Sunday, February 26, 2012

geochemical and microfaunal proxies to assess environmental quality conditions during the recovery process of a heavily polluted estuary: the bilbao estuary case (n. spain)

E. Leorri, A Cearreta, M.J. Irabien, I. Yusta
Elsevier. Science of the Total Environment 396 (2008) 12-27

There is a clear preference for focusing on benthic organisms as ecological indicators, given their inherent ability to integrate sediment quality (Quintino et al., 2006) and to respond to changing environmental conditions (Salas et al., 2006). The use of indicators is becoming an integral part of decision support systems for coastal zone management (Bortone, 2005). Among the characteristics that define a good ecological indicator are: (a) handling easiness, (b) sensitivity to small variations of environmental stress, and (c) applicability in extensive geographical areas and in the greatest possible number of communities or ecological environments (Salas et al., 2006).
Studies of pollution effects on benthic foraminifera (class Foraminifera, phylum Granuloreticulata) and of the possible use of these organisms as proxies were initiated in the 1960s. Since then, benthic foraminifera are increasingly used as environmental bioindicators, especially in polluted environments. These works study the relationship between foraminifera and the anthropogenic impact using surface sediment samples and short cores in shallow marine areas around the world (see Ernst et al., 2006 and Tsujimoto et al., 2006 for further references).
Shallow water benthic foraminifera are among the most abundant and conspicuous protozoa in marine and coastal environments (Ernst et al., 2006). As lower trophic level members, foraminifera are important to biological communities (Lipps, 1983) and can be valuable indicators of the overall faunal health of an area (Buzas-Stephens et al., 2003). Foraminifera are easy to collect and their analysis is most cost-effective. They are often found in high-density populations and provide an adequate statistical base (even in small volume samples). These characteristics make them ideal candidates for comprehensive environmental assessments (Buzas-Stephens et al., 2003). Because they have a short life cycle and specific habitats, they respond fast to environmental changes (Ernst et al., 2006)—as other meiobenthic organisms, they respond much faster than macrobenthic organisms (Salas et al., 2006)—and can be used as an early warning indicator (Kramer and Botterweg, 1991). Foraminifera respond not only to the natural environmental variability in such parameters as temperature and salinity but also to anthropogenic stresses such as pollution, eutrophication, and hypoxia (see Tsujimoto et al., 2006 and references therein). Recent studies have demonstrated that some benthic species seem extremely sensitive to heavy metals and/or organic compounds concentration levels (Ferraro
et al., 2006). Additionally, foraminifera present fossilizable tests, and when they die, those tests accumulate in the sediment (dead assemblage) providing a time-averaged picture of the environment (Murray, 1991). They have a particularly good fossil record and their taxonomic composition and general ecological distribution in coastal marine settings are the best known of all the microfossil groups, giving access to the pre-pollution background microfaunas (Hayward et al.,2004).
Foraminifera generally react to adverse environmental conditions by undergoing changes in abundance and diversity or by producing deformed tests. Environmental disturbances have various degrees of destructive impacts on benthic communities, and can lead to defaunation when a certain lethal threshold is reached (Buzas-Stephens et al., 2003; Alve, 1999). These benthic habitats severely disturbed by human activity can be recolonised by foraminifera after effective recovery has occurred (Alve, 1999). The recolonization
pattern will depend upon the hydraulic regime in, and the transit time from, the source area. Although species such as Ammonia tepida and Haynesina germanica are pollution tolerant and have been reported to dominate in both natural and polluted areas, substrate properties (e.g., recently reoxygenated or severely contaminated sediments) may delay colonization by months or even years (Alve, 1999).

under the stairs

Ekaterina Koroleva

Friday, February 24, 2012

lindsey stirling




lindsey stirling is amazing.
http://www.lindseystirlingviolin.com/

sundaland

Because of lowered sea levels, many of today's islands were joined to the continents: The Indonesian islands as far east as Borneo and Bali were connected to the Asian continent in a landmass called SundalandPalawan was also part of Sundaland, while the rest of the Philippine Islands formed one large island separated from the continent only by the Sibutu Passage and the Mindoro Strait
Sundaland is a biogeographical region of Southeastern Asia which encompasses the Sunda shelf; the part of the Asian continental shelf that was exposed during the last ice age. It included theMalay Peninsula on the Asian mainland, as well as the large islands of BorneoJava, and Sumatraand their surrounding islands. The eastern boundary of Sundaland is the Wallace Line, identified byAlfred Russel Wallace, which marks the eastern boundary of the Asia's land mammal fauna, and is the boundary of the Indomalaya and Australasia ecozones. The islands east of the Wallace line are known as Wallacea, and are considered part of Australasia.

anglers eat squid!

Scavenger swarm

GJ 1214b


The exoplanet GJ 1214b, just 40 light-years away, is a so-called "Super Earth" - bigger than our planet, but smaller than gas giants such as Jupiter.
Observations using the Hubble telescope now seem to confirm that a large fraction of its mass is water.
The planet's high temperatures suggest exotic materials might exist there.
"GJ 1214b is like no planet we know of," said lead author Zachory Berta, from the Harvard Smithsonian Center for Astrophysics.
The planet was discovered in 2009 by ground-based telescopes, orbiting its comparatively cool red-dwarf star at a distance of just two million km - meaning temperatures on GJ 1214b probably reach above 200C.
It is about 2.7 times the Earth's diameter but with a mass just seven times higher (at an equivalent density, to the Earth, it would have nearly 20 times the mass).
In 2010, astronomers released measurements of its atmosphere. These suggested that GJ 1214b's atmosphere was probably made up of water, but there was another possibility - that the planet was covered in a haze, of the type that envelopes Saturn's moon Titan.
Hot ice
Mr Berta and his colleagues used the Hubble Space Telescope's wide-field camera to study the planet as it crossed in front of its star - a transit. During these transits, the star's light is filtered through the planet's atmosphere, giving clues to the mixture of gases present.

The researchers said their results are more consistent with a dense atmosphere of water vapour, than one with a haze.
Calculations of the planet's density also suggest that GJ 1214b has more water than Earth. This means the internal structure of this world would be very different to that of our own.
"The high temperatures and pressures would form exotic materials like 'hot ice' or 'superfluid water', substances that are completely alien to our everyday experience," said Dr Berta.
The planet's short distance from Earth makes it a likely candidate for follow-up observations with the James Webb Space Telescope, which may launch by the end of this decade.
The study has been accepted for publication by the Astrophysical Journal.

bbc.co.uk

chinese swampland preserved in ash 300 million years ago


Researchers have unearthed a forest in northern China preserved under a layer of ash deposited 300 million years ago.
Preservation of the forest, just west of the Inner Mongolian district of Wuda, has been likened to that of the Italian city of Pompeii.
The researchers were able to "reconstruct" nearly 1,000 sq m of the forest's trees and plant distributions.

This rare insight into how the region once looked is described in Proceedings of the National Academy of Sciences.
The excavations sampled three sites across a large expanse that was covered with about a metre of ash.
Due to the pristine preservation of some of the plants, the team estimate the ash fell over the course of just a few days, felling and damaging some of the trees and plants under its weight but otherwise keeping them intact.
"It's marvelously preserved," said study co-author Hermann Pfefferkorn of the University of Pennsylvania in the US.
"We can stand there and find a branch with the leaves attached, and then we find the next branch and the next branch and the next branch. And then we find the stump from the same tree. That's really exciting."
The team identified six groups of trees, ranging from low-lying tree ferns to now-extinct 25m trees Sigillaria and Cordaites, as well well-preserved specimens of another extinct group called Noeggerathiales.
Prof Pfefferkorn said that, as a particularly complete and well-caught moment in time, the forest would serve as a "baseline" for assessing future finds.
Based on the findings, the team worked with a painter to depict what the forest would have looked like before the ash cloud descended.
"It's like Pompeii," he said. "Pompeii gives us deep insight into Roman culture, but it doesn't say anything about Roman history in and of itself.
"But on the other hand, it elucidates the time before and the time after. This finding is similar. It's a time capsule and therefore it allows us now to interpret what happened before or after much better."


bbc.co.uk

extinction of the Y chromosome?

Previous research has suggested the Y sex chromosome, which only men carry, is decaying genetically so fast that it will be extinct in five million years' time.

A gene within the chromosome is the switch which leads to testes development and the secretion of male hormones.
But a new US study in Nature suggests the genetic decay has all but ended.
Professor Jennifer Graves of Australian National University has previously suggestedthe Y chromosome may become extinct in as little as five million years' time, based on the rate at which genes are disappearing from the chromosome.
Genetics professor Brian Sykes predicted the demise of the Y chromosome, and of men, in as little as 100,000 years in his 2003 book Adam's Curse: A Future without Men.
The predictions were based on comparisons between the human X and Y sex chromosomes. While these chromosomes were once thought to be identical far back in the early history of mammals, the Y chromosome now has about 78 genes, compared with about 800 in the X chromosome.

