Melt inclusions in volcanic rocks

We studied melt inclusions from Mutnovsky Volcano, Kamchatka, Russia as part of a larger project designed to contrain the eruptive history of Mutnovsky. Transmitted and reflected light petrographic microscopy was used to characterize melt inclusions in grain mounts of mineral separates, standard 30 micron thin sections, and 200 micron thick sections of the samples from the Mutnovsky. The inclusions were further divided into three main categories: recrystallized, partially recrystallized, and glassy inclusions. After all the melt inclusions have been categorized, they will be analyzed by using LA-ICP-MS to determine their major, minor and trace element compositions

Magma chamber processes at Mutnovsky Volcano, Russia

This dissertation is composed of two manuscripts about the evolution of Mutnovsky Volcano in Kamchatka, Russia. Mutnovsky has been active for the past approximately 80,000 years, during which there was the formation and subsequent eruption of four major stratocones. These four eruptive centers, named Mutnovsky I, II, III, and IV from oldest to youngest, have a range of erupted product compositions from basalt to dacite. The first major goal of this project was to investigate the melt source for Mutnovsky. Whole rock trace element and Nd, Sr, and Pb isotopic data were used to determine that the melt source was fluid flux melting of the mantle wedge with very little crustal or slab surface sediment-melt input. The second major goal of this project was to determine the cause of the compositional heterogeneity of erupted products at Mutnovsky. Whole rock geochemical modeling demonstrated that melts were generated both above and below the garnet/spinel transition at approximately 67 km depth in the mantle wedge. Different degrees of partial melting of these two mantle compositions, followed by fractional crystallization, was initially determined to be the cause of the range of compositions found at Mutnovsky. However, melt inclusion data collected later provided new insight into magmatic differentiation processes. Melt inclusion data have a much wider range of values for the major and trace elements than the whole rock data; whole rock compositions fall along mixing lines between the most and least evolved melt inclusion compositions. This observation, combined with mafic enclaves found in more felsic hosts in whole rock samples and a variety of types of zoning found in plagioclase, indicate that magma mixing is the major cause of the compositional heterogeneity at Mutnovsky. The third major goal of this study was to determine the structure of the preeruptive magma storage system for Mutnovsky. Two thermobarometers, orthopyroxene-liquid (Putirka, 2008) and clinopyroxene-liquid (Putirka et al., 2003), were used to determine the depths of pyroxene-melt equilibrium and thus the depths of magma stagnation. Both thermobarometers indicated that the depth of magma storage chambers was increasing with time, from Mutnovsky I to IV

ParticipACTION: A mass media campaign targeting parents of inactive children; knowledge, saliency, and trialing behaviours

<p>Abstract</p> <p>Background</p> <p>In late 2007, Canada's ParticipACTION national physical activity mass media campaign was re-launched, with an initial campaign targeting parents of elementary school-aged children. The campaign informed them about the risks of physical inactivity for children and youth. The purpose of this study was to assess campaign awareness and understanding following the campaign, and to identify whether exposure to this campaign was likely associated with behaviour change.</p> <p>Methods</p> <p>A convenience sample of 1,500 adults was recruited though an existing panel (n = 60,000) of Canadian adults to participate in online surveys. Initial campaign exposure included "prompted" and "unprompted" recall of specific physical activity messages from the 2007 ParticipACTION campaign, knowledge of the benefits of PA, saliency, and initial trial behaviours to help their children become more active.</p> <p>Results</p> <p>One quarter of respondents showed unprompted recall of specific message content from the ParticipACTION campaign, and prompted recall was 57%. Message recall and understanding was associated with knowledge about physical activity, and that in turn was related to high saliency. Saliency was associated with each of the physical activity-related trial behaviours asked.</p> <p>Conclusion</p> <p>Campaign awareness and understanding was high following this ParticipACTION campaign, and was associated with intermediate campaign outcomes, including saliency and trial behaviours. This is relevant to campaign evaluations, as it suggests that an initial focus on influencing awareness and understanding is likely to lead to more substantial change in campaign endpoints.</p

Evaluation of a gender-sensitive physical activity programme for inactive men in Ireland: Protocol paper for a pragmatic controlled trial

The excess burden of ill-health, mortality and premature death experienced by many men, and poorer men in particular, across the developed world has prompted calls for the development of gender sensitised health related services for men. An emergent body of evidence indicates that successful public health work with men can be accomplished when it utilises elements with which men are familiar and secure. In particular, physical activity (PA) is proven here to be a useful ‘hook’ to engage men. ‘Men on the Move’ (MoM) is a community-based PA programme designed to engage inactive men to improve their overall health and well-being. The MoM programme was delivered by practitioner partnerships in diverse communities and among diverse groups of men under ‘real world’ conditions to assess both its efficacy and replicability with a view to scaling-up the programme nationally for population wide impact. Establishing appropriate protocols is critical when conducting research that translates into practice, is replicable in practice and can be disseminated at a population level. The purpose of this paper is to detail the protocols used in the design, implementation and evaluation of the MoM programme. Specifically, the process of engaging men in a community based PA intervention and sustaining that engagement over the 12 weeks and the protocols used to evaluate the impact of participation in MoM on biopsychosocial health up to 52 weeks will be outlined. If the intervention proves successful, gender-sensitive community based PA interventions for men could be a promising avenue to address their health needs. These findings may be of support to both practitioners endeavouring to engage men and others engaged in translational research to ensure their research translates to meaningful action in practice

The impact of a gender-specific physical activity intervention on the fitness and fatness profile of men in Ireland

