IIFA: Modular Inter-app Intent Information Flow Analysis of Android Applications

Android apps cooperate through message passing via intents. However, when apps do not have identical sets of privileges inter-app communication (IAC) can accidentally or maliciously be misused, e.g., to leak sensitive information contrary to users expectations. Recent research considered static program analysis to detect dangerous data leaks due to inter-component communication (ICC) or IAC, but suffers from shortcomings with respect to precision, soundness, and scalability. To solve these issues we propose a novel approach for static ICC/IAC analysis. We perform a fixed-point iteration of ICC/IAC summary information to precisely resolve intent communication with more than two apps involved. We integrate these results with information flows generated by a baseline (i.e. not considering intents) information flow analysis, and resolve if sensitive data is flowing (transitively) through components/apps in order to be ultimately leaked. Our main contribution is the first fully automatic sound and precise ICC/IAC information flow analysis that is scalable for realistic apps due to modularity, avoiding combinatorial explosion: Our approach determines communicating apps using short summaries rather than inlining intent calls, which often requires simultaneously analyzing all tuples of apps. We evaluated our tool IIFA in terms of scalability, precision, and recall. Using benchmarks we establish that precision and recall of our algorithm are considerably better than prominent state-of-the-art analyses for IAC. But foremost, applied to the 90 most popular applications from the Google Playstore, IIFA demonstrated its scalability to a large corpus of real-world apps. IIFA reports 62 problematic ICC-/IAC-related information flows via two or more apps/components

Match-related physical performance in professional soccer: Position or player specific?

The purpose of this study was to examine to what extent the physical match performance of professional soccer players is both position and player specific. First, official match data from the 2019/20 German Bundesliga season was used to search for players that met the inclusion criteria of playing a minimum of four entire matches in at least two different playing positions. Overall, 25 players met the criteria prior to the COVID-19 induced break, playing a minimum of eight matches. Second, the physical match performance of these players was analyzed separately for each position they played. The following four parameters were captured: total distance, high-intensity distance, sprinting distance, and accelerations. Third, the 25 players’ physical match performance data was then compared to normative data for each position they played to understand whether players adapted their physical performance (position dependent), or maintained their performance regardless of which position they were assigned to (position independent). When switching the position, the change in physical match performance of the respective players could be explained by 44–58% through the normative positional data. Moreover, there existed large individual differences in the way players adapted or maintained their performance when acting in different positions. Coaches and practitioners should be aware that some professional soccer players will likely incur differences in the composition of physical match performance when switching positions and therefore should pay special consideration for such differences in the training and recovery process of these players

Adaptations and transformations of hunter-gatherers in forest environments: New archaeological and anthropological insights

Like any other living being, humans constantly influence their environment, be it intentionally or unintentionally. By extracting natural resources, they shape their environment and also that of plants and other animals. A great difference setting people apart from all other living beings is the ability to construct and develop their own niche intentionally, and the unique tool for this is cultural behaviour. Here, we discuss anthropogenic environmental changes of hunter-gatherers and present new palaeoecological and palynological data. The studies are framed with ethnoarchaeological data from Western Siberia to gain a better understanding of how different triggers lead to coping mechanisms. For archaeological implication, we use two Mesolithic case studies from Germany: One of them focuses on hazelnut economy around ancient Lake Duvensee, and the other broaches the issue of selective roe deer hunt and its consequences at the site of Friesack. We address the archaeological evidence from the perspective of active alteration and its consequences, starting our argumentation from a perspective of niche construction theory. This approach has rarely been applied to early Holocene hunter-gatherers in Northern Europe even though the available data render possible to discuss human–environment interaction from such a perspective. It is demonstrated that archaeological research has tools at hand that enables to detect anthropogenic niche construction. However, the ethnoarchaeological example shows limitations and archaeologically invisible triggers and consequent results of human adaptations. The critical revision of such perspectives based on empirical data provides a better understanding of social and environmental transformations in the early- and mid-Holocene

Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump

Background Treating severe forms of the acute respiratory distress syndrome and cardiac failure, extracorporeal membrane oxygenation (ECMO) has become an established therapeutic option. Neonatal or pediatric patients receiving ECMO, and patients undergoing extracorporeal CO2 removal (ECCO2R) represent low-flow applications of the technology, requiring lower blood flow than conventional ECMO. Centrifugal blood pumps as a core element of modern ECMO therapy present favorable operating characteristics in the high blood flow range (4 L/min–8 L/min). However, during low-flow applications in the range of 0.5 L/min–2 L/min, adverse events such as increased hemolysis, platelet activation and bleeding complications are reported frequently. Methods In this study, the hemolysis of the centrifugal pump DP3 is evaluated both in vitro and in silico, comparing the low-flow operation at 1 L/min to the high-flow operation at 4 L/min. Results Increased hemolysis occurs at low-flow, both in vitro and in silico. The in-vitro experiments present a sixfold higher relative increased hemolysis at low-flow. Compared to high-flow operation, a more than 3.5-fold increase in blood recirculation within the pump head can be observed in the low-flow range in silico. Conclusions This study highlights the underappreciated hemolysis in centrifugal pumps within the low-flow range, i.e. during pediatric ECMO or ECCO2R treatment. The in-vitro results of hemolysis and the in-silico computational fluid dynamic simulations of flow paths within the pumps raise awareness about blood damage that occurs when using centrifugal pumps at low-flow operating points. These findings underline the urgent need for a specific pump optimized for low-flow treatment. Due to the inherent problems of available centrifugal pumps in the low-flow range, clinicians should use the current centrifugal pumps with caution, alternatively other pumping principles such as positive displacement pumps may be discussed in the future

Über die numerische Bestimmung der Blutschädigung in Rotationsblutpumpen

Despite decades of research related to blood damage and numerical blood damage estimation, the accuracy of prediction algorithms for complex flows could not be improved significantly. Nonphysiologically high shear stresses are associated with blood trauma and many of the complications in mechanical circulatory support devices, but direct blood damage predictions (e.g. hemolysis or thrombosis) with Computational Fluid Dynamics (CFD) tend to be inaccurate. An important, but often underestimated factor for the accuracy of the entire simulation is mesh generation, describing the subdivision of a continuous geometric space into discrete geometric and topologic cells. The first publication details the strong dependency of mesh resolution on shear stress prediction within a generic rotary centrifugal blood pump. To avoid under prediction and to maintain a consistent quantification of the actual shear stress, much finer mesh resolutions were required, compared to the current state of the art. Accordingly, the mesh-induced error in subsequent hemolysis prediction was minimized. The second publication highlights crucial aspects for improved numerical accuracy with respect to result validation, choice of turbulence model and setup verification. Simulation results of a benchmark centrifugal blood pump from the FDA Critical Path Initiative were compared with experimental data, demonstrating that the simulation accuracy depends highly on the validation of both pump pressure head and internal velocity field. Furthermore, shear stress quantification demanded particularly high near-wall mesh resolutions, which were not required for the validation of pressure heads or velocity. Using the findings from the previous two publications, the third publication demonstrates the high risk of increased bleeding or clotting complications of currently used rotary blood pumps when operated at blood flow rates below 2 L/min, as in recent clinical use for ECCO2R systems or neonatal and pediatric ECMO applications. Using high resolution CFD analysis, it was observed that the pump internal flow recirculation rate increases 6-12-fold in these flow ranges, potentially increasing adverse effects due to multiple exposures to high shear stress. This dissertation discusses the importance of systematic model verification and result validation as decisive prerequisites for improved simulation accuracy. The findings will support the development of more advanced and more credible blood damage models in the future. Furthermore, CFD could contribute to the understanding of the deleterious consequences that present with the low-flow operation of current rotary blood pump systems, stressing the urgent need to design blood pumps dedicated for low flow applications

Deutsche Milchprodukt-Futurekontrakte: Qualität der Preissignale und Eignung als Preis- absicherungsinstrument

