Candidate Criterion Research Articles

Consideration of a Stress-Based Criterion for Local Failure and Its Implementation in a Damage Mechanics Model

Analyses of the notched tension tests of carbon steel show that ductile failure is initiated when the sum of flow stress and mean stress reaches the limit for the material, regardless of stress triaxiality. Therefore, this explicit critical stress condition could be a candidate criterion for local failure. An equation expressing the relation between stress triaxiality and critical strain was derived from the critical stress condition, and it was found that the critical strain diagram obtained by the equation nearly overlapped with that obtained by the conventional empirical equation. This suggests that the critical stress condition can be approximately determined if the critical strain diagram was obtained for a particular steel. The critical stress condition was consistent with the classical void nucleation theory, and the theory was incorporated into the void nucleation term of stress control in the Gurson–Tvergaard (GT) model—a well-known damage mechanics model for ductile failure. Since only the strain-controlled term is used in the recent GT model, herein, a finite element method (FEM) code was newly developed to implement the GT model with the stress-controlled term. Notched tension tests were analyzed with the critical stress condition using the developed code, and the analyses reproduced the failure behaviors and critical strains of the tests considerably well. These results strongly support the practicality of the stress-based criterion and demonstrate that ductile failure could be appropriately predicted by combining the GT model using the void nucleation term of stress control with the critical stress condition.

Predicting the Value of Product Service-Systems for Potential Future Implementers: Results from Multiple Industrial Case Studies

The great impact played by Product/Service-Systems (PSS) on industry and academia can be motivated by the need for modernizing business models, carrying out internal companies’ reconfiguration, enhancing environmental sustainability. Despite the large number of objectives pursued by PSS, sparks of criticism have recently emerged, as well as the results ensuing from PSS adoption have not been rigorously assessed. In particular, the authors highlight a lack of quantitative analysis concerning the service aspects of PSS and hurdles in service modeling and evaluation. The paper's objective is to contribute in this field by individuating factors, advantages and disadvantages that are not directly measurable in monetary terms by companies. This kind of assessment might result crucial, as the implementation of PSS-oriented strategies require a not negligible amount of commitment, besides propensity to risk. A first activity was carried out thanks to a pilot group of firms that have not implemented any PSS initiative so far, which have been exposed to business reconfiguration scenarios underpinning PSS. A model for generalizing pros and cons of future PSS implementation has been subsequently experimented by a larger group of industrial organizations. Such a model has represented the backbone for the creation of a tentative quantitative estimation tool, which assesses and forecasts the added value of services featured by the introduction of PSS and hence represents a candidate criterion for undertaking decisions concerning the implementation of PSS strategies. The paper clarifies which assumptions are introduced in order to achieve this result.

Genetic parameters of rabbit semen traits and male fertilising ability

This study aimed to estimate genetic parameters for rabbit semen production, semen characteristics and fertilising ability following artificial insemination. It involved five successive batches of 30–36 bucks each, 22 weeks of semen collection, and 11 weeks of semen recording per batch. Semen analyses were based on 2312 ejaculates. A total of 2019 inseminations were performed on 674 females with semen from 236 ejaculates from 128 bucks. Heritability estimates of semen traits ranged from 0.05 to 0.18. At approximately 0.05–0.06 for pH, volume and mass motility, they were higher for concentration (0.10) and the total number of sperms per ejaculate (0.12), and even higher for motility traits based on computer-assisted semen analysis. The percentage of motile sperms had the highest heritability (0.18) and appeared to be a good candidate criterion to select for both sperm number and motility. The heritability estimates were close to zero for all three criteria of fertilising ability: fertility (F), prolificacy (live births, LB) and their product (LB per insemination). A permanent environmental effect of the male seemed to be higher for LB (0.04) than for F (0.01). The rabbit does accounted for approximately 10% of the variance of the three criteria. With respect to the female, the male contribution was negligible for fertility and in a ratio of 4–10 for the number of live births. In our experimental conditions, prolificacy would thus be more highly influenced by the buck than fertility.

A method for discovering and inferring appropriate eligibility criteria in clinical trial protocols without labeled data

