490 research outputs found
Understanding the physiological basis for managing anaesthetic related cardiopulmonary side-effects in wildlife
A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the
degree of
Doctor of Philosophy.
Johannesburg, South Africa, 2017Immobilization of white rhinoceros (Ceratotherium simum) is a fundamental procedure used in the conservation of this threatened megaherbivore and allows for the capture, translocation and treatment of individuals. Immobilization also allows scientific investigation, which facilitates protection of this species. The potent opioids, including etorphine, are the only class of drugs which allow for a rapid and reversible immobilization, which is essential in the capture of rhinoceros. However, immobilization is associated with changes in respiratory and cardiovascular function which can result in high morbidity and mortalities. I therefore investigated the cardiorespiratory pathophysiological effects of etorphine and azaperone; pharmacological agents most often used in rhinoceros immobilization, and examined the effectiveness of butorphanol, a mixed agonist- antagonist opioid, in limiting these adverse effects. Reducing morbidity and mortality risks through an increased understanding and moderation of drug- induced cardiorespiratory changes in immobilized rhinoceros will contribute to future successes in managing this species.
In my first study, ten healthy captive white rhinoceros including four males and six females ranging in age from 3.5 to 15 yr were immobilized for a total of 13 procedures with etorphine plus azaperone, and administered butorphanol intravenously immediately after initial blood collection and physiological assessment. Respiratory and cardiovascular parameters, body temperature and arterial blood gases were monitored for 100 min. The results confirmed that severe hypoxaemia, hypercapnia, tachycardia and an increased alveolar-arterial (A-a) oxygen gradient occur in immobilized rhinoceros. Giving butorphanol appeared to decrease heart rate, increase arterial oxygen tension, and decrease the A-a gradient and respiratory rate. However as the study was observational, it could not be confirmed that these changes were caused by butorphanol. Despite the initial improvements in blood oxygen levels, the rhinoceros remained severely hypoxaemic and hypercapnic for the remainder of the procedure.
To further investigate the cardiorespiratory effects of butorphanol in immobilized rhinoceros, a randomised cross-over study design was used. Six healthy sub-adult male white rhinoceros were subjected to four drug interventions: 1) etorphine intramuscularly; 2) etorphine plus azaperone intramuscularly; 3) etorphine intramuscularly and post-induction butorphanol intravenously; and 4) etorphine plus azaperone intramuscularly, and post-induction butorphanol intravenously. The results from this study demonstrated that hypoxaemia and hypercapnia in etorphine-immobilized rhinoceros were not predominantly a result of a decrease in respiratory minute volume, as has been proposed in previous studies. Rather, an increase in metabolic oxygen consumption and carbon dioxide production, associated with muscle tremors, is suggested as the primary cause. In addition, a high alveolar-arterial oxygen gradient may have contributed to hypoxaemia and possibly also hypercapnia in immobilized rhinoceros. Although, decreased minute ventilation was not the fundamental cause of hypoxaemia and hypercapnia, low arterial oxygen partial pressure (PaCb) and high arterial carbon dioxide partial pressure (PaCC>2) did not stimulate ventilation, probably as a consequence of opioid-induced central and peripheral chemoreceptor inhibition. Butorphanol administered post-induction in etorphine-immobilized rhinoceros resulted in a moderate improvement in blood gases, although hypoxaemia and hypercapnia persisted. My results support the idea that improvements in PaC>2 and PaC02 after butorphanol administration resulted from reduced muscle tremors, metabolic oxygen consumption and carbon dioxide production rather than improved minute ventilation.
Cardiovascular changes in etorphine-immobilized rhinoceros included hypertension and tachycardia. The inclusion of azaperone with etorphine in the immobilizing drug combination reduced blood pressure to below normotensive values; however, heart rate remained elevated. The administration of butorphanol was followed by a reduction in heart rate with no clinical effect on blood pressures in etorphine-immobilized rhinoceros. Similarly, butorphanol did not change blood pressure but reduced tachycardia in individuals immobilized with etorphine plus azaperone.
