Induced decay of the neutral vaccum in overcritical fields occurring in heavy-ion collisions

In critical or nearly critical heavy-ion collisions, induced as well as spontaneous energyless e-e+ pair creation result in the decay of the neutral vacuum. Induced transitions from the negative-energy continuum into a vacant molecular 1s level can occur even in the absence of diving and produce a substantial enhancement and broadening of the previously considered spontaneous positron spectrum. Total cross sections of 5 b have been calculated for U-U collisions

Solution of the Dirac equation for strong external fields

The 1s bound state of superheavy atoms and molecules reaches a binding energy of -2mc2 at Z≈169. It is shown that the K shell is still localized in r space even beyond this critical proton number and that it has a width Γ (several keV large) which is a positron escape width for ionized K shells. The suggestion is made that this effect can be observed in the collision of very heavy ions (superheavy molecules) during the collision

Die Rotatorienfauna einiger Gewässer des Naturschutzgebietes „Heiliges Meer“ im Kreis Steinfurt

Die planktontische und die benthische Rotatorienfauna des NSG Heiliges Meer, Krs. Steinfurt, Nordrhein-Westfalen, wurde durch monatliche Beprobung von eutrophen, oligotrophen und dystrophen Gewässern zwischen Oktober 1999 und Oktober 2000 untersucht. Insgesamt konnten 195 Rädertierarten festgestellt werden, davon waren 166 Monogononta und 29 Bdelloidea.BetweenOctober 1999 and October 2000 the planctontic and benthic rotatoria of the nature reserve Heiliges Meer, North-Rhine-Westphalia, was investigated by monthly samples in eutrophic, oligotrophic and dystrophic waters. Totally we found 195 species of rotatoria, 166 Monogononta and 29 Bdelloidea resp

Import pathways of precursor proteins into mitochondria

The precursor of porin, a mitochondrial outer membrane protein, competes for the import of precursors destined for the three other mitochondrial compartments, including the Fe/S protein of the bc1- complex (intermembrane space), the ADP/ATP carrier (inner membrane), subunit 9 of the F0-ATPase (inner membrane), and subunit beta of the F1- ATPase (matrix). Competition occurs at the level of a common site at which precursors are inserted into the outer membrane. Protease- sensitive binding sites, which act before the common insertion site, appear to be responsible for the specificity and selectivity of mitochondrial protein uptake. We suggest that distinct receptor proteins on the mitochondrial surface specifically recognize precursor proteins and transfer them to a general insertion protein component (GIP) in the outer membrane. Beyond GIP, the import pathways diverge, either to the outer membrane or to translocation contact-sites, and then subsequently to the other mitochondrial compartments

Brief Studies

Toward A Missionary Church Liturgy in the Lutheran Church in German

Architectural Attack Propagation Analysis for Identifying Confidentiality Issues

Exchanging data between different systems enables us to build new smart services and digitise various areas of our daily life. This digitalisation leads to more efficient usage of resources, and an increased monetary value. However, the connection of different systems also increases the number of potential vulnerabilities. The vulnerabilities on their own might be harmless, but attackers could build attack paths based on the combination of different vulnerabilities. Additionally, attackers might exploit existing access control policies to further propagate through the system. For analysing this dependency between vulnerabilities and access control policies, we extended an architecture description language (ADL) to model access control policies and specify vulnerabilities. We developed an attack propagation analysis operating on the extended ADL, which can help to determine confidentiality violations in a system. We evaluated our approach by analysing the accuracy and the effort compared to a manual analysis using different scenarios in three case studies. The results indicate that our analysis is capable of identifying attack paths and reducing the effort compared to manual detection

Architecture-Based Attack Path Analysis for Identifying Potential Security Incidents

Manually estimating an attack path to a targeted software element can be complex since a software system consists of multiple vulnerable elements, such as components, hardware resources, or network elements. In addition, the elements are protected by access control. Software architecture describes the structural elements of the system, which may form elements of the attack path. However, estimating attack paths is complex since different attack paths can lead to a targeted element. Additionally, not all attack paths might be relevant since attack paths can have different properties based on the attacker\u27s capabilities and knowledge. We developed an approach that enables architects to identify relevant attack paths based on the software architecture. We created a metamodel for filtering options and added support for describing attack paths in an architectural description language. Based on this metamodel, we developed an analysis that automatically estimates attack paths using the software architecture. This can help architects to identify relevant attack paths to a targeted component and increase the system\u27s overall security. We evaluated our approach on five different scenarios. Our evaluation goals are to investigate our analysis\u27s accuracy and scalability. The results suggest a high accuracy and good runtime behavior for smaller architectures

A Taxonomy of Dynamic Changes Affecting Confidentiality

Industry 4.0 facilitates dynamic production processes for highly tailored individual products that require intense cooperation between different organisations. The enabler of such cooperation are cyber-physical systems (CPSs). A set of policies also considering dynamic changes of a request context during runtime has to protect the confidentiality of involved systems. Analysing policy effectiveness already during design time can avoid costly confidentiality flaws. However, the changes that can be evaluated during design time are not clear. Therefore, we identified typical dynamic changes from use cases we gathered with two industrial partners and categorized them accordingly