Search results for "fer"
showing 10 items of 33109 documents
Ferdinands Erdmanis Štolls. Sēņu pasaule
2023
“Muzeja sērijas” trešā grāmata “Ferdinands Erdmanis Štolls. Sēņu pasaule.” Tā ir neliels ieskats mikologa F. E. Štolla (Ferdinand. Erdman Stoll; 1874–1966) vairāk kā 1000 lapu lielajā sēņu attēlu kolekcijā, ko zinātnieks ir izveidojis pētot Latvijas sēnes un, kas pamatā sastāv no paša pētnieka zīmētajiem akvareļiem. Akvareļu kolekcija ir viens no Latvijas Universitātes Muzeja Botānikas un mikoloģijas kolekciju dārgumiem, kas joprojām ir ne tikai pētnieku interešu objekts, bet spēj iepriecināt jebkuru interesentu ar savām estētiskajām kvalitātēm. Publicētos akvareļus raksturo citāti no 1934. gadā izdotās F. E. Štolla grāmatas “Latvijas sēnes”, kas ir pirmā izdotā mikoloģijas grāmata latviešu…
Nestriktās ekvivalences nestriktās klasterizācijas algoritmā
2022
Maģistra darba mērķis ir iepazīstināt lasītāju ar izstrādātu, ERAF projekta ietvaros, klasterizācijas metodi FERC, un parādīt tās priekšrocības salīdzinājumā ar nestrikto C-means. Projekta rezultāti tiks publicēti žurnālā Springer. FERC metodē, mēs ieviešam nestrīktās ekvivalences attiecības dažādiem objekta atribūtiem, un tad mēs agregējam šīs nestriktās ekvivalences attiecības vienā, lai noteiktu objekta piederības pakāpi kādam klasterim. Darbā tiek parādīts, ka klasterizācijas procesā, katram objekta atribūtam var uzdot tā nozīmīgumu, ieviešot atribūtu svarus. Līdz šim klasterizācijas procesā, atribūtu svari netika izmantoti. Kā arī darbā tiek parādīti ilustratīvi piemēri.
Functional characterization of the human tRNA methyltransferases TRMT10A and TRMT10B
2020
Abstract The TRM10 family of methyltransferases is responsible for the N1-methylation of purines at position 9 of tRNAs in Archaea and Eukarya. The human genome encodes three TRM10-type enzymes, of which only the mitochondrial TRMT10C was previously characterized in detail, whereas the functional significance of the two presumably nuclear enzymes TRMT10A and TRMT10B remained unexplained. Here we show that TRMT10A is m1G9-specific and methylates a subset of nuclear-encoded tRNAs, whilst TRMT10B is the first m1A9-specific tRNA methyltransferase found in eukaryotes and is responsible for the modification of a single nuclear-encoded tRNA. Furthermore, we show that the lack of G9 methylation cau…
Eukaryotic rRNA Modification by Yeast 5-Methylcytosine-Methyltransferases and Human Proliferation-Associated Antigen p120.
2015
International audience; Modified nucleotide 5-methylcytosine (m(5)C) is frequently present in various eukaryotic RNAs, including tRNAs, rRNAs and in other non-coding RNAs, as well as in mRNAs. RNA: m(5)C-methyltranferases (MTases) Nop2 from S. cerevisiae and human proliferation-associated nucleolar antigen p120 are both members of a protein family called Nop2/NSUN/NOL1. Protein p120 is well-known as a tumor marker which is over-expressed in various cancer tissues. Using a combination of RNA bisulfite sequencing and HPLC-MS/MS analysis, we demonstrated here that p120 displays an RNA:m(5)C-MTase activity, which restores m(5)C formation at position 2870 in domain V of 25S rRNA in a nop2 Delta …
Absolute quantification of noncoding RNA by microscale thermophoresis
2019
Abstract Accurate quantification of the copy numbers of noncoding RNA has recently emerged as an urgent problem, with impact on fields such as RNA modification research, tissue differentiation, and others. Herein, we present a hybridization‐based approach that uses microscale thermophoresis (MST) as a very fast and highly precise readout to quantify, for example, single tRNA species with a turnaround time of about one hour. We developed MST to quantify the effect of tRNA toxins and of heat stress and RNA modification on single tRNA species. A comparative analysis also revealed significant differences to RNA‐Seq‐based quantification approaches, strongly suggesting a bias due to tRNA modifica…
T9+HUD: Physical Keypad and HUD can Improve Driving Performance while Typing and Driving
2016
We introduce T9+HUD, a text entry method designed to decrease visual distraction while driving and typing. T9+HUD combines a physical 3x4 keypad on the steering wheel with a head-up-display (HUD) for projecting output on the windshield. Previous work suggests this may be a visually less demanding way to type while driving than the popular case which requires shifts of visual attention away from the road. We present a prototype design and report first results from a controlled evaluation in a driving simulator. While driving, the T9+HUD text entry rate was equal compared to a dashboard-mounted touchscreen device, but it reduced lane deviations by 70%. Furthermore, there was no significant di…
Numerical Recovery of Source Singularities via the Radiative Transfer Equation with Partial Data
2013
The inverse source problem for the radiative transfer equation is considered, with partial data. Here we demonstrate numerical computation of the normal operator $X_{V}^{*}X_{V}$ where $X_{V}$ is the partial data solution operator to the radiative transfer equation. The numerical scheme is based in part on a forward solver designed by F. Monard and G. Bal. We will see that one can detect quite well the visible singularities of an internal optical source $f$ for generic anisotropic $k$ and $\sigma$, with or without noise added to the accessible data $X_{V}f$. In particular, we use a truncated Neumann series to estimate $X_{V}$ and $X_{V}^{*}$, which provides a good approximation of $X_{V}^{*…
Biomass estimator for NIR image with a few additional spectral band images taken from light UAS
2012
A novel way to produce biomass estimation will offer possibilities for precision farming. Fertilizer prediction maps can be made based on accurate biomass estimation generated by a novel biomass estimator. By using this knowledge, a variable rate amount of fertilizers can be applied during the growing season. The innovation consists of light UAS, a high spatial resolution camera, and VTT's novel spectral camera. A few properly selected spectral wavelengths with NIR images and point clouds extracted by automatic image matching have been used in the estimation. The spectral wavelengths were chosen from green, red, and NIR channels.
Measuring Distraction at the Levels of Tactical and Strategic Control: The Limits of Capacity-Based Measures for Revealing Unsafe Visual Sampling Mod…
2011
The control theory of driving suggests that driver distraction can be analyzed as a breakdown of control at three levels. Common approach for analyzing distraction experimentally is to utilize capacity-based measures to assess distraction at the level of operational control. Three driving simulation experiments with 61 participants were organized to evaluate which kind of measures could be used to analyze drivers' tactical visual sampling models and the related effects of distraction while searching textual information on in-car display. The effects of two different text types were evaluated. The utilized capacity-based measures seemed to be insufficient for revealing participants' tactical…
On shape differentiation of discretized electric field integral equation
2013
Abstract This work presents shape derivatives of the system matrix representing electric field integral equation discretized with Raviart–Thomas basis functions. The arising integrals are easy to compute with similar methods as the entries of the original system matrix. The results are compared to derivatives computed with automatic differentiation technique and finite differences, and are found to be in an excellent agreement. Furthermore, the derived formulas are employed to analyze shape sensitivity of the input impedance of a planar inverted F-antenna, and the results are compared to those obtained using a finite difference approximation.