16 research outputs found
483— Effectiveness of MMR Vaccination in Orthodox Jewish Neighborhoods
Measles is a highly contagious disease, where large outbreaks arise by direct contact between susceptible (unvaccinated) and infectious individuals. Many Orthodox Jewish neighborhoods were affected by measles from 2018-2019. To quantify the vaccination effort on this susceptible population, a retrospective analysis was used to study the NYC and Rockland County populations using a differential equations model. A subsequent model, known as a realistically-structured network model, studied only the NYC population, in relation to typical household size. Vaccination strategies were applied to three cohorts: unvaccinated family members, members with 1 prior MMR dose, and members with 2 prior MMR doses. The differential equations model suggested the need for earlier vaccination effort and no significant increase was found in the number of associated complications as prior vaccination dosage increased. The network model suggested significantly fewer sick individuals with 1 prior MMR dose (p \u3c 0.001) compared to none, and even more so with 2 prior doses. This study demonstrates the effectiveness of vaccinations, with the potential vulnerability for future complications not being as severe this epidemic, most probably due to rapid vaccination efforts and isolation of exposures
465— Modeling Vaccine Efficacy for Tuberculosis in a Prison Population
Tuberculosis is a highly contagious disease and is particularly problematic in confined communities such as prisons. I simulated how Tuberculosis moves through a prison population and tested how much vaccination effort is needed to control its spread. To explore this, I tested adding ever increasing numbers of randomly placed edges in a network and determined the size of the largest component. Afterwards, I removed edges in the model using two different methods, one illustrating if the edges were removed randomly and the other starting with prisoners that had the most connections, to simulate the effect of vaccination. My results show that as edges are taken off, one would have to put in less vaccination effort if distributing based on the degree of the vertex, at about 30-40% effort, rather than removing them randomly, which would need 40-60% effort. This research could help prison administrators reduce the likelihood of prisoners contracting diseases and can also aid scientists when they’re scrambling to develop a vaccine in a short time frame to see how much effort they need to reduce an epidemic
An assessment of indoor and outdoor air quality in a university environment : a case of University of Limpopo, South Africa
Air pollution of late has been the focus of many studies due to the detrimental health risks
that it poses to individuals. University environments have several academic departments
with peculiar activities that could be affecting the indoor and outdoor air quality (AQ) of
these environments. University settings differ from other environments because of the
variety of activities and different lines of work that go on inside buildings housing academic
departments and their surroundings, which are likely to have an impact on indoor air
quality (IAQ) and outdoor air quality (OAQ) in this environment. Only a few AQ studies
have been done in university sites and surrounds worldwide and in these studies, IAQ
was given primary importance; whereas, the outdoor environment was and is often
neglected. A study comparing both IAQ and OAQ is critical to further understand the
relationship between IAQ and OAQ within a university campus. The University of Limpopo
(UL) in the Mankweng township of South Africa has been undergoing some
refurbishments with numerous construction activities going on in addition to the academic
activities of UL. These activities may be affecting the AQ in this unique environment. The
main aim of this study was to determine differences between indoor and outdoor AQ in a
university environment and to understand how AQ in this unique environment varies with
seasons and building function. The study was carried out in three buildings housing three
different academic departments in UL namely: Department of Physiology and
Environmental Health (PEH), Department of Biochemistry, Microbiology, and
Biotechnology (BMBT) and the Department of Biodiversity (BIOD). Twenty indoor and 20
outdoor measuring sites were identified per departmental building from where real-time
measurements of 11 AQ parameters (linear air velocity (LAV), dry-bulb temperature (Tdb),
relative humidity (RH), carbon monoxide (CO), carbon dioxide (CO2), ozone (O3), sulphur
dioxide (SO2), nitrogen dioxide (NO2), hydrogen sulphide (H2S), non-methane
hydrocarbons (NMHCs) and volatile organic compounds (VOCs)) were taken over three
consecutive days per season. Thus, a total of 60 indoor and 60 outdoor measurements
were taken for each parameter in each of the three buildings of interest per season,
