Dołączył: 24 Paź 2018
|Wysłany: Sob Gru 08, 2018 07:55 Temat postu: www.wholesalecheapsoccerjerseyschina.com
|SAN FRANCISCO Emmanuel Sanders Hat , May 13 (Xinhua) -- A research using time-lapse photography in the Galapagos Marine Reserve, a thousand kilometers from the Ecuadorian mainland, suggests the presence of a key multilevel "trophic cascade" involving top- and mid-level predators as well as urchins and algae.
In the rocky, species-rich subtidal area, of about 133 Demaryius Thomas Hat ,000 square km off the Galapagos Islands, researchers examined the relationships among predatory fishes, urchins, the algae that the urchins graze on, and how the interactions among them were influenced by se
a lions and sharks at the top of the food chain.
The key question for researchers: Do predators high up in the chain affect the abundance of the "primary producers" at the bottom -- in this case algae -- thus causing a trophic cascade?
Using GoPro cameras Royce Freeman Hat , researchers from Oregon State University (OSU) and Brown University made a number of key findings regarding triggerfish, Spanish hogfish, pencil urchins, the larger green urchins and algae, including:
-- Among a diverse guild of predatory fishes Bradley Chubb Hat , triggerfish can control the abundance of pencil urchins and thus also the abundance of algae the urchins eat; the experiments showed grazing on algae was eliminated when the pencil urchins were exposed to triggerfish predation, meaning triggerfish are a candidate for protection because of their strong effects on ecosystem function.
-- Green urchins eat more algae than pencil urchins yet are not the urchin prey of choice for predatory fish.
That suggests those fish aren' t controlling green urchin populations and thus that green-urchin barrens in the Galapagos - areas where the urchins have stripped the sea floor of algae - are not the result of the overfishing of predatory fish.
-- Spanish hogfish are not major predators of urchins as earlier, survey-based research had suggested.
Hogfish mainly eat the smaller pencil urchins and also interfere with triggerfish feeding on large pencil urchins; the hassling hogfish cause triggerfish to spend more time to eat an urchin and in some cases force a fumble.
Statistical modeling of predation on pencil urchins indicates that two types of interference behavior -- the hogfish harassing the triggerfish, and sea lions and sharks startling the triggerfish -- could slow the rate of triggerfish predation on pencil urchins.
The researcher who did the modeling, Mark Novak of the College of Science at OSU Von Miller Hat , noted that historically, ecologists believed complex food webs typical of the tropics were more immune to trophic cascades than the simpler food webs of higher latitudes.
However, studies such as this one now suggest that is not the case, and that the dynamics of complex food webs can be as predictable as simpler ones provided you understand who the relevant players are.
"When the backbone of the system is strong, you can connect the top of the food chain to the bottom despite all of the indirect effects and the complexities of the system John Elway Hoodie ," Novak, assistant professor of integrative biology, was quoted as saying in a news release.
"It's important to know individual species identity when you've got a suite of consumers. The hogfish, the triggerfish, they all feed on very similar things Justin Simmons Hoodie , yet one of the two is most important, the one that drove that first link."
The findings, published in PLOS One, are important because they include detailed information about interactions in a complex food web, and crucial to knowing how to cause Jake Butt Hoodie , prevent or reverse population changes within the web.
Xi urges upgrading of free trade agreement with Switzerland
China, Uzbekistan vow to strengthen cooperation
10,860 lights illuminated to greet Belt and Road Forum
Belt and Road Forum for Int'l Cooperation to be held in Beijing
Chinese submersible explores turbidity current in South China Sea
Straw art gala held in E China's Shandong
Xinjiang Int'l Grand Bazaar held in Urumqi, NW China
8th China Peking Opera art festival to be held in Nanjing
Computers > Computer HardwareUsed Cisco and Ethernet cable can save you money
Posted by AngeloEverton in Computers on May 29th, 2012
Any organization has multiple computers in its office and all these computers are connected with each other and to the Internet. This connection is facilitated by a range of networking equipment. Among the very important networking hardware are Cisco and Ethernet. While you get very good quality Cisco and Ethernet in the market Garett Bolles Hoodie , they are liable to go bad after some time due to continued use. Instead of buying new Cisco and Ethernet all the time it makes sense to buy refurbished items. Used Cisco and Ethernet cable in good condition can be easily bought and they offer great value for money.
There are companies that dump Cisco and Ethernet because they either don’t need them anymore, they want to upgrade their hardware, or maybe because they have gone out of business. There are people that buy these pieces of hardware equipment by the hundreds, some of them in working condition and some in damaged condition. What do they do with these? They sort out those items of hardware that can be refurbished. Their team of engineers then gets to work on these pieces of hardware to get them back to perfect working condition. After they have been restored they are put back to the market as used Cisco and Ethernet cable.
Are there any buyers of used Cisco and Ethernet cable? There are plenty of them in fact. Who doesn’t want to save money when they can? You could be one of them too. Think of all the benefits that you get from these items of refurbished networking equipment. You get these items in perfect working condition and pay a lot less than what you would pay to buy new hardware equipment. So, if and when these pieces of hardware equipment go bad Courtland Sutton Hoodie , you wouldn’t feel bad about it because you di. http://www.wholesalecheapnhljerseysonline.com/ Wholesale Custom Jerseys Wholesale Cheap Jerseys China http://www.wholesalecheapnbajerseysonline.com/ Wholesale Cheap Baseball Jerseys Wholesale NHL Jerseys From China Wholesale Basketball Jerseys Cheap Jerseys Cheap Soccer Jerseys Cheap College Hockey Jerseys