Jump to content

Talk:Breathing: Difference between revisions

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
Content deleted Content added
Reply to Cruithne9 edit
Line 262: Line 262:


:::Most of what I say about inhalation and exhalation above, is explained in the [[Breathing#Mechanics|Mechanics]] section of the article. But somehow the corollary that the process of inhalation and exhalation is therefore unaffected by the ambient air pressure does not seem to be clear. What I therefore propose to do is replace the offending paragraph with a cut and paste copy of what I have said here (with some appropriate edits). [[User:Cruithne9|Cruithne9]] ([[User talk:Cruithne9|talk]]) 15:23, 7 October 2016 (UTC)
:::Most of what I say about inhalation and exhalation above, is explained in the [[Breathing#Mechanics|Mechanics]] section of the article. But somehow the corollary that the process of inhalation and exhalation is therefore unaffected by the ambient air pressure does not seem to be clear. What I therefore propose to do is replace the offending paragraph with a cut and paste copy of what I have said here (with some appropriate edits). [[User:Cruithne9|Cruithne9]] ([[User talk:Cruithne9|talk]]) 15:23, 7 October 2016 (UTC)

I have reinstated my explanation. It is concise and makes sense. I appreciate your additions, Cruithne9, although I find them at times contradictory. You state that the air pressure in the alveoli matches the ambient air pressure and then say it is entirely independent of it. Perhaps this could be clarified?

Revision as of 22:56, 7 October 2016

WikiProject iconPhysiology C‑class Mid‑importance
WikiProject iconThis article is within the scope of WikiProject Physiology, a collaborative effort to improve the coverage of Physiology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
CThis article has been rated as C-class on Wikipedia's content assessment scale.
MidThis article has been rated as Mid-importance on the importance scale.
Taskforce icon
This article has been classified as relating to the physiology of the brain, nerves and nervous system.
WikiProject iconMedicine C‑class Mid‑importance
WikiProject iconThis article is within the scope of WikiProject Medicine, which recommends that medicine-related articles follow the Manual of Style for medicine-related articles and that biomedical information in any article use high-quality medical sources. Please visit the project page for details or ask questions at Wikipedia talk:WikiProject Medicine.
CThis article has been rated as C-class on Wikipedia's content assessment scale.
MidThis article has been rated as Mid-importance on the project's importance scale.

Untitled

I would like to take out the word "waste" from the second paragraph of the article, I feel it gives the impression that cabon dioxide is generally a waste gas and should be removed from the body because it could be harmful, this can not be futher from the truth (Ref. The work of Dr. Buteyko and the Bohr effect both on wikipedia). Article paragraph: "Breathing is only part of the processes of delivering oxygen to where it is needed in the body and removing carbon dioxide waste. The process of gas exchange occurs in the alveoli by passive diffusion of gases between the alveolar gas and the blood passing by in the lung capillaries. Once in the blood the heart powers the flow of dissolved gases around the body in the circulation." Alexspence (talk) 14:20, 29 August 2009 (UTC)[reply]

Also I would like to place the following quote here: "‘…Normalisation of breathing immediately triggers a healing process..." the quote is from the following Google knol: Excerpt from the Buteyko Triolgy Volume 1 Chapter 17: The First Handbook Alexspence (talk) 23:11, 19 September 2009 (UTC)[reply]


i think this article should discuss various ways it is possible to breathe such as through the nose, mouth, with the chest or stomach and the differences between them. for example my gym teacher recommended breathing through the nose and exhaling through the mouth during exercise. these types of things need to be covered by someone knowledgeable.


FIXED YAY!bo sh ka laka

I took out "Breathing is in most cases executed by one nostril at a time...." because, without further discussing nasal congestion and linking to the nasal congestion article, it really looks like vandalism, so I think it's better left out unless elaborated. It probably *was* vandalism.

Why did this get moved withOUT disambiguation? -- Zoe

What's to disambiguate? Nothing at all links here apart from Samuel Beckett. I put the page at Breath (play) originally because I assumed there was already an article here. Thinking about it now, I don't know how an article about a breath could be anything more than a definition and a pointer to another article. If you think it needs a note in case somebody doesn't know what a breath is, give it one. --Camembert
LOL. I would think that at some point, somebody would write an article about breath.  :-) -- Zoe
I don't think it is possible to write an encyclopedia article about breath. Bad breath may be possible though. The play is fine to have here. --mav
an article about breath as a subject would be breathing or something like that. It would be wise to put a quick mention at the top of this one: "for yada yada yada see breathing. -- Tarquin

OK, I give.  :-) -- Zoe yaya yue better


Don't cave so easily, Zoe--I'm with you. "Breath" should probably link to an article on Respiration; I don't know if that one exists either, but if I were writing an article on something else, say first aid, I might put brackets around "breath" in something like "absence of breath indicates...", and I would be very surprized if it linked to an article about a play. It's not necessary to disambiguate everything, especially where there's no existing article. But I think in a case like this where the one meaning there's an article about is clearly not the most central, obvious meaning, it makes sense to be more pre-emptive. --LDC

But then whatever "breath" redirects to needs a link to "breath (play)" in case people are looking for the play. We need a quick cross-link either way. Having a crosslink on "breath" to "respiration" saves us a page with a () name. -- Tarquin
I'd say clarity for users (and future editors) should trump ease of interlinking on the part of editors. What's the big deal about typing Breath (play)? I'd even favor Breath (Samuel Beckett play). --Larry Sanger

I didn't say breath should be just a redirect; I said it should point (i.e., contain a link) to respiration; it should also contain a link to Breath (play). The important thing is to make ad-hoc links do something sensible, and linking to a page with pointers to multiple senses is eminently more sensible than linking to a page with one sense that's clearly wrong. The way you have it now (with the pointer and the text describing the play) is probably fine too. --LDC

Blimey, not only is the article longer than the play, so is the talk page! I'm pretty ambivalent about what points to what, for the record, although I guess LDC's suggestion seems sensible even if there are no non-Beckett links here at the moment. Incidentally, I made the move mainly because it seemed odd and wrong to have an article at Breath (play) but none at Breath. --Camembert

A disambiguation block will work just fine here. There is no need to have the play at a parenthetical title just because there is a dictionary word "breath". We needn't make linking to this article more difficult than necessary. --mav

But we do things here for the convenience and ease of understanding on the part of users, not editors. --Larry Sanger

I thought the whole point was that there was no distinction between users and editors. Maybe I'm misunderstanding the whole project, was I supposed to start drawing a paycheck when I started contributing? Perhaps you'd care to tell why the page in its current state is not sufficiently clear to users? As for the idea that "Breath (Samuel Beckett play)" is the best title - maybe we should put the entire bloody article in the page title. --Camembert
All users can edit, and I hope all editors also use the Wikipedia from time to time. But given a choice, we should be seeking ease of use, not ease of editing. Does that make more sense?Vicki Rosenzweig
Yes, I see the point. To be honest, I was in a foul mood last night, and probably overdid it a bit up there, for which my apologies. As I said before, I don't much mind where this article ends up, though I see nothing wrong with where it is now. Though I should probably say - I'm going to write pieces on Beckett's other plays-with-real-word-titles Embers, Rockaby, Quad and Catastrophe - if anybody thinks they need parentheses, they should probably say something now to avoid all this discussion again ;) --Camembert

Moved from User talk:Larry Sanger:


Hey Larry, would it at all be possible to have an encyclopedia article on Conjecture (philosophy)? The reason I ask is becuase Conjecture was just move to Conjecture (mathematics) but Conjecture still redirects to it. --mav


I don't know--I'm not aware of any special sense in philosophy. It's just that the sense of "conjecture" in question is unique to mathematics, and (this is my opinion, feel free to disagree) given that, the article should live at conjecture (mathematics), since otherwise people will start giving us the dictionary definition of "conjecture," as if there were a significant topic titled "conjecture" outside of math. (I don't know, maybe there is.) --Larry Sanger

If there isn't any other encyclopedic topic named "conjecture" then the article on the math term should be simply at conjecture. Thanks for the info. --mav
I respect that view (and don't really care much one way or the other), but for the record, I disagree with it. For one thing, I don't think it follows from the premise that there's only one encyclopedia-worthy topic titled "conjecture" that that topic should live at conjecture without any clarifying parentheses. This is because "conjecture" has an ordinary English meaning that is far more commonly known than the mathematics meaning. Consequently, having the article at conjecture is apt to make editors want to add an ordinary dictionary definition, which is exactly what did happen, and to make users wonder why we're only talking about the mathematics usage if the article is titled "conjecture" ("What about the more usual sense?"). For purposes of clarity, nothing else, I'd file it under conjecture (mathematics). Now go and do whatever you want, and I won't stop you. --Larry Sanger
I made pretty much that same argument on Breath, which was an article about the Smuel Beckett play. Because there is an obvious central meaning to the word, I do think that some pre-emptive clarification is needed, even if there's currently no article with that central meaning (or even if there won't ever be). --LDC

Larry, I think you have said once that Wikipedia is not a dictionary. So just because there is a dictionary definition doesn't mean that we must pre-emptively disambiguate from that term. Now that is just silly. If the article on conjecture is at a parenthetical title then all conjecture would ever be is a redirect. That doesn't make sense. Another thing is that redirects are not obvious and having the article at a parenthetical title will mean that new contributors will be typing the unnecessary [[conjecture (mathematics)|conjecture]]. Furthermore, when people follow conjecture and end up at conjecture (mathematics) many will feel that conjecture should be a disambiguation page. However when there is nothing other than dictionary definitions besides the mathematics term, then what would be created would be an unnecessary and invalid disambiguation page. Isn't one of the founding principles of our naming conventions the preservation of free-linking where ambiguities do not exist (such as here)? --mav

<sarcasm>Hm. The term "Jesus Christ" has an alternate dictionary definition in slang usage that differs from the meaning in our article Jesus Christ. I propose we move the article on the person to Jesus Christ (person). That way nobody will be encouraged to place dictionary defintions in the first line of this article.</sarcasm> Again, I hate this type of pre-emptive disambiguation. This is an encyclopedia and in that content we only need concern ourselves with disambiguating encyclopedic terms.--mav

"That is just silly" and "That doesn't make sense" indicate that perhaps you didn't understand the merits of Lee and my argument in the first place; you didn't address its merits in any case. Not that you're obligated to, but it would be nice. As to "Furthermore, when people follow conjecture and end up at conjecture (mathematics) many will feel that conjecture should be a disambiguation page": why would they feel that way? And if you think that's a problem, why not simply delete conjecture completely and ask editors to type the extra keystrokes? Another point that you missed is that we are writing here for the convenience and clarity of users, not editors. Users who, by the way, perhaps don't know or care, as we do, that Wikipedia is an encyclopedia and not a dictionary. (That was the main point, by the way.) As to your <sarcasm>, the slang usage is a lot less common and accorded much less importance by most people than the central meaning.

Could we take this off my user page (perhaps move it to yours)? --Larry Sanger

In a completely volunteer project which aims to write an entire encyclopedia it is not-reasonable to force contributors to hand-hold readers to such an extent by mandating that contributors have to type extra keystrokes for a term just to "disambiguate" from a dictionary definition. If we are to be slaves to readers then why don't we also use a hell of a lot of HTML, cgi and Flash in articles to make them look and work better for the readers too? That is a great way to loose contributors. Call me selfish, but I for one edit Wikipedia for the personal enjoyment I feel in creating something truly unique and very useful to both readers and contributors. A balance must be made between these two groups of people. But since Wikipedia is at best betaware and may be forever considered to be so by many, we should focus on erring on the side of contributors (a Nupedia distribution of Wikipedia could do the hand holding in the same way as many Linux distributions do). Also the arguement that newbies will insert purely dictionary definitions into article is rendered moot by the power of Recent Changes and revision histories (this has not been a problem but when I do see somebody insert such things I fix it accordingly -- others have done so as well). One great way to simplify matters for contributors is to have disambiguation only work to disambiguate encyclopedia terms.
Furthermore the number one naming convention around here is that contributors above all else copy the methods they see. If we start doing as you suggest and disambiguate terms from their purely dictionary meanings then we will have things like Jesus Christ (person). To you the slang dictionary definition is not nearly as used as the encyclopedic term but that is just your POV and some contributors won't see the "widest"-use distinction (in some circles the dictionary term is used daily whereas the encyclopedia term is only used on Sundays, if at all). We can continue this on my talk page, but I would rather drop the debate and simply agree that we disagree and then get back to work on creating the best encyclopedia for users and contributors on the planet. --mav 20:26 Sep 22, 2002 (UTC)


Just a point of information: the page Breath for the play has an early link to Respiration, which, while a stub, shows promising sings on development. -- Tarquin
We can agree to disagree about the importance of keystrokes vs. clarity for readers, then, Mav.
The only new argument I see here is that Lee's and my way of thinking would give us such silliness as Jesus Christ (person). But I don't see that at all: the primary meaning of "Jesus Christ" is the subject of the article, Jesus Christ, which is as it should be. Not so "breath" or a number of other common English words.
Understood properly, there are only a small number of articles where this rule would apply.
Yes, let's agree to disagree. And make sure that we do keep using some useful disambiguating words... --Larry Sanger

I'd just like to clarify that my concern here is indeed mostly for contributors, and in particular those who make ad-hoc links while writing other pages. It should be blindingly obvious that there is one, and only one, central, primary, and obvious meaning for "Jesus Christ", "Breath", and "Conjecture"; whether or not that central meaning has an article--or even should have an article--is secondary. Contributors to other articles ought to be able to simply put brackets around a word like that, comfortably assuming that the link will go somewhere sensible--that's my major concern here. If I put brackets around Breath, my first expectation would be that it went to an article on respiration; but I might be wrong (and in this case I would). My second choice would be that it went to an article that pointed to an article on respiration, and maybe had some other content. That's a reasonable second choice. The third, and to my mind clearly the worst, possibility, is that I get sent to an article about something totally unexpected without even a pointer to the normal usage. I'm not even too concerned about the "not a dictionary" mantra. To my mind, the most important thing is just this: ad-hoc links should go somewhere reasonable. That's all. --LDC


I just want to say that since all the above happened (months ago), I've softened, and wouldn't object to this being moved to Breath (play) (though I still don't think there's any particular reason to do so). --Camembert


How about; "Breath is the principle ingredient used in the breatharian diet (apart from chicken pies)" ;-) quercus robur 12:39 16 Jun 2003 (UTC)

Thank you for clearing this up

Before now I had no idea how to breathe. Now my life is complete. --Squirminator2k 17:05, 9 October 2005 (UTC)[reply]

Breathing is obviously for l00sers. --x1987x 21:48, 8 November 2005 (UTC)[reply]

Composition of breath

I once heard in a high school chemistry class that human breath usually composes of some percentage of water vapor and some percentage of carbon dioxide. If we can verify that, it would improve this article. We should also have citations for the "30,000 breaths per day" statement and other statistics currently found in the article. Maybe also have a section or mention of "bad breath"? --Mr. Billion 18:47, 13 January 2006 (UTC)[reply]


Halitosis added to "See Also" section.--IanUK 08:37, 21 September 2006 (UTC)[reply]
This sounds like a good location for a discussion of what happens when a person starts inhaling a deleterious substance like tobacco smoke. I notice it's complete absence from the subject matter discussion.WFPM (talk) 17:42, 3 September 2009 (UTC)[reply]


Who the hell gave those two 'rough' sets of numbers for the compositions of inhalation/exhalation? At least make them actually line up with each other. As it is now it seems as if the human body breathed out >4% more Argon than it takes in and also creates a miniscule amount of various gases that previously weren't in the air at all.

- 79.103.237.169 (talk) 21:28, 23 April 2015 (UTC) Bowbreaker[reply]

Breathing is evil

Breathing is evil! Hitler breathed! JIP | Talk 13:02, 18 May 2006 (UTC)[reply]

That's right breathing causeing CO2 so to stop Global Warming .tm we should stop breathing! —Preceding unsigned comment added by 69.253.64.213 (talk) 00:05, 28 November 2007 (UTC)[reply]

Gases found in the breathing cycle

The following table was in an exam question and I am stumped!!!

Gas Inhaled air % Exhaled air % Alveolar air % Oxygen 20.95 16.4 14.45 Carbon dioxide 0.04 4.1 6.05 Nitrogen 79.01 79.5 79.5 X variable variable saturated


Question 1a: What is gas X?

        1b: Why is this gas essential for the functioning of the cells in the alveoli?