leading to 360 measurements per season and 1440 measurement per parameter over the
one-year period of study across the study area. A hot-wire anemometer was used to
measure LAV, whereas the Q-Trak indoor AQ monitor was used in the measurement of
Tdb, RH, CO and CO2. Aeroqual AQ monitors were employed in the measurement of O3,
SO2, NO2, H2S, NMHCs and VOCs. The Wilcoxon signed ranks test was used to determine differences between indoor and outdoor environments. Significant differences
were found between the indoor and outdoor environments for LAV (all three buildings),
Tdb (PEH and BMBT), RH (BIOD), O3 (all three buildings), NO2 (all three buildings), CO
(all three buildings), CO2 (all three buildings), NMHCs (BMBT and BIOD), and VOCs (all
three buildings) (p < 0.05). Linear air velocity, O3, SO2, CO, CO2, and H2S
values/concentrations across the indoor/outdoor environments were within the
ASHRAE/DEA/WHO guidelines/standards, whereas Tdb, RH and NO2
values/concentrations were not. Air quality in the study area varied with building, with the
best AQ across both the indoor and outdoor environments being within the BIOD building,
whilst the worst AQ across both environments was encountered in the PEH building.
Seasonal differences between buildings were also identified between indoor and outdoor
environments among the PEH, BMBT and BIOD buildings (p < 0.008). Across the indoor
environment, the winter season was found to be the season with the best AQ, since all
the pollutants were found at minimum concentrations. Factors affecting AQ in the study
area included thermal comfort, occupant densities, building function, laboratory
emissions, renovation activities, generators, vehicular emissions, among others. The best
AQ across the outdoor environment occurred during the autumn season, since all the air
pollutants were present at minimal concentrations during this time. The best predictors of
LAV, Tdb, CO, CO2, NO2, and NMHCs were seasons (R2 = 1.000, p < 0.01). For the
parameters RH, H2S, and VOCs, the best predictor was building type (R2 = 1.000, p <
0.01). The indoor and outdoor environment were the best predictors for SO2 (R2 = 0.999,
p < 0.01). Ozone had no single predictor that was found to significantly influence its
concentration in this study. In relation to an air pollution index (API), generally all pollutant
indices fell within the fair, good to very good range when using mean and maxima
concentrations, whereas, corresponding NO2 concentrations throughout the study fell
within the poor to very poor range (105.660–250.000). University management should
take into consideration ventilation in laboratories, occupant densities and location of
standby generators and car parks in the management of AQ on the university campus. All
heating, ventilation and air conditioning (HVAC) systems need to be upgraded and work
in tandem with natural ventilation when having high occupant densities within buildings.
Future studies in this sector could incorporate larger sample sizes, be designed as a
longitudinal study, and make use of questionnaires and sample more AQ parameters to
get a detailed understanding of a university site and its surrounds.Environmental SciencesPh. D. (Environmental Science
The prevalence of asthma among children in South Africa is increasing - is the need for medication increasing as well? A case study in the Vaal Triangle
Asthma, a chronic inflammatory condition of the airways, is a global public health concern. In southern Africa the prevalence of asthma has increased over the last few decades. In the current study, all 10-year-old learners from three of the schools (one each in Sasolburg, Vanderbijlpark and Vereeniging) that participated in the 1990 Vaal Triangle Air Pollution and Health Study, were selected as the study population for a cross-sectional study conducted in 2010. Both the 1990 and 2010 studies investigated several exposure factors but focussed on respiratory illnesses as main health outcomes. Although the overall ethnicity profile in 2010 was different from that of 1990, the socioeconomic status of the study populations were very similar – the reason being that the same schools were used and the participating children were from the same immediate environment. The results of the 2010 study were then compared to the results of all 10-year-olds, from the same three schools, who participated in the 1990 study. The results showed the difference in prevalence of asthma during the two study years was statistically significant. The difference in the percentage of children who had ever been diagnosed with asthma and were reportedly on medication in 1990 and 2010 was, however, not statistically significant, indicating that although the prevalence of asthma increased, the demand for medication to control the condition may not have increased as well
351— Social Attention Bias in the Real World - Pilot Study
