Cultivar-Dependent Expression of a Maize Lipoxygenase Responsive to Seed Infesting Fungi

Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- or 13(S)-. Screening maize LOX expressed sequence tags (ESTs) identified one clone, cssap 92, which is highly expressed in Aspergillus spp.-infected seed susceptible to AF contamination and repressed in lines with resistance to AF contamination. The accumulation of cssap 92 transcript was similar during Fusarium spp. infection. The cDNA clone has 94% identity to the previously described L2 LOX gene from maize. Product-specificity analysis of the CSSAP 92 protein shows that it preferentially adds oxygen to carbon 9 of linoleic acid. Because 9(S)-hydroperoxy linoleic acid has been implicated as an aflatoxin-signaling molecule, it is possible that cssap 92 could be used as a biomarker that is indicative of AF resistance in maize lines

Cultivar-Dependent Expression of a Maize Lipoxygenase Responsive to Seed Infesting Fungi

Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- or 13(S)-. Screening maize LOX expressed sequence tags (ESTs) identified one clone, cssap 92, which is highly expressed in Aspergillus spp.-infected seed susceptible to AF contamination and repressed in lines with resistance to AF contamination. The accumulation of cssap 92 transcript was similar during Fusarium spp. infection. The cDNA clone has 94% identity to the previously described L2 LOX gene from maize. Product-specificity analysis of the CSSAP 92 protein shows that it preferentially adds oxygen to carbon 9 of linoleic acid. Because 9(S)-hydroperoxy linoleic acid has been implicated as an aflatoxin-signaling molecule, it is possible that cssap 92 could be used as a biomarker that is indicative of AF resistance in maize lines

Viability Conditions for a Compartmentalized Protometabolic System: A Semi-Empirical Approach

In this work we attempt to find out the extent to which realistic prebiotic compartments, such as fatty acid vesicles, would constrain the chemical network dynamics that could have sustained a minimal form of metabolism. We combine experimental and simulation results to establish the conditions under which a reaction network with a catalytically closed organization (more specifically, an ()-system) would overcome the potential problem of self-suffocation that arises from the limited accessibility of nutrients to its internal reaction domain. The relationship between the permeability of the membrane, the lifetime of the key catalysts and their efficiency (reaction rate enhancement) turns out to be critical. In particular, we show how permeability values constrain the characteristic time scale of the bounded protometabolic processes. From this concrete and illustrative example we finally extend the discussion to a wider evolutionary context

The reference frame for encoding and retention of motion depends on stimulus set size

YesThe goal of this study was to investigate the reference frames used in perceptual encoding and storage of visual motion information. In our experiments, observers viewed multiple moving objects and reported the direction of motion of a randomly selected item. Using a vector-decomposition technique, we computed performance during smooth pursuit with respect to a spatiotopic (nonretinotopic) and to a retinotopic component and compared them with performance during fixation, which served as the baseline. For the stimulus encoding stage, which precedes memory, we found that the reference frame depends on the stimulus set size. For a single moving target, the spatiotopic reference frame had the most significant contribution with some additional contribution from the retinotopic reference frame. When the number of items increased (Set Sizes 3 to 7), the spatiotopic reference frame was able to account for the performance. Finally, when the number of items became larger than 7, the distinction between reference frames vanished. We interpret this finding as a switch to a more abstract nonmetric encoding of motion direction. We found that the retinotopic reference frame was not used in memory. Taken together with other studies, our results suggest that, whereas a retinotopic reference frame may be employed for controlling eye movements, perception and memory use primarily nonretinotopic reference frames. Furthermore, the use of nonretinotopic reference frames appears to be capacity limited. In the case of complex stimuli, the visual system may use perceptual grouping in order to simplify the complexity of stimuli or resort to a nonmetric abstract coding of motion information

Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus

: Identifying genetic determinants of reproductive success may highlight mechanisms underlying fertility and identify alleles under present-day selection. Using data in 785,604 individuals of European ancestry, we identified 43 genomic loci associated with either number of children ever born (NEB) or childlessness. These loci span diverse aspects of reproductive biology, including puberty timing, age at first birth, sex hormone regulation, endometriosis and age at menopause. Missense variants in ARHGAP27 were associated with higher NEB but shorter reproductive lifespan, suggesting a trade-off at this locus between reproductive ageing and intensity. Other genes implicated by coding variants include PIK3IP1, ZFP82 and LRP4, and our results suggest a new role for the melanocortin 1 receptor (MC1R) in reproductive biology. As NEB is one component of evolutionary fitness, our identified associations indicate loci under present-day natural selection. Integration with data from historical selection scans highlighted an allele in the FADS1/2 gene locus that has been under selection for thousands of years and remains so today. Collectively, our findings demonstrate that a broad range of biological mechanisms contribute to reproductive success

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI