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Since the 1970s, mankind has become increasingly sensitive to major world environmental protection issues, and the globalenvironmental protection laws and regulations system formed to deal with suchspecific issues has rapidly expanded in scope and depth. From the initial environmental issues in the study of international relations theory to the development of environmental issues in the study of global governance, and then the concept of global environmental governance came out and developed rapidly. This trend provides a desire to deal with many environmental protection issues and various issues related to worldenvironmental protection issues. But are these wishes real? We must also doubtthe rationality of the legal systems of various countries that have been formedand fought to deal with all environmental protection relations, especially theworld environmental protection issues. Today, the world environmental problemhas formed a relatively perfect academic field. The concept theory of globalproblems starting from ecological problems has moved from ecological problemsto world governance problems. With the introduction and rapid improvement ofthe concept of world ecological problems. The articlestarts from the role of non-state actors in the original internationalframework, further expands and deepens, and presents a multiangle andall-round perspective, showing that international law can still play a crucial role in the settlement of international environmental problems. It not only caters to the needs of the current international situation and development but also provides forward-looking guidance for future environmental governance at the global level.

BackgroundThe HIV epidemic in key populations such as men who have sex with men (MSM) is a public health issue of worldwide concern. China has seen an increase in newly diagnosed HIV infections through male–male sexual contact in the past decade. In a long-term cohort, how the complex behaviour pattern of MSM changed and the association with the HIV risk are unclear at present.MethodsThis study was conducted from October 2011 to December 2019 in Tianjin. MSM were recruited by snowball sampling through online and offline ways. Demographic and sexual behavioural data were collected for analysis. Three indicators (condom use in last anal sex, frequency of condom use during anal sex and the number of sexual partners) were used to define the behaviour change. Participants with zero, one, and two or three risk indicators were categorised into behaviour types of ‘protective’, ‘moderate’, and ‘fragile’, respectively. Change in behaviour type between baseline and each visit was considered. Time-varying Cox models were performed to evaluate HIV infection risk.ResultsOf 2029 MSM included in the study, 127 were new HIV diagnoses. The overall incidence rate was 3.36 per 100 person-years. The percentage of ‘protective’ and ‘moderate’ behaviour types had a conspicuous growth trend as the follow-up. Furthermore, the HIV incidence rate in each visit among different behaviour transition types showed a general downward trend as the number of total follow-up times increased. Individuals who remained in ‘fragile’ (adjusted HR (aHR): 25.86, 95% CI: 6.92 to 96.57) or changed from ‘protective’ to ‘moderate’ (aHR: 4.79, 95% CI: 1.18 to 19.47), ‘protective’ to ‘fragile’ (aHR: 23.03, 95% CI: 6.02 to 88.13), and ‘moderate’ to ‘fragile’ (aHR: 25.48, 95% CI: 6.79 to 95.40) between baseline and the last follow-up had a higher HIV risk. Gained risk indicators were associated with the increase of HIV risk (gained one indicator, aHR: 2.67, 95% CI: 1.68 to 4.24; gained two or three indicators, aHR: 4.99, 95% CI: 3.00 to 8.31) while losing just one risk indicator could halve the risk (aHR: 0.43, 95% CI: 0.21 to 0.90).ConclusionsAmong MSM in Tianjin, it is necessary to get timely behaviour change for those with high-incidence behaviour patterns while sustaining for those with low-incidence patterns.Trial registration numberChinese Clinical Trials Registry (ChiCTR2000039500).

The accumulation of synthetic plastics used in packaging applications in landfills and the environment is a serious problem. This challenge is driving research efforts to develop biodegradable, compostable, or recyclable barrier materials derived from renewable sources. Cellulose, chitin/chitosan, and their combinations are versatile biobased packaging materials because of their diverse biological properties (biocompatibility, biodegradability, antimicrobial properties, antioxidant activity, non-toxicity, and less immunogenic compared to protein), superior physical properties (high surface area, good barrier properties, and mechanical properties), and they can be assembled into different forms and shapes (powders, fibers, films, beads, sponges, gels, and solutions). They can be either assembled into packaging films or used as fillers to improve the properties of other biobased polymers. Methods such as preparation of composites, multilayer coating, and alignment control are used to further improve their barrier, mechanical properties, and ameliorate their moisture sensitivity. With the growing application of cellulose and chitin-based packaging materials, their biodegradability and recyclability are also discussed in this review paper. The future trends of these biobased materials in packaging applications and the possibility of gradually replacing petroleum-based plastics are analyzed in the “Conclusions” section.

