Structural evolution drives diversification of the large LRR-RLK gene family

Cells are continuously exposed to chemical signals that they must discriminate between and respond to appropriately. In embryophytes, the leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) are signal receptors critical in development and defense. LRR‐RLKs have diversified to hundreds of genes in many plant genomes. Although intensively studied, a well‐resolved LRR‐RLK gene tree has remained elusive. To resolve the LRR‐RLK gene tree, we developed an improved gene discovery method based on iterative hidden Markov model searching and phylogenetic inference. We used this method to infer complete gene trees for each of the LRR‐RLK subclades and reconstructed the deepest nodes of the full gene family. We discovered that the LRR‐RLK gene family is even larger than previously thought, and that protein domain gains and losses are prevalent. These structural modifications, some of which likely predate embryophyte diversification, led to misclassification of some LRR‐RLK variants as members of other gene families. Our work corrects this misclassification. Our results reveal ongoing structural evolution generating novel LRR‐RLK genes. These new genes are raw material for the diversification of signaling in development and defense. Our methods also enable phylogenetic reconstruction in any large gene family

The effect of self-affine fractal roughness of wires on atom chips

Atom chips use current flowing in lithographically patterned wires to produce microscopic magnetic traps for atoms. The density distribution of a trapped cold atom cloud reveals disorder in the trapping potential, which results from meandering current flow in the wire. Roughness in the edges of the wire is usually the main cause of this behaviour. Here, we point out that the edges of microfabricated wires normally exhibit self-affine roughness. We investigate the consequences of this for disorder in atom traps. In particular, we consider how closely the trap can approach the wire when there is a maximum allowable strength of the disorder. We comment on the role of roughness in future atom--surface interaction experiments.Comment: 7 pages, 7 figure

Jacobian ensembles improve robustness trade-offs to adversarial attacks

Deep neural networks have become an integral part of our software infrastructure and are being deployed in many widely-used and safety-critical applications. However, their integration into many systems also brings with it the vulnerability to test time attacks in the form of Universal Adversarial Perturbations (UAPs). UAPs are a class of perturbations that when applied to any input causes model misclassification. Although there is an ongoing effort to defend models against these adversarial attacks, it is often difficult to reconcile the trade-offs in model accuracy and robustness to adversarial attacks. Jacobian regularization has been shown to improve the robustness of models against UAPs, whilst model ensembles have been widely adopted to improve both predictive performance and model robustness. In this work, we propose a novel approach, Jacobian Ensembles – a combination of Jacobian regularization and model ensembles to significantly increase the robustness against UAPs whilst maintaining or improving model accuracy. Our results show that Jacobian Ensembles achieves previously unseen levels of accuracy and robustness, greatly improving over previous methods that tend to skew towards only either accuracy or robustness

Neutrino induced reactions related to the ν\nu-process nucleosynthesis of 92{}^{92}Nb and 98{}^{98}Tc

It has recently been proposed that ${}^{92}_{41}$Nb and ${}^{98}_{43}$Tc may have been formed in the $\nu$-process. We investigate the neutrino induced reactions related to the $\nu$-process origin of the two odd-odd nuclei. The main neutrino reactions for ${}^{92}_{41}$Nb are the charged-current (CC) $^{92}$Zr($\nu_e,e^{-}$)$^{92}$Nb and the neutral-current (NC) $^{93}$Nb(${\nu} ({\bar \nu}), {\nu}^{'} ({\bar \nu})^{'}$ n)$^{92}$Nb reactions. The main reactions for ${}^{98}_{43}$Tc, are the CC reaction $^{98}$Mo($\nu_e,e^-$)$^{98}$Tc and the NC reaction $^{99}$Ru(${\nu} ({\bar \nu}), {\nu}^{'} ({\bar \nu})^{'}$ p)$^{98}$Tc. Our calculations are carried out using the quasi-particle random phase approximation. Numerical results are presented for the energy and temperature dependent cross sections. Since charge exchange reactions by neutrons may also lead to the formation of ${}^{92}_{41}$Nb and ${}^{98}_{43}$Tc, we discuss the feasibility of the $^{92}$Mo(n,p)$^{92}$Nb and $^{98}$Ru(n,p)$^{98}$Tc reactions to produce these nuclei.Comment: 21 pages, 8 figure

Analysis of genetic diversity in accessions of Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill

Amplified fragment length polymorphism (AFLP) was used to assess genetic diversity and relationships among 15 accessions of Irvingia gabonensis collected from Cameroun, Gabon, and Nigeria. Twelve AFLP+3 primers produced 384 polymorphic fragments. Average genetic distance (AGD) between the 15 accessions was 58.7% (32-88%). AGD and range of genetic distance among accessions from Cameroun, Nigeria and Gabon were 62% (53-76%), 52% (32.3 – 84.8%) and 50% (45- 53%), respectively, indicating more genetic diversity in Cameroun than Nigeria and Gabon. The unweighted pair-group method of the arithmetic average (UPGMA) and principal coordinate analysis (PCO) showed a clear distinction between the Gabon and Nigeria accessions into two separate clusters, with accessions from Cameroun overlapping them. Principal coordinate analysis (PCO) indicated a closer relationship between accessions from Cameroun and Gabon. In general the Cameroun germplasm appears to be a bridge between the genetically isolated Nigeria and Gabon accessions. This overlap of Gabon and Nigerian accessions by the accessions from Cameroun may be an indication that Cameroun is the center of diversity of I. gabonensis and also the primary source of original materials grown in the other countries. More collection in Cameroun is necessary to ensure the optimum collection and preservation of the existing genetic diversity in I. gabonensis.Keywords: Irvingia gabonensis, Accession, amplified fragment length polymorphism, genetic diversit

HA-grid: security aware hazard analysis for smart grids

Attacks targeting smart grid infrastructures can result in the disruptions of power supply as well as damages to costly equipment, with significant impact on safety as well as on end-consumers. It is therefore of essence to identify attack paths in the infrastructure that lead to safety violations and to determine critical components that must be protected. In this paper, we introduce a methodology (HA-Grid) that incorporates both safety and security modelling of smart grid infrastructure to analyse the impact of cyber threats on the safety of smart grid infrastructures. HA-Grid is applied on a smart grid test-bed to identify attack paths that lead to safety hazards, and to determine the common nodes in these attack paths as critical components that must be protected

Materials Selection of 3D Printing Filament and Utilization of Recycled Polyethylene Terephthalate (PET) in a Redesigned Breadboard

The demand for a novel and sustainable alternative materials for 3D printer filaments has been knowingly increasing. One alternative source for the filament is to reuse and recycle post-consumer plastic products, which is also a compelling approach to conserve energy and sustain the environment. Thus, this study is focused on the materials selection of virgin polymer resins and recycled post-consumer plastics for use in 3D printer filaments. A multi-criteria decision method of Elimination and Choice Expressing the Reality (ELECTRE) was utilized to determine the best materials for 3D printer filaments. The study has shown that the virgin low-density polyethylene (LDPE) and recycled polyethylene terephthalate (PET) are optimal materials as an alternative filament among other options such as virgin high-density polyethylene (HDPE), virgin PET, virgin polypropylene (PP) and recycled HDPE. Aside from the different options of the type of materials, the various properties considered in the calculation include tensile strength, melting point, glass transition temperature, melt flow index, coefficient of thermal expansion, and cost. Moreover, a redesigned breadboard was produced thru 3D printing using a recycled PET as filament source

Regional innovation and spillover effects of foreign direct investment in China: a threshold approach

Using a data set on twenty-nine Chinese provinces for the period 1985–2008, this paper establishes a threshold model to analyse the relationship between spillover effects of foreign direct investment (FDI) and regional innovation in China. There is clear evidence of double-threshold effects of regional innovation on productivity spillovers from FDI. Specifically, only when the level of regional innovation reaches the minimum innovation threshold will FDI in the region begin to produce positive productivity spillovers. Furthermore, positive productivity spillovers from FDI will be substantial only when the level of regional innovation attains a higher threshold. The double threshold divides Chinese provinces into three super-regions in terms of innovation, with most provinces positioned within the middle-level innovation super-region. Policy implications are discussed