Large Number Of Open Questions Research Articles

Modern perspectives in Proof Theory.

Modern perspectives in Proof Theory.

P-points, MAD families and Cardinal Invariants

P-points, MAD families and Cardinal Invariants

Spatial and seasonal distributions of frontal activity over the French continental shelf in the Bay of Biscay

The frontal activity in coastal regions remains a research field where a large number of open questions needs to be addressed to quantify the potential impact of these processes on dependent systems (e.g. biogeochemical activity). Spatial and seasonal distributions of Sea Surface Temperature (SST) fronts (∼1–100km) in the vicinity of main French rivers, Gironde and Loire, are explored over the continental shelf North of 45°N in the Bay of Biscay. A high resolution (1km spatial and daily temporal resolutions) dataset of 11years' (2003–2013) remotely sensed SST by MODIS sensor onboard Aqua and Terra satellites has been investigated and compared with coastal numerical model experiments. The detection and characterization fronts with fluctuating amplitudes is achieved through the Singularity Analysis (i.e. the process of calculating the degree of regularity or irregularity of a function at each point in a domain). Seasonality of frontal activity in the Bay of Biscay is then described based on the long-term satellite SST archive and coastal operational model simulations. The identified hot spots of higher frontal occurrences correspond on one hand to previously observed features (e.g. tidal fronts) but also reveal new features. These are investigated to identify fine-scale dynamical drivers. In winter, density fronts are prominent in a coastal strip where freshwater influence is important. In spring, this strip diminishes as plumes detach from the coast, while tidal fronts become apparent in other regions. In summer, tidal fronts in Ushant region and internal wave activity along the shelf break dominate. In autumn, coastal density fronts due to freshwater inputs reappear as these inputs increase, and reduced stratification causes a weakening of the Ushant and shelf break fronts. Additional information and an effort to dynamically interpret these fronts, based on a systematic investigation of the whole seasonal cycle and including modeling insights from coastal operational oceanography, complement the description of frontal activity in the Bay of Biscay.

Transcriptional and post-transcriptional regulation of NK cell development and function

Natural killer (NK) cells are specialized innate lymphoid cells that survey against viral infections and malignancy. Numerous advances have improved our understanding of the molecular mechanisms that control NK cell development and function over the past decade. These include both studies on the regulatory effects of transcription factors and translational repression via microRNAs. In this review, we summarize our current knowledge of DNA-binding transcription factors that regulate gene expression and thereby orchestrate NK cell development and activation, with an emphasis on recent discoveries. Additionally, we highlight our understanding of how RNA-binding microRNAs fine tune the NK cell molecular program. We also underscore the large number of open questions in the field that are now being addressed using new technological approaches and genetically engineered model organisms. Ultimately, a deeper understanding of the basic molecular biology of NK cells will facilitate new strategies to manipulate NK cells for the treatment of human disease.

Spinorial Regge trajectories and Hagedorn-like temperatures. Spinorial space-time and preons as an alternative to strings

The development of the statistical bootstrap model for hadrons, quarks and nuclear matter occurred during the 1960s and the 1970s in a period of exceptional theo- retical creativity. And if the transition from hadrons to quarks and gluons as fundamental particles was then operated, a transition from standard particles to preons and from the standard space-time to a spinorial one may now be necessary, including related pre-Big Bang scenarios. We present here a brief historical analysis of the scientific problematic of the 1960s in Particle Physics and of its evolution until the end of the 1970s, including cosmological issues. Particular attention is devoted to the exceptional role of Rolf Hage- dorn and to the progress of the statistical boostrap model until the experimental search for the quark-gluon plasma started being considered. In parallel, we simultaneously expose recent results and ideas concerning Particle Physics and in Cosmology, an discuss current open questions. Assuming preons to be constituents of the physical vacuum and the stan- dard particles excitations of this vacuum (the superbradyon hypothesis we introduced in 1995), together with a spinorial space-time (SST), a new kind of Regge trajectories is expected to arise where the angular momentum spacing will be of 1/2 instead of 1. Standard particles can lie on such Regge trajectories inside associated internal symmetry multiplets, and the preonic vacuum structure can generate a new approach to Quantum Field Theory. As superbradyons are superluminal preons, some of the vacuum excitations can have critical speeds larger than the speed of light c, but the cosmological evolution se- lects by itself the particles with the smallest critical speed (the speed of light). In the new Particle Physics and Cosmology emerging from the pattern thus developed, Hagedorn- like temperatures will naturally be present. As new space, time, momentum and energy scales are expected to be generated by the preonic vacuum dynamics, the Planck scale does not necessarily make sense in the new scenario. It also turns out that two potential evidences for a superbradyonic vacuum with a SST geometry exist already: i) the recent results on quantum entanglement at large distances favoring superluminal propagation of signals and correlations ; ii) the anisotropy of the cosmic microwave background radia- tion between two hemispheres observed by the Planck Collaboration, in agreement with the predictions of cosmic SST automatically generating a privileged space direction for each comoving observer. Simultaneously to the discussion of the large number of open questions, we comment on the required experimental and observational programs. T his paper is dedicated to the memory o f Rol f Hagedorn

Looking into laminin receptor: critical discussion regarding the non-integrin 37/67-kDa laminin receptor/RPSA protein.

