Using a wheat-rye amphihaploid population to map a rye gene responsible for dwarfness

Gene identification in cross-pollinating plants such as rye can be arduous and time consuming because of the difficulties involved with genetic population construction. Here, we provide an alternative approach for the construction of mapping populations to rapidly map genes in cross-pollinated cereal rye. The aim of the present experiments was to genetically analyze the dwarf stature expressed by a germplasm accession of rye. The dwarf phenotype was reversible when the seedlings were exposed to gibberellic acid; the reductions in plant height occurred via reductions in cell size. A mapping population was constructed by generating a set of wheat-rye amphihaploids bred from a single rye plant heterozygous for the dwarfing gene(s). The dwarfness phenotype was expressed in the amphihaploid background, and segregation in the mapping population was consistent with the presence of a single gene. Using rye SSR markers, the gene responsible was located on chromosome arm 1RL, which is also the location of the known rye dwarfing gene Ddw3. This gene is valuable for dwarf breeding of wheat as well as rye.     

An appreciation of the contribution of Frank Stevenson to the advancement of studies of soil organic matter and humic substances

Purpose

The aims of this paper are to outline the state of knowledge with regard to the chemistry of soil organic matter (SOM) prior to 1950; then, to review and evaluate the contributions made by Frank Stevenson during Stevenson’s research period (1950–1994); and subsequently to outline advances that are being made in the modern era.

Progress in the Stevenson period

Frank Stevenson’s research career began in the middle of the twentieth century when a number of techniques of colloid chemistry were available to him, but relatively few of the recently developed instrumental techniques and other procedures of analytical organic chemistry that have enabled significant advances to be made in the chemistry and properties of SOM components.The contributions that Frank Stevenson has made to the chemistry of SOM and of humic substances (HSs) are an integral part of his book (first and second editions) Humus Chemistry: Genesis, Composition, Reactions. The validity of the terms humus and HSs are being questioned as legitimate terms that describe definable components, and SOM is being viewed as a ‘continuum of progressively decomposing organic compounds’. The legitimacy of isolating the organic matter components from their native soil environment is questioned. Those who pose such questions would do well to consider how progress could have been made in the vital life sciences areas of, for example, proteomics and genomics, without the isolation of the relevant cellular components. We recognise the importance of clear and rigorous definitions of HS components and stress the need to isolate these components from the SOM matrix as a prerequisite to the study of the composition, structure and reactivity of these components. We disagree with proposals or suggestions that do not recognise HSs as a scientific entity, and we feel sure that Frank Stevenson would have supported this stance. Various studies of SOM and of HSs have taken place over the centuries, but progress was slow because the tools required to study such complex systems were not available. Frank Stevenson’s research involved many areas of humic chemistry, and his major advances were in aspects of functionality and in the interactions of humic functional groups with metals and to a lesser extent with anthropogenic organic chemicals. His studies of nitrogen and of ammonia in relation to organic matter also had a very great impact.

Progress in the modern era

Frank Stevenson can be said to have provided the stimulation that enabled beginners and established scientists to obtain a good grasp of the fundamentals of SOM and the humic sciences. His scientific contributions have catalysed many of the significant advances that have been made in the field since he retired. In the final section, some of the advances that have been made using modern analytical techniques are addressed and some of the controversial topics that have recently arisen are discussed.

     

Gender power in Kenyan dairy: cows,commodities, and commercialization

In Western Kenya, smallholder dairy production is becoming incrementally commercialized through the commodification and sale of milk through formal market channels. While commercialization is often construed as a way to boost rural livelihoods through increased income from milk, emerging evidence suggests that married women are not directly benefiting from formal milk market participation. This critical issue of gender power imbalance has been framed by development interventions in economic efficiency and social justice perspectives, but thus far interventions in the sector have not addressed how underlying social-market mechanisms embedded in gendered ideology influence smallholder engagement in dairy commercialization. Drawing on feminist theories of power and social embeddedness, this study investigates how gendered power relationships materialize and influence formal milk marketing engagement and practices in Western Kenya. Facilitated discussion groups with smallholder farmers revealed the gendered ideologies and norms that ascribe masculinized meaning to cattle, milk, and commercial enterprise. Key informant interviews with commercial dairy management and farmers were used to identify current practices for increasing women’s formal market participation—namely, direct payments to women for milk deliveries. Findings from this study indicate that cattle and formal dairy market participation are imbued with gendered meaning that create legitimacy around men’s privilege over dairy proceeds. Interventions in the sector aimed at addressing gender power imbalances must acknowledge this dynamic, and accept the social trade-offs and gendered costs of dairy commercialization.     

Multi-scale Modeling of Animal Movement and General Behavior Data Using Hidden Markov Models with Hierarchical Structures

Hidden Markov models (HMMs) are commonly used to model animal movement data and infer aspects of animal behavior. An HMM assumes that each data point from a time series of observations stems from one of N possible states. The states are loosely connected to behavioral modes that manifest themselves at the temporal resolution at which observations are made. Due to advances in tag technology and tracking with digital video recordings, data can be collected at increasingly fine temporal resolutions. Yet, inferences at time scales cruder than those at which data are collected and, which correspond to larger-scale behavioral processes, are not yet answered via HMMs. We include additional hierarchical structures to the basic HMM framework, incorporating multiple Markov chains at various time scales. The hierarchically structured HMMs allow for behavioral inferences at multiple time scales and can also serve as a means to avoid coarsening data. Our proposed framework is one of the first that models animal behavior simultaneously at multiple time scales, opening new possibilities in the area of animal movement and behavior modeling. We illustrate the application of hierarchically structured HMMs in two real-data examples: (i) vertical movements of harbor porpoises observed in the field, and (ii) garter snake movement data collected as part of an experimental design. Supplementary materials accompanying this paper appear online.     

