For many decades, ecologists have asked what prevents herbivores from consuming most of the plant biomass in terrestrial ecosystems, or "Why is the world green?" Here I ask the analogous question for detritivores: what prevents them from degrading most of the organic material in soils, or "Why is the ground brown?" For fresh plant detritus, constraints on decomposition closely parallel constrai...

The advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. The development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. These advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrast...

Fluorescence fluctuation methods have become invaluable research tools for characterizing the molecular-level physical and chemical properties of complex systems, such as molecular concentrations, dynamics, and the stoichiometry of molecular interactions. However, information recovery via curve fitting analysis of fluctuation data is complicated by limited resolution and challenges associated w...

The structure of diheteropeptin (1), a TGF-beta-like active substance from Diheterospora chlamydosporia Q58044, was determined to be a new cyclotetrapeptide, cyclo[2aminoisobutyryl-(S)-phenylalanyl-(R)-prolyl-(2S,8R,9R)-2-am ino-8,9-dihydroxydecanoyl-] by NMR, mass spectrometric and chemical studies.

A novel adaptive-gain twisting controller that is robust to the bounded disturbances with the unknown boundaries is proposed. The control algorithm is derived using the Lyapunov function technique. It is shown that an ideal or real second order sliding mode is established, and the adaptation algorithm does not overestimate the control gain. The efficacy of the proposed adaptive twisting control...

background: increasing attention to the concept of polycystic ovary syndrome (pcos) health-related quality of life has led to the development of tool that aims to measure this concept. objective: the purpose of this study was to conduct a systematic review of psychometric properties of the pcos health-related quality of life questionnaire. materials and methods: a search of database (pubmed, ps...

background : agaricus blazei mushrooms are one of the most important edible and therapeutic mushrooms, and they contain minerals, vitamins, and amino acids essential for the human body. this mushroom is used raw, dried, and in the form of pharmaceutical products. one of the most important processes after harvesting is drying in order to enhance the quality and the length of maintenance of the p...

background different measuring tools have been used to understand the outcomes of renal replacement therapies. the goal of renal transplantation is both to ensure survival, and to promote quality of life in the patients. one of the widely used disease-specific instruments to measure the quality of life is the kidney transplant questionnaire (ktq-25). objectives the current study aimed to perfor...

A detailed understanding of the sources, transformations and fates of organic species in the environment is crucial because of the central roles that they play in human health, biogeochemical cycles and the Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at ...