Carbon sequestration on Mars

On Earth, carbon sequestration in geologic units plays an important role in the carbon cycle, scrubbing CO_2 from the atmosphere for long-term storage. While carbonate is identified in low abundances within the dust and soils of Mars, at <1 wt% in select meteorites, and in limited outcrops, no massive carbonate rock reservoir on Mars has been identified to date. Here, we investigate the largest exposed carbonate-bearing rock unit, the Nili Fossae plains, combining spectral, thermophysical, and morphological analyses to evaluate the timing and carbon sequestration potential of rocks on Mars. We find that the olivine-enriched (∼20%–25%) basalts have been altered, by low-temperature in situ carbonation processes, to at most ∼20% Fe-Mg carbonate, thus limiting carbon sequestration in the Nili Fossae region to ∼0.25–12 mbar of CO_2 during the late Noachian–early Hesperian, before or concurrent with valley network formation. While this is large compared to modern-day CO_2 reservoirs, the lack of additional, comparably sized post–late Noachian carbonate-bearing deposits on Mars indicates ineffective carbon sequestration in rock units over the past ∼3.7 b.y. This implies a thin atmosphere (≲500 mbar) during valley network formation, extensive post-Noachian atmospheric loss to space, or diffuse, deep sequestration by a yet-to-be understood process. In stark contrast to Earth’s biologically mediated crust:atmosphere carbon reservoir ratio of ∼10^4–10^5, Mars’ ratio is a mere ∼10–10^3, even if buried pre-Noachian crust holds multiple bars

Interventions to mitigate the risks of COVID-19 for people experiencing homelessness, and their effectiveness: systematic review

ObjectivesPeople experiencing homelessness also experience poorer clinical outcomes of COVID-19. Various interventions were implemented for people experiencing homelessness in 2020-22 in different countries in response to varied national guidance to limit this impact of COVID-19. It is important to understand what was done and the effectiveness of such interventions. This systematic review aims to describe interventions to mitigate the risks of COVID-19 in people experiencing homelessness and their effectiveness.MethodsA protocol was developed and registered in PROSPERO. Nine databases were searched for studies on interventions to mitigate the impact of COVID-19 in people experiencing homelessness. Included studies were summarised with narrative synthesis.ResultsFrom 8233 references retrieved from the database searches and handsearching, 15 were included. There was a variety of interventions, including early identification of potential COVID-19 infections, provision of isolation space, healthcare support, and urgent provision of housing regardless of COVID-19 infection. ConclusionThe strategies identified were generally found to be effective, feasible and transferable. This review must be interpreted with caution due to the low volume of eligible studies, and low quality of the evidence available. <br/

Prevention of Postpartum Haemorrhage: Economic evaluation of the novel Butterfly device in a UK setting

ObjectivesTo explore the cost-effectiveness of a novel PPH device as compared with usual care.DesignA decision analytical model was used to explore the cost-effectiveness of the PPH Butterfly device compared with usual care. This was part of a United Kingdom, UK, clinical trial ISRCTN15452399 using a matched historical cohort who had standard PPH management without the use of the PPH Butterfly device. The economic evaluation was conducted from a UK National Health Service (NHS) perspective.SettingLiverpool Women's Hospital, UK.Participants57 women with 113 matched controls.InterventionThe PPH Butterfly is a novel device that has been invented and developed in the UK to facilitate bimanual compression of the uterus in the treatment of PPH.Main outcome measuresMain outcome measures included healthcare costs, blood loss, and maternal morbidity events.ResultsMean treatment costs in the Butterfly cohort were £3,459.66 as compared with standard care £3,223.93. Treatment with the Butterfly device resulted in decreased total blood loss in comparison with standard care. The Butterfly device had an incremental cost-effectiveness ratio of £3,795.78 per PPH progression avoided (defined as ≤ 1000 ml additional blood loss from device insertion point). If the NHS is prepared to pay £8,500 per PPH progression avoided, then the Butterfly device is cost-effective with a probability of 87 percent. In the PPH Butterfly treatment arm there were 9% fewer cases of massive obstetric haemorrhage (severe PPH of more than 2000mls or more than 4 units of blood transfusion required) recorded as compared with the standard care historical cohort. As a low-cost device, the PPH Butterfly device is cost-effective but can be cost-saving to the NHS.ConclusionThe PPH pathway can result in high-cost resource use such as blood transfusion or high dependence unit hospital stays. The Butterfly device is a relative low-cost device in a UK NHS setting with a high probability of being cost-effective. The National Institute for Health and Care Excellence (NICE) can use this evidence in considering the adoption of innovative technologies such as the Butterfly device in the NHS. Extrapolation on an international scale to lower and middle-income countries could prevent mortality associated with PPH

The impact of secondary forest regeneration on ground-dwelling ant communities in the Tropical Andes

Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants play crucial roles in ecosystem functioning, and a key question is how time since abandonment and elevation (and inherent temperature gradients therein) affect patterns of ant recovery within secondary forest systems. Focusing on the Colombian Andes across a 1300 m altitudinal gradient and secondary forest (2–30 years) recovering on abandoned cattle pastures, we find that over time ant community composition and species richness recovered towards that of primary forest. However, these relationships are strongly dependent on elevation with the more open and warmer pasturelands supporting more ants than either primary or secondary forest at a particular elevation. The loss of species richness and change in species composition with elevation is less severe in pasture than forests, suggesting that conditions within pasture and its remaining scattered trees, hedgerows and forest fragments, are more favourable for some species, which are likely in or near thermal debt. Promoting and protecting natural regenerating forests over the long term in the montane tropics will likely offer significant potential for returning ant communities towards primary forest levels