List of Titles

Can δ15N and δ13C stable isotopes and fatty acid signatures indicate changes in phytobenthos composition on an artificial substrate?

- Dalu, Tatenda, Froneman, P William

Authors: Dalu, Tatenda , Froneman, P William
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/68086 , vital:29197 , https://doi.org/10.2989/16085914.2014.974018
Description: Publisher version , Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown were investigated in 2012. High concentrations of diatom markers 16:1ω7 and 20:5ω3 fatty acids were recorded, especially at the downstream site, reflecting the importance of diatoms in contributing to the phytobenthos communities at that station. After day 7 at the downstream site the average δ15N value of the phytobenthos was lighter, gradually increasing by ∼2‰ and ∼5‰ overall to heavier values on day 28. At the upstream site there were no significant changes (<1‰ increase) in δ15N values of the phytobenthos over time. Stable nitrogen (δ15N) and carbon (δ13C) signatures in the phytobenthos communities were significantly different between sites (one-way ANOVA; p < 0.001). The stable isotope values and fatty acid concentrations of phytobenthos at the downstream site were different to those of the phytobenthos at the upstream site, and they changed concurrently with changes in the phytobenthos community structure. At the downstream site there was a strong correlation of the δ15N of phytobenthos with nitrates (R = 0.56) and time (weeks; R = 0.81). However, the fatty acids were not specific enough to characterise the composition of phytobenthos communities. Other biomarker methods, such as stable isotopes and microscopic examination of the communities, were found to be useful. The results from this relatively small-scale tile experiment indicate the complexity of changes in fatty acid composition and δ15N, δ13C stable isotope values of a phytobenthos community. Stable isotope and fatty acid composition can be successfully used to map changes in phytobenthos composition and carbon and nitrogen flow patterns along a river continuum.
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Date Issued: 2014

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Central obesity and normal-weight central obesity among adults attending healthcare facilities in Buffalo City Metropolitan Municipality, South Africa: a cross-sectional study

- Owolabi, Eyitayo Omolara, Ter Goon, Daniel, Adeniyi, Oladele Vincent

Authors: Owolabi, Eyitayo Omolara , Ter Goon, Daniel , Adeniyi, Oladele Vincent
Date: 2017
Subjects: Buffalo City Metropolitan Municipality, South Africa Obesity Central obesity, Overall obesity, Waist circumference, Waist-to-hip ratio, Waist-to-height ratio, NICE BMI-WC composite index, Health risk, Abdominal obesity Computer File
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/5887 , vital:44664 , https://DOI10.1186/s41043-017-0133-x
Description: Background Central obesity (CO) confers a significant threat on the cardio-metabolic health of individuals, independently of overall obesity. Disparities in the measures of fat distribution lead to misclassification of individuals who are at risk of cardio-metabolic diseases. This study sought to determine the prevalence and correlates of central obesity and normal-weight central obesity among adults attending selected healthcare facilities in Buffalo City Metropolitan Municipality (BCMM), South Africa, assess their health risk and examine the association between central obesity and cardio-metabolic diseases among adults with normal weight, measured by body mass index (BMI). Methods A cross-sectional survey of 998 adults was carried out at the three largest outpatient clinics in BCMM. Overall and central obesity were assessed using BMI, waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHTR). The WHO STEPwise questionnaire was used for data collection. Blood pressure and blood glucose were measured. Normal-weight central obesity was defined as CO among individuals with normal weight, as assessed by BMI. Health risk levels were assessed using the National Institute for Health and Clinical Excellence (NICE) BMI-WC composite index. Bivariate and multivariate analyses were used to determine the prevalence of CO, normal-weight central obesity and the predictors of CO. Results The mean age of participants was 42.6 (± 16.5) years. The prevalence of CO was 67.0, 58.0 and 71.0% by WC, WHR and WHTR, respectively. The prevalence of normal-weight central obesity was 26.9, 36.9 and 29.5% by WC, WHR and WHTR, respectively. About 41% of the participants had a very high health risk, 13% had increased risk or high risk and 33% had no health risk. Central obesity was significantly associated with hypertension but not associated with diabetes among those with normal weight (by BMI). Female sex, age over 30 years, marriage, secondary or tertiary level of education, non-smoking status, diabetes and hypertension significantly predicted central obesity among the study participants. Conclusion The prevalence of central obesity among the study participants is high, irrespective of the defining criteria. One in three adults of normal weight had central obesity. Body mass index should therefore not be used alone for clinical assessment by healthcare workers in the study setting.
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Date Issued: 2017

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Colonisation and community structure of benthic diatoms on artificial substrates following a major flood event: a case of the Kowie River (Eastern Cape, South Africa)

- Dalu, Tatenda, Froneman, P William, Chari, Lenin D, Richoux, Nicole B

Authors: Dalu, Tatenda , Froneman, P William , Chari, Lenin D , Richoux, Nicole B
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/143357 , vital:38239 , http://dx.doi.org/10.4314/wsa.v40i3.10
Description: A major flooding event that occurred during October–November 2012 caused major changes in the Kowie River hydromorphology and aquatic communities. The aim of our study was to identify the environmental variables that structure riverine benthic diatom communities at upstream and downstream locations 25 km apart on the Kowie River, South Africa. This was undertaken using tiles as artificial substrates so that we could study how the communities developed after the flood disturbance. The diatom community structure was assessed over a 28-day period following a flood event in October 2012. The Mann Whitney test indicated that there was a statistically significant difference (p 0.05) in total dissolved solids, salinity, pH and oxygen reduction potential between the two sites. In total, 58 diatom species belonging to 30 genera were identified over the 28-day study.
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Date Issued: 2014

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Coming to terms with the "Border War" in post-apartheid South Africa

- Baines, Gary F

Authors: Baines, Gary F
Date: 2008
Language: English
Type: Conference paper
Identifier: vital:6157 , http://hdl.handle.net/10962/d1007077
Description: If you are a white, male South African between the ages of about 35 and 60 it is very likely that you donned the nutria brown uniform of the South African Defence Force (SADF). Between 1967 and 1994 approximately 300 000 young white males were conscripted by the SADF. As far as most of these conscripts were concerned, there was no option other than heeding the call-up and performing national service or diensplig. Failure to do so meant harsh penalties. The alternatives were to object on conscientious (actually religious) grounds and face a six year jail sentence, or flee the country. And the obligation did not end with national service as conscripts were assigned to citizen force or commando units that were liable for periodical call-ups for camps that might have included deployment in the “operational areas” from 1974 or tours of duty in the black townships from 1984. Those - like myself - belonging to this national service generation were part-time soldiers for much of their adult lives. Most served willingly, some with patriotic fervour. Others did so reluctantly and with little enthusiasm.
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Date Issued: 2008

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Commentary: Negotiating distant influences: globalization and broadcasting policy reforms in Zambia and South Africa

- Banda, Fackson

Authors: Banda, Fackson
Date: 2006
Language: English
Type: text , article
Identifier: vital:6325 , http://hdl.handle.net/10962/d1008299 , https://doi.org/10.22230/cjc.2006v31n2a1785
Description: preprint , This commentary looks at the influences of globalisation on broadcasting policy reforms in Zambia and South Africa, with specific focus on such processes as deregulation, privatisation, commercialisation, communitarianism and technological convergence. It concludes that globalisation does not affect southern African countries uniformly; rather, it is refracted in accordance with the different cultural and political experiences of such countries.
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Date Issued: 2006

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Comparative ultrastructure of plasmodesmata of Chara and selected bryophytes: towards an elucidation of the evolutionary origin of plant plasmodesmata

- Cook, Martha E, Graham, Linda E, Botha, Christiaan E J, Lavin, Colleen A

Authors: Cook, Martha E , Graham, Linda E , Botha, Christiaan E J , Lavin, Colleen A
Date: 1997
Language: English
Type: Article
Identifier: vital:6506 , http://hdl.handle.net/10962/d1005933 , http://www.amjbot.org/cgi/reprint/84/9/1169
Description: We have used transmission electron microscopy to examine plasmodesmata of the charophycean green alga Chara zeylanica, and of the putatively early divergent bryophytes Monoclea gottschei (liverwort), Notothylas orbicularis (hornwort), and Sphagnum fimbriatum (moss), in an attempt to learn when seed plant plasmodesmata may have originated. The three bryophytes examined have desmotubules. In addition, Monoclea was found to have branched plasmodesmata, and plasmodesmata of Sphagnum displayed densely staining regions around the neck region, as well as ring-like wall specializations. In Chara, longitudinal sections revealed endoplasmic reticulum (ER) that sometimes appeared to be associated with plasmodesmata, but this was rare, despite abundant ER at the cell periphery. Across all three fixation methods, cross-sectional views showed an internal central structure, which in some cases appeared to be connected to the plasma membrane via spoke-like structures. Plasmodesmata were present even in the incompletely formed reticulum of forming cell plates, from which we conclude that primary plasmodesmata are formed at cytokinesis in Chara zeylanica. Based on these results it appears that plasmodesmata of Chara may be less specialized than those of seed plants, and that complex plasmodesmata probably evolved in the ancestor of land plants before extant lineages of bryophytes diverged.
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Date Issued: 1997

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Comparisons of the thermal physiology of water hyacinth biological control agents: predicting establishment and distribution pre-and post-release

- May, Bronwen, Coetzee, Julie A

Authors: May, Bronwen , Coetzee, Julie A
Date: 2013
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/123476 , vital:35446 , https://doi.10.1111/eea.120628
Description: Investigations into the thermal physiology of weed biological control agents may elucidate reasons for establishment failure following release. Such studies have shown that the success of water hyacinth biological control in South Africa remains variable in the high-lying interior Highveld region, because the control agents are restricted to establishment and development due to extreme winter conditions. To determine the importance of thermal physiology studies, both pre- and post-release, this study compared the known thermal requirements of Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae) released in 1996, with those of an agent released in 1990, Niphograpta albiguttalis (Warren) (Lepidoptera: Pyralidae) and a candidate agent, Megamelus scutellaris Berg (Hemiptera: Delphacidae), which is currently under consideration for release. The lower developmental threshold (to) and rate of development (K) were determined for N. albiguttalis and M. scutellaris, using a reduced axis regression, and incorporated into a degree-day model which compared the number of generations that E. catarinensis, N. albiguttalis, and M. scutellaris are capable of producing annually at any given site in South Africa. The degree-day models predicted that N. albiguttalis (K = 439.43, to = 9.866) can complete 4–11 generations per year, whereas M. scutellaris (K = 502.96, to = 11.458) can only complete 0–10 generations per year, compared with E. catarinensis (K = 342, to = 10.3) which is predicted to complete 3–14 generations per year. This suggests that the candidate agent, M. scutellaris, will not fare better in establishment than the other two agents that have been released in the Highveld, and that it may not be worth releasing an agent with higher thermal requirements than the agents that already occur in these high-lying areas. Thermal physiology studies conducted prior to release are important tools in biological control programmes, particularly those in resource-limited countries, to prevent wasting efforts in getting an agent established.
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Date Issued: 2013

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Complexes of mercury(II) and zinc(II) with primary aromatic amines

- Haigh, John M, Van Dam, M A, Thornton, D A

Authors: Haigh, John M , Van Dam, M A , Thornton, D A
Date: 1967
Language: English
Type: text , Article
Identifier: vital:6370 , http://hdl.handle.net/10962/d1006072
Description: A series of amine complexes has been prepared by reaction of zinc chloride and mercuric chloride with primary aromatic amines. A detailed assignment of the bands in the infra-red spectra of the complexes in the range 4000-625 cm [superscript]-1 is presented. The symmetric and asymmetric N-H stretching frequencies follow the relationship v(sym) = 345.5+ 0.876v(asym). The C-N stretching frequencies exhibit a linear relationship with the Hammett α-functions for the m- and p-substituted amines.
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Date Issued: 1967

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Conservation implications of fine scale population genetic structure of Ficus species in South African forests:

- Deng, Jun-Yin, van Noort, Simon, Compton, Stephen G, Chen, Yan, Greeff, Jaco M

Authors: Deng, Jun-Yin , van Noort, Simon , Compton, Stephen G , Chen, Yan , Greeff, Jaco M
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/163838 , vital:41074 , ttps://doi.org/10.1016/j.foreco.2020.118387
Description: Genetic considerations are rarely applied in forest conservation management strategies, but forest fragmentation can reduce pollen and seed dispersal both between and within isolated fragments. Gene flow and immigration rates determine the extent to which individual plants are related to each other at different distances from themselves. This gradation in relatedness is known as a population's fine scale spatial genetic structure (SGS). Specifically, reduced but clumped immigration from distant fragments reduces fine scale SGS, whereas reduced gene flow within fragments increases fine scale SGS. In addition, non-random mortality caused by post-dispersal ecological processes can also affect SGS. We studied the effects of fragmentation on the fine scale SGS of Ficus species with different habitat preferences and distributional ranges in an archipelago of South African forest patches.
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Date Issued: 2020

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Covalent attachment of cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine onto pre-grafted gold electrode for the determination of catecholamine neurotransmitters:

- Tshenkeng, Keamogetse, Mashazi, Philani N

Authors: Tshenkeng, Keamogetse , Mashazi, Philani N
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/163521 , vital:41045 , https://doi.org/10.1016/j.electacta.2020.137015
Description: The fabrication of electroactive thin films onto gold electrode surfaces yields very interesting surfaces with excellent electrocatalytic activity. Cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine (CoTCPhOPc) was successfully synthesized and fully characterized using FT-IR spectroscopy, ultraviolet-visible (UV–Vis) spectroscopy, magnetic circular dichroism (MCD) spectroscopy, elemental analysis, and mass spectrometry. The CoTCPhOPc was immobilized onto phenylethylamino (PEA) pre-grafted gold electrode surface, Au-PEA, using amide coupling reaction to obtain Au-PEA-CoTCPhOPc.
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Date Issued: 2020

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Cracks in reproductive health rights: knowledge of abortion legislation stipulations amongst learners in Buffalo City, South Africa

- Macleod, Catriona I, Seutlwadi, Lebogang, Steele, Gary I

Authors: Macleod, Catriona I , Seutlwadi, Lebogang , Steele, Gary I
Date: 2014
Language: English
Type: Article
Identifier: vital:6296 , http://hdl.handle.net/10962/d1014772
Description: Background: The Choice on Termination of Pregnancy (CTOP) Act legalised abortion on request in South Africa until up to 12 weeks of gestation and thereafter under specified conditions. Within the context of liberal legislation, accurate information is a necessary (although not sufficient) requirement for women to exercise their reproductive rights. Objectives: This research investigated Grade 11 learners’ knowledge of the CTOP Act and its stipulations. Methods: Survey research was conducted with respondents drawn from a range of schools in Buffalo City, South Africa. Multi-stage sampling was used, namely stratified random sampling of schools and purposive sampling of grades used within schools. The data were collected by means of self-administered questionnaires in group situations. Results: Results indicate that knowledge of the legal status of abortion, as well as of the various stipulations of the law, was poor. Various misunderstandings were evident, including that spousal approval is required in order for married women to have an abortion. Significant differences between the knowledge of respondents at the various schools were found, with those learners attending schools formerly designated for African learners during Apartheid having the least knowledge. Conclusion: Given the multiple factors that may serve as barriers to women accessing abortion, it is imperative that at least the most fundamental aspect of reproductive rights, that is, the right to information, is not undermined.
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Date Issued: 2014

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Customary management as TURFs: social challenges and opportunities

- Aswani, Shankar

Authors: Aswani, Shankar
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/145403 , vital:38435 , DOI: 10.5343/bms.2015.1084
Description: There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.
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Date Issued: 2017

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Dataset and ANN model prediction of performance of graphene nanolubricant with R600a in domestic refrigerator system

- Taiwo, Babarinde, Stephen, Akinlabi, Daniel Makundwaneyi, Madyira, Ekundayo, Funmilayo M, Paul Adeola, Adedeji