PLEASE HELP someone+

Disambiguation Page

A disambiguation page is desperately needed for both "breath" and "exhale". I don't know how to though. So someone else should. YSHOULDUKNOW123 01:53, 16 October 2006 (UTC)[reply]

Took a while, but they are there now, Breath (disambiguation), and Exhale (disambiguation). There's also Breathing, and Breathe. Tbone762 22:43, 23 May 2007 (UTC)[reply]

unclear

"The buildup of carbon dioxide making the blood acidic is what makes one desperate for a breath rather than lack of oxygen. Hyperventilating causes an influx of oxygen that lowers blood acidity to trick the brain into thinking it has more oxygen."

This is unclear, and the cited source is long so I don't know what part it's referencing. The second sentince reads something like "Hyperventilating gives you oxygen, which tricks the brain into thinking it has more oxygen." Wha? --Szabo 22:36, 21 January 2007 (UTC)[reply]

I've just changed it. As per the 'hyperventilation' article, it is a *drop in CO2* that causes blood acidity to lower, therefore tricking the brain - not an increase in 02. 139.184.30.19 18:31, 5 March 2007 (UTC)[reply]

Exhaled air merged into Breathing

I personally think that merging the page would be better for both articles because more people would visit breathing, than exhaled air. The same information could be included in the breathing article, making it easier to obtain knowledge for everyone. BlackBear 13:37, 7 April 2007 (UTC)[reply]

Cultural significance

I think the cultural signifcance section is severely lacking. Dessydes 14:07, 22 June 2007 (UTC)[reply]

Date?

When was it discovered that air was used to breathe? Surely it wasn't always known that oxygen was needed to sustain human life, such as in Biblical times and whatnot. Should this be in the article? —Preceding unsigned comment added by 71.36.17.122 (talk) 19:26, 24 February 2008 (UTC)[reply]

breathing

i was wondering why your breathing alters with exercice but here i doesnt tell you and also why people who smoke are more out of breath than people who dont it is no were to be found !!!!!!!!!!!!!!! —Preceding unsigned comment added by 91.105.3.233 (talk) 18:00, 25 February 2008 (UTC)[reply]

Move?

I propose moving this page to Breathing and the dab page that's currently there to Breathing (disambiguation). Any objections? If not, I'll go ahead in a few days. delldot on a public computer talk 02:19, 23 April 2008 (UTC)[reply]

Well, no objections, so I think I'll go ahead. Let me know if there are any problems. delldot talk 18:57, 29 April 2008 (UTC)[reply]



move

i win i dont brathe at all —Preceding unsigned comment added by 71.34.6.179 (talk) 23:59, 1 May 2008 (UTC)[reply]

Forgetting to breathe

I think we should mention in the "Control of breathing" section under "Unconscious control" when one's unconscious breathing control fails and they temporarily forget to breathe.

I don't know about other people, but I often forget to breathe when I'm walking, and then I suddenly notice that I'm out of breath and so I start breathing again.

92.1.189.245 (talk) 05:40, 3 August 2008 (UTC)[reply]

Spacecraft atmosphere composition

I am almost certain that contemporary spacecraft (eg ISS, shuttle) do NOT have a 100% oxygen atmosphere as indicated in the article body. EMUs used during EVAs do, however. This is why astronauts must spend approx 2hrs depressurizing and prepping for EVAs to remove dissolved nitrogen from the craft's atmosphere.

I've corrected the statement.

Ref: http://spaceflight.nasa.gov/station/eva/outside.html —Preceding unsigned comment added by 66.214.141.25 (talk) 15:07, 4 October 2008 (UTC)[reply]


I find it difficult to believe that astronauts breathe pure oxygen at any time. As a scuba diver, I'm aware of the effects of partial pressures of atmospheric gases. Granted, an astronaut works at far lower pressure than any scuba diver - still, that partial pressure of 100% is going to cause problems with is health. There may indeed be reasons to remove the nitrogen from a space walker's environment, but I'm certain that he's still not breathing 100% pure oxygen.

The person who made that claim should have citations available . . . — Preceding unsigned comment added by 69.57.121.212 (talk) 18:24, 4 March 2013 (UTC)[reply]

Exhaled Breath Temperature

There is new research on this subject and I have drafted a starting point for a possible section that should be for this area. I would like comments on this to help me publish it and would also like someone to look at including a portion of this inside breathing and any other existing topics where it would be appropriate to introduce this.

Please have a look at my talk page if you can help.

Many thanks.

