Localisation of iron in wheat grain using high resolution secondary ion mass spectrometry

Insufficient iron (Fe) is one of the most prevalent micronutrient deficiencies in humans, with billions of people affected. Cereal grains are an important source of Fe for humans but the bioavailability of Fe in cereals is generally low. Information regarding the cellular and sub-cellular localisation of Fe in wheat grain will aid optimising nutrient delivery for human health. In this study high resolution secondary ion mass spectrometry (NanoSIMS) was used to map the distribution of Fe in the aleurone layer and in the endosperm of immature wheat grain. Iron was shown to be localised strongly in the phytin globoids in the aleurone cells and to a lesser extent in the cytoplasm around the starch granules in the endosperm.     

The Effect of Consumption of Selenium Enriched Rye/Wheat Sourdough Bread on the Body’s Selenium Status

The potential of selenium-enriched rye/wheat sourdough bread as a route for supplementing dietary selenium intakes is reported. In addition to their normal diets, 24 female volunteers (24 to 25 years old) were fed either selenium-enriched bread or non-enriched bread each day (68.02 and 0.84 μg selenium day⁻¹ respectively) for 4 weeks. The chemical form of the selenium in the bread had been characterised using HPLC-ICP-MS, which showed that 42% of the extractable selenium was present as selenomethionine. Plasma selenium levels and plasma platelet glutathione peroxidase (GPx1) activity were measured in the volunteers’ blood over a 6-week period. A statistically significant difference (p = 0.001) was observed in the mean percentage change data, calculated from the plasma selenium level measurements for the enriched and control group, over the duration of the study. A comparable difference was not observed for the platelet GPx1 activity (p = 0.756), over the same period. Two weeks after cessation of the feeding stage, i.e., at t = 6 weeks, the mean percentage change value for the selenium plasma levels in the enriched group was still significantly elevated, suggesting that the absorbed selenium had been incorporated into the body’s selenium reserves, and was then being slowly released back into the volunteers’ blood.     

Niche partitioning among Prochlorococcus ecotypes along ocean-scale environmental gradients

Prochlorococcus is the numerically dominant phytoplankter in the oligotrophic oceans, accounting for up to half of the photosynthetic biomass and production in some regions. Here, we describe how the abundance of six known ecotypes, which have small subunit ribosomal RNA sequences that differ by less than 3%, changed along local and basin-wide environmental gradients in the Atlantic Ocean. Temperature was significantly correlated with shifts in ecotype abundance, and laboratory experiments confirmed different temperature optima and tolerance ranges for cultured strains. Light, nutrients, and competitor abundances also appeared to play a role in shaping different distributions.     

CoRoT measures solar-like oscillations and granulation in stars hotter than the Sun

Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars.     

The effect of dicyandiamide on pasture nitrate concentration,yield and N offtake under high N loading in winter and spring

High nitrate () concentrations in pastures and forages represent a health risk to grazing livestock. A field trial was conducted on the Lincoln University Dairy Farm, New Zealand, to investigate the effects of applying the nitrification inhibitor dicyandiamide (DCD) on soil extractable N and pasture concentrations in winter and spring. Treatments were control (T1), urea (T2), urea + DCD (T3), May urine + DCD (T4), August urine + DCD (T5), May urine (T6) and August urine (T7). Urine treatments were applied to the ryegrass‐white clover pasture in either May or August. The DCD treatments were applied at 10 kg DCD ha^?1 in May and August and urea at 25 kg N ha^?1 at selected intervals. Soil samples (0‐ to 75‐ and 75‐ to 150‐mm horizons) were taken regularly to monitor soil and ammonium () levels. Six pasture harvests were conducted from August 2007 to March 2008 and samples analysed for ‐N concentrations and total N content. Application of DCD significantly (P < 0·001) increased total dry‐matter (DM) production by 39 and 42% for the autumn and spring urine treatments, respectively, compared to the urine‐alone treatments. In addition, the application of DCD also significantly (P < 0·001) increased DM yield by 12% on the urea‐only treatment. DCD significantly (P < 0·001) reduced pasture concentrations in both autumn‐ and spring‐applied urine treatments where DCD was applied. This was directly linked to reductions in soil , and increases in soil , from DCD application. The preferential uptake by pasture for ‐N over ‐N may also have been a contributing factor. DCD application can therefore substantially reduce pasture ‐N concentrations to safe levels under high N‐loading (urine patch) conditions.     

Aspartame生产废液作为农业氮肥资源的评估研究

以美国佐治亚洲广为分布的红壤和沙质灰土以及棉花和玉米为试验材料，进行Aspartame生产废液（BST，下同）与传统氮肥尿素、硫酸铵的温室盆栽和恒温土培对比试验。结果表明，BST是很好的氮肥资源，等同于或某种程度上优于尿素和硫酸铵。对土壤的理化性质、氨态氮、硝态氮含量以及对作物吸收Ca,Mg，K等养分和生长发育的影响与常规氮肥相似。但废液中有机态氮的水解以及向硝态氮的转化比尿素要快一些。尿素和BST比硫酸铵更适于在红壤和沙质灰土上施用。     

Authentication of coffee by means of PCR-RFLP analysis and lab-on-a-chip capillary electrophoresis

Coffee is one of the most important world food commodities, commercial trade consisting almost entirely of Arabica and Robusta varieties. The former is considered to be of superior quality and thus attracts a premium price. Methods to differentiate these coffee species could prove to be beneficial for the detection of either deliberate or accidental adulteration. This study describes a molecular genetics approach to differentiate Arabica and Robusta coffee beans. This employs a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism to monitor a single nucleotide polymorphism within the chloroplastic genome. Samples were analyzed with a lab-on-a-chip capillary electrophoresis system. Coffee powder mixtures were analyzed with this technique, displaying a 5% limit of detection. The plastid copy number was found to be relatively constant across a wide range of bean samples, suggesting that this methodology can also be employed for the quantification of any adulteration of Arabica with Robusta beans.