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Terpou, Braeden A., Maria Densmore, Jean Théberge, Janine Thome, Paul Frewen, Margaret C. McKinnon, and Ruth A. Lanius. "The Threatful Self: Midbrain Functional Connectivity to Cortical Midline and Parietal Regions During Subliminal Trauma-Related Processing in PTSD." Chronic Stress 3 (January 2019): 247054701987136. http://dx.doi.org/10.1177/2470547019871369.
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Background The innate alarm system consists of a subcortical network of interconnected midbrain, lower brainstem, and thalamic nuclei, which together mediate the detection of evolutionarily-relevant stimuli. The periaqueductal gray is a midbrain structure innervated by the innate alarm system that coordinates the expression of defensive states following threat detection. In participants with post-traumatic stress disorder, the periaqueductal gray displays overactivation during the subliminal presentation of trauma-related stimuli as well as altered resting-state functional connectivity. Aberrant functional connectivity is also reported in post-traumatic stress disorder for the default-mode network, a large-scale brain network recruited during self-referential processing and autobiographical memory. Here, research lacks investigation on the extent to which functional interactions are displayed between the midbrain and the large-scale cortical networks in post-traumatic stress disorder. Methods Using a subliminal threat presentation paradigm, we investigated psycho-physiological interactions during functional neuroimaging in participants with post-traumatic stress disorder (n = 26) and healthy control subjects (n = 20). Functional connectivity of the periaqueductal gray was investigated across the whole-brain of each participant during subliminal exposure to trauma-related and neutral word stimuli. Results As compared to controls during subliminal threat presentation, the post-traumatic stress disorder group showed significantly greater periaqueductal gray functional connectivity with regions of the default-mode network (i.e., angular gyrus, precuneus, superior frontal gyrus). Moreover, multiple regression analyses revealed that the functional connectivity between the periaqueductal gray and the regions of the default-mode network correlated positively to symptoms of avoidance and state dissociation in post-traumatic stress disorder. Conclusion Given that the periaqueductal gray engages the expression of defensive states, stronger midbrain functional coupling with the default-mode network may have clinical implications to self-referential and trauma-related processing in participants with post-traumatic stress disorder.
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Schütte, Henning, and Kianoush Molla-Abbasi. "On the Influence of the Corner Singularity on Kinking Mixed-Mode Crack Propagation." Key Engineering Materials 348-349 (September 2007): 585–88. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.585.
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The aim of the presentation is to highlight the influence of the kink, developing at the beginning of mixed-mode crack growth, on the propagation behavior of the crack. Le et al. [1] have shown that the variational principle of a body containing a crack results in the principle of maximum energy release rate incorporating the stress intensity factors of the kinked crack. Here the influence of the kink and the kinking angle, resulting in a singular field around the corner, on the crack growth is analyzed. The generalized stress intensity factors at the kinks corner are computed with the help of a FEM strategy. The influence of these on the T-stresses and the plastic energy dissipated at the kink is determined using a small scale yielding approach. The impact of these results on mixed-mode crack propagation is discussed.
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Liu, Yong-Qiang, Hong-Quan Song, and Jiang Shen. "Interfacial potential approach for Ag/Si(111) interface." Modern Physics Letters B 30, no. 09 (April 10, 2016): 1650104. http://dx.doi.org/10.1142/s0217984916501049.
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By applying the Chen–Möbius inversion method, a concise formula is introduced to get the pair potentials of the Ag/Si(111) interface by inversion of the ab initio adhesive energies. The check shows that the inversed potentials are self-consistent. Then, by using the interfacial potentials obtained, we analyze the changes of the energy, stress and atomic structures, giving a detailed presentation of the fracture process about the Ag/Si(111) interface. Meanwhile, we know that there are three kinds of fracture mode. In this work, the fracture process is performed in mode II (shear).
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Larisa, Stepanova. "Intermediate self-similar asymptotic presentation of stress and damage fields in the vicinity of mixed mode crack tip under creep regime." Procedia Structural Integrity 13 (2018): 255–60. http://dx.doi.org/10.1016/j.prostr.2018.12.043.
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Liang, Dongxu, Nong Zhang, and Haoyu Rong. "Study on the Effect of Continuity and Load Angle of Prefabricated Cross-Flaws on Crack Initiation and Coalescence." Shock and Vibration 2021 (August 4, 2021): 1–17. http://dx.doi.org/10.1155/2021/8705178.
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In this study, a model that is closer to the state of fracture presentation in natural rocks has been developed, which is different from the previous. The cross-flaws can be characterized by the joint persistency ( k ) and the angle between the primary flaws and axial load ( α ). The two parameters were varied individually and, by combining them, nine specimens with different nodal parameters were formed. Laboratory specimens and numerical simulations were performed on these specimens to investigate the crack extension process and the variation of crack initiation and coalescence stresses. It is found that a new category of crack coalescence is discovered according to the experimental results besides those reported before, and the angle α affects whether tensile-shear cracks appear. Also, α has an impact on the location where crack first occurs. The joint persistency k alters rock failure mode and has a substantial effect on crack initiation stress. However, the effect on the aggregation stress is not significant. The crack initiation stress decreases in the case of cross-flaws in contrast to flat fissures. In addition, the flat-joint model in PFC2D is used for numerical simulation. It is possible to conduct a study that is difficult to achieve experimentally by using simulations, i.e., only changing one macroparameter without changing others and thus studying the changes in the effect on cracking during fracture. The simulation results are in good agreement with the experimental results. At the same time, the connection mode and the width of the crack coalescence zone of the primary defect, which is difficult to observe in the experiment, are found out from the numerical simulation.
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Pipinos, Iraklis I., Stanley A. Swanson, Zhen Zhu, Aikaterini A. Nella, Dustin J. Weiss, Tanuja L. Gutti, Rodney D. McComb, B. Timothy Baxter, Thomas G. Lynch, and George P. Casale. "Chronically ischemic mouse skeletal muscle exhibits myopathy in association with mitochondrial dysfunction and oxidative damage." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 295, no. 1 (July 2008): R290—R296. http://dx.doi.org/10.1152/ajpregu.90374.2008.
