1,076 research outputs found
Anti-Inflammatory Activity of Calotropis gigantea and Tridax procumbens on Carrageenin-Induced Paw Edema in Rats
The anti-inflammatory activities of extract of Calotropis gigantea R.Br. and Tridax procumbens Linn., were assessed on carrageenin-induced paw edema along with standard drug, Ibuprofen. The Ibuprofen significantly reduced paw edema at the dose of 200mg/Kg bw orally. The oral administration equi-effective dose (ED50) of C. gigantea (600mg/Kg bw) and T. procumbens (400 mg/Kg bw) individually revealed about 20-35% more activity than the one rendered by administration of 50mg/Kg bw of Ibuprofen. The effect of C. gigantea and T. procumbens along with various dose regimen of Ibuprofen showed greater anti-inflammatory activities than the Ibuprofen alone
Small crater modification on Meridiani Planum and implications for erosion rates and climate change on Mars
A morphometric and morphologic catalog of ~100 small craters imaged by the Opportunity rover over the 33.5 km traverse between Eagle and Endeavour craters on Meridiani Planum shows craters in six stages of degradation that range from fresh and blocky to eroded and shallow depressions ringed by planed off rim blocks. The age of each morphologic class from <50–200 ka to ~20 Ma has been determined from the size‐frequency distribution of craters in the catalog, the retention age of small craters on Meridiani Planum, and the age of the latest phase of ripple migration. The rate of degradation of the craters has been determined from crater depth, rim height, and ejecta removal over the class age. These rates show a rapid decrease from ~1 m/Myr for craters <1 Ma to ~ <0.1 m/Myr for craters 10–20 Ma, which can be explained by topographic diffusion with modeled diffusivities of ~10^(−6) m^2/yr. In contrast to these relatively fast, short‐term erosion rates, previously estimated average erosion rates on Mars over ~100 Myr and 3 Gyr timescales from the Amazonian and Hesperian are of order <0.01 m/Myr, which is 3–4 orders of magnitude slower than typical terrestrial rates. Erosion rates during the Middle‐Late Noachian averaged over ~250 Myr, and ~700 Myr intervals are around 1 m/Myr, comparable to slow terrestrial erosion rates calculated over similar timescales. This argues for a wet climate before ~3 Ga in which liquid water was the erosional agent, followed by a dry environment dominated by slow eolian erosion
Design for a Darwinian Brain: Part 1. Philosophy and Neuroscience
Physical symbol systems are needed for open-ended cognition. A good way to
understand physical symbol systems is by comparison of thought to chemistry.
Both have systematicity, productivity and compositionality. The state of the
art in cognitive architectures for open-ended cognition is critically assessed.
I conclude that a cognitive architecture that evolves symbol structures in the
brain is a promising candidate to explain open-ended cognition. Part 2 of the
paper presents such a cognitive architecture.Comment: Darwinian Neurodynamics. Submitted as a two part paper to Living
Machines 2013 Natural History Museum, Londo
Cardioembolic but Not Other Stroke Subtypes Predict Mortality Independent of Stroke Severity at Presentation
Introduction. Etiology of acute ischemic stroke (AIS) is known to significantly influence management, prognosis, and risk of recurrence.
Objective. To determine if ischemic stroke subtype based on TOAST criteria influences mortality.
Methods. We conducted an observational study of a consecutive cohort of patients presenting with AIS to a single tertiary academic center.
Results. The study population consisted of 500 patients who resided in the local county or the surrounding nine-county area. No patients were lost to followup. Two hundred and sixty one (52.2%) were male, and the mean age at presentation was 73.7 years (standard deviation, SD = 14.3). Subtypes were as follows: large artery atherosclerosis 97 (19.4%), cardioembolic 144 (28.8%), small vessel disease 75 (15%), other causes 19 (3.8%), and unknown 165 (33%). One hundred and sixty patients died: 69 within the first 30 days, 27 within 31–90 days, 29 within 91–365 days, and 35 after 1 year. Low 90-, 180-, and 360-day survival was seen in cardioembolic strokes (67.1%, 65.5%, and 58.2%, resp.), followed for cryptogenic strokes (78.0%, 75.3%, and 71.1%). Interestingly, when looking into the cryptogenic category, those with insufficient information to assign a stroke subtype had the lowest survival estimate (57.7% at 90 days, 56.1% at 180 days, and 51.2% at 1 year).
