48 research outputs found
Alkaline-Silicate REE-HFSE Systems
Development of renewable energy infrastructure requires critical raw materials, such as the rare earth elements (REEs, including scandium) and niobium, and is driving expansion and diversification in their supply chains. Although alternative sources are being explored, the majority of the world’s resources of these elements are found in alkaline-silicate rocks and carbonatites. These magmatic systems also represent major sources of fluorine and phosphorus. Exploration models for critical raw materials are comparatively less well developed than those for major and precious metals, such as iron, copper, and gold, where most of the mineral exploration industry continues to focus. The diversity of lithologic relationships and a complex nomenclature for many alkaline rock types represent further barriers to the exploration and exploitation of REE-high field strength element (HFSE) resources that will facilitate the green revolution. We used a global review of maps, cross sections, and geophysical, geochemical, and petrological observations from alkaline systems to inform our description of the alkaline-silicate REE + HFSE mineral system from continental scale (1,000s km) down to deposit scale (~1 km lateral). Continental-scale targeting criteria include a geodynamic trigger for low-degree mantle melting at high pressure and a mantle source enriched in REEs, volatile elements, and alkalies. At the province and district scales, targeting criteria relate to magmatic-system longevity and the conditions required for extensive fractional crystallization and the residual enrichment of the REEs and HFSEs. A compilation of maps and geophysical data were used to construct an interactive 3-D geologic model (25-km cube) that places mineralization within a depth and horizontal reference frame. It shows typical lithologic relationships surrounding orthomagmatic REE-Nb-Ta-Zr-Hf mineralization in layered agpaitic syenites, roof zone REE-Nb-Ta mineralization, and mineralization of REE-Nb-Zr associated with peralkaline granites and pegmatites. The resulting geologic model is presented together with recommended geophysical and geochemical approaches for exploration targeting, as well as mineral processing and environmental factors pertinent for the development of mineral resources hosted by alkaline-silicate magmatic systems
Resistência de clones e híbridos de porta-enxertos de citros à gomose de tronco causada por Phytophthora parasitica
Irrigation and Nitrogen Management Effects on Potato Yield, Tuber Quality, and Nitrogen Uptake
Are current case-finding methods underdiagnosing tuberculosis among women in Myanmar? An analysis of operational data from Yangon and the nationwide prevalence survey
10.1186/s12879-016-1429-yBMC Infectious Diseases16111
Using QSR-NVivo to facilitate the development of a grounded theory project: an account of a worked example
This paper demonstrates how the software package QSR-NVivo can be used to faciitate a grounded theory approach. Recent research evidence has questioned the methodological quality of many studies that claim to utilise grounded theory. This paper argues that qualitative data analysis software can be used to encourage good quality grounded theory research by facilitating many of the key processes and characteristics associated with this approach. To achieve this, the paper identifies a number of grounded theory characteristics, common to all revisions of the methodology. It then describes the development of a recent study, which examined how people successfully maintain long-term physical activity behaviour change. The purpose of this is to demonstrate how different functions of QSR-NVivo may be used in conjunction with the key grounded theory characteristics. In summary, QSR-NVivo is a powerful tool that, if used appropriately, can facilitate many aspects of the grounded theory process from the design and early sampling procedures, through to the analysis of data, theoretical development and presentation of findings
Selective serotonin re-uptake inhibitor treatment-emergent sexual dysfunction: randomized double-blind placebo-controlled parallel-group fixed-dose study of a potential adjuvant compound, VML-670
Sexual dysfunction is common during acute and continuation treatment of depressed patients with selective serotonin ( 5-hydroxytryptamine, 5-HT) re-uptake inhibitors ( SSRIs), but there is no consensus on clinical management. Compounds with 5-HT1A agonist properties have been proposed as adjuvant agents in patients continuing with SSRIs. Randomized double-blind placebo-controlled parallel-group fixed-dose 4-week treatment study. Previously depressed male or female patients in symptomatic remission receiving stable doses of fluoxetine or paroxetine but experiencing treatment-emergent sexual dysfunction were randomised to double-blind treatment with placebo or VML-670 ( a 5-HT1A and 5-HT1D agonist). Sexual dysfunction was assessed by the Arizona Sexual Experiences Scale ( ASEX). Two-hundred and eighty-eight patients ( 204 women, 84 men; mean age 44.2 years) received VML-670 ( n = 149; 107 women, 42 men) or placebo ( n = 139; 97 women, 42 men). In the intention-to-treat, last-observation carried forward analysis ( n = 282), proportionately more patients became free of sexual dysfunction with VML-670 ( 34.3% versus 27.9% with placebo) but this difference was not statistically significant. Male patients treated with VML-670 showed a significantly greater ( p = 0.01) improvement in ability to achieve and maintain penile erection ( a secondary outcome measure). A similar proportion of patients reported on-treatment, treatment-emergent adverse events with VML-670 ( 71.1%) and placebo ( 68.3%), and a similar proportion experienced at least one treatment-related adverse event ( 36.9% versus 35.3%). Double-blind treatment with VML-670 offered no significant advantage over placebo on the primary outcome measure in the overall sample. Further studies may be warranted in larger groups of male patients with sexual dysfunction
Supplementary Material for: Long-Term Follow-Up on Bilateral Posterior Hypothalamic Deep Brain Stimulation for Treating Refractory Aggressive Behavior in a Patient with Cri du Chat Syndrome: Analysis of Clinical Data, Intraoperative Microdialysis, and Imaging Connectomics
Posterior hypothalamic-deep brain stimulation (pHyp-DBS) has been reported as a successful treatment for reducing refractory aggressive behaviors in patients with distinct primary diagnoses. Here, we report on a patient with cri du chat syndrome presenting severe self-injury and aggressive behaviors toward others, who was treated with pHyp-DBS. Positive results were observed at long-term follow-up in aggressive behavior and quality of life. Intraoperative microdialysis and imaging connectomics analysis were performed to investigate possible mechanisms of action. Our results suggest the involvement of limbic and motor areas and alterations in main neurotransmitter levels in the targeted area that are associated with positive results following treatment