Tech

A new area in artificial intelligence involves using algorithms to automatically design machine-learning systems known as neural networks, which are more accurate and efficient than those developed by human engineers. But this so-called neural architecture search (NAS) technique is computationally expensive.

One of the state-of-the-art NAS algorithms recently developed by Google took 48,000 hours of work by a squad of graphical processing units (GPUs) to produce a single convolutional neural network, used for image classification and identification tasks. Google has the wherewithal to run hundreds of GPUs and other specialized circuits in parallel, but that's out of reach for many others.

In a paper being presented at the International Conference on Learning Representations in May, MIT researchers describe an NAS algorithm that can directly learn specialized convolutional neural networks (CNNs) for target hardware platforms -- when run on a massive image dataset -- in only 200 GPU hours, which could enable far broader use of these types of algorithms.

Resource-strapped researchers and companies could benefit from the time- and cost-saving algorithm, the researchers say. The broad goal is "to democratize AI," says co-author Song Han, an assistant professor of electrical engineering and computer science and a researcher in the Microsystems Technology Laboratories at MIT. "We want to enable both AI experts and nonexperts to efficiently design neural network architectures with a push-button solution that runs fast on a specific hardware."

Han adds that such NAS algorithms will never replace human engineers. "The aim is to offload the repetitive and tedious work that comes with designing and refining neural network architectures," says Han, who is joined on the paper by two researchers in his group, Han Cai and Ligeng Zhu.

"Path-level" binarization and pruning

In their work, the researchers developed ways to delete unnecessary neural network design components, to cut computing times and use only a fraction of hardware memory to run a NAS algorithm. An additional innovation ensures each outputted CNN runs more efficiently on specific hardware platforms -- CPUs, GPUs, and mobile devices -- than those designed by traditional approaches. In tests, the researchers' CNNs were 1.8 times faster measured on a mobile phone than traditional gold-standard models with similar accuracy.

A CNN's architecture consists of layers of computation with adjustable parameters, called "filters," and the possible connections between those filters. Filters process image pixels in grids of squares -- such as 3x3, 5x5, or 7x7 -- with each filter covering one square. The filters essentially move across the image and combine all the colors of their covered grid of pixels into a single pixel. Different layers may have different-sized filters, and connect to share data in different ways. The output is a condensed image -- from the combined information from all the filters -- that can be more easily analyzed by a computer.

Because the number of possible architectures to choose from -- called the "search space" -- is so large, applying NAS to create a neural network on massive image datasets is computationally prohibitive. Engineers typically run NAS on smaller proxy datasets and transfer their learned CNN architectures to the target task. This generalization method reduces the model's accuracy, however. Moreover, the same outputted architecture also is applied to all hardware platforms, which leads to efficiency issues.

The researchers trained and tested their new NAS algorithm on an image classification task in the ImageNet dataset, which contains millions of images in a thousand classes. They first created a search space that contains all possible candidate CNN "paths" -- meaning how the layers and filters connect to process the data. This gives the NAS algorithm free reign to find an optimal architecture.

This would typically mean all possible paths must be stored in memory, which would exceed GPU memory limits. To address this, the researchers leverage a technique called "path-level binarization," which stores only one sampled path at a time and saves an order of magnitude in memory consumption. They combine this binarization with "path-level pruning," a technique that traditionally learns which "neurons" in a neural network can be deleted without affecting the output. Instead of discarding neurons, however, the researchers' NAS algorithm prunes entire paths, which completely changes the neural network's architecture.

In training, all paths are initially given the same probability for selection. The algorithm then traces the paths -- storing only one at a time -- to note the accuracy and loss (a numerical penalty assigned for incorrect predictions) of their outputs. It then adjusts the probabilities of the paths to optimize both accuracy and efficiency. In the end, the algorithm prunes away all the low-probability paths and keeps only the path with the highest probability -- which is the final CNN architecture.

Hardware-aware

Another key innovation was making the NAS algorithm "hardware aware," Han says, meaning it uses the latency on each hardware platform as a feedback signal to optimize the architecture. To measure this latency on mobile devices, for instance, big companies such as Google will employ a "farm" of mobile devices, which is very expensive. The researchers instead built a model that predicts the latency using only a single mobile phone.

For each chosen layer of the network, the algorithm samples the architecture on that latency-prediction model. It then uses that information to design an architecture that runs as quickly as possible, while achieving high accuracy. In experiments, the researchers' CNN ran nearly twice as fast as a gold-standard model on mobile devices.

One interesting result, Han says, was that their NAS algorithm designed CNN architectures that were long dismissed as being too inefficient -- but, in the researchers' tests, they were actually optimized for certain hardware. For instance, engineers have essentially stopped using 7x7 filters, because they're computationally more expensive than multiple, smaller filters. Yet, the researchers' NAS algorithm found architectures with some layers of 7x7 filters ran optimally on GPUs. That's because GPUs have high parallelization -- meaning they compute many calculations simultaneously -- so can process a single large filter at once more efficiently than processing multiple small filters one at a time.

