436 research outputs found
Modal Logics for Mobile Processes Revisited
We revisit the logical characterisations of various bisimilarity relations for the finite fragment of the ?-calculus. Our starting point is the early and the late bisimilarity, first defined in the seminal work of Milner, Parrow and Walker, who also proved their characterisations in fragments of a modal logic (which we refer to as the MPW logic). Two important refinements of early and late bisimilarity, called open and quasi-open bisimilarity, respectively, were subsequently proposed by Sangiorgi and Walker. Horne, et. al., showed that open and quasi-bisimilarity are characterised by intuitionistic modal logics: OM (for open bisimilarity) and FM (for quasi-open bisimilarity). In this work, we attempt to unify the logical characterisations of these bisimilarity relations, showing that they can be characterised by different sublogics of a unifying logic. A key insight to this unification derives from a reformulation of the four bisimilarity relations (early, late, open and quasi-open) that uses an explicit name context, and an observation that these relations can be distinguished by the relative scoping of names and their instantiations in the name context. This name context and name substitution then give rise to an accessibility relation in the underlying Kripke semantics of our logic, that is captured logically by an S4-like modal operator. We then show that the MPW, the OM and the FM logics can be embedded into fragments of our unifying classical modal logic. In the case of OM and FM, the embedding uses the fact that intuitionistic implication can be encoded in modal logic S4
Improving Learning Engagement Among Ethnic Minority High School Students in China Through School-Based Social Support: An Intervention Study
The study aimed to examine the effect of school-based social support, specifically the integrated peer and teacher support on the learning engagement of ethnic minority high school students in China. Researchers designed a customized reading program to incorporate peer and teacher support through collaborative learning and dual-teacher classroom mechanisms. The intervention groups involve 192 first year high school students in an underdeveloped area in Yunnan province. Learning engagement was measured using a self-report interview and observation field note during the intervention. Results showed that the school-based social support has effectively promoted the student’s self-confidence, learning motivation, self-identity, and develop a positive learning environment. These findings suggest that school-based social support can be a productive way to improve learning engagement among ethnic minority high school students in China. Implications for education practice and future research are discussed
Multi-Agent Robust Control Synthesis from Global Temporal Logic Tasks
This paper focuses on the heterogeneous multi-agent control problem under
global temporal logic tasks. We define a specification language, called
extended capacity temporal logic (ECaTL), to describe the required global
tasks, including the number of times that a local or coupled signal temporal
logic (STL) task needs to be satisfied and the synchronous requirements on task
satisfaction. The robustness measure for ECaTL is formally designed. In
particular, the robustness for synchronous tasks is evaluated from both the
temporal and spatial perspectives. Mixed-integer linear constraints are
designed to encode ECaTL specifications, and a two-step optimization framework
is further proposed to realize task-satisfied motion planning with high spatial
robustness and synchronicity. Simulations are conducted to demonstrate the
expressivity of ECaTL and the efficiency of the proposed control synthesis
approach.Comment: 7 pages, 3 figure
Controlled generation of Poincar\'e sphere beams with inverse-designed multimode meta-waveguides
The angular momentum of light can be described by positions on various
Poincar\'e spheres, where different structured light beams have proven useful
for numerous optical applications. However, the dynamic generation and control
of arbitrary structured light on different Poincar\'e spheres is still handled
via bulky optics in free space. Here we propose and demonstrate multimode
silicon photonic integrated meta-waveguides to generate arbitrary structured
light beams on polarization/orbit/higher-order/hybrid Poincar\'e spheres. The
multimode meta-waveguides are inversely designed to map polarization
states/higher-order spatial modes to orbit angular momentum, generating
polarization-/charge-diverse orbit angular momentum modes. Based on the
fundamental orbit angular momentum mode basis enabled by the meta-waveguides,
different structured-light fields on polarization/orbit/higher-order/hybrid
Poincar\'e spheres could be flexibly generated by controlling the relative
amplitude and phase profiles of on-chip guided modes. The demonstrated photonic
integrated devices hold great potential for the flexible manipulation of
structure light beams in many applications
Mollusk allergy: Not simply cross-reactivity with crustacean allergens
[Extract] To the Editor,
Mollusk allergy is commonly thought of as clinical cross-reactivity after primary sensitization to shrimps, other crustaceans, or mites. Tropomyosin is the major allergen, with primary IgE sensitization in 70% of all shellfish allergies. A high frequency of IgE and basophil reactivity to several mollusk allergens is seen in crustacean and mite-sensitized patients. It is still unclear, however, whether mollusks are capable of producing primary allergic sensitization, or whether IgE reactivity is based solely on cross-reactive crustacean-specific antibodies
Identification of sugar transporter genes and their roles in the pathogenicity of Verticillium dahliae on cotton
IntroductionVerticillium wilt (VW) caused by Verticillium dahliae is a soil-borne vascular fungal disease that severely affects cotton yield and fiber quality. Sugar metabolism plays an important role in the growth and pathogenicity of V. dahliae. However, limited information is known about the sugar transporter genes and their roles in the growth and pathogenicity of V. dahliae.MethodIn this study, genome-wide identification of sugar transporter genes in V. dahliae was conducted and the expression profiles of these genes in response to root exudates from cotton varieties susceptible or resistant to V. dahliae were investigated based on RNA-seq data. Tobacco Rattle Virus-based host-induced gene silencing (TRV-based HIGS) and artificial small interfering RNAs (asiRNAs) were applied to investigate the function of candidate genes involved in the growth and pathogenic process of V. dahliae.ResultsA total of 65 putative sugar transporter genes were identified and clustered into 8 Clades. Of the 65 sugar transporter genes, 9 were found to be induced only by root exudates from the susceptible variety, including VdST3 and VdST12 that were selected for further functional study. Silencing of VdST3 or VdST12 in host plants by TRV-based HIGS reduced fungal biomass and enhanced cotton resistance against V. dahliae. Additionally, silencing of VdST12 and VdST3 by feeding asiRNAs targeting VdST12 (asiR815 or asiR1436) and VdST3 (asiR201 or asiR1238) inhibited fungal growth, exhibiting significant reduction in hyphae and colony diameter, with a more significant effect observed for the asiRNAs targeting VdST12. The inhibitory effect of asiRNAs on the growth of V. dahliae was enhanced with the increasing concentration of asiRNAs. Silencing of VdST12 by feeding asiR815+asiR1436 significantly decreased the pathogenicity of V. dahliae.DiscussionThe results suggest that VdST3 and VdST12 are sugar transporter genes required for growth and pathogenicity of V. dahliae and that asiRNA is a valuable tool for functional characterization of V. dahliae genes
- …