【Native Speaker每日综合训练—36系列】【36-18】科技Safety of GMO

cherry6891

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转基因食品的安全性一直是大家比较关注的问题，崔永元的美国考察并排宣传片，加上最近微信上疯传一篇美国证实转基因有害让我想证实这个问题，但是学术界对于转基因食品的安全性是支持者居多，不过也有学者分析是为了拿到科研基金对转基因的害处集体失声，anyway, GMO 到底是是人们尝试的第一个西红柿，或是潘多拉的魔盒呢？
今天和大家分享的第一篇文章是发表在Food and Chemical Toxicology的一篇研究，从7个方面来衡量转基因，我摘取其中一部分，第二篇文章对转基因持怀疑态度，Obstacle综合性的讨论阐明了学术界的最新成果和怎样使大众接受。

Part I: Speaker

The Wonderful World of Transgenic Animals

Source: ScientifAmerican
http://www.scientificamerican.com/podcast/episode/the-wonderful-world-of-transgenic-a-09-07-02/

[Rephrase1]

cherry6891

Part II: Speed

Safety and nutritional assessment of GM plants and derived

food and feed: the role of animal feeding trials.

Warm up:
Transgenesis is the process of introducing an exogenous gene – called a transgene – into a living organism so that the organism will exhibit a new property and transmit that property to its offspring. Transgenesis can be facilitated by liposomes, plasmid vectors, viral vectors, pronuclear injection, protoplast fusion, and ballistic DNA injection.

[Time2]
In this report the various elements of the safety and nutritional assessment procedure for genetically modified (GM) plant derived food and feed are discussed, in particular the potential and limitations of animal feeding trials for the safety and nutritional testing of whole GM food and feed. The general principles for the risk assessment of GM plants and derived food and feed are followed, as described in the EFSA guidance document of the EFSA Scientific Panel on Genetically Modified Organisms.

In Section 1 the mandate, scope and general principles for risk assessment of GM plant derived food and feed are discussed. Products under consideration are food and feed derived from GM plants, such as maize, soybeans, oilseed rape and cotton, modified through the introduction of one or more genes coding for agronomic input traits like herbicide tolerance and/or insect resistance. Furthermore GM plant derived food and feed, which have been obtained through extensive genetic modifications targeted at specific alterations of metabolic pathways leading to improved nutritional and/or health characteristics, such as rice containing β-carotene, soybeans with enhanced oleic acid content, or tomato with increased concentration of flavonoids, are considered.

The safety assessment of GM plants and derived food and feed follows a comparative approach, i.e. the food and feed are compared with their non-GM counterparts in order to identify intended and unintended (unexpected) differences which subsequently are assessed with respect to their potential impact on the environment, safety for humans and animals, and nutritional quality. Key elements of the assessment procedure are the molecular, compositional, phenotypic and agronomic analysis in order to identify similarities and differences between the GM plant and its near isogenic counterpart.
[275 words]

[Time3]
The safety assessment is focussed on (i) the presence and characteristics of newly expressed proteins and other new constituents and possible changes in the level of natural constituents beyond normal variation, and on the characteristics of the GM food and feed, and (ii) the possible occurrence of unintended (unexpected) effects in GM plants due to genetic modification. In order to identify these effects a comparative phenotypic and molecular analysis of the GM plant and its near isogenic counterpart is carried out, in parallel with a targeted analysis of single specific compounds, which represent important metabolic pathways in the plant like macro and micro nutrients, known anti-nutrients and toxins. Significant differences may be indicative of the occurrence of unintended effects, which require further investigation.

Section 2 provides an overview of studies performed for the safety and nutritional assessment of whole food and feed. Extensive experience has been built up in recent decades from the safety and nutritional testing in animals of irradiated foods, novel foods and fruit and vegetables. These approaches are also relevant for the safety and nutritional testing of whole GM food and feed.

Many feeding trials have been reported in which GM foods like maize, potatoes, rice, soybeans and tomatoes have been fed to rats or mice for prolonged periods, and parameters such as body weight, feed consumption, blood chemistry, organ weights, histopathology etc have been measured. The food and feed under investigation were derived from GM plants with improved agronomic characteristics like herbicide tolerance and/or insect resistance. The majority of these experiments did not indicate clinical effects or histopathological abnormalities in organs or tissues of exposed animals. In some cases adverse effects were noted, which were difficult to interpret due to shortcomings in the studies.

Many studies have also been carried out with feed derived from GM plants with agronomic input traits in target animal species to assess the nutritive value of the feed and their performance potential. Studies in sheep, pigs, broilers, lactating dairy cows, and fish, comparing the in vivo bioavailability of nutrients from a range of GM plants with their near isogenic counterpart and commercial varieties, showed that they were comparable with those for near isogenic non-GM lines and commercial varieties.
[367 words]

[Time4]
In Section 3 toxicological in vivo, in silico, and in vitro test methods are discussed which may be applied for the safety and nutritional assessment of specific compounds present in food and feed or of whole food and feed derived from GM plants. Moreover the purpose, potential and limitations of the 90-day rodent feeding trial for the safety and nutritional testing of whole food and feed have been examined.

Methods for single and repeated dose toxicity testing, reproductive and developmental toxicity testing and immunotoxicity testing, as described in OECD guideline tests for single well-defined chemicals are discussed and considered to be adequate for the safety testing of single substances including new products in GM food and feed.

Various in silico and in vitro methods may contribute to the safety assessment of GM plant derived food and feed and components thereof, like (i) in silico searches for sequence homology and/or structural similarity of novel proteins or their degradation products to known toxic or allergenic proteins, (ii) simulated gastric and intestinal fluids in order to study the digestive stability of newly expressed proteins and in vitro systems for analysis of the stability of the novel protein under heat or other processing conditions, and (iii) in vitrogenotoxicity test methods that screen for point mutations, chromosomal aberrations and DNA damage/repair.

The current performance of the safety assessment of whole foods is mainly based on the protocols for low-molecular-weight chemicals such as pharmaceuticals, industrial chemicals, pesticides, food additives and contaminants. However without adaptation, these protocols have limitations for testing of whole food and feed. This primarily results from the fact that defined single substances can be dosed to laboratory animals at very large multiples of the expected human exposure, thus giving a large margin of safety. In contrast foodstuffs are bulky, lead to satiation and can only be included in the diet at much lower multiples of expected human intakes. When testing whole foods, the possible highest concentration of the GM food and feed in the laboratory animal diet may be limited because of nutritional imbalance of the diet, or by the presence of compounds with a known toxicological profile.
[355 words]

Source: Biomedseatch

http://www.biomedsearch.com/nih/Safety-nutritional-assessment-GM-plants/18328408.html

ed

The Truth about Genetically Modified Food

Proponents of genetically modified crops say the technology is the only way to feed a warming, increasingly populous world. Critics say we tamper with nature at our peril. Who is right?

[Time5]
Robert Goldberg sags into his desk chair and gestures at the air. “Frankenstein monsters, things crawling out of the lab,” he says. “This the most depressing thing I've ever dealt with.”

Goldberg, a plant molecular biologist at the University of California, Los Angeles, is not battling psychosis. He is expressing despair at the relentless need to confront what he sees as bogus fears over the health risks of genetically modified (GM) crops. Particularly frustrating to him, he says, is that this debate should have ended decades ago, when researchers produced a stream of exonerating evidence: “Today we're facing the same objections we faced 40 years ago.”

Across campus, David Williams, a cellular biologist who specializes in vision, has the opposite complaint. “A lot of naive science has been involved in pushing this technology,” he says. “Thirty years ago we didn't know that when you throw any gene into a different genome, the genome reacts to it. But now anyone in this field knows the genome is not a static environment. Inserted genes can be transformed by several different means, and it can happen generations later.” The result, he insists, could very well be potentially toxic plants slipping through testing.

Williams concedes that he is among a tiny minority of biologists raising sharp questions about the safety of GM crops. But he says this is only because the field of plant molecular biology is protecting its interests. Funding, much of it from the companies that sell GM seeds, heavily favors researchers who are exploring ways to further the use of genetic modification in agriculture. He says that biologists who point out health or other risks associated with GM crops—who merely report or defend experimental findings that imply there may be risks—find themselves the focus of vicious attacks on their credibility, which leads scientists who see problems with GM foods to keep quiet.
[313 words]

[Tim6]
Whether Williams is right or wrong, one thing is undeniable: despite overwhelming evidence that GM crops are safe to eat, the debate over their use continues to rage, and in some parts of the world, it is growing ever louder. Skeptics would argue that this contentiousness is a good thing—that we cannot be too cautious when tinkering with the genetic basis of the world's food supply.

