CT SCan Mchina
JF-Expert Member
- Mar 13, 2013
- 1,311
- 289
Umeona eeh ameingia choo cha 'Mabibi' kabisa...
Mdee: Rais ameingizwa 'choo cha kike'
Mdee: Rais ameingizwa 'choo cha kike'
- Thread starter MGANGA WA KIENYEJI
- Start date
Umeona eeh ameingia choo cha 'Mabibi' kabisa...
OSOKONI
JF-Expert Member
- Oct 20, 2011
- 10,965
- 5,344
What are genetically-modified foods?
The term GM foods or GMOs (genetically-modified organisms) is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques. These plants have been modified in the laboratory to enhance desired traits such as increased resistance to herbicides or improved nutritional content.
The enhancement of desired traits has traditionally been undertaken through breeding, but conventional plant breeding methods can be very time consuming and are often not very accurate. Genetic engineering, on the other hand, can create plants with the exact desired trait very rapidly and with great accuracy. For example, plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant.
The new genetically-modified plant will gain drought tolerance as well. Not only can genes be transferred from one plant to another, but genes from non-plant organisms also can be used. The best known example of this is the use of B.t. genes in corn and other crops. B.t., or Bacillus thuringiensis, is a naturally occurring bacterium that produces crystal proteins that are lethal to insect larvae. B.t. crystal protein genes have been transferred into corn, enabling the corn to produce its own pesticides against insects such as the European corn borer. For two informative overviews of some of the techniques involved in creating GM foods, visit Biotech Basics (sponsored by Monsanto)
What are some of the criticisms against
GM foods?
Environmental activists, religious organizations, public interest groups, professional associations and other scientists and government officials have all raised concerns about GM foods, and criticized agribusiness for pursuing profit without concern for potential hazards, and the government for failing to exercise adequate regulatory oversight. It seems that everyone has a strong opinion about GM foods. Even the Vatican19 and the Prince of Wales20 have expressed their opinions. Most concerns about GM foods fall into three categories: environmental hazards, human health risks, and economic concerns.
Environmental hazards
 Unintended harm to other organisms Last year a laboratory study was published in Nature21 showing that pollen from B.t. corn caused high mortality rates in monarch butterfly caterpillars. Monarch caterpillars consume milkweed plants, not corn, but the fear is that if pollen from B.t. corn is blown by the wind onto milkweed plants in neighboring fields, the caterpillars could eat the pollen and perish. Although the Nature study was not conducted under natural field conditions, the results seemed to support this viewpoint. Unfortunately, B.t. toxins kill many species of insect larvae indiscriminately; it is not possible to design a B.t. toxin that would only kill crop-damaging pests and remain harmless to all other insects. This study is being reexamined by the USDA, the U.S. Environmental Protection Agency (EPA) and other non-government research groups, and preliminary data from new studies suggests that the original study may have been flawed22, 23. This topic is the subject of acrimonious debate, and both sides of the argument are defending their data vigorously. Currently, there is no agreement about the results of these studies, and the potential risk of harm to non-target organisms will need to be evaluated further.
 Reduced effectiveness of pesticides .Just as some populations of mosquitoes developed resistance to the now-banned pesticide DDT, many people are concerned that insects will become resistant to B.t. or other crops that have been genetically-modified to produce their own pesticides
.
 Gene transfer to non-target species . Another concern is that crop plants engineered for herbicide tolerance and weeds will cross-breed, resulting in the transfer of the herbicide resistance genes from the crops into the weeds. These "superweeds" would then be herbicide tolerant as well. Other introduced genes may cross over into non-modified crops planted next to GM crops. The possibility of interbreeding is shown by the defense of farmers against lawsuits filed by Monsanto. The company has filed patent infringement lawsuits against farmers who may have harvested GM crops. Monsanto claims that the farmers obtained Monsanto-licensed GM seeds from an unknown source and did not pay royalties to Monsanto. The farmers claim that their unmodified crops were cross-pollinated from someone else's GM crops planted a field or two away. More investigation is needed to resolve this issue.
