• Title/Summary/Keyword: role of laboratory work

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Bacterial Population in Intestines of Litopenaeus vannamei Fed Different Probiotics or Probiotic SupernatantS

  • Sha, Yujie;Liu, Mei;Wang, Baojie;Jiang, Keyong;Qi, Cancan;Wang, Lei
    • Journal of Microbiology and Biotechnology
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    • v.26 no.10
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    • pp.1736-1745
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    • 2016
  • The interactions of microbiota in the gut play an important role in promoting or maintaining the health of hosts. In this study, in order to investigate and compare the effects of dietary supplementation with Lactobacillus pentosus HC-2 (HC-2), Enterococcus faecium NRW-2, or the bacteria-free supernatant of a HC-2 culture on the bacterial composition of Litopenaeus vannamei, Illumina sequencing of the V1-V2 region of the 16S rRNA gene was used. The results showed that unique species exclusively existed in specific dietary groups, and the abundance of Actinobacteria was significantly increased in the intestinal bacterial community of shrimp fed with the bacteria-free supernatant of an HC-2 culture compared with the control. In addition, the histology of intestines of the shrimp from the four dietary groups was also described, but no obvious improvements in the intestinal histology were observed. The findings in this work will help to promote the understanding of the roles of intestinal bacteria in shrimps when fed with probiotics or probiotic supernatant.

The necrotroph Botrytis cinerea promotes disease development in Panax ginseng by manipulating plant defense signals and antifungal metabolites degradation

  • Chen, Huchen;Zhang, Shuhan;He, Shengnan;A, Runa;Wang, Mingyang;Liu, Shouan
    • Journal of Ginseng Research
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    • v.46 no.6
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    • pp.790-800
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    • 2022
  • Background: Panax ginseng Meyer is one of the most valuable medicinal plants which is enriched in anti-microbe secondary metabolites and widely used in traditional medicine. Botrytis cinerea is a necrotrophic fungus that causes gray mold disease in a broad range of hosts. B. cinerea could overcome the ginseng defense and cause serious leaf and root diseases with unknown mechanism. Methods: We conducted simultaneous transcriptomic and metabolomic analysis of the host to investigate the defense response of ginseng affected by B. cinerea. The gene deletion and replacement were then performed to study the pathogenic gene in B. cinerea during ginseng - fungi interaction. Results: Upon B. cinerea infection, ginseng defense responses were switched from the activation to repression, thus the expression of many defense genes decreased and the biosynthesis of antifungal metabolites were reduced. Particularly, ginseng metabolites like kaempferol, quercetin and luteolin which could inhibit fungi growth were decreased after B. cinerea infection. B. cinerea quercetin dioxygenase (Qdo) involved in catalyzing flavonoids degradation and ∆BcQdo mutants showed increased substrates accumulation and reduced disease development. Conclusion: This work indicates the flavonoids play a role in ginseng defense and BcQdo involves in B. cinerea virulence towards the P. ginseng. B. cinerea promotes disease development in ginseng by suppressing of defense related genes expression and reduction of antifungal metabolites biosynthesis.

Radiative Role of Clouds on the Earth Surface Energy Balance (지표 에너지 수지에 미치는 구름의 복사 역할)

