Is GM Food Safe To Eat ?
Traditional plant breeding involves crossing varietiesof the same species in w ays they could crossnaturally. For example, dia-resistant varieties of wh eat have been crosd with high-yield wheat to combine the properties. T his type of natural gene exchange is safe and fairly predictable.
Genetic engineering ( GE) involves exchanging genes between unrelated spe cies that cannotnaturally exchange genes with each other. GE can involve the exchange of genes betweenvastly different species— e.g. putting scor pion toxin genes into maize or fish antifreeze genes into tomatoes. It is po ssible that a scorpion toxin gene, even when it is in maize DNA1, will still g et the organism to produce scorpion toxin— but what other effects may i thave in this alien environment? We are already eing this problem — addi ng human growth hormone genes to pigs certainly makes them grow — but i t also gives them arthritis andmakes them cross-eyed, which was entirely un predictable.
It will be obvious, for example, that the gene for human intelligence will n ot have the sameeffect if inrted into cabbage DNA as it had in human DNA — but what side-effect would ithave? In other words, is GM food2 safe to ? The answer is that nobody knows becaulong-term tests have not been carr ied out.
Companies wanting a GM product approved in the UK or USA are required to provide regulatorybodies with results of their own safety tests. Monsanto’s3 s oya beans were apparently fed tofish for 10 weeks before being approved. Th ere was no requirement for independent testing,for long-term testing, for te sting on humans or testing for specific dangers to children or allergic4 peopl e.
The current position of the UK Government is that"There is no evidence of l ong-term dangersfrom GM foods."In the US, the American Food and Drug Ad ministration5 is currently beingprocuted for covering up rearch that sug gested possible risks from GM foods.扑尔敏的功效与作用
A consistent all-over tan may be impossible to achieve becau some body areas are much more resistant to tanning than others, a study has found.
每天喝牛奶的好处和坏处Rearchers - funded by the Medical Rearch Council (MRC) - at the University of Edinburgh say the results explain why some holidaymakers find it so hard to achieve an even tan all over their body.
The findings, published in the journal Experimental Dermatology, show that the buttock is much more resistant to sunshine but surprisingly when it does go red it tans less well than other areas.
It was also found that people with no freckles tanned more easily than tho without freckling.
The study reprents the first time that the depth of a person's tan, and not just skin redness, has been quantified.
花市灯如昼Scientists carried out the study to try and solve the puzzle of why different types of skin cancer tend to be found in different parts of the body, given that they are all caud by exposure to sunshine.
The team aimed to identify whether this is linked to variations in the way different parts of the body develop a tan.
项目立项申请书
The team analyd the skin of 100 volunteers, who were expod to six do of UVB on two areas of their body their back and their buttock.
The volunteers were given an injection to minimi the rush of blood that naturally occurs after the skin is expod to sunlight within the first 24 hours.
移精是怎么回事Rearchers say this redness is often confud with the start of tanning, but in fact is the skin's signal that it has been damaged.
After ven days, the volunteers' skin was analyd to find what colour remained after the redness had died down. This colour recognid as a suntan comes from the skin's production of melanin, a defence that blocks the skin absorbing too much harmful UVB radiation.
Jonathan Rees, Professor of Dermatology at the University of Edinburgh, who led the study said: "One A consistent all-over tan may be impossible to achieve becau some body areas are much more resistant to tanning than others, a study has found.
第三章
New findings from the Monell Center reveal that weight gain of formula-fed infants is influenced by the type of formula the infant is consuming. The findings have implications related to the infant's risk for the development of obesity, diabetes and other dias later in life. "Events early in life have long-term conquences on health and one of the most significant influences is early growth rate," said study lead author Julie Mennella, Ph.D., a developmental psychobiologist at Monell. "We already know that formula-fed babies gain more weight than
breast-fed babies. But we didn't know whether this was true for all types of formula."
While most infant formulas are cow's milk-bad, other choices include soy-bad and protein hydrolysate（水解物）-bad formulas. Protein hydrolysate formulas contain
pre-digested proteins and typically are fed to infants who cannot tolerate the intact（完整的，原封不动的）proteins in other formulas.
In adults, pre-digested proteins are believed to act in the intestine（肠）to initiate（创始，发起）the end of a meal, thus
leading to smaller meals and intake of fewer calories. Bad on this, the authors hypothesize that infants who were feeding protein hydrolysate formulas would eat less and have an altered growth pattern relative to infants feeding cow's milk-bad formula.
In the study, published online in the journal Pediatrics, infants who parents had already decided to bottle-feed were randomly assigned at two weeks of age to feed either a cow's milk-bad formula (35 infants) or a protein hydrolysate formula (24 infants) for ven monthes . Both formulas contained the same amount of calories, but the hydrolysate formula had more protein, including greater amounts of small peptides（多肽类，缩氨酸）and free amino acids.
想起Infants were weighed once each month in the
世界禁曲
laboratory , where they also were videotaped consuming a meal of the assigned formula. The meal continued until the infant signaled that s/he was full.
赞美老师的名人名言Over the ven months of the study, the protein hydrolysate infants gained weight at a slower rate than
