Animals are commonly trained to perform behaviors during routine husbandry procedures. However, some husbandry procedures have aversive consequences when the real procedure is performed. This commonly results in loss of the trained behavior. The present study assessed whether maintaining the antecedent environmental stimulus conditions between appetitive and aversive outcomes would prevent this effect and, conversely, whether adding a stimulus discrepancy would facilitate this effect. Three domestic rats served as participants in a multiple baseline across participants design with multi-element components. All three rats stopped performing a trained behavior when a discrepant stimulus reliably predicted an aversive outcome. In addition, all three rats continued to perform the same behavior when antecedent environmental stimulus conditions were consistent between aversive and appetitive outcomes. Results are discussed in terms of practical implications for behavior change agents and conceptual implications for learning theory.

Background: One approach to increasing the reach of syringe programs in rural areas could be through provision of syringes at community pharmacies. This study evaluated relationships between state-specific syringe policies, pharmacy, and pharmacist characteristics and pharmacists’ nonprescription syringe dispensing behaviors in a 3- state Appalachian region at high risk for HIV and HCV transmission. Methods: We conducted a telephone census of community pharmacies in the Appalachian counties of North Carolina, Tennessee, and Virginia from April–June 2018. Behaviors studied included having ever sold syringes without a prescription, quantity of individuals to whom nonprescription syringes were dispensed in the past 30 days, having ever denied a request for nonprescription syringes, and past 30-day denial of nonprescription syringe requests. Behavioral intention and perceptions of legality were elicited. Results: A response rate of 52.3 % was achieved (N = 391). North Carolina pharmacists reported increased past 30-day dispensing, less denial of nonprescription syringe requests, and decreased justification for syringe dispensing (proof of medical need) as compared to Tennessee and Virginia pharmacists. Behavioral intention to dispense did not vary by state but did vary by political affiliation. Perceptions of syringe dispensing legality in NC were significantly different from those in TN and VA. Conclusions: Significant differences in pharmacists’ perceptions and behaviors were noted across state lines with North Carolina pharmacists reporting more engagement in syringe dispensing as compared to pharmacists in Tennessee and Virginia. Policy allowing pharmacists to dispense syringes to people who inject drugs appears to foster some but not all pharmacist engagement in this harm reduction intervention.

Introduction: The aim of this study was to evaluate the frequency and amount of Ca(OH)2 extrusion in relation to the intracanal delivery technique, apical foramen size, and depth of placement. Methods: Standardized training blocks with j-shaped canals were used (n=64); half of the simulated canals were shaped to apical size #35(.06 taper) and the remaining 32 to #45(.06). The frequency and extent of Ca(OH)2 extrusion were measured relative to apical taper, the depth of insertion, and whether syringe or spiral filler was used. Blocks were immersed in pH-sensitive gel and observed for color change. The visible extent of extrusion, indicated by color change, was determined as area and expressed in mm2. Results: Extrusion of Ca(OH)2 occurred in 48/64 of the samples. At 3mm from the canal terminus, the device type had a significant effect on the frequency of extrusion, with syringe placement causing extrusion significantly (p<0.01) more frequently, irrespective of device size. Amounts of extrusion were significantly larger at 2mm short of the canal terminus (median 27.44mm2, IQR 10.02), compared to 3mm distance (median 19.69mm2, IQR 25.07; p<0.0001). Analyzed separately at 2 and 3mm distance, respectively, there was significantly more extrusion with placement using a syringe size #35 compared to spiral filler size #45. Conclusions: Considering the limits of the in vitro experimental design, a spiral filler at 500rpm, placed 3mm short of the apex found to minimize extrusion of Ca(OH)2 placed in root canals.

The study by Rehan et al. [1] was evaluated for support of the conclusion was by the data. The deviations from recommended practices were infrequent and not shown to be clinically significant. Although a strong study, the conclusion that world-wide education programs are needed is not warranted.

Background: The central Appalachian region is at an elevated risk for HIV/HCV outbreaks, primarily due to injection drug use. Regional risk assessments highlight gaps in the evidence-based continuum of primary, secondary, and tertiary prevention strategies to minimize HIV/HCV transmission. One potential strategy for increasing the reach of HIV/HCV prevention efforts in rural areas is through provision of services at community pharmacies. Objective: To qualitatively describe community pharmacists' HIV/HCV-related prevention behaviors, attitudes, and beliefs in a 3-state central Appalachian region. Methods: Key informant interviews were conducted with 15 practicing community pharmacists. Theory of Planned Behavior-based questions probed for perceptions about the role of pharmacies in preventing and reducing HIV/HCV outbreaks in rural areas through activities such as syringe services, screening for HIV/HCV, and linking people to treatment when appropriate. Investigators applied thematic analysis to deductively and inductively generate themes from the interview transcripts. Results: Two overarching themes regarding pharmacist engagement in HIV/HCV-related prevention services were generated: 1) current approaches to primary prevention through nonprescription syringe sales (e.g., gatekeeping behaviors) and 2) potential for uptake of the continuum of HIV/HCV-related prevention services in community pharmacies. Future engagement of community pharmacists in the continuum of HIV/HCV-related prevention services comprised 2 subthemes as possible underlying factors: general and specific willingness to provide services and perceived fit within the pharmacy profession. Conclusions: Central Appalachian community pharmacists express a general willingness to help patients who may benefit from HIV/HCV-related prevention services, but current engagement, willingness, and perceived fit for offering specific prevention services in the community pharmacy setting is variable. This has potential immediate implications, such as prioritizing the introduction of more widely accepted services (e.g., provision of HIV/HCV-related prevention education) to community pharmacy practice, and longer-term implications, such as the integration and framing of HIV/HCV-related prevention services as helping behavior within the pharmacist professional identity.

This dissertation presents three chapters of contemporary research in environmental and development economics. Each chapter echoes a common theme, in that achievement of regional goals constitute 'Wicked Problems' and that the approaches that parties may take to address these specific regional goals may have complex interactions with other regional goals. Decision-making, cost analysis, and multipurpose efficacy of the approaches that regional parties may take to achieve goals are evaluated in environmental and development contexts and implications for program analysis and policy design are discussed. The first chapter of this dissertation seeks to understand how regulated parties, i.e. Municipal Separate Storm Sewer Systems (MS4s), choose from the strategies at their disposal to achieve compliance with their Chesapeake Bay Total Maximum Daily Load (TMDL) obligations. To address declining Chesapeake Bay water quality, the United States Environmental Protection Agency (EPA) set extensive nutrient and sediment reduction goals under the 2010 Chesapeake Bay TMDL. Virginia has responded by passing along explicit nutrient and sediment reduction requirements to its MS4s, which can choose from a variety of urban stormwater, land use change, source control, and restoration practices to achieve reductions toward these requirements. MS4s in Virginia have also been granted flexibility to achieve reduction requirements through purchase of nutrient and sediment credits toward requirements through trade. In spite of the cost-savings that these credits provide, MS4s' interest in trading for these credits has been low. MS4s instead generally engage in onsite nutrient and sediment reduction themselves, in spite of the high costs of doing so. In response to low interest in trade, case analysis of MS4s' Bay TMDL compliance behavior and semi-structured interviews are conducted to better understand the role of trade in compliance strategy and the reasons for its non-use. Findings reveal that the Virginia MS4s studied typically choose to implement onsite urban stormwater