  • Hong, Sung-Chul;Chung, Ii-Ung;Kim, Hyung-Jin;Lee, Jae-Bum;Oh, Sung-Nam
    • Journal of Environmental Science International
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    • v.16 no.3
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    • pp.261-267
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    • 2007
  • In this study, the Slab Ocean Model (SOM) is coupled with an Atmospheric General Circulation Model (AGCM) which developed in University of Kangnung based on the land surface model of Biosphere-Atmosphere Transfer Scheme (BATS). The purposes of this study are to understand radiative role of clouds considering of the atmospheric feedback, and to compare the Clouds Radiative Forcing (CRF) come from the analyses using the clear-cloud sky method and CGCM. The new CGCM was integrated by using two sets of the clouds with radiative role (EXP-A) and without radiative role (EXP-B). Clouds in this two cases show the negative effect $-26.0\;Wm^{-2}$ of difference of radiation budget at top of atmosphere (TOA). The annual global means radiation budget of this simulation at TOA is larger than the estimations ($-17.0 Wm^{-2}$) came from Earth Radiation Budget Experiment (ERBE). The work showed the surface negative effect with $-18.6 Wm^{-2}$ in the two different simulations of CRF. Otherwise, sensible heat flux in the simulation shows a great contribution with positive forcing of $+24.4 Wm^{-2}$. It is found that cooling effect to the surface temperature due to radiative role of clouds is about $7.5^{\circ}C$. From this study it could make an accurate of the different CRF estimation considering either feedback of EXP-B or not EXP-A under clear-sky and cloud-sky conditions respectively at TOA. This result clearly shows its difference of CRF $-11.1 Wm^{-2}$.

Systematizing Information Use to Address Determinants of Health Worker Health in South Africa: A Cross-sectional Mixed Method Study

  • Muzimkhulu Zungu;Annalee Yassi ;Jonathan Ramodike;Kuku Voyi;Karen Lockhart;David Jones;Spo Kgalamono;Nkululeko Thunzi;Jerry Spiegel
    • Safety and Health at Work
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    • v.14 no.4
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    • pp.368-374
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    • 2023
  • Background: Recognizing that access to safe and healthy working conditions is a human right, the World Health Organization (WHO) calls for specific occupational safety and health (OSH) programs for health workers (HWs). The WHO health systems' building blocks, and the International Labour Organization (ILO), highlight the importance of information as part of effective systems. This study examined how OSH stakeholders access, use, and value an occupational health information system (OHIS). Methods: A cross-sectional survey of OSH stakeholders was conducted as part of a larger quasi experimental study in four teaching hospitals. The study hospitals and participants were purposefully selected and data collected using a modified questionnaire with both closed and open-ended questions. Quantitative analysis was conducted and themes identified for qualitative analysis. Ethics approval was provided by the University of Pretoria and University of British Columbia. Results: There were 71 participants comprised of hospital managers, health and safety representatives, trade unions representatives and OSH professionals. At least 42% reported poor accessibility and poor timeliness of OHIS for decision-making. Only 50% had access to computers and 27% reported poor computer skills. When existing, OHIS was poorly organized and needed upgrades, with 85% reporting the need for significant reforms. Only 45% reported use of OHIS for decision-making in their OSH role. Conclusion: Given the gap in access and utilization of information needed to protect worker's rights to a safe and healthy workplace, more attention is warranted to OHIS development and use as well as education and training in South Africa and beyond.

Causes of Sensori-Neural Hearing Impairment in Korean Children (감음신경성난청(感音神經性難聽)의 원인(原因)에 관(關)하여)