In summary, butorphanol administration reduced hypoxaemia and hypercapnia in immobilized white rhinoceros as a result of decreased muscle tremors and oxygen consumption. Reduced oxygen consumption may mitigate hypoxic and hypercapnic mortality risks associated with immobilization, especially in rhinoceros compromised due to old age, nutritional stress or disease. My findings indicate that butorphanol administration allows rhinoceros to be immobilized for extended periods, which facilitates clinical procedures in injured individuals or managing orphaned calves. The reduction in tachycardia suggests that butorphanol may have a myocardial oxygen-sparing effect and may lower the risk of an adverse outcome associated with immobilization.
My recommendations for the immobilization of white rhinoceros to reduce the morbidity and mortality risks associated with etorphine-induced respiratory and cardiovascular changes include azaperone administration in combination with the potent opioid. The inclusion of azaperone reduces hypertension in etorphine- immobilized rhinoceros. However, 1 suggest that lower azaperone doses be considered compared to those used in my studies to moderate the decrease in blood pressure and possible complications associated with reduced tissue perfusion. Butorphanol should be administered intravenously to etorphine plus azaperone-immobilized-rhinoceros as soon as possible after induction to limit increased opioid-induced metabolic effects and improve hypoxaemia and hypercapnia. The administration of butorphanol also has the advantage of reducing tachycardia with a potential myocardial oxygen sparing effect in immobilized-rhinoceros. Butorphanol should be administered in repeated doses (5 to 10 x etorphine dose in mg) until limb muscle tremoring is reduced and possibly halted, and an elevated heart rate slows to less than 100 beats per minute or slower.
Future research should focus on improving alveolar gas exchange and reducing the sympathomimetic and hypermetabolic effects of the potent opioids in immobilized-rhinoceros, and not only just improving ventilation and blood pressure.MT 201
A new mode of qualification supply: the realization of a high road strategy in the U.S. semiconductor industry
"Recent studies like 'Working in America' (Osterman et al. 2001) have shed some light on problems and processes of change in the American labour market, that areoften unnoticed from the German point of view. Contrary to common German perceptions of the U.S. American economic success as based on a labour market, that is quite deregulated and more or less market driven these studies are showing how only recent economic developments have resulted in a growing mismatch between a distinct institutional structure of the U.S. labour market and the reality of today's world of work. In the following the editor will focus on vocational education and training as anothercentral field of the U.S. labour market, that is not only deeply affected by the same socio-economic processes as well but that is marked by far-reaching processes of institutional change. Taking the example of the U.S. semiconductor industry the editor will show, that - despite the erosion of institutional foundations of traditional work relations - it's not just the logic of the market that now reigns. Instead there seem to evolve new institutional arrangements on the regional level. He will describe how the semiconductor industry has reorganized its qualification supply strategy with regard to shop floor qualifications. This evolving mode of qualification supply may shape work and labour relations in a new way and therefore represent kind of the other side of the coin. He will develop the argument in three steps: First he will outline the old mode of qualification supply as it was based on the traditional model of work relations and the established structure of the U.S. labour market. In a second step he will describe, how changing work organization strategies in the semiconductor industry resulted in problems in the supply with shop floor qualifications. Finally he will discuss the evolving new mode of qualification supply in semiconductor manufacturing and its implications for the regional commitment of the companies and for the local labour market." (Textauszug
Mapping temporal dynamics in social interactions with unified structural equation modeling: A description and demonstration revealing time-dependent sex differences in play behavior
Developmental science is rich with observations of social interactions, but few available methodological and statistical approaches take full advantage of the information provided by these data. The authors propose implementation of the unified structural equation model (uSEM), a network analysis technique, for observational data coded repeatedly across time; uSEM captures the temporal dynamics underlying changes in behavior at the individual level by revealing the ways in which a single person influences – concurrently and in the future – other people. To demonstrate the utility of uSEM, the authors applied it to ratings of positive affect and vigor of activity during children’s unstructured laboratory play with unfamiliar, same-sex peers. Results revealed the time-dependent nature of sex differences in play behavior. For girls more than boys, positive affect was dependent upon peers’ prior positive affect. For boys more than girls, vigor of activity was dependent upon peers’ current vigor of activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/123050/1/Mapping temporal dynamics in social interactions with unified structural equation modeling_ A description and demonstration revealing time-dependent sex differences in play behavior.pd
