Anthocyanin antioxidant activity and partition behavior in whey protein emulsion

The antioxidant activities of anthocyanins and anthocyanin fractions isolated from blackcurrants, raspberries, and lingonberries were investigated in whey protein-stabilized emulsion. The extent of protein oxidation was measured by determining the loss of tryptophan fluorescence and formation of protein carbonyl compounds and that of lipid oxidation by conjugated diene hydroperoxides and hexanal analyses. The antioxidant activity of berry anthocyanins increased with an increase in concentration. Blackcurrant anthocyanins were the most potent antioxidants toward both protein and lipid oxidation at all concentrations due to the beneficial combination of delphinidin and cyanidin glycosides. Most berry anthocyanins (69.4-72.8%) partitioned into the aqueous phase of the emulsion, thus being located favorably for antioxidant action toward protein oxidation. The presence of the lipid decreased the share of anthocyanin in the aqueous phase. Thus, the structure of food affects the antioxidant activity by influencing the partitioning of the antioxidant.     

Root morphology and acid phosphatase activity in tomato plants during development of and recovery from phosphorus stress

Changes in root morphology and acid phosphatase activity (APA) were followed during the developent of P‐deficiency in tomato plants grown for 7, 14, and 21 days in 0.16 P well aereated nutrient solutions, followed by a period of sufficiency (recovery) in 1 mM P. Plants were harvested weekly for APA, dry weight, and P concentration in roots, stems and leaves, and every 2 weeks for root morphology determinations. APA was highly correlated to development and recovery from P stress. Mixmium values were attained during growth under deficiency and decreased to that of the control plants after a period of recovery in 1 mM P nutrient solutions. Total root weight and average root diameter decreased under P‐stress and root surface area per unit dry weight increased. Efficiency of P utilization (g dry weight/mg absorbed P) was much higher at the end of the stress period but approached that of the controls as P‐supply was restored to sufficiency levels. The implications of these results in developing rapid and reliable screening technigues to detect successful plant performance under P‐stress is discussed.     

Crop biomass and humidity related factors reflect the spatial distribution of phytopathogenic <Emphasis Type="Italic">Fusarium</Emphasis> fungi and their mycotoxins in heterogeneous fields and landscapes

Fusarium head blight (FHB) is a global problem in small-grains agriculture that results in yield losses and, more seriously, produces harmful toxins that enter the food chain. This study builds on previous research identifying within-field humidity as an important factor in infection processes by Fusarium species and its mycotoxin production. Environmental variables describing topographic control of humidity (TWI), soil texture and related moisture by electrical conductivity (ECa), and canopy humidity by density (NDVI) were explored in their relationship to the fungal infection rates, the abundance of trichothecene-producing Fusarium spp. as determined by TRI 6 gene copies and mycotoxin accumulation. Field studies were performed at four field sites in northeastern Germany in 2009 and 2011. In the wet year 2011, a high Fusarium infection rate resulted in a high abundance of trichothecene-producing fungi as well as high concentrations of mycotoxins. Simultaneously, Fusarium spp. inhibited the development of other filamentous fungi. Overall, a very heterogeneous distribution of pathogen infections and mycotoxin concentrations were displayed in each field in each landscape. The NDVI serves as an important predictor of the occurrence of phytopathogenic Fusarium fungi and their mycotoxins in a field and landscape scale. In addition, the ECa reflects the distribution of the most frequently occurring mycotoxin deoxynivalenol within the fields and landscapes. In all cases, TWI was not found to be a significant variable in the models. All in all, the results extend our knowledge about suitable indicators of FHB infection and mycotoxin production within the field.     

Arginylation of beta-actin regulates actin cytoskeleton and cell motility

Posttranslational arginylation is critical for mouse embryogenesis, cardiovascular development, and angiogenesis, but its molecular effects and the identity of proteins arginylated in vivo are unknown. We found that beta-actin was arginylated in vivo to regulate actin filament properties, beta-actin localization, and lamella formation in motile cells. Arginylation of beta-actin apparently represents a critical step in the actin N-terminal processing needed for actin functioning in vivo. Thus, posttranslational arginylation of a single protein target can regulate its intracellular function, inducing global changes on the cellular level, and may contribute to cardiovascular development and angiogenesis.     

Grazing management strategies for Urochloa decumbens (Stapf) R. Webster in a silvopastoral system under rotational stocking

Our objective was to compare herbage accumulation and nutritive value of Urochloa decumbens (Stapf) R. Webster managed under pre-grazing canopy light interception (LI) targets of 90%, 95% and 100% in silvopastoral system (SPS) and 95% in open pasture (OP; U. decumbens under full sunlight) to establish a pre-grazing target for SPS of ~43% shade. The evaluations were made during two rainy seasons and one dry season. The total herbage accumulation in SPS was lower than in OP at all LI targets and seasons. However, the difference in total herbage accumulation between SPS and OP was reduced when SPS was harvested at 95% LI, with reductions of 20% and 28% in both rainy seasons (12,191 × 15,324 kg DM/ha and 11,158 × 15,424 kg DM/ha respectively). Moreover, under 95% LI in SPS, crude protein concentration was 18% and 19% greater than that in OP in both rainy seasons (155 × 131 g/kg DM and 144 × 121 g/kg DM respectively), thus representing the optimal pre-grazing LI target for U. decumbens in SPS. In addition, a canopy height of 20 cm was necessary for 95% LI in OP and a height of 40 cm in SPS. Therefore, U. decumbens should be grazed at 40 cm canopy height, in SPS with ~43% shade to keep 95% LI as the target. However, this target will only be effective if the shade level is maintained, which will reduce height variation over time.     

