4,300 research outputs found

    A Is Not For Ally

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    Most people can recall their first crush. They think fondly back to age ten or eleven when they first “went boy-crazy” or couldn’t focus on sixth-grade English because that cute girl was in their class. This did not happen for me. I do, however, vividly remember it happening for everyone around me. [excerpt

    The Weak Field Limit of the Magnetorotational Instability

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    We investigate the behavior of the magneto-rotational instability in the limit of extremely weak magnetic field, i.e., as the ratio of ion cyclotron frequency to orbital frequency (X) becomes small. Considered only in terms of cold two-fluid theory, instability persists to arbitrarily small values of X, and the maximum growth rate is of order the orbital frequency except for the range m_e/m_i < |X| < 1, where it can be rather smaller. In this range, field aligned with rotation (X > 0) produces slower growth than anti-aligned field (X < 0). The maximum growth rate is generally achieved at smaller and smaller wavelengths as |X| diminishes. When |X| < m_e/m_i, new unstable "electromagnetic-rotational" modes appear that do not depend on the equilibrium magnetic field. Because the most rapidly-growing modes have extremely short wavelengths when |X| is small, they are often subject to viscous or resistive damping, which can result in suppressing all but the longest wavelengths, for which growth is much slower. We find that this sort of damping is likely to curtail severely the frequently-invoked mechanism for cosmological magnetic field growth in which a magnetic field seeded by the Biermann battery is then amplified by the magneto-rotational instability. On the other hand, the small |X| case may introduce interesting effects in weakly-ionized disks in which dust grains carry most of the electric charge.Comment: 30 pages, including 4 figures; revised version resubmitted to Ap

    Alien Registration- Beals, Ellen I. (Blaine, Aroostook County)

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    https://digitalmaine.com/alien_docs/27192/thumbnail.jp

    High-fructose corn-syrup-sweetened beverage intake increases 5-hour breast milk fructose concentrations in lactating women

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    This study determined the effects of consuming a high-fructose corn syrup (HFCS)-sweetened beverage on breast milk fructose, glucose, and lactose concentrations in lactating women. At six weeks postpartum, lactating mothers (n = 41) were randomized to a crossover study to consume a commercially available HFCS-sweetened beverage or artificially sweetened control beverage. At each session, mothers pumped a complete breast milk expression every hour for six consecutive hours. The baseline fasting concentrations of breast milk fructose, glucose, and lactose were 5.0 &plusmn; 1.3 &micro;g/mL, 0.6 &plusmn; 0.3 mg/mL, and 6.8 &plusmn; 1.6 g/dL, respectively. The changes over time in breast milk sugars were significant only for fructose (treatment &times; time, p &lt; 0.01). Post hoc comparisons showed the HFCS-sweetened beverage vs. control beverage increased breast milk fructose at 120 min (8.8 &plusmn; 2.1 vs. 5.3 &plusmn; 1.9 &micro;g/mL), 180 min (9.4 &plusmn; 1.9 vs. 5.2 &plusmn; 2.2 &micro;g/mL), 240 min (7.8 &plusmn; 1.7 vs. 5.1 &plusmn; 1.9 &micro;g/mL), and 300 min (6.9 &plusmn; 1.4 vs. 4.9 &plusmn; 1.9 &micro;g/mL) (all p &lt; 0.05). The mean incremental area under the curve for breast milk fructose was also different between treatments (14.7 &plusmn; 1.2 vs. &minus;2.60 &plusmn; 1.2 &micro;g/mL &times; 360 min, p &lt; 0.01). There was no treatment &times; time interaction for breast milk glucose or lactose. Our data suggest that the consumption of an HFCS-sweetened beverage increased breast milk fructose concentrations, which remained elevated up to five hours post-consumption

    Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model.

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    The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH-SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH-SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH-SWCNTs' use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels &gt;20 ÎĽg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies

    Here's the TRIQ: The Tromsø Interest Development Questionnaire based on the four-phase model of interest development

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    The Tromsø Interest Questionnaire (TRIQ) is the first suite of self-report subscales designed for focused investigations on how interest is experienced in relation to Hidi and Renninger’s four-phase model of interest development. In response to the plethora of varied interest measures that already exist in terms of theoretical grounding, form, and tested quality, the TRIQ subscales were designed with a consistent form to measure general interest, situation dependence, positive affect, competence level, competence aspirations, meaningfulness, and self-regulation answered in relation to some object of interest. Two studies testing the subscales’ performance using different objects of interest (self-chosen “object-general,” and prespecified “object-specific”) provide evidence of the subscales’ internal consistency, temporal reliability, and phase-distinguishing validity. Patterns across the two studies demonstrate that the TRIQ is a sufficiently reliable and valid domain-tailorable tool that is particularly effective at distinguishing phase 1 (triggered situational) from phase 4 (well-developed individual) interest. The findings raise interesting questions for further investigation about the distinction and distance between all interest phases, the push-pull factors that influence how interests evolve and additional subscales to add to the suite
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