Nature News

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Re: Nature News

Inläggav Tryggve » tis 02 jun 2015, 14:36

Enligt artikeln så ska det också påstås att träden inte är påverkade av denna bakterie utan av en svamp, och att det finns ett botemedel med att forskarna hemlighåller/motverkar detta.

Lite känns ju argumenten igen, får man ju säga.
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Prionreistens upptäckt

Inläggav Tryggve » tor 11 jun 2015, 15:48

Kuru är en sjukdom som orsakas av prioner. Sjukdomen beskrevs av Daniel Carleton Gajdusek på 1950-talet, och förekom då på Nya Guinea där en del stammar ägnade sig åt rituell kannibalism. Sjukdomen överfördes av att man åt hjärnor. Upptäckten ledde till Nobelpris för Gajdusek 1976.

http://sv.wikipedia.org/wiki/Kuru_%28sjukdom%29

Nåväl, nyheten som jag tänkte skriva om är att ett forskarlag verkar ha upptäckt en gen som ger skydd mot d

http://www.nature.com/news/genetic-muta ... se-1.17725

Det har tidigare rapporterats om punktmutationer som verkar ge ökad resistens mot denna sjukdom, men nu har man funnit ytterligare en mutation, som verkar ge ökat skydd.

Scientists have noted previously that some people seem less susceptible to prion diseases if they have an amino-acid substitution in a particular region of the prion protein — codon 1293. And in 2009, a team led by John Collinge — a prion researcher at University College London who is also the lead author of the most recent analysis — found another protective mutation among the Fore, in codon 1274.

The group's latest work, reported on 10 June in Nature1, shows that the amino-acid change that occurs at this codon, replacing a glycine with a valine, has a different and more powerful effect than the substitution at codon 129. The codon 129 variant confers some protection against prion disease only when it is present on one of the two copies of the gene that encodes the protein. But transgenic mice with the codon-127 mutation were completely resistant to kuru and CJD regardless of whether they bore one or two copies of it.
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Bronsåldersgenom

Inläggav Tryggve » tor 11 jun 2015, 20:48

Här är en artikel om hur man har sekvenserat fler och fler genom från bronsåldersmänniskor. Detta har gett rätt mycket spännande data, som gås igenom i artikeln.

Som molekylärbiolog så kan jag inte låta bli att verkligen tycka att detta är helt fantastiskt, när jag började plugga en gång för många år sedan så var det EN frilevande organism som var helt sekvenserad, Haemophilus influenzae. E.coli kom sedan 1997.

Nu kan man sekvensera en människas genom mer eller mindre som rutin.... Tanken är faktiskt svindlande.

http://www.nature.com/news/dna-data-exp ... ge-1.17723

DNA data explosion lights up the Bronze Age

Population-scale studies suggest that migrants spread steppe language and technology.

Only half a decade after a 4,000-year-old tuft of hair yielded the first ancient-human genome1, researchers are starting to sequence ancient genomes by the dozen, much as they do with modern genomes.

Such population-scale sequencing is answering long-standing questions about the Eurasian Bronze Age. This tumultuous period between about 3000 bc and 1000 bc saw new technologies and cultural traditions — from the use of finely crafted weaponry and horse-drawn chariots to changes in burial practices — spread across Europe and Asia, starting in the steppe between the Black Sea and the Caspian Sea.

As DNA data flood in, researchers say, the mass-genome approach will paint an increasingly accurate picture of the past and show how ancient events shaped modern humanity — from what we eat to the diseases that ail us. “Christ, what does this mean?” says Greger Larson, an evolutionary geneticist at the University of Oxford, UK. “In another five years, we’ll be talking about tens of thousands of ancient genomes.”

