bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the order of odds ratios using the bootstrap
Authors: Schwartzbaum Judith A. , Hirschberg Joseph G.
Published: April 2007

We show the use of the bootstrap resampling method to examine further the order of a series of odds ratios. Specifically, the bootstrap provides a method for estimating the probabilities that one would find in subsequent independent samples from the same population the observed odds ratio rankings. To illustrate this use of the bootstrap, we modelled the responses of 77 white male physicians to an ethical dilemma involving hypothetical patients. Would the physician report positive HIV status to the health department or would he maintain patient confidentiality? To see if a patient's sex, race, or sexual preference would influence the physicians' decisions, each physician received one of eight randomly selected descriptions of a hypothetical patient. To evaluate the initial order of the patient categories, we constructed 1000 bootstrap samples. Black heterosexual males ranked first or second in 92.2 per cent of the bootstrap samples; black homosexual males ranked first, second or third in 88.6 per cent; and white homosexual females ranked sixth or seventh in 82.9 per cent. Thus we would expect to observe these rankings of the categories in a high percentage of subsequent independent samples.
Effect of regression to the mean in the presence of within‐subject variability
Authors: Johnson William D. , George Varghese T.
Published: April 2007

Regression to the mean arises often in statistical applications where the units chosen for study relate to some observed characteristic in the extreme of its distribution. Gardner and Heady attribute the effect of regression to the mean to measurement errors. They assume the modelYi = U + ei, where U is a fixed within‐subject component and ei is the random measurement error. They suggest several replicate measurements to reduce the regression effect under the assumption that the measurement errors ei are independent within subjects. While measurement errors play an important role in regression to the mean, one should not overlook within‐subject variation. In this paper, we consider a model to estimate the regression effect in the presence of correlated within‐subject effects as well as independent measurement errors.
Detection of outlying data in bioavailability/bioequivalence studies
Authors: Liu Jen‐Pei , Weng Chung‐Sing
Published: April 2007

This paper considers the problem of detecting outlying data in bioavailability/bioequivalence studies. We define outlying subjects as those whose responses in bioavailability to all formulations differ from the rest of the subjects. We also define an outlying observation as the response in bioavailability of a subject to a particular formulation which is grossly different from the average bioavailability of that formulation calculated from all subjects. We propose two test procedures. The first, based on two‐sample Hotelling T2, is to detect possible outlying subjects. The second, based on residuals from formulation means, is to identify possible outlying observations within subjects. Both procedures take into account the covariance structure of the responses to formulations, dependence of test statistics, and multiplicity of test procedures. We apply the Monte Carlo or bootstrap simulation to evaluate the sampling distributions of test statistics. An example from a 3‐way crossover bioequivalence study illustrates the two procedures.
Stochastic methods for short term projections of symptomatic HIV disease
Authors: Mode Charles J. , Fife Daniel , Troy Steven M.
Published: April 2007

We designed and implemented stochastic methods for short term projections of HIV disease at the local level, that accommodate various states or stages of the disease. We gave particular attention to projection of the number of patients with HIV disease who need care, when durations of stay in these various states depend on current methods for treating opportunistic infections. We consider two types of data as input to these projections. One concerns seroprevalence surveys conducted over time and from which we can obtain time series estimates of the numbers of HIV‐infected individuals. The other is a reported time series of AIDS cases adjusted for delays in reporting. Several projections, with data from the City of Philadelphia, illustrate this method. In addition, we consider a Monte Carlo method for computing confidence bounds on a projection.
Estimation of variance components for censored data with applications to blood pressure variability
Authors: Smith L. , Rosner B.
Published: April 2007

Ideally, the basis for estimation of variance components is large random samples selected from a well‐defined reference population. Some large biomedical studies, however, consist of a random sample (S) of individuals ascertained at an initial visit, with a selected subsample from S seen on one or more follow‐up visits. In this setting, the usual formulae for estimation of variance components are problematic since they do not take into account the censored nature of the data. For this purpose, we consider both maximum likelihood and moments estimation methods that take the censoring into account, and we compare their performance, in terms of bias and mean squared error, with that of the usual variance components estimators that ignore censoring. We find the maximum likelihood estimators somewhat more efficient than method of moments estimators, provided that the assumption of multivariate normality is met; furthermore, these estimators are substantially more efficient than those that ignore the censoring. It is important to record data on all individuals, even those who do not meet screening criteria; one can estimate between‐ and within‐person variance more accurately with use of all available data. The resulting estimates are crucial in calculation of power for the design of future studies.
A method of non‐parametric back‐projection and its application to aids data
Authors: Becker Niels G. , Watson Lyndsey F. , Carlin John B.
Published: April 2007