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A myopathy characterized by mitochondrial pathology and oxidative stress is present in patients with peripheral arterial disease (PAD). Patients with PAD differ in disease severity, mode of presentation, and presence of comorbid conditions. In this study, we used a mouse model of hindlimb ischemia to isolate and directly investigate the effects of chronic inflow arterial occlusion on skeletal muscle microanatomy, mitochondrial function and expression, and oxidative stress. Hindlimb ischemia was induced by staged ligation/division of the common femoral and iliac arteries in C57BL/6 mice, and muscles were harvested 12 wk later. Muscle microanatomy was examined by bright-field microscopy, and mitochondrial content was determined as citrate synthase activity in muscle homogenates and ATP synthase expression by fluorescence microscopy. Electron transport chain (ETC) complexes I through IV were analyzed individually by respirometry. Oxidative stress was assessed as total protein carbonyls and 4-hydroxy-2-nonenal (HNE) adducts and altered expression and activity of manganese superoxide dismutase (MnSOD). Ischemic muscle exhibited histological features of myopathy and increased mitochondrial content compared with control muscle. Complex-dependent respiration was significantly reduced for ETC complexes I, III, and IV in ischemic muscle. Protein carbonyls, HNE adducts, and MnSOD expression were significantly increased in ischemic muscle. MnSOD activity was not significantly changed, suggesting MnSOD inactivation. Using a mouse model, we have demonstrated for the first time that inflow arterial occlusion alone, i.e., in the absence of other comorbid conditions, causes myopathy with mitochondrial dysfunction and increased oxidative stress, recapitulating the muscle pathology of PAD patients.
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Gallo, Pasquale, and Alberto Sapora. "Brittle Failure of Nanoscale Notched Silicon Cantilevers: A Finite Fracture Mechanics Approach." Applied Sciences 10, no. 5 (February 29, 2020): 1640. http://dx.doi.org/10.3390/app10051640.
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The present paper focuses on the Finite Fracture Mechanics (FFM) approach and verifies its applicability at the nanoscale. After the presentation of the analytical frame, the approach is verified against experimental data already published in the literature related to in situ fracture tests of blunt V-notched nano-cantilevers made of single crystal silicon, and loaded under mode I. The results show that the apparent generalized stress intensity factors at failure (i.e., the apparent generalized fracture toughness) predicted by the FFM are in good agreement with those obtained experimentally, with a discrepancy varying between 0 and 5%. All the crack advancements are larger than the fracture process zone and therefore the breakdown of continuum-based linear elastic fracture mechanics is not yet reached. The method reveals to be an efficient and effective tool in assessing the brittle failure of notched components at the nanoscale.
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R., Vasuki, Arun P. S., and Rajesh Menon Moothedath. "A rare case of spontaneous gastric perforation in an adolescent." International Surgery Journal 5, no. 9 (August 25, 2018): 3171. http://dx.doi.org/10.18203/2349-2902.isj20183743.
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Incidence of Peptic ulcer perforation in children and adolescents are very rare. Perforated gastric ulcer is extremely rare with only handful of cases reported worldwide in the same age group. Pneumoperitoneum and peritonitis due to gastric perforation is a very rare presentation in children and adolescents and it can often be overlooked with disastrous consequences. Even though in young patients, peptic ulcerations can happen in association with H. pylori infection, secondary to medications like non-steroidal anti-inflammatory agents, corticosteroids, rarely due to Zollinger Ellison syndrome, related to stress, post burns or head trauma it is seldom common. Among perforations gastric perforation is very rare. Here we discuss a case of 15-year-old school student who presented with acute abdominal pain and features of peritonitis which we initially thought probably due to perforated appendix but turned out to be a gastric perforation. Plain radiograph of the abdomen showed pneumoperitoneum. When an emergency midline laparotomy was performed, we found a perforation in gastric antrum anteriorly with peritonitis which was treated by thorough decontamination and Graham's live omental patch closure. H. Pylori tests were negative. At a time when acute presentation of peptic ulcerations or perforation as its complication is decreasing in incidence worldwide, this case has come as an eye opener. Thus, perforated gastric/duodenal ulcer in pediatric and young adult patient should not be overlooked in a young patient presenting with acute abdomen. Many times, there is no clear etiology and then it is spontaneous perforation. Emergency surgical management is the preferred mode of treatment.
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Griffin, Dee. "76 Shipping calves to the Southern Great Plains: Impact of mode, timing, distance and cattle type." Journal of Animal Science 97, Supplement_1 (July 2019): 24–25. http://dx.doi.org/10.1093/jas/skz053.054.
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Abstract This presentation will discuss historical transportation information, recommendations and available transportation data. Stocker and feeder cattle transportation in the U.S. is virtually unchanged in the last five decades. Transportation stress continues to be accepted as an important factor in the morbidity and mortality of cattle shipped to Southern Great Plains feedyards and stocker operations. Transportation research has occurred in bits and pieces that provide glimpses into mechanisms involved but in general the results are puzzle pieces that have had little influence on transportation techniques. The Electronic Logging Device (ELD) use mandate in livestock hauling will impact stocker and feeder transport to the Great Plains. The extent of which is not yet known and recent delays in implementation with concurrent “exceptions” and “adjustments” make it unclear what the future will hold for stocker and feeder cattle transportation. The Livestock Marketing Association (LMA) has in recent decades developed voluntary livestock handling and transportation training for their customers. Some of the training has been accomplished in a partnership with the National Cattlemen’s Beef Association (NCBA). The first of these were the “Focal Point” training and “Master Transporter Guide.” More recent, NCBA has developed Beef Quality Assurance (BQA) Transportation certification training for both “Farmer/Rancher” and “Professional Drivers.” Packers have embraced this effort and the major packers currently require all drivers delivering livestock to their operations to be certified. The NCBA BQA Transportation training certification is applicable to stocker and feeder drivers hauling cattle to the Great Plains, but currently it is rare that stocker and feeder operations require drivers to have transportation certification that bring cattle to their operations. Interesting and useful data will be reviewed, such as transportation data collected from Dr. Richeson and Dr. Lawrence at West Texas A&M University. Finding examples include; cattle during transportation can take thousands of steps while on in the semi-trailer with differing number of steps and G-Forces being recorded for cattle on the top deck compared to cattle on the lower deck.
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Triantafyllidis, N., M. D. Nestorović, and M. W. Schraad. "Failure Surfaces for Finitely Strained Two-Phase Periodic Solids Under General In-Plane Loading." Journal of Applied Mechanics 73, no. 3 (September 1, 2005): 505–15. http://dx.doi.org/10.1115/1.2126695.
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For ductile solids with periodic microstructures (e.g., honeycombs, fiber-reinforced composites, cellular solids) which are loaded primarily in compression, their ultimate failure is related to the onset of a buckling mode. Consequently, for periodic solids of infinite extent, one can define as the onset of failure the first occurrence of a bifurcation in the fundamental solution, for which all cells deform identically. By following all possible loading paths in strain or stress space, one can construct onset-of-failure surfaces for finitely strained, rate-independent solids with arbitrary microstructures. The calculations required are based on a Bloch wave analysis on the deformed unit cell. The presentation of the general theory is followed by the description of a numerical algorithm which reduces the size of stability matrices by an order of magnitude, thus improving the computational efficiency for the case of continuum unit cells. The theory is subsequently applied to porous and particle-reinforced hyperelastic solids with circular inclusions of variable stiffness. The corresponding failure surfaces in strain-space, the wavelength of the instabilities, and their dependence on micro-geometry and macroscopic loading conditions are presented and discussed.
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GÂLEA, Meda V. "Investigations Regarding the Opinions of Researchers from the Scientific Research System of Romanian Academy upon the Results Periodically Reported." Journal for Ethics in Social Studies 2, no. 1 (2018): 82–104. http://dx.doi.org/10.18662/jess/12.
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The present paper aims to introduce several considerations regarding the shape, content and importance of the results obtained from the scientific research activity in the Romanian Academy as they are appreciated by the specialized personnel within the system. The study commences from the observations which adhere to the uniformity of the introduction manner of the research results across the entire national system of research-development from the international regulatory laws and the observations related to the different structure of results monitored and reported by the Romanian Academy. A proper management of the results obtained from the scientific research activity contributes, among others, to the assessment of the activities run by researches on personal level and further more to those run on institutional and national level. The results are elements of support for the analysis mode in which the system operates and they provide the basis of the next financing distribution. Thus, we regard as significant the special stress put on adjusting the manner of results presentation to the internationally agreed manner, in pusuit of visibility, competitiveness, comparability and increasing impact of the final outcomes upon the economic and social environment.
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Altzoumails, Alexandros, and Victor Kytopoulos. "On Novel Aspects of Hydrogen Effects on Applied Stress - Coupled Micromagnetic Activity in a Mild Steel After Exposure to NaCl – Water Solution: A Combined Approach." International Journal of Materials 8 (August 11, 2021): 30–42. http://dx.doi.org/10.46300/91018.2021.8.4.
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Hydrogen produced after exposure of a low – carbon steel to corrosive NaCl – Water solution may affect various its tensile mechanical and magnetic microstructural behaviour in a complex manner. This was investigated by introducing a relevant micromagnetic specific emission (ME) - response of this ferromagnetic material, where related processes and parameters of micromagnetic activity and mechanical response were implemented. In this manner, it was demonstrated that an increase in the hydrogen accumulation with corrosion time leads to an associated increase in the embrittling effect expressed by a substantial loss in the ductility of material. The competive and opposing effects of cumulative hydrogen, applied stress and plastic strain – induced microstructural damage were related to the specific ME- response parameter by which an increased magnetic hardening tendency of material with corrosion time was possible to establish. In this fashion and by using a stress as well as strain mode of presentation- aided combined approach, the complex interplay between micromagnetic activity, hydrogen accumulation and applied stress-strain was better revieled and analysed. It was also shown that the embrittlement is a product of hydrogen accumulation introduced by two highly localized processes. As such, accumulation occurs in two characteristic parallel ways: one of a common lattice diffusion and one of hydrogen transport and redistribution by moving dislocation towards the affected sites. Concerning the highly localized effects the dominating role of hydrogen – induced damage in form void initiation and growth over the hydrogen – assisted stress relief was reasonably demonstrated by using a simple modelling approach. Based on a mechanism of moving dislocation – assisted interaction between commulative hydrogen and magnetic domain walls, a Portervin – Le Chatelier – type micromagnetic process of a cooperative-corelated domain wall transport was proposed to explain certain subtle, quasiperiodic behaviour of ME- response. In the frame of the above findings the superior sensivity of ME – response compared to the mechanical one in early detecting cumulative hydrogen – assisted microstructural damage changes can be d educed.
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Durai, M. Ramula, J. Kiran Kumar, and Vijayanand. "A clinical study on the management of sigmoid volvulus." International Surgery Journal 4, no. 3 (February 25, 2017): 1039. http://dx.doi.org/10.18203/2349-2902.isj20170858.
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Background: Sigmoid volvulus is a surgical emergency and significant cause of large bowel obstruction with high mortality and morbidity. The disease is more prevalent in India, especially rural population. It constitutes 15% of total bowel obstructions. This study analyzes various management options in our institute which caters mainly to patients from the surrounding rural areas.Methods: The present work is study of 36 cases, carried out as regards to the etiological factors which predispose to the sigmoid volvulus, the clinical features, modes of treatment and the outcome. Particular stress has been laid on the various treatments. The duration study was 2 years between November 2014 and October 2016 at Government Chengalpattu medical college, Tamil Nadu, India.Results: The mean age of sigmoid volvulus was 49 years (range 19-75) and male to female ratio was 2:1. Comparatively less frequent in less than 20 years and above 70 years. Distention of abdomen (100%), followed by constipation in 88% were common mode of presentation. Sigmoidopexy done in 22% patients with nil mortality and, for primary resection and anastomosis, it was 17%. Common post-operative complication found to be wound infections.Conclusions: Primary resection anastamosis is found to be definitive safe procedure if the colon is viable. Hartman’s procedure is suitable only if the bowel is gangrenous. Absence of co morbid conditions a notable feature. Pre operative X-RAY helpful in diagnosis. Mortality found to be 17.5% in our study.
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Chabod, Amaury, and Nicolas Baron. "Digital Twin For Fatigue Analysis." Fatigue of Aircraft Structures 2020, no. 12 (December 1, 2020): 47–56. http://dx.doi.org/10.2478/fas-2020-0005.
