855 research outputs found
Theoretical development in ethical marketing decision making
Abstract The current state of knowledge about ethical marketing decision making is explored from a historical perspective. While much research focuses on ethical issues, our purpose is to provide a holistic perspective of existing theory, skills, and research. We address both normative and descriptive approaches to ethical decision making theory development. Additional dimensions of ethical decision making such as institutional, resource-advantage, and value chain theory are advanced for future research
Pediatric trainees\u27 engagement in the online nutrition curriculum: preliminary results
Background: The Pediatric Nutrition Series (PNS) consists of ten online, interactive modules and supplementary educational materials that have utilized web-based multimedia technologies to offer nutrition education for pediatric trainees and practicing physicians. The purpose of the study was to evaluate pediatric trainees\u27 engagement, knowledge acquisition, and satisfaction with nutrition modules delivered online in interactive and non-interactive formats. Methods: From December 2010 through August 2011, pediatric trainees from seventy-three (73) different U. S. programs completed online nutrition modules designed to develop residents\u27 knowledge of counseling around and management of nutritional issues in children. Data were analyzed using SPSS version 19. Both descriptive and inferential statistics were used in comparing interactive versus non-interactive modules. Pretest/posttest and module evaluations measured knowledge acquisition and satisfaction. Results: Three hundred and twenty-two (322) pediatric trainees completed one or more of six modules for a total of four hundred and forty-two (442) accessions. All trainees who completed at least one module were included in the study. Two-way analyses of variance (ANOVA) with repeated measures (pre/posttest by interactive/non-interactive format) indicated significant knowledge gains from pretest to posttest (p \u3c 0.002 for all six modules). Comparisons between interactive and non-interactive formats for Module 1 (N = 85 interactive, N = 95 non-interactive) and Module 5 (N = 5 interactive, N = 16 non-interactive) indicated a parallel improvement from the pretest to posttest, with the interactive format significantly higher than the non-interactive modules (p \u3c .05). Both qualitative and quantitative data from module evaluations demonstrated that satisfaction with modules was high. However, there were lower ratings for whether learning objectives were met with Module 6 (p \u3c 0.03) and lecturer rating (p \u3c 0.004) compared to Module 1. Qualitative data also showed that completion of the interactive modules resulted in higher resident satisfaction. Conclusions: This initial assessment of the PNS modules shows that technology-mediated delivery of a nutrition curriculum in residency programs has great potential for providing rich learning environments for trainees while maintaining a high level of participant satisfaction
Systems biologists seek fuller integration of systems biology approaches in new cancer research programs
Systems biology takes an interdisciplinary approach to the systematic study of complex interactions in biological systems. This approach seeks to decipher the emergent behaviors of complex systems rather than focusing only on their constituent properties. As an increasing number of examples illustrate the value of systems biology approaches to understand the initiation, progression, and treatment of cancer, systems biologists from across Europe and the United States hope for changes in the way their field is currently perceived among cancer researchers. In a recent EU-US workshop, supported by the European Commission, the German Federal Ministry for Education and Research, and the National Cancer Institute of the NIH, the participants discussed the strengths, weaknesses, hurdles, and opportunities in cancer systems biology
Spectral properties of the t-J model in the presence of hole-phonon interaction
We examine the effects of electron-phonon interaction on the dynamics of the
charge carriers doped in two-dimensional (2D) Heisenberg antiferromagnet. The
- model Hamiltonian with a Fr\"ohlich term which couples the holes to a
dispersionless (optical) phonon mode is considered for low doping
concentration. The evolution of the spectral density function, the density of
states, and the momentum distribution function of the holes with an increase of
the hole-phonon coupling constant is studied numerically. As the coupling
to a phonon mode increases the quasiparticle spectral weight decreases and a
``phonon satellite'' feature close to the quasi-particle peak becomes more
pronounced. Furthermore, strong electron-phonon coupling smears the
multi-magnon resonances (``string states'') in the incoherent part of the
spectral function. The jump in the momentum distribution function at the Fermi
surface is reduced without changing the hole pocket volume, thereby providing a
numerical verification of Luttinger theorem for this strongly interacting
system. The vertex corrections due to electron- phonon interaction are
negligible in spite of the fact that the ratio of the phonon frequency to the
effective bandwidth is not small.Comment: REVTeX, 20 pages, 9 figures, to be published in Phys. Rev. B (Nov. 1,
1996
Comparative Outcomes of Lung Volume Reduction Surgery and Lung Transplantation: A Systematic Review and Meta-Analysis
Background: Lung volume reduction (LVR) and lung transplantation (LTx) have been used in different populations of chronic obstructive pulmonary disease (COPD) patients. To date, comparative study of LVR and LTx has not been performed. We sought to address this gap by pooling the existing evidence in the literature.
Methods: An electronic search was performed to identify all prospective studies on LVR and LTx published since 2000. Baseline characteristics, perioperative variables, and clinical outcomes were extracted and pooled for meta-analysis.
Results: The analysis included 65 prospective studies comprising 3,671 patients [LTx: 15 studies (n=1,445), LVR: 50 studies (n=2,226)]. Mean age was 60 [95% confidence interval (CI): 58–62] years and comparable between the two groups. Females were 51% (95% CI: 30–71%) in the LTx group vs. 28% (95% CI: 21–36%) in LVR group (P=0.05). Baseline 6-minute walk test (6MWT) and pulmonary function tests were comparable except for the forced expiratory volume in 1 second (FEV1), which was lower in the LTx group [21.8% (95% CI: 16.8–26.7%) vs. 27.3% (95% CI: 25.5–29.2%), P=0.04]. Postoperatively, both groups experienced improved FEV1, however post-LTx FEV1 was significantly higher than post-LVR FEV1 [54.9% (95% CI: 41.4–68.4%) vs. 32.5% (95% CI: 30.1–34.8%), P\u3c0.01]. 6MWT was also improved after both procedures [LTx: 212.9 (95% CI: 119.0–306.9) to 454.4 m (95% CI: 334.7–574.2), P\u3c0.01; LVR: 286 (95% CI: 270.2–301.9) to 409.1 m (95% CI: 392.1–426.0), P\u3c0.01], however, with no significant difference between the groups. Pooled survival over time showed no significant difference between the groups.
Conclusions: LTx results in better FEV1 but otherwise has comparable outcomes to LVR
Frequency dependent specific heat of viscous silica
We apply the Mori-Zwanzig projection operator formalism to obtain an
expression for the frequency dependent specific heat c(z) of a liquid. By using
an exact transformation formula due to Lebowitz et al., we derive a relation
between c(z) and K(t), the autocorrelation function of temperature fluctuations
in the microcanonical ensemble. This connection thus allows to determine c(z)
from computer simulations in equilibrium, i.e. without an external
perturbation. By considering the generalization of K(t) to finite wave-vectors,
we derive an expression to determine the thermal conductivity \lambda from such
simulations. We present the results of extensive computer simulations in which
we use the derived relations to determine c(z) over eight decades in frequency,
as well as \lambda. The system investigated is a simple but realistic model for
amorphous silica. We find that at high frequencies the real part of c(z) has
the value of an ideal gas. c'(\omega) increases quickly at those frequencies
which correspond to the vibrational excitations of the system. At low
temperatures c'(\omega) shows a second step. The frequency at which this step
is observed is comparable to the one at which the \alpha-relaxation peak is
observed in the intermediate scattering function. Also the temperature
dependence of the location of this second step is the same as the one of the
peak, thus showing that these quantities are intimately connected to
each other. From c'(\omega) we estimate the temperature dependence of the
vibrational and configurational part of the specific heat. We find that the
static value of c(z) as well as \lambda are in good agreement with experimental
data.Comment: 27 pages of Latex, 8 figure
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Association between amygdala reactivity and a dopamine transporter gene polymorphism
Essential for detection of relevant external stimuli and for fear processing, the amygdala is under modulatory influence of dopamine (DA). The DA transporter (DAT) is of fundamental importance for the regulation of DA transmission by mediating reuptake inactivation of extracellular DA. This study examined if a common functional variable number tandem repeat polymorphism in the 3′ untranslated region of the DAT gene (SLC6A3) influences amygdala function during the processing of aversive emotional stimuli. Amygdala reactivity was examined by comparing regional cerebral blood flow, measured with positron emission tomography and [15O]water, during exposure to angry and neutral faces, respectively, in a Swedish sample comprising 32 patients with social anxiety disorder and 17 healthy volunteers. In a separate US sample, comprising 85 healthy volunteers studied with blood oxygen level-dependent functional magnetic resonance imaging, amygdala reactivity was assessed by comparing the activity during exposure to threatening faces and neutral geometric shapes, respectively. In both the Swedish and the US sample, 9-repeat carriers displayed higher amygdala reactivity than 10-repeat homozygotes. The results suggest that this polymorphism contributes to individual variability in amygdala reactivity
