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2019年11月22日 11:04:46

Researchers observed the behavior of amputated octopus arms, which remain very active for an hour after separation. Those observations showed that the arms never grabbed octopus skin, though they would grab a skinned octopus arm. The octopus arms didn’t grab Petri dishes covered with octopus skin, either, and they attached to dishes covered with octopus skin extract with much less force than they otherwise would.在截断章鱼的腕足后,研究人员观察发现断肢在离体一小时后仍相当有活力。断肢离体后的行为观察显示,断肢不会吸附章鱼皮肤,但是会吸附剥了皮的章鱼腕足;断肢也不会吸附覆盖着章鱼皮的培养皿。在吸附涂有章鱼皮肤提取物的培养皿时,会比吸附空培养皿时使用更小的力量。一只章鱼的八条腕足上密布着成百上千个吸盘,会吸附几乎任何东西,但有一个重要的例外。这些吸盘一般不会吸附章鱼自身;否则,这只极其灵活的动物很快就会发现自己整个纠缠在了一起。Now, researchers from the Hebrew University of Jerusalem report in the Cell Press publication Current Biology on May 15 that they have discovered how octopuses manage this feat, even as the octopuses’ brains are unaware of what their arms are doing. A chemical produced by octopus skin temporarily prevents their suckers from sucking.现在,耶路撒冷希伯来大学的研究人员于5月15日在细胞期刊数据库(Cell Press [i])的期刊《现代生物》(Current Biology)上发表了他们的研究成果,并称他们已发现章鱼实现这一壮举的原理,甚至是章鱼的大脑不知情的情况下完成这一行为。一种由章鱼皮肤产生的化学物质能够在短期内阻止其吸盘的吸附行为。“We were surprised that nobody before us had noticed this very robust and easy-to-detect phenomena,” says Guy Levy, who carried out the research with co-first author Nir Nesher. “We were entirely surprised by the brilliant and simple solution of the octopus to this potentially very complicated problem.”“这个现象非常强大且易于检测,在我们之前竟无人注意到这一点,我们感到很惊讶,”与共同第一作者尼尔-内舍(Nir Nesher)一同进行了研究后,盖伊-列维(Guy Levy)说。“更让我们惊讶的是章鱼精而又简单地解决了这本会非常复杂的问题。”Binyamin Hochner and his colleagues had been working with octopuses for many years, focusing especially on their flexible arms and body motor control. There is a very good reason that octopuses don’t know where their arms are exactly, in the same way that people or other animals do.本雅明-霍齐纳(Binyamin Hochner)和他的同事研究章鱼多年,尤其是关注他们灵活的腕足和身体运动的控制。他们发现,章鱼并不能像人与其他动物一样知道自己腕足的确切位置。“Our motor control system is based on a rather fixed representation of the motor and sensory systems in the brain in a formant of maps that have body part coordinates,” Hochner explains.“我们人类大脑中的感觉系统有分别对应特定身体部位的区域,而运动控制系统则是一个相对固定的感觉系统对动作的映射,”霍齐纳解释道。That works for us because our rigid skeletons limit the number of possibilities. “It is hard to envisage similar mechanisms to function in the octopus brain because its very long and flexible arms have an infinite number of degrees of freedom,” Hochner continues. “Therefore, using such maps would have been tremendously difficult for the octopus, and maybe even impossible.”这对于我们来说是适用的,因为我们僵硬的骨架限制了我们活动。“在章鱼大脑中也使用与之相似的机制是难以想象的,因为它那长而灵活的腕足可以进行各种角度的运动,”霍齐纳继续说道,“因此,如果章鱼大脑中也用相似的区域分布来控制运动,会是相当困难的,甚至是不可能的。”Indeed, experiments have supported the notion that octopuses lack accurate knowledge about the position of their arms. And that raised an intriguing question: How, then, do octopuses avoid tying themselves up in knots?事实上,实验结果表明章鱼确实并不能掌握其腕足确切位置。这样的结果也引出了一个有趣的问题:那么,章鱼是怎样避免把自己缠成一团乱麻的呢?To answer that question, the researchers observed the behavior of amputated octopus arms, which remain very active for an hour after separation. Those observations showed that the arms never grabbed octopus skin, though they would grab a skinned octopus arm. The octopus arms didn’t grab Petri dishes covered with octopus skin, either, and they attached to dishes covered with octopus skin extract with much less force than they otherwise would.为了找到,研究人员将章鱼腕足截取下来,观察其行为,这些腕足在离体一小时后仍然相当有活力。最终观察结果显示,腕足断肢不会吸附章鱼皮,但是会吸附剥了皮的章鱼腕足;不会吸附覆盖着章鱼皮的培养皿,但是在吸附涂有章鱼皮肤提取物的培养皿时,会比吸附空培养皿时使用更小的力量。“The results so far show, and for the first time, that the skin of the octopus prevents octopus arms from attaching to each other or to themselves in a reflexive manner,” the researchers write. “The drastic reduction in the response to the skin crude extract suggests that a specific chemical signal in the skin mediates the inhibition of sucker grabbing.”“目前为止,研究有了新发现:章鱼皮肤能够防止腕足间相互吸附或腕足吸附自身,”研究人员这样写道。“对皮肤粗提取物的反应急剧减弱说明皮肤中存在一种特定的化学信号,这种化学信号会调解对吸盘吸附的抑制作用。”In contrast to the behavior of the amputated arms, live octopuses can override that automatic mechanism when it is convenient. Living octopuses will sometimes grab an amputated arm, and they appear to be more likely to do so when that arm was not formerly their own.与腕足断肢的行为活动相比,章鱼能够在适当时候无视这种自动机制。章鱼有时会吸附一个断肢,而且如果那不是自己的断肢,他们更有可能这么做。Hochner and his colleagues haven’t yet identified the active agent in the animals’ self-avoidance behavior, but they say it is yet another demonstration of octopus intelligence. The self-avoidance strategy might even find its way into bioinspired robot design.霍齐纳和他的同事们还没能确定在动物自我回避行为中起作用的活化剂,但是他们说这是章鱼智慧的又一次完美呈现。这种自我回避策略也许将来会应用于仿生机器人的设计。“Soft robots have advantages [in] that they can reshape their body,” Nesher says. “This is especially advantageous in unfamiliar environments with many obstacles that can be bypassed only by flexible manipulators, such as the internal human body environment.”“柔软的机器人的优势在于他们可以改变身体形状,”内舍说。“这在一个陌生的环境中是尤其有利的,这样可以利用灵活的机械手绕过重重障碍,比如在人体的内部环境中。”In fact, the researchers are sharing their findings with European Commission project STIFF-FLOP, aimed to develop a flexible surgical manipulator in the shape of an octopus arm. “We hope and believe that this mechanism will find expression in such new classes of robots and their control systems,” Hochner says.事实上,研究者正在于欧洲委员会STIFF-FLOP项目共享他们的研究成果,该项目致力于研发章鱼腕足形状的手术操作臂。霍齐纳说:“我们希望并且相信这个机制能够在这种新型机器人和他们的控制系统中发光发热。” /201406/306791泉州腋臭手术医院5-year-old daughter, wanting her father to help her do something.Father: ;I#39;m so tired, if you praise me, I#39;ll Be fresh.;Daughter: ;Lao Zheng!;Dad: ;Hey!;Daughter: ;Your chick looks really nice ah ......;5岁的女儿让老爸帮她做某事。老爸:“爸爸很累啦,你夸我两句吧,你夸我两句我就又有劲了。”女儿:“老郑!”老爸:“哎!”女儿:“你家妞妞长得可真漂亮啊……”泉州附属第一医院狐臭To shield any future children from the fear she harbors of getting breast cancer, Katie Dowdy underwent a controversial procedure to select embryos of hers that were free of a genetic mutation linked to the disease. 为了不让孩子将来像自己一样害怕患上乳腺癌,凯蒂·道迪(Katie Dowdy)做了一项充满争议的检查,以挑选出不携带一种被认为与乳腺癌相关的基因突变的胚胎。Deciding to have the procedure, called preimplantation genetic diagnosis, or PGD, wasn#39;t easy, says Ms. Dowdy. Her husband initially #39;worried about playing God,#39; she says. #39;I thought, if I could have a healthy baby who doesn#39;t have to worry about the same thing I did, why wouldn#39;t I?#39; says the 34-year-old, who hasn#39;t had cancer. The couple, who live in Castle Pines, Colo., now have two young girls, both born using PGD. 道迪说,决定做这项名叫“着床前遗传学诊断”(简称PGD)的检查并不是一个容易的过程。她说,起初丈夫“担心自己是在扮演上帝的角色”。现年34岁、没有得过癌症的她说:“我想,如果我能有一个健康的孩子,不需要担心我所担心的事情,那我为什么不做呢?”夫妇俩家住科罗拉多州派恩堡,现有两个年幼的女儿,都是在做了PGD之后出生的。