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Abstract The main design parameters that impact the fatigue of components are geometry, material and loading. Simulation with Finite Element Analysis (FEA) and tests on a vibrating table are often used to understand the dynamic behaviour of components and thus validate those items. Accelerated tests are used for the mission profile and test definition, as described in GAM-EG-13, MIL-STD-810F and RTCA DO-160E. The shock response spectrum (SRS) and the extreme response spectrum (ERS) allow for a comparison of the power spectrum density (PSD) and the acceleration factor applied in terms of fatigue severity through the fatigue damage spectrum (FDS). In addition, the hypothesis of linear damage accumulation enables the combination of several events for specifying a mission profile. Ultimately, the mission profile, which represents a usage that might span over several years, can be reduced to a shorter duration with a damage extraction technique. This is particularly useful for the definition of vibrating table specifications. An advantage of the virtual vibrating table is the reduction of the number of prototypes and the understanding of failure modes. To achieve this objective, finite element analysis in the frequency domain (harmonic analysis) is used and the structural stress response is evaluated with a PSD loading. A statistical model of rainflow allows assessing the damage on the components. The presentation also shows the effects of the damping factor on damage results. To achieve accurate results and define a Digital Twin, the correlation between test results and the finite element analysis is fundamental. Experimental modal analysis, based on the measured acceleration responses, helps to validate calculated modal frequencies and to assess the damping for each mode. This study shows the importance and the sensitivity on damping of the structural response, and in turn on fatigue.
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Pamperin, Kenneth L., and Christopher D. Wickens. "The Effects of Modality and Stress across Task Type on Human Performance." Proceedings of the Human Factors Society Annual Meeting 31, no. 5 (September 1987): 514–18. http://dx.doi.org/10.1177/154193128703100507.
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This investigation integrates four different approaches to the study of attention and multiple task performance, to include the effects of stimulus modality presentation, the influence of spatial separation in visual stimulus presentation, the effects of stress, and the influence of task type (dual-task versus information-integration task), in a spatial vector monitoring task. A significant benefit of cross-modal (visual-auditory) presentation was found when information was integrated at both levels of stress, while an interaction between modality and stress level occurred in the dual task condition, favoring the intra-modal (visual-visual) presentations at the lower stress level. The auditory display tended to be more stress resistant. The results support Kahneman's concept of stress-related resource expansion, provide weak support for perceptual narrowing, and provide little support for a processing modalities dimension of the Multiple Resource Model. Instead, they are consistent with the concept of auditory pre-emption, discussed by Wickens (1987).
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Lorentzon, Maria. "Management of nursing in 19th-century London." British Homeopathic Journal 84, no. 01 (January 1995): 55–61. http://dx.doi.org/10.1016/s0007-0785(05)80738-0.
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AbstractExamination of manuscript sources from the London Homoeopathic Hospital (LHH) 1850–1899 are set in historical context by presentation of data from the House of Lords Select Committee on Metropolitan Hospitals Report (1892)1 and review of selected items from the literature. This material shows the gradual progress in nursing practice, education and management at London hospitals.Analysis of LHH primary historical source documents (Minutes of Board Meetings,2 Minutes of Governors and Subscribers Meetings,3 Minutes of the LHH Staff Committee4 and the Medical Staff Committee5 and Clinical Notes6) show development of management and education systems in nursing. Less stress was placed on clinical practice. Significant support for development of nurse education at LHH was provided by members of the medical staff. The few references made to clinical nursing practice were recorded in the Medical Staff Committee Minutes. The strongest emphasis in all source material was on management of nursing services.Exploration of nursing management in 19th century London, in particular at the London Homoeopathic Hospital, reveals many similarities between conditions then and the present. It also provides evidence of progress in professionalization of nursing, with enhanced autonomy in education and professional practice. In this context, it is worth exploring the mode of managing nursing in 19th century voluntary hospitals and, in particular, at the London Homoeopathic Hospital.
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Corrigan, Lisa, Jessica Eustace-Cook, Patrick Moran, and Deirdre Daly. "The effectiveness and characteristics of pregnancy yoga interventions: a systematic review protocol." HRB Open Research 2 (January 8, 2020): 33. http://dx.doi.org/10.12688/hrbopenres.12967.2.
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Background: The purpose of this review is to systematically examine the reported clinical effectiveness of pregnancy yoga. The review will use the FITT (frequency, intensity, time/duration and type) principle of physical activity to characterise the different types of yoga interventions that have been evaluated in the included studies. Studies will be categorised as effectiveness or efficacy studies and this continuum of efficacy versus effectiveness will be incorporated into the full review. Methods/design: The following electronic databases will be searched using a detailed search strategy: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga and reporting on effect will be included. Titles, abstracts and full articles will be screened by two investigators independently to identify eligible studies. The Cochrane Collaboration’s Risk of Bias Assessment tool will be used to assess study quality. Quality of the evidence will be evaluated using the GRADE criteria. A standardised data extraction form will be used to extract data. Effect sizes will be estimated using mean differences for continuous outcomes, and relative risks for dichotomous outcome. Where possible, pooling of effect estimates will be done using a random effect model. The outcomes of interest are quality of life, stress, anxiety, depression, mode of birth, labour duration and pain management in labour. Discussion: This review will synthesise the best available evidence on the effectiveness of yoga during pregnancy and provide valuable high-quality information for clinicians and health policymakers. Findings will be disseminated through publication in a peer-reviewed journal and presentation at relevant conference proceedings. The review will make recommendations for the appropriate volume, intensity and type of pregnancy yoga for maximum effect and may have implications for policy and practice relating to pregnancy yoga as an intervention. Registration: PROSPERO, CRD42019119916. Registered on 11th January 2019.
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Sanders, Matthew R., Geoffrey Cleghorn, Ross W. Shepherd, and Mark Patrick. "Predictors of Clinical Improvement in Children with Recurrent Abdominal Pain." Behavioural and Cognitive Psychotherapy 24, no. 1 (January 1996): 27–38. http://dx.doi.org/10.1017/s1352465800016817.
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Forty-three children with recurrent abdominal pain who had received treatment from a paediatric gastroenterology clinic were reassessed 6 and 12 months after initial presentation. Measures of children's pain included a pain diary (PD) which measured pain intensity, a parent observation record (POR) which assessed pain behaviour and a structured interview to assess the degree to which pain interferes with the child's activities. Pretreatment measures of the child's history of pain, coping strategies in dealing with pain, and their mother's caregiving strategies were examined as predictors of two indices of clinical improvement: the extent of change in pain on the child's pain diary from pre-test to 6 months follow-up, and the degree of interference to the child's activities. All children had shown significant improvement in the level of pain at follow up, with 74.4% being pain free at 12 month follow-up on the PD and 83.7% being pain free on the POR. The amount of change they showed varied, with some showing residual impairment even though they were significantly improved. Regression analyses showed that children with greatest reductions on the child's pain diary at the 6 month follow-up were those with a stress-related mode of onset, whose mothers used more adaptive caregiving strategies, and who received cognitive behavioural family intervention. There was also a non significant trend for younger children to fare better. These data suggest the importance of early diagnosis and routinely assessing parental caregiving behaviour and beliefs about the origins of pain in planning treatment for children with RAP.