There are several possible solutions to the three problems mentioned above. Genes are exchanged between plants via pollen. Two ways to ensure that non-target species will not receive introduced genes from GM plants are to create GM plants that are male sterile (do not produce pollen) or to modify the GM plant so that the pollen does not contain the introduced gene24, 25, 26. Cross-pollination would not occur, and if harmless insects such as monarch caterpillars were to eat pollen from GM plants, the caterpillars would survive.
Another possible solution is to create buffer zones around fields of GM crops27, 28, 29. For example, non-GM corn would be planted to surround a field of B.t. GM corn, and the non-GM corn would not be harvested. Beneficial or harmless insects would have a refuge in the non-GM corn, and insect pests could be allowed to destroy the non-GM corn and would not develop resistance to B.t. pesticides. Gene transfer to weeds and other crops would not occur because the wind-blown pollen would not travel beyond the buffer zone. Estimates of the necessary width of buffer zones range from 6 meters to 30 meters or more30. This planting method may not be feasible if too much acreage is required for the buffer zones.
Human health risks
 Allergenicity .Many children in the US and Europe have developed life-threatening allergies to peanuts and other foods. There is a possibility that introducing a gene into a plant may create a new allergen or cause an allergic reaction in susceptible individuals. A proposal to incorporate a gene from Brazil nuts into soybeans was abandoned because of the fear of causing unexpected allergic reactions31. Extensive testing of GM foods may be required to avoid the possibility of harm to consumers with food allergies. Labeling of GM foods and food products will acquire new importance, which I shall discuss later.
 Unknown effects on human health There is a growing concern that introducing foreign genes into food plants may have an unexpected and negative impact on human health. A recent article published in Lancet examined the effects of GM potatoes on the digestive tract in rats32, 33. This study claimed that there were appreciable differences in the intestines of rats fed GM potatoes and rats fed unmodified potatoes. Yet critics say that this paper, like the monarch butterfly data, is flawed and does not hold up to scientific scrutiny34. Moreover, the gene introduced into the potatoes was a snowdrop flower lectin, a substance known to be toxic to mammals. The scientists who created this variety of potato chose to use the lectin gene simply to test the methodology, and these potatoes were never intended for human or animal consumption.
On the whole, with the exception of possible allergenicity, scientists believe that GM foods do not present a risk to human health.
Economic concerns
Bringing a GM food to market is a lengthy and costly process, and of course agri-biotech companies wish to ensure a profitable return on their investment. Many new plant genetic engineering technologies and GM plants have been patented, and patent infringement is a big concern of agribusiness. Yet consumer advocates are worried that patenting these new plant varieties will raise the price of seeds so high that small farmers and third world countries will not be able to afford seeds for GM crops, thus widening the gap between the wealthy and the poor. It is hoped that in a humanitarian gesture, more companies and non-profits will follow the lead of the Rockefeller Foundation and offer their products at reduced cost to impoverished nations.
Patent enforcement may also be difficult, as the contention of the farmers that they involuntarily grew Monsanto-engineered strains when their crops were cross-pollinated shows. One way to combat possible patent infringement is to introduce a "suicide gene" into GM plants. These plants would be viable for only one growing season and would produce sterile seeds that do not germinate. Farmers would need to buy a fresh supply of seeds each year. However, this would be financially disastrous for farmers in third world countries who cannot afford to buy seed each year and traditionally set aside a portion of their harvest to plant in the next growing season. In an open letter to the public, Monsanto has pledged to abandon all research using this suicide gene technology
The term GM foods or GMOs (genetically-modified organisms) is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques. These plants have been modified in the laboratory to enhance desired traits such as increased resistance to herbicides or improved nutritional content.
