Density-based spatial clustering of applications with noise (DBSCAN) is a density-based clustering algorithm that has the characteristics of being able to discover clusters of any shape, effectively ...distinguishing noise points and naturally supporting spatial databases. DBSCAN has been widely used in the field of spatial data mining. This paper studies the parallelization design and realization of the DBSCAN algorithm based on the Spark platform, and solves the following problems that arise when computing macro data: the requirement of a great deal of calculation using the single-node algorithm; the low level of resource-utilization with the multi-node algorithm; the large time consumption; and the lack of instantaneity. The experimental results indicate that the proposed parallel algorithm design is able to achieve more stable speedup at an increased involved spatial data scale.
Anopheles sinensis is one of the major malaria vectors in China and other southeast Asian countries, including Vietnam, Cambodia, Thailand. Vector control is considered to be the critical measure for ...malaria control, while the increasing prevalence of insecticide resistance caused by long-term use of insecticides, especially pyrethroids, is threatening the successful control of An. sinensis. In order to understand the underlying resistance mechanisms involved and molecular basis, the principal malaria vector, An. sinensis from Jiangsu and Anhui provinces, Southeast China, was investigated.
The adult Anopheles mosquitoes were sampled from multiple sites across Jiangsu and Anhui provinces, and sufficient mosquitoes collected from eleven sites for insecticide susceptibility bioassays. The DIIS4-DIIS6 region of the para-type sodium channel gene was amplified and sequenced, then multiple PCR and Taqman assays were used to assess the frequencies of kdr mutations at the target gene.
In the present study, most of the adult An. sinensis populations were pyrethroids resistant, which indicated the presence of kdr resistance mutations in the para-type sodium channel gene. Sequence analyses demonstrated the kdr mutation existed at codon 1014 in Jiangsu and Anhui provinces. In adult An. sinensis, three mutant types (TTT L1014F, TTC L1014F, and TGT L1014C) of kdr alleles were detected, while no wild type (TTG L1014) was observed. The TTC L1014F mutation was first reported in Anhui province.
The highly polymorphic kdr alleles were observed in all the adult An. sinensis populations, which suggested that in-depth studies are required for carrying on insecticide resistance monitoring and specific resistance mechanisms studying into establish effective long-term malaria vector control program in eastern China.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this article, a hammer-blade hulling machine for Eucommia ulmoides Oliver that solves the current industry problem of low hulling efficiency and high manual input in EUO samaras is described. Its ...main working components are a hulling device and a screening device. Discrete element simulation was used to simulate the hulling process of a EUO samara hulling machine, and a EUO samara bond model was used to simulate the crushing process. The optimal parameters of the huller were determined as follows: the spindle speed was 2800 r/min, the hammer length was 70 mm and the other mechanism parameters were determined according to the working processes of components. Before the prototype test, EUO samaras were pretreated via soaking and insolation. The soaking and insolation times were used as the influence factors when carrying out the test. Their effect on hulling efficiency was evaluated by calculating the yield rates of the kernels and shell and the loss rate. The results show that under the optimal pretreatment conditions, the parameters of the huller meet the requirements, and the yield rate of kernels is more than 28%, the yield rate of shells is more than 38%, and the loss rate is less than 7%. The test indexes meet the use requirements and improve the efficiency of the hulling of the EUO samara, which has the advantages of high efficiency and high hulling rates.
The irreversible magnet demagnetisation phenomena are investigated, under both healthy and short-circuit conditions for a switched flux permanent magnet (SFPM) machine. The temperature effects on ...permanent magnet material are taken into account and the influence of short-circuit current over demagnetisation is evaluated. To calculate the short-circuit current (mainly inter-turn short circuit), the MATLAB/Simulink model has been employed. The aforementioned short-circuit current is then fed to the finite-element model, so the demagnetisation analysis can be carried out. Various fault scenarios are investigated, including a high speed and high fault severity. It is found that the short-circuit current has limited effect on the magnet demagnetisation due to particular features of the SFPM machines. The mechanism of demagnetisation has been revealed and found out to be mainly due to temperature rise and poor PM materials utilisation. Experiments have been carried out to validate the MATLAB/Simulink model for short-circuit current predictions.
Mimicking tactile perception is critical to the development of advanced interactive neuromorphic platforms. Inspired by cutaneous perceptual functions, a bionic tactile perceptual platform is ...proposed. PDMS-based tactile sensors act as bionic skin touch receptors. Flexible indium tin oxide neuromorphic transistors fabricated with a single-step mask processing act as artificial synapses. Thus, the tactile perceptual platform possesses the ability of information processing. Interestingly, the flexible tactile perception platform can find applications in information encryption and decryption. With adoption of cipher, signal transmitted by the perception platform is encrypted. Thus, the security of information transmission is effectively improved. The flexible tactile perceptual platform would have potentials in cognitive wearable devices, advanced human–machine interaction system, and intelligent bionic robots.
Methanol-based alternative energy sources are critical to maintaining energy security, reducing the need for oil imports, and safeguarding the environment in China. However, the use of methanol-based ...fuels in the field of thermal combustion has not been thoroughly investigated. Therefore, an evaluation of the costs, emissions, and usage of methanol boilers is necessary. The study finds that methanol heaters and air source heat pumps have comparable annual cost values. Methanol heating furnaces emit the least amount of NOx and produce no SO2. After the refurbishment, the boiler's emissions and energy consumption have significantly decreased upon conversion of coal-fired steam boilers to methanol-based fuel hot water boilers. Nevertheless, the economy has also somewhat declined. Additionally, 5499 tce (standard coal) less energy will be used during the heating season, and 1.8 million CNY less will be spent on dust removal and desulfurization. Unfortunately, the economic benefits of methanol are only apparent when the cost of methanol fuel is less than 1900 CNY/t. The research presented in this paper provides an essential technological foundation for the development of methanol-fueled fuel burners and for the renovation of small and medium-sized coal-fired boilers.