Single-cell RNA sequencing (scRNA-seq) technologies are used to characterize the heterogeneity of cells in cell types, developmental stages and spatial positions. The rapid accumulation of scRNA-seq data has enabled single-cell-type labelling to transform single-cell transcriptome analysis. Here we propose an interpretable deep-learning architecture using capsule networks (called scCapsNet). A capsule structure (a neuron vector representing a set of properties of a specific object) captures hierarchical relations. By utilizing competitive single-cell-type recognition, the scCapsNet model is able to perform feature selection to identify groups of genes encoding different subcellular types. The RNA expression signatures, which enable subcellular-type recognition, are effectively integrated into the parameter matrices of scCapsNet. This characteristic enables the discovery of gene regulatory modules in which genes interact with each other and are closely related in function, but present distinct expression patterns. The wealth of data gathered from single-cell RNA sequencing can be processed with deep learning techniques, but often those methods are too opaque to reveal why a single cell is labelled to be a certain cell type. Lifei Wang and colleagues present an RNA-sequencing analysis method that uses capsule networks and is interpretable enough to allow for identification of cell-type-specific genes.

Background- Recreational drug use among young men who have sex with men (YMSM) was a public health issue of worldwide concern. Evidence had shown the relevance between recreational drug use and human immunodeficiency virus (HIV) infection. This study aimed to investigate the current prevalence state of recreational drug use among YMSM in Tianjin, discern the characteristics of YMSM who used recreational drugs or not and examine the interaction effect of recreational drug use and unprotected anal intercourse (UAI) on HIV infection.Methods- In 2018, a cross-sectional study was conducted in Tianjin, China. The snowball sampling method was used to recruit YMSM. Participants were recruited from gay bars, gay bathhouses, social network sites (WeChat, QQ, gay chat website), gay apps and peer referrals. Structured questionnaires were used to collect data.Results- A total of 1075 YMSM met the eligibility criteria and were included in the study eventually. The overall HIV prevalence was 4.3% (46/1075). Of all the recreational drugs involved in this study (rush poppers, methamphetamine, capsule No.0), rush poppers (406/517,78.5%) were the most popular among YMSM in Tianjin. Compared with non-drug users, drug users were more likely to have first sex earlier, be bisexual, be male sex worker (MSW), have a higher education level, seek sex partners through physical venues, engage in UAI, have sexually transmitted infection (STI), and receive HIV testing. Moreover, recreational drug use and UAI were associated with the increased risk of HIV infection [adjusted OR:3.6 (95%CI: 1.7-7.6) and 4.9 (95%CI: 2.2-10.4), respectively]. There was additive interaction of recreational drug use and UAI on HIV infection [relative excess risk due to interaction (RERI): 6.949 (95%CI: 0.011‐13.887); attributable proportion due to interaction (AP): 0.809 (95%CI: 0.578‐1.039)].Conclusions- Recreational drug use was common and correlated with HIV infection among YMSM in Tianjin. There was an urgent need to build novel targeted HIV prevention strategies to discern and reduce recreational drug use among YMSM in China.

