bluuebunny/crossref_metadata_2025 huggingface dataset:
Shock Testing with the Rocket-Powered Pendulum
Authors: Hager R. W.
Published: August 2009

To meet ever increasing need for adequate testing of full-scale aircraft and ordnance structures and components, Sandia Corp. has developed the rocket-powered pendulum. This pendulum, which is accelerated by the thrust from a group of 3.5 in. bazooka rocket motors and decelerated by gravity, is capable of simulating certain operational shock loadings on prototype structures and components. Although the present design of the rocket-powered pendulum limits the magnitude and duration of the applied force, good simulation of sustained and water-impact shocks has been obtained on specimens with resonant frequencies above 40 cps.
Properties of Concrete at High Rates of Loading
Authors: Watstein D.
Published: August 2009

The effect of the rate of application of load was investigated in compression tests of a concrete having a nominal static strength of 2500 psi. The test specimens were 3 by 6-in. cylinders, and the loads were applied at stress rates ranging from about 10 to 2 × 107 psi per sec. The lower rates of loading were obtained using a conventional hydraulic testing machine, and the higher rates were achieved by loading the specimens in a drop-hammer machine. The duration of impact in the drop-hammer machine was controlled by placing rubber buffers of appropriate thickness and hardness on top of the concrete specimens. The compressive strength of the concrete increased with the rate of loading. The maximum ratio of dynamic to static compressive strength was about 1.8 for the maximum rate of loading obtained with the drop-hammer machine. There was a significant increase in the secant modulus of elasticity as the rate of loading increased. The resistance of concrete to impact, as measured by its ability to absorb strain energy, also increased with the rate of application of load.
Opening Remarks
Authors: Warwick C. L.
Published: August 2009

This symposium is an important step in a program initiated some six years ago when a Joint Committee on Measurement of Opinions, Attitudes and Consumer Wants was formed by the Social Science Research Council and the National Research Council—which brought into focus upon a problem of common interest the techniques being developed in the social and natural sciences. At about the same time, our Society, recognizing that it had been drawn into various spheres of the problem of ultimate consumer goods, had organized an Administrative Committee on this subject for the purpose of supervising the Society's activities in the field of consumer goods. Perhaps because no one else was in sight at the moment, I was asked to represent ASTM on the Joint Committee, and I think it is on that account that Mr. Olmstead, who chairmaned the group that organized this symposium, has suggested that I make these brief introductory remarks. The broad objective of the Joint Committee is to bring to bear on the problem of measurement of opinions, attitudes, and consumer wants the techniques that have been and are being developed in both the social and natural sciences, so that the Joint Committee might make an important contribution to the development of scientific knowledge in this field. Among the problems that are being considered and worked upon by the Joint Committee through the several subcommittees that have been appointed are those of sampling, of panel techniques, of validity, and in general of study design, including questionnaire construction and interviewer procedures. Clarification of some problems involved in some of the specific applications of research is also an objective of the committee, as for example in the measurement of consumer wants involving market research techniques in the development of standards for consumer goods. I must confess that at first I felt very strange in the Joint Committee since so many of the techniques that were being discussed were foreign to the engineering materials approaches with which I am familiar. However, as discussion progressed, and particularly as thoughts began to crystallize in our own Administrative Committee on Consumer Goods, one could begin to see how procedures in sampling, interview, and other methods of measurement could be developed into useful tools in working on some of the problems upon which ASTM might become engaged.
Some Applications of the Panel Method to the Study of Social Change
Authors: Glock Charles Y.
Published: August 2009

In recent years, social scientists at our universities and research people associated with both public and private organizations have given increasing attention, to the use of the panel method of repeated interviewing in carrying on their research. Briefly, the panel method involves recruiting a sample of individuals representing the universe to be studied and interviewing these people at two or more different points in time on the problems under consideration. The method has been most frequently employed to study trends in consumer brand preferences, listening and reading habits, and in some cases, to collect data on opinions and attitudes. Considerably less attention has been given to the applications of the technique to the study of short-term changes in attitude and behavior patterns for which panel studies are particularly suited. The following remarks are designed to call attention to some of the recent developments in the application of the panel process to investigating and understanding the phenomena of change. Among the questions relevant to studies of social change, whether undertaken by the social scientist, the business man or the civil servant, are three which are perhaps of primary importance: 1. What was the effect of a stimulus, in producing change? 2. What are the conditions which produce differential changes in attitudes or behavior among various groups in a population? 3. What is the mutual interaction between attitudes or behavior patterns which occur simultanepusly? The panel method, because of the special modes of analysis it permits, can provide answers to these questions; answers not readily obtainable from cross-sectional polls. The first attribute of panel analysis important in this respect is that it enables the analyst to identify individual changers objectively. If it develops that a respondent reports an attitude or habit, which differs from that reported in a previous interview, then he is a “changer” and can be studied as such. Cross-sectional polls must rely on the respondent's memory to identify him as a “changer.”
Effective Sampling Procedures for Use in Measuring Consumer Wants
Authors: Stephan Frederick F. , McCarthy Philip J.
Published: August 2009