BackgroundWe consider the user task of designing clinical trial protocols and propose a method that discovers and outputs the most appropriate eligibility criteria from a potentially huge set of candidates. Each document d in our collection D is a clinical trial protocol which itself contains a set of eligibility criteria. Given a small set of sample documents, a user has initially identified as relevant e.g., via a user query interface, our scoring method automatically suggests eligibility criteria from D, D ⊃ D', by ranking them according to how appropriate they are to the clinical trial protocol currently being designed. The appropriateness is measured by the degree to which they are consistent with the user-supplied sample documents D'.MethodWe propose a novel three-step method called LDALR which views documents as a mixture of latent topics. First, we infer the latent topics in the sample documents using Latent Dirichlet Allocation (LDA). Next, we use logistic regression models to compute the probability that a given candidate criterion belongs to a particular topic. Lastly, we score each criterion by computing its expected value, the probability-weighted sum of the topic proportions inferred from the set of sample documents. Intuitively, the greater the probability that a candidate criterion belongs to the topics that are dominant in the samples, the higher its expected value or score.ResultsOur experiments have shown that LDALR is 8 and 9 times better (resp., for inclusion and exclusion criteria) than randomly choosing from a set of candidates obtained from relevant documents. In user simulation experiments using LDALR, we were able to automatically construct eligibility criteria that are on the average 75% and 70% (resp., for inclusion and exclusion criteria) similar to the correct eligibility criteria.ConclusionsWe have proposed LDALR, a practical method for discovering and inferring appropriate eligibility criteria in clinical trial protocols without labeled data. Results from our experiments suggest that LDALR models can be used to effectively find appropriate eligibility criteria from a large repository of clinical trial protocols.

Reconsideration of the most appropriate criterion in the lowest classification of vision disability in Japan

To verify the current Japanese classification of vision disability in regard to visual acuity. A questionnaire was sent to 100 ophthalmology services in Japan. Each service was asked to extract 300 of their outpatient records. From these records, patients who had a sum of corrected visual acuity in both eyes of less than or equal to 0.62 were selected for the questionnaire. The questionnaire consisted of items related to prevalence, age, sex, with or without vision-disabled certification at any grade, the corrected visual acuity of each eye and the name of any disease the subject may have had. Sixty-five services responded, and, of 20,235 total records reviewed, 971 patients were eligible for the questionnaire. The average age was 66.9 ± 20.0 years, and 74.6% were over 60 years old. The distribution of corrected visual acuity showed three categories. Our analysis indicates that a new candidate criterion for vision-disabled certification is needed for the sixth grade, which, at present is defined as, "The sum of the corrected visual acuity of both eyes is more than 0.2, but less than or equal to 0.4."

Interleukin‐8 induction due to diffusely adherent Escherichia coli possessing Afa/Dr genes depends on flagella and epithelial Toll‐like receptor 5

DAEC is considered potentially diarrheagenic. For diffuse adhesion, the role of the Afa, which was originally identified as a uropathogenic factor, is now understood. However, the role of DAEC in diarrheal disease remains controversial because DAEC is often isolated not only from patients but also from healthy individuals. Previously, we suggested that Afa/Dr DAEC, which can induce high levels of IL-8 secretion in cultures of human carcinoma epithelial cells (HEp-2, Caco-2), is enterovirulent. In the present study, we examined whether IL-8 secretion induced by certain Afa/Dr DAEC strains was primarily due to flagella via TLR5. All IL-8 high-inducing strains were highly motile in swarming tests. Partially purified flagella induced IL-8 in a dose-dependent manner. However, IL-8 induction was inhibited by small-interfering RNA against TLR5 or by treating flagella with disialoganglioside-GD1a, a TLR5 blocker. TLR5 is reportedly located on the basolateral side of intestinal epithelia; flagella should not have reached TLR5 from the apical side beyond tight junctions. Reduction in the number of intracellular organisms by wortmannin, a PI3K inhibitor, did not reduce IL-8 secretion. Afa/Dr DAEC seemed to loosen the tight junctions because it quickly reduced transepithelial electrical resistance after infection. Decreased resistance led to increased IL-8 production. In conclusion, diffuse adhesion itself is insufficient to induce high levels of IL-8, and simultaneous stimulation by flagella via TLR5 is likely required for additional induction. Clinically, high motility may be a candidate criterion for predicting the ability of Afa/Dr DAEC strains to induce higher levels of IL-8 secretion.

Using field data and weight of evidence to develop water quality criteria

In the United States, ambient aquatic life water quality criteria are derived using guidelines developed in 1985 that include a clear and consistent methodology using data from standard toxicity tests. The methodology from these guidelines has been successful, but a broader methodology is needed because some effects of pollutants do not lend themselves to conventional toxicity testing. Criterion assessment is proposed as that methodology. In criterion assessment, a specific environmental goal is translated into a measurable benchmark of effect that is used together with a modeled exposure-response relationship to estimate a range of exposures that will achieve the specific goal. The model of the exposure-response relationships and the benchmark effect are developed from field data and laboratory data using multiple analytical methods. Then the model is solved for the effect, thereby estimating the criterion, an upper threshold for acceptable exposures. The resulting candidate criteria are synthesized to select criteria and other benchmark values, such as remedial goals. The criterion assessment process is illustrated using the US Environmental Protection Agency Framework for Developing for Suspended and Bedded Sediments Water Quality Criteria, which recommends developing alternative candidate criterion values and then evaluating them to select a final criterion. Candidate criteria may be derived from models of field observations, field manipulations, laboratory tests, or empirical and theoretical models. Final selection of a criterion uses a weight-of-evidence comparison that engenders confidence because causal associations are confirmed on the basis of different assumptions, independent data sets, and varied statistical methods, thereby compensating for the concerns raised by individual studies and methods. Thus, it becomes possible to specify criteria for agents with biological or physical modes of action, as well as those with chemical modes of action, to best achieve environmental goals.

