232 research outputs found
Molecular characterization and function analysis of the vitellogenin receptor from the cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera, Noctuidae)
Developing oocytes accumulate plentiful yolk protein during oogenesis through receptor-mediated endocytosis. The vitellogenin receptor (VgR), belonging to the low-density lipoprotein receptor (LDLR) family, regulates the absorption of yolk protein. In this work, the full-length vitellogenin receptor (HaVgR) in the cotton bollworm Helicoverpa armigera was identified, encoding a 1817 residue protein. Sequence alignment revealed that the sequence of HaVgR contained all of the conservative structural motifs of LDLR family members, and phylogenetic analysis indicated that HaVgR had a high identity among Lepidoptera and was distinct from that of other insects. Consistent with other insects, HaVgR was specifically expressed in ovarian tissue. The developmental expression pattern showed that HaVgR was first transcribed in the newly metamorphosed female adults, reached a peak in 2-day-old adults and then declined. Western blot analysis also revealed an ovarian-specific and developing expression pattern, which was consistent with the HaVgR mRNA transcription. Moreover, RNAi-mediated HaVgR knockdown strongly reduced the VgR expression in both the mRNA and protein levels, which inhibited the yolk protein deposition in the ovaries, led to the dramatic accumulation of vitellogenin and the up-regulation of HaVg expression in hemolymph, and eventually resulted in a declined fecundity. Together, all of these findings demonstrate that HaVgR is a specific receptor in uptake and transportation of yolk protein for the maturation of oocytes and that it plays a critical role in female reproduction
A finite element numerical simulation analysis of mine direct current method’s advanced detection under varied field sources
Ensuring the safety of coal mine production requires accurate forecasting of coal road heading faces in advance. Because of its high resistance to electromagnetic interference, the mine direct current (DC) method has been widely utilized in the advanced detection and prediction of coal mines. The layout of the field source significantly influences the detection outcomes obtained through this method. In this study, a variety of full-space three-dimensional geoelectric models were established based on the fundamental principle of DC resistivity, and the response features of geological anomalies located in various positions in front of a roadway were studied under different field source conditions using finite element numerical simulation. The electrical response characteristics were analyzed with the electrodes positioned in different directions and two-point to seven-point current sources located on the floor and side of the roadway, respectively. The electrical response of the geological anomalies was characterized with varying positions of the multi-point current source in the roadway and the pole distance of the power supply electrode. Furthermore, the electrical response characteristics of the mine DC method in advanced detection were compared for geological anomalies placed differently across the entire space. The results indicate that the response effect of the geological anomaly in front of the roadway is greater when the field source is placed on the shorter side of the roadway cross-section, with the number of field sources showing a positive correlation with the product of the pole distance and low-resistance amplitude. In advanced detection by DC method, the existence of geological anomalies on the side will affect the recognition of anomalies in front of the roadway
Research on Noise Reduction of Variable Speed Rotary Compressor with Large Capacity
With the increasing speed and capacity of variable-speed rotary compressors, the problem of noise especially low and medium frequency noise in the air conditioning system which can\u27t be solved by wrapping soundproof cotton has became more serious. In this paper, based on the noise problem of the rotor compressor with a working capacity of more than 80CC, the main frequency and the position of the noise source within 1000Hz are confirmed by simulation and experiment. Then on the base of this,the muffler and accumulator are respectively optimized and improved combining with Computer Aided Engineering (CAE) means. The final application results show that the optimized scheme can reduce noise by 6.1dB in 160Hz and 8.9dB in the frequency range of 500Hz to 800Hz, achieving good results
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Chronic treatment with anesthetic propofol attenuates β-amyloid protein levels in brain tissues of aged mice
Alzheimer’s disease (AD) is the most common form of dementia. At the present time, however, AD still lacks effective treatments. Our recent studies showed that chronic treatment with anesthetic propofol attenuated brain caspase-3 activation and improved cognitive function in aged mice. Accumulation of β-amyloid protein (Aβ) is a major component of the neuropathogenesis of AD dementia and cognitive impairment. We therefore set out to determine the effects of chronic treatment with propofol on Aβ levels in brain tissues of aged mice. Propofol (50 mg/kg) was administrated to aged (18 month-old) wild-type mice once a week for 8 weeks. The brain tissues of mice were harvested one day after the final propofol treatment. The harvested brain tissues were then subjected to enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Here we report that the propofol treatment reduced Aβ (Aβ40 and Aβ42) levels in the brain tissues of the aged mice. Moreover, the propofol treatment decreased the levels of β-site amyloid precursor protein cleaving enzyme (the enzyme for Aβ generation), and increased the levels of neprilysin (the enzyme for Aβ degradation) in the brain tissues of the aged mice. These results suggested that the chronic treatment with propofol might reduce brain Aβ levels potentially via decreasing brain levels of β-site amyloid precursor protein cleaving enzyme, thus decreasing Aβ generation; and via increasing brain neprilysin levels, thus increasing Aβ degradation. These preliminary findings from our pilot studies have established a system and postulated a new hypothesis for future research
