Production of carotenoid sarcinaxanthin by Kocuria palustris isolated from Northeastern Brazil Caatinga soil and their antioxidant and photoprotective activities

BackgroundThis study aimed to produce carotenoids of two bacterial strains obtained and isolated from Caatinga soil in Northeastern Brazil and to evaluate their antioxidant and photoprotective activities. The morphological identification of bacteria was performed by Gram staining and molecularly confirmed through the 16S rRNA gene. The production of carotenoids was performed on two 2³ factorial designs to analyze the influence of independent variables (temperature range, luminosity, agitation, spiral presence, and bacterial isolate type) for maximum carotenoid yield. The selected condition has been transferred to a bioreactor (10L). The identification of carotenoids was performed by liquid chromatography (HPLC) and mass spectrometry (LC-MS). Antioxidant activity was determined by inhibiting the β-carotene/linoleic acid system and the effectiveness as sunscreen was measured through its sun protection factor (SPF).ResultsThe results revealed that the isolates FT-7.22 and FT-5.12 were identified as Kocuria palustris; producers of a rare C50 carotenoid sarcinaxanthin. This is the first report on the production of carotenoids by this species from the Caatinga Domain. The pigment that was obtained from the Tryptic Soy Broth (TSB) medium in the best conditions of the factorial designs (increased agitation, aeration, and light exposure) exhibited a significant increase in the carotenoid production. The isolated FT-7.22 reached a higher sarcinaxanthin concentration (112,480 μg/L), and it exhibited promising antioxidant (76.53 ± 0.09%) and photoprotective activities (SPF = 9.36 ± 0.52).ConclusionsThis study demonstrated the ability of K. palustris to produce carotenoid sarcinaxanthin with antioxidant and photoprotective activities so that it can be applied in cosmetic formulations.How to cite: Mendes-Silva TCD, Vidal EE, de Souza RFR, et al. Production of carotenoid sarcinaxanthin by Kocuria palustris isolated from Northeastern Brazil Caatinga soil and their antioxidant and photoprotective activities. Electron J Biotechnol 2021;53. https://doi.org/10.1016/j.ejbt.2021.05.004     

足球运动员比赛应对方式特点的研究

摘要:采用描述性统计分析、平均数差异检验、单因素方差分析、多因素方差分析等方法对508名足球运动员的比赛应对方式,在运动等级、年龄、性别等方面的差异进行了考察。结论:总体上,我国足球运动员在比赛中遇到应激事件时,能够积极、成熟的应对。除了注重情绪的应对在年龄变量上没有显著差异外,两种应对均在年龄、性别和运动等级上表现出显著差异。男运动员比女运动员更多地选择注重问题的应对,女运动员比男运动员更多地选择注重情绪的应对;年长的运动员比年轻运动员更多的选择注重问题的应对;运动等级较高的运动员比运动等级较低的运动员更多的选择注重问题的应对。     

基于部门利益下的集体决策与投票博弈——兼论人事管理中的集体决策逻辑

部门利益下的集体决策与投票由于影响因素的不同可能会得出许多不同的结果。在建立基于利益相关部门之间、利益相关部门与其他部门之间、利益无关的各个部门之间视角下的假设基础上,讨论了这三种情况下对集体决策与投票的影响模型,分析其在实际运行中的可能性。通过对三种博弈模型的分析与归纳,探讨了公共部门人事管理中的集体决策逻辑。     

A simulated learning environment of history games for enhancing players’ cultural awareness

This research attempted to create the historical context of Southern Taiwan in the late nineteenth century based on the martial art novel “Xiao-Mao” (Pussy) by designing a role-play digital game “Taiwan Epic Game” about the war time; in which, Taiwanese history, geography, and culture are presented in an innovative way with virtual scenarios. Questionnaire surveys were conducted to investigate the effects of the digital game. The simulationist immersion premises were chosen to be the primary concern, with which the designers should pursue the supreme creation of situation, character, setting, and system. The results showed that the game can effectively enhance players' cognitive growth, as well as cultural awareness in terms of the sense of existence of the environment, local culture, folk arts, faith and festivals, and architectural characteristics. It can be concluded that the three-dimensional simulated learning environment created in the digital game can successfully merge “reality” and “virtuality.”     

Pre-service teachers’ perceptions on TPACK development after designing educational games

This qualitative case study aimed to investigate Early Childhood Education (ECE) pre-service teachers’ perception of development in their technological, pedagogical, content knowledge (TPACK) after designing educational computer games for young children. Participants included 21 ECE pre-service teachers enrolled in the course Instructional Technology and Material Design. The data were collected through focus group interviews, observations, and journals. The results indicated a perceived improvement in TPACK. Moreover, participants described initial difficulty designing educational computer games since they had limited technological knowledge (TK), design knowledge (DK), or experience designing educational computer games (TPACK). However, during the game design, specific TPACK was disseminated, and participants reported increased abilities in using technology and designing computer games for educational purposes.     

短文听写题型不同的作答方式对CET-4考生答题过程的影响研究

为探讨作答方式对考生答题过程的影响,验证听写题型的效度,采用即时追述和访谈的研究方法,对36名EFL考生短文听写时的答题过程进行分析。研究表明:虽然四组考生听写的总体得分差异并不显著,但在答题过程中使用母语作答的第三组考生使用了更多的策略,能较好地理解输入的信息和短文大意,并受与构念无关的因素影响较小,而第四组受试在没有语境的情况下,对语义的理解不深刻,使用的策略最少,测验材料没有较好的效度和区分度。另外,四组考生的实际答题表现与听写的指令要求也并不一致,表明指令的合理性存在问题。     

酌定情节裁量规范化和动态化研究

酌定情节是刑法规范文本的重要组成部分,酌定情节裁量是量刑规范化改革的重要内容。目前,酌定情节的裁量面临着酌定情节内涵不清、适用规则不明、裁量机制不健全等困境。酌定情节裁量规范化和动态化的提出,旨在化解酌定情节裁量困境,为正当有序地适用酌定情节开辟新的道路。从静态的规范思维分析,酌定情节内涵及其适用的规范化是应有之义,即酌定情节是特定时空下基于犯罪人、犯罪行为、被害人及其行为、刑事政策等能够反映犯罪整体严重程度的事实;从动态的司法运作分析,在司法场域内建立开放、平等和正当的动态博弈机制,乃是酌定情节裁量过程和结果正当合理化的机制保障。     

维果茨基创造力观及其教育意义

维果茨基基于社会文化的视角,借助最近发展区理论阐述了创造力基本内容,分析了游戏、白日梦及学校对儿童创造力培养的积极意义和对中小学教育的借鉴意义。     

大学生就业歧视的各方博弈分析及对策

大学生就业过程中面临诸多歧视,性别歧视、地域歧视、学校歧视、身份歧视等。大学毕业生就业求职是学生、用人单位、政府三方参与的博弈过程,通过构建学生与用人单位以及用人单位与政府之间的博弈模型并对模型求解,根据对混合纳什均衡解的分析,提出治理大学生就业市场中就业歧视行为的对策和建议。     

拟变分不等式在广义博弈论中的应用

由于拟变分不等式的特殊结构以及解稳定性的讨论,在此文中考虑有限广义博弈均衡点的存在性基础上,对可行策略映射φ的微小扰动后均衡点的稳定性.