The TabZIP15 gene encoding a 396 amino acid (aa) polypeptide in the fungus Trichoderma asperellum ACCC30536 was cloned and characterised. The protein includes a basic region motif (NR-x2-QR-x2-R) and has a pillar-like structure. The 25 basic region/leucine zipper transcription factors (TFs) identified in the T. asperellum genome were divided into YAP (14 TFs), ATF2 (5), GCN4 (2), Zip1 (2), BRLZ (1) and u1 (1) subfamilies based on conserved domains. T. asperellum was cultured in minimal media (MM) control, C-Hungry and N-Hungry medium (to simulate nutrient competition and interaction with pathogens, respectively), and differential expression analysis showed that 14 TabZIP genes (including TabZIP15) were significantly altered under both conditions; TabZIP23 responded strongly to N-Hungry media and TabZIP24 responded strongly to C-Hungry media. However, only YAP genes TabZIP15, TabZIP12 and TabZIP2 were significantly upregulated under both conditions, and expression levels of TabZIP15 were highest. T. asperellum was also cultured in the presence of five fungal pathogenic toxins, and RT-qPCR results showed that TabZIP15 was significantly upregulated in four of the five toxin stress conditions (MM + Rhizoctonia solani, MM + Fusarium oxysporum, MM + Alternaria alternata and MM + Cytospora chrysosperma).

Introduction: As both parties to commercial sex, MSW and SB are both at high risk of HIV infection. However, there are few studies on the comparison of HIV infection rates between these two groups of people.Methods: The method of snowball sampling was used to recruit research participants by means of baths, bars, and the Internet. The recruited participants should cooperate with the investigators to complete the questionnaire (including general demographic characteristics, high risky behaviors, status of HIV and AIDS infection, awareness of AIDS knowledge )and blood antibody / antigen tests / oral mucosal exudate antibody tests. The difference analysis was performed using the c2 test, and the correlates of HIV infection were analyzed using logistic regression.Results: The final analysis included 435 MSWs and 729 SBs with HIV infection rates of 7.1% and 2.6%, respectively. Compared with SB, the HIV infection rate of MSW was 2.775 (1.340 -5.746) times higher (after adjusting for age and marital status), 3.173 (1.512-6.659) times higher (after further adjusting the awareness rate of AIDS-related knowledge), 3.688 (1.711-7.950) times higher (after further adjusting the frequency of condom use in homosexual intercourse and commercial sex in the past six months).Conclusions: MSW is more likely to infect HIV than SB. Therefore, effective preventive measures should be focused on MSW.

Wireless networks of implantable electronic sensors and actuators at the microscale (sub-mm) level are being explored for monitoring and modulation of physiological activity for medical diagnostics and therapeutic purposes. Beyond the requirement of integrating multiple electronic or chemical functions within small device volumes, a key challenge is the development of high-throughput methods for the implantation of large numbers of microdevices into soft tissues with minimal damage. To that end, we have developed a method for high-throughput implantation of ~100–200 µm size devices, which are here simulated by proxy microparticle ensembles. While generally applicable to subdermal tissue, our main focus and experimental testbed is the implantation of microparticles into the brain. The method deploys a scalable delivery tool composed of a 2-dimensional array of polyethylene glycol-tipped microneedles that confine the microparticle payloads. Upon dissolution of the bioresorbable polyethylene glycol, the supporting array structure is retrieved, and the microparticles remain embedded in the tissue, distributed spatially and geometrically according to the design of the microfabricated delivery tool. We first evaluated the method in an agarose testbed in terms of spatial precision and throughput for up to 1000 passive spherical and planar microparticles acting as proxy devices. We then performed the same evaluations by implanting particles into the rat cortex under acute conditions and assessed the tissue injury produced by our method of implantation under chronic conditions. A low-injury, high-throughput technique to embed neural interfaces into brain tissue brings the idea of a ‘smart body’ closer to home. While some research groups focus on miniaturizing sensors and bio-actuators to implantable sizes, Brown University’s Stefan Sigurdsson and a team of US researchers have developed a technique to embed these devices into cortical tissue. In their method, microparticles (used in lieu of functional implants) are suspended in super-thin needles of polyethylene glycol, which are driven into the brain at high speed to minimize tissue damage. The polyethylene glycol is absorbed into the brain and the injection apparatus is removed, leaving the implants behind. The method can be scaled for rapid implantation of high numbers of devices and could see use in the development of human-computer integrations.

