Lunedì, 05 Marzo 2018
Lunedì, 05 Marzo 2018 09:55

How the brain makes predictions

 

Goethe University Frankfurt can boast another EU-funded research project: With the appointment of Yee Lee Shing as Chair of Developmental Psychology her PIVOTAL research project has accompanied her to Frankfurt. Professor Shing’s research work investigates how the brain makes predictions.

Imagine coming into the office in the morning. Within a split second you will be able to tell whether everything is in its usual place – the furniture, the computer, your files – or not, as the case may be, or whether something has been left on your desk that does not belong there, for example a box of chocolates. Behind this ability to assess our environment is the “predictive brain”, i.e. the interaction of brain processes that lead to predictions. On what principles these predictions are based and how the interaction of the processes involved differ across the lifespan is the subject of research work being conducted by Professor Yee Lee Shing, who has held the Chair of Developmental Psychology at Goethe University Frankfurt since January.

According to Professor Shing, the brain is essentially a “prediction machine” that is constantly busy comparing new input from the environment with predictions generated by internal models of the brain. Only in this way is the human brain able to adapt to ever new situations and grasp new environments. To date, however, no researcher has examined the nature of the underlying internal models themselves or how new experiences influence these models. What is also so far unknown is how such a supposedly universal principle manifests itself in different brains – for example young or old ones. The long-term memory that may underlie the brain’s internal models is potentially the episodic and the semantic memory, personal experiences on the one hand and learned knowledge of the world on the other. Whilst children are better at remembering episodic contexts – think how unbeatable they are when playing “Memory” – older people can rely more on their semantic memory.

Pubblicato in Scienceonline


Scienziati dell’OGS coinvolti nella scoperta di una mega inondazione sul fondo del Mediterraneo centrale


Nel Mar Mediterraneo sono state trovate le tracce della più grande inondazione del nostro pianeta: un’alluvione catastrofica avvenuta quasi 6 milioni di anni fa nel corso della quale, l’acqua, passando dallo Stretto di Gibilterra, ha inondato tutto il bacino mediterraneo. Lo studio, che è stato recentemente pubblicato sulla rivista internazionale “Scientific Reports”, è stato guidato da Aaron Micallef dell’Università di Malta e da Angelo Camerlenghi dell’Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, e ha coinvolto, oltre ad altri ricercatori OGS, anche ricercatori dell’ICTJA-CSIC (Spagna), dell’Università di Brest/CNRS (Francia), dell’Università di Catania, dell’Università di Kiel e GEOMAR (Germania).

Il team internazionale ha dimostrato come l'alluvione, nota come alluvione Zancleana, abbia messo fine alla cosiddetta Crisi di Salinità Messiniana, un periodo durante il quale, circa 6 milioni di anni fa, il Mar Mediterraneo si trasformò in un gigantesco lago salino a causa del restringimento della sua connessione con l'Oceano Atlantico e dell’intensa evaporazione. Una delle teorie proposte per spiegare il ritorno del Mar Mediterraneo alle normali condizioni marine alla fine della crisi di salinità, circa 640.000 anni dopo, è un'alluvione passata attraverso lo Stretto di Gibilterra.

Esaminando la più completa raccolta di dati di fondali marini provenienti dalla Sicilia orientale e dalle isole maltesi, i geologi hanno scoperto nelle profondità abissale del Mar Ionio una vasta massa di sedimenti sepolti che si pensa siano stati erosi e trasportati dall'alluvione Zancleana. Questa massa di detriti corrisponde a un'area equivalente a quella dell'isola di Creta e, in alcuni punti, ha uno spessore che raggiunge i 900 metri. Il passaggio dell'inondazione Zancleana attraverso la scarpata di Malta – un’enorme falesia calcarea sottomarina, al tempo parzialmente emersa - ha provocato una cascata alta 1,5 chilometri (equivalente a cinque volte l'altezza della Torre Eiffel). Questa acqua ha eroso un canyon di 5 chilometri di larghezza e 20 chilometri di lunghezza sul fondale marino che è ancora preservato sott'acqua al largo della città di Noto (Sicilia sud-orientale).

