12,497 research outputs found

    Interview with Aimee Brissette

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    Survival and Flight Characteristics of Captive-Reared and Wild Northern Bobwhites in Texas

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    Introductions of captive-reared northern bobwhite (Colinus virginianus) to bolster native populations have been largely unsuccessful. We compared the survival and flight characteristics of game-farm (n 46), first-generation (F1) (n = 48), wild translocated (n = 45), and wild native (n = 50) northern bobwhites. In November 1993, all birds were radio-collared, leg banded, sexed, and aged. Birds were then released on a study area in Brooks County, Texas in groups of about 15, 1 bird at a time. Upon release, the direction of departure, speed, and time required to reach cover were recorded. The mean flight speed and distance flown for wild bobwhites was significantly greater (P \u3c 0.01) than captive-reared bobwhites. Wild native, wild translocated, and F1 groups were non-randomly distributed in direction of departure at release site (P \u3c 0.01). Survival of wild groups was significantly higher than captive-raised groups (P \u3c 0.05). The major cause of mortality in all groups was mammalian depredation. Fifteen F1 quail and 1 game-farm quail integrated into wild coveys. Our results re-confirm the inability of game-farm and first-generation northern bobwhites to survive in the wild, and we offer flight speed as one potential causal factor

    Interview with Jean Lamb

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    https://digitalcommons.providence.edu/psp470_2023/1005/thumbnail.jp

    Light Scatterometry as an NDE Technique for Surface Characterization of Ge Windows

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    Germanium is a material with optimal infrared (IR) transmission properties but poor mechanical properties[1]. As a result, repeated water drop impacts on polished Ge windows with velocities greater than 170 m/s produce considerable amounts of surface and subsurface damage (see Figure 1). This results in IR transmission loss through these windows[2]. The mechanics of the water drop/solid surface interaction has been amply described in the literature[3] and will not be discussed here. In order to maintain optimum IR system performance, one needs to monitor the damage evolution on these windows. The technique required should be fast, quantitative, non-contacting and easy to interpret. In this paper we examine the use of light scatterometry as a possible approach for monitoring damage evolution

    Carbon Nanomaterials Promote M1/M2 Macrophage Activation

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    Toxic effects of certain carbon nanomaterials (CNM) have been observed in several exposure scenarios both in vivo and in vitro. However, most of the data currently available has been generated in a high-dose/acute exposure setup, limiting the understanding of their immunomodulatory mechanisms. Here, macrophage-like THP-1 cells, exposed to ten different CNM for 48 h in low-cytotoxic concentration of 10 mu g mL(-1), are characterized by secretion of different cytokines and global transcriptional changes. Subsequently, the relationships between cytokine secretion and transcriptional patterns are modeled, highlighting specific pathways related to alternative macrophage activation. Finally, time- and dose-dependent activation of transcription and secretion of M1 marker genes IL-1 beta and tumor necrosis factor, and M2 marker genes IL-10 and CSF1 is confirmed among the three most responsive CNM, with concentrations of 5, 10, and 20 mu g mL(-1) at 24, 48, and 72 h of exposure. These results underline CNM effects on the formation of cell microenvironment and gene expression leading to specific patterns of macrophage polarization. Taken together, these findings imply that, instead of a high and toxic CNM dose, a sub-lethal dose in controlled exposure setup can be utilized to alter the cell microenvironment and program antigen presenting cells, with fascinating implications for novel therapeutic strategies.Peer reviewe

    Can shoulder range of movement be measured accurately using the Microsoft Kinect sensor plus Medical Interactive Recovery Assistant (MIRA) software?

