Development of Statistical Models for Functional Near-infrared Spectroscopy Data Analysis Incorporating Anatomical and Probe Registration Prior Information

Functional near-infrared spectroscopy (fNIRS) is a non-invasive technology that uses low-levels of non-ionizing light in the range of 650 -- 900 nm (red and near-infrared) to record changes in the optical absorption and scattering of tissue. In particular, oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) have characteristic absorption spectra at these wavelengths, which are used to discriminate blood flow and oxygen metabolism changes. As compared with functional magnetic resonance imaging (fMRI), fNIRS is less costly, more portable, and allows for a wider range of experimental scenarios because it neither requires a dedicated scanner nor needs the subject to lay supine. Current challenges in fNIRS data analysis include: (i) a small change in brain anatomy or optical probe positioning can create huge differences in fNIRS measurements even though the underlying brain activity remains the same due to the existence of ``blind-spots"; (ii) fNIRS image reconstruction is a high-dimensional, under-determined, and ill-posed problem, in which there are thousands of parameters to estimate while only tens of measurements available and existing methods notably overestimate the false positive rate; (iii) brain anatomical information has rarely been used in current fNIRS data analyses. This dissertation proposes two new methods aiming to improve fNIRS data analysis and overcome these challenges -- one of which is a channel-space method based on anatomically defined region-of-interest (ROI) and the other one is an image reconstruction method incorporating anatomical and physiological prior information. The two methods are developed using advanced statistical models including a combination of regularization models and Bayesian hierarchical modeling. The performance of the two methods is validated via numerical simulations and evaluated using receiver operating characteristics (ROC)-based tools. The statistical comparisons with conventional methods suggest significant improvements

Scaling Multidimensional Inference for Big Structured Data

In information technology, big data is a collection of data sets so large and complex that it becomes difficult to process using traditional data processing applications [151]. In a world of increasing sensor modalities, cheaper storage, and more data oriented questions, we are quickly passing the limits of tractable computations using traditional statistical analysis methods. Methods which often show great results on simple data have difficulties processing complicated multidimensional data. Accuracy alone can no longer justify unwarranted memory use and computational complexity. Improving the scaling properties of these methods for multidimensional data is the only way to make these methods relevant. In this work we explore methods for improving the scaling properties of parametric and nonparametric models. Namely, we focus on the structure of the data to lower the complexity of a specific family of problems. The two types of structures considered in this work are distributive optimization with separable constraints (Chapters 2-3), and scaling Gaussian processes for multidimensional lattice input (Chapters 4-5). By improving the scaling of these methods, we can expand their use to a wide range of applications which were previously intractable open the door to new research questions

Serotonergic modulation of the ventral pallidum by 5HT1A, 5HT5A, 5HT7 AND 5HT2C receptors

Introduction: Serotonin's involvement in reward processing is controversial. The large number of serotonin receptor sub-types and their individual and unique contributions have been difficult to dissect out, yet understanding how specific serotonin receptor sub-types contribute to its effects on areas associated with reward processing is an essential step. Methods: The current study used multi-electrode arrays and acute slice preparations to examine the effects of serotonin on ventral pallidum (VP) neurons. Approach for statistical analysis: extracellular recordings were spike sorted using template matching and principal components analysis, Consecutive inter-spike intervals were then compared over periods of 1200 seconds for each treatment condition using a student’s t test. Results and conclusions: Our data suggests that excitatory responses to serotonin application are pre-synaptic in origin as blocking synaptic transmission with low-calcium aCSF abolished these responses. Our data also suggests that 5HT1a, 5HT5a and 5HT7 receptors contribute to this effect, potentially forming an oligomeric complex, as 5HT1a antagonists completely abolished excitatory responses to serotonin application, while 5HT5a and 5HT7 only reduced the magnitude of excitatory responses to serotonin. 5HT2c receptors were the only serotonin receptor sub-type tested that elicited inhibitory responses to serotonin application in the VP. These findings, combined with our previous data outlining the mechanisms underpinning dopamine's effects in the VP, provide key information, which will allow future research to fully examine the interplay between serotonin and dopamine in the VP. Investigation of dopamine and serotonins interaction may provide vital insights into our understanding of the VP's involvement in reward processing. It may also contribute to our understanding of how drugs of abuse, such as cocaine, may hijack these mechanisms in the VP resulting in sensitization to drugs of abuse

XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016)

En la presente edición, más de 150 trabajos de alto nivel científico van a ser presentados en 18 sesiones paralelas y 3 sesiones de póster, que se centrarán en áreas relevantes de la Ingeniería Biomédica. Entre las sesiones paralelas se pueden destacar la sesión plenaria Premio José María Ferrero Corral y la sesión de Competición de alumnos de Grado en Ingeniería Biomédica, con la participación de 16 alumnos de los Grados en Ingeniería Biomédica a nivel nacional. El programa científico se complementa con dos ponencias invitadas de científicos reconocidos internacionalmente, dos mesas redondas con una importante participación de sociedades científicas médicas y de profesionales de la industria de tecnología médica, y dos actos sociales que permitirán a los participantes acercarse a la historia y cultura valenciana. Por primera vez, en colaboración con FENIN, seJane Campos, R. (2017). XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/79277EDITORIA

Pediatric Acute Promyelocytic Leukemia and Fanconi Anemia: Case report and literature review

peer reviewe