The Lock-free kk-LSM Relaxed Priority Queue

Priority queues are data structures which store keys in an ordered fashion to allow efficient access to the minimal (maximal) key. Priority queues are essential for many applications, e.g., Dijkstra's single-source shortest path algorithm, branch-and-bound algorithms, and prioritized schedulers. Efficient multiprocessor computing requires implementations of basic data structures that can be used concurrently and scale to large numbers of threads and cores. Lock-free data structures promise superior scalability by avoiding blocking synchronization primitives, but the \emph{delete-min} operation is an inherent scalability bottleneck in concurrent priority queues. Recent work has focused on alleviating this obstacle either by batching operations, or by relaxing the requirements to the \emph{delete-min} operation. We present a new, lock-free priority queue that relaxes the \emph{delete-min} operation so that it is allowed to delete \emph{any} of the $\rho+1$ smallest keys, where $\rho$ is a runtime configurable parameter. Additionally, the behavior is identical to a non-relaxed priority queue for items added and removed by the same thread. The priority queue is built from a logarithmic number of sorted arrays in a way similar to log-structured merge-trees. We experimentally compare our priority queue to recent state-of-the-art lock-free priority queues, both with relaxed and non-relaxed semantics, showing high performance and good scalability of our approach.Comment: Short version as ACM PPoPP'15 poste

Qualitative Interviews with Irregular Migrants in Times of COVID-19: Recourse to Remote Interview Techniques as a Possible Methodological Adjustment

Forschungsdesigns erfordern Flexibilität. Wichtig ist aber, dass Anpassungen nicht immer ausschließlich mit Nachteilen verbunden sein müssen. In dieser Forschungsnotiz möchten wir unsere Überlegungen zu den Auswirkungen von COVID-19 auf die Durchführung von qualitativen Interviews mit irregulären Migrant*innen veranschaulichen. Die Ausführungen wurden in Anlehnung an eines unserer eigenen Projekte entwickelt, bei dem sich die Feldarbeit derzeit in der Planungsphase befindet. Aufgrund ihrer möglichen Relevanz für ähnliche Projekte möchten wir unsere methodischen Überlegungen teilen. Wir liefern Anmerkungen zur aktuellen Situation irregulärer Migrant*innen in verschiedenen (europäischen) Ländern sowie eine Einschätzung der methodischen Durchführbarkeit von qualitativen Face-to-Face-Interviews mit irregulären Migrant*innen und möglicher Alternativen zu dieser Methode (insbesondere verschiedener Formen von Ferninterviews). Abschließend kommen wir auf unsere Entscheidung zu sprechen, mit einem Mixed-Mode-Ansatz zu arbeiten, der es uns erlaubt, verschiedene Fernbefragungsmodi zu nutzen, und damit die nötige Flexibilität zur Anpassung an den Verlauf derartiger gesundheitlicher und gesellschaftlicher Krisen bietet.Research designs require flexibility, and adjustments made to the designs do not always have to lead exclusively to disadvantages. In this research note, we would like to share our reflections on the impact of COVID-19 on the conduct of qualitative interviews with irregular migrants. Since these considerations were developed in close connection with one of our own projects, in which fieldwork is currently in the planning phase, we believe they may be relevant to similar projects. We include a brief remark on the current situation of irregular migrants in different (European) countries, as well as an assessment of the methodological feasibility of qualitative face-to-face interviews with irregular migrants and possible alternatives to this method such as remote and online interview formats. We conclude with insights on our recommendation to rely on a mixed-mode approach, which allows us to use various remote interview modes, thus providing the necessary flexibility to adapt to profound health and social crises such as COVID-19

Hamster models of COVID-19 pneumonia reviewed: How human can they be?

The dramatic global consequences of the coronavirus disease 2019 (COVID-19) pandemic soon fueled quests for a suitable model that would facilitate the development and testing of therapies and vaccines. In contrast to other rodents, hamsters are naturally susceptible to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the Syrian hamster (Mesocricetus auratus) rapidly developed into a popular model. It recapitulates many characteristic features as seen in patients with a moderate, self-limiting course of the disease such as specific patterns of respiratory tract inflammation, vascular endothelialitis, and age dependence. Among 4 other hamster species examined, the Roborovski dwarf hamster (Phodopus roborovskii) more closely mimics the disease in highly susceptible patients with frequent lethal outcome, including devastating diffuse alveolar damage and coagulopathy. Thus, different hamster species are available to mimic different courses of the wide spectrum of COVID-19 manifestations in humans. On the other hand, fewer diagnostic tools and information on immune functions and molecular pathways are available than in mice, which limits mechanistic studies and inference to humans in several aspects. Still, under pandemic conditions with high pressure on progress in both basic and clinically oriented research, the Syrian hamster has turned into the leading non-transgenic model at an unprecedented pace, currently used in innumerable studies that all aim to combat the impact of the virus with its new variants of concern. As in other models, its strength rests upon a solid understanding of its similarities to and differences from the human disease, which we review here

Light-cone distribution amplitudes of the baryon octet

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using $N_f=2+1$ flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.Comment: Update to the version published in JHE

Foundations in Wisconsin: A Directory [33rd ed. 2014]

The 2014 release of Foundations in Wisconsin marks the 33rd edition of the print directory and the 14th year of the online version. The directory is designed as a research tool for grantseekers interested in locating information on private, corporate, and community foundations registered in Wisconsin. Each entry in this new edition has been updated or reviewed to provide the most current information available. Most of the data was drawn from IRS 990-PF tax returns filed by the foundations. Additional information was obtained from surveys, foundation websites, annual reports, and newsletters.https://epublications.marquette.edu/lib_fiw/1012/thumbnail.jp

SARS-CoV-2 infection of Chinese hamsters (Cricetulus griseus) reproduces COVID-19 pneumonia in a well-established small animal model

The SARS-CoV-2 pandemic has caused a yet unresolved global crisis. Effective medical intervention by vaccination or therapy seems to be the only possibility to control the pandemic. In this context, animal models are an indispensable tool for basic and applied research to combat SARS-CoV-2 infection. Here, we established a SARS-CoV-2 infection model in Chinese hamsters suitable for studying pathogenesis of the disease as well as pre-clinical testing of vaccines and therapies. This species of hamster is susceptible to SARS-CoV-2 infection as demonstrated by robust virus replication in the upper and lower respiratory tract accompanied by bronchitis and pneumonia as well as significant body weight loss following infection. The Chinese hamster features advantages compared to the Syrian hamster model, including more pronounced clinical symptoms, its small size, well-characterized genome, transcriptome and translatome data and availability of molecular tools

Spontaneous regression of multiple flow-related aneurysms following treatment of an associated brain arteriovenous malformation: A case report.

INTRODUCTION There is no consensus in the treatment strategy of intracranial aneurysms (IAs) associated with brain arteriovenous malformation (BAVM). In particular, it is unknown if a more aggressive approach should be considered in patients harboring a BAVM, in whom multiple aneurysms or a history of aneurysmal subarachnoid hemorrhage (aSAH) is present. CASE PRESENTATION We report on an elderly woman harboring multiple aneurysms with a history of SAH due to rupture of an unrelated IA. On evaluation, she was also found to harbor a contralateral, left parietal convexity BAVM. Following resection of the latter, spontaneous regression of two large flow-related aneurysms was encountered. DISCUSSION We discuss the therapeutic decision-making, risk stratification, and functional outcome in this patient with regard to the pertinent literature on the risk of hemorrhage in IAs associated with BAVM