Adhering interacting cells to two opposing coverslips allows super-resolution imaging of cell-cell interfaces

Cell-cell interfaces convey mechanical and chemical information in multicellular systems. Microscopy has revealed intricate structure of such interfaces, yet typically with limited resolution due to diffraction and unfavourable orthogonal orientation of the interface to the coverslip. We present a simple and robust way to align cell-cell interfaces in parallel to the coverslip by adhering the interacting cells to two opposing coverslips. We demonstrate high-quality diffraction-limited and super-resolution imaging of interfaces (immune-synapses) between fixed and live CD8+ T-cells and either antigen presenting cells or melanoma cells. Imaging methods include bright-field, confocal, STED, dSTORM, SOFI, SRRF and large-scale tiled images. The low background, lack of aberrations and enhanced spatial stability of our method relative to existing cell-trapping techniques allow use of these methods. We expect that the simplicity and wide-compatibility of our approach will allow its wide dissemination for super-resolving the intricate structure and molecular organization in a variety of cell-cell interfaces.

A specific basal body linker protein provides the connection function for basal body inheritance in trypanosomes

Centrioles and basal bodies (CBBs) are found in physically linked pairs, and in mammalian cells intercentriole connections (G1–G2 tether and S–M linker) regulate centriole duplication and function. In trypanosomes BBs are not associated with the spindle and function in flagellum/cilia nucleation with an additional role in mitochondrial genome (kinetoplast DNA [kDNA]) segregation. Here, we describe BBLP, a BB/pro-BB (pBB) linker protein in Trypanosoma brucei predicted to be a large coiled-coil protein conserved in the kinetoplastida. Colocalization with the centriole marker SAS6 showed that BBLP localizes between the BB/pBB pair, throughout the cell cycle, with a stronger signal in the old flagellum BB/pBB pair. Importantly, RNA interference (RNAi) depletion of BBLP leads to a conspicuous splitting of the BB/pBB pair associated only with the new flagellum. BBLP RNAi is lethal in the bloodstream form of the parasite and perturbs mitochondrial kDNA inheritance. Immunogold labeling confirmed that BBLP is localized to a cytoskeletal component of the BB/pBB linker, and tagged protein induction showed that BBLP is incorporated de novo in both new and old flagella BB pairs of dividing cells. We show that the two aspects of CBB disengagement—loss of orthogonal orientation and ability to separate and move apart—are consistent but separable events in evolutionarily diverse cells and we provide a unifying model explaining centriole/BB linkage differences between such cells.

Development of a Novel Miniaturized Electromagnetic Actuator for a Modular Serial Manipulator

This paper presents a novel miniaturized and modular dual-axis Electromagnetic Actuator (EMA). It mainly consists of two electromagnetic coils in an orthogonal orientation with a permanent magnet fixed on a free moving frame that rotates around two axes/joints. By actuating either of the coils, the free moving frame rotates around the corresponding axis. Simulations and experimental analyses are conducted in order to characterize the performance of our EMA. Thus, our actuator achieves a torque of 100 mNm at simulation and 80 mNm through experimentation for the same applied current. Additionally, it can achieve a rotation of 10∘ (≈0.2 rad), according to simulations and experimental work. Because of modularity, multiple units of our EMA can be connected together in different configuration to serve in several applications. As an example application, we used a pair of our EMA in order to generate a miniaturized 4-DOF robotic manipulator. This manipulator demonstrates the advantages of light weight, small size, and a high level of manipulability. Kinematic analyses and experimental work are performed in order to validate our manipulator and to prove the concept of our proposed EMA. Through this experiment, we applied an open-loop controller on our EMAs, so that the end-effector of our manipulator can track a predefined circular trajectory. The movement of the end-effector is detected while using image processing techniques. Although we used an open-loop controller, our manipulator is still able to track the trajectory with moderate errors.

Molecular Tuning of Filamin A Activities in the Context of Adhesion and Migration

The dynamic organization of actin cytoskeleton meshworks relies on multiple actin-binding proteins endowed with distinct actin-remodeling activities. Filamin A is a large multi-domain scaffolding protein that cross-links actin filaments with orthogonal orientation in response to various stimuli. As such it plays key roles in the modulation of cell shape, cell motility, and differentiation throughout development and adult life. The essentiality and complexity of Filamin A is highlighted by mutations that lead to a variety of severe human disorders affecting multiple organs. One of the most conserved activity of Filamin A is to bridge the actin cytoskeleton to integrins, thereby maintaining the later in an inactive state. We here review the numerous mechanisms cells have developed to adjust Filamin A content and activity and focus on the function of Filamin A as a gatekeeper to integrin activation and associated adhesion and motility.

Jahnsite-(CaMnZn) from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, and structural flexibility of jahnsite-group minerals

