Small mammal demographics in North Dakota conservation reserve program plantings

During the summers of 1989 and 1990, capture-recapture methods were used to de~ermine small mammal demographics and population dynamics in Conservation Reserve Program (CRP) plantings in north central North Dakota. Four age classes (1-4 years) of CRP plantings were sampled. Small mammal species diversity was low (H\u27=0.057-0.374). Eight species of small mammals were captured on CRP tracts, with deer mice (Peromyscus maniculatus) comprising 92% of all small mammals recorded. Largest deer mouse populations (64/ha .and 51/ha) occurred in late August and early September, 1990. Peak densities in 1990 were over twice as high as those of 1989. Home range sizes of male and female deer mice were not significantly different, although mean home range 6f males (0.18 ha) was larger than that of females (0.14 ha). Total number of male deer mice was not significantly different than females. Based on other studies and sampling of vegetation and small mammals in later successional plantings, a change in vegetation and small mammal species composition can be expected in CRP plantings over time~ Substantial populations of deer mice in early growth give way to potentially substantial populations of meadow voles (Microtus pennsylvanicus) if plantings are not manipulated (burned, grazed or mowed). This change in species composition may influence the occurrence of avian predators in these areas and may furnish desirable alternate prey to avian and mammalian predators of ground nesting birds

An MEG investigation of the differential responsivity of the human calcarine fissure and fusiform gyrus to the emotion of viewed faces

Darwin proposed that communication of information concerning psychological state was an evolved mechanism. Much emotional signaling in humans occurs via facial expression. Neuroimaging techniques have identified regions involved in facial emotion perception and, although successively more sophisticated models have sought to explain this processing, results suggest that further development is needed. Neuroimaging research in facial emotion perception is currently focused on characterizing major sources of activation in development of these models. Although facial processing is a visual task, decoding of expression has been theorized to take place not in the primary visual regions of the occipital cortex but later within specialized portions of temporal cortex. Portions of the fusiform gyrus respond preferentially to facial stimuli and, although current models hypothesize that processing of facial expression takes place elsewhere, some evidence suggests that facial expression modulates the fusiform response. Lewis et al. (2003) found differential activation of an equivalent current magnetic dipole in the right fusiform when viewing happy versus disgusted versus neutral faces. The current work sought to replicate and extend these findings by, 1) expanding the stimulus set to all six basic emotions and a non-face control condition, 2) investigating the primary visual response of the calcarine fissure for an emotion-dependent component, and 3) investigating effects of gender and age. Contrary to expectations, findings here included emotion-related differences in peak amplitude and latency in responses of both the calcarine and fusiform. In the calcarine happy faces were seen to elicit greater amplitude than neutral, swirled, and sad faces, while in the fusiform fearful and surprised faces resulted in greater amplitude than disgusted faces and non-face objects. In the fusiform swirled faces elicited longer response latencies than recognizable faces regardless of emotion with fewer significant comparisons making a similar suggestion in the calcarine. Surprised faces required greater latencies in the right fusiform than happy and neutral faces. Partial support for the findings of Lewis and colleagues is suggested. A main effect was found for gender, with women displaying greater amplitude, shorter-latency responses. The amplitude response of the fusiform was greater than the calcarine and this differential increased with age

Experimental study of optimal measurements for quantum state tomography

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test states. Those that are informationally complete for all states are found to be accurate and reliable even in the presence of errors in the measurements themselves, while those designed to be complete only for pure states are far more efficient but highly sensitive to such errors. Our results highlight the unavoidable tradeoffs inherent to quantum tomography.Comment: 5 pages, 3 figure

Detection of Topological Spin Textures via Nonlinear Magnetic Responses

Topologically nontrivial spin textures, such as skyrmions and dislocations, display emergent electrodynamics and can be moved by spin currents over macroscopic distances. These unique properties and their nanoscale size make them excellent candidates for the development of next-generation race-track memory and unconventional computing. A major challenge for these applications and the investigation of nanoscale magnetic structures in general is the realization of suitable detection schemes. We study magnetic disclinations, dislocations, and domain walls in FeGe and reveal pronounced responses that distinguish them from the helimagnetic background. A combination of magnetic force microscopy (MFM) and micromagnetic simulations links the response to the local magnetic susceptibility, that is, characteristic changes in the spin texture driven by the MFM tip. On the basis of the findings, which we explain using nonlinear response theory, we propose a read-out scheme using superconducting microcoils, presenting an innovative approach for detecting topological spin textures and domain walls in device-relevant geometries

Magnetic and geometric control of spin textures in the itinerant kagome magnet Fe3Sn2

Magnetic materials with competing magnetocrystalline anisotropy and dipolar energies can develop a wide range of domain patterns, including classical stripe domains, domain branching, and topologically trivial and nontrivial (skyrmionic) bubbles. We image the magnetic domain pattern of Fe3Sn2 by magnetic force microscopy and study its evolution due to geometrical confinement, magnetic fields, and their combination. In Fe3Sn2 lamellae thinner than 3 μm, we observe stripe domains whose size scales with the square root of the lamella thickness, exhibiting classical Kittel scaling. Magnetic fields turn these stripes into a highly disordered bubble lattice. Complementary micromagnetic simulations quantitatively capture the magnetic field and thickness dependence of the magnetic patterns, reveal strong reconstructions of the patterns between the surface and the core of the lamellae, and identify the observed bubbles as skyrmionic bubbles. Our results imply that geometrical confinement together with competing magnetic interactions can provide a path to fine-tune and stabilize different types of topologically trivial and nontrivial spin structures in centrosymmetric magnets

Spin-orbit interaction driven terahertz nonlinear dynamics in transition metals

The interplay of electric charge, spin, and orbital polarizations, coherently driven by picosecond long oscillations of light fields in spin-orbit coupled systems, is the foundation of emerging terahertz spintronics and orbitronics. The essential rules for how terahertz light interacts with these systems in a nonlinear way are still not understood. In this work, we demonstrate a universally applicable electronic nonlinearity originating from spin-orbit interactions in conducting materials, wherein the interplay of light-induced spin and orbital textures manifests. We utilized terahertz harmonic generation spectroscopy to investigate the nonlinear dynamics over picosecond timescales in various transition metal films. We found that the terahertz harmonic generation efficiency scales with the spin Hall conductivity in the studied films, while the phase takes two possible values (shifted by {\pi}), depending on the d-shell filling. These findings elucidate the fundamental mechanisms governing non-equilibrium spin and orbital polarization dynamics at terahertz frequencies, which is relevant for potential applications of terahertz spin- and orbital-based devices.Comment: 11 pages, 4 figure

When assessment defines the content—understanding goals in between teachers and policy

© 2020 The Authors. The Curriculum Journal published by John Wiley & Sons Ltd on behalf of British Educational Research Association.Education policy development internationally reflect a widespread expansion of learning outcome orientation in policy, curricula and assessment. In this paper, teachers’ perceptions about their work are explored, as goals and assessment play a more prominent role driven by the introduction of a learning outcomes‐oriented system. This is investigated through interviews of Norwegian teachers and extensive policy analysis of Norwegian policy documents. The findings indicate that the teachers are finding ways to negotiate and adjust to the language in the policies investigated in this study. Furthermore, the findings show that the teachers have developed their professional language according to the policies. The teachers referred to their self‐made criteria and goal sheets as central tools in explicating what is to be learned. In many ways, the tools for assessment, thus determine the content of education as well as what is valued in the educational system.publishedVersio