NMR structure of Citrobacter freundii AmpD, comparison with bacteriophage T7 lysozyme and homology with PGRP domains.

AmpD is a bacterial amidase involved in the recycling of cell-wall fragments in Gram-negative bacteria. Inactivation of AmpD leads to derepression of beta-lactamase expression, presenting a major pathway for the acquisition of constitutive antibiotic resistance. Here, we report the NMR structure of AmpD from Citrobacter freundii (PDB accession code 1J3G). A deep substrate-binding pocket explains the observed specificity for low molecular mass substrates. The fold is related to that of bacteriophage T7 lysozyme. Both proteins bind zinc at a conserved site and require zinc for amidase activity, although the enzymatic mechanism seems to differ in detail. The structure-based sequence alignment identifies conserved features that are also conserved in the eukaryotic peptidoglycan recognition protein (PGRP) domains, including the zinc-coordination site in several of them. PGRP domains thus belong to the same fold family and, where zinc-binding residues are conserved, may have amidase activity. This hypothesis is supported by the observation that human serum N-acetylmuramyl-L-alanine amidase seems to be identical with a soluble form of human PGRP-L

Multitask variational autoencoders

Variational autoencoders (VAEs) are widely used for generative modeling and repre- sentation learning tasks. This thesis presents two novel approaches aimed at enhancing the performance of VAEs through the integration of semi-conditional variational autoen- coders (SCVAEs). The integration of SCVAEs and VAEs is motivated by the potential for improvement in the effectiveness of capturing the underlying data distribution and the improvement in generating high-quality samples. The first method extends the traditional VAEs by incorporating a second conditioned decoder, thereby enabling the model to multi-task and learn better latent representations. The second method utilizes a unified decoder for both tasks by employing sophisticated training strategies. These approaches are implemented and evaluated on Gaussian VAEs and VQ-VAEs. Extensive experimentation is conducted across diverse image datasets, including MNIST, CIFAR10, and CelebA. The results show that, in certain cases, the proposed methods yield superior performance compared to standard VAE architectures. By bridg- ing the gap between SCVAEs and VAEs, this work gives new insights on how to improve the methods further and opens up new avenues for future research in the field of generative modeling.Masteroppgave i informatikkINF399MAMN-INFMAMN-PRO

Path Planning Usage For Mobile Robots

The paper deals with path planning programme for mobile robots. The aim of the paper is to develop a path planning programme for mobile robots that is based on simulation software development. The results of the careful analysis were considered for optimal path planning algorithms. The experimental evidence was proposed to demonstrate the effectiveness of the algorithm for steady covered space. The results described in this work can be extended in a number of directions, and applied to other algorithms

Growth of Silver birch (Betula pendula) & Downy birch (Betula pubescens) established in four different initial densities on one site in central Sweden

Nowadays, there is an increased demand for timber resources and more sustainable forest management, starting from the establishment phase of the forest, e.g., planting. Depending on the management goals, number of seedlings planted and thus initial spacing can be adjusted in order not to waste resources. However, there is very little existing knowledge on how different initial spacing arrangements in both Silver birch (Betula pendula) and Downy birch (Betula pubescens) would affect the further development of a stand, with this study being one of the few that comprises such a research question. The main objective of this study was to test different initial square spacings in Silver birch and Downy birch stands and compare their growth dynamics and long-term production. Long-term production of the different treatments was assessed by using the new basal area functions developed for genetically improved birch. In addition, an economic assessment of full rotation projections was done based on standard management. To do the above-mentioned analysis, long-term observational data was compiled, and additional data collected from one growth trial located in central Sweden, in which both birch species were planted in four different square spacings. Besides the above-mentioned simulations, statistical analyses (one-way Anova) were carried out to test the effect of initial spacing on different growth parameters. Statistical analysis revealed that initial spacing had a significant effect on diameter development and height of the living crown for both species and Gini index for Downy birch. Full rotation simulations revealed that the best results in terms of production/economy for both species were achieved from initial spacing of 1.8x1.8 m. The optimal rotation of the 1.8 x 1.8 m treatment was determined to be 48 years for Silver birch and 49 years Downy birch for timber and pulpwood as the main goal respectively. An evident observation that was not tested was the superior growth of Silver birch compared to its counterpart – Downy birch, which was also reflected in the considerably higher production/growth (MAI) (7.13 m3 ha-1 year-1 to 6.63 m3 ha-1 year-1) and better economy (LEV for timber), 34077 SEK compared to 26576 SEK

Path Planning Usage for Autonomous Agents

In order to achieve the wide range of the robotic application it is necessary to provide iterative motions among points of the goals. For instance, in the industry mobile robots can replace any components between a storehouse and an assembly department. Ammunition replacement is widely used in military services. Working place is possible in ports, airports, waste site and etc. Mobile agents can be used for monitoring if it is necessary to observe control points in the secret place. The paper deals with path planning programme for mobile robots. The aim of the research paper is to analyse motion-planning algorithms that contain the design of modelling programme. The programme is needed as environment modelling to obtain the simulation data. The simulation data give the possibility to conduct the wide analyses for selected algorithm. Analysis means the simulation data interpretation and comparison with other data obtained using the motion-planning. The results of the careful analysis were considered for optimal path planning algorithms. The experimental evidence was proposed to demonstrate the effectiveness of the algorithm for steady covered space. The results described in this work can be extended in a number of directions, and applied to other algorithms

Bosonic String in Affine-Metric Curved Space

The sigma model approach to the closed bosonic string on the affine-metric manifold is considered. The two-loop metric counterterms for the nonlinear two-dimensional sigma model with affine-metric target manifold are calculated. The correlation of the metric and affine connection is considered as the result of the ultraviolet finiteness (or beta-function vanishing) condition for the nonlinear sigma model. The examples of the nonflat nonRiemannian manifolds resulting in the trivial metric beta-function are suggested.Comment: 15 pages, LaTe

Epigramas

http://www.ester.ee/record=b3582058*es

Path Planning Methods in Chemical Engineering

Usually, when the practical motion planning and the shortest path are discoursed, mainly the limited number of tasks is observed. Almost all the tasks associated with the path from one point in 2D or 3D space to another point can be attributed to the usual issue in the practical application. Motion planning and the shortest path have vivid and indisputable importance as human activity in such areas as logistics and robotics. In our work we would like to draw particular attention to the field of application seems to be unnoticeable for the task such as motion planning and the shortest path problem. Due to quite simple examples used, we would like to show that the task of motion planning can be used for simulation and optimization of multi-staged and restricted processes which are presented in chemical engineering accordingly. In the article the simulation and optimization of three important chemical-technological processes for the chemical industry are discussed. The work done gave us the possibility to work out software for simulation and optimization of processes that in some cases facilitates and simplifies the work of professionals engaged in the field of chemical engineering

BVR Gym: A Reinforcement Learning Environment for Beyond-Visual-Range Air Combat

Creating new air combat tactics and discovering novel maneuvers can require numerous hours of expert pilots' time. Additionally, for each different combat scenario, the same strategies may not work since small changes in equipment performance may drastically change the air combat outcome. For this reason, we created a reinforcement learning environment to help investigate potential air combat tactics in the field of beyond-visual-range (BVR) air combat: the BVR Gym. This type of air combat is important since long-range missiles are often the first weapon to be used in aerial combat. Some existing environments provide high-fidelity simulations but are either not open source or are not adapted to the BVR air combat domain. Other environments are open source but use less accurate simulation models. Our work provides a high-fidelity environment based on the open-source flight dynamics simulator JSBSim and is adapted to the BVR air combat domain. This article describes the building blocks of the environment and some use cases.Comment: 8 pages, 8 figure

Mõne hauapanuse pindpanusest: taušeerimistehnikast eesti arheoloogilistel leidudel

Edvards Puciriusse lõputöös uuritakse Eesti muinas- ja keskaegses arheoloogilises materjalis laialt esindatud taušeerimistehnika, mille põhimõte on värviliste- või väärismetallide mehhaaniline kinnitamine rauast esemete pinnale. Töö eesmärk on allikmaterjale ja originaalesemeid uurides (tööriistajälgede ja muude tehniliste detailide avastamiseks) ning praktilisi metallitöö katseid tehes rekonstrueerida ja kirjeldada taušeerimistehnikat. Töös käsitletakse ka selle tehnikaga seotud terminoloogiat, kuna eestikeelses kirjanduses kasutatakse selle kohta sõnu “panustamine/ panustöö” ja „inkrusteerimine“. Uurimistöö käigus ilmnes aga, et täpsem oleks kasutada terminit “taušeerimine”. Praktilise töö raames valmisid kahe hobuvarustuse naastu ja ühe mõõgakäepideme rekonstruktsioonid. Lisaks taušeerimisele tuli kasutada erinevaid metallitöö võtteid nagu sepistamist, sepakeetmist, graveerimist, hõbe- ning kulla amalgaami ja niellot. Originaalesemete vaatluse käigus kogutud informatsiooni võrdlus praktiliste katsete tulemustega aitab paremini mõista erinevaid taušeerimistehnikas kaunistatud esemete tehnoloogilisi nüansse.https://www.ester.ee/record=b5437860*es