"This goes against previous human thinking," Han says. "The larger the search space, the more unknown things you can find. You don't know if something will be better than the past human experience. Let the AI figure it out."

Luke Frishkoff, University of Texas at Arlington assistant professor of biology, explores how human land use expedites biodiversity loss in a paper recently published in Nature Ecology & Evolution.

For a study conducted at the University of Toronto, Frishkoff, as a postdoctoral fellow, and his collaborators traveled to the Dominican Republic to take a census of the region's Anolis lizard species along an elevation gradient affected by deforestation. The species is a common group of tropical lizards that are a model system in ecology and evolutionary biology.

"This work uses elevation as a lens to understand the potential implications of climate change," Frishkoff said. "Temperature changes along an elevation gradient, and general climate temperatures are expected to continue warming. By comparing the highlands to the lowlands, we can, in some sense, get a picture of how these biological communities might look in the future."

The lowlands along the gradient are warmer than the highlands due to altitude, and a forest canopy blocks direct sunlight making the vegetation-dense areas cooler than their agricultural surroundings at any elevation. The study determined elevation plays a major role in which species survive as humans modify the habitat.

"The takeaway message is that the lizard communities in the lowlands are pretty good at coping with habitat conversion--they lose abundance, but don't go extinct," Frishkoff said. "When the forest is cut down in the highlands and the habitat warms, the pastures become filled with species from the warmer lowlands. Unlike the lowland species, the locally adapted forest lizards unique to the region's mountaintops cannot survive when the forest is cut down."

Frishkoff points out that biodiverse animals in any habitat act as "ecological players" to balance the ecosystem and often provide services that benefit humans in a variety of different ways. In order to get the most benefit from these ecological players, humans need to understand and have mechanisms to predict which species will survive as the climate warms and human land use changes, and Frishkoff's research indicates the effects of habitat conversion can change radically with elevation.

The Dominican Republic study is part of a larger project, Frishkoff said. Since coming to UTA in September 2018, he has begun looking at lizard populations throughout Jamaica, Puerto Rico, Central America and Texas to understand the rules that govern species survival in a variety of different climates and conditions.

"We need to be able to predict what species are going to do well in what environmental contexts," Frishkoff said. "The broader goal is to lay that foundation to predict biological communities across climates, across land uses. So that eventually policymakers can use that information eventually to make decisions that integrate human wellbeing and biological wellbeing."

In his research, Frishkoff focuses mainly on reptiles and amphibians. He said the placement of UTA offers a great wealth of biological diversity to support his research, which is enriched by the university's Amphibian and Reptile Diversity Research Center. The ARDRC is home to the largest herpetology collection in Texas with more than 200,000 specimens.

Using the collection, Frishkoff's lab is beginning to study morphological differences between species to understand whether certain body shapes allow various species to do better in urban environments like the one UTA lies at the center of.

"Luke's ongoing and developing research endeavors to address critical issues facing our global environment and support a sustainable urban community - two driving themes of our university's strategic plan," said Clay Clark, professor and chair of the Department of Biology. "He will make contributions to our growing footprint as a research enterprise."

Scientists at the University of Illinois at Chicago have developed a way to identify the beginning of every gene -- known as a translation start site or a start codon -- in bacterial cell DNA with a single experiment and, through this method, they have shown that an individual gene is capable of coding for more than one protein.

Historically, the generally taught scientific premise has been that each gene has one unique start site and is responsible for the creation of only one protein. However, the study, which is published in Molecular Cell, a leading journal on the topic of cellular processes, shows that some genes have more than one start site and can specify production of more than one functional protein.

Their method of identifying gene start sites relies on a common prescription drug called retapamulin, a topical antibiotic. Retapamulin, they showed for the first time, works by causing the ribosome, which reads genetic code, to become stalled at these start sites, inhibiting translation, a key part of the process by which the genetic code in DNA is used to create proteins.

UIC's Alexander Mankin and Nora Vázquez-Laslop led the research, which looked at E. coli cells in response to retapamulin in in vitro and in vivo experiments.

"First, we understood the antibiotic's mechanism and then we applied that knowledge to identify the special 'start' gene signals the cell uses to regulate protein synthesis," said Mankin, the Alexander Neyfahk Professor of Medicinal Chemistry and Pharmacognosy at the UIC College of Pharmacy. "In the past, these start codons were identified by rather difficult processes -- proteins often needed to be isolated and studied to discover where the start sites of their genes are located in the bacterial genome. Now, in a single experiment, we can profile the starts of all the thousands of bacterial genes in a more forward manner."

Mankin and Vázquez-Laslop say using retapamulin to aid in bacterial gene translation profiling opens many new avenues for research.