Attention bias is defined as the elevated processing of certain stimuli over others. Past research has discovered that attention bias is related to anxiety through behavioral experiments. Studies found that in a lab setting those who are more anxious are more vigilant towards a threat. Previous research is however limited in the study of examining how these behavioral experiments relate to a real-world context since most of the experiments that have been done occurred in a lab setting. To address this phenomenon, two Empatica E4 Wristbands were utilized in order to measure a participant’s anxiety through skin conductance, electrodermal activity, and heart rate. The current study is pilot work done to test the equipment’s accuracy and reliability as well as create a protocol for data collection. To assess the equipment, SED lab members have been following safe covid practices in order to minimize the risk of contracting or spreading the virus. Based on data collected by the Empatica E4 wristbands, we hypothesize that when put in a real-world situation, a more anxious person will focus their attention on threatening stimuli rather than non-threatening stimuli
The prevalence of asthma among children in South Africa is increasing - is the need for medication increasing as well? A case study in the Vaal Triangle
Asthma, a chronic inflammatory condition of the airways, is a global public health concern. In southern Africa the
prevalence of asthma has increased over the last few decades. In the current study, all 10-year-old learners from
three of the schools (one each in Sasolburg, Vanderbijlpark and Vereeniging) that participated in the 1990 Vaal
Triangle Air Pollution and Health Study, were selected as the study population for a cross-sectional study conducted
in 2010. Both the 1990 and 2010 studies investigated several exposure factors but focussed on respiratory illnesses
as main health outcomes. Although the overall ethnicity profile in 2010 was different from that of 1990, the socioeconomic
status of the study populations were very similar – the reason being that the same schools were used and
the participating children were from the same immediate environment. The results of the 2010 study were then
compared to the results of all 10-year-olds, from the same three schools, who participated in the 1990 study. The
results showed the difference in prevalence of asthma during the two study years was statistically significant. The
difference in the percentage of children who had ever been diagnosed with asthma and were reportedly on
medication in 1990 and 2010 was, however, not statistically significant, indicating that although the prevalence of
asthma increased, the demand for medication to control the condition may not have increased as well.http://www.cleanairjournal.org.zaam201
A Survey of the respiratory health status of 10-year-old children in the Vaal Triangle priority area in 1990 and in 2010
Background: The Vaal Triangle is an area generally associated with a number of
harmful determinants of health since it houses diverse industrial processes and
industrial development in South Africa, hence being categorised as an outdoor air
pollution priority area in 2006.
Method: A cross-sectional inter-comparative study to the 1990 Vaal Triangle Air
Pollution and Health Study (VAPS) was conducted in 2010. The main objectives of
this study were to measure the prevalence of upper and lower respiratory illnesses of
10-year-old children in 2010 and compare those findings to the 1990 study, and
lastly to identify risk and protective factors for respiratory illnesses in 1990 and in
2010. In addition, the association between exposure factors (risk and protective
factors) that are sources of indoor air pollution and factors related to diet and
household living conditions and their associations with upper and lower respiratory
health illnesses in 1990 and 2010 was determined.
Results and Discussion: The prevalence of the respiratory health outcomes in the
1990 study and 2010 study cannot be compared directly since a 1-year prevalence
was determined in 1990 and a 6-month prevalence in 2010. Throughout the
dissertation this should be kept in mind. The change in prevalence of a respiratory
health outcome observed in 1990 and in 2010 is just an indication of the possible
change. The 1990 1-year prevalence and the 2-week 2010 prevalence of asthma
were the same in the two study populations (i.e. 12%). The 6-month prevalence of
sinusitis, bronchitis and pneumonia in 2010 was lower when compared to the yearly
prevalence of these illnesses in the 1990 study. On completion of the multivariate
analyses, in 1990 study, the use of a gas heater acted as a risk factor for pneumonia
(a lower respiratory illness), with a odds ratio of 3.67 (1.15-11.71) and a p-value of
0.03, whilst environmental tobacco smoke within the household was protective of
hay fever and sinusitis (upper respiratory illnesses). In the 2010 study, the
consumption of chicken and/or fish and fruit at least three times a week was
protective of bronchitis (with odds ratios of 0.23 and 0.26 respectively).
Conclusion and Recommendations: It is not certain whether the change in the
respiratory health status of 10-year-olds living in the Vaal Triangle is real as the
prevalence of health outcomes in the two studies cannot be compared directly to one
another due to the differences in prevalence time periods in the two studies.
Nevertheless, a statistically significant change was observed in the prevalence of
sinusitis, earache, bronchitis, and pneumonia between the two study populations. It
is imperative to have a study protocol; this ensures all levels of measure are consistent in both studies and leads to a dataset of high quality. There is also a need
for more analytical epidemiological studies (i.e. cohort, time-series, case-crossover
and panel studies) to be done in South Africa, addressing indoor and outdoor air
pollution and respiratory health.Dissertation (MSc)--University of Pretoria, 2013.gm2014School of Health Systems and Public Health (SHSPH)unrestricte
The essentiality of non-coding RNAs in cell reprogramming
In mammals, short (mi-) and long non-coding (lnc) RNAs are immensely abundant and they are proving to be more functional than ever before. Particularly in cell reprogramming, non-coding RNAs are essential to establish the pluripotent network and are indispensable to reprogram somatic cells to pluripotency. Through systematic screening and mechanistic studies, diverse functional features of both miRNA and lncRNAs have emerged as either scaffolds, inhibitors, or co-activators, necessary to orchestrate the intricacy of gene regulation. Furthermore, the collective characterizations of both miRNA and lncRNA reveal their interdependency (e.g. sequestering the function of the other) to modulate cell reprogramming. This review broadly explores the regulatory processes of cell reprogramming - with key functional examples in neuronal and cardiac differentiations - in the context of both short and long non-coding RNAs. Keywords: miRNA, lncRNA, Reprogramming, Pluripotency, Neuron
Intraocular Injection of ES Cell-Derived Neural Progenitors Improve Visual Function in Retinal Ganglion Cell-Depleted Mouse Models
Retinal ganglion cell (RGC) transplantation is a promising strategy to restore visual function resulting from irreversible RGC degeneration occurring in glaucoma or inherited optic neuropathies. We previously demonstrated FGF2 induced differentiation of mouse embryonic stem cells (ESC) to RGC lineage, capable of retinal ganglion cell layer (GCL) integration upon transplantation. Here, we evaluated possible improvement of visual function by transplantation of ES cell derived neural progenitors in RGC depleted glaucoma mice models. ESC derived neural progenitors (ES-NP) were transplanted into N-Methyl-D-Aspartate (NMDA) injected, RGC-ablated mouse models and a pre-clinical glaucoma mouse model (DBA/2J) having sustained higher intra ocular pressure (IOP). Visual acuity and functional integration was evaluated by behavioral experiments and immunohistochemistry, respectively. GFP-expressing ES-NPs transplanted in NMDA-injected RGC-depleted mice differentiated into RGC lineage and possibly integrating into GCL. An improvement in visual acuity was observed after 2 months of transplantation, when compared to the pre-transplantation values. Expression of c-Fos in the transplanted cells, upon light induction, further suggests functional integration into the host retinal circuitry. However, the transplanted cells did not send axonal projections into optic nerve. Transplantation experiments in DBA/2J mouse showed no significant improvement in visual functions, possibly due to both host and transplanted retinal cell death which could be due to an inherent high IOP. We showed that, ES NPs transplanted into the retina of RGC-ablated mouse models could survive, differentiate to RGC lineage, and possibly integrate into GCL to improve visual function. However, for the survival of transplanted cells in glaucoma, strategies to control the IOP are warranted