Jahnsite-(CaMnZn), CaMn2+Zn2Fe3+2(PO4)4(OH)2⋅8H2O, is a new jahnsite-group mineral associated with alteration of phosphophyllite at the Hagendorf-Süd pegmatite, Bavaria. It forms as thin yellow crusts and brown epitactic growths on altered phosphophyllite, both of which comprise lath-like crystals in orthogonal orientation, up to 100 μm long. The crystals contain intergrowths of jahnsite-(CaMnZn) and jahnsite-(CaMnMn) on a scale of ~50 μm. The calculated density is 2.87 g cm−3 based on the empirical formula. Optically it is biaxial (–), with α = 1.675(2), β = 1.686(2) and γ = 1.691(2) (white light). The calculated 2V is 68°. Dispersion could not be observed, and the optical orientation is Z = b. Pleochroism was imperceptible. Electron microprobe analyses together with results from Mössbauer spectroscopy gives the formula (Ca0.59Mn0.24)Σ0.83Mn(Zn0.74Mn2+0.48Mg0.18Fe2+0.13Fe3+0.47)Σ2Fe3+2(P0.995O4)4(OH)2.03(H2O)7.97.Jahnsite-(CaMnZn) is monoclinic, P2/a, with a = 15.059(1), b = 7.1885(6), c = 10.031(2) Å, β = 111.239(8)° and V = 1012.1(2) Å3. The recent International Mineralogical Association approved nomenclature system for jahnsite-group minerals was applied to establish jahnsite-(CaMnZn) from the empirical formula. The structural flexibility of jahnsite-group minerals to accommodate cations of quite different sizes in the X and M1 sites is discussed in terms of rotations about the 7 Å axis of two independent octahedra centred at the M3 sites.

A Hidden Side of the Conformational Mobility of the Quercetin Molecule Caused by the Rotations of the O3H, O5H and O7H Hydroxyl Groups: In Silico Scrupulous Study

In this study at the MP2/6-311++G(2df,pd)//B3LYP/6-311++G(d,p) level of quantum-mechanical theory it was explored conformational variety of the isolated quercetin molecule due to the mirror-symmetrical hindered turnings of the O3H, O5H and O7H hydroxyl groups, belonging to the A and C rings, around the exocyclic C–O bonds. These dipole active conformational transformations proceed through the 72 transition states (TSs; C1 point symmetry) with non-orthogonal orientation of the hydroxyl groups relatively the plane of the A or C rings of the molecule (HO7C7C8/HO7C7C6 = ±(89.9–93.3), HO5C5C10 = ±(108.9–114.4) and HO3C3C4 = ±(113.6–118.8 degrees) (here and below signs ‘±’ corresponds to the enantiomers)) with Gibbs free energy barrier of activation ΔΔGTS in the range 3.51–16.17 kcal·mol−1 under the standard conditions (T = 298.1 K and pressure 1 atm): ΔΔGTSO7H (3.51–4.27) < ΔΔGTSO3H (9.04–11.26) < ΔΔGTSO5H (12.34–16.17 kcal mol−1). Conformational dynamics of the O3H and O5H groups is partially controlled by the intramolecular specific interactions O3H…O4, C2′/C6′H…O3, O3H…C2′/C6′, O5H…O4 and O4…O5, which are flexible and cooperative. Dipole-active interconversions of the enantiomers of the non-planar conformers of the quercetin molecule (C1 point symmetry) is realized via the 24 TSs with C1 point symmetry (HO3C3C2C1 = ±(11.0–19.1), HC2′/C6′C1′C2 = ±(0.6–2.9) and C3C2C1′C2′/C3C2C1′C6′ = ±(1.7–9.1) degree; ΔΔGTS = 1.65–5.59 kcal·mol−1), which are stabilized by the participation of the intramolecular C2′/C6′H…O1 and O3H…HC2′/C6′ H-bonds. Investigated conformational rearrangements are rather quick processes, since the time, which is necessary to acquire thermal equilibrium does not exceed 6.5 ns.

The SAMI Galaxy Survey: first detection of a transition in spin orientation with respect to cosmic filaments in the stellar kinematics of galaxies

ABSTRACT We present the first detection of mass-dependent galactic spin alignments with local cosmic filaments with &gt;2σ confidence using IFS kinematics. The 3D network of cosmic filaments is reconstructed on Mpc scales across GAlaxy and Mass Assembly fields using the cosmic web extractor DisPerSe. We assign field galaxies from the SAMI survey to their nearest filament segment in 3D and estimate the degree of alignment between SAMI galaxies’ kinematic spin axis and their nearest filament in projection. Low-mass galaxies align their spin with their nearest filament while higher mass counterparts are more likely to display an orthogonal orientation. The stellar transition mass from the first trend to the second is bracketed between $10^{10.4}$ and $10^{10.9}\, \mathrm{ M}_{\odot }$, with hints of an increase with filament scale. Consistent signals are found in the Horizon-AGN cosmological hydrodynamic simulation. This supports a scenario of early angular momentum build-up in vorticity rich quadrants around filaments at low stellar mass followed by progressive flip of spins orthogonal to the cosmic filaments through mergers at high stellar mass. Conversely, we show that dark matter only simulations post-processed with a semi-analytical model treatment of galaxy formation struggles to reproduce this alignment signal. This suggests that gas physics is key in enhancing the galaxy-filament alignment.

Fractal-Inspired Ultra-Wideband Diversity Slot Antenna for Wireless Communication Systems

A novel compact ultra-wideband (UWB) multiple-input multiple-output (MIMO) slot antenna with band notch characteristics is presented for portable wireless UWB applications. The antenna comprises of co-planar waveguide feed (CPW) and two radiating monopoles oriented in orthogonal orientation for providing orthogonal radiation patterns. A Minkowski fractal parasitic stub along with a Minkowski fractal grounded stub has been placed at 45° between the monopoles to reduce the coupling between them, which in turn establishes high isolation between the radiators. An excellent band notch characteristic is obtained at 5.5 GHz by etching a modified E-shaped compact slot on the radiators. Results show that the designed antenna meets -10 dB impedance bandwidth and -17 dB isolation throughout the entire operating band (3.1 -12 GHz). Novelty of this design lies in improving isolation using fractal which occupies less space in compared to other isolation mechanisms in MIMO structures. The simulated and measured results depict that the proposed antenna is convenient for MIMO diversity systems.