2,133 research outputs found
Performing Le Merle Nair: An investigation into the performance issues in the music of Olivier Messiaen
This paper investigates certain performance issues associated with Messiaen\u27s 1951 chamber work, Le Merle Noir. This paper can be seen as a practical guide to performers wishing to gain a deeper perspective on the interpretational issues associated with performing this work. It is ·written from the vantage point of a performer and should be seen to complement a number of already existing analytical studies of this piece. The paper can also be read as an exemplar of the research a performer makes when developing a coherent and truthful interpretation of a music work
A Study of Mothersâ Perceptions and Practices of Kindergarten Readiness
This study explored mothersâ perceptions about kindergarten readiness and practices in preparing their child for kindergarten. The relationship between maternal educational level and the developmental appropriateness of their perceptions and practices in preparing their children for kindergarten was examined. The relationship between the childâs birth status and the developmental appropriateness of mothersâ responses was also investigated.
A questionnaire asking parents about their perceptions and practices with their child entering kindergarten was sent home to 60 families who had enrolled their child in the Adele and Dale Young Child Development Laboratory at Utah State University during the 2010-2011 academic year; 33 mothers returned completed questionnaires.
The questionnaire contained statements for the parents to rate in importance and in frequency of their child participating in an activity. A variety of developmental areas such as literacy, math, motor, and social were included in the statements.
The findings from the study suggest that mothers were more developmentally appropriate in their responses to their perceptions of kindergarten readiness than they were in their responses about their actual practices in preparing their child for kindergarten. However, mothers were mostly developmentally appropriate in their responses in all areas. They seemed to understand the importance of literacy and mathematics in young childrenâs lives, but they may not understand how wide the spectrum is for a child learning about literacy and mathematics in developmentally appropriate ways. The participants had low means with their responses to some of the literacy practices, such as with how children should be taught letter and word recognition.
Mothers were most developmentally appropriate in their perceptions of being involved in their childâs education. They appeared to understand that being involved in their childâs education will help their child transition to and be more successful in school than if they were not involved. Overall, it was found that mothers had a reasonably good understanding of what is developmentally appropriate to prepare children for kindergarten; however, they were not as clear about what is less developmentally appropriate for preparing children for kindergarten. Limitations, implications, and suggestions for future research are discussed
Opioid and stimulant use among a sample of corrections-involved drug users : seeking an understanding of high-risk drug decisions within a system of constraint.
In the United States, high-risk drug use remains a significant social problem. Opioids and stimulants are two drug classes that have contributed to substantial recent increases in drug-related arrests, overdose, and mortality. Kentucky has been particularly devastated by high rates of opioid and stimulant use. Opioid and stimulant effects, while highly rewarding, can result in adverse consequences. Still, some people choose to use these drugs, and choose to continue using even after experiencing adverse consequences, such as incarceration. The aim of this study was to explore high-risk drug use among a sample of corrections-involved adults in Kentucky and to identify endogenous and exogenous factors with the potential to have influenced drug-related decision-making prior and subsequent to incarceration. Attention was paid to understanding concomitant opioid and stimulant use and heroin use. Survey data collected as part of an ongoing corrections-based substance use treatment program outcomes study were examined. The final sample (N=1,563) included adults released into Kentucky counties between 2012-2017. Non-parametric statistical tests and multinomial logistic regression were used to identify factors associated with opioid, stimulant, and concomitant use; binary logistic regression was used to identify factors associated with heroin use. Results indicate that opioid and stimulant use was endemic in this sample, though rates of use subsequent to incarceration were lower than pre-incarceration rates. During the 30-day period prior to incarceration, 29.0% of participants reported concomitant use, 28.5% reported opioid use, and 18.0% reported stimulant use. During the one-year post-release period, 11.9% of participants reported concomitant use, 12.5% reported opioid use, and 8.3% reported stimulant use. During this post-release period, 10.7% reported heroin use. Concomitant and heroin use positively correlated with many factors with the potential to adversely influence cognition and constrain choice. Similar relationships between many of these factors and outcomes involving other drug or no drug use were not observed. Behavioral economics, a molar view of choice and behavior, was used to conceptualize how factors in the lives of participants had the potential to influence and constrain decision-making in respect to high-risk drugs. Findings are discussed in light of how they may inform future research, policy, and practice
Modelling the characteristics of the baroreceptor
A dissertation submitted to the Faculty of Engineering and the Built Environment,
University of Witwatersrand in fulfilment of the requirements for the degree of Master of Science in Engineering. 2017The baroreceptor is a stretch receptor which detects changes in pressure in arterial blood vessels.
Baroreceptor nerves inform the brainstem of changes in blood pressure, which then influences
sympathetic and parasympathetic nervous activity to counteract that change. Due to the relationship
between essential hypertension, sympathetic nervous activity and the baroreflex, there is some debate
in the literature about whether the baroreflex can act as a long-term controller of blood pressure. This
debate has increased in recent years, due to the high prevalence of essential hypertension in all
societies and the introduction of new technologies to counteract drug-resistance hypertension. The
baroreflex has become a source of debate due to the complex physiological feedback control that
regulates blood pressure and due to new stimulating electrical devices, which have shown promising
results in reducing drug-resistant essential hypertension.
system. This is done through a literature survey extending through experimental and modelling
research, where selected mathematical models of the baroreceptor are then analysed and simulated to
find the best performing model, so that they may be simulated for an extended frequency response
than what would be experimentally possible. The purpose of this investigation is to determine, through
simulation, what the sensor static and dynamic characteristics are. Through this characterisation of
the sensor behaviour of the baroreceptor in the baroreflex control loop, it is then possible to infer
whether the baroreflex can act as a long-term controller of blood pressure.
An overview of experimental and analytical investigations on the baroreceptor over the last 70 years is
summarised. This overview includes mathematical models, which predict experimental results. A
subset of four models from Srinivasen et al., Bugenhagen et al., Beard et al. and Mahdi et al. are
selected. These models are implemented in MATLAB and Simulink. The parameters and experimental
conditions are integrated into the Simulink models, and the simulated results are compared to the
reported experimental data. In this way, each mathematical model is evaluated using secondary data
for its ability to simulate the expected behaviour. Thereafter, all simulated models are compared under
the same input conditions (a 0-230 mmHg step input over 12 s). These results are used to select the
best performing models, based on how well they were parameterised and validated for experimental
tests. The best performing models are those of Beard et al. and Bugenhagen et al. They are tested for a
wide range of artificial inputs at different frequencies, with sinusoidal inputs which have periods that
range from 0.1 s to 10 days and have a 100 mmHg operating point with a 1 mmHg peak amplitude.
All modelling techniques studied show that the baroreceptor firing response resets due to the rate of
change in strain in the visco-elastic arterial wall. Both tested model frequency responses, although
parameterised for different species and for different major vessels, show high sensitivity to inputs in range from 1 s to 1 min 36 s (0.01 Hz 1Hz), and very low sensitivity for changes that are longer
than 16 min 36s (0.001 Hz). This extrapolated simulation suggests a zero gain near DC.
The simulated frequency response of the best performing baroreceptor models, which were validated
against short-term experimental data, indicate that the baroreceptor is only able to sense changes that
happen in less than 1 min 16s. The critical analysis of all the simulated baroreceptor models show that
this characteristic of the baroreceptor is caused by the visco-elastic layers of the arterial wall, and is
likely in all baroreceptors regardless of type or species. It also indicates that under electrical
stimulation of the baroreceptor, the input signal from the electrical device bypasses the baroreceptor
nerve ending (which is embedded in the arterial wall) and that the electrical signal of the baroreceptor
is bypassed by the new stimulated electrical signal of the device. Furthermore, if the sensor can only
detect short-term changes, then it is unlikely that the baroreceptor can inform the brainstem on longterm
changes to mean arterial blood pressure. Therefore, based on the models examined in this study,
this suggests that the baroreceptor is unlikely to be involved in long-term blood pressure control. This
analysis of the best performing model is presented to show the limitations of the baroreflex in long
term control of blood pressure. It serves as a simulated experiment to rationalise the contentious debate
around the role of the baroreflex in long term blood pressure control, and to allow for future
improvements that can be made on the baroreceptor model to allow for more extended modelling on
sor characteristics. An improvement that could be applied to the best performing
baroreceptor models, implemented in this study, is to examine the effects of ageing and inter-species
variability on carotid sinus dimensions and visco-elastic wall properties.CK201
Simulation Machines or Checking Action System Refinements
Action systems provide a formal approach to modelling parallel and reactive systems. They have a well established theory of refinement supported by simulation-based proof rules. This paper introduces an automatic approach for verifying action system refinements utilising standard CTL model checking. To do this, we encode each of the simulation conditions as a simulation machine, a Kripke structure on which the proof obligation can be discharged by checking that an associated CTL property holds. This procedure transforms each simulation condition into a model checking problem. Each simulation condition can then be model checked in isolation, or, if desired, together with the other simulation conditions by combining the simulation machines and the CTL properties
Proving Temporal Properties of Z Specifications Using Abstraction
This paper presents a systematic approach to proving temporal properties of arbitrary Z specifications. The approach involves (i) transforming the Z specification to an abstract temporal structure (or state transition system), (ii) applying a model checker to the temporal structure, (iii) determining whether the temporal structure is too abstract based on the model checking result and (iv) refining the temporal structure where necessary. The approach is based on existing work from the model checking literature, adapting it to Z
An Exploratory Study of the Affect of Role Strain And The Juvenile Justice System\u27s Division in Power on Juvenile Probation Officers
This exploratory, qualitative study reports on the experiences of 20 participants currently working within the juvenile justice system. The study investigated whether role strain was present among juvenile probation officers (POs) in an unspecified, Mid-Atlantic state. This study examines probation officers\u27 role as it relates to the division in power between the state agency which employs the juvenile POs and the local juvenile courts in which they work closely with local judges. The state agency\u27s move to standardize was also explored in relation to an increase in role strain for juvenile probation officers. The expected role strain did not appear in the data. The POs in this study found ways to resolve the prospective conflict of balancing the dual goals of rehabilitation and protecting society. The study also found that juvenile POs have discovered creative ways in negotiating their place in the division of power and often use it to their advantage in accomplishing the goals of probation. This study unexpectedly found that regardless of rural or urban locality, the state agency\u27s increasing standardization has brought about a new conflict in which the POs in this study found it difficult to resolve--a conflict not discussed in previous literature: Traditional PO verses the Data Entry Personnel. Differences in findings between rural, urban, and administration participants are also discussed in this study as well as an application of Weberian theory and bureaucracy
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