In the great mass markets served by modern industry, the consumers of a product are so numerous and so widely dispersed geographically that the manufacturer cannot ask each potential user what qualities he wants the product to have or find out from each actual consumer how well he is satisfied by the product he gets. Consequently, unless a producer has unusually accurate information flowing back to him from dealers and salesmen through the channels of distribution, he must find out about the public response to his product in some other way. This often leads to a survey of the wants and reactions of a sample of people chosen in the hope that their responses will give him a fair indication of what all consumers desire. The designer of a new product has no group of regular consumers and must likewise turn to a sample of people to test the acceptability of the product in the entire market. Sampling people differs from sampling bulk materials or sampling a product on the production line because the people who are chosen must accept their selection and cooperate actively. Many other human factors are involved in the sampling of dispersed populations. However, some of the techniques of sampling that have been developed for use in engineering, agriculture, and testing can be applied to the problem of obtaining samples of people to represent accurately a large group of consumers or some other population group. During the past fifteen years or more, very impressive use has been made of these techniques in censuses and surveys conducted in America and elsewhere for a great variety of purposes. Many improvements have been made in the methods, and a substantial body of sampling theory is now available to guide the application of the techniques to human populations. With these modern sampling procedures it is possible to make quite accurate determinations from relatively small samples when the other phases of the process of measurement are also up to the same high standard of accuracy. However, these procedures are not always simple, inexpensive, or free of important technical and operating problems. Our analyses of a number of surveys and comparison of their performance have convinced us that there is no one sampling procedure that is uniformly most effective. The more successful instances of sampling are those in which the component techniques and operations were selected and combined in a design that is fitted to the characteristics of the population and adjusted to the specific purposes of the survey.
Closing Remarks
Authors: Herring Pendleton
Published: August 2009

Although I believe you invited me here as a silent partner in this symposium, I am very happy to say a word or two at the end of the meeting to indicate to you that even though I have been a silent partner, I have not been a sleeping partner during these discussions this afternoon and this evening. I found the papers not only very interesting, because of their own intrinsic content, but, likewise, the proceedings, as a whole, because they symbolize a convergence of interests and a bringing together of two lines of activity that I think are important, and will become increasingly so as we look ahead. Thinking back to the creation of the Joint Committee on Measurement of Opinion, Attitudes and Consumer Wants by the National Research Council and the Social Science Research Council over five years ago, I recall that the purpose was to appoint as members men from industry, government and polling agencies, and from the universities, all of whom shared a common interest. I believe this committee provided the first real opportunity for such a group to discuss thoughtfully together research problems of common concern with respect to the measurement of opinion, attitudes and consumer wants. The papers we have heard today are evidence of the leadership of this committee. I am sure that the audience will agree that there is a necessity for attention to the theoretical and technical research aspects of the field if good applied work is to be done. Such matters can not be expected to attract the interest of the general public and may be c limited interest to some practitioners But such attention is essential for the development of the field. Good applied work must be based upon a sound foundation, of theory. In this sense it is a practical necessity to be mindful of theory. The papers that we have heard indicate the kind of penetrating questions and the concern with self-analysis that are necessary for advance in any field. You have had good reports of the progress of the thinking that has gone forward at this level of theory and methodology.
Automatic Sampling of Industrial Water and Industrial Waste Water
Authors: Madarasz M. F.
Published: August 2009

Industry, having recognized water as an essential engineering material, is frequently called upon to evaluate its properties, both from the standpoint of its use and its disposal. In checking the quality of an industrial water or an industrial waste water, proper sampling is a most important factor. The application of automatic features to sampling provides the same sort of benefits that the application of automatic processes has introduced into so many other fields. It has been stated that sampling is the operation of removing a part, convenient in size for testing, from a whole of greater bulk in such a way that the distribution of the constituent or quality to be tested is the same in both the whole and the part removed or sampled (1). This definition of sampling will naturally hold for automatic as well as for manual procedures. In order to obtain a meaningful sample, the accuracy and character of the analysis to be made and the interpretation to be put on the results must, of course, be considered. Whether the sample for analysis may be required intermittently or continuously will naturally affect the design of the sampling apparatus. The amount of the sample to be taken is also important. Sometimes a balance will have to be struck between having enough sample and withdrawing an uneconomically large portion of the stream.
Continuous Recording of Chlorine Residuals and Determination of Chlorine Demand
Authors: Griffin A. E.
Published: August 2009

