bluuebunny/crossref_metadata_2025 huggingface dataset:
Gaze-Contingent Multiresolutional Displays: An Integrative Review
Authors: Reingold Eyal M. , Loschky Lester C. , McConkie George W. , Stampe David M.
Published: March 2004

Gaze-contingent multiresolutional displays (GCMRDs) center high-resolution information on the user's gaze position, matching the user's area of interest (AOI). Image resolution and details outside the AOI are reduced, lowering the requirements for processing resources and transmission bandwidth in demanding display and imaging applications. This review provides a general framework within which GCMRD research can be integrated, evaluated, and guided. GCMRDs (or “moving windows”) are analyzed in terms of (a) the nature of their images (i.e., “multiresolution,” “variable resolution,” “space variant,” or “level of detail”), and (b) the movement of the AOI (i.e., “gaze contingent,” “foveated,” or “eye slaved”). We also synthesize the known human factors research on GCMRDs and point out important questions for future research and development. Actual or potential applications of this research include flight, medical, and driving simulators; virtual reality; remote piloting and teleoperation; infrared and indirect vision; image transmission and retrieval; telemedicine; video teleconferencing; and artificial vision systems.
Bimodal Displays Improve Speech Comprehension in Environments with Multiple Speakers
Authors: Rudmann Darrell S. , McCarley Jason S. , Kramer Arthur F.
Published: March 2004

Attending to a single voice when multiple voices are present is a challenging but common occurrence. An experiment was conducted to determine (a) whether presenting a video display of the target speaker aided speech comprehension in an environment with competing voices, and (b) whether the “ventriloquism effect” could be used to enhance comprehension, as found by Driver (1996), using ecologically valid stimuli. Participants listened for target words from videos of an actress reading while simultaneously ignoring the voices of 2 to 4 different actresses. Target-word detection declined as participants had to ignore more distracting voices; however, this decline was reduced when a video display of the target speaker was provided. Neither a signal-detection analysis of performance data nor a gaze-contingent analysis revealed a ventriloquism effect. Providing a video display of a speaker when competing voices are present improves comprehension, but obtaining the ventriloquism effect appears elusive in naturalistic circumstances. Actual or potential applications of this research include those circumstances in which a listener must filter a relevant stream of speech from among multiple, competing voices, such as air traffic control and military environments.
The Vigilance Decrement Reflects Limitations in Effortful Attention, Not Mindlessness
Authors: Grier Rebecca A. , Warm Joel S. , Dember William N. , Matthews Gerald , Galinsky Traci L. , Szalma James L. , Parasuraman Raja
Published: March 2004

Robertson, Manly, Andrade, Baddeley, and Yiend (1997) proposed that the decline in performance efficiency over time in vigilance tasks (the vigilance decrement) is characterized by “mindlessness” or a withdrawal of attentional effort from the monitoring assignment. We assessed that proposal using measures of perceived mental workload (NASA-TLX) and stress (Dundee Stress State Questionnaire). Two types of vigilance task were employed: a traditional version, wherein observers made button-press responses to signify detection of rarely occurring critical signals, and a modified version, developed by Robertson et al. to promote mindlessness via routinization, wherein button-press responses acknowledged frequently occurring neutral stimulus events and response withholding signified critical signal detection. The vigilance decrement was observed in both tasks, and both tasks generated equally elevated levels of workload and stress, the latter including cognitions relating to performance adequacy. Vigilance performance seems better characterized by effortful attention (mindfulness) than by mindlessness. Actual or potential applications of this research include procedures to reduce the information-processing demand imposed by vigilance tasks and the stress associated with such tasks.
Attentional Models of Multitask Pilot Performance Using Advanced Display Technology
Authors: Wickens Christopher D. , Goh Juliana , Helleberg John , Horrey William J. , Talleur Donald A.
Published: March 2004

In the first part of the reported research, 12 instrument-rated pilots flew a highfidelity simulation, in which air traffic control presentation of auditory (voice) information regarding traffic and flight parameters was compared with advanced display technology presentation of equivalent information regarding traffic (cockpit display of traffic information) and flight parameters (data link display). Redundant combinations were also examined while pilots flew the aircraft simulation, monitored for outside traffic, and read back communications messages. The data suggested a modest cost for visual presentation over auditory presentation, a cost mediated by head-down visual scanning, and no benefit for redundant presentation. The effects in Part 1 were modeled by multiple-resource and preemption models of divided attention. In the second part of the research, visual scanning in all conditions was fit by an expected value model of selective attention derived from a previous experiment. This model accounted for 94% of the variance in the scanning data and 90% of the variance in a second validation experiment. Actual or potential applications of this research include guidance on choosing the appropriate modality for presenting in-cockpit information and understanding task strategies induced by introducing new aviation technology.
Operator Functional State Classification Using Multiple Psychophysiological Features in an Air Traffic Control Task
Authors: Wilson Glenn F. , Russell Chris A.
Published: March 2004

