Incompatibility between pregnancy and educational projects,from the perspective of socially vulnerable adolescent women and men in Mexico     

Lourdes Campero  Alejandra Benítez  Erika Atienzo  Guillermo González  Eréndira Marín 《Gender and education》2014,26(2):151-167

Research focused on adolescent pregnancy reports that this event acquires significance and has different consequences according to the context and social subjects who experience it. In this study, by means of a sample formed by adolescent women and men who are socially vulnerable in Mexico, with and without a history of pregnancy, we can see how this reproductive event turns into a factor of educational vulnerability and how their possibilities and expectations with respect to continuing in school are determined in a differentiated manner, according to gender. The findings show that adolescent pregnancy in vulnerable sectors is scarcely compatible with educational projects and that possibilities and expectations to continue in or re-enter the school system are determined by gender differences; these usually lead to fewer opportunities for adolescent women to return to school during or after pregnancy.  相似文献   

Fungal diversity in adult date palm (Phoenix dactylifera L.) revealed by culture-dependent and culture-independent approaches     

Ines Ben Chobba  Amine Elleuch  Imen Ayadi  Lamia Khannous  Ahmed Namsi  Frederique Cerqueira  Noureddine Drira  Néji Gharsallah  Tatiana Vallaeys 《Journal of Zhejiang University. Science. B》2013,14(12):1084-1099

Endophytic flora plays a vital role in the colonization and survival of host plants, especially in harsh environments, such as arid regions. This flora may, however, contain pathogenic species responsible for various troublesome host diseases. The present study is aimed at investigating the diversity of both cultivable and non-cultivable endophytic fungal floras in the internal tissues (roots and leaves) of Tunisian date palm trees (Phoenix dactylifera). Accordingly, 13 isolates from both root and leaf samples, exhibiting distinct colony morphology, were selected from potato dextrose agar (PDA) medium and identified by a sequence match search wherein their 18S–28S internal transcribed spacer (ITS) sequences were compared to those available in public databases. These findings revealed that the cultivable root and leaf isolates fell into two groups, namely Nectriaceae and Pleosporaceae. Additionally, total DNA from palm roots and leaves was further extracted and ITS fragments were amplified. Restriction fragment length polymorphism (RFLP) analysis of the ITS from 200 fungal clones (leaves: 100; roots: 100) using HaeIII restriction enzyme revealed 13 distinct patterns that were further sequenced and led to the identification of Alternaria, Cladosporium, Davidiella (Cladosporium teleomorph), Pythium, Curvularia, and uncharacterized fungal endophytes. Both approaches confirmed that while the roots were predominantly colonized by Fusaria (members of the Nectriaceae family), the leaves were essentially colonized by Alternaria (members of the Pleosporaceae family). Overall, the findings of the present study constitute, to the authors’ knowledge, the first extensive report on the diversity of endophytic fungal flora associated with date palm trees (P. dactylifera).  相似文献   

The “Pacifica” decision: Broadcasting and free expression     

Federal communications commission  Ben F. Waple Secretary 《广播与电子媒介杂志》2013,57(2):177-182

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组合压气机中尾迹与势流同频/异频干涉的叠加特性     

赵奔  杨策  老大中  张卫正 《情报工程》2013,(4):477-485

为揭示多级压气机中上下游叶轮对中间叶片叠加气动影响特性,阐述不同叠加干涉情况下下游叶轮进气角度变化,采用数值方法模拟了一级轴流和一级离心组成的组合压气机非定常流场。详细讨论了上游动叶尾迹和下游动叶势流对中间导流叶栅段气流非定常流动的异频和同频叠加干涉特性,依据计算结果,直观地展示了静叶通道中两种干涉间相互激励和抑制作用的位置和时间,与数学公式的推导结果相互印证。研究结果表明:当上下游动叶对中间静叶段异频干涉时,干涉的激励、抑制区域的轴向位置随时间发生变化;当上下游动叶对中间静叶干涉频率相同时,干涉的相互激励、抑制区域的轴向位置不随时间发生变化,但干涉的激励、抑制区域的轴向位置受时序位置影响。另外,上游动叶尾迹与下游离心叶轮势流的不同叠加情况,决定着下游离心叶轮进口相对气流角的大小及波动幅值。   相似文献   

Solid-state intramolecular motions in continuous fibers driven by ambient humidity for fluorescent sensors     

Yunmeng Jiang  Yanhua Cheng  Shunjie Liu  Haoke Zhang  Xiaoyan Zheng  Ming Chen  Michidmaa Khorloo  Hengxue Xiang  Ben Zhong Tang  Meifang Zhu 《国家科学评论(英文版)》2021,8(4)

