The decanting of acid mine drainage (AMD) from the Western Basin on the Witwatersrand in late 2010 raised concerns about AMD risks in other gold, coal and copper mining areas of South Africa. Field ...spectroscopy and the use of vegetation indices could offer an affordable and easy means of monitoring the impact of mine water and/or AMD on vegetation. The impact of raw and treated mine water or contaminated soil on wetland vegetation often manifests in growth inhibition and reduction of foliar pigments and nutrient levels. Surveying the impact on wetland vegetation or underlying soils can be difficult and expensive considering the cost of laboratory analysis of samples. The potential of field spectroscopy for detecting the impact of mine water on wetland vegetation was examined by assessing (1) whether there was a significant difference in leaf spectra between sites receiving mine water and a non-impacted control site and (2) whether there was a gradation of vegetation condition downstream from the decanting site. Two vegetation indices were derived from portable field spectrometer-measured spectra of five green leaves of Phragmites australis – the chlorophyll red edge position (REP) and the normalised difference vegetation index (NDVI) – for two dormant (winter) and peak growth (summer) seasons in 2011–2012. Mean REP and NDVI values were significantly (p<0.05) lower for affected sites compared to the control site for both seasons and years. The range of REP values for young green leaves in winter for affected sites was 695–720 nm compared to the narrower range of 705–721 nm for the control site. The mean REP values for young green leaves in winter was 708 nm for the affected sites compared to 716 nm for the control site. The downstream gradation, however, fluctuated for REP and NDVI over the study period. We conclude that field spectroscopy shows potential to serve as a relatively quick and affordable means to assess the condition and health of vegetation affected by AMD.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Testis cancer is a rare malignancy, and there are limited data describing Africa's clinical characteristics and outcomes. Aim We summarised 16 years of South African data, comparing it to ...available data for Africa and international data. Setting The retrospective review included males > 12 years with testicular germ cell tumours diagnosed and treated at Tygerberg Hospital from 01 January 2005 to 31 December 2020. Methods Self-declared racial status included Caucasian, mixed ethnicity, African and Asian. Patients were identified from uro-oncology and pathology records indicating any form of testicular cancer. Data were extracted for demographics, staging, treatment and outcomes. In addition, patients were contacted or tracked as part of a living status report by the Department of Home Affairs to determine the last contact date for survival outcomes. Results There were 142 patients in the study. The most common risk factor was cryptorchidism (14.1%), but most patients reported no known risk factors (82.4%). Seminomas presented 10 years later than non-seminomatous germ cell tumours (NSGCTs). Having no risk factors seems to be protective hazard ratio (HR) 0.18 and being diagnosed after 40 years carries an increased risk of death. The histopathological classification was fairly equal, with 70 seminoma and 72 NSGCTs. There was no statistical difference in the stage distribution between seminoma and NSGCTs. The overall 5-year survival was 91% for seminoma compared with 78% in NSGCTs. With a time horizon of 15 years, a patient was expected to survive 16% (1.9 years) longer in the seminoma group. Clinical stage (CS) three patients had a higher risk of dying compared with CS1 and CS2, and there was no difference between seminoma and NSGCTs (HR = 12.6). Conclusion The clinical characteristics of our patient population correspond to international data. There is a need for better health education to ensure patients present earlier and have access to appropriate medical care. Contribution Our data represent the largest series of testis cancer outcomes at a single centre in Africa and the aim is to motivate other centres to describe and analyse their oncological outcomes to ensure we provide the best possible care to all our patients in South Africa's future.
Remote sensing is considered a valuable tool for monitoring the impacts of global change on vegetation species composition, condition and distribution. Multi-season imagery has been shown to improve ...the classification of vegetation communities though the contribution of the winter season in multi-seasonal classifications remains to be assessed. The capability of multi-season images of RapidEye, a new generation high spatial resolution (5 m) space-borne sensor containing an additional red-edge band, was evaluated for the classification of several wetland and dryland communities. RapidEye images were obtained for four seasons (winter, spring, summer and autumn) between 2011 and 2012 for a subtropical coastal region of South Africa. The separability of nine wetland and dryland communities was assessed for each season using the Partial Least Square Random Forest (PLS-RF) algorithm. The four-seasons approach yielded a higher overall classification accuracy (OA = 86 ± 2.8%) when compared to using any single-season classification. The highest single-season accuracies were obtained in spring (80 ± 2.9%), summer (80 ± 3.1%), and autumn (79 ± 3.4%) compared to the winter (66 ± 3.1%). A three-season combination of autumn, winter and spring yielded the highest average OA (86 ± 3.1%), maximised the user’s accuracies and minimised the number of comparable pairs confused. The inclusion of indices in the classification scenarios showed a minor (±1 percentage points) difference in the average overall and user’s accuracies compared to the classification results where only bands were used. The red-edge band of RapidEye increased the overall and average user’s accuracy for most of the scenarios by 2–6 percentage points and thus contributed to the separability of communities which are dominated by evergreen tree species.
Temperate regions in the Southern Hemisphere make a small contribution to the global carbon sequestration of peatlands which, in these drier regions, are relatively rare and vulnerable to increasing ...anthropogenic and climate change pressures. Using South Africa as a case study, we review the availability of spatially explicit information on peatlands and their protection. The South African Peatland Database recorded 635 peatland observations, which reflect a carbon storage capacity of 29,254,495 ± 5,798,831 (total ± standard deviation) tons. Of the total 121,128 ha of peatlands mapped in this study, forested peatlands (11,851 ha, 10 % of all peatlands) were considered vulnerable. Non-forested peatlands (109,277 ha) had higher levels of uncertainty with regard to extent and degree of degradation, and most (74 %) of these had only partial protection. Cumulative anthropogenic pressures have resulted in an increase in the number and temporal frequency of peat fires, with 49 peatland sites having burned in the past five years, compared to 23 in the 24-year period preceding it. The total loss of carbon due to peat fires equates to 280,513 tons to date. The inventory, assessment and management of forested and non-forested peatlands in South Africa, and most probably in other southern-hemisphere temperate regions, requires urgent attention. The information presented demonstrates that forested peatlands have been historically well mapped because of their ease of detection with remote sensing. In contrast, the paucity of information on non-forested palustrine peatlands dictates that more extensive infield validation should be undertaken before their conservation status can be determined.
The objective of the study was to evaluate the benefits perceived by the use of cadaver models by IAMSurgery attendees and to define indications to standardize future similar training camps.
A ...25-item survey was distributed via e-mail to all the participants of previous training courses named as "Urological Advanced Course on Laparoscopic Cadaver Lab" held at the anatomy department of the University of Malta, for anonymous reply. Participants were asked to rate the training course, the Thiel's cadaveric model, and make comparison with other previously experienced simulation tools.
The survey link was sent to 84 attendees, with a response rate of 47.6% (40 replies). There was improvement in the median self-rating of the laparoscopic skills before and after the training camp with a mean difference of 0.55/5 points in the post-training skills compared to the basal (p < 0.0001). The 72.2% of the urologists interviewed considered Thiel's HCM better than other training methods previously tried, while five urologists (27.8%) considered it equal (p = 0.00077). Globally, 77.5% (31) of attendees found the training course useful, and 82.5% (33) would advise it to colleagues.
Thiel's fixed human cadaveric models seem to be ideal for training purposes, and their use within properly structured training camps could significantly improve the surgical skills of the trainees. An important future step could be standardization of the training courses using cadavers, and their introduction into the standardized European curriculum.
Depressional wetlands are highly vulnerable to changes in land surface temperature and rainfall but little is known about their responses to future climate change. This study assessed the variation ...in edaphic factors between wetlands and along their littoral gradients to detect the boundary between the endorheic wetlands and upland zones. A sample of 202 paired measurements of three edaphic factors were collected (Soil Moisture Content – SMC-g/g, Bulk Density – BD-g/cm
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and Salinity as Electrical Conductivity – EC-dS/m) in 10 m plots along 14 belt transects in eight representative wetlands in the Mpumalanga Lake District, South Africa. In general, there were significant differences between the eight wetlands for SMC and BD but not for EC.SMC and BD generally showed negative trends along the littoral gradients. The trends occurred over short distances, ranging from 30 to 70 m, reflecting the extent of the wetlands. Understanding of the spatial variation of edaphic factors helps in the management and monitoring of depressional wetlands under a changing climate. In addition, the study showed that the current wetland buffer zone stipulated in local legislation was too narrow and recommended that this be extended to 100 m.
The growing energy crisis has necessitated the expansion of thermal power stations to meet South Africa's electricity needs. Possessing vast amounts of coal deposits, the Waterberg region of the ...Limpopo Province is set to undergo rapid transformation as new power stations and coal mines are built, expected to exacerbate water shortages. Detailed baseline information to assess future impacts on key plant species is lacking compromising biodiversity conservation efforts in a region where eco – tourism is a major source of livelihood. In this study we evaluated the spatio – temporal distribution plant status during wet and dry seasons using two measures of plant stress namely the midday leaf water potential (LWP), and leaf nitrogen (N) concentrations. At leaf level, spectral indices such as the moisture stress index (MSI), normalized difference water index (NDWI), and the water index (WI) predicted more than 70% of LWP variation using leaf reflectance data. At landscape level, red edge based simple ratio indices were selected for mapping leaf water potential and leaf N for wet and dry season using RapidEye data. We conclude that remote sensing images can be applied for the long term vegetation monitoring for future biodiversity conservation efforts.
•Leaf water potential and leaf nitrogen used as an indicator of plant stress.•Vegetation indices with red-edge band provide opportunity to monitor plant stress.•Leaf water potential mapped for the first time at landscape level.•Remote sensing has potential for environmental monitoring.
In South Africa, penile loss is a recognised complication of ritual circumcision which has a profoundly negative effect on these men's psyches and their everyday lives. The purpose of this paper was ...to investigate the experiences of the first two South African penile allograft transplantation recipients in order to assess the psychosocial impact of this surgery.
A qualitative descriptive phenomenology approach was used. A total of four in-depth interviews were conducted with the two South African penile transplant recipients. The interviews were transcribed verbatim while adding the field and observational notes. Thematic analysis was used to derive meaning from the collected data.
After the penile loss, both participants reported feeling suicidal for the following reasons: their communities shunned them and regarded them as ‘dead,’ they felt severely ashamed of their disfigured bodies, they were unable to develop intimate relationships and could not have children. Transplantation gave them a fully functional penis, which resolved the majority of these issues. The participants were able to build relationships and satisfy their own and their partners' sexual and relationship needs. The transplant led to complete restoration of their self-image and manhood. They were, however, still persecuted by their traditional communities as they had not successfully completed the ritual circumcision ceremony.
This study emphasises the necessity of offering penile transplantation as treatment for penile loss as this is not only life enhancing but lifesaving, especially within the South African context.
•Recipients fully accepted the transplanted penis as their own.•Penile function was fully restored including sexual function and therefore the ability to reproduce.•Penile transplantation had positive impact on recipients' psychological state and self-image.•Despite need for lifelong immunosuppressants, recipients were satisfied with decision to have penile tansplant.•The emotional and social transformation which occurred in the recipients were not only life-enhancing, but lifesaving.
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