29 research outputs found
Studies of Regolithic Vestan Samples: Brecciated Eucrites and Howardites
Brecciated eucrites and howardites represent samples of the regolith of asteroid 4 Vesta. As such, they are a valuable source of data for understanding the products of surface alteration. Two different processes are investigated here: impact mixing of comminuted rocks to produce regolith samples, and formation of glasses in the regolith.
Chapter 1 describes four newly discovered eucrite breccias: three presumably paired meteorites, all named NWA 6105, and NWA 6106. For each meteorite, major- and minor-element compositions of minerals were determined using the electron microprobe. Pyroxene Fe-Mn co-variations and bulk-rock oxygen isotope compositions confirm their classification as eucrites. Variations in mineral compositions and textures are attributed to differences in clast types present (i.e., basaltic or cumulate eucrite). The pyroxene compositions support the hypothesis that samples NWA 6105,1; 6105,2; and 6105,3 are paired polymict eucritic breccias, whereas sample NWA 6106 is a monomict basaltic eucritic breccia. Two-pyroxene geothermometry yields temperatures too low for igneous crystallization. The variation in temperatures among samples suggests that metamorphism occurred prior to brecciation.
Chapter 2 is an investigation of glasses in eight howardites, with the aim of distinguishing their origins as impact melt or pyroclastic. Although theoretical calculations predict that pyroclastic eruptions could have taken place on Vesta, the occurrence of pyroclastic glasses in HED meteorites has never been documented. This study involved petrographic examination of textures, electron microprobe analysis of major and minor elements, and LA-ICP-MS analysis for selected trace elements. Previously documented textural and compositional differences between lunar impact melt and pyroclastic glasses partly guided this study. This work yielded no positive identification of pyroclastic glasses. The most likely explanations are that pyroclastic glasses never formed, either because Vesta contains insufficient volatiles to have powered explosive eruptions, or because eruptive conditions produced optically dense fire-fountains which produced deposits that accumulated in lava ponds. The impact-melt glasses were grouped (K-rich, low-alkali, and Ca-rich) based on compositions. The K-rich group is postulated to result from impacts into previously unsampled, feldspar-rich lithologies, while the low-alkali and Ca-rich glasses are the result of impacts onto known HED lithologies though the latter formed from a preferential melting of plagioclase
Club COO Leadership: A Comparative Study of Industry
A true leader continues the quest for personal knowledge. The quest is designed to better the leader\u27s life, not necessarily the leader\u27s livelihood. While change is a constant in the lives of club leaders, and some days the leader\u27s vision and purpose change, the underlying ideas and convictions remain constant. Many leadership qualities must be present to be an effective leader. The author\u27s survey club chief operating officers to elicit the characteristics and essential qualities of club leadershi
Emotional Intelligence and Organizational Commitment Among Private Club Board and Committee Volunteer Leaders: A Pilot Study
This pilot study explored the relationship between emotional intelligence and organizational commitment among provate club board and committee volunteer members. The top three items, ranked by mean scores, of each of three EI dimensions -- IN, OUT, and RELATIONSHIPS wer discussed. A sample of 57 volunteer leaders furhter was split into high EI and low EI groups based on respndents\u27 overall EO median score. Statistical differences between high and low EI groups in three aspects of organizational commitment - affective, continuance, and normative commitment - wer present. 4 t-test results showed that the difference between high and low EI groups in affective commitment among private club volunteer leaders was statistcally significant at p \u3c.05
The most primitive CM chondrites, Asuka 12085, 12169, and 12236, of subtypes 3.0–2.8: Their characteristic features and classification
CM chondrites (CMs) are the most abundant group of carbonaceous chondrites. CMs experienced varying degrees of secondary aqueous alteration and heating that modified or destroyed their primitive features. We have studied three chondrites, Asuka (A) 12085, A 12169, and A 12236. Their modal compositions, chondrule size distributions, and bulk composition indicate that they are CMs. However, the common occurrence of melilite in CAIs and glass in chondrules, abundant Fe–Ni metal, the absence of tochilinite-cronstedtite intergrowths, and almost no phyllosilicates, all suggest that these chondrites, especially A 12169, experienced only minimal aqueous alteration. The textures and compositions of metal and sulfides, the lack of ferroan rims on AOA olivines, the compositional distribution of ferroan olivine, and the Raman spectra of their matrices, indicate that these chondrites experienced neither significant heating nor dehydration. These chondrites, especially A 12169, are the most primitive CMs so far reported. The degree of the alteration increases from A 12169, through A 12236, to A 12085. We propose the criteria for subtypes of 3.0–2.8 for CMs. A 12169, A 12236, and A 12085 are classified as subtype 3.0, 2.9, and 2.8, respectively. The oxygen isotopic composition of the Asuka CMs is consistent with these samples having experienced only a limited degree of aqueous alteration. The CM and CO groups are probably not derived from a single heterogeneous parent body. These chondrites are also of particular significance in view of the imminent return of sample material from the asteroids Ryugu and Bennu
