Pre-treatment of patients undergoing cardiopulmonary bypass with hyperbaric oxygen : a prospective randomised double-blind evaluation of inflammatory response and neurocognitive outcome

Over the past few decades, implementation of findings from scientific research and incorporation of technological advances into practice have produced a significant reduction in the morbidity and mortality from coronary revascularisation. Despite these improvements subtle neurocognitive impairment, from diffuse cerebral injury due to micremboli during cardiopulmonary bypass, continues to occur following cardiac surgery.Previous human and animal studies have shown that hyperbaric oxygen can reduce some of the mediators of inflammation. Evidence from animal experiments also suggest that pretreatment with hyperbaric oxygen can induce cerebral and spinal ischaemic tolerance. Using the prospective randomised double-blind method we set out to test the hypothesis that pretreatment with hyperbaric oxygen could reduce inflammatory mediators and neurocognitive dysfunction following cardiopulmonary bypass.64 patients undergoing elective coronary revascularisation were either randomised to Group- A (air, 1.5 atmospheres absolute, n-31) or Group-B (hyperbaric oxygen, 2.4 atmospheres absolute, n-33). Both groups were comparable in terms operative and perioperative factors. Inflammatory markers were measured prior to anaesthesia and, 2 hours and 24 hrs after bypass. Neurocognitive assessment was performed 48 hours before the operation and 4 months after the operation. Neurocognitive impairment was defined as ≥1standard deviation (SD) decline in postoperative score in more than 20% of the neurocognitive tests. ANOVA, t-test and Chi-square tests was used as appropriate for statistical analysis.There was no difference in immediate postoperative clinical outcome. However analysis of variance revealed that the postoperative peak rise in the inflammatory markers soluble endothelial selectin (sE-selectin), heat shock protein-70 (HSP-70) and cluster differentiation antigen-IS (CD-IS) which was significant in group-A was not so in group-B. Analysis of data from the neurocognitive tests also revealed that the overall neurocognitive dysfunction was significantly higher in group-A compared to group-B.From our findings we concluded that pre-treatment with hyperbaric oxygen may have a potential beneficial role in reducing neurocognitive impairment and reducing some of the inflammatory mediators following cardiopulmonary bypass. Larger multi-centre prospective randomised trials are needed to further evaluate this form of therapy

P6_1 Increase in Human Brain Power as a Result of Cranial Frill Cooling

This paper outlines the effects of having a small cranial crest of frills containing thin blood vessels to aid with cooling of blood from the brain. We have calculated the increase in brain temperature that such a crest would facilitate to be 1.97C which corresponds to an increase in brain power of 689%. We have commented on the biological implications of this and deduced that in terms of physics this is a viable mechanism

Comparison of Strategies for the Constraint Determination of Simulink Models

The Simulink environment allows rapid prototyping of complex software systems. Because many of these systems are mission-critical, it is of utmost importance to determine their input and output constraints. Determining input constraints is a trivial matter, but the constraint determination of a system\u27s output values is a serious and challenging problem that historically has entailed an exhaustive exploration of the system\u27s input states. The work presented in this thesis recounts and extends a research project supported by NASA whose focus was to develop a strategy to constrain the outputs of a Simulink model. Simulink models are quite similar to mathematical functions and therefore optimization algorithms can be applied to constrain the outputs. Optimizations of simple mathematical functions paved the way for random functions and finally led to the development of two optimization algorithms. During the exploration of potential optimization algorithms, strategies such as Monte Carlo, the simplex method, simulated annealing, and evolution strategy were explored. In the end, a combined approach utilizing both simulated annealing and the simplex method was compared with evolution strategy for relative strengths and weaknesses. It was determined that the evolution strategy algorithm was more suited to optimization of Simulink models due to its more effective usage of model calls and to its higher success rate

Natural Environmental Gradients Predict The Microhabitat Use, Fine-Scale Distribution, And Abundance Of Three Woodland Salamanders In An Old-Growth Forest