Pubblicato in Ambiente
Lunedì, 05 Marzo 2018 09:35

Vitamin D reduces mortality

 

 

A normal intake of vitamin D can reduce the risk of death substantially in people with cardiovascular disease, a Norwegian study shows.
A study from the University of Bergen (UiB) concludes that people who have suffered from cardiovascular disease, and have a normal intake of vitamin D, reduce their risk of morality as a consequence of the disease by 30 per cent. 
“We discovered that the right amount of vitamin D reduces the risk of death substantially.  However, too much or too little increase the risk,” says Professor Jutta Dierkes at the Department of Clinical Medicine, UiB, which lead the study.
The study followed as many as 4 000 patients with cardiovascular diseases from year 2000, for a period of 12 years. The average age of the participants was 62 years old at the start of the study. 

Difficult recommendations

The study showed that it is favourable to have blood values around 42 to 100 nmol/l. If you have higher or lower values, you are at greater risk of dying from cardiovascular disease.  According to Dierkes, it is difficult to give general a recommendation of how much vitamin D supplementation one should take.  “The optimal amount of vitamin D-supplement varies from one person to another. It depends where you live, and what kind of diet you have,” Dierkes points out.  For example, the Nordic countries recommend an intake of 10 microgram per day from all vitamin D-sources, USA recommends 15 micrograms and Germany 20.
“Even if Norwegians receive less sun then the Germans, the Norwegians have more fish in their diet. Fish and cod liver oil are important sources to vitamin D during the winter, in addition to physical activities outdoors during the summer,” Dierkes explains. 

Pubblicato in Scienceonline

 

The human papillomavirus (HPV) is the most common sexually transmitted disease. While vaccines are helping stop its spread, HPV is still the cause of 72 percent of oropharyngeal cancers, which impact the base of the tongue, tonsils and walls of the pharynx. "Given the alarming increase of HPV-attributable oropharyngeal cancers, dentists and dental hygienists may be key agents for promoting HPV prevention," said lead investigator Ellen Daley, PhD, a professor at the University of South Florida College of Public Health. "However, there's a serious need for better training and education in the dental community." In a study highlighted on the cover this month's Journal of the American Dental Association, Dr. Daley concludes most dentists don't discuss HPV prevention methods with their patients for a number of reasons. Some study participants admitted to not knowing enough about how one contracts HPV-related oropharyngeal cancer, its symptoms, transmission, progression and/or best prevention methods.

Pubblicato in Scienceonline

There are very few archaeological sites that have provided us with fossilised human footprints dating earlier than 300,000 years ago. This makes the recent discovery at the Ethiopian site of Gombore II-2, part of the greater Melka Kunture site, all the more significant. The footprints found there can be dated to 700,000 years ago, thanks to the volcanic tufa that covers the entire site. The excavated area at the edge of a water hole was intensely frequented in pre-historic times by mankind and animals alike. Indeed, traces of various species are plentiful, along with those of human beings and very young children (age 1-3). In particular, one of the children left a series of heel- and toe-prints.

“It was a very intense moment for us,” explains Flavio Altamura, the young researcher who headed the study that has just been published on Nature’s Scientific Reports. “Gombore II-2 has provided us with what may be the closest thing we’ll ever see to a photo of prehistoric life. We can practically say that these are the first steps of a child from 700,000 years ago, while the rest of the group carried on their daily activities.” The site has preserved the traces of a full range of activities, including the production of lithic tools in obsidian and other volcanic rock and the butchering of various hippopotami. There also are superimposed traces on the bones left by the carnivores who approached the animal carcasses after the hominids were finished with them. This reveals that the hominids were in full control of the environment.

Pubblicato in Scienceonline

 

Scienzaonline con sottotitolo Sciencenew  - Periodico
Autorizzazioni del Tribunale di Roma – diffusioni:
telematica quotidiana 229/2006 del 08/06/2006
mensile per mezzo stampa 293/2003 del 07/07/2003
Scienceonline, Autorizzazione del Tribunale di Roma 228/2006 del 29/05/06
Pubblicato a Roma – Via A. De Viti de Marco, 50 – Direttore Responsabile Guido Donati

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