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The relation between depression symptoms and inflammatory markers associated with cardiovascular disease risk
No full textThe purpose of the present study was to examine the potential relation between depressive symptomatology and cardiovascular disease (CVD)-related inflammatory biomarkers in participants enrolled in the Healthy Aging in Neighborhoods of Diversity across the Lifespan Study (HANDLS). 2459 participants aged to 64 years old (M = 48 years, SD = 9.3) completed the completed the Center for Epidemiological Studies Depression scale (CES-D) and underwent blood draws to assess levels of white blood cells (WBCs). A subset of these participants (n = 210) were also assessed for levels of cytokines and C-reactive protein (CRP). The main analyses set consisted of multiple regressions with an aggregated CES-D score and the CES-D subscales of negative affect, positive affect, somatic complaints, and interpersonal relationship problems (entered separately) as predictors of CRP, total WBC count, neutrophil count, lymphocyte count, Il-1b, Il-6, Il-10, and TNF-α. Additional exploratory analyses were stratified by sex and contained CES-D score by race by poverty status interaction terms. Controlling for standard cardiovascular risk factors, results indicated no association between CES-D total score and the biomarkers; limited associations between CES-D subscales and the biomarkers, such that somatic complaints predicted WBCs and interpersonal relationship problems predicted Il-10; and complex associations between CES-D subscales, socio-demographic characteristics, and inflammatory biomarkers. It is concluded that the relation between depression and inflammation is complex and underlying pathophysiological mechanisms may distinctly differ across various population groups
Transformation of UV-filters by ozone: Reaction kinetics and removal of UV absorbance
No full textUltraviolet filters (UVFs) are used in a variety of personal care products, including sunscreens and cosmetics, to protect against ultraviolet (UV) radiation. Three of the most commonly employed UVFs are oxybenzone (OXY), octocrylene (OC), and octinoxate (OMC). While these compounds provide protection against harmful UV radiation, they also represent a unique human and ecological health risk. To address these concerns, ozone application to UVFs in water and wastewater matrices was carried out and transformation efficiency was calculated. Transformation efficiency varied with water/wastewater quality. For example, an applied ozone dose of 6 mol O3/mol OXY transformed approximately 62, 44, 23, and 13% of OXY in DI water, surface water, wastewater effluent, and raw wastewater, respectively. Second order rate constants were measured for UVF reaction with ozone; reactivity with ozone varied. Second-order rate constants for OXY kO3,app,OXY ranged from 3.65?102 to 1.68?106 M-1s-1; for OMC, kO3,OMC was 22(?2.14)?104 M-1s-1; and for OC, kO3,OC was 1.56 (?0.18) M-1s-1. The characteristic UV absorbance of solutions containing UVFs was measured as a function of wavelength, pH, and treatment level providing innovative insight into ozone attack mechanisms and identification of transformation products. Several transformation products were identified for ozonation of OXY, OMC, and OC and the corresponding structures represent similar environmental concerns as the parent UVFs
Parallel Regularized Maximum Likelihood Estimation For Proportional Odds Models
No full textOrdinal categorical random variables are random variables which take on values from a finite ordered set of possible values. They often result from qualitative assessments, such as rating a movie from one to five stars. Unlike continuous variables whose values are also ordered, ordinal categories are qualitative, so the distance between them may not be well-defined. This work focuses on computational aspects of predicting ordinal categorical random variables. We employ multinomial logistic models as the workhorse of our methodology. Beginning with the proportional odds version of the cumulative logit model, usually called the Proportional Odds Model (POM), we develop a regularized variant of that model. In particular, we study a special case of the generalized L1 regularized POM which we call the Fused Proportional Odds Model (FPOM) because it can result in coefficients whose values are equal, they can be fused together. FPOM incorporates a penalty term composed of a positive combination of terms: the absolute value of each coefficient, the absolute differences of coefficients, and the absolute differences of consecutive intercepts. This penalty makes sense when there is a notion of adjacency among coefficients, as occurs in signal processing, and when reduction of degrees of freedom is desired, e.g., in the context of high dimensional predictors. The geometry of this optimization, convex with edges and points, can aid finding a sparse solution, which is desirable in some contexts. As an illustration, we apply FPOM to a wine quality assessment dataset. We show, using various measures of prediction accuracy, that our model is competitive with other methods that have been applied to this data. Using a simulation, we show that FPOM can be used for variable selection. For many modern problems, especially those involving automated data collection, large quantities of data can be produced. Analyzing this data in a reasonable amount of time can be of practical importance. Accordingly, we study the use of parallel computation to speed up FPOM parameter estimation. Using computational nodes with two multi-core processors, we show that enabling parallel computation can result in an order of magnitude speedup on a single computational node
