学习啦【英语文摘】 编辑:韦彦 发布时间:2016-08-29



  听点小音乐 轻松学分数

  Stuck on a tricky math problem? Start clapping. Grade school kids who learned about fractions through a rhythm-and-music-based curriculum outperformed their peers in traditional math classes. The work is inEducational Studies in Mathematics.


  Fractions let you divide up a measure of music into notes of varying length. For example, one four-beat measure could contain a single whole note held for all four beats, two half notes of two beats apiece, four quarter notes of a beat each, and so on. In the Academic Music program, based on the Kodaly method of musical education, students clap, drum and chant to memorize the lengths of musical notes—then solve problems in which fractional notes must add up to a full measure of music.


  Sixty-seven students participated in the study. Half did math problems using the Academic Music system. And after six weeks, the students in the music program averaged 50 percent higher on tests than did the kids in regular math class. Fractions create a solid foundation for further math education—so mastering them is music to educators' ears.




  Archeologists have discovered a paint production studio in an ancient South African cave A new archaeological find may signify one of the great leaps in human cultural and cognitive history. Because researchers have discovered a 100,000-year-old art studio. It was known that ochre—rock with red or yellow pigments—was used for paint even that far back in history. But there was scant evidence for how it was prepared and handled. Then, in 2008, researchers uncovered an ochre mixing kit in a South African cave. They found two abalone shells, most likely used for paint mixing and storage. They also found ochre, bone, charcoal, grindstones and hammerstones. The researchers say the ochre was probably rubbed on quartzite slabs to create a fine powder. It was then mixed and heated with other crushed substances, including other stones or mammal-bone. Microscopic striations on the inner abalone surface likely are likely scrape marks left during paint mixing. The research was published in the journal Science. The paint may have been used for body adornment or for long-gone artwork. And the presence of this paint-production laboratory indicates that the early humans knew basic chemistry and could plan for the future.

  考古学家在南非的一个古老洞穴中发现了一个油漆制作工作室。这个新的考古发现可能是人类文化和认知历史的最伟大的跨越之一。因为研究人员发现的这个工作室产生于十万年前。众所周知,拥有红色或黄色色素的赭石岩一直被广泛运用于绘画中,但却少有证据显示它是如何制作并运用的。2008年,研究人员 在南非的山洞中发现了赭石混合工具, 两个可能用于调漆和储存的鲍鱼壳,除此之外他们还发现了赭石,骨头,炭笔和石锤。研究人员称,这些赭石很有可能经过在石英岩板上仔细研磨后,得到上等的粉末,然后再与 其他石头或者是哺乳动物的粉末混合并加热。用显微镜观察鲍鱼壳的内表面,你可以发现一些刮痕,这些都有可能是在混合颜料的过程中留下来的。这个发现已经被刊登在科学期刊上。这些颜料可能一直被运用在人体彩绘和长久失传的艺术品上。而且这些颜料制作工作室的存在表明了早期人类对化学已有了基本的了解并具有了规划未来的能力。颜料工具的一小步,人类历史的一大步——辛西亚莫。



  Fever can play a variety of roles, such as inhibiting pathogen replication. It also apparently increases the population of killer T cells of the immune system. Christopher Intagliata reports.


  I've always thought that when I get a fever, it's my body trying to make things uncomfortable for the invading pathogen. And that's often true—higher temperatures can inhibit the bad guys' ability to replicate. But my fever may actually be a one-two-punch. In addition to slowing down the invader, the heat helps the immune system recruit more troops for a counter-attack. That finding appears in the Journal of Leukocyte Biology.


  Researchers warmed up one group of mice to body temperatures of about 103 degrees Fahrenheit. They left another group at normal core temperature—about the same as ours. Then they injected both groups of mice with an antigen, a substance that attracts the attention of the immune system.


  Blood samples taken three days later revealed that the feverish mice had nearly twice as many killer T-cells: the kind of immune cells that can hunt down infected cells or tumor cells, and slaughter them.


  So when you're sick and you get the chills, the authors say, your body may be trying to tell you to hop under some blankets. Lie down, warm up and send a message. The heat is on.



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