Africa’s COVID-19 story: cheap innovation technology and climate protective effect to her rescue?

As the COVID-19 pandemic sweeps the globe, causing tens of thousands of deaths in most Western countries with economies round the world in turmoil, Africa has so far been largely spared the kind of impact that has thrown the United States, South America and Europe into crisis. Most African countries remain seriously unprepared to handle the pandemic of the nature the Western world is dealing with; Africa, from Mali to Ethiopia to Libya and down to South Africa, have insufficient ventilators or intensive care beds to cope with COVID-19 should it strike with ferocity as it is doing in the Western world. As COVID-19 reaches the shores of Africa, despite poor health facilities, poor living conditions and inadequate availability of clean water across the continent, Africans are still putting up a fight taking COVID-19 head on with use of cheap technology, and help from the continent’s protective climate. However, Africa cannot afford to be complacent. African countries must continue to adopt strict social distancing measures, educate their people on the importance of intake of regular vitamin D, good exercising habit, good sleep pattern, adequate hand hygiene measures, as well as strictly enforcing the “test, trace and isolate“ model to the letter for the continent to take on the fight head on and wage a proper war against COVID-19. Keywords: SARS-COV-2; COVID-19; innovation; technology; climate; Africa   English title: L'histoire du COVID-19 en Afrique: une technologie d'innovation bon marché et un effet protecteur du climat à sa rescousse? Alors que la pandémie du COVID-19 balaie le globe, causant des dizaines de milliers de morts dans la plupart des pays occidentaux avec des économies du monde entier en crise, l'Afrique a jusqu'à présent été largementépargnée par le type d'impact qui a jeté les États-Unis, l'Amérique du Sud et l'Europe en crise. La plupart despays africains ne sont pas vraiment préparés à faire face à la pandémie de la nature à laquelle le monde occidental est confronté; L'Afrique, du Mali à l'Éthiopie en passant par la Libye et jusqu'en Afrique du Sud, ne dispose pas de ventilateurs ou de lits de soins intensifs insuffisants pour faire face au COVID-19 s'il frappe avec férocité comme dans le monde occidental. Alors que le COVID-19 atteint les rives de l'Afrique, malgré des installations de santé médiocres, des conditions de vie médiocres et une disponibilité insuffisante d'eau potable à travers le continent, les Africains continuent de se battre en prenant le COVID-19 de front avec l'utilisation d'une technologie bon marché et l'aide de le climat protecteur du continent. Cependant, l'Afrique ne peut pas se permettre d'être complaisante. Les pays africains doivent continuer à adopter des mesures de distanciation sociale strictes, éduquer leur population sur l'importance de l'apport régulier de vitamine D, de bonnes habitudes d'exercice, un bon sommeil, des mesures d'hygiène des mains adéquates, ainsi que l'application stricte du «test, traçage et isolement». modèle à la lettre pour que le continent se batte de front et mène une véritable guerre contre le COVID-19. Mots clés: SRAS-COV-2; COVID-19; innovation; La technologie; climat; Afriqu

How robust is the evidence of an emerging or increasing female excess in physical morbidity between childhood and adolescence? Results of a systematic literature review and meta-analyses

For asthma and psychological morbidity, it is well established that higher prevalence among males in childhood is replaced by higher prevalence among females by adolescence. This review investigates whether there is evidence for a similar emerging female ‘excess’ in relation to a broad range of physical morbidity measures. Establishing whether this pattern is generalised or health outcome-specific will further understandings of the aetiology of gender differences in health. Databases (Medline; Embase; CINAHL; PsycINFO; ERIC) were searched for English language studies (published 1992–2010) presenting physical morbidity prevalence data for males and females, for at least two age-bands within the age-range 4–17 years. A three-stage screening process (initial sifting; detailed inspection; extraction of full papers), was followed by study quality appraisals. Of 11 245 identified studies, 41 met the inclusion criteria. Most (n = 31) presented self-report survey data (five longitudinal, 26 cross-sectional); 10 presented routinely collected data (GP/hospital statistics). Extracted data, supplemented by additional data obtained from authors of the included studies, were used to calculate odds ratios of a female excess, or female:male incident rate ratios as appropriate. To test whether these changed with age, the values were logged and regressed on age in random effects meta-regressions. These showed strongest evidence of an emerging/increasing female excess for self-reported measures of headache, abdominal pain, tiredness, migraine and self-assessed health. Type 1 diabetes and epilepsy, based on routinely collected data, did not show a significant emerging/increasing female excess. For most physical morbidity measures reviewed, the evidence broadly points towards an emerging/increasing female excess during the transition to adolescence, although results varied by morbidity measure and study design, and suggest that this may occur at a younger age than previously thought

Spin-Dependent Tunneling of Single Electrons into an Empty Quantum Dot

Using real-time charge sensing and gate pulsing techniques we measure the ratio of the rates for tunneling into the excited and ground spin states of a single-electron AlGaAs/GaAs quantum dot in a parallel magnetic field. We find that the ratio decreases with increasing magnetic field until tunneling into the excited spin state is completely suppressed. However, we find that by adjusting the voltages on the surface gates to change the orbital configuration of the dot we can restore tunneling into the excited spin state and that the ratio reaches a maximum when the dot is symmetric.Comment: 4 pages, 3 figure

Electrical control of spin relaxation in a quantum dot

We demonstrate electrical control of the spin relaxation time T_1 between Zeeman split spin states of a single electron in a lateral quantum dot. We find that relaxation is mediated by the spin-orbit interaction, and by manipulating the orbital states of the dot using gate voltages we vary the relaxation rate W= (T_1)^-1 by over an order of magnitude. The dependence of W on orbital confinement agrees with theoretical predictions and from these data we extract the spin-orbit length. We also measure the dependence of W on magnetic field and demonstrate that spin-orbit mediated coupling to phonons is the dominant relaxation mechanism down to 1T, where T_1 exceeds 1s.Comment: 4 pages, 3 figure

Energy Dependent Tunneling in a Quantum Dot

We present measurements of the rates for an electron to tunnel on and off a quantum dot, obtained using a quantum point contact charge sensor. The tunnel rates show exponential dependence on drain-source bias and plunger gate voltages. The tunneling process is shown to be elastic, and a model describing tunneling in terms of the dot energy relative to the height of the tunnel barrier quantitatively describes the measurements.Comment: 4 pages, 4 figure

Stage progression and neurological symptoms in Trypanosoma brucei rhodesiense sleeping sickness: role of the CNS inflammatory response

Background: Human African trypanosomiasis progresses from an early (hemolymphatic) stage, through CNS invasion to the late (meningoencephalitic) stage. In experimental infections disease progression is associated with neuroinflammatory responses and neurological symptoms, but this concept requires evaluation in African trypanosomiasis patients, where correct diagnosis of the disease stage is of critical therapeutic importance. Methodology/Principal Findings: This was a retrospective study on a cohort of 115 T.b.rhodesiense HAT patients recruited in Eastern Uganda. Paired plasma and CSF samples allowed the measurement of peripheral and CNS immunoglobulin and of CSF cytokine synthesis. Cytokine and immunoglobulin expression were evaluated in relation to disease duration, stage progression and neurological symptoms. Neurological symptoms were not related to stage progression (with the exception of moderate coma). Increases in CNS immunoglobulin, IL-10 and TNF-α synthesis were associated with stage progression and were mirrored by a reduction in TGF-β levels in the CSF. There were no significant associations between CNS immunoglobulin and cytokine production and neurological signs of disease with the exception of moderate coma cases. Within the study group we identified diagnostically early stage cases with no CSF pleocytosis but intrathecal immunoglobulin synthesis and diagnostically late stage cases with marginal CSF pleocytosis and no detectable trypanosomes in the CSF. Conclusions: Our results demonstrate that there is not a direct linkage between stage progression, neurological signs of infection and neuroinflammatory responses in rhodesiense HAT. Neurological signs are observed in both early and late stages, and while intrathecal immunoglobulin synthesis is associated with neurological signs, these are also observed in cases lacking a CNS inflammatory response. While there is an increase in inflammatory cytokine production with stage progression, this is paralleled by increases in CSF IL-10. As stage diagnostics, the CSF immunoglobulins and cytokines studied do not have sufficient sensitivity to be of clinical value

Protein-mediated dethreading of a biotin-functionalised pseudorotaxane

In this article, we describe the synthesis of new biotin-functionalised naphthalene derivatives 3 and 4 and their complexation behaviour with avidin and neutravidin using a range of analytical techniques. We have shown using 2-(4prime or minute-hydroxyazobenzene)benzoic acid displacement and ITC experiments{,} that compounds 3 and 4 have the propensity to form reasonably high-affinity bioconjugates with avidin and neutravidin. We have also demonstrated using 1H NMR{,} UV-vis and fluorescence spectroscopy that the naphthalene moiety of 3 and 4 facilitates the formation of pseudorotaxane-like structures with 1 in water. We have then investigated the ability of avidin and neutravidin to modulate the complexation between 1 and 3 or 4. UV-vis and fluorescence spectroscopy has shown that in both cases the addition of the protein disrupts complexation between the naphthalene moieties of 3 and 4 with 1