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Vision-language navigation (VLN) tasks require an agent to follow language instructions from a human guide to navigate in previously unseen environments using visual observations. This challenging field, involving problems in natural language processing (NLP), computer vision (CV), robotics, etc., has spawned many excellent works focusing on various VLN tasks. This paper provides a comprehensive survey and an insightful taxonomy of these tasks based on the different characteristics of language instructions. Depending on whether navigation instructions are given once or multiple times, we divide the tasks into two categories, i.e., single-turn and multiturn tasks. We subdivide single-turn tasks into goal-oriented and route-oriented tasks based on whether the instructions designate a single goal location or specify a sequence of multiple locations. We subdivide multiturn tasks into interactive and passive tasks based on whether the agent is allowed to ask questions. These tasks require different agent capabilities and entail various model designs. We identify the progress made on these tasks and examine the limitations of the existing VLN models and task settings. Hopefully, a well-designed taxonomy of the task family enables comparisons among different approaches across papers concerning the same tasks and clarifies the advances made in these tasks. Furthermore, we discuss several open issues in this field and some promising directions for future research, including the incorporation of knowledge into VLN models and transferring them to the real physical world. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prognostic factors of survival and develop a predictive nomogram model for elderly GBM patients. Methods: Elderly patients (> = 65 years) with histologically diagnosed GBM were extracted from the SEER database. Survival analysis of overall survival (OS) was performed by Kaplan–Meier analysis. Univariate and multivariate Cox regression analyses were used to determine independent prognostic factors and these factors were used to further construct the nomogram model. Results: A total of 9068 elderly GBM patients (5122 males and 3946 females) were included, with a median age of 72 years (65–96 years). All patients were divided randomly into the training group (n = 6044) and the validation group (n = 3024) by a ratio of 2:1. Cox regression analyses on OS showed eight independent prognostic factors (race, age, tumor side, tumor size, metastasis, surgery, radiotherapy, and chemotherapy) in the training cohort. Also, seven variables (except for race) were identified on CSS in the training group. By comprising these variables, the nomogram models on OS and CSS for predicting the 6-month, 1-year, and 2-year survival probability were constructed and exhibited moderate consistency, respectively. Then, they could be validated well in the validation cohort and by C-index, time-dependent ROC curve, calibration plot, and DCA curve. Conclusions: Nomogram models on OS and CSS could provide an applicable tool to predict the survival probability and provide clinical references regarding treatment strategies and prognosis. [ABSTRACT FROM AUTHOR]

Federated Learning coordinates many mobile devices to train an artificial intelligence model while preserving data privacy collaboratively. Mobile devices are usually equipped with totally different hardware configurations, leading to various training capabilities. At the same time, the distribution of the local training data is highly heterogeneous across different clients. Randomly selecting the clients to participate in the training process results in poor model performance and low system efficiency. In this paper, we propose GraphCS, a graph-based client selection framework for heterogeneity in Federated Learning. GraphCS first measures the distribution coupling across the clients via the model gradients. After that, it divides the clients into different groups according to the diversity of the local datasets. At the same time, it well estimates the runtime training capability of each client by jointly considering the hardware configuration and resource contention caused by the concurrently running apps. With the distribution coupling information and runtime training capability, GraphCS selects the best clients in order to well balance the model accuracy and overall training progress. We evaluate the performance of GraphCS with mobile devices with different hardware configurations on various datasets. The experiment results show that our approach improves model accuracy up to 45.69%. Meanwhile, it reduces communication and computation overhead 87.35% and 89.48% at best, respectively. Furthermore, GraphCS accelerates the overall training process up to 35×. • We observe that the distribution of the training data can be reflected by the gradient of a machine learning model. • We observe that the training capability is jointly affected by the hardware configuration and resource contention. • we design a framework selects the best clients with diverse local datasets and highest runtime training capability. • We prototype GraphCS on a Federated system consisting of mobile devices with heterogeneous hardware configurations. [ABSTRACT FROM AUTHOR]

Federated Learning is designed for multiple mobile devices to collaboratively train an artificial intelligence model while preserving data privacy. Instead of collecting the raw training data from mobile devices to the cloud, Federated Learning coordinates a group of devices to train a shared model in a distributed manner with the training data located on the devices. However, unbalanced data distribution and heterogeneous hardware configurations across different devices badly hurts the performance of collaborative model and severely impacts the overall training progress. Thus, a framework that can well balance the model accuracy and the training progress is urgently required. In this paper, we propose PAGroup, a privacy-aware grouping framework for high-performance Federated Learning. PAGroup intelligently divides the participating clients into different groups through carefully analyzing the privacy requirement of the training data and the solid social relationship of the participating clients. After that, PAGroup conducts data shaping and capability-ware training in order to improve the model performance while accelerating the overall training process. We evaluate the performance of PAGroup with both simulation and hardware testbed. The evaluation results show that PAGroup improves model accuracy up to 21%. Meanwhile, it decreases 81% communication overhead, 29% computation cost and 84% wall-clock time at best comparing with the baselines. • Specific private data that required by a learned model can be exchanged daily in certain social community. • PAGroup can share private date within task-specific groups organized according to strongly connected social community. • Training devices in a group can be viewed as a "super" client to compatibility to existing optimization algorithms. • The impact of local data scale, diversity, and label distribution to the model performance has been theoretically proved. [ABSTRACT FROM AUTHOR]

In this paper, a special ultrasonic microforming method, Micro Ultrasonic thin Sheetmetal Forming using molten plastic as a flexible punch (short as Micro-USF), was used to conduct micro-punching experiments on stainless steel sheet with thickness of 10 μm and 20 μm. The influence of ultrasonic vibration on forming force and forming quality were investigated. The experimental results showed that the forming force required for punching thin sheet metal decreased gradually as the ultrasonic time or ultrasonic power increased. By applying the ultrasonic vibration effect, the forming force could be decreased dramatically and the maximum value of forming force drop could reach 86%. Moreover, with the application of ultrasonic vibration, the size accuracy and shape accuracy of micro-holes could be increased by 36.92% and 22.65%, but the cross-section quality of micro-holes were not significantly improved. [ABSTRACT FROM AUTHOR]

