Valuing the influence of underlying attitudes and the demand for organic milk in Japan

Subjective perceptions about a product affect consumer choice. Accordingly, acquiring the underlying demand characteristics that consumers find desirable is vital for firms planning future marketing strategies. However, the extent to which product-specific perceptions affect consumer choice is poorly understood. New agricultural standards for organic livestock were introduced in Japan in November 2005 and are expected to influence the market significantly. Choice modeling (CM) is used to explore how consumers evaluate the latent demands and conventional attributes (or tangible values) of organic milk. The results suggest that latent demands, along with socioeconomic characteristics and conventional attributes, provide strong incentives for consumers to move from the purchase of conventional milk to organic milk. The analysis indicates that latent demands reflecting the safeness of organic milk, the better taste of organic milk, the image of environmental friendliness in the production process, and the image of the health and comfort of the cows are important factors that influence consumers' purchasing decisions. However, each specific factor has a corresponding conventional tangible attribute that needs to be targeted in marketing strategy.

Experiences in becoming a paramedic : a qualitative study examining the professional socialisation of university qualified paramedics

This thesis used qualitative methods to investigate the professional socialisation of university educated paramedics from Australia and the United Kingdom. The study tested existing professional socialisation theories, taken from other health disciplines, against the paramedical context and developed of a specific model depicting the professional socialisation of university educated paramedics.

Does calcium deposition play a role in the stability of atheroma? Location may be the key

Background: Rupture of vulnerable atheromatous plaque in the carotid and coronary arteries often leads to stroke and heart attack respectively. The role of calcium deposition and its contribution to plaque stability is controversial. This study uses both an idealized and a patient-specific model to evaluate the effect of a calcium deposit on the stress distribution within an atheromatous plaque. Methods: Using a finite-element method, structural analysis was performed on an idealized plaque model and the location of a calcium deposit within it was varied. In addition to the idealized model, in vivo high-resolution MR imaging was performed on 3 patients with carotid atheroma and stress distributions were generated. The individual plaques were chosen as they had calcium at varying locations with respect to the lumen and the fibrous cap. Results: The predicted maximum stress was increased by 47.5% when the calcium deposit was located in the thin fibrous cap in the model when compared with that in a model without a deposit. The result of adding a calcium deposit either to the lipid core or remote from the lumen resulted in almost no increase in maximal stress. Conclusion: Calcification at the thin fibrous cap may result in high stress concentrations, ultimately increasing the risk of plaque rupture. Assessing the location of calcification may, in the future, aid in the risk stratification of patients with carotid stenosis.

Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF

We present results of a search for anomalous production of two photons together with an electron, muon, $\tau$ lepton, missing transverse energy, or jets using $p\bar{p}$ collision data from 1.1-2.0 fb$^{-1}$ of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy.

An Empirical Investigation of Value-at-Risk in Long and Short Trading Positions

This paper uses the Value-at-Risk approach to define the risk in both long and short trading positions. The investigation is done on some major market indices(Japanese, UK, German and US). The performance of models that takes into account skewness and fat-tails are compared to symmetric models in relation to both the specific model for estimating the variance, and the distribution of the variance estimate used as input in the VaR estimation. The results indicate that more flexible models not necessarily perform better in predicting the VaR forecast; the reason for this is most probably the complexity of these models. A general result is that different methods for estimating the variance are needed for different confidence levels of the VaR, and for the different indices. Also, different models are to be used for the left respectively the right tail of the distribution.

Floquet generation of Majorana end modes and topological invariants

We show how Majorana end modes can be generated in a one-dimensional system by varying some of the parameters in the Hamiltonian periodically in time. The specific model we consider is a chain containing spinless electrons with a nearest-neighbor hopping amplitude, a p-wave superconducting term, and a chemical potential; this is equivalent to a spin-1/2 chain with anisotropic XY couplings between nearest neighbors and a magnetic field applied in the (z) over cap direction. We show that varying the chemical potential (or magnetic field) periodically in time can produce Majorana modes at the ends of a long chain. We discuss two kinds of periodic driving, periodic delta-function kicks, and a simple harmonic variation with time. We discuss some distinctive features of the end modes such as the inverse participation ratio of their wave functions and their Floquet eigenvalues which are always equal to +/- 1 for time-reversal-symmetric systems. For the case of periodic delta-function kicks, we use the effective Hamiltonian of a system with periodic boundary conditions to define two topological invariants. The first invariant is a well-known winding number, while the second invariant has not appeared in the literature before. The second invariant is more powerful in that it always correctly predicts the numbers of end modes with Floquet eigenvalues equal to + 1 and -1, while the first invariant does not. We find that the number of end modes can become very large as the driving frequency decreases. We show that periodic delta-function kicks in the hopping and superconducting terms can also produce end modes. Finally, we study the effect of electron-phonon interactions (which are relevant at finite temperatures) and a random noise in the chemical potential on the Majorana modes.

Multipole moments in general relativity and dynamical perturbations of black-hole magnetospheres

This thesis consists of two parts. In Part I, we develop a multipole moment formalism in general relativity and use it to analyze the motion and precession of compact bodies. More specifically, the generic, vacuum, dynamical gravitational field of the exterior universe in the vicinity of a freely moving body is expanded in positive powers of the distance r away from the body's spatial origin (i.e., in the distance r from its timelike-geodesic world line). The expansion coefficients, called "external multipole moments,'' are defined covariantly in terms of the Riemann curvature tensor and its spatial derivatives evaluated on the body's central world line. In a carefully chosen class of de Donder coordinates, the expansion of the external field involves only integral powers of r ; no logarithmic terms occur. The expansion is used to derive higher-order corrections to previously known laws of motion and precession for black holes and other bodies. The resulting laws of motion and precession are expressed in terms of couplings of the time derivatives of the body's quadrupole and octopole moments to the external moments, i.e., to the external curvature and its gradient.

In part II, we study the interaction of magnetohydrodynamic (MHD) waves in a black-hole magnetosphere with the "dragging of inertial frames" effect of the hole's rotation - i.e., with the hole's "gravitomagnetic field." More specifically: we first rewrite the laws of perfect general relativistic magnetohydrodynamics (GRMHD) in 3+1 language in a general spacetime, in terms of quantities (magnetic field, flow velocity, ...) that would be measured by the ''fiducial observers” whose world lines are orthogonal to (arbitrarily chosen) hypersurfaces of constant time. We then specialize to a stationary spacetime and MHD flow with one arbitrary spatial symmetry (e.g., the stationary magnetosphere of a Kerr black hole); and for this spacetime we reduce the GRMHD equations to a set of algebraic equations. The general features of the resulting stationary, symmetric GRMHD magnetospheric solutions are discussed, including the Blandford-Znajek effect in which the gravitomagnetic field interacts with the magnetosphere to produce an outflowing jet. Then in a specific model spacetime with two spatial symmetries, which captures the key features of the Kerr geometry, we derive the GRMHD equations which govern weak, linealized perturbations of a stationary magnetosphere with outflowing jet. These perturbation equations are then Fourier analyzed in time t and in the symmetry coordinate x, and subsequently solved numerically. The numerical solutions describe the interaction of MHD waves with the gravitomagnetic field. It is found that, among other features, when an oscillatory external force is applied to the region of the magnetosphere where plasma (e⁺e^-) is being created, the magnetosphere responds especially strongly at a particular, resonant, driving frequency. The resonant frequency is that for which the perturbations appear to be stationary (time independent) in the common rest frame of the freshly created plasma and the rotating magnetic field lines. The magnetosphere of a rotating black hole, when buffeted by nonaxisymmetric magnetic fields anchored in a surrounding accretion disk, might exhibit an analogous resonance. If so then the hole's outflowing jet might be modulated at resonant frequencies ω=(m/2) Ω_H where m is an integer and Ω_H is the hole's angular velocity.

Professores especiais para alunos especiais: uma experiência de grupo operativo na capacitação de professores

