At issue are overflows from “sanitary” sewer systems, as opposed to “combined” systems that also handle stormwater. EPA estimates that 40 percent of the 3 to 10 billion annual sanitary sewer overflows around the country are caused by hard deposits made up of fat, oil and grease (FOG) that clog sewage pipes. In other words, the FOG buildup is directly responsible for hundreds of millions of sewer overflows, as well as untold costs in health effects, environmental harm, cleanup expenses, and damaged public perception for the utilities.

Dr. Joel Ducoste, an associate professor of civil engineering at NC State, is launching a research effort to address the problem under a prestigious Science To Achieve Results grant from EPA.

“Our goal is to discover the fundamental chemical reactions that lead to these deposits,” Ducoste says, “because if we can understand it, we can figure out how to reduce it – via enhanced treatment technologies, more cost-effective maintenance and by setting appropriate regulatory standards.

“We think a reaction takes place in the sewage collection system when FOG interacts with calcium or other metal ions to form these hardened deposits,” Ducoste says, “similar to the chemical reactions that are used to make household soaps. We’ll be testing this as part of the grant and, if this is the case, we will explore ways to remove the substances that contribute to these deposits.

“Also,” Ducoste says, “once we understand the chemistry behind these deposits, we can develop models to identify potential ‘hot spots’ where FOG deposits may form.” Identifying these hot spots will allow utilities to use preventative maintenance to avoid overflows. Perhaps more importantly, the models could serve as useful tools for urban planners – helping them determine whether an existing sewer system can sustain population growth, or if the system needs to be modified in order to accommodate future growth.

The urban planning component is essential, Ducoste says, because significant amounts of FOG get into sewage systems from high-density residential areas, such as apartment blocks and condominiums. Local governments need to be aware of potential sewer overflow problems that could stem from population growth in a concentrated area. Currently, sewage systems try to keep out FOG by using grease interceptors – but they are found only at restaurants.

The EPA grant is for approximately $570,000 over three years.

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The bulk of neuron production in the central nervous system takes place before birth, and comes to a halt by birth. But scientists have identified specific regions in the core of the brain that retain stem cells into adulthood and continue to produce new neurons.

NC State researchers, investigating the subventricular zone, one of the regions that retains stem cells, have identified a gene that acts as a switch – transforming some embryonic stem cells into adult cells that can no longer produce new neurons. The research was done using mice. These cells form a layer of cells that support adult stem cells. The gene, called FoxJ1, increases its activity near the time of birth, when neural development slows down. However, the FoxJ1 gene is not activated in most of the stem cells in the subventricular zone – where new neurons continue to be produced into adulthood.

Genetically labeled FoxJ1+ cells (green) in a culture dish. These cells differentiate into a unique subset of cells that is distinguishable from known cell types in the adult stem cell niche in the mouse brain (the blue and red cells).

“Research into why and how some stem cells in the subventricular zone continue to produce new neurons is important because a biological understanding of how these cells function can contribute to new treatments to replace damaged or diseased brain tissue, hopefully in regions that cannot do this by themselves,” says Dr. Troy Ghashghaei, an assistant professor of neurobiology at NC State and the senior author of the research. “This research helps us understand brain development itself, which is key to identifying novel approaches for treatment of many neurological disorders.”

When the FoxJ1 gene is activated, it produces a protein that functions as a transcription factor. Transcription factors swim through the nucleus of a cell turning other genes on and off, turning the embryonic stem cell into an adult cell. Some of the adult cells will function as stem cells, creating new neurons, but most will not – instead serving to support the adult stem cells by forming a stem cell “niche.” This niche has a complex cellular architecture that allows adult stem cells to remain active in the subventricular zone.

Ghashghaei’s lab is now moving forward with new research to determine what activates the FoxJ1 gene and how the FoxJ1 protein regulates the expression of other genes. This understanding will reveal how the activation and inactivation of genes controlled by FoxJ1 orchestrates the development of the adult stem cell niche. Ghashghaei’s laboratory is a recent recipient of funding from the National Institutes of Health to support this line of research.

The research was co-authored by members of the Ghashghaei laboratory at NC State including graduate students Benoit Jacquet and Huixuan Liang, research associates Raul Salinas-Mondragon, Blair Therit and Michael Dykstra, as well as a biochemistry undergraduate student Justin Buie. The work was in part a collaboration with investigators from the Cincinnati Children’s Hospital Medical Center, UNC at Chapel Hill, and Washington University in St. Louis. The paper, “FoxJ1-dependent gene expression is required for differentiation of radial glia into ependymal cells and a subset of astrocytes in the postnatal brain,” is a featured article in the current issue of the journal Development.

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Note to editors: The study abstract follows.

“FoxJ1-dependent gene expression is required for differentiation of radial glia into ependymal cells and a subset of astrocytes in the postnatal brain”

Authors: Benoit V. Jacquet, Raul Salinas-Mondragon, Huixuan Liang, Blair Therit, Justin D. Buie, Michael Dykstra and H. Troy Ghashghaei, North Carolina State University; Kenneth Campbell, University of Cincinnati; Lawrence E. Ostrowski, UNC-Chapel Hill; and Steven L. Brody of Washington University.

Published: Nov. 11, 2009, Development

Abstract: Neuronal specification occurs at the periventricular surface of the embryonic central nervous system. During early postnatal periods, radial glial cells in various ventricular zones of the brain differentiate into ependymal cells and astrocytes. However, mechanisms that drive this time- and cell-specific differentiation remain largely unknown. Here, we show that expression of the forkhead transcription factor FoxJ1 in mice is required for differentiation into ependymal cells and a small subset of FoxJ1+ astrocytes in the lateral ventricles, where these cells form a postnatal neural stem cell niche. Moreover, we show that a subset of FoxJ1+ cells harvested from the stem cell niche can self-renew and possess neurogenic potential. Using a transcriptome comparison of FoxJ1-null and wild-type microdissected tissue, we identified candidate genes regulated by FoxJ1 during early postnatal development. The list includes a significant number of microtubule-associated proteins, some of which form a protein complex that could regulate the transport of basal bodies to the ventricular surface of differentiating ependymal cells during FoxJ1-dependent ciliogenesis. Our results suggest that time- and cell-specific expression of FoxJ1 in the brain acts on an array of target genes to regulate the differentiation of ependymal cells and a small subset of astrocytes in the adult stem cell niche.

“This research illustrates international disparities in treatment for a disease that we know how to address,” says Dr. Jeff Stonebraker, an assistant professor of business management at NC State and lead author of two new studies on hemophilia prevalence and treatment. “What we’ve found highlights the work that needs to be done by governments, health officials and pharmaceutical manufacturers to address the needs of those suffering with hemophilia in the developing world.”

Type A hemophilia is a hereditary bleeding disorder that affects about 400,000 people – predominantly men – around the world. The disorder prevents blood from clotting normally, creating the risk of serious bleeding or internal bleeding. Ultimately, the disorder can result in severe pain, joint deformities and death in childhood or young adulthood. But the condition can be treated by replacing the missing clotting factor VIII, which enables those suffering from hemophilia A to live relatively normal lives. Unfortunately, the treatment is expensive and new research shows that access to that treatment is severely limited.

“This is the best data there is on a relatively small global population,” says Mark Skinner, president of the World Federation of Hemophilia. “It will be incredibly useful to our members, to manufacturers of treatment products, ministries of health and researchers. These two very important papers help us see where progress is being made and how we can learn lessons that will help us continue to improve care and work toward our goal of treatment for all.”

In the first study, the researchers found that prevalence of hemophilia A in high-income countries was approximately 12.8 per 100,000 males. The prevalence in lower-income countries was approximately 6.6 per 100,000 males. “The medical community tells us that the incidence of hemophilia A – or the number of people born with the condition – is the same around the world,” Stonebraker explains, “so the difference in prevalence – or the number of people living with the condition at any given moment – appears to be due to much higher mortality in developing countries.”

The study also showed that prevalence of hemophilia has increased over the past 30 years, as treatments for the disorder have improved. In other words, better treatment is helping those with hemophilia A live longer. For example, the United Kingdom had a prevalence of 9.3 per 100,000 in 1974, but it had risen to 21.6 per 100,000 by 2006.

In a second study, Stonebraker and his colleagues found that decreased mortality related to hemophilia A is tied to a willingness – by government health-care agencies or private insurers – to pay for treatment. Correspondingly, the consumption of factor VIII drugs has increased significantly in developed countries – and that trend appears poised to continue, with high-income countries expected to consume more and more factor VIII drugs in the future.

Stonebraker says the two studies should be incredibly helpful as budget-planning tools for insurance companies and those countries that provide national health care, as well as for pharmaceutical companies that will want to project the amount of factor VIII drugs they will need to make to meet market demand. But, Stonebraker says, “the studies also show how much more needs to be done to address hemophilia in the developing world.”

The first study, “A study of variations in the reported hemophilia A prevalence around the world,” was co-authored by Stonebraker, Paula H.B. Bolton-Maggs of the Manchester Royal Infirmary, J. Michael Soucie of the U.S. Centers for Disease Control and Prevention, Irwin Walker of McMaster University and Mark Brooker of the World Federation of Hemophilia. The second study, “A study of reported factor VIII use around the world,” was co-authored by Stonebraker, Brooker, Robert E. Amand of the Biotherapeutic Modeling Group, Inc., Albert Farrugia of the Plasma Protein Therapeutics Association and Alok Srivastava of Christian Medical College. Both studies will be published in a forthcoming issue of Haemophilia.

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By using climate forecasts for short-term planning, water managers can better plan for potential shortages due to drought, says Dr. Sankar Arumugam, an assistant professor of civil, construction and environmental engineering at NC State and lead author of the paper. For example, managers could encourage stakeholders to put water-use restrictions in place and launch a water conservation campaign before the drought even arrives. Managers could also use this approach to determine how best to take advantage of surplus water supplies. For example, hydropower facilities could  generate additional power instead of spilling the excess water. Arumugam notes that the use of forecasts for planning would also make water managers better able to account for increased water demands due to population growth.

“Our paper proposes a framework that would use forecast data to improve water management, allowing water managers to be proactive with their planning rather than reacting to events after the fact,” Arumugam says. Water managers at the federal, state and local level determine how much water can be allotted to various uses, such as hydropower, agriculture, municipal use, recreation and the protection of aquatic species.

Arumugam says advances in the understanding of how changes in ocean temperature affect the atmosphere and, ultimately,  precipitation and temperature, make seasonal or longer-term climate forecasts increasingly reliable. At the same time, Arumugam says, water management is becoming more important due to increasing global population – which means greater water demand – and global climate change, which could stress both humid and arid regions with the former getting wetter and the latter becoming drier.

The proposed framework acknowledges that climate forecasts contain an element of uncertainty, and attempts to mitigate that uncertainty by incorporating water contracts. “These contracts give end-users, such as farmers and municipalities, some idea of what they can expect – allowing them to plan accordingly based on the uncertainty in the climate forecasts,” Arumugam says, “It also offers insurance in the form of compensation if the forecast is incorrect and water managers cannot meet the terms of the contract.” Similarly, Arumugam explains, if the forecast is accurate and the terms of the contract are met, water managers will have made the most efficient use of the available water resources and will receive a performance fee from the end-users who were party to the contract.

“Although there is  uncertainty associated with forecasts, they are correct over the long term, and using this framework would result in long-term benefits for both water users and managers,” Arumugam says. For example, the researchers performed a case study looking at the state of Ceara in Brazil, which is an arid region that receives little or no rainfall from June through the following January. “We found there would be significant benefits for the region, primarily in alleviating the vulnerability of poor farming communities if this framework was implemented,” Arumugam says.

The study, “Improved Water Allocation Utilizing Probabilistic Climate Forecasts: Short Term Water Contracts in a Risk Management Framework,” was co-authored by Arumugam, Dr. Upmanu Lall of Columbia University, Dr. Francisco Assis Souza Filho of the Federal University of Fortaleza and Dr. Ashish Sharma of the University of New South Wales. The research was funded by the National Oceanic and Atmospheric Administration and published in the Nov. 11 issue of Water Resources Research.

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Note to editors: The study abstract follows.

“Improved Water Allocation Utilizing Probabilistic Climate Forecasts: Short Term Water Contracts in a Risk Management Framework”

Authors: A. Sankarasubramanian, North Carolina State University; Upmanu Lall, Columbia University; Francisco Assis Souza Filho, Federal University of Fortaleza; Ashish Sharma, University of New South Wales

Published: Nov. 11, 2009, Water Resources Research

Abstract: Probabilistic, seasonal to inter-annual streamflow forecasts are becoming increasingly available as the ability to model climate teleconnections is improving. However, water managers and practitioners have been slow to adopt such products, citing concerns with forecast skill. Essentially, a management risk is perceived in “gambling” with operations using a probabilistic forecast, while a system failure upon following existing operating policies is “protected” by the official rules or guidebook. In the presence of a prescribed system of prior allocation of releases under different storage or water availability conditions, the manager has little incentive to change. Innovation in allocation and operation is hence key to improved risk management using such forecasts. A participatory water allocation process that can effectively use probabilistic forecasts as part of an adaptive management strategy is introduced here. Users can express their demand for water through statements that cover the quantity needed at a particular reliability, the temporal distribution of the “allocation”, the associated willingness to pay, and compensation in the event of contract non-performance. The water manager then assesses feasible allocations using the probabilistic forecast that try to meet these criteria across all users. An iterative process between users and water manager could be used to formalize a set of short term contracts that represent the resulting prioritized water allocation strategy over the operating period for which the forecast was issued. These contracts can be used to allocate water each year/season beyond long term contracts that may have precedence. Thus, integrated supply and demand management can be achieved. In this paper, a single period multi-user optimization model that can support such an allocation process is presented. The application of this conceptual model is explored using data for the Jaguaribe Metropolitan Hydro System in Ceara, Brazil. The performance relative to the current allocation process is assessed in the context of whether such a model could support the proposed short term contract based participatory process. A synthetic forecasting example is also used to explore the relative roles of forecast skill and reservoir storage in this framework.

It is no surprise that the mechanical properties of silicon nanowires are different from “bulk” – or regular size – silicon materials, because as the diameter of the wires decrease, there is an increasing surface-to-volume ratio. Unfortunately, experimental results reported in the literature on the properties of silicon nanowires have reported conflicting results. So the NC State researchers set out to quantify the elastic and fracture properties of the material.

“The mainstream semiconductor industry is built on silicon,” says Dr. Yong Zhu, assistant professor of mechanical engineering at NC State and lead researcher on this project. “These wires are the building blocks for future nanoelectronics.” For this study, researchers set out to determine how much abuse these silicon nanowires can take. How do they deform – meaning how much can you stretch or warp the material before it breaks? And how much force can they withstand before they fracture or crack? The researchers focused on nanowires made using the vapor-liquid-solid synthesis process, which is a common way of producing silicon nanowires.

Zhu and his team measured the nanowire properties using in-situ tensile testing inside scanning electron microscopy. A nanomanipulator was used as the actuator and a micro cantilever used as the load sensor. “Our experimental method is direct but simple,” says Qingquan Qin, a Ph.D. student at NC State and co-author of the paper. “This method offers real-time observation of nanowire deformation and fracture, while simultaneously providing quantitative stress and strain data. The method is very efficient, so a large number of specimens can be tested within a reasonable period of time.”

As it turns out, silicon nanowires deform in a very different way from bulk silicon. “Bulk silicon is very brittle and has limited deformability, meaning that it cannot be stretched or warped very much without breaking.” says Feng Xu, a Ph.D. student at NC state and co-author of the paper, “But the silicon nanowires are more resilient, and can sustain much larger deformation. Other properties of silicon nanowires include increasing fracture strength and decreasing elastic modulus as the nanowire gets smaller and smaller.”

