malaria infection among schoolchildren in highland Rwanda

Background Plasmodium infection and malaria in school children are increasingly recognized as a relevant public health problem, but data on actual prevalence and health consequences are insufficient. The present study from highland southern Rwanda aimed at estimating infection prevalence among children attending school, at identifying associated factors and at assessing the clinical consequences of these infections. Methods In a survey including 12 schools in the Huye district of Rwanda, 1089 children aged 6–10 years were clinically and anthropometrically examined, malaria parasites were diagnosed by microscopy and PCR, haemoglobin concentrations were measured, and socio- economic and behavioural parameters as well as medical histories were obtained. Results Upon examination, the vast majority of children was asymptomatic (fever 2.7%). Plasmodium infection was detected in 22.4% (Plasmodium falciparum, 18.8%); 41% of these were submicroscopic. Independent predictors of infection included low altitude, higher age, preceding antimalarial treatment, and absence of electricity or a bicycle in the household. Plasmodium infection was associated with anaemia (mean haemoglobin difference of −1.2 g/dL; 95% CI, −0.8 to −1.5 g/dL), fever, underweight, clinically assessed malnutrition and histories of fever, tiredness, weakness, poor appetite, abdominal pain, and vomiting. With the exception of underweight, these conditions were also increased at submicroscopic infection. Conclusion Malaria infection is frequent among children attending school in southern highland Rwanda. Although seemingly asymptomatic in the vast majority of cases, infection is associated with a number of non-specific symptoms in the children´s histories, in addition to the impact on anaemia. This argues for improved malaria surveillance and control activities among school children

Spitzer-IRS spectra of disks around T Tauri stars II. PAH emission features

Aims: We search for PAH features towards T Tauri stars and compare them with surveys of Herbig Ae/Be stars. The presence and strength of the PAH features are interpreted with disk radiative transfer models exploring the PAH feature dependence on the incident UV radiation, PAH abundance and disk parameters. Methods: Spitzer Space Telescope 5-35 micron spectra of 54 pre-main sequence stars with disks were obtained, consisting of 38 T Tauri, 7 Herbig Ae/Be and 9 stars with unknown spectral type. Results: Compact PAH emission is detected towards at least 8 sources of which 5 are Herbig Ae/Be stars. The 11.2 micron PAH feature is detected in all of these sources, as is the 6.2 micron PAH feature where short wavelength data are available. However, the 7.7 and 8.6 micron features appear strongly in only 1 of these 4 sources. PAH emission is observed towards at least 3 T Tauri stars (8% detection rate). The lowest mass source with PAHs in our sample is T Cha (G8). All 4 sources in our sample with evidence for dust holes in their inner disk show PAH emission, increasing the feature/continuum ratio. Typical 11.2 micron line intensities are an order of magnitude lower than those observed for the more massive Herbig Ae/Be stars. Measured line fluxes indicate PAH abundances that are factors of 10-100 lower than standard interstellar values. Conversely, PAH features from disks exposed to stars with Teff<=4200K without enhanced UV are predicted to be below the current detection limit, even for high PAH abundances. Disk modeling shows that the 6.2 and 11.2 micron features are the best PAH tracers for T Tauri stars, whereas the 7.7 and 8.6 micron bands have low feature over continuum ratios due to the strongly rising silicate emission.Comment: 20 pages, 15 figures, accepted for publication in A&

Probing atmospheric electric fields in thunderstorms through radio emission from cosmic-ray-induced air showers

We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study

Purpose: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course. Methods: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed. Results: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients. Conclusions: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

Beyond the Global Brain Differences:Intraindividual Variability Differences in 1q21.1 Distal and 15q11.2 BP1-BP2 Deletion Carriers

BACKGROUND: Carriers of the 1q21.1 distal and 15q11.2 BP1-BP2 copy number variants exhibit regional and globalbrain differences compared with noncarriers. However, interpreting regional differences is challenging if a globaldifference drives the regional brain differences. Intraindividual variability measures can be used to test for regionaldifferences beyond global differences in brain structure.METHODS: Magnetic resonance imaging data were used to obtain regional brain values for 1q21.1 distal deletion (n =30) and duplication (n = 27) and 15q11.2 BP1-BP2 deletion (n = 170) and duplication (n = 243) carriers and matchednoncarriers (n = 2350). Regional intra-deviation scores, i.e., the standardized difference between an individual’sregional difference and global difference, were used to test for regional differences that diverge from the globaldifference.RESULTS: For the 1q21.1 distal deletion carriers, cortical surface area for regions in the medial visual cortex, posterior cingulate, and temporal pole differed less and regions in the prefrontal and superior temporal cortex differedmore than the global difference in cortical surface area. For the 15q11.2 BP1-BP2 deletion carriers, cortical thicknessin regions in the medial visual cortex, auditory cortex, and temporal pole differed less and the prefrontal andsomatosensory cortex differed more than the global difference in cortical thickness.CONCLUSIONS: We find evidence for regional effects beyond differences in global brain measures in 1q21.1 distaland 15q11.2 BP1-BP2 copy number variants. The results provide new insight into brain profiling of the 1q21.1 distaland 15q11.2 BP1-BP2 copy number variants, with the potential to increase understanding of the mechanismsinvolved in altered neurodevelopment

