{"id":37393,"date":"2019-10-31T22:17:23","date_gmt":"2019-10-31T19:17:23","guid":{"rendered":"https:\/\/prohoster.info\/blog\/zubnaya-feya-tut-ne-rabotaet-struktura-emali-zubov-krokodilov-i-ih-doistoricheskih-predkov\/"},"modified":"2019-10-31T22:17:23","modified_gmt":"2019-10-31T19:17:23","slug":"zubnaya-feya-tut-ne-rabotaet-struktura-emali-zubov-krokodilov-i-ih-doistoricheskih-predkov","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/news\/zubnaya-feya-tut-ne-rabotaet-struktura-emali-zubov-krokodilov-i-ih-doistoricheskih-predkov","title":{"rendered":"Mikja e dh\u00ebmb\u00ebve k\u00ebtu nuk funksionon: struktura e esmalti t\u00eb dh\u00ebmb\u00ebve t\u00eb krokodil\u00ebve dhe t\u00eb parardh\u00ebsve t\u00eb tyre parahistorik\u00eb","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

\"Mikja
\n
\nJu hyni n\u00eb nj\u00eb korridor me drit\u00eb t\u00eb zbeht\u00eb, ku takoni shpirtra t\u00eb pafajsh\u00ebm, t\u00eb munduar nga dhimbja dhe vuajtjet. Por ata s'kan\u00eb pushim k\u00ebtu, sepse pas \u00e7do dere i pret m\u00eb shum\u00eb mundim dhe frik\u00eb, q\u00eb mbush \u00e7do celul\u00eb t\u00eb trupit dhe pushton \u00e7do mendim. Ju afroheni nj\u00ebrit prej dyerve, pas s\u00eb cil\u00ebs d\u00ebgjohet nj\u00eb dridhje dhe zhurm\u00eb djall\u00ebzore, q\u00eb kalon deri n\u00eb eshtra. Duke mbledhur mbetjet e guximit n\u00eb grusht, e shtrini dor\u00ebn e ftoht\u00eb nga frika drejt dor\u00ebs s\u00eb dyer, kur papritur dikush ju prek n\u00eb sup, dhe ju t\u00ebrhiqeni nga befasia. \"Doktori do t\u00eb lirohet pas pak minutash. Ndenjeni k\u00ebtu, ne do t'ju th\u00ebrras\u00ebm\", thot\u00eb nj\u00eb z\u00eb i but\u00eb i infermieres. Duket se k\u00ebshtu e imagjinon nj\u00eb vizit\u00eb te dentisti disa njer\u00ebz, t\u00eb cil\u00ebt kan\u00eb nj\u00eb q\u00ebndrim tep\u00ebr negativ ndaj k\u00ebtyre \"sadist\u00ebve\" n\u00eb k\u00ebmisha t\u00eb bardha. Por sot nuk do t\u00eb flasim p\u00ebr dentofobin\u00eb, do t\u00eb flasim p\u00ebr krokodil\u00ebt. Po, pik\u00ebrisht p\u00ebr ta, e m\u00eb sakt\u00ebsisht p\u00ebr dh\u00ebmb\u00ebt e tyre, t\u00eb cil\u00ebt nuk kan\u00eb nevoj\u00eb p\u00ebr trajtim stomatologjik. <\/p>\n

Shkenc\u00ebtar\u00ebt nga Universiteti i Missouri (SHBA) kan\u00eb kryer nj\u00eb studim mbi dh\u00ebmb\u00ebt e krokodil\u00ebve, i cili zbuloi tipare interesante t\u00eb esmalti t\u00eb k\u00ebtyre gjuetar\u00ebve t\u00eb p\u00ebrsosur, q\u00eb mb\u00ebshteten pik\u00ebrisht n\u00eb \u00e7el\u00ebsat e tyre. \u00c7far\u00eb zbuluan shkenc\u00ebtar\u00ebt, \u00e7far\u00eb i ndan dh\u00ebmb\u00ebt e krokodil\u00ebve modern\u00eb nga ata parahistorik\u00ebt dhe \u00e7far\u00eb dobie sjell ky studim? P\u00ebr k\u00ebt\u00eb do t\u00eb m\u00ebsojm\u00eb nga raporti i grupit hulumtues.<\/a><\/noindex><\/p>\n