  • Rhee, Kyu-Shik;Kim, Young-Soon;Kwon, Do-Ha;Kim, Joo-Ho;Kwon, Yo-Han;Rhee, Tae-Yung;Paik, Choon-Ki;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.9 no.1
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    • pp.55-64
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    • 1976
  • This paper presents the results of a survey for the causes of sensori-neural hearing impairment in Korea, The subjects were 1,676 children of total 2,928 enrolled in 16 Deaf Schools; two schools in each area of Seoul, Busan, Kyoungbook, Kyoungnam, Kyounggi and Chunbug, and each one in Chungnam, Chungbug, Chunnam and Jaeju. The data were collected by questionaire with 28 items distributed to their parents. The filling in the check lists were performed by their class teachers, interviewer, for 18 months from September, 1975 to february, 1976. The questionable or missed problems were reaffirmed. The results obtained were as follows. Most of the reasons, 78.5% were acquired characters that could be developed during pregnant period, the time of delivery and the time of after birth. The pure hereditary reasons except the cases complexed with one or two were only 11.3%. Those who could not be defined with any reasons were 10.2%. Among the acquired causes, 5.8% of total subjects were developed for pregnancy: 3.3%, during delivery; and 69.7%, after birth. In the pregnant period, the drug intoxications were 2.4% of total subjects, several diseases such as influenja, bleeding, surgical operation, venereal diseases and rubella etc. were about one percent, and the accompanied with some symptoms of pregnancy intoxication and traumatic events were 2.4%, During time, the cases with delayed rhythmical pain were 16 persons, the immaturities were 11, the asphyxial cases were nine, the errors of forceps delivery were seven, the cases of low body weight inspite of full term were four, the cases with cesarian section were three, the head injuries were two, and the accompanied with three kinds of above reasons were three. During after birth, the cases with acute communicable diseases were 35.4% of total subjects, the fever unknown origin were 16.1%, the chronic otitis media were 3.7%, the meningitis were 3.5%, the gastric and nutritional diseases were 3.5%, the drug intoxications were 4.8%, the blood diseases were 0.3% and the other causes were 2.2%. Here by acute communicable diseases, some importants were measle, 10.1% of total subjects; meningitis, 7.3%; convulsion with some reasons, 4.9%; poliomyelitis. 3.2%; encephalitis, 2.4%; and mumps, rubella, pertusis, scarlet fever, and small pox were somewhat played a role in. Among 59 cases with train diseases, 53 were concussion by the accidents, such as traffic and falling or sliping down etc., the cerebral paralysis and hydrocephalus were two, respectively. And the blood diseases were severe newjaundice in all five cases. If we were summarized with the above mentioned, most of the hearing impairments were introduced by the combined reasons with familial or hereditary factors and the acquired, than by a simple disease. Among the congenital or hereditary hearing impairments classified to now a day, we suppose that the many cases with the acquired causes during pregnancy, delivery and after birth were complexed. Subsequently, the maternal and child health should be more and more developed in our country, also.

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Thermal study of a scanning beam in granular flow target

  • Ping Lin;Yuanshuai Qin;Changwei Hao;Yuan Tian ;Jiangfeng Wan ;Huan Jia ;Lei Yang ;Wenshan Duan ;Han-Jie Cai ;Sheng Zhang
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4310-4321
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    • 2022
  • The concept of dense granular-flow target (DGT) for the China Initiative Accelerator Driven Subcritical system (CiADS) is an attractive choice for high heat removal ability, low chemical toxicity, and radiotoxicity. A wobbling hollow beam is proposed to enhance the homogeneity of temperature rise of flowing particles in beam-target coupling zone. In this paper, the design procedure of target and beam parameters was discussed firstly. Then we simulated the heat deposition and transfer of the scanning beam in DGT to study the effect of beam parameters. The results show the flux density of proton beam plays a crucial role in the distribution of temperature rise while the contributions from scanning frequency heat transfer are also obvious. Moreover, heat transfer in transversal directions is insignificant, resulting in a low heat flux towards the sidewalls of DGT. This work not only contributes to the design of DGT, but also beneficial for understanding the beam-target coupling in porous materials.

An Efficient Markov Chain Based Channel Model for 6G Enabled Massive Internet of Things

  • Yang, Wei;Jing, Xiaojun;Huang, Hai;Zhu, Chunsheng;Jiang, Qiaojie;Xie, Dongliang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.4203-4223
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    • 2021
  • Accelerated by the Internet of Things (IoT), the need for further technical innovations and developments within wireless communications beyond the fifth generation (B5G) networks is up-and-coming in the past few years. High altitude platform station (HAPS) communication is expected to achieve such high levels that, with high data transfer rates and low latency, millions of devices and applications can work seamlessly. The HAPS has emerged as an indispensable component of next-generations of wireless networks, which will therefore play an important role in promoting massive IoT interconnectivity with 6G. The performance of communication and key technology mainly depend on the characteristic of channel, thus we propose an efficient Markov chain based channel model, then analyze the HAPS communication system's uplink capability and swing effect through experiments. According to the simulation results, the efficacy of the proposed scheme is proven to meet the requirements of ubiquitous connectivity in future IoT enabled by 6G.