Molecular characterization of two papaya ringspot virus isolates that cause devastating symptoms in Norte de Santander,Colombia

Papaya ringspot virus is an RNA virus that belongs to the genus Potyvirus, family Potyviridae and affects both papaya and cucurbits, causing great economic losses. PRSV isolates are divided into biotypes P and W; both biotypes naturally infect plants in the family Cucurbitaceae, whereas the P type also naturally infects papaya (Carica papaya L). In the present study, we report the full-length genome sequence of two PRSV-P isolates sampled from the Campo Hermoso (PRSV-CH) and Villa del Rosario (PRSV-VR) localities in Norte de Santander, Colombia. The genomes of these PRSV isolates are 10,326 nt in length and have a predicted ORF of 3344 aa. The identity among Colombian PRSV isolates is 96.9% and 97.3% at the nucleotide and deduced amino acid levels, respectively. PRSV isolates from China had the lowest identity at 78.3% and 89.2% (nucleotide-amino acid), whereas the highest identities were detected in PRSV isolates from Mexico, Venezuela and Hawaii. At the polyprotein level, the amino acid composition surrounding the active polyprotein cleavage sites differ in the Colombian PRSV sequences. The predicted cleavage site in P1/HC-Pro is LEQY/N – LEQY/S instead of MEQY/N. Both of the Colombian PRSV isolates have a putative recombination event in the P1 coding region, which is common in all PRSV isolates from the American continent. The new full-length PRSV sequences from Colombia provide a better understanding of the dynamics of papaya ringspot virus infections in papaya in Colombia and worldwide.     

Effect of heat treatment temperature and time on sound absorption coefficient of <Emphasis Type="Italic">Larix kaempferi</Emphasis> wood

Heat treatment improves the dimensional stability and hydrophobicity of wood, and heat-treated wood is currently attracting attention as a new interior material. However, there are few evaluations where the acoustic properties of heat-treated wood are reported when such wood is used as an interior material. In this study, Larix kaempferi wood, typically used as a building material, was heat-treated at 200, 220, and 240 °C for 9, 12, 15, and 18 h. The sound absorption coefficients of the treated wood samples were measured at 250, 500, 1000, 2000, and 4000 Hz in a reverberation room. The sound absorption coefficient increased with the treatment temperature and the treatment time. The results of this study showed that the high-frequency band range sound absorption coefficient of wood can be increased dramatically by heat treatment.     

Comparative study on sizing properties of amphoteric starch and phosphorylated starch for warp sizing

By varying the ratios of N-(3-chloro-2-hydroxypropl) trimethylammonium chloride and orthophosphate to starch, a series of amphoteric starch with different degree of substitution (DS) were prepared for evaluating sizing effect of amphoteric starch for cotton warps. The amphoteric starch contained quaternary ammonium and phosphate groups simultaneously, and was set to electric neutrality by varying relative quantity of anionic and cationic groups in order to prevent adverse effects of negative and positive charges. The influence of amphoteric modification of starch on the adhesion to cotton fibers was assessed by measuring tensile strength and work-to-break of slightly sized cotton roving and comparing the adhesion of amphoteric starch with those of phosphorylated one. Comparison on mechanical performances of amphoteric starch film over phosphorylated one was evaluated in terms of tensile strength, breaking extension and wear loss of starch film. The properties such as increase in tensile strength, loss in elasticity, abrasion resistance, and hairiness of cotton yarns sized with amphoteric starch were evaluated through control tests by the comparison with those of phosphorylated one. When zeta potential of amphoteric starch was set close to zero, the adhesion increased and the properties of sized yarns enhanced as the modification level increased. The amphoteric starch was evidently superior to phosphorylated one in improving the quality of sized cotton yarns. The amphoteric starch with neutral zeta potential and DS levels of 0.02–0.03 for quaternary ammonium groups and phosphate ones, respectively, could be applied to size cotton warp yarns for the improvement of yarn quality.     

The influence of thermal stabilization stage on the molecular structure of polyacrylonitrile fibers prior to the carbonization stage

Structural transformation from a linear chain structure to crosslinked chain structure, occuring during the thermal stabilization stage of carbon fiber manufacture, was followed through the use of infrared spectroscopy, differential scanning calorimetry (DSC), elemental analysis and gel-fraction measurements. The results obtained from the analysis of IR spectroscopy showed the gradual and continuous loss of intensity of the nitrile (C≡N) vibration at 2242 cm⁻¹ closely associated with the cyclization reactions whereas the intensity loss of the methylene (CH₂) groups vibration around 2920–2939 cm⁻¹ has been attributed to the loss of hydrogen atoms as part of the dehydrogenation reactions. The dehydrogenation index, evaluated using the absorbance ratio of A₁₄₅₂/A₁₃₆₈, also indicated the gradual loss of hydrogens in agreement with decreasing hydrogen content with progressing stabilization process. IR spectroscopy also showed the emergence of new absorption bands attributed to the formation of crosslinked ladder-like structure in the 1590–1600 cm⁻¹ region. The amount of newly formed crosslinked structure was characterized using DSC conversion index, IR conversion index and gel-fraction measurements. The results are compared and discussed in detail.