Baza e k\u00ebrkimit<\/h3>\n

\nP\u00ebr shumic\u00ebn e vertebror\u00ebve, dh\u00ebmb\u00ebt jan\u00eb nj\u00eb atribut i panegociuesh\u00ebm p\u00ebr marrjen dhe konsumimin e ushqimit (nuk p\u00ebrfshihen anteater\u00ebt). Disa prej grabitqar\u00ebve mb\u00ebshteten n\u00eb shpejt\u00ebsi gjat\u00eb gjuetis\u00eb (gepardi), disa n\u00eb kolektiv (luan\u00ebt), nd\u00ebrsa p\u00ebr disa, nj\u00eb rol t\u00eb madh luan fuqia e kafshimit. Kjo i p\u00ebrket gjithashtu krokodil\u00ebve, t\u00eb cil\u00ebt afrohen n\u00eb m\u00ebnyr\u00eb te heshtur ndaj viktimave t\u00eb tyre n\u00eb uj\u00eb dhe i kapin ato me \u00e7el\u00ebsat e tyre t\u00eb fuqish\u00ebm. P\u00ebr t\u00eb mos lejuar q\u00eb viktima t\u00eb arrij\u00eb t\u00eb shp\u00ebtoj\u00eb, kapja duhet t\u00eb jet\u00eb e fuqishme, dhe kjo krijon ngarkesa t\u00eb m\u00ebdha n\u00eb struktur\u00ebn kockore. P\u00ebr t\u00eb balancuar efektin negativ t\u00eb kafshimeve t\u00eb tyre t\u00eb fuqishme, krokodil\u00ebt kan\u00eb nj\u00eb palat\u00eb t\u00eb dyt\u00eb kockor, i cili \u00ebsht\u00eb i pal\u00ebvizsh\u00ebm dhe i bashkangjitur me kafk\u00ebn. <\/p>\n

\"Mikja
\nDemonstrimi vizual i mbylljes dhe hapjes s\u00eb \u00e7el\u00ebsit t\u00eb krokodil\u00ebve.<\/i><\/p>\n

Nj\u00eb nga tiparet kryesore t\u00eb dh\u00ebmb\u00ebve t\u00eb krokodil\u00ebve \u00ebsht\u00eb z\u00ebvend\u00ebsimi i vazhduesh\u00ebm me t\u00eb rinj, kur t\u00eb vjetr\u00ebt konsumohen. N\u00eb fakt, dh\u00ebmb\u00ebt e krokodil\u00ebve duken si matryoshka, brenda t\u00eb cil\u00ebs zhvillohen dh\u00ebmb\u00eb t\u00eb rinj. Cdo dy vjet, secili nga dh\u00ebmb\u00ebt n\u00eb nofull nd\u00ebrron me t\u00eb rinj.<\/p>\n

\"Mikja
\nKujdesuni se sa ngusht\u00eb mbyllet ky \"kapak dh\u00ebmb\u00ebsh\".<\/i><\/p>\n

Dh\u00ebmb\u00ebt e krokodil\u00ebve ndahen n\u00eb disa kategori sipas form\u00ebs dhe funksionit p\u00ebrkat\u00ebs. N\u00eb fillim t\u00eb nofull\u00ebs ka 4 kanina t\u00eb m\u00ebdha, t\u00eb cilat jan\u00eb t\u00eb nevojshme p\u00ebr kapjen efektive t\u00eb preys. N\u00eb mes ndodhen dh\u00ebmb\u00ebt m\u00eb t\u00eb trash\u00eb, t\u00eb cil\u00ebt rriten p\u00ebrgjat\u00eb nofull\u00ebs. Kjo pjes\u00eb \u00ebsht\u00eb e nevojshme p\u00ebr prerjen e preys. N\u00eb baz\u00eb t\u00eb dh\u00ebmb\u00ebve zgjatet dhe b\u00ebhet m\u00eb e shesht\u00eb, duke lejuar krokodil\u00ebt t\u00eb thyejn\u00eb kapak\u00ebt e molusk\u00ebve dhe mburojat e k\u00ebshtjellave, si fara. <\/p>\n

Sa e fort\u00eb \u00ebsht\u00eb nofulla e krokodil\u00ebve? Natyrisht, kjo varet nga madh\u00ebsia dhe lloji. P\u00ebr shembull, n\u00eb vitin 2003 u zbulua se nj\u00eb aligator i Kull\u00ebs s\u00eb Mississippi-s\u00eb me pesh\u00eb 272 kilogram\u00eb kafshon me forc\u00eb rreth 9500 N (N \u2013 Njutoni, 1 N = 1 kg\u00b7m\/s\u00b2). Nd\u00ebrsa nj\u00eb krokodil m\u00eb e madhe me pesh\u00eb 1308 kilogram \u00ebsht\u00eb treguar se ka nj\u00eb forc\u00eb t\u00eb tronditshme rreth 34500 N. P\u00ebr t\u00eb th\u00ebn\u00eb, fuqia absolute e kafshimit t\u00eb njeriut \u00ebsht\u00eb rreth 1498 N.<\/p>\n

Forca e kafshimit nuk varet aq nga dh\u00ebmb\u00ebt, sa nga muskujt e nofullave. Tek krokodil\u00ebt, k\u00ebta muskuj jan\u00eb shum\u00eb t\u00eb fort\u00eb dhe t\u00eb shumt\u00eb. Megjithat\u00eb, ekziston nj\u00eb ndryshim i fort\u00eb midis muskujve shum\u00eb t\u00eb zhvilluar q\u00eb p\u00ebrgjigjen p\u00ebr mbylljen e goj\u00ebs (\u00e7ka jep edhe at\u00eb forc\u00ebn e kafshimit) dhe muskujve t\u00eb dob\u00ebt q\u00eb p\u00ebrgjigjen p\u00ebr hapjen e goj\u00ebs. Kjo shpjegon pse goja e mbyllur e krokodil\u00ebve mund t\u00eb mbahet me nj\u00eb senc\u00eb t\u00eb thjesht\u00eb.<\/p>\n

\"Mikja
\nHajde, tregoni kush t\u00eb quajti t\u00eb vog\u00ebl.<\/i><\/p>\n

Por nofulla e krokodil\u00ebve \u00ebsht\u00eb e nevojshme jo vet\u00ebm p\u00ebr vrasjet e pa m\u00ebshirshme p\u00ebr ushqim, por edhe p\u00ebr kujdesin p\u00ebr shpirtin e saj. Femrat e krokodil\u00ebve shpesh i bartin ndihm\u00ebsit e tyre fare pran\u00eb goj\u00ebs (\u00ebsht\u00eb e v\u00ebshtir\u00eb t\u00eb gjendet nj\u00eb vend m\u00eb t\u00eb sigurt p\u00ebr ta, pasi kush do t\u00eb guxoj\u00eb t\u00eb hyj\u00eb aty). Goja e krokodil\u00ebve \u00ebsht\u00eb e pajisur me receptor\u00eb shum\u00eb t\u00eb ndjesh\u00ebm, q\u00eb u lejojn\u00eb ata t\u00eb rregullojn\u00eb forc\u00ebn e kafshimit, duke i lejuar ata t\u00eb mbajn\u00eb m\u00eb mir\u00eb prejn\u00eb ose t\u00eb bartin me kujdes f\u00ebmij\u00ebt e tyre.<\/p>\n