Conclusion. Cardioembolic ischemic stroke subtype determined by TOAST criteria predicts long-term mortality, even after adjusting for age and stroke severity
Implications of Electronics Constraints for Solid-State Quantum Error Correction and Quantum Circuit Failure Probability
In this paper we present the impact of classical electronics constraints on a
solid-state quantum dot logical qubit architecture. Constraints due to routing
density, bandwidth allocation, signal timing, and thermally aware placement of
classical supporting electronics significantly affect the quantum error
correction circuit's error rate. We analyze one level of a quantum error
correction circuit using nine data qubits in a Bacon-Shor code configured as a
quantum memory. A hypothetical silicon double quantum dot quantum bit (qubit)
is used as the fundamental element. A pessimistic estimate of the error
probability of the quantum circuit is calculated using the total number of
gates and idle time using a provably optimal schedule for the circuit
operations obtained with an integer program methodology. The micro-architecture
analysis provides insight about the different ways the electronics impact the
circuit performance (e.g., extra idle time in the schedule), which can
significantly limit the ultimate performance of any quantum circuit and
therefore is a critical foundation for any future larger scale architecture
analysis.Comment: 10 pages, 7 figures, 3 table
Roughness Signature of Tribological Contact Calculated by a New Method of Peaks Curvature Radius Estimation on Fractal Surfaces
This paper proposes a new method of roughness peaks curvature radii calculation and its application to tribological contact analysis as characteristic signature of tribological contact. This method is introduced via the classical approach of the calculation of radius of asperity. In fact, the proposed approach provides a generalization to fractal profiles of the Nowicki's method [Nowicki B. Wear Vol.102, p.161-176, 1985] by introducing a fractal concept of curvature radii of surfaces, depending on the observation scale and also numerically depending on horizontal lines intercepted by the studied profile. It is then established the increasing of the dispersion of the measures of that lines with that of the corresponding radii and the dependence of calculated radii on the fractal dimension of the studied curve. Consequently, the notion of peak is mathematically reformulated. The efficiency of the proposed method was tested via simulations of fractal curves such as those described by Brownian motions. A new fractal function allowing the modelling of a large number of physical phenomena was also introduced, and one of the great applications developed in this paper consists in detecting the scale on which the measurement system introduces a smoothing artifact on the data measurement. New methodology is applied to analysis of tribological contact in metal forming process
Coping with an Advanced Stage Lung Cancer Diagnosis: Patient, Caregiver, and Provider Perspectives on the Role of the Health Care System
Although lung cancer is the leading cause of cancer death in the USA, there have been few studies on patient-centered advanced lung cancer treatment practices. As part of a larger research study on how to use a patient-inclusive approach in late-stage lung cancer treatment, this present study describes patient, caregiver, and provider perspectives on the role of the health care system in helping patients cope with an advanced stage lung cancer diagnosis. Four focus group sessions were conducted with six to eleven participants per group for a total of 36 participants. Two focus groups were held with patients and family members/caregivers and two with physicians and nurses. A major theme that emerged concerned coping with an advanced lung cancer diagnosis, which is the subject of this paper. The patients, caregivers, and providers spoke passionately about interactions with the health care system and volunteered examples of supportive and non-supportive relationships between patients and clinicians. They advocated for better patient-provider communication practices as well as the expanded use of patient navigation and new patient orientation programs. This study contributes additional knowledge by including the perspectives of caregivers and providers who live and work closely with patients with advanced lung cancer. The findings can inform the development of comprehensive patient-centered care plans for patients living with an advanced lung cancer diagnosis
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