Charge-parity (CP) violation in the tau-charm energy region is a promising area for sensitive tests of Standard Model (SM) predictions and searches for new, beyond the SM physics. A future Tau-Charm Facility that operates at center-of-mass energies between 2.0 and 7.0 GeV, with a peak luminosity of 0.5×1035 cm−2 s−1, would provide huge numbers of hadrons and tau (τ) leptons that are produced in low-background environments and with well understood kinematic properties. In this report, prospects for unique studies of CP violation in the decay of charmed hadrons, and in the production and decay of hyperons and τ leptons at a next-generation tau-charm facility are discussed. In addition, opportunities for improved tests of CPT invariance test in K0−K̄0 mixing are presented.
Satellite remote sensing altimetry data have demonstrated that wintertime low sea level anomaly off northwestern Luzon (NWL-SLA) is a common feature. The genesis of the wintertime low NWL-SLA and its response to the most recent two super El Nino-Southern Oscillation (ENSO) in 1997-1998 and 2015-2016 are explored by conducting a series of numerical experiments based on a well-validated three-dimensional South China Sea (SCS) model. Our analysis emphasizes that the generation of low NWL-SLA and its super-ENSO-related variability are triggered by different dynamical processes. The wintertime local positive wind stress curl off northwestern Luzon serves as the primary driver of low NWL-SLA formation. However, remote signals originating in the tropical western Pacific Ocean represent the dominant source to regulate the super-ENSO-related changes in NWL-SLA, rather than the variabilities of local wind stress curl and ocean currents in the vicinity of Luzon Strait. These remote signals originate from the baroclinic component of sea level changes and propagate westward at speeds of the first-mode baroclinic Rossby wave; subsequently, they enter the SCS clockwise through the southernmost gap of Sibutu Passage and Mindoro Strait at speeds of the baroclinic coastal Kelvin wave. Furthermore, faster wave propagation speeds are observed during La Nina years than El Nino years because of the greater reduced gravity associated with stronger stratification during La Nina years.
Background and Objective Expansion microscopy is an innovative technique that employs swellable polymers to physically enlarge biological specimens, enabling high-resolution imaging beyond traditional optical diffraction limits. However, specimen expansion may result in non-uniform, anisotropic deformation across the sample dilation process. A method to quantify and correct this anisotropic expansion is required. Herein, we used cultured cells, HeLa (a cancer cell line) with stained microtubules, followed by 4X expansion. Lattice lightsheet microscopy captured 3D pre- and post-expansion images on the identical cell. The present imaging analysis method is based on these two sets of 3D images. Methods To address anisotropic deformation, we implemented both rigid and B-spline-based non-rigid image registration algorithms for effective 3D image warping. Furthermore, we developed a numerical technique, the registration field equilibrium smoothing method, which modifies the deformation field obtained from image registration to ensure compliance with physical laws. Results Our technique integrates the finite element method with the Lagrange multiplier method, guaranteeing that the deformation field conforms to linear elastic material equilibrium equations. Conclusions This research not only offers a method for examining anisotropic deformation in specimens processed via expansion microscopy but also enables direct analysis of mechanical strain distribution in biological samples. Furthermore, this numerical methodology could be applicable to larger samples.
Two novel mononuclear copper(II) complexes, [Cu(H4N9-mpz)]Cl2 center dot H2O (1) and [Cu(H4N9-mpz)](ClO4)2 center dot 2CH3OH (2), were synthesized for the first time utilizing the pyrazine-modulated long-chain pentapyridyltetraamine ligand, N2,N2 '-(pyrazine-2,6-diyl)bis(N6-(pyridin-2-yl)pyridine-2,6-diamine) (H4N9-mpz). Both complexes were structurally characterized, and their in vitro cytotoxic activities were systematically evaluated. In each compound, the Cu(II) center is five-coordinate, adopting a slightly distorted trigonal bipyramidal geometry, with Addison distortion parameter tau values of 0.84 for complex (1) and 0.86 for complex (2). The H4N9-mpz ligand adopts an all-anti conformation, coordinating to the copper center as a pentadentate monohelical ligand. This trigonal bipyramidal coordination environment was further corroborated by electronic spectroscopy and the observation of "inverted-type" electron paramagnetic resonance (EPR) spectra. The cytotoxic effects of the free H4N9-mpz ligand and complexes 1 and 2 were evaluated against the DLD-1 and PC3 cancer cell lines, as well as the L929 healthy cell line, and compared with the reference drug cisplatin. Complex 2 exhibited superior antiproliferative activity compared to 1, yielding significantly lower IC50 values of 6.401 & micro;M in DLD-1 cells and 2.956 & micro;M in PC3 cells. However, toxicity profiles on healthy L929 cells revealed that complex 1 possesses a higher selectivity index than complex 2. Molecular docking simulations revealed distinct, target-dependent interaction profiles; the free ligand exhibited the highest predicted affinity toward Bcl-2, whereas the copper (II) complexes demonstrated more favorable docking scores against HSP90. These findings provide preliminary computational insights into potential ligand-protein interactions, prompting further experimental validation.
Extratropical North Atlantic cooling has been tied to droughts over the Sahel in both paleoclimate observations and modeling studies. This study, which uses an atmospheric general circulation model (GCM) coupled to a slab ocean model that simulates this connection, explores the hypothesis that the extratropical North Atlantic cooling causes the Sahel droughts via an atmospheric teleconnection mediated by tropospheric cooling. The drying is also produced in a regional climate model simulation of the Sahel when reductions in air temperature (and associated geopotential height and humidity changes) from the GCM simulation are imposed as the lateral boundary conditions. This latter simulation explicitly demonstrates the central role of tropospheric cooling in mediating the atmospheric teleconnection from extratropical North Atlantic cooling. Diagnostic analyses are applied to the GCM simulation to infer teleconnection mechanisms. An analysis of top of atmosphere radiative flux changes diagnosed with a radiative kernel technique shows that extratropical North Atlantic cooling is augmented by a positive low cloud feedback and advected downstream, cooling Europe and North Africa. The cooling over North Africa is further amplified by a reduced greenhouse effect from decreased atmospheric specific humidity. A moisture budget analysis shows that the direct moisture effect and monsoon weakening, both tied to the ambient cooling and resulting circulation changes, and feedbacks by vertical circulation and evaporation augment the rainfall reduction. Cooling over the Tropical North Atlantic in response to the prescribed extratropical cooling also augments the Sahel drying. Taken together, they suggest a thermodynamic pathway for the teleconnection. The teleconnection may also be applicable to understanding the North Atlantic influence on Sahel rainfall over the twentieth century.
