Simulations of secondary Farley-Buneman instability driven by a kilometer-scale primary wave: anomalous transport and formation of flat-topped electric fields

Since the 1950s, high frequency and very high frequency radars near the magnetic equator have frequently detected strong echoes caused ultimately by the Farley‐Buneman instability (FBI) and the gradient drift instability (GDI). In the 1980s, coordinated rocket and radar campaigns made the astonishing observation of flat‐topped electric fields coincident with both meter‐scale irregularities and the passage of kilometer‐scale waves. The GDI in the daytime E region produces kilometer‐scale primary waves with polarization electric fields large enough to drive meter‐scale secondary FBI waves. The meter‐scale waves propagate nearly vertically along the large‐scale troughs and crests and act as VHF tracers for the large‐scale dynamics. This work presents a set of hybrid numerical simulations of secondary FBIs, driven by a primary kilometer‐scale GDI‐like wave. Meter‐scale density irregularities develop in the crest and trough of the kilometer‐scale wave, where the total electric field exceeds the FBI threshold, and propagate at an angle near the direction of total Hall drift determined by the combined electric fields. The meter‐scale irregularities transport plasma across the magnetic field, producing flat‐topped electric fields similar to those observed in rocket data and reducing the large‐scale wave electric field to just above the FBI threshold value. The self‐consistent reduction in driving electric field helps explain why echoes from the FBI propagate near the plasma acoustic speed.NSF grants PHY-1500439 and AGS-1755350 and NASA grant NNX14AI13G supported the research presented in this work. This work used TACC and XSEDE computational resources supported by the National Science Foundation grant ACI-1053575. This paper did not use any data; simulation runs are archived on the TACC Ranch system. The authors thank one anonymous reviewer for helpful comments. (PHY-1500439 - NSF; AGS-1755350 - NSF; NNX14AI13G - NASA; ACI-1053575 - National Science Foundation)Published version2019-07-0

Implementation of the Water Framework Directive in Italy: state of the art and selected research issues

The Water Framework Directive (WFD) was implemented rather late in Italy. The actual implementation took place in 2006 with decree 152/2006 but the Directive was not completely effective until the beginning of 2009, when law 13/2009 provided for the implementation of river basin plans by basin authorities. The objective of this paper is to describe the implementation of the WFD in Italy and to discuss selected policy and research issues. The paper begins with an introduction highlighting the specificities of Italy in terms of water management. With regard to implementation, the general administrative setting, as well as the interpretation of WFD categories related to economic evaluations will be illustrated. Two major issues of particularly high relevance in the present debate are then discussed: a) the evaluation of environmental and resource costs; and b) water regulation in agriculture.Department of Agricultural Economics and Engineering, University of Bologna (Italy). Department of Statistics, University of Bologna (Italy)

Inflammasomes make the case for littermate-controlled experimental design in studying host-microbiota interactions

Several human diseases are thought to evolve due to a combination of host genetic mutations and environmental factors that include alterations in intestinal microbiota composition termed dysbiosis. Although in some cases, host genetics may shape the gut microbiota and enable it to provoke disease, experimentally disentangling cause and consequence in such host-microbe interactions requires strict control over non-genetic confounding factors. Mouse genetic studies previously proposed Nlrp6/ASC inflammasomes as innate immunity regulators of the intestinal ecosystem. In contrast, using littermate-controlled experimental setups, we recently showed that Nlrp6/ASC inflammasomes do not alter the gut microbiota composition. Our analyses indicated that maternal inheritance and long-term separate housing are non-genetic confounders that preclude the use of non-littermate mice when analyzing host genetic effects on intestinal ecology. Here, we summarize and discuss our gut microbiota analyses in inflammasome-deficient mice for illustrating the importance of littermate experimental design in studying host-microbiota interactions

