Factors that influence freezing in the sub-Antarctic springtail Tullbergia antarctica

first_imgEffects of 12 biotic and abiotic factors on the freezing point of the sub-Antarctic springtail, Tullbergia antarctica, were investigated. Repeated cooling of individual springtails five times resulted in very similar freezing points suggesting that ice nucleation in this freeze-susceptible species is likely to be initiated by intrinsic factors rather than being a stochastic event. Mean supercooling point (SCP) was influenced by cooling protocol, showing a linear increase in mean SCP with cooling rates from 8 to 0.1 °C min−1. However, the opposite effect (decreasing SCP) was seen with slower cooling. Slower rates may be ecologically realistic and allow time for appropriate physiological and biochemical changes. Feeding and food presence in the gut had no effect on SCP, and there was no correlation between the ice nucleating activity of bacteria isolated from the guts and the whole springtail SCP. Habitat altitude and diurnal light and temperature regimes also had no effect on SCP. There was no correlation between the cryoprotectant concentration of fresh animals and their SCP, but experimental desiccation resulted in increased osmolality and decreased SCP, although with considerable individual variation. The most significant influence on SCP was associated with ecdysis. As springtails cease feeding for a period either side of ecdysis, shedding the entire gut lining, moulting may be an efficient mechanism of clearing the gut of all ice nucleating material. This previously unrecognised relationship between ecdysis, cold tolerance and seasonal survival tactics may play an important role in over-winter survival of some arthropods.last_img read more

The Predictive Enterprise (Part 2)

first_imgWith the very initiation of a data science-powered transformation, the endeavor and whoever is driving it are acknowledging that the status quo for analytics utilization does not deliver against the believed potential value for the given business (however defined). As a result, any individual (wherever they are on the totem pole), technology, and even organization overly associated with legacy or the status quo will find themselves exposed to some degree of uncertainty and possibly even vulnerability. What transpires when an enterprise kicks off such an initiative ranges within two extremes. On one side – the “bad outcome” – the effort yields a hot mess of organizational wrangling over concepts like “data ownership” and “where analytics should live”, shortsighted technology investments or the digging-in-of-heels around legacy platforms, and analytical project work-to-nowhere – all with the enterprise’s competitive advantage wavering on a precipice.On the other end of the spectrum – the “good outcome” – the effort can yield a complete rebirth or transformation of the company built upon data-derived innovation, resulting in data science-generated intellectual property and competitive advantage. On this end of the spectrum, I often see an executive alignment on prioritization for data initiatives, a thriving data science culture, a drumbeat focus on smart data instrumentation and data quality processes, and modeling efforts with clearly defined paths to operationalization for top- or bottom-line impacting actions.I am frequently asked by our Analytics Labs customers which levers they should control to drive towards the “good outcome” as they embrace data science. The levers are numerous, and each is integral to the success of the effort. I’ve mentally cultivated my list over an extended period of time, based on my team’s data science work with our customers and prospects, my observations of the travails and successes of various Greenplum customers, and my pre-Greenplum days at Yahoo!, where I ran central Insights Services and led globalized data solutions during the company’s data “glory days”.For more on the Predictive Enterprise, read my full post on Greenplum’s Datastream Blog.last_img read more