Ethical perceptions of accounting students in a Portuguese university: the influence of individual factors and personal traits
Our purpose is to empirically examine whether gender, age, work experience, and attendance of a course on ethics affect the ethical perceptions of Portuguese accounting students and analyze the influence of some individual factors that may affect their ethical decision-making. Additionally, we consider the degree of importance assigned to a list of personal traits and their relationship with those factors. We concluded that gender influenced the degree of importance attributed by students to initiative/entrepreneurship, obedience, and responsibility; age influenced the degree of importance attributed by students to integrity; work experience influenced the degree of importance attributed by students to obedience; and attendance of a course on ethics influenced the degree of importance attributed to independence. For each of these factors, the influence did not prove to be statistically significant in decision-making. Similarly, the study identified some reservations regarding attitudes the students’ peers might have, and when asked about this, they had negative opinions, believing their colleagues would have lower ethical standards. Our results add to the literature, especially because, in Portugal, little has been done to understand which factors may affect students’ ethical decision-making processes. We expect to bring added value to stakeholders, teachers, and scholars engaged with these matters
Light emission from a scanning tunneling microscope: Fully retarded calculation
The light emission rate from a scanning tunneling microscope (STM) scanning a
noble metal surface is calculated taking retardation effects into account. As
in our previous, non-retarded theory [Johansson, Monreal, and Apell, Phys. Rev.
B 42, 9210 (1990)], the STM tip is modeled by a sphere, and the dielectric
properties of tip and sample are described by experimentally measured
dielectric functions. The calculations are based on exact diffraction theory
through the vector equivalent of the Kirchoff integral. The present results are
qualitatively similar to those of the non-retarded calculations. The light
emission spectra have pronounced resonance peaks due to the formation of a
tip-induced plasmon mode localized to the cavity between the tip and the
sample. At a quantitative level, the effects of retardation are rather small as
long as the sample material is Au or Cu, and the tip consists of W or Ir.
However, for Ag samples, in which the resistive losses are smaller, the
inclusion of retardation effects in the calculation leads to larger changes:
the resonance energy decreases by 0.2-0.3 eV, and the resonance broadens. These
changes improve the agreement with experiment. For a Ag sample and an Ir tip,
the quantum efficiency is 10 emitted photons in the visible
frequency range per tunneling electron. A study of the energy dissipation into
the tip and sample shows that in total about 1 % of the electrons undergo
inelastic processes while tunneling.Comment: 16 pages, 10 figures (1 ps, 9 tex, automatically included); To appear
in Phys. Rev. B (15 October 1998
The Roles of Cyclin A2, B1, and B2 in Early and Late Mitotic Events
This paper presents evidence that chromatin condensation, like nuclear envelope breakdown, is brought about through the combined effects of cyclins A2 and B1, and that cyclins B1 and B2 are largely responsible for maintenance of a spindle assembly checkpoint arrest
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