NEW ORLEANS─The number of total knee replacement (TKR) procedures continues to climb, as does the number of revision total knee replacement (RTKR) surgeries. In the study, "The Epidemiology of Revision Total Knee Arthroplasty in the United States," presented today at the 2014 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS), researchers used the Nationwide Inpatient Sample (NIS) to evaluate the cause of knee failure for 301,718 revision RTKR surgeries performed between 2005 and 2010.

Poisoning of dingoes - wild dogs - has a deleterious effect on small native mammals such as marsupial mice, bandicoots and native rodents, according to a new paper which found that loss of dingoes after baiting is associated with greater activity by foxes, which prey on small marsupials and native rodents.

As well, the number of kangaroos and wallabies increases when dingoes, the top predators in the Australian bush, disappear. Grazing by these herbivores reduces the density of the vegetation in which the small ground-dwelling mammals live.

The instant gratification and the pleasure derived from consuming excessive chocolate and deep-fried foods can lead way to a double-edged sword of negative consequences ranging from weight gain to feelings of low self-esteem. According to a new study in the Journal of Consumer Research, combating this type of self-destructive behavior may be achieved simply by making a person feel sad.

"We found that when people who are sad are exposed to pictures of indulgent food or indulgent words, their sadness highlights the negative consequences of indulging and encourages them to indulge less," write authors Anthony Salerno, Juliano Laran (both University of Miami), and Chris Janiszewski (University of Florida).

Children who use their hands to gesture during a math lesson gain a deep understanding of the problems they are taught, according to new research from University of Chicago's Department of Psychology.

Previous research has found that gestures can help children learn. This study in particular was designed to answer whether abstract gesture can support generalization beyond a particular problem and whether abstract gesture is a more effective teaching tool than concrete action.

"We found that acting gave children a relatively shallow understanding of a novel math concept, whereas gesturing led to deeper and more flexible learning," explained the study's lead author, Miriam A. Novack, a PhD student in psychology.

A new study in the Journal of the American Geriatrics Society found that a diet high in animal protein - meat - may helped elderly individuals function at higher levels physically.

People with bipolar disorder, as much as one percent of the population, undergo a veritable roller coaster of emotions.

They experience extreme shifts in mood, from manic phases with delusions of grandeur, increased drive and a decreased need for sleep as well as depressive episodes with a severely depressed mood to the point of suicidal thoughts. 

Under the direction of scientists from Bonn, Mannheim and Basel, an international collaboration of researchers discovered two new gene regions that are connected to the prevalent disease. In addition, they were able to confirm three additional suspect genes. In a new worldwide study, scientists utilized an unprecedented numbers of patients. 

A timid jumping spider uses the scent of ants as a secret weapon to save itself from becoming the somewhat soggy prey of the predatory spitting spider. The downside to this plan is that jumping spiders are also a favorite snack of its very own saviors. To overcome this additional hazard, the spider has made yet another plan in the form of an ant-proof nest, writes Ximena Nelson of the University of Canterbury in New Zealand and Robert Jackson of the University of Canterbury and the International Centre of Insect Physiology and Ecology in Kenya, in Springer's journal Behavioral Ecology and Sociobiology.

This news release is available in German.

Adolescents with antisocial personality disorder inflict serious physical and psychological harm on both themselves and others. However, little is yet known about the underlying neural processes. Researchers at the University of Leiden and the Max Planck Institute for Human Development have pinpointed a possible explanation: Their brain regions responsible for social information processing and impulse control are less developed.

It is said that nothing dies of old age in the ocean, that everything gets
eaten and all that remains of anything is waste.

But that waste is pure gold to
oceanographer David Siegel, director of the Earth Research Institute at U.C. Santa
Barbara.

In a study of the ocean's role in the global carbon cycle, Siegel and his colleagues used those nuggets to their advantage. They incorporated the lifecycle of phytoplankton
and zooplankton — small, often microscopic animals at the bottom of the food chain —into a novel mechanistic model for assessing the global ocean carbon export. 

DURHAM, N.C. -- Brain imaging using radioactive dye can detect early evidence of Alzheimer's disease that may predict future cognitive decline among adults with mild or no cognitive impairment, according to a 36-month follow-up study led by Duke Medicine.

The national, multicenter study confirms earlier findings suggesting that identifying silent beta-amyloid plaque build-up in the brain could help guide care and treatment decisions for patients at risk for Alzheimer's. The findings appeared online March 11, 2014, in Molecular Psychiatry, a Nature Publishing Group journal.