Mice Sharpen Their Teeth by Gnawing

Animals such as squirrels, mice, beavers and capybaras are all characterized as rodents on account of one common characteristic: their wide, sharp-edged teeth incisors. They have 2 pairs of incisors in the upper and lower jaws (4 total) that they use for biting, gnawing on plants, and defending themselves against predators. Because rodents have no other way of defending themselves, their incisors evolved to continuously grow throughout life, instead of waiting for old teeth fall out before they grow new ones. As such, these animals must keep their incisors short and sharp by constantly gnawing on hard things; otherwise, the teeth will grow too long, making it impossible for them to eat. Nowadays, some people who keep squirrels or hamsters as pets need to cut and shorten their teeth because the animals have stopped gnawing on hard objects, causing their teeth to grow too long. Also, the inside and outside of rodent incisors wear differently. The outer surface of the teeth is made of hard, thick enamel, while the inside of the teeth is made of soft dentin. When the incisors in the upper jaw rub the incisors in the lower jaw, it causes the dentin on the inside of the teeth to curve, leaving the enamel on the exterior of the teeth intact, forming the teeth into a sharp, chiseled shape. Rodent’s mechanism for self-sharpening their incisors is very efficient. The scientific name of rodent is Rodentia, which means “gnaw (bite)” in Latin; hence, the name of rodent stems from this characteristic gnawing or biting of teeth.

Efficiency(Energy Saving, Resource Saving, Light):: Self-sharpening

Defense/Stability:: Living tissue control

Long life

Attenborough, D. 1979. Life on earth. Boston, MA: Little, Brown and Company. 319 George McKay; Fred Cooke; Stephen Hutchinson; Richard Vogt; Hugh Dingle. 2004. The Encyclopedia of Animals: A Complete Visual Guide. Berkeley: University of California Press. 608 p.

The mechanism of rodent self-sharpening teeth can be used to create blades for industrial machines. For instance, tractor blades are quickly worn down through soil cultivation; a self-sharpening mechanism would prevent them from deteriorating over long periods of time. This mechanism could also be utilized in dental treatment methods, for the regeneration of teeth, as well as hair, and organs, such the liver and kidneys. Many of our everyday tools have blades that need sharpening to maintain their effectiveness: scissors to cut paper, kitchen knives, and pruning shears are just a few examples. When the blades become irreversibly dull, they are simply replaced. If these tools instead had self-sharpening blades, they would stay sharp for a long time without needing maintenance or replacement.

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	9	maybe slow
SHOW FULL COLUMNS FROM `attachments_revs`	13	13	1	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items`	5	5	9	maybe slow
SHOW FULL COLUMNS FROM `related_items`	6	6	1	maybe slow
SHOW FULL COLUMNS FROM `contents_related_items_revs`	8	8	1	maybe slow
SHOW FULL COLUMNS FROM `contents_tags`	5	5	1	maybe slow
SHOW FULL COLUMNS FROM `tags`	7	7	1	maybe slow
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` = 136 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` = (136)	1	1	0
SELECT `ContentsRelatedItem`.`content`, `ContentsRelatedItem`.`related_item_id`, `ContentsRelatedItem`.`content_id` FROM `contents_related_items` AS `ContentsRelatedItem` WHERE `ContentsRelatedItem`.`content_id` = (136)	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` = (136)	3	3	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 60	1	1	0
SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 5	1	1	0
SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 84	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` = 99	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	7.93 MB

Message	Time in ms	Graph
Core Processing (Derived)	351.03
Component initialization and startup	15.93
Controller action	47.93
Render Controller Action	61.86
» Rendering View	58.23
» » Rendering APP/views/contents/view.ctp	37.95
» » Rendering APP/views/layouts/default.ctp	17.99
» » » Rendering APP/views/elements/header.ctp	9.69
» » » Rendering APP/views/elements/content_sidebar.ctp	0.33
» » » Rendering APP/views/elements/footer.ctp	0.41

Mice Sharpen Their Teeth by Gnawing

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