【每日阅读训练第四期——速度越障15系列】【15-05】科技

2012Michelle

周二的作业来咯。

文章题目隐藏了，回复可见。

Enjoy reading! ^_^


Food Delivers a Cocktail of Hormone-Like Signals to Body

[attachimg=385,215]114774[/attachimg]
【Time1】
The chicken pesto pasta on your plate is more than just tasty fuel to keep you going. The dish has carbohydrates, fats and proteins to be sure, but it also contains other nutrients and chemicals that send subtle cues and instructions to your cells. More and more researchers are arguing that to better grasp how diet affects health, experts should consider the signals our food sends.

Cells talk to each other in a complex language of chemical messages. They instruct each other to grow, to move and to respond to threats. Problems in cell communication lead to diseases such as diabetes and cancer. The messages take many forms, including hormones and charged molecules called ions. Cells also listen to signals that come from outside the body.

Recent findings show that molecules found in food can change cell chatter. For example, in 2010 a team of researchers in California and Japan found that omega-3 fatty acids from food bind to a specialized protein studding cell surfaces. That protein, called GPR120, is found in adipose and muscle tissues. When omega-3 fatty acid attaches to the protein, fitting like a key in a lock, GPR120 sets off a chain reaction of cellular events that ultimately protect against weight gain and inflammation.

Understanding the influence of food on cells could offer a better way to design diets, says Randy J. Seeley, the director of the Cincinnati Diabetes Center at the University of Cincinnati. A special diet to tone down inflammation might also combat weight gain or protect against diabetes.
【255】

【Time2】
Seeley and his colleague, Karen K. Ryan, argue that food’s effects on the body are so complex and specific that a meal is almost like a cocktail of hormones.

Hormones are chemicals pumped out by one tissue or gland that travel through blood or body fluids to reach another part of the body. There, they instruct targeted cells to produce some other chemical or action. While food components aren’t produced in the body, they can elicit specific reactions from cells, making them much like hormones.

The metaphor of food as hormones is interesting, says Donald Jump, a professor and biochemist at the School of Biological and Population Health Sciences at Oregon State University. “It’s really clear that food is just a pile of biochemicals,” he says. “Trying to sort that out is a mess.”

Jump explains that researchers have been trying to understand of how food can regulate and influence cells for decades. The public health challenge is translating these specific findings into clear diet recommendations.

Current recommendations do jibe with the newer findings: For example, The American Heart Association advises people to eat fish because omega-3 fatty acids have been linked to heart-healthy measures including reduced risk of abnormal heartbeats and slightly lower blood pressure. Those guidelines, and others, are based on large-scale population studies. Seeley says that in the future, scientists might know which foods promote health by understanding the way the food interacts at the cellular level. Diets could be designed “from the bottom up,” he says.
【250】

【Time3】
Dietary messages to the public need to be kept simple, Jump says. But they also need to be informed by an understanding of the hormone-like actions of food.

Fatty acids aren’t the only hormone-like food elements. Amino acids can also activate a chain reaction of events in cells related to cell growth and insulin. Vitamin D and other vitamins are involved with the body’s immune response. More interactions could be discovered: the receptor activated by omega-3 fatty acids is part of a family of proteins call “G-protein coupled receptors” that are involved in cell signals. Scientists know what many members of the family do, but they still don’t know what molecules turn them on or off, Seeley says. These locks in search of keys could also play a role in food and cell receptor interactions.

The idea of food acting like a cocktail of hormones “certainly establishes a basis for further research,” writes the New York University professor of nutrition and public health Marion Nestle in an email. “In the meantime, for most practical purposes, healthy diets are still composed of plenty of vegetables, relatively unprocessed foods of all types and balanced calories.”
【193】


Fragments of Continents Hidden Under Lava in Indian Ocean:
New Micro-Continent Detected Under Reunion and Mauritius

[attachimg=300,456]114775[/attachimg]
【Time4】
The islands Reunion and Mauritius, both well-known tourist destinations, are hiding a micro-continent, which has now been discovered. The continent fragment known as Mauritia detached about 60 million years ago while Madagascar and India drifted apart, and had been hidden under huge masses of lava.

Such micro-continents in the oceans seem to occur more frequently than previously thought, says a study in the latest issue of Nature Geoscience.

The break-up of continents is often associated with mantle plumes: These giant bubbles of hot rock rise from the deep mantle and soften the tectonic plates from below, until the plates break apart at the hotspots. This is how Eastern Gondwana broke apart about 170 million years ago. At first, one part was separated, which in turn fragmented into Madagascar, India, Australia and Antarctica, which then migrated to their present position.

Plumes currently situated underneath the islands Marion and Reunion appear to have played a role in the emergence of the Indian Ocean. If the zone of the rupture lies at the edge of a land mass (in this case Madagascar / India), fragments of this land mass may be separated off. The Seychelles are a well-known example of such a continental fragment.
【201】

【Time5】
A group of geoscientists from Norway, South Africa, Britain and Germany have now published a study that suggests, based on the study of lava sand grains from the beach of Mauritius, the existence of further fragments. The sand grains contain semi-precious zircons aged between 660 and 1970 million years, which is explained by the fact that the zircons were carried by the lava as it pushed through subjacent continental crust of this age.

This dating method was supplemented by a recalculation of plate tectonics, which explains exactly how and where the fragments ended up in the Indian Ocean. Dr. Bernhard Steinberger of the GFZ German Research Centre for Geosciences and Dr. Pavel Doubrovine of Oslo University calculated the hotspot trail: "On the one hand, it shows the position of the plates relative to the two hotspots at the time of the rupture, which points towards a causal relation," says Steinberger. "On the other hand, we were able to show that the continent fragments continued to wander almost exactly over the Reunion plume, which explains how they were covered by volcanic rock." So what was previously interpreted only as the trail of the Reunion hotspot, are continental fragments which were previously not recognized as such because they were covered by the volcanic rocks of the Reunion plume. It therefore appears that such micro-continents in the ocean occur more frequently than previously thought.
【231】

Obstacle


The “Language” Gene and Women’s Wagging Tongues  
Aka, How to Twist Science to Reinforce Gender Stereotypes

[attachimg=448,259]114776[/attachimg]
Genes are subject to multiple layers of regulation. An early regulatory point is transcription. During this process, regulatory proteins bind to DNA regions (promoters and enhancers) that direct gene expression. These DNA/protein complexes attract the transcription apparatus, which docks next to the complex and proceeds linearly downstream, producing the heteronuclear (hn) RNA that is encoded by the gene linked to the promoter. The hnRNA is then spliced and either becomes structural/regulatory RNA or is translated into protein.

Transcription factors are members of large clans that arose from ancestral genes that went through successive duplications and then diverged to fit specific niches. One such family of about fifty members is called FOX. Their DNA binding portion is shaped like a butterfly, which has given this particular motif the monikers of forkhead box or winged helix. The activities of the FOX proteins extend widely in time and region. One of the FOX family members is FOXP2, as notorious as Fox News – except for different reasons: FOXP2 has become entrenched in popular consciousness as “the language gene”. As is the case with all such folklore, there is some truth in this; but as is the case with everything in biology, reality is far more complex.

FOXP2, the first gene found to “affect language” (more on this anon), was discovered in 2001 by several converging observations and techniques. The clincher was a large family (code name KE), some of whose members had severe articulation and grammatical deficits with no accompanying sensory or cognitive impairment. The inheritance is autosomal dominant: one copy of the mutated gene is sufficient to confer the trait. When the researchers definitively identified the FOXP2 gene, they found that the version of FOXP2 carried by the KE affected members has a single point mutation that alters an invariant residue in its forkhead domain, thereby influencing the protein’s binding to its DNA targets.

Like all transcription factors, FOXP2 regulates many promoters. The primary domains of FOXP2 influence are brain and lung development. Some of its downstream targets are themselves regulators of brain function (most prominently neurexin CNTNAP2). Not surprisingly, deleting or mutating both FOXP2 copies in mice results in early death, whereas doing so to one copy leads to decreased vocalization and slightly impaired motor learning. FOXP2 is broadly conserved across vertebrates, but its critical functional regions have tiny but telling differences even between humans and their closest ape relatives. Like other genes that influence human-specific attributes, human FOXP2 seems to have undergone positive selection during the broad intervals of crucial speciation events. Along related lines, Neanderthals and Denisovans apparently had the same FOXP2 allele as contemporary humans, and by this criterion were fully capable of the articulation that makes language possible.

Which brings us to the nub of the issue. What does FOXP2 do in brain? Genes don’t encode higher-order functions, let alone behavior. Also recall that the KE family members have a very circumscribed defect, despite its dramatic manifestation. Finally, keep firmly in mind that language in humans includes a complex genetic component that involves many loci and just as many environmental interactions. FOXP2 does not encode inherent language ability. Instead, the time and place of its expression as well as studies in cell systems and other organisms (zebra finches, rodents) indicate that FOXP2 may be involved in neuronal plasticity, which in turn modulates capacity for learning by forming new synaptic connections. FOXP2 may also be involved in regulation of motor neuron control in certain brain regions (cortical motor areas, cerebellum, striatum) that affect the ability to vocalize, sing and, in humans, form the complex sounds of language.

Given its connection, however over-interpreted, to “what makes a human” as well as its chromosomal location (in 7q31, which also harbors candidates for autism and dementia), it’s not surprising that FOXP2 has acquired quasi-mythic dimensions in the lay imagination. However, careful studies have shown that the genes on 7q31 responsible for autism and dementia are distinct from FOXP2. Also, as I said earlier, FOXP2 does not code for language ability – and even less for its culturally determined manifestations (many of which are a minefield of confirmation biases, unquestioned assumptions and simply sloppy work).

[attachimg=336,336]114777[/attachimg]
The latest round in the misrepresentation of FOXP2 is the gone-viral variation of “there’s more of this ‘language protein’ in the left hemisphere of 4-year girls and that’s why women are three times as talkative as men”. This came from the PR pitch of a research team who did a study primarily on rats (which confirmed the link between FOXP2 levels and vocalization) and then, perhaps attempting to latch onto a catchy soundbite, extended the gender link to humans based on… a single PCR amplification of ten Broca’s area cortices (from postmortem brains of 4-year olds, five from each sex; Broca’s area is involved in language processing).

To begin with, all studies conducted so far definitively show that women and men utter the same number of words by any metric chosen – and that in fact men talk more than women in mixed-gender conversations (to say nothing of the gender-linked ratio of interruptions). And whereas it’s true that girls develop vocal competence slightly earlier than boys and show higher linguistic skills during the early acquisition window, this difference is transient. Furthermore, the FOXP1 control that the authors of the study argue does not show a gender-correlated change (unlike FOXP2) in fact is on the verge of doing so, and the relative statistical significances might well change if a larger number of samples were tested. Finally, whereas decrease of FOXP2 reduces vocalization and increases pitch in male rat pups, it has the opposite effect in female rat pups. In other words, the correlation between FOXP2 levels and vocalization/pitch is not straightforward even in rats.

In the larger context of expression and reception of vocalizations, the difference is not how much women talk, but how welcome and/or valued their input is. Even trivial zomboid blathering is given higher value if it’s culturally coded as masculine (examples: sport newscasters; most congressmen). In fairness to the researchers of the study that caused all this rehashing of kneejerk stereotypes and evopsycho Tarzanism, here is the concluding paragraph of their paper. It states something both measured and, frankly, obvious:
“Gender is a purely human construct consisting of both self and others’ perception of one’s sex and is arguably the first and most salient of all phenotypic variables. Sex differences in how language is received and processed and how speech is produced has the potential to influence gender both within and external to an individual. Whether human sex differences in FOXP2, and possibly FOXP1 as well, contribute to gender variation in language is a question for future research.”
【1111】

Cybill

回复看题目

女王的肥皂

怎么基因的文章这样难。

spencerX

谢谢米线的分享~

越障看得我有点头晕...

0:01:13
0:01:15
0:00:58
0:00:52
0:01:16

0:06:29

浅吟天

先回复再读
----------------------------------
1, 1;54  food can change the signal of the cells
2,  1;57  the function of food is same as the hormone. and scientists hope to promote health  by providing certain food to change  cellular level in the future.
3,  1;49  there are many food act as hormone. but scientists don't know they trigger which molecules that turn the protein on. more researches are needed
4,  2;27  there is a micro-continent between U and M. the micro-continents are more frequent than we see before.
5,  2;25  scientists suggest that there are more fragments due to the age of the sand grain.
越障 12；14  其实没读太懂的。。

windbear

恢复看看

cheungby

加班聚餐到家就读今天的作业，刚读完发现周二的已经发出来了，哎，赞高效

Time1——1'45''——145wpm——The new discovery about how food influent cells.
Time2——1'43''——145wpm——This part explained though the food was not hormone but the complex components in food can have similar effect like hormone.
Time3——1'16''——151wpm——In this part the author listed some other examples that a certain kind of food component like amino acid, vitmin D, etc, can effect cells like hormone. The researcher also claimed that further information was still unknown and they needed do more research.
Time4——1'53''——106wpm——This paragraph explained the process of how the micro-continent islands formed and ?fragments of the continent?
Time5——1'37''——142wpm——This part explained the method how the scientists dated the existence of the micro-continets.
Obstacle:9'15''——119wpm——main idea: The article is about some new discoveries on the transcription protain family FOX, how the FOXP2 and FOXP1 influent the expression of the gene and the FOX protain difference between men and  wemen. The difference may  cause the defferences about the vocal system and language between different genders.

JFB3017

aaaaaaaaaaaaaa

cleotina

1'30
1'37
55'
1'10
1'05
6'40

jasmine1793