Published reports have shown that Asian-Indians have a higher rate of coronary heart disease than other ethnic groups, and their small arteries may be to blame. Researchers from Jamaica Hospital Medical Center in New York explored the differences in the sizes of coronary arteries between Asian-Indians, Caucasians, and African-Americans (n=273). Results showed that ethnic group significantly predicted the diameter of all arteries. Even after controlling for other risk factors, the left anterior descending and left circumflex arteries were significantly smaller in Asian-Indians than other ethnic groups.

Despite increased awareness of pulmonary arterial hypertension (PAH), the disease is being diagnosed later and in women who are reaching middle age, according to research from Baylor College of Medicine in Texas. The researchers looked at data from the current REVEAL registry compared with the original National Institutes of Health registry, the French Registry, and a large, single-center US registry. The REVEAL registry confirms that in the 21st century, the US population of patients with PAH is older (mean age of 48), with a higher female preponderance of PAH (4:1) than reported previously. In addition, despite increased awareness of PAH, the time from symptoms to diagnosis has increased by 10 months.

The use of MP3 players may be an effective way for physicians to improve their recognition of the different types of heart murmurs. In a new study by researchers at Temple University School of Medicine, 255 general internists took a pretest consisting of five heart murmurs played in random order. They then listened to audio files of five basic murmurs on an MP3 player, while viewing posters with phonocardiograms of each sound. The audio files consisted of 200 repetitions of each of the five murmurs played during a single 30-minute session. All participants took a posttest consisting of the same murmurs played in a random order. The murmurs used in the training session were simulated heart sounds, while the murmurs used for both the pretest and posttest were human heart sounds. Participants’ correct answers improved from 53.2 on the pretest to 78.9 on the posttest.

Female hospital staff members have more difficulty performing adequate chest compressions (CC) than male hospital staff. Researchers from Albert Einstein College of Medicine in New York compared the CC technique of 28 male and 30 female medical housestaff using a patient simulator, before and after CC training. Subjects also went through a posttraining endurance test where they attempted to perform adequate CC for 120 seconds or until fatigue prevented further effort. Prior to training, 50 percent of the male group performed adequate CC, while none of the female group performed adequate CC. Post-training, 89 percent of the male group performed adequate CC and 37 percent of the female group performed adequate CC. There was no correlation between body mass index and adequate CC in either group, however taller females performed better CC than shorter females. Regardless of gender, only 14 percent of subjects were able to maintain adequate CC for 120 seconds, the recommended guideline for one cycle of compressions.

Hospitalized patients who undergo repeated in-hospital CPR have a high mortality rate. Researchers from Western Pennsylvania Hospital in Pittsburgh reviewed the charts of 151 patients, aged 25 to 99 years, who underwent CPR as a consequence of cardiopulmonary arrest. Out of these patients, only 16 (eight men and eight women) required repeated CPR after the first successful attempt. None of these patients survived to the time of hospital discharge. Researchers suggest that patients who are seriously ill, as well as their families, should be well informed regarding the expected outcome of multiple in-hospital resuscitation events.

Difficulty falling asleep may be associated with a lower risk of hypertension than researchers once believed. Researchers from the University of Kentucky proposed the hypothesis that insomnia would predict hypertension, particularly among African-Americans. Data were analyzed from 1,419 older individuals with a mean age of 73.4 years who were not hypertensive at baseline. Researchers found that difficulty falling asleep, alone or in combination with other sleep complaints, predicted a significantly reduced risk of incident hypertension for men who were not African-American over a 6-year period of follow up. Furthermore, insomnia complaints did not predict hypertension in women or in African-Americans, although there may not have been enough power to show a significant association for African-Americans.

New research shows that the erectile dysfunction drug, tadalafil, may be an effective adjunct therapy for patients with pulmonary arterial hypertension (PAH). Italian researchers randomized 405 patients with PAH, of whom 53 percent were taking concomitant bosentan, to two study arms. The groups received either tadalafil or placebo orally once daily as monotherapy or as add-on therapy to bosentan. Compared with placebo, tadalafil, 40 mg, increased 6-minute walk distance, delayed the time to clinical worsening, and improved six of the eight short form (SF)-36 domains. In addition, tadalafil, 40 mg, increased cardiac output and reduced pulmonary artery pressures and pulmonary vascular resistance compared with baseline. Discontinuation due to adverse events was low (11 percent for tadalafil vs. 16 percent for placebo). Researchers conclude that tadalafil may provide an effective oral, once-daily therapy that can be combined with bosentan therapy for patients with PAH.

