PCR技术在法医生物学中的应用

遗传学认为,DNA是人体性状及遗传变异的物质基础,它是遗传信息的携带者.DNA决定着我们的肤色、性别、身高、健康状况等个体特征.每个人的DNA都是不完全一样的.在法医学上,往往需要鉴别现场留下的物证是否属于犯罪嫌疑人.传统的方法主要是通过指纹、脚印、唇纹、化学物质等物证进行核对,这在一些情况下能起到作用.然而,有时候犯罪分子相当狡猾,或者现场被破坏的很严重,根本找不到上述痕迹.但是在理论上,只要犯罪分子在现场留下血渍、精斑、头发、阴毛、唾液等,通过分析其中的DNA,仍可查获真凶.另外,也可通过分析在现场找到的死者的残留物(如毛发、牙齿、骨骼等)中所含的DNA,来验明他们的真实身份.以前由于这些物证中DNA的含量甚微,再加上无法排除在分析时受到的干扰,DNA分析还或多或少是一种幻想.直到1985年,诺贝尔奖获得者Kary mullis发明了聚合酶链反应(polymerasechain reaction,PCR).再加上1988年Saiki对PCR的重大改进,才使DNA分析在法医学领域的应用取得了惊人的突破.所谓PCR,就是通过特定的DNA序列作为引物,在酶的作用下,经过几十次循环,使目的DNA得以快速复制、扩增,从而得到足以进行检测和分析的目的DNA片段.目的DNA(或称模板DNA)就好象是“轮子”,引物好象有汽车的“方向”,酶好象是“(?)力     

抗氧化剂补充在体育生物科学中运用方向的研究

概述了运动、自由基和抗氧化剂间的联系，总结了目前自由基生物学理论在体育生物科学中的研究运用方向以及各种抗氧化剂的补充情况。     

病原生物学课程整合中实验教学的融合与创新

为加快病原生物学课程整合,在实验教学中对实验教学的内容、教学场地及教学方法的选择、师资队伍建设等方面进行了改革与创新,实践证明实验的有机融合有助于学生临床观念的建立与实践、创新能力的培养。     

动态系统理论视角下的二语词汇习得研究

动态系统理论是应用语言学界的最新发展动态,它关注语言习得过程中各个内在系统的相互作用和系统内部各因素的相互联系。本文从该理论的基本概念出发,以二语词汇习得为研究点,结合动态系统理论的特点,讨论了该理论在二语词汇习得中的应用,并提出相关策略,以寻求词汇习得的新途径。     

Graphicacy in biology textbooks: analysis of activities with images / Alfabetización gráfica en libros de texto de biología: análisis de las actividades con imágenes

The aim of this study is to analyse how graphicacy is promoted through activities with images of the human body in third to sixth year primary school textbooks from three different publishers. The analysis was based on categories related to type of image, type of task, procedures, cognitive processing level required and whether there are explicit instructions on how to use the image. The results show that illustrations and visual diagrams are the most frequent images. The main task is image interpretation, whereas production tasks are scarce. Moreover, the tasks are not evenly distributed among the different procedures. The processing level required is low and requires superficial processing of the images, resulting in a learning process based on copy and repetition. There is some evidence of activities being sequenced according to educational level. We conclude that the kind of graphicacy found in the textbook activities is insufficient for acquiring competence in the use of images.     

Reviewing the Family Unit as a Stakeholder in Talent Development: Is It Undervalued?

As elite youth sport becomes more organized and professionalized, the role of the family is increasingly acknowledged as being significant in the development of young talent. High-profile examples across a range of professional sports, both positive and negative, have drawn attention toward this important stakeholder. Accordingly, this review first examines the key issues in relation to family involvement in talent development in relation to what is perceived as good and bad practice on behalf of the family. Next the key theoretical underpinning is considered, Family Systems Theory, and how it may be integrated within elite youth sport. Finally, the article concludes with a summary of where the current literature leaves us and where we can progress from here. Two possible inputs are suggested that could benefit the effectiveness of family involvement: a focus on the family holistically and a second on the role different family members can play.     