Continuous recording of residual chlorine is not a new idea. Rather this has been the aim of scientists and operating personnel since chlorination of potable water was first placed on a continuous basis in 1908. Actually the development of reliable equipment for this purpose could not take place until the nature and characteristics of residual chlorine in water, in small concentrations (0.1 to 10.0 ppm), had been thoroughly studied and certain instruments such as the photoelectric cell and amperometric titrator had been perfected. The perfection and acceptance of the photoelectric cell offered one of the first avenues of approach to the problem. Early work was devoted largely to the measurement and recording of the various intensities of color, which are proportional to the amount of chlorine present, produced by the addition of certain reacting chemicals, such as potassium iodide or orthotolidine. Several instruments utilizing this principle were constructed and placed in operation during the early thirties. Some were notably successful, particularly those making use of orthotolidine. However, practically every scheme using the photoelectric cell method was subject to certain fundamental errors, the most common of which was the accumulation of material on the glass surfaces of the water cell. These accumulations changed the intensity of the color measured by the photoelectric cell and introduced errors that were difficult to overcome. In addition, the equipment was either complicated or required a degree of skill in operation.
Measurement of Color, Turbidity, Hardness, and Silica in Industrial Waters
Authors: Staats F. C.
Published: August 2009

The quality of water is of daily concern to most chemical companies, because product quality is often dependent on water quality. Continuous analysis should permit realization of the close control needed. Accepted laboratory methods for measuring color, turbidity, hardness, and silica in industrial waters are reviewed with particular emphasis on those which offer greatest promise for continuous analysis application. Standards for color and turbidity are also discussed.
Fundamentals of Atmospheric Elements
Authors: Haynes B. C.
Published: August 2009

The general effects of weather on the erosion and deterioration of materials have long been recognized, but only in the last few years has it been possible to relate cause and effect by direct measurements. To provide some guidance on the use of meteorological parameters in developing criteria for the design of structures, this paper, while not exhaustive, outlines some of the methods of measuring atmospheric elements, and also discusses some of the local variations which may be expected when the basic data used are observed from a standard weather station. The variations in the weather elements from day to day, month to month, and even year to year, require careful consideration when weathering tests are conducted. The weather records for the test period should be compared with the means obtained from the climatological records for the area and the tests evaluated accordingly. Exposed materials are affected by solar radiation, terrestrial radiation, air temperature, humidity, precipitation, wind, and atmospheric impurities.
Conditioning and Weathering of Paper
Authors: Willets William R.
Published: August 2009

The main atmospheric component in the conditioning of paper is relative humidity which determines moisture content. This moisture acting as a plasticizer affects strength, rigidity, and plasticity. Changes in moisture content produce dimensional changes in the fibers which in turn are translated into over-all dimensional changes in the sheet. Examples are given showing the importance of relative humidity in testing, specification, converting, and end use. Other conditioning and weathering factors are discussed.
Conditioning and Weathering of Adhesives and Plastics
Authors: Reinhart Frank W.
Published: August 2009

Special conditioning is often required in the handling of adhesives and the processing of plastics. Tests to determine these conditions are straightforward and offer no particular problem to technologists. This phase is not subject to standardization. Conditioning for and during testing of adhesives and plastics is necessary in the evaluation of the results and to obtain comparable results. The conditions are fairly well standardized and correlated as evidenced by the work of the ASTM and the Federal Specifications Technical Committees. Further standardization is needed in accelerated service tests; some of this work, particularly on adhesives, is under way. The principal faults in these tests are (a) variability in service conditions, (b) inaccurate knowledge of service conditions, (c) distortions caused by using more strenuous laboratory test conditions to obtain acceleration, and (d) differences in concentration of degradation products in the materials. With factors such as these, a high degree of correlation between accelerated laboratory tests and behavior in service is not to be expected except in rare instances, although reasonably good correlation has been obtained in some cases. Experience in interpreting the results of the accelerated laboratory tests is one key to the problem. Accelerated weathering testing is in an unsatisfactory state. The degree of correlation between laboratory tests and behavior on exposure is far from satisfactory. This lack of correlation is attributed to (a) the great variability in outdoor weather, (b) variability in laboratory accelerated weathering test equipment, (c) distortions caused by using greater light intensities, higher temperatures, different moisture conditions, and more prolonged periods of these conditions to obtain acceleration in the laboratory test, and (d) the resulting increased concentration of degradation products in the adhesive and plastic.
Weathering of Some Organic Coatings
Authors: Dunn E. J.
Published: August 2009

A paint film is a dynamic entity. During its life it is in a slow but continuous state of change. Good weathering requires an unusual balance or compromise of physical and chemical forces within the paint film as it ages. There are perhaps some thirty types of physical and chemical actions within a paint film that cause it to change as it weathers. Many of these forces have been measured, and the rate of change of these forces in the aging film appears to dictate the useful life of the film. The importance of such factors as relative humidity, uniformity of film, film thickness, film shrinkage, moisture sorption, amount of film applied, and physical structure and a rating system for summarizing film properties are discussed in this paper. The field of weathering is so broad that only two general types of films weathered under atmospheric conditions will be considered in this paper: white type house paints and metal protective paints. House paints are primarily linseed oil base paints and metal protective paints are primarily oleoresinous base paints. The weathering of paints is big business. At our test fences and marinebasin at Sayville, L. L., there probably are 25,000 tests under way this year even though only 400 or 500 tests are added each year. There are two andone-half miles of test panels. ASTM Committee D-1 is considering weathering test sites because of the importance of having adequate weathering data.
Weathering Tests on Metallic Coatings
Authors: Blum William
Published: August 2009

