Selective control of SNARE recycling by Golgi retention

AbstractTwo distinct sets of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) catalyze membrane fusion in the cis-Golgi and trans-Golgi. The mechanism that controls Golgi localization of SNAREs remains largely unknown. Here we tested three potential mechanisms, including vesicle recycling between the Golgi and the endoplasmic reticulum, partitioning in Golgi lipid microdomains, and selective intra-Golgi retention. Recycling rates showed a linear relationship with intra-Golgi mobility of SNAREs. The cis-Golgi SNAREs had higher mobility than intra-Golgi SNAREs, whereas vesicle SNAREs had higher mobility than target membrane SNAREs. The differences in SNARE mobility were not due to preferential partitioning into detergent-resistant membrane microdomains. We propose that intra-Golgi retention precludes entropy-driven redistribution of SNAREs to the endoplasmic reticulum and endocytic compartments

i-SNAREs: inhibitory SNAREs that fine-tune the specificity of membrane fusion

A new functional class of SNAREs, designated inhibitory SNAREs (i-SNAREs), is described here. An i-SNARE inhibits fusion by substituting for or binding to a subunit of a fusogenic SNAREpin to form a nonfusogenic complex. Golgi-localized SNAREs were tested for i-SNARE activity by adding them as a fifth SNARE together with four other SNAREs that mediate Golgi fusion reactions. A striking pattern emerges in which certain subunits of the cis-Golgi SNAREpin function as i-SNAREs that inhibit fusion mediated by the trans-Golgi SNAREpin, and vice versa. Although the opposing distributions of the cis- and trans-Golgi SNAREs themselves could provide for a countercurrent fusion pattern in the Golgi stack, the gradients involved would be strongly sharpened by the complementary countercurrent distributions of the i-SNAREs

Self-consistent calculations of radiative nuclear reaction characteristics for 56

The photon strength functions (PSF), neutron capture cross sections and average radiative widths of neutron resonances for three double-magic nuclei 56Ni, 132Sn and 208Pb have been calculated within the self-consistent version of the microscopic theory. Our approach includes phonon coupling (PC) effects in addition to the standard QRPA approach. With our microscopic PSFs, calculations of radiative nuclear reaction characteristics have been performed using the EMPIRE 3.1 nuclear reaction code. Three nuclear level density (NLD) models have been used: the phenomenological so-called GSM, phenomenological Enhanced GSM (EGSM) and microscopical combinatorial HFB model. For all the considered characteristics, we found a noticeable contribution of the PC effects and a significant disagreement between the results obtained with the GSM and the other two NLD models. The results confirm the necessity of using consistent microscopic approaches for calculations of radiative nuclear characteristics in double-magic nuclei

Adipocyte mesenchymal transition contributes to mammary tumor progression

Obesity is associated with increased cancer incidence and progression. However, the relationship between adiposity and cancer remains poorly understood at the mechanistic level. Here, we report that adipocytes from tumor-invasive mammary fat undergo de-differentiation to fibroblast-like precursor cells during tumor progression and integrate into the tumor microenvironment. Single-cell sequencing reveals that these de-differentiated adipocytes lose their original identities and transform into multiple cell types, including myofibroblast- and macrophage-like cells, with their characteristic features involved in immune response, inflammation, and extracellular matrix remodeling. The de-differentiated cells are metabolically distinct from tumor-associated fibroblasts but exhibit comparable effects on tumor cell proliferation. Inducing de-differentiation by Xbp1s overexpression promotes tumor progression despite lower adiposity. In contrast, promoting lipid-storage capacity in adipocytes through MitoNEET overexpression curbs tumor growth despite greater adiposity. Collectively, the metabolic interplay between tumor cells and adipocytes induces adipocyte mesenchymal transition and contributes to reconfigure the stroma into a more tumor-friendly microenvironment

Investigation and development of digital power amplifier for single-sideband-modulated (ssm) signals with compensation of quantization errors