Assessing the impact of future CAP reforms on the demand of production factors

The CAP reform process has been a central issue for agricultural economics research in recent years, and is gaining further attention in view of the post-2013 perspectives. The objective of this paper is to assess ex-ante the effect of different post-2013 CAP and market scenarios on the demand of productions factors. The paper is based on the use of farm household dynamic programming models maximising the net present value with a time horizon until 2030. A representative model has been implemented for 18 different farming systems in 8 EU countries. Changes in marginal values of selected resource constraints (land, labour and capital) are used to assess the potential effect of different scenarios on farm-household demand of production factors. Results highlight that both policy and market conditions change strongly the demand of productive factors

How Does SARS-CoV-2 Affect the Central Nervous System? A Working Hypothesis

Interstitial pneumonia was the first manifestation to be recognized as caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, in just a few weeks, it became clear that the coronavirus disease-2019 (COVID-19) overrun tissues and more body organs than just the lungs, so much so that it could be considered a systemic pathology. Several studies reported the involvement of the conjunctiva, the gut, the heart and its pace, and vascular injuries such as thromboembolic complications and Kawasaki disease in children and toddlers were also described. More recently, it was reported that in a sample of 214 SARS-CoV-2 positive patients, 36.4% complained of neurological symptoms ranging from non-specific manifestations (dizziness, headache, and seizures), to more specific symptoms such hyposmia or hypogeusia, and stroke. Older individuals, especially males with comorbidities, appear to be at the highest risk of developing such severe complications related to the Central Nervous System (CNS) involvement. Neuropsychiatric manifestations in COVID-19 appear to develop in patients with and without pre-existing neurological disorders. Growing evidence suggests that SARS-CoV-2 binds to the human Angiotensin-Converting Enzyme 2 (ACE2) for the attachment and entrance inside host cells. By describing ACE2 and the whole Renin Angiotensin Aldosterone System (RAAS) we may better understand whether specific cell types may be affected by SARS-CoV-2 and whether their functioning can be disrupted in case of an infection. Since clear evidences of neurological interest have already been shown, by clarifying the topographical distribution and density of ACE2, we will be able to speculate how SARS-CoV-2 may affect the CNS and what is the pathogenetic mechanism by which it contributes to the specific clinical manifestations of the disease. Based on such evidences, we finally hypothesize the process of SARS-CoV-2 invasion of the CNS and provide a possible explanation for the onset or the exacerbation of some common neuropsychiatric disorders in the elderly including cognitive impairment and Alzheimer disease

An Exploration of Young Australian Women's Smoking Cessation Goals across the Trajectory of Pregnancy and Post Birth

Objective: Young pregnant women are more likely than other pregnant women to smoke tobacco during pregnancy and post birth. This study explored young women’s perceptions of the factors which impact their smoking cessation goals throughout pregnancy and post birth. Methods: This qualitative descriptive study was performed at two metropolitan obstetric hospitals in Western Australia. Forty three women aged 16 to 24 years old who reported smoking tobacco at their first antenatal visit were interviewed at each scheduled antenatal visit and every two weeks up to six weeks post birth. Interviews were subjected to thematic analysis. Results: A total of 244 interviews were performed; a mean of six interviews per woman (four in pregnancy and two post birth). Four overarching themes across three time periods were identified: the baby; the social bond of smoking; the chaotic nature of life; and access to social support. Pregnant women had a foetus-centric approach to cessation. Post birth those who sustained cessation held this belief for their newborn, whilst those who relapsed did not. The social bond of smoking highlighted smoking as the norm. Initially, women sought out non-smokers to support them. A partner’s smoking status post birth appeared pivotal to remaining tobacco free. The chaotic nature of life, reflected through multiple stressful, negative events, challenged women in achieving their smoking cessation goals. Women who sought social support appeared to stay smoke free post birth. Conclusion: The longitudinal nature of this study provides new insight into complex issues faced by this marginalised group of young, pregnant, tobacco smokers throughout the journey of pregnancy and post birth. Findings enhance our understanding of the complex real life issues some young pregnant Australian smokers face and may be considered when women focused smoking cessation interventions are developed