Patients receiving donated lungs may develop arrhythmias, including atrial fibrillation. Researchers from Baylor College of Medicine in Texas reviewed the charts of all lung transplant recipients in 2006 and 2007. Of the 75 patients who underwent lung transplant, 38 percent developed arrhythmias within 30 days of transplantation. The most common arrhythmia was atrial fibrillation, followed by atrial flutter. Researchers speculate that the donor-derived tissue (atrial cuff or pulmonary vein) is a likely source of the arrhythmias passed to lung recipients.

The first known case of someone born without the ability to recognise voices has been reported in a paper by UCL (University College London) researchers, in a study of a rare condition known as phonagnosia. The UCL team are calling for other people to come forward if they think they have also grown up with the condition.

The case study, reported in the online issue of the journal Neuropsychologia, is of a woman who is unable to recognise people by their voice, including her own daughter whom she has great difficulty identifying over the phone. The woman, known as KH, avoids answering the phone where possible, and for many years has only answered ‘booked calls’. KH books calls with friends or co-workers, so she knows who to expect when the telephone rings at a certain time. In the 1980s, KH had a job in which she introduced herself with a different form of her first name so she would know that it was someone related to her job when they called and asked for her using that name.

KH, a 60-year old successful professional woman, was aware from an early age that there was something she couldn’t do that others clearly could. But it was only when reading an article in a popular science magazine years later that KH finally understood her lifelong problem. The article discussed prosopagnosia, a condition where people have severe difficulty recognising faces. KH realized she might have the vocal analogue of prosopagnosia, and contacted the magazine, who put her in touch with UCL’s Dr Brad Duchaine.

Dr Brad Duchaine, co-author of the paper, says: “Occasionally, people have experienced problems recognising voices following a stroke or brain damage, but this is the first documented case of someone growing up with this condition. We suspect that there are other people out there with similar problems, and we’d like to get in touch with them. If you think you might be phonagnosic, please contact us.”

“Voice recognition may not seem as important as face recognition, given that failing to recognise someone in front of you can cause much more social anxiety than not recognising them over the phone. Yet we rely on voice recognition in our day-to-day lives, to identify people on the phone or those speaking on the radio.”

In the study, Dr Duchaine and Lucia Garrido of the UCL Institute of Cognitive Neuroscience presented KH with a series of tasks involving the recognition of faces, voices, vocal emotions, speech perception and music. KH struggled to recognise the voices of famous actors and politicians, and also had difficulty learning and recognising new voices. Compared to a control group of volunteers, nearly all of whom identified the voices of Margaret Thatcher, David Beckham, Dawn French, Chris Tarrant, Joanna Lumley, Sean Connery and Ann Widdecombe, KH was only able to identify the voice of Sean Connery.

However, KH performed well on nearly all other tasks. For example, in a test involving emotional sounds - achievement/triumph, amusement, anger, disgust, fear, pleasure, relief, sadness and surprise - KH could identify the emotional state of the person speaking roughly 80 per cent of the time, similar to the control group. KH also did well on all music tasks, identifying famous tunes and discriminating between instruments. KH says that she is able to enjoy and appreciate music, though she usually doesn’t recognize singers.

Phonagnosia has only been documented so far in people with brain lesions in the right hemisphere following a stroke or brain damage, and the mechanisms behind it are not well understood. In KH’s case, a MRI brain scan showed no evidence of brain damage in regions associated with voice or auditory perception, and her hearing abilities were found to be normal.

About 5 million people in the United States suffer from heart failure (HF). While some reports indicate that changes to diet can reduce HF risk, few large, prospective studies have been conducted. In a new study researchers observed over 14,000 participants for more than 13 years and found that whole grain consumption lowered HF risk, while egg and high-fat dairy consumption raised risk. Other food groups did not directly affect HF risk. The results are published in the November 2008 issue of the Journal of the American Dietetic Association.Diet is among the prominent lifestyle factors that influence major HF risk factors: coronary artery disease, obesity, diabetes and insulin resistance and hypertension. Using data from the Atherosclerosis Risk in Communities (ARIC) study, researchers from the Division of Epidemiology and Community Health, University of Minnesota and the Department of Epidemiology and Cardiovascular Diseases Program, University of North Carolina, analyzed the results of baseline exams of more than 14,000 White and African American adults conducted in 1987-89, with follow-up exams completed during 1990-92, 1993-95, and 1996-98. Four field centers participated in the study: Forsyth County, NC; Jackson, MS; northwest Minneapolis suburbs, MN; and Washington County, MD. The study also collected demographic characteristics and lifestyle factors, as well as other medical conditions such as cardiovascular disease, diabetes and hypertension.

Writing in the article, Jennifer A. Nettleton, Ph.D., states, “Although risk estimates were modest (7% lower risk per 1-serving increase in whole grain intake; 8% greater risk per 1-serving increase in high-fat dairy intake; 23% greater risk per 1-serving increase in egg intake), the totality of literature in this area suggests it would be prudent to recommend that those at high risk of HF increase their intake of whole grains and reduce intake of high-fat dairy and eggs, along with following other healthful dietary practices consistent with those recommended by the American Heart Association.”

Ants prefer salty snacks to sugary ones, at least in inland areas that tend to be salt-poor, according to a new study published this week in the journal Proceedings of the National Academy of Sciences.Ecologists from the University of California, Berkeley, the University of Arkansas at Little Rock (UALR) and the University of Oklahoma tested the salt versus sugar preferences of ants from North, Central and South America, using ant populations at varying distances from the ocean. While ocean spray and storms can spread salt tens of miles from the coast, areas farther inland are often deprived of salt, and the researchers suspected they might find different taste choices between coastal and inland ants.

In fact, they found that ants living more than 60 miles inland often preferred a 1 percent salt solution over a sugar solution 10 times more concentrated. This was true primarily for plant-eating ants, however. Carnivorous ants, such as fire ants, apparently get enough salt from their prey. For similar reasons, grazing animals such as bison and deer seek out salt licks to complement their salt-poor vegetarian diet, while carnivores like mountain lions and wolves get all the salt they need from bloody meat.

“Attractiveness to salt increases with distance from the ocean,” said co-author Robert Dudley, UC Berkeley professor of integrative biology. “It’s really fascinating that we see a pattern on this grand, continental scale.”

“Ants will always go for the sugar because they need sugar to provide the basic energy for life and for their activity,” said co-author Steve Yanoviak, an assistant professor of biology at UALR. “But when you see ants spending increasing amounts of time or employing increasingly large numbers of individuals foraging for salt, it suggests that salt is a resource that is limiting to them. Their ability to be competitive and maintain themselves in different environments could be limited by a resource like salt.”

What holds true for ants may well be true of all insects and even microbes, the researchers argue, pointing to a role for salt, or sodium chloride, in the ecosystem that has not been recognized before.

“One implication of this study is that even basic ecosystem processes, like the whole carbon cycle, may be influenced by the availability of sodium,” said ant ecologist and lead author Michael E. Kaspari of the University of Oklahoma in Norman. “If you want to have a nice lawn or grow vegetables, you add the big-three nutrients: nitrogen, phosphorous and potassium. Salt is almost like fertilizer for animals.”

Kaspari plans to test whether spraying salt on the litter of the forest floor cranks up ecosystem activity and decomposition, releasing more carbon dioxide, in the same way salty Gatorade improves the performance of sports teams.

Dudley, Yanoviak and Kaspari instigated the study after spending several “intolerable” days doing research on insects in the treetops of Peru, near the headwaters of the Amazon River and far from the Pacific Ocean - an area that contrasts starkly with the relatively pest-free treetop conditions in Panama, where no place is more than 25 kilometers from the ocean. The three researchers were tossing ants from the tree canopy to study the insects’ ability to glide.

“We were working up in the trees in the Western Amazon on hot, still days, and tiny sweat bees were swarming all around and flying up our noses, something I hadn’t noticed in Panama,” he said. “Why were there so many?”

Because ants are easier to study than bees, Kaspari designed a “cafeteria experiment” that offered ants a choice between salt and sugar. The researchers tested not only Peruvian and Panamanian ants, but also ants from Costa Rica, Arkansas, Oklahoma, Arizona and Florida. In all, they conducted experiments at 17 sites, ranging from rainforest trails in the Amazon to Kaspari’s front yard.

“What makes this experiment so elegant is Mike’s simple design: fill up vials with sugar or salt and drop them along the trail in the forest,” Yanoviak said. “What we didn’t realize was how tiring it is to bend over and pick up more than a hundred vials.”