In vitro assay to select rainbow trout with variable resistance/susceptibility to viral haemorrhagic septicaemia virus

The merit of a candidate criterion of resistance to viral haemorrhagic septicaemia virus (VHSV) was tested with the view of producing experimental trout progeny with a predictable level of resistance. The criterion, the measure of in vitro viral replication in excised fin tissue (VREFT) was previously developed. Three experiments were performed, using both ordinary and homozygous doubled-haploid breeders. A set of 48 progeny was tested. Breeders were individually scored for repeated measures of VREFT, and the progeny were tested against VHSV (strain 07-71, serotype 1) through a waterborne challenge (5 x 10(4) pfu ml(-1) during 2 h). Analysis of repeated measures of VREFT revealed the risk of identifying 'false' resistant individuals. The highest value should be considered the most predictive of the resistance status. Survival of progeny ranged from 0 to 100% according to the group and the experiment. The survival was correlated to the mean VREFT value of the breeders in Expts 1 and 2 (R = 0.96 and 0.61 respectively), but not in Expt 3 (R = 0.36, ns) where all tested progeny were highly susceptible. Results thus indicate that viral growth in fin tissue is genetically correlated to resistance to waterborne disease and may be used to produce selected progeny, at least at the experimental scale. Possible implications of the relationship between VREFT and resistance for the study of resistance mechanisms are discussed.

Closer

Criteria of identity should mirror the identity relation in being reflexive, symmetrical, and transitive. However, this logical requirement is only rarely met by the criteria that we are most inclined to propose as candidates. The present paper addresses the question how such obvious candidates are best approximated by means of relations that have all of the aforementioned features, i.e., which are equivalence relations. This question divides into two more basic questions. First, what is to be considered a ‘best’ approximation. And second, how can these best approximations be found? In answering these questions, we both rely on and constructively criticize ground-breaking work done by Timothy Williamson. Guiding ideas of our approach are that we allow approximations by means of overlapping equivalence-relations, and that closeness of approximation is measured in terms of the number of mistakes made by the approximation when compared to the obvious candidate criterion.

Separating Pharmacokinetic and Pharmacodynamic Components in Empirical Adjustment Factor Distributions

ABSTRACT For a particular chemical, one can treat the chemical-by-chemical variation in relative doses for equal toxicity in experimental animals and humans as a characterization of the likelihoods of extrapolation factors of different magnitudes. An emerging approach to noncancer risk assessment is to use such empirical distributions in place of fixed Uncertainty Factors. This paper discusses dividing the overall variation into two sub-distributions representing pharmacokinetic (PK) and pharmacodynamic (PD) contributions to the variation among chemicals in the animal-to-human toxicologically equivalent dose. If a physiologically based pharmacokinetic model (PBPK model) is used to derive a compound specific adjustment factor (CSAF) for the pharmacokinetic component, the deconvolution of the PK and PD components allows one to remove the PK component (to be replaced with the CSAF), while retaining the uncertainty in pharmacodynamics that PBPK models do not address. One must then add back the uncertainty in the PBPK determination of the CSAF (which may be considerable). A candidate criterion for whether one can use an uncertain PBPK model is whether the generic uncertainty about cross-species pharmacokinetics (reflected in the PK component of the overall empirical distribution) is larger than the chemical-specific uncertainty in the determination of kinetically equivalent doses in experimental animals and humans.

On not knowing what or who one is: Reflections on the intelligibility of dualism

Beginning with Descartes' caution not “imprudently” to “take some other object in place of myself”, I consider first the problems of self-identification confronted by variousamnesiacs, both ordinary and Cartesian. Noting thatcogitationes as such do not individuate, I proceed to examine conclusions drawn from certain sorts of “body-switching” thought experiments. This, in turn, gives rise to a general critique of “psychological connectedness” or “unity of consciousness” as a candidate criterion of personal identity. I conclude that our ability to apply any notion of personal identity is parasitic upon the existence of a conceptual apparatus for individuating, identifying, and reidentifying objects. Finally, I argue that, if ‘person’ is a proper sortal predicate to begin with, Descartes'res cogitans cannot be understood as a species of the (metaphysical) genusres, distinct fromres extensa and only problematically in “interaction” with it. Cartesian dualism is a multiply untenable doctrine.