Analysing the socioeconomic determinants of hypertension in South Africa: A structural equation modelling approach

Includes bibliographical references.Epidemiological research has long since observed that the prevalence of hypertension varies across populations' socioeconomic strata. Higher socioeconomic status (SES) has been consistently associated with lower levels of blood pressure in most studies from Europe and North America, while research in low- and middle-income countries at an earlier stage of the epidemiological transition revealed mixed patterns. The causal mechanisms underlying these varying relationships are largely unknown. Only in recent years the pathways through which SES impacts the cardiovascular system have been explored in large-scale studies, with results suggesting that body mass index, heart rate, and to a lesser extent physical exercise, alcohol use and smoking, may play a role in mediating these associations. However, these results refer to high-income countries, while similar research in low- and middle-income countries, and sub-Saharan Africa in particular, is lacking. In 2008, the National Income Dynamics Study (NIDS) collected a broad range of information on a representative sample of the population of South Africa, a medium-income country undergoing rapid epidemiological transition. Among other topics, information was gathered on blood pressure, biologic and behavioural risk factors, education, income and other indicators of socioeconomic position

Variable Scale Statistics For Cardiac Segmentation and Shape Analysis

A novel framework for medical image analysis, known as Shells and Spheres, has been developed by our research lab. This framework utilizes spherical operators of variable radius, centered at each image pixel and sized to reach, but not cross, the nearest boundary. Statistical population tests are performed on the populations of pixels within adjacent spheres to compare image regions across boundaries, delineating bothindependent image objects and the boundaries between them. This research has focused on developing the Shells and Spheres frameworkand applying it to the problem of segmentation of anatomical objects. Furthermore, we have rigorously studied the framework and its applications to clinical segmentation, validating and improving our n-dimensional segmentation algorithm. To this end, we have enhanced the original Shells and Spheres segmentation algorithm by adding a priori information, developing techniques for optimizing algorithm parameters, implementing a software platform for experimentation, and performing validation experiments using real 3D ovine cardiac MRI data. The system developed provides automated 3D segmentation given a priori information in the form of a trivial 2D manual training procedure, which involves tracing a single 2D contour from which 3D algorithm parameters are then automatically derived. We apply this system tosegmentation of the Right Ventricular Outflow Tract (RVOT) to aid in research toward the creation of a Tissue Engineered Pulmonary Valve(TEPV). Experimental methods are presented for the development and validation of the system, as well as a detailed description of the Shells and Spheres framework, our segmentation algorithm, and the clinical significance of this work

Shells and Spheres: A Novel Framework for Variable Scale Statistical Image Analysis

A framework for analyzing images, called emph{Shells and Spheres},has been developed based on a set of spheres with adjustable radii,with exactly one sphere centered at each image pixel. This set ofspheres, known as a emph{sphere map}, is considered optimized wheneach sphere reaches, but does not cross, the nearest boundary.Calculations denoted as emph{Variable-Scale Statistics} (VSS) areperformed on populations of pixels within spheres, as well aspopulations of adjacent and overlapping spheres, in order to deducethe proper radius of each sphere. Spheres grow or shrink by addingor deleting an outer shell one pixel thick . Unlike conventionalfixed-scale kernels, our spherical operators consider as many pixelsas possible to differentiate between objects and accuratelydelineate boundaries. The term ``sphere" is used for brevity, thoughthe approach is not limited to 3D and is valid in $n$-dimensions.The approach is illustrated using both real images and noiselesssynthetic images containing objects with uniform intensity, and moreclosely examined and validated using various synthetic images withadded white noise and multiple contrast enhanced CT scans of theaortic arch. A particular algorithm using Shells and Spheres isdescribed and demonstrated on segmentation of the aortic arch in acontrast-enhanced CT scan, both in 2D and 3D