Wireless networks of implantable electronic sensors and actuators on the microscale (sub-mm) are being explored for monitoring and modulation of physiological activity for medical diagnostics and therapeutic purposes. Beyond the requirement of integrating multiple electronic or chemical functions within small device volumes, a key challenge is the development of high-throughput methods for implantation of large numbers of microdevices into soft tissues with minimal damage. To that end, we have developed a method for high-throughput implantation of ∼100-200 μm size devices which are here simulated by proxy microparticle ensembles. While generally applicable to subdermal tissue, our main focus and experimental testbed is the implantation of microparticles into the brain. The method deploys a scalable delivery tool composed of a 2-dimensional array of polyethylene glycol tipped microneedles which confine the microparticle payloads. Upon dissolution of the bioresorbable polyethylene glycol, the supporting array structure is retrieved and the microparticles remain embedded in the tissue, distributed spatially and geometrically according to the design of the microfabricated delivery tool. We first evaluated the method in an agarose testbed in terms of spatial precision and throughput for up to 1000 passive spherical and planar microparticles acting as proxy devices. We then performed the same evaluations of particles implanted into the rat cortex under acute conditions and assessed the tissue injury produced by our method of implantation under chronic conditions.

For the reason of high temperature strength, high oxidation resistance and low density, Ti2AlNb-based alloy is expected to replace nickel-based alloy in the range of working temperature 600–800 °C and become a new generation of high-temperature structural alloys in the aerospace industry. However, Ti2AlNb-based alloys have great high-temperature deformation resistance and high brittleness, which greatly restricts its preparation and processing using traditional technology. In this research, an innovation method named double-wire arc additive manufacturing technology was adopted to in-situ manufacture Ti-22Al-24Nb (at%) alloy, and the TiNb and pure Al wire with designed feeding speed were taken as raw materials. The deposited component was investigated systematically. Results show that the composition error between the average testing value and designed value are under 1.1%, but there are also existing local segregation of composition and microstructure. The segregation phenomenon further deteriorates its mechanical properties, which means the ultimate tensile properties and elongation under room temperature and high temperature (650 °C) are 504 ± 38.59 MPa, 0.41 ± 0.03% and 375 ± 32.60 MPa, 0.76 ± 0.05% respectively on average. At the same time, the prepared alloy exhibits fully lamellar structure and XRD results show that the basic composition phases B2, O and α2 of the Ti2AlNb-based alloy successfully appeared. The in-situ manufacturing method demonstrated in this work is expected to significantly promote the wider application of AM due to its low cost advantage and high flexibility.

Background HIV prevalence among young men who have sex with men (YMSM) (

In the NeurIPS 2018 Artificial Intelligence for Prosthetics challenge, participants were tasked with building a controller for a musculoskeletal model with a goal of matching a given time-varying velocity vector. Top participants described their algorithms in this paper. Many solutions use similar relaxations and heuristics, such as reward shaping, frame skipping, discretization of the action space, symmetry, and policy blending. However, each team implemented different modifications of the known algorithms by, for example, dividing the task into subtasks, learning low-level control, or by incorporating expert knowledge and using imitation learning.

We address the estimation problem for general finite mixture models, with a particular focus on the elliptical mixture models (EMMs). Compared to the widely adopted Kullback-Leibler divergence, we show that the Wasserstein distance provides a more desirable optimisation space. We thus provide a stable solution to the EMMs that is both robust to initialisations and reaches a superior optimum by adaptively optimising along a manifold of an approximate Wasserstein distance. To this end, we first provide a unifying account of computable and identifiable EMMs, which serves as a basis to rigorously address the underpinning optimisation problem. Due to a probability constraint, solving this problem is extremely cumbersome and unstable, especially under the Wasserstein distance. To relieve this issue, we introduce an efficient optimisation method on a statistical manifold defined under an approximate Wasserstein distance, which allows for explicit metrics and computable operations, thus significantly stabilising and improving the EMM estimation. We further propose an adaptive method to accelerate the convergence. Experimental results demonstrate the excellent performance of the proposed EMM solver., This work has been accepted to AAAI2020. Note that this version also corrects a small error on the Equation (16) in proof

