Specific Justification Research Articles

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We thank Dr Hofman for commenting on our article on prenatal ultrasound detection of facial clefts1. Dr Hofman claims we are making a descriptive error by reporting an overall detection rate of cleft lip and palate of 45% given the fact that the rate of associated anomalies amongst the detected cases was approximately 20%. Dr Hofman refers to this calculated 20% detection as ‘a relevant detection rate’. We disagree with this statement. Most parents of children with isolated cleft lip and palate would disagree, too. In fact, it was the parental interest group for children with cleft lip and palate who first made contact with us during the late 1980s to focus on the importance of making these diagnoses antenatally. Such parents are provided with detailed counseling to be prepared for the rather extensive surgical therapy the child has to go through from around 3 months of age and subsequently, depending on the extent of the anomaly. Due to the recurrence risk, parents with an affected child are also particularly interested in prenatal ultrasound in future pregnancies in order to be informed of the presence or absence of the indicated diagnosis as early as possible. Due to the high rate of serious associated conditions, including chromosomal aberrations, syndromes and sequences, found amongst cases with cleft lip and palate anomalies, the detection of such cases is important. We have reported an increase in the detection rate of cleft lip and palate from 34% to 58% and have reasons to believe this detection rate will increase. In contrast to Dr Hofman's belief, we consider ultrasound to be a good method for detecting fetal anomalies. The detection rate of different anomalies varies extensively depending on the organ system in question. Series have shown increasing detection rates over time as the field of fetal medicine, including the quality of equipment, advances2, 3. Most likely, the detection rate of anomalies in general will continue to increase. We also disagree with the claimed ‘second error’—the naturalistic fallacy. As stated above, cleft lip and palate is associated with an overall risk of additional anomalies of around 50%. This risk included an overall risk of chromosomal aberrations of 12% in our population. The claim that ‘screening needs specific justification’ and the possibility that ‘Detecting less severe, and operable, defects such as facial clefts, may lead to parental decisions for abortions’ certainly are important issues of medical ethics. This fundamental ethical discussion was considered beyond the scope of the descriptive presentation in our article. However, ethical issues will remain an important part of the development of fetal medicine. K. Offerdal*, S. H. Eik-Nes*, * National Center for Fetal Medicine, Women and Children's Center, St Olavs University Hospital and Institute of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, 7006 Trondheim, Norway

The Best Rodent for the Job: NTP Workshop Compares Models

Vol. 115, No. 9 EnvironewsOpen AccessThe Best Rodent for the Job: NTP Workshop Compares Models Julia R. Barrett Julia R. Barrett Search for more papers by this author Published:1 September 2007https://doi.org/10.1289/ehp.115-a460bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Researchers have long used rats and mice to understand the potential links between environmental exposures and incidences of breast, ovarian, testicular, and prostate tumors. Concern exists, however, that rodent models are not optimal for detecting carcinogens that act through the hormone system. To address this concern, the National Toxicology Program (NTP) organized a workshop in May 2006 to evaluate the utility of current two-year rodent bioassays to adequately evaluate these hormon ally mediated tumors and the relevance of the findings to humans [EHP 115:1351–1356; Thayer and Foster].The workshop, part of a series of events aimed at evaluating and refining the NTP’s testing program, included representatives from academia, industry, government, and nonprofit groups, as well as a panel of invited experts in endocrinology, cancer biology, reproductive toxicology, statistics, and other fields. Workshop participants were concerned that many hormonally mediated tumors, such as those in the testes and breasts, are initiated in fetal or early neonatal life, yet these periods of exposure are not covered in the NTP’s standard cancer bioassay. In response to this concern, the NTP has committed to routinely include perinatal exposures in these studies unless there is a specific justification not to do so.Furthermore, some rat and mouse strains used in testing either do not develop certain tumors or have a high incidence of spontaneous tumors. For example, the F344/N rat typically used by the NTP has high background incidences of testicular Leydig cell tumors and mononuclear cell leukemia, along with unresolved issues about declining fertility, sporadic seizures, and chylothorax (accumulation of lymphatic fluid in the pleural cavity, which can result from lymphoma). By press time, in response to this and other workshop findings, the NTP had selected the Wistar Han as its standard rat strain cancer and noncancer end points, although other strains will be used when appropriate.Although rodent models are considered to have certain deficiencies and can be improved, they are considered valuable nonetheless. Rodent models for prostate and ovarian tumors are the most problematic for understanding human disease because of significant interspecies differences in anatomy and tumor prevalence. Participants in the workshop recommended using alternative models, such as genetically engineered models and in vitro systems, to address some of these deficiencies. They also recommended more in-depth investigation of how noncancerous changes observed in rodents might be relevant to human diseases.FiguresReferencesRelatedDetails Vol. 115, No. 9 September 2007Metrics About Article Metrics Publication History Originally published1 September 2007Published in print1 September 2007 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

