2,412 research outputs found

    Early-Season Phenology and Temporal Dynamics of the Common Asparagus Beetle, \u3ci\u3eCrioceris Asparagi\u3c/i\u3e (Coleoptera: Chrysomelidae), in Southern Minnesota

    Get PDF
    During the years 1991-1994, studies were conducted to determine the early-season phenology and temporal dynamics of Crioceris asparagi (L.) (Co- leoptera: Chrysomelidae) in southern Minnesota asparagus. To document the early-season phenology, asparagus plots were sampled for egg, larval, and adult stages of C. asparagi during the months of May and June. Temporal dynamics of C. asparagi were determined by measuring the diurnal activity of adults and sampling asparagus plots at specific times (7 am, 9 am, 11 am, 1 pm, 3 pm and 5 pm) throughout May and June. We first detected C. asparagi adults in early May and they remained active throughout the sampling period. Eggs and larvae were also found; larval infestations on spears, however, were consistently lower than those for eggs. The temporal dynamics of C. asparagi adults showed that a higher percentage of asparagus plants were observed to be infested with beetles during the afternoon hours of 1 and 5 pm. The information provided in this paper illustrates the importance of determining the optimum time of day for sampling and will assist in properly targeting sampling efforts in future asparagus research and integrated pest management (IPM) programs

    Undergraduate Knowledge of School Psychology and the Effects of Presentation on Graduate and Career Pursuit

    Get PDF
    With the increasing national demand for credentialed school psychologists, it is essential that every effort be made to recruit qualified individuals into the field of school psychology. This paper describes the important role and function of the school psychologist. Research demonstrating the present and future need for school psychological services is presented. Literature investigating several factors that contribute to the gap between supply and demand is reviewed. An intervention is presented based on the recommendations of the reviewed research. A brief informational presentation on school psychology, in conjunction with distributed materials about the profession, was assessed with a retrospective pretest-posttest design. The intervention was shown to increase undergraduates\u27 knowledge of school psychological service, the amount of information they had on school psychology as a potential career choice, and the amount of information they had on graduate training in school psychology. The intervention also significantly increased the number of students considering graduate training in school psychology. The majority of the students indicated that they planned on seeking more information about school psychology. The intervention was deemed relevant, interesting, and informative by the participants

    Spatial-Temporal Imaging of Anisotropic Photocarrier Dynamics in Black Phosphorus

    Get PDF
    As an emerging single elemental layered material with a low symmetry in-plane crystal lattice, black phosphorus (BP) has attracted significant research interest owing to its unique electronic and optoelectronic properties, including its widely tunable bandgap, polarization dependent photoresponse and highly anisotropic in-plane charge transport. Despite extensive study of the steady-state charge transport in BP, there has not been direct characterization and visualization of the hot carriers dynamics in BP immediately after photoexcitation, which is crucial to understanding the performance of BP-based optoelectronic devices. Here we use the newly developed scanning ultrafast electron microscopy (SUEM) to directly visualize the motion of photo-excited hot carriers on the surface of BP in both space and time. We observe highly anisotropic in-plane diffusion of hot holes, with a 15-times higher diffusivity along the armchair (x-) direction than that along the zigzag (y-) direction. Our results provide direct evidence of anisotropic hot carrier transport in BP and demonstrate the capability of SUEM to resolve ultrafast hot carrier dynamics in layered two-dimensional materials.Comment: 21 pages, 6 figure

    MPEC 2020-A99: 2020 AV2

    Get PDF
    [no abstract

    Grand Challenges in School Social Work: Collaboration and Constraint in School Social Workers’ Sexuality Support for Children with Disabilities

    Get PDF
    Children with disabilities (CWD) face challenges to the development of their sexuality, in part due to a lack of appropriate, tailored sexual education in schools, role ambiguity regarding provision of sexual health services, and widespread discomfort with the topic. However, CWD have unique sexual health needs, an increased vulnerability to sexual and other forms of violence, and desire for skills and knowledge to build relationships. Using a phenomenological lens, authors conducted semistructured interviews with eight school social workers to understand how they are working with other professionals to support sexual and relational health of CWD (ages three to 11). Results indicate that school social workers collaborated with other professionals, although they also described multiple contexts in which other professionals had sole responsibility for sexual education and deferred to their expertise. Role ambiguity, policy restrictions, proscribed roles, and discomfort with the topic limited provision of needed services. Findings can assist school social workers seeking to build interdisciplinary collaboration, reduce role ambiguity, foster comfortable environments, and advocate for appropriate formats to support the sexual and relational health and well-being of CWD. They also suggest areas for policy change so that sexual support services are inclusive of all youths

    Bending Nanoindentation and Plasticity Noise in FCC Single and Polycrystals

    Get PDF
    Abstract: We present a high-throughput nanoindentation study of in situ bending effects on incipient plastic deformation behavior of polycrystalline and single-crystalline pure aluminum and pure copper at ultranano depths (\u3c 200 nm). We find that hardness displays a statistically inverse dependence on in-plane stress for indentation depths smaller than 10 nm, and the dependence disappears for larger indentation depths. In contrast, plastic noise in the nanoindentation force and displacement displays statistically robust noise features, independently of applied stresses. Our experimental results suggest the existence of a regime in Face Centered Cubic (FCC) crystals where ultranano hardness is sensitive to residual applied stresses, but plasticity pop-in noise is insensitive to it

    Near-Earth asteroid (3200) Phaethon. Characterization of its orbit, spin state, and thermophysical parameters

    Full text link
    The near-Earth asteroid (3200) Phaethon is an intriguing object: its perihelion is at only 0.14 au and is associated with the Geminid meteor stream. We aim to use all available disk-integrated optical data to derive a reliable convex shape model of Phaethon. By interpreting the available space- and ground-based thermal infrared data and Spitzer spectra using a thermophysical model, we also aim to further constrain its size, thermal inertia, and visible geometric albedo. We applied the convex inversion method to the new optical data obtained by six instruments and to previous observations. The convex shape model was then used as input for the thermophysical modeling. We also studied the long-term stability of Phaethon's orbit and spin axis with a numerical orbital and rotation-state integrator. We present a new convex shape model and rotational state of Phaethon: a sidereal rotation period of 3.603958(2) h and ecliptic coordinates of the preferred pole orientation of (319∘^{\circ}, −-39∘^{\circ}) with a 5∘^{\circ} uncertainty. Moreover, we derive its size (DD=5.1±\pm0.2 km), thermal inertia (Γ\Gamma=600±\pm200 J m−2^{-2} s−1/2^{-1/2} K−1^{-1}), geometric visible albedo (pVp_{\mathrm{V}}=0.122±\pm0.008), and estimate the macroscopic surface roughness. We also find that the Sun illumination at the perihelion passage during the past several thousand years is not connected to a specific area on the surface, which implies non-preferential heating.Comment: Astronomy and Astrophysics. In pres
    • …
    corecore