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Deep learning-based object detection has made tremendous progress in the field of intelligent vision systems. However, one of its major complaints is the high demand for large amounts of experimental data. Few-shot object detection (FSOD) aims to identify novel objects with only a few training samples. Existing techniques don't fully explore the potential mapping relationships between support and query features due to the limitation of global matching contrast. In this work, we propose a multi-projection filtering network (MPF-Net) to exploit feature relevance and aggregate the information between multiple scales, ensuring an optimal global representation. Furthermore, we take the lead in proposing a feature contrast filtering paradigm for the classification and regression subtasks in order to fully utilize fine-grained features for contrastive match. The multi-visual contrast approach motivates our model to gracefully handle a variety of difficult detection challenges such as scale discrepancies, occlusions, and feature confusions. MPF-Net accurately perceives features at various scales and adaptively excavates category information. Extensive experiments on PASCAL VOC and MS COCO datasets have demonstrated that our detectors significantly improve upon baseline detectors, especially for extremely low-shot settings (average accuracy improvement is up to 3.5% in 1-shot scenarios and 2.5% in 2-shot scenarios). In general, we propose a novel strategy to construct the few-shot feature space and achieve remarkable results. [ABSTRACT FROM AUTHOR]

Both intra-pore hydrate morphology and inter-pore hydrate distribution influence the physical properties of hydrate-bearing sediments, yet there has been no pore-scale observations of hydrate habit under pressure in preserved pressure core samples so far. We present for the first time a pore-scale micro-CT study of natural hydrate-bearing cores that were acquired from Green Canyon Block 955 in UT-GOM2-1 Expedition and preserved within hydrate pressure–temperature stability conditions throughout sub-sampling and imaging processes. Measured hydrate saturation in the sub-samples, taken from units expected to have in-situ saturation of 80% or more, ranges from 3 ± 1% to 56 ± 11% as interpreted from micro-CT images. Pore-scale observations of gas hydrate in the sub-samples suggest that hydrate in silty sediments at the Gulf of Mexico is pore-invasive rather than particle displacive, and hydrate particles in these natural water-saturated samples are pore-filling with no evidence of grain-coating. Hydrate can form a connected 3D network and provide mechanical support for the sediments even without cementation. The technical breakthrough to directly visualize particle-level hydrate pore habits in natural sediments reported here sheds light on future investigations of pressure- and temperature-sensitive processes including hydrate-bearing sediments, dissolved gases, and other biochemical processes in the deep-sea environment. [ABSTRACT FROM AUTHOR]

The status detection for rotating parts is difficult since the sensor is influenced by the rotation in the inflammable, explosive, and strong magnetic environment. Based on the fiber Bragg grating sensing technology, this paper studies the influence of the natural frequency and deformation of a rotor blade affected by the size of crack in the blade. Test results show that the speed of the equipment and blade excited vibration frequency are two main factors or deformation and vibration frequency of the blade. With an increase in the crack depth, the blade deformation is increased while the stimulated natural frequency of the blade is decreased; at a low rotational speed, the deformation is mainly caused by the rotating speed of the blade. On the contrary, the vibration blade itself contributes to the deformation at a high speed. During the process of full speed rotation, the influence of the rotational speed on the blade deformation almost remains the same, and the influence of the natural vibration on blade deformation is increased with an increase in the rotational speed. [ABSTRACT FROM AUTHOR]

Though adding a groove to a plasmonic end-coupled perfect ring (PR) resonator, two additional resonance modes, which can be controlled by the length of the groove, will arise in this proposed ring-groove (RG) joint metal-insulator-metal (MIM) waveguide. By further cascading, the PR resonator and the RG joint resonator, single and dual Fano resonances with asymmetric line shapes are obtained due to the interference effects between the dark modes and the bright modes. High figure of merit and high refractive-index sensitivity are achieved, and thus this structure is suitable for the biochemistry sensing area. Interestingly, normal and abnormal dispersions are also investigated for the Fano peaks and dips, respectively. The performances of the proposed structure are investigated by using the finite-difference time-domain method. [ABSTRACT FROM AUTHOR]

A tunable multimode plasmonic filter is proposed by using a side-coupled ring-groove joint resonator. In addition to the integer resonance modes of the perfect ring resonator (RR), extra non-integer resonance modes are excited by adding a groove on the RR. According to the simulations with finite difference time domain method, it is investigated that two integer and two non-integer modes are obtained. When the groove is placed on the antinodes of the magnetic fields, the effective resonance lengths for the corresponding modes will be changed by the groove. In this case, one can linearly manipulate the wavelengths by changing the length of the groove. On the contrary, the wavelengths of the specific modes will be always fixed when the groove locates at the nodes of the modes. Compared to those perfect structured Fabry-Pérot (FP) resonators, this compact device can provide more channels and manipulate the wavelengths flexibly. Therefore, it may find widely applications in the on-chip optical signal processing area. [ABSTRACT FROM AUTHOR]

A plasmonic bidirectional/unidirectional wavelength splitter based on asymmetric metal-dielectric-metal (MDM) waveguides is proposed. In the splitter, owing to the interference effects caused by the unequal phase delays from the two asymmetric arms of MDM waveguides, surface plasmon polaritons (SPPs) will only transmit through the output port that is close to the arm where constructive interference arises. The transmission wavelengths can be linearly modulated by changing the lengths of the arms. Since two different SPP modes are obtained in two output ports, respectively, the structure can act as a bidirectional wavelength splitter. Interestingly, both SPP modes can be manipulated to transmit through the same port by adding a notch in one arm. In this case, the notch must simultaneously locate at the anti-node and at the node of the magnetic fields of two SPP modes respectively. As a result, additional phase delay for the specific mode will be produced by the notch, but without any impact on the other mode. Then, the propagation directions of both modes will turn to be identical. High transmission and high cross-talk isolation are investigated for all the cases by using the finite-difference time-domain method. [ABSTRACT FROM AUTHOR]

A plasmonic metal-dielectric-metal (MDM) waveguide structure is proposed by placing a slot cavity below or above a groove. The groove and the slot cavity can act as a reflector and a resonator, respectively. Due to the interactions between the broad dark mode and the narrow bright mode caused by the groove and the side-coupled slot cavity, single Fano resonance with sharp asymmetric spectral profile is achieved. Interestingly, dual Fano resonances can also be obtained by using two different slot cavities, which are simultaneously distributed on both sides of the groove. The line shape can be transformed by changing the length of the groove, while the wavelength of the resonance peak can be manipulated linearly with the length of the slot cavity. The proposed structure yields a highest sensitivity of ∼1131 nm/RIU and a figure of merit of ∼1.6 × 10, and thus, we believe that it can serve as an on-chip nanosensor. [ABSTRACT FROM AUTHOR]

A plasmonic nano-sensor is proposed by means of Fano resonance in a metal-insulator-metal (MIM) waveguide structure, which consists of two identical slot cavities placed nearby two symmetrical grooves in a MIM bus waveguide. Due to the interaction of the broad bright mode and the narrow dark mode caused by the grooves and the side-coupled slot cavities, respectively, the transmission spectrum possesses a sharp asymmetrical profile. The spectral line shape can be manipulated by changing the length of the grooves, and the wavelength of the resonance peak has a linear relationship with the length of the slot cavity. These characteristics offer flexibility to design the device. This nano-sensor yields a sensitivity of ~903 nm/RIU and a figure of merit (FOM) of ~3.1 × 10. Besides, dual Fano resonance peaks are also achieved by shifting the slot cavities away from the center of the grooves, resulting in a FOM as high as 4.6 × 10. The proposed structure may find important applications in the on-chip nano-sensing area. [ABSTRACT FROM AUTHOR]

We determined the allele frequencies and forensic parameters for the 26 short tandem repeat (STR) autosomal markers in two commercial kits (the Investigator HDplex and AmpFLSTR Identifiler systems) for 183 unrelated individuals from the Han population of the Hebei Province of China. The 26 STRs were all in Hardy-Weinberg equilibrium. No linkage disequilibrium was detected between any pair of loci. The combined power of discrimination and the combined power of exclusion for the 26 STR loci were 1-7.74E−31 and 1-1.21E−11, respectively. Six rare alleles of D10S2325 were identified and named 20, 21, 22, 23, 24, and 31. All the length of the six rare alleles were out of the range of allelic ladder. We calculated the population pairwise genetic distance based on the allele frequencies, using published population data including German, central Polish, south Dutch, northeastern Polish, south Brazilian, Korean, Sichuan Han of China, and Shanghai Han of China. Also we examined the population pairwise genetic distance of loci included in Identifiler system between Hebei Han and other ethnic population of China. These 26 autosomal STR loci could provide highly informative polymorphic data for paternity testing and forensic identification in the Hebei Han population in China. Because they are all in linkage equilibrium, they could be used together to solve deficient kinship cases or cases with mutations. [ABSTRACT FROM AUTHOR]

We developed multiple gene expression pipelines and assembled them into a web-based tool called Pop's Pipes to facilitate preprocessing and analysis of substantial poplar gene expression data. The input data can be spatiotemporal microarray and RNA-seq data from comparable tissues, time points, or treatment-vs-control conditions. Pop's Pipes can be used to identify differentially expressed genes between one or multiple paired tissues, time points, or treatment-vs-control conditions in a single in silico analysis. The differentially expressed genes (DEGs) obtained for each comparison will be automatically analyzed by Pop's Pipes for identifying significantly enriched gene ontologies and interpro protein domains. Also, significantly changed metabolic pathways across all input data sets will be identified. We also integrated a pipeline into Pop's Pipes for constructing any of three type gene ontology trees when a short list of gene ontologies from biological processes, molecular functions, or cellular components is used as an input. The resulting information from Pop's Pipes enables scrutiny to create spatiotemporal models and hypotheses to understand how poplar develops and functions. Pop's Pipes can analyze a microarray or RNA-seq data set with 10 time points in 4-10 h, with each time point containing three replicates of treatments and three controls. Such a data set usually takes a bioinformatician a few months to a year to analyze. Pop's Pipes can thus save users tremendous amounts of research time when large numbers of comparative data need to be analyzed. [ABSTRACT FROM AUTHOR]

A subwavelength intersection structure with wavelength filtering functionality is proposed by using an open loop which consists of four slot cavities and four metal-insulator-metal (MIM) drop waveguides. The slot cavities are used as the resonators while the MIM waveguides serve as the input/output ports. The SPPs propagations and the transmission wavelengths in two pairs of matched input/output ports are immune to each other, which satisfy the intersection characters. The results based on finite difference time domain (FDTD) method demonstrate that high transmittance for the expected output port and high isolation for other ports have been achieved. Specifically, the transmittance and isolation is larger than 0.64 and 14 dB, respectively. In addition, a transmission peak, whose wavelength can be modulated by adjusting the length of the slot cavities, is available for the output port. Such a device can find applications in various optical systems, such as the wavelength filtering area and the optical intersection area. [ABSTRACT FROM AUTHOR]

In this study, a series of waterborne polyurethanes (WPUs) with different ionic group contents were synthesized by varying the amount of the internal emulsifier 2,2-dimethylolpropionic acid (DMPA). The effects of the ionic group content on the stability and adhesion behavior of WPUs were investigated in terms of particle size, viscosity, surface tension, interfacial tension, contact angle, and adhesion performance. It was found that stable WPUs could be obtained when the DMPA content was larger than 3.5 wt% (with respect to the total solid content). Adhesion performance of WPUs to substrates was mainly affected by the wetting of WPUs on the substrates and the molecular interactions between them. With the increase of DMPA content, the surface tension of WPUs as well as the interfacial tension and contact angle between WPUs and polyethylene terephthalate (PET) films increased. Moreover, the adhesion strength of the WPUs firstly increased and then gradually decreased. The type of debonding failure of all the synthesized WPUs on PET films was cohesion failure due to their lower cohesion strength, which was theoretically testified by the comparison between the adhesion energy and cohesion energy. [ABSTRACT FROM AUTHOR]

Molecular subtypes of glioblastoma (GBM) with distinct alterations have been identified. There is need for reproducible, versatile preclinical models that resemble specific GBM phenotypes to facilitate preclinical testing of novel therapies. We present a cell line-based murine proneural GBM model and characterize its response to radiation therapy. Proneural gliomas were generated by injecting PDGF-IRES-Cre retrovirus into the subcortical white matter of adult mice that harbor floxed tumor suppressors (Pten and p53) and stop-floxed reporters. Primary cell cultures were generated from the retrovirus induced tumors and maintained in vitro for multiple passages. RNA sequencing-based expression profiling of the resulting cell lines was performed. The tumorigenic potential of the cells was assessed by intracranial injection into adult naïve mice from different strains. Tumor growth was assessed by bioluminescence imaging (BLI). BLI for tumor cells and brain slices were obtained and compared to in vivo BLI. Response to whole-brain radiation was assessed in glioma-bearing animals. Intracranial injection of PdgfPtenp53luciferase glioma cells led to formation of GBM-like tumors with 100 % efficiency ( n = 48) and tumorigenesis was retained for more than 3 generations. The cell lines specifically resembled proneural GBM based on expression profiling by RNA-Seq. PdgfPtenp53luciferase cell number correlated with BLI signal. Serial BLI measured tumor growth and correlated with size and location by ex vivo imaging. Moreover, BLI predicted tumor-related mortality with a 93 % risk of death within 5 days following a BLI signal between 1 × 10 and 5 × 10 photons/s cm. BLI signal had transient but significant response following radiotherapy, which corresponded to a modest survival benefit for radiated mice ( p < 0.05). Intracranial injection of PdgfPtenp53luciferase cells constitutes a novel and highly reproducible model, recapitulating key features of human proneural GBM, and can be used to evaluate tumor-growth and response to therapy. [ABSTRACT FROM AUTHOR]

Noticeable performance improvement via ever-increasing transistors is gradually trapped into a predicament since software cannot logically and efficiently utilize hardware resource, such as multi-core resource. This is an inevitable problem in dynamic binary translation (DBT) system as well. Though special purpose hardware as aide tool, through some interfaces, provided by DBT enables the system to achieve higher performance, the limitation of it is significant, that is, it is impossible to be used widely by another one. To overcome this drawback, we focus on building compatible software architecture to acquire higher performance without platform dependence. In this paper, we propose a novel multithreaded architecture for DBT system through partitioning distinct function module, which is to adequately utilize multiprocessors resource. This new architecture devides couples the common DBT system (DBTs) working routine into dynamic translation, optimization, and translated code execution phases, and then ramifies them into different threads to enable them concurrently executed. In this new architecture, several efficient novel methods are presented to cope with intractable work that puzzles most researchers, such as communication mechanism, cache layout, and mutual exclusion between threads. Experimental results using SPECint 2000 indicate that this new architecture for DBT system can achieve higher performance - speed up the traditional DBT system by about average 10.75%, with better CPU utilization. [ABSTRACT FROM AUTHOR]

The effects of cavity-dispersion noncoaxiality (CDN) on the generation of ultrabroadband femtosecond pulses in KLM Ti:sapphire laser were investigated theoretically and experimentally. It was predicted that when the laser sub-cavity works near the coaxial operation point, the limitation of CDN on the bandwidth broadening is minimum, which is favorable for ultrabroadband pulse generation. On the basis of this prediction, femtosecond pulses with bandwidth of 650 to 1000 nm were directly generated from a home built KLM Ti:sapphire laser. To our knowledge, they are the broadest bandwidth pulses produced from KLM Ti:sapphire laser with similar oscillator configuration and gain crystal length of 3 mm. [ABSTRACT FROM AUTHOR]

In Qibainong, a steep-mountainous karst region in southwestern China, self-sustaining societies have long existed, but increasing socioeconomic liberation has fuelled the recent rapid structural change of its economy. Consequently, environmental deterioration and exhaustion of resources have become problematic issues. We carried out a field survey in Qibainong in southwestern China and used both estimated and measured N flows and N balances from obtained results. Our results are summarized as follows (1) farmers used large amounts of chemical N fertilizers at intensities of 113–1124 kg N ha−1; (2) substantial application of chemical fertilizer in Qibainong has contributed to an increase in potential NO3-N leaching of 6–511 kg N ha−1, followed by NH3 volatilization; (3) crop products are largely distributed to feed livestock, the products of which are a major income source; (4) this area has a great requirement for imported food; (5) in addition, unused manure N (up to 191 kg N ha−1) is generated by the increase in manure N production. Chemical fertilizer application, in addition to unused manure can be regarded as a major source of environmental damage. Based on the relationship between the N application rate and the NO3-N leaching potential, we estimated the critical limit of the N application rate of chemical fertilizer + manure to be 297 kg N ha−1. In Qibainong, unused manure, which is an important nutrient resource, was applicable within the critical limit. We recommend that all manure N produced within the village be used effectively on arable land, and that any shortages be supplemented by chemical N fertilizer up to 297 kg N ha−1 to maintain water resource quality. Further improvement might be achieved through incorporating chemical fertilizers, P and K supplemented manure, and so on. [ABSTRACT FROM AUTHOR]

The compatibility between a fiber optical sensor and concrete structure in the optic fiber smart concrete is studied. The methods of improving the compatibility are proposed based on theory analysing, and a novel fiber optical sensor was developed. The experimental results show that the novel structure of fiber optical sensor and the scheme of the protecting layer of epoxy resin bed composite not only enable the sensor to be applied in strict environment, but also can monitor the beginning propagation and breaking of concrete craks. The results also indicate that the sensor will maintain its properties in the case of large deformation and that it has the high compatibility with concrete structure and con meet special needs of the intelligent materials and structure. [ABSTRACT FROM AUTHOR]

Coumarin derivatives are an important class of C6-C3 plant metabolites that show a variety of bioactivities. Currently, most clinical anticoagulant agents are coumarins, such as warfarin, dicoumarol and acenocoumarol, and patients taking these drugs must be monitored for adverse reactions. In a search for safe and effective anticoagulant compounds from Chinese herbal medicine, a screening procedure on the whole plant of Ainsliaea fragrans was performed. The phytochemical investigation of this plant afforded five new coumarin derivatives, including a pair of natural 4-hydroxycoumarin enantiomers (1), a pair of coumarin enantiomers with a rare polycyclic pyrano[3-2c] carbon skeleton (2) and a 7-hydroxycoumarin derivative (3), together with 5 known biogenetically related compounds (4-8). Enantioseparation of 1 and 2 produced optically pure compounds 1a, 1b, 2a and 2b. The absolute configurations of the new compounds were confirmed by single-crystal X-ray diffraction analysis. In addition, we evaluated the anticoagulant activity of all isolates via activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) assays in vitro and in vivo. Of note, compound 3 displayed potent anticoagulant activity and no significant hepatic or renal toxicity, which could make it a promising agent for further preclinical evaluation for preventing abnormal blood clotting. [ABSTRACT FROM AUTHOR]