A rate-dependent damage model for brittle materials based on the dominant crack

A rate-dependent, continuum damage model is developed for brittle materials under dynamic loading. This model improves on the approach (ISOSCM) of [Addessio, F.L., Johnson, J.N., 1990. A constitutive model for the dynamic response of brittle materials. Journal of Applied Physics 67, 3275–3286] in several respects. (1) A new damage surface is found by applying the generalized Griffith instability criterion to the dominant crack (having the most unstable orientation), rather than by averaging the instability condition over all crack orientations as done previously. The new surface removes a discontinuity in the damage surface in ISOSCM when the pressure changes sign. (2) The strain due to crack opening is more consistent with crack mechanics, with only the tensile principal stresses contributing to the crack opening strain. This is achieved by incorporating a projection operator in the equation for the crack opening strain. One consequence of incorporating the projection operator is a prediction of shear dilatancy, which is not accounted for in ISOSCM. (3) The evolution of damage, which is based on the energy-release rate for the dominant crack, has a physical basis, whereas in the previous approach the damage growth rate was assumed to be an exponential function of the distance from the stress state to the damage surface without specific physical justification. An implicit algorithm has been developed so that a larger time step can be used than with the explicit algorithm used in ISOSCM. The numerical results of a silicon carbide (SiC) ceramic under several loading paths (hydrostatic tension/compression, uniaxial strain, uniaxial stress, and shear) and strain rates are presented to illustrate the main features of the model.

An Ontology of Data Modelling Languages

Data modelling languages are used in today’s information systems engineering environments. Many have a degree of hype surrounding their quality and applicability with narrow and specific justification often given in support of one over another. We want to more deeply understand the fundamental nature of data modelling languages. We thus propose a theory, based on ontology, that should allow us to understand, compare, evaluate, and strengthen data modelling languages. In this paper we present a method (conceptual evaluation) and its extension (conceptual comparison), as part of our theory. Our methods are largely independent of a specific ontology. We introduce Chisholm’s ontology and apply our methods to analyse some data modelling languages using it. We find a good degree of overlap between all of the data modelling languages analysed and the core concepts of Chisholm’s ontology, and conclude that the data modelling languages investigated reflect an ontology of commonsense-realism.

La maladie de Horton simple : modalités thérapeutiques

Corticosteroids remain the basis of treatment of Horton's syndrome, with prednisone the molecule of choice, since they improve the symptoms and considerably reduce the risk of blindness. Several clinical forms of the disease must be distinguished in order to specify the modalities of corticosteroid treatment and any eventual associated treatments. SIMPLE HORTON'S SYNDROME: The simple forms of the disease are defined by the absence of ocular involvement, the absence of clinical involvement of the large arteries, the absence of corticosteroid resistance and the absence of corticosteroid dependence (simple forms subsequently complicated). MODALITIES OF CORTICOSTEROID THERAPY: These simple forms justify an attack treatment with 0.7 mg/kg/d of prednisone although cortisone assaults do not have a specific justification. Initiation with lower daily doses of prednisone at 0.5/mg/kg or even less appear to expose the patient to a higher risk of progression of the disease, but merit assessment. SATELLITE QUESTIONS: The iatrogeneity of corticosteroids raises problems in corticosteroid dependent patients and those receiving prolonged attack treatment. The risk of cortisone-induced osteoporosis is particularly high during Horton's syndrome. There is still no prospective study specifying the indications for treatment of the disease with anticoagulants or platelet antiaggregants.

Administrative prescription review procedures and use of atypical antipsychotic medications in the Department of Veterans Affairs.

