السبت، 13 يوليو 2013

Abortions Are Safe When Performed by Nurses Practitioners, Physician Assistants and Certified Nurse Midwives, Study Suggests



First trimester abortions are just as safe when performed by trained nurse practitioners, physician assistants and certified nurse midwives as when conducted by physicians, according to a new six-year study led by UCSF.

The study posted online January 18 in the American Journal of Public Health in advance of the print edition.
The publication comes a week before the 40th anniversary of the Roe vs. Wade, the landmark Supreme Court decision that made abortion legal in the United States.
Currently in the United States, a patchwork of state regulations determines who can provide abortions, with several states specifically prohibiting non-physician clinicians from performing the procedure.
The new study was designed to evaluate the safety of early aspiration abortions when performed by nurse practitioners, physician assistants and certified nurse midwives trained in the procedure. The study was conducted under a legal waiver from the Health Workforce Pilot Projects Program, a division of the California Office of Statewide Health Planning and Development. California law requires a legal clarification about who can perform aspiration abortions.
The researchers report in their study that the results show the pool of abortion providers could be safely expanded beyond physicians to include other trained health care professionals. They found that:
Nurse practitioners, certified nurse midwives and physician assistants can provide early abortion care that is clinically as safe as physicians;
Outpatient abortion is very safe, whether it is provided by physicians or by nurse practitioners, certified nurse midwives or physician assistants.
Nationally, 92 percent of abortions take place in the first trimester but studies find that black, uninsured and low-income women continue to have less access to this care, according to the researchers.
In California, 13 percent of women using state Medicaid insurance obtain abortions after the first trimester. Because the average cost of a second trimester abortion is substantially higher than a first trimester procedure and abortion complications increase as the pregnancy advances, shifting the population distribution of abortions to earlier gestations may result in safer, less costly care, according to the research team.
"Increasing the types of health care professionals who can provide early aspiration abortion care is one way to reduce this health care disparity,'' said lead author Tracy Weitz, PhD, MPA, a UCSF associate professor and director of Advancing New Standards in Reproductive Health at the UCSF Bixby Center for Global Reproductive Health. "Policy makers can now feel confident that expanding access to care in this way is evidence-based and will promote women's health.''
Currently, non-physicians are allowed to perform aspiration abortions in four states: Montana, Oregon, New Hampshire and Vermont. In other states, non-physician clinicians are permitted to perform medication but not aspiration abortions. In recent years, in an effort to limit abortion availability, several states have put laws on the books to prohibit non-physician clinicians from performing abortions.
In the study, 40 nurse practitioners, certified nurse midwives and physician assistants from four Planned Parenthood affiliates and from Kaiser Permanente of Northern California were trained to perform aspiration abortions. They were compared to a group of nearly 100 physicians, who had a mean of 14 years of experience providing abortions.
Altogether, 5,675 abortions were performed in the study by nurse practitioners, certified nurse midwives and physician assistants, compared to 5,812 abortions by physicians. The abortions were performed between August 2007 and August 2011 at 22 clinical facilities in California.
The researchers found that both groups of abortion providers had few complications -- less than 2 percent, including incomplete abortions, minor infection and pain. Statistically, according to the researchers, the complication rates were not different between the two groups of providers.
"The value of this study extends beyond the question of who can safely perform aspiration abortion services in California because it provides an example of how research can be used to answer relevant health care policy issues,'' said study co-author Diana Taylor, PhD, RNP, professor emeritus in the UCSF School of Nursing. "As the U.S. demand for cost-effective health care increases, workforce development has become a key component of health care reform. All qualified health professionals should perform clinical care to the fullest extent of their education and competency.''
The study was funded by grants from private foundations including the John Merck Foundation, the Educational Foundation of America, the David & Lucile Packard Foundation, and the Susan Thompson Buffet Foundation.

الجمعة، 12 يوليو 2013

Link Between Quantum Physics and Game Theory Found


A deep link between two seemingly unconnected areas of modern science has been discovered by researchers from the Universities of Bristol and Geneva.

While research tends to become very specialized and entire communities of scientists can work on specific topics with only a little overlap between them, physicist Dr Nicolas Brunner and mathematician Professor Noah Linden worked together to uncover a deep and unexpected connection between their two fields of expertise: game theory and quantum physics.
Dr Brunner said: "Once in a while, connections are established between topics which seem, on the face of it, to have nothing in common. Such new links have potential to trigger significant progress and open entirely new avenues for research."
Game theory -- which is used today in a wide range of areas such as economics, social sciences, biology and philosophy -- gives a mathematical framework for describing a situation of conflict or cooperation between intelligent rational players. The central goal is to predict the outcome of the process. In the early 1950s, John Nash showed that the strategies adopted by the players form an equilibrium point (so-called Nash equilibrium) for which none of the players has any incentive to change strategy.
Quantum mechanics, the theory describing the physics of small objects such as particles and atoms, predicts a vast range of astonishing and often strikingly counter-intuitive phenomena, such as quantum nonlocality. In the 1960s, John Stewart Bell demonstrated that the predictions of quantum mechanics are incompatible with the principle of locality, that is, the fact that an object can be influenced directly only by its immediate surroundings and not by distant events. In particular, when remote observers perform measurements on a pair of entangled quantum particles, such as photons, the results of these measurements are highly correlated. In fact, these correlations are so strong that they cannot be explained by any physical theory respecting the principle of locality. Hence quantum mechanics is a nonlocal theory, and the fact that Nature is nonlocal has been confirmed in numerous experiments.
In a paper published in Nature Communications, Dr Brunner and Professor Linden showed that the two above subjects are in fact deeply connected with the same concepts appearing in both fields. For instance, the physical notion of locality appears naturally in games where players adopt a classical strategy. In fact the principle of locality sets a fundamental limit to the performance achievable by classical players (that is, bound by the rules of classical physics).
Next, by bringing quantum mechanics into the game, the researchers showed that players who can use quantum resources, such as entangled quantum particles, can outperform classical players. That is, quantum players achieve better performance than any classical player ever could.
Dr Brunner said: "Such an advantage could, for instance, be useful in auctions which are well described by the type of games that we considered. Therefore, our work not only opens a bridge between two remote scientific communities, but also opens novel possible applications for quantum technologies."

Air Pollution Responsible for More Than 2 Million Deaths Worldwide Each Year, Experts Estimate


More than two million deaths occur worldwide each year as a direct result of human-caused outdoor air pollution, a new study has found.

In addition, while it has been suggested that a changing climate can exacerbate the effects of air pollution and increase death rates, the study shows that this has a minimal effect and only accounts for a small proportion of current deaths related to air pollution.
The study, which has been published today, 12 July, in IOP Publishing's journal Environmental Research Letters, estimates that around 470,000 people die each year because of human-caused increases in ozone.
It also estimates that around 2.1 million deaths are caused each year by human-caused increases in fine particulate matter (PM2.5) ? tiny particles suspended in the air that can penetrate deep into the lungs, causing cancer and other respiratory disease.
Co-author of the study, Jason West, from the University of North Carolina, said: "Our estimates make outdoor air pollution among the most important environmental risk factors for health. Many of these deaths are estimated to occur in East Asia and South Asia, where population is high and air pollution is severe."
According to the study, the number of these deaths that can be attributed to changes in the climate since the industrial era is, however, relatively small. It estimates that a changing climate results in 1500 deaths due to ozone and 2200 deaths related to PM2.5 each year.
Climate change affects air quality in many ways, possibly leading to local increases or decreases in air pollution. For instance, temperature and humidity can change the reaction rates which determine the formation or lifetime of a pollutant, and rainfall can determine the time that pollutants can accumulate.
Higher temperatures can also increase the emissions of organic compounds from trees, which can then react in the atmosphere to form ozone and particulate matter.
"Very few studies have attempted to estimate the effects of past climate change on air quality and health. We found that the effects of past climate change are likely to be a very small component of the overall effect of air pollution," continued West.
In their study, the researchers used an ensemble of climate models to simulate the concentrations of ozone and PM2.5 in the years 2000 and 1850. A total of 14 models simulated levels of ozone and six models simulated levels of PM2.5.
Previous epidemiological studies were then used to assess how the specific concentrations of air pollution from the climate models related to current global mortality rates.
The researchers' results were comparable to previous studies that have analysed air pollution and mortality; however, there was some variation depending on which climate model was used.
"We have also found that there is significant uncertainty based on the spread among different atmospheric models. This would caution against using a single model in the future, as some studies have done," continued West.

الخميس، 11 يوليو 2013

NASA's OPALS to Beam Data From Space Via Laser

PASADENA, Calif. -- NASA will use the International Space Station to test a new communications technology that could dramatically improve spacecraft communications, enhance commercial missions and strengthen transmission of scientific data.



The Optical Payload for Lasercomm Science (OPALS), an optical technology demonstration experiment, could improve NASA's data rates for communications with future spacecraft by a factor of 10 to 100. OPALS has arrived at NASA's Kennedy Space Center in Florida from the agency's Jet Propulsion Laboratory in Pasadena, Calif. It is scheduled to launch to the space station later this year aboard a SpaceX Dragon commercial resupply capsule on the company's Falcon 9 rocket.

"OPALS represents a tangible stepping stone for laser communications, and the International Space Station is a great platform for an experiment like this," said Michael Kokorowski, OPALS project manager at JPL. "Future operational laser communication systems will have the ability to transmit more data from spacecraft down to the ground than they currently do, mitigating a significant bottleneck for scientific investigations and commercial ventures."

OPALS will be mounted on the outside of the International Space Station and communicate with a ground station in Wrightwood, Calif., a mountain town near Los Angeles.

"It's like aiming a laser pointer continuously for two minutes at a dot the diameter of a human hair from 30 feet away while you're walking," explained OPALS systems engineer Bogdan Oaida of JPL.

The OPALS instrument was built at JPL and is slated to fly on the Dragon capsule in late 2013. The mission is expected to run 90 days after installation on the station.

The OPALS Project Office is based at JPL, a division of the California Institute of Technology in Pasadena. 

Geothermal Power Facility Induces Earthquakes, Study Finds


An analysis of earthquakes in the area around the Salton Sea Geothermal Field in southern California has found a strong correlation between seismic activity and operations for production of geothermal power, which involve pumping water into and out of an underground reservoir.

"We show that the earthquake rate in the Salton Sea tracks a combination of the volume of fluid removed from the ground for power generation and the volume of wastewater injected," said Emily Brodsky, a geophysicist at the University of California, Santa Cruz, and lead author of the study, published online in Science on July 11.
"The findings show that we might be able to predict the earthquakes generated by human activities. To do this, we need to take a large view of the system and consider both the water coming in and out of the ground," said Brodsky, a professor of Earth and planetary sciences at UCSC.
Brodsky and coauthor Lia Lajoie, who worked on the project as a UCSC graduate student, studied earthquake records for the region from 1981 through 2012. They compared earthquake activity with production data for the geothermal power plant, including records of fluid injection and extraction. The power plant is a "flash-steam facility" which pulls hot water out of the ground, flashes it to steam to run turbines, and recaptures as much water as possible for injection back into the ground. Due to evaporative losses, less water is pumped back in than is pulled out, so the net effect is fluid extraction.
During the period of relatively low-level geothermal operations before 1986, the rate of earthquakes in the region was also low. Seismicity increased as the operations expanded. After 2001, both geothermal operations and seismicity climbed steadily.
The researchers tracked the variation in net extraction over time and compared it to seismic activity. The relationship is complicated because earthquakes are naturally clustered due to local aftershocks, and it can be difficult to separate secondary triggering (aftershocks) from the direct influence of human activities. The researchers developed a statistical method to separate out the aftershocks, allowing them to measure the "background rate" of primary earthquakes over time.
"We found a good correlation between seismicity and net extraction," Brodsky said. "The correlation was even better when we used a combination of all the information we had on fluid injection and net extraction. The seismicity is clearly tracking the changes in fluid volume in the ground."
The vast majority of the induced earthquakes are small, and the same is true of earthquakes in general. The key question is what is the biggest earthquake that could occur in the area, Brodsky said. The largest earthquake in the region of the Salton Sea Geothermal Field during the 30-year study period was a magnitude 5.1 earthquake.
The nearby San Andreas fault, however, is capable of unleashing extremely destructive earthquakes of at least magnitude 8, Brodsky said. The location of the geothermal field at the southern end of the San Andreas fault is cause for concern due to the possibility of inducing a damaging earthquake.
"It's hard to draw a direct line from the geothermal field to effects on the San Andreas fault, but it seems plausible that they could interact," Brodsky said.
At its southern end, the San Andreas fault runs into the Salton Sea, and it's not clear what faults there might be beneath the water. A seismically active region known as the Brawley Seismic Zone extends from the southern end of the San Andreas fault to the northern end of the Imperial fault. The Salton Sea Geothermal Field, located on the southeastern edge of the Salton Sea, is one of four operating geothermal fields in the area.

Researchers Regenerate Retina in Mice Using Neuronal Reprogramming


Researchers from the Centre for Genomic Regulation (CRG) in Barcelona have managed to regenerate the retina in mice using neuronal reprogramming. There are currently several lines of research that explore the possibility of tissue regeneration through cell reprogramming. One of the mechanisms being studied is reprogramming through cell fusion.


The researcher Pia Cosma and her team have used the cell fusion mechanism to reprogram the neurons in the retina. This mechanism consists of introducing bone marrow stem cells into the damaged retina. The new undifferentiated cells fuse with the retinal neurons and these acquire the ability to regenerate the tissue.
"For the first time we have managed to regenerate the retina and reprogram its neurons through in vivo cell fusion. We have identified a signalling pathway that, once activated, allows the neurons to be reprogrammed through their fusion with bone marrow cells," explains Pia Cosma, head of the Reprogramming and Regeneration group at the Centre for Genomic Regulation and ICREA research professor. "This discovery is important not only because of the possible medical applications for retinal regeneration but also for the possible regeneration of other nervous tissues," says Daniela Sanges, first author of the work and postdoctoral researcher in Pia Cosma's laboratory.
The study, published by the journal Cell Reports, demonstrates that the regeneration of nervous tissue by means of cell fusion is possible in mammals and describes this new technique as a potential mechanism for the regeneration of more complex nervous tissue.
This research is in the very early stages but already there are laboratories interested in being able to continue the work and take it to a more applied level.

Bioenergy With Carbon Capture: Scientists Set out Path for Global Warming Reversal


 Bioenergy with carbon capture and storage (BECCS) can reverse the global warming trend and push temperatures back below the global target of 2°C above pre-industrial levels, even if current policies fail and we initially overshoot this target.

This is according to a new study, published today, 11 July, in IOP Publishing's journal Environmental Research Letters, which shows that ambitious temperature targets can be exceeded then reclaimed by implementing BECCS around mid-century.
The researchers, from Chalmers University of Technology in Sweden, show that if BECCS is implemented on a large-scale along with other renewable energy sources, temperature increases can be as low as 1.5°C by 2150.
Co-author of the study, Professor Christian Azar, said: "What we demonstrate in our paper is that even if we fail to keep temperature increases below 2°C, then we can reverse the warming trend and push temperatures back below the 2°C target by 2150.
"To do so requires both large-scale use of BECCS and reducing other emissions to near-zero levels using other renewables -- mainly solar energy -- or nuclear power."
BECCS is a greenhouse gas mitigation technology based on bioenergy that produces fuel for power plants or transportation while simultaneously removing carbon dioxide from the atmosphere. Trees and crops give off carbon dioxide when they are burnt as fuel, but also act as a carbon sink as they grow beforehand, absorbing carbon dioxide from the atmosphere. These two processes cancel each other out, resulting in net zero emissions of carbon dioxide.
When combined with carbon capture and storage -- techniques that aim to pull carbon dioxide out of the flue gases from power plants and redirect it into geological storage locations -- the overall carbon dioxide emissions are negative. If applied on a global scale, this could help to reverse global warming.
In their study, the researchers developed an integrated global energy system and climate model that enabled them to assess the most cost-effective way forward for a given energy demand scenario and temperature target.
They find that stringent temperature targets can be met at significantly lower costs if BECCS is implemented 30 to 50 years from now, although this may cause a temporary overshoot of the 2°C target.
"The most policy relevant implication of our study is that even if current political gridlock causes global warming in excess of 2°C, we can reverse the temperature trend and reach targets later. This means that 2°C targets or even more ambitious targets can remain on the table in international climate negotiations," Azar continues.
However, the authors caution against interpreting their study as an argument for delaying emission reductions in the near-term.
Azar says: "BECCS can only reverse global warming if we have net negative emissions from the entire global energy system. This means that all other CO2 emissions need to be reduced to nearly zero.
"Also, temperatures can only be reduced by about 0.6°C per century, which is too slow to act as an 'emergency brake' if climate damages turn out to be too high. The more we reduce emissions now, the more ambitious targets we can achieve in the long term -- even with BECCS."