The human brain is wired to react fearfully to snakes, including in people without a conscious fear of snakes, says a study in this month's issue of Biological Psychology.
《华尔街日报》―发表于《生物心理学》(Biological Psychology)二月刊的研究论文称，人类大脑对蛇天生的反应就是畏惧，没意识到自己怕蛇的人也包括在内。
The study suggests the brain evolved to pay greater attention to the presence of snakes than other creatures, because snakes were among the earliest human predators and posed a daily threat.
该研究指出，比较其他生物，大脑在进化过程中变得更能注意到蛇的存在，因为蛇是人类最早的掠食者之一，每天都带来威胁。
This heightened awareness of snakes is embedded in the brain's circuitry, even though snakes are no longer a danger to most people, researchers said. Fear of spiders, while also common, has no evolutionary associations, as spiders weren't predatory, they said.
研究人员称，即便蛇对大多数人来说不再危险，但这种对蛇的高度戒备却深深印入了人脑的神经回路中。他们还指出，虽然人类对蜘蛛的畏惧也很常见，但这与进化没有关联，因为蜘蛛不是人类的掠食者。
The study involved 24 non-phobic Norwegian women, 18 to 31 years old. The women viewed two sets of color photos while an EEG measured activity in their brain. In the first set, 600 pictures each of snakes, spiders and small birds were randomly displayed on a computer at a rate of three per second. This test assessed which creature attracted the subjects' instant -- but unconscious -- attention. They then viewed 30 pictures of each species at a slower speed to assess the brain's continuous neural response.
该研究的受试者为24名年龄在18至31岁、无恐惧症的挪威女性。她们观看了两组彩色照片，同时脑电图(EEG)会检测她们大脑的活动。在第一组实验中，各600张蛇、蜘蛛和小鸟的照片以每秒三张的速度在电脑上随机展示。该测试评估的是哪种生物会引起受试者迅速但无意识的关注。随后她们还观看了以更慢的速度展示的各物种的30张照片，目的是评估她们大脑的持续性神经反应。
Before the tests, the subjects rated their fear on a scale from 0 (none) to 45 (very high). The average scores for snakes, spiders and birds were 16, 12 and 4, respectively. Compared with the spider and bird pictures, the speedy display of snake images evoked a significantly stronger brain response that was most pronounced in the brain's occipital or visual processing region, researchers said.
在实验之前，受试者按照从0（毫不害怕）到45分（非常害怕）的量级给她们的恐惧评分。对蛇、蜘蛛和小鸟的平均恐惧分数分别为16分、12分和4分。研究者称，与蜘蛛和小鸟的照片相比，蛇照片的快速展示引发了明显更强烈的大脑反应，该反应在大脑的枕骨叶即视觉处理区表现得最显著。
The response to the spider pictures was closely associated with the subjects' self-reported fear. Spider fear is learned and stems from disgust rather than fear of physical harm, the study suggests.
受试者对蜘蛛图片的反应与她们自己所陈述的恐惧密切相关。研究显示，对蜘蛛的畏惧是后天的，它源自厌恶而非对身体伤害的恐惧。
In the second test, the brain responses to spiders and snakes weren't significantly different, but were stronger than for birds.
在第二个实验中，大脑对蜘蛛和蛇的反应并无明显区别，但要强于对小鸟图片的反应。
Caveat: The study was small and only involved women.
警告：该研究规模较小，而且受试者只有女性。
Breast-milk benefit: A specialized antibody in breast milk may play an important role in a newborn's susceptibility to intestinal infections and inflammatory bowel diseases as they mature, suggests a study published online in the Proceedings of the National Academy of Sciences.
母乳的好处：发表于《美国国家科学院学报》(Proceedings of the National Academy of Sciences)网络版的一项研究显示，母乳中的一种特殊抗体或许对新生儿逐渐长大时是否易于患上肠道感染和炎症性肠病有很大的影响。
Breast milk contains an antibody called secretory immunoglobin A (SIgA), which protects against infection and helps infants develop a healthy mix of gastrointestinal bacteria. When breast-feeding stops, other mucus-secreting organs, such as the nose, throat and eyes, start to produce SIgA, but it wasn't known if the initial exposure to SIgA through breast milk had long-term benefits, researchers said.
母乳含有一种名为分泌型免疫球蛋白A(SIgA)的抗体，它可以抵御感染，有助于婴儿的胃肠菌群实现健康的混合比例。研究人员称，在停止母乳喂养后，婴儿其他分泌黏液的器官，如鼻子、喉咙和眼睛就会开始生成SIgA，不过一开始通过母乳接触SIgA是否有长远益处还不明确。
A purified form of SIgA might be a potential treatment for intestinal infections and inflammation, particularly in formula-fed infants or older children and adults who don't produce enough of the antibody, they said.
研究人员还指出，纯正的SIgA或许是治疗肠道感染和炎症的潜在疗方，特别是对用配方奶喂养的婴儿或年纪较大的儿童以及生成的抗体不足的成年人而言。
Experiments at the University of Washington in Seattle were conducted on the offspring of mice that produced breast milk with SIgA and mice bred to produce milk without the antibody. Analysis of fecal samples showed SIgA was present only in offspring that received the antibody and fell to low levels after weaning. Within a week, the weaned mice began to produce SIgA through other tissues, while SIgA wasn't detected at any time in mice that didn't receive the antibody. Mice lacking SIgA had significantly different gut bacteria than mice with the antibody, including Ochrobactrum anthropi, a bacterium linked to hospital-acquired infections.