Sporthesia: Augmenting Sports Videos Using Natural Language
Augmented sports videos, which combine visualizations and video effects to
present data in actual scenes, can communicate insights engagingly and thus
have been increasingly popular for sports enthusiasts around the world. Yet,
creating augmented sports videos remains a challenging task, requiring
considerable time and video editing skills. On the other hand, sports insights
are often communicated using natural language, such as in commentaries, oral
presentations, and articles, but usually lack visual cues. Thus, this work aims
to facilitate the creation of augmented sports videos by enabling analysts to
directly create visualizations embedded in videos using insights expressed in
natural language. To achieve this goal, we propose a three-step approach - 1)
detecting visualizable entities in the text, 2) mapping these entities into
visualizations, and 3) scheduling these visualizations to play with the video -
and analyzed 155 sports video clips and the accompanying commentaries for
accomplishing these steps. Informed by our analysis, we have designed and
implemented Sporthesia, a proof-of-concept system that takes racket-based
sports videos and textual commentaries as the input and outputs augmented
videos. We demonstrate Sporthesia's applicability in two exemplar scenarios,
i.e., authoring augmented sports videos using text and augmenting historical
sports videos based on auditory comments. A technical evaluation shows that
Sporthesia achieves high accuracy (F1-score of 0.9) in detecting visualizable
entities in the text. An expert evaluation with eight sports analysts suggests
high utility, effectiveness, and satisfaction with our language-driven
authoring method and provides insights for future improvement and
opportunities.Comment: 10 pages, IEEE VIS conferenc
Dynamics-Driven Evolution to Structural Heterogeneity in Complex Networks
The mutual influence of dynamics and structure is a central issue in complex
systems. In this paper we study by simulation slow evolution of network under
the feedback of a local-majority-rule opinion process. If performance-enhancing
local mutations have higher chances of getting integrated into its structure,
the system can evolve into a highly heterogeneous small-world with a global hub
(whose connectivity is proportional to the network size), strong local
connection correlations and power law-like degree distribution. Networks with
better dynamical performance are achieved if structural evolution occurs much
slower than the network dynamics. Structural heterogeneity of many biological
and social dynamical systems may also be driven by various dynamics-structure
coupling mechanisms.Comment: Figure 2 updated. Final version as appear in Physica
Gene therapy with tumor-specific promoter mediated suicide gene plus IL-12 gene enhanced tumor inhibition and prolonged host survival in a murine model of Lewis lung carcinoma
<p>Abstract</p> <p>Background</p> <p>Gene therapy is a promising therapeutic approach for cancer. Targeted expression of desired therapeutic proteins within the tumor is the best approach to reduce toxicity and improve survival. This study is to establish a more effective and less toxic gene therapy of cancer.</p> <p>Methods</p> <p>Combined gene therapy strategy with recombinant adenovirus expressing horseradish peroxidase (HRP) mediated by human telomerase reverse transcriptase (hTERT) promoter (AdhTERTHRP) and murine interleukin-12 (mIL-12) under the control of Cytomegalovirus (CMV) promoter (AdCMVmIL-12) was developed and evaluated against Lewis lung carcinoma (LLC) both <it>in vivo </it>and <it>in vitro</it>. The mechanism of action and systemic toxicities were also investigated.</p> <p>Results</p> <p>The combination of AdhTERTHRP/indole-3-acetic acid (IAA) treatment and AdCMVmIL-12 resulted in significant tumor growth inhibition and survival improvement compared with AdhTERTHRP/IAA alone (tumor volume, 427.4 ± 48.7 mm<sup>3 </sup><it>vs </it>581.9 ± 46.9 mm<sup>3</sup>, <it>p </it>= 0.005 on day 15; median overall survival (OS), 51 d <it>vs </it>33 d) or AdCMVmIL-12 alone (tumor volume, 362.2 ± 33.8 mm<sup>3 </sup><it>vs </it>494.4 ± 70.2 mm<sup>3</sup>, <it>p </it>= 0.046 on day 12; median OS, 51 d <it>vs </it>36 d). The combination treatment stimulated more CD4<sup>+ </sup>and CD8<sup>+ </sup>T lymphocyte infiltration in tumors, compared with either AdCMVmIL-12 alone (1.3-fold increase for CD4<sup>+ </sup>T cells and 1.2-fold increase for CD8<sup>+ </sup>T cells, <it>P </it>< 0.01) or AdhTERTHRP alone (2.1-fold increase for CD4<sup>+ </sup>T cells and 2.2-fold increase for CD8<sup>+ </sup>T cells, <it>P </it>< 0.01). The apoptotic cells in combination group were significantly increased in comparison with AdCMVmIL-12 alone group (2.8-fold increase, <it>P </it>< 0.01) or AdhTERTHRP alone group (1.6-fold increase, <it>P </it>< 0.01). No significant systematic toxicities were observed.</p> <p>Conclusions</p> <p>Combination gene therapy with AdhTERTHRP/IAA and AdCMVmIL-12 could significantly inhibit tumor growth and improve host survival in LLC model, without significant systemic adverse effects.</p
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