2,635 research outputs found
Contextual metrical invisibility
No full textIn some languages, certain vowels are invisible to syllable-sensitive processes, but only in certain contexts. This paper argues that metrically invisible vowels are undominated by a syllable node in prosodic structure. Considering mainly Mohawk and Passamaquoddy, the behavior of these "weak vowels" is derived from pressure to avoid using weak vowels as syllable nuclei, countered by pressure to realize underlying segments in well-formed syllables. Because not only epenthetic vowels can be weak vowels, their unsuitability as syllable nuclei is derived representationally, through amount of underlying prosodic structure. Existing analyses of the data are critiqued, and the theoretical implications and potential extensions are discussed.The definitive version of this paper was published in PF: Papers at the Interface (1997) and is available at http://mitwpl.mit.edu/catalog/mwpl30/Hagstrom, P. (1997). Contextual metrical invisibility. In B. Bruening, Y. Kang, & M. McGinnis (Eds.) PF: Papers at the interface (pp. 113-181). Cambridge, MA: Department of Linguistics and Philosophy, Massachusetts Institute of Technology
The portraits of the female author: the case of Ángela Figuera Aymerich
No full textEste artículo se enmarca en el Programa Severo Ochoa (referencia PA-17-PF-BP16126) de Ayudas predoctorales para la investigación y la docencia del Gobierno del Principado de Asturias
The prosodic structure of Serbo-Croatian function words: An argument for tied constraints
No full textThe question of the proper treatment of clitics has received considerable attention in literature on the syntax-morphology and morphology-phonology interfaces. Selkirk (1996) proposes an elegant theory of the prosodification of clitic function words crosslinguistically, demonstrating that variation in the behavior of function words both within a language (English) and across dialects of a language (Serbo-Croatian) follows straightforwardly from re-rankings of universal constraints in an Optimality Theory. In this paper I argue that, in addition to strict re-rankings of constraints, tied constraints are also needed within such a system, in order to capture the Serbo-Croatian facts. I discuss three empirical shortcomings of Selkirk¹s analysis, all involving optionality, and show how they can be remedied by appealing to a particular notion of what it means for constraints to be tied in rank. To the extent that Selkirk¹s basic insights are correct, this supports the conclusion that tied constraints play an important role in OT accounts of the ways in which dependent and independent morphemes are combined into larger prosodic units. It adds to the growing evidence for "crucial nonranking", whereby separate tableaux are computed for each ordering of the relevant constraints and the output of each is a valid possibility in the language.The definitive version of this paper was published in MITWPL 30: PF: Papers at the Interface (1997) and is available at http://mitwpl.mit.edu/catalog/mwpl30/Schütze, C.T. (1997). The Prosodic Structure of Serbo-Croatian Function Words: An Argument for Tied Constraints. In B. Bruening, Y. Kang, & M. McGinnis (Eds.) PF: Papers at the Interface. Cambridge, MA : MIT Dept. of Linguistics
Stochastic Nodal Analysis: EnKF and PF applied to petroleum production systems
No full textA petroleum production system is generally modelled based on the concept of nodal analysis, where the entire system is broken down into discrete elements such as near-well bore, tubing, surface choke and flow line. Operating flow rates and pressures can be estimated with a nodal analysis procedure by calculation of the intersection of performance curves. Input parameters in nodal analysis of production systems are considered deterministic, however, some of these parameters are better represented as distributions. In this report, the ensemble-based data assimilation methods “ensemble Kalman filter” (EnKF) and “particle filter” (PF) are applied to steady-state models of a production system for tuning of uncertain model parameters during the test separator phase. The performance of the EnKF and the PF is tested with the use of twin experiments. The calibrated model parameters of the choke, tubing and the near-well bore elements with EnKF and PF can be used to create an ensemble of performance curves leading to an ensemble of operating flow rates and pressures. The foreseen next step is to use the posterior distributions of model parameters as inputs for soft sensing of flow rates during semi-steady-state production for a single phase oil reservoir, where the oil rate and reservoir pressure are considered as unknown parameters. In the twin experiments as used in this thesis, a total number of three steady-state pressure drop measurements was used to estimate a total of six independent parameters which constitutes an ill-posed problem, resulting in non-unique parameter estimates. It is recommended to alleviate this issue by either reducing the number of parameters or by using multiple separator tests at different flow rates.Petroleum Engineering and Geo-science
PI3K/mTOR Dual Inhibitor PF-04691502 Is a Schedule-Dependent Radiosensitizer for Gastroenteropancreatic Neuroendocrine Tumors
No full textPatients with advanced-stage gastroenteropancreatic neuroendocrine tumors (GEP-NETs) have a poor overall prognosis despite chemotherapy and radiotherapy (e.g., peptide receptor radionuclide therapy (PRRT)). Better treatment options are needed to improve disease regression and patient survival. The purpose of this study was to examine a new treatment strategy by combining PI3K/mTOR dual inhibition and radiotherapy. First, we assessed the efficacy of two PI3K/mTOR dual inhibitors, PF-04691502 and PKI-402, to inhibit pAkt and increase apoptosis in NET cell lines (BON and QGP-1) and patient-derived tumor spheroids as single agents or combined with radiotherapy (XRT). Treatment with PF-04691502 decreased pAkt (Ser473) expression for up to 72 h compared with the control; in contrast, decreased pAkt expression was noted for less than 24 h with PKI-402. Simultaneous treatment with PF-04691502 and XRT did not induce apoptosis in NET cells; however, the addition of PF-04691502 48 h after XRT significantly increased apoptosis compared to PF-04691502 or XRT treatment alone. Our results demonstrate that schedule-dependent administration of a PI3K/mTOR inhibitor, combined with XRT, can enhance cytotoxicity by promoting the radiosensitivity of NET cells. Moreover, our findings suggest that radiotherapy, in combination with timed PI3K/mTOR inhibition, may be a promising therapeutic regimen for patients with GEP-NET
LASER SPECTROSCOPY OF THE STATE
No full text A.E. Douglas, M. Frackoviak, Can. J. Phys. 40, 832 (1962)Author Institution: Department of Chemistry, Kansas State UniversitySpectra of the PF bands were recorded using laser excitation spectroscopy. The PF molecules in the ground electronic state were produced by passing a mixture through a microwave discharge in a flow reactor at room temperature. The obtained spectroscopic constants are consistent with the earlier results of Douglas and for . The strong dependence of the lambda doubling in the state on the vibrational quantum number and irregular spacing of the vibrational energies indicate interactions with the and another state. The dipole function of the A-X transition was calculated from the radiative lifetimes and dispersed fluorescence spectra
Cyanophage Pf-WMP4, a T7-like phage infecting the freshwater cyanobacterium Phormidium foveolarum: Complete genome sequence and DNA translocation
No full textAbstractWe report the complete 40,938-bp genome sequence of a cyanophage, Pf-WMP4, which infects the freshwater cyanobacterium Phormidium foveolarum Gom. Nine of the forty-five potential open reading frames in the Pf-WMP4 genome share similarities with the genes found in T7-like phages. Using in vitro transcription, we found that seven promoters at the leftmost end of the genome can be recognized by the host RNA polymerase. By blocking transcriptional and translational inhibitors, we found that Pf-WMP4 DNA translocation, with an average translocation rate of 19.8±2.7 bp s−1 at 28 °C, requires both host transcription and protein synthesis of an unknown factor. Therefore the mechanism of cyanophage Pf-WMP4 DNA injection may be driven both by a T7-like internalization mechanism as well as an additional unknown mechanism requiring de novo protein synthesis. Our analysis of the Pf-WMP4 genome sheds new light on the translocation strategies and evolutionary traces of phages belonging to the T7 supergroup
Evaluating the impact of a sport-for-development intervention on the physical and mental health of young adolescents in Gulu, Uganda - a post-conflict setting within a low-income country
No full textIntroduction: Physical inactivity is thought to contribute to the emergence of non-communicable diseases in post-conflict settings of low-income countries. Sport-for-development (SfD) organisations in these regions claim to improve the health of programme participants. However, there is a paucity of supporting evidence. I assessed the impact of a voluntary community-based SfD intervention on the physical activity (PA), physical fitness (PF) and mental health (MH) of adolescents in Gulu, Uganda.Methods: The Acholi Psychosocial Assessment Instrument (APAI), standing broad jump (SBJ), multi-stage fitness test (MSFT) and BMI-for-age (BFA) were adapted to the local context. I tested their feasibility and reliability with a repeat-measures design (n=70). A cross-sectional analysis of a random sample was used to assess the local needs and establish