To researchers such as Goldberg, however, the persistence of fears about GM foods is nothing short of exasperating. “In spite of hundreds of millions of genetic experiments involving every type of organism on earth,” he says, “and people eating billions of meals without a problem, we've gone back to being ignorant.”

So who is right: advocates of GM or critics? When we look carefully at the evidence for both sides and weigh the risks and benefits, we find a surprisingly clear path out of this dilemma.

Benefits and Worries
The bulk of the science on GM safety points in one direction. Take it from David Zilberman, a U.C. Berkeley agricultural and environmental economist and one of the few researchers considered credible by both agricultural chemical companies and their critics. He argues that the benefits of GM crops greatly outweigh the health risks, which so far remain theoretical. The use of GM crops “has lowered the price of food,” Zilberman says. “It has increased farmer safety by allowing them to use less pesticide. It has raised the output of corn, cotton and soy by 20 to 30 percent, allowing some people to survive who would not have without it. If it were more widely adopted around the world, the price [of food] would go lower, and fewer people would die of hunger.”

In the future, Zilberman says, those advantages will become all the more significant. The United Nations Food and Agriculture Organization estimates that the world will have to grow 70 percent more food by 2050 just to keep up with population growth. Climate change will make much of the world's arable land more difficult to farm. GM crops, Zilberman says, could produce higher yields, grow in dry and salty land, withstand high and low temperatures, and tolerate insects, disease and herbicides.
[368 words]

Source: ScientificAmerican
http://www.scientificamerican.com/article/the-truth-about-genetically-modified-food/

cherry6891

Part III: Obstacle

[Paraphrase 7]

It’s no secret that people are nervous about foods made from genetically modified organisms. A July Gallup poll found that 48 percent of respondents believed that GM foods “pose a serious health hazard,” compared to 36 percent who didn’t. California voters may have rejecteda ballot initiative to require labeling of GM foods last fall, but a New York Times survey found overwhelming support for mandatory labeling on the packaging of GM foods.

Within the scientific community, the debate over the safety of GM foods is over. The overwhelming conclusion is, in the words of the American Association for the Advancement of Science, that “consuming foods containing ingredients derived from GM crops is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques.” Major scientific and governmental organizations agree. The U.S. National Academy of Sciences found that “no adverse health effects attributed to genetic engineering have been documented in the human population,” and a report issued by the European Commission made the same claim. The World Health Organization has concluded that GM foods “are not likely, nor have been shown, to present risks for human health.”

The scientific literature backs this up. In February, the Journal of Agricultural and Food Chemistry published a literature review covering 20 years of safety studies. The authors found “overwhelming evidence” that using biotechnology to genetically modify crops “is less disruptive of crop composition compared with traditional breeding, which itself has a tremendous history of safety.” An overview of safety studies appearing this month in Nature Biotechnology noted that, despite disagreement over a need for more long-term safety studies, both critics and proponents of GMOs agree that so far “genetically modified foods have failed to produce any untoward health effects.”

In other words, the scientific consensus is that GMOs do not pose risks to our health or the environment that are any different from the risks posed by the non-GM crops created with modern breeding programs.

The discrepancy between the public debate over GM foods and the debate within the scientific community has left many scientists puzzling over the question: What evidence will it take to convince the public that GM foods are as safe as non-GM foods?

The editors at Nature Biotechnology argue that evidence is not the problem. The issue is that, so far, people have no reason to believe GM foods are being created for their benefit. Changing negative attitudes will “require a concerted and long-term effort to develop GM foods that clearly provide convincing benefits to consumers—something that seed companies have conspicuously failed to do over the past decade.” The question of benefits has been buried because the GMO debate has been framed around the unhelpful distinction between GM and non-GM foods. Instead of asking if GM foods in general are less safe, the editors argue, we should be focused on the specific risks and benefits of individual products, whether they are GM or not.

