The model for predicting visual clarity — based on measurements taken by today’s highly accurate aberrometers — could also enable surgeons to more accurately assess and correct the vision of patients undergoing lasik or refractive surgery.

New technology in aberrometers means ophthalmologists and others can accurately measure refractive error and other abnormalities in the eye’s optics. But these instruments cannot use these measurements to predict visual acuity, or how well a person can actually see. Usually, ophthalmologists and optometrists rely on a patient’s ability to identify characters on an eye chart to determine visual clarity.

A study recently published in the online, peer-reviewed Journal of Vision, published by the Association for Research in Vision and Ophthalmology (ARVO) evaluates the performance of several simple metrics that predict visual acuity from wavefront aberrations — the eye measurements provided by an aberrometer.

To do so, authors Andrew B. Watson and Albert J. Ahumada Jr (both of NASA Ames Research Center, CA) make a clear distinction between a metric and model.

“A metric is a formula that describes a quantitative relationship,” explains Watson. “It is accurate but not necessarily adaptable to different situations. A model is a mechanistic description that explains why a relationship exists. If the parameters of a model change, one can make predictions of how an outcome will change.”

The authors developed a model that successfully predicts visual acuity using both wavefront aberrations and simulations of the complex task of identifying individual letters from the widely used Sloan letter set. They then designed a simple metric that performs as well as the more elaborate model.

The metric could be used internationally. Explains Watson: “The same metric, because of its generality, can predict acuity measured with other symbol sets, such as Chinese characters.

“With this metric, the aberrometer will be able to give direct predictions of visual acuity, and could also provide an automatic optimal refractive prescription for the patient.”

[Joanne Olson @ Association for Research in Vision and Ophthalmology]

In a preclinical study, Lauren Akers, D.O., postdoctoral fellow from the Children’s Cancer Hospital at M. D. Anderson, found that combining a novel glycolysis inhibitor, 3-BrOP, with mTOR inhibitor, rapamycin, induced more than 90 percent cell death in human tissue cultures of acute lymphocytic leukemia. She presented her study at the American Society of Pediatric Hematology/Oncology annual conference on May 16.

“We already knew that 3-BrOP was effective in preclinical research of glioblastoma, colon cancer and lymphoma, and most recently acute leukemias” says Akers, lead investigator on the study. “We also knew that mTOR inhibitors intensify cellular starvation. This study showed that the two together have a more powerful impact on treating acute lymphocytic leukemia, which is the most common childhood cancer.”

Glycolysis is a process that turns glucose into energy for cells. Unlike healthy cells that get their energy for growth from both glycolysis and respiration, cancer cells are highly dependent on glycolysis. Using the M. D. Anderson-developed drug, 3-BrOP, researchers inhibited glycolysis, thus starving the leukemia cells from their energy source while leaving healthy cells free to get their energy from respiration.

Rapamycin is an mTOR inhibitor that keeps cancer cells from coping with stress, thus resulting in cell death. When researchers on the study combined the two drugs, they discovered a synergistic effect.

“We found that a lower dosage of 3-BrOP with rapamycin created the same results of more than 90 percent tumor cell death,” says Akers. “Theoretically, we believe that patients will better tolerate the therapy by lowering the dosage of 3-BrOP and combining it with rapamycin.”

Other researchers on the study include senior investigator Patrick Zweidler-McKay, M.D., Ph.D., Anna Franklin, M.D. and Wendy Fang, M.D., all from the Children’s Cancer Hospital at M. D. Anderson. Peng Huang, M.D., Ph.D., from the Department of Molecular Pathology at M. D. Anderson was also an investigator and was responsible for the development of 3-BrOP.

The team of researchers plans to conduct additional mouse studies, which could lead to a Phase I clinical trial some time in the future.

[Sara Farris @ University of Texas M. D. Anderson Cancer Center]

Magellan set out from Spain in 1519 with hopes of claiming the wealth of the Spice Islands, or Moluccas, for the Spanish. Two years later the explorer claimed the first European contact with a Pacific island culture when he landed on Guam — 1,500 miles north of the Spice Islands. How did he make it that far, and how did he miss the Spice Islands by that much?

