Articoli filtrati per data: Lunedì, 20 Marzo 2017

The whip-like tail of the sperm has a particular rhythm that pulls the head backwards and sideways to create a jerky fluid flow.

Researchers have developed a mathematical formula based on the rhythmic movement of a sperm’s head and tail, which significantly reduces the complexities of understanding and predicting how sperm make the difficult journey towards fertilising an egg. Researchers at the Universities of York, Birmingham, Oxford and Kyoto University, Japan, found that the sperm’s tail creates a characteristic rhythm that pushes the sperm forward, but also pulls the head backwards and sideways in a coordinated fashion. Successful fertility relies on how a sperm moves through fluid, but capturing details of this movement is a complicated issue.
Pubblicato in Scienceonline

The purified water is compared with its original source, as well as a reference sample from the tap. Photo: KTH Royal Institute of Technology


What can the forests of Scandinavia possibly offer to migrants in faraway refugee camps? Clean water may be one thing. A bacteria-trapping material developed from wood by researchers KTH Royal Institute of Technology is now being tested for use as a water purification filter. The aim is to use it in places where there is no infrastructure or clean water supply. The material, which combines wood cellulose with a positively-charged polymer, can trap bacteria by attracting and binding the bacteria to the material surface. It shows promise for bandages, plasters and packaging that kill bacteria without releasing toxins into the environment. Led by Professor Monica Ek, the Swedish research team is investigating whether the material can enable portable on-site water treatment where no facilities or wells exist to meet demand.

Pubblicato in Scienceonline
Lunedì, 20 Marzo 2017 10:16

Comunità microbiche sahariane sulle Alpi

Pubblicata su Microbiome una ricerca di Fondazione Edmund Mach, Istituto di biometeorologia del Cnr, Università di Firenze, Innsbruck, Venezia. Studiando la polvere sahariana depositata e ‘sigillata’ sulla neve delle Alpi dolomitiche, sono state identificate migrazioni di microorganismi dalle aree sahariane. Si tratta di uno degli effetti del cambiamento climatico e dell’uso del suolo

 

Il cambiamento climatico e l’uso del suolo stanno provocando migrazioni che non si possono fermare, quelle dei microorganismi. Un team multidisciplinare di microbiologi, geologi, chimici e bioclimatologi di Fondazione Edmund Mach di San Michele all’Adige, Istituto di biometeorologia del Consiglio nazionale delle ricerche (Ibimet-Cnr) , Università di Firenze, Venezia e Innsbruck, ha studiato la carica microbica di uno tra i più intensi eventi di trasporto di polveri sahariane che ha raggiunto le Alpi nel 2014, pubblicando i risultati sulla prestigiosa rivista Microbiome.

Pubblicato in Scienze Naturali

Drinking horns were status symbols and widely used as gifts, both in the Middle Ages and in the centuries after the Reformation. The picture shows one of the few drinking horns that have remained in Icelandic possession, called the "Three kings horn." It shows Saint Olav juxtaposed with Old Testament kings Solomon and David. Photo: National Museum of Iceland

After the Reformation, Norway's Olav Haraldsson was no longer supposed to be worshipped as a saint. An Icelandic drinking horn offers some clues on how the saint’s status changed over time. Drinking horns were considered valuable objects, and were imbued with great symbolic value in the Middle Ages. Among other things, it was said that these kinds of horns came from the foot or claw of the fabled griffin. Drinking horns often had names, and were status symbols and collector’s items. Some were stolen and many ended up in princely cabinets. “Mediaeval drinking horns are scattered in collections throughout northern Europe. They were coveted collectibles. Mediaeval art often remained in churches until it went out of fashion or was removed due to errors in iconography, whereas drinking horns ended up in princely collections and cabinets and have kept their status to the present day,” says Associate Professor Margrethe Stang, from the Norwegian University of Science and Technology’s (NTNU) Department of Art and Media Studies.

Pubblicato in Scienceonline

Antarctica. Photo: Pablo Ruiz, Instituto Antártico Chileno (INACH)

 

For over 70 years seven different countries have claimed sovereignty over parts of Antarctica. But are these claims legitimate? This issue is now going to be considered by a group of philosophers. Queen Maud's Land constitutes one sixth of Antarctica, and Norway has claimed this territory since 1939, but this has never been approved by the rest of the world. The same applies to the claims of six other countries; New Zealand, Australia, France, Great Britain, Chile and Argentina have all made territorial claims over different parts of Antarctica. All of these countries also believe that they have an entitlement to the South Pole. A group of philosophers from Norway, Ireland, Canada, Australia, the United Kingdom and Chile are now getting to grips with this matter. They believe that it is high time to look at these claims from a moral point of view.

Pubblicato in Scienceonline

The American Society of Clinical Oncology (ASCO) today issued a clinical practice guideline on human papillomavirus (HPV) vaccination for the prevention of cervical cancer. This is the first guideline on primary prevention of cervical cancer that is tailored to multiple regions of the world with different levels of socio-economic and structural resource settings, offering evidence-based guidance to health care providers worldwide. The guideline includes specific recommendations according to four levels of resource settings: basic, limited, enhanced and maximal. The levels pertain to financial resources of a country or region, as well as the development of its health system — including personnel, infrastructure and access to services. The guideline complements ASCO’s two other global, resource-stratified guidelines on cervical cancer, also stratified to these four levels of resources.1,2

Pubblicato in Scienceonline

 

Patients with recurrent fainting episodes (syncope) who received a pacemaker delivering a pacing program designed to detect and stop the abnormal heart rhythms that precede syncope had a seven-fold reduction in fainting compared with patients in a placebo pacing group, according to research presented at the American College of Cardiology’s 66th Annual Scientific Session. The study—the first prospective double-blind placebo-controlled trial to show robustly positive results for the pacing program, known as Closed Loop Stimulation (DDD-CLS), in patients with recurrent syncope—met its primary endpoint of a significant reduction in fainting episodes with DDD-CLS compared to placebo pacing.

Pubblicato in Scienceonline

 

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Autorizzazioni del Tribunale di Roma – diffusioni:
telematica quotidiana 229/2006 del 08/06/2006
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Scienceonline, Autorizzazione del Tribunale di Roma 228/2006 del 29/05/06
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