Codonopsis pilosula twines either to the left or to the right

We report the twining handedness of Codonopsis pilosula, which has either a left- or right-handed helix among different plants, among different tillers within a single plant, and among different branches within a single tiller. The handedness was randomly distributed among different plants, among the tillers within the same plants, but not among the branches within the same tillers. Moreover, the handedness of the stems can be strongly influenced by external forces, i.e. the compulsory left and right forming inclined to produce more left- and right-handed twining stems, respectively, and the reversing could make a left-handed stem to be right-handed and vice versa. We also discuss the probable mechanisms these curious cases happen

Characterization and Removal of Filter Cake Generated by Ilmenite Water-Based Drilling Fluids

With the development of the oil and gas industry, people started to drill deeper wells to get oil and gas. New weighting materials have been developed to help solve the problem caused by the most commonly used barite. Ilmenite is among one of those with higher specific gravity. It can achieve the same density with adding less weighting materials than using barite. Less solids content in drilling fluid is an advantage in rheological properties. Recently, micronized ilmenite has again been tested in labs, after resolving the abrasiveness and magnetic problem that normal ilmenite created. Due to the composition of ilmenite, iron is likely to precipitate in acidic condition and cause formation damage when using acid to remove the filter cake. The effectiveness of using lower concentration of hydrochloric acid (HCl) as well as using 7.5 wt% HCl and 7.5 wt% hydroxyethyl ethylenediamine triacetic acid (HEDTA) to remove the filter cake generated by ilmenite water-based drilling fluids were investigated. To prepare the ilmenite water-based muds, a high speed mixer was used. After preparing the fluid, the filter cake was generated by high pressure high temperature (HP/HT) filter press at 300 psi and 250°F on a sandstone core with 2.5 in. diameter and 1 in. thickness. Cores with filter cakes were computerized tomography (CT) scanned. Then, the filter cake was soaked with HCl and HCl + HEDTA for several hours. After removal, cores with remaining filter cakes were CT scanned again and compare with the initial. Solutions after reaction were analyzed by inductively coupled plasma (ICP) to determine different cation concentrations. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was used to analyze the filter cake, as well as the residual filter cake. The results showed that lower concentration of HCl cannot completely remove the filter cake generated by ilmenite water-based drilling fluids. With limited volume of the acid, higher concentration of HCl, which can increase the initial acid to ilmenite ratio, will be more efficient to remove the filter cake generated by ilmenite water-based drilling fluids

Removing Ilmenite-Based Filter Cakes Using Hydrochloric Acid and Chelating Agent – Experimental Study

Ilmenite is often used as a weighting agent in drilling fluids to increase the fluid density, but the formation of a filter cake on the borehole wall can impact cementing operations and reduce well productivity. To remove the filter cake, various techniques can be employed such as chemical treatments, mechanical methods, or a combination of both. The goal of this study is to evaluate the effectiveness of chemical removal of ilmenite-based filter cake using 7.5 wt.% hydrochloric acid (HCl) and hydroxyethyl ethylenediamine triacetic acid (HEDTA) – chelating agent. The filter cakes were generated using API filter press under harsh conditions of 300 psi pressure and 250°F temperature. Sandstone cores (2.5-in. diameter and 1-in. thickness) were utilized to replicate the formation during filtration experiments. The filtrate fluid was collected and the sandstone cores with filter cakes were scanned using computerized tomography (CT) technology. Immediately after that, the cores and filter cakes were soaked with HCl–HEDTA solution for 6 hours, followed by CT-scanning the cores and remaining filter cakes again. After acidizing, the effluent solution was analyzed using inductively coupled plasma (ICP). Scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS) was used to analyze the dried filter cakes and remaining residue. The results showed that, the use of 7.5 wt.% HCl was effective in partially removing the ilmenite-based filter cake. Additionally, the use of HEDTA showed limited effect on the efficiency of filter cake removal, but it effectively prevented corrosion problems during the treatment. This study presents useful findings on removing ilmenite-based filter cake with a low acid concentration and reducing the risk of corrosion issues

Estimation of Asian Dust Aerosol Effect on Cloud Radiation Forcing Using Fu-Liou Radiative Model and CERES Measurements