Preimplantation genetic diagnosis has long been available during IVF, or in vitro fertilization, to eliminate the risk of passing on severe disorders such as spinal muscular atrophy and cystic fibrosis. Now, fertility clinics say they are seeing a small but increasing number of women choosing PGD to avoid giving birth to children who carry mutations in the BRCA genes, which increase the risk for breast and other cancers. 防范于未然着床前遗传学诊断(PGD)检查胚胎有没有某种可能会从父母身上遗传而来的遗传缺陷。以下是PGD检查的一些疾病:#39;It#39;s on the rise because more people are becoming aware that there#39;s a genetic component to breast cancer,#39; says Mark Hughes, founder of Genesis Genetics, in Plymouth, Mich., which offers reproductive-genetics-diagnosis services to fertility clinics nationwide. 囊性纤维化Critics fear genetically vetting embryos can be used to create so-called designer babies. Embryos with the gene mutation may be discarded, which some critics also oppose. Gender selection is one form of embryo-testing that stirs ethical questions. Some clinics will agree to select for a specific sex only for health reasons -- to avoid a disease such as hemophilia, for example, which typically is passed only to boys. Opponents of PGD for breast cancer also say that having a BRCA-gene mutation doesn#39;t mean a person will necessarily get the disease and that there are options for detecting and treating the cancer. 血友病A parent with a mutation on the BRCA1 or BRCA2 genes has a 50-50 chance of transmitting it to the next generation. Between 45% and 65% of women with the mutations are expected to be diagnosed with breast cancer by age 70, according to the National Cancer Institute. That compares with about 12% of women in the general population. 亨廷顿氏舞蹈症BRCA mutations, which also increase the risk for ovarian, prostate and other cancers in men and women, are relatively rare, accounting for 5% to 10% of all breast cancers. Some women undergo prophylactic mastectomy to reduce their chances of getting the disease. 马方氏综合征In Ms. Dowdy#39;s family, the specter of breast cancer hovers. Her paternal grandmother died in 1979, five months before Ms. Dowdy was born. Several of her grandmother#39;s sisters also got breast cancer. Ms. Dowdy#39;s father had a genetic test and found he had inherited the BRCA1 mutation. When she was 27, a test showed Ms. Dowdy also had the mutation. 肌肉萎缩After her aunt, who shares the same mutation, had a prophylactic mastectomy, Ms. Dowdy researched her options and learned about PGD. Ms. Dowdy says she and her husband had struggled to conceive. Figuring they would need fertility assistance, also doing PGD to avoid passing on the BRCA mutation seemed like an obvious precaution. 地中海贫血The PGD process begins with standard IVF. After two weeks of hormonal stimulation, eggs are retrieved, fertilized and left to multiply for five days. Then a laboratory scrutinizes several cells, looking for gene mutations. The analysis isn#39;t believed to harm the embryo. Embryos without BRCA mutations are earmarked for transfer into a woman#39;s uterus. 黑蒙性白痴Two of Ms. Dowdy#39;s seven embryos were BRCA-mutation free. Both were transferred to her uterus. One implanted and grew to become a daughter, Reagan, born in 2010. Ms. Dowdy and her husband opted for PGD again to conceive another child, Mackenzie, born in March. 脊髓性肌萎缩Only recently have some doctors started discussing PGD with women who have a breast-cancer mutation. More often, BRCA-positive women learn about the procedure on their own. #39;We write about it in our newsletter and we#39;ve done webinars on it, but not everyone knows about it,#39; says Sue Friedman, executive director of Force, a nonprofit patient-support group focused on hereditary breast and ovarian cancers. 镰状细胞贫血For women who have no trouble conceiving, the choice to do PGD involves the added hassle of fertility treatment. PGD can add about ,000 to the price of IVF, which runs at least ,000, depending on the clinic, plus thousands of dollars more for medications. 资料来源:纽约大学生殖中心(NYU Fertility Center)很久以来,在试管受精的操作过程中,都可以通过着床前遗传学诊断来消除将脊髓性肌萎缩、囊性纤维化等严重缺陷遗传下去的风险。而现在,据生殖医院说,数量不大但越来越多的女性都在选择做PGD以避免生下携带BRCA基因突变的孩子。BRCA基因突变会增加患乳腺癌和其他癌症的风险。#39;It#39;s by no means 100% [of eligible women] who are choosing to do it,#39; says William Schoolcraft, medical director of the Colorado Center for Reproductive Medicine in Lone Tree, Colo., and Ms. Dowdy#39;s doctor. Dr. Schoolcraft says he has done about 10 PGD procedures to eliminate a BRCA mutation in the past three years. He has heard some patients say #39; #39;My grandma had it, my aunt had it, my mom had it. I want to stop this train.#39; Others have the attitude that if my baby turns out like me, so be it.#39; 密歇根州普利茅斯堡的Genesis Genetics为全国生殖医院提供生殖遗传学诊断务。创始人马克·休斯(Mark Hughes)说:“之所以数量在上升,是因为越来越多的人懂得乳腺癌包含遗传成分。”Even after an embryo selected through PGD is successfully implanted, some doctors recommend an amniocentesis or another prenatal test called CVS to make sure there isn#39;t a BRCA-gene mutation. 批评者担心,经过遗传学检查的胚胎有可能被用于制造“定制婴儿”(designer baby)。含有基因突变的胚胎可能被抛弃,这也是一些批评者所反对的。性别选择是激起伦理争议的胚胎检查形式之一。一些医院只会同意出于健康原因而选择某个性别,比如说规避常常只遗传给男孩的血友病等。乳腺癌PGD反对者还说,携带BRCA基因突变并不意味着人一定会得这种病,而且乳腺癌的侦测和治疗还有其他方法。#39;You have to think of it from the perspective of a woman whose life has been turned upside down by breast cancer and the guilt associated with choosing to have a baby that could have those same problems,#39; says James Grifo, director of the Division of Reproductive Endocrinology and Infertility at NYU Fertility Center. 携带BRCA1或BRCA2基因突变的父母有50%的概率将它遗传给下一代。根据国家癌症研究所(National Cancer Institute)数据,45%到65%携带这些突变的女性预计会在70岁之前被诊断出乳腺癌。相比之下,一般女性的这个概率在12%左右。Bonnie RochmanBRCA突变也会增加男性和女性罹患上卵巢癌、前列腺癌等癌症的风险。这类突变相对少见,占所有乳腺癌的5%到10%。有些女性通过做预防性乳房切除术来降低患乳腺癌的风险。 /201404/291935泉州植发

泉州市泉海口腔医院专家在线咨询泉州激光去皱医院哪家好It#39;s easy to get caught up in stress and to be hard on yourself when it comes to work, finance, and relationships, but the best way to stay happy and healthy is to lighten up a little bit. Here are three ways to cut yourself some slack in the holiday:面对工作、经济问题和人际关系时很容易有压力而且对自己有高要求,但是保持愉快和健康最重要的方法就是放轻松些。下面有三个方法可以让你在假期里“放自己一马”:1. Schedule time for yourself. In between work commitments and everyday errands, it can be tough to find time for the things that fulfill you. Still, it#39;s crucial let yourself indulge. Whether it#39;s exercise, spa treatments, lunch dates, or just 10 minutes to sit and breathe. Even tiny moments of joy will have an impact on your mind-set.1. 自己规划时间。在工作要求与日常琐事间,找时间做自己的事非常困难。但是,让你自己沉浸在喜欢的事中是非常重要的。不管是运动、温泉疗法、午餐约会,还是仅仅花10分钟时间坐下来,调整呼吸节奏,即使是短暂的欢乐时光也会对心态产生影响。 /201309/257879福建省泉州丰泽区美白针多少钱一次泉州治疗红色胎记费用

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