Topics (384k) Articles (398k) Users (410) Discussions (242) Comments (383) Files (13k) New article
Rapid onset or worsening of heart failure. Pulmonary congestion, circulatory impairment or both can occur, making the clinical state more informative than assuming one uniform change in heart size.[ref]
Acute heart failure by NICE. Scope and clinical assessment
The aortic valve lies between the left ventricle and aorta. Its cusps open when the pressure difference favors ventricular outflow and close as the pressure relation reverses. This limits backflow during ventricular relaxation without requiring the cusps to act as an independent muscular pump.
Cardiac output is the volume of blood pumped by one ventricle per unit time. With stroke volume and heart rate , . The product connects beat-by-beat mechanics to total flow.
For an invented arithmetic example, beats per minute and millilitres per beat give millilitres per minute, or litres per minute. A change in heart rate alone need not produce the proportional output change if filling and stroke volume also change.
The left ventricle receives blood from the left atrium and pumps it into the aorta through the aortic valve. Its muscular wall supplies the pressure needed for systemic circulation. Pressure generation and the volume ejected are different measures of ventricular performance.
A heart valve permits predominantly one-way blood flow through the heart. Leaflet motion follows changing pressure differences and structural constraints. The four main human valves occupy different chamber or outflow boundaries, so valve dysfunction has location-specific consequences.[ref]
The atrioventricular node is specialized conducting tissue between atrial activation and ventricular conduction pathways. Its conduction properties contribute a delay in the sequence of cardiac excitation. Electrical transmission and mechanical valve opening are related in time but are different processes.
A cardiac ventricle is a lower pumping chamber of the heart. In the human circulation, the right ventricle drives pulmonary flow and the left ventricle drives systemic flow. Their pressure loads differ even though their long-term net outputs normally match.
A heap data structure stored as a complete rooted tree with up to children per vertex, where . The final level is filled from left to right. For zero-based array storage, the parent of entry is , and its child number has index when that index is inside the active heap. There are at most levels containing entries.
Making storage available for reuse after its object is no longer accessible to any legitimate user. Concurrent readers retaining old pointers make safe memory reclamation a separate problem from atomic pointer publication.
A partially applied infix operator:
(a op) means \x -> a op x, and (op b) means \x -> x op b, subject to Haskell's syntax rules. In particular, (f .) maps a function g to the function composition f . g. Composing such a section with a curried binary function composes at two argument levels: ((f .) . g) x y = f (g x y) on total inputs.[ref]Haskell 2010 Language Report. §3.5, Sections
The higher-order function with type
(a -> [b]) -> [a] -> [b] and value concat (map f xs). It replaces each input element by a list and concatenates those lists in input order. A direct definition is concatMap f = foldr (\x rest -> f x ++ rest) []. This formulation processes an input element's produced list once; it need not repeatedly append an already accumulated output prefix.The higher-order function
iterate :: (a -> a) -> a -> [a], satisfying iterate f x = x : iterate f (f x). Its result begins with the initial value and continues with successive applications. Lazy evaluation permits finite prefixes of this infinite list to be observed whenever the necessary applications terminate.The higher-order function
takeWhile :: (a -> Bool) -> [a] -> [a] retains the longest initial segment whose elements all satisfy its predicate. It stops at the first failure and does not resume later. Thus it differs from a list filter, which tests later elements as well.The function
zip :: [a] -> [b] -> [(a,b)] pairs corresponding list positions, stopping when either input ends. Pairing a finite list with [0..] attaches its zero-based indices without constructing an infinite result. With the unbounded Integer index type this avoids index overflow for arbitrarily long finite inputs.Formation of a blood clot through interacting cellular and molecular processes.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact