Lagrangian single particle turbulent statistics through the Hilbert-Huang Transform

The Hilbert-Huang transform is applied to analyze single particle Lagrangian velocity data from numerical simulations of hydrodynamic turbulence. The velocity trajectory is described in terms of a set of intrinsic mode functions, C_{i}(t), and of their instantaneous frequency, \omega_{i}(t). On the basis of this decomposition we define the \omega-conditioned statistical moments of the C_{i} modes, named q-order Hilbert Spectra (HS). We show that such new quantities have enhanced scaling properties as compared to traditional Fourier transform- or correlation-based (Structure Functions) statistical indicators, thus providing better insights into the turbulent energy transfer process. We present a clear empirical evidence that the energy-like quantity, i.e. the second-order HS, displays a linear scaling in time in the inertial range, as expected from dimensional analysis and never observed before. We also measure high order moment scaling exponents in a direct way, without resorting the Extended Self Similarity (ESS) procedure. This leads to a new estimate of the Lagrangian structure functions exponents which are consistent with the multifractal prediction in the Lagrangian frame as proposed in [Biferale et al., Phys. Rev. Lett. vol. 93, 064502 (2004)].Comment: 5 pages, 5 figure

Protective effect of crude polysaccharide from Pao-TianXiong derived from monkshood, against chronic renal failure in mice

Purpose: To investigate the effect of crude polysaccharide isolated from pao-tian-xiong on chronic renal failure in mice, and its monosaccharide composition. Methods: Male Kunming mice were orally treated with adenine (211.5 mg/kg/day) for 7 days, followed by either crude polysaccharides (125, 250 or 500 mg/kg), or positive drug solution (jinguishenqi pill, 2000 mg/kg) for another 7 days (each group had 15 mice). Mice in normal and negative control groups were given saline. Mental and physical states, blood urine nitrogen (BUN) and serum creatinine (SCr), kidney morphological changes and organ indices were determined. Histopathological examination of spleen and kidney tissues was also performed. The monosaccharide composition of crude polysaccharide was determined by high-performance liquid chromatography (HPLC) and gas chromatography and mass spectrometry (GC-MS). Results: Compared with negative control group, serum BUN (6.71 mmol/L vs. 8.61 mmol/L) and Cr (107.74 vs. 113.39 μmol/L) were significantly decreased by the crude polysaccharide isolate (p < 0.05), whereas epididymis index (0.2556 vs. 0.2135 %) and seminal vesicle index (0.5547 vs. 0.3945 %) were increased (p < 0.05). Histopathological examination showed that injuries to kidney, spleen, testis and epididymis decreased significantly. The crude polysaccharides contained mainly glucose, rhamnose, arabinose, galactose, mannose, galacturonic acid, glucuronic acid and xylose, and their contents ranged from 0.7 to 65 %. Conclusion: These results suggest that the crude polysaccharides of Pao-tian-xiong ameliorates CRF symptoms in mice, thereby providing experimental evidence in support of its use as an anti-CRF drug

Responses of Hydroponically Grown Sorghum (Sorghum bicolor L.M) to Zinc (Zn) Stress

Abiotic stress especially due heavy metals is one of the major environmental problems that threatens food security and pose greater risks to human health worldwide. In this research, greenhouse hydroponic experiments were carried out to study the morphological and biochemical responses of Sorghum bicolor L.M to different Zinc (Zn) levels. Two-week-old seedlings transplanted in hydroponic solutions were treated with different doses of Zn in the concentration ranges of 5, 25, 50, 100 and 200 mg/L supplied as ZnSO4. 5H2O. After 21 day of culture, the plants were harvested, blotted to dryness and separated into roots and shoots. The root and shoot lengths, dry weights and non-enzymatic biochemical parameters such as proline, Chlorophyll a, b, Carotenoids (pigments) were determined. The results indicate that Zn applications significantly (P<0.05) depressed the lengths of root and shoot, dry weights and pigment contents compared to untreated plants (control). The effects were more pronounced with increased Zn dosage. The accumulation of the metal and proline contents in treated plants however, increase gradually with increasing Zn concentrations (P<0.05). The changes in these parameters had resulted in toxicity symptoms and overall growth retardation especially at elevated concentrations and the estimated critical toxicity thresholds in both solution and tissue concentrations suggest that sorghum bicolor L.M should not be grown beyond Zn concentration of above 3.2 mg/L. &nbsp