One planet, two stars

When we are going to approach to the binary system Kepler-16 (image source) we'll see two different stars: the largest of the couple, the star A, is a K dwarf with a mass of about 0.69 solar mass and about 0.65 Sun's radius, and a little red dwarf, the stra B, with a mass of about 0.2 solar mass and about 0.23 Sun's radius. But when we'll arrive at about 0.5 au from the gravitational centre of the binary system we'll see a great surprise: a little planet with a mass of 0.333 ± 0.016 and a radius of 0.7538 ± 0.0025 those of Jupiter⁽¹⁾.

In this momenti is very difficult to suppose the properties⁽²⁾ (like composition and surface temperature) of Kepler-16b, but the most important thing is that Kepler can discover, using the transit technique, also a planet around a binary system! I think that this is the principle reason becuase the paper was accepted by Science. And it's clear that all nerd and sci-fi fan think about Skywalker family's planet, Tatooine:

A solution to a maximal independent set problem

A distributed system is a set of autonomous computer that comunicate in a network in order to reach a certain goal. So a maximal independent set (MIS) is a distributed system's subject. But, what we intend for MIS?

In graph theory, a maximal independent set or maximal stable set is an independent set that is not a subset of any other independent set.

Some example of MIS are in the graph of cube:

(Commons in public domain)

You can see that every maximal independent set is constituted by point that aren't adjacent.
The goal of maximum independet set problem is find the maximum size of the maximal independent set in a given graph or network. In other words the problem is the search of the leaders in a local network of connected processors, and forleaderwe intend an active node connected with an inactive node. This problem is a NP-problem.

Following Afek, Alon, Barad, Hornstein, Barkai and Bar-Joseph,

no methods has been able to efficiently reduce message complexity without assuming knowledge fo the number of neighbours.

But a similar network occurs in the precursors of the fly's sensory bristles, so researchers idea is to use data from this biological network to solve the starting computational problem!

Such system is called sensory organ precursors, SOP.

Retrieval learning practice

Jeffrey Karpicke and Janell Blunt published on Science express a report about their research on retrieval practice in learning.
Karpicke studied the subject just in 2008 with Roediger III in The critical importance of retrieval for learning. Here and in the successful paper he confrounts retrieval with elaborative studying. Just in the 2008 paper he writes

repeated testing produced a large positive effect

But what is retrieval?
I found on Purdue the following definition:

Retrieval is a process of recalling what we have in memory.

So retrieval practice is the practice used by students to recall informations. In this vision I think that retrieval and elaborative studying are not so different in principle in the use of our brain, but, according to Karpicke and Blunt's results, retrieval is probably more useful for exams and elaborative is more useful if you want obtain more persistence results.
Karpicke and Blunt performed two experiments. In the first test 80 Purdue University undergraduate students studied on Sea Otters. Students are divided in 4 groups: study, repeated study, concept mapping, retrieval practice.
In data elaboration researchers pay attention in different learning activities: they can depend on the strucuture of the materials.
The conclusions:

Research on retrieval practice suggests a view of how the human mind works that differs from everyday intuitions. Retrieval is not merely a read out of the knowledge stored in one's mind – the act of reconstructing knowledge itself enhances learning. This dynamic perspective on the human mind can pave the way for the design of new educational activities based on consideration of retrieval processes.

are supported by data, summarized in the following istograms: