Biologjia

Anana

Primus registratum
Re: Biologjia

Generally speaking...

Aggressive is bad, nice is boring.

Ehhh....kur do gjejme rehat....
 

Guest
Re: Biologjia

Meqe nuk dime nga tja fillojme po e nis une me dmth e termit biologji.

Biologjia = vjen nga greqishtja qe do te te thote njohuri mbi jeten(bios=jeta, logos= dituri ,njohuri) /pf/images/graemlins/laugh.gif
 

ruki

Primus registratum
Re: Biologjia

termi biologji d.m.th gjdo gje qe jeton dhe qe ben translacionin e gjeneve te tjetrit per te krijuar nje individ te ri per te zgjatur perjetsin e njerzimit dhe jetes. dhe gjdo gje qe eshte e ndertuar prej nje maqine me te persosur si eshte qeliza. si dhe shumimit te ti dhe kontrodhin e te gjitha mesazheve gjenetike bartjen e informacioneve gjenetike leximin e tyre.
 
Re: Biologjia

Dicka interesante qe lezova sot,marre nga gazeta shekulli!
Shekulli

Kerkues te nje laboratori po analizojne nje rrjedhoje gjenetike. Sfida: gjetja e nje ilaci qe mund te bllokoje genin e lidhur me plakjen. Ne kete zbulim, te gjithin italian, synojne jo vetem shkencetaret, por edhe biznesmene. Fjalekalimi eshte "aksidentale". Po, pasi vete zbulimi i Xhuzepe Pelici ishte i rastesishem dhe i papritur. Kater vjet me pare ai zbuloi se nje gen i vetem mund te kontrollonte tek nje mi jetegjatesine e tij. Dhe nje vit me vone, arriti te saktesoje rrjedhojat e funksioneve metabolike, qe percaktojne procesin e plakjes. Eshte nje histori e jashtezakonshme, e realizuar nga bioteknologjite e reja. Dhe nuk ka perfunduar. Madje tani fillon. Pasi probabiliteti qe ne prespektive te mund te nderhyhet ne organizmin tone dhe te gjendet ilaci qe te disaktivizoje ate gen, duke parandaluar demet e plakjes, te mos shfaqet me si nje pikesynim i larget. Sfida ka nisur keto dite me lindjen e "Genextra", shoqeria biotech e krijuar nga financieri Francesco Micheli. Geni, nje prej 30 mije geneve te qenies njerezore, quhet P66 dhe kur bllokohet zgjat jeten. Minjte jetojne me shume dhe nuk goditen nga semundjet e moshes, si ateroskleroza. "Eshte e padiskutueshme qe prosesi i plakjes eshte i shkruar ne adn-ne tone. E influencojne genet dhe ambjenti. Genet qe shkaktojne plakjen jane zbuluar ne drosofili. Miu eshte nje gjitar, qe ka ngjashmerine me te madhe gjenetike me njeriun, pervecse ka pothuajse te njejtin numer genesh ", shpjegon

Pier Xhuzepe Pelici, drejtor i departamentit te onkologjise eksperimentale ne Milano, i cili mban dhe patenten e zbulimit. Shkencetari prej dy vitesh e ndan kete aventure entuziasmuese ne kerkimin e molekulave antimoshe me Pier Paolo Di Fiore, drejtor shkencor i 'Ifom, Instituti i onkologjise molekulare. Si jeni ndeshur ne kete gen te jashtezakonshem, i cili duket se ka nje funksion te vetem? "Kemi arritur deri tek ai nga kerkimi i tumorit. Rastesisht. Ne vitin '92 identifikuam nje gen Shc (te cilin ne e quajme Shik), dhe po perpiqeshim te deshifronim sinjalet e tij. Ky gen eshte i barabarte me dy proteina te njejta ne 90%, por me funksione te kunderta: p52 qe rregullon rritjen qelizore, si rrjedhoje dhe ate tumoriale, dhe p66 e cila kontrollon vdekjen e qelizes. Nje funksion qe duhej sqaruar. Ndaj dhe krijuam nje trung me minj te modifikuar gjenetikisht. Vume re se ata jetonin 1/3 me shume se minjte qe e kishin genin ne vend", tregon Pelici. Edhe testet e mevonshme konfirmuan se proteina e genit p66 zgjat jeten e brejtesve dhe zhdukja e tij, duket se nuk krijon ndonje problem apo efekte anesore. Per te kuptuar se si funksiononte dhe per te verifikuar se si influenconte tek jetegjatesia. Ekzaktesisht para nje viti, pane qe e "mesonte" genin te prodhoje substancat oksiduese, ato qe na plakin cdo dite, eshte nje tjeter gen, p53, i cili na mbron nga kanceri, i njohur prej dekadash nga onkologjistet. "Sa here qe nje qelize i nenshtrohet stresit te ambjentit, p53 aktivizohet dhe dergon nje sinjal p66, duke e mesuar te prodhoje substanca oksiduese, radikalet e lira. Nese jane me tepri, cojne ne apoptozin e qelizes, pra ne vdekjen e programuar te adn-se se saj. Ne rast se prodhon me pak, qeliza nuk vdes, vetem demtohet dhe plaket", shpjegon Di Fiore. Ne praktike geni p53 ka dy funksione: nga njera ane mbron nga tumoret dhe nga ana tjeter eshte pergjegjes per plakjen. "Eshte dicka e vecante, nese eleminohet p66 nuk shkaktohet tumori tek minjte. Nuk ndodh keshtu ne rast se humbet p53", vezhgon Pelici. Zbulime te rendesishme qe ripropozojne pikepyetjet e perhershme: pse ka gene si p66, qe rrisin demtimin qelizor dhe bejne qe ne te plakemi? Eshte e mundur qe i njejti gen te jete i lidhur me mekanizma te tjera, qe mbrohen nga demi, si p53 dhe ne vecanti nga kanceri? Apo qe plakja eshte cmimi qe duhet te paguajme, pasi mesuam te mbrohemi nga kanceri dhe demtimi i adn-se eshte i domosdoshem per evoluimin e species? "Ne organizmin tone ekziston nje ekuiliber kostant, por i perkohshem mes demit dhe riparimit", vazhdon Pelici. "Eshte nje gen, qe ben dicka te mire dhe favorizon vetevrasjen e qelizave, nje funksion i favorshem. Por avantazhi ne termat e zhvillimit duhet shkembyer me plakjen".

Nese miu pa p66 fiton 30% jete me shume, sa vite jete mund te ishin per njerezit?

Ne teori mund te arrinim fare lehte tek 100 vjet. Dhe ne shendet. Pasi minjte pa p66, qe iu nenshtruan nje diete te pasur me yndyrna, dolen te paprekur nga eksperimenti, ndersa simotrat e tyre, geni i te cileve ishte aktiv zhvilluan semundjen e aterosklerozes. "Radikalet e lira, te pergjegjshme per degjenerimin qelizor, jane edhe per semundjet e lidhura me moshen, si ateroskleroza, kanceri, shqetesime venore. Venia ne funksion e nje molekule, qe bllokon kete proces vicioz te lidhur me p66, para zgjatjes se jetes, do te thote permiresim te cilesise, duke e liruar nga semundjet e plakjes. Perndryshe nuk do te quhej avantazh", thekson Pelici. "Tek njerezit nuk mund te eleminohet stresi oksidues, as nuk mund te mendohet te shuhet geni si tek minjte. Por mund te nderhyhet me nje substance kimike, qe te bllokoje aktivizimin e p66. Per shembull, duke ndaluar fosforolizimin, proces qe rrit sasine e radikaleve te lira", thote Di Fiore. Dhe pikerisht tek ky mikrolaborator i qelizes, mitokondriu, perqendrohet vemendja. Ne bote. Ne te pakten 30 laboratore, rremohet ne sekretet qelizore dhe molekulare, per te zbuluar sherues te demeve te kohes. Dhe prospektivat te lene te shpresosh se mirazhi i burimit te rinise se perjetshme apo i pavdekesie, i hyre ne laboratore mund te shnderrohet ne realitet.


Do ishte bukur!
 

eM

Paper Moon
Re: Biologjia

Me falni per Anglishten...

In his recent biography of James D. Watson, longtime science writer Victor K. McElheny refers to his subject as "a detonator in biology." This characterization reflects Watson's explosive influence on the direction of biology, from his very first detonation, the 1953 Nature paper that he wrote with Francis Crick describing the structure of DNA, to his directorship of the Human Genome Project in the late 20th century. But Watson's bombshells have not been limited to scientific advances; he has also initiated unprecedented forays of the scientific community into ethical and social realms. His brusque, quirky, contradictory and even cranky behavior has provoked controversy in nearly all of these endeavors, evoking a mixture of admiration and outrage. Now, to gauge the man and his impact, on the 50th anniversary of the Nature paper, we have not only McElheny's biography, Watson and DNA: Making a Scientific Revolution, but also DNA: The Secret of Life, Watson's own account, with coauthor Andrew Berry, of his Nobel Prize-winning DNA work and its consequences for biology.

McElheny largely lets Watson speak for himself. Although he has known Watson for decades and worked for him for four years at Cold Spring Harbor Laboratory he didn't interview him for the book (a curious omission that is not satisfactorily explained-McElheny just notes that Watson was busy with his own projects); rather, he has culled a series of quotations from Watson's writings, speeches and books and from interviews with his colleagues and students. These excerpts allow readers to frame their own portrait of the man-not a difficult task, since, as McElheny puts it, the "self-editing inculcated in most of us was absent" in Watson.

The persona we encounter in Watson's book is much toned down in comparison. This may be a sign of his coauthor's influence, or he may have decided that a softer presentation would help him reach his intended audience, those "with zero biological knowledge." Nevertheless, controversy and pet convictions pervade the narrative.

When Watson and Crick, with the unwitting help of x-ray crystallographer Rosalind Franklin, deduced the structure of DNA in 1953, they won what had been for them a frantic race to beat the chemist Linus Pauling. Their discovery provided a framework that suddenly allowed biologists to speak the same language as they tied research questions (how are genes passed from generation to generation, how do they code for proteins, how do mutations occur) to a "visible" chemical structure.

Watson also had other important successes in biology, as McElheny reminds us. For example, he participated in one of the last major fundamental findings in the formative period of molecular biology: the discovery in 1960 of messenger RNA, the molecule that mediates between genes and the protein products they encode. In the 1970s, he took over the Cold Spring Harbor Laboratory on Long Island and turned it into a world center for cancer research, showing a surprisingly strong talent for fundraising. And, in the 1980s and 1990s, he promoted and ultimately led the Human Genome Project, which revolutionized the practice of biology and the biomedical sciences.

Although the central concern of most science biographies is to catalog the important findings of the protagonist, an account of Watson's life must deal with a host of other factors, such as his impact on the environment within science. He was part of, and eventually became the most prominent symbol of, a rebellion of molecular biologists against the more stolid academic traditions and behavioral norms of an older generation of chemists, biologists and biochemists. McElheny notes that geneticist Francois Jacob described this new American generation of molecular biologists as "without barriers or hierarchies, . . . young students who did not hesitate to challenge the official stars. . . . A sort of horde unleashed on science." Watson eventually codified this rebellious behavior in his controversial 1968 book The Double Helix, which may have spurred the influx of an even larger "horde" of young scientists into molecular biology. These new behavioral norms had both pluses and minuses: On the one hand, young scientists felt free to pursue their own ideas and initiatives, fueling an extraordinarily creative period in biology. On the other hand, the field became extremely competitive, sometimes brutally so.

As McElheny recounts, biologist Peter Medawar observed in a review of The Double Helix that "Many of the things Watson says about the people in his story will offend them, but his own artless candor excuses him, for he betrays in himself faults graver than those he professes to discern in others." Statements by Watson that give a sense of how he raised people's ire are well represented in the quotations McElheny has selected. For example, Watson once interrupted the lecture of a visiting scientist by asking, "When are you going to do anything significant?" And at his 70th birthday party, giving advice on dealing with Harvard administrators, he said, "[They've] got to think that you're more important than the French department or any of these other departments which have great histories, but which, if they vanished, wouldn't make any difference." McElheny also includes some of Watson's acerbic evaluations of himself-for example, "I like women but they, don't seem to like me," and "I'm still as flawed as I was at thirteen."

In The Double Helix, Watson portrayed Rosalind Franklin unflatteringly fueling a long-lasting controversy over his treatment of her. He had seen Franklin's crucial x-ray photograph of DNA without her knowledge and did not fully acknowledge this until 1968. In DNA: The Secret of Life, he attempts to redress those wrongs when he suggests that, had Franklin still been alive when he, Crick and Maurice Wilkins won the Nobel Prize in Physiology or Medicine in 1962, the Prize committee would have had to consider whether Franklin should replace Wilkins in the group of three winners; he speculates that perhaps the committee would have resolved this by giving both Wilkins and Franklin the Nobel Prize in Chemistry. However, Watson may also still be trying, defensively, to put Franklin in a negative light, as when he cites her cutting description of her Ph.D. adviser (future Nobel laureate Ronald Norrish) as "stupid, bigoted, deceitful, ill-mannered and tyrannical." (For a very different perspective, see Brenda Maddox's biography Rosalind Franklin: The Dark Lady of DNA [HarperCollins, 2002].)

Watson's forays into the realm of science and social policy are also worthy of being considered detonations. McElheny points out Watson's little-known 1971 congressional testimony, which Watson adapted into an article for The Atlantic; in it he expressed strong concerns about genetic engineering and reproductive technologies, focusing mainly on surrogate motherhood. He was chided by Science editor Philip Abelson for "premature and unrealistic" talk of genetic engineering, which "could lead to harmful restrictions on all scientific research." This petulant response ironically prefigures some of Watson's own reactions to later controversies. Watson's leading role in establishing a moratorium on certain kinds of recombinant DNA research in the mid-1970s generated a firestorm. He quickly came to regret his participation in this unprecedented move by scientists to restrain themselves while they considered the potential dangers of their work.

Watson surprised the scientific world when, after assuming the directorship of the Human Genome Project in 1988, he announced that he would set aside 3 percent of its budget for research intended to anticipate its potential harmful social consequences. This decision to investigate the social implications of a scientific project at its inception was a first in the history of science. Watson may have been doing this for political cover, but surely he recognized the broader significance of such a step.

Watson is to be applauded for having been one of the few leading scientists to speak out about social concerns related to biological research. But he often denigrated others for doing likewise. McElheny notes that after Watson came to regret initiating the moratorium on recombinant DNA research, he characterized critics of the research as "a bizarre collection of kooks, sad incompetents, and down-right shits." In DNA: The secret of Life, Watson lucidly describes the horrors of the eugenics movement of the early 20th century and refers to the right of prospective mothers to make their own decisions about what kind of child they will have. But from McElheny, we hear of Watson's cruel retort to a woman who said she would proceed with a pregnancy knowing that she would bear a child with a deformity: "I'd hate to be the child you were so eager to bring into the world!"

Moreover, Watson is among the many geneticists who see heredity as the source of most social problems and who believe the solutions are to be found in genetic research. As a result, in his new book he tends to be overly optimistic about the progress and promise of agricultural and behavior genetics, and he downplays potential obstacles. For example, he looks to genetic engineering of crops for the solution to world hunger, ignoring scientific difficulties and complex social, economic, cultural and political factors.

In 1989 Watson was famously quoted in Time magazine as saying: "Now we know, in large measure, our fate is in our genes." In DNA: The secret of Life, he admits that geneticists have had enormous difficulty in locating genes associated with various behaviors, and he manifests much more sensitivity to the interaction of nature and nurture. Yet he cites behavior geneticist Robert Plomin's preliminary study looking for genes that affect IQ and Thomas Bouchard's findings on intelligence in his studies of identical twins at the University of Minnesota, ignoring the problems that bedevil this area of research. Results of preliminary and controversial reports on the genetics of homosexuality, violence and risk-taking are presented relatively uncritically. It is disappointing, but perhaps not surprising, to find one of the most brilliant scientists of his time, one who has been unsparingly critical of the quality of other scientists' work, passing over significant problems in studies of human behavior genetics.

That said, Watson offers a more balanced presentation of the issues than one might have expected, given his past pronouncements. DNA: The secret of Life is, in fact, an illuminating ac count of DNA and genetics from the 19th century to the present. The book opens with a brief history of genetics and the events leading up to the Watson-Crick discovery; subsequent chapters describe the dramatic changes in biology and its relationship with the outside world that follow directly from understanding the structure of DNA. I found two chapters particularly engaging and informative: "Out of Africa," which recounts the ongoing contributions of DNA analysis to understanding human evolution and migrations, and "Genetic Fingerprinting," an account of how DMA analysis has entered the legal system. Caveats aside, Watson's latest volume is a rich source both for budding scientists and for the general public interested in science.

These two books are full of details on the original discovery of the structure of DNA, providing peeks into the workings of science. They enrich our understanding of the accomplishment, even though we know much of the story already from previous accounts.

McElheny remarks on the irony that "A beautiful insight could solve a jigsaw puzzle even when the best solid evidence had been ignored." And Watson comments that the chemical structure of DNA was solved by "a biologist [Watson] and a physicist [Crick], neither of whom possessed a detailed command even of undergraduate chemistry." McElheny quotes Francois Jacob's explanation for the immediate acceptance of the Watson-Crick paper by the scientific community: "This structure was of such simplicity, such perfection, such harmony, such beauty even, and biological advantages flowed from it with such rigor and clarity, that one could not believe it to be untrue." Observations such as these give a richer, broader picture of science than we find in our science textbooks. For all its warts-jealousy, secrecy, nastiness and extreme competitiveness-this story of one of biology's landmark discoveries is an important one, worth reading again and again.


James Watson eshte njeriu qe cracki codin gjenetik. Artikull interesant.
 

Darien

Primus registratum
Re: Biologjia

Kur themi fjalën kompjuter, çfarë mendojmë? Teknologjitë e përdorura për kompjuterat po përshtaten gjithnjë e më tepër për përdorim në mjekësi dhe në biologji. Kjo m'u kujtua nga ky artikulli tek New Scientist, Chip promises faster multiple virus tests

Artikulli bën fjalë për një ide që e kam parë disa herë tani. Teknologjia që zakonisht përdoret për prodhimin e mikroproçesorëve këtu lejon krijimin e një matrice antitrupash. Kur antitrupat bien në kontakt me viruset, i kapin ato dhe bëjnë të mundur diagnostikimin e infeksionit.

Në artikull kjo është e mundur me anë të mikroskopit, po është mëse e mundshme që të krijohen kontaktet e nevojshme elektronike dhe të ndizet sinjali që i korrespondon virusit të kapur. Diagnostikim brenda pak sekondash! Kjo aftësi është e dëshirueshme, po për më tepër besoj se do bëhet e domosdoshme. Me teknologji të tilla mundësohet mbrojtja nga armët biologjike, pasi i përdor dikush me qëllim ose pasi shpëtojnë aksidentalisht nga laboratori.
 
Z

zarife

Guest
Re: Biologjia

Kur themi fjalën kompjuter, çfarë mendojmë? Teknologjitë e përdorura për kompjuterat po përshtaten gjithnjë e më tepër për përdorim në mjekësi dhe në biologji. Kjo m'u kujtua nga ky artikulli tek New Scientist, Chip promises faster multiple virus tests

Artikulli bën fjalë për një ide që e kam parë disa herë tani. Teknologjia që zakonisht përdoret për prodhimin e mikroproçesorëve këtu lejon krijimin e një matrice antitrupash. Kur antitrupat bien në kontakt me viruset, i kapin ato dhe bëjnë të mundur diagnostikimin e infeksionit.

Në artikull kjo është e mundur me anë të mikroskopit, po është mëse e mundshme që të krijohen kontaktet e nevojshme elektronike dhe të ndizet sinjali që i korrespondon virusit të kapur. Diagnostikim brenda pak sekondash! Kjo aftësi është e dëshirueshme, po për më tepër besoj se do bëhet e domosdoshme. Me teknologji të tilla mundësohet mbrojtja nga armët biologjike, pasi i përdor dikush me qëllim ose pasi shpëtojnë aksidentalisht nga laboratori.
 
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