Hoeveel mensen hebben er ooit geleefd? | Mens en samenleving: Diversen

Hoeveel mensen hebben er ooit geleefd? | Mens en samenleving: Diversen: "Er zijn in de afgelopen decennia verschillende schattingen gemaakt van het totaal aantal mensen dat ooit heeft geleefd. Deze gingen uit van evolutionistische modellen op basis van vele tienduizenden jaren menselijke geschiedenis. Maar wat als men uitgaat van een creationistisch model op basis van Bijbelse gegevens? Het blijkt dat de uitkomsten elkaar niet eens zoveel ontlopen."

Gut bacteria steer the development of the young brain | Not Exactly Rocket Science

Gut bacteria steer the development of the young brain | Not Exactly Rocket Science: "

This isn’t something a mother wants to hear: when you gave birth to your child, you laced it with millions of unseen forces that are shaping the way it thinks and behaves. Under their influence, your baby’s nerves will grow and connect in ways that will affect everything from how anxious to how coordinated it is. Thanks to your very first birthday present, your infant’s brain is being shaped by its gut. Or, more accurately, what’s inside its gut.

The bowels of every baby are filled with trillions of bacteria that outnumber the cells of our own body by ten to one. This “microbiome” acts like on of our own organs, harvesting energy from our food and blocking the growth of harmful bacteria. It’s also a gift from our mothers. In the womb, we’re largely sterile. It’s only when we pass through the vagina that we’re seeded with our first set of bacteria. This community of passengers changes as we grow up, shifting in membership as we move from milk to solid food.

But the bacterial passengers of HMS Baby don’t just react as their vehicle develops; they help to steer it too. By studying mice, Rochellys Diaz Heijtz from the Karolinska Institute has found that a mammal’s gut bacteria can affect the way its brain develops as it grows up. They could even influence how it behaves as an adult.

Heijtz worked with two strains of mice – one that was completely free of germs, and another that had an intact microbiome but no disease-causing bacteria. The two strains behaved differently. The germ-free mice were more active, and spent more time scurrying around their enclosures. They were also less anxious and more likely to take risks, such as spending long periods of time in bright light or open spaces.

Could it really be that gut bacteria were behind these differences? Hejitz proved as much by transplanting the microbiome of the disease-free mice into the bowels of the germ-free ones. Sure enough, when the inoculated babies grew up, they behaved in the “normal” cautious way, just like the disease-free ones. This only worked if Hejitz did the transplants on baby mice. If she gave sterile adults a shot of gut bacteria, their behaviour didn’t change.

These differences aren’t just skin-deep. The absence of the gut bacteria also triggered a slew of changes in the rodents’ brains. Hejitz compared her germ-free and disease-free mice and found that over a hundred genes were twice as active in the brains of one strain compared to the other. Some of these genes are involved in providing cells with energy, others in chemical communications across the brain, and yet others in strengthening the connections between nerve cells.

How do these bacteria, lurking within the bowels, affect the fate of the brain, half a body away? For a start, they have a direct phone – the vagus nerve. This long branching nerve transmits information about what happens in the gut (and other organs) to the brain. But the bacteria could also route their calls via hormones. By definition, these are chemicals that can affect parts of the body over long distances. By changing hormone levels, the microbiome can ensure that what happens in the gut doesn’t stay in the gut.

For example, a Japanese team found that gut bacteria can change levels of stress hormones in the body. And an American group found that germ-free mice have almost three times more serotonin in their blood than normal ones. Hejitz herself found that chemicals like noradernaline and dopamine came and went at a faster pace in her germ-free mice. All of these chemicals could affect the way the young brain develops.

Hejitz’s mice tell us that there’s an important window in early life when the microbiome can affect the way its host develops. And this could very well depend on the bacteria that you start with. For example, babies end up with a less diverse set of skin and gut bacteria if they are delivered through Caesarean section than through the vagina. This could affect how susceptible they are to diseases. If Hejitz’s work in mice applies to humans too (and other microbiome studies have found comparable results between the two species), the way a child is born could affect its brain and behaviour.

Hejitz’s work is part of a rapidly growing number of studies, which show the wide-ranging influence of our hitch-hiking trillions. She joins Gil Sharon from Tel Aviv University, who found that the bacteria can change the sexual preferences of fruit flies. And other scientists have put forward specific species of gut bacteria as potential culprits in the development of autism.

These passengers do much more than process our food, and we are much more than just their containers. They’re part of us and our evolutionary history (you can even recap the evolution of apes by looking at the bacteria in our guts). We’re each like a superorganism – a unified alliance between the genes of several different species, only one of which is human.

Reference: Hejitz, Wang, Anuar, Qian, Björkholm, Samuelsson, Hibberd, Forssberg & Petterson. 2011. Normal gut microbiota modulates brain development and behaviour. PNAS http://dx.doi.org/10.1073/pnas.1010529108

Images by Shushruth and Rama

More on the microbiome:

• An introduction to the microbiome


• Gut bacteria change the sexual preferences of fruit flies


• You are what you eat – how your diet defines you in trillions of ways


• Baby’s first bacteria depend on route of delivery


• The bacterial zoo in your bowel


• Gut bacteria reflect diet and evolutionary past


• Gut bacteria – fat or thin, family or friends, shared or unique


• Gut bacteria recap the evolution of apes


• Gut bacteria in Japanese people borrowed sushi-digesting genes from ocean bacteria


• Human gut bacteria linked to obesity

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the force was stark in this young one

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Lepra in Nederland: zo'n 400 mensen in Nederland met lepra | Mens en gezondheid: Ziekten

Lepra in Nederland: zo'n 400 mensen in Nederland met lepra | Mens en gezondheid: Ziekten: "In Nederland zijn zo’n dikke 400 leprapatienten. Bijna niemand in hun omgeving weet dat ze aan de ziekte lijden, omdat veel mensen zich er voor schamen. Lepra is een derdewereldziekte, maar toch zijn er dus in Nederland ook mensen met Lepra. Hoe komt het dat mensen in Nederland ook aan lepra lijden en wat betekent dit voor hen?"

Rechtszaken worden veel duurder | Zakelijk: Juridisch

Rechtszaken worden veel duurder | Zakelijk: Juridisch: "n 2013 wil de overheid dat rechtszaken kostendekkend worden. Dit betekent dat wat een rechtszaak kost, ook betaald moet worden door degene die de rechtzaak aanspant. In de praktijk betekent het dat de griffierechten heel erg zullen stijgen. Maar dat betekent dat een rechtzaak voor veel mensen onbetaalbaar wordt en zij dus hun gelijk niet kunnen halen.

Rechtzaken duurder: het staat in het regeerakkoord
In het regeerakkoord staat dat de overheid de rechtspraak kostendekkend wil maken. Daarmee moet dan 240 miljoen euro in de schatkist vloeien. Alle kosten die worden gemaakt, moeten dus betaald worden door de persoon die de rechtzaak aanspant of degene die verliest. Dit betekent dat de tarieven enorm omhoog gaan. In 2011 kost een ontslagzaak bij de kantonrechter bijvoorbeeld nog 210 euro. In 2013 wordt dan maar liefst 1540 euro."

noteert u het effe

Mubarak met collega-dictators uit protest de straat op

Mubarak met collega-dictators uit protest de straat op: "

Overal ter wereld zijn dictators woedend de straat op gegaan om te protesteren tegen de Egyptische opstand. De dictators willen hiermee laten zien dat president Hosni Mubarak niet alleen staat in zijn strijd tegen ongewapende betogers. “Mubaraks levenswerk staat op het spel”, aldus een woedende Kim Jong-Il (Schitterende Ster van de Paektu Berg, Noord-Korea). “Je investeert jaren van je leven in het opzetten van een efficiënte geheime dienst, martelt honderden burgers en verziekt de toch al corrupte economie van je land, en wat krijg je ervoor terug? Boze burgers die je partijbureau in de fik steken.”

Aleksandr Loekasjenko (Stalen Leidsman, Wit-Rusland) is bang dat het hek van de dam is als de demonstraties in de Arabische wereld nog langer doorgaan. “Ik zie het somber in als de Egyptenaren blijven volharden in dit onverantwoordelijke gedrag”, aldus de alleenheerser. “Ik roep alle rechtgeaarde fascisten en antidemocraten daarom op om zo snel mogelijk een einde te maken aan deze wandaden.”

Robert Mugabe (Neger des Heils, Rhodesië) ziet de invloed van blanke infiltranten in het Noord-Afrikaanse land als doorslaggevend. “Witte mensen kunnen daar ongehinderd over straat. Dan vraag je natuurlijk om moeilijkheden. Bij ons laten ze het al een jaar of twintig uit hun hoofd na Roberts speciale voetzolenbehandeling. Twee dagen voor een revolutie zwaaien met gummiknuppels is daarbij vergeleken ronduit amateuristisch.”