Using the antibiotic, the researchers from Mankin and Vázquez-Laslop's lab, which included Sezen Meydan, James Marks, Dorota Klepacki and Amira Kefi, were able to identify "cryptic," or alternative start sites within some bacterial genes.

"We saw that many previously hidden proteins were initiated at sites in the middle of the gene and that those proteins were functional and that initiation at alternative start sites is widespread in bacteria," said Vázquez-Laslop, research professor of medicinal chemistry and pharmacognosy at the UIC College of Pharmacy and the Center for Biomolecular Sciences.

The researchers found more than 100 E. coli genes, out of around 4,000, that could initiate protein synthesis at more than one site.

"Proteins initiated at these unknown sites may constitute a previously hidden fraction of the proteome -- the entire set of proteins that can be expressed -- in bacteria and their initiation at these sites may play a role in the life of the cell," said Mankin, who is also director of the Center for Biomolecular Science. "By better understanding the cell and the mechanisms of antibiotic action, we can apply that knowledge to learn more about what makes bacteria become pathogenic."

"We can also apply that knowledge to better understand how to prevent or stop bacteria from causing harm," Vázquez-Laslop said.

Most people who immigrated to the United States for a chance to live the "American Dream" are more satisfied with their lives in the "land of the free" than those who were born here, according to new research from Florida State University.

A team of researchers, including FSU Assistant Professor of Sociology Dawn Carr, found immigrants from white, Hispanic and other racial groups have higher levels of happiness and overall life satisfaction than those born in the United States.

Their findings were recently published in the February 2019 print edition of the Journal of Aging and Health.

"We discovered that people who are foreign-born and living in the United States do have higher levels of life satisfaction," Carr said. "We examined life satisfaction because it is a useful global measure for understanding how people are doing on the whole with regard to how they feel about their life. It's a good way of capturing their overall well-being."

Scholars found Hispanic immigrants in the United States had the highest overall life satisfaction of any other racial group. Study participants had lived in the United States for an average of about 30 years.

"The older adult immigrants in our sample adjusted to life in the United States, and they're thriving more than their native-born counterparts," Carr said. "This is particularly true for Hispanics, who maintain their well-being despite having fewer resources than their native-born counterparts. They seem to have developed a life that provides a good old age."

In the past 50 years, scholars have examined a concept known as the "Hispanic Paradox," which refers to the observation that older Hispanic immigrants in the United States tend to have better health outcomes than non-Hispanic whites despite their more limited socioeconomic resources.

"We wanted to see if this was also true for overall well-being," Carr said.

The paradox is believed to stem from cultural and social factors specific to immigrants of Hispanic origin.

"It might be that those cultural factors are quite beneficial in terms of maintaining well-being," Carr said. "For instance, it may be their overall spirituality or sense of community. Studies have shown there are expectations for support in the Hispanic culture. However, we were unable to identify specific mechanisms that explain these effects."

Researchers examined data from more than 7,000 participants 60 years and older who were surveyed for the most recent wave of the Health and Retirement Study in 2014. This study is the largest and most comprehensive study of older adults in the US.

The team also found that foreign-born blacks did not report the same increases in overall life satisfaction as compared to other races.

"It was very discouraging to see this outcome for the black sample," Carr said. "Blacks in general have lower levels of life satisfaction than everybody else and foreign-born blacks do not experience any better outcomes."

Carr and her colleagues also studied how levels of education were linked with overall life satisfaction. For whites, higher levels of education translated to higher levels of life satisfaction. However, they found for both native and foreign-born blacks, the more education they had, the lower their life satisfaction.

"That was a puzzling discovery," Carr said. "This means that education does not seem to enhance the lives of minorities like we might expect. We do not know the reasons for these trends, but we might guess that factors like discrimination are involved, detracting from their overall happiness. For instance, someone who has a college degree, who is in a job with similarly educated individuals who are not minority, might be more overtly aware of the discrimination they're experiencing."

Researchers found higher levels of education for native-born Hispanics also was associated with lower life satisfaction.

Carr said further research needs to take place to determine what factors are at the root of these varying levels of happiness in later life.

In an Addiction analysis of relevant published studies, investigators found some evidence for a positive association between anxiety during childhood and adolescence with later alcohol use disorders.

Approximately 43 percent of associations were positive, meaning that anxiety was associated with a higher likelihood of later alcohol use disorders; however, 11 percent of associations were negative, with anxiety being associated with a lower likelihood of later alcohol use disorders. Approximately 30 percent of associations were equivocal and 15 percent were unclassifiable based on the information reported.

The authors of the analysis noted that it is important to establish which anxious individuals consume more alcohol and develop alcohol use disorders in order to develop targeted interventions.

