abstract : avian influenza virus (aiv) infection is a major cause of influenza mortality in birds and can cause human mortality and morbidity. although the risk of infection with avian influenza virus (aiv) is generally low for most people, the pathogenic virus can cross the species barrier and acquires the ability to infect and be transmitted among the human population; therefore the rapid ide...

Structural subtyping is popular in research languages, but all mainstream object-oriented languages use nominal subtyping. Since languages with structural subtyping are not in widespread use, the empirical questions of whether and how structural subtyping is useful have thus far remained unanswered. This study aims to provide answers to these questions. We identified several criteria that are i...

B Properties of the Declarative System 23 1 Lemma (Declarative Weakening) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2 Lemma (Declarative Term Substitution) . . . . . . . . . . . . . . . . . . . . . . . . 23 3 Lemma (Reflexivity of Declarative Subtyping) . . . . . . . . . . . . . . . . . . . . . 23 4 Lemma (Subtyping Inversion) . . . . . . . . . . . . . . . . . . . . . . . . . ....

In this paper we investigate the object-oriented notion of subtyping in the context of behavioural formalisms. Subtyping in OO-formalisms is closely related to the concept of inheritance. The central issue in the choice of subtyping relations among classes is the principle of substitutability: an instance of the subtype should be usable wherever an instance of the supertype was expected. Depend...

A constrained type is a type that comes with a set of subtyping constraints on variables occurring in the type. Constrained type inference systems are a natural generalization of Hindley/Milner type inference to languages with subtyping. This paper develops several subtyping relations on polymorphic constrained types of a general form that allows recursive constraints and multiple bounds on typ...

background: blastocystis is one of the most common parasites, reported from both human and animals. this parasite is more prevalent in regions with low levels of hygiene, close contact with animal and unsuitable disposal systems. the aim of the study was to subtype blastocystis sp., isolated from diarrheic and non-diarrheic patients using sequencing of 18s ribosomal dna. methods: totally, 300 s...

Object type constructors have been introduced as an approach to adding container object types to a language with type inference. Useful subtyping for object type constructors requires a flexible subtype rule for type constructors that is not simply the pointwise extension of subtyping for types. At the same time, subtyping should avoid requiring run-time type checks, as in the Java subtype rule...

Classes play a dual rôle in mainstream statically-typed object-oriented languages, serving as both object generators and object types. In such languages, inheritance implies subtyping. In contrast, the theoretical language community has viewed this linkage as a mistake and has focused on subtyping relationships determined by the structure of object types, without regard to their underlying impl...

Subtyping occurs when atypical examples are excluded from consideration in judging a category. In three experiments, we investigated whether subtyping can influence category learning. In each experiment, participants learned about a category where most, but not all, of the exemplars corresponded to a theme. The category structure included a subtyping dimension, which had one value for theme-con...