Doctor of Philosophy / Department of Anatomy and Physiology / Thomas J. Barstow / The primary aim of this dissertation was to describe the changes in microvascular hematocrit, as total[hemoglobin+myoglobin] (T[Hb+Mb] measured with near-infrared spectroscopy (NIRS), during post-occlusive reactive hyperemia (PORH). Mechanisms of reactive hyperemia within skeletal muscle were also explored. The investigation detailed in Chapter 2 of this dissertation found that the differing time courses of the kinetic responses of both oxy- and deoxy[Hb+Mb], are related to changes in T[Hb+Mb]. We also determined that adipose tissue thickness had no effect on a purely temporal analysis of NIRS data. In Chapter 3 we observed that brachial artery reactive hyperemia preceded changes in T[Hb+Mb] during reactive hyperemia. Assuming that myoglobin remained constant, we posited that changes in T[Hb+Mb] must reflect alterations in red blood cell concentration in the microvasculature, i.e., microvascular hematocrit. In Chapter 4 comparisons were made between brachial artery blood flow, cutaneous and skeletal muscle flux and T[Hb+Mb]. The conduit artery response was faster than the microvascular responses in all tissues. Within skeletal muscle, time to peak and the time constant for the on-kinetics were faster in T[Hb+Mb] compoared with intramuscular flux as measured with intramuscular laser-Doppler. We observed no differences in temporal responses between cutaneous and intramuscular measures and suggested that in a purely temporal analysis the cutaneous microvasculature could serve as an analog for the skeletal muscle microvasculature. Finally, in Chapter 5 we found that prostaglandin inhibition with ibuprofen altered the initial T[Hb+Mb] response during PORH without impacting cutaneous flux or brachial artery blood flow. Chapter 5 also discussed that the addition of a wrist cuff to our standard instrumentation prevented the accumulation of T[Hb+Mb] during the occlusion period.

Master of Science / Biological & Agricultural Engineering / Donghai Wang / The growing demands for renewable energy sources have led researchers to investigate other biomass sources, aside from maize. Grain sorghum is comparable to maize in its starch content and can be grown in regions with drier climates, where maize is a less suitable crop for these areas. In attempts to increase yield prior to harvest and for ethanol production, this study focuses on mutant grain sorghum. One hundred and nine mutant grain sorghum samples were analyzed for their chemical and physical properties and fermented into ethanol. The current method for starch analysis is time-consuming and tedious. Near infrared spectroscopy (NIR) models were developed as fast, cost-effective, and non-destructive methods for grain sorghum starch content analysis. Each mutated grain sorghum sample was scanned in a wavelength range from 4,000 to 10,000 cmˉ¹ as a whole grain and in flour form. Partial Least Squares (PLS) regression method was used for NIR model development. The coefficients of determination (R²) of 0.77 and 0.90 were achieved for starch content calibration and prediction models, respectively. This model demonstrates the possibility of a positive correlation between the actual and calculated values for starch content. Another PLS first derivative model with R² = 0.95 for calibration and a reduced wavelength range (4,000-5,176 cmˉ¹), using 39 of the original 109 samples (27 for calibration and 8 for validation), was created to predict the fermentation efficiency.

Orientador: Celio Pasquini / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-09T09:59:17Z (GMT). No. of bitstreams: 1 Povia_GiovanaSoato_M.pdf: 1681817 bytes, checksum: d59818d169390e4a42e0555251507c27 (MD5) Previous issue date: 2007 / Resumo: Este trabalho visa o desenvolvimento de um método analítico para a determinação dos parâmetros de qualidade em detergentes em pó utilizando a Espectroscopia de Infravermelho Próximo (NIR) e técnicas de calibração multivariada. Foram utilizados dois conjuntos de amostras: o primeiro para as análises quantitativas e o segundo para análises qualitativas. As amostras do primeiro conjunto tiveram os parâmetros de qualidade determinados pelos respectivos métodos de referência. A técnica estatística utilizada para as calibrações foi o PLS. Foram desenvolvidos modelos de calibrações para a previsão do teor de umidade, matéria ativa e densidade. O desempenho dos modelos de calibrações foi avaliado por meio de validação externa. A determinação do teor de umidade apresentou RMSEP = 0,29% (m/m). O valor de RMSEP para a determinação da matéria ativa foi de 0,37% (m/m) e para a determinação da densidade o valor de RMSEP = 14 g L . Os modelos construídos apresentaram resultados satisfatórios e os erros encontrados são aceitáveis para a faixa de controle utilizada na indústria. O segundo conjunto é composto de 4 grupos, que apresentam características distintas. Foram avaliados dois métodos de classificação: SIMCA e PLS DA. É possível observar que ocorre a discriminação das amostras que apresentam teor de matéria ativa mais elevado, no entanto, os outros grupos não puderam ser discriminados. Os dois métodos de classificação avaliados apresentaram resultados semelhantes, com acerto de 100% na classificação de amostras externas somente em seus respectivos grupos / Abstract: This work aims the development of an analytical method for the determination of quality parameters on powder detergents using the near infrared spectroscopy (NIR) and multivariate calibration techniques. Two sets of samples were used: the first one for the quantitative analysis and the second one for qualitative analysis. The samples of the first set had the quality parameters determined by their respective methods of reference. The chemometric technique used for calibration was the PLS1. Calibrations for the prediction of de moisture content, active matter and density were developed. The performance of the calibration models was evaluated through external validation. The determination of the moisture content presented a RMSEP = 0,29% (w/w). The value of RMSEP for the determination of the active matter was 0,37% (w/w) and for the determination of moisture the value of RMSEP was 14 g L. The constructed models presented satisfactory results and the errors that were found are acceptable for the control range used in industry. The second set is composed of four groups of power detergents which present different characteristics. Two methods of classification were evaluated: SIMCA and PLS DA. It was possible to observe the discrimination of the samples which presents higher active matter content. However, the other groups could not be discriminated. Both methods of classifications evaluated presented similar results, with 100% correcte results of the classification of samples only in their respective groups / Mestrado / Quimica Analitica / Mestre em Química