In this effort to summarize the purposes, methods, and application of weathering tests of metallic coatings, reference will be made chiefly to the atmospheric exposure tests of electroplated coatings that have been conducted since 1932 by the American Electroplaters' Society, ASTM Committee B-8 on Electrodeposited Metallic Coatings, and the National Bureau of Standards in cooperation. Consideration will be given especially to the factors involved in these tests, rather than to specific results, most of which have been published.
Development of a Moisture Resistance Test
Authors: Lascaro Charles P.
Published: August 2009

Foreword.—This paper is an account of work conducted at the Signal Corps Engineering Laboratories which pertains to the development of the Standard Cycle for Moisture Resistance Testing of Component Parts for use in electronic equipment The recent increasing interest in reliability and tropical tests has led the author to believe that his experiences in this field may to some extent be a contribution to the state of the art. In the latter part of 1943, the extent of failures of communication equipment occurring in the tropics, where vital phases of the war were being fought, had become a serious concern to the Signal Corps Engineering Laboratories. Many types of failures, such as in Fig. 1, including corrosion, loss of set sensitivity, inoperation and others were attributed to the severe tropical conditions being encountered. The laboratories, located at Fort Monmouth, N. J., are responsible for the research and development of all communication equipment for the Department of the Army. As quick action was taken to improve the performance of equipment in the tropics, many protective techniques, such as the use of hermetic seals, coating materials, impregnants, etc., were being developed and used. In order to insure performance, some variety of either a humidity test, immersion, or “dunk” cycle or a salt spray exposure would usually be included in the applicable specification. In a short time, the types of tropical tests being specified were so diverse and numerous that it was necessary to standardize quickly on a test procedure. The many varieties of test procedures created a confusion as to the significance of results, since many were founded on an incomplete knowledge of tropical field conditions. In some specifications, two equipments would require that the same transformers should meet two different requirements although intended for the same field environments. It then became impossible to compare the results of tests of various subcontractors' parts or to correlate either result with field reports. The increased procurement during the war created an immense demand for humidity test facilities, and the resulting backlog made it necessary to standardize on a single test procedure so that a large work load could be handled efficiently and expeditiously.
Outdoor Exposure Testing on Racks and Test Fences
Authors: Compton K. G.
Published: August 2009

In the atmospheric exposure of materials for test purposes, consideration must be given to many factors. The relative importance of these factors depends, to some extent, on the purpose of the test, whether acceleration is wanted or simulated actual service is intended. It is the purpose of the present paper to discuss the influence and interrelation of these factors on the several kinds of materials exposed to the outdoor atmosphere.
Introduction
Authors: Converse Frederick J.
Published: August 2009

Considerable difference of opinion exists as to the usefulness of direct shear tests of soil in the field of foundation engineering. The development of this symposium resulted from an expressed desire by members of ASTM Committee D-18 on Soils for Engineering Purposes for more information on the present status of this type of test before considering ASTM standard. The papers in the symposium were designed to show examples of the successful use of direct shear methods, and to outline the advantages, disadvantages, and limitations of direct shear testing. Three papers give examples of use in practice. R. R. Proctor explains his equipment and method of analysis for determining the stability of earth dams. His long and successful practice in this field lends weight to the value of his conclusions. E. S. Barber discusses the use of direct shear tests in highway design and concludes that they have special value where consolidated tests are required. F. J. Converse points out the value of direct shear tests in the analysis of the foundations of buildings on irregularly bedded deposits of recent aluvium.
Use of Direct Shear Tests in Highway Design
Authors: Barber Edward S.
Published: August 2009

The direct shear test has many applications in highway design. While for some purposes the triaxial test may be preferred, the direct shear test is more convenient, especially where completely consolidated tests are required. Shear test results are presented for various materials and the effect of various procedures is discussed. The application of direct shear test results to analysis of stability is outlined for swelling cuts or fills and for consolidating foundations.
Use of Direct Shear Tests in Earthwork Projects under Construction
Authors: Proctor R. R.
Published: August 2009

The design of a direct shear machine to simulate as nearly as possible the actual failure of compacted fills and foundations along planes of sliding is described. Methods for placing compacted fill and undisturbed foundation samples in the equipment for shear test at the same density and under the same loading as they would have at the possible points of failure in the structure are explained. Methods for determining the factor of safety in a typical earthfill dam cross-section for each sample of soil tested are shown, together with a typical summary and discussion of actual test results applied to one structure.
A Direct Shear Test with Drainage Control
Authors: Taylor Donald W.
Published: August 2009