西雅图华盛顿大学 (University of Washington in Seattle)对老鼠的后代展开了实验，其中一些老鼠分泌含SIgA的乳汁，另一些因喂食方法分泌的是不含该抗体的乳汁。对排泄物采样的分析表明，SIgA只在喂有含该抗体的乳汁的幼鼠中出现，但抗体水平在断奶后降至低位。在一周之内，断奶幼鼠的其他器官组织便开始生成SIgA，而未被喂食含SIgA乳汁的幼鼠从未被检测出该抗体。缺乏SIgA的老鼠与含该抗体的老鼠的肠道细菌大为不同，其中包括与医院获得性感染有关的人苍白杆菌。
The addition of a chemical used to induce colitis in laboratory mice caused significantly greater tissue damage in the mice that didn't receive SIgA. Intestinal gene patterns also differed significantly between the two groups.
研究人员添加了一种化学物在实验鼠身上诱发结肠炎，结果是不含SIgA的老鼠的器官组织遭到了明显更严重的损害。此外，这两组老鼠的肠基因模式也截然不同。
Caveat: It's possible that maternal differences in gut microbes at the time of delivery contributed to the genetic changes in offspring independently of SIgA in breast milk, researchers said. The research was conducted on rodents and hasn't been tested in human studies.
警告：研究人员称，母鼠在分娩时的肠道微生物的差异有可能引发了与乳汁中SIgA无关的幼鼠基因的改变。该研究在老鼠身上展开，尚未对人类进行实验。
Reducing salt consumption by half a teaspoon a day significantly improved blood-vessel function in overweight and obese individuals with normal blood pressure, potentially lowering their risk of cardiovascular disease, according to a report in the March issue of Atherosclerosis.
《动脉硬化》(Atherosclerosis) 杂志三月刊的一项报告指出，将每日的盐摄入量减少半匙可改善超重人群及血压正常的肥胖人士的血管功能，有可能降低他们患上心血管疾病的风险。
The magnitude of the blood-vessel changes recorded in the study could shift a person from a high-risk category to a low-risk one for heart attack and stroke, which are associated with a high-salt diet, researchers said.
研究人员称，该研究记录到的血管变化的量值，显示一个人从心脏病及中风高危人群转为低危人群。这两种疾病与高盐饮食有关。
The Centers for Disease Control and Prevention recommends consuming no more 6 grams (2,300 milligrams of sodium), or one teaspoon of salt a day. For African-Americans, diabetics and people older than 51 or with high blood pressure, the CDC recommends consumption be limited to two-thirds of a teaspoon (about 4 grams of salt or 1,500 milligrams of sodium). Most Americans consume an average of 9 grams of salt (3,450 milligrams of sodium) a day, according to the CDC.
美国疾病控制与预防中心(Centers for Disease Control and Prevention，简称“CDC”)建议每日的食盐量不要超过六克（2,300毫克钠），也就是一天一茶匙盐。对于非裔美国人、糖尿病患者以及51岁以上的人群或高血压患者，CDC的建议把摄入量控制在三分之二茶匙（约为四克盐或1,500毫克钠）。根据该中心的数据，美国人每日的盐摄入量平均为九克（3,450毫克钠）。
Researchers at the University of South Australia recruited 25 men and women ages 40 to 70 for the 12-week study. The subjects followed a diet containing 9 grams of salt a day for six weeks and a reduced salt diet of 6 grams a day for six weeks. Flow-mediated dilatation, an ultrasound technique used to assess blood-vessel elasticity, was measured at the start of the study and after two, six and 12 weeks.
南澳大学(University of South Australia)的研究人员征集了25名年龄在40岁至70岁的男女受试者参加为期12周的实验。受试者前六周的饮食遵照的是每天九克的盐摄入量，在接下来的六周中将摄入量减至每天六克。与此同时，研究人员分别在研究一开始、两周后、六周后以及12周后检测采用血流介导的血管舒张功能，这是一种用于评估血管扩张度的超声波技术。
Blood-vessel function significantly increased on the reduced salt diet after two days compared with the higher salt diet, and by 45% over six weeks. Levels of endothelin-1, proteins that constrict blood vessels and raise blood pressure, decreased by 14%.
与盐摄入量较高时期相比，受试者的血管功能在减少盐摄入量两天后便大幅提高，在六周中提高了45%。内皮素-1的水平则降低了14%，该类蛋白质会使血管收缩、血压升高。
The subjects' blood pressure and weight remained the same, indicating the reduced-salt diet had an independent effect on vascular health, researchers said.
研究人员称，受试者的血压与体重在实验期保持不变，这表明少盐饮食对血管健康的作用是独立的。
Caveat: The study was small and lacked a control group of normal-weight people.
警告：该研究规模较小，缺乏一个由正常体重人群组成的控制组。