608 research outputs found
Weerbaarheid, ook tegen plantenvirussen
Op een nieuwe manier naar de aanpak van virussen kijken. Dat doen de onderzoekers Maarten de Kock en Ineke Stijger. In dit artikel gaan ze na welke mogelijkheden er liggen op het gebied van weerbaarheid om plantenvirussen aan te pakken
Non-persistente virusoverdracht door bladluizen in bloembollen
Dit driejarig onderzoeksproject naar non-persistente virusoverdracht door bladluizen in bloembollen heeft direct toepasbare kennis en gewasbeschermingsadviezen opgeleverd, maar ook heldere adviezen voor zowel de chemische als biologische bestrijding van virusoverdracht door bladluizen. Deze adviezen vormen de basis voor verder onderzoek om uiteindelijk de non-persistente virusverspreiding door bladluizen nog effectiever te kunnen bestrijden
Pulmonary hematoma presenting as pseudotumor
A 65-year old man presented at the emergency department with acute shortness of breath, chest pain, cough and haemoptysis. The patient is an ex-smoker with a total of 35 pack years and an extensive medical history, including a serious traffic accident with neurotrauma, chronic obstructive pulmonary disease, degenerative spine and hip disease, ethylism, a type A aortic dissection and atrial fibrillation. His medication list is extensive and includes a bronchodilator, an antiepileptic, several antihypertensive drugs, pain medication, amiodarone, acetylsalicyc acid and subcutaneous low molecular weight heparin. Chest X-ray showed a rounded opacity in the mediobasal segment of the right lower lobe that could not be seen on previous radiographs (Fig. A). Biochemistry demonstrated an elevated CRP (48 mg/L) and elevated D-dimers (2190 ng/ml). CT thorax was performed to rule out pulmonary embolism. CT thorax showed a sharply demarcated relatively hyperdense mass (mean density on pulmonary artery phase images of 46 HU) with a maximum diameter of 5,5 cm in the mediobasal segment of the right lower lobe abutting the distal vena cava superior (Fig. B). An endobronchial ultrasounded (EBUS) guided biopsy of the lesion was performed. Pathologic examination showed pulmonary tissue with signs of hemorhage and fibrotic changes. No signs of malignancy were seen. An old thorax CT made in another hospital revealed that the location of the mass corresponded exactly with the location of a large bulla (Fig. C). Based on this new information the diagnosis of pulmonary hematoma within a bulla was made
A systematic literature review of sustainable urban planning challenges associated with developing countries
CITATION: Jooste, A. F., De Kock, I. H. & Musango, J. K. 2019. A systematic literature review of sustainable urban planning challenges associated with developing countries. South African Journal of Industrial Engineering, 30(3):253-261, doi:10.7166/30-3-2247.The original publication is available at http://sajie.journals.ac.zaENGLISH ABSTRACT: The purpose of this study is to uncover the most prominent challenges that urban planners face when tackling sustainable practices in developing countries. The time frame was set to after the 2012 Rio +20 global summit. Therefore, only articles that were produced from 1 January 2013 till 31 March 2019 were included, as they would have adhered to the contributions and protocols set forth at the largest UN Earth Summit conference. In this study, a review of the sustainable urban planning challenges was conducted. The challenges are then grouped into topics that align with the theme of the type of challenge. Finally, the challenges are analysed to identify the most well-known and disruptive challenges that restrict urban planners in developing countries.http://sajie.journals.ac.za/pub/article/view/2247Publisher's versio
Impatiens-vlekkenvirus in Phalaenopsis
In de teelt van Phalaenopsis worden telers de laatste jaren geconfronteerd met een bladsymptoom bestaande uit concentrische kringen, vooral op de jongste bladeren. De aantasting varieert van mild (een enkele chlorotische kring) tot ernstig (afstervende bladdelen). In mei 2009 signaleerde men een sterke toename aan symptomen, waarbij in verschillende partijen tot 25% van de planten was aangetast. Middels een ELISA-toets is de aanwezigheid van Impatiens-vlekkenvirus (Impatiens necrotic spot virus, INSV) vastgesteld. De symptomen van INSV kunnen verschillend zijn en zijn afhankelijk van de waardplant, de omstandigheden waarin de plant wordt geteeld en het gedrag van een individuele trips die een plant koloniseert. Necrotische vlekken, strepen, kringvlekken, groeiachterstand en verwelking zijn een aantal van de vele symptomen die door dit virus kunnen worden veroorzaakt. Ook is het mogelijk dat het virus symptoomloos in de plant voorkomt. INSV wordt overgedragen via trips en de Californische trips (Frankliniella occidentalis) is de voornaamste vector. Alleen de larven van de trips kunnen het virus opnemen uit besmette planten. Nadat de larven volgroeid zijn, verspreiden de volwassen exemplaren het virus naar andere planten. Rondvliegende volwassen mannetjes zijn de belangrijkste verspreiders. 'Schone' volwassen tripsen kunnen het virus niet meer opnemen. De overdracht van het virus is persistent. Uit de overdrachtsexperimenten is gebleken dat tripsen niet de voorkeur geven aan Phalaenopsis-planten. Het zou kunnen zijn dat geïnfecteerde tripsen de planten testen als geschikte voedselbron bij gebrek aan beter. Zodra ze een betere waardplant vinden zullen ze niet meer op de Phalaenopsis-planten blijven. In de overdrachtsproeven is een verschil te zien tussen een gedwongen verblijf van de tripsen en een vrije keus. Bij een gedwongen verblijf van geïnfecteerde tripsen op gezonde bladeren zijn de symptomen al na ongeveer een week zichtbaar dit in tegenstelling tot de vrije keus waarbij symptomen rond de vier weken zichtbaar waren
