The Neuronal Channel NALCN Contributes Resting Sodium Permeability and Is Required for Normal Respiratory Rhythm

SummarySodium plays a key role in determining the basal excitability of the nervous systems through the resting “leak” Na+ permeabilities, but the molecular identities of the TTX- and Cs+-resistant Na+ leak conductance are totally unknown. Here we show that this conductance is formed by the protein NALCN, a substantially uncharacterized member of the sodium/calcium channel family. Unlike any of the other 20 family members, NALCN forms a voltage-independent, nonselective cation channel. NALCN mutant mice have a severely disrupted respiratory rhythm and die within 24 hours of birth. Brain stem-spinal cord recordings reveal reduced neuronal firing. The TTX- and Cs+-resistant background Na+ leak current is absent in the mutant hippocampal neurons. The resting membrane potentials of the mutant neurons are relatively insensitive to changes in extracellular Na+ concentration. Thus, NALCN, a nonselective cation channel, forms the background Na+ leak conductance and controls neuronal excitability

Influence of heat- and mass-transfer coupling on the optimal performance of a non-isothermal chemical engine

The cyclic model of a non isothermal chemical engine operated between two reservoirs with different temperatures and chemical potentials is established in which the irreversibilities resulting from the heat and mass transfer between the working fluid and the reservoirs are taken into account Expressions for the power output and efficiency of the engine are analytically derived and used to analyze the performance characteristics of the engine at the maximum power output The general characteristics of the efficiency of the engine are searched in detail The optimal criteria for some important parameters such as the power output and efficiency are obtained and the reasonably operating region of the engine is determined Some interesting cases are specially discussed The results obtained here can reveal the performance characteristics of a non isothermal chemical engine affected by the irreversibilities of heat and mass transfer couplingNational Natural Science Foundation, People's Republic of China [10875100

Harvest-aid application strategy in different cotton planting densities by unmanned aerial vehicle

Harvest aids are widely used for defoliating leaves and accelerating the opening of green bolls to facilitate machine harvesting in cotton (Gossypium hirsutum L.) production areas. Cotton harvest aids applied by ground-based mechanical sprayers are inefficient due to mechanical damage to cotton crops and soil and low flexibility. For the last few years, small plant protection unmanned aerial vehicles (UAVs) have been used for applying pesticides across the world due to their high efficiency, high pesticide utilization, low volume and no harmful damage to crops and soil. This study mainly focuses on developing the technology of harvest aid application by UAVs with respect to the dosage and application frequency. Compared with previous studies, this work performs miscellaneous field trials for two years in three experimental sites located in high-density planting areas and two sites in sparse-density planting areas, wherein both cotton cultivation modes and weather conditions are different. In the study, single-round, dual-round and reduced dosage applications are tested, where the defoliation rate, boll opening rate, fiber quality and lint cotton yield are assessed based on the collected data. It is concluded from the experimental results that the achieved defoliation rate and boll opening rate of treatments with a single-round application using the recommended dosage fail to meet the harvest requirements in the case of high planting density (180,000-195,000 plants/hm2). However, with the dual-round application of the exact recommended dosage or 20% lower than the recommended dosage, the achieved defoliation rate, and boll opening rate meet the machine harvest requirements. In sparse-density planting areas (≤90,000 plants/ha), the results of treatment with the recommended dosage and single-round application by UAV spraying meet the requirements. In all the experimental sites, the harvest-aid dosage and application frequency do not affect fiber quality and lint cotton yield. In summary, considering the cost and environmental protection, harvest aid application by UAVs with a dual-round application at 80% of the recommended dosage at a 7-day interval is encouraged in high-density planting areas, while in sparse-density planting areas, single-round application of harvest aids at the recommended dosage by UAVs is encouraged. The results provide paramount guidance for cotton farmers and scholars in this field. Possible future studies are also discussed in this paper

Experimental evaluation of UAV spraying for peach trees of different shapes: effects of operational parameters on droplet distribution