By merely counting the ant species attracted to cotton balls soaked in salt or sucrose (table sugar) solutions, they discovered that herbivorous or omnivorous species more than 10-100 kilometers (6-60 miles) from the ocean preferred salt over sugar, and the farther inland, the greater the preference for salt. Ants living mostly on green vegetation had a greater preference for salt than did those living among the decaying leaves of the forest floor, while carnivorous ants had little preference for salt over sugar.

Activity at sugar baits was highest between 10 and 100 kilometers from the shore, suggesting that this near-coastal belt may be a sweet spot for animals with “just enough salt to meet requirements, but not enough to be toxic or inhibit the plants they feed on,” Kaspari said.

Animals’ need for salt stems from the high sodium concentrations needed to maintain the body’s nerve and muscle activity and water balance, Dudley said. Animal blood and fluids, including those of humans, are 100 to 1,000 times saltier than the average salt concentration - 1 milligram of sodium per kilogram of weight - in terrestrial plants.

Meat eaters get adequate salt in the diet, but animals that rely primarily on plants for food must seek out environmental sources: human settlements have historically been near supplies of salt; grazing animals require natural or human-supplied salt licks; gorillas look for salt in decaying logs; butterflies cluster around evaporating pools of urine to obtain salt; and some crickets are known to cannibalize their brethren for salt.

Similarly, carnivorous ants appear to get sufficient salt from their diet of termites, mites and other forest-floor creatures. Those in the genus Formica, however, which feed on pollen, nectar and plant exudates, show increased attraction to salt with increasing distance from the ocean. In Oklahoma, Kaspari found that carpenter ants preferred sodium chloride over sugar; in Peru and Panama, the gliding ants in the genus Cephalotes showed increasing preference for salt the farther inland they lived.

“One of the most effective ways to attract ants is to put out a Pecan Sandy™, a shortbread cookie. It turns out this is effective not only because they’re packed with fat, protein, carbohydrates and sugar, but because they’re one of the saltiest cookies out there,” Kaspari said.

Dudley noted that the salt content of a specific environment depends on soil, rainfall and other conditions in addition to distance from the ocean, but the new findings show the importance of micronutrients in determining the distribution of animals.

“Here, we’ve established that salt puts limits on an ecosystem, and show that micronutrients can be just as important as macronutrients in some cases,” he said.

The researchers are continuing their study of salt limitations, including experiments to determine whether it is the sodium or the chloride in salt that is essential to the well-being of ants, and possibly to that of other animals.

The teeth and bones of mammals, the protective shells of mollusks, and the needle-sharp spines of sea urchins and other marine creatures are made-from-scratch wonders of nature.Used to crush food, for structural support and for defense, the materials of which shells, teeth and bones are composed are the strongest and most durable in the animal world, and scientists and engineers have long sought to mimic them.

Now, harnessing the process of biomineralization may be closer to reality as an international team of scientists has detailed a key and previously hidden mechanism to transform amorphous calcium carbonate into calcite, the stuff of seashells. The new insight promises to inform the development of new, superhard materials, microelectronics and micromechanical devices.

In a report today (Oct. 27) in the Proceedings of the National Academy of Sciences (PNAS), a group led by University of Wisconsin-Madison physicist Pupa Gilbert describes how the lowly sea urchin transforms calcium carbonate — the same material that forms “lime” deposits in pipes and boilers — into the crystals that make up the flint-hard shells and spines of marine animals. The mechanism, the authors write, could “well represent a common strategy in biomineralization….”

“If we can harness these mechanisms, it will be fantastically important for technology,” argues Gilbert, a UW-Madison professor of physics. “This is nature’s bottom-up nanofabrication. Maybe one day we will be able to use it to build microelectronic or micromechanical devices.”

Gilbert, who worked with colleagues from Israel’s Weizmann Institute of Science, the University of California at Berkeley and the Lawrence Berkeley National Laboratory, used a novel microscope that employs the soft-X-rays produced by synchrotron radiation to observe how the sea urchin builds its spicules, the sharp crystalline “bones” that constitute the animal’s endoskeleton at the larval stage.

Similar to teeth and bones, the sea urchin spicule is a biomineral, a composite of organic material and mineral components that the animal synthesizes from scratch, using the most readily available elements in sea water: calcium, oxygen and carbon. The fully formed spicule is composed of a single crystal with an unusual morphology. It has no facets and within 48 hours of fertilization assumes a shape that looks very much like the Mercedes-Benz logo.

These crystal shapes, as those of tooth enamel, eggshells or snails, are very different from the familiar faceted crystals grown through non-biological processes in nature. “To achieve such unusual — and presumably more functional — morphologies, the organisms deposit a disordered amorphous mineral phase first, and then let it slowly transform into a crystal, in which the atoms are neatly aligned into a lattice with a specific and regular orientation, while maintaining the unusual morphology,” Gilbert notes.

The question the Wisconsin physicist and her colleagues sought to answer was how this amorphous-to-crystalline transition occurs. The sea urchin larval spicule is a model system for biominerals, and the first one in which the amorphous calcium carbonate precursor was discovered in 1997 by the same Israeli group co-authoring the current PNAS paper. A similar amorphous-to-crystalline transition has since been observed in adult sea urchin spines, in mollusk shells, in zebra fish bones and in tooth enamel. The resulting biominerals are extraordinarily hard and fracture resistant, compared to the minerals of which they are made.

“The amorphous minerals are deposited and they are completely disordered,” Gilbert explains. “So the question we addressed is ‘how does crystallinity propagate through the amorphous mineral?’”

To answer it, Gilbert and her colleagues observed spicule development in 2- to 3-day-old sea urchin larvae. The sea urchin spicule is formed inside a clump of specialized cells and begins as the animal lays down a single crystal of calcite in the form of a rhombohedral seed, from which the rest of the spicule is formed. Starting from the crystalline center, three arms extend at 120 degrees from each other, as in the hood ornament of a Mercedes-Benz. The three radii are initially amorphous calcium carbonate, but slowly convert to calcite.

“We tried to find evidence of a massive crystal growth, with a well defined growth front, propagating from the central crystal through the amorphous material, but we never observed anything like that,” Gilbert says. “What we found, instead, is that 40-100 nanometer amorphous calcium carbonate particles aggregate into the final morphology. One starts converting to crystalline calcite, then another immediately adjacent converts as well, and another, and so on in a three-dimensional domino effect. The pattern of crystallinity, however, is far from straight. It resembles a random walk, or a fractal, like lightning in the sky or water percolating through a porous medium,” explains Gilbert.

The new work, according to Gilbert, brings science a key step closer to a thorough understanding of how biominerals form and transform. Knowing the step-by-step process may permit researchers to develop new crystal structures that can be used in applications ranging from new microelectronic devices to medical applications.

Measuring an electrical current in an organism is pretty straightforward. All you need is an electrode. Measuring the flow of chemicals in cells or live tissue, however, is much more difficult because the molecules diffuse, mix with one another, and interact with their surroundings.

So to help understand biological processes, university researchers have invented a new device, the “chemistrode,” that makes it possible to stimulate, record, and analyze molecular signals at high resolution—in terms of precisely when, where, and in what sequence the signals occurred.

The chemistrode will help researchers study any surface that responds to chemical stimulation, including cells, tissue, biofilms and catalytic surfaces. It may also help neurologists, cardiologists, and endocrinologists study and diagnose diseases, according to those who developed the device in the Ismagilov Lab in the Department of Chemistry at the University of Chicago. Researchers in the Lab have already used it to measure how a single murine islet responds to glucose.

The developers have begun to apply for a patent on the new device, and their research describing it will be published online Oct. 27, 2008, by the Proceedings of the National Academy of Science. (The paper will appear in the print version of the prestigious journal on Nov. 4, 2008.)

“An analogue of the electrode, the chemistrode is a droplet-base microfluidic device that will provide exciting opportunities to study stimulus-response dynamics in chemistry and biology,” said Rustem Ismagilov, Associate Professor in Chemistry, who conceived the device, coined its name, and heads up the team that developed it.

Previous techniques for stimulating and measuring chemical reactions in organisms relied on laminar flow, which allows the chemicals in question to intermingle and disperse, making them hard to control and measure. The new V-shaped device, on the other hand, traps the chemicals in water droplets and suspends the droplets in a fluorocarbon carrier fluid. This keeps the chemical-laden droplets intact, allowing a controlled stream of stimulating chemicals to enter on one end of the device and a steady stream of distinct resultant chemicals to be captured on the other end. The chemical-laden droplets can be analyzed immediately or stored for future analysis. Furthermore, the droplets can be split up for parallel study by different techniques.

