Nanodissected elastically loaded clathrin lattices relax to increased curvature

Clathrin-mediated endocytosis (CME) is the major endocytosis pathway for the specific internalization of large compounds, growth factors, and receptors. Formation of internalized vesicles from the flat plasma membrane is accompanied by maturation of cytoplasmic clathrin coats. How clathrin coats mature and the mechanistic role of clathrin coats are still largely unknown. Maturation models proposed clathrin coats to mature at constant radius or constant area, driven by molecular actions or elastic energy. Here, combining high-speed atomic force microscopy (HS-AFM) imaging, HS-AFM nanodissection, and elasticity theory, we show that clathrin lattices deviating from the intrinsic curvature of clathrin form elastically loaded assemblies. Upon nanodissection of the clathrin network, the stored elastic energy in these lattices drives lattice relaxation to accommodate an ideal area-curvature ratio toward the formation of closed clathrin-coated vesicles. Our work supports that the release of elastic energy stored in curvature-frustrated clathrin lattices could play a major role in CME.

Time Dependent Effect of flow properties on addition of heat to the air flow at Compressible Subsonic Speeds

Heat addition process is a governing phenomenon in turbojet and ramjet burners, where heat is added to the flow during the fuel-air combustion process. In the present work, an analytical study has been performed to investigate the effect of heat addition on the basic flow properties based on compressible Rayleigh flow model between the subsonic and sonic flow regime. The unsteady nature of flow properties in these regimes have been evaluated analytically by adding heat through the walls of a constant area, frictionless duct in which air flow occurs over different periods of time. Sudden variation of temperature, pressure, velocity and kinetic energy of the flow were found at flow Mach number M = 0.94. Flow velocity and kinetic energy increases until the flow approaches M = 0.94, afterwards there is a rapid increase in the flow velocity and kinetic energy until it reaches sonic conditions. Conversely, pressure decreased till the flow reaches M = 0.94, there after a sudden drop was observed. Flow enthalpy increased initially, reached maximum at flow M = 0.845 and then reduced till sonic conditions. Based on the observations, it has been concluded that the heat energy contributed to increase the kinetic energy thereby reducing the temperature of the flow.

Axisymmetric membranes with edges under external force: buckling, minimal surfaces, and tethers

We use theory and numerical computation to determine the shape of an axisymmetric fluid membrane with a resistance to bending and constant area. The membrane connects two rings in the...

Experimental study on heat transfer performance of variable area straight fin heat sinks with PCM

The thermal performance of heat sinks with variable area straight fins with and without PCM is quantitatively explored in this article. The effects of diverse fin geometries (constant area straight fin, variable area straight fin, circular pin fin, hemispherical pin fin, and elliptical pin fin), varying Reynolds numbers, and fin densities on boosting electronics cooling performance were investigated. The goal of this research is to develop the best fin geometry for electronics cooling technologies. This research demonstrates that altering fin density can improve heat sink thermal performance while also reducing heat sink weight. The base temperature of the heat sink is found to be lower in variable area straight fins. In comparison to alternative configurations for heat transfer with PCM, the results show that variable area straight fin heat sinks are the most effective. The thermal resistance of the improved heat sink with variable fin density was reduced by 9%.

Dynamics of Area Change in Vegetable Production in Karnataka

Area under production of vegetables is increasing over the years despite the gradual fall in total cultivable area in India. Nonetheless, growth in area is not same for all the vegetables. To the assess growth in area and address its disparity, the present study was carried out for the state of Karnataka for the period 1998-99 to 2017-18. About forty percent increase in area of vegetables has been observed over the period of two decades. Among the vegetables potato, and leafy vegetables recorded negative growth rate. Inequality between districts has also been observed for growth in area under vegetables. Markov chain analysis was employed to obtain transitional probability matrix of area under different vegetables. Projection for area of individual vegetable/vegetable groups for period of eight years has been made by simulating the transition probabilities. Tomato, gourds, cole crops and other vegetables group show positive trend of area over the study period. However, onion and leafy vegetables would have more or less constant area over the projected period. The unbalanced growth within the vegetable group could impact to the economy either by affecting dietary diversity or increasing import dependency for vegetables.

A Symmetric Multichamber Hydraulic Cylinder with Variable Piston Area: An Approach to Compact and Efficient Electrohydrostatic Actuation

This paper presents an approach for designing symmetric (effective cylinder area during extension is the same as that during retraction) multichamber cylinders with discretely variable piston area. The design methodology is presented in a generalizable manner and is demonstrated on an example five chamber cylinder design. A method for finding symmetric multichamber cylinder configurations from a given cylinder topology is presented, and subsequently, a method for discretely varying the effective piston area is developed, subject to a cylinder symmetry constraint. Furthermore, an algorithm is presented to optimally switch the effective cylinder area of an electrohydrostatic actuation system either to minimize the magnitude of motor torque or to minimize resistive power losses in the system. Additionally, a method for optimizing standard (constant area) hydraulic cylinders to minimize motor torque magnitude or resistive power losses is presented. These methods are then demonstrated on an example electrohydrostatic actuation system via simulation. Results indicate that this multichamber cylinder approach with discretely variable piston area may allow for the design of compact and efficient actuators relative to standard methods.

A maskless exposure device for rapid photolithographic prototyping of sensor and microstructure layouts

A very cost effective maskless exposure device (MED) for the fast lithographic prototyping of various layouts is presented. The device is assembled using a digital light processing projector (DLP), an optical microscope, alignment stages and a web camera. Layouts created on a computer screen can be easily transferred to substrate surfaces without using expensive photomasks and the process can be repeated by introducing new drawings on the screen. Components are tuned for a constant area of exposure and a resolution of around 20 μm is possible at the moment without using any reduction lenses. The MED has been used in patterning the surfaces of silicon, glass, metal etc. successfully. The device can be assembled using commercially available components at a very minimum cost and can be effectively used in fast prototyping applications like in MEMS, microfluidics, patterning of sensor and electrode structures.