A study of changes in fishing effort, abundance, and yield for yellowfin and skipjack tuna in the Eastern Tropical Pacific Ocean

ENGLISH: The rapid growth of the Eastern Pacific fishery for yellowfin and skipjack tuna since the end of World War II has given rise to questions concerning the rational utilization of these resources. As part of the Inter-American Tropical Tuna Commission's program of research designed to investigate these problems, a study was undertaken to determine from the historical records of the fishery the effects of fishing upon the stocks of yellowfin and skipjack tuna of the Eastern Pacific region and to evaluate the present condition of these stocks with respect to the maximum equilibrium yield. SPANISH: EI rápido crecimiento, desde la terminación de la Segunda Guerra Mundial, de la pesquería de atún aleta amarilla y barrilete en el Pacifico Oriental, ha dado lugar a que se hagan algunos comentarios sabre la racional utilización de estos recursos. Como parte del programa de la Comisión Interamericana del Atún Tropical designado para la investigación de estos problemas, un estudio fué llevado a cabo para determinar, de los informes historicós de la pesquería, los efectos de la pesca sobre los stocks de atún aleta amarilla y barrilete de la región del Pacifico Oriental y para evaluar la presente condición de estos stocks con respecto al máximo rendimiento de equilibria. (PDF contains 123 pages.

Vacuum fluctuations and the thermodynamics of chiral models

We consider the thermodynamics of chiral models in the mean-field approximation and discuss the relevance of the (frequently omitted) fermion vacuum loop. Within the chiral quark-meson model and its Polyakov loop extended version, we show that the fermion vacuum fluctuations can change the order of the phase transition in the chiral limit and strongly influence physical observables. We compute the temperature-dependent effective potential and baryon number susceptibilities in these models, with and without the vacuum term, and explore the cutoff and the pion mass dependence of the susceptibilities. Finally, in the renormalized model the divergent vacuum contribution is removed using the dimensional regularization.Comment: 9 pages, 5 figure

Thermodynamics of (2+1)-flavor QCD: Confronting Models with Lattice Studies

The Polyakov-quark-meson (PQM) model, which combines chiral as well as deconfinement aspects of strongly interacting matter is introduced for three light quark flavors. An analysis of the chiral and deconfinement phase transition of the model and its thermodynamics at finite temperatures is given. Three different forms of the effective Polyakov loop potential are considered. The findings of the (2+1)-flavor model investigations are confronted to corresponding recent QCD lattice simulations of the RBC-Bielefeld, HotQCD and Wuppertal-Budapest collaborations. The influence of the heavier quark masses, which are used in the lattice calculations, is taken into account. In the transition region the bulk thermodynamics of the PQM model agrees well with the lattice data.Comment: 13 pages, 7 figures, 3 tables; minor changes, final version to appear in Phys. Rev.

Center phase transition from matter propagators in (scalar) QCD

Novel order parameters for the confinement-deconfinement phase transition of quenched QCD and fundamentally charged scalar QCD are presented. Similar to the well-known dual condensate, they are defined via generalized matter propagators with $U(1)$-valued boundary conditions. The order parameters are easily accessible with functional methods. Their validity and accessibility is explicitly demonstrated by numerical studies of the Dyson-Schwinger equations for the matter propagators. Even in the case of heavy scalar matter, where the propagator does not show a signature of the phase transition, a discontinuity due to the transition can be extracted in the order parameters, establishing also fundamentally charged scalar matter as a probe for color confinement.Comment: accepted versio

Universal deformation rings and tame blocks

Let k be an algebraically closed field of positive characteristic, and let W be the ring of infinite Witt vectors over k. Suppose G is a finite group and B is a block of kG of infinite tame representation type. We find all finitely generated kG-modules V that belong to B and whose endomorphism ring is isomorphic to k and determine the universal deformation ring R(G,V) for each of these modules.Comment: 14 page

Spectral properties of Bunimovich mushroom billiards

Properties of a quantum mushroom billiard in the form of a superconducting microwave resonator have been investigated. They reveal unexpected nonuniversal features such as, e.g., a supershell effect in the level density and a dip in the nearest-neighbor spacing distribution. Theoretical predictions for the quantum properties of mixed systems rely on the sharp separability of phase space - an unusual property met by mushroom billiards. We however find deviations which are ascribed to the presence of dynamic tunneling.Comment: 4 pages, 7 .eps-figure

Diffractive charged meson pair production

We investigate the possibility to measure the nonforward gluon distribution function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in polarized lepton nucleon scattering. The resulting cross sections are small and are dominated by the gluonic contribution. We find relatively large spin asymmetries, both for \pi^+\pi^- and for K^+K^- pairs.Comment: 15 pages, version with changed kinematical cuts, to be pubished in Phys.Lett.

Higher-order ratios of baryon number cumulants

The relevance of higher order cumulants of net baryon number fluctuations for the analysis of freeze-out and critical conditions in heavy-ion collisions at LHC and RHIC is addressed. The sign structure of the higher order cumulants in the vicinity of the chiral crossover temperature might be a sensitive probe and may allow to elucidate their relation to the QCD phase transition. We calculate ratios of generalized quark-number susceptibilities to high orders in three flavor QCD-like models and investigate their sign structure close to the chiral crossover line.Comment: presented at the International Conference "Critical Point and Onset of Deconfinement - CPOD 2011", Wuhan, November 7-11, 2011; version to appear in Cent. Eur. J. Phy

Health 4.0: How Digitisation Drives Innovation in the Healthcare Sector

Driven by networked Electronic Health Record systems, Artificial Intelligence, real-time data from wearable devices with an overlay of invisible user interfaces and improved analytics, a revolution is afoot in the healthcare industry. Over the next few years, it is likely to fundamentally change how healthcare is delivered and how the outcomes are measured. The focus on collaboration, coherence, and convergence will make healthcare more predictive and personalised. This revolution is called Health 4.0. Data portability allows patients and their physicians to access it anytime anywhere and enhanced analytics allows for differential diagnosis and medical responses that can be predictive, timely, and innovative. Health 4.0 allows the value of data more consistently and effectively. It can pinpoint areas of improvement and enable decisions that are more informed. What it also does is help move the entire healthcare industry from a system that is reactive and focused on fee-for-service to a system that is value-based, which measures outcomes and ensures proactive prevention (Thuemmler, Bai, 2017). In this paper, the authors discuss how digitisation is paving the way for data-driven innovation in the healthcare systems. They elaborate on the opportunities and challenges for all stakeholders involved and discuss how emerging technologies can help overcome the inherent rigidity of today’s healthcare ecosystem. Following on from this, the authors explain the importance of research on the actual design of smart healthcare products and product service systems of the future and the challenges faced from the viewpoint of design practice