280 research outputs found

    Propositional calculus for adjointness lattices

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    Recently, Morsi has developed a complete syntax for the class of all adjointness algebras (L,≤,A,K,H)\left( L,\leq ,A,K,H\right) . There, (L,≤)\left( L,\leq \right) is a partially ordered set with top element 11, KK is a conjunction on (L,≤)\left( L,\leq \right) for which 11 is a left identity element, and the two implication-like binary operations AA and HH on LL are adjoints of KK. In this paper, we extend that formal system to one for the class ADJLADJL of all 9-tuples (L,≤,1,0,A,K,H,∧,∨)\left( L,\leq ,1,0,A,K,H,\wedge ,\vee \right) , called \emph{% adjointness lattices}; in each of which (L,≤,1,0,∧,∨)\left( L,\leq ,1,0,\wedge ,\vee \right) is a bounded lattice, and (L,≤,A,K,H)\left( L,\leq ,A,K,H\right) is an adjointness algebra. We call it \emph{Propositional Calculus for Adjointness Lattices}, abbreviated AdjLPCAdjLPC. Our axiom scheme for AdjLPCAdjLPC features four inference rules and thirteen axioms. We deduce enough theorems and inferences in AdjLPCAdjLPC to establish its completeness for ADJLADJL; by means of a quotient-algebra structure (a Lindenbaum type of algebra). We study two negation-like unary operations in an adjointness lattice, defined by means of 00 together with AA and HH. We end by developing complete syntax for all adjointness lattices whose implications are SS-type implications

    NANOEMULSION AS A NOVEL OPHTHALMIC DELIVERY SYSTEM FOR ACETAZOLAMIDE

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    Objective: The aim of this work was to formulate the antiglaucoma drug acetazolamide as ocular nanoemulsion of high therapeutic efficacy and prolonged effect. Methods: Eighteen nanoemulsion formulaions consisting of different oils, surfactants and cosurfactants at various ratios and constant water content (39%) were prepared based on their constructed pseudoternary-phase diagrams. According to the In vitro release studies, three nanoemulsions which exhibited fast drug release were used to prepare acetazolamide nanoemulsions with higher water content (59%). The six nanoemulsions at either water content (39 or 59%) were evaluated for their physicochemical properties and ex- vivo corneal permeability. In addition, Draize rabbit eye irritation test was performed. Moreover, biological evaluation of acetazolamide nanoemulsions for their intraocular pressure lowering activity on glaucomatous albino rabbits was carried out. Results: Isopropyl myristate nanoemulsion prepared with cremophor EL and transcutol P exhibited the fastest drug release among all isopropyl myristate nanoemulsions. Oleic acid nanoemulsion prepared with mixture of tween 80 and cremophor EL as surfactants together with transcutol P showed the fastest drug release among other oleic acid nanoemulsion formulae. Similar results were also observed for peanut oil nanoemulsions. The above mentioned formulations either at 39% or 59% water content showed acceptable physicochemical properties and higher acetazolamide permeability coefficient through goat corneas than that reported for the free drug. They also were non irritant to rabbit eye. Therapeutic efficacy testing revealed that peanut oil nanoemulsion at 39% water content showed better and prolonged intraocular pressure lowering effect relative to either commercial brinzolamide eye drops (Azopt®) or the commercial oral acetazolamide tablet (Cidamex®). Conclusion: Acetazolamide was successfully formulated in nanoemulsion form which revealed high therapeutic efficacy in treatment of glaucoma together with a prolonged effect

    Eficiencia de la extracción asistida por ultrasonido de pétalos de Delonix regia como antioxidante natural en la estabilidad oxidativa del aceite de girasol

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    The possibility of improving the oxidative stability of sunflower oil by enriching it with carotenoids from Delonix regia petals was studied. A combination of ultrasound-assisted extraction and stirring techniques was used. The optimal conditions were material/solvent ratio of 1:20 (w/v), ultrasonic power of 30 W and extraction time of 50 min. Under these conditions, the yield of total carotenoids was 503.0 μg/g dry weight. Increasing the acoustic power density degraded carotenoids. A HPLC analysis was used for the quantification of β-carotene in the extract. The DPPH radical scavenging activity and ferric reducing antioxidant power of the carotenoid-rich extract were found to be superior to the standard Butylated hydroxyl toluene (BHT). The enrichment of sunflower oil with carotenoid-rich extract at 67.46 mg carotenoids/kg oil improved its oxidative stability by more than 50% as measured by the Rancimat method. These results suggest that the investigated extract has the potential to be used as a bio-preservative in food products.Se estudió la posibilidad de mejorar la estabilidad oxidativa del aceite de girasol enriqueciéndolo con carotenoides de pétalos de Delonix regia. Se utilizaron técnicas combinadas de extracción asistida por ultrasonido y técnicas de agitación. Las condiciones óptimas fueron una relación material/ disolvente de 1:20 (p/v), una potencia ultrasónica de 30 W y un tiempo de extracción de 50 min. En estas condiciones, el rendimiento de carotenoides totales fue de 503,0 ?g/g de peso seco. El aumento de la densidad de potencia acústica degrada a los carotenoides. El análisis por HPLC se utilizó para la cuantificación de β-caroteno en el extracto. Se encontró que la actividad de captación de radicales DPPH y el poder antioxidante reductor férrico del extracto rico en carotenoides es superior al del butilhidroxitolueno estándar (BHT). El enriquecimiento de aceite de girasol con extracto rico en carotenoides a 67,46 mg de carotenoides/kg de aceite mejoró su estabilidad oxidativa en más del 50% según lo medido por el método de Rancimat. Estos resultados proponen que el extracto investigado tiene el potencial de ser utilizado como conservante biológico en productos alimenticios