Zusammenfassung Im Zuge der weitgehenden Liberalisierung des europä ischen Milchmarkts ist die Volatilität von Milchpreisen seit dem Jahr 2007 deutlich gestiegen. Das vorliegende Forschungsprojekt nimmt diese Entwicklung zum Ausgangspunkt, um die Frage n ach der Eignung von Milchprodukt-Futures der European Energy Exchange (EEX) als Informations - und Absicherungsinstrument zu beantwor- ten. Falls Milchprodukt-Futurekontrakte die Funktio n der Preisführerschaft erfüllen, liefern Fu- turepreise zuverlässige Informationen für die zugru nde liegenden Kassamärkte und stellen für unternehmerische Entscheidungen eine bedeutende Inf ormationsquelle dar. Besitzen Milchpro- dukt-Futurekontrakte eine hohe Absicherungseffektiv ität, stellen diese Futures eine Möglichkeit im Rahmen des privaten Risikomanagements der Milchb ranche dar und können eines der In- strumente zur Existenzsicherung sein. Vor dem Hinte rgrund der zurückliegenden drei Milchpreis- krisen der Jahre 2009, 2012 und 2015/2016 kommt die ser Eigenschaft besondere Bedeutung zu. Das Forschungsprojekt widmet sich den an der EEX se it 2010 gehandelten Butter- und Mager- milchpulver-Futurekontrakten sowie dem im Jahr 2012 eingeführten Molkenpulverkontrakt. Em- pirische Resultate liegen für die drei Milchprodukt -Futures in der Literatur bislang nicht vor, ver- sprechen aber wertvolle Einsichten in die potentiel le Rolle von Futures als Teil des privaten Risi- komanagements vor dem Hintergrund der gehäuft aufge tretenen Milchpreishöhen und -täler zu liefern. Trotz des geringen Alters der Futureproduk te und einer niedrigen Liquidität zeigen die empirischen Resultate, dass die drei Milchprodukt-F uturekontrakte sowohl die Preiserkennungs- als auch die Absicherungsfunktion erfüllen. Damit s tellen Milchprodukt-Futurepreise eine zuver- lässige Informationsquelle dar, und die drei EEX Ko ntrakte eignen sich als Instrument zum Ma- nagement von Milchpreisrisiken. Die praktischen Empfehlungen leiten sich aus der Be trachtung institutioneller Merkmale des deutschen Milchmarkts und der empirischen Analyse d er Milchprodukt-Futurekontrakte ab. Zu den Implikationen zählen i) die Verbesserung der Be reitstellung qualitativ hochwertiger Kassa- marktdaten, ii) Überlegungen zur Verwendung gewicht eter Kassaindexaggregate anstelle gleich- gewichteter Indizes als Grundlage der Milchprodukt- Futurekontrakte, iii) die Einführung eines Rohmilch-Futurekontrakts, iv) die Schaffung von Anr eizen für Finanzinvestoren zur Erhöhung der Liquidität durch spekulative Aktivitäten begleitet durch eine Informationskampagne und v) eine auf Milcherzeuger ausgerichtete Kommunikation zur F unktionsweise und zum Nutzen von Milch- produkt-Futures als Absicherungsinstrument. Abstract Due to the liberalization of the European dairy mar ket the volatility of dairy prices increased since the year 2007. The research project empirical ly investigates the price discovery function and the function of hedging effectiveness of three European Energy Exchange (EEX) dairy futures. If dairy futures fulfill the price discovery functi on price signals from the future markets provide valuable information for the underlying cash market s and are a sensible source of information for decision on the company level. Moreover, if dairy f utures fulfill the role of hedging effectiveness the future contracts can be sensibly used as risk m anagement tools. Against the background of the milk price crises in 2009, 2012 and 2015/2016 t he role of hedging effectiveness is of special importance. The research project analyses the butter, skimmed m ilk powder and whey milk powder futures contracts launched by the EEX in 2010 and 2012, res pectively. So far empirical findings are not available in the literature. Nevertheless, empirica l findings provide valuable insights into the im- portance of futures as part of the sector’s private risk management tool kid. Despite the low li- quidity the three futures contracts fulfill the pri ce discovery function and exhibit a high degree of hedging effectiveness. Hence, dairy futures prices provide reliable information to the cash mar- kets and the three dairy futures can be used as a r isk management tool. The practical implications are based on the analysi s of the institutional peculiarities of the Ger- man dairy market and the empirical results for the three dairy futures contracts. In particular, we recommend i) improvements of the provision of high quality spot market data, ii) a discussion on value weighted instead of equally weighted spot ind ices as reference prices for the futures con- tracts, iii) the introduction of a raw milk future contract, iv) incentives for financial investors to improve liquidity complemented by an information ca mpaign and v) communication about the functioning and the utility of dairy futures for th e dairy sector

Chloroplast β-barrel proteins are assembled into the mitochondrial outer membrane in a process that depends on the TOM and TOB complexes

Membrane-embedded β-barrel proteins are found in the outer membranes (OM) of Gram-negative bacteria, mitochondria and chloroplasts. In eukaryotic cells, precursors of these proteins are synthesized in the cytosol and have to be sorted to their corresponding organelle. Currently, the signal that ensures their specific targeting to either mitochondria or chloroplasts is ill-defined. To address this issue, we studied targeting of the chloroplast β-barrel proteins Oep37 and Oep24. We found that both proteins can be integrated in vitro into isolated plant mitochondria. Furthermore, upon their expression in yeast cells Oep37 and Oep24 were exclusively located in the mitochondrial OM. Oep37 partially complemented the growth phenotype of yeast cells lacking Porin, the general metabolite transporter of this membrane. Similarly to mitochondrial β-barrel proteins, Oep37 and Oep24 expressed in yeast cells were assembled into the mitochondrial OM in a pathway dependent on the TOM and TOB complexes. Taken together, this study demonstrates that the central mitochondrial components that mediate the import of yeast β-barrel proteins can deal with precursors of chloroplast β-barrel proteins. This implies that the mitochondrial import machinery does not recognize signals that are unique to mitochondrial β-barrel proteins. Our results further suggest that dedicated targeting factors had to evolve in plant cells to prevent mis-sorting of chloroplast β-barrel proteins to mitochondria