practices, source control practices, and restoration practices in order to generate long-lasting local benefits, like erosion control, flood risk reduction, and progress toward local TMDL obligations, alongside reductions toward the Bay TMDL. MS4s refrain from term credit purchases out of concern over future availability and refrain from perpetual credit purchases because they have been able to use funding sources to achieve reductions from long-lasting onsite practices at similar per-pound costs, while also receiving local benefits. Implications are that supply-side efforts to support trade markets may not generate the level of activity expected, given that would-be buyers have generally limited interest in trade as a compliance strategy. The second chapter studies the degree to which the practices used to meet local TMDL water quality obligations contribute to Bay TMDL compliance for the Loudoun County MS4. Linear programming is used to estimate the minimal cost of achieving Bay compliance in addition to local obligations through representative nutrient and sediment reduction strategies. The model estimates that Loudoun County MS4 faces substantial costs just to meet local water quality goals ($11 million/yr). Since many of the actions taken to meet local water quality goals also generate pollutant reductions to the Chesapeake Bay, adding Bay TMDL obligations adds 0.2%, 3%, and 32.9% to these costs, depending on the water quality trading used to reach Bay TMDL compliance. Findings shed additional light on Chapter 1's goal of investigating the role of trade by explaining low interest in trade as stemming from heavy local water quality needs. Implications are that the burden imposed by the Bay TMDL may not be as high as generally thought. The third chapter shifts focus to the Opioid Crisis to evaluate the efficacy of Syringe Exchange Programs, best known for their efforts to prevent bloodborne illness transmission, at achieving their secondary intervention goal of preventing opioid overdose. While research has established that Syringe Exchange Programs, or SEPs, are effective at preventing bloodborne illness, little focus has been given to their ability to prevent fatal overdose, which they aim to do by engaging in intervention practices like naloxone and fentanyl test strip distribution. In response for need for understanding of Syringe Exchange Programming's impact on overdose, fixed effects analysis is used to empirically study the impact of county-level SEP in North Carolina following the state's 2016 SEP legalization. Need-based programming complicates analysis and likely biases findings of the impact of SEP on overdose upward. Regardless, findings consistently fail to find that SEP has a significant effect on fatal overdose from four categories of opioids, which should reduce concerns in recent literature that they may increase overdose death. Implications are that, since SEPs have a richly documented history of saving lives through the prevention of bloodborne illness and do not appear to increase overdose, contrary to findings in other work, policy makers should continue to incorporate SEP into their portfolio of strategies used to address the Opioid Crisis. / Doctor of Philosophy / This dissertation presents three chapters of contemporary research in environmental and development economics. Each chapter echoes a common theme, in that achievement of regional goals constitute 'Wicked Problems' and that the approaches that parties may take to address these specific regional goals may have complex interactions with other regional goals. Decision-making, cost analysis, and multipurpose efficacy of the approaches that regional parties may take to achieve goals are evaluated in environmental and development contexts and implications for program analysis and policy design are discussed. The first chapter of this dissertation seeks to understand how regulated parties, i.e. Municipal Separate Storm Sewer Systems (MS4s), choose from the strategies at their disposal to achieve compliance with their Chesapeake Bay Total Maximum Daily Load (TMDL) obligations. To address declining Chesapeake Bay water quality, the United States Environmental Protection Agency (EPA) set extensive nutrient and sediment reduction goals under the 2010 Chesapeake Bay TMDL. Virginia has responded by passing along explicit nutrient and sediment reduction requirements to its MS4s, which can