Small-scale plant protection Unmanned Aerial Vehicles (UAVs) are finding a wide range of applications in modern agriculture management (including aerial spraying) due to their high efficiency and flexibility, low labour/water requirement and no damage to crops and soils, which substantially increase agricultural productivity and sustainability. UAV operational parameters, however, have remarkable effects on droplet distribution in UAV spraying, which significantly affect pesticide utilization rate and treatment effectiveness. Therefore, this work aimed to evaluate the effects of UAV operational parameters on droplet distribution for orchard trees. In particular, peach, an important orchard tree worldwide, is investigated in this study, and two typical tree shapes were considered including Y-shape and Central Leader (CL)-shape. Specifically, UAV spraying experiments were performed in Shandong Institute of Pomology, Shandong Province, China, and gas powered helicopter 3WQF120-12 was chosen as the spraying platform. The UAV operational parameters under consideration include flight route (intra-row, inter-row), flight velocity (four levels: 2, 3, 4, 5 m/s), number of spray times (1 vs 2) and nozzle flow rate. Droplet coverage rate at different positions and layers, obtained by water sensitive papers, was chosen as the metric to evaluate spraying performance. Experimental results show that: (1) the spraying uniformity is different between Y-shape and CL-shape peach tree, where Y-shape exhibits uniformity for positions at inner or outer layers. CL-shape results in a higher droplet coverage at top layer while with uniformity at lower three layers; (2) for Y-shape peach, intra-row route obtained a higher droplet coverage rate; while for CL-shape peach inter-row not only saved spraying volume but also results in a higher droplet coverage rate; (3) for both tree shapes, the increase in flight velocity (2--5 m/s) significantly decreased the droplet coverage rate; (4) for Y-shape peach with doubling the number of spraying times decreased the spraying performance for unit area. (5) for CL-shape peach with intra-row route, increasing the nozzle flow rate from 1.8 to 2.2 $L\cdot min^{-1}$ can significantly improve the droplet coverage rate at top and bottom two layers. It is envisioned that this study can provide some fundamental guidance of the operation of small UAVs for the aerial spraying of peach trees and similar orchards

UAV spraying on citrus crop: impact of tank-mix adjuvant on the contact angle and droplet distribution

Adding tank-mix adjuvants into the spray mixture is a common practice to improve droplet distribution for field crops (e.g., rice, wheat, corn, etc.) when using Unmanned Aerial Vehicle (UAV) sprayers. However, the effectiveness of tank-mix adjuvant for UAV spraying in orchard crops is still an open problem, considering their special canopy structure and leaf features. This study aims to evaluate the effects of a typical tank-mix adjuvant concentrations (i.e., Nong Jian Fei (NJF)) on Contact Angle (CA) and droplet distribution in the citrus tree canopy. Three commonly used parameters, namely dynamic CA, droplet coverage, and Volume Median Diameter (VMD), are adopted for performance evaluation. The dynamic CAs on the adaxial surface of citrus leaves, for water-only and NJF-presence sprays, respectively, are measured with five concentration levels, where three replications are performed for each concentration. The sprays with 0.5‰ NJF are adopted in the field experiment for evaluating droplet distributions, where Water Sensitive Papers (WSPs) are used as collectors. Two multi-rotor UAVs (DJI T20 and T30) which consist of different sizes of pesticide tanks and rotor diameters are used as the spraying platforms. Both water-only and NJF-presence treatments are conducted for the two UAVs, respectively. The results of the CA experiment show that NJF addition can significantly reduce the CAs of the sprays. The sprays with 0.5‰ NJF obtain the lowest CA within the observing time, suggesting a better spread ability on solid surface (e.g., WSPs or/and leaves). With respect to the effects of NJF addition on individual UAVs, the field trial results indicate that NJF addition can remarkably increase both the droplet coverage and VMD at three canopy layers, except for T30 droplet coverage of the inside and bottom layers. Comparing the difference of droplet coverage between two UAVs, while significant difference is found in the same layer before NJF addition, there is no notable difference appearing in the outside and bottom layers after NJF addition. The difference of VMD in the same layer between two UAVs is not affected by NJF addition except for the bottom layer. These results imply that the differences of droplet coverage among different UAVs might be mitigated, thus the droplet distribution of some UAVs could be improved by adding a tank-mix adjuvant into the sprays. This hypothesis is verified by investigating the droplet penetration and the correlation coefficient (CC) of droplet coverage and VMD. After NJF addition, the total percentage of T20 droplet coverage in the bottom and inside layers is increased by 5%. For both UAVs, the CCs indicate that both droplet coverage and VMD increase at the same time in most cases after NJF addition. In conclusion, the addition of a tank-mix adjuvant with the ability to reduce CA of the sprays, can effectively improve droplet distribution using UAV spraying in the citrus canopy by increasing droplet coverage and VMD