the PF and MH of the adolescents reached by the intervention (n=1464). This was also the baseline assessment for the impact evaluation. It comprised a randomised control trial (n=144) nested within a cohort study (n=1400) and triangulated by cross-sectional assessment of PA using accelerometry (n=54).Results: The adapted PF and MH measures demonstrated good intra-tester reliability (ICC>0.75). Adolescents in Gulu predominantly had “healthy” BFA (>90%). They performed better than global norms for the SBJ (p<0.001), but worse for the MSFT (p<0.05). The girls who registered for the intervention had higher PF at baseline (p<0.05) and experienced no significant benefits when compared to the community. The aerobic capacity of the boys intervention group increased relative to the community (p<0.01), but was not significantly different to the trial control group whose PF also improved. The PA results concurred with this finding. Boys in the intervention group experienced a deterioration in MH relative to their peers (p<0.05).Implications: It is feasible to apply rigorous evaluation methods to SfD interventions. Although adolescents in Gulu have poor aerobic capacity, a voluntary programme may not reach those at risk. Interpreting the impact evaluation was limited by a lack of programme development theory, but suggested that opportunities for non-competitive play may confer PF benefit without harming MH. Further investigation is warranted
Swamp dredge: Research into grunge
No full textFor this project I have researched grunge music and created a body of work influenced by this genre. During my extended contextual research into the genre, I looked at both the artists and producers. I wrote/co-wrote the songs, played some of the instruments and produced the recordings. These are now available for download on www.soundcloud.com/swampdredg
Negative group delay-enabled reconfigurable non-foster elements and beamforming networks
No full textAs a counterintuitive phenomenon, negative group delay (NGD) was first found in regions of strong anomalous dispersion. The peak of the pulse emerges from the device's output at an instant before the peak of the pulse enters its input. Later, the circuit approaches of NGD are realized. In this work, reconfigurability enhanced distributed amplifier (DA) -based NGD circuit and its applications in realizing non-Foster elements and beamforming networks will be discussed. The proposed circuit incorporates varactors at the input and output ports of the DA-based NGD circuit, notably enhances the tuning range for the amplitude, overall phase, and the NGD responses, thereby enables flexible S-parameter synthesis with a wider reconfigurable range. Compared with other approaches, the reconfigurability enhanced DA-based NGD circuit has the advantages of:
1) Simple structure that enables gain, phase, and NGD to be widely tuned individually
2) Wide bandwidth performance with the distributed amplifier design
3) Good impedance matching and unconditionally stability
4) Can be fabricated on MMIC platform, easy to work at higher frequency
Firstly, we will give a review of the current NGD circuits and their performances. Secondly, a description of the proposed distributed-amplifier-based NGD circuit will be provided, including the theory and objectives. In the theory part, a general N-stage transfer function for the proposed reconfigurable NGD circuit is derived and discussed. A 2-stage case is given as an illustrative proof-of-concept example. The objectives include how to create tunable non-Foster elements and tunable squint-free beamforming networks by applying the reconfigurability enhanced NGD circuits into the design. Thirdly, prototypes based on the reconfigurable NGD circuits will be demonstrated, including a reconfigurable negative capacitor, squint-free antenna beamforming networks, and others.
A tunable NGD enabled negative capacitor is simulated and fabricated; the prototype shows it can be tuned within an outstanding range from -1.0 pF to -4.0 pF over a bandwidth of 100 MHz at 1 GHz. A series-type squint-free antenna array feeding network is simulated and fabricated, and devices with/without varactors are compared. By synthesizing a low-dispersion superluminal antenna array feeding line, we first realized a main beam steerable series-type squint-free antenna array. Experimental results show that the main beam of the NGD-enabled antenna array has a tuning range from -15° to 15° within a squint-free bandwidth of 100 MHz at 2 GHz. Compared with the one without varactors, the main beam tuning range has tripled.
Due to the transversal-filter-based design, the above applications can benefit from a wider operation bandwidth by either applying more parallel stages or cascading more series unit cells.Ph.D.Includes bibliographical reference
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