Marzo 2026

Dagli scavi a Melka Kuture, la scoperta di un percorso evolutivo discontinuo dal genere Homo all’Homo sapiens

Tracciare il percorso dell’evoluzione umana è possibile, specialmente in Africa orientale dove si trovano i siti archeologici che meglio raccontano il percorso dei nostri antenati. L’associazione diretta tra una determinata specie umana e una specifica tecnica di produzione degli utensili in pietra (industria litica) ha, fino a oggi, consentito di raccontare questo percorso come un fenomeno unitario. Nell’articolo pubblicato sul Journal of Anthropological Sciences, Margherita Mussi del Dipartimento di Scienze dell’Antichità della Sapienza e direttrice delle ricerche archeologiche a Melka Kunture (Etiopia), uno dei Grandi Scavi della Sapienza, propone, insieme a Rosalia Gallotti, una nuova interpretazione dello sviluppo dell’Acheuleano, cultura del Paleolitico inferiore. Questa cultura rappresenta una fase molto lunga (da 1, 8 milioni a 100.000 anni fa) e importante dell’evoluzione umana ed è caratterizzata da una innovazione tecnica nella scheggiatura dei manufatti – che comprendono i caratteristici “bifacciali” a forma di mandorla –, evidenziando un vero e proprio salto di qualità rispetto ai periodi precedenti. Le industrie acheuleane più antiche sono state rinvenute appunto in Africa.

Pubblicato in Paleontologia

Lunedì, 16 Ottobre 2017 13:58

This ingenious approach not only binds CO2, but also improves the soil

Biochar can help us address many environmental challenges. This form of CO2 capture and storage reduces the need for fertilisers and may lead to better crop yields. It can also remove heavy metals from the soil. Photo: Lisbet Jære.

If 4,000 Norwegian farms and nurseries produced biochar and mixed it with the soil, we could halve CO2 emissions from the agricultural sector. This entirely natural approach also produces more robust and healthy plants. There is a new addition among the greenhouses at the Skjærgaarden nursery – Norway’s first biochar plant. Biochar is identical to charcoal (or barbecue coal), but can be manufactured not only from wood, but also from other kinds of organic material. The nursery is hosting the first biochar demo plant in Norway, which has been installed in collaboration with the cross-disciplinary research project CAPTURE+. “Our motivation for starting biochar production is to improve the soil”, says Kristin Stenersen, who runs the Skjærgaarden nursery together with her husband Bjørge Madsen. “We want more robust and healthier plants, and to reduce our use of synthetic pesticides and artificial fertilisers. Of course, the fact that biochar also binds CO2 is an added benefit”, she says. “People are welcome to come and see for themselves how it works in practice”, says Maria Kollberg Thomassen, who is a Senior Researcher at SINTEF and Project Manager for CAPTURE+.

Pubblicato in Scienceonline

Lunedì, 16 Ottobre 2017 09:35

Sleep Duration May Affect the Integrity of Sperm DNA

A new study found a link between sleep duration and a measure of chromosomal health in sperm. The findings are published in the Journal of Sleep Research. In the study of 2020 semen samples provided by 796 male volunteers from colleges in Chongqing (China) from 2013 to 2015, volunteers with more than 9 hours per day of sleep and those with 6.5 hours or less per day sleep had 41% and 30% lower High DNA Stainability—an index that represents the proportion of sperm with abnormal chromatin—than did volunteers with 7 to 7.5 hours per day of sleep. Chromatin is a complex of DNA and proteins that forms chromosomes. “This is new information after our pervious finding that sleep duration has an inverse U-shaped association with semen volume and total sperm count. In the previous study, we found that these two semen parameters were highest when sleep is 7.0 to 7.5 hours per day, and either longer or shorter sleep was associated with the decrease of the two semen parameters.”, said Dr. Jia Cao, co-author of the study.

Pubblicato in Scienceonline

Lunedì, 16 Ottobre 2017 08:50

World’s Largest University Subject Rankings: 2017 Edition

The Center for World University Rankings (CWUR), publisher of the largest academic ranking of global universities, released today its inaugural subjects ranking. The ranking features the top global universities in 227 subjects covering all academic disciplines in the sciences and social sciences.

Harvard University leads the way globally, achieving Top-10 placements in 112 subjects, including 72 top places.

Institutions with the most Top-10 placements worldwide are:

1. Harvard University, USA (112 Top-10 subjects)
2. University of Toronto, Canada (66 Top-10 subjects)
3. University of Michigan, USA (57 Top-10 subjects)
4. University of Pennsylvania, USA (54 Top-10 subjects)
5. Johns Hopkins University, USA (51 Top-10 subjects)
6. University of California, Berkeley, USA (50 Top-10 subjects)
7. Stanford University, USA (48 Top-10 subjects)
8. University of Oxford, United Kingdom (47 Top-10 subjects)
9. University of Washington, USA (45 Top-10 subjects)
10. Massachusetts Institute of Technology, USA (41 Top-10 subjects)

Pubblicato in Scienceonline

Lunedì, 16 Ottobre 2017 08:14

Mapping migrant communities across Europe to support local integration

The JRC’s new dataset shows maps of migrant communities across Europe.