To better apply the biocontrol agent Trichoderma spp. in Northeast China, collecting and screening more suitable native Trichoderma strains is necessary. In the present study, 10 isolates were obtained from Juglans mandshurica rhizosphere soils in Heilongjiang Province, and were identified as T. asperellum (four isolates), T. harzianum (four), T. hamatum (one), T. atroviride (one). The fastest-growing isolate per species on potato dextrose agar medium were further evaluated in stress tolerance tests (salt, alkali, nutritional stress, and low temperature) and confrontation assays (eight pathogens), which showed that T. asperellum TaspHu1 possessed the best adaptation and biological control ability. Then, Solanum lycopersicum (tomato) seeds were sown and treated with a series of concentrations of TaspHu1 spore suspension, as was unsown soil. Tomato seedlings treated by TaspHu1 had a significantly greater height, stem diameter, soluble protein content and soluble sugar content. Furthermore, their nitrate reductase activity and catalase activity were significantly increased, and these promoting effects depended on the concentration of the spore suspension. Meanwhile, a decrease in chlorophyll content was observed in the tomato seedlings treated with TaspHu1. In addition, strain TaspHu1 enhanced the tomato seedlings' absorption of available nitrogen, but did not influence the soil available nitrogen content. Furthermore, the resistance of tomato seedlings against Alternaria alternata was enhanced by TaspHu1 (smaller, fewer leaf spots), the seedlings' hormone signal transduction genes JAR1, MYC2, NPR1, PR1, and GH3.2 were highly expressed. Thus, TaspHu1 is a promising biocontrol candidate for use in agriculture and forestry.

We propose a new structure for the complex-valued autoencoder by introducing additional degrees of freedom into its design through a widely linear (WL) transform. The corresponding widely linear backpropagation algorithm is also developed using the \(\mathbb {CR}\) calculus, to unify the gradient calculation of the cost function and the underlying WL model. More specifically, all the existing complex-valued autoencoders employ the strictly linear transform, which is optimal only when the complex-valued outputs of each network layer are independent of the conjugate of the inputs. In addition, the widely linear model which underpins our work allows us to consider all the second-order statistics of inputs. This provides more freedom in the design and enhanced optimization opportunities, as compared to the state-of-the-art. Furthermore, we show that the most widely adopted cost function, i.e., the mean squared error, is not best suited for the complex domain, as it is a real quantity with a single degree of freedom, while both the phase and the amplitude information need to be optimized. To resolve this issue, we design a new cost function, which is capable of controlling the balance between the phase and the amplitude contribution to the solution. The experimental results verify the superior performance of the proposed autoencoder together with the new cost function, especially for the imaging scenarios where the phase preserves extensive information on edges and shapes.

We previously demonstrated that for long-term spastic limb paralysis, transferring the seventh cervical nerve (C7) from the nonparalyzed side to the paralyzed side results in increase of 17.7 in Fugl-Meyer score. One strategy for further improvement in voluntary arm movement is selective activation of five target muscles innervated by C7 during recovery process. In this study, we develop an implantable multisite optogenetic stimulation device (MOSD) based on shape-memory polymer. Two-site stimulation of sciatic nerve bundles by MOSD induces precise extension or flexion movements of the ankle joint, while eight-site stimulation of C7 nerve bundles induce selective limb movement. Long-term implant of MOSD to mice with severed and anastomosed C7 nerve is proven to be both safe and effective. Our work opens up the possibility for multisite nerve bundle stimulation to induce highly-selective activations of limb muscles, which could inspire further applications in neurosurgery and neuroscience research., Optogenetic stimulation of damaged peripheral nerves has advantages over electrical stimulation but it’s limited to single-site stimulation. Here the authors develop a spiral-shaped LED implant for precise optogenetic stimulation of peripheral nerve bundles at multiple sites and use it to induce distinct limb movements in mice.

Mixture modelling using elliptical distributions promises enhanced robustness, flexibility and stability over the widely employed Gaussian mixture model (GMM). However, existing studies based on the elliptical mixture model (EMM) are restricted to several specific types of elliptical probability density functions, which are not supported by general solutions or systematic analysis frameworks; this significantly limits the rigour and the power of EMMs in applications. To this end, we propose a novel general framework for estimating and analysing the EMMs, achieved through Riemannian manifold optimisation. First, we investigate the relationships between Riemannian manifolds and elliptical distributions, and the so established connection between the original manifold and a reformulated one indicates a mismatch between those manifolds, the major cause of failure of the existing optimisation for solving general EMMs. We next propose a universal solver which is based on the optimisation of a re-designed cost and prove the existence of the same optimum as in the original problem; this is achieved in a simple, fast and stable way. We further calculate the influence functions of the EMM as theoretical bounds to quantify robustness to outliers. Comprehensive numerical results demonstrate the ability of the proposed framework to accommodate EMMs with different properties of individual functions in a stable way and with fast convergence speed. Finally, the enhanced robustness and flexibility of the proposed framework over the standard GMM are demonstrated both analytically and through comprehensive simulations., Comment: This work has been accepted to IEEE Transactions on Neural Networks and Learning Systems with DOI:10.1109/TNNLS.2020.3010198. The abstract link is https://ieeexplore.ieee.org/document/9153118

Background Widespread opsin expression in the cortex of rats, where transgenic models have not been established, is not practical to achieve with the traditional diffusion-based virus transduction methods (DBD). New method We developed protocols for convection-enhanced delivery (CED) of virus for optogenetic transduction of the rat cortex. Targeting the motor forelimb area as an example, we performed dual-site CED (6 μL of virus per site, 3 mm pitch between sites) in the rat motor cortex. Results We identified injection parameters optimized for horizontal spread of infusate in the agarose gel model and then demonstrated in vivo widespread opsin expression over the cortical area (7.4 ± 1.0 mm in the AP direction, 4.4 ± 1.1 mm in the ML direction, N = 13 rats) using CED. The optogenetic transduction was also functionally robust, in which both optical modulation of neuronal activity and elicitation of overt motor responses was reliably observed. Comparison with existing method(s) CED led to about 24-fold increase in the volume of opsin expression, compared with the conventional DBD method. The total injection time was also reduced by at least 10 times, if similar extent of expression were to be achieved with the conventional DBD method. Conclusions CED is a reliable and effective method of virus delivery for optogenetic transduction of planar superficial structures, such as the cortex in rats.

During heavy vertical lathe working, heat caused by oil film friction and self-generated is transmitted to worktable through contact surface between oil film and worktable .That makes temperature distribution of worktable uneven and lead large thermal deformation which can affect the machining accuracy. In this article, the temperature field of worktable with reinforcing plate in different locations is simulated. Based on heat transfer theory and the actual working conditions, convective heat transfer coefficient of worktable and the initial boundary conditions are calculated. The simulation reveals the influence law of reinforcing plate arrangement on temperature distribution of worktable and the optimum position of reinforcing plate is obtained. These results provide a theoretical basis for the structural design of worktable.

Dopamine (DA) release and uptake dynamics in the nucleus accumbens (NAc) have important implications for neurological diseases and mammalian animal behaviors. We demonstrate here the use of cell-type-specific optogenetic targeting in conjunction with fast-scan cyclic voltammetry applied to brain slices prepared from specifically tailored transgenic mice, which conditionally express channelrhodopsin-2 (ChR2) through dopamine transporter (DAT)-Cre. Terminal dopaminergic dynamics and the direct manipulation of induced DA release level by controlling light intensity, pulse width, and the shape of stimulation waveforms were studied. Effective cell terminal-targeting optogenetic induction of DA release at physiological levels in NAc is demonstrated and discussed. It was found that delivering more light energy by increasing stimulation intensity and length is not the only way to control DA release; the temporal shape of the stimulus waveform at light onset is also critically related to induced DA concentrations. In addition, DA uptake dynamics as well as the recovery of the presynaptic releasable DA pool are studied and modeled. More broadly, our experimental findings provide important further evidence for effectively applying optogenetics to induce neurotransmitter release in the behaviorally relevant region of the brain in a highly cell-type selective context.