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Ranasinghe, R. B. D., D. A. Abeysiriwardana, P. P. Sathananthan, R. A. T. K. Ranasinghe, and P. A. I. Muthukumarana. "Triggers, modes of presentation and outcomes of stress cardiomyopathy." Journal of the Ceylon College of Physicians 51, no. 2 (December 14, 2020): 139. http://dx.doi.org/10.4038/jccp.v51i2.7908.
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Grebik, Oleg, Petro Savchuk, Aleksandr Valkevich, Aleksandr Panasyuk, and Anatoliy Khomich. "Injuries During Physical Education Students as a Pedagogical Problem." Physical education, sports and health culture in modern society, no. 2(38) (June 30, 2017): 80–84. http://dx.doi.org/10.29038/2220-7481-2017-02-80-84.
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The article focuses on the prevention of trauma in the process of physical education among students of higher educational institutions. It has been determined that pedagogical conditions for the prevention of accidents are the best means of combating injuries. The preventive focus of Ukrainian health care determines the implementation of a set of preventive measures for the preservation and strengthening of human health. These measures include a large-scale system of measures for the prevention of injuries, in particular in the process of physical education. To achieve this, you need to properly organize the classes, create the necessary conditions for the proper level of physical perfection. Promoting this will be the acquisition of elementary knowledge and skills that prevent injury, serious damage, and deterioration of health. Before performing physical exercises it is necessary to worry about the proper equipment – clothes, footwear, and protective equipment. All components of the sport form must be fitted in accordance with the figure, clean. The neglect of special means of safety is absolutely inadmissible. Nobody needs a reassessment of their physical perfection, the erroneous belief that insuring means of heavy and uncomfortable that they create the impression of lack of genuine courage provoke students to injuries. The next rule is qualitative warm-up. And this is not a formality, as it often seems to students. Preparatory exercises, presentation of the structure of the previous movements help to bring the nervous system to the optimum state, activate respiration and blood circulation, «warm up muscles» and «scroll» the joints. Man begins to better orient in space, its movements become more economical, internal organs and systems acquire the ability to withstand the most severe mode of physical and neuro-emotional stress.
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Chen, Pei-Chin, Chiun-Chieh Yu, Yueh-Sheng Chen, Cheng-Hsien Lu, Shan-Ho Chan, Kun-Hsien Chou, Mei-Hsiu Chen, Meng-Hsiang Chen, and Wei-Che Lin. "The Potential Effects of Oxidative Stress-Related Plasma Abnormal Protein Aggregate Levels on Brain Volume and Its Neuropsychiatric Consequences in Parkinson’s Disease." Oxidative Medicine and Cellular Longevity 2021 (August 14, 2021): 1–10. http://dx.doi.org/10.1155/2021/3666327.
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Background. Oxidative stress has been implicated in the pathogenesis of many diseases, including Parkinson’s disease. Large protein aggregates may be produced after the breakdown of the proteostasis network due to overt oxidative stress. Meanwhile, brain volume loss and neuropsychiatric deficits are common comorbidities in Parkinson’s disease patients. In this study, we applied a mediation model to determine the potential influences of oxidative stress-related plasma abnormal protein aggregate levels on brain volume and neuropsychiatric consequences in Parkinson’s disease. Method. 31 patients with PD and 24 healthy controls participated in this study. The PD patients were further grouped according to the presentation of cognitive decline or not. All participants received complete examinations to determine plasma abnormal protein aggregates levels, brain volume, and neuropsychiatric performance. The results were collected and analyzed in a single-level three-variable mediation model. Results. Patients with PD cognitive decline exhibited higher plasma NfL levels, decreased regional brain volume, and poor neuropsychiatric subtest results compared with PD patients with normal cognition, with several correlations among these clinical presentations. The mediation model showed that the superior temporal gyrus completely mediated the effects of elevated plasma NfL levels due to the poor psychiatric performance of picture completion and digit span. Conclusion. This study provides insight into the effects of oxidative stress-related plasma abnormal protein aggregate levels on regional brain volume and neuropsychiatric consequences in Parkinson’s disease patients.
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Li, Yuzhu, Martin Bechmann Fredberg, Bjarke Eltard Larsen, and David R. Fuhrman. "SIMULATING BREAKING WAVES WITH THE REYNOLDS STRESS TURBULENCE MODEL." Coastal Engineering Proceedings, no. 36v (December 28, 2020): 17. http://dx.doi.org/10.9753/icce.v36v.waves.17.
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The present study formally proved that Reynolds stress models (RSMs) are unconditionally stable in the potential flow regions. RSMs resolve all components of the Reynolds stress, eliminating e.g. the assumed isotropy of turbulence inherent within two-equation models. The present study implemented and applied Wilcox stress-omega turbulence model for simulating breaking waves. It shows that the Wilcox stress-omega turbulence model can predict accurate results from pre-breaking all the way into the inner surf zone, especially for the undertow velocity profiles in the inner surf zone, which even stabilized two-equation models fails to accurately predict.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/hZqqlGbHpkA
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Al-Qaisi, Mohmmad, Erin A. Horst, Sara Kvidera, Edith J. Mayorga, Megan A. Abeyta, Brady M. Goetz, Leo Timms, and Lance H. Baumgard. "211 Young Scholar Presentation: Developing and validating a heat stress model in dairy cows." Journal of Animal Science 97, Supplement_2 (July 2019): 121. http://dx.doi.org/10.1093/jas/skz122.214.
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Abstract Heat stress (HS) negatively impacts production parameters, including milk yield and composition, growth and reproduction. Precisely studying HS typically requires expensive climate-controlled facilities, resources often inaccessible to most scientists. Therefore, we evaluated the efficacy of using an electric heat blanket (EHB) as an alternative and cost-effective method to study HS and determine whether EHB-induced hyperthermia affects physiological and production parameters similar to natural HS. This was the first proof of concept study examining this model. Results indicated increased body temperature indices (i.e., rectal temperature and respiration rate) and reduced DMI and milk yield, as well as altered milk composition similar to natural and climate-controlled HS studies. In experiment 2, we examined the EHB model in combination with a pair-feeding (PF) design. By employing the PF design, we clearly illustrated that a lowered nutritional plane explains only approximately 50% of the decreased milk yield in HS cows, with the remaining portion due to changes in post-absorptive changes in nutritional physiology. In addition, the EHB blunted adipose tissue mobilization and increased plasma biomarkers of muscle catabolism. Results from this study validated that the EHB is a valid model to study HS; therefore, experiment 3 was designed to assess nutritional HS mitigation strategies using the EHB model. Dietary electrolyte, osmolyte, and energetic compounds (EOEC) were evaluated as re-hydration therapy on body temperature indices in HS lactating Holstein cows. Skin temperature was increased in EOEC-supplemented cows relative to controls which suggests that EOEC increased heat dissipation. In addition, EOEC-supplemented cows had increased glucose and insulin levels compared with controls which is due to the energetic compounds (i.e., dextrose) present in the EOEC supplement. Collectively, employing EHB model provides an excellent new platform for discovery research and evaluating pragmatic HS mitigation strategies.
