Assessing High-Speed Internet Access in the State of Iowa, October 2000

Report for the Iowa Utilities Board and the Iowa Department of Economic Development

Assessing High-Speed Internet Access in the State of Iowa: Second Assessment, February 2002

Report for Iowa Utilities Board

Assessing High-Speed Internet Access in the State of Iowa: Third Assessment, May 2003

Report for the Iowa Utilities Board.

Sustainable Development and Concrete Technology, May 2004

For a variety of reasons, the concrete construction industry is not sustainable. First, it consumes huge quantities of virgin materials. Second, the principal binder in concrete is portland cement, the production of which is a major contributor to greenhouse gas emissions that are implicated in global warming and climate change. Third, many concrete structures suffer from lack of durability which has an adverse effect on the resource productivity of the industry. Because the high-volume fly ash concrete system addresses all three sustainability issues, its adoption will enable the concrete construction industry to become more sustainable. In this paper, a brief review is presented of the theory and construction practice with concrete mixtures containing more than 50% fly ash by mass of the cementitious material. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes cracking due to thermal and drying shrinkage, and enhances durability to reinforcement corrosion, sulfate attack, and alkali-silica expansion. For countries like China and India, this technology can play an important role in meeting the huge demand for infrastructure in a sustainable manner.

Breathhold three-dimensional coronary magnetic resonance angiography using real-time navigator technology.

The acquisition duration of most three-dimensional (3D) coronary magnetic resonance angiography (MRA) techniques is considerably prolonged, thereby precluding breathholding as a mechanism to suppress respiratory motion artifacts. Splitting the acquired 3D volume into multiple subvolumes or slabs serves to shorten individual breathhold duration. Still, problems associated with misregistration due to inconsistent depths of expiration and diaphragmatic drift during sustained respiration remain to be resolved. We propose the combination of an ultrafast 3D coronary MRA imaging sequence with prospective real-time navigator technology, which allows correction of the measured volume position. 3D volume splitting using prospective real-time navigator technology, was successfully applied for 3D coronary MRA in five healthy individuals. An ultrafast 3D interleaved hybrid gradient-echoplanar imaging sequence, including T2Prep for contrast enhancement, was used with the navigator localized at the basal anterior wall of the left ventricle. A 9-cm-thick volume, with in-plane spatial resolution of 1.1 x 2.2 mm, was acquired during five breathholds of 15-sec duration each. Consistently, no evidence of misregistration was observed in the images. Extensive contiguous segments of the left anterior descending coronary artery (48 +/- 18 mm) and the right coronary artery (75 +/- 5 mm) could be visualized. This technique has the potential for screening for anomalous coronary arteries, making it well suited as part of a larger clinical MR examination. In addition, this technique may also be applied as a scout scan, which allows an accurate definition of imaging planes for subsequent high-resolution coronary MRA.

Are patterns of bone loss in anorexic and postmenopausal women similar? Preliminary results using high resolution peripheral computed tomography.

This study intended to compare bone density and architecture in three groups of women: young women with anorexia nervosa (AN), an age-matched control group of young women, and healthy late postmenopausal women. Three-dimensional peripheral quantitative high resolution computed-tomography (HR-pQCT) at the ultradistal radius, a technology providing measures of cortical and trabecular bone density and microarchitecture, was performed in the three cohorts. Thirty-six women with AN aged 18-30years (mean duration of AN: 5.8years), 83 healthy late postmenopausal women aged 70-81 as well as 30 age-matched healthy young women were assessed. The overall cortical and trabecular bone density (D100), the absolute thickness of the cortical bone (CTh), and the absolute number of trabecules per area (TbN) were significantly lower in AN patients compared with healthy young women. The absolute number of trabecules per area (TbN) in AN and postmenopausal women was similar, but significantly lower than in healthy young women. The comparison between AN patients and post-menopausal women is of interest because the latter reach bone peak mass around the middle of the fertile age span whereas the former usually lose bone before reaching optimal bone density and structure. This study shows that bone mineral density and bone compacta thickness in AN are lower than those in controls but still higher than those in postmenopause. Bone compacta density in AN is similar as in controls. However, bone inner structure in AN is degraded to a similar extent as in postmenopause. This last finding is particularly troubling.