This week scientists unveiled a unique dataset that maps the diverse migrant communities living in the EU. The maps will provide policy makers with new insights and a better overall picture to develop local policies to help migrants integrate in their host countries. The maps show residential patterns of migrant communities by their nationality or the country where they were born, at the level of neighbourhoods. From the underlying data researchers can calculate the concentration, diversity and segregation of migrants from different countries and compare these indicators within and across cities. For example, JRC scientists found that Chinese and Filipino communities in Europe are likely to be highly clustered and segregated from their host communities. Scientists also found that there is a general correlation between how segregated a migrant community may be and the geographical and linguistic distance between their countries of origin and destination.

Pubblicato in Scienceonline

Lunedì, 16 Ottobre 2017 08:03

New antibiotic resistance genes found

Erik Kristiansson, Professor in biostatistics at Chalmers University of Technology

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have found several previously unknown genes that make bacteria resistant to last-resort antibiotics. The genes were found by searching large volumes of bacterial DNA and the results are published in the scientific journal Microbiome. The increasing number of infections caused by antibiotic-resistant bacteria is a rapidly growing global problem. Disease-causing bacteria become resistant through mutations of their own DNA or by acquiring resistance genes from other, often harmless, bacteria. By analysing large volumes of DNA data, the researchers found 76 new types of resistance genes. Several of these genes can provide bacteria with the ability to degrade carbapenems, our most powerful class of antibiotics used to treat multi-resistant bacteria. “Our study shows that there are lots of unknown resistance genes. Knowledge about these genes makes it possible to more effectively find and hopefully tackle new forms of multi-resistant bacteria”, says Erik Kristiansson, Professor in biostatistics at Chalmers University of Technology and principal investigator of the study.

Pubblicato in Scienceonline

Lunedì, 16 Ottobre 2017 07:47

Così il miglio resiste alla desertificazione

L’aumento delle temperature e della frequenza di eventi climatici estremi, come le ondate di caldo che si verificano in molte parti del mondo, sono destinati a portare ad un calo delle rese produttive delle più importanti colture alla base dell’alimentazione umana. Oggi, con la decifrazione della sequenza del genoma del miglio perlato, un progetto che ha coinvolto un team internazionale di 65 scienziati appartenenti a 30 diverse istituzioni di ricerca, è possibile svelare le strategie vincenti messe in atto da questa coltura per affrontare condizioni climatiche estreme. L’analisi della variabilità genetica di un migliaio di linee di questo cereale, tipicamente ben adattato a crescere nelle regioni desertiche, ha permesso di comprendere meglio come esso possa sopravvivere a temperature estreme (oltre 42°C) e sia eccezionalmente tollerante al secco. Lo studio, pubblicato sulla prestigiosa rivista Nature Biotechnology(doi:10.1038/nbt.3943), getta le basi per il potenziale sviluppo di analoghe strategie adattative in altri importanti cereali. La ricerca, co-diretta dall'International Crops Research Institute for Semi-Arid Tropics (Icrisat), India, dal Beijing Genomics Institute (Bgi)-Shenzhen, Cina e dall’Istituto nazionale di ricerca per lo sviluppo sostenibile (Ird), Francia, e che ha visto anche il coinvolgimento dell’Istituto di biologia e biotecnologia agraria del Consiglio nazionale delle ricerche (Ibba-Cnr) di Milano, “ha impiegato le tecnologie di sequenziamento e analisi del Dna più innovative per identificare nuovi strumenti genetici, come marcatori molecolari correlati alla tolleranza alla siccità e alle alte temperature, così come ad altri importanti caratteri (migliore profilo nutrizionale, resistenza a patogeni)”, spiega Francesca Sparvoli dell’Ibba-Cnr.

Pubblicato in Scienze Naturali

Lunedì, 16 Ottobre 2017 07:37

Infezioni da hpv e cervicocarcinoma

Aspetti epidemiologici dell’infezione da Hpv

Figura 1: Prevalenza delle infezioni da Hpv per classe d’età nella popolazione generale in Italia

L’infezione da Hpv è estremamente frequente nella popolazione: si stima, infatti, che fino all’80% delle donne sessualmente attive si infetti nel corso della propria vita con un virus Hpv di qualunque tipo, e che oltre il 50% si infetti con un tipo ad alto rischio oncogeno. Una revisione sistematica di studi condotti in Italia [1] ha rilevato una prevalenza di Hpv oncogeni nella popolazione generale pari all’8%, senza differenze sostanziali fra Sud, Centro e Nord. È opportuno sottolineare che il calcolo di questa prevalenza ha considerato solo gli studi con campione casuale della popolazione; infatti gli studi che reclutano donne che si presentano spontaneamente a un ambulatorio ginecologico riportano una stima di prevalenza generalmente più alta degli studi che reclutano le donne in base a un invito attivo della popolazione generale. Questo probabilmente, è dovuto al fatto che le donne che accedono spontaneamente agli ambulatori ginecologici hanno, in proporzione variabile, pregressi Pap test positivi.