Shearing strength data are presented as a function of intergranular pressure on the sample just before start of shear and maximum intergranular pressure in the past. Strengths by “controlled” direct shear tests, with prevention of change in sample thickness used to approximate a no-drainage condition during shear, are shown to be in reasonable agreement with triaxial test results. Results of controlled and uncontrolled direct shear tests are compared to demonstrate that without control unacceptable irregularities are introduced by variable factors, the most important one being the amount of direct pressure on the sample during shear.
"There is no anachronism": Indian Dancing Girls in Ancient Carthage in Berlioz's Les Troyens
Authors: Van Rij Inge
Published: August 2009

Relatively early in the composition of Les Troyens Berlioz declared his intention to include a "pas d'almées with the music and dancing exactly like the Bayadères' ballet which I saw here sixteen or seventeen years ago." Despite Berlioz's claim that he had "gone into it" and "there is no anachronism," historical evidence would suggest that the presence of Indian dancing girls in Dido's Carthage is actually highly inauthentic and anachronistic. Indeed, Berlioz's immediate inspiration for the ballet in question was not ancient history but, rather, a group of Indian dancers and musicians who had visited Paris in 1838. An investigation of the context of the bayadères' performances and the reception of the dancers and their music reveals that issues of authenticity and anachronism were a constant preoccupation for their French audiences, most of whom had previously encountered bayadères only through the exoticizing lens of Western representations. Berlioz's own references to the bayadères are examined in relation to contemporary reviews and the text of a highly self-reflexive play that was performed as a prologue and that shaped audiences' responses to the bayadères' performances at the Théâtre des Variétés in Paris. Although Berlioz is generally thought to have abandoned his intention to embody the 1838 bayadères in Les Troyens, I argue that he actually retained aspects of his original Indian inspiration in the act IV ballet; moreover, an awareness of the impact of the bayadères' performances on Berlioz and his contemporaries greatly informs our appreciation of the contribution of the act IV ballet to the wider imperial subtext of Les Troyens. If, rather than simply dismissing anachronism, we are willing to embrace it as a concept fundamental to Berlioz's opera, the act IV ballet—often cut in recent productions—can be newly appreciated as occupying a significant role in the historical dialectic of Les Troyens as a whole.
Flying Leaves: Between Berlioz and Wagner
Authors: Kolb Katherine
Published: August 2009

This article analyzes the writings of Berlioz on Wagner and, to a lesser extent, of Wagner on Berlioz, emphasizing the covert innuendoes of their verbal sparring during the period surrounding the Tannhäuser debacle at the Paris Opéra (1860) and Berlioz's tribulations with Les Troyens (ca. 1853–63). Because Berlioz's style and subtlety have worked against him in this famous rivalry, the priority goes to him, and especially to his magnum opus as critic, the volume A travers chants (1862). A selection from thirty years of music criticism both serious and light ("flying leaves"), A travers chants reveals itself as an unconventional counterpart to Wagner's treatises; as a tactical response to Wagner, both in the reprinted review of his 1860 concerts and in the structure, themes, and allusions of the text as a whole; as an object lesson in reading Berlioz, whose engaging clarity and humor can be more deceptive, in their ironic undertones, than the thickets of Wagner's famously tangled prose. This article interrogates some of that prose, revealing Wagner's deep ambivalence toward a predecessor of intimidating prestige to whom his music is frequently indebted—as Berlioz occasionally finds coded ways of reminding him. It shows Berlioz, for his part, continually sympathetic to the younger man's practical difficulties and high artistic ideals. And it shows him eventually coming to acknowledge the power and legitimacy of his music, despite strong aversion to Wagner's harmonic idiom and to the two cardinal points of his aesthetic: an "impious" insistence on the primacy of the word; belief in a musical progress culminating in his own Gesamtkunstwerk. In a late letter wrongly omitted from the Correspondance générale (its authenticity and correct date are here established), Berlioz movingly implies the injustice of his earlier prejudice toward a practice sanctioned by his own unshakeable creed of artistic freedom.
"Vous qui faites l'endormie": The Phantom and the Buried Voices of the Paris Opéra
Authors: Newark Cormac
Published: August 2009

