ω\omega-recurrence in cocycles

After relating the notion of $\omega$-recurrence in skew products to the range of values taken by partial ergodic sums and Lyapunov exponents, ergodic $\mathbb{Z}$-valued cocycles over an irrational rotation are presented in detail. First, the generic situation is studied and shown to be $1/n$-recurrent. It is then shown that for any $\omega(n) <n^{-\epsilon}$, where $\epsilon>1/2$, there are uncountably many infinite staircases (a certain specific cocycle over a rotation) which are \textit{not} $\omega$-recurrent, and therefore have positive Lyapunov exponent. A further section makes brief remarks regarding cocycles over interval exchange transformations of periodic type

Infinite-volume mixing for dynamical systems preserving an infinite measure

In the scope of the statistical description of dynamical systems, one of the defining features of chaos is the tendency of a system to lose memory of its initial conditions (more precisely, of the distribution of its initial conditions). For a dynamical system preserving a probability measure, this property is named `mixing' and is equivalent to the decay of correlations for observables in phase space. For the class of dynamical systems preserving infinite measures, this probabilistic connection is lost and no completely satisfactory definition has yet been found which expresses the idea of losing track of the initial state of a system due to its chaotic dynamics. This is actually on open problem in the field of infinite ergodic theory. Virtually all the definitions that have been attempted so far use "local observables", that is, functions that essentially only "see" finite portions of the phase space. In this note we introduce the concept of "global observable", a function that gauges a certain quantity throughout the phase space. This concept is based on the notion of infinite-volume average, which plays the role of the expected value of a global observable. Endowed with these notions, whose rigorous definition is to be specified on a case-by-case basis, we give a number of definitions of infinite mixing. These fall in two categories: global-global mixing, which expresses the "decorrelation" of two global observables, and global-local mixing, where a global and a local observable are considered instead. These definitions are tested on two types of infinite-measure-preserving dynamical systems, the random walks and the Farey map.Comment: 15 pages, 3 figure

550,000 years of marine climate variability in the western Mediterranean Sea revealed by cold-water corals

Cold-water corals are common throughout the Alboran Sea (AS; western Mediterranean Sea), however large coral mound provinces have only been discovered along the Moroccan margin. During research cruise MSM36 "MoccoMeBo", the Bremen drill rig MeBo successfully drilled 70 m long coral bearing cores from the East Melilla Coral Province (EMCP) presented here. Using high precision U-series dating method, the two cores presented here provide a unique insight into the mound evolution over 550 ka. For the second time ever, a CWC mound has been fully penetrated and thus the timing of the onset of coral growth in this location could be determined. The other mound, potentially drilled to only half its height (70 m), may provide a first estimate of the basin-wide onset of coral growth in the AS. However, the discontinous temporal evolution of both mounds revealed unprecedented complex age-depth profiles and thus two different mound evolution models over several full glacial-interglacial cycles are proposed. The predominantly interglacial evolution of CWC occurrence in the AS provided close contraints of the climate conditions during interglacial periods facilitating vigorous coral growth. Changes in climate conditions during interglacial periods determined the decline of flourishing coral growth, leading to a glacial demise of CWC in the AS. Based on the Li/Mg proxy, the past temperature variability of the near Bottom Water Temperature (nBWT) was closely regarded. For the first time, a high-resolution nBWT record in the AS was conducted and compared with published Sea surface Temperatures (SST). The observed variability in temperature suggests a common global driver of SST variability and coral occurrence in the AS. MSM36 "MoccoMeBo" was motivated by the hypotheses of a "Gibraltar seesaw pattern", describing the long-term development of predominantly glacial CWC growth in the Gulf of Cádiz (GoC) and predominantly interglacial CWC growth in the AS. Combined U-series records from both sides of the Strait if Gibraltar, may have revealed a common global driver of the observed seesaw pattern and thus, may have unveiled a most possible onset of CWC growth in the Mediterranean Region during the Mid-Pleistocene Transition. Lastly, the evolution of seawater ẟ234U, an indicator of the global weathering rate and crucial for the high precision U-series dating method, was closely investigated. Contrary to the general assumption of global ẟ234U, a Mediterranean Sea offset, compared to the Atlantic ẟ234U, is presented. Furthermore, the combined Atlantic and MEditerranean records comprised of over 1500 published and unpublished data provide unique insights into the ẟ234U evolution over several full glacial-interglacial cycles

Shifting Identity/Shifting Discourse: Re‐Naming in Contemporary Literature by Zadie Smith, Jeffrey Eugenides, and Salman Rushdie

Re­‐naming one’s self is an empowering act of self­‐definition; re­‐naming others is an attempt to codify, contain and censure identity. Re­‐naming emerges as a compelling theme in contemporary transnational literature, appearing in three notable texts: Zadie Smith\u27s White Teeth (2000), Jeffrey Eugenides\u27 Middlesex (2002) and Salman Rushdie\u27s memoir Joseph Anton (2012). These texts depict stories of diaspora, the forced migration or dispersal away from a homeland. Communities of diaspora negotiate between two cultures: an originary culture and the culture of the new geographic location. From these negotiations emerge a third, hybridized identity that reimagines the majority culture and challenges structural inequity. Personal acts of re­‐naming parallel diasporic experience, and this thesis demonstrates how re­‐naming and hybrid identities call for more plural epistemologies of belonging in an increasingly globalized and interconnected world

“Glocal Education” Through Virtual Exchange? Training Pre-Service EFL Teachers to Connect Their Local Classrooms to the World and Back

A key goal of global education in language teaching is to “have students ‘think globally and act locally’” (Cates, 2013, p. 278) – an idea in line with the concept of glocality. Virtual exchange – i.e. connecting learners with different lingua-cultural backgrounds over extended periods of time via digital communication technologies (The EVALUATE Group, 2019) – is a promising approach towards this aim. O’Dowd suggests designing such exchanges following a “transnational model” (2019) in which learners collaborate on shared tasks based on local and global real-world problems using a lingua franca. These ideas are compatible with European policy discourses on global education (Schreiber &amp; Siege, 2016), aiming at supporting learners in becoming agents of change in an increasingly globalized world. Within the context of a trilateral project between universities in Germany, Turkey, and Sweden, this paper explores how global education can be integrated into foreign language teaching with the help of virtual exchanges through a synthesis of two models of virtual exchange (O’Dowd &amp; Ware, 2009; O’Dowd, 2019) and the complex competence task approach (Hallet, 2012) to task-based language teaching. A transnational virtual exchange between these universities exemplifies how such a telecollaborative project can be implemented. During the exchange, pre-service EFL teachers compare and analyze cultural practices and educational frameworks to design tasks dealing with global issues that can be implemented in their respective local classrooms through virtual exchange

The Perfect Balance: Combining Global and Local Strategies for Effective International Public Relations

This paper discusses the benefits of using a combination of global and local public relations tactics to optimize global marketing activities and reach target publics. It also compares various cultures and public relations practices around the world, and offers examples of international public relations campaigns that have successfully reached their target markets by incorporating global strategies with cultural twists that are specifically tailored to local communities. In today’s progressively more globalized world, where people are connecting more quickly than ever before, it is vital that organizations know how to communicate correctly. While many theorists prefer either global strategies or local strategies, this paper argues that organizations should be combining global and local public relations strategies to communicate with their worldwide publics. My methodology for obtaining this information consisted of interviews and extensive research of books, articles, blogs, interviews and case studies. I conducted over 40 literature reviews, comparing and contrasting various public relations theories. I also spoke with public relations professionals around the world to gain insight into their day-to-day experiences with global campaigns. My Capstone findings demonstrate that global campaigns with localized tactics that cater to specific target groups are the most effective way to reach a broad market and attract a loyal base of consumers. Public relations practitioners must understand the markets in which their clients want to do business as well as how their target audiences receive information. Effective public relations can boost sales and build trust among an organization’s stakeholders

Influence of athlete heart rate, rate of perceived exertion, and anxiety in rowing practice and competition

The purpose of this study was to investigate whether there is a significant correlation between heart rate (HR) and rate of perceived exertion (RPE) in rowing, how athlete perception of pre-race anxiety relates to HR and RPE, and how these variables change between practice and competition. Four subjects were tested over the course of their rowing season for somatic and cognitive anxiety, self-confidence, HR, and RPE in three different 2000 meter racing conditions: indoor ergometer, on-water racing, and on-water practice. There was no correlation between HR and RPE, and only maximum HR showed a difference between trial types. Studying more subjects and ensuring the same number of each type of trial would enhance the results of this study

The effect of particle shape on rockfall events

The effects of rock shape and initial orientation on the rockfall phenomena are studied using a two-dimensional polygonal discrete element method (DEM). In the simulation, rock particles with the same mass but different shapes are dropped from the same height onto a straight slope to investigate the variations in both translational and rotational kinetic energies and the runout distance. Parametric studies under varied angularity and aspect ratio of the rock revealed a significant effect of rock shape and initial orientation on the runout distance

Crystal structure of a murine α-class glutathione S-transferase involved in cellular defense against oxidative stress

Glutathione S-transferases (GSTs) are ubiquitous multifunctional enzymes which play a key role in cellular detoxification. The enzymes protect the cells against toxicants by conjugating them to glutathione. Recently, a novel subgroup of α-class GSTs has been identified with altered substrate specificity which is particularly important for cellular defense against oxidative stress. Here, we report the crystal structure of murine GSTA4-4, which is the first structure of a prototypical member of this subgroup. The structure was solved by molecular replacement and refined to 2.9 Å resolution. It resembles the structure of other members of the GST superfamily, but reveals a distinct substrate binding site.