109 research outputs found
A precise modeling of Phoebe's rotation
Although the rotation of some Saturn's satellites in spin-orbit has already
been studied by several authors, this is not the case of the rotation of
Phoebe, which has the particularity of being non resonant. The purpose of the
paper is to determine for the first time and with precision its
precession-nutation motion. We adopt an Hamiltonian formalism of the motion of
rotation of rigid celestial body set up by Kinoshita (1977) based on Andoyer
variables and canonical equations. First we calculate Phoebe's obliquity at
J2000,0 from available astronomical data as well as the gravitational
perturbation due to Saturn on Phoebe rotational motion. Then we carry out a
numerical integration and we compare our results for the precession rate and
the nutation coefficients with pure analytical model. Our results for Phoebe
obliquity (23{\deg}95) and Phoebe precession rate (5580".65/cy) are very close
to the respective values for the Earth. Moreover the amplitudes of the
nutations (26" peak to peak for the nutaton in longitude and 8" for the
nutation in obliquity) are of the same order as the respective amplitudes for
the Earth. We give complete tables of nutation, obtained from a FFT analysis
starting from the numerical signals. We show that a pure analytical model of
the nutation is not accurate due to the fact that Phoebe orbital elements e, M
and Ls are far from having a simple linear behaviour. The precession and
nutation of Phoebe have been calculated for the first time in this paper. We
should keep on the study in the future by studying the additional gravitational
effects of the Sun, of the large satellites as Titan, as well as Saturn
dynamical ellipticity.Comment: 11 pages,15 figures, accepted for publication in A&
Interrelation of posterior cranial fossa parameters and size characteristics of human skull in different craniotypes
The aim of this work was to study the correlation between the linear dimensions of the posterior cranial fossa and linear and angular parameters of the skull, depending on the magnitude of basilar angle. Material studies provided one hundred skulls of adult humans, divided into three craniotypes. Used by craniotopometric method measurements of these parameters with subsequent calculation of estimated average values and drawing the correlation model. The results showed that the most intimate degree of multidirectional communication studied parameters were observed in platibasilar craniotype have flexibasilar craniotype strong positive dependence is present in the width of the posterior fossa, the mediobasilar craniotipe connection parameters predominantly moderate and mild. Dimensions cerebellar pits exposed to greater variabilit
Relation of linear parameters of anterior cranial fossa with dimensional characteristics of facial part of the skull in different craniotypes
Objective: to determine the relation of linear parameters of the anterior cranial fossa with dimensional facial characteristics of the human skull in various craniotypes. Research Material: 100 adult skulls divided into three craniotypes have been used. Methods. Craniotopometry has been used for the measurement of the average values and the correlation model construction. Results. It has been revealed that the most significant correlation has been observed in the parameters of fleksibasilar craniotypes, in medio- and platybasilar craniotypes the multidirectional dependence of the studied parameters has been characterized as of moderate and mild degree. Conclusion. Results of research are necessary theoretical base for possible use by clinical physicians in elaboration of tactics of stereotaksichesky approach to tumoral or other pathological processes in the field of front and brain departments of a skull
Social and professional status of nurses in a context of innovative reforms in nursing practice
The article states the results of sociological research of basic medical and social factors that influence the formation of social and professional status of nurses in a context of innovative reforms in nursing practic
Nekódující RNA v oocytu a časném embryu