Atypical antipsychotic medications vary in cost with limited evidence of differences in effectiveness. Administrative prescription review has been proposed as a way of encouraging use of less expensive medication when there is no specific clinical justification for using more expensive medication. This study examined data from a national GAO survey of 876 veterans affairs (VA) psychiatrists, and national administrative data on the proportion of veterans actually receiving atypical antipsychotic medications. The proportion of psychiatrists in each region reporting that they did not feel free to prescribe expensive drugs when indicated was negatively correlated with the proportion of patients who filled prescriptions for clozapine, the most expensive atypical. The proportion reporting review procedures for prescribing olanzapine was significantly and negatively correlated with the proportion of veterans actually receiving prescriptions for olanzapine and, positively associated with the proportion prescribed risperidone. Nondirective administrative review procedures in VA are significantly associated with actual prescribing patterns and may generate modest cost savings in the prescription of atypical antipsychotic medication.

The Behaviour of Financial Ratios for Capital and Labour Intensive Enterprises During the Economic Cycle

The objectives of the study are firstly, to analyse and investigate patterns to determine whether or not there are specific justification(s) for the behaviour exhibited by capital intensive (CI) and labour intensive (LI) enterprises for a particular ratio during either or both the upswing and decline phases of the economic cycle. The second objective is to isolate financial indicators which could possibly be used to forecast financial performance by identifying leads and lags.The findings of the research suggest that CI and LI enterprises differ in terms of the behaviour of certain financial indicators during either or both an upswing and decline of the economic cycle. It is therefore not possible to consider the universal use of financial indicators. It also appears that it is possible to use a large number of traditional indicators to forecast financial performance as they follow the trade cycle. Several indicators suggest the possibility of leading the economic cycle and therefore could provide an indication of an economic upswing or decline.

NON-DISCRIMINATORY TRADE RESTRICTIONS AFTER KECK

IN its Keck judgment—famous or notorious according to taste—the Court of Justice drew a distinction, for the purposes of the application of the prohibition in Article 28 EC against measures having equivalent effect to quantitative restrictions (“MEEQRs”), between two categories of national measures. On the one hand were “product requirements”: measures specifying requirements to be met, in order to obtain access to the market of a Member State, by products coming from other Member States where they are lawfully manufactured and marketed, like the minimum alcohol requirement for fruit liqueurs in Cassis de Dijon (Case 120/78 [1997] E.C.R. 649). Such product requirements are liable to constitute MEEQRs, and therefore require specific justification, in order to escape prohibition, on one of the public interest grounds recognised by Community law. On the other hand was the category of measures described in the judgment as “provisions restricting or prohibiting certain selling arrangements”. An example was the legislation at issue in the main proceedings in Keck, which prohibited the resale of products below their purchase price, thereby depriving retailers of a form of sales promotion. Other examples, attested by the case law post-Keck, are measures regulating advertising methods, the kind of shop in which goods of a certain description can be sold, shops’ opening hours and Sunday trading. National provisions in this latter category are not normally such as to hinder trade between Member States under the test formulated by the Court in Dassonville (Case 8/74 [1974] E.C.R. 837, at para. 5), and so do not call for justification; not, that is, “so long as those provisions apply to all relevant traders operating within the national territory and so long as they affect in the same manner, in law and in fact, the marketing of domestic products and those from other Member States”: see Joined Cases C-267 and 268/9 [1993] E.C.R. I-6097, at paras. 15–17.

Why we fought: Holocaust memory in Spielberg's Saving Private Ryan

–Steven Spielberg's film Saving Private Ryan has been criticized for its failure to frame narrative action in terms of national, moral purpose. This criticism can be understood in terms of the constraints that the “Vietnam syndrome” places upon contemporary cinematic narratives of war; Vietnam memory subverts earnest declaration of high national principle. This essay examines how Saving Private Ryan “reillusions” American national identity in the wake of Vietnam by giving presence to an even more distant past. Supported by close textual analysis of key scenes centering upon the sole Jewish character in the film, this reading argues that the specific moral justification for waging war and accepting its horrors and sacrifices is found in a moral crusade against the Nazi program of Holocaust. By suturing the Holocaust into the film as its moral foundation, the film participates in the “Americanization” of Holocaust memory, circumvents Vietnam as a source of traumatic memory, manufactures a redemptive national identity, and constructs an ethically usable past in the present.

