Sediment rates and structures in Bay of Kiel, Baltic Sea

Density and diversity of bottom fauna population as dependent on sediment types and water depth is largely well known in Kiel Bay. This is in contrast to structures and processes of bioturbation, although generally it has a big influence on the benthic boundary layer and its processes, e.g., the metabolism of the bottom fauna, the mechanical properties, the age dating, and the large field of chemical processes. In the densely inhabited sands and muddy sands of the shallower waters with sediment thicknesses of some decimeters only, bioturbation is usually ubiquitous, and most of the structures left are monotonously of "biodeformational" character. At greater water depths, however, where a sedimentary column of several meters of Holocene is developed, the X-ray radiographs of numerous sediment cores show heterogeneous biogenic structures with regional and stratigraphical differentiation. They are described in terms of ichnofabrics and are interpreted on ethological knowledge of the related macrobenthos species. lmportant organisms creating specific traces include the bivalve Arctica (Cyprina) islandica and the polychaete worm Pectinaria koreni. These species are abundant in Kiel Bay and produce by their crawling-plowing mode of locomotion, a characteristic biogenic stratification, the "plow-sole structure". Other typical biogenic structures are tube traces, which are left by a number of different polychaetes occurring either singly, or as U-pairs mainly in mud sediments. Although sea urchins are rare to absent in Kiel Bay, layers of their characteristic traces Scolicia occur as witness of paleohydrographic events in channel sediments of the central bay. Plow-sole traces, polychaete-tube ichnofabric, Scolicia layers and alternations of laminated and bioturbated layers are considered as building blocks of a future "ichnostratigraphy" of Kiel Bay.

Relational work in synchronous text-based CMC of virtual teams

Based on close examinations of instant message (IM) interactions, this chapter argues that an interactional sociolinguistic approach to computer-mediated language use could provide explanations for phenomena that previously could not be accounted for in computer-mediated discourse analysis (CMDA). Drawing on the theoretical framework of relational work (Locher, 2006), the analysis focuses on non-task oriented talk and its function in forming and establishing communication norms in the team, as well as micro-level phenomena, such as hesitation, backchannel signals and emoticons. The conclusions of this preliminary research suggest that the linguistic strategies used for substituting audio-visual signals are strategically used in discursive functions and have an important role in relational work

Women and peace in a divided society:peace-building potentials of feminist advocacy and reform in Bosnia and Herzegovina

Despite an improving international rhetoric highlighting the necessity of women’s participation in postwar settings, women still tend to be disadvantaged in peace-building processes (Chinkin and Charlesworth, 2006; United Nations, 2002). This chapter argues that women’s struggles for rights entail important potentials for peace-building in divided postwar societies. Women frequently are among the first who cooperate across ethnic divisions established and hardened during ethno-political wars. Feminist policy reforms often strengthen common state structures and their legitimacy, contributing to the overcoming of ethnic divisions. Women’s participation and contributions should, therefore, be much more recognized and promoted in peace-building processes. However, it is feminist advocacy that is key, not women’s participation per se. Women have often promoted nationalistic and violent agendas; yet, only if they champion the rights of women independent of their ethnic and political differences can peace-building potentials come into effect.

A Developmental Approach to Sport Expertise

This chapter examines the personal and contextual factors of youth sport that affect sport expertise and developmental outcomes. The developmental model of sport participation (DMSP) is used as a comprehensive framework that outlines different pathways of involvement in sport. Activities and contexts that promote continued sport participation and expert performance are discussed as the building blocks of all effective youth sport programs. This chapter provides evidence that performance in sport, participation, and psychological development should be considered as a whole instead of as separate entities by youth sport programmers. Adults in youth sports (i.e. coaches, parents, sport psychologists, administrators) must consider the differing implications of concepts such as deliberate play, deliberate practice, sampling, specialization, and program structure at different stages of an athlete's talent development. Seven postulates are presented regarding important transitions in youth sport and the role that sampling and deliberate play, as opposed to specialization and deliberate practice, can have during the childhood in promoting continued participation and elite performance in sport

