91 research outputs found

    Genetic Diversity and Relationships in Cocksfoot by Molecular Markers

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    Cocksfoot (Dactylis glomerata L.) originated from the Northern Hemisphere, including Eurasia and North Africa. It is widely distributed in temperate climates and has been widely used in the world more than 100 years, especially in North America, Europe and Japan. Genetic variability of cocksfoot had been detected by RAPD (Kölliker et al. 1999), and the correlation between genome size of natural populations of cocksfoot and location altitude has been analyzed by AFLP (Reeves et al. 1999). To date, information on the genetic diversity of cocksfoot at the molecular level is still scarce, This study is the first to combine the genetic diversity research of cocksfoot with SRAP (Sequence Related Amplified Polymorphism) and ISSR (inter-simple sequence repeat) markers evaluating genetic diversity among 45 populations of cocksfoot collected from eight different countries from four continents. The objectives of the research were: (1) to evaluate the levels and patterns of genetic diversity about cocksfoot; (2) to compare ISSR and SRAP markers for the molecular characterization of cocksfoot, including the evaluation of the degree of polymorphism generated from each technique as a pre-requisite for (3) their applicability to formulate appropriate strategies for the conservation and utilization of the wild cocksfoot genetic resources available and to discuss scientific breeding measures according to the status of cultivars

    Learning-based robotic grasping: A review

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    As personalization technology increasingly orchestrates individualized shopping or marketing experiences in industries such as logistics, fast-moving consumer goods, and food delivery, these sectors require flexible solutions that can automate object grasping for unknown or unseen objects without much modification or downtime. Most solutions in the market are based on traditional object recognition and are, therefore, not suitable for grasping unknown objects with varying shapes and textures. Adequate learning policies enable robotic grasping to accommodate high-mix and low-volume manufacturing scenarios. In this paper, we review the recent development of learning-based robotic grasping techniques from a corpus of over 150 papers. In addition to addressing the current achievements from researchers all over the world, we also point out the gaps and challenges faced in AI-enabled grasping, which hinder robotization in the aforementioned industries. In addition to 3D object segmentation and learning-based grasping benchmarks, we have also performed a comprehensive market survey regarding tactile sensors and robot skin. Furthermore, we reviewed the latest literature on how sensor feedback can be trained by a learning model to provide valid inputs for grasping stability. Finally, learning-based soft gripping is evaluated as soft grippers can accommodate objects of various sizes and shapes and can even handle fragile objects. In general, robotic grasping can achieve higher flexibility and adaptability, when equipped with learning algorithms

    Willingness of people living with HIV to receive a second COVID-19 booster dose: a multicenter cross-sectional study in China

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    BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has significantly affected the global population, with People Living with HIV (PLWH) being particularly vulnerable due to their compromised immune systems. Although vaccination is a crucial preventative measure against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, little is understood about the willingness of PLWH to receive a second COVID-19 booster dose and the factors that may influence this decision. This study investigates the willingness of PLWH in China to receive a second COVID-19 booster dose and its influencing factors, comparing these with a group of healthy individuals.MethodsA multicenter cross-sectional study was conducted across five Chinese cities, namely, Beijing, Tianjin, Zhengzhou, Hohhot, and Harbin. Participants were recruited through five community-based organizations. Data were collected via participant self-administered questionnaires included demographic information, willingness to receive a second COVID-19 booster dose, and knowledge about HIV and COVID-19 vaccination. Factors influencing vaccination willingness were identified using multivariable logistic regression analyzes.ResultsA total of 156 PLWH and 151 healthy individuals were included in the study. After adjusting for potential confounders, it was found that PLWH demonstrated a lower willingness to receive a second COVID-19 booster dose compared to healthy individuals (77.6% vs. 88.7%, p = 0.009). Lower willingness was associated with HIV positive status (Adjusted Odds Ratio [AOR]: 0.39, 95%CI: 0.20, 0.75), perceived barriers (AOR: 0.05, 95%CI: 0.01, 0.26), and perceived severity (AOR: 0.32, 95%CI: 0.12, 0.90).ConclusionPLWH in China demonstrated a lower willingness to receive a second COVID-19 booster dose compared to healthy individuals. The findings suggest that perceptions and understanding of the COVID-19 vaccination and its necessity for protection against SARS-CoV-2 could influence this willingness. Efforts should be made to strengthen and disseminate knowledge about HIV and COVID-19 vaccinations among this population. In addition, developing interventions and policies that target specific subgroups and address misconceptions about vaccination could be instrumental in improving vaccination rates among PLWH

    Gene cloning, expression, and characterization of two endo-xylanases from Bacillus velezensis and Streptomyces rochei, and their application in xylooligosaccharide production