The aim of the work is to develop the operation theory and construction methods of the digital power amplifiers for single-sideband signals having a small level of the quantization noises at high energetical and increased mass-dimensional indices. The investigations of device mock-up have been performed. The methods for calculating parameters of the SSM signal digital power amplifiers with compensation of quantization errors, mathematical model for supply circuits of the key generators taking their sluggishness into consideration, mathematical model of the power amplifier taking sluggishness of the discharge generator into consideration have been developed. The investigation of influencing compensation channel parameters on the output spectrum and amplifier efficiency has been performed. The calculation and design methods of digital power amplifiers with compensation of the quantization errors have been developed; the recommendations on the selection of key generators and methods of their summation have been given; the parameters of the quantization error compensation channel and methods of their realization have been determined; the power amplifier mock-up has been developed and tested. The proposed designs and recommendations permit to decrease the level of the combinated distortions 15-20 dB and extrasideband radiations 20-30 dB in comparison with analogous devicesAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Logic Artificial Intelligence Application for the Students Individual Trajectories Introduction

The individual trajectories and other student learning individualization forms introduction in engineering education are becoming an important competitive university advantage. However, you should be mindful of the choices of learning paths within the framework of requirements of Federal State Educational Standards (FSES): to receive a diploma the student must fulfill all requirements of the FSES. Individualization cannot be arbitrary and must fit within the established framework of the curriculum. Students can study more than the established requirements of the FSES on an individual program. On the other hand, within the established restrictions of the FSES, there are enough alternatives for individualized training to choose the specialization of a certain professional area. For example, for students studying information technology, this specialization can be a choice between different economy sectors: banks, telecommunications, industrial production, logistics, aircraft and rocket engineering, car industry, Internet companies, social networks, etc. If we take developing computer technologies as a basis, then individualization can consist in a more detailed study of one area in IT: databases; expert systems; data security; distributed registries; artificial intelligence (AI); machine learning and image recognition; understanding of natural language; automated systems management and technological processes; robotics, etc. As we can see, opportunities for individualization of training for students exist even within the strict framework of training standards. The paper provides examples of such individualization of training with BMSTU students. Practical work has shown that individualization complicates the work and increases the time spent by university staff on managing trajectories in student learning. The achievements of mivar technologies of logical artificial intelligence allow automating routine operations for managing students’ individual trajectories. In general, artificial intelligence can help in almost all tasks of engineering education in the transition to continuous people training “through life”

Broadband and Efficient Envelope Amplifier for Envelope Elimination and Restoration/Envelope Tracking Higher-Efficiency Power Amplifiers

Increasing the efficiency of transmitters, as the largest consumers of energy, is relevant for any wireless communication devices. For higher efficiency, a number of methods are used, including envelope tracking and envelope elimination and restoration. Increasing the bandwidth of used frequencies requires expanding envelope modulators bandwidth up to 250–500 MHz or more. The possibility of using amplifiers with input signal quantization (AISQ), as an alternative to the most common hybrid envelope tracking modulators, is considered. An approach has been developed for optimizing AISQ characteristics according to the criterion of minimum loss when amplifying modern telecommunication signals with Rayleigh envelope distribution. The optimal quantization levels are determined and the energy characteristics of AISQ are calculated. AISQ loss power is shown to decrease by 1.66 times with two-level quantization, by 2.4 times with three-level quantization, and by a factor of 3.0–3.7 for four–five quantization levels compared to a class B amplifier. With these parameters, AISQ becomes competitive with respect to hybrid envelope tracking modulators but does not have electromagnetic interference from the pulse width modulation (PWM) path

Challenges of Using the L-Band and S-Band for Direct-to-Cellular Satellite 5G-6G NTN Systems

This article presents a comprehensive study of the potential utilization of the L-band and S-band frequency ranges for satellite non-terrestrial network (NTN) technologies. This study encompasses an interference analysis in the S-band, investigating the coexistence of NTN satellite systems with mobile satellite networks such as Omnispace and Lyra, and an interference analysis in the L-band between NTN satellites and the mobile satellite network Inmarsat. This study simulates an NTN satellite network with typical characteristics defined by 3GPP and ITU-R for the n255 and n256 bands. Furthermore, it provides calculations illustrating the signal-to-noise ratio degradation of low-Earth-orbit (LEO), medium-Earth-orbit (MEO), and geostationary-Earth-orbit (GEO) satellite networks operating in the L-band and S-band when exposed to interference from NTN satellites