The dawn of ancient population genomics is the result of cheap DNA sequencing and the rise of boutique lab techniques that can separate highly degraded ancient DNA from contemporary contaminants.
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Re: Nature News

Inläggav micke.d » tor 11 jun 2015, 22:53

Hädanefter kallar jag dem Daesh.
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Tobak

Inläggav Tryggve » ons 16 sep 2015, 12:06

Detta är inte Nature utan Science, men det passar väl rätt bra här. Funderade på GMO-tråden, men det handlar ju inte om livsmedelsproduktion här.

http://news.stanford.edu/news/2015/sept ... 91015.html

Forskare på Stanford har lyckats producera Etoposid, eller snarare prekursor till detta ämnet, i tobak. Varför är detta spännande? Jo,ämnet används i kemoterapi, och man tror att detta skulle kunna innebära ett bättre sätt att producera ämnet.

Ämnet sägs igad utvinnas från växter som är svåra att odla, eller i visa fall utrotningshotade. Detta skulle då kunna vara ett bättre sätt att producera ämnet.

Ämnet i fråga.
https://en.wikipedia.org/wiki/Etoposide

Lite om klassen av ämnen som det tillhör. podofyllotoxin.
Svenska
https://sv.wikipedia.org/wiki/Podofyllotoxin

Engelska
https://en.wikipedia.org/wiki/Podophyllotoxin
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DNA som bevismaterial

Inläggav Tryggve » tor 29 okt 2015, 14:04

En artikel där författaren redogör för en del möjliga brister i hanteringen av DNA som bevismaterial.

http://www.nature.com/news/forensic-dna ... le-1.18654

Forensic DNA evidence is not infallible

As DNA analysis techniques become more sensitive, we must be careful to reassess the probabilities of error, argues Cynthia M. Cale.

Earlier this month, the Texas Forensic Science Commission raised concerns about the accuracy of the statistical interpretation of DNA evidence, and it is now checking whether convictions going back more than a decade are safe.

Despite how it is often portrayed, in the media and in courts, the forensic science of DNA is far from infallible. Particularly concerning is that police and prosecutors now frequently talk of 'touch DNA' — genetic profiles of suspects and offenders that have been generated in a laboratory from just a handful of skin cells left behind in a fingerprint.

Research done by me and others at the University of Indianapolis in Indiana has highlighted how unreliable this kind of evidence can be. We have found that it is relatively straightforward for an innocent person's DNA to be inadvertently transferred to surfaces that he or she has never come into contact with. This could place people at crime scenes that they had never visited or link them to weapons they had never handled.

Such transfer could also dilute the statistics generated from DNA evidence, and thereby render strong genetic evidence almost insignificant. (This issue is the focus of the Texas investigation.)

We urgently need to review how DNA evidence is assessed, viewed and described. Everyone in the medico-legal community — forensic scientists and technicians, DNA analysts, potential jurors, judges and lawyers for both the prosecution and defence— must know and understand the potential for mistakes.

The term 'touch DNA' conveys to a courtroom that biological material found on an object is the result of direct contact. In fact, forensic scientists have no way of knowing whether the DNA was left behind through such primary, direct transfer. It could also have been deposited by secondary transfer, through an intermediary. (If I shake your hand then I could pass some of your skin cells onto something that I touch next.)


It is important to recognize that DNA amplification kits have become much more sensitive than they were in the past. As a result, the types of samples being analysed have expanded. Investigators no longer need to identify and request analysis of body fluids such as blood, semen and saliva. They can swab surfaces for otherwise invisible cells left behind, on the handle of a weapon or on a windowsill, perhaps, and ask labs to generate a DNA profile from them. The new kits can generate a full genetic profile of a suspect from as little as 100 picograms (trillionths of a gram) of DNA.
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Re: Nature News

Inläggav Tryggve » tor 29 okt 2015, 14:21

I USA så har en behandling mot cancer som involverar virus godkänts. Det rör sig om ett modifierat herpesvirus som har en starkt reducerad förmåga att orsaka herpes, utan i stället ska replikera sig i tumörceller. Väl där så ska de förstöra de cancerceller som de har infekterat, och dessutom producera antigen som gör att kringliggande celler känns igen av immunförsvaret och angrips av dessa.

http://www.nature.com/news/cancer-fight ... al-1.18651

First cancer-fighting virus approved

US regulators clear a viral melanoma therapy, paving the way for a promising field with a chequered past.