The method of back‐projection has been used to estimate the unobserved past incidence of infection with the human immunodeficiency virus (HIV) and to obtain projections of future AIDS incidence. Here a new approach to back‐projection, which avoids parametric assumptions about the form of the HIV infection intensity, is described. This approach gives the data greater opportunity to determine the shape of the estimated intensity function. The method is based on a modification of an EM algorithm for maximum likelihood estimation that incorporates smoothing of the estimated parameters. It is easy to implement on a computer because the computations are based on explicit formulae. The method is illustrated with applications to AIDS data from Australia, U.S.A. and Japanese haemophiliacs.
Falsificationism and clinical trials
Authors: Senn S. J.
Published: April 2007

The relevance of the philosophy of Sir Karl Popper to the planning, conduct and analysis of clinical trials is examined. It is shown that blinding and randomization can only be regarded as valuable for the purpose of refuting universal hypotheses. The purpose of inclusion criteria is also examined. It is concluded that a misplaced belief in induction is responsible for many false notions regarding clinical trials.
Calculating centile curves using kernel density estimation methods with application to infant kidney lengths
Authors: Rossiter J. E.
Published: April 2007

Observing a clinical measurement for an individual is of little value, unless it can be compared with measurements obtained from a healthy population, thought of as standard. The range of measurements observed will, in general, vary with age or some function of time. The usual approach is to assume a distributional form for the population density, but this is inappropriate for variables which do not follow a simple distribution. A method of estimating the centiles of a conditional distribution using multidimensional kernel density estimation, to allow conditioning on the value of one or more covariates, is proposed. By careful choice of the kernel used, the percentiles may easily be calculated using a Newton‐Raphson procedure. The method is illustrated using kidney lengths and birthweights of a sample of newborn infants.
Comparative efficiency of a survival‐based case‐control design and a random selection cohort design
Authors: Commenges Daniel , Moreau Thierry
Published: April 2007

Ambidirectional studies are useful when information about disease status is available on a cohort but a risk factor has still to be recorded. An example is the study of the influence of HLA phenotypes on the progression of HIV carriers towards AIDS. An ambidirectional design is proposed in which the cases and controls are defined by the survival duration of the subjects; it includes as special cases some other ambidirectional designs. Its efficiency is compared with that of a random selection cohort design both analytically and by computer simulation. It is shown that when the size of the cohort is large, appreciable gains in power can be achieved by this type of design even when there is no censoring.
The unseen sample in cohort studies: Estimation of its size and effect
Authors: Hoover D. R. , Muñoz A. , Carey V. , Odaka N. , Taylor J. M. G. , Chmiel J. S. , Armstrong J. , Vermund S. H.
Published: April 2007

Recruitment of disease‐free subjects into cohort studies and measurement of their time from exposure/infection to disease selectively excludes individuals (the unseen sample) who had earlier exposure and who have shorter times to disease. The unseen and observed samples may differ in other characteristics in addition to incubation period and exposure/infection time. For data with known truncation times, we develop non‐parametric maximum likelihood estimates of the size, exposure/infection dates and distribution of incubation time in the unseen sample. We provide procedures to estimate and compensate for the biasing effects due to exclusion of the unseen sample in descriptive and survival analysis. We give consistency properties of these estimates and assess variability using bootstrap methods. One can use imputation to derive the above estimates from data with unknown truncation times that have been estimated parametrically. Application is made to an AIDS cohort study of over 5000 homosexual men. Important estimates obtained from this application are the annual seroconversion rates from 1978 to 1983, not otherwise obtainable in this study population.
Collinearity diagnosis for a relative risk regression analysis: An application to assessment of diet‐cancer relationship in epidemiological studies
Authors: Wax Yohanan
Published: April 2007

In epidemiologic studies, two forms of collinear relationships between the intake of major nutrients, high correlations, and the relative homogeneity of the diet, can yield unstable and not easily interpreted regression estimates for the effect of diet on disease risk. This paper presents tools for assessing the magnitude and source of the corresponding collinear relationships among the estimated coefficients for relative risk regression models. I show how to extend three tools (condition indices, variance decomposition proportions, and standard inflation factors) for diagnosing collinearity in standard regression models to likelihood and partial likelihood estimation for logistic and proportional hazards models. This extension is based on the analogue role of the information matrix in such analyses and the cross‐product matrix in the standard linear model. I apply the methodology to relative risk models that relate crude intakes (on the log scale) and nutrient densities to breast cancer cases in the NHANES‐I follow‐up study. The three diagnostic tools provide complementary evidence of the existence of a strong collinearity in all models that is due largely to homogeneity of the population with respect to our risk scale for the crude intakes. The analysis suggests that the non‐significant relative risks for the crude intakes in these models may be due to their involvement in collinear relationships, while the nonsignificant relative risks for the nutrient densities are far less affected by multicollinearity.
The area between curves (ABC)—measure in nutritional anthropometry
Authors: Böhning Dankmar , Hempfling Axel , Schelp Frank‐Peter , Schlattmann Peter
Published: April 2007

