A case for a joint strategy of diversified bet hedging and plasticity in the pea aphid wing polyphenism.

Phenotypic plasticity and diversified bet hedging are strategies for coping with variable environments. Plasticity is favoured when an organism can predict future conditions using environmental cues, while bet hedging is favoured when predictive cues are not available. Theoretical analyses suggest that many organisms should use a mixture of both strategies, because environments often present both scenarios. Here, we examine if the pea aphid wing polyphenism, a well-known case of plasticity, is potentially a mixture of plasticity and bet hedging. In this polyphenism, asexual females produce more winged offspring in crowded conditions, and wingless offspring in uncrowded conditions. We find that pea aphids use plasticity to respond to crowding and we find considerable genetic variation for this response. We further show that individual aphids produce both winged and wingless offspring, consistent with the variability expected in a bet hedging trait. We conclude that the pea aphid wing polyphenism system is probably a mixture of plasticity and bet hedging. Our study adds to a limited list of empirical studies examining mixed strategy usage, and suggests that mixed strategies may be common in dispersal traits.

Evaluation of articles in metabolism research on the basis of their citations.

INTRODUCTION: The number of research papers and journals each year is increasing and millions of dollars are spent. Despite this there is evidence to suggest that many publications do not impact clinical practice. We used citation analysis to measure the influence of metabolism publications from 2003-2013. Those papers with lower citation rates are likely to be of the least value and high rates of such publications may be a marker of research waste. MATERIALS AND METHODS: We analysed 67 journals with 81,954 articles related to metabolism indexed on the Scopus station database from 2003-2013. We identified those articles with less than 5 citations within 5 years from publication date as poorly cited. Journals were ranked by the percentage of articles that were poorly cited or uncited. RESULTS: Over the 10-year period, the number of total articles increased by 127%. We found that 24% of articles were poorly cited within 5 years of publication. Journals in the bottom 25% and top 25% of rankings by citation rates accounted for a similar proportion of poorly cited articles. Most of the open access journals were ranked in the top 25% for citation rates. CONCLUSIONS: Our analysis contradicts concerns over increasing amounts of publications with little impact. The proportion of poorly cited articles are low, with little change in the trend over 10 years. The top and bottom ranked journals produced similar proportions of poorly cited articles. These findings suggest the necessity of pursuing further research to study waste in metabolism research.

Sterol metabolism and protein metabolism are differentially correlated with sarcopenia in Asian Chinese men and women.

OBJECTIVES: Our aim was to investigate the prevalence and predictive variables of sarcopenia. METHODS: We recruited participants from the Peking Union Medical College Hospital Multicenter Prospective Longitudinal Sarcopenia Study (PPLSS). Muscle mass was quantified using bioimpedance, and muscle function was quantified using grip strength and gait speed. Logistic regression revealed the relationships between sarcopenia and nutritional, lifestyle, disease, psychosocial and physical variables. RESULTS: The prevalence of sarcopenia and sarcopenic obesity was 9.2%-16.2% and 0.26%-9.1%, respectively. Old age, single status, undernourishment, higher income, smoking, low physical activity, poor appetite and low protein diets were significantly associated with sarcopenia. Multiple logistic regression analysis showed that age was a risk factor for all stages of sarcopenia, and participants above 80 years were greater than fivefold more susceptible to sarcopenia, while lower physical activity was an independent risk factor. The optimal cut-off value for age was 71 years, which departs from the commonly accepted cut-off of 60 years. Female participants were greater than twofold less susceptible to sarcopenia than male participants. The sterol derivative 25-hydroxyvitamin D was associated with fourfold lower odds of sarcopenia in male participants. Several protein intake variables were also correlated with sarcopenia. Based on these parameters, we defined a highly predictive index for sarcopenia. CONCLUSIONS: Our findings support a predictive index of sarcopenia, which agglomerates the complex influences that sterol metabolism and nutrition exert on male vs female participants.