1,552 research outputs found

    Functional plasticity and tolerance to drought conditions of 11 apple tree varieties grown in Morocco

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    In this study, 11 varieties were grown in the experimental chamber in order to determine the morphological, anatomical and physiological characteristics of each. The experimental protocol was carried out under controlled conditions of irrigation, temperature and hygrometry. The values obtained of the thickness, the cuticle, length of the ostiole, density and size of the stomata and then of stomatal and cuticular sweat have made it possible to calculate the stomatic resistance of each variety and to evaluate its potential to adapt to drought conditions. We have highlighted significant differences related to variety through the Duncan test. 4 groups are identified and the results are discussed in this article

    Interactive sections of an Internet-based intervention increase empowerment of chronic back pain patients: Randomized controlled trial

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    Background Chronic back pain (CBP) represents a significant public health problem. As one of the most common causes of disability and sick leave, there is a need to develop cost-effective ways, such as Internet-based interventions, to help empower patients to manage their disease. Research has provided evidence for the effectiveness of Internet-based interventions in many fields, but it has paid little attention to the reasons why they are effective. Objective This study aims to assess the impact of interactive sections of an Internet-based self-management intervention on patient empowerment, their management of the disease, and, ultimately, health outcomes. Methods A total of 51 patients were recruited through their health care providers and randomly assigned to either an experimental group with full access to the Internet-based intervention or a control group that was denied access to the interactive sections and knew nothing thereof. The intervention took 8 weeks. A baseline, a mid-term after 4 weeks, and a final assessment after 8 weeks measured patient empowerment, physical exercise, medication misuse, and pain burden. Results All patients completed the study. Overall, the intervention had a moderate effect (F =2.83, P=.03, η =0.30, d=0.55). Compared to the control group, the availability of interactive sections significantly increased patient empowerment (midterm assessment: mean difference=+1.2, P=.03, d=0.63; final assessment: mean difference=+0.8, P=.09, d=0.44) and reduced medication misuse (midterm assessment: mean difference=−1.5, P=.04, d=0.28; final assessment: mean difference=−1.6, P=.03, d=−0.55) in the intervention group. Both the frequency of physical exercise and pain burden decreased, but to equal measures in both groups. Conclusions Results suggest that interactive sections as part of Internet-based interventions can positively alter patients’ feelings of empowerment and help prevent medication misuse. Detrimental effects were not observed. Trial Registration ClinicalTrials.gov: NCT02114788; http://www.clinicaltrials.gov/ct2/show/NCT02114788 (Archived by WebCite at http://www.webcitation.org/6ROXYVoPR)

    The 8 o'clock Arc: A Serendipitous Discovery of a Strongly Lensed Lyman Break Galaxy in the SDSS DR4 Imaging Data

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    We report on the serendipitous discovery of the brightest Lyman Break Galaxy (LBG) currently known, a galaxy at z=2.73 that is being strongly lensed by the z=0.38 Luminous Red Galaxy (LRG) SDSS J002240.91+143110.4. The arc of this gravitational lens system, which we have dubbed the "8 o'clock arc" due to its time of discovery, was initially identified in the imaging data of the Sloan Digital Sky Survey Data Release 4 (SDSS DR4); followup observations on the Astrophysical Research Consortium (ARC) 3.5m telescope at Apache Point Observatory confirmed the lensing nature of this system and led to the identification of the arc's spectrum as that of an LBG. The arc has a spectrum and a redshift remarkably similar to those of the previous record-holder for brightest LBG (MS 1512-cB58, a.k.a "cB58"), but, with an estimated total magnitude of (g,r,i) = (20.0,19.2,19.0) and surface brightness of (mu_g,mu_r,mu_i) = (23.3, 22.5, 22.3) mag/arcsec^2, the 8 o'clock arc is thrice as bright. The 8 o'clock arc, which consists of three lensed images of the LBG, is 162deg (9.6arcsec) long and has a length-to-width ratio of 6:1. A fourth image of the LBG -- a counter-image -- can also be identified in the ARC 3.5m g-band images. A simple lens model for the system assuming a singular isothermal ellipsoid potential yields an Einstein radius of 2.91+/-0.14 arcsec, a total mass for the lensing LRG (within the (10.6+/-0.5)/h kpc enclosed by the lensed images) of 1.04x10^12/h Msun, and a magnification factor for the LBG of 12.3(+15/-3.6). The LBG itself is intrinsically quite luminous (approximately 6L*) and shows indications of massive recent star formation, perhaps as high as 160/h Msun/year.Comment: 4 pages 5 figures, submitted to ApJ Letter

    Large Scale Structure in the SDSS Galaxy Survey

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    The Large Scale Structure (LSS) in the galaxy distribution is investigated using the Sloan Digital Sky Survey Early Data Release (SDSS EDR). Using the Minimal Spanning Tree technique we have extracted sets of filaments, of wall-like structures, of galaxy groups, and of rich clusters from this unique sample. The physical properties of these structures were then measured and compared with the expectations from Zel'dovich' theory. The measured characteristics of galaxy walls were found to be consistent with those for a spatially flat Λ\LambdaCDM cosmological model with Ωm≈\Omega_m\approx 0.3 and ΩΛ≈\Omega_\Lambda \approx 0.7, and for Gaussian initial perturbations with a Harrison -- Zel'dovich power spectrum. Furthermore, we found that the mass functions of groups and of unrelaxed structure elements generally fit well with the expectations from Zel'dovich' theory, although there was some discrepancy for lower mass groups which may be due to incompleteness in the selected sample of groups. We also note that both groups and rich clusters tend to prefer the environments of walls, which tend to be of higher density, rather than the environments of filaments, which tend to be of lower density. Finally, we note evidence of systematic differences in the properties of the LSS between the Northern Galactic Cap stripe and the Southern Galactic Cap stripe -- in particular, in the physical properties of the walls, their spatial distribution, and the relative numbers of clusters embedded in walls. Because the mean separation of walls is ≈\approx 60 -- 70h−1h^{-1} Mpc, each stripe only intersects a few tens of walls. Thus, small number statistics and cosmic variance are the likely drivers of these systematic differences.Comment: 13 pages, 11 figures, MNRAS submitte

    Histotripsy Effects on the Bladder Trigone: Functional and Histologic Consequences in the Canine Model

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    Background: Histotripsy is an extracorporeal therapeutic ultrasound (US) technology, where high-amplitude acoustic energy is applied to targeted tissue. Previous research has demonstrated the feasibility, safety, and effectiveness of histotripsy tissue homogenization and debulking of the prostate in the canine model. Before translating this technology for human use, it is prudent to examine the susceptibility of critical periprostatic structures to cavitation injury in the event of histotripsy mistargeting. In this study, we sought to characterize the tissue effects and biologic response of directly treating the bladder trigone with histotripsy. Materials and Methods: In eight anesthetized canines, 750,000 histotripsy pulses were applied uniformly across a 2?1.5-cm area encompassing the bladder trigone and ureteral orifices. Prostate and bladder trigone were harvested immediately after treatment (2 subjects) or at 14 days (6 subjects). Flexible cystourethroscopy, US imaging, and creatinine levels were obtained at intervals until harvest, 14 days after treatment. In one control subject, harvested at 2 days, the same treatment algorithm was applied to the prostate. Results: Transrectal US imaging revealed a cavitation bubble cloud on the surface of the bladder trigone and progressive development of tissue edema during treatment. Flexible cystourethroscopy immediately after treatment confirmed edema and erythema of the trigone. In the six subjects survived 2 weeks after treatment, one incidence of transient, self-limited ureteral obstruction was noted based on hydronephrosis and creatinine levels. At harvest, ureteral orifices were confirmed patent by passage of a guide wire. Histologic evaluation revealed hemorrhage acutely with mild localized fibrosis at 14 days. Conclusions: In this study, designed along the lines of a worst-case, destructive testing scenario, direct targeting of the bladder trigone with supratherapeutic histotripsy failed to induce significant tissue damage or clinical complication. These results are reassuring and will guide treatment strategy in upcoming human clinical trials of histotripsy treatment for benign prostatic hyperplasia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140374/1/end.2013.0234.pd
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