The over-production of β-amyloid (Aβ) has been strongly correlated to neuronal dysfunction and altered synaptic plasticity in Alzheimer's disease (AD). Accordingly, it has been proposed that ...disrupted synaptic transmission and neuronal network instability underlie memory failure that is evident in the early phases of AD. Homeostatic synaptic plasticity (HSP) serves to restrain neuronal activity within a physiological range. Therefore a disruption of this mechanism may lead to destabilization in synaptic and neural circuit function. Here, we report that during HSP by neuronal activity deprivation, application of Aβ results in an aberrant over-response of the up-regulation of AMPA receptor (AMPAR)-mediated synaptic currents and cell-surface AMPAR expression. In the visual cortex, in vivo HSP induced by visual deprivation shows a similar over-response following an Aβ local injection. Aβ increases the expression of GluA2-lacking, calcium permeable AMPARs (CP-AMPARs), which are required for the initiation, but not maintenance of HSP. Both GluA2-lacking and GluA2-containing AMPARs contribute to the Aβ-mediated over-scaling of HSP. We also find that Aβ induces the dissociation of HDAC1 from the miR124 transcription factor EVI1, leading to an up-regulation of miR124 expression and increased amount of CP-AMPARs. Thus, via aberrant stimulation of miR124 expression and biogenesis of CP-AMPARs, Aβ is able to induce an over response in HSP. This Aβ-mediated dysregulation in homeostatic plasticity may play an important role in the pathogenesis of altered neural function and memory deficits in the early stages of AD.
Both the polarization-resolved chaotic bandwidth enhancement and time-delay signature suppression have been numerically investigated based on a slave vertical-cavity surface-emitting laser (S-VCSEL) ...driven by dual chaotic optical injections (DCOIs) from two master VCSELs (M-VCSELs) under optical feedbacks. The bandwidth and time-delay signature of polarization-resolved chaos generated in VCSELs are evaluated quantitatively via the effective bandwidth and autocorrelation function, respectively. The results show that, in contrast to the polarization-resolved chaos generated from S-VCSEL subject to single chaotic optical injection, for the equivalent injection conditions, the chaos generated by the DCOI configuration can simultaneously realize the bandwidth enhancement and time-delay signature suppression in the distinctly wider injection parameter spaces of injection strength and frequency detuning. By further exploring the influences of different injection parameters from two injection M-VCSELs on the bandwidth and time-delay signature of chaos, it is found that for the DCOI, the moderate injection strengths and relatively larger frequency detuning of two different injection paths are preferred to obtain the desired wideband polarization-resolved chaos with successful time-delay signature suppression.
Nickel-based superalloys have become essential materials due to their excellent comprehensive properties as the miniaturization of products in the aerospace and energy fields develops. The complex ...microstructure and various strengthening mechanisms of nickel-based superalloys make the plastic deformation behavior extremely complicated at the mesoscopic scale. In this paper, compression experiments of nickel-based superalloy samples with different feature sizes (i.e. the sample diameter to grain size ratio, D/d) and different aging times at the mesoscopic scale were carried out. The coupling effect of feature size and δ phase on the compressive deformation behavior was studied. The results show that the δ phase plays a role in precipitation strengthening during compressive deformation at the mesoscopic scale. When D/d is in the range of 9.7–10.9, the flow stress decreases significantly with the increase of grain size, and a “smaller is weaker” size effect appears. When D/d is less than 9.7, the flow stress increases with the grain size, and a “smaller is stronger” size effect appears. Considering grain boundary strengthening, solid solution strengthening, and precipitation strengthening, a size effect model of flow stress was established. The calculated values were in good agreement with the experimental values. The inhomogeneity of the end surface and side surface increases with the decrease of feature size and the decrease of aging time. The presence of the δ phase reduces the inhomogeneous deformation of nickel-based superalloys during compressive deformation at the mesoscopic scale.
Background
Phosphogluconate dehydrogenase (PGD) is involved in the regulation of various tumors. However, its role in hepatocellular carcinoma (HCC) is poorly understood. This study tried to ...determine the prognostic efficacy of PGD and its value for immunotherapy in HCC.
Methods
The data from the TCGA database was used to explore the predictive power of PGD expression and methylation on the overall survival (OS) of HCC through Cox regression and the Kaplan-Meier analysis. Then, we used the GEO and ICGC database to further verify the predictive power. Finally, the relationship between PGD and immune cells and the relationship between PGD and the efficacy of immunotherapy were explored through bioinformatics analysis in HCC.
Results
PGD is highly expressed in HCC tissues, which is negatively regulated by PGD methylation. Low PGD expression and PGD hypermethylation predict better OS in HCC patients. Besides, a meta-analysis based on the TCGA, GSE14520, and ICGC databases further confirms that low PGD expression is closely related to favorable OS. Then, we find significant differences of immune cell infiltrations between high and low PGD expression groups. Expressions of immune checkpoints, most HLA members and tumor mutation burden (TMB) are higher in the high PGD expression group, which indicates beneficial efficacy of immunotherapy in this group. And the potential mechanisms of PGD are exhibited.
Conclusion
PGD is an independent prognostic factor of HCC patients and plays an important role in immune cell infiltration and immunotherapy, which indicates that PGD can be used as a predictive biomarker for HCC immunotherapy.
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