"The evidence from prospective cohort studies is suggestive but not conclusive of a positive association between anxiety during childhood and adolescence and subsequent alcohol use disorder," said lead author Maddy Dyer, of the University of Bristol, in the UK. "Associations of anxiety with later drinking frequency or quantity and binge drinking were inconsistent. Further research is needed to understand why there are differences in associations for consumption levels versus problematic use, and to determine which individuals with anxiety develop alcohol problems."

Osteoarthritis (OA) has traditionally been viewed as a highly prevalent but milder condition when compared with rheumatoid arthritis (RA), and some may believe that it is part of a normal aging process requiring acceptance, not treatment. A new study in Arthritis & Rheumatology indicates that OA and RA have similar impacts or burdens on patients when they first visit rheumatologists, however.

Also, after treatment, OA was associated with a higher burden of disease than RA, indicating that treatment leads to significant improvements in patients with RA compared with those with OA.

The study included 149 patients with OA and 203 patients with RA who completed a health assessment questionnaire at multiple visits.

"This new information may have important implications for public health and control of healthcare costs. Osteoarthritis is one of the three most common health conditions in the US population, at least 20 times more common than rheumatoid arthritis, and has been estimated to involve costs of 1 percent of the gross domestic product," said senior author Dr. Theodore Pincus, of Rush University Medical Center, in Chicago. "Our results appear to indicate an urgent need for improved treatments and strategies for prevention of osteoarthritis."

Previous studies have revealed a link between hot tea drinking and risk of esophageal cancer, but until now, no study has examined this association using prospectively and objectively measured tea drinking temperature. A new International Journal of Cancer study achieved this by following 50,045 individuals aged 40 to 75 years for a median of 10 years.

During follow-up, 317 new cases of esophageal cancer were identified. Compared with drinking less than 700 ml of tea per day at less than 60°C, drinking 700 ml per day or more at a higher temperature (60°C or higher) was associated with a 90 percent higher risk of esophageal cancer.

"Many people enjoy drinking tea, coffee, or other hot beverages. However, according to our report, drinking very hot tea can increase the risk of esophageal cancer, and it is therefore advisable to wait until hot beverages cool down before drinking," said lead author Dr. Farhad Islami, of the American Cancer Society.

Labiodental sounds, such as F and V, have been known to be rarely met in hunter-gatherer languages. To understand how this has occurred, the authors undertook a massive statistical inquiry. 2,400 languages were analyzed, and a biomechanical model of mouth and lip movements was created.

The following explanation was put forth - when transition from hunter-gatherer society to agriculture and animal husbandry happens, diets also undergo major changes; specifically, foods become softer. This leads to changes in bite configuration and thus facilitates easier pronunciation of labiodentals.

It isn't easy being green. It takes thousands of genes to build the photosynthetic machinery that plants need to harness sunlight for growth. And yet, researchers don't know exactly how these genes work.

Now a team led by Princeton University researchers has constructed a public "library" to help researchers to find out what each gene does. Using the library, the team identified 303 genes associated with photosynthesis including 21 newly discovered genes with high potential to provide new insights into this life-sustaining biological process. The study was published online this week in Nature Genetics.

"The part of the plant responsible for photosynthesis is like a complex machine made up of many parts, and we want to understand what each part does," said Martin Jonikas, assistant professor of molecular biology at Princeton. "This library, we hope, will be one of the foundations that people will build on to make the next generation of discoveries."

Unlocking the role of each gene could allow researchers to engineer plants to grow more quickly, potentially meeting future world food needs. Plants could also potentially be altered to absorb more carbon dioxide, helping to address climate challenges.

The library, funded in large part through a grant from the National Science Foundation, consists of thousands of single-celled, pond-dwelling algae known as Chlamydomonas reinhardtii, or Chlamy for short. Each "book" in the library is a strain of Chlamy with a single mutation. The 62,000-plus mutant strains, housed at the University of Minnesota's Chlamydomonas Resource Center, cover more than 80 percent of Chlamy's genes.

Similar libraries have been made in other single-celled organisms, such as yeast, but this is the first such endeavor for any single-celled photosynthetic organism. The rapid growth of single-celled organisms makes them valuable as research tools.

"Because this algal species is often used as a model to understand a wider range of biological processes, this library will be an important resource," said Karen Cone, a program director at the National Science Foundation, which was the primary funder for this research. "The partnership between the Jonikas group and the Chlamydomonas Resource Center enhances community accessibility to this valuable resource, which in turn will enable new discoveries, especially in one of NSF's research priority areas, 'Understanding the Rules of Life.'"

Due to various challenges inherent in Chlamy's genome, the project took nine years to complete. Throughout the project, researchers used robots to keep generations of cells alive by changing the nutrient-rich liquid media in which they live.

The project started in 2010 while Jonikas and his team were at the Carnegie Institution for Science on the Stanford University campus, and was completed at Princeton where the Jonikas laboratory moved in 2016. The project was a collaboration with Arthur Grossman, a senior staff scientist at Carnegie and with the Chlamydomonas Resource Center run by Paul Lefebvre, a professor of plant and microbial biology at the University of Minnesota.