This paper considers a statistic — recently suggested by Mora — for the deviation of a sample distribution from a reference distribution which typically arises in anthropometry when using the nutritional indicators height/age, weight/age or weight/height. The statistic measures the area between curves (ABC) and stands for the mass of the sample distribution which is not covered by the reference distribution. The paper provides a statistical framework for the ABC and includes some minor corrections of Mora's original paper. For the normal distribution situation with common or different variances, formulae are derived which include a partition of ABC into parts corresponding to malnourished and well‐nourished groups. However, the main result is a non‐parametric generalization of the ABC, motivated by the fact that the nutritional indicators often have skewed distributions with heavier left tails. Non‐parametric statistical inference is provided by linking the ABC to the Kolmogorov‐Smirnov statistic.
A retrospective assessment of the 75/75 rule in bioequivalence
Authors: Dobbins Thomas W. , Thiyagarajan Balasamy
Published: April 2007

The 75/75 rule was originally proposed by the U.S. Food and Drug Administration (FDA) as an alternative means of testing the bioequivalence of two formulations of a pharmaceutical agent. The rule specified that the ratio of test‐to‐reference formulation of a bioavailability measure arising in a bioequivalence study must be between 75 and 125 per cent of unity in at least 75 per cent of subjects to declare two formulations bioequivalent. The rule has garnered criticism in the literature and the FDA no longer uses the rule formally in assessing bioequivalence. The basis, however, for all criticism of the rule has been simulation arguments. In this paper, we derive the sampling model implied by the rule and place the rule in the framework of a statistical hypothesis test. We show how the significance level of the test depends upon variability of the formulations, and thus why the rule performs in the way that has received criticism.
Creation of a semiannual report for a multicentre co‐operative clinical trials group
Authors: Goodman Phyllis J. , Crowley John J. , Benson Carl
Published: April 2007

The Southwest Oncology Group (SWOG) is a multicentre co‐operative group that performs prospective clinical trials in cancer. The SWOG Statistical Center is responsible for preparing a report of studies for the semiannual meetings. The report includes a summary of study design and eligibility criteria, current accrual, baseline patient characteristics, toxicity, and, for studies closed to accrual and with sufficiently mature outcome data, tumour response or patient survival. A software program, Statisticians' Report Worksheet (SRW), has been developed by the programming staff at the SWOG Statistical Center. This program enables each disease specific chapter to be created independently, but ensures that tables and graphs for all chapters are of uniform style. We describe here the coordination of the report, and the use of the SRW program. This reporting system can serve as a model for other groups.
Bayesian methods for phase I clinical trials
Authors: Gatsonis Constantine , Greenhouse Joel B.
Published: April 2007

Phase I clinical trials are conducted to determine the dose‐response curve of a new drug with respect to toxic side effects and, in particular, to estimate the maximum tolerated dose (MTD). In this paper we take a Bayesian approach to the problem of making inferences about the MTD. Working with broad classes of priors, we obtain the posterior distribution of the MTD and study its properties. We also address the question of providing updated assessments of the risk of toxicity for new patients entering the study at a specific dose level. These assessments would be useful in deciding issues of study management and ethics. Our analysis pays particular attention to the sensitivity of the inferences and risk assessments to the choice of prior and the choice of model for the dose‐response relationship.
The changing geographical coherence of measles morbidity in the United States, 1962–88
Authors: Cliff Andrew D. , Haggett Peter , Stroup Donna F. , Cheney Elizabeth
Published: April 2007

Geographical coherence may be defined as the degree to which the behaviour of a time series in one geographical area corresponds with the time series behaviour in another. This paper illustrates the concept using the epidemiological time series of reported monthly measles morbidity for the states of the United States for the 27 years from January 1962 to December 1988. Over this period, as measles morbidity has declined in response to vaccination campaigns, and as the seasonal peaking of the disease in late spring has become less pronounced, the geographical coherence has altered at the national, divisional, regional and state levels. There was a steady decline in coherence from 1962 to 1980. In 1981, a dramatic reduction occurred, but there has been some recovery since. The implications for spatial forecasting models of these reducing levels of coherence are discussed.
Calculating the prevalence of cancer
Authors: Coldman Andrew J. , McBride Mary L. , Braun Terry
Published: April 2007

Incidence, prevalence and mortality are commonly used measures to assess the impact of disease on human populations. Prevalence, although regularly assessed for a number of different diseases, has only had recent use to measure the impact of cancer. The calculation of the prevalence of cancer presents several difficulties since there is no reporting mechanism established to measure the proportion of the community that has the disease. In the absence of such a mechanism, mortality data linked to incidence data from cancer registries have been used. The assumption is made that once diagnosed with cancer an individual remains a prevalent case until death. In this paper we present alternatives to this assumption and use them to produce estimates of cancer prevalence. We illustrate the effect of these assumptions on the calculated prevalence of cancer using data from the British Columbia Cancer Registry.
Estimating prevalence by group testing using generalized linear models
Authors: Farrington C. P.
Published: April 2007

