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The relevance of upper division mathematics courses for future secondary teachers is a longstanding thorny issue. Suggested improvements include capstone courses and revised upper division content courses to explicitly address future teachers’ relevant secondary mathematics content knowledge, beliefs about teaching and learning, and experience with learning mathematics while engaging in authentic mathematical practices. In this report, we investigate prospective teachers’ reflections on their opportunities in an upper division Inquiry-Oriented Dynamical Systems course to engage in the eight Common Core State Standards for Mathematical Practice. Analysis of students’ self-reported engagement in the eight Practices revealed five practices that strongly resonated with them and the various ways that their experiences in an inquiry-oriented classroom supported meaningful and powerful engagement in these Mathematical Practices. We conclude with implications for practice. 

This paper presents an investigation of terahertz (THz) signals generated using photoconductive antennas (PCAs) based on different electrode geometries. The geometry of the electrodes influences the shape of the THz pulse and its frequency spectrum. The geometry can be used to provide improvements to the bandwidth of the PCA. We used the transient solution of the RF module of COMSOL Multiphysics to simulate the radiated electric field based on using the photoconductive current as a time domain source in the gap of the antenna. The dimensions of a previously published bowtie H-dipole antenna were used as reference that was modified to three new configurations. The results show that the bowtie-H-dipole antenna provided broader bandwidth compared with the fractal, slot, and/or circular shape electrodes PCAs. 

This paper presents an investigation of terahertz (THz) signals generated using photoconductive antennas (PCAs) based on different electrode geometries. The geometry of the electrodes influences the shape of the THz pulse and its frequency spectrum. The geometry can be used to provide improvements to the bandwidth of the PCA. We used the transient solution of the RF module of COMSOL Multiphysics to simulate the radiated electric field based on using the photoconductive current as a time domain source in the gap of the antenna. The dimensions of a previously published bowtie H-dipole antenna were used as reference that was modified to three new configurations. The results show that the bowtie-H-dipole antenna provided broader bandwidth compared with the fractal, slot, and/or circular shape electrodes PCAs. 

This paper presents the signal generation measurements of LT-GaAs photoconductive antenna (PCA) emitters. These measurements were developed in an open-bench time-domain spectroscopy (TDS) system. The main challenges presented here are associated with the alignment of the PCA devices and the location of the terahertz (THz) pulse with respect to the optical delay in the system. The position of the slow delay line was crucial for the location of the THz pulse, which helped in the correct alignment process of the emitter and detector devices. 

We report on progress in the understanding of the effects of kilotesla-level applied magnetic fields on relativistic laser–plasma interactions. Ongoing advances in magnetic-field–generation techniques enable new and highly desirable phenomena, including magnetic-field–amplification platforms with reversible sign, focusing ion acceleration, and bulk-relativistic plasma heating. Building on recent advancements in laser–plasma interactions with applied magnetic fields, we introduce simple models for evaluating the effects of applied magnetic fields in magnetic-field amplification, sheath-based ion acceleration, and direct laser acceleration. These models indicate the feasibility of observing beneficial magnetic-field effects under experimentally relevant conditions and offer a starting point for future experimental design. 

This paper presents an investigation of terahertz (THz) signals generated using photoconductive antennas (PCAs) based on different electrode geometries. The geometry of the electrodes influences the shape of the THz pulse and its frequency spectrum. The geometry can be used to provide improvements to the bandwidth of the PCA. We used the transient solution of the RF module of COMSOL Multiphysics to simulate the radiated electric field based on using the photoconductive current as a time domain source in the gap of the antenna. The dimensions of a previously published bowtie H-dipole antenna were used as reference that was modified to three new configurations. The results show that the bowtie-H-dipole antenna provided broader bandwidth compared with the fractal, slot, and/or circular shape electrodes PCAs. 

Abstract Due to its peculiar and highly variable nature, the blazar 3C 454.3 has been extensively monitored by the WEBT team. Here, we present for the first time these long-term optical flux and color variability results using data acquired inB,V,R, andIbands over a time span of about two decades. We include data from WEBT collaborators and public archives such as SMARTS, Steward Observatory, and Zwicky Transient Facility. The data are binned and segmented to study the source over this long term when more regular sampling was available. During our study, the long-term spectral variability reveals a redder-when-brighter trend, which, however, stabilizes at a particular brightness cutoff of ∼14.5 mag in theIband, after which it saturates and evolves into a complex state. This trend indicates increasing dominance of jet emission over accretion disk (AD) emission until jet emission completely dominates. Plots of the variation in spectral index (followingF_ν∝ν^−α) reveal a bimodal distribution using a one-day binning. These correlate with two extreme phases of 3C 454.3, an outburst or high-flux state and a quiescent or low-flux state, which are respectively jet- and AD-dominated. We have also conducted intraday variability studies of nine light curves and found that six of them are variable. Discrete correlation function analysis between different pairs of optical wave bands peaks at zero lags, indicating cospatial emission in different optical bands. 

Purpose of Review This paper focuses on the advances in the resilience of electricity systems and energy markets. The objective is to identify how the progress on system resilience may influence market rules while uncovering the gaps in the literature. Recent Findings This review distills three findings. First, significant advances have been achieved both in the design and configuration of power systems for resilience. Second, topological and architectural advances appear isolated from market operations. Third, there is room to integrate self-healing resilience into power systems and bridge the bifurcation between increasing network resilience and having the market adequately value resilience. Summary Evidently, the incidences of disruptions to electricity networks are on the rise, making a change from having a merely reliable electricity network to one that is resilient and adaptive a necessity. This review showcases the qualitative value inherent in processes to enhance adaptive resilience while promoting the requisite signals for power market integration. 

Abstract Given the rapid loss of biodiversity as consequence of climate change, greater knowledge of ecophysiological and natural history traits are crucial to determine which environmental factors induce stress and drive the decline of threatened species. Liolaemus montanezi (Liolaemidae), a xeric-adapted lizard occurring only in a small geographic range in west-central Argentina, constitutes an excellent model for studies on the threats of climate change on such microendemic species. We describe field data on activity patterns, use of microhabitat, behavioral thermoregulation, and physiology to produce species distribution models (SDMs) based on climate and ecophysiological data. Liolaemus montanezi inhabits a thermally harsh environment which remarkably impacts their activity and thermoregulation. The species shows a daily bimodal pattern of activity and mostly occupies shaded microenvironments. Although the individuals thermoregulate at body temperatures below their thermal preference they avoid high-temperature microenvironments probably to avoid overheating. The population currently persists because of the important role of the habitat physiognomy and not because of niche tracking, seemingly prevented by major rivers that form boundaries of their geographic range. We found evidence of habitat opportunities in the current range and adjacent areas that will likely remain suitable to the year 2070, reinforcing the relevance of the river floodplain for the species’ avoidance of extinction.