De verbijsterde despoten hebben een Facebook-pagina in het leven geroepen om Mubarak te steunen, genaamd ‘Tyrants United’. Hier zijn tal van emotionele reacties te vinden, onder andere van de Libische leider Khadaffi die verklaart de ‘gezamenlijke folteravondjes nooit te zullen vergeten.’

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jasmijn

Het enige knappe aan internet is dat we (het westen) nu ook het recht menen te hebben andere landen achterlijk te noemen en hun intelligentie te beledigen.
De jasmijn revolutie bewijst het tegendeel tot de nieuwe dictator.
Een slimmer gebruik van internet is wellicht voor de permanente verkiezing,
onder het voorbehoud dat niet alles te hacken is en de kiezer bij de les blijft.

He’s a lumberjack, and he’s okay. He sleeps all...

He’s a lumberjack, and he’s okay.
He sleeps all...: "

He’s a lumberjack, and he’s okay.

He sleeps all night and he works all day.

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I guess that guy on the left is completely screwed with the axe-guy

Do the Hustle…

Do the Hustle…: "

Do the Hustle…

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Gravity Simulator

Gravity Simulator: "The Kozai Mechanism
The Kozai Mechanism causes a periodic exchange between the inclination and eccentricity of an orbit.

It has been theorized that the Kozai Mechanism is responsible for the high eccentricities observed in the orbits of exosolar planets. If the parent star has a massive yet unseen substellar companion, orbiting at a great distance, and in an orbit highly inclined to the plane of the planets' orbits, the Kozai Mechanism should induce high eccentricities into the orbits of the planets.

It is also theorized that the Kozai Mechanism may be responsible for the high eccentricities observed in the orbits of many Kuiper Belt Objects such as 2003 UB313. The pull of the Milky Way Galaxy causes an object with a high eccentricity to periodically trade this eccentricity for a gain in inclination."

Humans Left Trees 4.2 Million Years Ago

Humans Left Trees 4.2 Million Years Ago: "Wrist bones of human ancestors reveal when humans switched from living in trees to on the ground."

The 4% Universe: My Washington Post review | The Loom

The 4% Universe: My Washington Post review | The Loom: "

The Washington Post asked me to review The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality. Back in my green days as a science writer and editor, I kept up fairly well with things cosmological, but the seductions of biology have distracted me from the sky for some time now. So it was a pleasure to get back up to speed–and to discover just how weird things have gotten in the universe–with Panek’s book:

In 1969, an astronomer named Jeremiah Ostriker realized that the Milky Way was spinning too fast. That may sound odd, given that it takes the sun 230 million years to make a full orbit. But when Ostriker tried to simulate the Milky Way on a computer, he found that it was spinning so quickly that it should have ripped itself apart long ago. There weren’t enough stars to hold it together.

Ostriker went to his fellow Princeton scientist James Peebles to share his puzzle. “There’s something wrong here,” Ostriker said to Peebles. The two scientists decided there could only be one solution: The stars we ...

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PirateBox lets you share files with anyone close by

PirateBox lets you share files with anyone close by: "The device anonymously connects anyone nearby who wants to share files, whether they're legal or not

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How Was Egypt's Internet Access Shut Off?

How Was Egypt's Internet Access Shut Off?: "

Egyptians earlier this week took to the Web-- Facebook and Twitter , in particular--as a means of organizing their protests against Egyptian President Hosni Mubarak 's three-decade-old government. As of Friday morning, however, there no longer was much of a Web to take to--at least not in Egypt. In an unprecedented turn of events, at 12:34 A.M. local time in Cairo five of the country's major Internet service providers (ISPs) shut down their connections to the Internet. [More]

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Is speculation in multiverses as immoral as speculation in subprime mortgages?

Is speculation in multiverses as immoral as speculation in subprime mortgages?: "

I'm becoming a moralistic prig in my dotage. Someone dear to me just proudly told me that her son, a freshly minted Harvard grad, is training to be an investment banker. This privileged young man, I grumbled, should try to make the world a better place rather than playing in a rigged, high-stakes gambling racket. [More]

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Instead of 3 dimensions + time, einstein proposed 4 dimensions in space-time, and all those new theories do, like einstein, is adding more demensions and create only speculation.
It is the next logical step in making hypothesis but after 100 years of einstein and assuming dark matter and energy to uphold the hypothesis is hardly any progress.