We studied 2 classifiers to determine their ability to discriminate among 4 levels of mental workload during a simulated air traffic control task using psychophysiological measures. Data from 7 air traffic controllers were used to train and test artificial neural network and stepwise discriminant classifiers. Very high levels of classification accuracy were achieved by both classifiers. When the 2 task difficulty manipulations were tested separately, the percentage correct classifications were between 84% and 88%. Feature reduction using saliency analysis for the artificial neural networks resulted in a mean of 90% correct classification accuracy. Considering the data as a 2-class problem, acceptable load versus overload, resulted in almost perfect classification accuracies, with mean percentage correct of 98%. In applied situations, the most important distinction among operator functional states would be to detect mental overload situations. These results suggest that psychophysiological data are capable of such discriminations with high levels of accuracy. Potential applications of this research include test and evaluation of new and modified systems and adaptive aiding.
Head Up versus Head Down: The Costs of Imprecision, Unreliability, and Visual Clutter on Cue Effectiveness for Display Signaling
Authors: Yeh Michelle , Merlo James L. , Wickens Christopher D. , Brandenburg David L.
Published: March 2004

We conducted 2 experiments to investigate the clutter-scan trade-off between the cost of increasing clutter by overlaying complex information onto the forward field of view using a helmet-mounted display (HMD) and the cost of scanning when presenting this information on a handheld display. In the first experiment, this tradeoff was examined in terms of the spatial accuracy of target cuing data in a relatively sparse display; in the second, the spatial accuracy of the cue was varied more radically in an information-rich display. Participants were asked to detect and identify targets hidden in the far domain while performing a monitoring task in the near domain using either an HMD or a handheld display. The results revealed that on a sparse display, the reduced scanning from the HMD presentation of cuing outweighed the costs of clutter for cued targets, regardless of cue precision, but no benefit was found for uncued targets. When the HMD displayed task-irrelevant information, however, target detection was hindered by the extraneous clutter in the forward field of view relative to the handheld display condition, and this cost of clutter increased as the amount of data that needed to be inspected increased. Potential applications of this research include the development of design considerations for head-up displays for aviation and military applications.
Comparing Statistical and Machine Learning Classifiers: Alternatives for Predictive Modeling in Human Factors Research
Authors: Carnahan Brian , Meyer Gérard , Kuntz Lois-Ann
Published: March 2004

Multivariate classification models play an increasingly important role in human factors research. In the past, these models have been based primarily on discriminant analysis and logistic regression. Models developed from machine learning research offer the human factors professional a viable alternative to these traditional statistical classification methods. To illustrate this point, two machine learning approaches - genetic programming and decision tree induction - were used to construct classification models designed to predict whether or not a student truck driver would pass his or her commercial driver license (CDL) examination. The models were developed and validated using the curriculum scores and CDL exam performances of 37 student truck drivers who had completed a 320-hr driver training course. Results indicated that the machine learning classification models were superior to discriminant analysis and logistic regression in terms of predictive accuracy. Actual or potential applications of this research include the creation of models that more accurately predict human performance outcomes.
Spatial Orientation in 3-D Desktop Displays: Using Rooms for Organizing Information
Authors: Colle Herbert A. , Reid Gary B.
Published: March 2004

Understanding how spatial knowledge is acquired is important for spatial navigation and for improving the design of 3-D perspective interfaces. Configural spatial knowledge of object locations inside rooms is learned rapidly and easily (Colle & Reid, 1998), possibly because rooms afford local viewing in which objects are directly viewed or, alternatively, because of their structural features. The local viewing hypothesis predicts that the layout of objects outside of rooms also should be rapidly acquired when walls are removed and rooms are sufficiently close that participants can directly view and identify objects. It was evaluated using pointing and sketch map measures of configural knowledge with and without walls by varying distance, lighting levels, and observation instructions. Although within-room spatial knowledge was uniformly good, local viewing was not sufficient for improving spatial knowledge of objects in different rooms. Implications for navigation and 3-D interface design are discussed. Actual or potential applications of this research include the design of user interfaces, especially interfaces with 3-D displays.
Effects of Deliberate Practice on Crisis Decision Performance
Authors: McKinney Earl H. , Davis Kevin J.
Published: March 2004

This study examined the impact of deliberate practice on pilot decision making in once-in-a-career crisis decision scenarios. First we explored the impact of deliberate practice on pilot decision-making performance for crisis flying scenarios that had been practiced in their entirety. Then we looked at the impact of deliberate practice in which one aspect of the crisis scenario - the particular malfunction - was unpracticed. We analyzed pilot decision-making performance in response to 160 airborne mechanical malfunctions. We initially found that deliberate practice significantly improves decision-making performance for wholly practiced crises but does not improve decision-making performance when the specific malfunction has not been practiced. We then split decision making for each crisis into two phases: assessment and action selection. For wholly practiced crisis scenarios, additional deliberate practice positively impacts each decision-making phase. However, for part-practiced scenarios, deliberate practice appears to differentially affect phase of error. Specifically, pilots with more deliberate practice erred in action selection, whereas less-practiced pilots erred in assessment. Actual or potential applications of this research include training proscriptions for crisis decision making.
Determining the Effectiveness of the Usability Problem Inspector: A Theory-Based Model and Tool for Finding Usability Problems
Authors: Andre Terence S. , Hartson H. Rex , Williges Robert C.
Published: March 2004

