Flavoenzymes at the crossroads of biocatalysis and structural biology

Flavine-bevattende eiwitten zijn veelvoorkomende en veelzijdige natuurlijke katalysatoren. Deze eiwitten zijn in staat een grote verscheidenheid aan reductieve en oxidatieve reacties te versnellen. Om flavine-bevattende eiwitten beter te begrijpen, en hun potentiaal beter te kunnen benutten in een industriële setting, zijn gedetailleerde studies nodig. In dit proefschrift wordt de ontdekking, structuur opheldering en biochemische karakterisering van een aantal nieuwe (deaza)flavine-bevattende eiwitten beschreven. Deze enzymen zijn gevonden door middel van genome mining, en de behaalde resultaten laten zien hoe enzymologie en structurele biologie met elkaar verweven zijn. De ontdekte eiwitten zijn voorbeelden van robuuste biokatalysatoren die gemakkelijk op recombinante wijze verkregen en vervolgens gezuiverd kunnen worden. Met behulp van de opgehelderde structuur kunnen deze eiwitten verder ontwikkeld worden tot bruikbare oxidative enzymen om op grote schaal gebruikt te worden in biotechnologische toepassingen

Security for Multi-hop Communication of Two-tier Wireless Networks with Different Trust Degrees

Many effective strategies for enhancing network performance have been put forth for wireless communications' physical-layer security. Up until now, wireless communications security and privacy have been optimized based on a set assumption on the reliability or network tiers of certain wireless nodes. Eavesdroppers, unreliable relays, and trustworthy cooperative nodes are just a few examples of the various sorts of nodes that are frequently categorized. When working or sharing information for one another, wireless nodes in various networks may not always have perfect trust in one another. Modern wireless networks' security and privacy may be enhanced in large part by optimizing the network based on trust levels. To determine the path with the shortest total transmission time between the source and the destination while still ensuring that the private messages are not routed through the untrusted network tier, we put forth a novel approach. To examine the effects of the transmit SNR, node density, and the percentage of the illegitimate nodes on various network performance components, simulation results are provided

“I choose fish”:Understanding informal civil society in Vietnam through environmental grievances and actions

This paper focuses on informal civil society in an authoritarian context, particularly the unprecedented nation-wide protests and civic action in Vietnam, triggered by the industrial pollution and the resulting mass fish death on the central coast in 2016. We explore civil society actors' motivations and tactics to take action under political restrictions. Data was collected from semi-structured interviews with civil society actors. The findings illustrate how informal civil society in Vietnam is built on independent or partly NGO-affiliated individuals working together to promote non-violent change, although the process of doing so might involve challenging the government apparatus. The activists were motivated to take action by the dead fish’ symbolism of endangered livelihood, environmental protection, and to demand transparency from the government. Critical factors further contributing to the mobilisation of citizens included the combination of food symbolism and anti-China nationalism, the tactical use of Facebook by urban activists, and religious leadership in the rural areas. The protests resulting from the coastal pollution can be seen as boundary-spanning events through which Vietnamese civil society actors ‘invent’ spaces of (political) participation amidst limited ‘invited’ space

Some Characteristics And Allopurinol Release Of Carrageenan/ Allopurinol Films Using Polyethylene Oxide As A Dispersion Aid Agent

This paper presents the effect of carrageenan (CG) on some characteristics and drug release of allopurinol in the presence of polyethylene oxide (PEO) as a dispersion aid agent. The samples were prepared in film shape by solution method, in which, the content of PEO was changed from 1 wt.% to 5 wt.% and the content of allopurinol was fixed at 10 wt.% in comparison with carrageenan weight. FTIR , FESEM, UV-Vis methods were used to evaluate characterizations and morphology of CG/PEO/allopurinol films

Establishing an Assessment Criteria System for Architectural Heritage of Colonial Educational Buildings in Hanoi

A number of educational buildings were built up by the French in Hanoi during their dominance. Most of these buildings still exist in the downtown area and have become an integral part of the valuable heritage, and their preservation is increasingly imperative. To preserve and promote more efficiently the values of the colonial building heritage assets, there is a need of a set of criteria for an assessment and classification. This paper presents the development of an assessment criteria system for the architectural heritage of colonial educational buildings in Hanoi. According to the proposals, colonial educational buildings can be classified into three groups of Special Value, Notable Value, Average Value. A set of criteria including factors related to both the internal and external values of these buildings have been proposed and validated with expert judgements. Each criterion then is incorporated with a set of scores showing the value it can bring to a colonial educational building to be assessed. The set of criteria and their scores can be used by the city authority to establish regulations to preserve and promote heritage values of the colonial educational buildings in Hanoi

Security for Two-Way Untrusted Relay against Constant and Reactive Jamming with Fixed Signals

Active attacking in physical-layer security has not been significantly studied while potentially causing serious consequences for the legitimate networks. In this paper, we propose a novel method to estimate and remove the jamming signals from multiple multi-antenna jammers in a two-way relay network with multi-antenna legitimate and relay nodes. We carefully consider the signals in the time slots in order to exploit the repetition of the signals and design the transmitted signals which can work in different cases. The numerical results show that the secrecy maximum achievable sum-rate (MASR) at the legitimate nodes is higher than that of the conventional method when considering the affect of transmit SNR; the number antennas at the legitimate and relay nodes; normalized distance between one legitimate node and the relay; and the vertical coordinate of the relay

Modified Dijkstra's Routing Algorithm for Security with Different Trust Degrees

A great number of efficient methods to improve the performance of the networks have been proposed in physical-layer security for wireless communications. So far, the security and privacy in wireless communications is optimized based on a fixed assumption about the trustworthiness or trust degrees (TD) of certain wireless nodes. The nodes are often classified into different types such as eavesdroppers, untrusted relays, and trusted cooperative nodes. Wireless nodes in different networks do not completely trust each other when cooperating or relaying information for each other. Optimizing the network based on trust degrees plays an important role in improving the security and privacy for the modern wireless network. We proposed a novel algorithm to find the route with the smallest total transmission time from the source to the destination and still guarantee that the accumulated TD is larger than a trust degree threshold. Simulation results are presented to analyze the affects of the transmit SNR, node density, and TD threshold on different network performance elements