Mobility, independent agency, and cosmopolitan settlement: Evidence from Chinese senior undergraduates

Cosmopolitan cities share similarities with historical frontiers, including potential opportunities for economic success, high social mobility, weakened traditional conventions, and adventure and novel experiences. Individuals with high independence typically prefer to settle in cosmopolitan cities. However, previous research testing this cosmopolitan settlement hypothesis did not consider the influence of relational mobility and residential mobility. Moreover, the mechanisms that drive people to prefer cosmopolitan cities remain unclear. This study examines the relationships among independence, relational mobility, residential mobility, and preference for cosmopolitan cities among 296 Chinese senior undergraduates. The results indicate that: (1) independence remains a positive predictor of the preference for cosmopolitan cities above and beyond relational mobility, residential mobility (i.e., history, state, and intention), and other covariates; (2) intention of residential mobility also positively predicts preference for cosmopolitan cities when controlling for related covariates; and (3) relational mobility indirectly predicts perceived preference for cosmopolitan cities through dependence. This research underscores the importance of identifying the factors and mechanisms affecting cosmopolitan settlement

Type-I-IFN-Stimulated Gene TRIM5γ Inhibits HBV Replication by Promoting HBx Degradation

To understand the molecular mechanisms that mediate the anti-hepatitis B virus (HBV) effect of interferon (IFN) therapy, we conduct highthroughput bimolecular fluorescence complementation screening to identify potential physical interactions between the HBx protein and 145 IFNstimulated genes (ISGs). Seven HBx-interacting ISGs have consistent and significant inhibitory effects on HBV replication, among which TRIM5g suppresses HBV replication by promoting K48-linked ubiquitination and degradation of the HBx protein on the K95 ubiquitin site. The B-Box domain of TRIM5g under overexpression conditions is sufficient to trigger HBx degradation and is responsible both for interacting with HBx and recruiting TRIM31, which is an ubiquitin ligase that triggers HBx ubiquitination. High expression levels of TRIM5g in IFN-a-treated HBV patients might indicate a better therapeutic effect. Thus, our studies identify a crucial role for TRIM5g and TRIM31 in promoting HBx degradation, which may facilitate the development of therapeutic agents for the treatment of patients with IFN-resistant HBV infection

An Experimental Novel Study: Angelica sinensis

With laminectomy being widely accepted as the treatment for lumbar disorders, epidural fibrosis (EF) is a common complication for both the patients and the surgeons alike. Currently, EF is thought to cause recurrent postoperative pain after laminectomy or after discectomy. Angelica sinensis is a traditional Chinese medicine which has shown anti-inflammatory, antifibrotic, and antiproliferative properties. The object of this study was to investigate the effects of Angelica sinensis on the prevention of post-laminectomy EF formation in a rat model. A controlled double-blinded study was conducted in sixty healthy adult Wistar rats that underwent laminectomy at the L1-L2 levels. They were divided randomly into 3 groups according to the treatment method, with 20 in each group: (1) Angelica sinensis treatment group, (2) saline treatment group, and (3) sham group (laminectomy without treatment). All rats were euthanized humanely 4 weeks after laminectomy. The hydroxyproline content, Rydell score, vimentin cells density, fibroblasts density, inflammatory cells density, and inflammatory factors expressions all suggested better results in Angelica sinensis group than the other two groups. Topical application of Angelica sinensis could inhibit fibroblasts proliferation and TGF-β1 and IL-6 expressions and prevent epidural scar adhesion in postlaminectomy rat model