One striking feature of molecular rotors is their ability to change conformation with detectable optical signals through molecular motion when stimulated. However, due to the strong intermolecular interactions, synthetic molecular rotors have often relied on fluid environments. Here, we take advantage of the solid-state intramolecular motion of aggregation-induced emission (AIE) molecular rotors and one-dimensional fibers, developing highly sensitive optical fiber sensors that respond to ambient humidity rapidly and reversibly with observable chromatic fluorescence change. Moisture environments induce the swelling of the polymer fibers, activating intramolecular motions of AIE molecules to result in red-shifted fluorescence and linear response to ambient humidity. In this case, polymer fiber provides a process-friendly architecture and a physically tunable medium for the embedded AIE molecules to manipulate their fluorescence response characteristics. Assembly of sensor fibers could be built into hierarchical structures, which are adaptive to diverse-configuration for spatial-temporal humidity mapping, and suitable for device integration to build light-emitting sensors as well as touchless positioning interfaces for intelligence systems.  相似文献   

To Sign or Not to Sign? The Impact of Encouraging Infants to Gesture on Infant Language and Maternal Mind‐Mindedness     

Elizabeth Kirk  Neil Howlett  Karen J. Pine  Ben Fletcher 《Child development》2013,84(2):574-590

Findings are presented from the first randomized control trial of the effects of encouraging symbolic gesture (or “baby sign”) on infant language, following 40 infants from age 8 months to 20 months. Half of the mothers were trained to model a target set of gestures to their infants. Frequent measures were taken of infant language development and dyadic interactions were scrutinized to assess mind‐mindedness. Infants exposed to gesture did not differ from control conditions on language outcomes; thus, no support was found for previous claims that encouraging gesturing with infants accelerates linguistic development. Microgenetic analysis revealed mothers in the gesture training conditions were more responsive to their infants' nonverbal cues and encouraged more independent action by their infant.  相似文献   

Education recoded: policy mobilities in the international ‘learning to code’ agenda     

Ben Williamson  Annika Bergviken Rensfeldt  Catarina Player-Koro  Neil Selwyn 《教育政策杂志》2013,28(5):705-725

Abstract

Education policy increasingly takes place across borders and sectors, involving a variety of both human and nonhuman actors. This comparative policy paper traces the ‘policy mobilities,’ ‘fast policy’ processes and distributed ‘policy assemblages’ that have led to the introduction of new computer programming practices into schools and curricula in England, Sweden and Australia. Across the three contexts, government advisors and ministers, venture capital firms, think tanks and philanthropic foundations, non-profit organizations and commercial companies alike have promoted computer programming in schools according to a variety of purposes, aspirations, and commitments. This paper maps and traces the evolution of the organizational networks in each country in order to provide a comparative analysis of computing in schools as an exemplar of accelerated, transnationalizing policy mobility. The analysis demonstrates how computing in schools policy has been assembled through considerable effort to create alignments between diverse actors, the production and circulation of material objects, significant cross-border movement of ideas, people and devices, and the creation of strategic partnerships between government centres and commercial vendors. Computing in schools exemplifies how modern education policy and governance is accomplished through sprawling assemblages of actors, events, materials, money and technologies that move across social, governmental and geographical boundaries.  相似文献   

Fear of Falling and Older Adult Peer Production of Audio-Visual Discussion Material     

Cathy Bailey  Karen King  Ben Dromey  Ciaran Wynne 《Educational gerontology》2013,39(9):781-797

A growing body of work suggests that negative stereotypes of, and associations between, falling, fear of falling, and ageing, may mean that older adults reject falls information and advice. Against a widely accepted backdrop of demographic ageing in Europe and that alleviating the impacts of falls and fear of falling are pressing health care matters, this is a critical issue. This paper describes a recent peer learning and sharing strategy that set out to iteratively produce a series of short audio visual discussion programs on falling and fear of falling. Key outcomes included older adults appreciating peer group sharing as an acceptable way of opening up the silence surrounding falls incidences, enjoying participating in a problem solving strategy, and emphasizing that falls prevention is not just their responsibility. Outcomes suggest that peer learning and sharing are valuable falls and fear of falling support strategies.  相似文献   

核心稳定性在人体运动中的作用   总被引：1，自引：0，他引：1  

周瑾 《北京体育大学学报》2008,31(12)

在体育运动中,核心的主要作用是稳定身体、是肌肉发力的基础,这一点日益得到公认。从跑步到投掷等各项体育运动中,稳定的核心是有效发挥人体生物力学功能的关键因素,从而使肌肉发力最大化并最大限度减小关节负荷。我们将核心肌群的功能理解为中枢神经系统预设的程序,这个程序整合局部的、单关节和多个关节上的肌群活动,在保持整体稳定的同时完成体育动作。近端的稳定性是远端灵活性的基础,在这个基础上可以建立从近端向远端的发力模式,并且可以通过肌群的协同作用力在完成远端动作的同时保护远端关节。评估动态核心能力是一项重要任务,其中包括对躯干特定功能和三维运动能力的评估。运动康复训练计划应该包括核心能力的重建,并且应该将核心视为远端肢体运动的基础。  相似文献   

牛膝中植物甾酮类成分的研究进展   总被引：4，自引：0，他引：4  

郑义哲  刘本 《科技通报》2008,24(6)

植物甾酮类成分是怀牛膝的主要有效成分,具有调节糖代谢、抗脂质过氧化、保护内皮细胞、调节基因表达、影响细胞繁殖等作用。本文综述了近几年对怀牛膝中植物甾酮类成分的研究情况,就其结构性质、分离分析和药理作用作一概述。  相似文献