Dolphins Sleep Half Awake, Half Asleep

If you have ever seen dolphins at an aquarium, you may have noticed some of them swimming around slowly with their eyes closed. Similar to how some humans sleep walk, dolphins are able to swim while sleeping. You may have notice at that same aquarium some dolphins swimming around with only one eye open. For humans, as well as most other animals, it is normal for both eyes to be closed when asleep. So what does it mean when a dolphin leaves just one eye open? It turns out that this is due to a phenomenon known as unihemispheric sleep, exhibited by migratory birds and aquatic mammals. Unihemispheric sleep refers to a state where one hemisphere of an animal’s brain is asleep while the other stays awake. This allows the dolphin to watch its surroundings with one eye so that it can react quickly to any threat or emergency that may arise. In particular, while their young are small, they will always sleep while keeping the eye facing their child open, literally never letting them out of their sight. Migratory birds, such as sea gulls and albatrosses, also exhibit unihemispheric sleep. They must travel long distances each season, chasing a warm and comfortable climate. Unihemispheric sleep allows them to fly continuously without stopping to sleep.

Defense/Stability:: Dormancy

Energy saving

Police officers and security guards are required to remain on stand-by for long periods of time, and then react quickly when an emergency arises. If they were capable of unihemispheric sleep, they might be able to rest while maintaining their concentration and ablity to react quickly when necessary. While the structure of animals’ brains do vary somewhat, it is thought that they operate in fundamentally the same way. Therefore, a deeper understanding of the sleep mechanism of dolphins could potentially be useful in developing treatments for human sleep disorders.

Query	Affected	Num. rows	Took (ms)	Actions
SHOW FULL COLUMNS FROM `contents`	16	16	2	maybe slow
SELECT CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.COLLATIONS WHERE COLLATION_NAME= 'utf8_general_ci';	1	1	1
SHOW FULL COLUMNS FROM `users`	10	10	1	maybe slow
SHOW FULL COLUMNS FROM `groups`	4	4	1	maybe slow
SHOW FULL COLUMNS FROM `permissions`	5	5	1	maybe slow
SHOW FULL COLUMNS FROM `groups_permissions`	3	3	1	maybe slow
SHOW FULL COLUMNS FROM `groups_users`	3	3	1	maybe slow
SHOW FULL COLUMNS FROM `contents_searches`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `attachments`	11	11	1	maybe slow
SHOW FULL COLUMNS FROM `attachments_revs`	13	13	15	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items`	5	5	2	maybe slow
SHOW FULL COLUMNS FROM `related_items`	6	6	29	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items_revs`	8	8	1	maybe slow
SHOW FULL COLUMNS FROM `contents_tags`	5	5	9	maybe slow
SHOW FULL COLUMNS FROM `tags`	7	7	7
SHOW FULL COLUMNS FROM `tag_groups`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `contents_tags_revs`	7	7	1	maybe slow
SHOW FULL COLUMNS FROM `contents_revs`	18	18	1	maybe slow
SELECT `Content`.`id`, `Content`.`user_id`, `Content`.`last_edit_user_id`, `Content`.`post_date`, `Content`.`post_date_year`, `Content`.`post_date_month`, `Content`.`post_date_day`, `Content`.`title`, `Content`.`title_en`, `Content`.`content`, `Content`.`plain_content`, `Content`.`page_view`, `Content`.`flag`, `Content`.`mod_count`, `Content`.`created`, `Content`.`modified` FROM `contents` AS `Content` WHERE `id` = 170 LIMIT 1	1	1	0
SELECT `Attachment`.`file_name`, `Attachment`.`dir`, `Attachment`.`model`, `Attachment`.`foreign_key` FROM `attachments` AS `Attachment` WHERE `file_name` <> 'default.jpg' AND `Attachment`.`foreign_key` = (170)	1	1	0
SELECT `ContentsRelatedItem`.`content`, `ContentsRelatedItem`.`related_item_id`, `ContentsRelatedItem`.`content_id` FROM `contents_related_items` AS `ContentsRelatedItem` WHERE `ContentsRelatedItem`.`content_id` = (170)	11	11	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 1	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 2	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 4	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 6	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 7	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 8	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 11	1	1	0
SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 12	1	1	0
SELECT `ContentsTag`.`id`, `ContentsTag`.`tag_group_id`, `ContentsTag`.`mod_count`, `ContentsTag`.`tag_id`, `ContentsTag`.`content_id` FROM `contents_tags` AS `ContentsTag` WHERE `ContentsTag`.`content_id` = (170)	2	2	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 88	1	1	0
SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 6	1	1	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 97	1	1	0
SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 7	1	1	0
SELECT `RelatedItem`.`id`, `RelatedItem`.`code`, `RelatedItem`.`name`, `RelatedItem`.`created`, `RelatedItem`.`modified`, `RelatedItem`.`flag` FROM `related_items` AS `RelatedItem` WHERE `code` = 'function' LIMIT 1	1	1	0
SELECT `Content`.`id`, `Content`.`title`, `Content`.`title_en` FROM `contents` AS `Content` WHERE id = (NULL) ORDER BY `id` desc	0	0	0

Message	Memory use
Component intitailization	6.79 MB
Controller action start	6.83 MB
Controller render start	6.90 MB
View render complete	7.92 MB

Message	Time in ms	Graph
Core Processing (Derived)	403.66
Component initialization and startup	16.09
Controller action	42.39
Render Controller Action	66.88
» Rendering View	63.21
» » Rendering APP/views/contents/view.ctp	32.76
» » Rendering APP/views/layouts/default.ctp	28.85
» » » Rendering APP/views/elements/header.ctp	1.54
» » » Rendering APP/views/elements/content_sidebar.ctp	0.32
» » » Rendering APP/views/elements/footer.ctp	0.41

Dolphins Sleep Half Awake, Half Asleep

default

Query Explain:

Memory

Timers

Dolphins Sleep Half Awake, Half Asleep

Request History

Session

Request

Cake Params

$_GET

Cookie

Current Route

Sql Logs

default

Query Explain:

Memory

Timers

Logs

View Variables