Consumer Satisfaction with Websites of Banks - The Moderating Effect of Consumer Technology Attractiveness

The websites are becoming the firms’ first contact interface with their clients. Hence, understanding customers’ online attitudes and behaviors have been capturing increased research attention. The extant research has pointed customers’ satisfaction with the websites as the main reason for customers’ online behaviors. This research has used mostly variables related to the characteristics of the websites as the predictors of customers’ website satisfaction. However, recent research shows that groups of individuals displaying distinctive characteristics react differently to the same context. Therefore, behavior may be considerably different among groups of customers. In this study, we develop a conceptual model of the influence of individual characteristics on the traditional website quality – website satisfaction relationship. We propose a model based on the construct of consumer technology attractiveness (CTA) to represent the genuine positive propensity of individuals toward technology. We further test the moderating effect of this construct on the commonly used predictors of customer’s website satisfaction using Hierarchical Multiple Regression. The empirical study was based on websites of banks operating in Portuguese market. The commercial banking industry is one of the Portuguese industries that better uses the Internet to establish relationships with clients. Data were collected through an online website satisfaction survey, participated by the lecturers and postgraduate students from four Portuguese Universities and Polytechnic Institutes. Our final sample comprised 276 valid questionnaires. Our study permits to conclude that the most commonly used antecedents of website overall satisfaction are still relevant for analyzing consumer’s satisfaction with the banks websites. We also conclude that CTA has a significant moderating effect on almost all customers’ website satisfaction variables used in the study. This study contributes to highlight the theoretical importance and significant influence of consumers’ personal characteristics on their online behavior. Moreover, for the practitioners, a better understanding of these individual characteristics will assist them in developing customized websites that will meet customers’ expectations. O estudo dos comportamentos dos consumidores em ambientes online tem vindo a ter um crescente interesse, uma vez que os websites estão a transformar-se num importante ponto de contacto entre as empresas e os seus clientes. A satisfação dos clientes com os websites tem sido apontada pela Literatura como o principal condicionante dos comportamentos online dos consumidores. No entanto, a investigação científica tem conseguido provar que grupos de indivíduos com características distintas reagem de forma diferente quando submetidos a contextos idênticos, o que poderá levar a diferenças significativas no comportamento online de consumidores pertencentes a diferentes grupos. Neste estudo desenvolvemos um modelo conceptual que reflecte a influência de características individuais na relação entre a qualidade e a satisfação com os websites. Propomos um modelo assente na atractividade tecnológica do consumidor (CTA), que representa a propensão genuína que os indivíduos possuem em relação à tecnologia. Testamos o efeito moderador deste conceito sobre as variáveis mais utilizadas nos estudos sobre a satisfação dos consumidores com os websites, utilizando a Regressão Múltipla Hierárquica. O estudo empírico baseou-se nos websites dos bancos que operam no mercado português, uma vez que este sector é um dos que melhor utiliza a Internet na sua relação com os clientes. Os dados foram recolhidos através de um questionário sobre satisfação com os websites, colocado online e dirigido a docentes e estudantes de programas de pós-graduações, mestrados e doutoramentos de quatro universidades e instituto politécnico portugueses, tendo resultado numa amostra final de 276 questionários validados estatisticamente. Este estudo permitiu concluir que as variáveis que são mais utilizadas como antecedentes da satisfação dos consumidores com os websites, continuam a ser igualmente válidas para a análise dos websites dos bancos. Também concluímos que a CTA tem efeitos moderadores significativos na grande maioria das variáveis utilizadas neste estudo. Assim, conseguimos realçar a importância teórica das características pessoais dos consumidores no seu comportamento online. Para os gestores, uma melhor compreensão destas características individuais permitir-lhes-á desenvolver websites customizados que irão satisfazer as expectativas dos seus clientes.

