2,459 research outputs found

    The effects of large extra dimensions on associated ttˉh0t\bar{t} h^0 production at linear colliders

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    In the framework of the large extra dimensions (LED) model, the effects of LED on the processes \rrtth and \eetth at future linear colliders are investigated in both polarized and unpolarized collision modes. The results show that the virtual Kaluza-Klein (KK) graviton exchange can significantly modify the standard model expectations for these processes with certain polarizations of initial states. The process \rrtth with s=3.5TeV\sqrt{s}=3.5 TeV allows the effective scale ΛT\Lambda_T to be probed up to 7.8 and 8.6 TeV in the unpolarized and Pγ=0.9P_{\gamma} = 0.9, J=2 polarized γγ\gamma \gamma collision modes, respectively. For the \eetth process with s=3.5TeV\sqrt{s}=3.5 TeV, the upper limits of ΛT\Lambda_T to be observed can be 6.7 and 7.0 TeV in the unpolarized and Pe+=0.6P_{e^+} = 0.6, Pe=0.8P_{e^-} = 0.8, +-+ polarized e+ee^+e^- collision modes, respectively. We find the \rrtth channel in J=2 polarized photon collision mode provides a possibility to improve the sensitivity to the graviton tower exchange.Comment: To be appeard in Physical Review

    SLITRK5 is a negative regulator of hedgehog signaling in osteoblasts

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    Hedgehog signaling is essential for bone formation, including functioning as a means for the growth plate to drive skeletal mineralization. However, the mechanisms regulating hedgehog signaling specifically in bone-forming osteoblasts are largely unknown. Here, we identified SLIT and NTRK-like protein-5(Slitrk5), a transmembrane protein with few identified functions, as a negative regulator of hedgehog signaling in osteoblasts. Slitrk5 is selectively expressed in osteoblasts and loss of Slitrk5 enhanced osteoblast differentiation in vitro and in vivo. Loss of SLITRK5 in vitro leads to increased hedgehog signaling and overexpression of SLITRK5 in osteoblasts inhibits the induction of targets downstream of hedgehog signaling. Mechanistically, SLITRK5 binds to hedgehog ligands via its extracellular domain and interacts with PTCH1 via its intracellular domain. SLITRK5 is present in the primary cilium, and loss of SLITRK5 enhances SMO ciliary enrichment upon SHH stimulation. Thus, SLITRK5 is a negative regulator of hedgehog signaling in osteoblasts that may be attractive as a therapeutic target to enhance bone formation

    Experimental Wireless Communication Using Chaotic Baseband Waveform

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    This work was supported by NSFC under Grants 61401354, 61172070, and 61502385, in part by the Key Basic Research Fund of Shaanxi Province under Grant 2016ZDJC0067, in part by the Natural Science Basic Research Plan in Shaanxi Province of China under Grant 2016JQ6015, in part by the Scientific and Technological Innovation Leading Talents Program of Shaanxi Province, and in part by the Foundation of Shaanxi Educational Committee under Grant 17JS086.Peer reviewedPostprin

    A convolutional neural network based Chinese text detection algorithm via text structure modeling

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    Text detection in natural scene environment plays an important role in many computer vision applications. While existing text detection methods are focused on English characters, there is strong application demands on text detection in other languages, such as Chinese. As Chinese characters are much more complex than English characters, innovative and more efficient text detection techniques are required for Chinese texts. In this paper, we present a novel text detection algorithm for Chinese characters based on a specific designed convolutional neural network (CNN). The CNN model contains a text structure component detector layer, a spatial pyramid layer and a multi-input-layer deep belief network (DBN). The CNN is pretrained via a convolutional sparse auto-encoder (CSAE) in an unsupervised way, which is specifically designed for extracting complex features from Chinese characters. In particular, the text structure component detectors enhance the accuracy and uniqueness of feature descriptors by extracting multiple text structure components in various ways. The spatial pyramid layer is then introduced to enhance the scale invariability of the CNN model for detecting texts in multiple scales. Finally, the multi-input-layer DBN is used as the fully connected layers in the CNN model to ensure that features from multiple scales are comparable. A multilingual text detection dataset, in which texts in Chinese, English and digits are labeled separately, is set up to evaluate the proposed text detection algorithm. The proposed algorithm shows a significant 10% performance improvement over the baseline CNN algorithms. In addition the proposed algorithm is evaluated over a public multilingual image benchmark and achieves state-of-the-art results for text detection under multiple languages. Furthermore a simplified version of the proposed algorithm with only general components is compared to existing general text detection algorithms on the ICDAR 2011 and 2013 datasets, showing comparable detection performance to the existing algorithms

