The evolution of parasitism from mutualism in wasps pollinating the fig, Ficus microcarpa, in Yunnan Province, China.

Theory identifies factors that can undermine the evolutionary stability of mutualisms. However, theory's relevance to mutualism stability in nature is controversial. Detailed comparative studies of parasitic species that are embedded within otherwise mutualistic taxa (e.g., fig pollinator wasps) can identify factors that potentially promote or undermine mutualism stability. We describe results from behavioral, morphological, phylogenetic, and experimental studies of two functionally distinct, but closely related, Eupristina wasp species associated with the monoecious host fig, Ficus microcarpa, in Yunnan Province, China. One (Eupristina verticillata) is a competent pollinator exhibiting morphologies and behaviors consistent with observed seed production. The other (Eupristina sp.) lacks these traits, and dramatically reduces both female and male reproductive success of its host. Furthermore, observations and experiments indicate that individuals of this parasitic species exhibit greater relative fitness than the pollinators, in both indirect competition (individual wasps in separate fig inflorescences) and direct competition (wasps of both species within the same fig). Moreover, phylogenetic analyses suggest that these two Eupristina species are sister taxa. By the strictest definition, the nonpollinating species represents a "cheater" that has descended from a beneficial pollinating mutualist. In sharp contrast to all 15 existing studies of actively pollinated figs and their wasps, the local F. microcarpa exhibit no evidence for host sanctions that effectively reduce the relative fitness of wasps that do not pollinate. We suggest that the lack of sanctions in the local hosts promotes the loss of specialized morphologies and behaviors crucial for pollination and, thereby, the evolution of cheating.

Development of innovative tools for investigation of nutrient-gut interaction.

The gastrointestinal tract is the key interface between the ingesta and the human body. There is wide recognition that the gastrointestinal response to nutrients or bioactive compounds, particularly the secretion of numerous hormones, is critical to the regulation of appetite, body weight and blood glucose. This concept has led to an increasing focus on "gut-based" strategies for the management of metabolic disorders, including type 2 diabetes and obesity. Understanding the underlying mechanisms and downstream effects of nutrient-gut interactions is fundamental to effective translation of this knowledge to clinical practice. To this end, an array of research tools and platforms have been developed to better understand the mechanisms of gut hormone secretion from enteroendocrine cells. This review discusses the evolution of in vitro and in vivo models and the integration of innovative techniques that will ultimately enable the development of novel therapies for metabolic diseases.

Bird diversity in northern Myanmar and conservation implications.

We conducted four bird biodiversity surveys in the Putao area of northern Myanmar from 2015 to 2017. Combined with anecdotal information collected between 2012 and 2015, we recorded 319 bird species, including two species (Arborophila mandellii and Lanius sphenocercus) previously unrecorded in Myanmar. Bulbuls (Pycnonotidae), babblers (Timaliidae), pigeons and doves (Columbidae), and pheasants and partridges (Phasianidae) were the most abundant groups of birds recorded. Species richness below 1 500 m a. s. l. was higher than species richness at higher elevations. Our results suggest that the current protected areas in this region should be expanded to lower elevations to cover critical conservation gaps.

Synthesis and luminescent properties of nanoscale Gd2Si2O7:Eu3+ phosphors.

Gd2Si2O7:Eu3+ nanoparticles were prepared by the sol-gel method with citric acid as an additive in the precursor solutions. The crystal structure was analyzed by means of X-ray diffraction (XRD). The results indicate that the alpha-Gd2Si2O7 powders in size 35 nm are obtained at a synthesis temperature of 1,100 degrees C, and the doping ion contents do not influence the crystal structure. The excitation and emission spectra of samples were measured. The dependence of photoluminescence intensity and lifetime of level on Eu3+ concentration and synthesis temperature of samples are also discussed.

[Protective effect of rosiglitazone on myocardium in diabetic cardiomyopathy of rats].

OBJECTIVE: To investigate the protective effect of PPARgamma ligands rosiglitazone on myocardium in diabetic cardiomyopathy of rats. METHODS: The rat model of diabetes was induced by administration of streptozotocin (STZ) for 6 or 10 weeks. In the treatment group the STZ-induced diabetic rats were treated with rosiglitazone. The left ventricular muscle specimens were taken from treatment and control group; then were examined under transmission electron microscope. RESULT: Cardiac myofibrils of diabetic rats in control group were obviously fewer and broken. There were fewer and smaller dissolved mitochondria with incomplete membrane and mixed cristae and karyopyknosis. Myocardium of diabetic rats treated with rosiglitazone was markedly improved although their blood glucose levels were still high. CONCLUSION: Hyperglycemia can cause destruction of myocardial cell structure. Rosiglitazone has protective effect on myocardial cells of diabetic rats, which seems to be independent of blood glucose levels.