251 research outputs found

    Representation and design of wavelets using unitary circuits

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    The representation of discrete, compact wavelet transformations (WTs) as circuits of local unitary gates is discussed. We employ a similar formalism as used in the multiscale representation of quantum many-body wave functions using unitary circuits, further cementing the relation established in the literature between classical and quantum multiscale methods. An algorithm for constructing the circuit representation of known orthogonal, dyadic, discrete WTs is presented, and the explicit representation for Daubechies wavelets, coiflets, and symlets is provided. Furthermore, we demonstrate the usefulness of the circuit formalism in designing WTs, including various classes of symmetric wavelets and multiwavelets, boundary wavelets, and biorthogonal wavelets

    Representation and design of wavelets using unitary circuits

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    The representation of discrete, compact wavelet transformations (WTs) as circuits of local unitary gates is discussed. We employ a similar formalism as used in the multiscale representation of quantum many-body wave functions using unitary circuits, further cementing the relation established in the literature between classical and quantum multiscale methods. An algorithm for constructing the circuit representation of known orthogonal, dyadic, discrete WTs is presented, and the explicit representation for Daubechies wavelets, coiflets, and symlets is provided. Furthermore, we demonstrate the usefulness of the circuit formalism in designing WTs, including various classes of symmetric wavelets and multiwavelets, boundary wavelets, and biorthogonal wavelets

    The Physical Conditions and Dynamics of the Interstellar Medium in the Nucleus of M83: Observations of CO and CI

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    This paper presents CI, CO J=4-3, and CO J=3-2 maps of the barred spiral galaxy M83 taken at the James Clerk Maxwell Telescope. Observations indicate a double peaked structure which is consistent with gas inflow along the bar collecting at the inner Lindblad resonance. This structure suggests that nuclear starbursts can occur even in galaxies where this inflow/collection occurs, in contrast to previous studies of barred spiral galaxies. However, the observations also suggest that the double peaked emission may be the result of a rotating molecular ring oriented nearly perpendicular to the main disk of the galaxy. The CO J=4-3 data indicate the presence of warm gas in the nucleus that is not apparent in the lower-J CO observations, which suggests that CO J=1-0 emission may not be a reliable tracer of molecular gas in starburst galaxies. The twelve CI/CO J=4-3 line ratios in the inner 24'' x 24'' are uniform at the 2 sigma level, which indicates that the CO J=4-3 emission is originating in the same hot photon-dominated regions as the CI emission. The CO J=4-3/J=3-2 line ratios vary significantly within the nucleus with the higher line ratios occurring away from peaks of emission along an arc of active star forming regions. These high line ratios (>1) likely indicate optically thin gas created by the high temperatures caused by star forming regions in the nucleus of this starburst galaxy.Comment: 15 pages with 10 figures. To appear in the August 10 1998 issue of The Astrophysical Journa

    Distinct features of seizures induced by cocaine and amphetamine analogs

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    Abstract Seizure-related emergencies caused by stimulants of abuse have been increasing. To better understand the nature of these drug-induced convulsions, we characterized the seizure patterns associated with high doses of cocaine, and the amphetamine analogs, metham-Ž . phetamine, methylenedioxymethamphetamine MDMA and 4-methylaminorex. The features of the stimulant-induced seizures were Ž . Ž . distinct and included the following: 1 the duration of convulsive activity was shortest for cocaine and longest for methamphetamine, 2 Ž . only MDMA produced a secondary clonic phase after the initial ictal event, and 3 4-methylaminorex manifested a very steep dose-response curve. Differential preventive profiles of anticonvulsant agents on the stimulant-induced seizures also were observed. For example, cocaine-related seizures were most effectively prevented by, while methamphetamine-induced seizures were completely refractory to, phenytoin pretreatment. The only anticonvulsants which appeared to influence methamphetamine-related convulsions were diazepam and valproate. A unique feature of 4-methylaminorex was that related seizures were almost completely blocked by the calcium channel blocker, flunarizine.

    At-home use of parasacral transcutaneous electrical nerve stimulation for pediatric voiding dysfunction: a randomized controlled trial to assess its safety and feasibility

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    IntroductionTreating pediatric voiding dysfunction involves behavioral changes that require significant time or medications that are often avoided or discontinued due to side effects. Using parasacral transcutaneous electrical nerve stimulation (PTENS) has shown to have reasonable efficacy, but the safety and feasibility of its off-label use for pediatric voiding dysfunction are not well-established. Concerns have also been raised over treatment adherence. In-home therapy might improve adherence compared with office-based therapy; however, no studies have evaluated in-home feasibility to date. This study aims to assess the safety and feasibility of off-label use of PTENS for pediatric voiding dysfunction.Materials and methodsA single-institution prospective, randomized controlled study was conducted from March 2019 to March 2020. Participants aged 6–18 years diagnosed with voiding dysfunction, overactive bladder, or urinary incontinence were eligible for the study. Those with known neurologic disorders, implanted electrical devices, anatomic lower urinary tract abnormality, and recurrent urinary tract infections and those taking bladder medications were excluded. Children with primary monosymptomatic nocturnal enuresis were also excluded due to previous work suggesting a lack of efficacy. Participants were randomly assigned to receive 12 weeks of urotherapy alone (control) or urotherapy plus at-home PTENS treatment. Families were contacted weekly to assess for adverse events (AEs) and treatment adherence. The primary and secondary outcomes were safety, defined as the absence of AEs and treatment adherence, respectively.ResultsA total of 30 eligible participants were divided into two groups, with 15 participants in each arm. The median age was 9.4 years (interquartile range: 7.7–10.6). In total, 60% were male. Baseline demographics and urotherapy compliance were similar between the two groups. With PTENS use, two AEs were reported, including mild pruritus at the pad site and discomfort when removing pads, while no AEs were noted in the control group. In total, 60% of patients completed three 30-min sessions per week, and all participants were able to complete treatment sessions for at least 10 weeks, involving 30 min of PTENS treatment each time.ConclusionThis randomized controlled study confirms that at-home use of PTENS is feasible with reasonable treatment adherence and minimal AEs. Future collaborative, multi-institutional studies may better determine the efficacy of this treatment modality
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