    A Low Frequency Survey of the Galactic Plane Near l=11 degrees: Discovery of Three New Supernova Remnants

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    We have imaged a 1 deg^2 field centered on the known Galactic supernova remnant (SNR) G11.2-0.3 at 74, 330, and 1465 MHz with the Very Large Array radio telescope (VLA) and 235 MHz with the Giant Metrewave Radio Telescope (GMRT). The 235, 330, and 1465 MHz data have a resolution of 25 arcsec, while the 74 MHz data have a resolution of 100 arcsec. The addition of this low frequency data has allowed us to confirm the previously reported low frequency turnover in the radio continuum spectra of the two known SNRs in the field: G11.2-0.3 and G11.4-0.1 with unprecedented precision. Such low frequency turnovers are believed to arise from free-free absorption in ionized thermal gas along the lines of site to the SNRs. Our data suggest that the 74 MHz optical depths of the absorbing gas is 0.56 and 1.1 for G11.2-0.3 and G11.4-0.1, respectively. In addition to adding much needed low frequency integrated flux measurements for two known SNRs, we have also detected three new SNRs: G11.15-0.71, G11.03-0.05, and G11.18+0.11. These new SNRs have integrated spectral indices between -0.44 and -0.80. Because of confusion with thermal sources, the high resolution (compared to previous Galactic radio frequency surveys) and surface brightness sensitivity of our observations have been essential to the identification of these new SNRs. With this study we have more than doubled the number of SNRs within just a 1 deg^2 field of view in the inner Galactic plane. This result suggests that future low frequency observations of the Galactic plane of similar quality may go a long way toward alleviating the long recognized incompleteness of Galactic SNR catalogs.Comment: 31 pages, 9 figures. Figure 7 is in color. Accepted to A

    Chandra Observations of G11.2-0.3: Implications for Pulsar Ages

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    We present Chandra X-ray Observatory imaging observations of the young Galactic supernova remnant G11.2-0.3. The image shows that the previously known young 65-ms X-ray pulsar is at position (J2000) RA 18h 11m 29.22s, DEC -19o 25' 27.''6, with 1 sigma error radius 0.''6. This is within 8'' of the geometric center of the shell. This provides strong confirming evidence that the system is younger, by a factor of ~12, than the characteristic age of the pulsar. The age discrepancy suggests that pulsar characteristic ages can be poor age estimators for young pulsars. Assuming conventional spin down with constant magnetic field and braking index, the most likely explanation for the age discrepancy in G11.2-0.3 is that the pulsar was born with a spin period of ~62 ms. The Chandra image also reveals, for the first time, the morphology of the pulsar wind nebula. The elongated hard-X-ray structure can be interpreted as either a jet or a Crab-like torus seen edge on. This adds to the growing list of highly aspherical pulsar wind nebulae and argues that such structures are common around young pulsars.Comment: 16 pages, 3 figures, Accepted for publication in ApJ. For a full resolution version of Fig 1, see http://www.physics.mcgill.ca/~vkaspi/G11.2-0.3/f1.ep

    The Deepest Radio Study of the Pulsar Wind Nebula G21.5-0.9: Still No Evidence for the Supernova Shell

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    We report on sensitive new 1.4-GHz VLA radio observations of the pulsar wind nebula G21.5-0.9, powered by PSR J1833-1034, and its environs. Our observations were targeted at searching for the radio counterpart of the shell-like structure seen surrounding the pulsar wind nebula in X-rays. Some such radio emission might be expected as the ejecta from the <~ 1000 yr old supernova expand and interact with the surrounding medium. We find, however, no radio emission from the shell, and can place a conservative 3-sigma upper limit on its 1-GHz surface brightness of 7 x 10^-22 W/m^2/Hz/sr, comparable to the lowest limits obtained for radio emission from shells around other pulsar-wind nebulae. Our widefield radio image also shows the presence of two extended objects of low-surface brightness. We re-examine previous 327-MHz images, on which both the new objects are visible. We identify the first, G21.64-0.84, as a new shell-type supernova remnant, with a diameter of ~13' and an unusual double-shell structure. The second, G21.45-0.59, ~1' in diameter, is likely an HII region.Comment: 8 Pages, submitted to MNRA

    Is Adherence to Imatinib Mesylate Treatment Among Patients with Chronic Myeloid Leukemia Associated with Better Clinical Outcomes in Qatar?