Signatures of the post-hydration heating of highly aqueously altered CM carbonaceous chondrites and implications for interpreting asteroid sample returns
The CM carbonaceous chondrites have all been aqueously altered, and some of them were subsequently heated in a parent body environment. Here we have sought to understand the impact of short duration heating on a highly aqueously altered CM through laboratory experiments on Allan Hills (ALH) 83100. Unheated ALH 83100 contains 83 volume per cent serpentine within the fine-grained matrix and altered chondrules. The matrix also hosts grains of calcite and dolomite, which are often intergrown with tochilinite, Fe(Ni) sulphides (pyrrhotite, pentlandite), magnetite and organic matter. Some of the magnetite formed by replacement of Fe(Ni) sulphides that were accreted from the nebula. Laboratory heating to 400 °C has caused partial dehydroxylation of serpentine and loss of isotopically light oxygen leading to an increase in bulk δ18O and fall in Δ17O. Tochilinite has decomposed to magnetite, whereas carbonates have remained unaltered. With regards to infrared spectroscopy (4000–400 cm-1; 2.5–25 µm), heating to 400 °C has resulted in decreased emissivity (increased reflectance), a sharper and more symmetric OH band at 3684 cm-1 (2.71 µm), a broadening of the Si—O stretching band together with movement of its minimum to longer wavenumbers, and a decreasing depth of the Mg—OH band (625 cm-1; 16 µm). The Si—O bending band is unmodified by mild heating. With heating to 800 °C the serpentine has fully dehydroxylated and recrystallized to ∼Fo60/70 olivine. Bulk δ18O has further increased and Δ17O decreased. Troilite and pyrrhotite have formed, and recrystallization of pentlandite has produced Fe,Ni metal. Calcite and dolomite were calcined at ∼700 °C and in their place is an un-named Ca-Fe oxysulphide. Heating changes the structural order of organic matter so that Raman spectroscopy of carbon in the 800 °C sample shows an increased (D1 + D4) proportional area parameter. The infrared spectrum of the 800 °C sample confirms the abundance of Fe-bearing olivine and is very similar to the spectrum of naturally heated stage IV CM Pecora Escarpment 02010. The temperature-related mineralogical, chemical, isotopic and spectroscopic signatures defined in ALH 83100 will help to track the post-hydration thermal histories of carbonaceous chondrite meteorites, and samples returned from the primitive asteroids Ryugu and Bennu
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
The Effect of Temperature on the Reaction Time of Vinegar and Baking Soda
The purpose of this study was to investigate if the temperature of vinegar had any effect on the time it took for its reaction to stop, when mixed with baking soda. It was hypothesized that the temperature of the vinegar will cause a change in reaction time, specifically colder temperatures causing a slower reaction time, while hotter resulted in a faster time. Four different temperatures of vinegar were tested, based off of the room temperature vinegar: -2℃ (50° below room temperature) 12℃ (25° below room temperature) 40℃ (25° above room temperature), and 52℃ (50° room temperature). The heated or cooled vinegar was poured into the baking soda, and when put together, was timed until the reaction completely stopped without being touched or tampered with. The results supported past experiments; the vinegar with higher temperatures had a significantly faster reaction time, while the vinegar that was cooled, or had a lower temperature, took much longer to fully react with the baking soda
The Effect of a Residing US Region on the Toxic Masculinity of a Public High School Student
The purpose of this social experiment was to discover if the environment, more specifically the region, in which high school boys reside impacts their toxic masculinity. The researchers hypothesized that the boys residing in the Northeast region of the United States would have a higher concentration of toxic masculinity. The experimenters created an anonymous quiz with 14 questions, including possible situations the teenage boy may experience which may indeed indicate whether he has toxic masculinity or not. The researchers emailed an anonymous quiz to 8 public schools, two from each region of the United States, which totalled 200 responses. The researchers appreciate that this is probably too small of a sample to be statistically significant, but it is felt that the results are meaningful and provide a basic understanding of the issue. After receiving all of the boy\u27s results, the researchers concluded that overall, the public school boys residing in both the West and Midwest had a higher level of toxic masculinity. In certain circumstances public school boys from the Northeast and south did indeed show more toxic masculinity compared to those from the West and Midwes. However, the majority of the results indicated that public school boys residing in both the West and Midwest exhibited more toxic masculinity more often. In conclusion, the researcher\u27s hypothesis was refuted. The data shows that public school boys from the West and Midwest have more toxic traits than boys residing in the Northeast and South