Active geothermal systems with entrained seawater as analogues for low-sulphidation epithermal mineralization

The paradigm for low-sulphidation (LS) volcanic-arc associated mineralization is the active geothermal systems located along the Taupo Volcanic Zone (e.g. Broadlands). However, this analogue is inapt where fluid salinities are consistently in excess of 3.5 wt % NaCl. LS mineralization on Milos (Aegean arc) records high paleofluid-salinities. The δD and δ18O data do not exemplify 18O-shifted meteoric waters—typical of terrestrial geothermal systems. Nor is a submarine origin indicated—stable isotope data show mixing between meteoric, seawater and volcanic-arc gases. Strontium isotope data are comparable to a nearby active seawater-entrained geothermal system. These are features seen in hydrothermal systems associated with emergent volcanoes. For the Milos LS mineralization, high-salinity fluids show it cannot be explained by a Broadlands-type model. The absence of saliferous sequences and significant intrusive rocks preclude these as salinity sources. The similarities between paleo and active systems in terms of salinity, δD–δ18O and strontium isotope systematics strongly suggest that seawater is the main source for Na and Cl. We suggest geothermal systems, containing seawater, associated with emergent volcanoes are an alternative analogue for LS epithermal mineralization. Furthermore, they bridge the gap between submarine, and large-scale terrestrial geothermal systems—the modern analogues for VHMS and epithermal mineralisation in the scheme of intrusion-centered hydrothermal mineralization

A burden of knowledge: A qualitative study of experiences of neonatal intensive care nurses’ concerns when keeping information from parents

© 2014, © The Author(s) 2014. Improved life-sustaining technology in the neonatal intensive care has resulted in an increased probability of survival for extremely premature babies. In the neonatal intensive care, the condition of a baby can deteriorate rapidly. Nurses and parents are together for long periods at the bedside and so form close and trusting relationships. Neonatal nurses as the constant caregivers may be presented with contradictory demands in attempting to meet the baby’s needs and being a patient and family advocate. This article aims to explore the issues arising for neonatal nurses when holding information about changes to a condition of a baby that they are unable to share with parents. Data were collected via interviews with 24 neonatal nurses in New South Wales, Australia. A qualitative approach was used to analyse the data. The theme ‘keeping secrets’ was identified and comprised of three sub-themes ‘coping with potentially catastrophic news’, ‘fear of inadvertent disclosure’ and ‘a burden that could damage trust’. Keeping secrets and withholding information creates internal conflict in the nurses as they balance the principle of confidentiality with the parent’s right to know information. The neonatal nurses experienced guilt and shame when they were felt forced by circumstances to keep secrets or withhold information from the parents of extremely premature babies

Time for nursing to eradicate hair discrimination

Nurses worldwide have been rightly lauded for their tireless contributions during the global COVID‐19 pandemic. Amid a serious global shortage, nursing remains plagued by recruitment and retention problems as it struggles to attract, educate and retain the best potential nurses who reflect the diverse composition of their communities. The world has been shaken by the Black Lives Matter movement and the growing awareness that many health professions and workplaces are pervasively white, structurally and systemically racist and must change to become welcoming, encouraging places for all members of society. Amid all of this, it is incomprehensible that black nurses in particular continue to be subjected to organisations’ discriminatory ‘hair policies’ (Grant, 2018)

Will nurse leaders help to eradicate 'hair racism' from Nursing and Health Services?

Aims Nurse managers play key roles in creating and enforcing organisational hair policies and practices. This challenging paper will provoke discussion, debate and hopefully the dismantling of racist hair policies that disproportionately target black students and nurses. Background Black people have suffered from centuries of hair racism that continues today. Unfortunately, many nurse leaders underestimate the significance of this issue, while perpetuating the injustice. Evaluation This paper is based on research literature, media reports and authors’ lived experiences regarding hair racism experienced by black people and nurses in particular. Key Issues Nurse managers often create and police organisational hair policies and dress codes. As health services pledge to eradicate racism ‘in principle’, ending discriminatory hair policies offers nurse managers a practical way to make this principle a reality. Conclusions Hair racism is real and damaging for many black nurses and has no place in a modern health service. Rather than designing and policing such structural racism, nurse managers can be instrumental in ending it. Implications for Nursing Management Health service hair policies targeting black nurses especially are not ‘neutral’. Nurse managers can challenge this institutional discrimination, demonstrating health services’ commitment to ending racism in all of its guises

Transition to turbulence in particulate pipe flow

We investigate experimentally the influence of suspended particles on the transition to turbulence. The particles are monodisperse and neutrally-buoyant with the liquid. The role of the particles on the transition depends both upon the pipe to particle diameter ratios and the concentration. For large pipe-to-particle diameter ratios the transition is delayed while it is lowered for small ratios. A scaling is proposed to collapse the departure from the critical Reynolds number for pure fluid as a function of concentration into a single master curve.Comment: 4 pages, 4 figure

Non-deforestation drivers of fires are increasingly important sources of aerosol and carbon dioxide emissions across Amazonia

Deforestation rates have declined substantially across the Brazilian Legal Amazon (BLA) over the period from 2000–2017. However, reductions in fire, aerosol and carbon dioxide have been far less significant than deforestation, even when accounting for inter-annual variability in precipitation. Our observations and analysis support a decoupling between fire and deforestation that has exacerbated forest degradation in the BLA. Basing aerosol and carbon dioxide emissions on deforestation rates, without accounting for forest degradation will bias these important climate and ecosystem-health parameters low, both now and in the future. Recent increases in deforestation rate since 2014 will enhance such degradation, particularly during drought-conditions, increasing emissions of aerosol and greenhouse gases. Given Brazil’s committed Nationally Determined Contribution under the Paris Agreement, failure to account for forest degradation fires will paint a false picture of prior progress and potentially have profound implications for both regional and global climate

Biomass burning aerosol over the Amazon: analysis of aircraft, surface and satellite observations using a global aerosol model

Vegetation fires emit large quantities of aerosol into the atmosphere, impacting regional air quality and climate. Previous work has used comparisons of simulated and observed aerosol optical depth (AOD) in regions heavily impacted by fires to suggest that emissions of aerosol particles from fires may be underestimated by a factor of 2–5. Here we use surface, aircraft and satellite observations made over the Amazon during September 2012, along with a global aerosol model to improve understanding of aerosol emissions from vegetation fires. We apply three different satellite-derived fire emission datasets (FINN, GFED, GFAS) in the model. Daily mean aerosol emissions in these datasets vary by up to a factor of 3.7 over the Amazon during this period, highlighting the considerable uncertainty in emissions. We find variable agreement between the model and observed aerosol mass concentrations. The model reproduces observed aerosol concentrations over deforestation fires well in the western Amazon during dry season conditions with FINN or GFED emissions and during dry–wet transition season conditions with GFAS emissions. In contrast, the model underestimates aerosol concentrations over savanna fires in the Cerrado environment east of the Amazon Basin with all three fire emission datasets. The model generally underestimates AOD compared to satellite and ground stations, even when the model reproduces the observed vertical profile of aerosol mass concentration. We suggest it is likely caused by uncertainties in the calculation of AOD, which are as large as ∼90 %, with the largest sensitivities due to uncertainties in water uptake and relative humidity. Overall, we do not find evidence that particulate emissions from fires are systematically underestimated in the Amazon region and we caution against using comparison with AOD to constrain particulate emissions from fires

Travelling waves in pipe flow

A family of three-dimensional travelling waves for flow through a pipe of circular cross section is identified. The travelling waves are dominated by pairs of downstream vortices and streaks. They originate in saddle-node bifurcations at Reynolds numbers as low as 1250. All states are immediately unstable. Their dynamical significance is that they provide a skeleton for the formation of a chaotic saddle that can explain the intermittent transition to turbulence and the sensitive dependence on initial conditions in this shear flow.Comment: 4 pages, 5 figure

Deaf children's understanding of emotions: desires take precedence

Deaf children frequently have trouble understanding other people's emotions. It has been suggested that an impaired theory of mind can account for this. This research focused on the spontaneous use of mental states in explaining other people's emotions by 6- and 10-year-old deaf children as compared to their hearing peers. Within both age-groups deaf children referred to others' beliefs as often as their hearing peers and their references to desires even exceeded those of hearing children. This relative priority for the expression of desires is discussed in terms of possible communicative patterns of deaf children. The specific problems that deaf children meet in their daily communication might explain their abundance of desire-references: plausibly, they give a high priority to stress their own desires and needs unambiguously