“The inspiration for this work was the microelectrode, but the key to its success was encapsulating the chemicals in aqueus droplets so that the chemicals could be delivered to and picked up from the reactive site in a controllable, measurable fashion,” said Delai Chen, a graduate student in the Department of Chemistry and Institute for Biophysical Dynamics at the University of Chicago. Chen was one of the four lead authors of the PNAS research paper, along with University post-doctoral researchers Wenbin Du and Ying Liu, and graduate student Weishan Liu.

A year and one-half in the making, the chemistrode is compatible with traditional methods of culturing cells and tissues because—like the electrode—it can be used on any surface. The device is used by being brought into contact with the surface of a cell or tissue under investigation. An array of tiny droplets containing chemical stimuli is then delivered to the sample; chemical reactions occur or molecules are released from the sample, as in the case of a hormone; and the resultant chemical-laden droplets are carried away. All the while, the fluorocarbon carrier fluid remains in contact with the droplets and shields them from the wall of the device.

“The chemistrode offers a time-resolved, high-fidelity record of molecular stimulation and response dynamics,” Ismagilov said. “Our PNAS paper describes the physical principles that guide the operation of the chemistrode. It also implements the chemistrode to test the feasibility of each step and the compatibility of this platform with living cells.”

For now, the device “allows you to look very hard and precisely at living cells in a dish, but it has the potential to be used in whole organisms, as well,” said Louis Philipson, a professor in the Department of Medicine and co-author on the paper. “The chemistrode offers real-time input-output analysis captured in excellent resolution. As such, it will facilitate research in a lot of areas and holds the potential for widespread applications in medicine.

“The development of this device is a wonderful example of the lack of walls at the University of Chicago,” Philipson added. “Here, physicians can interact with other scientists in unconventional ways and bring together different kinds of technology. The result is new ways of looking at things and new answers to old problems.”

A nutritious diet is not seen as being as important as physical activity when it comes to college students’ health and wellness efforts, according to Indiana University researchers, even when the students live in an environment that provides classes, cues and motivation to eat healthily. “Personal preferences triumph over discipline,” the researchers note. The researchers examined the eating habits of college students as they transitioned from high school to university life and to living in residence halls or apartments. Habits that college students establish as they leave home may have long-reaching effects on their health and that of their future families, the researchers note. The students, they say, bring to college the eating habits established at home, where most skipped breakfast and almost 40 percent ate out for dinner or were on their own. This “grab and go” view of food and a preference for restaurant-style foods was apparent in the study. Researchers found that regardless of the variety available in the residence hall or the need to prepare meals in apartment living, foods that can require more preparation or are more perishable are eaten less often. The researchers studied three groups of students — students in apartments, students living in a residence hall and students living in a Fitness and Wellness Living-Learning Center, a themed residential community that provides students with an onsite fitness facility and educational material — including a required course on healthy living. Students in all three groups achieved similar levels of physical activity, with around 56 percent meeting the recommended three bouts of exercise weekly. Compared to how they ate at home, the students reported eating the same amount or less of the healthy foods examined. Students in the Living and Learning Center reported eating even less of these healthy foods. The findings suggest that school and college health educators should consider providing students with tools to “internalize that fitness = exercise = healthy food,” and to find ways for them to eat healthy in our grab-and-go world.

A growing amount of research is finding that smoke-free air laws help smokers quit or reduce the amount that they smoke. Rather than changing smokers’ own attitudes about smoking, the influence of the policies, particularly the strong ones, might lie more in changing smokers’ perceptions of other people’s attitudes about smoking — changing the perceived social norms, according to an Indiana University study involving smoke-free air laws in four Texas communities. “Everyone knows it’s unhealthy to smoke,” said Jon Macy, the study’s lead researcher. “Our study suggests that the success of strong smoke-free air policies may be more about changing the social acceptability of smoking.” The IU study used a telephone survey of 407 adults to compare perceived norms about smoking between adults living in two cities with strong smoke-free air laws and adults living in two cities with weak smoke-free air laws. Those who lived in cities with a strong smoke-free air law perceived a lower prevalence of smoking in their city, were less likely to report that other people in their city believed smoking was acceptable, and were more likely to report that people in their city believed that smokers should take measures to not smoke. Macy said that while researchers are aware that smoke-free air policies, which are designed primarily to protect the public from the harm of secondhand tobacco smoke, also influence smoking behavior, the mechanism or cause has not been nailed down. This study offers one possible explanation. Macy said insights provided by this study could help with public communication messages that accompany smoke-free air policies. The messages, for example, could tap into the impact societal norms have on smoking behavior.