An engineered herpesvirus that provokes an immune response against cancer has become the first treatment of its kind to be approved for use in the United States, paving the way for a long-awaited class of therapies. On 27 October, the US Food and Drug Administration (FDA) approved a genetically engineered virus called talimogene laherparepvec (T-VEC) to treat advanced melanoma. Four days earlier, advisers to the European Medicines Agency had endorsed the drug.

With dozens of ongoing clinical trials of similar ‘oncolytic’ viruses, researchers hope that the approval will generate the enthusiasm and cash needed to spur further development of the approach. “The era of the oncolytic virus is probably here,” says Stephen Russell, a cancer researcher and haematologist at the Mayo Clinic in Rochester, Minnesota. “I expect to see a great deal happening over the next few years.”

Many viruses preferentially infect cancer cells. Malignancy can suppress normal antiviral responses, and sometimes the mutations that drive tumour growth also make cells more susceptible to infection. Viral infection can thus ravage a tumour while leaving abutting healthy cells untouched, says Brad Thompson, president of the pharmaceutical-development firm Oncolytics Biotech in Calgary, Canada.
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Re: Nature News

Inläggav Tryggve » tor 29 okt 2015, 20:46

Och här var det en artikel som diskuterar problemet med reproducerbarhet inom forskning. Inom fältet biomedicin. Artikeln är en intervju med Dorothy Bishop, en forskare inom fältet, som ledde ett stort mötet där detta problem diskuterades.

http://www.nature.com/news/how-to-make- ... le-1.18684

How to make biomedical research more reproducible

Neuropsychologist Dorothy Bishop discusses a UK report on irreproducibility in science.

Research that cannot be reproduced has become one of the most debated issues in science. In April, a group of influential UK biomedical funding agencies held a meeting to discuss the problem — and have just released their findings. Dorothy Bishop, a researcher in developmental neuropsychology at the University of Oxford who led the April meeting, talks to Nature about the reproducibility problem and how to solve it.


Your report notes that it is difficult to quantify the scale of the reproducibility problem. Do you think it is a major problem?

It is very clear that there are things that are not being done optimally and that people are quite often absolutely unaware of this. In psychology, we have recently obtained quantification of this from the reproducibility project [a collaborative effort which found that the results of more than half of psychology studies could not be replicated]. Those results are a bit disturbing. It’s not just a minor problem on the fringe of the subject.

The group that is most interesting are the early-career researchers who seem to be both aware of the problem and terribly worried about it. If they are bold and do some of the things we have recommended in the report — such as adopting preregistration, being more collaborative, using open data and open methods — then I think they feel that they might be putting themselves at a career disadvantage. They have a sense that a lot of very senior figures either are unaware of the problem or disapprove of these solutions.

Is it true that senior scientists disapprove of these solutions?

I can only speak here for psychology. I’m very enthusiastic about the idea that you preregister your studies — you make a quite detailed protocol of your design and intended analysis, and get that reviewed before you do the study. But I think a lot of other scientists felt under personal attack from those advocating preregistration, that others were saying they weren’t doing science properly. There were scientists talking about the ‘reproducibility police’ or even ‘reproducibility Nazis’. That has to some extent calmed down. But it’s still the case that you get kickback.
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Re: Nature News

Inläggav Tryggve » lör 21 nov 2015, 14:46

Det förefaller som om biosäkerheten har allvarliga problem på sina håll, i alla fall i USA. Det vore väl märkligt om det inte fanns motsvarande problem på annat håll.
I denna artikel så ta exemplet upp med personal som hanterade prov med anthrax på ett felaktigt sätt. Man lyckades inte sterilisera de prover som man lämnade ut, p g a felaktig hantering. 41 personer utsattes vid en incident för potentiell smitta.
Det är möjligt att man har skickat ut potentiellt farliga prov till 52 olika laboratorier i världen.