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    Background: Despite the revolutionary success of introducing tyrosine kinase inhibitors (TKIs), such as imatinib mesylate (IM), for treating chronic myeloid leukemia (CML), a substantial proportion of patients' treatments fail. Aim: This study investigates the correlation between patient adherence and failure of TKIs' treatment in a follow-up study. Methods: This is a follow-up study of a new cohort of CML patients. Adherence to IM is assessed using the Medication Event Monitoring System (MEMS 6 TrackCap, AARDEX Ltd). The 9-item Morisky Medication Adherence Scale, medication possession ratio (MPR) calculation, and the electronic medical records are used for identifying potential factors that influence adherence. Clinical outcomes are assessed according to the European LeukemiaNet 2013 guidelines via reverse transcriptase quantitative polymerase chain reaction measurement of the level of BCR-ABL1 transcripts in peripheral blood. Response is classified at the hematological, cytogenetic, and molecular levels into optimal, suboptimal, or failure. Results: A total of 36 CML patients (5 citizens and 31 noncitizen residents) consented to participate in the study. The overall mean MEMS score was 89. Of the 36 patients, 22 (61%) were classified as adherent (mean: 95) and 14 (39%) were classified as nonadherent (mean: 80.2). Adherent patients were significantly more likely to obtain optimal response (95%) compared to the nonadherent group (14.3%; P < 0.0001). The rate of poor adherence was as high as 39% using MEMS, which correlates with 37% treatment failure rate. The survey results show that 97% of patients increased the IM dose by themselves when they felt unwell and 31% of them took the missing IM dose when they remembered. Other factors known to influence adherence show that half of patients developed one or more side effects, 65% of patients experienced lack of funds, 13% of patients declared unavailability of the drug in the NCCCR pharmacy, and 72% of patients believed that IM would cure the disease. The MPR results reveal that 16% of patients had poor access to treatment through the hospital pharmacy. Discussion and conclusion: This is the first prospective study to evaluate CML patients' adherence and response to IM in Qatar. The high rate of treatment failure observed in Qatar is explained by poor adherence. An economic factor (unaffordable drug prices) is one of the main causes of nonadherence and efforts should be made locally to improve access to medication for cancer diseases. Other risk factors associated with poor adherence could be improved by close monitoring and dose adjustment. Monitoring risk factors for poor adherence and patient education that include direct communication between the health-care teams, doctors, nurses, pharmacists, and patients are essential components for maximizing the benefits of TKI therapy and could rectify this problem. The preliminary results show that patients' response to treatment may be directly linked to patients' adherence to treatment. However, further in-depth and specific analysis may be necessary in a larger cohort

    Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Planets and Celestial Calibration Sources

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    (Abridged) We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23 - 94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274 and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1-sigma of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase, and limits (but no detections) on linear polarization. Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 micron, reproduce WMAP seasonally averaged observations of Mars within ~2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61 and 94 GHz bands; the smallest uncertainty for Neptune is ~8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at ~30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps, and are tabulated for Stokes I, Q and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A.Comment: 72 pages, 21 figures; accepted to ApJS; (v2) corrected Mars model scaling factors, added figure 21, added text to Mars, Saturn and celestial sources section

    The Expansion and Radio Spectral Index of G21.5-0.9: Is PSR J1833-1034 the Youngest Pulsar?

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    We report on new 5-GHz VLA radio observations of the pulsar-powered supernova remnant G21.5-0.9. These observations have allowed us to make a high-quality radio image of this remnant with a resolution of ~0.7". It has a filamentary structure similar to that seen in the Crab Nebula. Radio structure suggestive of the torus seen around the Crab pulsar is tentatively identified. We also compared the new image with one taken ~15 yr earlier at 1.5 GHz, both to find the expansion speed of the remnant and to make a spectral index image. Between 1991 and 2006, we find that the average expansion rate of the remnant is 0.11 +/- 0.02 %/year, corresponding, for a distance of 5 kpc, to a speed of 910 +/- 160 km/s wrt. the centre of the nebula. Assuming undecelerated expansion, this expansion speed implies that the age of G21.5-0.9 is 870 (+200,-150) yr, which makes PSR J1833-1034 one of the youngest, if not the youngest, known pulsars in the Galaxy.Comment: Accepted for publication in the MNRAS. 8 pages; For an animation showing the expansion of G21.5-0.9, see http://www.yorku.ca/bartel/G21new.html . (The only change in V3 of the preprint is to add the above url

    Implicator-conjunctor based models of fuzzy rough sets: definitions and properties

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    Ever since the first hybrid fuzzy rough set model was proposed in the early 1990' s, many researchers have focused on the definition of the lower and upper approximation of a fuzzy set by means of a fuzzy relation. In this paper, we review those proposals which generalize the logical connectives and quantifiers present in the rough set approximations by means of corresponding fuzzy logic operations. We introduce a general model which encapsulates all of these proposals, evaluate it w.r.t. a number of desirable properties, and refine the existing axiomatic approach to characterize lower and upper approximation operators
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