Our ancestors evolved faster after dinosaur extinction

A team at University College London showed that the speed of evolution of placental mammals -- including humans- was stable in presence of dinosaurs and increased drastically after their extinction. An other team from UCL showed last year that the mammal diversity exploded after dinosaur extinction. I believe that these two studies show that the removal of the selection pressure, which was the presence of dinosaurs, allowed mammal evolution to flourish. I would love to know more from your side as I am not an expert in this domain.

Sources:

• Image: FlickR
• Please click on hyperlinks

Paternel obesity related to increased breast cancer risk in daughter, a mice study says

In mammals, epigenetic information is transmitted from one generation to the next one. Epigenetic information meaning DNA methylation, histone modification and also non-coding RNA. This information is also considered the memory of the previous generation and can be transmitted to the next one through the germ-line.

In this study, the authors tried to determine the contribution of paternal consumption of an obesity-diet and overweight around the time of conception on their daughters mammary development and breast cancer risk.

The male mice were fed from 3rd week to 10th week either with control diet or obesity-inducing diet (OID). An increased weight in the OID fathers and a mis-regulation of several miRNAs was observed.

After mating the OID father with female mice in a control diet, the female offsprings have been analysed. The authors observed that at birth the daughters show overweight. This weight increase persisted until puberty and disappeared compared to control in adult animals.

The mammary glad development has been analysed. The authors looked at mammary tissue susceptible to carcinogen induced initiation in breast cancer in rodents (TEBs). The number of TEBs was higher in daughters from OID fathers compared to controls. The authors measured an other parameter, the elongation of the mammary ductal adjusted to body weight and observed a higher one from OID female. It could correlate with and increased cell proliferation.

The link between the miRNA mis-regulation in the OID father and OID females and the risk of cancer has been strongly established. 

This study will need to be confirmed and performed in human in order to really be sure that there is a link between fathers obesity and daughters risk of breast cancer. 

I also think that this study increase our awareness.
We can always learn!

Source:

• Image: Common creative
•  Fontelles, C. C. et al. Paternal overweight is associated with increased breast cancer risk in daughters in a mouse model. Sci. Rep. 6, 28602; doi: 10.1038/srep28602 (2016).

MS breakthrough: Replacing diseased immune system halts progression, allows repair

Hi Everyone,

A clinical trial, in Canada, managed to eliminate all signs of damaging brain inflammation in people with early, agressive multiple sclerosis (MS). Amazing? right!

How did they do?

24 participant were included in trial that lasted for 13 years. The authors removed all the immune system and regenerated a new one using blood stem cells. This procedure also lead to lasting recovery.

Unfortunately this treatment option is very complex and cannot be used for every patient worldwide. It should be performed in specialized centers.

Source:

• Ottawa Hospital Research Institute. "MS breakthrough: Replacing diseased immune system halts progression, allows repair." ScienceDaily. ScienceDaily, 9 June 2016. <www.sciencedaily.com/releases/2016/06/160609222439.htm>

Monetary reward do not increase reactivated human memory, a study shows

Imagine you are studying for a test. Then the memory of the lecture needs to be kept and reactivated for the actual test. It would be nice to find ways to ensure the strength of that reactivation.
Dayan and colleagues studied the impact of monetary reward on the strength of reactivated skill memory.
They asked 36 people right-handed to tap repeatedly with their left hand 5-digit as quickly and as accuretely as possible.
They realised that monetary reward did not reinforce skill memory reactivation.
I found it surprising. I am not expert in such study but could it be that motivation left by the simple feedback is more important for skill memory reactivation? What do you think ?


Source:

• http://rdcu.be/iUAd