Författaren lägger fram en del idéer om vad som kan förbättras. Mest menar han att det är säkerhetstänkandet som brister.

http://www.nature.com/news/biological-r ... ty-1.18747

Biological research: Rethink biosafety

Tim Trevan calls on those working with organisms that are hazardous, or could be so, to take lessons from the nuclear industries, hospitals and other sectors that have established a safety culture.
Two months ago, the US Department of Defense froze operations at nine biodefence laboratories where work is done on dangerous pathogens. Inspectors had discovered live anthrax outside a containment area at the US Army's Dugway Proving Ground — a facility in Utah that tests defence systems against biological and chemical weapons.

The discovery at Dugway is the latest of several concerning finds. In June 2014, workers at a US Centers for Disease Control and Prevention (CDC) biosafety-level-3 laboratory in Atlanta, Georgia, sent anthrax samples to three other laboratories on the same campus. The samples were meant to have been sterilized but several factors meant that 41 people were potentially exposed to live bacteria1. Then in May this year, an investigation revealed that for several years, staff at Dugway had been improperly sterilizing anthrax samples, and that live spores may have been sent to 52 laboratories in the United States, Canada, Australia and South Korea.
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Kaffe, kaffe, kaffe

Inläggav Tryggve » ons 02 dec 2015, 13:30

I avdelningen viktig forskning så går detta förstås in. Man har tittat på vad det finns för bakterier i spillbehållarna i kaffemaskiner. Både sådana som finns hemma hos folk, och sådana som står i fikarum.

http://www.nature.com/articles/srep17163


The coffee-machine bacteriome: biodiversity and colonisation of the wasted coffee tray leach

Microbial communities are ubiquitous in both natural and artificial environments. However, microbial diversity is usually reduced under strong selection pressures, such as those present in habitats rich in recalcitrant or toxic compounds displaying antimicrobial properties. Caffeine is a natural alkaloid present in coffee, tea and soft drinks with well-known antibacterial properties. Here we present the first systematic analysis of coffee machine-associated bacteria. We sampled the coffee waste reservoir of ten different Nespresso machines and conducted a dynamic monitoring of the colonization process in a new machine. Our results reveal the existence of a varied bacterial community in all the machines sampled, and a rapid colonisation process of the coffee leach. The community developed from a pioneering pool of enterobacteria and other opportunistic taxa to a mature but still highly variable microbiome rich in coffee-adapted bacteria. The bacterial communities described here, for the first time, are potential drivers of biotechnologically relevant processes including decaffeination and bioremediation.
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Re: Kaffe, kaffe, kaffe

Inläggav Hexmaster » tor 03 dec 2015, 10:07

Caffeine is a natural alkaloid present in coffee, tea and soft drinks with well-known antibacterial properties.

Visste inte att koffein hade den egenskapen också. Snacka om intelligent design!
We sampled the coffee waste reservoir of ten different Nespresso machines

Den här studien var knappast sponsrad..?
Detta skall jag visa dig medelst ett stort papper som jag har fyllt med faktiska upplysningar! - Strindberg
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Re: Kaffe, kaffe, kaffe

Inläggav Tryggve » tor 03 dec 2015, 14:39

Hexmaster skrev:Visste inte att koffein hade den egenskapen också. Snacka om intelligent design!

Visst är det?

Hexmaster skrev:Den här studien var knappast sponsrad..?