How students reason about matter flows and accumulations in complex biological phenomena: An emerging learning progression for mass balance

In recent years, there has been a strong push to transform STEM education at K-12 and collegiate levels to help students learn to think like scientists. One aspect of this transformation involves redesigning instruction and curricula around fundamental scientific ideas that serve as conceptual scaffolds students can use to build cohesive knowledge structures. In this study, we investigated how students use mass balance reasoning as a conceptual scaffold to gain a deeper understanding of how matter moves through biological systems. Our aim was to lay the groundwork for a mass balance learning progression in physiology. We drew on a general models framework from biology and a covariational reasoning framework from math education to interpret students' mass balance ideas. We used a constant comparative method to identify students' reasoning patterns from 73 interviews conducted with undergraduate biology students. We helped validate the reasoning patterns identified with >8000 written responses collected from students at multiple institutions. From our analyses, we identified two related progress variables that describe key elements of students' performances: the first describes how students identify and use matter flows in biology phenomena; the second characterizes how students use net rate-of-change to predict how matter accumulates in, or disperses from, a compartment. We also present a case study of how we used our emerging mass balance learning progression to inform instructional practices to support students' mass balance reasoning. Our progress variables describe one way students engage in three dimensional learning by showing how student performances associated with the practice of mathematical thinking reveal their understanding of the core concept of matter flows as governed by the crosscutting concept of matter conservation. Though our work is situated in physiology, it extends previous work in climate change education and is applicable to other scientific fields, such as physics, engineering, and geochemistry.     

Isolation,resilience, and faith: Experiences of Black Christian students in biology graduate programs

To increase participation of students of color in science graduate programs, research has focused on illuminating student experiences to inform ways to improve them. In biology, Black students are vastly underrepresented, and while religion has been shown to be a particularly important form of cultural wealth for Black students, Christianity is stigmatized in biology. Very few studies have explored the intersection of race/ethnicity and Christianity for Black students in biology where there is high documented tension between religion and science. Since graduate school is important for socialization and Black students are likely to experience stigmatization of their racial and religious identity, it is important to understand their experiences and how we might be able to improve them. Thus, we interviewed 13 Black Christian students enrolled in biology graduate programs and explored their experiences using the theoretical lens of stigmatized identities. Through thematic content analysis, we revealed that students negotiated experiences of cultural isolation, devaluation of intelligence, and acts of bias like other racially minoritized students in science. However, by examining these experiences at the intersection of race/ethnicity and religion, we shed light on interactions students have had with faculty and peers within the biology community that cultivated perceptions of mistrust, conflict, and stigma. Our study also revealed ways in which students' religious/spiritual capital has positively supported their navigation through biology graduate school. These results contribute to a deeper understanding of why Black Christian graduate students are more likely to leave or not pursue advanced degrees in biology with implications for research and practice that help facilitate their success.     

四旋翼飞行器控制系统研究

本文着重就四旋翼飞行器控制系统的硬件组成、结构和软件算法进行研究。介绍了四旋翼飞行器的组成结构和飞行原理,包括四旋翼飞行器的优势和特点以及今后的应用领域;讨论了控制系统的硬件组成结构及其特点,如主控制器MCU芯片的选择、所需传感器种类的确定、数据传输模块的设计和硬件通信协议的分析;研究了姿态解算的方法,包括捷联惯导系统、姿态解算的四元数方法、互补滤波;研究了四旋翼飞行器的控制方法,采用了经典的PID控制方法,设计偏航、俯仰、滚转的三路并行PID控制器。     

电子图书馆异构系统联合检索整合方法研究

首先提出当前电子图书馆由于系统异构造成的兼容问题,然后就Z39．50、OAI-PM H和OpenURL等协议及标准对整合异构系统及所含资源的作用和效果进行详细分析,并就使用OAI-PM H协议进行系统整合的步骤和方法加以说明,最后对电子图书馆的联合检索应用前景进行总结和展望。