88 research outputs found
The perceptions of research values and priorities in water resource management from the 3rd Orange River Basin Symposium
Research has played an important role in water resource management and a consensus on research objectives would increase the efficiency of these practices. In this paper we aimed to elicit the views of attendees of the 3rd Orange River Basin Symposium regarding water-related research, by using both quantitative and qualitative responses to a questionnairesurvey, and purposeful sampling methods. Overall, research was perceived to play an important role in water resource management and there was significant agreement on which sectors are responsible for carrying out this research. Although clear strengths in water resource management in southern Africa were identified, we found that most perceived weaknessesrelated to the lack of enforcement or to human resource constraints. Despite this fact, the identified research priorities, which were aligned to those of the Water Research Commission, tended to be technical in nature and would not address these perceived weaknesses. Our recommendations were that, by incorporating previously ignored sectors into research,such as private consultants and non-governmental organisations, and addressing human capacity and enforcement issues, unique and unexplored research opportunities could improve water resource management
Potential groundwater contamination from oil drilling in the Okavango
Canadian oil and gas company, Reconnaissance Energy Africa (ReconAfrica), plans to exploit potential oil reserves in the Cubango Okavango River Basin (CORB) in Namibia and Botswana, where little is known about the local groundwater systems and how contamination and its effects could impact the region. Using borehole data from target oil and gas areas, we calculated hydraulic gradients, flow direction, and flow velocity to map potential groundwater contamination effects from oil and gas drilling in the region. We also plotted the major geological structures, calculated flowpaths, and estimated travel times for contaminated groundwater that may travel along these preferential flowpaths from the drill sites to the Okavango River and Delta. Results indicate that contaminated groundwater from the oil lease areas could take 3–23.5 years to reach the Okavango River system via the shallow sandy aquifer, but in a worst-case scenario, contamination could reach the Delta within four days via structures associated with dykes and faults that serve as primary flowpaths. Such contamination could adversely affect human health and the region's ecosystems and biodiversity. We recommend prohibiting oil exploration and production activities within the CORB until future studies can determine the impacts of hydrocarbon extraction with greater certainty
Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and
NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a
quiescent state since at least early 2015, reactivated between 2017 March 19
and April 5. The radio flux density, while variable, is approximately 100x
larger than during its dormant state. The X-ray flux one month after
reactivation was at least 800x larger than during quiescence, and has been
decaying exponentially on a 111+/-19 day timescale. This high-flux state,
together with a radio-derived rotational ephemeris, enabled for the first time
the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV
pulsed fraction is comparable to the smallest observed for magnetars. The
overall pulsar geometry inferred from polarized radio emission appears to be
broadly consistent with that determined 6-8 years earlier. However, rotating
vector model fits suggest that we are now seeing radio emission from a
different location in the magnetosphere than previously. This indicates a novel
way in which radio emission from magnetars can differ from that of ordinary
pulsars. The torque on the neutron star is varying rapidly and unsteadily, as
is common for magnetars following outburst, having changed by a factor of 7
within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure
Confronting historical legacies of biological anthropology in South Africa-Restitution, redress and community-centered science: The Sutherland Nine
We describe a process of restitution of nine unethically acquired human skeletons to their families, together with attempts at redress. Between 1925-1927 C.E., the skeletonised remains of nine San or Khoekhoe people, eight of them known-in-life, were removed from their graves on the farm Kruisrivier, near Sutherland in the Northern Cape Province of South Africa. They were donated to the Anatomy Department at the University of Cape Town. This was done without the knowledge or permission of their families. The donor was a medical student who removed the remains from the labourers' cemetery on his family farm. Nearly 100 years later, the remains are being returned to their community, accompanied by a range of community-driven interdisciplinary historical, archaeological and analytical (osteobiographic, craniofacial, ancient DNA, stable isotope) studies to document, as far as possible, their lives and deaths. The restitution process began by contacting families living in the same area with the same surnames as the deceased. The restitution and redress process prioritises the descendant families' memories, wishes and desire to understand the situation, and learn more about their ancestors. The descendant families have described the process as helping them to reconnect with their ancestors. A richer appreciation of their ancestors' lives, gained in part from scientific analyses, culminating with reburial, is hoped to aid the descendant families and wider community in [re-]connecting with their heritage and culture, and contribute to restorative justice, reconciliation and healing while confronting a traumatic historical moment. While these nine individuals were exhumed as specimens, they will be reburied as people