Human capital, the structure of production and growth

Do high levels of human capital foster economic growth by facilitating technology adoption? If so, countries with more human capital should have adopted more rapidly the skilled-labor augmenting technologies becoming available since the 1970 s. High human capital levels should therefore have translated into fast growth in more compared to less human-capital-intensive industries in the 1980 s. Theories of international specialization point to human capital accumulation as another important determinant of growth in human-capital-intensive industries. Using data for a large sample of countries, we find significant positive effects of human capital levels and human capital accumulation on output and employment growth in human-capital-intensive industries.

Complementarity between technology make and buy in innovation strategies: Evidence from Belgiam manufacturing firms

This paper characterizes the innovation strategy of manufacturing firms andexamines the relation between the innovation strategy and importantindustry-, firm- and innovation-specific characteristics using Belgiandata from the Eurostat Community Innovation Survey. In addition to importantsize effects explaining innovation, we find that high perceived risks andcosts and low appropriability of innovations do not discourage innovation,but rather determine how the innovation sourcing strategy is chosen. Withrespect to the determinants of the decision of the innovative firm toproduce technology itself (Make) or to source technology externally (Buy),we find that small firms are more likely restrict their innovation strategyto an exclusive make or buy strategy, while large firms are more likely tocombine both internal and external knowledge acquisition in their innovationstrategy. An interesting result that highlights the complementary nature ofthe Make and Buy decisions, is that, controlled for firm size, companies forwhich internal information is an important source for innovation are morelikely to combine internal and external sources of technology. We find thisto be evidence of the fact that in-house R&D generates the necessaryabsorptive capacity to profit from external knowledge acquisition. Also theeffectiveness of different mechanisms to appropriate the benefits ofinnovations and the internal organizational resistance against change areimportant determinants of the firm's technology sourcing strategy.

High frequency of functionally active Melan-a-specific T cells in a patient with progressive immunoproteasome-deficient melanoma.

Tumor-reactive T cells play an important role in cancer immunosurveillance. Applying the multimer technology, we report here an unexpected high frequency of Melan-A-specific CTLs in a melanoma patient with progressive lymph node metastases, consisting of 18 and 12.8% of total peripheral blood and tumor-infiltrating CD8+ T cells, respectively. Melan-A-specific CTLs revealed a high cytolytic activity against allogeneic Melan-A-expressing target cells but failed to kill the autologous tumor cells. Loading of the tumor cells with Melan-A peptide reversed the resistance to killing, suggesting impaired function of the MHC class I antigen processing and presentation pathway. Mutations of the coding region of the HLA-A2 binding Melan-A26-35 peptide or down-regulation of the MHC class I heavy chain, the antigenic peptide TAP, and tapasin could be excluded. However, PCR and immunohistochemical analysis revealed a deficiency of the immunoproteasomes low molecular weight protein 2 and low molecular weight protein 7 in the primary tumor cells, which affects the quantity and quality of generated T-cell epitopes and might explain the resistance to killing. This is supported by our data, demonstrating that the resistance to killing can be partially reversed by pre-exposure of the tumor cells to IFN-gamma, which is known to induce the immunoproteasomes. Overall, this is the first report of an extremely high frequency of tumor-specific CTLs that exhibit competent T-cell-effector functions but fail to lyse the autologous tumor cells. Immunotherapeutic approaches should not only focus on the induction of a robust antitumor immune response, but should also have to target tumor immune escape mechanisms.

From radiobiology to technology: what is changing in radiotherapy for prostate cancer.

In the last decades, new technologies have been introduced in the daily clinical practice of the radiation oncologist: 3D-Conformal radiotherapy (RT) became almost universally available, thereafter, intensity modulated RT (IMRT) gained large diffusion, due to its potential impact in improving the clinical outcomes, and more recently, helical and volumetric arc IMRT with image-guided RT are becoming more and more diffused and used for prostate cancer patients. The conventional dose-fractionation results to be the best compromise between the efficacy and the safety of the treatment, but combining new techniques, modern RT allows to overcame one of the major limits of the 'older' RT: the impossibility of delivering higher total doses and/or high dose/fraction. The evidences regarding radiobiology, clinical and technological evolution of RT in prostate cancer have been reported and discussed.

Thermal modeling and management in ultrathin chip stack technology

This paper presents a thermal modeling for power management of a new three-dimensional (3-D) thinned dies stacking process. Besides the high concentration of power dissipating sources, which is the direct consequence of the very interesting integration efficiency increase, this new ultra-compact packaging technology can suffer of the poor thermal conductivity (about 700 times smaller than silicon one) of the benzocyclobutene (BCB) used as both adhesive and planarization layers in each level of the stack. Thermal simulation was conducted using three-dimensional (3-D) FEM tool to analyze the specific behaviors in such stacked structure and to optimize the design rules. This study first describes the heat transfer limitation through the vertical path by examining particularly the case of the high dissipating sources under small area. First results of characterization in transient regime by means of dedicated test device mounted in single level structure are presented. For the design optimization, the thermal draining capabilities of a copper grid or full copper plate embedded in the intermediate layer of stacked structure are evaluated as a function of the technological parameters and the physical properties. It is shown an interest for the transverse heat extraction under the buffer devices dissipating most the power and generally localized in the peripheral zone, and for the temperature uniformization, by heat spreading mechanism, in the localized regions where the attachment of the thin die is altered. Finally, all conclusions of this analysis are used for the quantitative projections of the thermal performance of a first demonstrator based on a three-levels stacking structure for space application.

Risque thrombotique sous procréation médicalement assistée [Thrombotic risk in assisted reproductive technology].

Use of assisted reproductive technology (ART) is increasing in many developed countries. Arterial and venous thromboembolic complications are reported during ART with an incidence of 0.1%. The development of these events has been mainly ascribed to the presence of ovarian hyperstimulation syndrome (OHSS). Precise mechanisms by which OHSS and exogenous hormonal stimulation used in ART induce thromboembolic events remain unclear. However, vascular endothelial growth factor secreted during OHSS, high estradiol concentrations, and blood hyperviscosity play a major role in inducing a prothrombotic state. Therefore, before planning an ART, individual thromboembolic risk should be assessed and thromboprophylaxis offered to high risk patients. Prophylaxis should be initiated in women who develop moderate-to-severe OHSS.

Microinductive signal conditioning with resonant differential filters: high-sensitivity biodetection applications

Inductive-based devices integrated with Si technology for biodetection applications are characterized, using simple resonant differential filter configurations. This has allowed the corroboration of the viability of the proposed circuits, which are characterized by their very high simplicity, for microinductive signal conditioning in high-sensitivity sensor devices. The simulation of these simple circuits predicts sensitivities of the differential output voltage which can achieve values in the range of 0.1-1 V/nH, depending on the coil parameters. These very high-sensitivity values open the possibility for the experimental detection of extremely small inductance changes in the devices. For real microinductive devices, both series resistance and parasitic capacitive components contribute to the decrease of the differential circuit sensitivity. Nevertheless, measurements performed using micro-coils fabricated with relatively high series resistance and coupling parasitic effects have allowed detection of changes in the range of 2 nH. which are compatible with biodetection applications with estimated detection limits below the picomolarity range.

Residual Stress Measurement on a MEMS Structure With High-Spatial Resolution

A new approach to the local measurement of residual stress in microstructures is described in this paper. The presented technique takes advantage of the combined milling-imaging features of a focused ion beam (FIB) equipment to scale down the widely known hole drilling method. This method consists of drilling a small hole in a solid with inherent residual stresses and measuring the strains/displacements caused by the local stress release, that takes place around the hole. In the presented case, the displacements caused by the milling are determined by applying digital image correlation (DIC) techniques to high resolution micrographs taken before and after the milling process. The residual stress value is then obtained by fitting the measured displacements to the analytical solution of the displacement fields. The feasibility of this approach has been demonstrated on a micromachined silicon nitride membrane showing that this method has high potential for applications in the field of mechanical characterization of micro/nanoelectromechanical systems.