Gaston Leroux's Le Fantôme de l'Opéra (1909–10), as well as providing the model for some famous adaptations in other media, represents an important late stage in the development of a venerable French novelistic tradition: the soirée à l'Opéra. Notwithstanding his obvious lack of musical expertise (or perhaps because of it), Leroux's keen exploration of operatic reception deserves its place alongside more eminent contributors to that tradition such as Balzac, Dumas, and Flaubert. The richness of his portrayal of the institution's mythology and place in contemporary popular consciousness derives partly from his direct use of a large number of sources, which goes far beyond the conventions of the Gothic novel. These range from real and fictional operas to reportage concerning the famous fatal accident at the Opéra in 1896 and the rivalry between Christine Nilsson and Marie Miolan-Carvalho. The most significant of them, though, is the set of gramophone records buried underneath the Opéra in 1907, which was Leroux's inspiration and which emerges as the metaphorical key to interpreting the novel—if not the tradition as a whole.
The Roles of Multiple UNC-40 (DCC) Receptor-Mediated Signals in Determining Neuronal Asymmetry Induced by the UNC-6 (Netrin) Ligand
Authors: Xu Zhennan , Li Haichang , Wadsworth William G
Published: August 2009

The polarization of post-mitotic neurons is poorly understood. Preexisting spatially asymmetric cues, distributed within the neuron or as extracellular gradients, could be required for neurons to polarize. Alternatively, neurons might have the intrinsic ability to polarize without any preestablished asymmetric cues. In Caenorhabditis elegans, the UNC-40 (DCC) receptor mediates responses to the extracellular UNC-6 (netrin) guidance cue. For the HSN neuron, an UNC-6 ventral-dorsal gradient asymmetrically localizes UNC-40 to the ventral HSN surface. There an axon forms, which is ventrally directed by UNC-6. In the absence of UNC-6, UNC-40 is equally distributed and the HSN axon travels anteriorly in response to other cues. However, we find that a single amino acid change in the UNC-40 ectodomain causes randomly oriented asymmetric UNC-40 localization and a wandering axon phenotype. With UNC-6, there is normal UNC-40 localization and axon migration. A single UNC-6 amino acid substitution enhances the mutant phenotypes, whereas UNC-6 second-site amino acid substitutions suppress the phenotypes. We propose that UNC-40 mediates multiple signals to polarize and orient asymmetry. One signal triggers the intrinsic ability of HSN to polarize and causes randomly oriented asymmetry. Concurrently, another signal biases the orientation of the asymmetry relative to the UNC-6 gradient. The UNC-40 ectodomain mutation activates the polarization signal, whereas different forms of the UNC-6 ligand produce UNC-40 conformational changes that allow or prohibit the orientation signal.
In Utero Valvuloplasty for Pulmonary Atresia With Hypoplastic Right Ventricle: Techniques and Outcomes
Authors: Tworetzky Wayne , McElhinney Doff B. , Marx Gerald R. , Benson Carol B. , Brusseau Roland , Morash Donna , Wilkins-Haug Louise E. , Lock James E. , Marshall Audrey C.
Published: August 2009

BACKGROUND: Prenatal intervention for fetuses with pulmonary atresia with an intact ventricular septum (PA/IVS) has the potential to alter right heart physiologic features in utero, facilitating right heart growth and improving the prospect of a biventricular outcome after birth.

METHODS: Since 2002, we have considered prenatal intervention for fetal PA/IVS in patients with (1) membranous pulmonary atresia, with identifiable pulmonary valve (PV) leaflets or membrane; (2) an intact or highly restrictive ventricular septum; and (3) right heart hypoplasia, with a tricuspid valve annulus z score of −2 or below and an identifiable but small right ventricle. Intervention was performed through direct cardiac puncture under ultrasound guidance, with percutaneous access or access through a limited laparotomy.

RESULTS: Ten fetuses underwent attempted balloon dilation of the PV in utero. The first 4 procedures were technically unsuccessful, and the most-recent 6 were technically successful. Compared with control fetuses with PA/IVS who did not undergo prenatal intervention and had univentricular outcomes after birth, the tricuspid valve annulus, right ventricle length, and PV annulus grew significantly more from midgestation to late gestation in the 6 fetuses who underwent successful interventions.

CONCLUSIONS: In utero perforation and dilation of the PV in midgestation fetuses with PA/IVS is technically feasible and may be associated with improved right heart growth and postnatal outcomes for fetuses with moderate right heart hypoplasia in midgestation. There is an important learning curve for this procedure, and much remains to be learned about the selection of appropriate fetuses for prenatal intervention.
Early EEG Findings in Hypoxic-Ischemic Encephalopathy Predict Outcomes at 2 Years
Authors: Murray Deirdre M. , Boylan Geraldine B. , Ryan Cornelius A. , Connolly Sean
Published: August 2009

OBJECTIVE: We examined the evolution of electroencephalographic (EEG) changes after hypoxic injury.

METHODS: Continuous, multichannel, video-EEG was recorded for term infants with hypoxic-ischemic encephalopathy, from <6 hours to 72 hours after delivery. One-hour segments at 6, 12, 24, and 48 hours of age of the EEG were analyzed visually, and neurologic outcome was assessed at 24 months.

RESULTS: Forty-four infants completed neurodevelopmental follow-up. Of those, 20 (45%) had abnormal outcomes. The EEG grade assigned correlated significantly with outcome. EEG abnormalities improved with time, with the worst EEG grade seen on the earliest recording in all cases. The best predictive ability was seen at 6 hours of age (area under the receiver operator characteristic curve: 0.958 [95% confidence interval: 0.88–1.04]; P = .000). Normal/mildly abnormal EEG results at 6, 12, or 24 hours had 100% positive predictive values for normal outcomes and negative predictive values of 67% to 76%. By 48 hours, many of the EEG findings had improved significantly. This led to the positive predictive value of abnormal EEG results being greater at 48 hours (93%), with a concurrent negative predictive value of 71%. EEG features that were associated with abnormal outcomes were background amplitude of <30 μV, interburst interval of >30 seconds, electrographic seizures, and absence of sleep-wake cycling at 48 hours.

CONCLUSIONS: Early EEG is a reliable predictor of outcome in HIE. A normal or mildly abnormal EEG results within 6 hours after birth were associated with normal neurodevelopmental outcomes at 24 months.
What Do Families Want From Well-Child Care? Including Parents in the Rethinking Discussion
Authors: Radecki Linda , Olson Lynn M. , Frintner Mary Pat , Tanner J. Lane , Stein Martin T.
Published: August 2009

OBJECTIVE: The content and systems surrounding well-child care have received increasing attention, and some propose that it is time to rethink both the delivery structure and central themes of well-child visits. A key, but largely missing perspective in these discussions has been that of parents, whose experiences and expectations are central to developing approaches responsive to family needs. In this study, we asked parents to address several core issues: why they attend well-child visits; aspects of well-child care that they find most valuable; and changes that could enhance the well-child care experience.

METHODS: Twenty focus groups with parents (n = 131 [91% mothers]) were conducted by using a semistructured interview guide. Verbatim transcripts were coded for key words, concepts, and recurrent themes.

RESULTS: Primary reasons for visit attendance included reassurance (child and parent) and an opportunity to discuss parent priorities. Families valued an ongoing relationship with 1 clinician who was child-focused and respected parental expertise, but continuity of provider was not an option for all participants. Suggestions for enhancement included improved promotion of well-child care, greater emphasis on development and behavior, and expanded options for information exchange.

CONCLUSIONS: As the consumers of care, it is critical to understand parents' needs and desires as changes to the content and process of well-child care are considered. Taking into account the multifaceted perspectives of families suggests both challenges and opportunities for the rethinking discussion.
Sitting-Meditation Interventions Among Youth: A Review of Treatment Efficacy
Authors: Black David S. , Milam Joel , Sussman Steve
Published: August 2009

OBJECTIVE: Although the efficacy of meditation interventions has been examined among adult samples, meditation treatment effects among youth are relatively unknown. We systematically reviewed empirical studies for the health-related effects of sitting-meditative practices implemented among youth aged 6 to 18 years in school, clinic, and community settings.

METHODS: A systematic review of electronic databases (PubMed, Ovid, Web of Science, Cochrane Reviews Database, Google Scholar) was conducted from 1982 to 2008, obtaining a sample of 16 empirical studies related to sitting-meditation interventions among youth.

RESULTS: Meditation modalities included mindfulness meditation, transcendental meditation, mindfulness-based stress reduction, and mindfulness-based cognitive therapy. Study samples primarily consisted of youth with preexisting conditions such as high-normal blood pressure, attention-deficit/hyperactivity disorder, and learning disabilities. Studies that examined physiologic outcomes were composed almost entirely of African American/black participants. Median effect sizes were slightly smaller than those obtained from adult samples and ranged from 0.16 to 0.29 for physiologic outcomes and 0.27 to 0.70 for psychosocial/behavioral outcomes.

CONCLUSIONS: Sitting meditation seems to be an effective intervention in the treatment of physiologic, psychosocial, and behavioral conditions among youth. Because of current limitations, carefully constructed research is needed to advance our understanding of sitting meditation and its future use as an effective treatment modality among younger populations.
Participation in a Family-Centered Prevention Program Decreases Genetic Risk for Adolescents’ Risky Behaviors
Authors: Brody Gene H. , Chen Yi-fu , Beach Steven R.H. , Philibert Robert A. , Kogan Steven M.
Published: August 2009

OBJECTIVE: The present research addressed the following important question in pediatric medicine: can participation in an efficacious preventive intervention ameliorate the risk that a genetic vulnerability factor is hypothesized to confer on increases in risk behaviors across preadolescence?

METHODS: As part of the Strong African American Families preventive intervention study, data were collected from 641 black families in rural Georgia, assigned randomly to the prevention or control condition. The prevention condition consisted of 7 consecutive meetings at community facilities, with separate parent and youth skill-building curricula and a family curriculum. Each meeting included separate, concurrent sessions for parents and youths, followed by a joint parent-youth session in which families practiced skills they learned in the separate sessions. Involvement in risk behaviors was assessed when the youths were 11 (pretest), 12 (posttest), and 14 (long-term follow-up) years of age. A genetic vulnerability factor, that is, a variable-nucleotide repeat polymorphism in the promoter region of the SLC6A4 gene (5HTT), was assessed 2 years after the long-term follow-up assessment.

