The cosmic ray spectrum above 10(17) eV

The final analysis of the data obtained by the Sydney University Giant Airshower Recorder (SUGAR) is presented. The data has been reanalysed to take into account the effects of afterpulsing in the photomultiplier tubes. Event data was used to produce a spectrum of equivalent vertical muon number and from this a model dependent primary energy spectrum was obtained. These spectra show good evidence for the Ankle: a flattening at 10(19) eV. There is no sign of the cut-off which would be expected from the effects of the universal black body radiation

Impact of glucosinolate structure on the performance of the crucifer pest Phaedon cochleariae (F.)

Glucosinolates (GS) are sulfur-rich secondary metabolites found in the Brassicaceae and other related families of the order Brassicales. GS consist of structurally-related compounds with different side chains. To explore the possibility that various side chain confer divergent biological activities to individual GS, we have investigated the performance of the specialist pest beetle, Phaedon cochleariae (F.) on Arabidopsis thaliana L. mutants and Columbia wild-type (WT) which differ in the main group of GS. Plant lines of A. thaliana altered for the expression of MAM3, because of the introduction of an overexpression construct of MAM3 (mam3+) or containing double knockouts of CYP79B2 and CYP79B3 (cyp79B2-/cyp79B3-) were used for the study in comparison to the WT.A. thaliana genotypes differed in their GS profiles. The highest GS content was present in the WT followed by mam3+ and cyp79B2-/ cyp79B3-. A modified aliphatic GS content was detected for the mam3+ as compared to the WT lines. Furthermore, indolyl GS were completely absent in cyp79B2-/cyp79B3-. The percentage weight increase of larvae raised on each of the three plant genotypes was significant different. Larval performance was poorest on plants of cyp79B2-/cyp79B3- and best on WT, but there was no significant difference found in percentage weight increase on mam3+ and WT. There was no correlation between the weight increase of the larvae on genotypes and induced levels of aliphatic, indolyl, and total GS. However, the poor performance of beetle larvae on cyp79B2-/ cyp79B3-compared to WT and mam3+ might be explained by comparable high aliphatic GS levels of this mutant, a different induction of secondary metabolites, and the absence of indolyl GS. Basic knowledge about the relationship of GS structures and their insect pests may help in further resistance breeding of crucifer crops

Exceeding the threshold value for Trioza apicalis Förster 1848 in carrot fields did not cause damage as revealed during monitoring in Germany from 2017–2020

The carrot psyllid Trioza apicalis Förster 1848 is a carrot pest in Europe that can cause serious damages in case of massive occurrence. Damages up to a total loss of yield have been reported from Scandinavian countries but also from Switzerland. The action threshold to control the pest with chemical pesticides is 0.2 T. apicalis per day and trap caught by sticky traps. We investigated the number of T. apicalis with sticky traps on carrot fields of the study regions Lüneburg/Uelzen and Hameln/Bad Pyrmont in Germany, during the period 2017–2020. The number of T. apicalis caught was generally very low in both study regions. On several fields in successive weeks almost no individuals were found in the study region Hameln/Bad Pyrmont. In Lüneburg/Uelzen was at least one field each year where the number of carrot psyllid was clearly higher than in all other fields and exceeded the threshold level. Surprisingly on carrot fields in close proximity to carrot fields from the previous year, the T. apicalis numbers were only slightly increased. Nonetheless, no loss of yield was reported for any of the fields in the four years of the study, although the generally defined threshold has been exceeded on many of the investigated carrot fields.Bundesanstalt für Landwirtschaft und Ernährung http://dx.doi.org/10.13039/501100010771Bundesanstalt für Landwirtschaft und Ernährung (DE)Julius Kühn-Institut (JKI), Bundesforschungsinstitut für Kulturpflanzen (4250)Peer Reviewe

Exceeding the threshold value for Trioza apicalis Förster 1848 in carrot fields did not cause damage as revealed during monitoring in Germany from 2017–2020

The carrot psyllid Trioza apicalis Förster 1848 is a carrot pest in Europe that can cause serious damages in case of massive occurrence. Damages up to a total loss of yield have been reported from Scandinavian countries but also from Switzerland. The action threshold to control the pest with chemical pesticides is 0.2 T. apicalis per day and trap caught by sticky traps. We investigated the number of T. apicalis with sticky traps on carrot fields of the study regions Lüneburg/Uelzen and Hameln/Bad Pyrmont in Germany, during the period 2017–2020. The number of T. apicalis caught was generally very low in both study regions. On several fields in successive weeks almost no individuals were found in the study region Hameln/Bad Pyrmont. In Lüneburg/Uelzen was at least one field each year where the number of carrot psyllid was clearly higher than in all other fields and exceeded the threshold level. Surprisingly on carrot fields in close proximity to carrot fields from the previous year, the T. apicalis numbers were only slightly increased. Nonetheless, no loss of yield was reported for any of the fields in the four years of the study, although the generally defined threshold has been exceeded on many of the investigated carrot fields