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Pereira, A. T., C. Marques, M. J. Martins, A. I. Araújo, C. Cabaços, M. J. Brito, L. Mendonça, and A. Macedo. "Portuguese Validation of the Perfectionism Self Presentation Scale." European Psychiatry 41, S1 (April 2017): S255. http://dx.doi.org/10.1016/j.eurpsy.2017.02.051.
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IntroductionPerfectionist Self Presentation represents the interpersonal expression of perfectionism wherein individuals engage in strategies that promote their supposed perfection and conceal their perceived imperfections (Hewitt et al., 2003).ObjectiveTo investigate the psychometric properties of the Portuguese version of the Perfectionist Self Presentation Scale/PSPS.MethodsTwo hundred and eighty-six university students (69.2% females; mean age = 21.09 ± 2.133) answered the Portuguese preliminary version of the PSPS, and the Portuguese validated versions of: Multidimensional Perfectionism Scales, Dirty Dozen and Depression Anxiety and Stress Scale. To study the temporal stability, 30 participants (66.7% females) answered the PSPS again after six weeks. SPSS and MPlus were used.ResultsThe PSPS Cronbach alpha was .91. The test-retest correlation coefficient was .66 (P < .01). Exploratory factor analysis resulted in a three dimension's model (χ2 = 1974.015, P < .01; RMSEA = 0.079, 90% CI = 0.069–0.088; CFI = 0.869; TLI = 0.812; SRMR = 0.046). The three factors presented good internal consistency: F1 Perfectionist self-presentation (PSPS; a = .85), F2 Interpersonal Concern over mistakes (ICM; a = .79); F3 Perfectionist image (PI; a = .70).PSP and ICM (and PI with fewer significant coefficients and lower magnitudes) were moderately to highly correlate with personal standards, concern over mistakes, doubts about action, self-oriented perfectionism and social prescribed perfectionism (≥ .40). Correlations with narcissism and machiavellianism, anxiety and stress were moderate (r = .30) (all P < .01).ConclusionsThe Portuguese version of PSPS has good reliability and validity, with the factorial model presenting an acceptable fit (Hair et al., 2004). It could be very useful both in clinical and research contexts, namely in an ongoing research project on the relationship between perfectionism and interpersonal functioning.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Tu, Joseph W. "Resting-state functional network models for posttraumatic stress disorder." Journal of Neurophysiology 125, no. 3 (March 1, 2021): 824–27. http://dx.doi.org/10.1152/jn.00705.2020.
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Four recent articles were examined for their use of resting-state functional magnetic resonance imaging on participants with posttraumatic symptoms. Theory-driven computations were complemented by the novel use of network metrics, which revealed reduced global centrality and higher efficiency within the default mode network for participants with posttraumatic symptoms. Data-driven methods from other studies revealed associations between functional networks and posttraumatic stress disorder (PTSD) symptoms and clusters of functional activation corresponding to different PTSD presentations.
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Tammayan, Manita, Nattinee Jantaratnotai, and Praewpat Pachimsawat. "Differential responses of salivary cortisol, amylase, and chromogranin A to academic stress." PLOS ONE 16, no. 8 (August 12, 2021): e0256172. http://dx.doi.org/10.1371/journal.pone.0256172.
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Salivary biomarkers have been widely used to help diagnose stress, anxiety, and/or depression. This study aimed to compare the responses of three commonly investigated salivary stress biomarkers that represent the hypothalamic-pituitary-adrenal activity (cortisol; sCort) and the sympathetic activity (alpha-amylase; sAA and chromogranin A; sCgA), using academic oral presentation as a model of stress. Twenty postgraduate dental students attended the seminar class as presenter and audience. The presenters’ performances were evaluated by the instructors suggesting more stress than the audience. The saliva was collected two times: before attending class and after an academic presentation (for presenters) or during the class (for audience). The pulse rates (PR) were also recorded. The results showed that the levels of all three biomarkers, as well as PR, were significantly higher in the presenter group compared with the audience group; however, the changes were most prominent with sCort and sAA (99.56 ± 12.76% for sCort, 93.48 ± 41.29% for sAA, 16.86 ± 6.42% for sCgA, and 15.06 ± 3.41% for PR). When compared between pre-post presentation, the levels of sCgA were not different, while those of sCort and sAA were significantly increased. These results suggest more sensitive reactivity to academic stress of sCort and sAA compared with sCgA and that the response of sCgA did not necessarily follow sAA pattern even though both are claimed to reflect the sympathetic activity. More studies are needed to elucidate the roles of sCgA in stress.
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Arbeli, Y. "(P1-77) Helping Children Cope with Ongoing Stress." Prehospital and Disaster Medicine 26, S1 (May 2011): s123. http://dx.doi.org/10.1017/s1049023x11004092.
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Stress is a major health risk factor. The origin of the stress or stressful situations might come from internal and/or external causes. In this presentation, two groups of Israeli children who are living under stressful conditions that are affecting their health, their daily functioning, and their learning abilities will be presented. The first group is a group of children living in a town that has experienced terrorist activities for many years. The other group is children from families that have to leave their permanent home due to the Israeli Parliamentary and governmental decision to withdraw from the Gaza Strip. This plan included forced relocation of approximately 8,000 civilians from their communities to temporary sites elsewhere in Israel, and the dismantling of their homes. Using the classical epidemiological triad model of host-agent-environment, the hazard dynamic and its outcomes will be presented. Activities to help the children cope with the stressful situations also will be presented. The objective of this presentation is to describe exposure to risk factors and responses from public health nurses that are aimed at ameliorating the associated negative heath effects.
