Homotypic fusion of endoplasmic reticulum membranes in plant cells

The endoplasmic reticulum (ER) is a membrane-bounded organelle whose membrane comprises a network of tubules and sheets. The formation of these characteristic shapes and maintenance of their continuity through homotypic membrane fusion appears to be critical for the proper functioning of the ER. The atlastins (ATLs), a family of ER-localized dynamin-like GTPases, have been identified as fusogens of the ER membranes in metazoans. Mutations of the ATL proteins in mammalian cells cause morphological defects in the ER, and purified Drosophila ATL mediates membrane fusion in vitro. Plant cells do not possess ATL, but a family of similar GTPases, named root hair defective 3 (RHD3), are likely the functional orthologs of ATLs. In this review, we summarize recent advances in our understanding of how RHD3 proteins play a role in homotypic ER fusion. We also discuss the possible physiological significance of forming a tubular ER network in plant cells

An identification based network link backup method

in order to solve the problem of network link failure or link congestion, this paper proposes an identifi cation based link backup method, which uses the identification network to carry out collaborative backup of links, formulates the link level through the network identifi cation mechanism, divides the routing characteristics through the link level, and calculates the link level through the link backup protocol between routers. When the high priority link fails or the link congestion occurs, the low priority link can be used for routing; When the transmission rate of a single link decreases, the low priority link can also be enabled. So as to achieve network load balancing and maximize link utilization. Through mini net simulation, the experimental topology is built and verifi ed. The results show that this method can quickly repair the link failure, quickly switch the link, reduce the network interruption delay, when the high priority link failure or congestion, it can quickly establish the route update, and quickly recover, so as to achieve the purpose of network load balancing

Methyl 2-{[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl­idene)(thio­phen-2-yl)meth­yl]amino}-3-phenyl­propionate

In the title compound, C25H23N3O3S, an intra­molecular N—H⋯O inter­action generates an S(6) ring, which stabilizes the enamine–keto form of the compound. This S(6) ring and the pyrazole ring are essentially coplanar, making a dihedral angle of 1.49 (6)°. The bond lengths within the S(6) ring of the mol­ecule lie between classical single- and double-bond lengths, indicating extensive conjugation. The structure exhibits a thienyl-ring flip disorder, with occupancy factors in the ratio 64.7 (3):35.3 (3)

Tests of conservation laws in post-Newtonian gravity with binary pulsars

General relativity is a fully conservative theory, but there exist other possible metric theories of gravity. We consider non-conservative ones with a parameterized post-Newtonian (PPN) parameter, $\zeta_2$. A non-zero $\zeta_2$ induces a self-acceleration for the center of mass of an eccentric binary pulsar system, which contributes to the second time derivative of the pulsar spin frequency, $\ddot{\nu}$. In our work, using the method in Will (1992), we provide an improved analysis with four well-timed, carefully-chosen binary pulsars. In addition, we extend Will's method and derive $\zeta_2$'s effect on the third time derivative of the spin frequency, \dddot{\nu}. For PSR B1913+16, the constraint from \dddot{\nu} is even tighter than that from $\ddot{\nu}$. We combine multiple pulsars with Bayesian inference, and obtain an upper limit, $\left|\zeta_{2}\right|<1.3\times10^{-5}$ at 95% confidence level, assuming a flat prior in $\log_{10} \left| \zeta_{2}\right|$. It improves the existing bound by a factor of three. Moreover, we propose an analytical timing formalism for $\zeta_2$. Our simulated times of arrival with simplified assumptions show binary pulsars' capability in limiting $\zeta_{2}$, and useful clues are extracted for real data analysis in future. In particular, we discover that for PSRs B1913+16 and J0737$-$3039A, \dddot{\nu} can yield more constraining limits than $\ddot{\nu}$.Comment: 14 pages, 5 figures, 4 tables; accepted by Ap

Scanning tunneling microscopy study of the possible topological surface states in BiTeCl

Recently, the non-centrosymmetric bismuth tellurohalides such as BiTeCl are being studied as possible candidates of topological insulators. While some photoemission studies showed that BiTeCl is an inversion asymmetric topological insulator, others showed that it is a normal semiconductor with Rashba splitting. Meanwhile, first-principle calculationsfailed to confirm the existence of topological surface states in BiTeCl so far. Therefore, the topological nature of BiTeCl requires further investigation. Here we report low temperature scanning tunneling microscopy study on the surface states of BiTeCl single crystals. On the tellurium-terminated surfaces with low defect density, strong evidences for topological surface states are found in the quasi-particle interference patterns generated by the scattering of these states, both in the anisotropy of the scattering vectors and the fast decay of the interference near step edges. Meanwhile, on samples with much higher defect densities, we observed surface states that behave differently. Our results help to resolve the current controversy on the topological nature of BiTeCl.Comment: 13pages,4figure

1,5-Dimethyl-4-(1-methyl-3-oxo-3-phenylprop-1-enyl­amino)-2-phenyl-1H-pyrazol-3(2H)-one

In the title compound, C21H21N3O2, an intra­molecular N—H⋯O inter­action generates an S(6) ring, which stablizes the enamine–keto tautomer. The S(6) ring makes dihedral angles of 33.07 (7), 56.50 (8) and 38.59 (8)°, respectively, with the benzoyl­acetone benzene ring and the anti­pyrine pyrazole and benzene rings

