Frontiers in Microbiology
Insights into fungal communities in composts revealed by 454-pyrosequencing: Implications for human health and safety
Composting is a process for converting waste into materials beneficial for plant growth through the action of microbes, especially of fungi which can break down large molecules. But fungi involved in composting are not always harmless. Vidya De Gannes and colleagues show that composts can contain more fungi that are potentially harmful to humans than was previously realized. Using intensive DNA-sequencing to analyze fungal communities in three different composts of tropical agricultural plant waste, the authors found many fungal species not previously known to occur in composts. These include 15 species of opportunistic pathogens that can cause a variety of diseases, especially in people whose immune system has been weakened. Intensive DNA-sequencing can therefore serve as a “sentinel” technology to identify a potential health risk, conclude the authors.
Frontiers in Oncology
The role of microRNAs in the tumorigenesis of ovarian cancer
Despite intensive research on epithelial ovarian cancer over the last decade, there is still an urgent need to develop new genetic markers and treatments to detect, treat and cure the disease. It was recently discovered that so-called microRNAs, short RNA molecules that are not translated into protein, play a major role in the origin and the progression of ovarian cancer. Carlo Croce and Gianpiero Di Leva from the Ohio State University here review the most recent evidence on this subject. After discussing the essentials of microRNA activity in human cancer, the authors show that the measurement of the expression profile of microRNAs within the ovary can be used to identify neoplastic tissues, to distinguish between subtypes of ovarian cancers, and to predict the response to chemotherapy. Croce and di Leva conclude that microRNAs are a powerful avenue for the detection and diagnosis of ovarian cancer.
Frontiers in Neuroscience
On the nature of extraversion: variation in conditioned contextual activation of dopamine-facilitated affective, cognitive, and motor processes
The difference between extroverts and introverts comes down to a person’s sensitivity to the neurotransmitter dopamine in the brain. When we encounter “rewards”, dopamine activates positive emotions, such as, euphoria and elation, and motivational feelings like desire and craving. Richard Depue and Yu Fu from Cornell University, USA, here explain why extroverts consistently seek out rewarding environments: in extroverts, dopamine has a stronger capacity to promote the formation of mental associations between environmental stimuli and rewards. Over four consecutive days, Depue and Yu gave methylphenidate, a drug that activates dopamine, to volunteers to increase their perception of subjective reward. They found that extroverts more readily associated stimuli with reward, as shown by an increase of those motor, affective, and cognitive processes that are regulated by dopamine. These results suggest that extraversion is associated with individual variation in the capacity to encode rewarding stimuli in memory.