Abstract Dispersive liquid-liquid microextraction (DLLME) and high performance liquid chromatography – UV detection was presented for extraction determination of nandrolone testosterone in human urines. Chloroform at microliter volume level acetonitrile were used as dispersive solvents, respectively. The main advantages method are speed, enrichment factor, recovery, good repeatability solvent µ...

A frequent observation in plant-animal mutualistic networks is that abundant species tend to be more generalised, interacting with a broader range of interaction partners than rare species. Uncovering the causal relationship between abundance and generalisation has been hindered by a chicken-and-egg dilemma: is generalisation a by-product of being abundant, or does high abundance result from ge...

We show how to simulate any BPP algorithm in polynomial time by using a weak random source of r bits and min-entropy r for any γ > 0. This follows from a more general result about sampling with weak random sources. Our result matches an information-theoretic lower bound and solves a question that has been open for some years. The previous best results were a polynomial time simulation of RP [M....

We propose a spectral imaging method for piecewise "macropixel" objects, which allows a regular digital camera to be converted into a digital snapshot spectral imager by equipping the camera with only a disperser and a demultiplexing algorithm. The method exploits a "multiplexed spectrum" intensity pattern, i.e., the superposition of spectra from adjacent different image points, formed on the i...

Factors that determine the effectiveness of primates as seed dispersers include (i) the microsite into which they deposit seed, (ii) secondary removal of seed by other taxa and (iii) the effect of gut passage and/or spitting on subsequent seed germination. This contribution evaluated these factors in the little studied putty-nosed monkey, Cercopithecus nictitans, in a Nigerian montane forest. F...

In this work, a procedure for preconcentration of silver using dispersive liquid–liquid microextraction with the reagent dithizone as complexing reagent was developed. At pH 2, silver ions are complexed with dithizone and extracted into the fine droplets formed when mixing carbon tetrachloride (extraction solvent), ethanol (disperser solvent) and the sample solution. After extraction, the phase...

Invasive vertebrate predators are directly responsible for the extinction or decline of many vertebrate species, but their indirect impacts often go unmeasured, potentially leading to an underestimation of their full impact. When invasives extirpate functionally important mutualists, dependent species are likely to be affected as well. Here, we show that the invasive brown treesnake, directly r...

Recent increased demand for stingless bee honey in Malaysia have stimulated alternative methods to increase honey yields by using plastic cups as artificial honey pots within the beehives. However, honey’s acidity may lead to possible migration of plastic additives, where prolonged consumption may affect body’s physiological responses. This study was carried out to determine the presence of dib...