Despite the increased focus on usability and on the processes and methods used to increase usability, a substantial amount of software is unusable and poorly designed. Much of this is attributable to the lack of cost-effective usability evaluation tools that provide an interaction-based framework for identifying problems. We developed the user action framework and a corresponding evaluation tool, the usability problem inspector (UPI), to help organize usability concepts and issues into a knowledge base. We conducted a comprehensive comparison study to determine if our theory-based framework and tool could be effectively used to find important usability problems in an interface design, relative to two other established inspection methods (heuristic evaluation and cognitive walkthrough). Results showed that the UPI scored higher than heuristic evaluation in terms of thoroughness, validity, and effectiveness and was consistent with cognitive walkthrough for these same measures. We also discuss other potential advantages of the UPI over heuristic evaluation and cognitive walkthrough when applied in practice. Potential applications of this work include a cost-effective alternative or supplement to lab-based formative usability evaluation during any stage of development.
The Impact of Mental Fatigue on Exploration in a Complex Computer Task: Rigidity and Loss of Systematic Strategies
Authors: van der Linden Dimitri , Frese Michael , Sonnentag Sabine
Published: March 2004

We investigated the impact of mental fatigue on exploration in a complex computer task. The exploration behavior of participants who underwent a fatigue manipulation (N = 36) was compared with that of a control (nonfatigued) group (N = 32). A distinction was also made between participants with high or low levels of general computer experience. Results showed that fatigued participants used significantly less systematic exploration and made more errors than did nonfatigued participants. Fatigued participants with low computer experience also showed significantly more rigid behavior than did the other participants. No differences were found on the number of subtasks solved. Compared with low-experience participants, highly experienced participants showed significantly more systematic exploration, less unsystematic trial and error, solved more subtasks, and made fewer errors (marginally significant p = .056). Findings were interpreted as the result of reduced task engagement under fatigue and reduced involvement of executive control on behavior. Actual or potential applications of this research include guidelines to prevent detrimental effects of mental fatigue on exploration behavior.
Traffic Signal Color Recognition Is a Problem for Both Protan and Deutan Color-Vision Deficients
Authors: Atchison David A. , Pedersen Carol A. , Dain Stephen J. , Wood Joanne M.
Published: March 2004

We investigated the effect of color-vision deficiency on reaction times and accuracy of identification of traffic light signals. Participants were 20 color-normal and 49 color-deficient males, the latter divided into subgroups of different severity and type. Participants performed a tracking task. At random intervals, stimuli simulating standard traffic light signals were presented against a white background at 5° to right or left. Participants identified stimulus color (red/yellow/green) by pressing an appropriate response button. Mean response times for color normals were 525, 410, and 450 ms for red, yellow, and green lights, respectively. For color deficients, response times to red lights increased with increase in severity of color deficiency, with deutans performing worse than protans of similar severity: response times of deuteranopes and protanopes were 53% and 35% longer than those of color normals. A similar pattern occurred for yellow lights, with deuteranopes and protanopes having increased response times of 85% and 53%, respectively. For green lights, response times of all groups were similar. Error rates showed patterns similar to those of response times. Contrary to previous studies, deutans performed much worse than protans of similar severity. Actual or potential applications of this research include traffic signal design and driver licensing.
What to Expect from Immersive Virtual Environment Exposure: Influences of Gender, Body Mass Index, and Past Experience
Authors: Stanney Kay M. , Hale Kelly S. , Nahmens Isabelina , Kennedy Robert S.
Published: March 2004

For those interested in using head-coupled PC-based immersive virtual environment (VE) technology to train, entertain, or inform, it is essential to understand the effects this technology has on its users. This study investigated potential adverse effects, including the sickness associated with exposure and extreme responses (emesis, flashbacks). Participants were exposed to a VE for 15 to 60 min, with either complete or streamlined navigational control and simple or complex scenes, after which time measures of sickness were obtained. More than 80% of participants experienced nausea, oculomotor disturbances, and/or disorientation, with disorientation potentially lasting >24 hr. Of the participants, 12.9% prematurely ended their exposure because of adverse effects; of these, 9.2% experienced an emetic response, whereas only 1.2% of all participants experienced emesis. The results indicate that designers may be able to reduce these rates by limiting exposure duration and reducing the degrees of freedom of the user's navigational control. Results from gender, body mass, and past experience comparisons indicated it may be possible to identify those who will experience adverse effects attributable to exposure and warn such individuals. Applications for this research include military, entertainment, and any other interactive systems for which designers seek to avoid adverse effects associated with exposure.
Adult education in the urban context
Authors: Martin Larry G.
Published: March 2004

Context is vitally important for urban adult education because it tends to create physical, psychological, and
sociocultural distance between and among learners and various providers of adult and continuing education
programs, thereby creating barriers and the differential provision of adult learning opportunities for some urban
populations.
Discriminative justice: Can discrimination be just?
Authors: Rocco Tonette S. , Gallagher Suzanne J.
Published: March 2004

Educators of urban adults should attempt to deconstruct the dynamics in the classroom that replicate the
social, political, and economic discourse of the dominant group. We must work to surface the complexity of diverse
experiences represented by multiple oppressed groups.
Learning to rejuvenate metropolitan communities
Authors: Isaac E. Paulette , Tempesta Martha Strittmatter
Published: March 2004

Responsive community programming assists urban learners in revitalizing their communities. This chapter examines
two community‐based organizations that are creating positive changes in local neighborhoods with collaborated
strategies for the delivery of educational programming.
Narrowing the digital divide in low‐income, urban communities
Authors: Norris Daniel T. , Conceição Simone
Published: March 2004

The digital divide is leaving millions disenfranchised from the opportunity to use technology to change
their lives and to participate fully in democracy, in their own communities, and in today's job
market.
Transformative learning and the urban context
Authors: Kappel Patricia Leong , Daley Barbara J.
Published: March 2004

The urban context generates a barrage of disorienting dilemmas for urban learners, thereby complicating and
challenging the promotion of transformative learning.
HEAVY METALS AND ADSORBENTS EFFECTS ON ACTIVATED SLUDGE MICROORGANISMS
Authors: Ong S.A. , Lim P.E. , Seng C.E.
Published: March 2004

The sorption of Cu(II) and Cd(II) from synthetic solution by powdered activated carbon (PAC), biomass, rice husk (RH) and activated rice husk (ARH) were investigate under batch conditions. After activated by concentrated nitric acid for 15 hours at 60‐65 °C, the adsorption capacity for RH was increased. The adsorbents arranged in the increasing order of adsorption capacities to the Langmuir Q° parameter were biomass > PAC > ARH > RH. The addition of adsorbents in base mix solution had increased the specific oxygen uptake rate (SOUR) activated sludge microorganisms with and without the presence of metals. The increased of SOUR were due to the ability of PAC and RH in reducing the inhibitory effect of metals on microorganisms and provide a reaction site between activated sludge microorganisms and substrates.
IMPROVING THE ANALYTICAL PERFORMANCES OF INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROMETRY BY MULTIVARIATE ANALYSIS TECHNIQUES
Authors: Grotti Marco
Published: March 2004

The various multivariate analysis techniques which have been successfully applied to maximize the analytical performances of ICP‐OES are reviewed. These include optimization procedures, spectral data processing and calibration methods as well as classification and pattern recognition techniques.
Gas‐liquid displacement method for estimating membrane pore‐size distributions
Authors: Shao P. , Huang R. Y. M. , Feng X. , Anderson W.
Published: March 2004

A gas‐liquid displacement method is investigated for characterizing pore‐size distributions of microfiltration (MF) membranes. The complexities of using gas as displacing fluid are analyzed in terms of the gas transport regimes involved, showing that slip flow features gas transport in MF membranes, and Knudsen diffusion can be effectively suppressed by an appropriate selection of the pore‐filling liquid. A universal mathematical model for evaluating pore‐size distributions is developed based on the fundamental equation governing slip flow. An approximate model is also presented where only the Hagen‐Poiseuille regime is considered. The pore‐size distributions of two MF membranes are evaluated using the universal and the approximate models, respectively. It is found that the approximate model overestimates the probability of the larger pore (relative to the peak pore) and underestimates the probability of the smaller pore. It is recommended that the universal model be used if no priori analyses on gas transport regimes is carried out. 2004 American Institute of Chemical Engineers AIChE J, 50:557–565, 2004)
Experimentally‐validated micromixing‐based CFD model for fed‐batch stirred‐tank reactors
Authors: Akiti Otute , Armenante Piero M.
Published: March 2004

A model was developed to predict the final product distribution in fed‐batch, stirred‐tank reactors carrying out fast, parallel, chemical reactions, and the predictions were compared with experimental data. The following reaction system was chosen:

equation image

Comparison between the experimentally determined flow field inside the reactor, obtained with a laser‐doppler velocimeter (LDV), and the predictions from computational fluid dynamics (CFD) simulations was favorable. A model was developed to predict the yield, XS, of forming S from A, using CFD to describe the velocity distribution inside the reactor, two micromixing models to represent the interaction between turbulence effects and chemical reactions, and a multiphase model (Volume of Fluid (VOF) model) to track the reacting zone in a Lagrangian fashion. Model predictions for XS were compared with experimental data. The agreement between the experiments and the results of the simulations was good. © 2004 American Institute of Chemical Engineers AIChE J, 50:566–577, 2004
Carbon membranes for high temperature gas separations: Experiment and theory
Authors: Sznejer Gabriel A. , Efremenko Irena , Sheintuch Moshe
Published: March 2004

The transport and separation of hydrogen and light alkanes are studied in a molecular‐sieve carbon membrane hollow‐fiber module at the temperature range of 25–400°C; nitrogen is used as a sweeping gas in the study of mixtures, and the fluxes of pure components are studied under a pressure gradient. The membrane selectivity, the ratio of hydrogen to hydrocarbon permeabilities, may reach 100 to 1,000 in propane, or in (normal or iso‐) butane mixtures with hydrogen, making the membrane an excellent candidate for a membrane dehydrogenation reactor. The permeabilities measured in pure‐component studies differ from those in mixtures. Specifically, counterdiffusion of nitrogen and C2 to C4 alkanes significantly inhibits the fluxes of both, whereas the hydrogen flux is only slightly diminished. To account for these results, molecular mechanics simulations are used to find the energetics of adsorption, diffusion, and desorption of individual gases in cylindrical nanopores modeled by carbon nanotubes. In pore sizes that are up to 2–3 times the dimension of the molecule, diffusion of the molecule inside the pore is nonactivated, whereas desorption is activated and typically is the rate limiting step; the molecular transport proceeds essentially by the single‐file diffusion mechanism. A rate expression for a single‐species transport in a molecular‐sieve carbon membrane is derived by a mean‐field approach. The pore‐size distribution calculated by comparing experimental and computed fluxes favorably compares with the measured distribution. © 2004 American Institute of Chemical Engineers AIChE J, 50: 596–610, 2004
New approach to refinery process simulation with adaptive composition representation
Authors: Briesen Heiko , Marquardt Wolfgang
Published: March 2004

The established technique for simulation of refinery processes is the use of pseudocomponents. However, in order to increase the economical benefit of plant operation, it seems inevitable to include molecular information in petroleum mixtures characterization. This will lead to a strong increase of problem size. For this new class of models, there currently seems to be no special algorithms available. The classic pseudocomponent approach is compared with a newly developed solution strategy, which is explicitly developed to efficiently solve simulation problems with a high detail in composition representation. The new solution strategy is an adaptive multigrid method based on a wavelet–Galerkin discretization. With the wavelet–Galerkin discretization the model can easily be formulated on various levels of detail. In an iterative procedure the multigrid concept exploits these different formulations to construct correction‐term approximations to the true solution. The discretization of these correction‐term models is now done with a detail in composition representation that is determined by a residual‐based adaptation strategy. The proposed method has been implemented for a simple 9‐stage distillation column and tested for a variety of feed mixtures. In all investigated tests the proposed method proved to be superior to the conventional pseudocomponent approach in terms of accuracy and efficiency. © 2004 American Institute of Chemical Engineers AIChE J, 50: 633–645, 2004
Control of reversible reactions in supercritical water: I. alkylations
Authors: Sato Takafumi , Sekiguchi Gaku , Adschiri Tadafumi , Arai Kunio
Published: March 2004

The reaction rates of alkylation of phenol and that of dealkylation of alkylphenol were evaluated in sub‐ and supercritical water. Dehydration of 2‐propanol gave propene, and then alkylation with phenol, which produced 2‐isopropylphenol. Then 2‐propylphenol was formed by rearrangement of 2‐isopropylphenol. The alkylation rate was higher than the dealkylation rate, as water density increased and temperature decreased at 613–713 K and 0.3–0.6 g/cm3 of water density. At around 673 K, the order of magnitude of the alkylation and dealkylation rates reversed and become sensitive to the system temperature and density. These results demonstrate some of the specific features of supercritical water: the reaction rate of both forward and reverse reactions, such as alkylation and dealkylations, can be controlled through manipulation of temperature and density (pressure). © 2004 American Institute of Chemical Engineers AIChE J, 50: 665–672, 2004
Skin‐layer formation on porous membrane by immobilized dextransucrase
Authors: Kawakita Hidetaka , Saito Kyoichi , Sugita Kazuyuki , Tamada Masao , Sugo Takanobu , Kawamoto Hiroshi
Published: March 2004

A porous hollow‐fiber membrane with an average pore diameter of 360 nm and a porosity of 71% was used as a starting polymer. An epoxy‐group‐containing monomer, glycidyl methacrylate, was grafted onto the porous hollow‐fiber membrane by radiation‐induced graft polymerization. The produced epoxy group was quantitatively converted into a 2‐hydroxyethylamino group as an anion‐exchange group by reaction with ethanolamine. Dextransucrase solution was forced to permeate radially outward through the pore from the inside surface of the porous hollow‐fiber membrane to be immobilized by the grafted polymer chains based on an anion‐exchange interaction. Subsequently, sucrose solution as substrate was fed to the inside surface of the dextransucrase‐immobilized porous hollow‐fiber membrane. Dextran produced by the enzymatic reaction formed a skin layer on the inside surface of the membrane with a thickness of approximately 4 μm and an estimated pore diameter of 50 nm. © 2004 American Institute of Chemical Engineers AIChE J, 50: 696–700, 2004
Using “prosurfactants” to enhance rates of delivery of surfactants
Authors: Rosslee Craig A. , Khripin Constantine , Foley Theresa M. D. , Abbott Nicholas L.
Published: March 2004

A strategy for accelerating the rate of transport of surfactant within a system by delivering the surfactant as a precursor to the surface‐active state (“prosurfactant”) and subsequently transforming it to a functional form (surfactant) is reported. An increase in the overall rate of transport of a redox‐active surfactant across a polycarbonate membrane containing pores with a diameter of 10 nm is demonstrated. This redox‐active molecule, which is molecularly dispersed in aqueous solutions in its oxidized state (prosurfactant), but assembles into globular micellar aggregates (Rh = 5 nm) in its reduced state (surfactant), was rapidly transported across the membrane in its oxidized state to a concentration of 0.2 mM. Subsequent delivery of ascorbic acid (a reducing agent) by diffusion through the same membrane led to reduction of the oxidized precursor and formation of surfactant and micelles. The sequential delivery of the prosurfactant and then transforming agent resulted in a greater than sixfold increase in the overall rate of delivery of surfactant as compared to a procedure in which the surfactant was diffused across the membrane. These observations are compared to calculations based on hindered diffusion through cylindrical pores. © 2004 American Institute of Chemical Engineers AIChE J, 50: 708–714, 2004
Microwaves in soil remediation from VOCs. 2. Buildup of a dedicated device
Authors: Acierno Domenico , Barba Anna A. , d'Amore Matteo , Pinto Innocenzo M. , Fiumara Vincenzo
Published: March 2004

This work presents the design of a microwave opened applicator useful to perform the Microwave Induced Steam Distillation (MISD) process for soil remediation treatments. The prototype has been also realized and used to irradiate a 40 x 30 cm area with a given electromagnetic field distribution. Experiments carried out by in situ operations on a soil contaminated with VOC's are reported. Finally, the experimental data collected are described by a mathematical model previously proposed. © 2004 American Institute of Chemical Engineers AIChE J, 50:722–732, 2004
The Workers' Compensation System: Worker friend or foe?
Authors: Strunin Lee , Boden Leslie I.
Published: March 2004

Background

The workers' compensation system was designed to help injured workers who have substantial medical expenses and perhaps have lost a great deal of income. This study determines both similarities and differences in how workers experience their interactions with the workers' compensation systems in Florida and Wisconsin.

Methods

Ethnographic open‐ended interviews with 204 workers from Florida and 198 workers in Wisconsin were conducted. All the workers had back injuries in 1990 and were either paid workers' compensation temporary disability benefits for at least 4 weeks or received permanent disability benefits or compromise settlements.

Results

Some interactions with the workers' compensation system were positive. However, the majority of respondents in both states experienced their encounters with the workers' compensation system as cumbersome, frustrating, and demeaning.

Conclusions

Mistrust, stigmatization, payment delays, and refusal of insurer personnel to pay benefits contribute to workers' negative experiences with the workers' compensation system. These insurer behaviors raise the costs to injured workers of workers' compensation benefits and thus may reduce the propensity of eligible workers to apply for benefits. Am. J. Ind. Med. 45:338–345, 2004. © 2004 Wiley‐Liss, Inc.
Unilateral linear hyperpigmentation of the skin with ipsilateral sectorial hyperpigmentation of the retina
Authors: Meyer Carsten H. , Freyschmidt‐Paul Pia , Happle Rudolf , Kroll Peter
Published: March 2004

A 32‐year‐old Caucasian man had a mosaic hyperpigmentation on his left arm, arranged in a pattern following the lines of Blaschko. In addition, a mosaic hyperpigmentation was noted in his left eye, in the form of grouped congenital hypertrophy of the retinal pigment epithelium (CHRPE). Such “bear tracks” are segmentally oriented, well‐demarcated, flat, hyperpigmented lesions originating with small dots at the optic disk and expanding towards the periphery. We hypothesize that these mosaic pigmentary lesions involving the skin and the eye on the same side of the body may have originated from an early postzygotic mutation and thus may be etiologically related. © 2003 Wiley‐Liss, Inc.
Preimplantation genetic diagnosis of human congenital heart malformation and Holt–Oram syndrome
Authors: He Jie , McDermott Deborah A. , Song Yan , Gilbert Fred , Kligman Isaac , Basson Craig T.
Published: March 2004

Holt–Oram syndrome (HOS) is a multiple malformation syndrome associated with congenital heart malformation (CHM) and caused by mutations in the TBX5 transcription factor. Effective prenatal genetic diagnosis of HOS is limited by factors that modify clinical manifestations and confound prediction of an individual's phenotype. Although preimplantation genetic diagnosis (PGD) has been applied to complex disorders with some cardiovascular manifestations, its utility in Mendelian CHM has not been previously demonstrated. We tested whether PGD and in vitro fertilization (IVF) technology, including oocyte donation, can identify fertilized eggs affected by HOS for potential embryo selection. Five donor oocytes were fertilized in vitro with sperm from a HOS patient heterozygous for a Glu69ter‐TBX5 mutation and then underwent embryo biopsy and genotyping. One carried the Glu69ter‐TBX5 mutation; all others had wildtype genotypes. Two wildtype blastocysts were transferred to the mother, and the resulting singleton pregnancy was successfully delivered. Mutational analysis of fetal amniocytes and postpartum umbilical cord blood confirmed PGD. Fetal ultrasonography as well as postpartum electrocardiography and echocardiography also validated accurate prediction of normal skeletal and cardiac phenotypes. We conclude that PGD is an effective reproductive strategy for HOS patients. As more genetic etiologies for CHM are identified, application of PGD as adjunctive therapy to IVF will be increasingly available to prevent transmission of such diseases from affected parents to their children. Clinical application of PGD must balance the benefits of avoiding disease transmission with the medical risks and financial burdens of IVF. © 2003 Wiley‐Liss, Inc.
Mosaicism of a TCOF1 mutation in an individual clinically unaffected with treacher collins syndrome
Authors: Shoo Brenda A. , McPherson Elizabeth , Jabs Ethylin Wang
Published: March 2004

Treacher Collins syndrome (TCS) or mandibulofacial dysostosis is an autosomal dominant disorder of craniofacial development with 60% of its cases arising de novo. Other modes of inheritance such as autosomal recessive, gonadal mosaicism, and chromosomal rearrangement have also been proposed. This syndrome can result from TCOF1 gene mutations. In this study we identified a TCOF1 1408delAG heterozygous mutation in a patient with the clinical diagnosis of TCS. This same mutation was found in the clinically unaffected mother's leukocytes, hair root bulbs, buccal mucosa, urine, and stool. The mother has a clinically unaffected child and the maternal grandparents do not have the mutation. Because the mother has the mutation in cells derived from all three germ layers, we suspected the mutation was nonpenetrant. However, we could not detect the mutation in her skin fibroblasts, suggesting she is mosaic secondary to cell type specific selection. © 2003 Wiley‐Liss, Inc.
Recurrence risk of preeclampsia in twin and singleton pregnancies
Authors: Trogstad Lill , Skrondal Anders , Stoltenberg Camilla , Magnus Per , Nesheim Britt‐Ingjerd , Eskild Anne
Published: March 2004

The etiology of preeclampsia is unknown. The relatively high risk of recurrence of preeclampsia in subsequent pregnancies to the same mother suggests a genetic basis for the disease, but the mode of inheritance is uncertain. We compare the risk of preeclampsia in second pregnancies for mothers whose first preeclamptic pregnancy was either a singleton or a twin pregnancy. The crude and adjusted recurrence risks of preeclampsia in twin and singleton pregnancies were estimated in a population‐based register including the first and second pregnancies of 550,218 women registered in the Medical Birth Registry of Norway, 1967–1998. The recurrence risk of preeclampsia in second pregnancy for women with a singleton pregnancy with preeclampsia the first time was 14.1% (95% CI: 13.6–14.6). For women with a first time twin pregnancy the recurrence risk was lower, 6.8% (CI: 4.3–10.1), P < 0.001. Thus, the crude excess risk for recurrent preeclampsia was 7.3% (95% CI: 4.5–10.0) in women with a first time singleton as compared to women with a first time twin pregnancy. The recurrence risk of preeclampsia is lower when the first pregnancy was a twin as compared to a singleton pregnancy. This observation is consistent with a polygenic liability model. © 2003 Wiley‐Liss, Inc.
Macrocephaly‐cutis marmorata telangiectatica congenita: Seven cases including two with unusual cerebral manifestations
Authors: Giuliano Fabienne , David Albert , Edery Patrick , Sigaudy Sabine , Bonneau Dominique , Cormier‐Daire Valérie , Philip Nicole
Published: March 2004

Macrocephaly‐cutis marmorata telangiectatica congenita (M‐CMTC) is a recently described multiple congenital anomaly/mental retardation (MCA/MR) syndrome of unknown cause. This condition is easily recognizable at birth in children with macrocephaly, cutis marmorata, face and/or body segmental overgrowth, toe syndactyly, midface capillary malformation, and hemimegalencephaly. Cutis marmorata may be absent in some cases. Most patients are developmentally delayed. We describe seven new patients, including two with unusual cerebral manifestations and severe outcome. One of two had a complex congenital heart defect (CHD) and died in the neonatal period. Brain magnetic resonance imaging (MRI) showed generalized cortical dysplasia. The other patient had a stroke episode at age 14 years. Cerebral arteriography showed an abnormal vascular pattern. These findings are consistent with the fact that M‐CMTC is a generalized vasculopathy. © 2003 Wiley‐Liss, Inc.
A novel type of autosomal recessive syndactyly: Clinical and molecular studies in a family of Pakistani origin
Authors: Malik Sajid , Arshad Muhammad , Amin‐ud‐Din Muhammad , Oeffner Frank , Dempfle Astrid , Haque Sayedul , Koch Manuela C. , Ahmad Wasim , Grzeschik Karl‐Heinz
Published: March 2004

Non‐syndromic syndactylies have been classified into five major types (I–V), all showing autosomal dominant mode of inheritance. Later, the classification was extended and three additional variants (VI–VIII) were defined. Type VII, the Cenani–Lenz syndactyly, is the only non‐syndromic, autosomal recessive type. It is characterized by fusion of all phalanges with metacarpal synostosis, dislocated and dysplastic carpals and infrequently, radio‐ulnar fusion. Here, we present a Pakistani family with a novel non‐syndromic autosomal recessive syndactyly manifesting a unique combination of clinical features. In both hands, reduction of certain phalanges is evident. Radiological examination shows synostosis of third and fourth metacarpals bearing single phalanges. The first three toes are webbed, with hypoplastic terminal phalanx in all the toes. Besides Cenani–Lenz syndactyly, the phenotype segregating in our family is the second well‐documented autosomal recessive, non‐syndromic syndactyly. A phenotype similar to our family was described in a Turkish kindred but was considered to be a homozygous expression of type I syndactyly. Since the clinical features in our family had minimal overlap with syndactyly types I, II, and III, we have performed microsatellite marker screening to look for the cosegregation of this phenotype with any of the known loci for these respective types. We show that the phenotype in our family is not linked to chromosomal regions 2q34‐q36, 2q31, and 6q22‐q23 encompassing loci for syndactyly types I, II, and III. © 2003 Wiley‐Liss, Inc.
Goethe's bone and the beginnings of morphology
Authors: Opitz John M.
Published: March 2004

Biologyas a discipline per se and its agenda, seems not to have been burdened from its beginnings as heavily with neo‐Platonism as its subspecialtymorphology, conceptualized at the same time by Goethe and Burdach. One of the reasons may have been that biologists were then regarded as “mere” naturalists, “doing” anatomy and embryology, breeding, and field work (as did Darwin, Wallace, Bateson and a legion of others during the 19th century), whereas the, perhaps more elitist, morphologists,ab initiodevoted themselves to the origin, even to the Kantian analysis ofcausesof development and its variability within and between species. Since Goethe included abnormal plant development in his studies, his definition ofmorphology as the science of the form, formation and transformationof living organisms may be modified to include the concept ofmalformation, although the embryological and comparative analysis of vertebrate/mammalian malformation had its real inception somewhat later with the younger Meckel. In view of the meaning attached by his French contemporaries to the termtransformisme(eventually defined as evolution) one would err considering Goethe as a prophet of “descent;” he was not, referring primarily to the continuous state of flux of living beings. Nonetheless, Goethe and Burdach independently coined the concept of morphology and set its agenda, increasingly freed ofNaturphilosophie, an agenda that dominated 19th century biology but which did not come to fruition in its causal analysis of form and its formation until the 20th century, after Mendel, Darwin and the pioneers of experimental embryology (a.o., Roux, Driesch, Spemann, Vogt). In his discovery of the intermaxillary bone in humans (Goethe's bone), he had a startling insight, against conventional wisdom, into the anatomical, hence developmental, similarity of primate/mammals. During his lifetime, this was still calledanalogieby his great French contemporary Etienne Geoffroy St‐Hilaire who actually meant what Owen later called homology which became one of Darwin's most powerful arguments for descent. A case of a pearl found by a blind chicken? Definitely not; Goethe had his nose far too close to the ground to have missed any of the major intellectual trends in the “life‐sciences” in the late 18th/early 19th century; but, he was too much of an amateur to have had the kind of insights of grand plans granted to von Baer, Mendel and Darwin. © 2004 Wiley‐Liss, Inc.
Mutation of SFTPC in infantile pulmonary alveolar proteinosis with or without fibrosing lung disease
Authors: Tredano Mohammed , Griese Matthias , Brasch Frank , Schumacher Silja , Blic Jacques de , Marque Stéphanie , Houdayer Claude , Elion Jacques , Couderc Rémy , Bahuau Michel
Published: March 2004

Pulmonary surfactant protein C (SP‐C) is a highly hydrophobic peptide produced by type‐II alveolar cells through the processing of a high‐molecular weight precursor (pro‐SP‐C), that enhances surface tension and facilitates the recycling of pulmonary surfactant in vitro. Recently, two seemingly dominant‐negative mutations of the pro‐SP‐C‐encoding gene (SFTPC, MIM 178620), were reported in families with vertically‐inherited interstitial lung disease (Nogee et al. [2001: N Engl J Med 344:573–579]; Thomas et al. [2002: Am J Respir Crit Care Med 165:1322–1328]). We have examined the SP‐C protein and its precursor as well as the encoding gene, in a cohort of 34 sporadic or familial cases with unexplained respiratory distress (URD) in which surfactant protein B (SP‐B) deficiency related to SFTPB mutation had been ruled out. One patient with complete SP‐C deficiency had no detectable mutation of SFTPC. Of the 10 patients with abnormal pro‐SP‐C processing, as suggested from analysis of broncho‐alveolar lavage (BAL) fluid, two distinct heterozygous SFTPC missense mutations were identified. The first, g.1286T > C (p.I73T), was de novo and resulted in progressive respiratory failure with intra‐alveolar storage of a granular, protein‐ and lipid‐rich, periodic acid Schiff (PAS)‐positive material (pulmonary alveolar proteinosis (PAP)), and interstitial lung disease. The second, g.2125G > A (p.R167Q), was found in two PAP patients from the endogamous white settler population of Réunion Island in which URD has an unexpectedly high prevalence. Since this mutation was diagnosed in subjects from this subpopulation who did not have evidence for lung disease, we propose environmental exposures or modifier genes to play a role in the phenotype, as suggested from murine models lacking the SP‐C protein, although we cannot rule out a rare polymorphism, hitherto restricted to that subpopulation. Most remarkably, these observations extend the phenotypic spectrum related to SFTPC mutation from interstitial lung disease to PAP. Notably, the reported mutations do not appear to be dominant negatives. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148‐7299/suppmat/index.html. © 2004 Wiley‐Liss, Inc.