O objetivo desta pesquisa foi estudar a contribuição que a interação vivenciada em grupos operativos pode oferecer ao desenvolvimento da capacidade de aprendizagem no amplo processo de capacitação docente, numa perspectiva psicopedagógica. Buscou-se perceber como a técnica dos grupos operativos contribuiria para a modificação da pratica pedagógica desenvolvida por professores de aceleração de aprendizagem no sentido de otimizar os resultados do trabalho por eles desenvolvidos junto aos alunos dessas classes.Foram acompanhados, em dinâmica de grupo operativo, vinte docentes de classes de aceleração incluídos em um projeto de capacitação para professores desenvolvido em Mangaratiba, RJ. A tarefa explicita nesse grupo foi a elaboração de temas sobre a aprendizagem dos alunos e dos professores, considerando a auto-estima acadêmica de ambos.A base teórica adotada foi a Epistemologia Convergente, na qual Jorge Visca propõe um modelo específico de intervenção psicopedagógica. Neste modelo, a perspectiva relacional está fundada nas contribuições da psicologia social, conforme é compreendida por Pichon-Riviére. Aí, a técnica dos grupos operativos é utilizada para favorecer o desenvolvimento relacional do grupo participante, otimizando suas possibilidades de aprender. Realizou-se então, uma intervenção psicopedagógica para a capacitação de docentes de classe de aceleração de aprendizagem e um dos instrumentos dessa intervenção foi a vivencia em grupo operativo. A pesquisa acompanhou o desenvolvimento desse grupo observando e interagindo para que se produzissem os movimentos que contribuíram para mobilizar a resignificação do modelo de aprendizagem dos seus membros.Essa resignificação possibilitou ao professor considerar a capacidade para aprender em grupo fator de grande importância na tarefa docente, aspecto considerado original na capacitação realizada. Os resultados qualitativos observados tornaram-se explícitos ao longo da vivencia grupal na significativa mudança da relação do grupo com a produção de conhecimento e da auto-estima profissional dos participantes. A pesquisa concluiu que os processos de capacitação docente devem continuar buscando alternativas mais coerentes com os aspectos que se deseja formar nos professores e apresenta os grupos operativos como estratégia psicopedagógica de excelentes possibilidades na capacitação dos mesmos.Enfatiza ainda, a possibilidade de reconstrução do sentido e pratica da cidadania na dinâmica desses grupos já que neles, os sujeitos encontram oportunidades de redefinição dos papeis que desempenham, pelo exercício da flexibilização dos mesmos. Confirma a certeza de que o professor que poderá ensinar a construir conhecimento deverá, ele mesmo, ter construído o seu como a condição para que possa ajudar o aluno a superar as inúmeras dificuldades inerentes à aprendizagem presentes nas estruturas sociais, nos sistemas escolares e em sua própria historia pessoal. É nessa superação que alunos e professores já marcados pelas vivências de fracasso escolar poderão retomar no grupo social a construção de sua condição cidadã, justificando o empenho realizado pela educação escolar.

Robust network reconstruction in polynomial time

This paper presents an efficient algorithm for robust network reconstruction of Linear Time-Invariant (LTI) systems in the presence of noise, estimation errors and unmodelled nonlinearities. The method here builds on previous work [1] on robust reconstruction to provide a practical implementation with polynomial computational complexity. Following the same experimental protocol, the algorithm obtains a set of structurally-related candidate solutions spanning every level of sparsity. We prove the existence of a magnitude bound on the noise, which if satisfied, guarantees that one of these structures is the correct solution. A problem-specific model-selection procedure then selects a single solution from this set and provides a measure of confidence in that solution. Extensive simulations quantify the expected performance for different levels of noise and show that significantly more noise can be tolerated in comparison to the original method. © 2012 IEEE.

Life cycle assessments of biodegradable, commercial biopolymers - A critical review

Biopolymers are generally considered an eco-friendly alternative to petrochemical polymers due to the renewable feedstock used to produce them and their biodegradability. However, the farming practices used to grow these feedstocks often carry significant environmental burdens, and the production energy can be higher than for petrochemical polymers. Life cycle assessments (LCAs) are available in the literature, which make comparisons between biopolymers and various petrochemical polymers, however the results can be very disparate. This review has therefore been undertaken, focusing on three biodegradable biopolymers, poly(lactic acid) (PLA), poly(hydroxyalkanoates) (PHAs), and starch-based polymers, in an attempt to determine the environmental impact of each in comparison to petrochemical polymers. Reasons are explored for the discrepancies between these published LCAs. The majority of studies focused only on the consumption of non-renewable energy and global warming potential and often found these biopolymers to be superior to petrochemically derived polymers. In contrast, studies which considered other environmental impact categories as well as those which were regional or product specific often found that this conclusion could not be drawn. Despite some unfavorable results for these biopolymers, the immature nature of these technologies needs to be taken into account as future optimization and improvements in process efficiencies are expected. © 2013 Elsevier B.V. All rights reserved.

Modeling the evolution of regulatory elements by simultaneous detection and alignment with phylogenetic pair HMMs.

