236 research outputs found
The independent effect of living in malaria hotspots on future malaria infection: an observational study from Misungwi, Tanzania.
BACKGROUND: As malaria transmission declines, continued improvements of prevention and control interventions will increasingly rely on accurate knowledge of risk factors and an ability to define high-risk areas and populations at risk for focal targeting of interventions. This paper explores the independent association between living in a hotspot and prospective risk of malaria infection. METHODS: Malaria infection status defined by nPCR and AMA-1 status in year 1 were used to define geographic hotspots using two geospatial statistical methods (SaTScan and Kernel density smoothing). Other malaria risk factors for malaria infection were explored by fitting a multivariable model. RESULTS: This study demonstrated that residing in infection hotspot of malaria transmission is an independent predictor of malaria infection in the future. CONCLUSION: It is likely that targeting such hotspots with better coverage and improved malaria control strategies will result in more cost-efficient uses of resources to move towards malaria elimination
The potential use of plant species within a Renosterveld landscape for the phytoremediation of glyphosate and fertiliser
CITATION: Jacklin, D. M., Brink, I. C. & De Waal, J. 2020. The potential use of plant species within a Renosterveld landscape for the phytoremediation of glyphosate and fertiliser. Water SA, 46(1):94-103, doi:10.17159/wsa/2020.v46.i1.7889.The original publication is available at: http://www.scielo.org.zaENGLISH ABSTRACT: In South Africa, fertiliser and herbicide pollutants resulting from agricultural practices indirectly lead to the degradation of surface freshwater and groundwater quality. Nitrogen and phosphorus, and glyphosate, derived from agricultural fertiliser and herbicide applications, respectively, contribute to watercourse toxicity. Adjacent to many of the surface freshwater systems are some of South Africa's most productive agricultural lands, where natural ecosystems are converted to croplands, resulting in the degradation of natural vegetation and deterioration of freshwater quality. The critically endangered status of some Renosterveld vegetation types is the product of agricultural expansion, nutrient loading through fertilisation and the spraying of herbicides. A buffer of Renosterveld vegetation along river corridors may contribute to the remediation of agricultural pollutants prior to entering watercourses. The utilisation of wetland plants occurring within Renosterveld for agricultural pollutant extraction can increase river corridor biodiversity, creating indigenous refuges and facilitating habitat connectivity. A laboratory phytoremediation system was designed and constructed to investigate the pollutant-removal potential of indigenous species occurring in Renosterveld vegetation (amongst other areas), compared with commonly used invasive alien plants (IAP) in floating wetland designs. Five pollutant parameters - ammonia, nitrate, orthophosphate and two glyphosate concentrations - reflect environmental stresses on 14 wetland species naturally occurring within Renosterveld vegetation. Effluent analyses indicated significant removal efficiencies for the indigenous vegetation across both fertiliser and herbicide pollutants, with the two most effective species identified as Phragmites australis and Cyperus textilis, with 95.87% and 96.42% removal, respectively. All wetland species displayed greater pollutant removal than the unvegetated soil control and when compared to an IAP and palmiet assemblage, indicated similar pollutant-removal efficiencies, justifying their use as an acceptable alternative.Publisher's versio
KMT-2016-BLG-2052L: Microlensing Binary Composed of M Dwarfs Revealed from a Very Long Time-scale Event
We present the analysis of a binary microlensing event KMT-2016-BLG-2052, for
which the lensing-induced brightening of the source star lasted for 2 seasons.
We determine the lens mass from the combined measurements of the microlens
parallax \pie and angular Einstein radius \thetae. The measured mass
indicates that the lens is a binary composed of M dwarfs with masses of
and . The measured relative
lens-source proper motion of is smaller
than of typical Galactic lensing events, while
the estimated angular Einstein radius of \thetae\sim 1.2~{\rm mas} is
substantially greater than the typical value of .
Therefore, it turns out that the long time scale of the event is caused by the
combination of the slow and large \thetae rather than the heavy mass of
the lens. From the simulation of Galactic lensing events with very long time
scales ( days), we find that the probabilities that long
time-scale events are produced by lenses with masses and
are and 2.6\%, respectively, indicating that
events produced by heavy lenses comprise a minor fraction of long time-scale
events. The results indicate that it is essential to determine lens masses by
measuring both \pie and \thetae in order to firmly identify heavy stellar
remnants such as neutron stars and black holes.Comment: 9 pages, 11 figure
OGLE-2016-BLG-0613LABb: A Microlensing Planet in a Binary System
We present the analysis of OGLE-2016-BLG-0613, for which the lensing light
curve appears to be that of a typical binary-lens event with two caustic spikes
but with a discontinuous feature on the trough between the spikes. We find that
the discontinuous feature was produced by a planetary companion to the binary
lens. We find 4 degenerate triple-lens solution classes, each composed of a
pair of solutions according to the well-known wide/close planetary degeneracy.
One of these solution classes is excluded due to its relatively poor fit. For
the remaining three pairs of solutions, the most-likely primary mass is about
while the planet is a super-Jupiter. In all cases the
system lies in the Galactic disk, about half-way toward the Galactic bulge.
However, in one of these three solution classes, the secondary of the binary
system is a low-mass brown dwarf, with relative mass ratios (1 : 0.03 : 0.003),
while in the two others the masses of the binary components are comparable.