RESULTS: Youths at genetic risk who were assigned to the control condition displayed greater increases in risk behaviors across the 29 months that separated the pretest and long-term follow-up assessments, compared with youths at genetic risk who were assigned to the Strong African American Families condition and youths without genetic risk who were assigned to either condition.

CONCLUSION: This is the first study to demonstrate that participation in an efficacious preventive intervention can ameliorate a genetic risk for increasing involvement in health-compromising risk behaviors across preadolescence.
Efficacy and Safety of Spinosad and Permethrin Creme Rinses for Pediculosis Capitis (Head Lice)
Authors: Stough Dow , Shellabarger Susan , Quiring John , Gabrielsen Alvin A.
Published: August 2009

OBJECTIVE: Studies compared spinosad creme rinse and permethrin lice treatment under “actual-use” conditions for pediculosis capitis (head lice).

SUBJECTS AND MATERIALS: Two phase-3, multicenter, randomized, evaluator/investigator-blinded studies compared 0.9% spinosad without nit-combing to 1% permethrin with combing (according to product instructions) in 1038 males and females aged ≥6 months. Spinosad-with-combing groups were included for descriptive, noninferential purposes only. Within 391 households, youngest members having ≥3 live lice were designated primary participants. All household members with lice received the same treatment. Participants administered product 1 to 2 times during the 21-day home-use period on the basis of complete lice eradication after a single use or the presence of lice requiring a second treatment. Scalp evaluations were performed at baseline, day 7, and day 14 (and day 21 for participants treated twice). The primary end point was the proportion of lice-free primary participants 14 days after last treatment.

RESULTS: A total of 84.6% (study 1) and 86.7% (study 2) of spinosad-treated participants were lice free versus 44.9% and 42.9% permethrin-treated participants (P < .001). Most spinosad-treated participants required 1 application, whereas most permethrin-treated participants required 2 applications. Few adverse events were reported, but those occurring were mild to moderate, including eye irritation (permethrin), ocular hyperemia, and application-site erythema/irritation (both medications). No laboratory measure changed significantly.

CONCLUSIONS: Spinosad, which did not require nit combing, was significantly more effective than permethrin in 2 studies reflecting actual-use conditions, and most spinosad-treated participants required only 1 application. Spinosad is a more convenient and effective treatment for pediculosis capitis.
A Comparison of Respiratory Patterns in Healthy Term Infants Placed in Car Safety Seats and Beds
Authors: Kornhauser Cerar Lilijana , Scirica Christina V. , Štucin Gantar Irena , Osredkar Damjan , Neubauer David , Kinane T. Bernard
Published: August 2009

OBJECTIVE: The purpose of this work was to compare the incidence of apnea, hypopnea, bradycardia, or oxygen desaturation in healthy term newborns placed in hospital cribs, infant car safety beds, or infant car safety seats.

METHODS: A consecutive series of 200 newborns was recruited on the second day of life. Each subject was studied while placed in the hospital crib (30 minutes), car bed (60 minutes), and car seat (60 minutes). Physiologic data, including oxygen saturation, frequency, and type of apnea, hypopnea, and bradycardia were obtained and analyzed in a blinded manner.

RESULTS: The mean oxygen saturation level was significantly different among all of the positions (97.9% for the hospital crib, 96.3% for the car bed, and 95.7% for the car seat; P < .001). The mean minimal oxygen saturation level was lower while in both safety devices (83.7% for the car bed and 83.6% for the car seat) compared with in the hospital crib (87.4%) (P < .001). The mean total time spent with an oxygen saturation level of <95% was significantly higher (P = .003) in both safety devices (car seat: 23.9%; car bed: 17.2%) when compared with the hospital crib (6.5%). A second study of 50 subjects in which each infant was placed in each position for 120 minutes yielded similar results.

CONCLUSIONS: In healthy term newborns, significant desaturations were observed in both car beds and car seats as compared with hospital cribs. This study was limited by lack of documentation of sleep stage. Therefore, these safety devices should only be used for protection during travel and not as replacements for cribs.
Ingredients Necessary for Proton Transfer in Enzymes
Authors: Scheiner Steve
Published: August 2009

The transfer of a proton across a hydrogen bond can be influenced by a number of factors, including H‐bond length, intramolecular angles, and the presence of neighboring groups. The ability of different factors to push a proton across the H‐bond is examined for a specific and very important pair of catalytic groups, Ser‐195 and His‐57, within the context of a serine proteinase enzyme. The influence of residue Asp‐102 is considered for different charge states, as is the nature of the surrounding medium. Also examined are the perturbations introduced by the substrate and external ions and dipoles.