The computational detection of regulatory elements in DNA is a difficult but important problem impacting our progress in understanding the complex nature of eukaryotic gene regulation. Attempts to utilize cross-species conservation for this task have been hampered both by evolutionary changes of functional sites and poor performance of general-purpose alignment programs when applied to non-coding sequence. We describe a new and flexible framework for modeling binding site evolution in multiple related genomes, based on phylogenetic pair hidden Markov models which explicitly model the gain and loss of binding sites along a phylogeny. We demonstrate the value of this framework for both the alignment of regulatory regions and the inference of precise binding-site locations within those regions. As the underlying formalism is a stochastic, generative model, it can also be used to simulate the evolution of regulatory elements. Our implementation is scalable in terms of numbers of species and sequence lengths and can produce alignments and binding-site predictions with accuracy rivaling or exceeding current systems that specialize in only alignment or only binding-site prediction. We demonstrate the validity and power of various model components on extensive simulations of realistic sequence data and apply a specific model to study Drosophila enhancers in as many as ten related genomes and in the presence of gain and loss of binding sites. Different models and modeling assumptions can be easily specified, thus providing an invaluable tool for the exploration of biological hypotheses that can drive improvements in our understanding of the mechanisms and evolution of gene regulation.

The induced innovation hypothesis and energy-saving technological change

We develop a methodology for testing Hicks's induced innovation hypothesis by estimating a product-characteristics model of energy-using consumer durables, augmenting the hypothesis to allow for the influence of government regulations. For the products we explored, the evidence suggests that (i) the rate of overall innovation was independent of energy prices and regulations; (ii) the direction of innovation was responsive to energy price changes for some products but not for others; (iii) energy price changes induced changes in the subset of technically feasible models that were offered for sale; (iv) this responsiveness increased substantially during the period after energy-efficiency product labeling was required; and (v) nonetheless, a sizable portion of efficiency improvements were autonomous.

Evidence for a modifier of onset age in Huntington disease linked to the HD gene in 4p16

Huntington disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the HD gene on chromosome 4p16.3. A recent genome scan for genetic modifiers of age at onset of motor symptoms (AO) in HD suggests that one modifier may reside in the region close to the HD gene itself. We used data from 535 HD participants of the New England Huntington cohort and the HD MAPS cohort to assess whether AO was influenced by any of the three markers in the 4p16 region: MSX1 (Drosophila homeo box homologue 1, formerly known as homeo box 7, HOX7), Delta2642 (within the HD coding sequence), and BJ56 (D4S127). Suggestive evidence for an association was seen between MSX1 alleles and AO, after adjustment for normal CAG repeat, expanded repeat, and their product term (model P value 0.079). Of the variance of AO that was not accounted for by HD and normal CAG repeats, 0.8% could be attributed to the MSX1 genotype. Individuals with MSX1 genotype 3/3 tended to have younger AO. No association was found between Delta2642 (P=0.44) and BJ56 (P=0.73) and AO. This study supports previous studies suggesting that there may be a significant genetic modifier for AO in HD in the 4p16 region. Furthermore, the modifier may be present on both HD and normal chromosomes bearing the 3 allele of the MSX1 marker.

Threshold effects in the Teaching Space Allocation Problem with Splitting

Universities aim for good “Space Management” so as to use the teaching space efficiently. Part of this task is to assign rooms and time-slots to teaching activities with limited numbers and capacities of lecture theaters, seminar rooms, etc. It is also common that some teaching activities require splitting into multiple events. For example, lectures can be too large to fit in one room or good teaching practice requires that seminars/tutorials are taught in small groups. Then, space management involves decisions on splitting as well as the assignments to rooms and time-slots. These decisions must be made whilst satisfying the pedagogic requirements of the institution and constraints on space resources. The efficiency of such management can be measured by the “utilisation”: the percentage of available seat-hours actually used. In many institutions, the observed utilisation is unacceptably low, and this provides our underlying motivation: to study the factors that affect teaching space utilisation, with the goal of improving it. We give a brief introduction to our work in this area, and then introduce a specific model for splitting. We present experimental results that show threshold phenomena and associated easy-hard-easy patterns of computational difficulty. We discuss why such behaviour is of importance for space management.

An Empirical Analysis of Scale and Scope Economies and Technical Change in an Irish Multiproduct Banking Firm

In contrast to most empirical investigations of the efficiency of multiproduct financial institutions, which either estimate scale and scope economies with a given state of technology, or only analyse technical change in the presence of overall scale economies, this study estimates overall scale economies, product-specific scale economies and scope economies in the presence of both neutral and non-neutral technical change. Also, in contrast to most other empirical studies in this area, standard errors are computed for all relevant statistics. The findings indicate diseconomies of scope; overall diseconomies of scale; product-specific economies are decreasing for investments and increasing for loans; in addition to substantial neutral technical change, biased technical change is labour- and capital-saving and deposits-using in character.