Time filter

Source Type

Caxias do Sul, Brazil

News Article
Site: http://www.nature.com/nature/current_issue/

As Barack Obama prepares to leave office, Nature examines the scientific highs and lows of his presidency. Read the other stories in this series about his policies on biomedicine, space and climate change. Many researchers who watched Barack Obama’s inauguration in 2009 were thrilled by his pledge to “restore science to its rightful place”. But scientists and legal scholars say that, in many ways, Obama has failed to live up to that lofty promise. In general, government researchers have enjoyed more freedom — and endured less political meddling — than they did under the previous president, George W. Bush. Bush’s administration was accused of muzzling or ignoring scientists on subjects ranging from stem cells to climate change. In March 2009, Obama instructed agencies to develop policies to reduce political interference and increase transparency about the research used in policy decisions. And when the Union of Concerned Scientists (UCS) surveyed federal researchers in 2015, most said that their agency adhered to its scientific-integrity policy. But critics say that Obama’s White House has not shied away from exerting political influence over science. In 2011, the Environmental Protection Agency (EPA) sent a proposal to the White House that would strengthen controls on ozone pollution, based on guidance from its scientific advisers. But Obama directed the agency to withdraw the plan, citing the cost of the stricter limits at a time when the economy was still recovering from a recession. And that same year, Health and Human Services secretary Kathleen Sebelius overruled the Food and Drug Administration’s finding that the emergency contraceptive ‘Plan B One-Step’ was safe to dispense over the counter for all women and girls. In both cases, science eventually won out: the EPA approved stronger ozone standards in 2015, and the FDA approved unrestricted sales of Plan B in 2013 after judges ruled against the agency. Nevertheless, these examples show how political considerations have sometimes trumped scientific ones during Obama’s tenure, says Lisa Heinzerling, a law professor at Georgetown University in Washington DC. “There are structures in place that threaten scientific integrity and encourage the injection of politics into matters that are supposed to be scientific or technical,” says Heinzerling, who worked at the EPA for two years under Obama. Science advocates are concerned about how political influence shapes science behind closed doors at the White House. The president’s Office of Management and Budget, which reviews proposals for new rules and regulations, can make substantial changes or kill a policy without explaining why. “In some cases, the White House is messing around, and it’s not doing it transparently,” says Wendy Wagner, a law professor at the University of Texas at Austin. The recent UCS survey revealed room for improvement at several agencies. Nearly half the scientists at the Centers for Disease Control and Prevention said that their agency gave too much weight to political interests; that proportion rose to 73% at the Fish and Wildlife Service. And less than 60% of scientists at the four agencies surveyed said they could openly express concerns about the work of their employer without fear of retaliation. “We have a lot of new policies and pro-cedures in place that are tremendously beneficial,” says Gretchen Goldman, a UCS analyst who led the study. “But what we’re finding is that there’s more work to be done.”

Migowski P.,Federal University of Rio Grande do Sul | Zanchet D.,Brazilian Synchrotron Light Laboratory (LNLS) | MacHado G.,UCS | Gelesky M.A.,Federal University of Rio Grande do Sul | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2010

Hydrogen reduction of cationic or neutral Ir(i) compounds, namely [Ir(COD)2]BF4 and [Ir(COD)Cl]2respectively. in the ionic liquid (IL) 1-alkyl-3-methylimidazolium tetrafluoroborate affords either irregularly sized spherical (from 1.9 ± 0.4 to 3.6 ± 0.9 nm) or worm-like metal nanoparticles, depending on the nature of the imidazolium alkyl group and the type of iridium precursor. The ionic Ir(i) precursor tends to be dissolved and concentrated on the IL polar domains (populated by the imidazolium nucleus and tetrafluoroborate anions) while the neutral precursor dissolves preferentially in the non-polar region of the IL (populated mainly by N-alkyl side chains). The size, or volume, of the nano-region where the Ir(i) precursor is dissolved and reduced, determines the size and, probably, the shape of the formed nanoparticles. The HR-TEM image shows that the Ir(0) with worm-like shape are polycrystalline and formed from aggregation individual "spherical" nanoparticles of around 1.9 nm. The catalytic activity of Ir(0) NPs on the hydrogenation of cyclohexene (0.01 mol L-1 of Ir atoms in IL, 75°C, 8 bar of H2, 500 rpm stirring, 1/1000 Ir(0)/cyclohexene ratio) is always greater in C1C 10I·BF4 than C1C4I· BF4, regardless of the nature of Ir(i) precursor. Moreover, the cyclohexene hydrogenations performed with Ir(0) nanocatalysts made from ionic Ir(i) precursor are approximately twice faster than those NPs obtained from the neutral Ir(i) precursor, in the same IL. © the Owner Societies. Source