To scientifically evaluate and utilize high-oleic acid rape germplasm resources and cultivate new varieties suitable for planting in the Hunan Province, 30 local high-oleic acid rape germplasms from Hunan were used as materials. The 12 personality indices of quality, yield, and resistance were comprehensively evaluated by variability, correlation, principal component, and cluster analyses. The results of variability showed that except for oleic acid, the lowest coefficient of variation was oil content, which was 0.06. Correlation analysis showed that oil content was positively correlated with main traits such as yield per plant and oleic acid, which could be used in the early screening of high-oleic rape germplasm. The results of principal component analysis showed that the 12 personality indicators were integrated into four principal components, and the cumulative contribution rate was 62.487%. The value of comprehensive coefficient 'F' was positively correlated with the first, second, and fourth principal components and negatively correlated with the third principal component. Cluster analysis showed that 30 high-oleic rape germplasms could be divided into four categories consisting of 9 (30%), 6 (20%), 7 (23%), and 8 (27%) high-oleic rape germplasms, each with the characteristics of "high disease resistance", "high yield", "high protein", and "more stability". This study not only provides a reference basis for high-oleic rape breeding but also provides a theoretical basis for their early screening. [ABSTRACT FROM AUTHOR]

Plant-parasitic nematodes infect a diversity of crops, resulting in severe economic losses in agriculture. Microbial volatile organic compounds (VOCs) are potential agents to control plant-parasitic nematodes and other pests. In this study, VOCs emitted by a dozen bacterial strains were analyzed using solid-phase microextraction followed by gas chromatography–mass spectrometry. Fumigant toxicity of selected VOCs, including dimethyl disulfide (DMDS), 2-butanone, 2-pentanone, 2-nonanone, 2-undecanone, anisole, 2,5-dimethylfuran, glyoxylic acid, and S-methyl thioacetate (MTA) was then tested against Caenorhabditis elegans. DMDS and MTA exhibited much stronger fumigant toxicity than the others. Probit analysis suggested that the values of LC50 were 8.57 and 1.43 μg/cm3 air for DMDS and MTA, respectively. MTA also showed stronger fumigant toxicity than DMDS against the root-knot nematode Meloidogyne incognita, suggesting the application potential of MTA. [ABSTRACT FROM AUTHOR]

In this paper, an automatic and quick evaluating method for the micro-hole size and form accuracy with a computer-aided technique was proposed. A special ultrasonic microforming method, that is, micro-ultrasonic thin-sheet-metal forming using molten plastic as flexible punch (short as Micro-USF), was used to punch out micro-holes with diameters of 500, 600, and 700 μm on a copper sheet with a thickness of 30 μm. Using the evaluation method proposed in this paper, the forming accuracy of micro-holes was discussed. The experimental results showed that the ratios of the maximum size error and the maximum roundness error of micro-holes to the corresponding punching die diameter were 1.40 and 1.47%, respectively. The ratios of the maximum size error range and the maximum roundness error range of micro-holes to the corresponding punching die diameter were 0.70 and 0.72%, respectively. This indicated that the accuracy and precision in the Micro-USF method were high for punching micro-holes. Moreover, it was found that there is no significant direct correlation between micro-holes sample errors and these forming parameters when the forming parameters such as ultrasonic power, ultrasonic time, and cylinder pressure were varied, which indicated that the sample errors were random to some extent. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to investigate the relationship between pulsatility index (PI) or optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in patients with traumatic brain injury (TBI), and the ability of ONSD and ICP to predict intracranial hypertension. Methods: A total of 68 patients with TBI were included in this retrospective study. After receiving surgery treatment, they underwent transcranial Doppler ultrasound (TCD). The statistical correlation between PI or ONSD and ICP 1 week after surgery was analyzed. Furthermore, the areas under the curve (AUCs) of ONSD or PI or a combination of them were calculated to predict intracranial hypertension. Results: There was a correlation between ONSD and ICP. This correlation still remained at ONSD ≥ 5 mm. Furthermore, there was a strong correlation between PI and ICP. There was a moderate correlation between ICP and PI on days 3, 4, and 5 after surgery (r = 0.508, p <.001), and a strong correlation on days 6 and 7 after surgery (r = 0.645, p <.001). Moreover, for predicting intracranial hypertension with PI ≥ 1.2 mm or ONSD ≥ 5 mm or a combination of them, the AUC was 0.729, 0.900, and 0.943, respectively (p <.001). Conclusions: The correlation between ONSD or PI and invasive ICP was different with different levels of ICP in different periods in patients with TBI after surgery. When ONSD ≥ 5 mm and PI ≥ 1.2, it could predict elevated ICP more accurately. [ABSTRACT FROM AUTHOR]

For the context-dependent Text-to-SQL task, the generation of SQL query is placed in a multi-turn interaction scenario. Each turn of Text-to-SQL must take historical interactive information and database schema into account. Accordingly, how to encode and integrate these different types of texts (the question sentence, the corresponding SQL query, and database schema) is a tough problem. In previous work, these series of texts are usually concatenated into sequences and encoded by various variants of recurrent neural networks (RNN). However, the RNNs cannot model the intrinsic relationship of the text directly. To this end, we propose an interaction-modeling mechanism to represent and aggregate these texts. Firstly, different types of texts are represented as individual graphs. Then, heterogeneous graph aggregation is used to capture the interactions and aggregate graphs into a holistic representation. Finally, the corresponding SQL query is generated based on the current question and the aggregated information. We evaluate our model on the SparC and CoSQL dataset to demonstrate the benefits of interaction-modeling. Experimentally, our model has a competitive performance and space–time cost. [ABSTRACT FROM AUTHOR]

purpose of this study was to explore the effect of coagulopathy in patients with traumatic brain injury (TBI) during the early postoperative period. Methods: The baseline characteristics, intraoperative management, and follow-up data of 462 patients with TBI between January 2015 and June 2019 were collected and retrospectively analyzed by multivariate logistic regression. Coagulopathy was defined as activated partial thromboplastin time > 40 s, international normalized ratio > 1.4, or platelet counts < 100× 109/L. Results: Multivariate logistic regression analysis revealed that the Glasgow Coma Scale (GCS) on admission, Injury Severity Score (ISS) on admission, pupil mydriasis, duration of surgery, intraoperative blood loss, and intraoperative crystalloid resuscitation were independent risk factors for patients who developed coagulopathy after surgery. There were statistical differences in mortality (p = 0.049), the Glasgow Outcome Scale-Extended (GCS-E; p = 0.024), and the modified Rankin Scale (p = 0.043) between the patients with and without coagulopathy 1 week after surgery. Coagulopathy within 72 h after surgery revealed the higher mortality at 1 week (66.7%), 3 months (71.4%), and 6 months (76.2%). Coagulopathy within 72 h after surgery in patients with a TBI predicted worse disease progression and unfavorable neurologic outcomes. Conclusion: Taking practical and reasonable measures to manage these risk factors may protect patients with TBI from postoperative coagulopathy. [ABSTRACT FROM AUTHOR]