A method is described for estimating prevalence by group testing using generalized linear models. This provides a simple way of analysing such data using widely available software. Existing methodology to correct for overdispersion using quasi‐likelihoods is applied to the group testing model. The methods are illustrated by an estimation of salmonella contamination in eggs, and of yellow fever virus infection in a mosquito population.
Analysis of a clinical trial involving a combined mortality and adherence dependent interval censored endpoint
Authors: Moyé Lemuel A. , Davis Barry R. , Hawkins C. Morton
Published: April 2007

Clinical trials often involve a variety of clinical and laboratory measures that are used as endpoints and sometimes two of these measures are combined in one endpoint. When the individual components of such a combined endpoint are ‘time to event’ measurements, the analysis is straightforward if each of the components is measured frequently and regularly over time. However, the analysis of the combined endpoint is more difficult when one component of the endpoint is right censored and the other is interval censored. This paper describes a statistic, based on a rank ordering of events for such a combined measure. The power of the test statistic is explored.
The concept of residual confounding in regression models and some applications
Authors: Becher Heiko
Published: April 2007

In this paper the concept of residual confounding is generalized to various types of regression models such as logistic regression or Cox regression. Residual confounding and a newly suggested parameter, the relative residual confounding, are defined on the regression parameters of the models. The estimator gives the proportion of confounding which has been removed by incomplete adjustment. The concept quantifies the effects of categorizing continuous covariables and of model misspecification. These are investigated by a simulation study and with data from an epidemiological investigation. A case‐control study of laryngeal cancer is used to illustrate the residual confounding effect of arbitrary transformation of a continuous confounder, smoking, on the effect of alcohol consumption on laryngeal cancer risk. The data also showed that categorization into two levels can yield high residual confounding. The parameters described in this paper are of some use in quantifying the effect of inadequate adjustment for confounding variables.
Control sample size when cases are given in constant ratio stratum‐matched case‐control studies
Authors: Nam Jun‐Mo , Fears Thomas R.
Published: April 2007

Strata‐matched case‐control studies based on a given number of cases and k times as many controls are common. We obtain a necessary and sufficient condition for there to exist a numerical solution for k with a desired level of a power. We derive the maximum power of the Cochran test, which may be less than one, when the number of cases is fixed. We provide an approximate formula for the minimum number of cases required for a specified power. There exists a numerical solution (that is, convergence of an iterative method) for k if the number of cases given is greater than this minimum number and no such a solution otherwise. We also show that the incremental gain in relative efficiency of the test with respect to k is diminished as k gets large.
Self‐Repairing Coatings Containing Active Nanoreservoirs
Authors: Shchukin Dmitry G. , Möhwald Helmuth
Published: April 2007

Nanocontainers with the ability to release encapsulated active materials in a controlled way can be employed to develop a new family of self‐repairing multifunctional coatings, which possess not only passive functionality but also rapid feedback activity in response to changes in local environment. Several approaches to fabricate self‐repairing coatings on plastic and metal substrates were surveyed. The release of the active materials occurs only when triggered, which prevents leakage of the active component out of the coating and increases coating durability. This Review also covers some principles and recent developments in the fabrication of nanocontainers with good compatibility with the coating components, the possibility to encapsulate and upkeep active material, and permeability properties of the shell controlled by external stimuli. Depending on the nature of the sensitive components introduced into the container shell, reversible and irreversible changes of the shell permeability can be induced by various stimuli. Different responses can be then observed varying from fine effects like tunable permeability to more drastic ones like total rupture of the container shell.
Ground motion environment of the Los Angeles region
Authors: Somerville Paul G. , Graves Robert W. , Day Steven M. , Olsen Kim B.
Published: April 2007

This paper reviews aspects of fault geometry and geological structure that cause spatial variations in the level of ground motions expected from large‐scenario earthquakes. These conditions include style of faulting, differences between surface faulting and buried faulting earthquakes, rupture directivity effects, basin effects and basin edge effects. These effects are illustrated in large‐scale ground motion simulations of scenario earthquakes on the Puente Hills Blind Thrust and the Southern San Andreas fault. The impact of these effects on probabilistic seismic hazard is also explored by means of CyberShake calculations in which the ground motions at a given site from a very large number of earthquake scenarios are represented by simulated time histories in place of conventional ground motion attenuation equations used in probabilistic seismic hazard analysis. We find that the seismic hazard estimates are quite similar in some locations, such as downtown Los Angeles, but quite different at others, such as Whittier. These differences are attributable to the coupling of rupture directivity and basin effects that are present in the CyberShake and TeraShake calculations but not in the conventional attenuation relations. Copyright © 2006 John Wiley & Sons. Ltd.
Poorly worded, ill‐conceived, and unnecessary code provisions
Authors: Searer Gary R.
Published: April 2007

Both the Uniform Building Code (UBC) and the International Building Code (IBC)—to some degree or another—have poorly worded provisions that are unnecessarily complex, are ambiguous, are not justifiable, and/or are overly restrictive. This paper presents just a few of these provisions, the reported justification for these provisions, and suggestions to simplify and improve the codes. Provisions discussed in this paper include the redundancy/reliability factor, the vertical earthquake, minimum base shear and drift limits, and accidental torsion. Copyright © 2006 John Wiley & Sons, Ltd.
Nonlinear dynamic analysis capabilities and limitations
Authors: Powell Graham
Published: April 2007

Nonlinear dynamic analysis is feasible for tall buildings, and can be done for reasonable cost. This paper looks briefly at the following questions. How does nonlinear dynamic analysis differ from linear? What are the steps? How are the analysis results used to assess structural performance? What skills are needed? Does nonlinear analysis lead to better design? Is it necessary to use capacity design? Is it necessary to consider geometric nonlinearity (large displacement) effects? How much computer time does it take? What are some other limitations? Can static pushover analysis be used instead of dynamic analysis? Copyright © 2006 John Wiley & Sons, Ltd.
Performance‐based design of tall reinforced concrete ductile core wall systems
Authors: Klemencic Ron , Fry J. Andrew , Hooper John D.
Published: April 2007

The tenets of performance‐based design have been around for decades, yet are just recently being applied to the design of high‐rise superstructures. Successful projects using a ductile core wall structural system, following a performance‐based design methodology, have been implemented by Magnusson Klemencic Associates and can be seen in completed structures around the world. However, provisions often arbitrarily placed in the current prescriptive Building Code (regarding height limits and building response, for example) make it difficult for structural engineers to apply rational engineering methodologies in design of performance‐based structures. Instead, engineers must incorporate less‐than‐ideal design practices, such as requiring redundant dual frame systems on buildings more than 240 feet high or allowing construction compromises in the impractical regulations governing diagonal steel reinforcing of coupling beams. Additionally, the lack of peer review process standards often pit two well‐intended opinions against each other, with the building design usually changed per the reviewer's wishes and for the sake of being expeditious. To improve the design and construction process for performance‐based tall buildings, among other things, appropriate interpretations of the Building Code should be permitted, and even required, and the scope and authority of peer reviews should be standardized. Copyright © 2006 John Wiley & Sons, Ltd.
Materials, effects and components for tunable micro‐optics
Authors: Friese Christoph , Werber Armin , Krogmann Florian , Mönch Wolfgang , Zappe Hans
Published: April 2007

An overview of recent activities in the area of tunable micro‐optical components is given. These include polymer‐based deformable mirrors for adaptive optics, tunable microlenses and arrays using fluids and membranes, pneumatically actuated scanning micromirrors and tunable Bragg filters and mirrors using swelling polymers. For each device, the structure, essential fabrication technology and optical characteristics, as well as a discussion of application areas are presented. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Fabrication of densely arrayed Si needles with large height for transdermal drug delivery system application
Authors: Sasaki Hikaru , Shikida Mitsuhiro , Sato Kazuo
Published: April 2007

The effects of varying etching conditions for microneedle fabrication were investigated in order to form densely arrayed, sharply angled Si needles with large height for application in transdermal drug delivery systems (DDSs). A sharply angled needle shape could be fabricated by using 34.0 wt% KOH (representing a typical etching‐rate diagram at a highly alkaline etching solution concentration). The needle height could be increased by 20% by adding a compensation mask pattern or by increasing the KOH concentration to 51.0 wt%. The trade‐off relationship between the maximum needle height and the needle density was calculated. These experiments provided useful parameters for designing densely arrayed, sharply angled Si needles for transdermal DDS application. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Design and modeling of compliant micromechanism for mechanical digital‐to‐analog conversion of displacement
Authors: Sarajlic Edin , Collard Dominique , Toshiyoshi Hiroshi , Fujita Hiroyuki
Published: April 2007

A microelectromechanical digital‐to‐analog converter (MEMDAC) converts digital motion of shuttle actuators operated by the corresponding bits of a binary code into an output displacement proportional to the analog value represented by the input code. In this paper a MEMDAC with improved kinematic design is devised that allows large travel range and high positioning resolution while making the microfabrication process less critical. A lumped‐parameter model of the compliant mechanism of anN‐bit MEMDAC is derived and used to determine the stiffness ratio of flexible members needed for proper mechanical digital‐to‐analog conversion. Furthermore, we analytically investigated the effect of nonuniformity in the device geometry due to the limitations of the microfabrication processes on the linearity of the output displacement. Successful fabrication and release of a 12‐bit MEMDAC demonstrated the manufacturability of the new mechanism, revealing opportunities for MEMS applications in which micropositioners with open‐loop operation, relatively large output range, fine positioning resolution and high repeatability are required. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Devices, structures, and processes for optical MEMS
Authors: Choo Hyuck , Muller Richard S.
Published: April 2007

New processes and devices in the area of optical microelectromechanical systems (MEMS) as researched in the Berkeley Sensor & Actuator Center (BASC) are described. A technique and fabrication procedure is presented to produce high‐quality microlenses at selected locations in a micro‐optical system. Polarization beam splitters are produced by another process, and their performance is measured and described. A new, much simplified process to fabricate vertically offset comb actuating structures is applied in the design of high‐performance scanners, which are in turn used to control a laser ablation system. Very favorable performance comparisons are demonstrated between the researched system and a conventional commercial laser ablation system. A second system demonstration is a prototype Shack–Hartmann (SH) sensor, in which microlenses are mounted in carriages that can be individually addressed using the selectivity of their mechanically resonant mountings. This design is shown to increase markedly the dynamic range in wave aberration to which the SH sensor can be applied. A final application of optical MEMS design is to a reduced‐size, enhanced‐performance, phase shifting interferometer. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Pressure sensing by electrical admittance measurement of a comb‐drive actuator
Authors: Ayanos Kenjiro , Hashiguchim Gen
Published: April 2007

This paper describes a micromachined pressure sensor that senses pressure not by a diaphragm structure but by a resonantly vibrating comb‐drive actuator. The electrical admittance of the comb‐drive actuator was directly measured using a lock‐in amplifier, and its pressure dependence was examined. From the experiment, it was found that the resonant frequency of the comb‐drive actuator gradually drops as the pressure increases. The sensitivity of the comb‐drive actuator as a pressure sensor was 0.34 Hz/MPa at atmospheric pressure and 0.1 Hz/MPa at 0.4 MPa absolute pressure. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Fabrication of metallic nanopatterns using the vacuum type UV‐NIL equipment
Authors: Fukuhara Non‐member Makoto , Mizuno Jun , Saito Mikiko , Homma Takayuki , Shoji Shuichi
Published: April 2007

Nanoscale dot patterns of cobalt alloy were formed on a silicon substrate using the ultra‐violet nanoimprint lithography (UV‐NIL) technology in combination with an electrodeposition process. We developed an improved UV‐NIL equipment that can evacuate the chamber during imprinting. Using this equipment, we successfully imprinted 240‐nm dot patterns with 500 nm pitch on a photocurable resin with high dimensional accuracy. Thickness control of the resin and imprinting under vacuum are important issues to obtain fine nanopatterns. Using these resin patterns as a mask layer, 300‐nm cobalt alloy patterns are successfully formed by the electrodeposition process. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Occurrence of gossypol in dried bract of the cotton plant
Authors: Loewenschuss Hana , Wakelyn P. J.
Published: April 2007

Gossypol has been identified as a component of bract (FDB) from frost‐killed, field‐grown cotton by its chromatographic behavior on films of silica and cellulose (four eluents and five methods of detection). In addition, a derivative of gossypol was detected, and it was shown chromatographically that gossypol was removed from extracts of FDB by a divalent metal and by aniline. The total gossypol content, by spectrophotometric determination of gossypol‐aniline complex, of FDB was 0.93%, but for a sample of bract from a cotton plant that had been grown in a hothouse it was only 0.048%. However the free gossypol contents in both were similar (0.065% and 0.044%, respectively). Both bract samples were from glanded cotton varieties. It is worthwhile to investigate the effect of gossypol on lung tissue to see if it can contribute to the acute response of byssinosis. In addition, it is noted that the waste from ginned cotton which is sometimes used as livestock feed may contain gossypol.
Continuous miscella soapstock acidulation process
Authors: Crauer L. S.
Published: April 2007

A process is described for the continuous splitting of miscella soapstock in a pressurized two‐stage centrifugal system. Data collected from such a process, functioning at specified operational conditions, has yielded a recovery of 92% or more of the fatty acid from cottonseed miscella soap as a quality acid oil, analyzing 94% or better TFA content. The hexane in the soap feed is recovered for reuse from the vacuum stripper.
Effects of fresh and used hydrogenated soybean oil on reproduction and teratology in rats
Authors: Nolen Granville A.
Published: April 2007

Groups of 25 pairs of two generations of male and female rats were fed diets containing 15% of either fresh hydrogenated soybean oil (iodine value, 107), a similar fat used 56 hr for deep frying or an unhydrogenated mixture of fats and oils with a fatty acid composition similar to the hydrogenated soybean oil. The first two litters of each generation were permitted to be born naturally. During the third pregnancy of each generation, one‐half of the females were sacrificed on day 13 of gestation and inspected for early embryonic death. The remaining females were sacrificed on day 21 of gestation, and the fetuses were examined for either skeletal or softtissue abnormalities. There was no evidence of any deleterious effects on the reproductive parameters nor any teratogenic effects due to either hydrogenated soybean oil, a similar oil used for frying foods for 56 hr or an unhydrogenated mixture of fats and oils.
Isocyanates derived from fatty acids by the trimethylsilyl azide modification of the curtius rearrangement
Authors: Washburne S. S. , Peterson W. R.
Published: April 2007