Authors: Taiwo, Babarinde , Stephen, Akinlabi , Daniel Makundwaneyi, Madyira , Ekundayo, Funmilayo M , Paul Adeola, Adedeji
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/3139 , vital:43150 , (https://www.sciencedirect.com/science/article/pii/S2352340920309926)
Description: This work evaluated the steady state performance of R600a in the base lubricant and graphene nanolubricant. The measuring instruments required and their uncertainties were provided, step by step method and procedures for preparation of graphene nanolubricant concentration and substituting it with the base lubricant in domestic refrigerator system are described. The system temperatures data was captured at the inlet and outlet of the system components. Also, the pressures data was recorded at the compressor inlet and outlet. The data was recorded for 3 h at 30 min interval at an ambient temperature of 27 °C. The experimental dataset, Artificial Neural Network (ANN) training and testing dataset are provided. The artificial intelligence approach of ANN model to predict the performance of graphene nanolubricant in domestic refrigerator is explained. Also, the ANN model prediction statistical performance metrics such as Root Mean Square Error (RMSE) and Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE) and coefficient of determination (R2) are also provided. The data is useful to researchers in the field of refrigeration and energy efficiency materials, for replacing nanolubricant with the base lubricant in refrigerator systems. The data can be reuse for simulation and modelling vapour compression energy system.
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Date Issued: 2020

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Deep phylogeographic structure may indicate cryptic species within the Sparid genus Spondyliosoma:

- McKeown, Niall J, Gwilliam, Michael P, Healey, Amy J E, Skujina, Ilze, Potts, Warren M, Sauer, Warwick H H, Shaw, Paul W

Authors: McKeown, Niall J , Gwilliam, Michael P , Healey, Amy J E , Skujina, Ilze , Potts, Warren M , Sauer, Warwick H H , Shaw, Paul W
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/158085 , vital:40147 , DOI: 10.1111/jfb.14316
Description: Two geographically nonoverlapping species are currently described within the sparid genus Spondyliosoma: Spondyliosoma cantharus (Black Seabream) occurring across Mediterranean and eastern Atlantic waters from NW Europe to Angola and S. emarginatum (Steentjie) considered endemic to southern Africa. To address prominent knowledge gaps this study investigated range‐wide phylogeographic structure across both species. Mitochondrial DNA sequences revealed deep phylogeographic structuring with four regionally partitioned reciprocally monophyletic clades, a Mediterranean clade and three more closely related Atlantic clades [NE Atlantic, Angola and South Africa (corresponding to S. emarginatum)]. Divergence and distribution of the lineages reflects survival in, and expansion from, disjunct glacial refuge areas. Cytonuclear differentiation of S. emarginatum supports its validity as a distinct species endemic to South African waters.
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Date Issued: 2020

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Deposition of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shells around CdSeTe alloyed core quantum dots: effects on optical properties

- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C

Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
Date: 2015
Language: English
Type: Article
Identifier: vital:7289 , http://hdl.handle.net/10962/d1020342
Description: In this work, we synthesized water-soluble L-cysteine-capped alloyed CdSeTe core quantum dots (QDs) and investigated the structural and optical properties of deposition of each of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shell layers. Photophysical results showed that the overcoating of a CdS shell around the alloyed CdSeTe core [quantum yield (QY) = 8.4%] resulted in effective confinement of the radiative exciton with an improved QY value of 93.5%. Subsequent deposition of a ZnSe shell around the CdSeTe/CdS surface decreased the QY value to 24.7%, but an increase in the QY value of up to 49.5% was observed when a ZnS shell was overcoated around the CdSeTe/CdS/ZnSe surface. QDs with shell layers showed improved stability relative to the core. Data obtained from time-resolved fluorescence measurements provided useful insight into variations in the photophysical properties of the QDs upon the formation of each shell layer. Our study suggests that the formation of CdSeTe/CdS core/shell QDs meets the requirements of quality QDs in terms of high photoluminescence QY and stability, hence further deposition of additional shells are not necessary in improving the optical properties of the core/shell QDs. Copyright © 2015 John Wiley & Sons, Ltd. , Original publication is available at http://dx.doi.org/10.1002/bio.3013
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Date Issued: 2015

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