Plant-specific WRKY transcription factors play important roles in regulating the expression of defense-responsive genes against pathogen attack. A multiple stress-responsive WRKY gene, ZmWRKY65, was identified in maize by screening salicylic acid (SA)-induced de novo transcriptomic sequences. The ZmWRKY65 protein was localized in the nucleus of mesophyll protoplasts. The analysis of the ZmWRKY65 promoter sequence indicated that it contains several stress-related transcriptional regulatory elements. Many environmental factors affecting the transcription of ZmWRKY65 gene, such as drought, salinity, high temperature and low temperature stress. Moreover, the transcription of ZmWRKY65 gene was also affected by the induction of defense related plant hormones such as SA and exogenous ABA. The results of seed germination and stomatal aperture assays indicated that transgenic Arabidopsis plants exhibit enhanced sensitivity to ABA and high concentrations of SA. Overexpression of ZmWRKY65 improved tolerance to both pathogen attack and abiotic stress in transgenic Arabidopsis plants and activated several stress-related genes such as RD29A, ERD10, and STZ as well as pathogenesis-related (PR) genes such as PR1, PR2 and PR5; these genes are involved in resistance to abiotic and biotic stresses in Arabidopsis. Together, this evidence implies that the ZmWRKY65 gene is involved in multiple stress signal transduction pathways. [ABSTRACT FROM AUTHOR]

The combination catalyst of CeO2 and H-FAU zeolite was effective for the direct synthesis of diethyl carbonate from CO2 and ethanol with 2,2-diethoxypropane as a dehydrating regent, where H-FAU catalyzed hydrolysis of 2,2-diethoxypropane. The combination catalyst provided high activity and a high diethyl carbonate yield of 72% based on 2,2-diethoxypropane at a low temperature of 393 K. [ABSTRACT FROM AUTHOR]

Optimization and kinetic modeling of methyl ester production from non-edible tung nut oil (Vernicia fordii) and methanol using a solid acidic ionic liquid polymer as a catalyst were performed in this study. A solid acidic ionic liquid polymer was synthesized using vinyl imidazole, 1, 3-propane sulfonate, N, N- dimethyl dodecylamine, allyl bromide and toluene, characterized and used for transesterification of tung nut oil for methyl esters synthesis. The optimum reaction conditions resulted in highest methyl ester yield of 91% were a tung-nut- oil -to-methanol molar ratio of 1:1.5, solid acidic ionic liquid polymer catalyst loading of 160 wt % based on the oil, reaction time of 6 h, agitation speed of 400 rpm and reaction temperature of 65 °C. Further kinetic studies performed at different temperatures revealed that the conversion of tung nut oil to methyl ester follows the first order reaction. Methyl esters were purified using an ion exchange resin and then analyzed by GC-MS. The activation energy (Ea) was calculated as 72.81 kJ mol−1. The properties of methyl esters such as kinematic viscosity at 40 °C, density at 25 °C, cloud point and pour point were also determined. Methyl esters met the quality standard defined under ASTM. Image 1 • The novel solid acidic ionic liquid polymer has been synthesized and characterized. • The solid acidic ionic liquid polymer showed high capacity in methyl esters production. • Maximum yield of methyl esters (91%) at 65 °C for 6 h with 400 rpm. • The process can generate biodiesel of high purity that meets the quality demands. [ABSTRACT FROM AUTHOR]

Bitcoin is a cryptocurrency and a financial transaction network implemented using blockchain technology. Users in the Bitcoin network use pseudonymous Bitcoin addresses and conduct transactions with others without revealing their real identities. In order to further enhance their privacy and convenience, users often use a large number of different addresses. In this paper, we analyze different patterns of transactions occurring in the Bitcoin network in order to cluster addresses that share the same ownership. In order to evaluate the proposed clustering approach, Bitcoin addresses belonging to known entities are tagged and these are used in conjunction with the Gini impurity index to test the accuracy of the recovered identity-based clusters. The results show that our heuristic was able to detect relationships between Bitcoin addresses that were missed by the existing heuristics. [ABSTRACT FROM AUTHOR]

Objective. The human lipidomic profile reflects lipid metabolism, including the early phase of pathophysiological changes associated with diseases. An investigation of the association between the plasma lipidomic profile and adolescent obesity might provide new insights into the biological mechanisms of obesity. Therefore, we aimed to investigate the association of the plasma lipidome with obesity in Chinese adolescents using lipidomics. Methods. Using a combination of liquid chromatography and electrospray ionization tandem mass spectrometry, we quantified 328 lipid species from 24 lipid classes and subclasses in 100 male adolescents aged 14-16 years who were categorized into four groups: (1) normal weight with traditional normal clinical plasma lipid levels (NN); (2) normal weight with traditional abnormal clinical plasma lipid levels (NA); (3) obese with traditional normal clinical plasma lipid levels (ON); and (4) obese with traditional abnormal clinical plasma lipid levels (OA). The concentrations of all the lipid species were compared between obese and normal-weight adolescents at different traditional clinical plasma lipid levels using the Kruskal-Wallis test followed by the Mann-Whitney U test. A partial least squares discriminant analysis (PLS-DA) was applied to select lipids with a significant abilityto discriminate adolescent obesity. Results. The lipidomic profile distinguished obese adolescents from normal-weight subjects. Regardless of whether traditional clinical plasma lipid levels were normal or abnormal, we observed a significant reduction in the levels of five lysophosphatidylcholines (LPC) species (LPC18:2, LPC18:1, LPC20:2, LPC20:1, and LPC20:0) in the obese group compared with the normal-weight group (difference = -31.29% to -13.19%; P = 9.91 x 10 -5 to 2.28 x 10-2). The ability of these five LPC species to discriminate adolescent obesity was confirmed in the PLS- DA model. Conclusions. The findings provided evidence for the association of some LPC species with adolescent obesity. The discriminatory effects of five LPC species were identified between normal-weight and obese adolescents, independent of traditional clinical plasma lipid levels. These results will provide a basis for validation in subsequent studies. [ABSTRACT FROM AUTHOR]

The harmless treatment and resource utilization of the high boiling chlorosilane produced by products in the process of polycrystalline silicon production can be realized by using organic amine catalyst. The effects of reaction temperature and catalyst type on the catalytic cracking of high-boiling chlorosilane was investigated and the reaction mechanism was analyzed. The results showed that, using N,N-dimethylbenzylamine as the catalyst, at a reaction temperature of 130 ~ 135 °C, a reaction time of 1.5 h, and a catalyst amount of 8%, the yield of monosilane product could reach 79.99%. [ABSTRACT FROM AUTHOR]

Cerebral hemodynamic transformation is a relatively common finding in patients with traumatic brain injury (TBI). Knowledge of cerebral hemodynamic disturbance may assist in predicting the management outcome. Transcranial Doppler ultrasonography (TCD) monitoring of patients with TBI can be used to reveal various pathologic hemodynamic changes. The objective of this study was to compare the clinical outcomes of postoperative routine intracranial pressure (ICP) monitoring versus ICP monitoring combined with TCD monitoring in patients with brain trauma after decompressive craniectomy. This was a retrospective study of 30 patients with TBI who underwent ICP combined with TCD monitoring (after 2015) compared with a historical control group of 30 patients who only underwent routine ICP monitoring (in 2013–2014). ICP, partial pressure of carbon dioxide, hemoglobin, and hematocrit values were monitored and recorded on a daily basis for 7 days after operation. Neuroimaging was also performed at admission. Neurologic outcome was assessed at 2 weeks and 6 months after operation using the Glasgow Outcome Score Extended (GOS-E). Unconditional multivariable logistic regression was conducted to analyze the factors for favorable clinical outcome. Two weeks after operation, there were no differences in mortality rate between the 2 groups (P = 0.643). When considering the GOS-E score at 6 months, there were no differences in clinical prognosis between the 2 groups (P = 0.101), but the ICP combined with TCD monitoring group showed a higher frequency of patients with favorable outcome compared with the routine ICP monitoring group (P = 0.043). Unconditional multivariable logistic regression results showed that no factor was independently associated with GOS-E at 6 months. TCD could be helpful for the serial monitoring of cerebral hemodynamic changes after decompressive craniectomy for TBI, which could be beneficial for neurologic outcome improvement. [ABSTRACT FROM AUTHOR]

The feasibility of solid-state fermentation was studied for sea buckthorn seed residues (SBSR). Effects of different fermentation parameters were evaluated regarding the levels of biomass and compounds in aqueous and non-aqueous extracts. In the latent and logarithmic phases of fermentation, the total phenols and flavonoids were increased. The microbes' decomposition on fibrous matter allowed the active components to be fully extracted. The changes of total sugar levels had a contrary trend with the changes of total phenol and flavonoid contents. The monosaccharide and polypeptide contents decreased dramatically and then kept steady along with the fermentation. Unsuitable environments led to weak growth of the fungi, limited enzyme contents, low enzyme activity, and a poor degradation of the substrates. The active compounds considered in the study were protected, and the contents reached a maximum under conditions that were usually not suitable for the fungal growth. The chemical structure was another important factor influencing the content and stability of the compounds. The content of procyanidins decreased dramatically because of its sensitivity to heat and alkaline environments. Antioxidant abilities of SBSR extracts, both aqueous and non-aqueous, increased after fermentation. These results reflected a possibility to recycle SBSR for further use in the food industry. [ABSTRACT FROM AUTHOR]

Abstract: The present study describes the skeletal development and the occurrence of deformities in American shad, Alosa sapidissima, larvae from hatching to 45 days after hatching (DAH). The ontogeny of the vertebral column started at 16 DAH (days after hatching), with the formation of the posterior neural and haemal arches, and was complete at 28 DAH. In comparison, the vertebral centra started to form at 16 DAH, with ossification being visible in all centra at 38 DAH. The pectorals were the only fins that formed before the onset of feeding (at 2 DAH), with ossification being complete at 45 DAH. The caudal fin formed at 5 DAH, with ossification being complete at 40 DAH. Dorsal and pelvic fin development began at 6 DAH and 20 DAH respectively. The ossification of both the dorsal and pelvic fins was visible at 45 DAH. The anal fin began forming at 14 DAH, and was complete at 30 DAH. The ossification of the anal fin was complete at 45 DAH. Overall, 22 types of skeletal deformities were detected in about 41% of individuals. Most anomalies were detected in the haemal region, while the fewest anomalies were detected in the anal fin. In addition, the frequency of deformities gradually increased with fish age at the different developmental stages. Our results are expected to contribute baseline information on how rearing conditions impact skeletal development, in addition to identifying potential causative factors of skeletal deformities. [ABSTRACT FROM AUTHOR]

Textual analysis has been applied to various fields, such as discourse analysis, corpus studies, text leveling, and automated essay evaluation. Several tools have been developed for analyzing texts written in alphabetic languages such as English and Spanish. However, currently there is no tool available for analyzing Chinese-language texts. This article introduces a tool for the automated analysis of simplified and traditional Chinese texts, called the Chinese Readability Index Explorer (CRIE). Composed of four subsystems and incorporating 82 multilevel linguistic features, CRIE is able to conduct the major tasks of segmentation, syntactic parsing, and feature extraction. Furthermore, the integration of linguistic features with machine learning models enables CRIE to provide leveling and diagnostic information for texts in language arts, texts for learning Chinese as a foreign language, and texts with domain knowledge. The usage and validation of the functions provided by CRIE are also introduced. [ABSTRACT FROM AUTHOR]

This paper reports a new finding and related mechanism: the forcing effect of the tropical Atlantic (TA) sea surface temperature (SST) on the atmosphere-ocean coupling in the western North Pacific (WNP) and northern Indian Ocean (NIO). Since the early 1980s, the TA SST has increased and, notably, exhibited an enhanced interannual statistical relationship with the WNP subtropical high and NIO SST in boreal summer. Empirical diagnostics reveal the following spatial pattern linking the TA SST and the atmosphere-ocean coupling in the Pacific and Indian Ocean: 1) a cyclonic (anticyclonic) circulation pair straddling the equator over the eastern Pacific, 2) an anticyclonic (cyclonic) circulation pair straddling the equator in the WNP and Indian Ocean, 3) overturning circulation with ascending (descending) and descending (ascending) anomalies over the TA and tropical western Pacific, respectively, and 4) positive (negative) SST anomaly in the TA and NIO. The characteristics of this pattern are consistent with those of a WNP-NIO coupling pattern identified in a previous study. Empirical diagnostics and numerical simulations indicate that the TA SST serves as a forcing to induce low-level divergence and streamfunction anomalies in the Indian Ocean and the western Pacific. The latter in turn induces anomalous heat storage in the NIO and enhances the WNP-NIO coupling system, which is an intrinsic pattern engendered by the atmosphere-ocean interaction in the region. Without the remote influence of the TA SST forcing, the WNP-NIO coupling pattern and its impacts on the summer monsoon and TC variability in South Asia, East Asia, and the WNP would be considerably less significant than observed. [ABSTRACT FROM AUTHOR]