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Gamst, Glenn, Leticia Arellano-Morales, Lawrence S. Meyers, Dylan G. Serpas, Jessica Balla, Angelica Diaz, Kaycee Dobson, et al. "Shifting Can Be Stressful for African American Women: A Structural Mediation Model." Journal of Black Psychology 46, no. 5 (July 2020): 364–87. http://dx.doi.org/10.1177/0095798420939721.
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The present study was designed to examine shifting, the phenomenon of altering or modifying one’s self-presentation in different social contexts, as a mediator of the predictive effects of African American women’s acculturation on their perceived race-related stress. To explore this issue, measures of African American acculturation, shifting, and race-related stress were examined within a structural model. The current study quantitatively examined the relationships of these variables among a sample of 366 African American women. Results of a structural equation model indicated full mediation; greater levels of immersion in African American acculturation resulted in greater levels of shifting, which, in turn, generated increased levels of race-related stress. These data extend previous work and expand the literature regarding African American women’s shifting. Implications for clinical work and future research with African American women are also discussed.
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Li, Qian, Kehong Lyu, Jing Qiu, and Guanjun Liu. "Research on intermittent failure re-presentation of electrical connector based on accelerated test." Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability 233, no. 3 (May 10, 2018): 317–27. http://dx.doi.org/10.1177/1748006x18773009.
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The intermittent failure re-presentation is the basis of intermittent failure detection and diagnosis of electrical connectors. Recently, the method for intermittent failure re-presentation is applying the whole working stress to the electrical connector. To further shorten the re-present cycle, the research on intermittent failure re-presentation of electrical connector based on accelerated test is carried out in this article. First, the model of electric contact and the intermittent failure mechanism of electrical connector is analyzed, and the frequency of intermittent failure is selected as a signature of intermittent failure re-presentation. Then, the accelerated intermittent failure re-presentation model is constructed based on the reaction theory, and the intermittent failure acceleration factor is given. Subsequently, the distribution of intermittent failure frequency is determined using the method of Anderson–Darling goodness-of-fit test. Finally, taking the rectangular electrical connector as the example, the intermittent failure re-presentation based on accelerated test is implemented, and the intermittent failure frequency is obtained. By comparing the estimated value and the measured value, the validity and applicability of the intermittent failure re-presentation method based on accelerated test is verified.
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BARTHOLDI, LAURENT, and OLIVIER SIEGENTHALER. "THE TWISTED TWIN OF THE GRIGORCHUK GROUP." International Journal of Algebra and Computation 20, no. 04 (June 2010): 465–88. http://dx.doi.org/10.1142/s0218196710005728.
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We study a twisted version of Grigorchuk's first group, and stress its similarities and differences to its model. In particular, we show that it admits a finite endomorphic presentation, has infinite-rank multiplier, and does not have the congruence property.
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Montesi, Giuseppe, and Giovanni Papiro. "Bank Stress Testing: A Stochastic Simulation Framework to Assess Banks’ Financial Fragility." Risks 6, no. 3 (August 17, 2018): 82. http://dx.doi.org/10.3390/risks6030082.
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We present a stochastic simulation forecasting model for stress testing that is aimed at assessing banks’ capital adequacy, financial fragility, and probability of default. The paper provides a theoretical presentation of the methodology and the essential features of the forecasting model on which it is based. Also, for illustrative purposes and to show in practical terms how to apply the methodology and the types of outcomes and analysis that can be obtained, we report the results of an empirical application of the methodology proposed to the Global Systemically Important Banks (G-SIB) banks. The results of the stress test exercise are compared with the results of the supervisory stress tests performed in 2014 by the Federal Reserve and EBA/ECB.
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Chaudonneret, Madeleine. "A Simple and Efficient Multiaxial Fatigue Damage Model for Engineering Applications of Macro-Crack Initiation." Journal of Engineering Materials and Technology 115, no. 4 (October 1, 1993): 373–79. http://dx.doi.org/10.1115/1.2904232.
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This paper is devoted to the presentation of a multiaxial fatigue damage model, derived from Chaboche’s uniaxial formulation. Fit for use in the entire range of crack initiation life, it takes a number of different effects into account, including mean-stress influence and cumulative damage under nonperiodic proportional and nonproportional loadings. Its identification and integration is described, and it is shown as a simple but efficient engineering tool. Several examples, taken from different authors allows us to validate this kind of model.
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Yuyang, Liu, Liu Shiqi, and Pan Mao. "Finite Element Simulation of Oil and Gas Reservoir In Situ Stress Based on a 3D Corner-point Grid Model." Mathematical Problems in Engineering 2020 (February 25, 2020): 1–14. http://dx.doi.org/10.1155/2020/7384085.
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A three-dimensional (3D) corner-point grid model gives a relatively accurate description of the structural properties and spatial distribution of oil and gas reservoirs than Cartesian grids. The finite element simulation of the stress field provides a relatively probable presentation of the in situ stress distribution. Both methods are of great importance to the exploration and development of oil and gas fields. Implementing the finite element simulation of in situ stress on a 3D corner-point grid model not only retains the structural attributes of a reservoir but also allows the accurate simulation of the 3D stress distribution. In this paper, we present a method for implementing the finite element simulation of in situ stress based on a 3D corner-point grid model. We first established a fine 3D reservoir model with corner-point grids and then converted the grids into corresponding 3D finite element grid models using a grid conversion algorithm. Next, we simulated the in situ stress distribution with the finite element method. The stress model is then resampled to corresponding corner-point grid geological models using the reverse algorithm. The grid conversion algorithm is to provide data support for the subsequent numerical simulation and other research efforts, thereby guaranteeing procedure continuity and data consistency. Finally, we simulated the stress distribution of a real oil field, the X region. Comparing the simulated result with the measured result, the high agreement validated the effectiveness and accuracy of the proposed method.
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Bhopal, Sunil, Deepali Verma, Reetabrata Roy, Gauri Divan, Zelee Hill, and Betty Kirkwood. "Mothers explanatory models of infant stress & adversity in rural Haryana, India: qualitative findings from the Early Life Stress sub-study of the SPRING cluster-randomised controlled trial (SPRING-ELS)." Wellcome Open Research 3 (December 3, 2018): 153. http://dx.doi.org/10.12688/wellcomeopenres.14943.1.
