Initial results from the InSight mission on Mars

NASA’s InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018. It aims to determine the interior structure, composition and thermal state of Mars, as well as constrain present-day seismicity and impact cratering rates. Such information is key to understanding the differentiation and subsequent thermal evolution of Mars, and thus the forces that shape the planet’s surface geology and volatile processes. Here we report an overview of the first ten months of geophysical observations by InSight. As of 30 September 2019, 174 seismic events have been recorded by the lander’s seismometer, including over 20 events of moment magnitude Mw = 3–4. The detections thus far are consistent with tectonic origins, with no impact-induced seismicity yet observed, and indi- cate a seismically active planet. An assessment of these detections suggests that the frequency of global seismic events below approximately Mw = 3 is similar to that of terrestrial intraplate seismic activity, but there are fewer larger quakes; no quakes exceeding Mw = 4 have been observed. The lander’s other instruments—two cameras, atmospheric pressure, temperature and wind sensors, a magnetometer and a radiometer—have yielded much more than the intended supporting data for seismometer noise characterization: magnetic field measurements indicate a local magnetic field that is ten-times stronger than orbital estimates and meteorological measurements reveal a more dynamic atmosphere than expected, hosting baroclinic and gravity waves and convective vortices. With the mission due to last for an entire Martian year or longer, these results will be built on by further measurements by the InSight lander

Properties of the cellular prion protein expressed in Xenopus oocytes

The cellular prion protein (PrPC) from different species can be reproducibly expressed in Xenopus oocytes following injection of in vitro transcribed mRNAs. The level of PrPC accumulation increases with the amount of RNA injected and with the duration of incubation. PrPC expressed in oocytes is similar in size and abundance to PrPC: protein in mouse brain and > 100 ng of PrPC is expressed per oocyte allowing complete experiments to be carried out in single living cells. The protein is glycosylated, fully protease sensitive and expressed on the cell surface. Xenopus oocytes therefore provide a useful model system for the study of prion proteins and their associated disease processes

Prion Protein Accumulation and Neuroprotection in Hypoxic Brain Damage

The function of the normal conformational isoform of prion protein, PrP(C), remains unclear although lines of research have suggested a role in the cellular response to oxidative stress. Here we investigate the expression of PrP(C) in hypoxic brain tissues to examine whether PrP(C) is in part regulated by neuronal stress. Cases of adult cerebral ischemia and perinatal hypoxic-ischemic injury in humans were compared with control tissues. PrP(C) immunoreactivity accumulates within neuronal processes in the penumbra of hypoxic damage in adult brain, and within neuronal soma in cases of perinatal hypoxic-ischemic injury, and in situ hybridization analysis suggests an up-regulation of PrP mRNA during hypoxia. Rodents also showed an accumulation of PrP(C) in neuronal soma within the penumbra of ischemic lesions. Furthermore, the infarct size in PrP-null mice was significantly greater than in the wild type, supporting the proposed role for PrP(C) in the neuroprotective adaptive cellular response to hypoxic injury

Individual socio-demographic factors and perceptions of the environment as determinants of inequalities in adolescent physical and psychological health: the Olympic Regeneration in East London (ORiEL) study.

BACKGROUND: Populations living in urban areas experience greater health inequalities as well as higher absolute burdens of illness. It is well-established that a range of social and environmental factors determine these differences. Less is known about the relative importance of these factors in determining adolescent health within a super diverse urban context. METHODS: A cross-sectional sample of 3,105 adolescent participants aged 11 to 12 were recruited from 25 schools in the London boroughs of Newham, Tower Hamlets, Hackney and Barking & Dagenham. Participants completed a pseudo-anonymised paper-based questionnaire incorporating: the Warwick-Edinburgh Mental Well-being Scale used for assessing positive mental well-being, the Short Moods and Feelings Questionnaire based on the DSM III-R criteria for assessment of depressive symptoms, the Youth-Physical Activity Questionnaire and a self-assessment of general health and longstanding illness. Prevalence estimates and unadjusted linear models estimate the extent to which positive well-being scores and time spent in physical/sedentary activity vary by socio-demographic and environmental indicators. Logistic regression estimated the unadjusted odds of having fair/(very)poor general health, a long standing illness, or depressive symptoms. Fully adjusted mixed effects models accounted for clustering within schools and for all socio-demographic and environmental indicators. RESULTS: Compared to boys, girls had significantly lower mental well-being and higher rates of depressive symptoms, reported fewer hours physically active and more hours sedentary, and had poorer general health after full adjustment. Positive mental well-being was significantly and positively associated with family affluence but the overall relationship between mental health and socioeconomic factors was weak. Mental health advantage increased as positive perceptions of the neighbourhood safety, aesthetics, walkability and services increased. Prevalence of poor health varied by ethnic group, particularly for depressive symptoms, general health and longstanding illness suggesting differences in the distribution of the determinants of health across ethnic groups. CONCLUSIONS: During adolescence perceptions of the urban physical environment, along with the social and economic characteristics of their household, are important factors in explaining patterns of health inequality

Male Infertility and DNA Damage in Doppel Knockout and Prion Protein/Doppel Double-Knockout Mice

The prion protein (PrP) and Doppel (Dpl) have many structural and biochemical properties in common, leading to the suggestion that the lack of an obvious phenotype in PrP-deficient mice maybe because of compensation by Dpl. To test this hypothesis and also investigate the function of Dpl we have generated Prnd(−/−) and Prnp(−/−)/Prnd(−/−) mouse lines. Both develop normally and display an identical male sterility phenotype that differs from that reported for another Prnd(−/−) mouse line. Sperm from both our mutant lines were present at normal concentrations, had normal motility, and no morphological abnormalities. Despite only rarely fertilizing oocytes in vivo, because of an inability to perform the acrosome reaction, mutant sperm were capable of fertilization in vitro, albeit at reduced rates compared to wild type. Elevated levels of oxidative DNA damage were found in both types of mutant sperm and resulting embryos failed at an early stage. Therefore we found no evidence that Dpl compensates for the loss of PrP function in mutant mouse lines, but it does have an important anti-oxidant function necessary for sperm integrity and male fertility