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    Endo-xylanase hydrolyzing xylan in cellulosic residues releasing xylobiose as the major product at neutral pH are desirable in the substitute sweeteners industry. In this study, two endo-xylanases were obtained from Streptomyces rochei and Bacillus velezensis. SrocXyn10 showed the highest identity of 77.22%, with a reported endo-xylanase. The optimum reaction temperature and pH of rSrocXyn10-Ec were pH 7.0 and 60°C, with remarkable stability at 45°C or pHs ranging from 4.5 to 11.0. rBvelXyn11-Ec was most active at pH 6.0 and 50°C, and was stable at 35°C or pH 3.5 to 10.5. Both rSrocXyn10-Ec and rBvelXyn11-Ec showed specific enzyme activities on wheat arabinoxylan (685.83 ± 13.82 and 2809.89 ± 21.26 U/mg, respectively), with no enzyme activity on non-xylan substrates. The Vmax of rSrocXyn10-Ec and rBvelXyn11-Ec were 467.86 U mg−1 and 3067.68 U mg−1, respectively. The determined Km values of rSrocXyn10-Ec and rBvelXyn11-Ec were 3.08 g L−1 and 1.45 g L−1, respectively. The predominant product of the hydrolysis of alkaline extracts from bagasse, corncob, and bamboo by rSrocXyn10-Ec and rBvelXyn11-Ec were xylooligosaccharides. Interestingly, the xylobiose content in hydrolysates by rSrocXyn10-Ec was approximately 80%, which is higher than most reported endo-xylanases. rSrocXyn10-Ec and rBvelXyn11-Ec could be excellent candidates to produce xylooligosaccharides at neutral/near-neutral pHs. rSrocXyn10-Ec also has potential value in the production of xylobiose as a substitute sweetener

    ULK1 phosphorylates Exo70 to suppress breast cancer metastasis

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    乳腺癌是威胁女性生命健康的“头号杀手”,而远处转移是乳腺癌患者死亡的主要原因。因此,了解乳腺癌如何发动侵袭和转移,对于有效治疗乳腺癌、延长病人生存期具有重要意义。本研究中,该团队发现ULK1通过结合并磷酸化胞泌蛋白复合体关键亚基Exo70来抑制乳腺癌转移。ULK1对Exo70上Ser47,Ser59和Ser89位点的磷酸化,严重地削弱了Exo70的自身寡聚化和与其它胞外分泌复合体亚基的结合,进而减少了细胞运动伪足形成以及基质金属蛋白酶的分泌,从而抑制乳腺癌细胞的迁移和侵袭。该论文首次揭示了胞外分泌复合体重要成员Exo70在乳腺癌中受到ULK1和ERK1/2的双重磷酸化调控,从而使得乳腺癌细胞可以根据外环境来决定潜伏还是发动侵袭转移,为乳腺癌的治疗提供了新的理论基础。 本论文的通讯作者为占艳艳副教授、郭巍教授和胡天惠教授。医学院博士生毛丽媛、占艳艳副教授、吴斌博士和医学院博士生于强为共同第一作者。【Abstract】Increased expression of protein kinase ULK1 was reported to negatively correlate with breast cancer metastasis. Here we report that ULK1 suppresses the migration and invasion of human breast cancer cells. The suppressive effect is mediated through direct phosphorylation of Exo70, a key component of the exocyst complex. ULK1 phosphorylation inhibits Exo70 homo-oligomerization as well as its assembly to the exocyst complex, which are needed for cell protrusion formation and matrix metalloproteinases secretion during cell invasion. Reversely, upon growth factor stimulation, Exo70 is phosphorylated by ERK1/2, which in turn suppresses its phosphorylation by ULK1. Together, our study identifies Exo70 as a substrate of ULK1 that inhibits cancer metastasis, and demonstrates that two counteractive regulatory mechanisms are well orchestrated during tumor cell invasion.This work was supported by the grants from the National Natural Science Foundation of China (81572589, U1405228, 81472568, and 31770860), the Natural Science Foundation of Fujian grant (2017J06020, 2018J01400, 2017R1036-4, 2017R1036-6, 2016R1034-1, and 2016R1034-4), and the Xiamen Science and Technology grant (3502Z20159013) to Y.-y.Z. and T.H., and National Institute of Health R01 GM111128 to W.G.该论文的研究成果是在国家自然科学基金和福建省基金的资助下,与美国宾夕法尼亚大学和清华大学共同协作完成的

    Responses of sequential and hierarchical phenological events to warming and cooling in alpine meadows

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    Organisms' life cycles consist of hierarchical stages, from a single phenological stage (for example, flowering within a season), to vegetative and reproductive phases, to the total lifespan of the individual. Yet phenological events are typically studied in isolation, limiting our understanding of life history responses to climate change. Here, we reciprocally transfer plant communities along an elevation gradient to investigate plastic changes in the duration of sequential phenological events for six alpine species. We show that prolonged flowering leads to longer reproductive phases and activity periods when plants are moved to warmer locations. In contrast, shorter post-fruiting leaf and flowering stages led to shorter vegetative and reproductive phases, respectively, which resulted in shorter activity periods when plants were moved to cooler conditions. Therefore, phenological responses to warming and cooling do not simply mirror one another in the opposite direction, and low temperature may limit reproductive allocation in the alpine region

    DESIGN AND DEVELOPMENT OF SOFT ROBOTIC ARMS TOWARDS CLOSE HUMAN-ROBOT INTERACTION

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    Ph.DDOCTOR OF PHILOSOPHY (FOE

    On the use of imaginary faults in palaeostress analysis

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    The imaginary fault refers to the counterpart of a certain given fault that has a similar expression about the Wallace Bott hypothesis. It is included to further reduce the feasible fields for the principal stress directions using the right dihedra method. The given fault and its imaginary fault have a similar dip-slip sense under the extensional or compressional regime but, as proved in this paper, a different dip-slip sense under the strike-slip regime. Their relation in dip-slip sense does no change with the rotation of the coordinate system, thus making possible the general use in the reduction of the imaginary faults under any tectonic regime. A procedure for this use is proposed and applied to a real example to demonstrate the feasibility of this method. (C) 2017 Elsevier Ltd. All rights reserved
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