Search results for "M2"

Terminal tendon cell differentiation requires the glide/gcm complex.

2004

International audience; Locomotion relies on stable attachment of muscle fibres to their target sites, a process that allows for muscle contraction to generate movement. Here, we show that glide/gcm and glide2/gcm2, the fly glial cell determinants, are expressed in a subpopulation of embryonic tendon cells and required for their terminal differentiation. By using loss-of-function approaches, we show that in the absence of both genes, muscle attachment to tendon cells is altered, even though the molecular cascade induced by stripe, the tendon cell determinant, is normal. Moreover, we show that glide/gcm activates a new tendon cell gene independently of stripe. Finally, we show that segment p…

Reliable numerical solution of a class of nonlinear elliptic problems generated by the Poisson-Boltzmann equation

2020

We consider a class of nonlinear elliptic problems associated with models in biophysics, which are described by the Poisson-Boltzmann equation (PBE). We prove mathematical correctness of the problem, study a suitable class of approximations, and deduce guaranteed and fully computable bounds of approximation errors. The latter goal is achieved by means of the approach suggested in [S. Repin, A posteriori error estimation for variational problems with uniformly convex functionals. Math. Comp., 69:481-500, 2000] for convex variational problems. Moreover, we establish the error identity, which defines the error measure natural for the considered class of problems and show that it yields computa…

Tramvaju kustības radīto atmosfēras aerosolu izcelsmes un izplatības novērtējums Rīgā

2021

Bakalaura darbā raksturota atmosfēras piesārņojuma problemātika, īpaša uzmanība pievērsta videi draudzīgākajam satiksmes veidam – tramvaju satiksmei. Tramvaju radītais cieto daļiņu (PM10, PM2,5) atmosfēras piesārņojums analizēts vērtējot dažādus aspektus – ekspluatētais tramvaja modeļa veids, kustības režīms, papildus vērtēta arī meteoroloģisko apstākļu ietekme. Eksperimentālā daļa realizēta Rīgā, veicot tiešos mērījumus laika periodā no 2020. gada rudens līdz 2021.gada pavasarim, tādējādi mērījumi tika veikti 3 dažādās sezonās, dažādos meteoroloģiskajos apstākļos, mainīga novietojuma un noslogotatības maršruta daļās.

Gaisa aerosolu frakciju skaita un sastāva analīze dzelzceļa apkārtnē

2018

Gaisa aerosolu frakciju skaita un sastāva analīze dzelzceļa apkārtnē. Bite I., vadītājs Dr. ķīm., doc. Osīte A. Bakalaura darbs, 31 lappuses, 10 attēli, 10 tabulas, 28 literatūras avoti, 2 pielikumi. Latviešu valodā. Literatūras apskatā veikts aerosolu klasifikācijas izvērtējums pēc to rašanās avotiem, kā arī raksturoti pētījumu rezultāti par dzelzceļa un metro staciju apkārtnē ievāktajiem aerosoliem un to ietekmi uz cilvēku organismu. Eksperimentālajā daļā veikta gaisa aerosolu frakciju PM10 un PM2.5, kā arī ultrasmalko aerosolu daļiņu masas un skaita koncentrāciju analīze dzelzceļa stacijas Torņakalns tuvumā. Paraugi ievākti, izmantojot aerosolu spektrometru, dihotomo impaktoru, mobilu ae…

THE EFFECTS OF MUSCARINIC AGONISTS AND ANTAGONISTS ON ACETYLCHOLINE RELEASE FROM PERIPHERAL CHOLINERGIC NERVES IN THE ABSENCE AND PRESENCE OF A CHOLI…

1980

Lack of association betweenMDM2promoter SNP309 and clinical outcome in patients with neuroblastoma

2014

While a polymorphism located within the promoter region of the MDM2 proto-oncogene, SNP309 (T > G), has previously been associated with increased risk and aggressiveness of neuroblastoma and other tumor entities, a protective effect has also been reported in certain other cancers. In this study, we evaluated the association of MDM2 SNP309 with outcome in 496 patients with neuroblastoma and its effect on MDM2 expression. No significant difference in overall or event-free survival was observed among patients with neuroblastoma with or without MDM2 SNP309. The presence of SNP309 does not affect MDM2 expression in neuroblastoma. Pediatr Blood Cancer 2014; 61:1867–1870. © 2014 Wiley Periodicals,…

Influence of M23C6 carbides on the heterogeneous strain development in annealed 420 stainless steel

2020

Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and …

Phorbol Esters and Muscarinic Receptor Agonists Activate Phospholipase D in Heart and Brain

1991

Phospholipase D (PLD) hydrolyzes phosphatidylcholine and thereby seems to play a key role in a novel pathway of signal transduction. PLD activity in rat hippocampal slices and atria of rat, guinea pig and chicken hearts was determined by measuring the catalytic products choline (Ch), phosphatidic acid (PA) and, in the presence of a primary alcohol, phosphatidylpropanol or phosphatidylethanol. It was found that the PLD activity was high, even under resting conditions, in both tissues, especially in the hippocampus, and that the enzyme activity could be enhanced by activation of protein kinase C and by muscarinic receptor stimulation.

Atmosfēras piesārņojuma personificētais monitorings

2020

Bakalaura darbā “Atmosfēras piesārņojuma personificētais monitorings” apkopota zinātniskā literatūra par atmosfēras piesārņojumu, avotiem, ietekmi uz veselību, raksturota situācija Latvijā. Darba praktiskā daļā veikti cieto daļiņu (PM10, PM2,5), slāpekļa dioksīda un gaistošo organisko savienojumu mērījumi dažādos selektīvi izvēlētos maršrutos laika periodā no 20.02.2020. līdz 29.04.2020. realizējot personificēto monitoringu. Mērījumi veikti izmantojot ar gaisa kvalitātes sensoriem aprīkotu iekārtu – individuālo dozimetru. Iegūtie mērījumi sistematizēti un apstrādāti, lai novērtētu indivīdam uzņemto piesārņojuma dozu.

Aqueous-phase reactive species formed by fine particulate matter from remote forests and polluted urban air

2021

In the aqueous phase, fine particulate matter can form reactive species (RS) that influence the aging, properties, and health effects of atmospheric aerosols. In this study, we explore the RS yields of aerosol samples from a remote forest (Hyytiälä, Finland) and polluted urban locations (Mainz, Germany; Beijing, China), and we relate the RS yields to different chemical constituents and reaction mechanisms. Ultra-high-resolution mass spectrometry was used to characterize organic aerosol composition, electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping technique was applied to determine the concentrations of ⚫OH, O2⚫-, and carbon- or oxygen-centered organic radicals, and a …