The enhancement of desired traits has traditionally been undertaken through breeding, but conventional plant breeding methods can be very time consuming and are often not very accurate. Genetic engineering, on the other hand, can create plants with the exact desired trait very rapidly and with great accuracy. For example, plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant.
The new genetically-modified plant will gain drought tolerance as well. Not only can genes be transferred from one plant to another, but genes from non-plant organisms also can be used. The best known example of this is the use of B.t. genes in corn and other crops. B.t., or Bacillus thuringiensis, is a naturally occurring bacterium that produces crystal proteins that are lethal to insect larvae. B.t. crystal protein genes have been transferred into corn, enabling the corn to produce its own pesticides against insects such as the European corn borer. For two informative overviews of some of the techniques involved in creating GM foods, visit Biotech Basics (sponsored by Monsanto)
What are some of the criticisms against
GM foods?
Environmental activists, religious organizations, public interest groups, professional associations and other scientists and government officials have all raised concerns about GM foods, and criticized agribusiness for pursuing profit without concern for potential hazards, and the government for failing to exercise adequate regulatory oversight. It seems that everyone has a strong opinion about GM foods. Even the Vatican19 and the Prince of Wales20 have expressed their opinions. Most concerns about GM foods fall into three categories: environmental hazards, human health risks, and economic concerns.
Environmental hazards
 Unintended harm to other organisms Last year a laboratory study was published in Nature21 showing that pollen from B.t. corn caused high mortality rates in monarch butterfly caterpillars. Monarch caterpillars consume milkweed plants, not corn, but the fear is that if pollen from B.t. corn is blown by the wind onto milkweed plants in neighboring fields, the caterpillars could eat the pollen and perish. Although the Nature study was not conducted under natural field conditions, the results seemed to support this viewpoint. Unfortunately, B.t. toxins kill many species of insect larvae indiscriminately; it is not possible to design a B.t. toxin that would only kill crop-damaging pests and remain harmless to all other insects. This study is being reexamined by the USDA, the U.S. Environmental Protection Agency (EPA) and other non-government research groups, and preliminary data from new studies suggests that the original study may have been flawed22, 23. This topic is the subject of acrimonious debate, and both sides of the argument are defending their data vigorously. Currently, there is no agreement about the results of these studies, and the potential risk of harm to non-target organisms will need to be evaluated further.
 Reduced effectiveness of pesticides .Just as some populations of mosquitoes developed resistance to the now-banned pesticide DDT, many people are concerned that insects will become resistant to B.t. or other crops that have been genetically-modified to produce their own pesticides
.
 Gene transfer to non-target species . Another concern is that crop plants engineered for herbicide tolerance and weeds will cross-breed, resulting in the transfer of the herbicide resistance genes from the crops into the weeds. These "superweeds" would then be herbicide tolerant as well. Other introduced genes may cross over into non-modified crops planted next to GM crops. The possibility of interbreeding is shown by the defense of farmers against lawsuits filed by Monsanto. The company has filed patent infringement lawsuits against farmers who may have harvested GM crops. Monsanto claims that the farmers obtained Monsanto-licensed GM seeds from an unknown source and did not pay royalties to Monsanto. The farmers claim that their unmodified crops were cross-pollinated from someone else's GM crops planted a field or two away. More investigation is needed to resolve this issue.
There are several possible solutions to the three problems mentioned above. Genes are exchanged between plants via pollen. Two ways to ensure that non-target species will not receive introduced genes from GM plants are to create GM plants that are male sterile (do not produce pollen) or to modify the GM plant so that the pollen does not contain the introduced gene24, 25, 26. Cross-pollination would not occur, and if harmless insects such as monarch caterpillars were to eat pollen from GM plants, the caterpillars would survive.
