Seed Longevity of Melaleuca quinquenervia: A Burial Experiment in South Florida

Burial and removal techniques with seed bags were used to examine the viability and longevity of Melaleuca quinquenervia seeds at four field sites representing different soil types and hydrological conditions in South Florida. Seed viability was determined over different burial durations in the soil through a combination of germination tests and 2,3,5-triphenyl- tetrazolium chloride (TTC) treatments. Control seeds kept dry at 25 C in the laboratory maintained same viability of ca. 15% over the 3-year study. In the field, seed viability decreased with increased burial duration.(PDF has 4 pages.

Easy and rapid detection of iron in rice grain

In this study, we show how a preliminary determination of grain Fe in rice may be made with reaction to Perls’ Prussian blue, a stain for Fe (III). Differential localization of Fe in grain parts was indicated by the intensity of reaction of tissue Fe to the dye. The blue colour reaction was most intense in the embryo, weak in the aleurone layer of the pericarp and invisible in the endosperm. The staining intensity also varied with the region of the embryo, generally being strongest in the scutellum, intermediate in the coleorhiza and weakest in the coleoptile. Variation in the reaction to Perls’ Prussian blue was observed among eleven rice genotypes with varying grain Fe contents. The intensity of the blue colour reaction in the embryo of different rice genotypes was indicative of their grain Fe contents for both brown and white (polished) rice. Those with high grain Fe, >14 mg Fe kg-1, were clearly distinguishable from those with <10 mg Fe kg-1 with Perls’ Prussian blue. We suggest that this simple staining procedure may be used to quickly screen for high Fe contents in large germplasms containing hundreds of rice entries, using reactions in genotypes with known grain contents as standards

Effects of cooking on anthocyanin concentration and bioactive antioxidant capacity in glutinous and non-glutinous purple rice

Purple rice is a source of bioactive antioxidants for rice consumers. Loss of the major antioxidant compounds after a range of cooking processes was evaluated by measuring the change in anthocyanin concentration (ATC) and antioxidant capacity (DPPH activity) of four non-glutinous and four glutinous genotypes. However, soaking in water prior to cooking generally decreased ATC and DPPH activity more in non-glutinous than in glutinous genotypes. Wet cooking (WC) and soaking before wet cooking (S-WC) led to almost all the ATC and DPPH activity being lost with only slight variation between genotypes. In the glutinous genotype PES, which had the highest raw rice ATC, the highest ATC remained when cooked by the WC method. By contrast, almost no ATC remained after WC and S-WC in the low ATC genotypes such as KDK. Overall, the loss of ATC on cooking was greater in non-glutinous than glutinous genotypes for both WC and S-WC, but the reverse occurred for DPPH activity. Wet cooking using electric rice cooker retained higher ATC than the pressure cooking. Thus, for genotypes with high ATC and antioxidant capacity, the selection of cooking method is critical for retaining and stabilizing rice quality

Macroscopic behavior of bidisperse suspensions of noncolloidal particles in yield stress fluids

We study both experimentally and theoretically the rheological behavior of isotropic bidisperse suspensions of noncolloidal particles in yield stress fluids. We focus on materials in which noncolloidal particles interact with the suspending fluid only through hydrodynamical interactions. We observe that both the elastic modulus and yield stress of bidisperse suspensions are lower than those of monodisperse suspensions of same solid volume fraction. Moreover, we show that the dimensionless yield stress of such suspensions is linked to their dimensionless elastic modulus and to their solid volume fraction through the simple equation of Chateau et al.[J. rheol. 52, 489-506 (2008)]. We also show that the effect of the particle size heterogeneity can be described by means of a packing model developed to estimate random loose packing of assemblies of dry particles. All these observations finally allow us to propose simple closed form estimates for both the elastic modulus and the yield stress of bidisperse suspensions: while the elastic modulus is a function of the reduced volume fraction $\phi/\phi_m$ only, where $\phi_m$ is the estimated random loose packing, the yield stress is a function of both the volume fraction $\phi$ and the reduced volume fraction

Variation of milling and grain physical quality of dry season Pathum Thani 1 in Thailand

Pathum Thani 1 (PTT1) is a photoperiod-insensitive, aromatic Thai rice variety that is grown year-round. The rice from some locations is often priced lower than others due to sub-standard grain quality. This study sought to determine the limiting grain quality characteristic(s) in dry season PTT1 and their distribution across Thailand’s irrigated rice regions. To do so, we evaluated the milling and physical quality of milled rice grain of dry season PTT1 from 24 provinces in 5 regions in Thailand. Sixty-seven paddy rice samples were collected and evaluated for head rice yield, chalkiness, whiteness, and translucency. Head rice yield varied by region, with the highest (48.1%) found in samples from the Central region, compared to 34.5-39.7% elsewhere. Head rice chalkiness was the physical quality that varied more widely among the provinces within each region than among regions, with chalkiness at a level that would adversely affect price in more than one-half of the samples. Contrary to the general perception that chalky grain is less resistant in milling, head rice yield actually increased with total chalkiness, expressed as % chalky grain by weight. The total chalkiness correlated negatively with translucency, while the head rice chalkiness correlated positively with whiteness. Grain chalkiness was identified as the grain quality attribute of PTT1 rice that varied with location; this directly affected the price of milled rice grain, as well as indirectly through its relationship with head rice yield and visual appearance of the milled rice grai

Responses of milling quality to nitrogen and water management in modern long grain rice varieties

This study determined how nitrogen (N) fertilizer and water management affect grain yield and milling quality of 9 modern rice varieties with long, slender grain in two field experiments. The effect of N on rice grown in wetland culture was evaluated at 0, 60 and 120 kg N ha-1. In a second experiment the rice in aerobic and wetland culture were compared. The rice in both experiments were grown to maturity and evaluated for yield, head rice yield and chalkiness. Grain yield increased with increasing N application, head rice yield increased with increasing N in 8 varieties, while chalkiness was more than halved in 7 varieties. Grain N also increased with increasing N fertilizer, but high head rice yield in several varieties was associated with relatively low grain N. Under aerobic cultivation, all 9 varieties yielded less than in wetland culture, the head rice yield was lower and chalkiness was higher except in 2 varieties. In both experiments, grain yield was associated positively with head rice yield and negatively with chalkiness. Head rice yield and chalkiness were negatively associated in the water experiment but not in the N experiment. This study has shown that modern high yielding rice varieties generally respond positively to nitrogen fertilizer in better milling quality as well as in yield. Grain chalkiness of the varieties was more stable against variation in the environment than head rice yield

Imaging Proteins, Cells, and Tissues Dynamics during Embryogenesis with Two-Photon Light-Sheet Microscopy

Two-photon light sheet microscopy combines nonlinear excitation with the novel sheet-illumination, orthogonal to the detection direction, to achieve high penetration depth, high acquisition speed, and low photodamage, compared with conventional imaging techniques. These advantages allow unprecedented observation of the processes that govern embryogenesis, where the ability to image fast the dynamic three dimensional structure of the developing embryo, over extended periods of time, is critical. We present a selection of applications where two-photon light sheet microscopy is utilized to observe the dynamics of proteins, cells, and tissues, toward an understanding of the construction program of the developing embryos

Cost driver analysis of statin expenditure on Australia’s pharmaceutical benefits scheme

The Australian Pharmaceutical Benefits Scheme (PBS) provides universal access to subsidised medicines. In 2013, statins as a class had the highest expenditure on the PBS. To assess the influence of policies and drivers affecting PBS statin utilisation and expenditure between 1992 and 2013. Analyses conducted from 1992 to 2013 and over three distinct time periods, including monthly expenditure/prescription, annual utilisation (calculated as Defined Daily Doses/1000 inhabitants/day) and statin strengths dispensed. The major driver of increased PBS expenditure for statins was increased volumes. After adjusting for inflation, the average PBS expenditure on statin prescriptions was the major negative driver. Other influential drivers included the increased use of newer statins and increased strength of statins dispensed. Whilst the inflation-adjusted reimbursed price of statins decreased, increased utilisation, including increased use of patented statins, increased total statin expenditure. Successful measures adopted by other countries could be applied to Australia to decrease total medicines expenditure

Simultaneous Quantification of Anthocyanins and Phenolic Acids in Pigmented Rice (Oryza sativa) using UPLC-PDA/ESI-Q-TOF

Anthocyanins and phenolic acids are the major antioxidants in purple rice. The method conditions were specified and not coved for both anthocyanins and phenolic acids. The objective of this study was to adopt the UPLC coupled with ESI-MS method for determination of the major anthocyanins and phenolic acids under the same condition in purple, red and white rice varieties. A UPLC-PDA/ESI-Q-TOF method was optimized with a high linearity for all analyzed compounds with regression coefficients greater than 0.99. Repeatability was good with the relative standard deviation values generally less than 5.5%. The limit of detection and quantification ranged from 1.9-36.6 and 5.0-123.1 mu g kg(-1), respectively. Spike recoveries were between 81-116%. Mass spectroscopy was used to confirm identity in the positive ion mode for all analyzed compounds Cyanidin-3-glucoside and ferulic acid were the most abundant anthocyanins and phenolic acids, respectively. Bound ferulic acid was higher in purple rice than in red and white rice flours. This developed procedure can be used to facilitate the rapid screening of rice seed banks for anthocyanins and phenolic acids of interest for rice pre-breeding