Application of Mineral Equilibria to Constrain the Nature of Mantle Fluids Using Mantle Xenoliths

Mantle processes (e.g., melting and deformation) are controlled, in part, by the availability of H₂O. Therefore, determining values of the activity of H₂O (aH₂O) will yield a better understanding of these complex mantle processes. The amount of H₂O contained in the mantle is typically estimated from the H₂O contents of nominally anhydrous mantle minerals (NAMs). Mineral equilibria have also been used to estimate values of aH₂O as well as values of hydrogen (ƒH₂) and oxygen fugacities (ƒO₂) in samples from the Earth’s mantle. Unlike NAMs, which may be prone to H-loss via diffusion during emplacement on Earth’s surface, dehydration equilibria are relatively resistant to re-equilibration and therefore, may be a better approach at constraining the H₂O content of the upper mantle. Equilibria between co-existing minerals have been used to estimate values of temperature (T), pressure (P), ƒO₂, ƒH₂ (where ƒ = fugacity) and aH₂O for twenty amphibole-bearing xenoliths from three different regions, Eastern Australia, Southwestern U.S.A, and South Africa. The xenoliths contain an assemblage of olivine + orthopyroxene + clinopyroxene + amphibole + spinel ± garnet. All of the samples record low values of aH₂O (<0.20), as inferred from amphibole dehydration equilibria at PT conditions that range from 1.1 to 3.0 GPa and 690 to 980°C, respectively. Values of ƒH₂ estimated using amphibole dehydrogenation equilibria, and values of ƒO₂ estimated using oxidation equilibria involving spinel + olivine + orthopyroxene were combined toyield a second estimate of aH₂O; values, which are consistent with the values of aH₂O, estimated using amphibole equilibria. These low values of aH₂O are also consistent with low H₂O contents in NAMS that have been measured using FTIR spectroscopy. Furthermore, values of ƒO₂ have been used to constrain values of the fugacities of other fluid species in the C-O-H system. Calculations based on C-O-H equilibria yield H₂O rich conditions, which are significantly different from values of aH₂O from amphibole equilibria suggesting that the fluid pressure is lower than the lithostatic pressure and that these samples equilibrated in a fluid-absent system

Addressing Nature-Deficit Disorder Using A Multi-program Area, Multi-State Approach

Youth are spending less time outdoors compared to previous generations. Because youth spend much of their time in school, teachers can provide the critical linkages that introduce students to nature. Unfortunately, teachers often lack access to standards-based STEAM curricula focused on natural resources, do not feel comfortable taking their students outside, and may not be knowledgeable about how to incorporate nature into the classroom. Addressing the nature deficit disorder facing today’s youth and the lack of professional development for teachers requires involvement from Extension (agriculture and natural resources specialists, health and human science educators) and natural resources professionals

Clinical Study Arterial Injury and Endothelial Repair: Rapid Recovery of Function after Mechanical Injury in Healthy Volunteers

Objective. Previous studies suggest a protracted course of recovery after mechanical endothelial injury; confounders may include degree of injury and concomitant endothelial dysfunction. We sought to define the time course of endothelial function recovery using flow-mediated dilation (FMD), after ischaemia-reperfusion (IR) and mechanical injury in patients and healthy volunteers. The contribution of circulating CD133 + /CD34 + /VEGFR2 + &quot;endothelial progenitor&quot; (EPC) or repair cells to endothelial repair was also examined. Methods. 28 healthy volunteers aged 18-35 years underwent transient forearm ischaemia induced by cuff inflation around the proximal biceps and radial artery mechanical injury induced by inserting a wire through a cannula. A more severe mechanical injury was induced using an arterial sheath and catheter inserted into the radial artery of 18 patients undergoing angiography. Results. IR and mechanical injury produced immediate impairment of FMD (from 6.5 ± 1.2% to 2.9 ± 2.2% and from 7.4 ± 2.3% to 1.5 ± 1.6% for IR and injury, resp., each &lt; 0.001) but recovered within 6 hours and 2 days, respectively. FMD took up to 4 months to recover in patients. Circulating EPC did not change significantly during the injury/recovery period in all subjects. Conclusions. Recovery of endothelial function after IR and mechanical injury is rapid and not associated with a change in circulating EPC

Neonicotinoid seed treatments of soybean provide negligible benefits to US farmers

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST + NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST + N ST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST + N ST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike

Neonicotinoid seed treatments of soybean provide negligible benefits to US farmers

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST + NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST + N ST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST + N ST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike

Testing natural biomaterials in animal models

Animal models have been extensively developed in the last decades in biomedical field. Their use has shown particular relevance in fields such as cell biology, genetics, anatomy and development, biochemistry, infection and immunity, cancer research, drugs and vaccine development, tissue engineering and regenerative medicine. The induced host tissue trauma and the inflammatory process resulting from the implantation of a medical device are of utmost importance for a successful outcome. Features of a chronic inflammation are usually attributed to the host response towards the implant, while an early acute inflammatory response is mainly endorsed by the implantation procedure. Animal testing comprises a midway step between in vitro studies and human clinical trials, which precede real clinical application. As every animal model has its advantages and disadvantages, a comprehensive analysis of each available species needs to be conducted when planning an animal study.(undefined)info:eu-repo/semantics/publishedVersio

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Measuring factors influencing valuation of nonmotorized improvement measures

This paper presents the application of a new methodology for data collection based on multiple survey methods to study how drivers and transit users value nonmotorized improvements. This multi-method survey consisted on a combination of user’s willingness to change, stated tolerance and contingent valuation experiments. Random parameter probit models were used to analyze data on willingness to cycle. Willingness to change to cycling is related to travel purpose, transportation mode, travel time and education level. Policies for promoting the use of bicycles should target these profiles so as to be more effective. Random parameter ordered probit models were used to study how different cycling measures were valued by respondents. The protection and maintenance of cycle lanes are significantly more valued than other improvement measures. The design of future cycling facilities should consider increasing safety and travel time reduction. Senior citizen’s willingness to change to cycling value to a lesser extent cycling improvement measures than people traveling to work or study. Strategies to promote cycling in each case are discussed.Ruiz Sánchez, T.; Bernabé, JC. (2014). Measuring factors influencing valuation of nonmotorized improvement measures. Transportation Research Part A: Policy and Practice. 67:195-211. doi:10.1016/j.tra.2014.06.008S1952116