The fact that silicon nanowires have more deformability and strength is a big deal. “These properties are essential to the design and reliability of novel silicon nanodevices,” Zhu says. “The insights gained from this study not only advance fundamental understanding about size effects on mechanical properties of nanostructures, but also give designers more options in designing nanodevices ranging from nanosensors to nanoelectronics to nanostructured solar cells.”

The study, “Mechanical Properties of Vapor-Liquid-Solid Synthesized Silicon Nanowires,” was co-authored by Zhu, Xu, Qin, University of Michigan (UM) researcher Wei Lu and UM Ph.D. student Wayne Fung. The study is published in the Nov. 11 issue of Nano Letters, and was funded by grants from the National Science Foundation and NC State.

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Note to editors: The study abstract follows.

“Mechanical Properties of Vapor-Liquid-Solid Synthesized Silicon Nanowires”

Authors: Yong Zhu, Feng Xu, Qingquan Qin, North Carolina State University; Wayne F. Fung, Wei Lu, University of Michigan.

Published: November 11, 2009, Nano Letters

Abstract: The Young’s modulus and fracture strength of silicon nanowires with diameters between 15 and 60 nm and lengths between 1.5 and 4.3 micrometers were measured. The nanowires, grown by the vapor-liquid-solid process, were subjected to tensile tests in situ inside a scanning electron microscope. The Young’s modulus decreased while the fracture strength increased up to over 12 GPa, as the nanowire diameter decreased. The fracture strength also increased with the decrease of the side surface area; the increase rate for the chemically synthesized silicon nanowires was found to be much higher than that for the microfabricated silicon thin films. Repeated loading and unloading during tensile tests demonstrated that the nanowires are linear elastic until fracture without appreciable plasticity.

“Some companies commit financial statement fraud, and a good portion of those overstate their revenue,” says Dr. Joe Brazel, an assistant professor of accounting at NC State and co-author of the research. “They’re able to do that because they can manipulate the accounting. But there are NFMs that can’t be manipulated as easily.” These NFMs include the number of employees, as well as industry-specific measures, such as the square footage of facilities in the manufacturing sector, the number of retail outlets in the retail sector or the number of hospital visits in the hospital industry.

Brazel explains that companies may fraudulently claim inflated revenues in order to meet market expectations and maintain, or improve, their stock price – as well as protecting company management from criticism.

But, Brazel says, “when these firms commit fraud, we found a huge gap between their reported revenue growth and related NFMs – their revenue was up, but the NFMs were either flat or declining. And when you looked at their competitors, you see revenue growth and NFMs closely correlated. So when you see that gap, it’s a red flag – you need to take a closer look.”

For example, Brazel says that researchers found a difference of approximately 4 percent between revenue growth and employee growth in companies that did not commit fraud. The difference between revenue growth and employee growth in fraudulent companies was 20 percent. “It’s pretty obvious, when you look at it,” Brazel says.

Furthermore, the NFM data are easy to find. Brazel explains that each company’s NFMs and revenue numbers are disclosed in the same financial filings, which the company is required to submit each year to the U.S. Securities and Exchange Commission.

The researchers evaluated 220 companies when evaluating employee growth versus revenue growth  – 110 companies that were known to have committed fraud between 1994 and 2002, and 110 that had not. Similarly, they looked at 100 companies when evaluating other NFMs, 50 fraudulent and 50 that had not committed fraud.

The researchers are now in the process of developing an online tool that will perform the NFM analysis, as well as conducting experimental studies with auditors to help detect fraud and with investors to help make wise investment decisions.

The paper, “Using Nonfinancial Measures to Assess Fraud Risk,” was co-authored by Brazel, Dr. Keith Jones of George Mason University and Dr. Mark Zimbelman of Brigham Young University. The work was funded by the Institute of Internal Auditors Research Foundation and the Financial Industry Regulatory Authority Investor Education Foundation, and will be published in the Journal of Accounting Research later this year.

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Note to Editors: The research abstract follows.

“Using Nonfinancial Measures to Assess Fraud Risk”

Authors: Joseph F. Brazel, North Carolina State University; Keith L. Jones, George Mason University; Mark F. Zimbelman, Brigham Young University

Published: Winter 2009, Journal of Accounting Research

Abstract: This study examines whether auditors can effectively use nonfinancial measures (NFMs) to assess the reasonableness of financial performance and, thereby, help detect financial statement fraud (hereafter, fraud). If auditors or other interested parties (e.g., directors, lenders, investors, or regulators) can identify NFMs (e.g., facilities growth) that are correlated with financial measures (e.g., revenue growth), inconsistent patterns between the NFMs and financial measures can be used to detect firms with high fraud risk. We find that the difference between financial and nonfinancial performance is significantly greater for firms that committed fraud than for their nonfraud competitors. We also find that this difference is a significant fraud indicator when included in a model containing variables that have previously been linked to the likelihood of fraud. Overall, our results provide empirical evidence suggesting that NFMs can be effectively used to assess the likelihood of fraud.

Newspapers and magazines often embellish charts or graphs to draw attention to them or to highlight information. Some experts describe these graphic embellishments as “chart junk,” which they argue detracts from a graph or chart’s effectiveness. So, can those graphics be too distracting, making it more difficult or time-consuming to read a graph accurately?

Researchers from NC State and the University of Idaho show that the answer is yes, and no.

When people look at charts or graphs, two things happen. In the first stage, a person quickly (and unconsciously) takes in all the elements of the image at the same time. In this stage any contrasting features “pop out” at the viewer, explains Dr. Doug Gillan, co-author of the study and professor and head of psychology at NC State. In the second stage, which is slower and requires some focused attention, the viewer examines each component of the graph or chart separately.

“Imagine a bar graph showing the number of ACC championships won by each school’s basketball team,” Gillan says. “In the second stage the viewer is examining each bar in the graph to see which team has won the most championships.”

To determine whether design elements – such as background pictures – affect a viewer’s ability to read a graph, the researchers ran an experiment using rectangular bar graphs. They tested how accurately people could read the bar graph when it was presented against three different backgrounds: a blank background, a background filled with rectangles, and a background filled with circles.

The researchers found that people were most accurate when reading the bar graph against a background filled with circles – the contrast between the rectangular bars and the circles made the graph pop out during that first stage. People performed worse when the background was blank, and worst when the bar graph was displayed against a background that contained rectangular shapes.

In other words, background images can actually enhance one’s ability to read a chart or graph – as long as the images contrast with the chart or graph itself. If the background image is too similar, it can actually make it more difficult to read the chart or graph accurately.

Are you listening, USA Today?

The research, “Effects of Graph Backgrounds on Visual Search,” was co-authored by Gillan and Dr. Douglas Sorenson of the University of Idaho. The work was presented Oct. 22 at the 53d Annual Meeting of the Human Factors and Ergonomics Society in San Antonio.

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Note to Editors: The presentation abstract follows.

“Effects of Graph Backgrounds on Visual Search”

Authors: Douglas J. Gillan, North Carolina State University; Douglas Sorenson, University of Idaho

Presented: Oct. 22, 2009, at the 53d Annual Meeting of the Human Factors and Ergonomics Society in San Antonio

Abstract: Tufte (1983) proposed a measure, the data-ink ratio, and a rule that the data-ink ratio be maximized.  The present research tested this rule by examining the effect of the relation between the physical features in the graph indicators and those in the background on graph reading performance.  Eighteen participants performed comparison and difference tasks with bar graphs (rectangular indicators) or line graphs (circular indicators). Graphs had no background, a pictorial background containing circles, or a pictorial background containing rectangles.  Accuracy was highest for the difference task when the features in the indicators and background of a graph differed.  The role of preattentive processing during visual search in graph reading and the pop-out effect that occurs when background and search target features differ are discussed.