A pure Ti plate with a smooth surface and a gradient nanostructured layer was achieved using surface mechanical attrition treatment method with 3 mm zirconia balls at room temperature. The twinning and dislocation slips layer, transition layer, ultrafine grains layer and nanograins layer appeared in sequence from the matrix to the topmost surface, representing different stages of microstructural evolutions. The dislocation slips and 10 1 ¯ 2 twins coordinated and competed with each other to adapt to plastic deformation. An additional misorientation and mirror symmetry line separation resulted from the interaction between slips and 10 1 ¯ 2 twin boundaries, causing the twin boundaries to gradually transform into high angle grain boundaries. A stronger dislocation–twin boundary interaction in the transition layer triggered the continuous formation and accumulation of high angle grain boundaries, which subdivided the twins into blocks or submicronic polygonal grains. It is proved that a combination of continuous dynamic recrystallization and discontinuous dynamic recrystallization leads to the generation of nanograins. [Display omitted] • A smooth surface with nanostructured layer was achieved. • The gradient nanostructured layer of Ti after SMAT was discussed. • The interaction of slips and twin boundaries plays a dominant role in the mechanism of microstructure evolution. • cDRX and dDRX combine to generate the nanograins. [ABSTRACT FROM AUTHOR]

In this paper, we propose a multistep Legendre–Gauss spectral collocation method for the nonlinear Volterra functional integro-differential equations (VFIDEs) with vanishing delays. This method is easy to implement and possesses the high-order accuracy. We also provide a rigorous convergence analysis of the hp -version of the multistep spectral collocation method under H 1 -norm. Numerical results confirm the theoretical analysis. [ABSTRACT FROM AUTHOR]

Due to the limitations of current treatment regimes, gene therapy is a promising strategy being explored to correct blood glucose concentrations in diabetic patients. In the current study, we used a retroviral vector to deliver either the human insulin gene alone, the rat NeuroD1 gene alone, or the human insulin gene and rat NeuroD1 genes together, to the rat liver cell line, H4IIE, to determine if storage of insulin and pancreatic transdifferentiation occurred. Stable clones were selected and expanded into cell lines: H4IIEins (insulin gene alone), H4IIE/ND (NeuroD1 gene alone), and H4IIEins/ND (insulin and NeuroD1 genes). The H4IIEins cells did not store insulin; however, H4IIE/ND and H4IIEins/ND cells stored 65.5 ± 5.6 and 1475.4 &#177l 171.8 pmol/insulin/ 5 × 106 cells, respectively. Additionally, several β cell transcription factors and pancreatic hormones were expressed in both H4IIE/ND and H4IIEins/ND cells. Electron microscopy revealed insulin storage vesicles in the H4IIE/ND and H4IIEins/ND cell lines. Regulated secretion of insulin to glucose (0-20 mmol/L) was seen in the H4IIEins/ND cell line. The H4IIEins/ND cells were transplanted into diabetic immunoincompetent mice, resulting in normalization of blood glucose. This data shows that the expression of NeuroD1 and insulin in liver cells may be a useful strategy for inducing islet neogenesis and reversing diabetes. [ABSTRACT FROM AUTHOR]

In this paper, we propose a multistep Legendre-Gauss spectral collocation method for nonlinear second-kind Volterra integral equations (VIEs) with vanishing variable delays. This method is easy to implement and possesses high-order accuracy. We also provide a rigorous convergence analysis of the hp-version of the multistep spectral collocation method under L2-norm. Numerical results confirm the theoretical predictions. [ABSTRACT FROM AUTHOR]

With the current high demand for energy saving and low power consumption, numerous studies have been conducted to meet this requirement. Higher switch efficiency is one of the factors for power saving in power inverters and converters. Among the methods for improved switch efficiency, the modified package structure is one of the solutions. An embedded power module enables shortened transmitting routes and lower parasitic reactions, suggesting better power switching performance. Meanwhile, embedding allows the power devices to integrate active or passive devices above or beneath a component, leading to a three-dimensional packaging structure. This feature is also applicable in the integration of power devices because of its double side contact structure. Four dies that contain two insulated gate bipolar transistors and two diodes in this study were embedded and integrated in a carrier substrate to produce a next-generation power inverter module. The process began by attaching a die on a Cu lead frame by a SAC305 solder paste. This is followed by a lamination process to form a built-up dielectric layer on the Cu lead frame. The conducting vias and circuits were formed on the built-up dielectric layer by a UV laser and were metalized with sputtered seed layer and electroplating. The circuit layout can be revealed with subsequent etching processes by hatching another layer of electroplated Sn using UV laser. Finally, a layer of solder mask was printed to prevent electric shock on the surface layer. Structure and process features are discussed, and electrical testing and reliability tests are conducted in this paper. [ABSTRACT FROM AUTHOR]

A new highly porous polyhedron-based metal-organic framework, namely [Co 3 (5-Bipa) 2 (5-BipaH) 2 (H 2 O) 3 ](DEF) 6 (H 2 O) 3 ( 1 ), built from a linear Co3 cluster and the 5-bromo-Isophthalic acid (5-BipaH 2 ) organic ligand has been synthesized and structurally determined. The resulting 3-D framework 1 features cubo-octahedral and octahedral cages as the Supermolecular Building Block (SBB) with an eight connected reo topology. More importantly, the solvent-free samples of 1 exhibit a high BET surface area of 882 m 2 /g and a large C 2 H 2 uptake capability of 178 cm 3 /g at room temperature and 1 bar. [ABSTRACT FROM AUTHOR]

In this study, receiver function analysis is carried out at 32 broadband stations spread all over the Gujarat region, located in the western part of India to image the sedimentary structure and investigate the crustal composition for the entire region. The powerful Genetic Algorithm technique is applied to the receiver functions to derive S-velocity structure beneath each site. A detail image in terms of basement depths and Moho thickness for the entire Gujarat region is obtained for the first time. Gujarat comprises of three distinct regions: Kachchh, Saurashtra and Mainland. In Kachchh region, depth of the basement varies from around 1.5 km in the eastern part to 6 km in the western part and around 2–3 km in the northern part to 4–5 km in the southern part. In the Saurashtra region, there is not much variation in the depth of the basement and is between 3 km and 4 km. In Gujarat mainland part, the basement depth is 5–8 km in the Cambay basin and western edge of Narmada basin. In other parts of the mainland, it is 3–4 km. The depth of Moho beneath each site is obtained using stacking algorithm approach. The Moho is at shallower depth (26–30 km) in the western part of Kachchh region. In the eastern part and epicentral zone of the 2001 Bhuj earthquake, large variation in the Moho depths is noticed (36–46 km). In the Saurashtra region, the crust is more thick in the northern part. It varies from 36–38 km in the southern part to 42–44 km in the northern part. In the mainland region, the crust is more thick (40–44 km) in the northern and southern part and is shallow in Cambay and Narmada basins (32–36 km). The large variations of Poisson’s ratio across Gujarat region may be interpreted as heterogeneity in crustal composition. High values of σ (∼0.30) at many sites in Kachchh and few sites in Saurashtra and Mainland regions may be related to the existence of high-velocity lower crust with a mafic/ultramafic composition and, locally, to the presence of partial melt. The existing tectono-sedimentary models proposed by various researchers were also examined. [ABSTRACT FROM AUTHOR]

During bipedal walking, it is critical to detect and adjust the robot postures by feedback control to maintain its normal state amidst multi-source random disturbances arising from some unavoidable uncertain factors. The radical basis function (RBF) neural network model of a five-link biped robot is established, and two certain disturbances and a randomly uncertain disturbance are then mixed with the optimal torques in the network model to study the performance of the biped robot by several evaluation indices and a specific Poincaré map. In contrast with the simulations, the response varies as desired under optimal inputting while the output is fluctuating in the situation of disturbance driving. Simulation results from noise inputting also show that the dynamics of the robot is less sensitive to the disturbance of knee joint input of the swing leg than those of the other three joints, the response errors of the biped will be increasing with higher disturbance levels, and especially there are larger output fluctuations in the knee and hip joints of the swing leg. [ABSTRACT FROM AUTHOR]

In the present paper, an Ir(III) complex of Ir(PD)(PBT) 2 was synthesized, where PD and PBT stand for pentane-2,4-dione and 2-phenylbenzo[d]thiazole, respectively. The molecular identity of Ir(PD)(PBT) 2 was confirmed by its single crystal. It was found that Ir(PD)(PBT) 2 belonged to monoclinic system with two molecules in each unit cell. Theoretical calculation on Ir(PD)(PBT) 2 suggested that the onset electronic transitions owned a mixed character of metal-to-ligand-charge-transfer and ligand-to-ligand-charge-transfer. By doping this complex into a polymer matrix of poly(vinylpyrrolidone) (PVP), the photophysical features of the resulting composite fibers were discussed and compared with those of Ir(PD)(PBT) 2 solution. It was found that the immobilization in PVP host could improve the photoluminescence performance by restraining the excited state geometric relaxation, showing higher emission energy, longer excited state lifetime and better photostability. [ABSTRACT FROM AUTHOR]

We introduce a multistep Legendre-Gauss spectral collocation method for the nonlinear Volterra integral equations of the second kind. This method is easy to implement and possesses high order accuracy. In addition, it is very suitable for long time calculations. We also derive the optimal convergence of the hp-version of the multistep collocation method under the L²-norm. Numerical experiments confirm the theoretical expectations. [ABSTRACT FROM AUTHOR]

Todevelop a greener process for reclaiming phenolic compoundsfrom low temperature coal tar, extractive performance of twelve extractants,including mono-, di-, and triethanol amines (MEA, DEA, TEA), six protonatedionic liquids (ILs) thereof with formate (FA) or acetate (Ac) anion,choline chloride, and two polyols (glycol, glycerol), were studiedat varying conditions, along with the back extractability of phenolsby ether. The extraction performance is MEA > DEA > TEA ≈ILs> glycol > glycerol, while the back extraction performance ofetheris just the opposite. The coexistent toluene in oil and temperatureshow a little influence on the extraction performance of alcoholicamines and their corresponding ILs. The extraction performance ofextractants is consistent with their complexability with phenol, i.e.ethanol amines > ether > ILs > polyols, as manifested bythe red shiftof the UV spectrum of phenol in the above solvents. [HMEA]FA is themost promising extractant for its overall extraction performance,cheapness, and other favorable physical attributes. [ABSTRACT FROM AUTHOR]

Highlights: [•] A finite element model is developed to study the behavior of a flatfish cage system. [•] The pith and mooring line tension of the flatfish cage in waves and currents are calculated. [•] The effect of netting mesh types on behavior of the flatfish cage is investigated. [•] The effect of different bottom frame weight on pitch of the flatfish cage is analyzed. [ABSTRACT FROM AUTHOR]

Vaccinia virus envelope protein A27 has multiple functions and is conserved in the Orthopoxvirus genus of the poxvirus family. A27 protein binds to cell surface heparan sulfate, provides an anchor for A26 protein packaging into mature virions, and is essential for egress of mature virus (MV) from infected cells. Here, we crystallized and determined the structure of a truncated form of A27 containing amino acids 21–84, C71/72A (tA27) at 2.2 Å resolution. tA27 protein uses the N-terminal region interface (NTR) to form an unexpected trimeric assembly as the basic unit, which contains two parallel α-helices and one unusual antiparallel α-helix; in a serpentine way, two trimers stack with each other to form a hexamer using the C-terminal region interface (CTR). Recombinant tA27 protein forms oligomers in a concentration-dependent manner in vitro in gel filtration. Analytical ultracentrifugation and multi-angle light scattering revealed that tA27 dimerized in solution and that Leu47, Leu51, and Leu54 at the NTR and Ile68, Asn75, and Leu82 at the CTR are responsible for tA27 self-assembly in vitro. Finally, we constructed recombinant vaccinia viruses expressing full length mutant A27 protein defective in either NTR, CTR, or both interactions; the results demonstrated that wild type A27 dimer/trimer formation was impaired in NTR and CTR mutant viruses, resulting in small plaques that are defective in MV egress. Furthermore, the ability of A27 protein to form disulfide-linked protein complexes with A26 protein was partially or completely interrupted by NTR and CTR mutations, resulting in mature virion progeny with increased plasma membrane fusion activity upon cell entry. Together, these results demonstrate that A27 protein trimer structure is critical for MV egress and membrane fusion modulation. Because A27 is a neutralizing target, structural information will aid the development of inhibitors to block A27 self-assembly or complex formation against vaccinia virus infection. [ABSTRACT FROM AUTHOR]

A coordination polymeric crystal 1 was successfully synthesized from H 4 L (5,5′-(1,4-phenylenebis (methoxy))diisophthalic acid), bidpe (4,4′-bis(lmidazolyl)diphenyl ether), and Zn(NO 3) 2 ·6H 2 O under solvothermal conditions, and characterized by single-crystal X-ray diffraction. Then, two new crystals 1 Fe and 1 Cu were obtained with metal ion exchange when 1 was dipped into the DMF solution for FeCl 2 and CuCl 2 , respectively. The exchange process demonstrated that the high valence metal ion with strong acidity could be destroyed the structure of the crystals. Therefore, it should be exchanged with lower valence ion and then oxidized to the high valence state, which could be a feasible way to obtain the crystals with high valence metal ions. Further, the magnetic property and the synergistic CO 2 conversion with epoxide for 1 Fe and 1 Cu were also investigated, and the results shown that 1 Fe could be regarded as a potential catalyst for this conversion. Three two dimensional two-fold interpenetrated MOFs 1 , 1 Fe and 1 Cu were successfully synthesized via solvothermal or post-synthetic modification. 1 Fe and 1 Cu shown excellent abilities for catalyzed cycloaddition of CO 2 to epoxides. [Display omitted] 1. Three novel dimensional MOFs 1 , 1 Fe and 1 Cu , have been synthesized via solvent-thermal treatment and post-synthetic exchange approach. 2. Zn(II) ions were exchange with Fe(III) ions in 1 Fe. But, due to the strong acidity of Fe(III) ions could destroy the crystal framework, the exchange only could be happen when 1 was dipped into the freshly FeCl 2 -DMF solution. 3. Variable-temperature magnetic studies indicate that 1 Fe contains the weak ferromagnetic chain while 1 Cu contains the weak antiferromagnetic (AF) interactions. 4. The catalytic properties of 1 , 1 Fe and 1 Cu for epoxides' cycloaddition reactions with CO 2 , and the results shown that 1 Fe and 1 Cu could be good catalysts for this reaction. [ABSTRACT FROM AUTHOR]

