8,526 research outputs found

    Familial influences on the full range of variability in attention and activity levels during adolescence: A longitudinal twin study

    Get PDF
    AbstractTo investigate familial influences on the full range of variability in attention and activity across adolescence, we collected maternal ratings of 339 twin pairs at ages 12, 14, and 16, and estimated the transmitted and new familial influences on attention and activity as measured by the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior Scale. Familial influences were substantial for both traits across adolescence: genetic influences accounted for 54%–73% (attention) and 31%–73% (activity) of the total variance, and shared environmental influences accounted for 0%–22% of the attention variance and 13%–57% of the activity variance. The longitudinal stability of individual differences in attention and activity was largely accounted for by familial influences transmitted from previous ages. Innovations over adolescence were also partially attributable to familial influences. Studying the full range of variability in attention and activity may facilitate our understanding of attention-deficit/hyperactivity disorder's etiology and intervention.</jats:p

    Trans-Planckian physics and signature change events in Bose gas hydrodynamics

    Get PDF
    We present an example of emergent spacetime as the hydrodynamic limit of a more fundamental microscopic theory. The low-energy, long-wavelength limit in our model is dominated by collective variables that generate an effective Lorentzian metric. This system naturally exhibits a microscopic mechanism allowing us to perform controlled signature change between Lorentzian and Riemannian geometries. We calculate the number of particles produced from a finite-duration Euclidean-signature event, where we take the position that to a good approximation the dynamics is dominated by the evolution of the linearized perturbations, as suggested by Calzetta and Hu [Phys. Rev. A 68 (2003) 043625]. We adapt the ideas presented by Dray et al. [Gen. Rel. Grav. 23 (1991) 967], such that the field and its canonical momentum are continuous at the signature-change event. We investigate the interplay between the underlying microscopic structure and the emergent gravitational field, focussing on its impact on particle production in the ultraviolet regime. In general, this can be thought of as the combination of trans-Planckian physics and signature-change physics. Further we investigate the possibility of using the proposed signature change event as an amplifier for analogue "cosmological particle production" in condensed matter experiments.Comment: 18 pages, revtex

    The effect of cultural and environmental factors on potato seed tuber morphology and subsequent sprout and stem development

    Get PDF
    Seed crops of the variety Estima were grown in each of 2 years using two planting dates, two harvest dates, two plant densities and two irrigation regimes to produce seed tubers which had experienced different cultural and environmental conditions. The effects of these treatments on tuber characteristics, sprout production and stem development in the ware crop were then determined in subsequent experiments using storage regimes of 3 and 10 °C. Time of planting the seed crop affected numbers of eyes, sprouts and above ground stems in the subsequent ware crop because environmental conditions around the time of tuber initiation appeared to alter tuber shape. Cooler, wetter conditions in the 7 days after tuber initiation were associated with tubers which were longer, heavier and had more eyes, sprouts and above ground stems. In contrast, the time of harvesting the seed crop did not affect tuber shape or numbers of above ground stems and there was no interaction with tuber size. The density of the seed crop had no effect on any character measured and irrigation well after tuber initiation did not affect tuber shape, numbers of sprouts or numbers of stems. Seed production treatments, which resulted in earlier dormancy break, were associated with tubers that produced more sprouts and above ground stems, in contrast to the conventional understanding of apical dominance. Storage at 3 °C gave fewer sprouts, a lower proportion of eyes with sprouts and fewer stems than storage at 10 °C. The major effects on stem production appear to result from environmental conditions at the time of tuber initiation of the seed crop and sprouting temperature

    Creation and characterization of vortex clusters in atomic Bose-Einstein condensates

    Full text link
    We show that a moving obstacle, in the form of an elongated paddle, can create vortices that are dispersed, or induce clusters of like-signed vortices in 2D Bose-Einstein condensates. We propose new statistical measures of clustering based on Ripley's K-function which are suitable to the small size and small number of vortices in atomic condensates, which lack the huge number of length scales excited in larger classical and quantum turbulent fluid systems. The evolution and decay of clustering is analyzed using these measures. Experimentally it should prove possible to create such an obstacle by a laser beam and a moving optical mask. The theoretical techniques we present are accessible to experimentalists and extend the current methods available to induce 2D quantum turbulence in Bose-Einstein condensates.Comment: 9 pages, 9 figure

    Immunoregulatory Potential of Exosomes Derived from Cancer Stem Cells.

    Get PDF
    Head and neck squamous cell carcinomas (HNSCCs) are malignancies that originate in the mucosal lining of the upper aerodigestive tract. Despite advances in therapeutic interventions, survival rates among HNSCC patients have remained static for years. Cancer stem cells (CSCs) are tumor-initiating cells that are highly resistant to treatment, and are hypothesized to contribute to a significant fraction of tumor recurrences. Consequently, further investigations of how CSCs mediate recurrence may provide insights into novel druggable targets. A key element of recurrence involves the tumor's ability to evade immunosurveillance. Recent published reports suggest that CSCs possess immunosuppressive properties, however, the underlying mechanism have yet to be fully elucidated. To date, most groups have focused on the role of CSC-derived secretory proteins, such as cytokines and growth factors. Here, we review the established immunoregulatory role of exosomes derived from mixed tumor cell populations, and propose further study of CSC-derived exosomes may be warranted. Such studies may yield novel insights into new druggable targets, or lay the foundation for future exosome-based diagnostics

    C-Band All-Sky Survey: A First Look at the Galaxy

    Get PDF
    We present an analysis of the diffuse emission at 5 GHz in the first quadrant of the Galactic plane using two months of preliminary intensity data taken with the C-Band All Sky Survey (C-BASS) northern instrument at the Owens Valley Radio Observatory, California. Combining C-BASS maps with ancillary data to make temperature-temperature plots we find synchrotron spectral indices of β=−2.65±0.05\beta = -2.65 \pm 0.05 between 0.408 GHz and 5 GHz and β=−2.72±0.09 \beta = -2.72 \pm 0.09 between 1.420 GHz and 5 GHz for −10∘<∣b∣<−4∘-10^{\circ} < |b| < -4^{\circ}, 20∘<l<40∘20^{\circ} < l < 40^{\circ}. Through the subtraction of a radio recombination line (RRL) free-free template we determine the synchrotron spectral index in the Galactic plane (∣b∣<4∘ |b| < 4^{\circ}) to be β=−2.56±0.07\beta = -2.56 \pm 0.07 between 0.408 GHz and 5 GHz, with a contribution of 53±853 \pm 8 per cent from free-free emission at 5\,GHz. These results are consistent with previous low frequency measurements in the Galactic plane. By including C-BASS data in spectral fits we demonstrate the presence of anomalous microwave emission (AME) associated with the HII complexes W43, W44 and W47 near 30 GHz, at 4.4 sigma, 3.1 sigma and 2.5 sigma respectively. The CORNISH VLA 5 GHz source catalogue rules out the possibility that the excess emission detected around 30\;GHz may be due to ultra-compact HII regions. Diffuse AME was also identified at a 4 sigma level within 30∘<l<40∘30^{\circ} < l < 40^{\circ}, −2∘<b<2∘-2^{\circ} < b < 2^{\circ} between 5 GHz and 22.8 GHz.Comment: 16 pages, 9 figures, submitted to MNRAS, referee's corrections made, awaiting for final approval for publicatio

    Teen Dating Violence: The Influence of Friendships and School Context

    Get PDF
    Prior research has examined parental and peer influences on teen dating violence (TDV), but fewer studies have explored the role of broader social contexts. Using data from the Toledo Adolescent Relationships Study (TARS), the present research examines the effect of variations in school context on teen dating violence perpetration, while taking into account parental, peer, and demographic factors. Drawing on interview data from 955 adolescents across 32 different schools, results indicate that net of parents’ and friends’ use of violence, the normative climate of schools, specifically school-level teen dating violence, is a significant predictor of respondents’ own violence perpetration. School-level dating norms (non-exclusivity in relationships) also contribute indirectly to the odds of experiencing TDV. However, a more general measure of school-level violence toward friends is not strongly related to variations in TDV, suggesting the need to focus on domain-specific influences. Implications for theories emphasizing social learning processes and for TDV prevention efforts are discussed

    The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region

    Get PDF
    The C-Band All-Sky Survey C-BASS is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity 4.7 GHz map of the North Celestial Pole (NCP) region of sky, above declination +80 deg, which is limited by source confusion at a level of ~0.6 mK rms. We apply the template-fitting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies ~20-40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change significantly (<10%) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408 MHz map as a tracer of synchrotron radiation. We measure template coefficients of 9.93±0.359.93\pm0.35 and 9.52±0.349.52\pm0.34 K per unit τ353\tau_{353} when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 55±2 μ55\pm2\,\muK rms at 22.8 GHz and accounts for ~60% of the total foreground emission. Our results suggest that a harder (flatter spectrum) component of synchrotron emission is not dominant at frequencies >5 GHz; the best-fitting synchrotron temperature spectral index is β=−2.91±0.04\beta=-2.91\pm0.04 from 4.7 to 22.8 GHz and β=−2.85±0.14\beta=-2.85\pm0.14 from 22.8 to 44.1 GHz. Free-free emission is weak, contributing ~7 μ7\,\muK rms (~7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.Comment: 18 pages, 6 figures, version matches version accepted by MNRA

    Isolated Medial Cuneiform Fractures: A Systematic Search and Qualitative Analysis of Case Studies

    Get PDF
    Background: Isolated medial cuneiform fracture is a rare but diagnostically challenging condition. Diagnostic delay in these cases may lead to delays in ideal treatment approaches and prolonged symptoms. An understanding of clinical presentation is needed to expedite diagnosis, facilitate decision making, and guide treatment approach. Methods: Case studies/series were searched in four databases until September 2019. Included studies had participants with a history of traumatic closed medial cuneiform fracture. Studies were excluded if the medial cuneiform fractures were open fractures, associated with multitrauma, or associated with dislocation/Lisfranc injury. Three blinded reviewers assessed the methodological quality of the studies, and a qualitative synthesis was performed. Results: Ten studies comprising 15 patients were identified. Mean ± SD patient age was 38.0 ± 12.8 years, with 86.7% of reported participants being men. The overall methodological quality was moderate to high, and reporting of the patient selection criteria was poor overall. The most commonly reported clinical symptoms were localized tenderness (60.0%) and edema (53.3%). Direct blow was the most common inciting trauma (46.2%), followed by axial load (30.8%) and avulsion injuries (23.1%). Baseline radiographs were occult in 72.7% of patients; magnetic resonance imaging and computed tomography were the most common diagnostic modalities. Mean ± SD diagnostic delay was 64.7 ± 89.6 days. Conservative management was pursued in 54.5% of patients, with reported resolution of symptoms in 3 to 6 months. Surgical intervention occurred in 45.5% of patients and resulted in functional restoration in 3 to 6 months in all but one patient. Conclusions: Initial radiographs for isolated medial cuneiform fractures are frequently occult. Due to expedience and relatively low cost, radiographs are still a viable first-line imaging modality. If clinical concern remains, magnetic resonance imaging may be pursued to minimize diagnostic delay. Conservative management is a viable treatment method, with expected return to full function in 3 to 6 months
    • …
    corecore