Role of DNA methylation in embryonic development of animals

Tijekom razvoja životinja, njihove stanice i tkiva prolaze kroz različite oblike ekspresije gena. Ekspresija gena u životinja je regulirana metiliranjem njihove genomske DNA molekule. Nakon oplodnje dolazi do pada metiliranosti DNA, a procesi u kojem se to događa se nazivaju aktivna i pasivna demetilacija. Ponovno metiliranje DNA molekule obavljaju enzimi koji se nazivaju DNA metiltransferaze (Dnmt). DNA metiltransferaze se mogu podijeliti u tri proteinske obitelji, a njihova uloga je de novo metilacija i održavanje postojećeg metilacijskog uzorka koji je naslijeđen od roditelja. U ovom radu iznesene su neke od osnovnih uloga metilacije DNA u embrionalnom razvoju životinja. DNA metilacija sudjeluje u procesima kao što su reprogramiranje embrija u predimplantaciji, reprogramiranje primordijalnih zametnih stanica, regulacija transkripcije metilacijom, genomski „imprinting“ i u inaktivaciji jednog od dva x kromosoma. Pravilna regulacija ovih procesa metilacijom DNA pridonosi zdravom razvoju samog embrija, dok nepravilnosti u nekom od ovih procesa mogu pridonijeti razvoju tumora ili nepravilnostima u živčanom sustavu životinja.During animal development, their cells and tissues undergoing various forms of gene expression. Gene expression in animals is regulated by methylating their genomic DNA. After fertilization occurs the fall in DNA methylation pattern, processes by which this happens are called active and passive demethylation. New methylation of DNA molecules perform enzymes called DNA methyltransferases (Dnmt's). DNA methyltransferases can be divided into three protein families, and their role is to perform de novo methylation and maintenance of the existing methylation pattern that is inherited from parents. This paper work is presenting some of the fundamental roles of DNA methylation in the embryonic development of animals. DNA methylation participates in processes such as embryo preimplantacion reprogramming, reprogramming of the primordial germ cells, methylation based regulation of transcription, genomic imprinting and inactivation one of the two x chromosomes. Proper regulation of this processes by DNA methylation contributes to the healthy development of the embryo, while irregularities in some of these processes may contribute to the development of tumors or irregularities in the animal nervous system

Hormones and behavior

Hormoni su kemikalije koje se prirodno pojavljuju u tijelu. Oni upravljaju mnogim biokemijskim funkcijama, kao što su skladištenje i korištenje energije, održavanje i rast organizma. Hormoni u velikoj mjeri utječu i na ponašanje. Hormone uglavnom proizvode endokrine žlijezde. Tipične endokrine žlijezde su hipofiza, štitna žlijezda, nadbubrežna žlijezda, paratiroidna žlijezda, gonde (testisi i jajnci). Endokrine žlijezde otpuštaju vrlo male količine hormona u krv koje imaju veliki utjecaj u cijelom tijelu. U ovom radu izložen je kratki pregled najvažnijih hormona, s naglaskom na spolne hormone i njihov utjecaj na spolne razlike i spolno ponašanje.Hormones are chemicals that naturally occur in the body. These chemicals direct many biochemical functions, including energy storage and utilization, maintenance, and growth. Hormones have huge impact on animal behavior. Hormones are released mainly by the endocrine glands. Specific endocrine glands include the pituitary, thyroid, adrenals, parathyroids, gonads (e.g., testes and ovaries). The endocrine glands release very small quantities of hormones into the blood, but these small quantities have a large impact throughout the body. This work is a short review of the most important hormons with an emphasise on sexual hormones and their effect on sex differences and sexual behavior

Naprava za rezanje bloka papira

Ovim radom konstruirana je naprava za rezanje bloka papira. Cilj rada je analizirati neka postojeća rješenja, te dati konstrukcijsko rješenje za izradu modela, za rezanje bloka papira od maksimalno 150 komada. Uređaju treba omogućiti ručni pogon ili pogon motorom, a u slučaju ručnog pogona potrebna ručna sila ne smije biti veća od 150 N. Prije svega analiziralo se tržište, te su razmotrena postojeća konstrukcijska rješenja. Izradio se koncept i odabir elemenata strojeva za pogon. Za potrebe proračuna elemenata provedeno je mjerenje potrebne sile rezanja za blok od 150 papira. Kod određivanja potrebne sile rezanja koristila se računalna aplikacija Catman Professional, te mjerno pojačalo Spider 8 i davač sile HBM. Nakon proračuna, odabira potrebnih elemenata, te koncepta rezača izradio se model. Za izradu Cad modela koristila se računalna aplikacija SolidWorks u kojoj je izrađen 3D model. Dimenzije 3D modela izvedene su nakon razmatranja potrebnih komponenti, njihovih dimenzija i međusobnih odnosa. \Na kraju se izradila tehnička dokumentacija

Transoral Excision of a Parapharyngeal Space Tumor: Case Report

Tumors of the parapharyngeal space are rare tumors comprising less than 1% of all head and neck neoplasms. They are mainly salivary gland or neurogenic tumors. Clinical presentation is very variable. Surgical resection by different approaches remains to be the best possible treatment option. We present a case of 45 years old female patient admitted at the ENT Department due to the unilateral hearing loss and swallowing difficulties. Clinical examination revealed the diagnosis of a pleomorphic adenoma of the parapharyngeal space. Tumor was surgical (transorally) excised. Two years following the surgery there is no recurrence of the initial symptoms and primary disease

Transoral Excision of a Parapharyngeal Space Tumor: Case Report

Tumors of the parapharyngeal space are rare tumors comprising less than 1% of all head and neck neoplasms. They are mainly salivary gland or neurogenic tumors. Clinical presentation is very variable. Surgical resection by different approaches remains to be the best possible treatment option. We present a case of 45 years old female patient admitted at the ENT Department due to the unilateral hearing loss and swallowing difficulties. Clinical examination revealed the diagnosis of a pleomorphic adenoma of the parapharyngeal space. Tumor was surgical (transorally) excised. Two years following the surgery there is no recurrence of the initial symptoms and primary disease

VPLIV MEDKULTURNIH RAZLIK NA VODENJE

Followers' needs and expectations have the moderating effects on the effectiveness of various types of leader’s behavior or style. They vary from one culture to another. Their consideration is very important as work organizations become increasingly international and different leadership's styles are efficient in different cultures. Assuming that leaders can identify which style of leadership is appropriate for certain culture, they have to assure that they behave in a way which is interpreted as consistent with that style

Role of DNA methylation in embryonic development of animals

Tijekom razvoja životinja, njihove stanice i tkiva prolaze kroz različite oblike ekspresije gena. Ekspresija gena u životinja je regulirana metiliranjem njihove genomske DNA molekule. Nakon oplodnje dolazi do pada metiliranosti DNA, a procesi u kojem se to događa se nazivaju aktivna i pasivna demetilacija. Ponovno metiliranje DNA molekule obavljaju enzimi koji se nazivaju DNA metiltransferaze (Dnmt). DNA metiltransferaze se mogu podijeliti u tri proteinske obitelji, a njihova uloga je de novo metilacija i održavanje postojećeg metilacijskog uzorka koji je naslijeđen od roditelja. U ovom radu iznesene su neke od osnovnih uloga metilacije DNA u embrionalnom razvoju životinja. DNA metilacija sudjeluje u procesima kao što su reprogramiranje embrija u predimplantaciji, reprogramiranje primordijalnih zametnih stanica, regulacija transkripcije metilacijom, genomski „imprinting“ i u inaktivaciji jednog od dva x kromosoma. Pravilna regulacija ovih procesa metilacijom DNA pridonosi zdravom razvoju samog embrija, dok nepravilnosti u nekom od ovih procesa mogu pridonijeti razvoju tumora ili nepravilnostima u živčanom sustavu životinja.During animal development, their cells and tissues undergoing various forms of gene expression. Gene expression in animals is regulated by methylating their genomic DNA. After fertilization occurs the fall in DNA methylation pattern, processes by which this happens are called active and passive demethylation. New methylation of DNA molecules perform enzymes called DNA methyltransferases (Dnmt's). DNA methyltransferases can be divided into three protein families, and their role is to perform de novo methylation and maintenance of the existing methylation pattern that is inherited from parents. This paper work is presenting some of the fundamental roles of DNA methylation in the embryonic development of animals. DNA methylation participates in processes such as embryo preimplantacion reprogramming, reprogramming of the primordial germ cells, methylation based regulation of transcription, genomic imprinting and inactivation one of the two x chromosomes. Proper regulation of this processes by DNA methylation contributes to the healthy development of the embryo, while irregularities in some of these processes may contribute to the development of tumors or irregularities in the animal nervous system

Fizička opterećenja radnika pri radu motornom pilom

Šumarstvo je gospodarska djelatnost, struka i znanost potrajnog gospodarenja šumama, kao i ostalim ekosustavima i resursima vezanim uz šumu. U sječi šuma koristi se razna mehanizacija, od strojeva do alata. U hrvatsko šumarstvo su motorne pile prvi puta uvedene nakon završetka Drugog svjetskog rata. Otkako su se počele primjenjivati motorne pile kao glavni stroj za sječu i izradu, primjećen je njihov štetan utjecaj. Od pojave profesionalnih bolesti, buke i vibracije do različitih fizičkih opterećenja radnika, kao što su opterećenja kralježnice, oštećenja meniskusa koljena usred neprestanog opterećenja i nefiziološkog položaja. Da bi se opterećenja i ozljede smanjili, radnik bi morao većinu radnog vremena provesti u uvjetno-uspravnom položaju jer je u tom položaju opterećenje najmanje, trup tijela je uspravan, a noge su ispružene ili u koljenima blago savijene. Isto tako, da bi se smanjila mogućnost ozljeđivanja na radu, bilo bi poželjno prije početka rada aktivno provoditi vježbe istezanja i zagrijavanja mišićnih skupina.Forestry is an economic activity, profession and science of sustainable forest management, as well as other ecosystems and resources related to forest. The deforestation is used miscellaneous equipment, from machines to tool. The Croatian forestry are chainsaws first introduced after World War II. Since they started to apply chainsaws as the main machine for logging, noticed their harmful impact. Since the occurrence of occupational diseases noise and vibration to different physical loads of workers, such as loading of the spine, knee meniscus damage in the midst of constant load and maintaining a position. To load and reduce worker injuries would have most of his time in the conditional-upright position because in this position the load at least, is the trunk of the body erect and legs are extended or knees slightly bent. Also to reduce the risk of injury at work it would be advisable before you start working actively to implement stretching and warm-up muscle groups