Jennifer Hughes and colleagues at the Whitehead Institute in Cambridge, Massachusetts, have sought to determine whether rumours of the Y chromosome's demise have been exaggerated.
In a previous Nature paper in 2005, they compared the human Y chromosome with that of the chimpanzee, whose lineage diverged from that of humans about six million years ago.
They have now sequenced the Y chromosome of the rhesus monkey, which is separated from humans by 25 million years of evolution.
The conclusion from these comparative studies is that genetic decay has in recent history been minimal, with the human chromosome having lost no further genes in the last six million years, and only one in the last 25 million years.
"The Y is not going anywhere and gene loss has probably come to a halt," Dr Hughes told BBC News. "We can't rule out the possibility it could happen another time, but the genes which are left on the Y are here to stay.
"They apparently serve some critical function which we don't know much about yet, but the genes are being preserved pretty well by natural selection."
X-Y crossing
Most humans cells contain 23 sets of chromosomes, including one pair of sex chromosomes. In women, this sex pair consist of two X chromosomes, while men have one X and one Y chromosome. It is a gene within the Y chromosome which triggers the development in the embryo of male testes and the secretion of male hormones.

Genetic deterioration of the Y chromosome has occurred because unlike with the two X chromosomes in women, there is very little swapping of genetic material between the Y and X chromosome during reproduction. This means mutations and deletions in the Y chromosome are preserved between (male) generations.
"The X is fine because in females it gets to recombine with the other X but the Y never gets to recombine over almost its entire length, and shutting down that recombination has left the Y vulnerable to all these degenerative forces," said Dr Hughes, "which is why we're left with the Y we have today."
Commenting on the paper, Professor Mark Pagel, an evolutionary biologist at the University of Reading and author of Wired for Culture: Origins of the Human Social Mind, said that while there might be some squabbling in academic circles over the timings of the events, the paper told us there was a future for males in the very long term.
"It's a very nice piece of work, showing that gene loss in the male-specific region of the Y chromosome proceeds rapidly at first - exponentially in fact - but then reaches a point at which purifying selection brings this process to a halt."

google flu trends

Google's estimates for the percentage of patients with flu-like illnesses closely match reports from the CDC.

translate their concerns into universal rather than religion-specific values

my baby's the shit

newt gingrich vs dwight schrute

the real 99%

they've made the plant illegal

Wednesday, February 22, 2012

Uterus Didelphys

 Uterus Didelphys- Variations of this condition aren't uncommon, occurring once in a few thousand births. The reproductive tract develops from paired tubes that fuse prenatally, and sometimes the fusion is incomplete, producing a range of arrangements illustrated below.

triquetra of biology

plate tectonics

animals, protists, and plants over time


C:N diets

glacial valley


horse evolution

ostrich

how athiests testify under oath

joana garrido

open up

we need a new plague

inner workings


dirty valentines day cards

Tuesday, February 21, 2012

niah national park

bintulu

I'm going back to Malaysia this summer! Last year we stayed in Kuala Terengganu and this year I'll be flying into Bintulu and working on a cruise in the South China Sea.

i didn't mean to

Science

Science is the academic journal of the American Association for the Advancement of Science and is considered one of the world's most prestigious scientific journals. The peer-reviewed journal, first published in 1880 is circulated weekly and has a print subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is one million people.
And last week a FORAM was on the cover! :)

ripples

hardcore pride

i'm allergic to grammatical errors

Monday, February 20, 2012

buccal cavity

cruella


northwest

fallopitarians and prostates

mcgowan

the world forgetting, by the world forgot.


How happy is the blameless vestal's lot!
The world forgetting, by the world forgot.
Eternal sunshine of the spotless mind!
Each pray'r accepted, and each wish resign'd;
Alexander Pope, "Eloisa to Abelard" English poet & satirist (1688 - 1744)

spiff kidz

misconception vs fact

Misconception No. 1: Most of what Americans spend their money on is made in China.

Fact: Just 2.7% of personal consumption expenditures go to Chinese-made goods and services. 88.5% of U.S. consumer spending is on American-made goods and services.
 
Misconception No. 2: We owe most of our debt to China.

Fact: China owns 7.6% of U.S. government debt outstanding.
 
Misconception No. 3: We get most of our oil from the Middle East.

Fact: Just 9.8% of oil consumed in the U.S. comes from the Middle East.
dailyfinance.com

Friday, February 17, 2012