Ciências é TOP

02/11/2018

How amazing!!!! Living and learning!

30/05/2018

31/03/2018

23/11/2017

Para quem acha que a vacina da polio é desnecessária e para quem segue na área de medicina buscando sempre melhorias. Vivendo e aprendendo. Também para aqueles que se acham vitimas ou incapazes....querer é poder. Podemos não alcançar tudo mas não podemos desistir.

05/10/2017

05/09/2017

Mini-cannibals

Full-grown sand tiger sharks are approximately 8.2 feet (2.5 meters) long, and mothers typically give birth to two baby sharks, each about 3.3 feet (1 m) long.

Since the 1980s, when detailed autopsies of sand tiger sharks revealed embryos in the stomachs of other embryos, researchers had known that the shark fetuses cannibalized each other in utero about five months into their nearly year-long gestation. Legend has it that a shark embryo actually bit a researcher's hand during a dissection when the researcher reached into the uterus of the shark's mother, Chapman said.

While 12 littermates may start out the journey, all but one is devoured by the biggest in the pack. That strategy allows sand tiger sharks to have much larger babies at birth than other shark species, making the little ones relatively safe from other predators, Chapman said.

But scientists didn't know why the sharks were cannibalizing each other. To find out, Chapman and his colleagues studied genetic samples from 15 pregnant female sharks that had died in nets off the coast of South Africa. (The nets were put in place to protect swimmers from deadly bites from great white sharks and bull sharks, but the nets occasionally snare and kill sand tiger sharks.)

Paternity struggle

Of those 15 female sharks, 10 of the sharks carried just two embryos, while the remaining five were in an earlier stage of gestation and had five to seven embryos in utero.

The team then used DNA analysis to determine paternity.

"It's exactly the same sort of DNA testing that you might see on Maury Povich to figure out how many dads there are," Chapman told LiveScience.

Those litters with five to seven embryos had at least two fathers (embryos from other fathers may have already disappeared), while the litters with just two sharks more often had just one father.

That suggested one embryo — possibly the one that grew biggest first — tended to devour embryos from other fathers over its full siblings.

02/09/2017

What is Down syndrome (trisomy 21)? Down syndrome is a set of symptoms that arise from a genetic abnormality, in which an individual's cells have an extra co...

01/09/2017

Enjoy first film from my new science series - Scientific curiosities. Today you can watch this interesting story about electrolysis. If you like my films ple...

26/07/2017

TOP FACTS for CHILDREN by Kids Hut. ✿ Top 10 Facts for Kids List: 00:00 How is a Rainbow Formed? 02:21 Why do we get Hiccups? 04:15 How Do Fish Breathe In Wa...

26/07/2017

Presenting "Things To Know - Kids Video | Basic Science For Kids | Good To Know " by KIDS HUT. ------------------------------------- TWINKLE TWINKLE PLAYLIST...