Design and assembly sequence analysis of option 3 for CETF reference space station

A design and assembly sequence was conducted on one option of the Dual Keel Space Station examined by a NASA Critical Evaluation Task Force to establish viability of several variations of that option. A goal of the study was to produce and analyze technical data to support Task Force decisions to either examine particular Option 3 variations in more depth or eliminate them from further consideration. An analysis of the phasing assembly showed that use of an Expendable Launch Vehicle in conjunction with the Space Transportation System (STS) can accelerate the buildup of the Station and ease the STS launch rate constraints. The study also showed that use of an Orbital Maneuvering Vehicle on the first flight can significantly benefit Station assembly and, by performing Station subsystem functions, can alleviate the need for operational control and reboost systems during the early flights. In addition to launch and assembly sequencing, the study assessed stability and control, and analyzed node-packaging options and the effects of keel removal on the structural dynamics of the Station. Results of these analyses are presented and discussed

Effect of substrate thermal resistance on space-domain microchannel

In recent years, Fluorescent Melting Curve Analysis (FMCA) has become an almost ubiquitous feature of commercial quantitative PCR (qPCR) thermal cyclers. Here a micro-fluidic device is presented capable of performing FMCA within a microchannel. The device consists of modular thermally conductive blocks which can sandwich a microfluidic substrate. Opposing ends of the blocks are held at differing temperatures and a linear thermal gradient is generated along the microfluidic channel. Fluorescent measurements taken from a sample as it passes along the micro-fluidic channel permits fluorescent melting curves to be generated. In this study we measure DNA melting temperature from two plasmid fragments. The effects of flow velocity and ramp-rate are investigated, and measured melting curves are compared to those acquired from a commercially available PCR thermocycler

Prey preference in a kleptoplastic dinoflagellate is linked to photosynthetic performance

Dinoflagellates of the family Kryptoperidiniaceae, known as “dinotoms”, possess diatom-derived endosymbionts and contain individuals at three successive evolutionary stages: a transiently maintained kleptoplastic stage; a stage containing multiple permanently maintained diatom endosymbionts; and a further permanent stage containing a single diatom endosymbiont. Kleptoplastic dinotoms were discovered only recently, in Durinskia capensis; until now it has not been investigated kleptoplastic behavior and the metabolic and genetic integration of host and prey. Here, we show D. capensis is able to use various diatom species as kleptoplastids and exhibits different photosynthetic capacities depending on the diatom species. This is in contrast with the prey diatoms in their free-living stage, as there are no differences in their photosynthetic capacities. Complete photosynthesis including both the light reactions and the Calvin cycle remain active only when D. capensis feeds on its habitual associate, the “essential” diatom Nitzschia captiva. The organelles of another edible diatom, N. inconspicua, are preserved intact after ingestion by D. capensis and expresses the psbC gene of the photosynthetic light reaction, while RuBisCO gene expression is lost. Our results indicate that edible but non-essential, “supplemental” diatoms are used by D. capensis for producing ATP and NADPH, but not for carbon fixation. D. capensis has established a species-specifically designed metabolic system allowing carbon fixation to be performed only by its essential diatoms. The ability of D. capensis to ingest supplemental diatoms as kleptoplastids may be a flexible ecological strategy, to use these diatoms as “emergency supplies” while no essential diatoms are available.Open Access funding enabled and organized by Projekt DEAL.We are grateful to Dr Benjamin Bailleul for discussing the photoactivity possibility of N. inconspicua, and to Prof Dieter Spiteller and Dr Adrien Lapointe for suggesting the feeding experiment of D. capensis with four selected diatoms. We also thank Dr Martin Stöckl, from the Bioimaging Centre at University of Konstanz, for technical support of the CLSM. Our thanks also go to Ms Selina Pucher and Mr Alexander H. Fürst for discussing the RT-qPCR data analyses and evaluation, and to Mr Niccolo Mosesso for discussing the TEM protocol improvement. This research was supported by the Bridging Stipend of University of Konstanz (No.638/20, granted to NY), the DFG Research Grant (No. YA 577/2-1, granted to NY), and the Symbiosis Model Systems Award (No. GBMF9360, granted to NY, RT, DGM, PGK) of the Gordon and Betty Moore Foundation. The CERCA Programme of Generalitat of Catalonia is also acknowledged. The Royal Botanic Garden Edinburgh is supported by the Scottish Government’s Rural and Environment Science and Analytical Services Division.info:eu-repo/semantics/publishedVersio

Mortalité néonatale au centre hospitalier universitaire de Tengandogo, Ouagadougou, Burkina Faso: une étude de cohorte retrospective: Neonatal mortality at Tengandogo University Hospital, Ouagadougou, Burkina Faso: a retrospective cohort study

Introduction: Selon l’organisation mondiale de la santé, les décès néonataux représentent 41% de la mortalité infanto-juvénile. L’Afrique subsaharienne a le taux de mortalité néonatale le plus élevé à 28‰. L’objectif de l’étude était de mesurer le taux de mortalité néonatale et d’identifier les facteurs associés au décès au Centre hospitalier universitaire de Tengandogo, Ouagadougou, Burkina Faso. Méthodes: Les nouveaux nés de 0 à 28 jours, hospitalisés entre le 1er janvier 2013 et le 31 décembre 2017 ont été inclus dans cette étude de cohorte rétrospective au service de néonatologie et de pédiatrie. Les informations ont été extraites à partir des dossiers cliniques. La survie a été estimée par la méthode de Kaplan Meier. Un modèle de Cox a permis d’identifier les facteurs associés. Résultats: Au total 641 nouveau-nés ont été inclus. Les enfants admis dès le premier jour de leur naissance représentaient 80%. La durée médiane de séjour était de 6 jours avec un intervalle interquartile de 3-12 jours. Les principaux diagnostics étaient la prématurité (36,05%), les infections néonatales (33,23%) et l’asphyxie (17,86%). Le taux de mortalité néonatale était de 22,25 pour 1000 personnes jours. Après ajustement, le poids de naissance inferieur 1500gramme (HRa = 4,13 ; IC 95% (2,58-6,67)) et la notion de réanimation à la naissance (HRa2,62 ; IC 95% [1,64-4,39)) étaient les facteurs de risque. Conclusion: Le taux de mortalité néonatale reste élevé. Le suivi prénatal, la prévention des infections, le renforcement des moyens de réanimation et la compétence des acteurs sont essentiels pour réduire ce taux. Introduction: According to the World Health Organization, neonatal deaths account for 41% of infant and child mortality. Sub-Saharan Africa has the highest neonatal mortality rate at 28‰. The objective of the study was to measure the neonatal mortality rate and identify factors associated with death at the Tengandogo University Hospital, Ouagadougou, Burkina Faso. Method: New-borns aged 0 to 28 days, hospitalised between 1 January 2013 and 31 December 2017 were included in this retrospective cohort study in the neonatology and paediatrics department. Information was extracted from clinical records. Survival was estimated by the Kaplan Meier method. A Cox model was used to identify associated factors. Results: A total of 641 new-borns were included. Children admitted on the first day of birth accounted for 80%. The median length of stay was 6 days with an interquartile range of 3-12 days. The main diagnoses were prematurity (36.05%), neonatal infections (33.23%) and asphyxia (17.86%). The neonatal mortality rate was 22.25 per 1000 person days. After adjustment, birth weight below 1500 grams (HRa = 4.13; 95% CI (2.58-6.67)) and the notion of resuscitation at birth (HRa2.62; 95% CI (1.64-4.39)) were the risk factors. Conclusion: The neonatal mortality rate remains high. Prenatal follow-up, infection prevention, strengthening of resuscitation resources and competence of actors are essential to reduce this rate

A community effectiveness trial of strategies promoting intermittent preventive treatment with sulphadoxine-pyrimethamine in pregnant women in rural Burkina Faso

<p>Abstract</p> <p>Background</p> <p>Intermittent preventive treatment with sulphadoxine-pyrimethamine for pregnant women (IPTp-SP) is currently being scaled up in many countries in sub-Saharan Africa. Despite high antenatal clinic (ANC) attendance, coverage with the required two doses of SP remains low. The study investigated whether a targeted community-based promotion campaign to increase ANC attendance and SP uptake could effectively improve pregnancy outcomes in the community.</p> <p>Methods</p> <p>Between 2004 and 2006 twelve health centres in Boromo Health District, Burkina Faso were involved in this study. Four were strategically assigned to community promotion in addition to IPTp-SP (Intervention A) and eight were randomly allocated to either IPTp-SP (Intervention B) or weekly chloroquine (Control). Primi- and secundigravidae were enrolled at village level and thick films and packed cell volume (PCV) taken at 32 weeks gestation and at delivery. Placental smears were prepared and newborns weighed. Primary outcomes were peripheral parasitaemia during pregnancy and at delivery, placental malaria, maternal anaemia, mean and low birth weight. Secondary outcomes were the proportion of women with ≥ 3 ANC visits and ≥ 2 doses of SP. Intervention groups were compared using logistic and linear regression with linearized variance estimations to correct for the cluster-randomized design.</p> <p>Results</p> <p>SP uptake (≥ 2 doses) was higher with (Intervention A: 70%) than without promotion (Intervention B: 49%) (OR 2.45 95%CI 1.25–4.82 p = 0.014). Peripheral (33.3%) and placental (30.3%) parasite rates were significantly higher in the control arm compared to Intervention B (peripheral: 20.1% OR 0.50 95%CI 0.37–0.69 p = 0.001; placental: 20.5% OR 0.59 95%CI 0.44–0.78 p = 0.002) but did not differ between Intervention A (17.4%; 18.1%) and Intervention B (20.1; 20.5%) (peripheral: OR 0.84 95%CI 0.60–1.18 p = 0.280; placental: OR 0.86 95%CI 0.58–1.29 p = 0.430). Mean PCV and birth weight and prevalence of anaemia and low birth weight did not differ between study arms.</p> <p>Conclusion</p> <p>The promotional campaign resulted in a major increase in IPTp-coverage, with two thirds of women at delivery having received ≥ 2 SP. Despite lower prevalence of malaria infection this did not translate into a significant difference in maternal anaemia or birth weight. This data provides evidence that, as with immunization programmes, extremely high coverage is essential for effectiveness. This critical threshold of coverage needs to be defined, possibly on a regional basis.</p

Therapeutic hypothermia

Pioneer works on therapeutic hypothermia (TH) half a century ago already showed promising results but clinical application was limited by a lack of understanding of the underlying pathophysiology, lack of reliable method for temperature control and lack of intensive care facilities to deal with possible complications. More recently, 2 studies in 2002 supported the application of moderate TH (32.0-34.0℃) in post-cardiac arrest patients. Although the studies included only patients suffering from out-of-hospital VF, many ICUs world-wide are applying the therapy to all post-cardiac arrest patients irrespective of site or presenting rhythm. While primary coagulopathy and cardiogenic shock are usually stated as relative contraindications, evidences are accumulating to support the application of TH in patients with cardiogenic shock. TH can be divided into 4 phases: Induction, maintenance, de-cooling and normothermia. Induction is usually achieved by infusion of cold isotonic fluid. The precautions included avoidance of over-cooling, hypokalaemia, hyperglycaemia, and shivering. TH can be maintained by many different methods, varying in their level of invasiveness, cost and effectiveness. Issues including changes in pharmacokinetics and haemodynamics, and susceptibility to infection need to the addressed. The optimal duration of maintenance is unknown but the usual practice is 12-24 hours. De-cooling and rewarming is especially challenging because complications can be serious if temperature rise by more than 1℃ every 3-5 hours. Life-theatening hyperkalaemia can occur especially if patient suffers from renal insufficiency. Fever is a frequent complication either due to infection or post-cardiac arrest syndrome but patient must be kept normothermic for 72 hours

An improved method for constructing and selectively silanizing double-barreled, neutral liquid-carrier, ion-selective microelectrodes

We describe an improved, efficient and reliable method for the vapour-phase silanization of multi-barreled, ion-selective microelectrodes of which the silanized barrel(s) are to be filled with neutral liquid ion-exchanger (LIX). The technique employs a metal manifold to exclusively and simultaneously deliver dimethyldichlorosilane to only the ion-selective barrels of several multi-barreled microelectrodes. Compared to previously published methods the technique requires fewer procedural steps, less handling of individual microelectrodes, improved reproducibility of silanization of the selected microelectrode barrels and employs standard borosilicate tubing rather than the less-conventional theta-type glass. The electrodes remain stable for up to 3 weeks after the silanization procedure. The efficacy of a double-barreled electrode containing a proton ionophore in the ion-selective barrel is demonstrated in situ in the leaf apoplasm of pea (Pisum) and sunflower (Helianthus). Individual leaves were penetrated to depth of ~150 μm through the abaxial surface. Microelectrode readings remained stable after multiple impalements without the need for a stabilizing PVC matrix