Weathering of the Rio Blanco quartz diorite, Luquillo Mountains, Puerto Rico: Coupling oxidation, dissolution, and fracturing
Highway infrastructure health monitoring using micro-electromechanical sensors and systems (MEMS)
The development of novel smart structures by embedding sensing capabilities directly into the construction material during the manufacturing and deployment process has attracted significant attention in autonomous structural health monitoring (SHM). Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of SHM of highway infrastructure systems, including improved system reliability, improved longevity and enhanced system performance, improved safety against natural hazards and vibrations, and a reduction in life cycle cost in both operating and maintaining the infrastructure. Advancements in MEMS technology and wireless sensor networks provide opportunities for long-Term, continuous, real-Time structural health monitoring of pavements and bridges at low cost within the context of sustainable infrastructure systems. Based on a comprehensive review of literature and vendor survey, the latest information available on off-The-shelf MEMS devices, as well as research prototypes, for bridge, pavement, and traffic applications are synthesized in this paper. In addition, the paper discusses the results of a laboratory study as well as a small-scale field study on the use of a wireless concrete monitoring system based on radio-frequency identification (RFID) technology and off-The-shelf MEMS-based temperature and humidity sensors
Quantification of the impact in mid-latitudes of chemical ozone depletion in the 1999/2000 Arctic polar vortex prior to the vortex breakup
International audienceFor the winter 1999/2000 transport of air masses out of the vortex to mid-latitudes and ozone destruction inside and outside the northern polar vortex is studied to quantify the impact of earlier winter (before March) polar ozone destruction on mid-latitude ozone. Nearly 112 000 trajectories are started on 1 December 1999 on 6 different potential temperature levels between 500?600 K and for a subset of these trajectories photo-chemical box-model calculations are performed. We linked a decline of ?0.9% of mid-latitude ozone in this layer occurring in January and February 2000 to ozone destruction inside the vortex and successive transport of these air masses to mid-latitudes. Further, the impact of denitrification, PSC-occurrence and anthropogenic chlorine loading on future stratospheric ozone is determined by applying various scenarios. Lower stratospheric temperatures and denitrification were found to play the most important role in the future evolution of polar ozone depletion
Implicit complexity for coinductive data: a characterization of corecurrence
We propose a framework for reasoning about programs that manipulate
coinductive data as well as inductive data. Our approach is based on using
equational programs, which support a seamless combination of computation and
reasoning, and using productivity (fairness) as the fundamental assertion,
rather than bi-simulation. The latter is expressible in terms of the former. As
an application to this framework, we give an implicit characterization of
corecurrence: a function is definable using corecurrence iff its productivity
is provable using coinduction for formulas in which data-predicates do not
occur negatively. This is an analog, albeit in weaker form, of a
characterization of recurrence (i.e. primitive recursion) in [Leivant, Unipolar
induction, TCS 318, 2004].Comment: In Proceedings DICE 2011, arXiv:1201.034
The Costs and Benefits of the Dark Triad: Implications for Mate Poaching and Mate Retention Tactics
The Dark Triad - narcissism, Machiavellianism, and psychopathy - have traditionally been considered to be undesirable traits. However, emerging work suggest that not only may there be a positive side to possessing these traits but they may also serve important adaptive functions, even if the strategies associated with them are viewed as socially undesirable. In an online survey (N = 336), we investigated the costs and benefits of the Dark Triad within the domain of mating psychology. The social style and lower order personality traits of the Dark Triad traits facilitated increased mateships in the form of poaching mates from others and being poached oneself to form mateships, pointing to possible benefits of possessing the Dark Triad traits. However, the costside was evidenced with rates of mates abandoning their current relationship for a new one. Mate retention is a problem faced by those with these traits and the tactics used to retain mates were characteristic of the Dark Triad: aggressive and narcisstic. Results are discussed using an adaptionist paradigm
Using a novel ambulatory monitoring system to support patient safety on an acute infectious disease ward during an unfolding pandemic
Aim: To gain staff feedback on the implementation and impact of a novel ambulatory monitoring system to support coronavirus patient management on an isolation ward.