Another possible solution is to create buffer zones around fields of GM crops27, 28, 29. For example, non-GM corn would be planted to surround a field of B.t. GM corn, and the non-GM corn would not be harvested. Beneficial or harmless insects would have a refuge in the non-GM corn, and insect pests could be allowed to destroy the non-GM corn and would not develop resistance to B.t. pesticides. Gene transfer to weeds and other crops would not occur because the wind-blown pollen would not travel beyond the buffer zone. Estimates of the necessary width of buffer zones range from 6 meters to 30 meters or more30. This planting method may not be feasible if too much acreage is required for the buffer zones.
Human health risks
 Allergenicity .Many children in the US and Europe have developed life-threatening allergies to peanuts and other foods. There is a possibility that introducing a gene into a plant may create a new allergen or cause an allergic reaction in susceptible individuals. A proposal to incorporate a gene from Brazil nuts into soybeans was abandoned because of the fear of causing unexpected allergic reactions31. Extensive testing of GM foods may be required to avoid the possibility of harm to consumers with food allergies. Labeling of GM foods and food products will acquire new importance, which I shall discuss later.
 Unknown effects on human health There is a growing concern that introducing foreign genes into food plants may have an unexpected and negative impact on human health. A recent article published in Lancet examined the effects of GM potatoes on the digestive tract in rats32, 33. This study claimed that there were appreciable differences in the intestines of rats fed GM potatoes and rats fed unmodified potatoes. Yet critics say that this paper, like the monarch butterfly data, is flawed and does not hold up to scientific scrutiny34. Moreover, the gene introduced into the potatoes was a snowdrop flower lectin, a substance known to be toxic to mammals. The scientists who created this variety of potato chose to use the lectin gene simply to test the methodology, and these potatoes were never intended for human or animal consumption.
On the whole, with the exception of possible allergenicity, scientists believe that GM foods do not present a risk to human health.
Economic concerns
Bringing a GM food to market is a lengthy and costly process, and of course agri-biotech companies wish to ensure a profitable return on their investment. Many new plant genetic engineering technologies and GM plants have been patented, and patent infringement is a big concern of agribusiness. Yet consumer advocates are worried that patenting these new plant varieties will raise the price of seeds so high that small farmers and third world countries will not be able to afford seeds for GM crops, thus widening the gap between the wealthy and the poor. It is hoped that in a humanitarian gesture, more companies and non-profits will follow the lead of the Rockefeller Foundation and offer their products at reduced cost to impoverished nations.
Patent enforcement may also be difficult, as the contention of the farmers that they involuntarily grew Monsanto-engineered strains when their crops were cross-pollinated shows. One way to combat possible patent infringement is to introduce a "suicide gene" into GM plants. These plants would be viable for only one growing season and would produce sterile seeds that do not germinate. Farmers would need to buy a fresh supply of seeds each year. However, this would be financially disastrous for farmers in third world countries who cannot afford to buy seed each year and traditionally set aside a portion of their harvest to plant in the next growing season. In an open letter to the public, Monsanto has pledged to abandon all research using this suicide gene technology
Bukanga
JF-Expert Member
- Dec 13, 2010
- 2,857
- 1,937
Asante kwa kumuweka wazi huyu kilaza wa Bumbuli ambaye hajawahi kupigiwa kura popote pale duniani!
Natamani ugombee uongozi katika jamii au uteuliwe halafu uwaoneshe wenzako namna ya kuongoza. Its easier said than done.
Kiranga
Platinum Member
- Jan 29, 2009
- 85,777
- 145,567
What is this? A witchhunt? a smear campaign? If it is, then look for something more substantive.This is weak indeed even for some of us who are bent on zero tolerance.
Restating an idea is not plagiarism, nor is it lack of giving proper credit, plagiarism involves a definite lack of inventiveness rooted in restating an idea with a deplorable degree of verbatim diction.
If you fault Mdee for this, there is not one of Nyerere's speeches that will stand your test. You may actually go so far as needing everybody to invent their own language anytime they want to speak or write, a scenario that would put Babel to shame.
