267 research outputs found
A new species of Confusacris (Orthoptera: Acrididae), with a key to the known species
The genus Confusacris Yin & Li, 1987 belongs to Acrididae: Chrysochraontinae with 4 described species. It is readily distinguished from the related genera as follows: the antennae sharply ensiform, especially in the female; elytra of male with irregular quadrilateral cell, and the apex of the elytra being concave; lateral carinae of pronotum distinct or more distinct; first segment of hind tarsus longer than third one distinctly. All species of the genus are distributed in northern China. A new species, Confusacris xinjiangensis Wang & Zheng sp. n. is described in this paper. A key to the known species of the genus is given
The Puzzle of Insular Domains: A Longitudinal Study of Knowledge Structuration and Innovation in Biotechnology Firms
The Dynamic Impact of Innovative Capability and Inter-firm Network on Firm Valuation: A Longitudinal Study of Biotechnology Start-ups
Prior research suggests that a high technology start-up's innovative capability and inter-firm network influence its performance and consequently, firm valuation. Few studies consider their joint influence and even fewer consider the temporal change of those effects on firm valuation. In this study, we propose that firm age, a key organizational variable, represents both the development of organizational routines from a start-up's perspective and the accumulation of accessible information from an investor's viewpoint. As such, an investor's evaluation of a high technology start-up's innovative capability and inter-firm network evolves with firm age. Using panel data of 170 biotechnology start-ups, our results suggest that the relative value of network status declines while the impact of innovative capability increases with firm age. Interestingly, there is a growing complementary effect of innovative capability and network heterogeneity on firm valuation. The implications of these findings for entrepreneurial practice and theories of firm capabilities and inter-firm network are discussed. © 2009 Elsevier Inc.link_to_subscribed_fulltex
Effect of amber powder on endometrial ultrastructure and MAPK pathway in endometriosis model rats
Purpose: To explore the therapeutic role of amber powder in endometriosis by investigating its effect on endometrial ultrastructure, ERK1/2, p38MAPK, and NF-κB mRNA pathways and CSRC/EFR/ERK1/2 proteins.
Methods: Sprague Dawley (SD) rats were randomly divided into blank group, disease model group (untreated), amber powder high-dose group, amber powder medium-dose group, amber powder lowdose group and danazol group. Morphological changes in endometrial cells were studied using transmission electron microscopy. The expression of ERK1/2, p38MAPK, and NF-κB mRNA in endometrial tissues of each group was determined using quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry was utilized for the measurement of C-SRC/EFR/ERK1/2 pathway protein expression.
Results: The endometriosis rats treated with a high-, medium- and low-dose amber powder showed a decrease in the volume of ectopic lesions, compared with the untreated disease model group. The expressions of ERK1/2, p38MAPK, NF-κB mRNA, and C-SRC/EFR/ERK1/2 protein were higher in the eutopic and ectopic endometrial tissues in untreated disease group than those in normal control group. Moreover, treatment of endometriosis rats with amber powder revealed a reduction in the expressions of ERK1/2, p38MAPK, NF-κB mRNA and C-SRC/EFR/ERK1/2 proteins in eutopic and ectopic endometrium tissues.
Conclusion: Amber powder reduces ectopic lesions and slows down the development of endometriosis, probably via inhibition of MAPK pathway genes in eutopic and ectopic endometrial tissues
Advances in Convolutional Neural Networks
Deep Learning, also known as deep representation learning, has dramatically improved the performances on a variety of learning tasks and achieved tremendous successes in the past few years. Specifically, artificial neural networks are mainly studied, which mainly include Multilayer Perceptrons (MLPs), Convolutional Neural Networks (CNNs) and Recurrent Neural Networks (RNNs). Among these networks, CNNs got the most attention due to the kernel methods with the weight sharing mechanism, and achieved state-of-the-art in many domains, especially computer vision. In this research, we conduct a comprehensive survey related to the recent improvements in CNNs, and we demonstrate these advances from the low level to the high level, including the convolution operations, convolutional layers, architecture design, loss functions, and advanced applications
Strain Induced One-Dimensional Landau-Level Quantization in Corrugated Graphene
Theoretical research has predicted that ripples of graphene generates
effective gauge field on its low energy electronic structure and could lead to
zero-energy flat bands, which are the analog of Landau levels in real magnetic
fields. Here we demonstrate, using a combination of scanning tunneling
microscopy and tight-binding approximation, that the zero-energy Landau levels
with vanishing Fermi velocities will form when the effective pseudomagnetic
flux per ripple is larger than the flux quantum. Our analysis indicates that
the effective gauge field of the ripples results in zero-energy flat bands in
one direction but not in another. The Fermi velocities in the perpendicular
direction of the ripples are not renormalized at all. The condition to generate
the ripples is also discussed according to classical thin-film elasticity
theory.Comment: 4 figures, Phys. Rev.
