My picks from ScienceDaily

Lots of cool stuff today:

Nature Could Have Used Different Protein Building Blocks, Chemists Show:

Chemists at Yale have done what Mother Nature chose not to -- make a protein-like molecule out of non-natural building blocks, according to a report featured early online in the Journal of the American Chemical Society. Nature uses alpha-amino acid building blocks to assemble the proteins that make life as we know it possible. Chemists at Yale now report evidence that nature could have used a different building block -- beta-amino acids -- and show that peptides assembled from beta-amino acids can fold into structures much like natural protein.

Lipid Plays Big Role In Embryonic Development:

A little-known lipid plays a big role in helping us grow from a hollow sphere of stem cells into human beings, researchers have found. They found that in the first few days of life, ceramide helps stem cells line up to form the primitive ectoderm from which embryonic tissues develop, says Dr. Erhard Bieberich, biochemist at the Medical College of Georgia.

Beyond DNA: Chemical Signatures Reveal Genetic Switches In Genome:

Investigators from the Ludwig Institute for Cancer Research (LICR) and the University of California, San Diego (UCSD) School of Medicine have made a breakthrough in identifying functional elements in the human genome, according to a report published online today in Nature Genetics. While the DNA sequence can identify genes (the 'what') within the genome, it cannot answer the more fundamental questions of 'how,' 'when' and 'where' gene products are expressed. However, the LICR team and collaborators have developed a novel method to identify and predict the 'promoter' and 'enhancer' regions that switch on transcription, the first step in gene expression. This study is an important step towards large-scale functional annotation of 'enhancers,' which establish the rate at which gene expression occurs and determine the tissues in which genes are expressed.

NOTCHing Up Heart Development:

Defects in the heart and/or blood vessels (cardiovascular defects) in both humans and mice can result from mutations in any one of a number of genes encoding proteins that are part of the Notch signaling cascade. However, it has not been determined which cell type these mutations affect to cause these cardiovascular defects. In a study that appears in the February issue of the Journal of Clinical Investigation, Jonathan Epstein and colleagues from the University of Pennsylvania, Philadelphia, show that mice in which the Notch signaling cascade is only inhibited in cells of the neural crest lineage (which includes both smooth and skeletal muscle cells) develop cardiovascular defects.

What Makes A Good Leader: The Assertiveness Quotient:

Organizational leaders who come across as low or high in assertiveness tend to be seen as less effective, according to a study coming out in the February issue of the Journal of Personality and Social Psychology, published by the American Psychological Association (APA). Leaders in the middle may have an "optimal" level of assertiveness, but there is plenty of company on the extremes. The research suggests that being seen as under- or over-assertive may be the most common weakness among aspiring leaders.

In a series of studies, Daniel Ames, PhD, a professor at Columbia Business School, and Francis Flynn, PhD, a professor at Stanford Graduate School of Business, asked workers for their views of colleagues' leadership strengths and weaknesses. The most common strengths reported included conventional leadership traits like intelligence, self-discipline, and charisma. But the most common weaknesses reported revealed a surprising picture that was not just the reverse of strengths. Across several samples of leaders and potential leaders, Ames and Flynn found that assertiveness was by far the most frequently-mentioned problem, sometimes more than charisma, intelligence, and self-discipline combined.

Rogue Odour Theory Could Be Right:

A controversial theory that explains the molecular mechanism which gives our sense of smell razor-sharp precision has been given a boost thanks to a study by a team of UCL researchers at the London Centre for Nanotechnology (LCN). Reporting in an upcoming edition of the journal Physical Review Letters, they demonstrate that vibration theory, the process by which the body distinguishes one odour molecule from another by the way it vibrates, is viable.

Brain's Reward Circuit Activity Ebbs And Flows With A Woman's Hormonal Cycle:

Fluctuations in sex hormone levels during women's menstrual cycles affect the responsiveness of their brains' reward circuitry, an imaging study at the National Institute of Mental Health (NIMH), a component of the National Institutes of Health (NIH), has revealed. While women were winning rewards, their circuitry was more active if they were in a menstrual phase preceding ovulation and dominated by estrogen, compared to a phase when estrogen and progesterone are present.

"These first pictures of sex hormones influencing reward-evoked brain activity in humans may provide insights into menstrual-related mood disorders, women's higher rates of mood and anxiety disorders, and their later onset and less severe course in schizophrenia," said Karen Berman, M.D., chief of the NIMH Section on Integrative Neuroimaging. "The study may also shed light on why women are more vulnerable to addictive drugs during the pre-ovulation phase of the cycle."