Thesis (M.S.)--Eastern Illinois University, 1993. / Includes bibliographical references (leaves 53-57).

Thesis (M.A.)--Rowan University, 2009. / Typescript. Includes bibliographical references.

Magister Pharmaceuticae - MPharm / The objective of the study was to perform a comparative review of pathways, timelines and improvements of countries with markets that the South African Health Products Authority (SAHPRA) benchmark themselves against. Furthermore, this study intends to identify the factors that improved and accelerated submissions and approval process in investigated countries and potential introduction of these strategies into the South African market.

Temporal features in the vocalizations of animals and insects play an important role in a diverse range of species-specific activities such as mate selection, territoriality, and hunting. The neural mechanisms underlying the response to such stimuli remain largely unknown. Two species of anuran amphibian provide a starting point for the investigation of the neurological response to species-specific advertisement calls. Neurons in the anuran midbrain of Rana pipiens and Hyla regilla exhibit an atypical response when presented with a fixed number of advertisement calls. The general response to these calls is mostly inhibitory; only when the correct number of calls is presented at the correct repetition rate will this inhibition be overcome and the neurons reach a spiking threshold. In addition to rate-dependent call-counting, these neurons are sensitive to missed calls: a pause of sufficient duration—the equivalent of two missed calls—effectively resets a neuron to its initial condition. These neurons thus provide a model system for investigating the neural mechanisms underlying call-counting and interval specificity in audition. We present a minimal computational model in which competition between finely-tuned excitatory and inhibitory synaptic currents, combined with a small propagation delay between the two, broadly explains the three key features observed: rate dependence, call counting, and resetting. While limitations in the available data prevent the determination of a single set of parameters, a detailed analysis indicates that these parameters should fall within a certain range of values. Furthermore, while network effects are counter-indicated by the data, the model suggests that recruitment of neurons plays a necessary role in facilitating the excitatory response of counting neurons—although this hypothesis remains untested. Despite these limitations, the model sheds light on the mechanisms underlying the biophysics of counting, and thus provides insight into the neuroethology of amphibians in general.

Temporal features in the vocalizations of animals and insects play an important role in a diverse range of species-specific activities such as mate selection, territoriality, and hunting. The neural mechanisms underlying the response to such stimuli remain largely unknown. Two species of anuran amphibian provide a starting point for the investigation of the neurological response to species-specific advertisement calls. Neurons in the anuran midbrain of Rana pipiens and Hyla regilla exhibit an atypical response when presented with a fixed number of advertisement calls. The general response to these calls is mostly inhibitory; only when the correct number of calls is presented at the correct repetition rate will this inhibition be overcome and the neurons reach a spiking threshold. In addition to rate-dependent call-counting, these neurons are sensitive to missed calls: a pause of sufficient duration—the equivalent of two missed calls—effectively resets a neuron to its initial condition. These neurons thus provide a model system for investigating the neural mechanisms underlying call-counting and interval specificity in audition. We present a minimal computational model in which competition between finely-tuned excitatory and inhibitory synaptic currents, combined with a small propagation delay between the two, broadly explains the three key features observed: rate dependence, call counting, and resetting. While limitations in the available data prevent the determination of a single set of parameters, a detailed analysis indicates that these parameters should fall within a certain range of values. Furthermore, while network effects are counter-indicated by the data, the model suggests that recruitment of neurons plays a necessary role in facilitating the excitatory response of counting neurons—although this hypothesis remains untested. Despite these limitations, the model sheds light on the mechanisms underlying the biophysics of counting, and thus provides insight into the neuroethology of amphibians in general.

Abstract In this research, a facilitated transport membrane was developed. The reactive membrane consisted of a carrier entrapped in poly(vinyl alcohol) "PVA" matrix cast on a polysulfone support. PVA was selected to hold the reactive carrier because of its hydrophilicity and compatibility with the carrier. Several reactive amines were examined for their suitability as carrier. Among the amines tested as a carrier for CO₂, diethanolamine "DEA" demonstrates a greater improvement in the permeation of CO₂ as well as selectivity over N₂. DEA is a secondary amine and one of the most commonly used amines for gas treating due to its favourable reaction kinetics with acid gases and because of its stability when regenerated. Initially, pure gas permeation was employed for materials selection and membrane preparation procedures. The effects of process conditions on the membrane performance, which involve carrier concentrations, feed pressures and operating temperatures were examined. Then the effects of membrane thickness and long-term stability tests were conducted. Once the appropriate membrane materials and preparation procedures were established, the next phase of the study involved the determination of the actual separation of CO₂/N₂ mixtures. These experiments were carried out by adjusting the feed gas composition, feed pressures and operating temperature. In general, the results obtained with CO₂/N₂ mixtures were in agreement with those obtained with pure gas permeation experiments. It was found that facilitation is more significant at lower CO₂ partial pressure differential across the membrane. At higher partial pressure differentials, the reactive membrane may no longer serve as a facilitating medium due to the saturation of the reactive part of the membrane. Under such conditions the permeance values and selectivity obtained were simply due to the solubility and diffusivity of the CO₂ and N₂ in the membrane matrix. Since it was not possible to analyze concentration profiles inside the thin membrane experimentally, it was decided to analyze the effects of various parameters through the analytical transport equations. The zwitterion mechanism was used to illustrate the kinetics of the CO₂-DEA systems. The mass transport equations were solved numerically. All relevant physicochemical properties needed to implement the mass transport equations were taken from the literatures. The calculated results support the experimental trends that were observed for the CO₂ permeance as a function of partial pressure differentials and carrier concentrations.

Abstract In this research, a facilitated transport membrane was developed. The reactive membrane consisted of a carrier entrapped in poly(vinyl alcohol) "PVA" matrix cast on a polysulfone support. PVA was selected to hold the reactive carrier because of its hydrophilicity and compatibility with the carrier. Several reactive amines were examined for their suitability as carrier. Among the amines tested as a carrier for CO₂, diethanolamine "DEA" demonstrates a greater improvement in the permeation of CO₂ as well as selectivity over N₂. DEA is a secondary amine and one of the most commonly used amines for gas treating due to its favourable reaction kinetics with acid gases and because of its stability when regenerated. Initially, pure gas permeation was employed for materials selection and membrane preparation procedures. The effects of process conditions on the membrane performance, which involve carrier concentrations, feed pressures and operating temperatures were examined. Then the effects of membrane thickness and long-term stability tests were conducted. Once the appropriate membrane materials and preparation procedures were established, the next phase of the study involved the determination of the actual separation of CO₂/N₂ mixtures. These experiments were carried out by adjusting the feed gas composition, feed pressures and operating temperature. In general, the results obtained with CO₂/N₂ mixtures were in agreement with those obtained with pure gas permeation experiments. It was found that facilitation is more significant at lower CO₂ partial pressure differential across the membrane. At higher partial pressure differentials, the reactive membrane may no longer serve as a facilitating medium due to the saturation of the reactive part of the membrane. Under such conditions the permeance values and selectivity obtained were simply due to the solubility and diffusivity of the CO₂ and N₂ in the membrane matrix. Since it was not possible to analyze concentration profiles inside the thin membrane experimentally, it was decided to analyze the effects of various parameters through the analytical transport equations. The zwitterion mechanism was used to illustrate the kinetics of the CO₂-DEA systems. The mass transport equations were solved numerically. All relevant physicochemical properties needed to implement the mass transport equations were taken from the literatures. The calculated results support the experimental trends that were observed for the CO₂ permeance as a function of partial pressure differentials and carrier concentrations.

Temporal features in the vocalizations of animals and insects play an important role in a diverse range of species-specific activities such as mate selection, territoriality, and hunting. The neural mechanisms underlying the response to such stimuli remain largely unknown. Two species of anuran amphibian provide a starting point for the investigation of the neurological response to species-specific advertisement calls. Neurons in the anuran midbrain of Rana pipiens and Hyla regilla exhibit an atypical response when presented with a fixed number of advertisement calls. The general response to these calls is mostly inhibitory; only when the correct number of calls is presented at the correct repetition rate will this inhibition be overcome and the neurons reach a spiking threshold. In addition to rate-dependent call-counting, these neurons are sensitive to missed calls: a pause of sufficient duration—the equivalent of two missed calls—effectively resets a neuron to its initial condition. These neurons thus provide a model system for investigating the neural mechanisms underlying call-counting and interval specificity in audition. We present a minimal computational model in which competition between finely-tuned excitatory and inhibitory synaptic currents, combined with a small propagation delay between the two, broadly explains the three key features observed: rate dependence, call counting, and resetting. While limitations in the available data prevent the determination of a single set of parameters, a detailed analysis indicates that these parameters should fall within a certain range of values. Furthermore, while network effects are counter-indicated by the data, the model suggests that recruitment of neurons plays a necessary role in facilitating the excitatory response of counting neurons—although this hypothesis remains untested. Despite these limitations, the model sheds light on the mechanisms underlying the biophysics of counting, and thus provides insight into the neuroethology of amphibians in general.

From an agronomic perspective, the spreading of manure (sometimes containing antibiotics) onto agricultural fields is beneficial to the soil as a renewable source of fertilizer by increasing organic matter and providing nutrient inputs for crops. However, the use of antibiotics can be excessive, resulting in manures containing residual antibiotics contaminating soils and waterways. Thus, there is a need to improve existing or develop new management practices to minimize the losses of antibiotics from manure entering waterways and groundwater. Biochar is a carbon-rich material produced from the oxygen-free pyrolysis of biomass. Generally, biochars have high surface area and sorb organic compounds and trace metals; thus, it is reasonable to hypothesize that biochars sorb antibiotics. The main goal of this research was to investigate if incorporated biochar to soil facilitates the transport of antibiotics under simulated rainstorm events. The specific objectives were to investigate the losses of surface-applied antibiotics to soils with different (1) application rates of biochar and rainfall intensities, and (2) if the losses were antibiotic type-dependent. <br>

This study examines facilitated communication as it was experienced by three people who were affected by acquired brain injury. Facilitated communication is a type of augmentative communication purported to allow persons with a severe communication impairments to communicate. The assumption is made that people with global apraxia can communicate if given physical support. The technique usually involves a facilitator providing physical support to the arm, hand or elbow of the person with the severe communication impairment to assist them to point to objects, pictures, printed letters and words or to a keyboard. Facilitated communication is a controversial method because it is difficult to establish the existence, or extent of the facilitator's influence in the communication of the person with a disability. Although much of the research on facilitated communication has been conducted with people with intellectual or developmental disabilities, research on the use of the technique with people with brain injury offers several advantages. Firstly, most people with brain injury were known to be competent communicators prior to the brain injury. Secondly, many recover sufficiently to allow a retrospective examination of the issues that faced them when they were using the technique. Thirdly, there can be a large amount of data available about the person's diagnosis, their prognosis and the course of their history following the event. Consequently, the current study uses a case study methodology to explore the application of facilitated communication with people with brain injury and draws on personal recollections of people with brain injury, interviews with families and medical and therapist reports. The three people interviewed in the study displayed varying language and memory abilities. They indicated a preference for independent communication techniques and they reported frustrations with using facilitated communication. They quickly rejected the method when speech began to appear even though their speech was inadequate for communication purposes, for two of them, for an extended period. One of the interviewees reported that facilitator influence was overwhelming at times but not always present. Two of the interviewees felt that facilitated communication gave them a start in their recovery process. Two of the interviewees reported that meaningful exchanges with others occurred only with speech. In addition to these findings the study, although not experimental, was able to shed light on some of the contentious issues surrounding facilitated communication. The method is reported to be designed to overcome the motor difficulties of the disabled communicator by providing physical assistance to individuals with poor fine motor control thus breaking the perseveration cycle that can be present . However the task of coping with facilitator influence may actually require some motor skills. Also, the physical effort involved in using facilitated communication for some individuals may have been underestimated by its supporters. However the study has shown that some individuals with severe communication impairments felt that facilitated communication had some merit but saw their ability to communicate independently as the significant achievement in their recovery.