Extrinsic Sources Research Articles

Suppression of Intensity and Frequency Noise at Low-Sensitivity Operating Points of Period-One Dynamics of Optically Injected Semiconductor Lasers

Period-one (P1) dynamics induced by an optically injected semiconductor laser oscillate at microwave frequencies. The oscillation frequency of a P1 dynamic can be rendered nearly insensitive to small-signal parameter fluctuations and intrinsic laser noise at appropriate operating conditions of the master and slave lasers. In this paper, the noise-canceling properties of the various low-sensitivity (LS) operating points is demonstrated through their dependency on the noise fluctuation frequency and power. The three different types of LS operating points show their effectiveness in suppressing not only P1 intensity and frequency fluctuations caused by narrowband laser perturbations but also intensity and frequency noise caused by broadband intrinsic and extrinsic noise sources.

The competition of Hund’s coupling and impurity on transport anisotropy in iron-based superconductors

The origin of anisotropic transport in the nematic phase of the iron-based superconductors is still controversial. Two main explanations include the extrinsic sources induced by impurity scattering and the intrinsic mechanism which highlights the orbital order or spin scenarios. Based on an inhomogeneous three-orbital Hubbard model, we study the effects of Hund’s coupling and substitutions on the nematic susceptibility and anisotropic conductance. We find that nematic susceptibility is tuned by Hund’s coupling in undoped case and reaches a peak at J∕U = 0.12. However, this anisotropic electron state is fragile and can easily be destroyed by weak doping. The anisotropy of resistivity ρanis = (ρa∕ρb) − 1 rapidly reduces in the small doping level and then gradually increases with doping concentration. However, the twofold nanostructure induced by impurities will be suppressed when we increase the Hund’s coupling, consistent with the scanning tunnelling experiments on iron pnictides. These results also explain the contradictory dependence of ρanis on substitutions in tetragonal and orthorhombic phase.

Is your assay stable? Using process stability and capability to evaluate assay performance

BackgroundMany laboratories are involved in efforts to increase precision and improve process capability. Metrics to evaluate performance, assess potential for improvement, and prioritize improvement projects would facilitate these efforts. We show how stability analysis can provide metrics to evaluate assay performance and indicate potential for improvement. We also show how stability analysis along with capability analysis can be used to prioritize assays for improvement. Stability reflects the degree to which a process is free of extrinsic sources of variation. Capability reflects the ability of a process to meet external requirements. MethodsWe used the SR test and analysis of variance to compare the short-term and long-term stability of two assays. We illustrate the analysis with detailed calculations for two assays. ResultsOne assay (thyroid stimulating hormone) was stable and the other, (methotrexate) was unstable. ConclusionStability analysis provides metrics that can be used evaluate assay performance and to prioritize process improvement efforts.

Transmission loss measurements of plastic scintillating optical fibres

The wavelength dependent attenuation spectra of a range of commercially available and in-house fabricated scintillating polymer optical fibres have been measured using cut-back and side induced fluorescence techniques. The fibre transmission loss was found to be dependent on the scintillator formulation, core size and cladding, the effects of which are discussed in relation to various intrinsic and extrinsic loss sources.

Host investment into symbiosis varies among genotypes of the legume Acmispon strigosus, but host sanctions are uniform.

Efficient host control predicts the extirpation of ineffective symbionts, but they are nonetheless widespread in nature. We tested three hypotheses for the maintenance of symbiotic variation in rhizobia that associate with a native legume: partner mismatch between host and symbiont, such that symbiont effectiveness varies with host genotype; resource satiation, whereby extrinsic sources of nutrients relax host control; and variation in host control among host genotypes. We inoculated Acmispon strigosus from six populations with three Bradyrhizobium strains that vary in symbiotic effectiveness on sympatric hosts. We measured proxies of host and symbiont fitness in single- and co-inoculations under fertilization treatments of zero added nitrogen (N) and near-growth-saturating N. We examined two components of host control: 'host investment' into nodule size during single- and co-inoculations, and 'host sanctions' against less effective strains during co-inoculations. The Bradyrhizobium strains displayed conserved growth effects on hosts, and host control did not decline under experimental fertilization. Host sanctions were robust in all hosts, but host lines from different populations varied significantly in measures of host investment in both single- and co-inoculation experiments. Variation in host investment could promote variation in symbiotic effectiveness and prevent the extinction of ineffective Bradyrhizobium from natural populations.