Former Secretary of State Condoleezza Rice talks foreign policy

first_imgFormer National Security Advisor and Secretary of State Condoleezza Rice spoke Thursday evening about global affairs and America’s role in the world at a lecture co-hosted by the Rooney Center for the Study of American Democracy and the Notre Dame International Security Center (NDISC). Professor Michael Desch, director of NDISC, moderated the discussion.Rice spoke at length about current events in the international sphere, commenting on Middle East politics and North Korea. She also offered broader analysis of the current state of the international order.This order is currently in a state of flux, Rice said, identifying three major changes since the post-World War II order was established that have made the world more complicated. First, she said conceptions of security have changed, particularly as they relate to mutual defense under the terms of the NATO alliance, which has underpinned the global system. Members of the alliance regard an attack on one member state as an attack on all member states.“Security is just different than it was in 1945. … I was National Security Advisor on 9/11,” she said. “ … The problem was not marching armies, it was ungoverned spaces. Afghanistan was the fifth poorest country in the world at the time. And so we have to worry about the high mountains between Afghanistan and Pakistan. We’d have to now worry about Mali, or Libya, the area in Syria where people worry ISIS could be reborn again. And that makes you wonder, what does ‘an attack upon one means an attack upon all’ mean?”Second, Rice said “great powers” such as Russia and China are behaving more belligerently again.“Great powers [are] behaving badly again,” she said. “Whether it’s the Chinese … in the South China Sea, the Chinese in cybersecurity threats, trying to force — it seems — the United States out of the Asia-Pacific. A rising power. But then a declining power in Russia [that’s] mostly disruptive. Interfering in other people’s elections, taking their neighbor’s territory, propping up [Syrian dictator] Bashar al-Assad. Great powers are challenging the system.”On the whole, Rice said recent populist movements are presenting a particular challenge to the post-1945 international order.“Finally — and most importantly from my point of view — we’re experiencing what I call the rise of the Four Horseman of the Apocalypse: populism, nativism, isolationism and protectionism,” she said. “They tend to ride together. We’re seeing that people who didn’t succeed in globalization …are saying — as a friend of mine said about the 2016 election but you could say it about the Five Star Movement in Italy, you can say it about the Alternative for Germany, you can say it about Brexit — ‘Do you hear me now?’”Rice said those left behind by globalization search for scapegoats and, in so doing, weaken the international system.“And they’re turning to populists who have an answer for them about why they’re not doing well,” Rice said. “If you’re on the left, it’s big banks. If you’re on the right, it’s immigrants. If you’re on the left or right, it’s China. And so populists are appealing to people and it’s undermining the foundations of that system, which actually believed in free trade, believed in a U.S. that was very involved in promoting and sustaining democracy and I think that’s why this feels so unstable.”In response to a question from Desch about whether President Trump was “wrong” to withdraw American forces from Syria after declaring victory against ISIS, Rice responded in the affirmative. Earlier this week, Turkey launched attacks against American-allied Kurdish forces after seeming to get Washington’s blessing for such a move.“Yeah, he was wrong,” Rice said. “There’s no other way to say it. I don’t think it was particularly well-thought out. I think he actually fell into a trap that [Turkish president Recep Tayyip Erdogan] set. Erdogan is a very clever man, and I think he probably said something like, ‘I know you want to bring your troops home. This is the chance to do it.’ And the president took it. I’m quite sure afterwards his aides said to him, ‘Do you know what you just did?’ and he probably said ‘No I didn’t,’ and they probably said, ‘Yes you did.’”Rice said the administration’s decision could threaten progress made against ISIS on the ground in Syria.“They’ve been trying to backtrack on it ever since, because it was 100 American soldiers,” she said. “The whole idea was that you were just saying to the Turks ‘Don’t go after the Kurds.’ The Kurds in return were keeping the jails for the 1,500 or so ISIS soldiers and their families. The Kurds are fighters, so if the Turks come after them the Kurds are not going to lay down. They’re going to fight. They’re going to leave those ISIS fighters right where they are and go fight. Then, you will have released 1,500 ISIS personnel into that very unstable region. So I think it was a big mistake. But maybe now — I hope — that what is happening is that underneath is someone is going to Erdogan and saying, ‘Don’t go any further.’”In response to a question regarding recent tensions between the United States and Iran, Rice praised the Trump administration for showing military restraint in the face of increased Iranian aggression in the region. Iran is accused of attacking oilfields in Saudi Arabia last month and of shooting down an American drone over the summer. In response to the second incident, President Trump approved a retaliatory strike but called it off before it could be carried out.“I don’t see the circumstances in which the use of military force in a large-scale way against Iran is either possible, necessary or appropriate,” Rice said. “I will not say that a time may not come when one has to use more limited force against Iran. I don’t think that time has come now. First of all, you certainly wouldn’t use force against Iran for shooting down an unarmed American drone. That makes no sense. But when Iran decided to go after the Saudi oil supply, they also didn’t make anything go boom in the night, and I think that was a very smart ploy.”One of the administration’s responses to Iran that Rice praised was the imposition of financial sanctions on Tehran.“So what did they do? They used what we used to call the ‘nuclear weapon of financial sanctions,’” she said. “Which is Treasury 311 sanctions, which when you list an entity under Treasury 311 sanctions for either money laundering or nonproliferation or for terrorism, no entity that does business with it can do business in the United States. So, who did they list? The Iranian Central Bank. That means that nobody will do business with the Iranian Central Bank and the Iranians are now frozen out of the international financial system.”Over the course of an answer to a question about the proliferation of nuclear weapons, Rice cited North Korea’s nuclear program as a continued cause of international concern.“You have a regime in North Korea — a crazy regime, right?” she said. “Do you really want this regime to have nuclear weapons? One of the things that really has frightened people about North Korea is despite all the efforts to stop their program — I tried diplomacy with them, everybody’s tried diplomacy with them — their program seems to be continuing to march forward. At the beginning of this term for President Trump, there were actually people who were talking about a North Korean weapon that could reach the West Coast of the United States.”While Rice acknowledged the frightful nature of that scenario, she said there are ways to hinder the North Korean program through inspections and testing moratoriums.“That’s a scary prospect,” Rice said. “But I will say, if you can do two things you might prevent that from happening. The first thing is get inspectors on the ground. I know we want them to denuclearize. They’re not going to give up their weapons of mass destruction, but get inspectors on the ground. I would actually be willing to give up on some of the sanctions to get that done. Because inspectors can teach you a lot about what’s going on. The other issue is if you can keep them from testing. Nuclear testing is actually binary. You can fail, fail, fail, fail, fail and then one day you succeed. It’s not that you get 10% better, 20% better … so if you can keep them from testing, perhaps they’ll never get to the place where they can threaten the United States.”While Rice said Trump’s first meeting with North Korean dictator Kim Jong Un brought some benefit, she was critical of the president’s choice to sit down with the autocrat a second time.“I do think that the administration did something that at the time I didn’t think was very smart, which is when President Trump decided to meet with Kim Jong Un. I thought ‘Oh goodness, what are you doing?’ Then I thought ‘You know, nothing else has worked,” Rice said. “Might as well try it. That first meeting was actually pretty useful. They should never have had the second meeting … what you saw was a Kim Jong Un who I actually think believed our press that Donald Trump wanted a Nobel Prize so badly he would do anything. Then, to his credit, when the president walked away, Kim Jong Un was furious.”Tags: Condoleezza Rice, Foreign Policy, international affairs, Iran, North Korea, populism, Syria, turkeylast_img read more

