Decadal Variation of the Southwest U.S. Summer Monsoon Circulation and Rainfall in a Regional Model

Previous studies have identified several major causes for summer rainfall variations over the southwest United States, for example, land memory (i.e., relationships between antecedent winter season precipitation and snow cover anomalies and subsequent summer rainfall anomalies over the southwest United States; these anomalies are likely most important in the northwest United States, although antecedent anomalies in the southwest United States also may be important in determining summer rainfall variations) and sea surface temperature (SST) anomalies in the North Pacific. Atmospheric responses to these “boundary forces” interact with moisture flows from the Gulf of Mexico and from the Gulf of California to influence the rainfall in the Southwest. The land memory and the SST effects were further found to be “naturally separated,” in the sense that they each played a dominant role influencing the monsoon rainfall variation during different periods of the last century. This separation was also manifested by different dominant low-level moisture transport anomalies in those periods. Several new questions have arisen from these findings: How have the land memory and the SST effects been “separated,” so as to affect the monsoon rainfall variations during different periods, or “regimes”? And, what are the corresponding changes of low-level flows, and hence moisture transports into the southwest United States that help achieve the land memory or the SST effects on the rainfall variations during these different regimes? These questions, and related issues, are addressed using a numerical model of regional climate. The model was used to simulate 14 individual warm seasons (April–October) in each of the postulated regimes. Analyses of the simulation results showed systematic and significant changes in atmospheric circulation anomalies between the two regimes. In the early regime (1961–90), when the land memory effect was strong, the average geopotential height was lower and storm activity was more intense over the central and western United States than in the more recent regime (from 1990 on), indicating reduced eddy energy and momentum exchanges between high and low latitudes in the western United States. The effects of these changes on the monsoon rainfall were achieved by very different low-level flow and moisture transport anomalies. In the earlier regime, low-level flow and moisture transport anomalies in the southwest United States were primarily due to easterlies and southeasterlies into the Southwest for its wet monsoon conditions, with reversed anomalies for dry conditions. In the recent regime, these anomalies changed, with primarily southerlies and south- westerlies from the Gulf of California into the Southwest during its wet monsoon conditions, and reversed flow anomalies for dry conditions. These changes indicate that different physical processes, including those responsible for the planetary-scale atmospheric circulation, led to monsoon rainfall variations during each of these regimes

Automatic emotion perception using eye movement information for E-Healthcare systems.

Facing the adolescents and detecting their emotional state is vital for promoting rehabilitation therapy within an E-Healthcare system. Focusing on a novel approach for a sensor-based E-Healthcare system, we propose an eye movement information-based emotion perception algorithm by collecting and analyzing electrooculography (EOG) signals and eye movement video synchronously. Specifically, we extract the time-frequency eye movement features by firstly applying the short-time Fourier transform (STFT) to raw multi-channel EOG signals. Subsequently, in order to integrate time domain eye movement features (i.e., saccade duration, fixation duration, and pupil diameter), we investigate two feature fusion strategies: feature level fusion (FLF) and decision level fusion (DLF). Recognition experiments have been also performed according to three emotional states: positive, neutral, and negative. The average accuracies are 88.64% (the FLF method) and 88.35% (the DLF with maximal rule method), respectively. Experimental results reveal that eye movement information can effectively reflect the emotional state of the adolescences, which provides a promising tool to improve the performance of the E-Healthcare system.Anhui Provincial Natural Science Research Project of Colleges and Universities Fund under Grant KJ2018A0008, Open Fund for Discipline Construction under Grant Institute of Physical Science and Information Technology in Anhui University, and National Natural Science Fund of China under Grant 61401002

A framework for orchestrating secure and dynamic access of IoT services in multi-cloud environments

IoT devices have complex requirements but their limitations in terms of storage, network, computing, data analytics, scalability and big data management require it to be used it with a technology like cloud computing. IoT backend with cloud computing can present new ways to offer services that are massively scalable, can be dynamically configured, and delivered on demand with largescale infrastructure resources. However, a single cloud infrastructure might be unable to deal with the increasing demand of cloud services in which hundreds of users might be accessing cloud resources, leading to a big data problem and the need for efficient frameworks to handle a large number of user requests for IoT services. These challenges require new functional elements and provisioning schemes. To this end, we propose the usage of multi-clouds with IoT which can optimize the user requirements by allowing them to choose best IoT services from many services hosted in various cloud platforms and provide them with more infrastructure and platform resources to meet their requirements. This paper presents a novel framework for dynamic and secure IoT services access across multi-clouds using cloud on-demand model. To facilitate multi-cloud collaboration, novel protocols are designed and implemented on cloud platforms. The various stages involved in the framework for allowing users access to IoT services in multi-clouds are service matchmaking (i.e. to choose the best service matching user requirements), authentication (i.e. a lightweight mechanism to authenticate users at runtime before granting them service access), and SLA management (including SLA negotiation, enforcement and monitoring). SLA management offers benefits like negotiating required service parameters, enforcing mechanisms to ensure that service execution in the external cloud is according to the agreed SLAs and monitoring to verify that the cloud provider complies with those SLAs. The detailed system design to establish secure multi-cloud collaboration has been presented. Moreover, the designed protocols are empirically implemented on two different clouds including OpenStack and Amazon AWS. Experiments indicate that proposed system is scalable, authentication protocols result only in a limited overhead compared to standard authentication protocols, and any SLA violation by a cloud provider could be recorded and reported back to the user.N/

ChatGPT Is A User-Generated Knowledge-Sharing Killer

Large Language Models (LLMs), e.g., ChatGPT, is expected to reshape a broad spectrum of domains. This study examines the impact of ChatGPT on question aksing in Q&A communitits via the natural experiment. Safe-guided by supporting evidence of parallel trends, a difference-in-difference (DID) analysis suggests the launching trigger an average 2.6% reduction of question-asking on Stack Overflow, confirming a lower-search-cost-enabled substitution. Our further analysis suggests that, this substitution effect has resulted in more longer, less readable and less cognitive and hence more sophisticated questions on average. Finally, the insignificant change in the score given by viewers per question suggests no improvement in the question quality and decreased platform-wide engagement. Our moderation analysis further ascertain the types of individuals who are more susceptible to ChatGPT. Taken together, our paper suggests LLMs may threaten the survival of user-generated knowledge-sharing communities, which may further threaten the sustainable learning and long-run improvement of LLMs

Contrastive Loss Based Frame-wise Feature disentanglement for Polyphonic Sound Event Detection

Overlapping sound events are ubiquitous in real-world environments, but existing end-to-end sound event detection (SED) methods still struggle to detect them effectively. A critical reason is that these methods represent overlapping events using shared and entangled frame-wise features, which degrades the feature discrimination. To solve the problem, we propose a disentangled feature learning framework to learn a category-specific representation. Specifically, we employ different projectors to learn the frame-wise features for each category. To ensure that these feature does not contain information of other categories, we maximize the common information between frame-wise features within the same category and propose a frame-wise contrastive loss. In addition, considering that the labeled data used by the proposed method is limited, we propose a semi-supervised frame-wise contrastive loss that can leverage large amounts of unlabeled data to achieve feature disentanglement. The experimental results demonstrate the effectiveness of our method.Comment: accepted by icassp202

Metal-Free Synthesis of \u3ci\u3eN-Heterocycles via Intramolecular Electrochemical C-H Aminations

N-heterocycles are key structural units in many drugs, biologically interesting molecules and functional materials. To avoid the residues of metal catalysts, the construction of N-heterocycles under metal-free conditions has attracted much research attention in academia and industry. Among them, the intramolecular electrochemical C-H aminations arguably constitute environmentally friendly methodologies for the metal-free construction of N-heterocycles, mainly due to the direct use of clean electricity as the redox agents. With the recent renaissance of organic electrosynthesis, the intramolecular electrochemical C-H aminations have undergone much progress in recent years. In this article, we would like to summarize the advances in this research field since 2019. The emphasis is placed on the reaction design and mechanistic insight. The challenges and future developments in the intramolecular electrochemical C-H aminations are also discussed

Fractional Calculus Guidance Algorithm in a Hypersonic Pursuit-Evasion Game

Aiming at intercepting a hypersonic weapon in a hypersonic pursuit-evasion game, this paper presents a fractional calculus guidance algorithm based on a nonlinear proportional and differential guidance law. First, under the premise of without increasing the complexity degree of the guidance system against a hypersonic manoeuvering target, the principle that the differential signal of the line-of-sight rate is more sensitive to the target manoeuver than the line-of-sight rate is employed as the guidelines to design the guidance law. A nonlinear proportional and differential guidance law (NPDG) is designed by using the differential derivative of the line-of-sight rate from a nonlinear tracking differentiator. By using the differential definition of fractional calculus, on the basis of the NPDG, a fractional calculus guidance law (FCG) is proposed. According to relative motions between the interceptor and target, the guidance system stability condition with the FCG is given and quantitative values are also proposed for the parameters of the FCG. Under different target manoeuver conditions and noisy conditions, the interception accuracy and robustness of these two guidance laws are analysed. Numerical experimental results demonstrate that the proposed guidance algorithms effectively reduce the miss distance against target manoeuvers. Compared with the NPDG, a stronger robustness of the FCG is shown under noisy condition

Transcriptome And Expression Profiling Analysis Link Patterns Of Gene Expression To Antennal Responses In Spodoptera Litura

Background: The study of olfaction is key to understanding the interaction of insects with their environment and provides opportunities to develop novel tactics for control of pest species. Recent developments in transcriptomic approaches enable the molecular basis of olfaction to be studied even in species with limited genomic information. Here we use transcriptome and expression profiling analysis to characterize the antennal transcriptome of the noctuid moth and polyphagous pest Spodoptera litura. Results: We identify 74 candidate genes involved in odor detection and recognition, encoding 26 ORs, 21 OBPs, 18 CSPs and 9 IRs. We examine their expression levels in both sexes and seek evidence for their function by relating their expression with levels of EAG response in male and female antennae to 58 host and non-host plant volatiles and sex pheromone components. The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs. A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased. Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses. Conclusions: Our results provide the molecular basis for elucidating the olfactory profile of moths and the sexual divergence of their behavior and could enable the targeting of particular genes, and behaviors for pest management

Improvement of alveolarization arrest in newborn rats with bronchopulmonary dysplasia via inhibiting alveolar epithelial cell pyroptosis

Objective·To study the effect of gasdermin D (GSDMD) inhibitor necrosulfonamide (NSA) on alveolarization arrest in lipopolysaccharide (LPS)-induced bronchopulmonary dysplasia (BPD) newborn rats via inhibiting alveolar epithelial cell pyroptosis.Methods·Pregnant SD rats were randomly assigned to four groups as follows: control, BPD, BPD with NSA and NSA group, and then were prepared to receive intra-amniotic injection of LPS. Lung tissues of newborn rats on the first, third and seventh day after birth were stained by hematoxylin-eosin (H-E) to observe lung development. The expressions of GSDMD-N-terminal in lungs of newborn rats in each group were detected by immunofluorescence. The mRNA levels of interleukin-1β (IL-1β) of newborn rats' lungs was detected by real-time PCR. In vitro, the mouse alveolar epithelial cell line MLE-12 was cultured and treated with LPS/adenosine triphosphate (ATP) and NSA. The cell viability of MLE-12 cells was detected by CCK-8 method, the pyroptosis was detected by Hoechst 33342 and propidium iodide (PI) staining, and the expressions of surfactant protein C (SFTPC) and GSDMD-N protein in MLE-12 cells were detected by immunofluorescence.Results·In vivo, intra-amniotic injection of LPS hindered lung development, resulting in the pathological hallmarks of BPD. The GSDMD-N expression of alveolar epithelial cells increased in the BPD rat model established by intra-amniotic injection of LPS, while NSA treatment significantly improved the lung development of BPD rats and inhibited the IL-1β mRNA expression (both P<0.05). In vitro, the study confirmed that LPS/ATP treatment decreased the viability of alveolar epithelial cells MLE-12 and induced pyroptosis, while NSA treatment increased alveolar epithelial cell viability and inhibited pyroptosis (both P<0.05). In addition, NSA treatment upregulated the SFTPC expression and inhibited the GSDMD-N expression in LPS/ATP-stimulated alveolar epithelial cells (both P<0.05).Conclusion·Inhibiting the alveolar epithelial cell pyroptosis can improve the alveolar development in BPD newborn rats