Over the past 3 decades, a diverse collection of small protein domains have been used as scaffolds to generate general purpose protein-binding reagents using a variety of protein display and enrichment technologies. To expand the repertoire of scaffolds and protein surfaces that might serve this purpose, we have explored the utility of (i) a pair of anti-parallel alpha-helices in a small highly disulfide-bonded 4-helix bundle, the CC4 domain from reversion-inducing Cysteine-rich Protein with Kazal Motifs and (ii) a concave beta-sheet surface and two adjacent loops in the human FN3 domain, the scaffold for the widely used monobody platform. Using M13 phage display and next generation sequencing, we observe that, in both systems, libraries of ∼30 million variants contain binding proteins with affinities in the low μM range for baits corresponding to the extracellular domains of multiple mammalian proteins. CC4- and FN3-based binding proteins were fused to the N- and/or C-termini of Fc domains and used for immunostaining of transfected cells. Additionally, FN3-based binding proteins were inserted into VP1 of AAV to direct AAV infection to cells expressing a defined surface receptor. Finally, FN3-based binding proteins were inserted into the Pvc13 tail fiber protein of an extracellular contractile injection system particle to direct protein cargo delivery to cells expressing a defined surface receptor. These experiments support the utility of CC4 helices B and C and of FN3 beta-strands C, D, and F together with adjacent loops CD and FG as surfaces for engineering general purpose protein-binding reagents. [ABSTRACT FROM AUTHOR]

The forecast uncertainty, particularly for precipitation, serves as a crucial indicator of the reliability of deterministic forecasts. Traditionally, forecast uncertainty is estimated by ensemble forecasting, which is computationally expensive since the forecast model is run multiple times with perturbations. Recently, deep learning methods have been explored to learn the statistical properties of ensemble prediction systems due to their low computational costs. However, accurately and effectively capturing the uncertainty information in precipitation forecasts remains challenging. In this study, we present a novel spatiotemporal transformer network (ST-TransNet) as an alternative approach to estimate uncertainty with ensemble spread and probabilistic forecasts, by learning from historical ensemble forecasts. ST-TransNet features a hierarchical structure for extracting multiscale features and incorporates a spatiotemporal transformer module with window-based attention to capture correlations in both spatial and temporal dimensions. Additionally, window-based attention can not only extract local precipitation patterns but also reduce computational costs. The proposed ST-TransNet is evaluated on the TIGGE ensemble forecast dataset and Global Precipitation Measurement (GPM) precipitation products. Results show that ST-TransNet outperforms both traditional and deep learning methods across various metrics. Case studies further demonstrate its ability to generate reasonable and accurate spread and probability forecasts from a single deterministic precipitation forecast. It demonstrates the capacity and efficiency of neural networks in estimating precipitation forecast uncertainty. [ABSTRACT FROM AUTHOR]

Abstract: While focusing on document clustering, this work presents a fuzzy semi-supervised clustering algorithm called fuzzy semi-Kmeans. The fuzzy semi-Kmeans is an extension of K-means clustering model, and it is inspired by an EM algorithm and a Gaussian mixture model. Additionally, the fuzzy semi-Kmeans provides the flexibility to employ different fuzzy membership functions to measure the distance between data. This work employs Gaussian weighting function to conduct experiments, but cosine similarity function can be used as well. This work conducts experiments on three data sets and compares fuzzy semi-Kmeans with several methods. The experimental results indicate that fuzzy semi-Kmeans can generally outperform the other methods. [Copyright &y& Elsevier]

Input torque is themain power to maintain bipedal walking of robot, and can be calculated from trajectory planning and dynamic modeling on biped robot. During bipedal walking, the input torque is usually required to be adjusted due to some uncertain parameters arising from objective or subjective factors in the dynamical model to maintain the pre-planned stable trajectory. Here, a planar 5-link biped robot is used as an illustrating example to investigate the effects of uncertain parameters on the input torques. Kinematic equations of the biped robot are firstly established by the third-order spline curves based on the trajectory planning method, and the dynamic modeling is accomplished by taking both the certain and uncertain parameters into account. Next, several evaluation indices on input torques are introduced to perform sensitivity analysis of the input torque with respect to the uncertain parameters. Finally, based on the Monte Carlo simulation, the values of evaluation indices on input torques are presented, from which all the robot parameters are classified into three categories, i.e., strongly sensitive, sensitive and almost insensitive parameters. [ABSTRACT FROM AUTHOR]

Calcium-dependent protein kinases (CDPKs) play a vital regulatory role in abiotic stress responses in plants. We isolated the ZmCK1 gene encoding a CDPK from maize seedlings. The predicted ZmCK1 protein contains a typical Ser/Thr protein kinase domain and four EF-hand calcium-binding motifs in its N-terminal and C-terminal halves, respectively. The catalytic and regulatory domains were linked by a well-conserved junction domain. A ZmCK1::hGFP fusion protein was found to localize into the cytoplasma and nucleus upon introduction into Arabidopsis mesophyll protoplasts. ZmCK1 transcription was highly activated by salt and cold, and moderately by drought and exogenous ABA in maize seedling. Isolation of the ZmCK1 promoter revealed some cis-acting elements responding to stresses. Overexpression of ZmCK1 improved drought, salt, and cold stress tolerance in transgenic Arabidopsis plants. Our results suggested that ZmCK1 produces a functional kinase that may play a regulatory role in abiotic stress response. [ABSTRACT FROM AUTHOR]