Measuring the Strength of Demographic Stochasticity

According to a well-established paradigm in conservation biology, demographic stochasticity as such is an improbable cause of extinction in populations larger than 100 individuals. However, the strength of demographic stochasity depends not only on population size, but on the life history characteristics of the population as well. Consequently, neglecting demographic stochasticity is not appropriate without specific justification. This paper introduces two new measures, demographic effective population size N D and strength of demographic stochasticity D. Thus, the role of 100 individuals being relatively safe from extinction caused by demographic stochasticity is reformulated by considering the effective population size instead of simply counting the number of individuals. Also, the measures render it possible to compare vulnerabilities to extinction caused by different types of life histories. Five examples, taking advantage of the theory of branching processes and Markov chains, illustrate the use of the measures.

Properties of Zeolite- and Cornstarch-Based Electrorheological Fluids at High Shear Strain Rates

The mechanical and electrical properties of zeolite- and cornstarch-based ER fluids are explored using a concentric cylinder viscometer. With cylinder radius to gap size ratio on the order of 400, we achieved shear strain rates ranging from 3000 to 20,000 sec-1. Two different volume fractions of zeolite and cornstarch suspensions in silicone oil were tested at a constant temperature of 30°C. The shear stresses and electric resistivity of the fluids were computed from experimental measurements as functions of shear strain rate. Although the cornstarch ER fluids indicated anomalous behavior, the zeolite ER fluids were found to be more stable under high shear strain rates and electric fields and were characterized by a Bingham viscoplastic model-like behavior. Dynamic yield stress was increased in proportion to a power of the electric field. The higher the volume fraction of dispersions, the higher the yield stress. Plastic viscosity, as defined by the Bingham model, remained unchanged with the variation of elec tric field for a fixed volume fraction. This work was motivated by the need for applications to rotor-bearing control, where for usual bearings, the shear rate is much higher than the maxima of most of the published experimental results. Moreover, for high shear rates, the validity of the Bingham model was questioned by many authors without specific experimental justification, which is attempted here for two different kinds of dispersed particles.

The normative purpose of economic ‘science’: Rediscovery of an eighteenth century method

The necessity of abstraction is self-evident. By its very nature, intellectual activity involves coming to terms with a chaos of observations through the imposition of an order which is itself an artifact of the mental process. In this activity, a selective strategy must be used. Irrelevances must be blotted out, where these consist of observations that tend to disprove, qualify, or overly complicate the sought-for mental picture. Any theory is abstracted from the reality perceived by the senses, and theory derives its potential value precisely because it is so abstracted. From this perspective, it follows that any theory, any model, can, and indeed must, be able to tolerate a certain amount of dissonance with perception before it loses its relative superiority over potential alternatives. This perspective suggests that there may well be many possible mental orders or constructs that can ‘explain’ a particular set of ‘facts’ within the tolerated range of ‘error.’ Which particular order chosen depends on many elements, including the tastes of the analyst, intellectual habits and fashions of the times, and the extent of congruence with the reality that is perceived (congruence that embodies predictive power as an important part). We leave as basically ‘mysterious’ the causal linkage between changes in these elements and a switching of mental orders (paradigms). In this paper, we are interested in one particular abstraction, one that is familiar to all economists. We are concerned with the model of man that is used in economic theory the model of man that actually takes its name from the discipline, home economicus. Our purpose is to develop a specific justification for that abstraction

THE INFLUENCE OF THE TYPE OF SOURCES USED ON THE RESULTS OF CITATION ANALYSES

Most citation analyses are based on references taken from two or three source journals. There are good theoretical reasons for believing that these may not be representative of all references. In the social science citation analyses carried out as part of the DISISS programme, references were collected from 140 journals, including forty‐seven drawn at random from a comprehensive list, and also from 148 monographs. Analyses of references drawn from high ranking and randomly selected journals showed differences in date distribution, forms of material cited and rank order of journals cited. Analyses of references drawn from journals and monographs showed differences, some of them large, in date distributions, forms of material cited, subject self‐citation and citations beyond the social sciences, and countries of publication cited. These differences may be peculiar to the social sciences, but any citation analyses that are based on only a limited number and type of sources without specific justification must be regarded with suspicion.