Wireless Vs. Wireless

3G and Wi-Fi are the two main mobile communications technologies today, but until recently they have been complementary services, the former offering users network access through cell phone masts forming a wide-area network (WAN), the latter based on hot-spot connections through a local-area network (LAN). Both then provide connectivity to the web, email and other services.

With the advent of Wi-Fi based municipal wireless networks, such as that launched by one telecommunications company in New York's Times Square and by a well-known supermarket chain across all its stores, there is, say Seungjae Shin of Mississippi State University -- Meridian and Martin Weiss of the University of Pittsburgh, Pennsylvania, a strong possibility that Wi-Fi will compete with the 3G cell phone network in city areas and perhaps even become a substitute.

Their study appears in theInternational Journal of Mobile Communications.

Shin and Weiss point out that substituting Wi-Fi for 3G would cut costs of peripatetic workers and others who need access to broadband internet services when not at devices connected directly to the internet, such as desktop computers. They have now used game theory to investigate how 3G and Wi-Fi would actually compete for users given a particular set of circumstances, costs, and availability. Their findings demonstrate which of the two technologies would be the winner in terms of market penetration and coverage percentages.

Their analysis shows that the 3G network would become more profitable as Wi-Fi coverage percentage increases, and that 3G is more favorable in areas of high population density. In contrast, Wi-Fi has the advantage when the market has a high penetration rate but a low coverage area. Until now, municipal wireless networks have not being active in big cities across the USA and the 3G cell phone service itself is relatively new and only being adopted as so-called smart phones become more prevalent and replaces old-style cell phones. As such, there has been little competition between the two wireless communications protocols.

The team suggests that as the market matures and competition increases between the two network service systems, the detailed results of the analysis will help to serve as a guideline for providers of either system to ensure ubiquitous mobile internet access.

Brain Responds More to Close Friends, Imaging Study Shows

People's brains are more responsive to friends than to strangers, even if the stranger has more in common, according to a study in the Oct. 13 issue of The Journal of Neuroscience. Researchers examined a brain region known to be involved in processing social information, and the results suggest that social alliances outweigh shared interests.

In a study led by graduate student Fenna Krienen and senior author Randy Buckner, PhD, of Harvard University, researchers investigated how the medial prefrontal cortex and associated brain regions signal someone's value in a social situation. Previous work has shown that perceptions of others' beliefs guide social interactions. Krienen and her colleagues wondered whether these brain regions respond more to those we know, or to those with whom we share similar interests.

"There are psychological and evolutionary arguments for the idea that the social factors of 'similarity' and 'closeness' could get privileged treatment in the brain; for example, to identify insiders versus outsiders or kin versus non-kin," Krienen said. "However, these results suggest that social closeness is the primary factor, rather than social similarity, as previously assumed."

The researchers first imaged the brain activity of 32 participants as they judged how well lists of adjectives described their personalities. This helped to identify brain regions that respond to personally relevant information. In separate experiments, 66 different participants provided personality information about themselves and two friends -- one friend whom they believed had similar preferences and one believed to be dissimilar.

The authors made up biographies of similar and dissimilar strangers for each volunteer based on their personality profiles. Then, while in a scanner, they played a game similar to the TV show "The Newlywed Game," in which participants predicted how another person would answer a question. For example, would a friend or stranger prefer an aisle or window seat on a flight?

The authors found activity in the medial prefrontal cortex increased when people answered questions about friends. Notably, whether the person had common interests made no difference in brain response.

"In all experiments, closeness but not similarity appeared to drive responses in medial prefrontal regions and associated regions throughout the brain," Krienen said. "The results suggest social closeness is more important than shared beliefs when evaluating others."

Read Montague, PhD, of Baylor College of Medicine, an expert on decision-making and computational neuroscience, said the study's large number of participants and experimental approach makes it a solid contribution to the field. "The authors address an important component of social cognition -- the relevance of people close to us," Montague said.

New Materials Could Replace Costly Gold in Electrical Applications

Researchers at the University of Connecticut, partnering with United Technologies Research Center engineers, have modeled and developed new classes of alloy materials for use in electronic applications that will reduce reliance on costly gold and other precious metals.

The research appears online in the October 12^th issue of the journalApplied Physics Letters.

With the price of gold currently hovering around $1,340 per ounce, manufacturers across the globe, including Connecticut's United Technologies Corporation (UTC), are scrambling for alternatives to the costly noble metals that are widely used in electronic applications, including gold, platinum, rhodium, palladium and silver. What makes these metals attractive is their combination of excellent conductivity paired with resistance to oxidation and corrosion. Finding less costly but equally durable and effective alternatives is an important aim.

Mark Aindow and S. Pamir Alpay, UConn professors of materials science and engineering, and Joseph Mantese, a UTRC Fellow, have developed new classes of materials that behave much like gold and its counterparts when exposed to the oxidizing environments that degrade traditional base metals. Their research was funded by a grant from the U.S. Army Research Office.

The team has investigated nickel, copper and iron -- inexpensive materials that may offer promise. Based on their research, they have laid out the theory and demonstrated experimentally the methodology for improving the electrical contact resistance of these base metals. Aindow said, "We used a combination of theoretical analysis to select the appropriate constituents, and materials engineering at the atomic level to create designer materials."

The researchers synthesized various alloys, using inexpensive base metals. Higher conductivity native oxide scales can be achieved in these alloys through one of three processes: doping to enhance carrier concentration, inducing mixed oxidation states to give electron/polaron hopping, and/or phase separation for conducting pathways.

Their work has demonstrated an improvement in contact resistance of up to one-million-fold over that for pure base metals, so that base metal contacts can now be prepared with contact properties near those of pure gold.

Bonus points for higher level Maths

Ireland's universities have agreed to give bonus points to Leaving Certificate students for higher level Maths.

This afternoon, the heads of the seven universities decided at a meeting to award an additional 25 points to students who get a D or more in the higher level paper.

A spokesman for the Irish Universities Association said this was to target students who drop from higher level to ordinary level at the last minute and also students who feel it is not worth their while to pursue the higher level course.

Tánaiste and Minister for Education Mary Coughlan said 'the introduction of bonus points for maths sends a clear signal to our leaving certificate students about the importance we attach to the study of maths.'

Employer's group IBEC also welcomed the move.