De uppger ju själva att det också har med reproducerbarhet att göra... :-)

To achieve this goal, we have chosen one of the most widespread coffee preparation systems, Nespresso, due to its popularity and standard nature. In fact, Nespresso-compatible machines are highly standardized coffee making devices (same capsule type, same basic design, same pressure: 19 bars), and they represent a unique oportunity for a massive biological screening.
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Re: Nature News

Inläggav Tryggve » mån 07 dec 2015, 18:05

I en av Natures systertidskrifter så har det publicerats en studie där en mygga har modifierats så att gener som orsakar infertilitet i honor kan spridas.

http://www.nature.com/news/mosquitoes-e ... es-1.18974

Mosquitoes engineered to pass down genes that would wipe out their species

'Gene drive' that spreads infertility could eliminate mosquitoes that transmit malaria in Africa.


The mosquito that is responsible for most of the world’s malaria has been genetically modified to spread genes that could wipe out its species.

Researchers engineered Anopheles gambiae mosquitoes — which spreads malaria across sub-Saharan Africa — to pass on genes that cause infertility in female offspring. The study, published in Nature Biotechnology1, relies on a technology known as a gene drive, and appears two weeks after a US team reported using the same concept to engineer malaria resistance into a different mosquito species2.

The team, led by molecular biologist Tony Nolan and vector biologist Andrea Crisanti, both at Imperial College London, identified three genes in Anopheles gambiae that, when mutated, lead to infertility in females.


Arbetet har gjorts med CRISPR-Cas9 teknik.
The work relies on the genome-editing system CRISPR–Cas9. When a mosquito inherits the DNA that encodes CRISPR–Cas9 along with a mutated gene, the system copies the genetic alteration from one chromosome to another (see 'CRISPR, the disruptor').


Det ska dock påpekas att det inte direkt är så att man står i begrepp att starta fältförsök med detta.
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Re: Nature News

Inläggav Tryggve » mån 07 dec 2015, 18:07

Och här är för övrigt en artikel om en "säkerhetsuppgradering" i tekniken med gene drives.

http://www.nature.com/news/safety-upgra ... ue-1.18799
Safety upgrade found for gene-editing technique

Tweak reduces chance of a mutation escaping into the wild, and can help to undo a mutation after it has spread.


A genome-editing method that could allow researchers to rapidly engineer entire populations has had an important upgrade. A US team has added safeguards to reduce the chances that such ‘gene drives’ will escape the laboratory, and found a way to erase the genetic mutations after they have spread.

Gene drives hold the potential to wipe out insect-borne diseases and can speed up some genetic studies in the laboratory. But if released into the wild — whether intentionally or not — gene drives could irrevocably scar entire ecosystems.

The safeguards, published today in Nature Biotechnology1, may calm some fears about the technology. One of the techniques provides a way of genetically separating the components that fuel a gene drive, so that the engineered mutation will not spread as rapidly through a population. Another is a molecular 'undo' button: sending a second gene drive out to undo the effects of the first.
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Venus

Inläggav Tryggve » tis 08 dec 2015, 13:25

Inte mitt ämne, men värt att nämna här i tråden kanske. Japan försökte 2010 lägga en rymdsond i omloppsbana kring Venus, något som man tydligen misslyackdes med. Men ny har man tydligen haft möjlighet till ett nytta försök, och nu verkar det ha gått!

http://www.nature.com/news/japan-s-venu ... ck-1.18979
Japan’s Venus orbiter makes comeback

Five years after a failed insertion into the planet’s orbit, Akatsuki finally reaches its target.

Japan’s Akatsuki spacecraft has entered orbit around Venus, five years after its first attempt failed. On 7 December, at 8:51 a.m. Japan time, Akatsuki ignited four small thruster engines for roughly 20 minutes. The tiny push was enough to nudge the probe into the pull of Venus’s gravity.

As Nature went to press, exactly what that orbit looks like remained unclear. But mission scientists are confident that the spacecraft has at least partly redeemed itself, after a 2010 attempt to reach Venus left Akatsuki spiralling around the Sun.

“It’s in orbit!” said Sanjay Limaye, a planetary researcher at the University of Wisconsin–Madison, and a participating scientist on the mission. “Everyone is very happy.”
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