A new analysis of behaviour in a structured population illuminates Darwin’s theories of co-operation and competition between kin, and provides an abstract model that could simplify scientists’ quest to map behaviour among disease-causing organisms within a cell. The study by Queen’s Mathematics and Statistics professor Peter Taylor, and co-authors Troy Day (Queen’s) and Geoff Wild (University of Western Ontario) presents a simple formula for balancing the benefit and cost in altruistic acts, allowing researchers to predict behaviour and summarize disparate results in a simple framework.
As temperature influences the toxic effects of chemicals, so does chemical exposure influence the temperature tolerance of an organism. The consequences of this harmful reciprocal relationship on four freshwater fish are explored in a new study published in the latest issue of Environmental Toxicology and Chemistry.
The greenhouse manager of the future walks around the greenhouse, pointing an infrared “flashlight” at potted plants. A tiny screen tells whether each plant has too much, too little, or just the right amount of nutrients. During the past three years, at a new facility in Toledo, Ohio, Agricultural Research Service (ARS) plant pathologist Jim Locke and horticulturist Jonathan Frantz have made a great deal of progress toward realizing this automated future. Frantz is testing commercial nutrient sensors with a view toward developing improved portable ones. Devices like these can give greenhouse growers a few–often critical–extra days to correct nutrient problems before their plants are seriously damaged.
A University of Adelaide project led by zoologist Dr Jeremy Austin is investigating whether the world-fabled Tasmanian Tiger may have survived beyond its reported extinction in the late 1930s. Dr Austin from the Australian Centre for Ancient DNA is extracting ancient DNA from animal droppings found in Tasmania in the late 1950s and ’60s, which have been preserved in the Tasmanian Museum and Art Gallery.
Picking a mate isn’t easy–if you are a female iguana. In a study published in the June 27th issue of PLoS ONE, Maren Vitousek of Princeton University and colleagues found that female Galápagos marine iguanas spend a lot of energy picking a mate from a wide range of suitors — energy they could otherwise spend foraging, producing eggs, or avoiding predators. Scientists have generally assumed that being choosy about potential mates carries low costs for females. These costs were thought to be particularly small when male territories are clustered together in groups, known as ‘leks’, which make it possible for females to assess many candidates without traveling far.
Scientists of the Department of Personality, Evaluation and Psychological Treatment of the University of Granada have studied how some psychological variables such as erotophilia (positive attitude towards sexuality), sexual fantasies and anxiety are related to sexual desire in human beings. The researcher Juan Carlos Sierra Freire states that there are very few reliable and valid instruments in Spain to evaluate sexual desire. Due to this vacuum, the researchers have adapted the Sexual Desire Inventory by Spector, Carey and Steinberg. This inventory is a tool that enables the researcher to measure, on the one hand, the solitary sexual motivation and, on the other hand, the interest in having sexual intercourse with another person (didactic sexual desire). This fact is of a great importance because “it gives relevant information about possible disagreements in sexual desire that may appear in a couple”. Regarding figures of the Spanish Association for Sexual Health, a loss of sexual desire is one of the main factors that cause sexual dysfunction in the Spanish female population.