choose from a variety of urban stormwater, land use change, source control, and restoration practices to achieve reductions toward these requirements. MS4s in Virginia have also been granted flexibility to achieve reduction requirements through purchase of nutrient and sediment credits toward requirements through trade. In spite of the cost-savings that these credits provide, MS4s' interest in trading for these credits has been low. MS4s instead generally engage in onsite nutrient and sediment reduction themselves, in spite of the high costs of doing so. In response to low interest in trade, case analysis of MS4s' Bay TMDL compliance behavior and semi-structured interviews are conducted to better understand the role of trade in compliance strategy and the reasons for its non-use. Findings reveal that the Virginia MS4s studied typically choose to implement onsite urban stormwater practices, source control practices, and restoration practices in order to generate long-lasting local benefits, like erosion control, flood risk reduction, and progress toward local TMDL obligations, alongside reductions toward the Bay TMDL. MS4s refrain from term credit purchases out of concern over future availability and refrain from perpetual credit purchases because they have been able to use funding sources to achieve reductions from long-lasting onsite practices at similar per-pound costs, while also receiving local benefits. Implications are that supply-side efforts to support trade markets may not generate the level of activity expected, given that would-be buyers have generally limited interest in trade as a compliance strategy. The second chapter studies the degree to which the practices used to meet local TMDL water quality obligations contribute to Bay TMDL compliance for the Loudoun County MS4. Linear programming is used to estimate the minimal cost of achieving Bay compliance in addition to local obligations through representative nutrient and sediment reduction strategies. The model estimates that Loudoun County MS4 faces substantial costs just to meet local water quality goals ($11 million/yr). Since many of the actions taken to meet local water quality goals also generate pollutant reductions to the Chesapeake Bay, adding Bay TMDL obligations adds 0.2%, 3%, and 32.9% to these costs, depending on the water quality trading used to reach Bay TMDL compliance. Findings shed additional light on Chapter 1's goal of investigating the role of trade by explaining low interest in trade as stemming from heavy local water quality needs. Implications are that the burden imposed by the Bay TMDL may not be as high as generally thought. The third chapter shifts focus to the Opioid Crisis to evaluate the efficacy of Syringe Exchange Programs, best known for their efforts to prevent bloodborne illness transmission, at achieving their secondary intervention goal of preventing opioid overdose. While research has established that Syringe Exchange Programs, or SEPs, are effective at preventing bloodborne illness, little focus has been given to their ability to prevent fatal overdose, which they aim to do by engaging in intervention practices like naloxone and fentanyl test strip distribution. In response for need for understanding of Syringe Exchange Programming's impact on overdose, fixed effects analysis is used to empirically study the impact of county-level SEP in North Carolina following the state's 2016 SEP legalization. Need-based programming complicates analysis and likely biases findings of the impact of SEP on overdose upward. Regardless, findings consistently fail to find that SEP has a significant effect on fatal overdose from four categories of opioids, which should reduce concerns in recent literature that they may increase overdose death. Implications are that, since SEPs have a richly documented history of saving lives through the prevention of bloodborne illness and do not appear to increase overdose, contrary to findings in other work, policy makers should continue to incorporate SEP into their portfolio of strategies used to address the Opioid Crisis.

