The Dynamics of Multi-Modal Networks

The widespread study of networks in diverse domains, including social, technological, and scientific settings, has increased the interest in statistical and machine learning techniques for network analysis. Many of these networks are complex, involving more than one kind of entity, and multiple relationship types, both changing over time. While there have been many network analysis methods proposed for problems such as network evolution, community detection, information diffusion and opinion leader identification, the majority of these methods assume a single entity type, a single edge type and often no temporal dynamics. One of the main shortcomings of these traditional techniques is their inadequacy for capturing higher-order dependencies often present in real, complex networks. To address these shortcomings, I focus on analysis and inference in dynamic, multi-modal, multi-relational networks, containing multiple entity types (such as people, social groups, organizations, locations, etc.), and different relationship types (such as friendship, membership, affiliation, etc.). An example from social network theory is a network describing users, organizations and interest groups, where users have different types of ties among each other, such as friendship, family ties, etc., as well as affiliation and membership links with organizations and interest groups. By considering the complex structure of these networks rather than limiting the analysis to a single entity or relationship type, I show how we can build richer predictive models that provide better understanding of the network dynamics, and thus result in better quality predictions. In the first part of my dissertation, I address the problems of network evolution and clustering. For network evolution, I describe methods for modeling the interactions between different modalities, and propose a co-evolution model for social and affiliation networks. I then move to the problem of network clustering, where I propose a novel algorithm for clustering multi-modal, multi-relational data. The second part of my dissertation focuses on the temporal dynamics of interactions in complex networks, from both user-level and network-level perspectives. For the user-centric approach, I analyze the dynamics of user relationships with other entity types, proposing a measure of the "loyalty" a user shows for a given group or topic, based on her temporal interaction pattern. I then move to macroscopic-level approaches for analyzing the dynamic processes that occur on a network scale. I propose a new differential adaptive diffusion model for incorporating diversity and trust in the process of information diffusion on multi-modal, multi-relational networks. I also discuss the implications of the proposed diffusion model on designing new strategies for viral marketing and influential detection. I validate all the proposed methods on several real-world networks from multiple domains

Maternal Healthcare Access and Obstetric Complications: A Cause and Effect Relationship?

Poverty-stricken migrant women, named ‘Kayayei or Kayayo’ because of the nature of their job in the informal sector, have high birth rates and are said to have many barriers affecting their access to maternal health resources. In this study, Kayayei in Madina Market were interviewed and both quantitative and qualitative data were gathered to determine whether a relationship exists between access to maternal health and the obstetric complications and outcomes experienced by Kayayei. A Chi-Squared Test of Independence and a Qualitative Content Analysis were both used to analyze the data. Due to a non-significant p-value, it was found that the Kayayei in Madina Market have access to both prenatal and antenatal care, however, the quality of this care varies. It was also found that a high percentage of Kayayei experienced pregnancy-induced Depression, Anxiety, Anemia, and High Blood Pressure. The results show that other factors must be examined to determine their relationship with obstetric complications among Kayayei

Aggressive Fluid Resuscitation in Severe Pediatric Hyperglycemic Hyperosmolar Syndrome: A Case Report

Objective. This report describes a severe case of hyperglycemic hyperosmolar syndrome complicated by rhabdomyolysis, acute kidney injury, hyperthermia, and hypovolemic shock, with management centred upon fluid administration. Design. Case report. Setting. Pediatric intensive care unit in university teaching hospital. Patients. 12 years old adolescent female presenting with hyperglycemic hyperosmolar syndrome with a new diagnosis of type 2 diabetes mellitus. Intervention. Aggressive fluid resuscitation and insulin. Main results. The patient had a good outcome, discharged home on hospital day 6. Conclusions. Hyperglycemic hyperosmolar syndrome is associated with a number of complications. Management strategies are undefined, given the rarity of its presentation, and further studies are warranted

Transperineal ultrasound evaluation of females with stress urinary incontinence

Background: Urinary incontinence has a significant influence on the well-being of affected females. No standard imaging modality is mandatory in initial evaluation of patients with urinary incontinence. Transperineal ultrasound has been proposed as a reliable method to assess female stress urinary incontinence. This study was conducted to evaluate the transperineal ultrasound findings in females with stress urinary incontinence.Methods: A case-control study including 40 females diagnosed to have stress urinary incontinence and 40 healthy females as their controls. The proximal pubo-urethral distance, the posterior urethro-vesical angle (β-angle) and the angle of urethral inclination (α-angle) were measured at rest and during straining.Results: On analyzing the transperineal ultrasound findings, no statistical significant difference was found between cases and controls at rest, but on straining, statistical significant difference was found regarding dynamic posterior urethral angle and dynamic pubo-urethral distance (p <0.001). Of the included 40 cases with SUI, 27 (67.5%) had cysto-urethrocele, and 5 (12.5%) had intrinsic sphincter defect (ISD). Urethral diameter was significantly different in patients with ISD (6.64±1.23 mm) when compared with patients with SUI without ISD (4.83±1.16 mm).Conclusions: Transperineal ultrasound is a simple, noninvasive, and easily conducted examination that can be used in the diagnostic workup of stress incontinence

