Mobilities of Organic Compounds in Reconstituted Cuticular Wax of Barley Leaves: Effects of Monodisperse Alcohol Ethoxylates on Diffusion of Pentachlorophenol and Tetracosanoic Acid

Effects of monodisperse alcohol ethoxylates on mobilities of ¹⁴C-labelled pentachlorophenol (PCP) and tetracosanoic acid (C₂₄AC) in reconstituted cuticular wax of barley leaves were measured. Depending on the respective alcohol ethoxylate investigated, the diffusion coefficient (D) of PCP in barley wax was increased by factors ranging from 3·3 to 19·6, whereas D of C₂₄AC, was increased by factors varying between 22 and 315. In order to analyse the relationship between the concentration of surfactants in the wax and their effects on D, the amounts of alcohol ethoxylates dissolved in the wax at equilibrium with external concentrations well above the critical micelle concentration (CMC) were determined. Wax/water partition coefficients (K_ww) of the alcohol ethoxylates were about one order of magnitude lower than cuticle/water partition coefficients (K_cw), which is a consequence of the semi-crystalline structure of the wax compared with amorphous cutin. Correlations between effects on D and maximum amounts of alcohol ethoxylates dissolved in the wax were obtained indicating an unspecific wax/surfactant interaction. This was solely dependent on the amount of surfactant sorbed to the wax, leading to increased mobilities of pesticides in the wax. Applying ESR-spectroscopy, which gave an insight into the molecular structure of the wax, supported this interpretation of an unspecific plasticising effect of the alcohol ethoxylates on the molecular structure of the wax. The results obtained in this study are in good accordance with the results obtained in a recent study investigating the effects of the same group of alcohol ethoxylates on mobilities of pesticides in isolated, but intact, cuticular membranes of Citrus. This demonstrates that the investigation of isolated and subsequently reconstituted cuticular wax is a useful model system analysing the mechanisms of the surfactant interaction with the transport-limiting barrier of plant cuticles.     

Asymmetrical, transitional, lumbosacral vertebral segments in six dogs: a characteristic spinal syndrome

Clinical findings in six dogs with asymmetrical, transitional, lumbosacral vertebral segments are reported. All dogs exhibited low back pain and varying degrees of asymmetrical cauda equina dysfunction. Results of myelography, epidurography, and magnetic resonance imaging (MRI) indicated a unilateral disk protrusion in all dogs. In the dogs with MRIs, focal degenerative alterations in the vertebral end plates and adjacent body of the vertebra were detected. All dogs were treated with a dorsal laminectomy or hemilaminectomy. Results following surgery were good or excellent in all six dogs.     

Physicochemical Properties of Rice Endosperm Proteins Extracted by Chemical and Enzymatic Methods

Rice proteins are nutritional, hypoallergenic, and healthy for human consumption. Efficient extraction with approved food‐grade enzymes and chemicals are essential for commercial production and application of rice protein as a functional ingredient. Rice endosperm proteins were isolated by alkali, salt, and enzymatic methods and evaluated for extractability and physicochemical properties. Alkali (RP_A) and salt (RP_S) methods extracted 86.9 and 87.3% of proteins with 65.9 and 58.9% yield, respectively. The enzymatic methods with Termamyl (RP_ET) and amylase S (RP_EA) extracted 85.8 and 81.0% proteins with 85.2 and 86.2% yield, respectively. Enthalpy values of RP_A (1.79 J/g), RP_S (1.22 J/g), RP_ET (nondetectable), and RP_EA (0.17 J/g), determined by differential scanning calorimetry, demonstrated that the varying level of denaturation of proteins depends on the method of extraction. Surface hydrophobicity data supported this observation. Alkali‐ and salt‐extracted proteins had higher solubility and emulsifying properties than those of enzyme‐extracted proteins. Comparatively, more favorable protein composition, lower surface hydrophobicity, higher solubility, and a lower degree of thermal denaturation of alkali‐ and salt‐extracted proteins contributed to higher emulsifying and foaming properties than those of enzyme‐extracted proteins; therefore, alkali‐ and salt‐extracted proteins can have enhanced functional use and a potential starting material for preparing tailored rice protein isolates.     