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

The association of a J-burst with a solar jet

Context. The Sun is an active star that produces large-scale energetic events such as solar flares and coronal mass ejections and numerous smaller-scale events such as solar jets. These events are often associated with accelerated particles that can cause emission at radio wavelengths. The reconfiguration of the solar magnetic field in the corona is believed to be the cause of the majority of solar energetic events and accelerated particles. Aims. Here, we investigate a bright J-burst that was associated with a solar jet and the possible emission mechanism causing these two phenomena. Methods. We used data from the Solar Dynamics Observatory (SDO) to observe a solar jet, and radio data from the Low Frequency Array (LOFAR) and the Nan\c{c}ay Radioheliograph (NRH) to observe a J-burst over a broad frequency range (33-173 MHz) on 9 July 2013 at ~11:06 UT. Results. The J-burst showed fundamental and harmonic components and it was associated with a solar jet observed at extreme ultraviolet wavelengths with SDO. The solar jet occurred at a time and location coincident with the radio burst, in the northern hemisphere, and not inside a group of complex active regions in the southern hemisphere. The jet occurred in the negative polarity region of an area of bipolar plage. Newly emerged positive flux in this region appeared to be the trigger of the jet. Conclusions. Magnetic reconnection between the overlying coronal field lines and the newly emerged positive field lines is most likely the cause of the solar jet. Radio imaging provides a clear association between the jet and the J-burst which shows the path of the accelerated electrons.Comment: 11 pages, 8 figure

Subcortical volumes across the lifespan: Data from 18,605 healthy individuals aged 3–90 years

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to examine age‐related trajectories inferred from cross‐sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3–90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter‐individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age‐related morphometric patterns

Cortical thickness across the lifespan: Data from 17,075 healthy individuals aged 3-90 years

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large‐scale studies. In response, we used cross‐sectional data from 17,075 individuals aged 3–90 years from the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to infer age‐related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta‐analysis and one‐way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes

Prevalence, risk factors, and manifestations of polyparasitism in school children in Rwanda with special consideration of artemisinin resistance in Plasmodium falciparum