Doctor of Philosophy

dissertationThe problem of pollution is not going away. As global Gross Domestic Product (GDP) rises, so does pollution. Due to the existence of environmental externalities, polluting firms lack the incentive to abate their pollution, and without regulations, markets do not adequately control pollution. While regulators are responsible for enacting regulations, the firms ultimately determine the environmental outcomes through their production decisions. Furthermore, polluting industries are typically large and concentrated, raising the concern that market power may be present in these industries. In this dissertation, we study the interactions between powerful, strategic, firms operating under pollution regulations and the regulator when markets are imperfectly competitive. An important contribution of this work is our integrated pollution-production model, which incorporates the firms' emissions, abatement technologies, the damage from pollution, and three widely-used regulatory mechanisms-Cap, Cap-and-Trade, and Tax. The firms compete with each other and control prices by setting their production quantities. In our model, the firms have many options to comply with the pollution constraints enforced by the regulator, including abating pollution, reducing output, trading in emission allowances, paying emission taxes, investing in abatement innovations, colluding, and combining some of these options. Following the introduction in Chapter 1, we address three broad questions in three separate chapters. • Chapter 2: What is the e↵ect of the pollution control mechanisms on firms, consumers, and society as a whole? Which mechanisms and policies should regulators use to control pollution in a fair, e↵ective, and practical manner? • Chapter 3: Does Cap-and-Trade enable collusion? If it does, what are the e↵ects of collusion? • Chapter 4: Which mechanisms encourage more investments in abatement innovations? Our results apply to di↵erent types of pollutants and market structures. Our research provides guidelines for both policy-makers and regulated firms

Corpi Privati. Micro-strategie di addomesticamento dello spazio delle celle nel carcere di Buoncammino a Cagliari

The article aims to retrospectively reconstruct a taxonomy of micro-mechanisms of “domestication” and personalization of the cells’ space along the three levels of the left arm of the former Buoncammino prison, in Cagliari. A field research and a detailed photographic documentation of the state of these places, in many ways remained as crystallized at the time of their disposal, on November 23, 2014, made it possible to detect the persistent tracks of their use, which evoke the strategies of individualization of the prison experience by the inmates. In segregative conditions that are extremely binding and endowed with reduced degrees of freedom, the relationship between the distribution and the exposure of the bodies in these places still manages to preserve margins of heterogeneity, dictated by the decorative objects allowed and then abandoned there, by the signs in the walls, designed to mark the uniqueness of one’s obligatory presence through messages or graphic reproductions of unavailable furnishings, by the colors applied to contrast the dominance of gray and green in the common spaces. The severe control and biopolitical discipline of the bodies kept in the cells, deprived of most of their multisensory capabilities seem nevertheless having left margins of individualized adaptation of the ways of living in prison. This still appear intensely echoed by the objects found in Buoncammino, and account for the personal attributions of meaning given to them by inmates. Nevertheless, it’s painful and difficult to think about new hypothetical uses of these spaces, despite they have been emptied for almost 6 years so far.Il contributo si propone di ricostruire retrospettivamente una tassonomia di micro-meccanismi di “addomesticamento” e personalizzazione dello spazio delle celle disposte lungo i tre livelli del braccio sinistro dell'ex-carcere di Buoncammino, nel centro di Cagliari, messi in atto da parte dell'ultima coorte di detenuti ospiti della struttura, ormai chiusa. Una ricognizione sul campo e una puntuale documentazione fotografica dello stato di questi ambienti, per molti versi rimasti come cristallizzati nel momento della loro dismissione, il 23 Novembre 2014, ha consentito di rilevare le tracce persistenti della loro fruizione, che evocano in modo ancora intensamente leggibile le strategie di individualizzazione delle modalità di permanenza in essi esperite dai reclusi. In condizioni segregative massimamente vincolanti e dotate di ridotti gradi di libertà espressiva, la relazione tra disposizione ed esposizione dei corpi nella metrica di questi luoghi riesce comunque a preservare margini di eterogeneità, dettati dagli oggetti decorativi consentiti e lì abbandonati, dai tratti segnici incisi nelle pareti, atti a marcare l'unicità del proprio soggiorno obbligato tramite messaggi o riproduzioni grafiche di suppellettili indisponibili, dai colori applicati per contrastare la dominanza del grigio e del verde spento degli spazi comuni. Il rigido controllo eteronormato e il disciplinamento biopolitico dei corpi custoditi nelle celle, privati di gran parte delle proprie capabilities multisensoriali, in termini di opportunità prossemiche, di discrezionalità dello sguardo tra luce e buio, di gestione termica delle percezioni tattili di freddo e caldo, sembra avere lasciato cionondimeno margini di adattamento individualizzato delle modalità dell'abitare il carcere. Queste ultime appaiono tuttora intensamente riecheggiate dai residui materiali reperibili a Buoncammino, e danno conto delle attribuzioni personali di senso ad esse impresse dai detenuti, spesso dolorose e difficilmente rimarginabili attraverso nuove destinazioni d'uso ipotetiche, nonostante lo spazio minimo della contenzione – la cella, appunto – sia stato svuotato e “scorporato” da ormai quasi 6 anni.

Hypocalcemia following total thyroidectomy: early factors predicting long-term outcome

Hypocalcemia following total thyroidectomy (TT) must be considered permanent in patients requiring calcium replacement therapy after one year. The aim of this study was to identify early risk factors predicting long-term outcome of postoperative hypocalcemia. Among 453 patients who underwent TT from January 1998 to May 2003, a cross-sectional study between 44 patients with transient hypocalcemia (9,7%) and 3 patients with permanent hypocalcemia (0,7%) was carried out. Both low serum calcium level (< 8 mg/dl) and high serum phosphorus level (>4,5 mg/dl), measured on postoperative day 7, were predictive for outcome. Central neck lymph node dissection, performed for thyroid carcinoma, also correlated with outcome. Serum phosphorus level >4,5 mg/dl on postoperative day 7 resulted the only independent factor predicting permanent hypoparathyroidism. Therefore indication for central dissection would be very strict. When serum phosphorus level is unfavorable a correct replacement therapy is mandatory to prevent the consequences of permanent hypocalcemia

Understanding blood pressure dynamics in the South African population: a latent variables approach to the analysis and comparison of data from multiple surveys

Background: The 2015 edition of the Global Burden of Diseases Study identified elevated systolic blood pressure─ defined as systolic blood pressure greater than the minimum risk category of 110–115 mm Hg ─ as the largest single contributor to the global burden of disease, responsible for 211.8 million disability adjusted life years lost, up 8.8% in the last decade. Middle‐income countries are currently bearing the highest share of this burden, and, because of the rapid demographic transition towards larger and older populations, the burden is bound to increase rapidly in the coming years, unless age‐specific values of blood pressure are substantially reduced to compensate for the unfavourable demographic changes. Achieving this more favourable blood pressure distribution in populations undergoing rapid changes in their socioeconomic structure requires knowledge of the mechanisms underlying temporal variations of blood pressure and the relationships of such variations with socioeconomic variables.However, evidence on these mechanisms and reliable information on the temporal trends of blood pressure themselves are scant outside high‐income countries. Given the large gain in health that would result in low‐ and middle‐income countries if an optimal blood pressure were to be achieved in large sectors of the population, there is little doubt that temporal trends in the distribution of blood pressure in these populations and their possible determinants are an open and important area for investigation. Objectives: Objectives of the study were: 1. To assess the level of quality and comparability of blood pressure data collected in a series of large‐scale surveys carried out between 1998 and 2015 in South Africa, a middle‐income country undergoing rapid demographic and epidemiological transition; 2. To explore the possibility of applying a series of latent variables techniques to improve the comparability of data from the different sources and to minimise the effect of measurement and representation error on the estimation of cross‐sectional relationships and temporal trends; 3. To estimate changes in the distribution of blood pressure and derived quantities ‐‐‐ such as prevalence of uncontrolled hypertension ‐‐‐ in the South African adult population between 1998 and 2015, taking into account between‐surveys differences and measurement and representation error that could lead to artefactual conclusions; 4. To estimate the extent to which the estimated changes in the blood pressure distribution during the study period could be explained by concurrent changes in the distribution of a series of biological, behavioural and socioeconomic risk factors. Methods: A series of techniques within the general framework of structural equation modelling were applied to jointly analyse the data and estimate the temporal trends and relationships of interest. Results: The average systolic and diastolic blood pressure of South African adult women has progressively decreased since 2003‐2004, reversing the previous rising trend. Among men, the reversal happened only for the systolic blood pressure, while the average diastolic blood pressure continued rising, although at a lower pace than previously.In both genders, this pattern resulted in a reduction of the prevalence of uncontrolled hypertension between 2003‐2004 and 2014‐2015, by 8 percentage points among women and by 4.5 percentage points among men. This consistent and rapid decrease cannot be explained by changes in the age structure of the population, smoking and alcohol consumption habits, distribution of body mass index or urbanization. The diffusion of antihypertensive treatment and, among women, cohort effects and rapidly increasing educational level partly explain the recent trend, but a substantial part of the observed decrease remains unexplained by the factors available in our analyses. Large seasonal variations in both systolic and diastolic blood pressure are present in the South African population, and their magnitude is greater among population strata with low socioeconomic status. From a methodological point of view, there were two further results of this study. First, estimates of blood pressure and related quantities from the eight large‐scale population surveys carried out in South Africa between 1998 and 2015are not directly comparable, because of methodological differences and overall data quality. Second, structural equation modelling (and, within this general framework, multiple group modelling, normal‐censored regression, mixture analysis with skew‐normal distributions and the use of additional parameters and phantom variables) represent a viable and advantageous alternative to current methods of comparative analysis of blood pressure data. Conclusions: Encouraging signs regarding the future development of the burden of diseases related to elevated blood pressure in the South African population emerge from this study. Age‐specific prevalence of uncontrolled hypertension seems to be decreasing, especially among women, and this decrease is accompanied by declining mortality for cardiovascular disease, particularly for stroke, recorded in burden of mortality studies. The reasons of this decrease are largely unexplained and warrant further investigation. However, among the possible drivers analysed in this study, increased accessibility and efficacy of antihypertensive treatment are likely to be playing a role in the observed decrease in blood pressure. The growing obesity epidemic, on the contrary, is likely to be limiting the achievable benefits. Both of these factors can be targeted to maintain and improve the current decline in population values of blood pressure and prevalence of hypertension. The large seasonal variations of blood pressure and their unequal distribution across socioeconomic strata also suggest that interventions to reduce exposure to low temperatures might have public health benefit. From the point of view of the epidemiological investigation, the results of this study suggest that the current methods for the analysis of survey data on blood pressure and the measurement protocols for future data collections should be improved to increase between‐surveys comparabilityand gather more reliable information on temporal changes in BP and gain better understanding of their drivers. Specifically, analytical methods should take explicitly into account known sources of measurement and representation error to reduce their biasing effects, especially when inter‐survey comparisons are involved. Protocols for future studies should routinely include collection of auxiliary information and/or explicit validation of devices and procedures in the specific population

Uni-Versi: l’Altro, il Quasi e le Distopie

The trend to compose everything to unity, and to define only one sort of order, seems to describe this very Age. And yet, to reflect in a counter-factual way, thanks to the question raised by Erri de Luca, on what could be "the opposite of One", allows us to set up a visionary game and an exercise in sociological imagination, associating each answer with as many dystopian literary uni-verses, in order to unravel the ambiguities of our lives. The opposite of One, of any kind of Regime, is the Other, the Exception, as proposed by Stefano Benni in "Baol", when the rebellion against the violence of conformism passes through a laugh out of the chorus. But the opposite of wholeness is also the “Almost”, the “Anymore”, or the “Not Yet”, as expressed by Margareth Atwood in "The Handmaid’s Tale", when the imposition of obligatory masculine and feminine careers stigmatizes biographical insufficiencies and any possible freedom of choice. Finally, the opposite of One is “the Other”, anyone who has to be confined beyond the perimeter of citizenship and defined as an outlier, just a stateless traveler among mutually hostile worlds, as in the extraordinary specular Apocalypse created by Ursula Le Guin in “The Dispossessed”. Three grotesque dystopias, but not so extraneous to our real life, if you think about it.La tendenza alla composizione in unità, alla definizione di uno e un solo ordine compiuto, sembra percorrere questa nostra epoca. Eppure, riflettere in modo contro-fattuale, sulla scorta dell’interrogativo lanciato da Erri de Luca, su cosa possa essere “il contrario di Uno”, consente di allestire un gioco visionario e un esercizio di immaginazione sociologica, associando a ciascuna risposta altrettanti uni-versi letterari distopici, che permettono di svelare le ambiguità della cronaca quotidiana. Il contrario dell’Uno, del Regime, è l’Altro, diventa l’Eccezione, come raccontato da Stefano Benni in “Baol”, quando la ribellione alla violenza del conformismo passa attraverso una risata fuori dal coro. Ma il contrario dell’interezza è anche il Quasi, il Non Più, o il Non Ancora, come espresso da Margareth Atwood ne “Il racconto dell’ancella”, dove l’imposizione di destini maschili e femminili obbligatori serve a stigmatizzare insufficienze biografiche e libertà di scelta. Infine, il contrario di Uno è l’Altro, chiunque sia confinato ai margini del perimetro della cittadinanza e definito come fuori-luogo, o viaggiatore apolide tra mondi reciprocamente ostili, come nella straordinaria Apocalisse speculare ricostruita da Ursula Le Guin in “I reietti dell’altro pianeta”. Tre distopie grottesche, ma non poi così aliene alla realtà fattuale, a ben pensarci

Multimorbidity patterns in South Africa: A latent class analysis

Introduction: South Africa has the largest burden of HIV worldwide and has a growing burden of non-communicable diseases; the combination of which may lead to diseases clustering in ways that are not seen in other regions. This study sought to identify common disease classes and sociodemographic and lifestyle factors associated with each disease class. Methods: Data were analyzed fromthe South AfricanDemographic andHealth Survey 2016. A latent class analysis (LCA) was conducted using nine disease conditions. Sociodemographic and behavioral factors associated with each disease cluster were explored. All analysis was conducted in Stata 15 and the LCA Stata plugin was used to conduct the latent class and regression analysis. Results: Multimorbid participants were included (n = 2 368). Four disease classes were identified: (1) HIV, Hypertension and Anemia (comprising 39.4% of the multimorbid population), (2) Anemia and Hypertension (23.7%), (3) Cardiovascular-related (19.9%) and (4) Diabetes and Hypertension (17.0%). Age, sex, and lifestyle risk factors were associated with class membership. In terms of age, with older adults were less likely to belong to the first class (HIV, Hypertension and Anemia). Males were more likely to belong to Class 2 (Anemia and Hypertension) and Class 4 (Diabetes and Hypertension). In terms of alcohol consumption, those that consumed alcohol were less likely to belong to Class 4 (Diabetes and Hypertension). Current smokers were more likely to belong to Class 3 (Cardiovascular-related). People with a higher body mass index tended to belong to Class 3 (Cardiovascular-related) or the Class 4 (Diabetes and Hypertension). Conclusion: This study a rmed that integrated care is urgently needed, evidenced by the largest disease class being an overlap of chronic infectious diseases and non-communicable diseases. This study also highlighted the need for hypertension to be addressed. Tackling the risk factors associated with hypertension could avert an epidemic of multimorbidity

Mettere al mondo: Uno sguardo antropologico sulla genitorialità in Italia

Review article of Claudia Mattalucci, a cura di, Antropologia e riproduzione: Attese, fratture e ricomposizioni della procreazione e della genitorialità in Italia, Milano, Raffaello Cortina, 2017, pp. 304; Martina Giuffrè, a cura di, Essere madri oggi tra biologia e cultura: Etnografie della maternità nell’Italia contemporanea, Pisa, Pacini, 2018, pp. 224.Nota critica di Claudia Mattalucci, a cura di, Antropologia e riproduzione: Attese, fratture e ricomposizioni della procreazione e della genitorialità in Italia, Milano, Raffaello Cortina, 2017, pp. 304; Martina Giuffrè, a cura di, Essere madri oggi tra biologia e cultura: Etnografie della maternità nell’Italia contemporanea, Pisa, Pacini, 2018, pp. 224