Free vibration responses of nonlinear FG-CNT distribution in a polymer matrix

  • Zerrouki, Rachid;Hamidi, Ahmed;Tlidji, Youcef;Karas, Abdelkader;Zidour, Mohamed;Tounsi, Abdelouahed
    • Smart Structures and Systems
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    • v.30 no.2
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    • pp.135-143
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    • 2022
  • The object of this paper is to investigate the free vibration behavior under the effect of carbon nanotube distribution in functionally graded carbon nanotube-reinforced composite (FG-CNTRC) by using higher-order shear deformation theories. In this work, we present a novel distribution method for carbon nanotubes in the polymer matrix by using a new exponential power law distribution of carbon nanotube volume fraction. It is assumed that the SWCNTs are aligned along the beam axial direction and the distribution of the SWCNTs may vary through the thickness of the beam with different patterns of reinforcement. The rule of mixtures is used in order to obtain material properties of the CNTRC beams. Hamilton's principle is used in deriving the equations of motion. The validity of the free Vibration results is examined by comparing them with those of the known data in the literature. The results that obtained indicate that the carbon nanotube volume fraction distribution play a very important role on the free vibrations characteristics of the CNTRC beam.

Simulating the influence of pore shape on the Brazilian tensile strength of concrete specimens using PFC2D

  • Haeri, Hadi;Sarfarazi, Vahab;Zhu, Zheming;Marji, Mohammad Fatehi
    • Computers and Concrete
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    • v.22 no.5
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    • pp.469-479
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    • 2018
  • The Brazilian tensile strength of concrete samples is a key parameter in fracture mechanics since it may significantly change the quality of concrete materials and their mechanical behaviors. It is well known that porosity is one of the most often used physical indices to predict concrete mechanical properties. In the present work the influence of porosity shape on concrete tensile strength characteristics is studied, using a bonded particle model. Firstly numerical model was calibrated by Brazilian experimental results and uniaxial test out puts. Secondly, Brazilian models consisting various pore shapes were simulated and numerically tested at a constant speed of 0.016 mm/s. The results show that pore shape has important effects on the failure pattern. It is shown that the pore shape may play an important role in the cracks initiation and propagation during the loading process which in turn influence on the tensile strength of the concrete samples. It has also been shown that the pore size mainly affects the ratio of uniaxial compressive strength to that of the tensile one in the simulated material samples.

Key Layouts of the 5,000 ton' New Scientific Research Vessel of KIOST (5,000톤급 대형 해양과학연구선 설계 특성)

  • Park, Cheong Kee
    • Ocean and Polar Research
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    • v.37 no.3
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    • pp.235-247
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    • 2015
  • The main purpose of procuring the oceanographic research vessel with state-of-the-art technology is to provide a floating laboratory to conduct field work on the global oceans. The vessel should be properly utilized to locate and evaluate unexplored natural resources as well as to contribute international efforts to better understand and manage global environmental issues. Top priorities in the vessel design are high safety standards, noise and vibration control efficiency, and effective application of research equipment. For the accomplishment of all activities, the vessel length over all should be extended ~100 m with a gross tonnage of ~5,900 ton. In particular, the dynamic positioning system II will essentially operate at sea state 6. The high efficiency emissions reduction system will also be adopted in preparation for entry into force of 3rd exhaust emission control (Tier III). About 130 navigational and scientific instruments will be installed. The final design and model test of the new research vessel were reviewed and completed, respectively, in 2014. Currently, the ship is being built on schedule and expected to be delivered in December 2015. Within the near future, the new vessel will assume the role of carrying out multidisciplinary oceanographic researches of the highest standards in a technologically advanced and environment friendly manner.