A focus on the risks and benefits of all new crops could move the debate in a direction that would prompt scientists, companies, and regulators to more clearly justify the role GMOs play in our food supply. To date, consumers nervous about GMOs have been given little reason to think that companies like Monsanto are designing GM crops to solve any problem other than the one of patents and profits. As journalist Mark Lynas put it in his rousing defense of GM foods, for most people GMOs are about a “big American corporation with a nasty track record, putting something new and experimental into our food without telling us.”

But many researchers working on GM crops are in fact trying to solve important problems, such as feeding a growing population, keeping food prices affordable worldwide, making healthier fruits and vegetableswidely available, confronting the challenging growing conditions of a changing climate, saving Florida’s oranges or Hawaii’s papaya from pests, and fighting malnourishment in the developing world. For many of these problems, genetic engineering is faster, more cost-effective, and more reliable than conventional breeding methods.

Our society’s unresolved controversy over GMOs is not about safety; it’s about whether we have an acceptable process in place to ensure that our health is not put at risk for the sake of biotech’s bottom line. Researchers, biotech companies, and regulators need to settle on an appropriately rigorous, transparent, and independent safety testing process for all new crops, one whose methods and results are publicly available. Currently, as the Nature Biotechnology review notes, safety assessments in the U.S. are a patchwork affair with weak legal underpinnings. But for GM solutions to our food challenges to be widely accepted, the public needs to know that they are not being coerced into eating something whose risks and benefits are unknown.

[794 words]

Source: Psmag

http://www.psmag.com/navigation/health-and-behavior/scientific-debate-gm-foods-theyre-safe-66711/

  

hysteries

这么早~~~~

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【Speed】
00:01:36
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00:02:08

【Obstacle】
00:05:43

疏离无罪

占~~~~~~~~~·

Speaker:Transgenic animals are vital in medical research and in other field.Whether the transgenic animals can provide us better life is still unknown.We should take this under control.

01:43
The risk assessment and safety assessment of GM plant are discussed in the report.

02:08
The main content of the safety assessment.Provide an overview of studies performed for the safety and nutritional assessment of whole food and feed.

01:45
Describe the method used to test the safety of the GM plants.The current methods are mainly based on the protocols for low-molecular-weight chemicals.

02:01
GM plants may be toxic several generations later.So the safety os GM plants is still a questions.But many fundings in this field are provided by companies who sell these seeds,many scinetist have to keep slient.

01:31
Although many evidences are given to show that the GM crops are safe,many people still do not think so.Some scientists think that the benefits outweigh the health risks.

06:05
Main Idea: GMOs are safe to people
Most people think that the GMOs have some riks to our health.But scientists said that comsuming foods with GMOs is no risker than comsuming foods with other plants and GMOs is less disruptive of crop composition compared with traditional breeding.
The problems is that the public have no reason to believe GM goods are being created for their benefits.The companies and scientists now should clearly provide convinceing benefits that GMOs can bring to people.The comparasion of the risks and benefits of all new crops can clearly show the evidence.
The most important thing now is to ensure that our health is not put at risk for the sake of biotech’s bottom line.

house887

1.34.6
1.44.5
1.30.0
1.10.4
2.11.5
6.00.7

小蘑菇开始打怪

如此早！还在补昨天的作业。。
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谢谢楼主！~

speaker:

we have used the transgenic tech to change the animals for a long time, but what is the potential result of the tech we still do not know

the approval of the use of milk?

time2:

the importance of testing the elements of GM food

time3:

the purpose of safety assessment

the assessment still has some shortcomings

how do animals perform when they are feed with GM plants

time4:

the availabilities of some testing methods

the current assessment is not enough because it has some limitations

time5:

in the past, scientists have limited acknowledge of the inserted genes, but they know now

the research about the potential harm leads some scientists see the GM more serious

time6:

the analysis of the benefits and worries about the GM plants

the GM plants can produce higher yields

time7:

from the survey, people care about the safety problems about the GM food and support for the law of mandating labeling on the packaging of GM foods

the association said that genetic food is no more risker than  plant modified by conventional plant improvement tech