Endolysins from Antarctic Pseudomonas Display Lysozyme Activity at Low Temperature

Organisms specialized to thrive in cold environments (so-called psychrophiles) produce enzymes with the remarkable ability to catalyze chemical reactions at low temperature. Cold activity relies on adaptive changes in the proteins’ sequence and structural organization that result in high conformational flexibility. As a consequence of flexibility, several such enzymes are inherently heat sensitive. Cold-active enzymes are of interest for application in a number of bioprocesses, where cold activity coupled with easy thermal inactivation can be of advantage. We describe the biochemical and functional properties of two glycosyl hydrolases (named LYS177 and LYS188) of family 19 (GH19), identified in the genome of an Antarctic marine Pseudomonas. Molecular evolutionary analysis placed them in a group of characterized GH19 endolysins active on lysozyme substrates, such as peptidoglycan. Enzyme activity peaks at about 25–35 °C and 40% residual activity is retained at 5 °C. LYS177 and LYS188 are thermolabile, with Tm of 52 and 45 °C and half-lives of 48 and 12 h at 37 °C, respectively. Bioinformatics analyses suggest that low heat stability may be associated to temperature-driven increases in local flexibility occurring mainly in a specific region of the polypeptide that is predicted to contain hot spots for aggregation.     

Application of a low-cost RGB sensor to detect basil (Ocimum basilicum L.) nutritional status at pilot scale level

Precision Agriculture - In this work, basil plants were fertilized with 0, 2.5&nbsp;mM and 10&nbsp;mM nitrogen (with different NO3?/NH4+ ratios), and then monitored using a low-power...     

Phosphorus homeostasis in dairy cows with abomasal displacement or abomasal volvulus

Abnormal phosphorus homeostasis occurs in dairy cows with an abomasal displacement or volvulus. The goal of this study was to identify potential mechanisms for hypophosphatemia and hyperphosphatemia in cows with a left displaced abomasum (LDA), right displaced abomasum (RDA), or abomasal volvulus (AV). Accordingly, the results of preoperative clinicopathologic analyses for 1,368 dairy cows with an LDA (n = 1,189), RDA, or AV (n = 179) (data set 1) and for 44 cows with an AV (data set 2) were retrieved. Laboratory values were compared by Student's t-tests, and correlation and regression analyses were performed. Thirty-four percent of the animals from data set 1 (463/1,368) were hypophosphatemic (serum phosphorus concentration ([Pi]) < 1.4 mmol/L), and 9% (122/1,368) were hyperphosphatemic ([Pi] >2.3 mmol/L). Serum [Pi] was significantly lower (P < .05) in cows with an LDA (1.60 +/- 0.53 mmol/L; mean +/- SD) than in cows with an RDA or AV (1.85 +/- 0.68 mmol/L). For cows with an LDA, [Pi] was correlated with serum urea nitrogen concentration ([SUN]) (r = 0.34) and serum concentration of magnesium ([Mg]) (r = 0.20). For cows with an RDA or AV, linear correlations existed between [Pi] and [SUN] (r = 0.45), [Mg] (r = 0.43), and serum chloride concentration ([Cl]) (r = -0.27). Stepwise logistic regression analysis indicated that low [SUN] and the diagnosis of an LDA had the strongest associations with hypophosphatemia. In cows with hyperphosphatemia, [Pi] was most strongly associated with azotemia. In cows with an AV, the strongest correlations with [Pi] were found for [SUN] and serum creatinine. We conclude that hypophosphatemia in cows with an LDA is primarily due to decreased feed intake. In contrast, hyperphosphatemia in cattle with an RDA or AV appears to result from dehydration and decreased renal blood flow.     

Mapping radiation interception in row-structured orchards using 3D simulation and high-resolution airborne imagery acquired from a UAV

This study was conducted to model the fraction of intercepted photosynthetically active radiation (fIPAR) in heterogeneous row-structured orchards, and to develop methodologies for accurate mapping of the instantaneous fIPAR at field scale using remote sensing imagery. The generation of high-resolution maps delineating the spatial variation of the radiation interception is critical for precision agriculture purposes such as adjusting management actions and harvesting in homogeneous within-field areas. Scaling-up and model inversion methods were investigated to estimate fIPAR using the 3D radiative transfer model, Forest Light Interaction Model (FLIGHT). The model was tested against airborne and field measurements of canopy reflectance and fIPAR acquired on two commercial peach and citrus orchards, where study plots showing a gradient in the canopy structure were selected. High-resolution airborne multi-spectral imagery was acquired at 10?nm bandwidth and 150?mm spatial resolution using a miniaturized multi-spectral camera on board an unmanned aerial vehicle (UAV). In addition, simulations of the land surface bidirectional reflectance were conducted to understand the relationships between canopy architecture and fIPAR. Input parameters used for the canopy model, such as the leaf and soil optical properties, canopy architecture, and sun geometry were studied in order to assess the effect of these inputs on canopy reflectance, vegetation indices and fIPAR. The 3D canopy model approach used to simulate the discontinuous row-tree canopies yielded spectral RMSE values below 0.03 (visible region) and below 0.05 (near-infrared) when compared against airborne canopy reflectance imagery acquired over the sites under study. The FLIGHT model assessment conducted for fIPAR estimation against field measurements yielded RMSE values below 0.08. The simulations conducted suggested the usefulness of these modeling methods in heterogeneous row-structured orchards, and the high sensitivity of the normalized difference vegetation index and fIPAR to background, row orientation, percentage cover and sun geometry. Mapping fIPAR from high-resolution airborne imagery through scaling-up and model inversion methods conducted with the 3D model yielded RMSE error values below 0.09 for the scaling-up approach, and below 0.10 for the model inversion conducted with a look-up table. The generation of intercepted radiation maps in row-structured tree orchards is demonstrated to be feasible using a miniaturized multi-spectral camera on board UAV platforms for precision agriculture purposes.