276 research outputs found

    Parameter recovery for transient signals

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 115-118).Transient signals naturally arise in numerous disciplines for which the decay rates and amplitudes carry some informational significance. Even when the decay rates are known, solving for the amplitudes results in an ill-conditioned formulation. Transient signals in the presence of noise are further complicated as the signal-to-noise ratio asymptotically decreases in time. In this thesis the Discrete-Time Transient Transform and the Discrete Transient Transform are defined in order to represent a general signal using a linear combination of decaying exponential signals. A common approach to computing a change of basis is to make use of the dual basis. Two algorithms are proposed for generating a dual basis: the first algorithm is specific to a general exponential basis, e.g., real exponential or harmonically related complex exponential bases are special cases of the general exponential basis, while the second algorithm is usable for any general basis. Several properties of a transient domain representation are discussed. Algorithms for computing numerically stable approximate transient spectra are additionally proposed. The inherent infinite bandwidth of a continuous-time transient signal motivates in part the development of a framework for recovering the decay rates and amplitudes of a discrete-time lowpass filtered transient signal. This framework takes advantage of existing parameter modeling, identification, and recovery techniques to determine the decay rates while an alternating projection method utilizing the Discrete Transient Transform determines the amplitudes.by Tarek A. Lahlou.S.M

    Gender and Crime: Addressing Threats to Construct Validity in the Criminological Research

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    In this article we argue that criminology is in need of a meta-theory that allows for a more complete treatment of the gender-crime relationship We suggest that one such metatheory is Integral Theory Integral Theory challenges disciplinary myopia and opens space for a more complete treatment of complex constructs such as gender We note that criminology would benefit from an ontological and epistemological pluralismthat accommodates the wide range of existing gender theories and recognizes the value of multiple methods designed to test those theories These arguments are supported via an analysis of recent research on the gender-crime relationshi

    Serum YKL-40 and assessment of severity of bronchial asthma in Egyptian children

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    Background: Serum and lung tissue levels of a chitinase-like protein YKL-40 have recently been found to be increased in patients with bronchial asthma. Furthermore, serum YKL-40 levels correlated positively with thickening of the lung sub-epithelial basement membrane, frequency of rescue inhaler use, and deterioration in pulmonary function in European asthmatic subjects. Objectives: to assess the role of YKL-40 measurement in evaluating asthma severity, compared to clinical assessment and the related pulmonary function tests. Methods: We quantified serum YKL-40 levels in two groups of Egyptian asthmatics: One group with mild to moderate asthma, and one with severe asthma. Serum YKL-40 was measured by enzyme-linked immunosorbent assay (ELISA) kits (Quidel). Clinical scoring of asthma severity by Pediatric Asthma Score (PAS) and pulmonary functions were performed. Results: The serum levels of YKL-40 were significantly elevated in severely asthmatic Egyptian children compared with the other group (151ng/ml- 72ng/ml; p < 05). YKL-40 levels were correlated positively to PAS (r=0.34, p < 0.05), and inversely to FEV1 (r= -0.32, p < 0.5). Best cut off value of YKL-40 for asthma prognosis was 90 ng/ml, sensitivity 86.5%, specificity 81%, and diagnostic accuracy of 85%. Conclusions: YKL-40 is found in increased quantities in the sera of severe asthmatics, and correlated significantly to PAS and pulmonary function deterioration. YKL-40 is considered a promising biomarker for asthma severity and pulmonary remodeling warranting further study as a potential novel pathway to disease management. Keywords: YKL-40, Asthma, severity, Egyptian, Children, biomarkerEgypt J Pediatr Allergy Immunol 2011;9(2):93-9

    Digenetic trematodes from siganid fish Amphacanthus sigan at Macady Bay, Southern Hurghada, Red Sea, Egypt

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    AbstractForty fish samples of Amphacanthus sigan were collected from Sharm El-Naga southern Hurghada to study the parasitic infection included and present a new individual to Helicometra species using light microscope and re-describe another digenean trematode species using scanning electron microscope (SEM). Two trematode species were identified and described; Helicometra siganus n. sp. Nov belonging to Helicometra Odhner, 1902 (family Opecoelidae Ozaki, 1925) which is different from all the listed species in many features as having an elongated body, tapering anteriorly and larger sucker ratio; the vitellaria extended from the intestinal bifurcation to the posterior extremity of the hind-body and finally the cirrus sac and cirrus longer than the other species and extended to the midpoint of esophagus level. So, these criteria are specific and sufficient to consider it as a new species. The other species, Gyliauchen volubilis Nagaty, 1956 (Gyliauchenidae Fuki, 1929 and Ozaki, 1933) which was described before but some other constituent are not evident and appeared using the electron microscope. However, the present sample illustrated transverse striations on the body surface, the acetabulum evaginates outward, ovoid shaped and surrounded by lip-like structures and finally, the excretory pore is situated at some distance from the acetabulum at the posterior end extremity

    Zonal allocation for thoracic organs in the united kingdom: Has it been successful? A single-center view

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    AbstractObjectives: The purpose of this study was to analyze the impact of the zonal allocation system for thoracic organs on the outcome of our transplant activity. Methods: We analyzed the results of thoracic transplants performed between 1987 and 1998. The transplants were divided into 3 groups: local donors retrieved by our team (171 hearts and 61 lungs; DL group); distant donors retrieved by our team (58 hearts and 35 lungs; DD group); and distant donors retrieved by other teams (51 hearts and 41 lungs; DX group). Results: No significant differences were observed among the groups in early postoperative events for either heart or lung transplantation. Heart transplants: Cardiac index was 2.6 ± 0.4 L/m2 for the DL group, 2.7 ± 0.6 L/m2 for the DD group, and 2.5 ± 0.7 L/m2 for the DX group (P = .4). The 30-day mortalities were 9.1%, 9.1%, and 8.3% ( P = .5) and the 1-year survivals 83%, 80%, and 82% ( P = .4) for the DL, DD, and DX groups, respectively. Lung transplants: Alveolar-arterial oxygen gradient was 358 ± 19 mm Hg for the DL group, 345 ± 17 mm Hg for the DD group, and 329 ± 21 mm Hg for the DX group (P = .07). The 30-day mortalities were 9.9%, 10.5%, and 12.8% (P = .2) and the 1-year survivals 79%, 75%, and 77% (P = .3) for the DL, DD, and DX groups, respectively. Conclusion: Zonal allocation for thoracic organs has been successfully applied to our program. Using donor organs retrieved by other teams, we have achieved equivalent outcomes for both heart and lung transplantation. (J Thorac Cardiovasc Surg 1999;118: 733-9

    Network Route Minimization Using Time Based Interface Control

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    The demand for networking is increasing day by day with the progressive need of communication. As a result the communication channel and state database are increased with correspondingly. A rise in the amount of state database maintenance is one of the important cost effective issues for communication devices. The most challenging think is router state database reducing. As of now, many different types of state table accomplishments method are proposed for router state database reducing. In this purpose, we apply and modify the SPF algorithm by time based interface control. Dijkstra’s SPF algorithms searching the shortest specific link among from the all link then build a router state database table. If the state table size is little amount, then router OS using little amount of clock cycle. Some of Network interface are down for a fixed amount of time in a router. Therefore, we proposed a time based interface control method on SPF algorithm for re-build a new state database table. The modified SPF time based interfaces control algorithm suggests a new approach on dynamic routing protocol for reducing routing table size and saving router state-database size, resulting in a better convergence time

    (Z)-Ethyl 2-cyano-2-{2-[5,6-dimethyl-4-(thio­phen-2-yl)-1H-pyrazolo­[3,4-b]pyridin-3-yl]hydrazinylidene}acetate

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    In the title compound, C17H16N6O2S, an intra­molecular N—H⋯O inter­action generates an S(6) ring. The pyridine ring makes a dihedral angle of 71.38 (11)° with the thio­phene ring. In the crystal, mol­ecules are linked by a pair of N—H⋯N hydrogen bonds, forming an inversion dimer. The dimers are stacked in columns along the b axis through weak inter­molecular C—H⋯N hydrogen bonds

    Structure-activity relationships and molecular docking studies of chromene and chromene based azo chromophores

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    The design of novel materials with significant biological properties is a main target in drug design research. Chromene compounds represent an interesting medicinal scaffold in drug replacement systems. This report illustrates a successful synthesis and characterization of two novel series of chromene compounds using multi-component reactions. The synthesis of the first example of azo chromophores containing chromene moieties has also been established using the same methodology. The antimicrobial activity of the new molecules has been tested against seven human pathogens including two Gm+ve, two Gm-ve bacteria, and four fungi, and the results of the inhibition zones with minimum inhibitory concentrations were reported as compared to reference drugs. All the designed compounds showed significant potent antimicrobial activities, among of them, four potent compounds 4b, 4c, 13e, and 13i showed promising MIC from 0.007 to 3.9 μg/mL. In addition, antiproliferative analysis against three target cell lines was examined for the novel compounds. Compounds 4a, 4b, 4c, and 7c possessed significant antiproliferative activity against three cell lines with an IC50 of 0.3 to 2 μg/mL. Apoptotic analysis was performed for the most potent compounds via caspase enzyme activity assays as a potential mechanism for their antiproliferative effects. Finally, the computational 2D QSAR and docking simulations were accomplished for structure-activity relationship analyses
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