The ability to observe a Chlamy cell with just one defective gene among all the other functioning genes allows researchers to figure out what that gene does. For example, if the cell has trouble moving, then the defective gene's function mostly likely involves governing movement.

Jonikas compared the Chlamy mutant library to a library containing thousands of copies of a manual for constructing a car, with each copy missing a different section. No matter which manual was used, the resulting car would be missing a part, making it unable to operate as expected.

"The horn might not work, or the steering wheel might not turn," Jonikas said. "Then you would know that the missing section contained the instructions for that part of the car."

The library enables researchers to test multiple mutant Chlamy strains at once because each mutation is labeled with a unique "DNA barcode." For the current study, investigators placed thousands of Chlamy strains in a single flask and exposed them to light. Strains that failed to grow were more likely to contain a gene involved in photosynthesis.

One of the newly identified genes is CPL3, which is thought to play a role in accumulating the protein "parts" of the photosynthetic machinery. The team is now exploring whether the gene helps the algae adjust their photosynthetic activity to changes in sunlight levels.

The mutant library can enable studies in other areas of plant biology, such as intracellular communication and Chlamy's ability to paddle around its environment using a tail-like cilium.

Xiaobo Li, the study's first author, was a postdoctoral researcher at Princeton when the team completed the library. "It is our hope that the Chlamydomonas mutant library and the genes identified will lead to numerous fundamental discoveries in photosynthesis, cell motility and many other processes," Li said.

Weronika Patena, a senior bioinformatics analyst in the Jonikas laboratory, wrote computer programs to analyze large amounts of data to identify genes most likely to be involved in photosynthesis. "I believe the success of this project will greatly accelerate research into photosynthesis and other processes for which Chlamy is a good model, and provide a lot of value to the scientific community," she said.

Tropical Cyclone Savannah weakened and "lost" its eye as high clouds filtered over it. NASA-NOAA's Suomi NPP satellite passed over the Southern Indian Ocean and captured a visible image of the tropical storm that revealed high clouds had moved over its eye.

Wind shear weakened Tropical Storm Savannah and satellite imagery showed that it had become slightly elongated with clouds pushing southeast of the center. In general, wind shear is a measure of how the speed and direction of winds change.

On March 18, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the Suomi NPP satellite showed that Savannah still had a defined center, although the storm appeared somewhat elongated to the southeast, as a result of northwesterly winds. Visible imagery showed bands of thunderstorms were wrapping around the center, but the eye disappeared.

The Joint Typhoon Warning Center, noted that "animated multispectral satellite imagery showed the system continued to weaken as deep rain bands unraveled and the eye, albeit discernible, became cloud-filled."

At 11 a.m. EDT (1500 UTC) Tropical Cyclone Savannah was located near latitude 17.7 degrees south and longitude 87.7 degrees east. That's approximately 1,115 nautical miles east-southeast of Diego Garcia, has tracked west-southwestward. Maximum sustained winds were near 60 knots (69 mph/111 kph) and the storm is on a weakening trend.

Savannah is forecast to continue to track west-southwestward and increasing vertical wind shear is expected to adversely affect the storm. The JTWC said that the overall unfavorable environment will gradually weaken Savannah leading to dissipation by four days (March 22), possibly sooner.

Don't feel so bad for binge-watching a political drama - it might lead to more civic participation, as long as the show features a female lead character.

A survey of fans of the TV shows "Madam Secretary," "The Good Wife" and "Scandal" found that viewers who felt most connected to the storyline and characters also reported increased political interest and participation. The findings are published online in the Journal of Broadcasting and Electronic Media.

"A lot of times, people think of entertainment television as being just that: purely entertainment," said Jennifer Hoewe, an assistant professor in Purdue University's Brian Lamb School of Communication. "But there's research, including this study, to show it can be more than that; we can get more out of entertainment media than just something fun and relaxing. This study is showing that when we have lead female characters, we can feel like we're part of the show, we enjoy the characters, and that can actually lead to positive political outcomes."

Hoewe and Lindsey Sherrill, a doctoral candidate at the University of Alabama, conducted the study of 218 fans, 70 percent of whom were women, recruited from Reddit forums and other online fan forums dedicated to the shows, as well as Twitter. Although many political thrillers and comedies have become popular on television and digital streaming services, the three shows were chosen for their more accurate depictions of women in political leadership.

Respondents were first tested on whether or not they felt two common experiences in narrative fiction: feeling emotionally invested in a story, what researchers call transportation, and feeling connected to characters, also known as parasocial relationships. On a one-to-seven scale, they were asked to rate how the shows affected them emotionally, how much they related to the characters and how interested and active they were in politics, among other criteria.