Five fatty acid chlorides—myristoyl (14:0), palmitoyl (16:0), linoleoyl (18:2), oleyl (18:1) and stearoyl (18:0)—were smoothly converted in a one‐pot, one‐step reaction to the isocynates with one less carbon atom in the alkyl chain by treatment with trimethylsilyl azide in aromatic solvents at 100 C. The yields were consistently greater than 70%, and NMR and IR spectra of the products were consistent with the assigned isocyanate structures.
Determination of aflatoxin and aflatoxin‐producing cultures in recently ginned cottonseed in Central America
Authors: Schneider S. , de Leon R. , García‐Prendes M. , Rolz C.
Published: April 2007

Aflatoxins were found in four of the 99 samples of recently ginned cottonseed analyzed. From these same 99 samples, four cultures ofAspergillus and one ofPenicillium capable of producing aflatoxin were isolated. In only one case was an aflatoxin producer isolated from an aflatoxin contaminated sample.
Free radical addition of dialkyl phosphites to N,N‐disubstituted amides of unsaturated fatty acids and screening of the products for antimicrobial activity
Authors: Mod R. R. , Harris J. A. , Arthur J. C. , Magne F. C. , Sumrell G. , Novak Arthur F.
Published: April 2007

Free radical addition of dibutyl phosphites to terminal and internal double bonds of monounsaturated amides was attained in high yield. The reaction was initiated by irradiation using Cobalt‐60. Attempts to add diphenyl phosphite to the unsaturated amides failed with the amides being recovered unchanged. Similar attempts to add dialkyl phosphites to N‐linoleoylmorpholine resulted in products that were deficient in phosphorus. Screening for antimicrobial activity againstEscherichia coli, Trichosporon capitatum, Trichoderma viride andCandida lipolytica indicated that terminal addition products may be more active than the internal addition products, with the former strongly inhibiting the growth of all four test organisms.
A micromethod to generate and collect odor constituents from heated cooking oils
Authors: Selke E. , Rohwedder W. K. , Dutton H. J.
Published: April 2007

A small stainless steel reactor about one‐millionth the volume of a home kitchen, was built to generate odors from cooking oils heated to deep fat frying temperatures. This “microroom” was designed so that volatiles could be collected from 1–5 ml of heated oils (193 C) directly on a gas chromatographic column, cooled to ‐60 C and subsequently separated by temperature programing up to 250 C. Evaluations showed that heated oil odors from the microroom were similar to those room odors produced by heating to 193 C 300 ml of cooking oil in an open vessel; exposure to subambient conditions did not affect the separation efficiency of the gas chromatographic column. Provisions were made for three independent means of effluent monitoring: flame ionization detection, odor analyses and mass spectrometry.
Soap‐based detergent formulations: III. Surface activity of fatty derivatives of 3‐hydroxypropanesulfonic acid
Authors: Parris N. , Weil J. K. , Linfield W. M.
Published: April 2007

Pure 3‐sulfopropylesters, ethers and amides were prepared from fatty acids, alcohols and amides by reaction with 1,3‐propanesultone. Their solution properties, including Krafft point, critical micelle concentration, lime soap dispersing power and detergency, were compared with those of the analogous 2‐sulfoethyl esters. The N‐3‐sulfopropylamides exhibited superior lime soap dispersing power as well as detergency in soap‐based formulations at 300 ppm water hardness. The sulfopropyl ethers and amides displayed excellent stability to acid and alkaline hydrolysis. The sulfopropyl esters were much more stable to alkaline hydrolysis than the sulfoethyl esters, but only slightly more stable to acid hydrolysis.
Level and position of unsaturation in alpha olefin sulfonates
Authors: Kuemmel D. F. , Liggett S. J.
Published: April 2007

A comparison of the levels of unsaturation in α‐olefin sulfonates (AOS) and related derivatives determined by iodination, bromination and hydrogenation techniques showed that quantitative hydrogenation is the only method having wide applicatbility. Although halogenation methods frequently give results in agreement with hydrogenation data, they can show variations with reaction time and composition of the sample. Unsaturation in sulfonate methyl esters could not be determined by halogenation. The amount of †1‐isomer in alkene sulfonate sodium salts determined by oxidative cleavage with periodate‐permanganate was always low compared to that determined by NMR. Oxidative cleavage of the sulfonate methyl esters gave †1‐isomer levels in agreement with NMR results.
Castor meal antigen deactivation: Pilot plant lime process
Authors: Mottola A. C. , Mackey B. , Walker H. G. , Kohler G. O.
Published: April 2007

Castor meals treated with Ca(OH)2 to reduce their allergen content have been re‐evaluated using a more sensitive biological assay procedure. Results indicate that treatment with 4% lime at 120 C for 15 min should produce optimal deallergenization. Amino acid analysis of treated products shows that steam and lime deallergenization procedures tend to destroy more labile amino acids than ammonia treatment does.
Amino acids of citrus seed meal
Authors: Braddock R. J. , Kesterson J. W.
Published: April 2007

Defatted seed meal from oranges and grapefruit contained more sulfur amino acids but less lysine than some common oilseed proteins. Grapefruit seed meal had less tryptophan and more sulfur amino acids than orange seed meal. Probable annual yields of Florida citrus seed oil, meal and hulls are 17, 23 and 13 million lb, respectively.
Surface activity of glycerol glycoside palmitates
Authors: Feuge R. O. , Brown Mona , White J. L.
Published: April 2007

A glycoside ester product was prepared by the transglycosylation of starch and glycerol, which yielded a mixture of 2,3‐dihydroxypropyl‐α‐D‐glucopyranoside and other glycerol glycosides, followed by interesterification of the crude glycerol glycosides with a mixture of mono‐, di‐ and tripalmitin. The purified reaction product, consisting of ca. 77% glycerol glycoside palmitates, 14% palmitins and 9% free palmitic acid, was found to be extremely effective in lowering the interfacial tension between cottonseed oil and water—a 0.04% concentration in the oil phase lowering the interfacial tension to 1.3 dynes/cm.
Selective hydrogenation with copper catalysts: I. Isolation and identification of isomers formed during hydrogenation of linolenate
Authors: Koritala Sambasivarao , Scholfield C. R.
Published: April 2007

Methyl linolenate was hydrogenated with 10% copper chromite catalyst at 150 C and atmospheric hydrogen pressure. The product was separated into monoene, diene and triene fractions by countercurrent distribution. These fractions were further separated into various geometrical isomers. The double bond location in the various fractions was determined by reductive ozonolysis. Double bonds in bothcis andtrans monoene fractions, as well as incis,trans andtrans,trans conjugated dienes, were extensively isomerized. A monoene containing vinylic unsaturation was one of the major products. The nonconjugated dienes were mostly dienes whose double bonds were widely separated. Results are explained on the basis of conjugation of the double bonds in linolenate followed by hydrogen addition.
Selective hydrogenation with copper catalysts: II. Kinetics
Authors: Koritala Sambasivarao , Butterfield R. O. , Dutton H. J.
Published: April 2007

To explain the unusually high selectivity of copper catalysts toward linolenate, model compounds were hydrogenated (150 C and atmospheric pressure) and the reaction products analyzed. Products varied depending upon location of the double bonds. Monoenes were not reduced by copper chromite except when the double bond was next to a carboxyl group. Dienes with isolated double bonds also were not reduced. Binary mixtures of model compounds were hydrogenated with copper chromite. From the composition of the initial and final products, a competitive rate ratio of the two compounds was determined. Esters with conjugated double bonds reacted faster than esters containing methylene interrupted double bonds. Kinetic data on the hydrogenation of linolenate indicated conjugation of the double bonds. Simulation of the kinetic data gave competitive reaction rates for the different isomers formed.
Monohydroxylation of unsaturated oils: III. Use of halogen intermediates
Authors: Venkateswara Rao G. , Subbarao R. , Achaya K. T.
Published: April 2007

Hydroxylation of safflower and linseed oils by routes involving halogen compounds is described. A product containing 20.5% Br was obtained by treatment of safflower oil in CCl4 solution with N‐bromosuccinimide (NBS) in presence of benzoyl peroxide and UV illumination. Bromine was totally removed using Ag2O in 50% dioxan; the resulting hydroxyl value (HV) was only 100, against an expected HV of 180, perhaps because of dehydration and ether formation. Using other silver salts, bromine replacement with hydroxyl was always incomplete. Such residual bromine was totally replaced by hydrogen, without altering other characteristics, by treatment of the product with zinc amalgam in acetic acid. Linseed oil by similar NBS bromination (Br 22.2%) and Ag2O treatment gave a product with Br 2.9%, HV 74, conj. diene 15% and conj. triene 4%. Halogenreplacement difficulties also attended the hydrobromination of these oils at the double bonds, followed by hydroxylation. Addition of hypochlorous or hypobromous acid to safflower oil, followed by total replacement of halogen with hydrogen using zinc amalgam, yielded products of HV 75 and 83 respectively. The degree of hydroxylation was only half of that expected from the loss of unsaturation.
Quantitative measure of geometrical isomerization during the partial hydrogenation of triglyceride oils
Authors: Albright Lyle F. , Allen Robert R. , Moore M. C.
Published: April 2007

A mathematical model has been developed using a digital computer for the calculation of the isomerization index for partially hydrogenated oils such as cottonseed, soybean, peanut or corn oil. The isomerization index is defined as the ratio of the rate of geometrical isomerization of an unsaturated group to the rate of hydrogenation. Isomerization indices from about 0.3 to 11 were found to occur for hydrogenations using commercial nickel catalysts. Calculation of both an isomerization index and a selectivity ratio will be useful methods of quantitatively characterizing the partial hydrogenation of triglyceride oils or the type of hydrogenation which can be obtained by various catalysts.