Analyzing the effects of risk and uncertainty on optimal tillage and nitrogen fertilizer intensity for field crops in Germany

This study provides a risk analysis of long-term field experiments in Germany (Bavaria) on various field crops (potato, wheat and corn), grown in rotation, under a variety of different tillage and nitrogen management systems. The field experiment provided yield and input data for the analysis, and was combined with market data relevant to the case-study region. The emphasis of the analysis is on the interaction between risk and tillage and nitrogen strategies. Over the whole rotation (corn-wheat-potato-wheat), conventional tillage combined with conventional nitrogen rates is optimal, both for risk-neutral and risk-averse farmers. Although less intensive management practices involve lower risk, the decrease in risk premium is not sufficient to alter the ranking of strategies, even for farmers with higher levels of risk aversion. Reducing nitrogen rates would be costly to farmers, especially under reduced or shallow tillage. Decoupled farm subsidies within the expected utility model show that even for a scenario with no subsidies our conclusions do not change.     

Prevalence of subclinical mastitis in dairy farms in urban and peri-urban areas of Kampala, Uganda

It is widely recognized that subclinical mastitis (SCM) is an extensive problem in the dairy industry worldwide. It is of particular concern in developing countries. The aim of this study was to establish the prevalence of SCM in dairy cattle in the urban and peri-urban areas of Kampala, Uganda and to gain information about pathogens and antibiotic resistance patterns. The study was conducted as a field study in 18 smallholder dairy farms in peri-urban Kampala, Uganda. All cows at the farms were physically examined, and cows with signs of clinical mastitis were excluded. Cows (n?=?195) were tested with California Mastitis Test (CMT), and udder quarters with CMT score ≥3 (scale 1–5) were milk sampled for bacteriological analysis. To allow further sub-analysis of the results, the stage of lactation, parity, milk production, production type, udder hygiene, and cow breed were recorded. Results indicate that 86.2 % (n?=?168) of the tested cows had SCM in one or more quarters. The most common bacteriological outcome was infection with coagulase-negative staphylococci (54.7 %), followed by negative growth (24.9 %) and streptococci (16.2 %); all of which (n?=?34) were sensitive to penicillin. Of the tested staphylococci (n?=?17), the majority (58.9 %) were positive for penicillinase production. Factors with significant impact on the prevalence of SCM at cow level were the stage of lactation, parity, and production type. The results suggest that the prevalence of SCM in Uganda is substantially higher than reported in previous studies and in other comparable developing countries. This implies that SCM deserves more attention and that improvement in dairy cow husbandry in terms of hygiene and management is necessary.     

Social behavior in hatchling green iguanas: life at a reptile rookery

Hatchling green iguanas (Iguana iguana) emerge from the ground in small groups in a communal nesting area on a small Panamanian islet and engage in complex social interactions. Iguanas from different clutches often join together before and during departure from the nest site. They also usually move around the islet and migrate from it to the larger adjacent landmass in social groups. These and other observations indicate that the sophistication of saurian social organization and neonate behavior has been underestimated.     

Genome-wide insertional mutagenesis of Arabidopsis thaliana

Over 225,000 independent Agrobacterium transferred DNA (T-DNA) insertion events in the genome of the reference plant Arabidopsis thaliana have been created that represent near saturation of the gene space. The precise locations were determined for more than 88,000 T-DNA insertions, which resulted in the identification of mutations in more than 21,700 of the approximately 29,454 predicted Arabidopsis genes. Genome-wide analysis of the distribution of integration events revealed the existence of a large integration site bias at both the chromosome and gene levels. Insertion mutations were identified in genes that are regulated in response to the plant hormone ethylene.