The paper, co-authored by Fitzpatrick and University of Calgary researcher Dr. Richard Callaghan, uses computer modeling and historical data to determine the role oceanographic conditions may have played in Magellan’s smooth voyage after rounding the notorious Cape Horn at the southernmost tip of South America and in his decision to sail far north of the Spice Islands — which Magellan knew lay along the equator.

The paper, “Magellan’s Crossing of the Pacific: Using Computer Simulations to Examine Oceanographic Effects on One of the World’s Greatest Voyages,” was highlighted in the “Random Samples” section of the May 16 issue of Science, and will be published in the Journal of Pacific History in August.

The paper concludes that unusually benign weather conditions, likely associated with an El Nino event, allowed Magellan to sail north and may have persuaded him to continue in that direction to avoid starvation — making Magellan’s voyage not only the first to circumnavigate the globe, but apparently the earliest historical record of an El Nino event.

Specifically, the paper finds that Magellan likely sailed around Cape Horn and directly into the tail end of an El Nino event, resulting in much smoother sailing than would normally have been the case and allowing him to easily sail to the north along the coast of Chile. Fitzpatrick and Callaghan also hypothesize that, after leaving the Chilean coast, Magellan may have chosen to continue on his northerly route in order to take advantage of prevailing winds and currents that had them moving at a good speed and allowed him to rest his sailors, who were by then suffering from scurvy and other maladies.

Magellan claimed that he sailed far to the north of the Spice Islands due to concerns that the islands had no food, and Fitzpatrick and Callaghan found some evidence to support this hypothesis. Their paper notes that the Pacific region appears to have been experiencing an El Nino event in 1519 and 1520 — during the bulk of Magellan’s voyage — and that an El Nino is often associated with drought and accompanying famines in the area.

[Matt Shipman @ North Carolina State University]

Could a business practice usually reserved for boosting profits be used to help turn companies green by reducing their energy use? Writing in the International Journal of Six Sigma and Competitive Advantage (IJSSCA), researchers in India provide an answer.

According to mechanical engineer Prabhakar Kaushik of NC College of Engineering in Haryana, India, and colleagues, energy conservation should be at the forefront of company efforts. In a global economy with environmental pressures high on the agenda, organizations are under increasing pressure to control costs, maintain high levels of safety and quality, and save energy. Energy conservation, of course, offers the parallel advantages of helping to reduce costs, improving efficiency, as well as reducing the carbon footprint.

Kaushik’s team has now turned to the principles of Six Sigma methodology to help demonstrate how organizations might improve their energy profile. Six sigma is a strategy originally used by Motorola to improve their business practices. It involves seeking out and eradicating the causes of defects and errors using quality management and statistics. Today, countless companies in many different sectors use Six Sigma to improve their bottom line.

The researchers tested their approach on the operations of a thermal power plant with the aim of conserving energy rather than simply boosting profits. They point out that demineralized (DM) water in these plants is one of the expensive input materials. It has been found that 0.1 percent increase in DM make up water consumption increases the generation cost by approximately 0.2 million dollar per annum. Demineralized water, however, is “critical to quality” and so its use cannot be circumvented.

Project recommendations from a Six Sigma study demonstrated that the overall costs of using demineralized water could be cut significantly. The study points to detection and repair of faults associated with steam and water analysis systems, problem valves, vacuum pump overflow, and other issues. The researchers explain that the energy savings are equivalent to a fiscal cost of more than three quarters of a million dollars each year at today’s prices.

The consumption of demineralized water is just one example of energy conservation measures that could be implemented using the Six Sigma approach, the researchers add. They point out that given that India is set to commission dozens of new thermal power plants in coming years, the total energy savings with respect to this particular factor could be enormous.

[Parbhakar Kaushik @ Inderscience Publishers]