Computation offloading in blockchain-enabled MCS systems : A scalable deep reinforcement learning approach

In Mobile Crowdsensing (MCS) systems, cloud service providers (CSPs) pay for and analyze the sensing data collected by mobile devices (MDs) to enhance the Quality-of-Service (QoS). Therefore, it is necessary to guarantee security when CSPs and users conduct transactions. Blockchain can secure transactions between two parties by using the Proof-of-Work (PoW) to confirm transactions and add new blocks to the chain. Nevertheless, the complex PoW seriously hinders applying Blockchain into MCS since MDs are equipped with limited resources. To address these challenges, we first design a new consortium blockchain framework for MCS, aiming to assure high reliability in complex environments, where a novel Credit-based Proof-of-Work (C-PoW) algorithm is developed to relieve the complexity of PoW while keeping the reliability of blockchain. Next, we propose a new scalable Deep Reinforcement learning based Computation Offloading (DRCO) method to handle the computation-intensive tasks of C-PoW. By combining Proximal Policy Optimization (PPO) and Differentiable Neural Computer (DNC), the DRCO can efficiently make the optimal/near-optimal offloading decisions for C-PoW tasks in blockchain-enabled MCS systems. Extensive experiments demonstrate that the DRCO reaches a lower total cost (weighted sum of latency and power consumption) than state-of-the-art methods under various scenarios

PRKAA1/AMPKα1 is required for autophagy-dependent mitochondrial clearance during erythrocyte maturation

AMP-activated protein kinase α1 knockout (prkaa1−/−) mice manifest splenomegaly and anemia. The underlying molecular mechanisms, however, remain to be established. In this study, we tested the hypothesis that defective autophagy-dependent mitochondrial clearance in prkaa1−/− mice exacerbates oxidative stress, thereby enhancing erythrocyte destruction. The levels of ULK1 phosphorylation, autophagical flux, mitochondrial contents, and reactive oxygen species (ROS) were examined in human erythroleukemia cell line, K562 cells, as well as prkaa1−/− mouse embryonic fibroblasts and erythrocytes. Deletion of Prkaa1 resulted in the inhibition of ULK1 phosphorylation at Ser555, prevented the formation of ULK1 and BECN1- PtdIns3K complexes, and reduced autophagy capacity. The suppression of autophagy was associated with enhanced damaged mitochondrial accumulation and ROS production. Compared with wild-type (WT) mice, prkaa1−/− mice exhibited a shortened erythrocyte life span, hemolytic destruction of erythrocytes, splenomegaly, and anemia, all of which were alleviated by the administration of either rapamycin to activate autophagy or Mito-tempol, a mitochondria-targeted antioxidant, to scavenge mitochondrial ROS. Furthermore, transplantation of WT bone marrow into prkaa1−/− mice restored mitochondrial removal, reduced intracellular ROS levels, and normalized hematologic parameters and spleen size. Conversely, transplantation of prkaa1 −/− bone marrow into WT mice recapitulated the prkaa1−/− mouse phenotypes. We conclude that PRKAA1-dependent autophagy-mediated clearance of damaged mitochondria is required for erythrocyte maturation and homeostasis

Monounsaturated and polyunsaturated fatty acids concerning prediabetes and type 2 diabetes mellitus risk among participants in the National Health and Nutrition Examination Surveys (NHANES) from 2005 to March 2020

ObjectiveUnsaturated fatty acids (UFA) may be related to glycometabolism. While associations between UFA intake (especially their subtype) and prediabetes or type 2 diabetes mellitus (T2DM) need to be further studied. In this study, we aimed to evaluate the potential relation of UFA with prediabetes and T2DM.MethodsA total of 16,290 adults aged older than 18 years from the National Health and Nutrition Examination Survey (NHANES) from 2005 to March 2020 were included in the present analysis. Dietary intake was assessed by two day, 24-hour dietary recalls and daily intake of total monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA); four specific fatty acids of MUFA and seven specific fatty acids of PUFA were calculated. Prediabetes and T2DM were diagnosed by fasting glucose, glycohemoglobin, and self-reported medication or insulin. Rao–Scott modified chi-square tests, the Taylor series linearization method, and multivariable logistic regression analyses were applied to analyze the associations of dietary MUFA and PUFA intake with diabetes risk.ResultsOf the participants, 44.34% had prediabetes and 13.16% had T2DM patients. From multivariate analysis, we found that intake of MUFA, PUFA, and some subtypes was negatively associated with the risk of prediabetes and T2DM in Americans. Compared with adults in the lowest tertile, those in the highest MUFA (PUFA) tertile had an approximately 50% (49%) and 69% (68%) lower risk of prediabetes and T2DM, respectively. Moreover, the effects of the subtypes of MUFA and PUFA on prediabetes and T2DM were different. Higher intakes of MFA 18:1, MFA 20:1, PFA 18:2, and PFA 18:3 and higher tertile intakes of MFA 16:1 and PFA 20:4 were related to a lower risk of prediabetes and T2DM. Similarly, the effects of MUFA, PUFA, and subtype on prediabetes and T2DM varied among different age groups, being weakened along with age.ConclusionOur study suggested that total MUFA and PUFA intake might be essential in preventing prediabetes and T2DM, especially in Americans. However, this protective effect may decrease with age. Moreover, the effects of the specific UFA on prediabetes and T2DM need further consideration