Outcomes of babies born before arrival at a tertiary hospital in Johannesburg, South Africa

This research report is submitted in partial fulfillment of the requirements for the degree of Master of Medicine in the Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Witwatersrand, Johannesburg November 2014Background. Babies born before arrival to hospital (BBBAs) constitute a high-risk newborn population. The literature demonstrates that BBBAs have increased perinatal mortality and morbidity. Objectives. To describe the maternal and neonatal characteristics of BBBAs presenting to Charlotte Maxeke Johannesburg Academic Hospital (CMJAH), South Africa, and assess whether they have increased morbidity and mortality compared with inborn babies. Methods. This was a matched case-controlled retrospective record review of newborns presenting to the neonatal unit of CMJAH between 1 January 2011 and 31 January 2013. BBBAs were matched 1:1 with the next consecutive inborn on birth-weight category and gender. Results. A total of 356 neonates were analysed. BBBAs had higher mortality than inborn controls within the first 24 hours of hospital presentation (7.9% v. 3.9%; p=0.05). Mothers of BBBAs were more likely to be unbooked (58.4% v. 10.7%; p<0.001) and of higher parity (p=0.0008). HIV prevalence was similar amongst cases and controls (24% v. 28.7%), however there were significantly more unknown HIV status in mothers of BBBA’s (49.6% v. 32%; p=0.01). Cases had a higher prevalence of early sepsis (22.9% v. 3.6%; p=0.03) and birth asphyxia (14.5% v. 0.8%; p<0.001) than controls. Overall, more deaths occurred in the very-lowbirth- weight (VLBW) (24% v. 10%; p=0.06) and low-birth-weight (LBW) (7.46% v. 0%; p=0.02) BBBA’s compared to controls. Conclusion. We demonstrated higher mortality in the immediate postnatal period and in the VLBW and LBW categories compared with hospital-delivered neonates. Once admitted, there was no difference in mortality, length of stay or number of ICU admissions between cases and controls. Mothers who delivered out of hospital were more likely to be multiparous and unbooked and to have unknown HIV, RPR and Rh results. Neonatal resuscitation, transport and immediate care on arrival at the hospital should be prioritised in the management of BBBAs

Evaluating Maximum Likelihood Estimation Methods to Determine the Hurst Coefficient

A maximum likelihood estimation method implemented in S-PLUS (S-MLE) to estimate the Hurst coefficient (H) is evaluated. The Hurst coefficient, with 0.5\u3cHS-MLE was developed to estimate H for fractionally differenced (fd) processes. However, in practice it is difficult to distinguish between fd processes and fractional Gaussian noise (fGn) processes. Thus, the method is evaluated for estimating H for both fd and fGn processes. S-MLE gave biased results of H for fGn processes of any length and for fd processes of lengths less than 210. A modified method is proposed to correct for this bias. It gives reliable estimates of H for both fd and fGn processes of length greater than or equal to 211

The Social Construction of the DSM-5 & its Impact on Patient Dignity

The Diagnostic and Statistical Manual for Mental Disorder (5th Ed. or DSM-5) represents a foundational text within the psychiatric and mental health field, a document that is historically and socially positioned within the field as the global standard for diagnostic health information. Significant criticism, though, has been levelled against the DSM-5, highlighting concerns around its underlying ethnocentric positioning as well as scientific concerns around the reliability and validity of different diagnoses. This study explores the current state of the DSM-5. It seeks to understand how its development has shaped and promoted a variety of discourses within the mental health field, as well as looking at the impact these discourses have had on the dignity and day-to-day functioning of millions of patients, both younger and elder, for whom it has been conceived to offer therapeutic interventions. Drawing on Social Constructionist and Foucauldian frameworks to conduct this discursive analysis of the DSM-5, I identify the dominant discourses of the DSM-5, as well as the discursive rules which have been reinforced by the American Psychiatric Association to promote these practices. The dominant discourses identified include expertise, medicalizing normality, conceptualizations of culture, and control

Minimizing the effect of sinusoidal trends in detrended fluctuation analysis

The detrended fluctuation analysis (DFA) [Peng et al., 1994] and its extensions (MF-DFA) [Kantelhardt et al., 2002] have been used extensively to determine possible long-range correlations in self-affine signals. While the DFA has been claimed to be a superior technique, recent reports have indicated its susceptibility to trends in the data. In this report, a smoothing filter is proposed to minimize the effect of sinusoidal trends and distortion in the log-log plots obtained by DFA and MF-DFA techniques

Analog Computer Analysis of Dispersion of Indicator in the Circulation

journal articleBiomedical Informatic

Ion-channel-like behavior in lipid bilayer membranes at the melting transition

It is well known that at the gel-liquid phase transition temperature a lipid bilayer membrane exhibits an increased ion permeability. We analyze the quantized currents in which the increased permeability presents itself. The open time histogram shows a "-3/2" power law which implies an open-closed transition rate that decreases like $k(t) \propto t^{-1}$ as time evolves. We propose a "pore freezing" model to explain the observations. We discuss how this model also leads to the $1/f^{\alpha}$ noise that is commonly observed in currents across biological and artificial membranes.Comment: 5 pages, 4 figure

Multi-Scale Modeling of Hypertension

The focus of this work is the coupling of a 1-D lumped parameter model representing the circulatory system to a 3-D finite element based left ventricle (LV) model in order to study the effects of mild hypertension on the cardiovascular system. A Finite Element LV model under normotensive loading (116/80 mmHg) was developed as well as a mild hypertension (165/90 mmHg) model. In both cases, coupled analysis was utilized so that at one diastolic time point and four systolic time points the values for the LV volumes and pressures were determined from the steady-state JSim solution. The normotensive model had an average first principal stress of 39.1KPa while the hypertensive case showed an increased value of 51.8KPa representing a 32.3 % increase. A relatively mild increase in the afterload resulted in a pronounced increase in workload to maintain the same systemic flow. 1

Biomechanics-based in silico medicine: The manifesto of a new science

In this perspective article we discuss the role of contemporary biomechanics in the light of recent applications such as the development of the so-called Virtual Physiological Human technologies for physiology-based in silico medicine. In order to build Virtual Physiological Human (VPH) models, computer models that capture and integrate the complex systemic dynamics of living organisms across radically different space–time scales, we need to re-formulate a vast body of existing biology and physiology knowledge so that it is formulated as a quantitative hypothesis, which can be expressed in mathematical terms. Once the predictive accuracy of these models is confirmed against controlled experiments and against clinical observations, we will have VPH model that can reliably predict certain quantitative changes in health status of a given patient, but also, more important, we will have a theory, in the true meaning this word has in the scientific method. In this scenario, biomechanics plays a very important role, biomechanics is one of the few areas of life sciences where we attempt to build full mechanistic explanations based on quantitative observations, in other words, we investigate living organisms like physical systems. This is in our opinion a Copernican revolution, around which the scope of biomechanics should be re-defined. Thus, we propose a new definition for our research domain “Biomechanics is the study of living organisms as mechanistic systems”