Background: Amid increasing concerns about rising obesity rates and unhealthy lifestyle behaviours, physical activity (PA) is seen as a prophylactic to many chronic conditions affecting men. Men respond best to community-based PA programmes, using gender-specific promotional and delivery strategies. ‘Men on the Move’ (MOM) was developed on this basis and targeted inactive adult men in Ireland. Methods: Sedentary men (n=927; age=50.7±10.9yr; Weight=92.7±16.0kg; METS=6.06±2.13) were recruited across 8 counties; 4 ‘intervention group’ (IG; n=501), and 4 ‘comparison-in-waiting group’ (CG; n=426). The MOM programme involved structured group exercise twice weekly for 12 weeks, along with health-related workshops with the groups maintained up to 52W. Primary outcome measures (aerobic fitness, bodyweight and waist circumference (WC)) together with self-administered questionnaires were used to gather participant data at baseline, 12, 26 and 52 weeks (W). Results: Results show a net positive effect on aerobic fitness, bodyweight and WC, with significant (p<0.05) net change scores observed in the IG compared to the CG (METS: 12W=+2.20, 26W=+1.89, 52W=+0.92; Weight: 12W=-1.72kg, 26W=-1.95kg, 52W=-1.89kg; WC: 12W=-4.54cm, 26W=-2.69cm, 52W=-3.16cm). The corresponding reduction in cardiovascular disease risk is particularly significant in the context of a previously inactive and overweight cohort. The high ‘dropout’ (42.7% presenting at 52W) however, is of particular concern, with ‘dropouts’ having lower levels of aerobic fitness and higher bodyweight/WC at baseline. Conclusions: Notwithstanding dropout issues, findings address an important gap in public health practice by informing the translational scale-up of a small controllable gender-specific PA intervention, MOM, to a national population based PA intervention targeting inactive men

Temperature links to compositional variations at Mutnovsky Volcano, Kamchatka, Russia

Full petrographic descriptions of fifty two rock samples collected from one hundred thousand year old Mutnovsky Volcano, Kamchatka, Russia are being studied to determine the magma compositions of the volcano through time. I expect that the composition will change with time owing to variation in input at the base of the volcano pluming system, above the subducting Pacific Ocean crust. This variation in composition, including the abundance of important atmospheric gases, water, and carbon dioxide, may play a key role in the abundance and type of greenhouse gases being emitted. The samples will also be analyzed by using electron probe microanalysis (EPMA) to determine the major and minor element abundances in co-existing pyroxene and olivine minerals, and these chemical data will be used to calculate the temperature and pressure of magma crystallization. The temperature of crystallization is a function of the water and carbon dioxide concentration of the magma

Asthma Knowledge, Adherence, and Administration Techniques in Hispanic Caregivers of Pediatrics

7.5% of Hispanics in the United States suffer from asthma-related diseases, and Latino children are not as likely to use preventative asthma medications as compared with Caucasians. Educational interventions may reduce the number of visits to emergency-care. The reasons for non-adherence are currently unknown, and discovering these reasons will help to address the problem

Stress Preconditioning of Spreading Depression in the Locust CNS

Cortical spreading depression (CSD) is closely associated with important pathologies including stroke, seizures and migraine. The mechanisms underlying SD in its various forms are still incompletely understood. Here we describe SD-like events in an invertebrate model, the ventilatory central pattern generator (CPG) of locusts. Using K+ -sensitive microelectrodes, we measured extracellular K+ concentration ([K+]o) in the metathoracic neuropile of the CPG while monitoring CPG output electromyographically from muscle 161 in the second abdominal segment to investigate the role K+ in failure of neural circuit operation induced by various stressors. Failure of ventilation in response to different stressors (hyperthermia, anoxia, ATP depletion, Na+/K+ ATPase impairment, K+ injection) was associated with a disturbance of CNS ion homeostasis that shares the characteristics of CSD and SD-like events in vertebrates. Hyperthermic failure was preconditioned by prior heat shock (3 h, 45°C) and induced-thermotolerance was associated with an increase in the rate of clearance of extracellular K+ that was not linked to changes in ATP levels or total Na+/K+ ATPase activity. Our findings suggest that SD-like events in locusts are adaptive to terminate neural network operation and conserve energy during stress and that they can be preconditioned by experience. We propose that they share mechanisms with CSD in mammals suggesting a common evolutionary origin

Metric trees of generalized roundness one

Every finite metric tree has generalized roundness strictly greater than one. On the other hand, some countable metric trees have generalized roundness precisely one. The purpose of this paper is to identify some large classes of countable metric trees that have generalized roundness precisely one. At the outset we consider spherically symmetric trees endowed with the usual combinatorial metric (SSTs). Using a simple geometric argument we show how to determine decent upper bounds on the generalized roundness of finite SSTs that depend only on the downward degree sequence of the tree in question. By considering limits it follows that if the downward degree sequence $(d_{0}, d_{1}, d_{2}...)$ of a SST $(T,\rho)$ satisfies $|\{j \, | \, d_{j} > 1 \}| = \aleph_{0}$, then $(T,\rho)$ has generalized roundness one. Included among the trees that satisfy this condition are all complete $n$-ary trees of depth $\infty$ ($n \geq 2$), all $k$-regular trees ($k \geq 3$) and inductive limits of Cantor trees. The remainder of the paper deals with two classes of countable metric trees of generalized roundness one whose members are not, in general, spherically symmetric. The first such class of trees are merely required to spread out at a sufficient rate (with a restriction on the number of leaves) and the second such class of trees resemble infinite combs.Comment: 14 pages, 2 figures, 2 table