fluorescent reporter with contrasting levels of cell wall insolubilization in prx01,44,73 and PRX44-overexpressing background plants. In this study, we propose that PRX01, PRX44, and PRX73 control EXT-mediated cell wall properties during polar expansion of root hair cells.

Morphologies of Wolf–Rayet Planetary Nebulae Based on IFU Observations

Integral field unit (IFU) spectroscopy of planetary nebulae (PNe) provides a plethora of information about their morphologies and ionization structures. An IFU survey of a sample of PNe around hydrogen-deficient stars has been conducted with the Wide Field Spectrograph (WiFeS) on the ANU 2.3-m telescope. In this paper, we present the Hα kinematic observations of the PN M 2-42 with a weak emission-line star (wels), and the compact PNe Hen 3-1333 and Hen 2-113 around Wolf–Rayet ([WR]) stars from this WiFeS survey. We see that the ring and point-symmetric knots previously identified in the velocity [N ii] channels of M 2-42 are also surrounded by a thin exterior ionized Hα halo, whose polar expansion is apparently faster than the low-ionization knots. The velocity-resolved Hα channel maps of Hen 3-1333 and Hen 2-113 also suggest that the faint multipolar lobes may get to a projected outflow velocity of ∼100 ± 20 km s−1 far from the central stars. Our recent kinematic studies of the WiFeS/IFU survey of other PNe around [WR] and wels mostly hint at elliptical morphologies, while collimated outflows are present in many of them. As the WiFeS does not have adequate resolution for compact (≤6 arcsec) PNe, future high-resolution spatially-resolved observations are necessary to unveil full details of their morpho-kinematic structures.

Electrodeposition as an Alternative Approach for Monolithic Integration of InSb on Silicon.

High-performance electronics would greatly benefit from a versatile III-V integration process on silicon. Unfortunately, integration using hetero epitaxy is hampered by polarity, lattice, and thermal expansion mismatch. This work proposes an alternative concept of III-V integration combining advantages of pulse electrodeposition, template-assisted selective epitaxy, and recrystallization from a melt. Efficient electrodeposition of nano-crystalline and stochiometric InSb in planar templates on Si (001) is achieved. The InSb deposits are analysed by high resolution scanning transmission electron microscopy (HR-STEM) and energy-dispersive X-ray spectroscopy (EDX) before and after melting and recrystallization. The results show that InSb can crystallise epitaxially on Si with the formation of stacking faults. Furthermore, X-ray photoelectron (XPS) and Auger electron (AE) spectroscopy analysis indicate that the InSb crystal size is limited by the impurity concentration resulting from the electrodeposition process.

An efficient finite-element method and error analysis for the fourth-order elliptic equation in a circular domain

In this paper, we propose an efficient finite-element method based on dimension reduction scheme to solve the fourth-order elliptic equation in a circular domain. First of all, by using polar coordinate transformation and Fourier basis function expansion, the necessary pole conditions are derived and the original problem is decomposed into a series of equivalent one-dimensional fourth-order problems. Based on the pole conditions, the appropriate weighted Sobolev spaces are introduced and the error estimate of finite-element solution is proved for each one-dimensional fourth-order problem. Then we construct the cubic Hermite interpolation basis functions and derive the matrix form corresponding to the discrete scheme. Furthermore, the sparsity of mass matrix and stiffness matrix are illustrated. Finally, we provide some numerical experiments, and the numerical results show that our method is very effective.

Sphingolipid Profile during Cotton Fiber Growth Revealed That a Phytoceramide Containing Hydroxylated and Saturated VLCFA Is Important for Fiber Cell Elongation.

Cotton fiber is a single-celled seed trichrome that arises from the epidermis of the ovule’s outer integument. The fiber cell displays high polar expansion and thickens but not is disrupted by cell division. Therefore, it is an ideal model for studying the growth and development of plant cells. Sphingolipids are important components of membranes and are also active molecules in cells. However, the sphingolipid profile during fiber growth and the differences in sphingolipid metabolism at different developmental stages are still unclear. In this study, we detected that there were 6 classes and 95 molecular species of sphingolipids in cotton fibers by ultrahigh performance liquid chromatography-MS/MS (UHPLC-MS/MS). Among these, the phytoceramides (PhytoCer) contained the most molecular species, and the PhytoCer content was highest, while that of sphingosine-1-phosphate (S1P) was the lowest. The content of PhytoCer, phytoceramides with hydroxylated fatty acyls (PhytoCer-OHFA), phyto-glucosylceramides (Phyto-GluCer), and glycosyl-inositol-phospho-ceramides (GIPC) was higher than that of other classes in fiber cells. With the development of fiber cells, phytosphingosine-1-phosphate (t-S1P) and PhytoCer changed greatly. The sphingolipid molecular species Ceramide (Cer) d18:1/26:1, PhytoCer t18:1/26:0, PhytoCer t18:0/26:0, PhytoCer t18:1/h20:0, PhytoCer t18:1/h26:0, PhytoCer t18:0/h26:0, and GIPC t18:0/h16:0 were significantly enriched in 10-DPA fiber cells while Cer d18:1/20:0, Cer d18:1/22:0, and GIPC t18:0/h18:0 were significantly enriched in 20-DPA fiber cells, indicating that unsaturated PhytoCer containing hydroxylated and saturated very long chain fatty acids (VLCFA) play some role in fiber cell elongation. Consistent with the content analysis results, the related genes involved in long chain base (LCB) hydroxylation and unsaturation as well as VLCFA synthesis and hydroxylation were highly expressed in rapidly elongating fiber cells. Furthermore, the exogenous application of a potent inhibitor of serine palmitoyltransferase, myriocin, severely blocked fiber cell elongation, and the exogenous application of sphingosine antagonized the inhibition of myriocin for fiber elongation. Taking these points together, we concluded that sphingolipids play crucial roles in fiber cell elongation and SCW deposition. This provides a new perspective for further studies on the regulatory mechanism of the growth and development of cotton fiber cells.

POS0326 ROLE OF THE IL-25 / IL-17RB AXIS IN TH9 POLARIZATION IN PATIENTS WITH PROGRESSIVE SYSTEMIC SCLEROSIS

Background:Systemic sclerosis (SSc) is an inflammatory connective tissue disease leading to chronic and progressive fibrosis, typically affecting the skin and internal organs. The alteration of both innate and adaptive immune responses plays a pivotal role in SSc pathophysiology, although it has not yet been fully elucidated [1].Recent findings have demonstrated interleukin (IL)-9 overexpression and significant group 2 innate lymphoid cells (ILC2) expansion in patients with SSc. Th9-ILC2-mast cells axis seems to be involved in SSc tissue damage and in the induction of fibrosis [2]. Activation and production of IL-9 by Th9 cells are promoted by transforming growth factor (TGF)-β, thymic stromal lymphopoietin (TSLP), IL-25 and IL-33. Thus, the IL-25 / IL-17RB pathway would act as a key player in SSc.Objectives:The purpose of this study was to evaluate the role of the IL-25 / IL-17RB axis as a driver in Th9 polarization and ILC2 expansion and polarization in SSc patients.Methods:26 patients were enrolled in this study. Peripheral blood and skin biopsy specimens were obtained from SSc patients. PBMCs were isolated and incubated with and without recombinant (r)IL-25 for 24-48-72 hours and the frequencies of Th9 cells, Th17 cells and ILC2 were assessed by flow cytometry analysis. Moreover, the ex vivo expression of IL-17RB in ILC2 was also assessed. Immunofluorescence analysis was performed on biopsy skin samples to evaluate IL-17RB expression in ILC2.Results:In SSc samples, Th9 cells frequency progressively increased after stimulation with rIL-25, compared to healthy controls in which IL-9 frequency decreased over time regardless of rIL-25.Simultaneously, we evaluated the role of the IL-25 / IL-17RB axis in Th17 cells.In the SSc pool, the initially low rate of IL-17 increased at 72 hours after stimulation with rIL-25. In unstimulated SSc samples, the initially higher IL-17 rate decreased at 72 hours; conversely, it was consistently low in healthy controls, at both baseline and stimulated conditions.Our results confirmed the presence of IL-25-dependent clonal ILC2 expansion, suggesting a greater and progressive expansion over time in patients with SSc, compared to controls.Interestingly, increased IL-17RB expression was found in circulating ILC2 from SSc patients supporting the characterization of ILC2 inflammatory phenotype.Consistently, immunofluorescence on the skin of SSc patients showed a marked infiltrate of CD3-GATA3+ IL-17RB+ cells, confirming the presence of the activated inflammatory phenotype ILC2, absent in skin biopsies of healthy controls (Figure 1).Conclusion:These preliminary data suggest an active role of the IL-25/IL-17RB axis in SSc. It results in Th9 polarization and Th17 clonal expansion, inducing the production of IL-9 and, to a lesser extent, IL-17. Moreover, in addition to promoting Th9-mediated ILC2 differentiation, IL-25 directs the polarization of ILC2 towards the inflammatory phenotype.

Monte Carlo Simulation on the Stiefel Manifold via Polar Expansion

Motivated by applications to Bayesian inference for statistical models with orthogonal matrix parameters, we present a general approach to Monte Carlo simulation from probability distributions on the Stiefel manifold. To bypass many of the well-established challenges of simulating from the distribution of a random orthogonal matrix we construct a distribution for an unconstrained random matrix X such that the orthogonal component of the polar decomposition of is equal in distribution to The distribution of X is amenable to Markov chain Monte Carlo (MCMC) simulation using standard methods, and an approximation to the distribution of Q can be recovered from a Markov chain on the unconstrained space. When combined with modern MCMC software, polar expansion allows for routine and flexible posterior inference in models with orthogonal matrix parameters. We find that polar expansion with adaptive Hamiltonian Monte Carlo is an order of magnitude more efficient than competing MCMC approaches in a benchmark protein interaction network application. We also propose a new approach to Bayesian functional principal component analysis which we illustrate in a meteorological time series application. Supplementary materials for this article are available online.

Rho of Plants GTPases and Cytoskeletal Elements Control Nuclear Positioning and Asymmetric Cell Division during Physcomitrella patens Branching

Branching morphogenesis is a widely used mechanism for development [1, 2]. In plants, it is initiated by the emergence of a new growth axis, which is of particular importance for plants to explore space and access resources [1]. Branches can emerge either from a single cell or from a group of cells [3-5]. In both cases, the mother cells that initiate branching must undergo dynamic morphological changes and/or adopt oriented asymmetric cell divisions (ACDs) to establish the new growth direction. However, the underlying mechanisms are not fully understood. Here, using the bryophyte moss Physcomitrella patens as a model, we show that side-branch formation in P.patens protonemata requires coordinated polarized cell expansion, directional nuclear migration, and orientated ACD. By combining pharmacological experiments, long-term time-lapse imaging, and genetic analyses, we demonstrate that Rho of plants (ROP) GTPases and actin are essential for cell polarization and local cell expansion (bulging). The growing bulge acts as a prerequisite signal to guide long-distance microtubule (MT)-dependent nuclear migration, which determines the asymmetric positioning of the division plane. MTs play an essential role in nuclear migration but are less involved in bulge formation. Hence, cell polarity and cytoskeletal elements act cooperatively to modulate cell morphology and nuclear positioning during branch initiation. We propose that polarity-triggered nuclear positioning and ACD comprise a fundamental mechanism for increasing multicellularity and tissue complexity during plant morphogenesis.