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In dieser Arbeit wurden neuartige Proteasen aus psychrotoleranten Bakterienstämmen isoliert und auf ihre biochemischen Eigenschaften charakterisiert. Des Weiteren konnten S8 Familie Proteasen Gene amplifiziert werden und Unterschiede in der Aminosäuresequenz konnten in Zusammenhang mit den biochemischen Eigenschaften der Proteasen in Verbindung gebracht werden.
A relatively new research field of neurosciences, called Connectomics, aims to achieve a full understanding and mapping of neural circuits and fine neuronal structures of the nervous system in a variety of organisms. This detailed information will provide insight in how our brain is influenced by different genetic and psychiatric diseases, how memory traces are stored and ageing influences our brain structure. It is beyond question that new methods for data acquisition will produce large amounts of neuronal image data. This data will exceed the zetabyte range and is impossible to annotate manually for visualization and analysis. Nowadays, machine learning algorithms and specially deep convolutional neuronal networks are heavily used in medical imaging and computer vision, which brings the opportunity of designing fully automated pipelines for image analysis. This work presents a new automated workflow based on three major parts including image processing using consecutive deep convolutional networks, a pixel-grouping step called connected components and 3D visualization via neuroglancer to achieve a dense three dimensional reconstruction of neurons from EM image data.
Prototype-based classification methods like Generalized Matrix Learning Vector Quantization (GMLVQ) are simple and easy to implement. An appropriate choice of the activation function plays an important role in the performance of (deep) multilayer perceptrons (MLP) that rely on a non-linearity for classification and regression learning. In this thesis, successful candidates of non-linear activation functions are investigated which are known for MLPs for application in GMLVQ to realize a non-linear mapping. The influence of the non-linear activation functions on the performance of the model with respect to accuracy, convergence rate are analyzed and experimental results are documented.
Cryptorchidism describes a disease, in which one or both testes do not descend into the scrotum properly. With a prevalence of up to 10%, cryptorchidism is one of the most common birth defects of the male genital tract. Despite its associated health risks and accompanying economic damage, resulting from surgery and losses in breeding, studies on canine cryptorchidism and its causes are relatively rare. In this study a relational database for genetic causes of cryptorchidism was established and used as a basis for the identification of candidate genes. Associated regions were analysed by nanopore sequencing with the goal to identify genetic variants correlated with cryptorchidism in German Sheep Poodle.
The epithelial membrane proteins (EMP1-3), which belong to the family of peripheral myelin proteins 22-kDa (PMP22), are involved in epithelial differentiation. EMP2 was found to be a downstream target gene of the tumor suppressor gene HOPX, a homeobox-containing gene. Additionally, a dysregulation of EMP2 has been observed in various cancers, but the function of EMP2 in human lung cancer has not yet been clarified.
In this study, a real-time RT-PCR, Western blot and cytoblock analysis were performed to analyze the expression of EMP2. Gain-of-function was achieved by stable transfection with an EMP2 expression vector and loss-of-function by siRNA knockdown. Stable transfection led to overexpression of EMP2 at both mRNA and protein levels in the transfected cell lines H1299 and H2170.
Functional assays including proliferation, colony formation, migration and invasion assays as well as cell cycle analyzes were performed after stable transfection and it was found that the ectopic EMP2 expression resulted in a reduced cell proliferation, migration and invasion as well as a G1 cell cycle arrest. After the EMP2 gene was silenced by the siRNA knockdown, inhibition of the cell invasive property was observed. These phenomena were accompanied by reduced AKT, mTor and p38 activities.
Taken together, the data suggest that the epithelial membrane protein 2 (EMP2) is a tumor suppressor and exerts its tumor suppressive function by inhibiting AKT and MAPK signaling pathways in human lung cancer cells.