Long intergenic non-coding RNA expression signature in human breast cancer
Breast cancer is a complex disease, characterized by gene deregulation. There is less systematic investigation of the capacity of long intergenic non-coding RNAs (lincRNAs) as biomarkers associated with breast cancer pathogenesis or several clinicopathological variables including receptor status and patient survival. We designed a two-stage study, including 1,000 breast tumor RNA-seq data from The Cancer Genome Atlas (TCGA) as the discovery stage, and RNA-seq data of matched tumor and adjacent normal tissue from 50 breast cancer patients as well as 23 normal breast tissue from healthy women as the replication stage. We identified 83 lincRNAs showing the significant expression changes in breast tumors with a false discovery rate (FDR) < 1% in the discovery dataset. Thirty-seven out of the 83 were validated in the replication dataset. Integrative genomic analyses suggested that the aberrant expression of these 37 lincRNAs was probably related with the expression alteration of several transcription factors (TFs). We observed a differential co-expression pattern between lincRNAs and their neighboring genes. We found that the expression levels of one lincRNA (RP5-1198O20 with Ensembl ID ENSG00000230615) were associated with breast cancer survival with P < 0.05. Our study identifies a set of aberrantly expressed lincRNAs in breast cancer
Effect of Central Antileptin Antibody on the Onset of Female Rat Puberty
The effect of intracerebroventricular (ICV) antileptin antibody on the onset of puberty in
the female rat and the relationship between serum leptin, luteinizing hormone (LH), and body
weight were investigated. Antileptin antibody (group A) was infused ICV from days 23–36
in prepubertal female rats whereas the control (group B) received ICV goat immunoglobulin
G (IgG).
In the antileptin group, mean day of vaginal opening (VO) was postponed (day 34 versus day 30,
P < .01
). Body weight trended higher after 30 days in the antileptin group but not significantly. However, there was no difference in serum leptin and LH between the two
groups on the day of VO. Serum leptin was relatively constant from day 23 through day 31
and did not correlate with LH (r = 0.14, P = .10).
These studies demonstrate that central leptin promotes the onset of female rat puberty as
evidenced by VO. Finally, central leptin impacts female rat pubertal onset in distinction from
serum leptin and body weight
Comparative Transcriptome Profiling Reveals Compatible and Incompatible Patterns of Potato Toward <i>Phytophthora infestans</i>
Late blight, caused by Phytophthora infestans (P. infestans), is a devastating disease in potato worldwide. Our previous study revealed that the Solanum andigena genotype 03112-233 is resistant to P. infestans isolate 90128, but susceptible to the super race isolate, CN152. In this study, we confirmed by diagnostic resistance gene enrichment sequencing (dRenSeq) that the resistance of 03112-233 toward 90128 is most likely based on a distinct new R gene(s). To gain an insight into the mechanism that governs resistance or susceptibility in 03112-223, comparative transcriptomic profiling analysis based on RNAseq was initiated. Changes in transcription at two time points (24 h and 72 h) after inoculation with isolates 90128 or CN152 were analyzed. A total of 8,881 and 7,209 genes were differentially expressed in response to 90128 and CN152, respectively, and 1,083 differentially expressed genes (DEGs) were common to both time points and isolates. A substantial number of genes were differentially expressed in an isolate-specific manner with 3,837 genes showing induction or suppression following infection with 90128 and 2,165 genes induced or suppressed after colonization by CN152. Hierarchical clustering analysis suggested that isolates with different virulence profiles can induce different defense responses at different time points. Further analysis revealed that the compatible interaction caused higher induction of susceptibility genes such as SWEET compared with the incompatible interaction. The salicylic acid, jasmonic acid, and abscisic acid mediated signaling pathways were involved in the response against both isolates, while ethylene and brassinosteroids mediated defense pathways were suppressed. Our results provide a valuable resource for understanding the interactions between P. infestans and potato
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