Daniels, Bright, and Peters medal at SA Youth Championships

first_imgWITH two silver and a bronze medals, Linden’s Daniel Williams prevailed as the most successful athlete of the four who represented Guyana at the South American Youth Championships in Concordia, Argentina, last weekend, where Tyrell Peters and CARIFTA Games bronze medallist Chantoba Bright also medalled. Despite battling the challenge of coping with the constantly fluctuating temperature of Argentina’s climate and tough competition from the Brazil team, the Guyana team managed to perform remarkably well, with Bright finishing third in the Girls’ long jump and Peters also earning a bronze.The three medals allowed Williams to take up podium position in all of his events, namely the Boys’ 200m, 400m and high jump.In the 200m Williams clocked 22.11 seconds for the bronze, unable to beat Brazil’s Moraes Vinicius (21.41s) and Junior Cleverson (21.93s).Only Brazil’s Da Silva Bruno’s 48.12 seconds finish was better than the 48.57 seconds Daniel clocked in the 400m. In the high jump Daniel cleared 2 metres, ending behind Chile’s Francisco Moraga who also had 2 metres.In spite of gaining medals, some of the athletes were not altogether happy with their performances, which they said were severely affected by the climate conditions.“It was hard to get warm, you weren’t sweating, you would be warming up, warming up but you weren’t sweating you were just getting tired. And as soon as I took off my sweater to go jump I got cold right away,” said Bright, on her return to Guyana last Tuesday morning. Bright took a best leap of 5.96m for her bronze. This was an improvement of the 5.77m she performed last month at the Inter-Guiana Games, but still below her target of keeping her jumps above 6m which she had been clearing earlier this year.The event was won by Columbia’s Andrea Quinto with a jump of 6.13 metres. In the triple jump Bright finished fourth with 12.29m, in an event where the win again went to Columbia, this time through Marcela Cuesta who leaped 13.20m.Tyrell Peters was in the 100m and 200m, managing to grab silver in the 100m after a 10.68 seconds run in the final, bettering the 10.87 seconds he had in the heats. However, he ended fifth in the 200m off a time of 22.47 seconds.“I wasn’t satisfied with my timings because my personal best is 21.40 (seconds) and I ran 22.47 (seconds), so I’m not proud of that performance. But the climate was real bad, because it was like hot at one point and then really cold at other points, we had to just constantly adjust to whatever we had,” Peters told Chronicle Sport.Battling illness, compounded by the climate, sprinter Kenisha Phillips was the only athlete who was unable to medal. Phillips was in the Girls’ 100m and 200m; finishing fifth in the 100m final in 12.13 seconds and fourth in the 200m with 25.12 seconds.last_img read more