72 research outputs found

    Noise characteristics of passive components for phased array applications

    Get PDF
    The results of a comparative study on noise characteristics of basic power combining/dividing and phase shifting schemes are presented. The theoretical basics of thermal noise in a passive linear multiport are discussed. A new formalism is presented to describe the noise behavior of the passive circuits, and it is shown that the fundamental results are conveniently achieved using this description. The results of analyses concerning the noise behavior of basic power combining/dividing structures (the Wilkinson combiner, 90 deg hybrid coupler, hybrid ring coupler, and the Lange coupler) are presented. Three types of PIN-diode switch phase shifters are analyzed in terms of noise performance

    Altos nĂ­veis de cobre no solo e nas folhas reduz crescimento e produtividade de tomateiros

    Get PDF
    Fertilizantes, fungicidas e bactericidas cúpricos são usados em larga escala em casas de vegetação na Turquia. Informações sobre os efeitos das aplicações destes produtos sobre as plantas são escassas. Este trabalho investiga os efeitos da aplicação de Cu na forma de CuSO4.5H2O a um solo calcário (0, 1000 e 2000 mg Cu kg-1) e em cobertura (controle, semanal e duas vezes por semana), nas formas de oxicloreto de cobre ou calda bordalesa na produção total, número de frutas, peso seco da raiz e altura de tomateiros cultivados em casa de vegetação. Produtividade total, número de frutas por planta, peso seco da raiz e altura das plantas foram reduzidas pelo aumento da quantidade de Cu aplicado ao solo. O aumento da concentração de CU no solo e folhas diminuiu número final de frutos por planta, peso seco da raiz e altura da planta na quarta, quinta e sexta semanas. A aplicação combinada de Cu ao solo e em cobertura pode ser mais deletéria às plantas que a aplicação de Cu somente ao solo ou em cobertura.Copper-containing fertilizers, fungicides and bactericides are extensively used in greenhouses in Turkey. Informations on effects of these applications to plants are scarce. The aim of the present study was to investigate effects of Cu application to a calcareous soil and to leaves on the yield and growth of tomato plants. Cu was first applied to soil as CuSO4.5H2O in three different levels (0, 1000, and 2000 mg Cu kg-1) and then to leaves in three different frequencies (no application, biweekly and weekly) using two cupric fungicides (Cu oxychloride, and Cu salts of fatty and rosin acids) in pot experiments carried out in a computer-controlled greenhouse. Total yield, fruit number, dry root weight and plant height decreased with increasing Cu application to soil. Increasing levels of Cu applied to soil and leaves resulted in decreasing final fruit number, dry root weight and plant height in 4th, 5th and 6th weeks. Combined applications of Cu to soil and leaves could be more deleterious to plants than when Cu is applied only to soil or leaves

    Evolutionary Sequence Modeling for Discovery of Peptide Hormones

    Get PDF
    There are currently a large number of “orphan” G-protein-coupled receptors (GPCRs) whose endogenous ligands (peptide hormones) are unknown. Identification of these peptide hormones is a difficult and important problem. We describe a computational framework that models spatial structure along the genomic sequence simultaneously with the temporal evolutionary path structure across species and show how such models can be used to discover new functional molecules, in particular peptide hormones, via cross-genomic sequence comparisons. The computational framework incorporates a priori high-level knowledge of structural and evolutionary constraints into a hierarchical grammar of evolutionary probabilistic models. This computational method was used for identifying novel prohormones and the processed peptide sites by producing sequence alignments across many species at the functional-element level. Experimental results with an initial implementation of the algorithm were used to identify potential prohormones by comparing the human and non-human proteins in the Swiss-Prot database of known annotated proteins. In this proof of concept, we identified 45 out of 54 prohormones with only 44 false positives. The comparison of known and hypothetical human and mouse proteins resulted in the identification of a novel putative prohormone with at least four potential neuropeptides. Finally, in order to validate the computational methodology, we present the basic molecular biological characterization of the novel putative peptide hormone, including its identification and regional localization in the brain. This species comparison, HMM-based computational approach succeeded in identifying a previously undiscovered neuropeptide from whole genome protein sequences. This novel putative peptide hormone is found in discreet brain regions as well as other organs. The success of this approach will have a great impact on our understanding of GPCRs and associated pathways and help to identify new targets for drug development