Schema Free Querying of Semantic Data
No full textDeveloping interfaces to enable casual, non-expert users to query complex structured data has been the subject of much research over the past forty years. We refer to them as schema-free query interfaces, since they allow users to freely query data without understanding its schema, knowing how to refer to objects, or mastering the appropriate formal query language. Schema-free query interfaces address fundamental problems in natural language processing, databases and AI to connect users' conceptual models and machine representations. However, schema-free query interface systems are faced with three hard problems. First, we still lack a practical interface. Natural Language Interfaces (NLIs) are easy for users but hard for machines. Current NLP techniques are still unreliable in extracting the relational structure from natural language questions. Keyword query interfaces, on the other hand, have limited expressiveness and inherit ambiguity from the natural language terms used as keywords. Second, people express or model the same meaning in many different ways, which can result in the vocabulary and structure mismatches between users' queries and the machines' representation. We still rely on ad hoc and labor-intensive approaches to deal with this ``semantic heterogeneity problem''. Third, the Web has seen increasing amounts of open domain semantic data with heterogeneous or unknown schemas, which challenges traditional NLI systems that require a well-defined schema. Some modern systems gave up the approach of translating the user query into a formal query at the schema level and chose to directly search into the entity network (ABox) for the matchings of the user query. This approach, however, is computationally expensive and has an ad hoc nature. In this thesis, we develop a novel approach to address the three hard problems. We introduce a new schema-free query interface, SFQ interface, in which users explicitly specify the relational structure of the query as a graphical skeleton and annotate it with freely chosen words, phrases and entity names. This circumvents the unreliable step of extracting complete relations from natural language queries. We describe a framework for interpreting these SFQ queries over open domain semantic data that automatically translates them to formal queries. First, we learn a schema statistically from the entity network and represent it as a graph, which we call the schema network. Our mapping algorithms run on the schema network rather than the entity network, enhancing scalability. We define the probability of observing a path on the schema network. Following it, we create two statistical association models that will be used to carry out disambiguation. Novel mapping algorithms are developed that exploit semantic similarity measures and association measures to address the structure and vocabulary mismatch problems. Our approach is fully computational and requires no special lexicons, mapping rules, domain-specific syntactic or semantic grammars, thesauri or hard-coded semantics. We evaluate our approach on two large datasets, DBLP+ and DBpedia. We developed DBLP+ by augmenting the DBLP dataset with additional data from CiteSeerX and ArnetMiner. We created 220 SFQ queries on the DBLP+ dataset. For DBpedia, we had three human subjects (who were unfamiliar with DBpedia) translate 33 natural language questions from the 2011 QALD workshop into SFQ queries. We carried out cross-validation on the 220 DBLP+ queries and cross-domain validation on the 99 DBpedia queries in which the parameters tuned for the DBLP+ queries are applied to the DBpedia queries. The evaluation results on the two datasets show that our system has very good efficacy and efficiency
Engineering tools to analyze beta-amyloid's effect on cellular mechanisms linked to the neurodegeneration observed in Alzheimer's disease
No full textAlzheimer's disease (AD) is a progressive neurodegenerative disorder that primarily affects the elderly population above 65 years of age. The disease is characterized by cognitive impairment, neuronal degeneration and eventual cell death. Current treatments for AD only slow down the progression of the disease and minimize its symptoms. Due to a lack of consensus of hypothesis among researchers, the cellular mechanism behind AD is not completely understood. Consequently, no effective treatment that stops or reverses the progression of the disease has been identified yet. In our work we applied analytical techniques and engineered tools to study the cellular mechanism of AD. We based our studies on the amyloid hypothesis, which states that beta-amyloid peptide, the primary component of senile plaques found in the brains of AD patients is the chief proponent of the disease. This hypothesis is supported in the past by research where Abeta in its aggregated form was found to be toxic to neuronal cells. We worked with the toxic forms of the peptide, Abeta 1-40 and 1-42 aggregated into fibrils, in all our studies. We first studied the interaction of Abeta with differentiated SY5Y neuroblastoma cells. We studied Abeta peptide's residue specific interactions in the vicinity of the integrin receptor on the cell membrane. We deduced from our results that Abeta's cellular interaction is influenced by both biological and electrostatic factors, and that certain residues of Abeta including its first seven residues affect the extent of interaction. These findings provide information for development of potential inhibitors of Abeta cellular binding. We next focused on signaling pathways related to the learning, memory and survival processes in SY5Y cells that are possibly perturbed by Abeta upon binding to the cell membrane. Using a combination of experimental studies and kinetic modeling, we investigated the effect of Abeta on the set of cellular signaling pathways and identified a plausible mechanism for its toxicity. This toxicity effect of Abeta was attenuated upon blocking specific pathways in the mechanism under the experimental conditions conducted. These findings provide insight for possible therapeutics that inhibit Abeta's toxic activity . While binding of Abeta to cells and the subsequent downstream signaling are important intial steps in tha AD pathway, these phenomenon cannot explain long term manifestations of the disease. Recent evidence points to the role of epigenetics in AD, and proposes DNA methylation to be a symptom of Abeta's effect on cells. As such, we began to explore the effect of Abeta on epigenetics of cells, specifically methylation changes in SY5Y cells and neural stem cells (NSCs). We first attempted to develop a novel technique for detection of methylation changes in a target DNA sequence. The method was partly successful in that target DNA was captured and its methylation levels detected, but the level of detection was lower than expected. The results from our technique development provide a basis for a cost-effective assay of methylation changes in cellular DNA samples. We continued our work on study of methylation changes upon Abeta exposure using established microarray technology.We examined global DNA and gene sequence specific methylation changes in SY5Y cells as well as NSCs upon exposure to Abeta. We accomplished this through a genome wide microarray analysis of methylation changes in cells, focusing especially on gene regions implicated in AD and involved in the regulation of the differentiation state of NSCs. The findings from these studies provide insights into Abeta's effect on the methylation levels of cells that can be linked to its effect on cellular differentiation and perturbation of events in the progression of AD. This work elucidates the impact of epigenetics on AD and could lead to the development of effective stem cell therapies for AD. In summary, we studied the Abeta peptide's interaction with the cellular membrane, the subsequent perturbation of intracellular signaling pathways and the effect on the epigenetic makeup of cells. These studies provide a picture of Abeta's effects on cellular processes related to their learning, memory, differentiation and survival that could have an impact on AD. The results pinpoint us and other researchers towards future treaments for this disease
Optical Measurement on Quantum Cascade Lasers Using Femtosecond Pulses
No full textQuantum cascade lasers (QCLs) as the state-of-the-art mid-infrared (mid-IR) coherent sources have been greatly developed in aspects such as output power, energy efficiency and spectral purity. However, there are additional applications of QCLs in high demand, namely mode-locking, mid-IR modulation, etc. The inherent optical properties and ultrafast carrier dynamics can lead to solutions to these challenges. In this dissertation, we further characterize QCLs using mid-IR femtosecond (fs) pulses generated from a laser system consisting of a Ti:sapphire oscillator, a Ti:sapphire regenerative amplifier, an optical parametric amplifier and a difference frequency generator. We study the Kerr nonlinearity of QCLs by coupling resonant and off-resonant mid-IR fs pulses into an active QCL waveguide. We observe an increase in the spectral width of the transmitted fs pulses as the coupled mid-IR pulse power increases. This is explained by the self-phase modulation effect due to the large Kerr nonlinearity of QCL waveguides. We further confirm this effect by observing the intensity dependent far-field profile of the transmitted mid-IR pulses, showing the pulses undergo self-focusing as they propagate through the active QCL due to the intensity dependent refractive index. The finite-difference time-domain simulations of QCL waveguides with Kerr nonlinearity incorporated show similar behavior to the experimental results. The giant Kerr nonlinearity investigated here may be used to realize ultrafast pulse generation in QCLs. In addition, we temporally resolved the ultrafast mid-infrared