5,472 research outputs found
Financial disclosure and the Board: A case for non-independent directors
In listed companies, the Board of directors has ultimate responsibility for information disclosure. The conventional wisdom is that director independence is an essential factor in improving the quality of that disclosure. In a sense, this approach subordinates expertise to independence. We argue that effective certification may require firm-specific expertise, in particular for intangible-intensive business models. However, this latter form of expertise is negatively related to independence as it is commonly measured and evaluated. Accordingly, there exists an optimal share of independent directors for each company, related to the level of intangible resources.
New experimental limits on neutron - mirror neutron oscillations in the presence of mirror magnetic field
Present probes do not exclude that the neutron () oscillation into mirror
neutron (), a sterile state exactly degenerate in mass with the neutron,
can be a very fast process, in fact faster than the neutron decay itself. This
process is sensitive to the magnetic field. Namely, if the mirror magnetic
field exists at the Earth, oscillation probability can be
suppressed or resonantly amplified by the applied magnetic field ,
depending on its strength and on the angle between and
. We present the results of ultra-cold neutron storage measurements
aiming to check the anomalies observed in previous experiments which could be a
signal for oscillation in the presence of mirror magnetic field ~G. Analyzing the experimental data on neutron loses, we obtain a new lower
limit on oscillation time s (95 % C.L.) for any
between 0.08 and 0.17 G, and s (95 % C.L.)
for any in the interval () G
Inhibition of in-stent stenosis by oral administration of bindarit in porcine coronary arteries
<p><b>Objective:</b> We have previously demonstrated that bindarit, a selective inhibitor of monocyte chemotactic proteins (MCPs), is effective in reducing neointimal formation in rodent models of vascular injury by reducing smooth muscle cell proliferation and migration and neointimal macrophage content, effects associated with the inhibition of MCP-1/CCL2 production. The aim of the current study was to evaluate the efficacy of bindarit on in-stent stenosis in the preclinical porcine coronary stent model.</p>
<p><b>Methods and Results:</b> One or 2 bare metal stents (Multi-Link Vision, 3.5 mm) were deployed (1:1.2 oversize ratio) in the coronary arteries of 42 pigs (20 bindarit versus 22 controls). Bindarit (50 mg/kg per day) was administered orally from 2 days before stenting until the time of euthanasia at 7 and 28 days. Bindarit caused a significant reduction in neointimal area (39.4%, P<0.001, n=9 group), neointimal thickness (51%, P<0.001), stenosis area (37%, P<0.001), and inflammatory score (40%, P<0.001) compared with control animals, whereas there was no significant difference in the injury score between the 2 groups. Moreover, treatment with bindarit significantly reduced the number of proliferating cells (by 45%, P<0.05; n=6 group) and monocyte/macrophage content (by 55%, P<0.01; n=5â6 group) in stented arteries at day 7 and 28, respectively. These effects were associated with a significant (P<0.05) reduction of MCP-1 plasma levels at day 28. In vitro data showed that bindarit (10â300 micromol/L) reduced tumor necrosis factor-alpha (50 ng/mL)âinduced pig coronary artery smooth muscle cell proliferation and inhibited MCP-1 production.</p>
<p><b>Conclusion:</b> Our results show the efficacy of bindarit in the prevention of porcine in-stent stenosis and support further investigation for clinical application of this compound.</p>
Dendroecological testing of the pyroclimatic hypothesis in the central Great Basin, Nevada, USA
In the Great Basin region of western North America, records of past climate and wildfire variability are needed not only for fire use, but also for understanding the mechanisms behind the centuryâlong expansion of piñonâjuniper woodlands. The Mt. Irish area (Lincoln County, southâeastern Nevada) is a remote mountain ecosystem on the hydrographic boundary between the Great Basin and the Colorado River Basin. Nonâscarred ponderosa pines (Pinus ponderosa C. Lawson var. scopulorum Engelm.) and singleâneedle pinyons (Pinus monophylla Torr. & FrĂ©m.) were used to develop a treeâring reconstruction of drought (mean PDSI for MayâJuly from NV Climate Division 3) from 1396 to 2003. A hypothetical fire regime was obtained from the PDSI reconstruction and from explicitly assumed relationships between climate and wildfire occurrence. A census of fireâscarred trees was then sampled at the study area, and crossdated fireâscar records were used to generate the fire history, independently of the preâexisting pyroclimatic model. Out of 250 collected fireâscar wood sections, 197 could be crossdated (about 89% from ponderosa pines), covered the period from 1146 to 2006, and contained 485 fire scars, 390 of which could be dated to a single year. Numerical summaries were computed for the period 1550â2006, when recorder trees ranged from 16 to 169, using a total of 360 fire scars on 176 sections. Up to 1860, the time of EuroâAmerican settlement, fires that scarred at least two trees were very frequent (minimum fire interval: 1 year, mean: 4, median: 2, Weibull median: 3, maximum: 19), while fires that scarred at least 10% of the recorder trees were relatively rare (minimum fire interval: 40 years, mean: 66, median: 50, Weibull median: 63, maximum: 123). Fire frequency remained high during the 1780â1840 period, when fire was reduced or absent in other areas of the western United States. Both the âexpectedâ and the âobservedâ fire history showed lower fire frequency after EuroâAmerican settlement, which most likely displaced Native people and any deliberate use of fire, but did not introduce publicly organized suppression in the area. Therefore, less favorable climatic conditions, not postâsettlement fire management, were responsible for reduced wildfire occurrence in the modern era
An Unusual Case of Adrenal Metastasis from Colorectal Cancer: Computed Tomography and Fluorine 18-Fluoro-Deoxy-Glucose Positron Emission Tomography-Computed Tomography Features and Literature Review
Incidentally discovered adrenal masses are a common diagnostic problem. While computed tomography (CT) and magnetic resonance (MR) imaging can adequately characterize most benign or malignant adrenal masses, in some cases the results are indeterminate. We report and discuss a case of an adrenal metastasis with misleading clinical and CT features, in which an abnormal metabolic uptake detected through fluorine 18-fluoro-deoxy-glucose positron emission tomography (18F-FDG PET)-CT raised the suspicion of adrenal metastasis relatively early compared with apparently normal results on repeated follow-up CT examinations
Water level measurements using COSMO-SkyMed synthetic aperture radar
In this work, temporal series of Synthetic Aperture Radar (SAR) data are used to estimate water elevations. The proposed method is based on a Sub-Pixel Offset Tracking (technique) to retrieve the displacement of the double-bounce scattering effect of man-made structures located in the proximity of the water surface. The experimental setup is focused on the cases of the Mosul dam in Iraq and the Missouri river in Kansas City. The proposed approach is applied to real data from the COSMO-SkyMed program. Results validated with in-situ and satellite radar altimeter measurements prove the effectiveness of the proposed method in measuring the water levels
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