Riproduzione grafica (a) e immagine al microscopio ottico (b) del fotorivelatore grafene/silicio realizzato dall’Imm-Cnr in collaborazione con il Cambridge Graphene Centre

Un recente studio dell’Istituto per la microelettronica e microsistemi del Cnr, in collaborazione con il Graphene Centre dell’Università di Cambridge, ha trovato il modo di convertire la luce infrarossa in corrente integrando silicio e grafene, avvicinando così l’ipotesi di fabbricare fotorivelatori in silicio funzionanti nel vicino infrarosso. La ricerca è pubblicata su ACSNano

I fotorivelatori sono dispositivi in grado di convertire luce in corrente. Alle lunghezze d’onda del vicino infrarosso tale conversione viene in genere realizzata con materiali quali l’Arseniuro di Gallio e Indio, particolarmente costoso da lavorare, oppure il Germanio, difficilmente integrabile con una circuiteria microelettronica preesistente. Il più economico silicio, invece, sebbene sia ampiamento utilizzato per la conversione di luce a lunghezze d’onda del visibile (380-750nm), non può essere utilizzato nel vicino infrarosso (750-2500nm) a causa di alcuni limiti intrinseci del materiale. Un recente studio condotto da un team di ricercatori dell’Istituto per la microelettronica e microsistemi dell’unità di Napoli del Consiglio nazionale delle ricerche (Imm-Cnr), in collaborazione con il Graphene Centre dell’Università di Cambridge, ha trovato il modo di convertire la luce infrarossa in corrente, integrando il silicio - materiale ormai maturo come tecnologia di fabbricazione di dispositivi grazie agli investimenti messi in campo dalla microelettronica - con un materiale emergente come il grafene, consentendo così di avvicinare l’ipotesi di fabbricare fotorivelatori in silicio funzionanti nel vicino infrarosso. La ricerca è pubblicata sulla rivista ACSNano.

Research team headed by Freiburg psychologist finds previously unknown effects

Just how it works is not known - but human beings have an internal clock which enables us to perceive and estimate periods of time subconsciously. A research team under Dr. Roland Thomaschke of the University of Freiburg's Department of Psychology showed in experiments that this mental time-processing system is able to adapt quickly and flexibly to predictive time patterns. The study has been published in the specialist journal "Emotion." The psychologists examined time periods between one and three seconds. Their test subjects were given the task of sorting nouns - which appeared one after another on a computer screen - according to gender (German nouns are grammatically masculine, feminine, or neuter). During the transition to the next word, a small cross was shown. What the test subjects did not know - they were looking at concepts which are seen as positive or negative, such as love and friendship on the one hand, torture and death on the other. With most of the "positive" nouns, the cross appeared before them for half a second; with most of the negative nouns it was for two seconds. "The pattern influenced the test subjects although they were not aware of it," says Thomaschke. "If the combination was unusual, like a long interval before a positive concept, they had considerable difficulty sorting according to gender." But this irritation was not manifested when no emotions were involved. With other test subjects, the psychologists used concrete and abstract concepts instead of positive and negative ones - and the effect was not observed in this case.

Children who experience social exclusion in preschool are at greater risk of becoming so-called “school losers”. Norwegian researchers are studying what happens to children who are marginalized. It has long been known that children – like adults – can become anxious and depressed when they feel they don’t belong and don’t have good peer relationships. But can the lack of friends also affect cognitive characteristics like concentration, attention and self-regulation?

Gap in the research
The number of ADHD-diagnosed children has skyrocketed. Researcher Frode Stenseng believes that some of this trend could have been averted if fewer children had experienced social exclusion in early childhood.
Earlier experiments with students were based on the “need-to-belong theory”, which suggests that the ability to regulate one’s thoughts and feelings is weakened when a person feels socially excluded. Research on young children in the same situation hadn’t been done, and “this is where we saw a gap in the research,” says Stenseng. He is currently employed as an associate professor at the Norwegian University of Science and Technology's (NTNU) Regional Centre for Child and Youth Mental Health and Child Welfare (RKBU), and as a professor at Queen Maud University College in Trondheim.

 Amphibian chytridiomycosis, caused by infection with the Batrachochytrium dendrobatidis fungus, is the most devastating vertebrate disease on record. The fungus infects more than 600 species of amphibian and has been implicated as the primary cause of decline in more than 200 species. A new Animal Conservation study indicates that the common eastern froglet, Crinia signifera, can carry infections without experiencing mortality. Therefore, the presence of the froglets at sites where species have become threatened or extinct inhibits efforts to reintroduce these species. "Crinia signifera appears to be an important player in maintaining levels of disease within the ecosystem," said lead author Dr. Laura Brannelly, of the University of Pittsburgh. "The common eastern froglet has a wide distribution in Australia and can occur in high densities. They co-occur in high numbers at the sites where other frog species have declined and may have played a key role in those declines."

Link to Study:

http://onlinelibrary.wiley.com/doi/10.1111/acv.12380/full

In Sweden and in other parts of Europe there are concerns that seals and birds compete with humans for fish resources. For the Baltic Sea, an international study now shows that this competition is a reality. “Because fish is nutrient-rich food and angling provides valuable recreation, the increased populations of seals and fish-eating birds in the Baltic have resulted in a sometimes contentious debate over the effects of these animals on the fish stocks. The debates are often based on assumptions, which is why I took the initiative to look at the problem from a scientific viewpoint,” said Sture Hansson, Professor of Ecology, Environment and Plant Sciences at Stockholm University. Together with four researchers from the Swedish University of Agricultural Sciences (SLU) and seven other colleagues from countries around the Baltic, Hansson has estimated birds’ and seals’ fish consumption. Seals are the primary fish-eating mammals, and their consumption is about the same as that of all birds together. Humans catch 3 to 4 times more fish than seals and birds combined.

Researchers from the University of Granada (UGR), who belong to the Brain, Mind and Behavior Research Center (CIMCYC, from its abbreviation in Spanish) and the Faculty of Psychology, have proven that cortisol levels (a steroid hormone secreted as a response to stress) present in the hair of pregnant women during the first or third trimesters of pregnancy may indicate which of them are more likely to suffer postpartum depression. Their work, published in the renowned PLoS ONE journal, showed that hair cortisol levels in women who developed postpartum depression were higher throughout pregnancy than those seen in women who hadn’t developed it, being that difference statistically more significant during the first and third trimesters. The UGR researchers carried out their study doing a follow-up on 44 pregnant women throughout the whole gestation period and after giving birth. Each trimester the mothers underwent a series of tests that evaluated their stress and psychopathological symptoms while simultaneously taking hair samples from which the researchers extracted the cortisol corresponding to the last three months.

A team of researchers from Universidad Carlos III de Madrid, the Universidad de Extremadura and the Universidad de Sevilla have defined a theoretical framework that could explain the Mpemba effect, a counterintuitive physical phenomenon revealed when hot water freezes faster than cold water.

The researchers, who have recently published the findings in Physical Review Letters, have confirmed how this phenomenon occurs in granular fluids, that is, those composed of particles that are very small and interact among those that lose part of their kinetic energy. Thanks to this theoretical characterization, “we can simulate on a computer and make analytical calculations to know how and when the Mpemba effect will occur,” said Antonio Lasanta. Lasanta is from the UC3M Gregorio Millán Barbany University Institute for Modeling and Simulation on Fluid Dynamics, Nanoscience and Industrial Mathematics. “In fact,” he said, “we find not only that the hottest can cool faster but also the opposite effect: the coldest can heat faster, which would be called the inverse Mpemba effect.”