Photosynthetic adaptation of two semi-arid species of Gethyllis (Kukumakranka) to drought-and-shade stress

Gethyllis multifolia and Gethyllis villosa are winter-growing, summer-blooming, deciduous and bulbous geophytes that grow naturally in the semi-arid ‘Succulent Karoo Biome’ of South Africa. G. multifolia is threatened in its natural habitat and resides in the ‘Vulnerable’ category of the ‘Red Data List of Southern African Plants’. Previous investigations suggested that G. multifolia is more sensitive to drought stress than G. villosa and that both species adopted certain morphological changes in their leaves during shade stress. Current models indicate that this biome is being exposed to increasingly drier conditions and shading from encroaching indigenous plant species. In this study, the photosynthetic gas exchange responses of both species to drought and shade stresses were investigated and the ‘Vulnerable’ conservation status of G. multifolia. This investigation found that during drought stress G. villosa had a more enhanced photosynthetic performance than G. multifolia which appears not to be related to foliar adaptations such as specific leaf mass (SLM), but to the G. villosa's leaves maintaining their stomatal conductance (Gs), photosynthetic light compensation (LCP) and photon yields. Furthermore, during shade stress G. villosa also had an improved photosynthetic performance by not altering its photosynthetic LCP during reduced light conditions. It can be concluded that G. multifolia has a lower capacity than G. villosa to adapt its photosynthetic apparatus to changing environments such as increasing drought and shaded conditions. This may be a contributing factor to the threatened conservation status of G. multifolia.Web of Scienc

Collaboration in agricultural research

Meeting: Canadian Agricultural Economics Society, Annual Meeting, 15 Aug. 1977, Guelph, Ont., CAPhotocopyIDRC personnel. Paper on international cooperation in agricultural research - discusses development of interdisciplinary research programmes based on farmer's requirements in developing countrys, national and regional research centres, role of IDRC and cultivation systems research

The american pediatric society and society for pediatric research joint statement against racism and social injustice

Although the coronavirus disease 2019 pandemic has served as a flashlight, illuminating and unmasking deep socio-economic and health care divides in our country, the terrible events surrounding the horrific murder of Mr. George Floyd in Minneapolis has spawned even greater outrage. As we all know, Mr. Floyd’s death is not an isolated incident, as there have been a tragic string of such deaths in recent years that further reflect deep issues regarding racism and systemic underlying causes of injustice. Unfortunately, the country’s inability to fully address these systemic foundations of injustice persists

Cloaked websites: propaganda, cyber-racism and epistemology in the digital era

This article analyzes cloaked websites, which are sites published by individuals or groups who conceal authorship in order to disguise deliberately a hidden political agenda. Drawing on the insights of critical theory and the Frankfurt School, this article examines the way in which cloaked websites conceal a variety of political agendas from a range of perspectives. Of particular interest here are cloaked white supremacist sites that disguise cyber-racism. The use of cloaked websites to further political ends raises important questions about knowledge production and epistemology in the digital era. These cloaked sites emerge within a social and political context in which it is increasingly difficult to parse fact from propaganda, and this is a particularly pernicious feature when it comes to the cyber-racism of cloaked white supremacist sites. The article concludes by calling for the importance of critical, situated political thinking in the evaluation of cloaked websites

Post-acute COVID-19 neuropsychiatric symptoms are not associated with ongoing nervous system injury

A proportion of patients infected with severe acute respiratory syndrome coronavirus 2 experience a range of neuropsychiatric symptoms months after infection, including cognitive deficits, depression and anxiety. The mechanisms underpinning such symptoms remain elusive. Recent research has demonstrated that nervous system injury can occur during COVID-19. Whether ongoing neural injury in the months after COVID-19 accounts for the ongoing or emergent neuropsychiatric symptoms is unclear. Within a large prospective cohort study of adult survivors who were hospitalized for severe acute respiratory syndrome coronavirus 2 infection, we analysed plasma markers of nervous system injury and astrocytic activation, measured 6 months post-infection: neurofilament light, glial fibrillary acidic protein and total tau protein. We assessed whether these markers were associated with the severity of the acute COVID-19 illness and with post-acute neuropsychiatric symptoms (as measured by the Patient Health Questionnaire for depression, the General Anxiety Disorder assessment for anxiety, the Montreal Cognitive Assessment for objective cognitive deficit and the cognitive items of the Patient Symptom Questionnaire for subjective cognitive deficit) at 6 months and 1 year post-hospital discharge from COVID-19. No robust associations were found between markers of nervous system injury and severity of acute COVID-19 (except for an association of small effect size between duration of admission and neurofilament light) nor with post-acute neuropsychiatric symptoms. These results suggest that ongoing neuropsychiatric symptoms are not due to ongoing neural injury

Large-scale phenotyping of patients with long COVID post-hospitalization reveals mechanistic subtypes of disease

One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain–gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials

Comparative antioxidant-capacity and -content of leaves, bulbs, roots, flowers and fruit of Gethyllis multifolia L. Bolus and G. villosa Thunb. species

The total polyphenol, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), radical cation scavenging ability, flavonol and flavanone contents were measured in the leaves, bulbs, roots, flowers and fruit (dry weight) of two natural populations of Gethyllis multifolia (Kukumakranka) and Gethyllis villosa. The flowers and fruit of G. multifolia and G. villosa showed higher, and in some cases significantly (P < 0.05) higher antioxidant activities when compared to the leaves, bulbs and roots. This, however, was not true for the flavanone content in both species. The total polyphenol content in the fruits of G. multifolia (21.54 mg GAE/g) and G. villosa (27.64 mg GAE/g) were found to be in agreement with those of raisins (28.30 mg GAE/g), blueberries (24 mg GAE/g) and strawberries (15.40 mg GAE/g). The FRAP values of G. multifolia flowers (76.66 μmole AAE/g) and fruit (91.51 μmole AAE/g) were found to be significantly (P < 0.05) higher than those of the other plant parts (16.76 to 39.08 μmol AAE/g). On the other hand, the flowers (590.23 μmol TE/g) and fruit (741.16 μmol TE/g) of G. villosa revealed a significantly (P < 0.05) higher ORAC when compared to the other plant parts (251.25 to 410.60 μmol TE/g). A strong correlation was evident in the fruit of both species between the total polyphenols and FRAP (r = 0.95), ORAC (r = 0.95) and flavonol content (r = 0.79). © 2011 Elsevier B.V. All rights reserved.Article in Pres