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    BackgroundThis study compared the accuracy of measuring shoulder range of movement (ROM) with a simple laptop-sensor combination vs. trained observers (shoulder physiotherapists and shoulder surgeons) using motion capture (MoCap) laboratory equipment as the gold standard. MethodsThe Microsoft Kinect sensor (Microsoft Corp., Redmond, WA, USA) tracks 3-dimensional human motion. Ordinarily used with an Xbox (Microsoft Corp.) video game console, Medical Interactive Recovery Assistant (MIRA) software (MIRA Rehab Ltd., London, UK) allows this small sensor to measure shoulder movement with a standard computer. Shoulder movements of 49 healthy volunteers were simultaneously measured by trained observers, MoCap, and the MIRA device. Internal rotation was assessed with the shoulder abducted 90° and external rotation with the shoulder adducted. Visual estimation and MIRA measurements were compared with gold standard MoCap measurements for agreement using Bland-Altman methods. Results There were 1670 measurements analyzed. The MIRA evaluations of all 4 cardinal shoulder movements were significantly more precise, with narrower limits of agreement, than the measurements of trained observers. MIRA achieved ±11° (95% confidence interval [CI], 8.7°-12.6°) for forward flexion vs. ±16° (95% CI, 14.6°-17.6°) by trained observers. For abduction, MIRA showed ±11° (95% CI, 8.7°-12.8°) against ±15° (95% CI, 13.4°-16.2°) for trained observers. MIRA attained ±10° (95% CI, 8.1°-11.9°) during external rotation measurement, whereas trained observers only reached ±21° (95% CI, 18.7°-22.6°). For internal rotation, MIRA achieved ±9° (95% CI, 7.2°-10.4°), which was again better than TOs at ±18° (95% CI, 16.0°-19.3°). ConclusionsA laptop combined with a Microsoft Kinect sensor and the MIRA software can measure shoulder movements with acceptable levels of accuracy. This technology, which can be easily set up, may also allow precise shoulder ROM measurement outside the clinic setting

    First Study of a HEXITEC Detector for Secondary Particle Characterisation during Proton Beam Therapy

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    Online proton range verification is a rapidly emerging field characterised by its ability to reduce the error margins during proton beam therapy, as it is patient-specific and in vivo. In particular, secondary prompt gamma detection is a promising tool to monitor the dose delivery. The present research evaluates the capability of a HEXITEC detector to identify the prompt gammas produced during proton beam therapy, and assesses its potential for online range verification. To achieve this, the detector is placed at one side of a water phantom, which is irradiated at different proton energies in the University College London Hospital Proton Centre. For further analysis, Monte Carlo simulations are performed using Geant4 and the same geometry as the experiment. The results show that HEXITEC has the potential to be part of a detection system that could identify secondary prompt gammas within the secondary field produced inside the target, allowing for the in-detector discrimination of these particles via cluster size analysis. The comparison between data sets shows that there is a high level of accuracy between the model and the experimental measurements in terms of secondary flux and charge diffusion inside the detector, which poses the model as a fundamental tool for future optimisation studies

    Molecular Gas in Candidate Double Barred Galaxies III. A Lack of Molecular Gas?

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    Most models of double-barred galaxies suggest that a molecular gas component is crucial for maintaining long-lived nuclear bars. We have undertaken a CO survey in an attempt to determine the gas content of these systems and to locate double barred galaxies with strong CO emission that could be candidates for high resolution mapping. We observed 10 galaxies in CO J=2-1 and J=3-2 and did not detect any galaxies that had not already been detected in previous CO surveys. We preferentially detect emission from galaxies containing some form of nuclear activity. Simulations of these galaxies require that they contain 2% to 10% gas by mass in order to maintain long-lived nuclear bars. The fluxes for the galaxies for which we have detections suggest that the gas mass fraction is in agreement with these models requirements. The lack of emission in the other galaxies suggests that they contain as little as 7 x 10^6 solar masses of molecular material which corresponds to < 0.1% gas by mass. This result combined with the wide variety of CO distributions observed in double barred galaxies suggests the need for models of double-barred galaxies that do not require a large, well ordered molecular gas component.Comment: 17 pages (3 figures embedded on pg 17). To appear in the March 10 issue of the Astrophysical Journa

    Local spinfoam expansion in loop quantum cosmology

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    The quantum dynamics of the flat Friedmann-Lemaitre-Robertson-Walker and Bianchi I models defined by loop quantum cosmology have recently been translated into a spinfoam-like formalism. The construction is facilitated by the presence of a massless scalar field which is used as an internal clock. The implicit integration over the matter variable leads to a nonlocal spinfoam amplitude. In this paper we consider a vacuum Bianchi I universe and show that by choosing an appropriate regulator a spinfoam expansion can be obtained without selecting a clock variable and that the resulting spinfoam amplitude is local.Comment: 12 page
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