The 37/67-kDa laminin receptor (LAMR/RPSA) was originally identified as a 67-kDa binding protein for laminin, an extracellular matrix glycoprotein that provides cellular adhesion to the basement membrane. LAMR has evolutionary origins, however, as a 37-kDa RPS2 family ribosomal component. Expressed in all domains of life, RPS2 proteins have been shown to have remarkably diverse physiological roles that vary across species. Contributing to laminin binding, ribosome biogenesis, cytoskeletal organization, and nuclear functions, this protein governs critical cellular processes including growth, survival, migration, protein synthesis, development, and differentiation. Unsurprisingly given its purview, LAMR has been associated with metastatic cancer, neurodegenerative disease and developmental abnormalities. Functioning in a receptor capacity, this protein also confers susceptibility to bacterial and viral infection. LAMR is clearly a molecule of consequence in human disease, directly mediating pathological events that make it a prime target for therapeutic interventions. Despite decades of research, there are still a large number of open questions regarding the cellular biology of LAMR, the nature of its ability to bind laminin, the function of its intrinsically disordered C-terminal region and its conversion from 37 to 67 kDa. This review attempts to convey an in-depth description of the complexity surrounding this multifaceted protein across functional, structural and pathological aspects.

Combinatorial Aspects of Flashcard Games

We study a certain family of discrete dynamical processes introduced by Novikoff, Kleinberg and Strogatz that we call flashcard games. We prove a number of results on the evolution of these games, an in particular we settle a conjecture of NKS on the frequency with which a given card appears. We introduce a number of generalizations and variations that we believe are of interest, and provide a large number of open questions and problems.

Perception and use of uncertainty in severe weather warnings by emergency services in Germany

In the course of the WEXICOM project at the Hans-Ertel-Centre for Weather Research of the Deutscher Wetterdienst (DWD), a survey was conducted in autumn 2012 to question how weather warnings are communicated to professional end-users in the emergency community and how the warnings are converted into mitigation measures.161 members of emergency services (e.g. fire fighters, police officers and civil servants) across Germany answered an online questionnaire. Questions included user's confidence in forecasts, their understanding of probabilistic information and their perception and use of uncertainty in forecasts and warnings. A large number of open questions were selected to identify new topics of interest, unknown problems, and research gaps in the field of communicating weather information in Germany.Results show that the emergency service personnel who participated in this survey generally have a good appreciation of the uncertainty of weather forecasts. Although no single probability threshold could be identified for organisations to start with preparatory mitigation measures, it became clear that emergency services tend to avoid forecast based on low probabilities as basis for their decisions.This paper suggests that when trying to enhance weather communication by reducing the uncertainty in forecasts, the focus should not only be on improving computer models and observation tools, but also on the communication aspect, as uncertainty also arises from linguistic origins. Here, improvements are also possible and thus uncertainty might be reducible.

Mini-Workshop: Linear Series on Algebraic Varieties

Linear series have long played a central role in algebraic geometry. In recent years, starting with seminal papers by Demailly and Ein-Lazarsfeld, local properties of linear series – in particular local positivity, as measured by Seshadri constants – have come into focus. Interestingly, in their multi-point version they are closely related to the famous Nagata conjecture on plane curves. While a number of important basic results are available by now, there are still a large number of open questions and even completely open lines of research.

VII.—The Battle of Bosworth

To make a satisfactory study of the story of a battle it is no doubt desirable to visit the field of action and examine it carefully with one's own eyes. Where much time has elapsed and many changes have taken place in the aspect of the country the written records are not always easy to interpret; and where even these are scanty and obscure a large number of open questions will naturally be the result. Such has been the case with the famous battle of Bosworth Field, of which we possess virtually only one narrative, and that not written by an eye-witness or even by an Englishman, but by an intelligent foreigner who settled in England some years after. Polydore Vergil, the first writer of a connected history of England, arrived in this country about eighteen years after the battle, and doubtless gained his information about it from those who had seen and taken part in it. The accounts given by the subsequent English chroniclers, Hall, Grafton, and Holinshed, are little more than translations, a little amplified, of the description given by Polydore. Nevertheless, their additions to the narrative, as we shall see, are not without significance.