Procedimentos analíticos espectrofotométricos foram desenvolvidos empregando etapas de separação e pré-concentração em sistemas de análises em fluxo com multi-impulsão ou lab-in-syringe, com aplicação a amostras de interesse agronômico (ferro em materiais vegetais e alimentos) e ambiental (cianeto dissociável em ácidos, ferro e antimônio em águas). A determinação de cianeto explorou a descoloração do complexo formado entre Cu(I) e ácido 2-2´-biquinolino-4,4´-dicarboxílico (BQA) pela presença de CN-, após a separação de HCN por difusão gasosa. Espectrofotometria com longo caminho óptico foi empregada para aumentar a sensibilidade, com resposta linear entre 5 e 200 g L-1, limite de detecção, coeficiente de variação (n = 10) e frequência de amostragem de 2,0 g L-1, 1,5% e 22 h-1, respectivamente. O procedimento consumiu apenas 48 ng de Cu(II), 5,0 g de ácido ascórbico e 0,9 g de BQA por determinação e gerou 2,6 mL de efluente. Tiocianato, nitrito e sulfito não afetaram a determinação de cianeto e peróxido de hidrogênio evitou a interferência de sulfeto até 200 g L-1. Os resultados para as amostras de águas naturais foram concordantes com o procedimento fluorimétrico em fluxo com 95% de confiança. Novas estratégias foram propostas para a extração em ponto nuvem (EPN) em fluxo: (i) a fase rica em surfactante foi retida diretamente na cela de fluxo, evitando a diluição; (ii) microbombas solenoide foram exploradas para melhorar a mistura e modular a vazão na retenção e remoção da fase rica, evitando a eluição com solvente orgânico e (iii) o calor liberado e os sais fornecidos por uma reação de neutralização em linha foram explorados para indução do ponto nuvem, sem dispositivo externo de aquecimento. Estas inovações foram demonstradas pela determinação espectrofotométrica de ferro baseada no complexo com 1-(2-tiazolilazo)-2-naftol (TAN). Resposta linear foi observada entre 10 e 200 g L-1, com limite de detecção, coeficiente de variação e frequência de amostragem de 5 g L-1, 2,3% (n = 7) e 26 h-1, respectivamente. O fator de enriquecimento foi de 8,9 com consumo apenas de 6 g de TAN e 390 g de Triton X-114 por determinação. Os resultados para amostras de águas foram concordantes com o procedimento de referência e os obtidos para digeridos de materiais de referência de alimentos concordaram com os valores certificados. A determinação espectrofotométrica de antimônio foi realizada explorando pela primeira vez a EPN em sistema lab-in-syringe. O complexo iodeto e antimônio forma um par iônico com H+, que pode ser extraído com Triton X-114. Planejamento fatorial demonstrou que as concentrações de ácido ascórbico, H2SO4 e Triton X-114, bem como as interações de segunda e de terceira ordem foram significativas (95% de confiança). Planejamento Box-Behnken foi aplicado para a identificação dos valores críticos. Robustez com 95% de confiança, resposta linear entre 5 e 50 g L-1, limite de detecção, coeficiente de variação (n = 5) e frequência de amostragem foram estimados em 1,8 g L-1, 1,6% e 16 h-1, respectivamente. Os resultados para amostras de águas naturais e medicamentos anti-leishmaniose foram concordantes com os obtidos por espectrometria de absorção atômica com geração de hidretos (HGFAAS) com 95% de confiança / Spectrophotometric analytical procedures were developed by exploiting separation and preconcentration steps in flow systems based on multi-pumping or lab-in-syringe approaches with application to agronomic (iron in plant materials and food) and environmental samples (acid dissociable cyanide, iron and antimony in waters). Cyanide determination exploited bleaching of the Cu(I)/2,2\'-biquinoline 4,4\'-dicarboxylic acid (BCA) complex by the analyte, after separation of HCN by gas diffusion. Long path length spectrophotometry was successfully exploited to increase sensitivity, thus achieving a linear response from 5 to 200 g L-1, with detection limit, coefficient of variation (n = 10) and sampling rate of 2 g L-1, 1.5% and 22 h-1, respectively. Each determination consumed 48 ng of Cu(II), 5 g of ascorbic acid and 0.9 g of BCA. As high as 100 mg L-1 thiocyanate, nitrite or sulfite did not affect cyanide determination and sample pretreatment with hydrogen peroxide avoided sulfide interference up to 200 g L-1. The procedure is environmentally friendly and presented one of the lowest detection limits associated to high sampling rate. The results for freshwater samples agreed with those obtained with the flow-based fluorimetric procedure at the 95% confidence level. Novel strategies were proposed for on-line cloud point extraction (CPE): (i) the surfactant-rich phase was retained directly into the flow cell to avoid dilution prior to detection; (ii) solenoid micro-pumps were explored to improve mixing and for flow modulation in the retention and removal of the surfactant-rich phase, thus avoiding the elution step with organic solvents and (iii) the heat released and the salts provided by an on-line neutralization reaction were exploited to induce cloud point without an external heating device. These approaches were demonstrated for the spectrophotometric determination of iron based on complex formation with 1-(2-thiazolylazo)-2-naphtol (TAN). A linear response was observed from 10 to 200 g L-1, with detection limit, coefficient of variation, and sampling rate of 5 g L-1, 2.3% (n = 7) and 26 h-1, respectively. The enrichment factor was 8.9 and the procedure consumed only 6 g of TAN and 390 g of Triton X-114 per determination. The results for freshwater samples agreed with the reference procedure and those obtained for certified reference materials of food agreed with the certified values. Spectrophotometric determination of antimony was performed for the first time exploiting CPE in the lab-in-syringe system. The antimony/iodide complex forms an ion-pair with H+, which can be extracted with Triton X-114. Factorial design showed that the concentrations of ascorbic acid, H2SO4 and Triton X-114, as well as the second and third order interactions were significant (95% confidence). The Box-Behnken design was applied to identify the critical values. The system is robust with 95% confidence and a linear response was observed from 5 to 50 g L-1, with detection limit, coefficient of variation (n = 5) and sampling rate of 1.8 g L-1, 1.6% and 16 h-1, respectively. The results for water samples and antileishmanial drugs agreed with those obtained by hydride generation atomic absorption spectrometry at the 95% confidence level

Procedimentos analíticos espectrofotométricos foram desenvolvidos empregando etapas de separação e pré-concentração em sistemas de análises em fluxo com multi-impulsão ou lab-in-syringe, com aplicação a amostras de interesse agronômico (ferro em materiais vegetais e alimentos) e ambiental (cianeto dissociável em ácidos, ferro e antimônio em águas). A determinação de cianeto explorou a descoloração do complexo formado entre Cu(I) e ácido 2-2´-biquinolino-4,4´-dicarboxílico (BQA) pela presença de CN-, após a separação de HCN por difusão gasosa. Espectrofotometria com longo caminho óptico foi empregada para aumentar a sensibilidade, com resposta linear entre 5 e 200 g L-1, limite de detecção, coeficiente de variação (n = 10) e frequência de amostragem de 2,0 g L-1, 1,5% e 22 h-1, respectivamente. O procedimento consumiu apenas 48 ng de Cu(II), 5,0 g de ácido ascórbico e 0,9 g de BQA por determinação e gerou 2,6 mL de efluente. Tiocianato, nitrito e sulfito não afetaram a determinação de cianeto e peróxido de hidrogênio evitou a interferência de sulfeto até 200 g L-1. Os resultados para as amostras de águas naturais foram concordantes com o procedimento fluorimétrico em fluxo com 95% de confiança. Novas estratégias foram propostas para a extração em ponto nuvem (EPN) em fluxo: (i) a fase rica em surfactante foi retida diretamente na cela de fluxo, evitando a diluição; (ii) microbombas solenoide foram exploradas para melhorar a mistura e modular a vazão na retenção e remoção da fase rica, evitando a eluição com solvente orgânico e (iii) o calor liberado e os sais fornecidos por uma reação de neutralização em linha foram explorados para indução do ponto nuvem, sem dispositivo externo de aquecimento. Estas inovações foram demonstradas pela determinação espectrofotométrica de ferro baseada no complexo com 1-(2-tiazolilazo)-2-naftol (TAN). Resposta linear foi observada entre 10 e 200 g L-1, com limite de detecção, coeficiente de variação e frequência de amostragem de 5 g L-1, 2,3% (n = 7) e 26 h-1, respectivamente. O fator de enriquecimento foi de 8,9 com consumo apenas de 6 g de TAN e 390 g de Triton X-114 por determinação. Os resultados para amostras de águas foram concordantes com o procedimento de referência e os obtidos para digeridos de materiais de referência de alimentos concordaram com os valores certificados. A determinação espectrofotométrica de antimônio foi realizada explorando pela primeira vez a EPN em sistema lab-in-syringe. O complexo iodeto e antimônio forma um par iônico com H+, que pode ser extraído com Triton X-114. Planejamento fatorial demonstrou que as concentrações de ácido ascórbico, H2SO4 e Triton X-114, bem como as interações de segunda e de terceira ordem foram significativas (95% de confiança). Planejamento Box-Behnken foi aplicado para a identificação dos valores críticos. Robustez com 95% de confiança, resposta linear entre 5 e 50 g L-1, limite de detecção, coeficiente de variação (n = 5) e frequência de amostragem foram estimados em 1,8 g L-1, 1,6% e 16 h-1, respectivamente. Os resultados para amostras de águas naturais e medicamentos anti-leishmaniose foram concordantes com os obtidos por espectrometria de absorção atômica com geração de hidretos (HGFAAS) com 95% de confiança / Spectrophotometric analytical procedures were developed by exploiting separation and preconcentration steps in flow systems based on multi-pumping or lab-in-syringe approaches with application to agronomic (iron in plant materials and food) and environmental samples (acid dissociable cyanide, iron and antimony in waters). Cyanide determination exploited bleaching of the Cu(I)/2,2\'-biquinoline 4,4\'-dicarboxylic acid (BCA) complex by the analyte, after separation of HCN by gas diffusion. Long path length spectrophotometry was successfully exploited to increase sensitivity, thus achieving a linear response from 5 to 200 g L-1, with detection limit, coefficient of variation (n = 10) and sampling rate of 2 g L-1, 1.5% and 22 h-1, respectively. Each determination consumed 48 ng of Cu(II), 5 g of ascorbic acid and 0.9 g of BCA. As high as 100 mg L-1 thiocyanate, nitrite or sulfite did not affect cyanide determination and sample pretreatment with hydrogen peroxide avoided sulfide interference up to 200 g L-1. The procedure is environmentally friendly and presented one of the lowest detection limits associated to high sampling rate. The results for freshwater samples agreed with those obtained with the flow-based fluorimetric procedure at the 95% confidence level. Novel strategies were proposed for on-line cloud point extraction (CPE): (i) the surfactant-rich phase was retained directly into the flow cell to avoid dilution prior to detection; (ii) solenoid micro-pumps were explored to improve mixing and for flow modulation in the retention and removal of the surfactant-rich phase, thus avoiding the elution step with organic solvents and (iii) the heat released and the salts provided by an on-line neutralization reaction were exploited to induce cloud point without an external heating device. These approaches were demonstrated for the spectrophotometric determination of iron based on complex formation with 1-(2-thiazolylazo)-2-naphtol (TAN). A linear response was observed from 10 to 200 g L-1, with detection limit, coefficient of variation, and sampling rate of 5 g L-1, 2.3% (n = 7) and 26 h-1, respectively. The enrichment factor was 8.9 and the procedure consumed only 6 g of TAN and 390 g of Triton X-114 per determination. The results for freshwater samples agreed with the reference procedure and those obtained for certified reference materials of food agreed with the certified values. Spectrophotometric determination of antimony was performed for the first time exploiting CPE in the lab-in-syringe system. The antimony/iodide complex forms an ion-pair with H+, which can be extracted with Triton X-114. Factorial design showed that the concentrations of ascorbic acid, H2SO4 and Triton X-114, as well as the second and third order interactions were significant (95% confidence). The Box-Behnken design was applied to identify the critical values. The system is robust with 95% confidence and a linear response was observed from 5 to 50 g L-1, with detection limit, coefficient of variation (n = 5) and sampling rate of 1.8 g L-1, 1.6% and 16 h-1, respectively. The results for water samples and antileishmanial drugs agreed with those obtained by hydride generation atomic absorption spectrometry at the 95% confidence level

The first part of this work is about history of infusion technology, specially about recent developments in electronic infusion devices. Then, there are described basic principles of infusion pumps and syringe pumps. The second part introduces safety features of infusion technology. An occlusion alarm is one of them. There is described a method of measurement that verifies the functionality of this alarm in two instruments of different producers with various settings. Data obtained by this method are statistically processed and the results discussed.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.