Woodland salamanders (Plethodonidae: Plethodon)－a group of sensitive, direct developing, lungless amphibians－are particularly responsive to gradients in environmental conditions. Because of their functional dominance in terrestrial ecosystems, woodland salamanders are responsible for the transformation of nutrients and translocation of energy between highly desperate levels of trophic organization (detrital food webs and high‐order predators). However, the spatial extent of woodland salamanders\u27 role in the ecosystem is likely contingent upon the distribution of their biomass throughout the forest. Therefore, a better understanding of woodland salamander spatial population dynamics is needed to further understand their role in terrestrial ecosystems. The objectives of this study were to determine if natural environmental gradients influence the microhabitat use, fine‐scale distribution, and abundance of three species of woodland salamander－Plethodon richmondi, P. kentucki, and P. glutinosus. These objectives were addressed by assessing microhabitat conditions and constructing occupancy, co‐occurrence, and abundance models from temporally‐replicated surveys (N = 4) at forty 0.08‐ha sample plots within a ca. 42 ha old‐growth forest in the Cumberland Plateau region of southeastern Kentucky. This study finds that patterns of microhabitat use, occupancy, and abundance of P. richmondi and kentucki reflected physiological restraints associated with desiccation vulnerability and thermo‐osmoregulatory requirements of small to mid‐sized salamanders. Plethodon richmondi occupied markedly cooler microhabitats, had the most restricted fine‐scale distribution (mean occupancy probability [ψ̄̂] = 0.737), and exhibited variable abundance, from \u3c250 to \u3e1000 N۰ha‐2, associated with increased soil moisture and reduced solar exposure due to slope face. While more ubiquitously distributed (ψ̄̂ = 0.95), P. kentucki abundance varied from \u3e1000 to \u3c400 N۰ha‐2 in association with increased solar exposure from canopy disturbance and landscape convexity. Plethodon glutinosus displayed a dramatic tolerance to thermal environments by preferentially occupying warm microhabitats and relying only minimally upon subterranean refugia for thermo‐osmoregulation (temporary vertical emigration). Given the critical role that woodland salamanders play in the maintenance of forest health, regions which support large populations of woodland salamanders, such as those highlighted in this study (mesic forest stands on north‐to‐east facing slopes with dense canopy and abundant natural cover) may provide enhanced ecosystem services and support the stability of the total forest

Investigation on cutting metals using induced currents

textNon-contact magnetic cutting (NCMC) is a recently developed metal-cutting technology that uses pulsed magnetic fields to advance and steer fine cuts in metal sheet. With this process, a coil is used to induce currents in a workpiece that has a starter feature such as a notch or slit. The induced currents are forced to bend tightly around the starter feature, which enhances the current and magnetic field density. Under the right conditions, resistive heating and large J × B forces cause localized melting and ejection of material. Each cut is only a fraction of a millimeter long; however, the process can be repeated and the coil can be moved to cut arbitrary lengths and shapes. While some promising results have been obtained, the operating space for making controlled cuts appears to be narrow. Furthermore, the process by which cutting occurs is not well understood. The objective of this dissertation is to provide the scientific underpinnings of NCMC by experimentally assessing the conditions for controlled cutting, developing a method for predicting conditions for optimal cutting, and identifying a path to reduce NCMC to practice.Electrical and Computer Engineerin

Bicarbonate or Carbonate Processes for Coupling Carbon Dioxide Capture and Electrochemical Conversion

Designing a scalable system to capture CO₂ from the air and convert it into valuable chemicals, fuels, and materials could be transformational for mitigating climate change. Climate models predict that negative greenhouse gas emissions will be required by the year 2050 in order to stay below a 2 °C change in global temperature. The processes of CO₂ capture, CO₂ conversion, and finally product separation all require significant energy inputs; devising a system that simultaneously minimizes the energy required for all steps is an important challenge. To date, a variety of prototype or pilot-level CO₂ capture and/or conversion systems have been designed and built targeting the individual objectives of either capture or conversion. One approach has focused on CO₂ removal from the atmosphere and storage of pure pressurized CO₂. Other efforts have concentrated on CO₂ conversion processes, such as electrochemical reduction or fermentation. Only a few concepts or analyses have been developed for complete end-to-end processes that perform both CO₂ capture and transformation

A social-cognitive model of trait and state levels of gratitude.

Three studies tested a new model of gratitude, which specified the generative mechanisms linking individual differences (trait gratitude) and objective situations with the amount of gratitude people experience after receiving aid (state gratitude). In Study 1, all participants (N = 253) read identical vignettes describing a situation in which they received help. People higher in trait gratitude made more positive beneficial appraisals (seeing the help as more valuable, more costly to provide, and more altruistically intended), which fully mediated the relationship between trait and state levels of gratitude. Study 2 (N = 113) replicated the findings using a daily process study in which participants reported on real events each day for up to14 days. In Study 3, participants (N = 200) read vignettes experimentally manipulating objective situations to be either high or low in benefit. Benefit appraisals were shown to have a causal effect on state gratitude and to mediate the relationship between different prosocial situations and state gratitude. The 3 studies demonstrate the critical role of benefit appraisals in linking state gratitude with trait gratitude and the objective situation