海绵宝宝

Scientists Explain Why Taxing Mental Work Wears You Out_我的网站

女生怒撕港独标语

A | A team of scientists has discovered a likely explanation for why one may feel exhausted after engaging in intense cognitive work.,In their study, published in the Current Biology last week, the researchers argue that intense cognitive work, when it lasts for several hours, results in the buildup of potentially toxic byproducts in the prefrontal cortex part of the human brain, which then affects a person’s behavior.,“Influential theories suggested that fatigue is a sort of illusion cooked up by the brain to make us stop whatever we are doing and turn to a more gratifying activity,” Mathias Pessiglione of Pitié-Salpêtrière University in Paris, said as quoted in a news release by Cell Press. “But our findings show that cognitive work results in a true functional alteration—accumulation of noxious substances—so fatigue would indeed be a signal that makes us stop working but for a different purpose: to preserve the integrity of brain functioning.”,During the course of their research, the team employed magnetic resonance spectroscopy to monitor the brain chemistry of two groups of people during a workday, with one group performing easy cognitive tasks while the other engaged in more complex mental activities.,Only the latter group ended up exhibiting signs of fatigue, as well as a tendency to favor “options proposing rewards at short delay with little effort,” as the news release put it.,AmericasChild Survives After 7 Minutes Without Blood Flow to Brain During Surgery, US Cardiologist Reveals11 August, 16:41 GMT,Furthermore, members of that group had higher levels of glutamate in the synapses of the prefrontal cortex, leading the researchers to suggest that the accumulation of glutamate “makes further activation of the prefrontal cortex more costly,” and thus a mentally exhaustive workday makes cognitive control more difficult.,Unfortunately, there seems to be no fancy way to deal with this problem other than the tried and tested method that is probably as old as history itself.,“I would employ good old recipes: rest and sleep!” Pessiglione remarked. “There is good evidence that glutamate is eliminated from synapses during sleep.”。

B |

【光明时评】又到一年开学季，“冷门”的天文学专业却备受关注。过去，天文学一直被视作理想主义者的选择，抬头望向月亮的代价似乎就是失去地上的六便士。

C | 近几年，随着国家对基础学科加大投入和更多天文空间项目建成，国内天文学人才需求进一步上升。南京大学天文与空间科学学院教授陈鹏飞曾撰文称，从1999年至2020年，国内平均每年增加一所高校成立天文系，全国天文学专业本科招生数从1994年的28人增长到了2018年的208人。2018年，基础学科拔尖学生培养计划在原有5个学科（数学、物理学、化学、生物科学、计算机科学）的基础上，增加了天文学等12个学科，让作为基础学科之一的天文学更加受到了重视。从高校举办天文学专业，开展天文学教育的办学趋势看，国内天文学教育虽然起步较晚，但目前已进入一个高速发展阶段，各个高校陆续建立天文学专业。有鉴于此，不少观察者指出，天文学这一高考报考中的传统冷门专业将迎来走热的机会。近年来，我国高度重视基础学科人才培养。2020年起，教育部启动实施“强基计划”，聚焦国家重大战略需求，探索选拔培养基础学科拔尖创新人才，3年来已经招收1.8万余人，其中就包括招生培养天文学人才。越来越多的高校重视包括天文人才的基础学科人才培养。我们乐见天文学专业的走热，也因此，更有必要重申尊重基础学科人才培养规律。高校在开设天文学专业时，有必要对现有的天文人才培养与社会人才需求情况进行客观评价。从现实看，按照目前的专业人才培养规模，天文学专业毕业生从事天文教育、科学研究的“就业对口率”并不高，仅有约50%。据统计，天文学本科毕业生毕业去向主要为深造，有的高校高达七成，但深造的专业有相当大的比例不是天文学。虽然基础学科专业的本科教育本来就不以就业为导向，而着重培养学生宽厚的基础学科能力与素质，但毋庸置疑，毕业生的“对口率”不高的去向分析势必会在一定程度上影响到专业的建设和发展。

D | 随着更多学校建立天文学专业，这一问题值得重视。开设天文学专业的高校应根据本校的办学定位、办学条件对新设专业进行科学、严谨的论证。另一个值得关注的问题是，我国基础教育要重视培养学生对基础学科的兴趣，以及成为基础学科领域拔尖人才的志向。我国基础教育学校，要重视呵护学生的好奇心，在课堂教学和课后社团活动中，要关注学生的学科素养、学科兴趣培养。尤其在高中教育阶段，应通过包括开设选修课在内的各种途径，拓宽学生的视野，帮助学生了解不同学科发展前沿，既培养学生的学科兴趣，又引导学生选择适合自己的大学与专业，确定自己的职业与事业发展方向。这一方面需要高中扭转“唯升学”倾向，在必修课之外，给学生提供选修课和各类探索活动，让学生有发现、发展自己兴趣的时间与空间；另一方面则需要大学积极参与基础教育，例如面向高中生开设基础学科先修课程，以此培养学生的基础学科兴趣，吸引更多学生选择基础学科专业。基于兴趣选择的大学和专业，对学生来说，就是属于自己的“热门”学校和专业。