Patient-Reported Outcome Measures may optimize shared decision-making for cancer risk management in BRCA mutation carriers
Purpose: The aim of this study was to compare patient-reported outcomes (PROs) of BRCA1/2 mutation carriers, either after bilateral prophylactic mastectomy (BPM) or during breast surveillance, to improve shared decision-making in their cancer risk management. Methods: Unaffected BRCA1/2 mutation carriers at least one year after BPM followed by immediate breast reconstruction (BPM-IBR) or one year under surveillance were eligible. After informed consent, the Hospital Anxiety and Depression Scale (HADS) and BREAST-Q were administered and compared between the different strategies. PROs were also compared to available normative data. Results: Ninety-six participants were analyzed in this study and showed significant differences between strategies in age, age at genetic testing, and time since BPM or starting breast surveillance. All HADS scores were below 8 suggesting no signs of anxiety or depression in both groups. Higher mean ‘Q-physical well-being’ scores were reported by the surveillance group (81.78 [CI 76.99–86.57]) than the BPM group (76.96 [CI 73.16 – 80.75]; p = 0.011). Overall, for both questionnaires better scores were seen when compared to age-matched normative data. Conclusions: No signs of anxiety or depression were seen in the surveillance or BPM-IBR group. Slightly better mean BREAST-Q scores were seen for the surveillance group in comparison to BPM-IBR, except for ‘Q-psychological well-being’. The difference in ‘Q-physical well-being’ was significantly worse for BPM-IBR. Approaches to obtain longitudinal PROs and reference values should be explored in the future, which could add value to shared decision-making in regards to breast cancer risk management in this specific patient population
Impacts of local human activities on the Antarctic environment
We review the scientific literature, especially from the past decade, on the impacts of human activities on the Antarctic environment. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived. Contemporary sewage management practices at many coastal stations are insufficient to prevent local contamination but no introduction of non-indigenous organisms through this route has yet been demonstrated. Human activities, particularly construction and transport, have led to disturbances of flora and fauna. A small number of non-indigenous plant and animal species has become established, mostly on the northern Antarctic Peninsula and southern archipelagos of the Scotia Arc. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity oil bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources and the Environmental Protocol, provide a framework within which management of human activities take place. In the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential, in order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values which remains a fundamental principle of the Antarctic Treaty System. These measures include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic Programmes and tourism activities
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Magnetic resonance enterography and intestinal ultrasound for the assessment and monitoring of Crohn’s disease
Magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) have developed rapidly in the last few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn’s disease (CD). In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and discuss point-of-care ultrasound. We also highlight exciting new developments including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities
Nuclear medium modifications of the NN interaction via quasielastic () and () scattering
Within the relativistic PWIA, spin observables have been recalculated for
quasielastic () and () reactions on a Ca
target. The incident proton energy ranges from 135 to 300 MeV while the
transferred momentum is kept fixed at 1.97 fm^{-1}. In the present
calculations, new Horowitz-Love--Franey relativistic NN amplitudes have been
generated in order to yield improved and more quantitative spin observable
values than before. The sensitivities of the various spin observables to the NN
interaction parameters, such as (1) the presence of the surrounding nuclear
medium, (2) a pseudoscalar versus a pseudovector interaction term, and (3)
exchange effects, point to spin observables which should preferably be measured
at certain laboratory proton energies, in order to test current nuclear models.
This study also shows that nuclear medium effects become more important at
lower proton energies ( 200 MeV). A comparison to the limited available
data indicates that the relativistic parametrization of the NN scattering
amplitudes in terms of only the five Fermi invariants (the SVPAT form) is
questionable.Comment: 10 pages, 6 Postscript figures, uses psfig.sty and article.sty,
submitted to Phys. Rev.
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