Setting a baseline for global urban virome surveillance in sewage
The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective
Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage
Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining representative data on AMR for healthy human populations is difficult. Here, we use meta-genomic analysis of untreated sewage to characterize the bacterial resistome from 79 sites in 60 countries. We find systematic differences in abundance and diversity of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America. Antimicrobial use data and bacterial taxonomy only explains a minor part of the AMR variation that we observe. We find no evidence for cross-selection between antimicrobial classes, or for effect of air travel between sites. However, AMR gene abundance strongly correlates with socio-economic, health and environmental factors, which we use to predict AMR gene abundances in all countries in the world. Our findings suggest that global AMR gene diversity and abundance vary by region, and that improving sanitation and health could potentially limit the global burden of AMR. We propose metagenomic analysis of sewage as an ethically acceptable and economically feasible approach for continuous global surveillance and prediction of AMR.Peer reviewe
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Concurrent evaluation of cytokines improves the accuracy of antibodies against Mycobacterium tuberculosis antigens in the diagnosis of active tuberculosis
Data availability statement: All the important data relevant to this study was reported in the manuscript. Any additional data will be made available upon request from the corresponding author.Copyright © 2022 The Authors. Background:
Antibodies against mycobacterial proteins are highly specific, but lack sensitivity, whereas cytokines have been shown to be sensitive but not very specific in the diagnosis of tuberculosis (TB). We assessed combinations between antibodies and cytokines for diagnosing TB.
Methods:
Immuoglubulin (Ig) A and IgM antibody titres against selected mycobacterial antigens including Apa, NarL, Rv3019c, PstS1, LAM, “Kit 1” (MTP64 and Tpx)”, and “Kit 2” (MPT64, Tpx and 19 kDa) were evaluated by ELISA in plasma samples obtained from individuals under clinical suspicion for TB. Combinations between the antibody titres and previously published cytokine responses in the same participants were assessed for diagnosing active TB.
Results:
Antibody responses were more promising when used in combination (AUC of 0.80), when all seven antibodies were combined. When anti-“Kit 1”-IgA levels were combined with five host cytokine biomarkers, the AUC increased to 97% (92–100%) with a sensitivity of 95% (95% CI, 73–100%), and specificity of 88.5% (95% CI, 68.7–97%) achieved after leave-one-out cross validation.
Conclusion:
When used in combination, IgA titres measured with ELISA against multiple Mycobacterium tuberculosis antigens may be useful in the diagnosis of TB. However, diagnostic accuracy may be improved if the antibodies are used in combination with cytokines.This work was part of the EDCTP1 programme supported by the European Union (grant number IP_2009_32040, AE-TBC; awarded to GW). The project was also supported by the South African Government through the National Research Foundation (NRF, awarded to NC) and the South African Medical Research Council (SAMRC, postgraduate scholarship to RJ)
The 1.28 GHz MeerKAT DEEP2 Image
We present the confusion-limited 1.28 GHz MeerKAT DEEP2 image covering one qb » ¢ 68 FWHM primarybeam area with θ = 7 6 FWHM resolution and s = m - n 0.55 0.01 Jy beam 1 rms noise. Its J2000 center position
α = 04h 13m 26 4, δ = −80° 00′ 00″ was selected to minimize artifacts caused by bright sources. We introduce
the new 64-element MeerKAT array and describe commissioning observations to measure the primary-beam
attenuation pattern, estimate telescope pointing errors, and pinpoint (u, v) coordinate errors caused by offsets in
frequency or time. We constructed a 1.4 GHz differential source count by combining a power-law count fit to the
DEEP2 confusion P(D) distribution from 0.25 to 10 μJy with counts of individual DEEP2 sources between 10 μJy
and 2.5 mJy. Most sources fainter than S ∼ 100 μJy are distant star-forming galaxies (SFGs) obeying the far-IR/
radio correlation, and sources stronger than 0.25 μJy account for ∼93% of the radio background produced by
SFGs. For the first time, the DEEP2 source count has reached the depth needed to reveal the majority of the star
formation history of the universe. A pure luminosity evolution of the 1.4 GHz local luminosity function consistent
with the Madau & Dickinson model for the evolution of SFGs based on UV and infrared data underpredicts our
1.4 GHz source count in the range -5 log Jy 4 [ ( )] S
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