Once considered as 'transcriptional noise' noncoding RNAs (ncRNAs) nowadays are known to be key molecules in major cellular processes. NcRNAs are expressed at very high levels as only 2% of transcribed genome corresponds to protein-coding RNAs in higher eukaryotes. Various ncRNAs are known to have structural, functional, or regulatory roles, but the influence of the majority of non-coding transcripts is still unclear. Among ncRNAs, long ncRNAs (lncRNAs, longer than 200 bp) are of particular interest. LncRNAs do not have a uniform function but many studies observed lncRNA-based regulations at the transcriptional and translational levels. Therefore, novel lncRNAs could specifically fine-tune protein synthesis in the highly differentiated cell types. Particularly, fully-grown mammalian oocyte and early embryo require precisely controlled translation of maternal transcripts to coordinate meiotic progression and early embryo development while transcription is silent. We aimed to study the involvement of ncRNAs in protein synthesis and consequent influence on the oocyte and early embryo physiology. For the first time, we analysed the expression and distribution of several ncRNAs, namely Brain cytoplasmic RNA 1 (BC1), lncRNA in Oocyte Specifically Expressed (Rose), RNA Component of 7SK Nuclear...(česky) Nekódující RNA (ncRNA), které byly dříve považovány za ‚transkripční šum', jsou dnes známé jako klíčové molekuly v hlavních buněčných procesech. NcRNA jsou exprimovány ve vysokých hladinách - pouze 2 % transkribovaného genomu u vyšších eukaryot odpovídá proteinům kódujícím RNA. Je známo, že řada různých ncRNA má strukturní, funkční či regulační role, ale vliv většiny nekódujících transkriptů zůstává nejasný. Mezi ncRNA jsou obzvláště zajímavé dlouhé ncRNA (lncRNAs, delší než 200 bp). LncRNA nemají jednotnou funkci, ale v mnoha studiích byly pozorovány regulace na transkripční a translační úrovni, které jsou založené na regulaci lncRNA. Proto by nové lncRNA mohly pomoct vylepšit syntézu proteinů ve vysoce diferencovaných buněčných typech. Zejména plně dorostlý savčí oocyt a rané embryo vyžadují přesně kontrolovanou translaci maternálních transkriptů k tomu, aby mohla být koordinována meiotická progrese a časný vývoj embrya, zatímco je transkripce umlčena. Zaměřili jsme se tedy na studium zapojení ncRNA do syntézy proteinů a následného vlivu na fyziologii oocytu a raného embrya. Nejdříve jsme analyzovali expresi a distribuci několika ncRNA během meiotického zrání a časného vývoje embrya - jmenovitě BC1 (Brain cytoplasmic RNA 1), Rose (lncRNA in Oocyte Specific Expressed), Rn7sk (RNA Component...Department of Cell BiologyKatedra buněčné biologieFaculty of SciencePřírodovědecká fakult
Special Issue “Specialty Optical Fibers, Fiber Lasers and Their Applications”
publishedVersionNon peer reviewe
ncRNA BC1 influences translation in the oocyte
Regulation of translation is essential for the diverse biological processes involved in development. Particularly, mammalian oocyte development requires the precisely controlled translation of maternal transcripts to coordinate meiotic and early embryo progression while transcription is silent. It has been recently reported that key components of mRNA translation control are short and long noncoding RNAs (ncRNAs). We found that the ncRNABrain cytoplasmic 1 (BC1) has a role in the fully grown germinal vesicle (GV) mouse oocyte, where is highly expressed in the cytoplasm associated with polysomes. Overexpression of BC1 in GV oocyte leads to a minute decrease in global translation with a significant reduction of specific mRNA translation via interaction with the Fragile X Mental Retardation Protein (FMRP). BC1 performs a repressive role in translation only in the GV stage oocyte without forming FMRP or Poly(A) granules. In conclusion, BC1 acts as the translational repressor of specific mRNAs in the GV stage via its binding to a subset of mRNAs and physical interaction with FMRP. The results reported herein contribute to the understanding of the molecular mechanisms of developmental events connected with maternal mRNA translation
The role of museum of Department of Human Anatomy in the educational process
The article contains information on the history of the formation of the fundamental educational and scientific museum of Human Anatomy department of Saratov State Medical University n.a. V. I. Razumovsky. The main collections of the fund of anatomy museum are presented. Features of registration and registration of anatomical preparations, as well as the purpose of their exposure, are described. The importance of the museum in the educational and scientific process of the department of human anatomy is considered.</p
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