An investigation of Hebbian phase sequences as assembly graphs

Hebb proposed that synapses between neurons that fire synchronously are strengthened, forming cell assemblies and phase sequences. The former, on a shorter scale, are ensembles of synchronized cells that function transiently as a closed processing system; the latter, on a larger scale, correspond to the sequential activation of cell assemblies able to represent percepts and behaviors. Nowadays, the recording of large neuronal populations allows for the detection of multiple cell assemblies. Within Hebb's theory, the next logical step is the analysis of phase sequences. Here we detected phase sequences as consecutive assembly activation patterns, and then analyzed their graph attributes in relation to behavior. We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods). Within assembly graphs, each assembly corresponded to a node, and each edge corresponded to the temporal sequence of consecutive node activations. The sum of all assembly activations was proportional to firing rates, but the activity of individual assemblies was not. Assembly repertoire was stable across experimental periods, suggesting that novel experience does not create new assemblies in the adult rat. Assembly graph attributes, on the other hand, varied significantly across behavioral states and experimental periods, and were separable enough to correctly classify experimental periods (Naïve Bayes classifier; maximum AUROCs ranging from 0.55 to 0.99) and behavioral states (waking, slow wave sleep, and rapid eye movement sleep; maximum AUROCs ranging from 0.64 to 0.98). Our findings agree with Hebb's view that assemblies correspond to primitive building blocks of representation, nearly unchanged in the adult, while phase sequences are labile across behavioral states and change after novel experience. The results are compatible with a role for phase sequences in behavior and cognition.

Role for cell-to-cell communication in stem cell specification toward pancreatic progenitors: relevance to the design of novel therapies for diabetes.

Thesis (Ph.D.)--University of Washington, 2016-08

Solar magnetic carpet II: coronal interactions of small-scale magnetic fields

This paper is the second in a series of studies working towards constructing a realistic, evolving, non-potential coronal model for the solar magnetic carpet. In the present study, the interaction of two magnetic elements is considered. Our objectives are to study magnetic energy build-up, storage and dissipation as a result of emergence, cancellation, and flyby of these magnetic elements. In the future these interactions will be the basic building blocks of more complicated simulations involving hundreds of elements. Each interaction is simulated in the presence of an overlying uniform magnetic field, which lies at various orientations with respect to the evolving magnetic elements. For these three small-scale interactions, the free energy stored in the field at the end of the simulation ranges from 0.2 – 2.1×1026 ergs, whilst the total energy dissipated ranges from 1.3 – 6.3×1026 ergs. For all cases, a stronger overlying field results in higher energy storage and dissipation. For the cancellation and emergence simulations, motion perpendicular to the overlying field results in the highest values. For the flyby simulations, motion parallel to the overlying field gives the highest values. In all cases, the free energy built up is sufficient to explain small-scale phenomena such as X-ray bright points or nanoflares. In addition, if scaled for the correct number of magnetic elements for the volume considered, the energy continually dissipated provides a significant fraction of the quiet Sun coronal heating budget.

The effect of ionic Co presence on the structural, optical and photocatalytic properties of modified cobalt–titanate nanotubes

With the aim of producing materials with enhanced optical and photocatalytic properties, titanate nanotubes (TNTs) modified by cobalt doping (Co-TNT) and by Na+ -> Co ion-exchange (TNT/Co) were successfully prepared by a hydrothermal method. The influence of the doping level and of the cobalt position in the TNT crystalline structure was studied. Although no perceptible influence of the cobalt ion position on the morphology of the prepared titanate nanotubes was observed, the optical behaviour of the cobalt modified samples is clearly dependent on the cobalt ions either substituting the Ti4+ ions in the TiO6 octahedra building blocks of the TNT structure (doped samples) or replacing the Na+ ions between the TiO6 interlayers (ion-exchange samples). The catalytic ability of these materials on pollutant photodegradation was investigated. First, the evaluation of hydroxyl radical formation using the terephthalic acid as a probe was performed. Afterwards, phenol, naphthol yellow S and brilliant green were used as model pollutants. Anticipating real world situations, photocatalytic experiments were performed using solutions combining these pollutants. The results show that the Co modified TNT materials (Co-TNT and TNT/Co) are good catalysts, the photocatalytic performance being dependent on the Co/Ti ratio and on the structural metal location. The Co(1%)-TNT doped sample was the best photocatalyst for all the degradation processes studied.

PERCEPTIONS OF THE PREPARATION OF EFFECTIVE MIDDLE SCHOOL PRINCIPALS

The primary purpose of this quantitative study was to examine middle school administrators’ perceptions of their preparation programs. The following research questions were addressed as a part of the study: 1. What skills, behaviors, and attitudes do middle school principals perceive to be important to be an effective middle school principal? 2. How do middle school principals perceive their level of preparedness in relation to the specific skills, behaviors, and attitudes? 3. To what degree do middle school principals believe that their level of preparation has influenced them to stay in their current role? 4. Which components of their preparation program do middle principals perceive to be the most valuable? 5. To what extent do middle school principals believe that the school district should design a program specifically to develop middle school principals? Middle school principals were selected to participate in this study. Quantitative data were gathered via online questionnaires. The research questions were addressed through analysis of the questionnaire data, using descriptive and inferential statistics. This study resulted in recommendations to provide a framework for the development of a principal preparation program designed to train effective middle school principals.

Quantitative Derivation of Effective Evolution Equations for the Dynamics of Bose-Einstein Condensates

This thesis proves certain results concerning an important question in non-equilibrium quantum statistical mechanics which is the derivation of effective evolution equations approximating the dynamics of a system of large number of bosons initially at equilibrium (ground state at very low temperatures). The dynamics of such systems are governed by the time-dependent linear many-body Schroedinger equation from which it is typically difficult to extract useful information due to the number of particles being large. We will study quantitatively (i.e. with explicit bounds on the error) how a suitable one particle non-linear Schroedinger equation arises in the mean field limit as number of particles N → ∞ and how the appropriate corrections to the mean field will provide better approximations of the exact dynamics. In the first part of this thesis we consider the evolution of N bosons, where N is large, with two-body interactions of the form N³ᵝv(Nᵝ⋅), 0≤β≤1. The parameter β measures the strength and the range of interactions. We compare the exact evolution with an approximation which considers the evolution of a mean field coupled with an appropriate description of pair excitations, see [18,19] by Grillakis-Machedon-Margetis. We extend the results for 0 ≤ β < 1/3 in [19, 20] to the case of β < 1/2 and obtain an error bound of the form p(t)/Nᵅ, where α>0 and p(t) is a polynomial, which implies a specific rate of convergence as N → ∞. In the second part, utilizing estimates of the type discussed in the first part, we compare the exact evolution with the mean field approximation in the sense of marginals. We prove that the exact evolution is close to the approximate in trace norm for times of the order o(1)√N compared to log(o(1)N) as obtained in Chen-Lee-Schlein [6] for the Hartree evolution. Estimates of similar type are obtained for stronger interactions as well.

An investigation of Hebbian phase sequences as assembly graphs

Hebb proposed that synapses between neurons that fire synchronously are strengthened, forming cell assemblies and phase sequences. The former, on a shorter scale, are ensembles of synchronized cells that function transiently as a closed processing system; the latter, on a larger scale, correspond to the sequential activation of cell assemblies able to represent percepts and behaviors. Nowadays, the recording of large neuronal populations allows for the detection of multiple cell assemblies. Within Hebb's theory, the next logical step is the analysis of phase sequences. Here we detected phase sequences as consecutive assembly activation patterns, and then analyzed their graph attributes in relation to behavior. We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods). Within assembly graphs, each assembly corresponded to a node, and each edge corresponded to the temporal sequence of consecutive node activations. The sum of all assembly activations was proportional to firing rates, but the activity of individual assemblies was not. Assembly repertoire was stable across experimental periods, suggesting that novel experience does not create new assemblies in the adult rat. Assembly graph attributes, on the other hand, varied significantly across behavioral states and experimental periods, and were separable enough to correctly classify experimental periods (Naïve Bayes classifier; maximum AUROCs ranging from 0.55 to 0.99) and behavioral states (waking, slow wave sleep, and rapid eye movement sleep; maximum AUROCs ranging from 0.64 to 0.98). Our findings agree with Hebb's view that assemblies correspond to primitive building blocks of representation, nearly unchanged in the adult, while phase sequences are labile across behavioral states and change after novel experience. The results are compatible with a role for phase sequences in behavior and cognition.

Simulation tools for the analysis of single electronic systems

Developments in theory and experiment have raised the prospect of an electronic technology based on the discrete nature of electron tunnelling through a potential barrier. This thesis deals with novel design and analysis tools developed to study such systems. Possible devices include those constructed from ultrasmall normal tunnelling junctions. These exhibit charging effects including the Coulomb blockade and correlated electron tunnelling. They allow transistor-like control of the transfer of single carriers, and present the prospect of digital systems operating at the information theoretic limit. As such, they are often referred to as single electronic devices. Single electronic devices exhibit self quantising logic and good structural tolerance. Their speed, immunity to thermal noise, and operating voltage all scale beneficially with junction capacitance. For ultrasmall junctions the possibility of room temperature operation at sub picosecond timescales seems feasible. However, they are sensitive to external charge; whether from trapping-detrapping events, externally gated potentials, or system cross-talk. Quantum effects such as charge macroscopic quantum tunnelling may degrade performance. Finally, any practical system will be complex and spatially extended (amplifying the above problems), and prone to fabrication imperfection. This summarises why new design and analysis tools are required. Simulation tools are developed, concentrating on the basic building blocks of single electronic systems; the tunnelling junction array and gated turnstile device. Three main points are considered: the best method of estimating capacitance values from physical system geometry; the mathematical model which should represent electron tunnelling based on this data; application of this model to the investigation of single electronic systems. (DXN004909)