Scatter, Scope and Structures: What fatigue fracture testing of fiber polymer composites is all about

The approach to cyclic fatigue fracture testing of metals and alloys with the data presentation as “Paris-Graph” developed by Paul Paris and co-workers has proven immensely useful for structural engineering. It is, therefore, understandable that the later development of fatigue fracture test methods for fiber-reinforced polymer (FRP) composites followed this route also. However, recently questions have been raised by several researchers that require looking at fatigue fracture of FRP composites in more detail in attempts at using the full potential of this class of materials in structural applications. One of these questions is how the apparent analogy in the shape of the curves between Paris-Graphs of metals, alloys and FRP composites relates to the material specific, physical damage mechanisms. For FRP composites, the investigation of these mechanisms has a long history, but only recently, there seems to be a real advance using sophisticated pattern recognition of acoustic emission waveforms with complementary methods such as multi-physics simulations or high-resolution X-ray computed tomography. Comparing, e.g., crack sizes on the order of tens of micrometers occurring on time-scales of microseconds or less with visually observed delamination propagation, it becomes clear that the data analysis for the Paris-graph is averaging over orders of magnitudes in both, length and time-scales and this inevitably involves some scatter. Another question raised concerns the apparently larger scatter in Paris-Graphs obtained for FRP composites compared to those of metals or alloys. Again, a full understanding of the sources of this scatter has not been reached yet, but likely, the complex morphology and microscopic damage mechanisms of FRP composites play a role. There are further effects from mesoscopic or large-scale fiber bridging in fatigue fracture due to special fiber lay-up used in testing. For structural design with FRP composites, it is not sufficient to select the material performing “best” in the fatigue fracture tests, but it is essential to have safe, reliable, but on the other hand realistic design limits. Scatter in the data and how much of that has to be taken into account first requires understanding the extrinsic (test related) and intrinsic (material related) scatter sources. The concept of a fatigue threshold is also important for fracture-based structural design, since there are indications that threshold values for FRP composites may be quite low.

A prospective, observational study investigating the use of carbon monoxide screening to identify maternal smoking in a large university hospital in Ireland

ObjectivesThis study evaluated breath carbon monoxide (BCO) testing in identifying maternal smokers as well as the difference between disclosers and non-disclosers of smoking status. We also investigated if other extrinsic...

Evaluation of the Painful Total Hip Arthroplasty

AbstractThe total hip arthroplasty (THA) remains as one of the most successful procedures improving function and quality of life. However, despite its success, failures do occur. The workup of a painful THA should be methodical, prioritizing the most likely to least likely etiologies. Intrinsic and extrinsic sources of pain must be evaluated from data collected through an accurate history, detailed physical examination, laboratory analysis, and imaging interpretation.

Noise in the Vertebrate Segmentation Clock Is Boosted by Time Delays but Tamed by Notch Signaling

SUMMARYTaming cell-to-cell variability in gene expression is critical for precise pattern formation during embryonic development. To investigate the source and buffering mechanism of expression variability, we studied a biological clock, the vertebrate segmentation clock, controlling the precise spatiotemporal patterning of the vertebral column. By counting single transcripts of segmentation clock genes in zebrafish, we show that clock genes have low RNA amplitudes and expression variability is primarily driven by gene extrinsic sources, which is suppressed by Notch signaling. We further show that expression noise surprisingly increases from the posterior progenitor zone to the anterior segmentation and differentiation zone. Our computational model reproduces the spatial noise profile by incorporating spatially increasing time delays in gene expression. Our results, suggesting that expression variability is controlled by the balance of time delays and cell signaling in a vertebrate tissue, will shed light on the accuracy of natural clocks in multi-cellular systems and inspire engineering of robust synthetic oscillators.

Low-frequency magnetic sensing by magnetoelectric metglas/bidomain LiNbO3 long bars

We present an investigation into the magnetic sensing performance of magnetoelectric bilayered metglas/bidomain LiNbO3 long thin bars operating in a cantilever or free vibrating regime and under quasi-static and low-frequency resonant conditions. Bidomain single crystals of Y + 128°-cut LiNbO3 were engineered by an improved diffusion annealing technique with a polarization macrodomain structure of the ‘head-to-head’ and ‘tail-to-tail’ type. Long composite bars with lengths of 30, 40 and 45 mm, as well as with and without attached small tip proof masses, were studied. ME coefficients as large as 550 V (cm · Oe)−1, corresponding to a conversion ratio of 27.5 V Oe−1, were obtained under resonance conditions at frequencies of the order of 100 Hz in magnetic bias fields as low as 2 Oe. Equivalent magnetic noise spectral densities down to 120 pT Hz−1/2 at 10 Hz and to 68 pT Hz−1/2 at a resonance frequency as low as 81 Hz were obtained for the 45 mm long cantilever bar with a tip proof mass of 1.2 g. In the same composite without any added mass the magnetic noise was shown to be as low as 37 pT Hz−1/2 at a resonance frequency of 244 Hz and 1.2 pT Hz−1/2 at 1335 Hz in a fixed cantilever and free vibrating regimes, respectively. A simple unidimensional dynamic model predicted the possibility to drop the low-frequency magnetic noise by more than one order of magnitude in case all the extrinsic noise sources are suppressed, especially those related to external vibrations, and the thickness ratio of the magnetic-to-piezoelectric phases is optimized. Thus, we have shown that such systems might find use in simple and sensitive room-temperature low-frequency magnetic sensors, e.g. for biomedical applications.

Planar Enteroids Reveal an Autonomous WNT And BMP Circuit Controlling Intestinal Epithelial Growth and Organization

The epithelial lining of the human intestine is a prime example of tight homeostatic control of cell proliferation, organization and fate determination. As a mechanism for dealing with constant mechanical, chemical and pathogen‐derived insults, the epithelium is in constant turnover, completely renewing every four days. Amazingly, this active process produces multiple cell types at just the right ratios and locations throughout our life span. Failure of this exquisite control is the basis for diseases including Crohn's disease, ulcerative colitis, and cancers of the esophagus, stomach, small and large intestine.A central challenge is to elucidate mechanisms required for robust control of tissue renewal. Opposing WNT and BMP signaling is essential in establishing epithelial homeostasis. However, it has been difficult to disentangle contributions from multiple sources of morphogenic signals in the tissue. Here, to dissect epithelial‐autonomous morphogenic signaling circuits, we developed a planar enteroid intestinal culture system that recapitulates key properties of the intestinal epithelium, specifically the ability to: maintain proliferative and differentiated zones, self‐renew, polarize and generate major intestinal cell types. We systematically perturb intrinsic and extrinsic sources of WNT and BMP signals to reveal a core morphogenic circuit that controls proliferation, tissue organization and cell fate. Our work demonstrates the ability of intestinal epithelium, even in the absence of 3D tissue architecture, to control its own growth and organization through morphogen‐mediated feedback.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Unfamiliar technology: Reaction of international students to blended learning

This study enquires into learners’ behavioural intentions towards the use of a blended learning program designed for post-graduate international IT students. The aim of this research is to develop a testing mechanism to measure the extent to which international students have built up digital capital. We use the unified theory of acceptance and use of technology (UTAUT) as a framework for this investigation, built around social influence (behavioural intention) performance and effort expectancy (attitude), and facilitating conditions (ease and usefulness), using a critical theoretical approach. We further attempt to understand whether motivation for engagement with blended learning comes from intrinsic or extrinsic sources. For this study, 95 Project Management students were introduced to a blended learning approach using Blackboard, a Learning Management System. Following an introductory session, data on attitude, social influence and facilitating conditions was gathered. Hierarchical multiple regressions were used to assess the influence of each variable in determining first behavioural intentions and latter attitude towards blended learning. This study contributes to the body of knowledge through identifying that social influence has a strong impact on both performance and effort expectation as well as behavioural intentions. This suggests that, overall, the social environments from which the cohort originated provided sufficient economic, social and cultural capital to also develop some digital capital.

Enteroid Monolayers Reveal an Autonomous WNT and BMP Circuit Controlling Intestinal Epithelial Growth and Organization

The intestinal epithelium maintains a remarkable balance between proliferation and differentiation despite rapid cellular turnover. A central challenge is to elucidate mechanisms required for robust control of tissue renewal. Opposing WNT and BMP signaling is essential in establishing epithelial homeostasis. However, it has been difficult to disentangle contributions from multiple sources of morphogen signals in the tissue. Here, to dissect epithelial-autonomous morphogenic signaling circuits, we developed an enteroid monolayer culture system that recapitulates four key properties of the intestinal epithelium, namely the ability to maintain proliferative and differentiated zones, self-renew, polarize, and generate major intestinal cell types. We systematically perturb intrinsic and extrinsic sources of WNT and BMP signals to reveal a core morphogenic circuit that controls proliferation, tissue organization, and cell fate. Our work demonstrates the ability of intestinal epithelium, even in the absence of 3D tissue architecture, to control its own growth and organization through morphogen-mediated feedback.

Otolith increments in European plaice (Pleuronectes platessa) reveal temperature and density-dependent effects on growth

Abstract European plaice (Pleuronectes platessa) is a commercially important flatfish species in the North Sea. Yet, the environmental factors that affect the growth of plaice remain unresolved. Here we examine the drivers of plaice growth variation by using a large archive of otoliths from female plaice collected in the northeastern part of the North Sea from 1993 to 2015, providing growth data over the period 1985–2014. We developed a series of increasingly complex mixed-effect models to explore intrinsic (within individual) and extrinsic (environmental factors: bottom temperature and plaice density) sources of growth variation. We analysed juvenile (0 and 1 year) and (sub)adult (≥2 years) growth separately due to different habitat utilization across life stages. Juvenile growth was positively correlated with bottom temperature, whereas growth of adults was negatively correlated with bottom temperature. Correlations for both were strongest during autumn (September to October). For juveniles, the temperature–growth relationship likely reflects a response to growing season length while for adults it could reflect temperature-dependent changes to metabolic rate or food availability. For both juveniles and adults, we also found inverse relationship between population density and growth. We suggest that the approach used in this study can find a much wider application in European waters.

Repair kinetics of DNA double-strand breaks and incidence of apoptosis in mouse neural stem/progenitor cells and their differentiated neurons exposed to ionizing radiation.

Neuronal loss leads to neurodegenerative disorders, including Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Because of their long lifespans, neurons are assumed to possess highly efficient DNA repair ability and to be able to protect themselves from deleterious DNA damage such as DNA double-strand breaks (DSBs) produced by intrinsic and extrinsic sources. However, it remains largely unknown whether the DSB repair ability of neurons is more efficient compared with that of other cells. Here, we investigated the repair kinetics of X-ray–induced DSBs in mouse neural cells by scoring the number of phosphorylated 53BP1 foci post irradiation. We found that p53-independent apoptosis was induced time dependently during differentiation from neural stem/progenitor cells (NSPCs) into neurons in culture for 48 h. DSB repair in neurons differentiated from NSPCs in culture was faster than that in mouse embryonic fibroblasts (MEFs), possibly due to the higher DNA-dependent protein kinase activity, but it was similar to that in NSPCs. Further, the incidence of p53-dependent apoptosis induced by X-irradiation in neurons was significantly higher than that in NSPCs. This difference in response of X-ray–induced apoptosis between neurons and NSPCs may reflect a difference in the fidelity of non-homologous end joining or a differential sensitivity to DNA damage other than DSBs.

Identification of Particles in Parenteral Drug Raw Materials.

The presence of particles in drug products is regulated. These particles may be present before the beginning of the manufacturing process-that is, from the raw materials. To prevent the inclusion of these particles, it is important to understand their composition and origin, so that raw material quality, processing, and shipping can be improved. Thus, it is important to correctly identify particles seen in raw materials. Raw materials need to be of a certain quality with respect to physical and chemical composition and need to have no contaminants in the form of particles, which could contaminate the product or indicate that the raw materials are not pure enough to make a high-quality product. Particles are often seen when handling raw materials because of their different color, size, or shape characteristics. Particles may appear to be very different to the eye than they actually are, so microscope, chemical, and elemental analyses are required for accuracy in proper identification. This paper shows how using three different spectroscopy tools correctly and together can help identify particles from extrinsic, intrinsic, and inherent sources. Particles can originate from material sources such as humans and the environment (extrinsic), from within the process (intrinsic), and as part of the formulation (inherent). Microscope versions of Raman spectroscopy, laser-induced breakdown spectroscopy, and infrared spectroscopy are excellent tools for identifying particles, because they are fast and accurate techniques needing minimal sample preparation that can provide chemical composition, as well as images, that can be used for identification. The micro-analysis capabilities allow for easy analysis of different portions of samples, so multiple components can be identified, and sample preparation can be reduced. Using just one of these techniques may be insufficient to give adequate identification results so that the source of contamination can be adequately identified. The complementarity of the techniques provides the advantage of identifying various chemical and molecular components, as well as elemental and image analyses. Correct interpretation of the results from these techniques is also very important.LAY ABSTRACT: The presence of particles in drug products is regulated. These particles may be present before the beginning of the manufacturing process-that is, from the raw materials. To prevent the inclusion of these particles, it is important to understand their composition and origin, so that raw material quality, processing, and shipping can be improved. Thus, it is important to correctly identify particles seen in raw materials. Raw materials need to be of a certain quality with respect to physical and chemical composition and need to have no contaminants in the form of particles, which could contaminate the product or indicate that the raw materials are not pure enough to make a high-quality product. Particles are often seen when handling raw materials because of their different color, size, or shape characteristics. Particles may appear to be very different to the eye than they actually are, so microscope, chemical, and elemental analyses are required for accuracy in proper identification. This paper shows how using three different spectroscopy tools correctly and together can help identify particles from extrinsic, intrinsic, and inherent sources. Particles can originate from material sources such as humans and the environment (extrinsic), from within the process (intrinsic), and as part of the formulation (inherent). Spectroscopy uses light to identify materials. This paper shows how using three different spectroscopy tools correctly and together can be used to identify particles from extrinsic, intrinsic, and inherent sources. These were Raman, laser-induced breakdown, and infrared spectroscopies. These techniques are excellent tools for identifying particles, because they are fast and accurate techniques needing minimal sample preparation that can provide chemical composition, as well as images, that can be used for identification. Versions of these that use micro-analyses capabilities allow for easy analysis of different portions of samples, so multiple components can be identified, and sample preparation can be reduced. Each technique has different capabilities that complement each other, and using all three provides the advantage of identifying various chemical and molecular components, as well as elemental and image analyses. However, each of these has limitations and different capabilities that make having them all available for analyses important. Also, it is very important to be able to correctly interpret the results from the instruments.

Adaptive influence of extrinsic and intrinsic factors on variation of incubation periods among tropical and temperate passerines

ABSTRACT Understanding intrinsic (physiological) and extrinsic (e.g., temperature) causes of variation in embryonic development time (incubation period) is important because they can have different impacts on individual quality. Robert Ricklefs and colleagues have argued that longer incubation periods result primarily from intrinsic physiological programs that increase individual quality and adult survival. They claim that incubation periods are largely invariant and that extrinsic factors like temperature have little impact. We have argued that adult survival may be a cause rather than a consequence of much of the variation in embryonic development time. A reduction in extrinsic sources of annual adult mortality (e.g., migration, predation, nonbreeding-season mortality) favors reduced parental effort during incubation to minimize costs to future reproduction and survival. Reduced parental effort, in turn, manifests as cooler average egg temperatures that yield longer incubation periods. Ricklefs and coll...

Abstract 11: APOBEC is a major source of mutations in head and neck squamous cell carcinoma

Abstract Background: Cancers arise from an accumulation of somatic mutations. Numerous intrinsic and extrinsic mutagenic sources exist, yet our understanding of which processes are active in a given cancer genome is limited. Specific mutagenic processes have mutational preferences, called signatures. Large-scale analyses of cancer genomes/exomes from The Cancer Genome Atlas (TCGA) have identified 30 unique signatures. APOBEC is a family of cytosine deaminases which function in the immune response to viral infection. A signature for APOBEC3 activity has been identified in a subset of cancers, including head and neck squamous cell carcinoma (HNSCC). The specifics of APOBEC activity in HNSCC remain poorly understood. Methods: We utilized bioinformatic approaches to explore the role of APOBEC mutations in tumor exomes, transcriptomes and germline exomes from 511 HNSCC patients in TCGA. Results: 58% of HNSCC are statically enriched for the APOBEC3 signature compared to all other cancers in TCGA. HPV+ HNSCC are statistically enriched for the APOBEC3 signature compared to HPV- samples (p < 0.0013). MutSig was used to test the prevalence of APOBEC3 mutations in known driver genes compared to passengers. While the mean rate of APOBEC3 mutations was similar between MuSig genes and all other genes (19.4% vs 21.9%), PIK3CA demonstrated a 20-fold increase above all other genes. When evaluated by HPV status, 87% of PIK3CA mutations in HPV+ samples were APOBEC3 mutations compared to 55% of mutations in HPV- samples (p <0.025). All APOBEC3 mutations in HPV + samples occurred at two known hotspots, while HPV- mutations were distributed throughout the gene, strongly arguing against a random occurrence in HPV+ samples. Isoform analysis revealed a slight predominance of APOBEC3A mutations compared to other APOBEC3 isoforms. RNA-Seq analysis of 511 transcriptomes showed a weak correlation between APOBEC3 mutation rates and APOBEC3 expression. RNA-Seq Pathway Analysis demonstrated an overrepresentation of immune pathway dysregulation in APOBEC3 mutation rich samples. Conclusions: APOBEC3 is a major source of mutations in HNSCC. HPV+ HNSCC have the highest enrichment of APOBEC3 mutations. APOBEC3 mutations are strongly overrepresented in PIK3CA at two known hotspots, suggesting these mutations are of functional importance. APOBEC3A is the most likely APOBEC to be active in HPV+ HNSCC; however, expression levels of APOBEC isoforms do not correlate well with APOBEC mutational rates, suggesting a temporal dissonance between enzyme activity and tumor sample harvest. APOBEC3 activity appears to correlate with upregulation of immune signaling pathways, supporting the hypothesis that APOBEC is acting as part of the innate response to viral infection, although its activity in HPV- cancer suggests other mechanisms of upregulation as well. Citation Format: Daniel L. Faden, Sean Thomas, Jeffrey Myers, Nishant Agrawal, Joseph DeRisi. APOBEC is a major source of mutations in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; April 23-25, 2017; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(23_Suppl):Abstract nr 11.

Stress in the Higher Education Sector: Causes and Yoga-Mindfulness Interventions

The Aim of this paper was to critically review the nature and causes of stress among academics in higher education workplaces and to undertake a pilot study of how yoga-mindfulness interventions might help to address these issues. The background to this subject comprises an increase in reported levels of stress and stress-related absenteeism in university employees. Universities have changed considerably from workplaces once thought of as secure and relaxed contexts, to those facing considerable upheaval due to the erosion of resource bases, temporary contractual work, and multifaceted job roles and rising expectations. Whilst the topic of stress in educational workplaces is broad one, this paper focuses on the causes and sources of stress identified by a selection of key research articles. This focus allows for an in-depth initial understanding of why stress is an increasing problem in this sector. The methods employed to undertake the first part of this work involved an extensive literature analysis. Key academic articles were selected using a range of inclusion and exclusion criteria. Studies were reviewed from across the developed world and many employed mixed qualitative and quantitative methodologies as part of their research. Databases used to select the final papers included the Cochrane library, Science Direct, Medline, PsychInfo, BMJ, Swetswise, Google Scholar, EPPI centre and Ebscho host. The methods employed for the second part of this work involved a pilot study survey assessing the perceived benefits of participation in a yoga-mindfulness based programme in a UK university. The findings collated for this review show that majority of stress causes among academic staff stem from the ‘external environment’ or extrinsic sources; i.e. the ‘organisation’ itself and how it is managed. The most common key stressors were reductions in resources/financial constraints; workload pressures (including job expectations, time constraints and increased administrative loads); job insecurity/contracts; ‘management’ styles and policies; and workplace relationships (issues with staff-management interfaces, unmotivated colleagues, and workload disparities). Interestingly, stressors concerned with ‘core’ functions of academics, those of teaching and student demands did not rank highly in most cases. Intrinsic causes of stress were related to issues of reward and recognition; increased lack of individual control; promotional prospects and maintaining a good work-life balance. Various differences were reported on correlations between the above stressors and variables such as age, gender, length of employment. The pilot study of the YMBI (Yoga-Mindfulness Based Intervention) indicated that there was a strong positive effect on individual’s perceived levels of personal coping abilities during the programme. This indicates a growing need for structural inclusion of targeted prevention as well as individual intervention strategies for stress management among faculty in universities. More work is needed on the relationship between stress in Higher Education and effective mind-body work-based interventions.

Impact of perturbative, non-axisymmetric impurity fueling on Alcator C-Mod H-modes

Experiments on Alcator C-Mod have been performed to investigate the impact of toroidally localized impurity injection on H-mode exhaust scenarios. Results help to inform sub-divertor gas injector designs, in particular that of the ITER machine, for which this work was primarily undertaken. In repeated EDA H-modes, the amount of N2 injected into the private flux region was scanned up to levels which strongly impacted normalized energy confinement, H98, and led to an H/L back-transition. Repeated scans increased the toroidal peaking of the gas injection, reducing from five equally spaced locations to a single toroidal and poloidal injector. Results show the impact on the pedestal and core plasma is similar between all cases as long as the total gas injection rate is held constant. An influence on toroidally localized impurity spectroscopy is shown, demonstrating a complication in using such data in interpreting experiments and supporting boundary modeling in cases where there are localized extrinsic or intrinsic impurity sources. These results, along with prior work in this area on Alcator C-Mod, form a comprehensive set of L-mode and H-mode data to be used for validation of 3D boundary physics codes.