To get a swish rather than a brick, you need the best possible conditions for releasing the basketball from your hand, say Drs. Chau Tran and Larry Silverberg, mechanical and aerospace engineers at NC State and co-authors of a peer-reviewed study.

The engineers used hundreds of thousands of three-dimensional computer simulations of basketball free-throw trajectories to arrive at their conclusions. After running the simulations, Tran and Silverberg arrived at a number of major recommendations to improve free-throw shooting.

First, the engineers say that shooters should launch the shot with about three hertz of back spin. That translates to the ball making three complete backspinning revolutions before reaching the hoop. Back spin deadens the ball when it bounces off the rim or backboard, the engineers assert, giving the ball a better chance of settling through the net.

Where to aim? Tran and Silverberg say you should aim for the back of the rim, leaving close to 5 centimeters – about 2 inches – between the ball and the back of the rim. According to the simulations, aiming for the center of the basket decreases the probabilities of a successful shot by almost 3 percent.

The engineers say that the ball should be launched at 52 degrees to the horizontal. If you don’t have a protractor in your jersey, that means that the shot should, at the highest point in its arc to the basket, be less than 2 inches below the top of the backboard.

Free-throw shooters should also release the ball as high above the ground as possible, without adversely affecting the consistency of the shot; release the ball so it follows the imaginary line joining the player and the basket; and release the ball with a smooth body motion to get a consistent release speed.

“Our recommendations might make even the worst free-throw shooters – you know who you are, Shaquille O’Neal and Ben Wallace – break 60 percent from the free-throw line,” Silverberg says with tongue firmly in cheek. “A little bit of physics and a lot of practice can make everyone a better shooter from the free-throw line.”

The engineers used a men’s basketball for the study; it is heavier and a bit larger than basketballs used in women’s games. They also assumed that the basketball player doing the shooting was 6 feet 6 inches tall, and that he released the ball 6 inches above his head, so the “release height” was set to 7 feet. The free-throw line is 15 feet from the backboard, a cylinder-shaped opening that is 10 feet off the ground. Though it looks smaller, the diameter of a regulation basketball hoop is 18 inches; the diameter of a men’s basketball is a bit more than 9 inches.

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To give some idea of the scale of the computer malware problem, a recent Internet security threat report showed a 1,000 percent increase in the number of new malware signatures extracted from the in-the-wild malware programs found from 2006 to 2008. Of these malware programs, “rootkits are one of the stealthiest,” says Dr. Xuxian Jiang, assistant professor of computer science at NC State and a co-author of the research. “Hackers can use rootkits to install and hide spyware or other programs. When you start your machine, everything seems normal but, unfortunately, you’ve been compromised.”

Rootkits typically work by hijacking a number of “hooks,” or control data, in a computer’s operating system. “By taking control of these hooks, the rootkit can intercept and manipulate the computer system’s data at will,” Jiang says, “essentially letting the user see only what it wants the user to see.” As a result, the rootkit can make itself invisible to the computer user and any antivirus software. Furthermore, the rootkit can install additional malware, such as programs designed to steal personal information, and make them invisible as well.

In order to prevent a rootkit from insinuating itself into an operating system, Jiang and the other researchers determined that all of an operating system’s hooks need to be protected. “The challenging part is that an operating system may have tens of thousands of hooks – any of which could potentially be exploited for a rootkit’s purposes,” Jiang says, “Worse, those hooks might be spread throughout a system. Our research leads to a new way that can protect all the hooks in an efficient way, by moving them to a centralized place and thus making them easier to manage and harder to subvert.”

Jiang explains that by placing all of the hooks in one place, researchers were able to simply leverage hardware-based memory protection, which is now commonplace, to prevent hooks from being hijacked. Essentially, they were able to put hardware in place to ensure that a rootkit cannot modify any hooks without approval from the user.

The research, “Countering Kernel Rootkits with Lightweight Hook Protection,” will be presented at the 16th ACM Conference on Computer and Communications Security in Chicago, Nov. 12. The study’s co-authors are Jiang, Dr. Peng Ning, associate professor of computer science at NC State, NC State Ph.D. student Zhi Wang and Weidong Cui of Microsoft Research.

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Note to Editors: The presentation abstract follows.

“Countering Kernel Rootkits with Lightweight Hook Protection”

Authors: Zhi Wang, Xuxian Jiang, Peng Ning, North Carolina State University; Weidong Cui, Microsoft Research

Presented: Nov. 12, 2009, at the 16th ACM Conference on Computer and Communications Security in Chicago.

Abstract: Kernel rootkits have posed serious security threats due to their stealthy manner. To hide their presence and activities, many rootkits hijack control flows by modifying control data or hooks in the kernel space. A critical step towards eliminating rootkits is to protect such hooks from being hijacked. However, it remains a challenge because there exist a large number of widely-scattered kernel hooks and many of them could be dynamically allocated from kernel heap and co-located together with other kernel data. In addition, there is a lack of flexible commodity hardware support, leading to the so-called protection granularity gap – kernel hook protection requires byte-level granularity but commodity hardware only provides page-level protection. To address the above challenges, in this paper, we present Hook-Safe, a hypervisor-based lightweight system that can protect thousands of kernel hooks in a guest OS from being hijacked. One key observation behind our approach is that a kernel hook, once initialized, may be frequently “read”-accessed, but rarely “write”-accessed. As such, we can relocate those kernel hooks to a dedicated page-aligned memory space and then regulate accesses to them with hardware-based page-level protection. We have developed a prototype of HookSafe and used it to protect more than 5,900 kernel hooks in a Linux guest. Our experiments with nine real-world rootkits show that HookSafe can effectively defeat their attempts to hijack kernel hooks. We also show that HookSafe achieves such a large-scale protection with a small overhead (e.g., around 6% slowdown in performance benchmarks).

“There has been a great deal of research into the use of manufactured carbon nanomaterials in various products, but there are still a lot of questions about how these materials will interact with biological systems,” says Dr. Nancy Monteiro-Riviere, a professor of investigative dermatology and toxicology at the Center for Chemical Toxicology Research and Pharmacokinetics at NC State and lead investigator of the study. “There is a crucial need to understand how these manufactured carbon nanomaterials will act once they are in the body – particularly where environmental or occupational exposure can occur.”

The two-year research project, which is being funded by NIH at approximately $658,000, has several specific goals. First, the researchers will determine how and whether the size and surface charge of four fullerenes – or specifically shaped carbon nanoparticles – effects how the fullerenes interact with the body. “Our hypothesis is that the size and charge of these fullerenes will dictate how the nanoparticles are absorbed by the body, how they are distributed within the body, how the body metabolizes the nanoparticles and – ultimately – how and whether the body can eliminate the nanoparticles,” says Monteiro-Riviere.

A second goal is to determine how fullerene size and surface charge affect the distribution of the nanoparticles in the body’s organs and plasma, when the fullerenes are injected intravenously. This component of the study will be performed in animal models that are well understood, and where the findings can then be extrapolated to humans. Researchers will also identify any adverse health effects resulting from acute exposure to the nanomaterials.

Finally, the researchers will assess how the body absorbs fullerenes when exposed to the nanomaterials orally or through abraded skin – two routes of exposure that are particularly relevant to real-world scenarios, such as exposure in the workplace.

“The work being done in this project will not only improve our understanding of how nanomaterials behave in the body, but will also help us identify in vitro assays, which can be performed in a laboratory, that predict how the nanomaterials will behave in the body,” says Monteiro-Riviere.

NC State’s research team working on the project includes Drs. Nancy Monteiro-Riviere, Jim Riviere, Burroughs Wellcome Fund Distinguished Professor of Pharmacology and director of the Center for Chemical Toxicology Research and Pharmacokinetics, Xin Xia, research assistant professor of pharmacology, and Keith Linder, assistant professor of pathology.

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