The impact of Asian dust on cloud radiative forcing during 2003-2006 is studied by using the Earth's Radiant Energy Budget Scanner (CERES) data and the Fu-Liou radiative transfer model. Analysis of satellite data shows that the dust aerosol significantly reduced the cloud cooling effect at TOA. In dust contaminated cloudy regions, the 4-year mean values of the instantaneous shortwave, longwave and net cloud radiative forcing are -138.9, 69.1, and -69.7 Wm(sup -2), which are 57.0, 74.2, and 46.3%, respectively, of the corresponding values in more pristine cloudy regions. The satellite-retrieved cloud properties are significantly different in the dusty regions and can influence the radiative forcing indirectly. The contributions to the cloud radiation forcing by the dust direct, indirect and semi-direct effects are estimated using combined satellite observations and Fu-Liou model simulation. The 4-year mean value of combination of indirect and semi-direct shortwave radiative forcing (SWRF) is 82.2 Wm(sup -2), which is 78.4% of the total dust effect. The direct effect is only 22.7 Wm(sup -2), which is 21.6% of the total effect. Because both first and second indirect effects enhance cloud cooling, the aerosol-induced cloud warming is mainly the result of the semi-direct effect of dust

Comparative phylogeography of the plateau zokor (Eospalax baileyi) and its host-associated flea (Neopsylla paranoma) in the Qinghai-Tibet Plateau

Background: Specific host-parasite systems often embody a particular co-distribution phenomenon, in which the parasite’s phylogeographic pattern is dependent on its host. In practice, however, both congruent and incongruent phylogeographic patterns between the host and the parasite have been reported. Here, we compared the population genetics of the plateau zokor (Eospalax baileyi), a subterranean rodent, and its host-associated flea species, Neopsylla paranoma, with an aim to determine whether the two animals share a similar phylogeographic pattern. Results: We sampled 130 host-parasite pairs from 17 localities in the Qinghai-Tibet Plateau (QTP), China, and sequenced a mitochondrial DNA (mtDNA) segment (~2,500 bp), including the complete COI and COII genes. We also detected 55 zokor and 75 flea haplotypes. AMOVA showed that the percentage of variation among the populations of zokors constituted 97.10%, while the within population variation was only 2.90%; for fleas, the values were 85.68% and 14.32%, respectively. Moreover, the flea Fst (fixation index) values were significantly smaller than in zokor. Although the Fst values between zokors and fleas were significantly and positively correlated (N =105, R =0.439, p =0.000), only a small amount (R2= 0.19) of the flea Fst variations could be explained by the zokor Fst variations. The two animals showed very distinct haplotype network structures from each other while co-phylogenetic analyses were unable to reject the hypothesis of an independence of speciation events. Conclusions: Zokors and fleas have very distinct population genetic patterns from each other, likely due to the influence of other sympatrically-distributed vertebrates on the transmission of fleas

Impact of dietary manganese on intestinal barrier and inflammatory response in broilers challenged with Salmonella Typhimurium

Growing concern for public health and food safety has prompted a special interest in developing nutritional strategies for removing waterborne and foodborne pathogens, including Salmonella. Strong links between manganese (Mn) and intestinal barrier or immune function hint that dietary Mn supplementation is likely to be a promising approach to limit the loads of pathogens in broilers. Here, we provide evidence that Salmonella Typhimurium (S. Typhimurium, 4 × 108 CFUs) challenge-induced intestinal injury along with systemic Mn redistribution in broilers. Further examining of the effect of dietary Mn treatments (a basal diet plus additional 0, 40, or 100 mg Mn/kg for corresponding to Mn-deficient, control, or Mn-surfeit diet, respectively) on intestinal barrier and inflammation status of broilers infected with S. Typhimurium revealed that birds fed the control and Mn-surfeit diets exhibited improved intestinal tight junctions and microbiota composition. Even without Salmonella infection, dietary Mn deficiency alone increased intestinal permeability by impairing intestinal tight junctions. In addition, when fed the control and Mn-surfeit diets, birds showed decreased Salmonella burdens in cecal content and spleen, with a concomitant increase in inflammatory cytokine levels in spleen. Furthermore, the dietary Mn-supplementation-mediated induction of cytokine production was probably associated with the nuclear factor kappa-B (NF-κB)/hydrogen peroxide (H2O2) pathway, as judged by the enhanced manganese superoxide dismutase activity and the increased H2O2 level in mitochondria, together with the increased mRNA level of NF-κB in spleen. Ingenuity-pathway analysis indicated that acute-phase response pathways, T helper type 1 pathway, and dendritic cell maturation were significantly activated by the dietary Mn supplementation. Our data suggest that dietary Mn supplementation could enhance intestinal barrier and splenic inflammatory response to fight against Salmonella infection in broilers