Jonathan (Singapore) --Jgeach (talk) 10:37, 2 December 2008 (UTC)[reply]

ghBold text —Preceding unsigned comment added by 59.92.240.243 (talk) 18:25, 10 April 2009 (UTC)[reply]


Relationship to death

Changed brain/mind can continue to function for many minutes - not true - anaerobic respiration in the brain only lasts a few minutes due to the high glucose need and the inability to store large amounts of glucose. If aerobic respiration does not occur within roughly 3 minutes, the brain cell will start to die. Thus 'many minutes' is misleading.

- 134.148.5.104 (talk) 12:03, 17 June 2009 (UTC)shagudiga 10.01 17 June 2009[reply]

Interwiqui ca:Respiració

In catalan is the same than spanish: repiració (in spanish repiración) for breathing and for Respiration (physiology).--Peer (talk) 19:20, 2 April 2011 (UTC)[reply]

finally!

found the % CO2 in exhaled air, after going through:

Carbon dioxide
Arterial blood gas
Pulmonology
Spirometry
Pulmonary function testing
Respiration (physiology)
Hypercapnia
Respiratory system
Exhalation
Cellular respiration
Cellular waste product
Cellular respiration
Respirometry
Basal metabolic rate
Harris-Benedict equation
Basal metabolic rate
Respiratory quotient
Respiratory exchange ratio
VO2 max
Respirometry
Carbon dioxide
Respiratory acidosis
Gas exchange
Capnograph
Capnography
Respiratory monitoring
Acute respiratory distress syndrome
and then I did a search for co2 in exhaled air....and landed here. I figured it could be found without google or searching, guess I was wrong... 84.197.184.6 (talk) 23:21, 6 November 2011 (UTC)[reply]

The effect of altitude on breathing

In the section entitled "Air pressure" the second paragraph reads:

When the atmospheric pressure is lower, the air pressure within the breathing system must be correspondingly lower in order for inhalation to occur i.e. lower than the atmospheric pressure. This means that in order to achieve inhalation, the air pressure within the breathing system must be lower at high altitudes than at low altitudes; this typically involves a relatively greater lowering of the thoracic diaphragm.

The implied physics of this statement is incorrect. The alveolar air is open (via the airways) to the atmosphere, with the result that alveolar air pressure is exactly the same as the ambient air pressure at sea level, at altitude, or in any artificial atmosphere (e.g. a diving bell) in which the individual is breathing freely. With expansion of the lungs, by lowering of the diaphragm, the alveolar air now occupies a larger volume, and the alveolar air pressure drops proportionately, causing air to flow in from the surroundings, through the airways, till the pressure in the alveoli is once again at the ambient air pressure. The reverse obviously happens during exhalation. This process is totally independent of the actual ambient air pressure, and is therefore the same at sea level, on top of Everest, or in a diving bell. There is therefore no "need" to lower the thoracic diaphragm to a greater extent at high altitude than at sea level, to achieve inhalation.

The confusion probably arises from the fact that at high altitudes the molar concentration of oxygen in the air is less than it is at sea level. Therefore, in order to breathe in the same amount of oxygen per minute, the person has to breathe in a proportionately greater volume of air per minute than at sea level. This is achieved by breathing deeper and faster (i.e. hyperventilation) than at sea level. The exact degree of hyperventilation is determined by the blood gas homeostat, which regulates the partial pressures of oxygen and carbon dioxide in the arterial blood.

I will try to think of a way of editing the quote above so that it is makes physical sense. Though maybe it should simply be deleted. It cannot be left as it is. Cruithne9 (talk) 15:10, 7 October 2016 (UTC)[reply]

Most of what I say about inhalation and exhalation above, is explained in the Mechanics section of the article. But somehow the corollary that the process of inhalation and exhalation is therefore unaffected by the ambient air pressure does not seem to be clear. What I therefore propose to do is replace the offending paragraph with a cut and paste copy of what I have said here (with some appropriate edits). Cruithne9 (talk) 15:23, 7 October 2016 (UTC)[reply]

I have reinstated my explanation. It is concise and makes sense. I appreciate your additions, Cruithne9, although I find them at times contradictory. You state that the air pressure in the alveoli matches the ambient air pressure and then say it is entirely independent of it. Perhaps this could be clarified?