Background: Infections with Plasmodium spp., Ascaris lumbricoides and Giardia duodenalis are common among school-aged children in sub-Saharan Africa. Data on the epidemiology and clinical manifestation of co-infections are rare, and while the impact of malaria on children’s health is well known, acute and long-term impairments from supposedly asymptomatic infections with Plasmodium spp. are increasingly recognized. The emergence of artemisinin resistance endangers the previous achievements of malaria control programs. Mutations in the Plasmodium falciparum Kelch 13 (K13) propeller domain are considered to confer artemisinin resistance. Methods: In 2014, 1,089 schoolchildren aged 6–10 years attending 12 schools in the Huye district of Rwanda were clinically and anthro-pometrically examined. Data on the children’s socioeconomic status and medical history were obtained and their blood and stool samples were collected. Infections with Plasmodium spp., A. lumbricoides and G. duodenalis were determined by microscopy and PCR assays. Furthermore, 222 samples of Plasmodium falciparum isolated from the region in 2010, 2014, and 2015 were investigated for the presence of K13 polymorphism. Results: The majority of the 1,089 schoolchildren were asymptomatic (fever 2.7%) upon examination. Plasmodium spp. was detected in 22.4% (41% submicroscopic infections) of children. Associated with Plasmodium spp. infection were anemia, fever, underweight, and clinically assessed malnutrition in addition to nonspecific symptoms (i.e. tiredness, weakness, vomiting) in the children’s medical history. Except for underweight, these conditions were also increased in submicroscopic infections. Considering the prevalence and implications of co-infections, full data on infection status were available for 878 children. Plasmodium spp., A. lumbricoides, and G. duodenalis were present in 22%, 35%, and 36% of children, respectively; 24% of children had co-infections with two or more parasites. The factors associated with parasite infections largely overlapped and reflected low socioeconomic status. Many of the reported and assessed signs and symptoms were associated with Plasmodium spp., and co-infections did not modify the clinical picture significantly. Furthermore, in 2014 and 2015, K13 polymorphisms were detected in 2.5% and 4.5% (none in 2010) of the children, respectively. Two isolates showed K13 resistance mutations (P574L and A675V) associated with delayed parasite clearance. Conclusion: Polyparasitism is common in Rwandan schoolchildren. While the clinical manifestation is predominated by Plasmodium infection, most children seem asymptomatic or present nonspecific symptoms that may nevertheless affect their long-term development. Emerging K13 poly-morphisms associated with artemisinin resistance may aggravate the impact on children’s health. The results form the basis for improved school-based health programs for children in Rwanda.Hintergrund: Infektionen mit Plasmodium spp., Ascaris lumbricoides und Giardia duodenalis sind häufig bei Schulkindern in Subsahara Afrika. Die Datenlage bezüglich der Epidemiologie und der klinischer Manifestation von Koinfektionen stellt sich jedoch unzureichend dar. Während der Einfluss von Malaria auf die kindliche Gesundheit bekannt ist, erhalten Akut- und Langzeitauswirkungen von asymptomatisch erscheinenden Plasmodium- Infektionen erst neuerlich Beachtung. Aufkommende Artemisinin-Resistenzen gefährden neuere Erfolge von Malaria-Kontrollprogrammen. Die Kelch 13 (K13) Propeller-Domaine von Plasmodium falciparum wird mit Artemisinin- Resistenz in Verbindung gebracht. Methoden: Im Jahr 2014 wurden 1089 Schulkinder im Alter von 6-10 Jahren, welche 12 Schulen im Huye-Bezirk Ruandas besuchten, klinisch sowie anthropometrisch untersucht, Daten bezüglich der individuellen medizinischen Vorgeschichte und Sozioökonomie eingeholt sowie deren Blutund Stuhlproben gesammelt. Die Bestimmung von Plasmodium spp., A. lumbricoides und G. duodenalis Infektionen erfolgte durch Mikroskopie und PCR-Verfahren. Weiterführend wurden insgesamt 222 Plasmodium falciparum Isolate von Kindern des Huye-Bezirkes aus den Jahren 2010, 2014 und 2015 mit der Frage nach einer möglichen Präsens von K13-Polymorphismen untersucht. Ergebnisse: Die Mehrheit der 1089 Schulkinder waren asymptomatisch (Fieber 2,7%) am Untersuchungstag. Plasmodium spp. konnte in 22,4% (davon 41% submikroskopische Infektionen) der Fälle detektiert werden. Plasmodium spp. zeigte sich assoziiert mit Anämie, Fieber, Untergewicht, klinischer Mangelernährung sowie weiterer unspezifischer, Symptome, in der medizinischen Vorgeschichte (u.a. Müdigkeit, Schwäche, Erbrechen). Mit der Ausnahme von Untergewicht imponierten diese Beschwerden ebenso im Falle von submikroskopischen Infektionen. Bezüglich der Prävalenz, Risikofaktoren und Auswirkungen von Koinfektionen lagen vollständige Datensätze für 878 der Kinder vor. Plasmodium spp., A. lumbricoides und G. duodenalis waren präsent in 22%, 35% und 36% der Kinder, 24% wiesen Koinfektionen mit zwei oder mehr Parasiten auf. Assoziierte Risikofaktoren für Koinfektionen spiegelten vor allem einen niedrigen soziökonomischen Status wider. Viele der erhobenen und beschriebenen Symptome waren mit einer Plasmodium-Infektion assoziiert, und Koinfektionen modifizierten kaum das klinische Erscheinungsbild. Desweiteren konnten 2014 und 2015 2,5% bzw. 4,5% K13-Polymorphismen von P. falciparum detektiert werden, während dies 2010 nicht der Fall war. Zwei Isolate zeigten K13-Mutationen (P574L und A675V), welche mit verzögerter Parasitenelimination von Artemisinin-Behandlung einhergehen. Schlussfolgerung: Polyparasitismus ist häufig unter ruandischen Schulkindern. Während die Manifestation vor allem durch Plasmodium spp. dominiert wird, präsentieren die meisten Kinder unspezifische Symptome, welche dennoch die Langzeitentwicklung der Kinder beeinflussen. Neu detektierte K13-Polymorphismen mit Assoziation zu Artemisinin-Resistenz gefährden die Gesundheit der Kinder zudem. Die Ergebnisse bilden eine Grundlage für verbesserte schulbasierte Gesundheitsprogramme bei Schulkindern in Ruanda