GMOs do not pose risks to our health

how can scientists convince the public that the GM plants are safe

the issue is that people have no reason to believe GM foods are being created for their benefit

some researchers are working on trying to solve the problems

whether our safe in the experiment of some biotech companies

public needs and has the right to know they do not eat something whose risks and benefits are unknown

TaoRs92

首页~~~~~~~~~~~~~~~~~~~~~~~~~


time:1:42.04
The subjects--some types of GMO food--soybeans...
How to study--compare GMO and their normal counterparts in different angles.
______________
time:2:12.82
Safety assesement--1 proteins and changes in natural constituents level in GMO.2 unintended effects on GMO.
Feeding trials.Whether animals feed on GMO have differences from animals feed on normal food.
________________
time:2:05.70
Safety and nutritional test for whole GMO food.Rodent trails.
The methods.
The current performances.
_______________
time:1:43.61
Debate towards GM crops remian many decades.
Risk or not?Genome is not a static environment.The reactions of transgene may appear generations later.So risks exist.
But schoolars may keep quiet for interests.
_______________
time:1:53.98
While evidences show that GM crops are safe,criticism towards GM crops also become louder.
Who is right?
The result--benifts surpresses health risks.Examples and advantages of GM crops.
_________________
time:4:21.63
In scientific field,the debate about whether GM food is safe is done--they are safe and put no more risks towards human health than normal food.
Evidences and examples.
Problem--how to convince the public.
people have no reason to believe the evidence.the unhelpful distinction between GM and non-GM.the focus the public is wrong.they should consider the risks and benifits,rather than the distinction itself.
the risk and benifits of GM:
risk--proved safety in scientific field.
benifits--help provide more food and more people can survive.more reliable than conventional breeding crops..
Advice--more transparent GM.consider risks and benifts.public should know that they are not consume food with potential risks.

cherry6891

早起的鸟儿有虫吃

Obstacle：

Almosthalf of respondents believed GM foods is harmful to health

The debateover the safety of GM food is over in scientific community then author citedscientific backed the conclusion up

How to convincethe public ?

Provideconvincing benefits to consumers

Focus onthe specific risks and benefits of individuals

The workon GM is trying to solve problems: feeding a growing population and makinghealthier fruits other than maintaining patents or profits for the company

Rigorous,transparent and independent safety testing process for new crops is needed andpublic have right to get access to it

Time2 34

The reportdiscussed about the safety and nutritional assessment procedure for GM

Scope:food and GM plants

Generalprinciple: comparative approach

Focus on:constituents in GM, unintended effects,

Section2 safety and nutritional assessment

Section3in vivo and vitro tests of safety

Time5

The biologists who point out health risksassociate with GM suffer vicious attacks on credibility, which lead them tokeep silent

Time6

The benefits of GM food

xiaofan0205

早啊～～～～～～

Speaker:
In Massachusetts, goats now produce milk with drugs embedded. The U.S. FDA aims to ensure the safe use of transgenic animals and approved the first drug from transgenic goat's milk earlier this year. But there's still the potential problem of whether animals with altered DNA can be safely controlled.

Time2: 2'08"
Time3: 2'46"
Time4: 2'44"
Transgenesis is the process of introducing a transgene into a living organism so that the organism will exhibit a new property and transmit that property to its offspring.
The various elements of the safety and nutritional assessment procedure for genetically modified (GM) plant derived food and feed are discussed, In Section 1 the mandate, scope and general principles for risk assessment of GM plant derived food and feed are discussed. Section 2 provides an overview of studies performed for the safety and nutritional assessment of whole food and feed. In Section 3 toxicological in vivo, in silico, and in vitro test methods are discussed which may be applied for the safety and nutritional assessment of specific compounds present in food and feed or of whole food and feed derived from GM plants.

Time5: 2'04"
Time6: 2'09"
Debate towards GM crops remian many decades. The genome is not a static environment. Inserted genes can be transformed by several different means, and it can happen generations later. Biologists who point out health or other risks associated with GM crops find themselves the focus of vicious attacks on their credibility, which leads scientists who see problems with GM foods to keep quiet.
Proponents of genetically modified crops say the technology is the only way to feed a warming, increasingly populous world.