The aim of this bachelor thesis was to establish extracytoplasmic function (ECF) σ factors as synthetic genetic regulators for biotechnological and synthetic biology applications in the new emerging model organism Vibrio natriegens. Therefore, synthetic genetic circuits were engineered on plasmids as test set-up for the investigated ECFs and their target promoters. The resulting plasmid library consisted of the reporter plasmids with the target promoter, fused to a lux cassette, a set of high-copy ECF plasmids and a backup set of lower-copy ECF plasmids. First, the high-copy plasmids were transformed in V. natriegens to test them for their functionality upon different inducer levels, which yielded good inducibility for few, but showed too high ECF-expression in most strains. For this reason, the set of lower copy plasmids was used for combinatorial co-transformation, to investigate the ECFs for their cross-talk to unspecific ECF target promoters. The switching to the lower-copy plasmid-set seemed to be partly helpful, while still much room for fine-tuning of the circuits remains. The knowledge gained can be used to achieve higher success rates when engineering synthetic circuits for various applications in V. natriegens, by using the ECFs here recommended as suitable synthetic genetic regulators.
Workload Optimization Techniques for Password
Guessing Algorithms on Distributed Computing Platforms
(2019)
The following thesis covers several ways to optimize distributed computing platforms for cryptanalytic purposes. After an introduction on password storage, password guessing attacks and distributed computing in general, a set of inital benchmark results for a variety of different devices will be analyzed. The shown results are mainly based on utilization of the open source password recovery tool Hashcat. The second part of this work shows an algorithmic implementation for information retrieval and workload generation. This thesis can be used for the conception of a distributed computing system, inventory analysis of available hardware devices, runtime and cost estimations for specific jobs and finally strategic workload distribution.
In today’s market, the process of dealing with textual data for internal and external processes has become increasingly important and more complex for certain companies. In this context,the thesis aims to support the process of analysis of similarities among textual documents by analyzing relationships among them. The proposed analysis process includes discovering similarities among these financial documents as well as possible patterns. The proposal is based on the exploitation and extension of already existing approaches as well as on their combination with well-known clustering analysis techniques. Moreover, a software tool has been implemented for the evaluation of the proposed approach, and experimented on the EDGAR filings, on the basis of qualitative criteria.
In the present bachelor thesis, nanopore sequencing and Illumina sequencing was compared using pollen DNA collected from honeybees and bumble bees. Therefore, nanopore sequencing was performed with the MinION sequencers and the generated reads were analysed with bash programming. A quantitative and qualitative (based on ITS2 sequences) BLAST run was performed. The results confirme the error probability of nanopore sequencing that is described in the literature. Nevertheless, with both sequencing methods similar sample preferences of the bees could have been observed, allowing ecological conclusions.
In the practice of software engineering, project managers often face the problem of software project management.
It is related to resource constrained project scheduling
problem. In software project scheduling, main resources are considered to be the employees with some skill set and required amount of salary. The main purpose of software
project scheduling is to assign tasks of a project to the available employees such that the total cost and duration of the project are minimized, while keeping in check that
the constraints of software project scheduling are fulfilled. Software project scheduling (SPSP) has complex combined optimization issues and its search space increases exponentially when number of tasks and employees are increased, this makes software project scheduling problem (SPSP) a NP-Hard problem. The goal of software project scheduling problem is to minimize total cost and duration of project which makes it multi-objective problem. Many algorithms are proposed up till now that claim to give near optimal results for NP-Hard problems, but only few are there that gives feasible set of solutions for software project scheduling problem, but still we want to get more efficient algorithm to get feasible and efficient results.
Nowadays, most of the problems are being solved by using nature inspired algorithms because these algorithms provide the behavior of exploration and exploitation. For solving
software project scheduling (SPSP) some of these nature inspired algorithms have been used e.g. genetic algorithms, Ant Colony Optimization algorithm (ACO), Firefly etc.
Nature inspired algorithms like particle swarm optimization, genetic algorithms and Ant Colony Optimization algorithm provides more promising result than naive and greedy algorithms. However there is always a quest and room for more improvement. The main purpose of this research is to use bat algorithm to get efficient results and solutions for software project scheduling problem. In this work modified bat algorithm is implemented where a different approach of random walk is used. The contributions of this thesis are to: (1) To adapt and apply modified multi-objective bat algorithm for solving software project scheduling (SPSP) efficiently, (2) to adapt and apply other nature inspired algorithms like genetic algorithms for solving software project scheduling (SPSP) and (3) to compare and analyze the results obtained by applied nature inspired algorithms and provide the conclusion.