Fatkeq\u00ebsisht, dh\u00ebmb\u00ebt e njeriut nuk rriten pas humbjes s\u00eb t\u00eb vjetr\u00ebve, por ka di\u00e7ka t\u00eb p\u00ebrbashk\u00ebt me krokodil\u00ebt \u2013 smalta.<\/p>\n

\"Mikja
\nImazhi nr. 1: dh\u00ebmbi kaudal i aligatorsit t\u00eb Mississippi (Alligator mississippiensis).<\/i><\/p>\n

Emaili \u00ebsht\u00eb mb\u00ebshtjell\u00ebsi i jasht\u00ebm i pjes\u00ebs koronare t\u00eb dh\u00ebmbit. Kjo \u00ebsht\u00eb pjesa m\u00eb e fort\u00eb e trupit t\u00eb njeriut, si dhe e shum\u00eb vertebror\u00ebve t\u00eb tjer\u00eb. Megjithat\u00eb, si\u00e7 e dim\u00eb, dh\u00ebmb\u00ebt tan\u00eb nuk ndryshojn\u00eb p\u00ebr dh\u00ebmb\u00eb t\u00eb rinj, prandaj emaili yn\u00eb duhet t\u00eb jet\u00eb m\u00eb i trash\u00eb. Nd\u00ebrsa te krokodil\u00ebt, dh\u00ebmb\u00ebt e konsumuar z\u00ebvend\u00ebsohen me t\u00eb rinj, k\u00ebshtu q\u00eb nuk ka nevoj\u00eb p\u00ebr nj\u00eb email t\u00eb trash\u00eb. Ting\u00ebllon mjaft logjikisht, por a \u00ebsht\u00eb gjith\u00e7ka k\u00ebshtu n\u00eb t\u00eb v\u00ebrtet\u00eb?<\/p>\n

Shkenc\u00ebtar\u00ebt thon\u00eb se kuptimi i ndryshimeve t\u00eb emailit brenda nj\u00eb taksoni do t\u00eb lejoj\u00eb m\u00eb von\u00eb t\u00eb mbajm\u00eb m\u00eb mir\u00eb mend se si ndryshon struktura e emailit n\u00eb var\u00ebsi t\u00eb biomekanik\u00ebs dhe diet\u00ebs s\u00eb kafsh\u00ebs. <\/p>\n

Krokodil\u00ebt, p\u00ebrkat\u00ebsisht Alligator mississippiensis<\/i>, jan\u00eb shum\u00eb t\u00eb p\u00ebrshtatsh\u00ebm p\u00ebr k\u00ebt\u00eb hulumtim p\u00ebr nj\u00eb mori arsyeh. S\u00eb pari, dh\u00ebmb\u00ebt e tyre, fuqia e kafshimit dhe struktura e emailit ndryshojn\u00eb n\u00eb var\u00ebsi t\u00eb mosh\u00ebs dhe p\u00ebrmasave t\u00eb individit, q\u00eb \u00ebsht\u00eb gjithashtu e ndikuar nga ndryshimi i diet\u00ebs. S\u00eb dyti, dh\u00ebmb\u00ebt e krokodil\u00ebve kan\u00eb morfologji t\u00eb ndryshme n\u00eb var\u00ebsi t\u00eb pozicionit n\u00eb nofull. <\/p>\n

\"Mikja
\nImazhi nr. 2: a dhe b tregojn\u00eb ndryshimin e dh\u00ebmb\u00ebve midis individ\u00ebve t\u00eb m\u00ebdhenj dhe t\u00eb vegj\u00ebl, nd\u00ebrsa c-e tregojn\u00eb dh\u00ebmb\u00ebt e paraardh\u00ebsve t\u00eb fosil\u00ebve t\u00eb krokodil\u00ebve modern\u00eb.<\/i><\/p>\n