Unless you can show that Halima Mdee used the exact words used by someone else who is not Halima Mdee (a hard feat given most JF users are anonymous) you cannot show plagiarism.
Otherwise you run the risk of accusing Halima Mdee of quoting herself, a possibly conceitedly Kiranga-like fashion, but certainly not plagiarism.
JF tunataka wabunge waje kuchukua mambo ya muhimu hapa na kuyapeleka bungeni.
Harry S. Truman once said "It is amazing what you can accomplish if you do not care who gets the credit."
The whole talk about credit is rather petty and distracting. I give Mdee credit for repping JF.
Ben Saanane
JF-Expert Member
- Jan 18, 2007
- 14,580
- 18,222
Last edited by a moderator:
CT SCan Mchina
JF-Expert Member
- Mar 13, 2013
- 1,311
- 289
Nenda kaseme wewe basi...
SINA JINA1
JF-Expert Member
- Feb 24, 2012
- 391
- 152
Kumbe watu wana shusha ngeli za kucopy and paste maneno ya other great thinker around tha world
Risa
Senior Member
- Feb 10, 2012
- 177
- 32
Duh!! naona una kazi maalumu ya kumfatilia Ben Saanane.
salimkabora
JF-Expert Member
- Nov 10, 2012
- 2,441
- 653
Jf ni wananchi na kazi ya mbunge ni kusikiliza wananchi wanasema nini na kupeleka mbele sasa hapo kakosea nini mpaka ataje na jina la mwananchi aliyempa hoja?
AdvocateFi
JF-Expert Member
- Jan 15, 2012
- 11,492
- 5,049
Pigo kwa CCM.
Hivi huyu JK amelogwa au anafanya makusudi, baadaye utamsikia mwigulu analalamika kumbe kimoyomoyo anjuwa wananchi tunagutuka
Yo Yo
JF-Expert Member
- May 31, 2008
- 11,210
- 1,738
Kama kawaida mods wanaibeba chadema. Wameiondoa thread
Ben Saanane
JF-Expert Member
- Jan 18, 2007
- 14,580
- 18,222
Akijua tunaendesha forums hata za Malawi kuliko wamalawi wenyewe.Moderators wengine wa JF watamcheka tu
winner forever
JF-Expert Member
- Mar 6, 2012
- 1,094
- 269
halima MDEE ni miongoni mwa wabunge vijana wanastahili kupongezwa kwa kufanya kazi usiku na mchana kuhakikisha watanzania wanapata haki zao. Go on Halima,many Tanzanians are behind you,
Mungo Park
JF-Expert Member
- Sep 14, 2010
- 2,115
- 1,834
Huyo Rais 'logically' atakuwa ni Rais wa Malawi..
Ng'wamapalala
JF-Expert Member
- Jun 9, 2011
- 6,811
- 6,506
Unajua kuna watu hapa wakituona tuko kimya wanafikiri sisi ni wakinga au wapumbavu fulani hivi.
This guy ( Ben Saanane) has been doing it not just once. Mabandiko yake mengi anayotumia lugha ya Queen Elizebert II anapakuwa kutoka sehemu mbali mbali bila hata ya ku-acknoledge.
Siasa kuchakachua, hata maneno na sentensi nazo kuchakachua. Tutafika kweli?.
Nyani Ngabu
Platinum Member
- May 15, 2006
- 97,100
- 136,732
Ben kesha-hint utetezi wa kwamba hata huko anaweza kuwa mwanachama pia.
MVUMBUZI
JF-Expert Member
- Jan 8, 2011
- 5,182
- 2,330
Kama JF ni author wa hiyo article ange quote na kuisifu lakini JF siyo author nao wameichukua google au kwenye mitandao mingine. Pia hii article inapatikana maeneo mengi online kwa hiyo kumtaka Mh. Halima Mdee ku apologize ni ushamba na badala yake tunatakiwa kumsifia kwa kutoa hoja za kisayansi ambazo ni well researched.
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