Attacks by a piercing-sucking insect (Myzus persicae Sultzer) or a chewing insect (Leptinotarsa decemlineata Say) on potato plants (Solanum tuberosum L.) induce differential changes in volatile compound release and oxylipin synthesis

Plant defensive strategies bring into play blends of compounds dependent on the type of attacker and coming from different synthesis pathways. Interest in the field is mainly focused on volatile organic compounds (VOCs) and jasmonic acid (JA). By contrast, little is known about the oxidized polyunsaturated fatty acids (PUFAs), such as PUFA-hydroperoxides, PUFA-hydroxides, or PUFA-ketones. PUFA-hydroperoxides and their derivatives might be involved in stress response and show antimicrobial activities. Hydroperoxides are also precursors of JA and some volatile compounds. In this paper, the differential biochemical response of a plant against insects with distinct feeding behaviours is characterized not only in terms of VOC signature and JA profile but also in terms of their precursors synthesized through the lipoxygenase (LOX)-pathway at the early stage of the plant response. For this purpose, two leading pests of potato with distinct feeding behaviours were used: the Colorado Potato Beetle (Leptinotarsa decemlineata Say), a chewing herbivore, and the Green Peach Aphid (Myzus persicae Sulzer), a piercing-sucking insect. The volatile signatures identified clearly differ in function with the feeding behaviour of the attacker and the aphid, which causes the smaller damages, triggers the emission of a higher number of volatiles. In addition, 9-LOX products, which are usually associated with defence against pathogens, were exclusively activated by aphid attack. Furthermore, a correlation between volatiles and JA accumulation and the evolution of their precursors was determined. Finally, the role of the insect itself on the plant response after insect infestation was highlighted

Productivity, profitability and energy budgeting of maize (Zea mays)/ greengram (Vigna radiata) intercropping system under rainfed conditions of Eastern Himalayan Region

A field experiment was conducted at Nagaland during 2009 and 2010 to study the productivity, profitability and energy budgeting of maize [Zea mays (L.)]/greengram [Vigna radiata (L.) Witczek] intercropping system under rainfed conditions of Eastern Himalayan Region on a sandy loam soil. There was significant superiority in growth and yield attributes as well as yield of maize (3.37 tonnes/ha) and greengram (1.34 tonnes/ha) under sole cropping as compared to their intercropping system. Maize equivalent yield (5.64 tonnes/ha) land equivalent ratio (1.43), Area Time Equivalency Ratio (1.19), Land Equivalent Coefficient (0.49), and Monetary Advantage Indices (` 3 273) was significantly higher with intercropping system (1:1, closely followed by 1:2 ratio) over other intercropping system under study. Moreover, higher Crop Performance Ratio (3.81) was recorded with 1:3 maize–greengram intercropping system. Intercropping system recorded the higher net return and B: C ratio as compared to either of the sole cropping. Among different row proportions, 1:1 row ratio recorded maximum energy efficiency (19.1) and energy productivity (1569.4 g/MJ) than other intercropping system

The ‘algebra of evolution’: the Robertson–Price identity and viability selection for body mass in a wild bird population

By the Robertson–Price identity, the change in a quantitative trait owing to selection, is equal to the trait’s covariance with relative fitness. In this study, we applied the identity to long-term data on superb fairy-wrens Malurus cyaneus, to estimate phenotypic and genetic change owing to juvenile viability selection. Mortality in the four-week period between fledging and independence was 40%, and heavier nestlings were more likely to survive, but why? There was additive genetic variance for both nestling mass and survival, and a positive phenotypic covariance between the traits, but no evidence of additive genetic covariance. Comparing standardized gradients, the phenotypic selection gradient was positive, βP = 0.108 (0.036, 0.187 95% CI), whereas the genetic gradient was not different from zero, βA = −0.025 (−0.19, 0.107 95% CI). This suggests that factors other than nestling mass were the cause of variation in survival. In particular, there were temporal correlations between mass and survival both within and between years. We suggest that use of the Price equation to describe cross-generational change in the wild may be challenging, but a more modest aim of estimating its first term, the Robertson–Price identity, to assess within-generation change can provide valuable insights into the processes shaping phenotypic diversity in natural populations. This article is part of the theme issue ‘Fifty years of the Price equation’G.K.H. was supported by the U.K. Natural Environment Research Council (grant no. NE/L002558/1) through the University of Edinburgh’s E3 Doctoral Training Partnership, and L.E.B.K. was funded by an ARC Future Fellowship FT110100453. The long-term superb fairy-wren study research has been facilitated by a series of Discovery Project grants from the Australian Research Council to A.C. and L.E.B.K., most recently DP150100298

Description and dosimetric verification of the PEREGRINE Monte Carlo dose calculation system for photon beams incident on a water phantom

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134919/1/mp1551.pd

Late Quaternary evolution of a lowland anastomosing river system: Geological-topographic inheritance, non-uniformity and implications for biodiversity and management

Lowland multiple-channel rivers are characterised by floodplain-corridor heterogeneity, high ecological and heritage value, and can be in quasi-stable states. This holistic study of a surviving temperate zone example (Culm, UK) uses geomorphological mapping, 14C, direct sediment dating (OSL, fallout radionuclides), and palaeoecology. This reveals the evolution of a channel-floodplain system from an initial braided state in the Late Pleistocene to its late Holocene anastomosing state. After the Pleistocene Holocene transition the reduced channel system incised into its braid-plain, only able to rework gravels locally due to reduced competence in relation to inherited bounding sediment calibre. This resulted in the creation of terrace islands, palaeochannels, and a stable anastomosing pattern dominated by channel junctions, bifurcations and palaeochannel intersections. Survey, coring and excavation reveal a persistence of mid-channel bars and riffles at channel junctions, and where channels crossed palaeochannel fills. In common with most other European lowland rivers this system evolves in the later Holocene due to both climate and catchment changes with a major hydrological critical transition in the mid-Holocene (c. 5300 BP). However, in the case of the Culm, the increase in fine sediment supply often seen in lowland catchments in the Middle-Late Holocene, occurred later, and was insufficient to convert the system to a single medium-low sinuosity channel-floodplain. This allowed the persistence of high heterogeneity and biodiversity (including the persistence of riffle beetles) as part of multiple-scales of non-uniformity. Indeed the pool-riffle persistence is an example of this system’s non-uniformity, being due, at least in part, to the effects of previous channel history. This paper reveals why this river survived in a multichannel state, and by implication, why others did not. These results are being used in the bespoke eco-heritage management of the Culm, but could also inform the restoration of other former multi-channel lowland temperate river systems worldwide

The effects of postmenopausal hormone therapy on social activity, partner relationship, and sexual life – experience from the EPHT trial

<p>Abstract</p> <p>Background</p> <p>With the exception of sexual functioning and weight, social and behavioural effects of postmenopausal hormone therapy (HT) have not been reported from trials. This paper reports such results from the EPHT-trial in Estonia.</p> <p>Methods</p> <p>A randomized trial, with a blind and non-blind sub-trial in Estonia. From 1999–2001, 1778 women were recruited. The mean follow-up was 3.6 years. Women's experiences were asked in the first and final study year by mailed questionnaires (74 and 81% response rates). Comparisons of the groups were made by cross-tabulation and logistic regression, adjusting for age.</p> <p>Results</p> <p>There were no differences between the HT and non-HT groups in regard to being employed, the extent of social involvement or marital status or opinions on aging. There was no difference in the frequency of free-time exercise, or overweight. Some of the indicators suggested less sexual inactivity, but the differences were small.</p> <p>Conclusion</p> <p>In a trial setting, postmenopausal hormone therapy did not influence work or social involvement or health behaviour.</p> <p>Trial registration</p> <p>ISRCTN35338757</p

A review of source tracking techniques for fine sediment within a catchment

Excessive transport of fine sediment, and its associated pollutants, can cause detrimental impacts in aquatic environments. It is therefore important to perform accurate sediment source apportionment to identify hot spots of soil erosion. Various tracers have been adopted, often in combination, to identify sediment source type and its spatial origin; these include fallout radionuclides, geochemical tracers, mineral magnetic properties and bulk and compound-specific stable isotopes. In this review, the applicability of these techniques to particular settings and their advantages and limitations are reviewed. By synthesizing existing approaches, that make use of multiple tracers in combination with measured changes of channel geomorphological attributes, an integrated analysis of tracer profiles in deposited sediments in lakes and reservoirs can be made. Through a multi-scale approach for fine sediment tracking, temporal changes in soil erosion and sediment load can be reconstructed and the consequences of changing catchment practices evaluated. We recommend that long-term, as well as short-term, monitoring of riverine fine sediment and corresponding surface and subsurface sources at nested sites within a catchment are essential. Such monitoring will inform the development and validation of models for predicting dynamics of fine sediment transport as a function of hydro-climatic and geomorphological controls. We highlight that the need for monitoring is particularly important for hilly catchments with complex and changing land use. We recommend that research should be prioritized for sloping farmland-dominated catchments

A review of source tracking techniques for fine sediment within a catchment

Excessive transport of fine sediment, and its associated pollutants, can cause detrimental impacts in aquatic environments. It is therefore important to perform accurate sediment source apportionment to identify hot spots of soil erosion. Various tracers have been adopted, often in combination, to identify sediment source type and its spatial origin; these include fallout radionuclides, geochemical tracers, mineral magnetic properties and bulk and compound-specific stable isotopes. In this review, the applicability of these techniques to particular settings and their advantages and limitations are reviewed. By synthesizing existing approaches, that make use of multiple tracers in combination with measured changes of channel geomorphological attributes, an integrated analysis of tracer profiles in deposited sediments in lakes and reservoirs can be made. Through a multi-scale approach for fine sediment tracking, temporal changes in soil erosion and sediment load can be reconstructed and the consequences of changing catchment practices evaluated. We recommend that long-term, as well as short-term, monitoring of riverine fine sediment and corresponding surface and subsurface sources at nested sites within a catchment are essential. Such monitoring will inform the development and validation of models for predicting dynamics of fine sediment transport as a function of hydro-climatic and geomorphological controls. We highlight that the need for monitoring is particularly important for hilly catchments with complex and changing land use. We recommend that research should be prioritized for sloping farmland-dominated catchments

Consequences of epistasis on growth in an erhualian × white duroc pig cross

Epistasis describes an interaction between the effects of loci. We included epistasis in quantitative trait locus (QTL) mapping of growth at a series of ages in a cross of a Chinese pig breed, Erhualian, with a commercial line, White Duroc. Erhualian pigs have much lower growth rates than White Duroc. We improved a method for genomewide testing of epistasis and present a clear analysis workflow. We also suggest a new approach for interpreting epistasis results where significant additive and dominance effects of a locus in specific backgrounds are determined. In total, seventeen QTL were found and eleven showed epistasis. Loci on chromosomes 2, 3, 4 and 7 were highlighted as affecting growth at more than one age or forming an interaction network. Epistasis resulted in both the QTL on chromosomes 3 and 7 having effects in opposite directions. We believe it is the first time for the chromosome 7 locus that an allele from a Chinese breed has been found to decrease growth. The consequences of epistasis were diverse. Results were impacted by using growth rather than body weight as the phenotype and by correcting for an effect of mother. Epistasis made a considerable contribution to growth in this population and modelling epistasis was important for accurately determining QTL effects