Pubblicato in Medicina

Lunedì, 16 Ottobre 2017 07:34

Construction of a full transcription map of human papillomavirus type 18 during productive viral infection.

Human papillomavirus type 18 (HPV18) is the second most common oncogenic HPV genotype, responsible for ∼15% of cervical cancers worldwide. In this study, we constructed a full HPV18 transcription map using HPV18-infected raft tissues derived from primary human vaginal or foreskin keratinocytes. By using 5' rapid amplification of cDNA ends (RACE), we mapped two HPV18 transcription start sites (TSS) for early transcripts at nucleotide (nt) 55 and nt 102 and the HPV18 late TSS frequently at nt 811, 765, or 829 within the E7 open reading frame (ORF) of the virus genome. HPV18 polyadenylation cleavage sites for early and late transcripts were mapped to nt 4270 and mainly to nt 7299 or 7307, respectively, by using 3' RACE.

Pubblicato in Scienceonline

Venerdì, 13 Ottobre 2017 16:52

Does size matter? Bigger cod contains more mercury

The levels of mercury in the Oslofjord cod has increased over the last 30 years, despite reduced emissions of this toxic element. In the same period, the average size of sampled cod has increased. Are the elevated levels of mercury simply a result of larger cod? Historical use and emissions of mercury have resulted in its leaking into the environment, and mercury has found its way to the Oslofjord cod. Mercury has toxic effects on the nerve system, and may have negative impacts on fine motor skills, cognitive abilities, attentiveness and memory. The Norwegian Institute of Water Research (NIVA) has been monitoring the mercury levels in the Oslofjord cod since 1984, and now a group of researchers can present the latest news about the fish in a newly published research article. This article may uncover the reasons behind the mysterious increase in mercury over the last thirty years.

More mercury

In several studies researchers have been investigating the processes by which mercury is taken up in wildlife. One would think that the mercury levels in wildlife were reduced over the last years, considering the deposition of mercury in Southeast Norway is reduced. But more intense rainfalls have increased wash-out of humus substances in inland waters, and in those environments mercury has possibly become more available for uptake in organisms, by processes that the researchers do not yet fully understand. Theoretically, this could contribute to the changes also observed in the Oslofjord cod. Another explanation for the elevated mercury levels could be a change in cod diet towards more contaminated prey. Unfortunately, there is no historic prey data available for comparison. NIVA researcher Anders Ruus still thinks they have come closer to an answer.

- Our analyses indicate that close to a third of the variation in mercury concentration was explained solely by variation in fish length, says Ruus.

Thus, it seems like bigger fish size causes higher mercury levels.

- The average length of the sampled Oslofjord cod has increased over the last decades, and this might be the main explanation of the pronounced increase in mercury levels. When we corrected the data for fish length, there was no significant increase in mercury concentrations.

Loves proteins

The concept of bigger and older organisms having higher levels of certain toxicants is well-established in the field of toxicology. It is called bioaccumulation: a toxicant is more easily absorbed through feed than excreted, and over time, the toxicant accumulates in the organism. Pure mercury is not readily taken up in organisms; but in aquatic environments where oxygen is not present, small microbes can transform mercury to methyl mercury. This substance easily binds to proteins. By this mechanism mercury enters the food chain, and the concentration builds up for each level in the chain. The compound is stored in protein-rich tissue like muscles, which is the part of the cod that humans prefer to eat. By this route, humans are also exposed.

Why is the cod larger?

There are two possible explanations to why the Oslofjord cod is bigger: Either there has been a change in the cod population, or there has been a shift in the sampling methods towards fishing larger cod.

- Beach seine surveys in the Inner Oslofjord have shown that cod recruitment has been low since the beginning of the 2000s. In 2014 there were no young fish observed at all, says Ruus.

The reason for these changes in the cod population is unknown, and this needs to be investigated further.

But the fact that there is a tolerance for fish length in the protocol for selecting fish could cause the analyses to show a trend that isn’t necessarily real.

- Since we started monitoring in the mid-eighties, there has been an increasing number of chemical parameters to be analysed, demanding sampling of more tissue per fish. As there is a tolerance for fish length in the protocol, we cannot exclude the possibility of a bias towards sampling more of the larger fish, even if all guidelines have been followed, Ruus explains.

Anyhow, length cannot be the only factor causing the increase in mercury, Ruus emphasizes. More research is needed to investigate other explaining factors.

This study was done by the Norwegian Institute of Water Research (NIVA) with economic support from the Research Council of Norway. Data collection is part of the Norwegian contribution to OSPAR´s (Oslo and Paris Commission) Joint Assessment and Monitoring Programme (JAMP). This is conducted by NIVA by contract from the Norwegian Environment Agency.

http://www.niva.no/en/stor-torsk-har-meir-kvikksoelv

Pubblicato in Scienceonline