transmission modulation of QCLs using a near-infrared pump/mid-infrared probe technique at room temperature. Two different femtosecond wavelength pumps are used with photon energy above and below the quantum well (QW) bandgap. The shorter wavelength pump modulates the mid-infrared probe transmission through interband transition assisted mechanisms, resulting in a high transmission modulation depth and several nanoseconds recovery lifetime. In contrast, pumping with a photon energy below the QW bandgap induces a smaller transmission modulation depth but much faster (several picoseconds) recovery lifetime, attributed to intersubband transition assisted mechanisms. The latter ultrafast modulation (>60 GHz) can provide a potential way to realize fast QCL based free space optical communication
Intimate partner violence recidivism over an 8-year follow-up
No full textThe study examined the criminal behavior of men who sought treatment for intimate partner violence (IPV). Criminal offenses were coded for the 5 years prior to treatment initiation and the 8 years after treatment initiation into three categories: Domestic Abuse, General Violence, and Other Protection Order Involvement. Of 115 men, 85 (73.91%) had no incidents coded as Domestic Abuse during the 8-year follow-up period. Overall, there were significant reductions in Domestic Abuse and General Violence between the two time periods. It was observed that 12 men (10.4%) accounted for 60% of the incidents of Domestic Abuse recidivism. The main study hypothesis was that borderline and antisocial personality characteristics would be predictive of criminal recidivism after treatment initiation. Counter to hypotheses, these personality characteristics were not predictive of criminal recidivism in the majority of analyses. Consistent with the hypothesis, self-report ratings of antisocial personality characteristics, assessed at treatment program intake, were significantly related to General Violence during the 8-year follow-up. When incidents of General Violence and Domestic Abuse recidivism were combined, this variable was also significantly related to previous self-ratings of antisocial personality characteristics. Self-reports of borderline personality characteristics were not significantly related to any of the criminal recidivism variables. The findings suggest that the majority of men seeking treatment for IPV have no criminal recidivism after treatment initiation, but that a small subsample of men maintain or increase the frequency of criminal behavior after treatment initiation. Future studies will need to examine other individual-level characteristics that may distinguish these men so that treatment can better target the risk factors of IPV recidivism
THE IMPACT OF INSURANCE TYPES ON WORK EXPERIENCE AND MEDICAL UTILIZATION OF DIABETICS
No full textTitle of Document:The Impact of Insurance Types on Work Experience and Medical Utilization of Diabetics Arpit Misra, PhD, 2014 Directed By: Dr. Marsha Goldfarb, Professor, Economics Department Research objectives: The first objective of this dissertation is to assess the economic burden of diabetes from the perspective of employers as well as how these cost burdens are affected by the nature of the worker's insurance coverage. The second objective is to assess the quality of diabetes care using quality measures by type of health plan. The final objective investigates whether diabetics enrolled in consumer directed health plans are more likely to be hospitalized, or hospitalized at a more severe disease stage, compared with diabetics enrolled in more traditional health insurance plans. Sources of Data: Truven MarketScan Commercial Claims and Encounters databases for time period 2004 through Q12011, Truven MarketScan Health and Productivity Management database, Truven MarketScan Laboratory Results database, and the Medical Episode Grouper. Key Results: The employer's direct medical costs for beneficiaries with diabetes were higher than for beneficiaries without diabetes. Inpatient hospital costs account for the majority of the incremental costs. The employer's indirect costs for beneficiaries with diabetes were higher than for beneficiaries without diabetes. A lack of statistical significance suggests that the adjusted medical cost for diabetics enrolled in CDHPs is no different than the adjusted medical cost for diabetics enrolled in PPOs. Diabetic men are more likely to retire earlier and diabetic women are likely to retire later than non-diabetic men. Diabetics enrolled in CDHPs are more likely to get the recommended tests and maintain the recommended LDL levels than diabetics with other forms of insurance, but they are also more likely to maintain poor HbA1c levels. CDHP diabetics are less likely to be admitted to inpatient facilities when compared to PPO diabetics; and when admitted, CDHP diabetics are presented at a comparable disease stage as PPO diabetics
Seven Gables
No full textA.J._Colombo__VCU__Richmond__VA__Seven_Gables_February_06__2014_at_0431PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe
Color and Gaze
No full textAlec_Pugliese_BFA_Towson_University__MD_Color_and_Gaze__2_February_22__2014_at_0404PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe