منابع مشابه
Asthma is a Serious Danger
میزان مرگ و میر آسم طی دهه گذشته بطور چشمگیری تغییر کرده است. با مبتلا کردن ۱۵ میلیون آمریکایی میزان مرگ و میر در سال ۱۹۷۸، به رقم ۱۸۷۲ نفر و ۹ سال بعد، به بیش از ۴۰۰۰ نفر رسید. علت چنین افزایش چشمگیری روشن نیست. علل احتمالی عبارتند از کاهش ظرفیت تنفس، استفاده بیش از حد از داروهای استثنائی و استنباط غلط بیماران و نیز مراکز درمانی نسبت به شدت بیماری است. بررسی دقیق، معالجات مناسب و آموزش به ب...
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We show that if a class of modules is closed under pure quotients, then it is precovering if and only if it is covering, and this happens if and only if it is closed under direct sums. This is inspired by a dual result by Rada and Saorín. We also show that if a class of modules contains the ground ring and is closed under extensions, direct sums, pure submodules, and pure quotients, then it for...
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Adámek and Sousa recently solved the problem of characterizing the subcategories K of a locally λ-presentable category C which are λ-orthogonal in C, using their concept of Kλ-pure morphism. We strenghten the latter definition, in order to obtain a characterization of the classes defined by orthogonality with respect to λ-presentable morphisms (where f :A B is called λ-presentable if it is a λ-...
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Many mathematicians have sought ‘pure’ proofs of theorems. There are different takes on what a ‘pure’ proof is, though, and it’s important to be clear on their differences, because they can easily be conflated. In this paper I want to distinguish between two of them. I want to begin with a classical formulation of purity, due to Hilbert: In modern mathematics one strives to preserve the purity ...
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Practical specification languages for imperative and object-oriented programs, such as JML, Eiffel, and Spec#, allow the use of program expressions including method calls in specification formulas. For coherent semantics of specifications, and to avoid anomalies with runtime assertion checking, expressions in specifications and assertions are typically required to be weakly pure in the sense th...
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ژورنال
عنوان ژورنال: The European Journal of Public Health
سال: 1996
ISSN: 1101-1262,1464-360X
DOI: 10.1093/eurpub/6.2.109