Bianchi O.,Federal University of Rio Grande do Sul | Castel C.D.,Federal University of Rio Grande do Sul | De Oliveira R.V.B.,Federal University of Rio Grande do Sul | Bertuoli P.T.,UCS | Hillig E.,UNICENTRO
Polimeros | Year: 2010

The thermal stability of wood and cellulosic materials is an important factor for applications of these natural renewable materials as fillers for reinforcing polymeric matrices. However, these materials have low thermal stability caused mainly by species that ignite at low temperatures. These characteristics contribute significantly to limit their use in situations where higher temperatures are required. In this work, the thermal degradation of two kinds of wood (Pinus and Garapeira) was evaluated using thermogravimetric measurements under nitrogen atmosphere. The parameters of thermal decomposition kinetics were estimated using the Flynn-Wall-Ozawa (FWO) method. The Garapeira wood showed lower activation energy at reaction degrees below 0.5, probably due to the presence of volatiles compounds, such as oil and wax. The Pinus wood had different characteristics in the initial reaction degree (up to 0.4). After this point, however, Garapeira becomes more stable than Pinus due to the formation of more thermally stable species and because of the higher amount of lignin. Besides, the thermal degradation processes of both woods were found to be mainly controlled by diffusion (Dn) of volatile species at reaction degrees up to 0.8, achieving a third order (F3) mechanism afterwards. Source

This is a prospective and longitudinal study which aimed to introduce the Braden Scale (BS) as an instrument to predict the risk of pressure ulcer (PU), and to analyze the results of its use in an intensive care unit. The sample was of 74 patients and the data were obtained by an instrument containing BS. Such data were analyzed by a simple descriptive statistic. 58 patients (78.37%) had a score < or = 13 and PU incidence of 25.67%. In 45 patients (60.80%), BS was daily filled in. From these patients, 5 (11.10%) developed PU. In 29 patients (39.10%), BS was not daily filled in. From these patients, 14 (48.20%) showed PU Results showed the efficiency of BS, which allowed identifying patients with PU risk. The difficulties of using BS refer to the periodic filling, which shows the need to educate and prepare nurses to use BS in the care of patients. Source

News Article
Site: http://cen.acs.org/news/ln.html

Dozens of scientists and others with expertise in climate change today called for U.S. presidential candidates to spell out how they intend to make the U.S. the world leader in clean energy. “The global transformation of our energy system away from fossil fuels is both a moral imperative, grounded in science, and one of the greatest economic opportunities of our time,” says a letter to the presidential candidates. The missive, organized by the Union of Concerned Scientists (UCS), an advocacy group, is signed by 74 climate experts, including former members of the Intergovernmental Panel on Climate Change and a former energy secretary. The letter urges candidates to “meet and exceed” the short-term pledge President Barack Obama has made: that the U.S. will reduce its greenhouse gas emissions 26–28% below 2005 levels by 2025. Obama made the promise in the run-up to negotiations now under way in Paris on a new global climate change treaty. “It’s imperative for the next President to build on the commitments the U.S. is making in Paris,” Peter Frumhoff, director of science and policy at UCS, told reporters at the Paris meeting. The letter, he said, is designed to “build demand among voters to expect all candidates to have clear and convincing answers about their commitments to a clean energy future.” The issue of climate change has received little attention on the presidential campaign trail thus far. A few Republican candidates, including top-polling Donald Trump, have dismissed the notion of human-caused climate change. Others seeking the Oval Office, including Democratic front-runner Hillary Clinton, accept the science about global warming, but they differ on whether or how to address it. “We need a president who will make good decisions and choices based on the available science,” said one of the letter’s signers, Katherine Hayhoe, director of the Climate Science Center at Texas Tech University. “There is certainly plenty of debate over what those solutions could look like, but the debate should not focus on whether there’s a real problem or not.” Clean energy technologies are already advancing “in leaps and bounds,” she said. Other signers of the letter include former Energy Secretary Steven Chu, a Stanford University physics professor; Scott C. Doney, chair of the marine chemistry & geochemistry department at the Woods Hole Oceanographic Institution; and Jerald L. Schnoor, professor of environmental engineering at the University of Iowa.

Discover hidden collaborations