These two possibilities can be distinguished in about 2024 when the measured
lens-source relative proper motion will permit separate resolution of the lens
and source.Comment: 14 pages, 9 figure
Bank insolvencies, priority claims and systemic risk
We review an extensive literature debating the merits of alternative priority structures for banking liabilities put forward by financial economists, legal scholars and policymakers. Up to now, this work has focused exclusively on the relative advantages of each group of creditors to monitor the activities of bankers. We argue that systemic risk is another dimension that this discussion must include. The main message of our work is that when bank failures are contagious then when regulators assign priority rights need also to take into account how the bankruptcy resolution of one institution might affect the survival of other institutions that have acted as its creditors. When the network structure is fixed the solution is straightforward. Other banks should have priority to minimize the risk of their downfall. However, if the choice of policy can affect the structure of the network, policy design becomes more complex.This is a fruitful avenue for future research
Career changers and fast-track induction: teacher perspectives on their early professional development
In this article, the early professional development of mature, early career teachers who entered the profession via an employment-based route to teaching in England is presented and explored from the teachers’ own perspectives. From a larger sample in a longitudinal study, the development of four career changers is traced in detail, using a model of professional learning which highlights teaching and professional skills. There is some evidence that those who undertake the programme experience a smoother induction into teaching than those from more traditional routes, although the internship year itself is challenging and demands a high level of commitment and resilience on the part of the pre-service teachers.
Contextual factors, such as school support and learning from experienced teachers, are vital in enabling early professional development and the absence of these can hinder learning and self-confidence. Findings are analysed with reference to the model, as well as research on teachers’ development, within a socio-cultural learning framework. The study makes a valuable contribution to knowledge about the professional development of mature entrants to teaching
UKIRT-2017-BLG-001Lb: A Giant Planet Detected through the Dust
We report the discovery of a giant planet in event UKIRT-2017-BLG-001, detected by the United Kingdom Infrared Telescope (UKIRT) microlensing survey. The mass ratio between the planet and its host is q = 1.50^(+0.17)_(-0.14) x 10^(-3), about 1.5 times the Jupiter/Sun mass ratio. The event lies 0.°35 from the Galactic center and suffers from high extinction of A_K = 1.68. Therefore, it could be detected only by a near-infrared (NIR) survey. The field also suffers from large spatial differential extinction, which makes it difficult to estimate the source properties required to derive the angular Einstein radius. Nevertheless, we find evidence suggesting that the source is located in the far disk. If correct, this would be the first source star of a microlensing event to be identified as belonging to the far disk. We estimate the lens mass and distance using a Bayesian analysis to find that the planet's mass is 1.28^(+0.37)_(-0.44) M_J, and it orbits a 0.81^(+0.21)_(-0.27) M⊙ star at an instantaneous projected separation of 4.18^(+0.96)_(-0.88) au. The system is at a distance of 6.3^(+1.6)_(-2.1) kpc, and so likely resides in the Galactic bulge. In addition, we find a non-standard extinction curve in this field, in agreement with previous results toward high-extinction fields near the Galactic center
UKIRT under new management: status and plans
The United Kingdom Infrared Telescope (UKIRT) observatory has been transferred to the ownership of the University of Hawaii (UH) and is now being managed by UH. We have established partnerships with several organizations to utilize the UKIRT for science projects and to support its operation. Our main partners are the U.S. Naval Observatory (USNO), the East Asian Observatory (EAO), and the UKIRT microlensing team (JPL/IPAC/OSU/Vanderbilt). The USNO is working on deep northern hemisphere surveys in the H and K bands and the UKIRT microlensing team is running a monitoring campaign of the Galactic bulge. EAO, UH, and USNO have individual P.I. research programs. Most of the observations are using the Wide Field Camera (WFCAM), but the older suite of cassegrain instruments are still fully operational. Data processing and archiving continue to be done CASU and WSA in the UK. We are working on a concept to upgrade the WFCAM with new larger infrared detector arrays for substantially improved survey efficiency
A new approach to treatment of resistant gram-positive infections: potential impact of targeted IV to oral switch on length of stay
BACKGROUND: Patients prescribed intravenous (IV) glycopeptides usually remain in hospital until completion of this treatment. Some of these patients could be discharged earlier if a switch to an oral antibiotic was made. This study was designed to identify the percentage of inpatients currently prescribed IV glycopeptides who could be discharged earlier if a switch to an oral agent was used, and to estimate the number of bed days that could be saved. We also aimed to identify the patient group(s) most likely to benefit, and to estimate the number of days of IV therapy that could be prevented in patients who remained in hospital. METHODS: Patients were included if they were prescribed an IV glycopeptide for 5 days or more. Predetermined IV to oral antibiotic switch criteria and discharge criteria were applied. A multiple logistic regression model was used to identify the characteristics of the patients most likely to be suitable for earlier discharge. RESULTS: Of 211 patients, 62 (29%) could have had a reduced length of stay if they were treated with a suitable oral antibiotic. This would have saved a total of 649 inpatient days (median 5 per patient; range 1–54). A further 31 patients (15%) could have switched to oral therapy as an inpatient thus avoiding IV line use. The patients most likely to be suitable for early discharge were those with skin and soft tissue infection, under the cardiology, cardiothoracic surgery, orthopaedics, general medical, plastic surgery and vascular specialities, with no high risk comorbidity and less than five other regularly prescribed drugs. CONCLUSION: The need for glycopeptide therapy has a significant impact on length of stay. Effective targeting of oral antimicrobials could reduce the need for IV access, allow outpatient treatment and thus reduce the length of stay in patients with infections caused by antibiotic resistant gram-positive bacteria
Gender and Management: new directions in research and continuing patterns in practice
This is the author’s version of the following article. The definitive version is available at www.interscience.wiley.com:Adelina Broadbridge and Jeff Hearn, Gender and management: New directions in research and continuing patterns in practice, 2008, British Journal of Management, (19), s1, 38-49. http://dx.doi.org/10.1111/j.1467-8551.2008.00570.xCopyright: British Academy of Management, Blackwell Publishing Ltdhttp://www.blackwellpublishing.com
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