Differential effects of gastric bypass and banding on the cardiovascular risk profile in morbidly obese subjects: The correlation with plasma apolipoprotein A-IV concentration

Background: Weight loss (5–10%) improves obesity-associated cardiovascular risk factors. The aim of this work was to study the effect of 2 commonly performed bariatric surgical procedures; laparoscopic Roux-en-Y gastric bypass (RYGBP) and laparoscopic gastric band (BAND), on the cardiovascular risk profile in morbidly obese patients and its correlation with the plasma apolipoprotein (apo) A-IV level.Patient and method: This study was carried prospectively on 34 patients scheduled for bariatric surgery. They were randomly assigned into two groups; group 1=BAND (18 cases), group 2= gastric bypass RYGBP (16 cases). Both groups were studied preoperatively and twelve months after surgery. Data collected included changes of body mass index (BMI), blood pressure, fasting blood sugar, fasting serum insulin, insulin resistance (HOMA-IR) and lipid profile. In addition, apo A-IV was determined by the Western blot technique.Results: The results demonstrated a highly significant reduction in body weight as determined by reduction in the BMI in both groups I &amp; II compared to preoperative measurements. Moreover, both groups had a significantly lower systolic blood pressure, fasting blood glucose (FBG), fasting serum insulin and HOMA-IR twelve months after operation. The changes in BMI, systolic blood pressure; FBG and HOMA-IR were significantly more in group II than in group I. The lipid profiles in group I &amp; II before surgery were similar. The HDL-cholesterol was significantly higher  in both groups I &amp; II 12 months after surgery. In addition, apo A-IV levels increased after surgery in both groups.Conclusion: Both gastric band and gastric bypass are associated with significant improvement of the cardiovascular risk profile, although it is more pronounced after gastric bypass. The improvement correlates well with the increase of apo A-IV in both groups. Thus Apo A-IV may play a positive role in improving the cardiovascular risk profile after bariatric surgery.Keywords: Obesity; Bariatric surgery; Apo A-IV; Weight loss; Cardiovascular risk factors; HOMA-I

Paroxysmal Autonomic Instability with Dystonia after Pneumococcal Meningoencephalitis

Streptococcus pneumoniae is a common cause of bacterial meningitis, frequently resulting in severe neurological impairment. A seven-month-old child presenting with Streptococcus pneumoniae meningoencephalitis developed right basal ganglia and hypothalamic infarctions. Daily episodes of agitation, hypertension, tachycardia, diaphoresis, hyperthermia, and decerebrate posturing were observed. The diagnosis of paroxysmal autonomic instability with dystonia was established. The patient responded to clonidine, baclofen, and benzodiazepines. Although this entity has been reported in association with traumatic brain injury, and as a sequel to some nervous system infections, this is the first case, to our knowledge, associated with pneumococcal meningoencephalitis

The Role of Genetic, Dietary and Lifestyle Factors in Pediatric Metabolic Syndrome: A Review of the Literature from Prenatal to Adolescence

The metabolic syndrome (MetS) is described as a cluster of health conditions that are associated with an increased risk of cardiovascular disease. The clinical diagnosis of MetS in pediatrics is challenging due to differing criteria, although the estimated prevalence continues to rise. The increased prevalence of childhood obesity and insulin resistance, in both developed and developing countries, is believed to be a major contributor to MetS diagnosis in children. We review the current literature surrounding genetic predisposition, maternal influence, epigenetics, environmental and lifestyle factors pertaining to pediatric MetS with a specific emphasis on obesity and insulin resistance. We highlight and discuss recent, key studies in prenatal through to adolescent populations and review evidence suggesting that children may be pre-disposed to obesity and insulin resistance, prenatally. We also discuss several key lifestyle drivers of these conditions including poor nutrition and dietary habits, insufficient physical activity, use of electronic devices, over-consumption of caffeinated and/or sugar-sweetened beverages, as well as the importance of sleep during childhood and adolescence in relation to metabolic health. We conclude with recommendations for preventable methods to tackle this growing pediatric public health issue, which, if current trends continue, will undoubtedly compromise the health and longevity of the next adult generation.

Toward a unified global regulatory capital framework for life insurers

In many regions of the world, the solvency regulation of insurers is becoming more principle-based and market oriented. However, the exact forms of the solvency standards that are emerging in individual jurisdictions are not entirely consistent. A common risk and capital framework can level the global playing field and possibly reduce the cost of capital for insurers. In the thesis, a conceptual framework for measuring the insolvency risk of life insurance companies will be proposed. The two main advantages of the proposed solvency framework are that it addresses the issue of incentives in the calibration of the capital requirements and it also provides an associated decomposition of the insurer's insolvency risk by term. The proposed term structure of insolvency risk is an efficient risk summary that should be readily accessible to both regulators and policyholders. Given the inherent complexity of the long-term guarantees and options of typical life insurance policies, the term structure of insolvency risk is able to provide stakeholders with more complete information than that provided by a single number that relates to a specific period. The capital standards for life insurers that are currently existing or have been proposed in Canada, U.S., and in the EU are then reviewed within the risk and capital measurement framework of the proposed standard to identify potential shortcomings