    Hábitos alimenticios de Calanus sinicus (Crustacea: Copepoda) durante primavera y otoño en el mar Bohai, investigados mediante un índice de herbivoría

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    Pigment ingestion rate (PIR) and egg production rate (EPR) of the dominant copepod Calanus sinicus, as well as chlorophyll-a concentration and phytoplankton assemblages were measured in the Bohai Sea, North China in June 1997, October 1998 and May 1999. A herbivore index (H) was also calculated as the carbon specific ratio of PIR and EPR, in order to investigate its feeding habits in the spring and autumn phytoplankton bloom respectively. On average, chlorophyll-a concentration was relatively similar (1-1.34 mg m-3) in the three cruises, but PIR was quite different. It was 3.24 µg C female-1 d-1 in October, equivalent to one half of the PIR for June and one third of the PIR for May. Average EPR was highest in May, and quite similar during the other two months. According to H values, herbivorous feeding contributed 100% of the egg production of C. sinicus in June, 82.5% in May, but only 47.8% in October. It is possible that omnivorous feeding of C. sinicus in October was induced by a prevalence of large-sized diatoms and sufficient non-phytoplankton food resources during the autumn bloom period.La tasa de ingestión de pigmentos (PIR) y la tasa de producción de huevos (EPR) del copépodo dominante Calanus sinicus ha sido determinada, conjuntamente con la concentración de clorofila- a y la composición del fitoplancton, en el mar de Bohai, norte de China, en junio 1997, octubre 1998 y mayo 1999. Para investigar los hábitos alimenticios durante los blooms de fitoplancton de primavera y otoño se ha determinado un índice de herbivoría (H), calculado como el cociente de las tasas específicas PIR y EPR en carbono. En promedio, la concentración de clorofila-a fue relativamente similar (1-1,34 mg m-3) en las tres campañas oceanográficas. Pero los valores de PIR difirieron bastante, variando desde 3,24 μg C hembra-1 d-1 en octubre a valores un medio y un tercio de dicho valor, respectivamente, en junio y mayo. Los valores promedio de EPR fueron máximos en mayo, y bastante similares durante los otros dos meses. Según los valores del índice H obtenidos, la herbivoría contribuyó un 100% en la producción de huevos de C. sinicus en junio y un 82,5% en mayo, mientras que sólo explicó un 47,8% de la producción de huevos en octubre. este estudio sugiere que la alimentación omnivora de C. sinicus en octubre fue inducida por la prevalencia de diatomeas de gran tamaño y la presencia suficiente de alimento no fitoplanctónico durante el periodo del bloom otoñal.

    Inverse Martensitic Transformation in Zr Nanowires

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    Like martensitic transformations (MTs), inverse martensitic transformations (IMTs) are shear-dominant diffusionless transformations, but are driven by reduction in interfacial energies rather than bulk free energies, and exhibit distinctive behavior such as instantaneous initiation (like spinodal decomposition) and self-limiting lengthscale. Bulk Zr metal is known to undergo normal MT from the high-temperature bcc phase to the low-temperature hcp phase. Using molecular dynamics simulations we demonstrate that, unlike in the bulk, an IMT to the bcc structure can occur in (1100)-oriented hcp Zr nanowires at low temperatures, which is driven by the reduction in the nanowire surface energy. The bcc domains subsequently become distorted and transform into a new (1120)-oriented hcp domain, leading to reorientation of the nanowire. This behavior has implications for the study of structural transformations at the nanoscale and surface patterning
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