Isospin diffusion in thermal AdS/CFT with flavor

We study the gauge/gravity dual of a finite temperature field theory at finite isospin chemical potential by considering a probe of two coincident D7-branes embedded in the AdS-Schwarzschild black hole background. The isospin chemical potential is obtained by giving a vev to the time component of the non-Abelian gauge field on the brane. The fluctuations of the non-Abelian gauge field on the brane are dual to the SU(2) flavor current in the field theory. For the embedding corresponding to vanishing quark mass, we calculate all Green functions corresponding to the components of the flavor current correlator. We discuss the physical properties of these Green functions, which go beyond linear response theory. In particular, we show that the isospin chemical potential leads to a frequency-dependent isospin diffusion coefficient.Comment: 26 pages, 8 figures, typos correcte

Qualité de la viande d’agneau de quatre races ovines suisses

La qualité de la viande des agneaux de boucherie dépend d’un grand nombre de facteurs. Outre l’âge au moment de l’abattage et le sexe, l’affouragement a une incidence prépondérante. En principe, un affouragement constitué principalement de céréales, comparé à du fourrage plutôt grossier, provoque les plus grandes différences dans la qualité de la viande. Une autre influence très discutée sur la qualité de la viande est la race; on dit que les races primitives comme le Heidschnucke ont une qualité de viande élevée, se rapprochant de celle du gibier. Certaines races primitives suisses ont également la réputation d’avoir une viande particulièrement bonne. Cet article traite de la question de savoir si la viande d’agneau des races Nez Noir du Valais, Blancs des Alpes, mouton de l’Engadine et mouton Miroir se distingue au niveau de la qualité

QGP thermodynamics and meson spectroscopy with AdS/CFT

In this talk we present applications of the AdS/CFT correspondence to strongly coupled systems at finite temperature and particle density. The model we investigate contains adjoint matter described by the gauge multiplet of N=4, as well as fundamental matter given by the hypermultiplet of N=2 Super Yang-Mills theory. In some aspects these systems can be thought of as models for the quark-gluon plasma. In the first part we review some properties of meson spectra obtained from these holographic models. We discuss the implications of finite temperature and particle density in these string-theory motivated setups. In particular, we find a broadening of the vector meson peaks in the relevant spectral function at finite density. However, we do not observe a movement of the resonances to lower frequencies. Moreover, we analyze the effects of strong coupling on heavy meson diffusion in medium. To do so, we make use of an effective model with dipole interaction, which is valid for heavy quarks at arbitrary coupling strength. We calculate the momentum broadening -- normalized to the in-medium mass shift -- and compare the large 't Hooft coupling AdS/CFT result with a perturbative result for weak coupling. We find that the momentum broadening is reduced at large 't Hooft coupling, leading to increased relaxation time.Comment: 6 pages, 3 figures, prepared for the proceedings of the 8th Conference "Quark Confinement and the Hadron Spectrum", September 1st-6th 2008, Mainz, Germany; to appear in Proceedings of Science, based on a talk given by Felix Rus

Lammfleischqualität von extensiv gehaltenen und seltenen Schweizer Schafrassen (Engadinerschaf, Schwarznasenschaf, Spiegelschaf) im Vergleich zum Weißen Alpenschaf

This study investigates meat quality of four autochthonous Swiss ovine breeds, White Alpine (WAS, n=15), Walliser blacknose sheep (SN, n=8), Engadine sheep (EN, n=9) and the Mirror sheep (SP, n=10). Especially for the latter two breeds, which are rare and endangered, information about meat quality and constitution is important for merchandising issues. All lambs (LW 20-25 kg) of each breed were fattened on pasture for 208 d and subsequently slaughtered. Evaluations were carried out for slaughter yield and classifications, pH-value, colorimetry (L*a*b*-System), shear force (Warner Bratzler method) and cooking losses in the Musculus longissimus dorsi. The results showed no meat quality defects in any breed. The main differences between breeds arose in slaughter yield (p<0.001) with SN being significantly inferior to WAS, and CHTAX where WAS was clearly superior to all other breeds. Compared to WAS, SN meat was less colored (L*-value; p<0.001) which is probably related to the higher pH24h (p<0.01) of SN when compared to WAS. Overall, this study showed that meat quality of WAS is superior with low-land pasture based fattening conditions in Switzerland. It is however possible that other fattening conditions (i.e. mountainous) would lead to different results because Black nose, Engadine and Mirror sheep are traditional alpine breeds which might substantially alter their production optimum

Lammfleischqualität von vier Schweizer Schafrassen

Die Fleischqualität von Schlachtlämmern wird von einer Vielzahl von Faktoren bestimmt. Neben dem Schlachtalter und dem Geschlecht hat v.a. die Fütterung einen grossen Einfluss auf die Fleischqualität. Grundsätzlich führt eine getreidelastige im Vergleich zu einer rauhfutterlastigen Fütterung zu den grössten Unterschieden in der Fleischqualität. Ein weiterer viel diskutierter Einfluss auf die Fleischqualität ist die Rasse. Beispielsweise wird ursprünglichen Rassen, wie z.B. der Heidschnucke, eine besonders hohe Fleischqualität nachgesagt, die sich auch in einem besonderen wildbretartigen Geschmack zeigen soll. Auch in der Schweiz wird gewissen ursprünglichen Rassen eine speziell gute Fleischqualität zugesprochen. Dieser Artikel befasst sich mit der Frage, ob das Lammfleisch der Rassen Walliser Schwarznasenschaf, Weisses Alpenschaf, Engadiner- und Spiegelschaf qualitativ unterschiedlich ist

Revisiting the IIoT Platform Graveyard: Key Learnings from Failed IIoT Platform Initiatives

The Industrial Internet of Things (IIoT) has led to a competitive race among digital and incumbent players to establish IIoT platforms. However, despite the undisputed potential of the IIoT, a first wave of IIoT platforms failed around 2018, with GE’s Predix being the most prominent one. Nevertheless, building upon valuable lessons learned, the IIoT platform market continued to grow significantly. We now experience a second wave of IIoT platform failures, with companies like Siemens, Google, and SAP divesting or restructuring significant parts of their IIoT platform. Acknowledging this, we revisited the IIoT platform graveyard to challenge and extend existing lessons learned. Hence, we interviewed major IIoT platforms and customers that were impacted by IIoT platform failures. We identified six key learnings that we integrated into a preliminary model for IIoT platform growth, highlighting evolutionary steps for successful platform growth. These findings provide practitioners strategic orientation for establishing IIoT platforms long-term

Finite baryon and isospin chemical potential in AdS/CFT with flavor

We investigate the thermodynamics of a thermal field theory in presence of both a baryon and an isospin chemical potential. For this we consider a probe of several D7-branes embedded in the AdS-Schwarzschild black hole background. We determine the structure of the phase diagram and calculate the relevant thermodynamical quantities both in the canonical and in the grand canonical ensemble. We discuss how accidental symmetries present reflect themselves in the phase diagram: In the case of two flavors, for small densities, there is a rotational symmetry in the plane spanned by the baryon and isospin density which breaks down at large densities, leaving a Z_4-symmetry. Finally, we calculate vector mode spectral functions and determine their dependence on either the baryon or the isospin density. For large densities, a new excitation forms with energy below the known supersymmetric spectrum. Increasing the density further, this excitation becomes unstable. We speculate that this instability indicates a new phase of condensed mesons.Comment: 62 pages, 32 figures. references and paragraph about non-Abelian DBI action adde

Assessment of Ecosystem Services across the Land–Sea Interface in Baltic Case Studies

Spatial assessments of ecosystem services (ES) are needed to fulfil EU policy requirements and to support practical applications of the ES concept in policy implementation. So far, ES assessments have largely focused on terrestrial systems. A joint approach for land and sea is especially lacking. To overcome this gap, we present a novel spatial habitat typology and ES classification for an assessment across the land–sea interface. We build upon existing approaches and common spatial definitions, like CORINE land cover (CLC) types, water bodies of the Water Framework Directive (WFD), and habitat types according to the Habitats Directive (HD). We show applications of the resulting ES matrix for an expert-based assessment of ES potentials in three Baltic study sites (Schlei, Greifswald Bay and Curonian Lagoon). A complementary indicator-based approach to assess ES flows is introduced and applied. It enables a quantification of ES potentials and flows and ensures comparability among case study sites. Comparisons between the results for ES potentials and flows show that development capacities exist in particular for provisioning ES for marine habitats. Our approaches are spatially expandable and transferrable and could be applied to support environmental policy implementation. Further, we discuss their practical relevance, current limitations, and future research perspective