Biology

Osteoblasts
HE stain that shows the bone formation cells (the blue cells aligning a bony spicule), the so-called osteoblasts, whose differentiation from stem cells are regulated by microRNAs according to a new study. Image from Wikimedia Commons (CC-share alike licence) by Nephron.
Researchers from Totteri University in Japan show in a new paper in PLoS One how miRNA (microRNA) regulates the development of mouse artificially derived stem cells

Stem cells are cells from multicellular animals that have the ability to differentiate into specialised cells. Two types of stem cells can be found in animals; embryonic stem cells, which are present in the early phase of the development of the embryo and adult stem cells, which are found in various tissue in adult animals and function as a repair system. However, in the current study, the Japanese scientists used a third type of stem cells, so-called induced pluripotent stem (iPS) cells, which are similar to embryonic stem cells, but are derived from adult somatic cells by inducing expression of specific genes.

Scientists from the University of Goettingen and their japanese colleagues recently discovered that hearing and gravity-sensing in flys is located in the same sense organ in the antennae of the insect. Two different neurones at the antenna basis are mechanically (by acoustic noise and movements) stimulated. This allows the fly to sense the gravity as well as hearing with just one sense organ.

Bat
Bats can locate crawling insects (Courtesy: Dietmar Nill/Leonie Baie)
Bats are known to locate their flying prey (flies, moths, midges and other night active aliferous "six-legs") with Echolocation . Little focus has been done on crawling night active arthropods and other animals.  Now it could be shown that insects crawling on the ground can be located by flying bats due to the noise their crawling causes. Spiders, carabid beetles and other ground dwelling small animals which can be suitable as bat-food produce characteristic sounds with their leg movements.

 


Blue jawed elephant nose
An Einstein among electrical fish, elephant fish from africa. Prof. Dr. Gerhard von der Emde with a model (Courtesy of G. von der Emde, University of Bonn, Germany)
The african elephant fish or blue jawed elephantnose (Gnathonemus tamandua) is able to navigate in total darkness, finding food, seeing and analysing different  objects and hindrances in size and structure. In their recent publication in "Journal of Experimental Biology" zoologists from the university in Bonn, Germany,  now reported several interesting and new findings about how sophisticated the animals behaviour is:
In the nose of the fish are more than 500 specialised electrical sensor cells located which are able to detect smallest changes of the electrical field which is surrounding the blue jawed elephantnose. The field is caused by muscle cells in the fishs tail which give small pulses with 80 Hz. The sensors in its nose can detect for example the electrical fields which are caused by potential prey like aquatic insect larvae which hide under the surface on the ground of a river or pond. Slowly swimming over the ground these smart fishes are turning left and right their nose with the sensor cells in it, working thus like gold miners using a metal detector. This way of navigation is called electrolocation.

Ingroup and outgroup moral - Double standards as biological principle. Will global human rights always remain an utopia? Actual political conflicts considered with the concepts of sociobiology. 

As groups of social animal species in nature (e.g. wolves, lions, many primates) defend territories  members of neighbouring groups of the same species and if necessary even fight and kill them, so does Homo sapiens to a far greater extend than obvious at first sight:  In native peoples' societies (Indian tribes of the Great Plains of North America for example), the warrior as an honoured member was admired for killing the enemy warrior of the hostile neighbouring tribe. As well as bringing home slaves and women from the other society in which often the same ethical principles were present. The european settlers and the white man called these people "savages". They did not see that also in their own "civilized" societies the soldier who kills an enemy is considered a hero.

 

A group of researchers from the University of Berne, Switzerland has shown that rats will help other rats whenever they have recieved help themselves before regardless of the identity of the new reciever. This is called "Generalized Reciprocity" and is shown for the first time in nonhumans.
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Researchers at the Max Planck Institute for Evolutionary Anthropology have found evidence that humans are not unique in altruistic behaviour toward unrelated individuals. Our closest living evolutionary relatives, the chimpanzees, were studied. In two experiments they helped an unfamiliar human to the same degree as human infants. The help was provided whether the chimpanzees were being rewarded or not and whether the helping was costly to the helper or not.

The indonesian island of Sulawsi is among biologists known for its rich endemic and seldom fauna. Scientist of the Humboldt University in Berlin/Germany now found in an ancient freshwater lake the first ever known association between a shrimp and and a sponge. The endemic shrimp (Caridina spongicola) and the sponge of the yet undescribed suborder Spongillina are interestingly restricted not only to the lake but to a certain area of it.

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