Dh\u00ebmb\u00ebt rostral jan\u00eb t\u00eb holl\u00eb dhe p\u00ebrdoren p\u00ebr kapjen e preys, nd\u00ebrsa dh\u00ebmb\u00ebt kaudal jan\u00eb t\u00eb shurdh\u00ebt dhe p\u00ebrdoren p\u00ebr t\u00eb thyer me forca m\u00eb t\u00eb m\u00ebdha kafshimi. N\u00eb fjal\u00eb t\u00eb tjera, ngarkesa mbi dh\u00ebmb varet nga pozita e tij n\u00eb nofull dhe nga p\u00ebrmasat e pronarit t\u00eb k\u00ebsaj nofulli.<\/p>\n

N\u00eb k\u00ebt\u00eb studim jan\u00eb paraqitur rezultatet e analiz\u00ebs dhe matjeve t\u00eb trash\u00ebsis\u00eb absolute t\u00eb emailit (AET) dhe trash\u00ebsis\u00eb relative t\u00eb normalizuar sipas p\u00ebrmasave (RET) t\u00eb dh\u00ebmb\u00ebve t\u00eb krokodilit.<\/p>\n

AET p\u00ebrfaq\u00ebson nj\u00eb vler\u00ebsim t\u00eb distanc\u00ebs mesatare nga kalimi i emailit-dentin deri n\u00eb sip\u00ebrfaqen ekst\u00ebrn t\u00eb emailit dhe p\u00ebrfaq\u00ebson nj\u00eb matje lineare. Nd\u00ebrsa RET \u00ebsht\u00eb nj\u00eb mas\u00eb dimensionale, q\u00eb lejon krahasimin e trash\u00ebsis\u00eb relative t\u00eb emailit n\u00eb shkall\u00eb t\u00eb ndryshme.<\/p>\n

Shkenc\u00ebtar\u00ebt kan\u00eb kryer nj\u00eb vler\u00ebsim t\u00eb AET dhe RET t\u00eb dh\u00ebmb\u00ebve rostral (n\u00eb 'hund\u00ebn' e nofullit), nd\u00ebrmjet\u00ebs (n\u00eb mes t\u00eb rreshtit) dhe kaudal (n\u00eb baz\u00ebn e nofullit) te shtat\u00eb individ\u00eb t\u00eb k\u00ebtij lloji. Alligator mississippiensis<\/i>.<\/p>\n

\u00cbsht\u00eb gjithashtu e r\u00ebnd\u00ebsishme t\u00eb theksohet se struktura e enamelit mund t\u00eb varet nga dieta e individit dhe e gjith\u00eb llojit n\u00eb t\u00ebr\u00ebsi. Tek krokodil\u00ebt, dieta \u00ebsht\u00eb shum\u00eb e gjer\u00eb (\u00e7far\u00eb kap\u00ebn, \u00ebsht\u00eb dita e dyt\u00eb), por ajo dallon nga ajo e t\u00eb af\u00ebrmve t\u00eb tyre, q\u00eb tashm\u00eb kan\u00eb vdekur. P\u00ebr t\u00eb verifikuar k\u00ebt\u00eb nga aspekti i enamelit, shkenc\u00ebtar\u00ebt kryen nj\u00eb analiz\u00eb AET dhe RET t\u00eb fosileve. Protosuchidae<\/i> (UCMP 97638), Iharkutosuchus<\/i> (MTM VER 2018.837) dhe Allognathosuchus<\/i> (YPM-PU 16989). Protosuchidae<\/i> \u00ebsht\u00eb p\u00ebrfaq\u00ebsues i periudh\u00ebs jurasike, Iharkutosuchus<\/i> \u2014 periudha e krejt, dhe Allognathosuchus<\/i> nga eoceni.<\/p>\n

Para fillimit t\u00eb matjeve faktike, studiuesit kryen nj\u00eb brainstorming dhe propozuan disa hipoteza teorike:<\/p>\n