Design: Qualitative service evaluation.
Methods: Semi-structured interviews were conducted with 15 multidisciplinary isolation ward staff in the United Kingdom between July 2020 and May 2021. Interviews were audio-recorded, transcribed and analysed using thematic analysis.
Findings: Adopting Innovation to Assist Patient Safety was identified as the overriding theme. Three interlinked sub-themes represent facets of how the system supported patient safety. Patient Selection was developed throughout the pandemic, as clinical staff became more confident in choosing which patients would benefit most. Trust In the System described how nurses coped with discrepancies between the ambulatory system and ward observation machines. Finally, Resource Management examined how, once trust was built, staff perceived the ambulatory system assisted with caseload management. This supported efficient personal protective equipment resource use by reducing the number of isolation room entries. Despite these reported benefits, face-to-face contact was still highly valued, despite the risk of coronavirus exposure.
Conclusion: Hospital wards should consider using ambulatory monitoring systems to support caseload management and patient safety. Patients in isolation rooms or at high risk of deterioration may particularly benefit from this additional monitoring. However, these systems should be seen as an adjunct to nursing care, not a replacement.
Implications for the Profession and/or Patient Care: Nurses valued ambulatory monitoring as a means of ensuring the safety of patients at risk of deterioration and prioritizing their workload.
Impact: The findings of this research will be useful to all those developing or considering implementation of ambulatory monitoring systems in hospital wards.
Reporting Method: This manuscript follows the Consolidated criteria for Reporting Qualitative Research (COREQ) guidelines with inclusion of relevant SQUIRE guidelines for reporting quality improvement.
Patient or Public Contribution: No Patient or Public Contribution
A Feasibility Study on Embedded Micro-Electromechanical Sensors and Systems (MEMS) for Monitoring Highway Structures
Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of structural health monitoring (SHM) of highway infrastructure systems, including improved system reliability, improved longevity and enhanced system performance, improved safety against natural hazards and vibrations, and a reduction in life cycle cost in both operating and maintaining the infrastructure. Advancements in MEMS technology and wireless sensor networks provide opportunities for long-term, continuous, real-time structural health monitoring of pavements and bridges at low cost within the context of sustainable infrastructure systems.
The primary objective of this research was to investigate the use of MEMS in highway structures for health monitoring purposes. This study focused on investigating the use of MEMS and their potential applications in concrete through a comprehensive literature review, a vendor survey, and a laboratory study, as well as a small-scale field study. Based on the comprehensive literature review and vendor survey, the latest information available on off-the-shelf MEMS devices, as well as research prototypes, for bridge, pavement, and traffic applications were synthesized.
A commercially-available wireless concrete monitoring system based on radio-frequency identification (RFID) technology and off-the-shelf temperature and humidity sensors were tested under controlled laboratory and field conditions. The test results validated the ability of the RFID wireless concrete monitoring system in accurately measuring the temperature both inside the laboratory and in the field under severe weather conditions.
In consultation with the project technical advisory committee (TAC), the most relevant MEMS-based transportation infrastructure research applications to explore in the future were also highlighted and summarized
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