In this paper, the performance of a complete halogen-free (HF) board assembled with five ball grid array components using daisy chains on an 8-layer high density interconnection printed circuit board (PCB) was examined using bending tests. The solder joint was composed of the SAC405 solder ball melted with the SAC105 solder paste on the Cu pad surface of either organic solderable preservative (OSP) or electroless nickel immersion gold (ENIG), and was tested to examine the extent of Ag3Sn intermetallic compound (IMC) formed. A board-level cyclic bending test was executed to the as-reflowed assemblies according to the JESD22-B113 standard to evaluate the reliability of various surface finished HF PCB assemblies under a recommended load condition. By Weibull analyzes the characteristic lives of the assemblies were 99098 and 130290 cycles on OSP soldering system and ENIG system respectively, indicating that the ENIG had a higher bending fatigue endurance as compared to the OSP. The dominant failure mode was the fracture of Cu trace within the micro-via caused by the crack of the resin coated copper layer. At the interface of the solder joint, the IMC formed on both OSP and ENIG was (Cu, Ni)6Sn5 with various Ni contents of 3.9 and 20.1 at%, and different thicknesses of 5.6 and 1.1 \mum, respectively. Numerical simulations showed that both composition and thickness of IMC influenced the stress concentrations and characteristic life of the HF test vehicle as they could slightly increase localized solder joint rigidity and result in more serious pull and drag behaviors at the corner joint. Although the (Cu, Ni)6Sn5 on the ENIG was stiffer than that on the OSP, the thicker IMC layer instead increased the stress on the OSP system due to size effect, and resulted in a lower characteristic life. [ABSTRACT FROM PUBLISHER]

Dehydration-responsive element-binding proteins (DREBs) play vital regulatory roles in abiotic stress responses in plants. A member of the DREB gene family in maize, isolated and designated as Zea mays dehydration-responsive element-binding protein 2 ( ZmDBP2), encoded a putative protein of 343 amino acids with a conserved DNA-binding domain. Transcription of the ZmDBP2 gene was highly induced by drought and moderately induced by salt and exogenous abscisic acid. Isolation of the ZmDBP2 promoter revealed some cis-acting elements responding to stresses. The ZmDBP2 protein activated C-repeat/dehydration responsive element-containing genes under normal growth conditions in transgenic Arabidopsis plants and accumulated throughout the cell. These results indicated that ZmDBP2 possibly interacts with another transcription factor(s) before acting via the nucleus. Overexpression of ZmDBP2 improved drought stress tolerance in transgenic Arabidopsis plants. Our data showed that ZmDBP2 could be a new member of DREB transcription factor family involved in activation of downstream genes in response to environmental stresses. [ABSTRACT FROM AUTHOR]

Abstract: Isoprenoids, most of them synthesized by prenyltransferases (PTSs), are a class of important biologically active compounds with diverse functions. The mint geranyl pyrophosphate synthase (GPPS) is a heterotetramer composed of two LSU·SSU (large/small subunit) dimers. In addition to C10-GPP, the enzyme also produces geranylgeranyl pyrophosphate (C20-GGPP) in vitro, probably because of the conserved active-site structures between the LSU of mint GPPS and the homodimeric GGPP synthase from mustard. By contrast, the SSU lacks the conserved aspartate-rich motifs for catalysis. A major active-site cavity loop in the LSU and other trans-type PTSs is replaced by the regulatory R-loop in the SSU. Only C10-GPP, but not C20-GGPP, was produced when intersubunit interactions of the R-loop were disrupted by either deletion or multiple point mutations. The structure of the deletion mutant, determined in two different crystal forms, shows an intact (LSU·SSU)2 heterotetramer, as previously observed in the wild-type enzyme. The active-site of LSU remains largely unaltered, except being slightly more open to the bulk solvent. The R-loop of SSU acts by regulating the product release from LSU, just as does its equivalent loop in a homodimeric PTS, which prevents the early reaction intermediates from escaping the active site of the other subunit. In this way, the product-retaining function of R-loop provides a more stringent control for chain-length determination, complementary to the well-established molecular ruler mechanism. We conclude that the R-loop may be used not only to conserve the GPPS activity but also to produce portions of C20-GGPP in mint. [ABSTRACT FROM AUTHOR]

Terpenes (isoprenoids), derived from isoprenyl pyrophosphates, are versatile natural compounds that act as metabolism mediators, plant volatiles, and ecological communicators. Divergent evolution of homomeric prenyltransferases (PTSs) has allowed PTSs to optimize their active-site pockets to achieve catalytic fidelity and diversity. Little is known about heteromeric PTSs, particularly the mechanisms regulating formation of specific products. Here, we report the crystal structure of the (LSU · SSU)2-type (LSU/SSU = large/small subunit) heterotetrameric geranyl pyrophosphate synthase (GPPS) from mint (Mentha piperita). The LSU and SSU of mint GPPS are responsible for catalysis and regulation, respectively, and this SSU lacks the essential catalytic amino acid residues found in LSU and other PTSs. Whereas no activity was detected for individually expressed LSU or SSU, the intact (LSU · SSU)2 tetramer produced not only C10-GPP at the beginning of the reaction but also C20-GGPP (geranylgeranyl pyrophosphate) at longer reaction times. The activity for synthesizing C10-GPP and C20-GGPP, but not C15-farnesyl pyrophosphate, reflects a conserved active-site structure of the LSU and the closely related mustard (Sinapis alba) homodimeric GGPPS. Furthermore, using a genetic complementation system, we showed that no C20-GGPP is produced by the mint GPPS in vivo. Presumably through protein–protein interactions, the SSU remodels the active-site cavity of LSU for synthesizing C10-GPP, the precursor of volatile C10-monoterpenes. [ABSTRACT FROM AUTHOR]

Abstract: The morphology and phase transformation of the intermetallic compounds (IMCs) formed at the Sn–9Zn–3.5Ag/Cu interface in a solid-state reaction have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The monoclinic η′-Cu6Sn5 transforms to the hexagonal η-Cu6Sn5 and the orthorhombic Cu5Zn8 transforms to the body-centered cubic (bcc) γ-Cu5Zn8 as aged at 180°C. The scallop-shaped Cu6Sn5 layer is retained after aging at 180°C for 1000h. In the solid-state reaction, Ag is repelled from η′-Cu6Sn5 and reacts with Sn to form Ag3Sn, and the Cu5Zn8 layer decomposes. Kirkendall voids are not observed at the Sn–9Zn–3.5Ag/Cu interface even after aging at 180°C for 1000h. [Copyright &y& Elsevier]

We derive the integral inequality of a Randers metric with isotropic S-curvature in terms of its navigation representation. Using the obtained inequality we give some rigidity results under the condition of Ricci curvature. In particular, we show the following result: Assume that an n-dimensional compact Randers manifold ( M, F) has constant S-curvature c. Then ( M, F) must be Riemannian if its Ricci curvature satisfies that Ric < −( n − 1) c 2. [ABSTRACT FROM AUTHOR]