'Shields to maximum, Mr. Scott': Simulating orbital debris impacts on spacecraft and fragment impacts on body armor

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Gold plunge impacts short term peak in Gold Silver ratio

About four years ago the ratio hit a long term peak of 83.7, with the low in early 2011 at 31.7.

LONDON(BullionStreet): While Gold prices plunged recently, the ratio between the gold and silver price hits short terms peak.

Analysts said recent extreme volatility in the precious metals markets has impacted the ratio which means the two metals are changing value at different speeds than the historical norm.

Take for example the 24 hour gold-silver ratio, which is trading at around 58.7, which is off the lows of 58.2 from a few hours earlier, but well off the 59.6 peak where is was placed just less than one day ago.

Spot gold is currently trading at around $1376 an ounce, with silver $23.40 an ounce.

Viewed over the short term of the past 60 days, the current ratio levels is at higher end with the peak over this period at around the 59.6 (the low is 53.7) highlighting that the price of gold has recently been outpacing that of silver, or in another way silver has been falling at a faster rate.

About four years ago the ratio hit a long term peak of 83.7, with the low in early 2011 at 31.7.

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Biodiversity crisis: The impacts of socio-economic pressures on natural floras and faunas

This shows an endangered species: Trifolium saxatile - clover. Copyright: Stefan Dullinger

A new study on extinction risk has shown that proportions of plant and animal species being classified as threatened on national Red Lists are more closely related to socioeconomic pressure levels from the beginning than from the end of the 20th century. Stefan Dullinger of the University of Vienna and Franz Essl from the Austrian Environment Agency together with an international group of researchers reports this new finding in the current issue of PNAS.

It is well understood that the survival of a substantial and increasing number of species is put at risk by human activity via e.g. habitat destruction, environmental pollution or introduction of alien species. Accordingly, the most recent global IUCN Red List classifies 31% of the 65,518 plant and animal species assessed as endangered. However, the temporal scale of cause-effect relationships is little explored. If extended time lags between human pressure and population decline are common, then the full impact of current high levels of anthropogenic pressures on biodiversity will only be realized decades into the future.

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This shows Spermophilus citellus - European ground squirrel. Copyright: Wolfgang Rabitsch

Historical legacy of species' population losses

Taking an historical approach, the new study provides circumstantial evidence that such time-lags are indeed substantial. The researchers demonstrate that proportions of vascular plants, bryophytes, mammals, reptiles, dragonflies and grasshoppers facing medium to high extinction risks are more closely matched to country-specific indicators of socio-economic pressures (i.e. human population density, per capita GDP, land use intensity) from the early or mid rather than the late 20th century. Accordingly, their results suggest a considerable historical legacy of species' population losses. In a related analysis they also show that current spending on environmental conservation only has a weak mitigating effect. This finding implies that current conservation actions are effective, but inadequate in scale, to halt species losses.

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This is Onosma helvetica ssp. austriaca. Copyright: Franz Essl

"The broad taxonomic and geographic coverage indicates that a so-called 'extinction debt' is a widespread phenomenon", says Stefan Dullinger from the University of Vienna. "This inertia is worrying as it implies that albeit numbers of species classified as threatened on Red Lists are increasing continuously and worldwide, these assessments might still underestimate true extinction risks", explains Franz Essl from the Austrian Environment Agency.

Increase in global conservation effort is urgently needed

Therefore, the scientists write "mitigating extinction risks might be an even greater challenge if temporal delays mean many threatened species might already be destined towards extinction". They expect that minimizing the magnitude of the current extinction crisis might be an even greater challenge when temporal delays are taken into account. Therefore a substantial increase in global conservation effort is urgently needed to conserve species diversity for future generations, warns Dullinger.

More information: Stefan Dullinger, Franz Essl, Wolfgang Rabitsch, Karl-Heinz Erb, Simone Gringrich, Helmut Haberl, Karl Hülber, Vojtech Jarošík, Fridolin Krausmann, Ingolf Kühn, Jan Pergl, Petr Pyšek, & Philip E. Hulme 2013: Europe's other debt crisis caused by the long legacy of future extinctions. Proceedings of the National Academy of Sciences (PNAS), April 15, 2013. DOI: www.pnas.org/cgi/doi/10.1073/pnas.1216303110

Journal reference: Proceedings of the National Academy of Sciences

Provided by University of Vienna

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