Control of Optically Induced Currents in Semiconductor Crystals

The generation and control of optically induced currents has the potential to become an important building block for optical computers. Here, shift and rectification currents are investigated that emerge from a divergence of the optical susceptibility. It is known that these currents react to the shape of the impinging laser pulse, and especially to the shape of the pulse envelope. The main goal is the systematic manipulation of the pulse envelope with an optical pulse shaper that is integrated into a standard THz emission setup. The initial approach, the chirping of the laser pulse only has a weak influence on the envelope and the currents. Instead, a second approach is suggested that uses the combined envelope of a phase-stable pulse-pair as a parameter. In a laser pulse, the position of the maxima of the electrical field and the pulse envelope are shifted relative to each other. This shift is known as the Carrier-Envelope Phase (CEP). It is a new degree of freedom that is usually only accessible in specially stabilized systems. It is shown, that in a phase-stable pulse-pair, at least the relative CEP is usable as a new degree of freedom. It has a great influence on the shape of the pulse envelope and thus on the current density. It is shown that this approach enables the coherent control of the current density. The experiments are corroborated by a theoretical model of the system. The potential of this approach is demonstrated in an application. A framework is presented that uses an iterative genetic algorithm to create arbitrarily shaped THz traces. The algorithm controls the optical pulse shaper, and varies the phase of the impinging laser pulses until the desired target trace is found

Does Brand Licensing Increase a Licensor's Shareholder Value?

This study examines 171 brand licensing announcements and subsequent changes in the licensor firms' shareholder values using the event study method. We find that although brand licensing announcements lead to positive abnormal returns on average, nearly 44% of the announcements in our sample are followed by negative abnormal returns. We argue that investors react more favorably to a brand licensing announcement when they believe (i) the brand has greater ability to stimulate licensee product sales (and thus generate higher royalties for the licensor) and (ii) the licensor firm has greater ability to limit licensee opportunism (and thus limit brand dilution and its adverse effect on sales of other products marketed under the brand name). In line with our hypotheses related to a brand's ability to stimulate licensee product sales, the study's findings suggest that investors react more favorably to announcements involving brands with greater brand fit and greater brand breadth. However, investors appear to react less favorably to announcements involving brands with higher advertising investments. In line with our hypotheses related to a licensor firm's ability to limit licensee opportunism, the study's findings suggest that investors react more favorably to announcements involving larger licensors; however, investors' reactions do not appear to be influenced by licensor firms' licensing experience. This paper was accepted by Pradeep Chintagunta, marketing. </jats:p

Taking stock of 10 years of published research on the ASHA programme: Examining India’s national community health worker programme from a health systems perspective

Background: As India’s accredited social health activist (ASHA) community health worker (CHW) programme enters its second decade, we take stock of the research undertaken and whether it examines the health systems interfaces required to sustain the programme at scale. Methods: We systematically searched three databases for articles on ASHAs published between 2005 and 2016. Articles that met the inclusion criteria underwent analysis using an inductive CHW–health systems interface framework. Results: A total of 122 academic articles were identified (56 quantitative, 29 mixed methods, 28 qualitative, and 9 commentary or synthesis); 44 articles reported on special interventions and 78 on the routine ASHA program. Findings on special interventions were overwhelmingly positive, with few negative or mixed results. In contrast, 55% of articles on the routine ASHA programme showed mixed findings and 23% negative, with few indicating overall positive findings, reflecting broader system constraints. Over half the articles had a health system perspective, including almost all those on general ASHA work, but only a third of those with a health condition focus. The most extensively researched health systems topics were ASHA performance, training and capacity-building, with very little research done on programme financing and reporting, ASHA grievance redressal or peer communication. Research tended to be descriptive, with fewer influence, explanatory or exploratory articles, and no predictive or emancipatory studies. Indian institutions and authors led and partnered on most of the research, wrote all the critical commentaries, and published more studies with negative results. Conclusion: Published work on ASHAs highlights a range of small-scale innovations, but also showcases the challenges faced by a programme at massive scale, situated in the broader health system. As the programme continues to evolve, critical comparative research that constructively feeds back into programme reforms is needed, particularly related to governance, intersectoral linkages, ASHA solidarity, and community capacity to provide support and oversight

Control of Optically Induced Currents in Semiconductor Crystals

The generation and control of optically induced currents has the potential to become an important building block for optical computers. Here, shift and rectification currents are investigated that emerge from a divergence of the optical susceptibility. It is known that these currents react to the shape of the impinging laser pulse, and especially to the shape of the pulse envelope. The main goal is the systematic manipulation of the pulse envelope with an optical pulse shaper that is integrated into a standard THz emission setup. The initial approach, the chirping of the laser pulse only has a weak influence on the envelope and the currents. Instead, a second approach is suggested that uses the combined envelope of a phase-stable pulse-pair as a parameter. In a laser pulse, the position of the maxima of the electrical field and the pulse envelope are shifted relative to each other. This shift is known as the Carrier-Envelope Phase (CEP). It is a new degree of freedom that is usually only accessible in specially stabilized systems. It is shown, that in a phase-stable pulse-pair, at least the relative CEP is usable as a new degree of freedom. It has a great influence on the shape of the pulse envelope and thus on the current density. It is shown that this approach enables the coherent control of the current density. The experiments are corroborated by a theoretical model of the system. The potential of this approach is demonstrated in an application. A framework is presented that uses an iterative genetic algorithm to create arbitrarily shaped THz traces. The algorithm controls the optical pulse shaper, and varies the phase of the impinging laser pulses until the desired target trace is found

Rethinking Customer Solutions: From Product Bundles to Relational processes

This study draws on depth interviews with 49 managers in customer firms and 55 managers in supplier firms and on discussions with 21 managers in two focus groups to propose a new way of thinking about customer solutions. Extant literature and suppliers interviewed for this study view a solution as a customized and integrated combination of goods and services for meeting a customer’s business needs. In contrast, customers view a solution as a set of customer–supplier relational processes comprising (1) customer requirements definition, (2) customization and integration of goods and/or services and (3) their deployment, and (4) postdeployment customer support, all of which are aimed at meeting customers ’ business needs. The relational process view can help suppliers deliver more effective solutions at profitable prices. In addition, field research suggests that the effectiveness of a solution depends not only on supplier variables but also on several customer variables. Supplier variables include contingent hierarchy, documentation emphasis, incentive externality, customer interactor stability, and process articulation. Customer variables include adaptiveness to supplier offerings and political an

A theories-in-use approach to building marketing theory

This article’s objective is to inspire and provide guidance on the development of marketing knowledge based on the theories-in-use (TIU) approach. The authors begin with a description of the TIU approach and compare it with other inductive and deductive research approaches. The benefits of engaging in TIU-based research are discussed, including the development of novel organic marketing theories and the opportunity to cocreate relevant marketing knowledge with practitioners. Next, they review criteria for selecting research questions that are particularly well-suited for examination with TIU-based research. This is followed by detailed suggestions for TIU research: focusing on developing new constructs, theoretical propositions (involving antecedents, moderators, and consequences), and arguments for justifying theoretical propositions. A discussion of TIU tradecraft skills, validity checks, and limitations follows. The authors close with a discussion of future theory-building opportunities using the TIU approach

Clinical Presentation of Hepatocellular Carcinoma in African Americans vs. Caucasians: A Retrospective Analysis

Hepatocellular carcinoma (HCC) remains an important form of cancer-related morbidity and mortality in the U.S. and worldwide. Previous U.S.-based studies on survival suggest ethnic disparities in HCC patients, but the complex interplay of multiple factors that contribute are still incompletely understood. Here we considered the influences of risk factors contributing towards HCC survival, including ethnic background, over ten years at a premier academic medical center with a majority (57.20%) African American (AA) population. Retrospective HCC data were collected from 2008–2018 at LSUHSC-Shreveport, an urban tertiary medical center. Data included demographics, comorbidities, liver disease characteristics, and tumor parameters. Statistical analysis was performed using Chi Square and one-way ANOVA. Results: 229 HCC patients were identified (male 78.6%). The mean HCC age at diagnosis was 61 years (SD = 7.3). Compared to non-Hispanic Caucasians (42.7%), AA patients (57.2% of total) were older at presentation, had more frequent diabetes/dyslipidemia/NAFLD (45 (34.3%) compared with 19 (19.3%) in non-Hispanic Caucasians, p = 0.02), and had a larger HCC burden at diagnosis. We conclude that compared to white patients, despite having similar BMI and MELD scores and rates of portal vein thrombosis, AA patients with HCC in our cohort were older at presentation, had a significantly increased incidence of modifiable metabolic risk factors including diabetes, higher AFP values, increased incidence of gallstones, and larger sized HCCs, and were more likely to be outside Milan criteria. These findings have important prognostic and diagnostic implications for developing a more targeted HCC surveillance program