Integrating social protection and climate change adaptation: a review

Policymakers are increasingly interested in how social protection is evolving in the context of climate change. This review assesses what the literature tells us about its role in facilitating adaptation in lower income countries. It also explores how far thinking on an integrated “adaptive social protection” (ASP) agenda considers transforming the socioeconomic and political contexts where vulnerability to climate change originates. The review finds that research to date focuses on how instruments such as cash or asset transfers can protect the poor from shocks and stresses, prevent households from falling into poverty as a result of climate change, and promote climate-resilient livelihoods. However, it cautions that such interventions must go beyond helping households to cope against shocks over short time horizons; they should enable the adoption of forward-looking strategies for long-lasting adaptation. Much less attention in the literature is given to whether social protection measures might have transformational effects for recipients. This is despite the fact that the earliest proponents of ASP favored a rights-based approach to social protection to address issues of inequality and marginalization which are at the root of poverty and vulnerability to climate change. Although the role of social protection should not be overstated, it holds promise as a tool for building adaptive capacity. However, the potential of ASP to be truly transformational for its recipients by tackling the structural causes of vulnerability to climate change is not yet harnessed by policymakers. This constitutes a missed opportunity for the agenda to deliver on the international community's promise to “leave no one behind.”. This article is categorized under: Climate and Development > Sustainability and Human Well-Being Vulnerability and Adaptation to Climate Change > Values-Based Approach to Vulnerability and Adaptation

Parthenium weed (Parthenium hysterophorus L.) research in Ethiopia: Investigation of pathogens as biocontrol agents

Parthenium is an exotic invasive weed that now occurs widely in Ethiopia. Surveys to determine the presence and distribution of pathogens associated with parthenium and further evaluation of the pathogens found as potential biocontrol agents were carried out in Ethiopia since 1998. Several fungal isolates of the genus Helminthosporium, Phoma, Curvularia, Chaetomium, Alternaria, and Eurotium were obtained from the seeds and other plant parts. However, all of the isolates tested were non-pathogenic except Helminthosporium isolates. The two most important diseases were the rust, Puccinia abrupta var. partheniicola and the phyllody, caused by a phytoplasma belonging to the species “Candidatus Phytoplasma aurantifolia”. Host specificity tests revealed that the rust, P. abrupta, only sporulates on parthenium while the phyllody infected parthenium, groundnut, sesame, grass pea, lentil, and chickpea. Suspected insect vectors were examined for phytoplasma infection by means of Polymerase Chain Reaction (PCR). The successful acquisition of phytoplasma’s by the leafhopper, Orosius cellulosus Lindberg (Cicadellidae), was determined by molecular detection of phytoplasma. Phytoplasma was also detected from a single bait plant after feeding by the leafhopper. Sequencing data from phytoplasma obtained from parthenium and the above mentioned crops was identical with sequence identities > 98%. The rust was commonly found at 1400 – 2500 m.a.s.l. with disease incidence up to 100% in some locations while phyllody was observed at 900 – 2300 m.a.s.l. with incidence up to 75%. Individual effects of the rust and phyllody diseases on Parthenium in different locations under field condition showed significant reduction on seed and morphological parameters. Seed production was reduced by 42 and 85% due to rust and phyllody, respectively

The giant planet orbiting the cataclysmic binary DP Leonis

Planets orbiting post-common envelope binaries provide fundamental information on planet formation and evolution, especially for the yet nearly unexplored class of circumbinary planets. We searched for such planets in \odp, an eclipsing short-period binary, which shows long-term eclipse-time variations. Using published, reanalysed, and new mid-eclipse times of the white dwarf in DP\,Leo, obtained between 1979 and 2010, we find agreement with the light-travel-time effect produced by a third body in an elliptical orbit. In particular, the measured binary period in 2009/2010 and the implied radial velocity coincide with the values predicted for the motion of the binary and the third body around the common center of mass. The orbital period, semi-major axis, and eccentricity of the third body are P_c = 28.0 +/- 2.0 yrs, a_c = 8.2 +/- 0.4 AU, and e_c = 0.39 +/- 0.13. Its mass of M_c sin(i_c) = 6.1 +/- 0.5 M_J qualifies it as a giant planet. It formed either as a first generation object in a protoplanetary disk around the original binary or as a second generation object in a disk formed in the common envelope shed by the progenitor of the white dwarf. Even a third generation origin in matter lost from the present accreting binary can not be entirely excluded. We searched for, but found no evidence for a fourth body.Comment: Accepted by A&

Light-Induced Metastable Magnetic Texture Uncovered by in situ Lorentz Microscopy

Magnetic topological defects, such as vortices and Skyrmions, can be stabilized as equilibrium structures in nanoscale geometries and by tailored intrinsic magnetic interactions. Here, employing rapid quench conditions, we report the observation of a light-induced metastable magnetic texture, which consists of a dense nanoscale network of vortices and antivortices. Our results demonstrate the emergence of ordering mechanisms in quenched optically driven systems, which may give a general access to novel magnetic structures on nanometer length scales

Nano-structured magnetic metamaterial with enhanced nonlinear properties

Nano-structuring can significantly modify the properties of materials. We demonstrate that size-dependent modification of the spin-wave spectra in magnetic nano-particles can affect not only linear, but also nonlinear magnetic response. The discretization of the spectrum removes the frequency degeneracy between the main excitation mode of a nano-particle and the higher spin-wave modes, having the lowest magnetic damping, and reduces the strength of multi-magnon relaxation processes. This reduction of magnon-magnon relaxation for the main excitation mode leads to a dramatic increase of its lifetime and amplitude, resulting in the intensification of all the nonlinear processes involving this mode. We demonstrate this experimentally on a two-dimensional array of permalloy nano-dots for the example of parametric generation of a sub-harmonic of an external microwave signal. The characteristic lifetime of this sub-harmonic is increased by two orders of magnitude compared to the case of a continuous magnetic film, where magnon-magnon relaxation limits the lifetime