Viewers who experienced the two narrative fiction phenomena also reported paying more attention to politics and being more involved in political activities, such as attending a public meeting, rally or speech, circulating a petition for a candidate or issue, or contacting a public official or political party.

"The more you watched, the more you felt engaged with the narrative, then the more you felt like those characters were relatable to you," Hoewe said. "Once those pieces were in place, that led to political interest, efficacy and downstream political participation, but only with the transportation and parasocial components in there."

The three shows included in the study are an exception in primetime TV, which still confines women to roles emphasizing sexuality, beauty and gender-stereotypical occupations, Hoewe said. But the findings are promising by showing that reversing those roles can be beneficial to viewers. Her next step is to assess whether or not political dramas with male lead characters can elicit the same response.

"Although not in the majority, we're seeing more shows featuring women in fictional roles in a greater number of contexts," Hoewe said. "Media depictions of political leadership can illustrate to people generally, not just women, that there is opportunity for people of all genders and colors to participate in politics."

Patients with prostate, bladder or kidney cancers are at greater risk of dying if they have had psychiatric care prior to the cancer treatment. In addition, patients with these cancers show greater suicide risk than the general population, even once the data is corrected for previous psychiatric care. These are the main findings of a new study presented at the European Association of Urology congress in Barcelona. They highlight the need for psychiatric care to be integrated into cancer treatment.

There is emerging evidence that cancer survival rate is influenced by the mental health state of the patient. This work is the first which relates urological cancer survival to previous (within 5 years) use of psychiatric services, giving scientists an indication of the mental health state of patient before the cancer diagnosis. This is part of a larger study looking at the effect of mental health on cancer survival.

What did they do?

A US/Canadian team led by Assistant Professor Zachary Klaassen (Georgia Cancer Centre, Augusta, Georgia) looked at the mental health records of 191,068 urology cancer patients from Ontario in Canada (where Professor Klaassen was on temporary assignment). These patients had either suffered from prostate, bladder, or kidney cancer. They then assigned each patient a score based on whether they had used psychiatric services within the previous 5 years. 57.1% had not used these services whereas the remaining patients had received outpatient treatment (41.6%), emergency department treatment (0.84%) or hospital admission (0.40%). The patients were matched to 528,387 control patients, i.e. patients who had not suffered any cancers. Full figures are available in the attached abstract.

What did they find?

The researchers found that patients previously treated for mental health conditions had a greater risk of dying of their cancer than those who had not been treated, with the mortality risk increasing in line with the intensity of the prior mental health treatment. For example, the odds of cancer mortality were 1.78 times greater in patients who had been hospitalised for mental health problems, when compared with controls (Hazard Ratio, 1.78).

Zachary Klaassen said
"This is the first large, population-level study to show that patients with previous mental health problems are at greater risk of dying of their cancer compared to patients with no mental health history. We believe that there will be several factors behind this, but we need more studies to understand the causes".

A second analysis looked at suicide rates following diagnosis and treatment with prostate, bladder, or kidney cancer. In common with other findings, the researchers found that suicide rates increased after cancer diagnosis. Professor Klaassen commented:

"This is the first population-level suicide study where we have been able to adjust for previous psychiatric history. We found that whereas the overall risk of suicide increased by around 16% (HR=1.16) for patients who had been diagnosed with these cancers, it went up by around 39% (HR=1.39) in patients who had no previous history of mental health treatment. This shows the significant toll that cancer diagnosis has on the mental health of patients.

In general, we can say that patients with genitourinary malignancies who have utilized psychiatric services in the five years leading up to their cancer diagnosis are at increased risk of dying of their cancer compared to patients with the same cancer who have not sought psychiatric help. Furthermore, these patients are at greater risk of suicide. The exact reason for this relationship is unknown, however it highlights the importance of identifying at-risk patients and having a multi-disciplinary approach (including psycho-oncology) to managing these patients".

"There are more than 20 population-level studies suggesting that cancer patients are at increased risk of suicide compared to the general population. This is the first study to account for pre-diagnosis psychiatric status, and it confirms that a cancer diagnosis in itself is a driving factor for suicidal risk. Considering that several studies have suggested that bladder cancer patients are amongst the highest-risk patients, at the Georgia Cancer Center we are working towards including prior psychiatric data on these patients to help us understand if early psychiatric assistance may help in the overall outcome. We think that this needs to be generally considered for these patients.

Commenting, Professor Francesco Montorsi (Milano), European Association of Urology's Adjunct Secretary General for Science said:

"This large study shows that pre-existing mental state can have a significant influence on cancer outcomes. In addition, it shows that just the diagnosis of cancer can have a bearing on whether or not the patient attempts suicide. The clinical community has a duty to treat the whole patient, not just the cancer, so we need to take note of these findings, and where possible to include appropriate precautions to take account of a patient's mental health history"

For the first time, scientists have identified compounds found in coffee which may inhibit the growth of prostate cancer. This is a pilot study, carried out on drug-resistant cancer cells in cell culture and in a mouse model; it has not yet been tested in humans. This work is presented at the European Association of Urology congress in Barcelona, after publication in the peer-reviewed journal The Prostate* (this press release contains additional material).

Coffee is a complex mixture of compounds which has been shown to influence human health in both positive and negative ways. There is increasing evidence that drinking certain types of coffee is associated with a reduction in incidence of some cancers, including prostate cancers**. Now Japanese scientists have studied the effects of two compounds found in coffee, kahweol acetate and cafestol, on prostate cancer cells and in animals, where they were able to inhibit growth in cells which are resistant to common anti-cancer drugs such as Cabazitaxel.

The researchers initially tested six compounds, naturally found in coffee, on the proliferation of human prostate cancers cells in vitro (i.e. in a petri-dish). They found that cells treated with kahweol acetate and cafestol grew more slowly than controls. They then tested these compounds on prostate cancer cells which had been transplanted to mice (16 mice). 4 mice were controls, 4 were treated with kahweol acetate, 4 with cafestol, with the remaining mice being treated with a combination of kahweol acetate and cafestol.

Study leader, Dr Hiroaki Iwamoto (Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Japan, first author of the study) said:

"We found that kahweol acetate and cafestol inhibited the growth of the cancer cells in mice, but the combination seemed to work synergistically, leading to a significantly slower tumour growth than in untreated mice. After 11 days, the untreated tumours had grown by around 3 and a half times the original volume (342%), whereas the tumours in the mice treated with both compounds had grown by around just over one and a half (167%) times the original size.

It is important to keep these findings in perspective. This is a pilot study, so this work shows that the use of these compounds is scientifically feasible, but needs further investigation; it does not mean that the findings can yet be applied to humans. We also found the growth reduction in transplanted tumour cells, rather than in native tumour cells. What it does show is that these compounds appear to have an effect on drug resistant cells prostate cancer cells in the right circumstances, and that they too need further investigation. We are currently considering how we might test these findings in a larger sample, and then in humans."

Kahweol acetate and cafestol are hydrocarbons, naturally found in Arabica coffee. The coffee-making process has been found to affect whether these compounds remain in coffee after brewing (as with espresso), or whether they are stripped out (as when filtered).

Professor Atsushi Mizokami (Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Japan) added:

"These are promising findings, but they should not make people change their coffee consumption. Coffee can have both positive and negative effects (for example it can increase hypertension), so we need to find out more about the mechanisms behind these findings before we can think about clinical applications. However, if we can confirm these results, we may have candidates to treat drug-resistant prostate cancer."

In an independent comment, Professor Zoran Culig (Professor of Experimental Urology, Medical University of Innsbruck) said:

"These are interesting findings. I would expect that those initial results will motivate researchers to use more recently developed models, such as patient-derived xenografts which express the androgen receptor. Such experiments will likely provide a definitive answer as to future perspective of this kind of treatment."

Scientists have found that sperm DNA from the testicles of many infertile men is as good as that of ejaculated sperm of fertile men. This may explain a major cause of male infertility and opens the possibility of using sperm taken directly from the testicles of these men; to overcome their infertility.

Infertility is a major public health issue. One couple in 6 is infertile across Europe1, with male infertility now being the biggest cause in couples seeking treatment. Sperm DNA damage is known to be a major cause of male infertility and reduces a couple's chances of having a family. This study shows that on the journey from the testicles along the long series of ducts before ejaculation, sperm DNA can suffer major damage, some of which is due to oxidative stress.

In new research, presented at the European Association of Urology Congress in Barcelona, UK-based scientists detail how they took sperm samples from the testicles from 63 infertile men, and matched them with ejaculated sperm samples produced the same men. These infertile men had failed previous fertility treatment (intracytoplasmic sperm injection; ICSI). The scientists also examined the sperm for two types of DNA strand breaks (single and double strand breaks) each in the testicular and ejaculated sperm. A group of 76 fertile volunteers also gave ejaculated sperm for comparison.

The group measured the DNA damage using the Comet assay2 which is able to measure double and single strand breaks separately.

According to researcher, Mr Jonathan Ramsay (Consultant Urologist, Imperial College, London):

"When we looked at ejaculated sperm, we found that the extent of sperm DNA damage was much higher in infertile men than in fertile men, with roughly 15 % in fertile men, but 40% in infertile men. It wasn't a surprise to see greater DNA damage in ejaculates of infertile men. What we didn't expect was the consistency in these results when we looked at sperm taken directly from the testicles of infertile men, we found that it was of similar quality to that of ejaculated, fertile sperm".

The majority of DNA damage caused in transit from testicles to ejaculate is caused by oxidative stress, which causes DNA single but not double strand breaks. This occurs when the sperm are subjected to poor lifestyle habits such as poor diet, sitting at a laptop all day or smoking. Diseases such as Crohn's disease and Type 2 Diabetes also cause oxidative stress".

Professor Sheena Lewis, Emeritus Professor Queens University Belfast and founder of ExamenLab Ltd:

"What this means is that the DNA in sperm from the testicles of infertile men are better quality than sperm from their ejaculates. This opens the way to taking sperm directly from the testes of men who have highly fragmented ejaculated DNA and failed cycles of treatment and trying to achieve fertility with these testicular sperm. We also noted in a subgroup that the amount of the more serious double stranded DNA breaks was lower in the sperm taken from testicles, so using these sperm is more likely to lead to an improvement in male fertility.

We need to be aware of what this study does and doesn't show. We can't yet prove that this sperm DNA damage is the main cause of male infertility or ART failure in these men, or that using testicular sperm directly would help improve their chance of getting pregnant, but the work certainly points in that direction. "

Commenting, Professor Maarten Albersen (UV Leuven, Belgium. member of the EAU Scientific Congress Office) said:

"Couples who face an unfulfilled child wish due to male infertility often have to resort to assisted reproductive techniques, such as in-vitro fertilization (IVF) or intracytoplasmic sperm injections (ICSI). Success rates of these techniques per cycle are rather low and various factors influence these rates. In many European countries, one, or a low number of cycles is reimbursed meaning that couples should optimize their chances for success. In this study, a group from London shows that DNA integrity in infertile men is higher in testicular sperm than in ejaculated sperm.

As DNA integrity is believed to play a role in fertilization rates in assisted reproduction, these results may assist in the decision-making whether or not to resort to testicular biopsy/testicular sperm aspiration rather than using ejaculated sperm to enhance success rates of assisted fertilization in infertile men with signs of DNA damage. However, improved fertilization rates and baby-take home rates would need to be confirmed before adopting this alternate strategy".

Even though most medical practitioners may opt not to perform procedures on higher-risk patients, new research finds that it may be a good idea for those who suffer from both atrial fibrillation and heart disease.

In a new study from the Intermountain Healthcare Heart Institute in Salt Lake City, researchers found that performing catheter ablations on patients who suffer from both atrial fibrillation and carotid arterial disease reduces their risk of dementia and stroke compared to managing their care with medications.

Catheter ablation is a procedure that makes small scars in heart tissue to prevent abnormal electrical signals from causing rapid and irregular heart rhythms, or atrial fibrillation.

The findings could lead to changes in how patients with atrial fibrillation and carotid arterial disease are treated, even if they traditionally haven't been candidates for more aggressive treatment, such as an ablation.

"Often in medicine, higher-risk patients are less often referred for an invasive procedure due to concerns of procedural risk," said T. Jared Bunch, MD, principal investigator of the study and medical director of Heart Rhythm Services for Intermountain Healthcare. "Our research shows that higher risk patients may be those who are most likely to benefit from ablation when the procedure can be performed safely in centers with expertise so that these patients' long-term risk of dementia and stroke can be positively impacted."

Results of the study were presented at the American College of Cardiology Scientific Sessions in Atlanta on March 16.

"Atrial fibrillation and dementia are two disease states that are becoming more common in our society and are placing an increasing burden on patients, families, and the healthcare system," Dr. Bunch.

"The results of our study raise the awareness of the significant connection between the two and show what a significant difference catheter ablation can make as we understand the potential benefits of restoring a normal heart rhythm to improve brain health."

In the study, researchers identified 5,786 atrial fibrillation patients with no history of dementia. Patients were then separated into those who had carotid arterial disease, and those who didn't.

Researchers found that performing catheter ablation to correct irregular heartbeats in patients with both atrial fibrillation and carotid arterial disease resulted in a lower five-year risk of dementia or stroke and dementia alone, compared to similar patients who didn't have the procedure done. They also found that ablation made less of a difference in patients with just atrial fibrillation.

"We have previously shown the both atrial fibrillation and carotid arterial disease can increase risk of both stroke and dementia, the next step was to understand how treatments may impact risks," added Dr. Bunch.

Dr. Bunch believes that atrial fibrillation, which is an irregular heartbeat that leads to interrupted blood flow to the brain, is compounded by carotid arterial disease, in which plaque builds up in the carotid arteries. That's because when an artery is blocked, the brain loses some of its ability to compensate for hemodynamic stress that can occur with abnormal heart rhythms and as a consequence brain injury and dysfunction can develop.

"There's not a known therapy that changes the natural progressive course of dementia. Dementia now is one of the most common causes of disability and death in developed countries. As a consequence, we have to identify people at risk of dementia earlier before they come into the clinic with cognitive decline to start potential disease altering therapies very early," said Dr. Bunch.

"Without treatments that can improve dementia progression, our efforts need to center on prevention within the multiple pathways that cause brain injury and dysfunction."