    Robust Speech Recognition by Topology Preserving Adaptation

    No full text
    The performance degradation as a result of acoustical environment mismatch remains an important practical problem in speech recognition.The problem carries a greater significance in applications overtelecommunication channels, especially with the wider use ofpersonal communications systems such as cellular phoneswhich invariably present challenging acoustical conditions. Such conditions are difficult to model analytically for a generalspeech representation, and most existing data-driven models require simultaneous ("stereo") recordings of training and testing environments,impractical to collect in most cases of interest.In this dissertation, we propose an invariance principle fornon-parametric speech representations in acoustical environments.We stipulate that the topology of the codevectors in a vector quantization (VQ) codebookas defined in terms of class posterior distributionswill be preserved in a certain information-theoretic sense,and make this invariance principle our basis in deriving normalizationalgorithms that correct for the acoustical mismatch betweenenvironments.We develop topology preserving algorithms in two frameworks, constrained distortionminimization (VQ with a topology preservation constraint) andinformation geometry (alternating minimization with a topology preservation constraint) and show their equivalence.Finally, we report results on the Wall Street Journal data,the Spoken Speed Dial corpus and the TI Cellular Corpus.The algorithm is shown to improve performancesignificantly in all three tasks, most notably in the more difficult problemof cellular hands free microphone speech wherethe technique decreases theword error for continuous ten digit recognition from 23.8% to 13.6% and the speaker dependent voice callingsentence error from 16.5% to 10.6%

    High level of copper application to soil and leaves reduce the growth and yield of tomato plants

    No full text
    Copper-containing fertilizers, fungicides and bactericides are extensively used in greenhouses in Turkey. Informations on effects of these applications to plants are scarce. The aim of the present study was to investigate effects of Cu application to a calcareous soil and to leaves on the yield and growth of tomato plants. Cu was first applied to soil as CuSO4.5H2O in three different levels (0, 1000, and 2000 mg Cu kg-1) and then to leaves in three different frequencies (no application, biweekly and weekly) using two cupric fungicides (Cu oxychloride, and Cu salts of fatty and rosin acids) in pot experiments carried out in a computer-controlled greenhouse. Total yield, fruit number, dry root weight and plant height decreased with increasing Cu application to soil. Increasing levels of Cu applied to soil and leaves resulted in decreasing final fruit number, dry root weight and plant height in 4th, 5th and 6th weeks. Combined applications of Cu to soil and leaves could be more deleterious to plants than when Cu is applied only to soil or leaves

    Integrating proteomics and genomic data to illuminatethe effects of Lapatinibin HER2+ cells

    No full text
    Poster given for NLM Training conference on understanding lapatinib sensitivity in HER2+ cell

    Frontal Sinus Pneumatization Affects Height of the Lateral Lamella and Position of Anterior Ethmoidal Artery

    No full text
    Preoperative evaluation of the frontal sinus (FS) and associated anatomical structures may reduce the risk of intraoperative complications and facilitate the management of potential complications. In this study, the authors aimed to evaluate relationship between FS pneumatization and critical anatomical structures. Paranasal sinus computerized tomography scans of 350 sides of 175 patients were evaluated. The pneumatization pattern of the FS, FS dimensions (on the axial, coronal, and sagittal slices), anterior ethmoidal artery, and depth of the of olfactory fossa were evaluated for every patient on both sides. There were 111 (63.4%) male and 64 (36.6%) female patients. The authors found a statistically significant correlation between the depth of olfactory fossa and the anterior ethmoidal artery position (P<0.001). As the FS pneumatization increases, the likelihood of the anterior ethmoid artery to run separately from the skull base also increases. Also, there was a statistically significant difference among the types in terms of the depth of the olfactory fossa (Kruskal-Wallis P = 0.002). The depth of the olfactory fossa increases depending on the increase of FS pneumatization
    • …
    corecore