The purpose of this study was to examine the consistency of near-infrared spectroscopy (NIRS) measures associated with a 10 minute vascular occlusion of the thigh during 5 consecutive days. A secondary purpose was to examine if the repeated daily occlusions modify the vascular response to such occlusions. The NIRS chromophores of oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), total hemoglobin (tHb), hemoglobin difference (HbDiff), and total saturation index (TSI) were monitored at the vastus lateralis muscle during each testing session. Participants were female (age 18-30 yrs) and were randomly assigned to one of two groups. The Test Group (age 23 ± 2yrs) completed an occlusion test every day for 5 consecutive days while the Control Group (age 21 ±1.6yrs) was tested on days 1, 3 and 5. Each testing session involved 10 minutes rest in a supine position, 10 minutes of femoral artery occlusion (preset at 250mmHg), 10 minutes of recovery. At onset of occlusion, the rapid cuff inflation system inflated in 0.3 seconds to the preset 250mmHg. Following the 10 minutes of occlusion, the cuff was deflated in 0.3 seconds. Heart rate was monitored throughout all testing sessions and mean arterial pressure was calculated and compared between groups. There were no significant group or day main effects found, nor any significant interactions for the following hemoglobin chromophores measures: HbO2, HHb, HbDiff, and TSI. In all participants, the NIRS response pattern to rest, occlusion and recovery was consistent for all testing days regardless of group. The response pattern to the occlusion initiated by the rapid cuff inflation was as follows: HbO2, tHb, HbDiff, and TSI decreased then slowly plateaued over the 10 minutes while HHb increased initially and then plateaued. Following the rapid cuff deflation, HbO2, tHb, HbDiff and TSI increased to their maximum reperfusion levels and then plateaued over the remainder of the 10 minutes of recovery. During that same period, HHb decreased initially upon reperfusion and then plateaued. Unlike the other measures, TSI and tHb demonstrated inconsistencies in their response pattern regardless of group or day. The consistency of hemoglobin chromophores response pattern to daily 10 minute vascular leg occlusions over 5 consecutive days is an important finding of this study. This response indicates that there is no apparent change in vascular response to repeated occlusions and has implications for exercise studies that use occlusion in their methodology. The study also emphasizes the inconsistency of tHb and TSI as primary hemoglobin response measures to occlusion. Similarly, the results demonstrate the potential misinterpretation of results if only relying on one hemoglobin measure during occlusion. / Graduate

This dissertation focuses on the use of near-infrared spectroscopy (NIRS) to identify trends in regional cerebral oxygen saturation (rSO2) in both conscious and anaesthetised healthy horses. A cerebral/somatic oximeter sensor recorded rSO2 from the dorsal sagittal sinus of 6 healthy horses. Values for rSO2, arterial and venous oxygen and carbon dioxide tensions (PaO2, PvO2, PaCO2 and PvCO2 respectively), along with arteriovenous oxygen saturations (SavO2) were recorded in unsedated (recording period [RP] 1), sedated (RP2), and anaesthetised horses (RP3-5); and during recovery (RP6-8). During anaesthesia, horses were ventilated to achieve states of normo- (RP3), hyper- (RP4) and hypocapnoea (RP5). Overall mean ± s.d. values for rSO2, PaO2, PvO2, PaCO2, SavO2 and mean arterial pressure (MAP) varied significantly by RP. Significant decreases in rSO2 were identified between RP1 and the post-anaesthetic periods however no significant differences in rSO2 values were identified between RP1 and the intra-anaesthesia periods. Regional cerebral oxygen saturation was significantly correlated with PaO2, PvO2 and SavO2. No correlation was identified between rSO2 and lactate concentration. This is the first study to identify trends in rSO2 in horses using NIRS. A significant positive correlation was identified between rSO2 and PvO2, suggesting that alterations in cerebral oxygenation may be reflected in jugular PvO2. Results of this study demonstrate that NIRS can be used during general anaesthesia to monitor trends in rSO2 in healthy horses, and has the potential to alert clinicians to cerebral desaturation events when used in a clinical setting. / Dissertation (MMedVet)--University of Pretoria, 2013. / gm2014 / Companion Animal Clinical Studies / unrestricted

In an attempt to reduce the costs and turn around times experienced with outsourcing starch analysis in finished feed products, the company decided to invest in a NIR instrument to carry out such analyses in house. The particular instrument purchased by the company comes with a build in calibration for specific finished feed products and the main objective of this investigation was to evaluate whether the instrumentation and build in calibration gives reliable analyses of a finished poultry feed. The results obtained showed that : - The NIR results obtained have a positive bias compared to the theoretical (formulation specified value) and also to the value obtained by enzymatic starch analysis. - Despite the positive bias, the starch values were well within the allowable limits - Repeatability measurements on the data generated by two different analysts showed that while the percentage relative standard deviations obtained (< 1.0 percent) were well within the company specifications of percentage RSD < 5.0 percent, the inter sample repeatability showed small, but significant variation. - The results for intermediate precision showed that there is no statistically significant difference between the results obtained by two different analysts, nor was there any difference in the results of the same samples analysed at different time periods. - Reproducibility could not be evaluated due to the lack of another instrument within the company that were similarly set up as the instrument used for the investigation. This investigation has shown that, given the restrictions enforced by the build incalibration of the NIR instrument, the use of NIR for the analyses of the finished feed product is valid, but will require that careful attention be paid to data collection procedures.

Near infrared spectroscopy (NIRS) is an emerging neuroimaging modality with high temporal and good spatial resolution. In this thesis, NIRS was applied to understand functionality of the fronto-temporal cortex in response to language-related tasks. A 32-channel NIRS system (Imagent ISS Inc.) was used to perform experimental studies on 15 right-handed normal adults. Block-design based Word Expression and Word Reception paradigms were independently presented to participants. Activation, functional connectivity and cortical lateralization analyses were performed. From word expression studies, results showed left anterior region (encompassing Broca) is majorly involved over right homologue and posterior regions. From the word reception studies, results showed that right posterior region (encompassing right homologue of Wernicke) is highly involved in language reception, with right anterior region (encompassing right homologue of Broca) also involved. The current study has potential future applications in surgical evaluation of language regions in populations with neurological disorders such as epilepsy, and schizophrenia.

Motion artifacts are often a significant component of the measured signal in functional near-infrared spectroscopy (fNIRS) experiments. A variety of methods have been proposed to address this issue, including principal component analyses (PCA), Kalman filtering, correlation-based signal improvement (CBSI), wavelet filtering, spline interpolation, and autoregressive algorithms. The efficacy of these techniques has been compared using simulated data; however, our understanding of how these techniques fare when dealing with task-based cognitive data is limited. Recently, Brigadoi et al. (2014) quantitatively compared 6 motion correction techniques in a sample of adult data measured during a simple cognitive task. Wavelet filtering showed the most promise as an optimal technique for motion correction. Because fNIRS is often used with infants and young children, it is critical to evaluate the effectiveness of motion correction techniques directly with data from these age groups. Here we examined which techniques are most effective with data from young children. The efficacy of each technique was compared quantitatively using objective metrics related to the physiological properties of the hemodynamic response using two different sets of parameters to ensure maximum retention of included trials. Results showed that targeted PCA (tPCA) and CBSI retained a higher number of trials. These techniques also performed well in direct head-to-head comparisons with the other approaches using both quantitative metrics and a qualitative assessment. The CBSI technique corrected many of the artifacts present in our data; however, this technique was highly influenced by the parameters used to detect motion. The tPCA technique, by contrast, was robust across changes in parameters while also performing well across all comparison metrics. We conclude, therefore, that tPCA is an effective technique for the correction of motion artifacts in fNIRS data from young children.

The use of near infrared (NIR) spectroscopy for predicting levels of degradation in laboratory soil block tests was investigated. Calibrations were developed for mass loss, compression strength, and exposure period using data measured from the prior methods, and untreated and mathematically treated (multiplicative scatter correction and first and second derivative) NIR spectra from various spans of wavelengths by partial least squares regression. Strong correlations were obtained from each study conducted, while calibrations developed from NIR spectra from the cross-sectional face of southern yellow pine presented the strongest predictions. Of them, calibrations for mass loss resulted in the strongest predictions. Calibrations constructed from spectra obtained from the radial face of southern yellow pine also produced strong predictions, where the strongest model was for exposure period. While, calibrations developed for cottonwood presented the weakest statistics, the strongest calibration found was for exposure period.

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