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Background Exposure to a range of biological and psychosocial adversities in early childhood is of negative consequence through the lifecourse. This is particularly important for children in low- and middle-income countries where at least 250 million children are at high-risk of not meeting their developmental potential. Minimal evidence describes mothers’ views of this. We therefore elicited an explanatory model exploring mothers’ perceptions of infant stress and adversity in rural Haryana, India. Methods We did eight focus-group discussions to explore the perspectives of mothers in the general population of this rural area of India using a discussion guide based on Kleinman’s explanatory model. Data were coded by two analysts and arranged in themes for presentation. Illustrative quotations were used for presentation of findings. Results All mothers identified several causes of adversity and stress for children, including poverty, neglect and violence. They described the consequences of this for emotions, behaviour and school readiness of children, and that some of the consequences were reversible with appropriate management. Mothers described younger children as being unable to be affected by adversity, because they were “too young to understand”. Conclusions Mothers agreed with much of the current biomedical model for early childhood development, however the predominant view was that young infants were “too young to understand” is an important deviation. These findings are of importance in designing behaviour change strategies for this crucial period of early childhood which is rising up the global policy agenda with the aim of giving every child the opportunity to thrive.
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Negreira, Alyson M., and Chadi G. Abdallah. "A Review of fMRI Affective Processing Paradigms Used in the Neurobiological Study of Posttraumatic Stress Disorder." Chronic Stress 3 (January 2019): 247054701982903. http://dx.doi.org/10.1177/2470547019829035.
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Posttraumatic stress disorder is a chronic and debilitating psychiatric disorder with a complex clinical presentation. The last two decades have seen a proliferation of literature on the neurobiological mechanisms subserving affective processing in posttraumatic stress disorder. The current review will summarize the neuroimaging results of the most common experimental designs used to elucidate the affective signature of posttraumatic stress disorder. From this summary, we will provide a heuristic to organize the various paradigms discussed and report neural patterns of activations using this heuristic as a framework. Next, we will compare these results to the traditional functional neurocircuitry model of posttraumatic stress disorder and discuss biological and analytic variables which may account for the heterogeneity within this literature. We hope that this approach may elucidate the role of experimental parameters in influencing neuroimaging findings.
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Garruchet, Sébastien, A. Hasnaoui, Olivier Politano, Tony Montesin, J. Marcos Salazar, G. Bertrand, and H. Sabar. "Determination of the Stress Distribution at the Interface Metal-Oxide: Numerical and Theoretical Considerations." Defect and Diffusion Forum 237-240 (April 2005): 145–50. http://dx.doi.org/10.4028/www.scientific.net/ddf.237-240.145.
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In this paper we give a brief presentation of the approaches we have recently developed on the oxidation of metals. Firstly, we present an analytical model based on non-equilibrium thermodynamics to describe the reaction kinetics present during the oxidation of a metal. Secondly, we present the molecular dynamics results obtained with a code specially tailored to study the oxidation and growth of an oxide film of aluminium. Our simulations present an excellent agreement with experimental results.
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Cloud, J. E., and P. E. Clark. "Alternatives to the Power-Law Fluid Model for Crosslinked Fluids." Society of Petroleum Engineers Journal 25, no. 06 (December 1, 1985): 935–42. http://dx.doi.org/10.2118/9332-pa.
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Summary Measuring the rheological properties of crosslinked fracturing fluids is difficult but important. Fluid properties play a key role in the determination of the final geometry of the created fracture and in the distribution of proppant within the fracture; therefore, an accurate knowledge of these parameters is necessary for optimum treatment design. The first paper1 in this series described a method to measure accurately and reproducibly the rheological properties of crosslinked fracturing fluids. The technique is the first that applies long-accepted mathematical methods to correct the measurements for the deviations in shear rate caused by the non-Newtonian nature of the fluids. This, in turn, allows the rigorous examination of mathematical fluid models to determine which, if any, best describes the flow properties of the fluids. Introduction The problems of characterizing crosslinked fracturing fluids were outlined in the first paper1 in this series. These problems made the application of accepted mathematical techniques to correct measurements for deviations caused by the non-Newtonian character of these fluids difficult to justify. As a result, not making corrections has often led to the wrong choice of fluid models when the mathematical description of the fluid flow is attempted. The technique1 that was used to gather data for this study has been described previously. Dynamic mechanical testing provides a quantity - called the complex viscosity (µ*) - that has been shown by Cox and Merz2 to equal the apparent viscosity (µa) determined in steady-shear measurements. Yasuela et al.3 recently confirmed this relationship with a wide variety of instruments. Use of this relationship, coupled with the increased sensitivity and reproducibility of the mechanical spectrometer, allows an examination of the data analysis techniques currently used in the industry. The API4 currently specifies that the data gathered on fracturing fluids be reported as n' and k', which have been derived from apparent Newtonian shear rates. This promotes consistency in the presentation of data but can lead to the misinterpretation of the results of an experiment. When necessary, model-independent shear-rate conversions were applied before analysis to all the input data in this study to avoid misinterpretation of the results. Background: Analysis of Laboratory Rheology Data The procedure for determining fluid-flow characteristics from laboratory data may be expressed generally as occurring in three distinct, but not independent, steps:data acquisition,analysis and data reduction, andscale-up with the fundamental equations of fluid mechanics or some generalized method, such as that of Metzner and Reed,5 that is based on those relationships. Only the first and second steps are discussed here; a complete discussion of the third step is beyond the scope of this study. Data Acquisition Data for scale-up are normally acquired in the laboratory with capillary-, tube- and extrusional-type rheometers or parallel-plate, cone-and-plate, and concentric-cylinder rotational-type rheometers. When crosslinked gels are measured, each measurement technique suffers from the effects of the viscoelastic nature1 of the gels. Slip at the wall in capillary- and tube-type rheometers makes data obtained with this type of measurement difficult to reproduce. Slip at the wall and the Weissenberg effect complicate the interpretation of data derived from the steady-shear mode of rotational-type viscometers. The method of dynamic testing1 avoids many of those problems and provides reproducible data for the next step in the scale-up process. Analysis and Data Reduction The first step in the data analysis process is the conversion of the experimental measurements - i.e., pressure drop and pump rate or torque and angular velocity - into estimates of shear stress and shear rate. Three methods of conversion can be used:equivalent (apparent) Newtonian shear rate or viscosity,model-dependent conversions, andmodel-independent conversions. Method 1 is specified by API as the method of reporting fluid data. The shear rate, computed as if the fluid were a Newtonian liquid, is used to estimate parameters for non-Newtonian fluid models. It can be shown that this technique is adequate for certain two-parameter models, provided that restrictions are applied to the range of scale-up shear rates and that the rheological parameters are used without modification in generalized methods of scale-up. This method is inadequate, however, if the object of the experiment is both fluid-model optimization and fluid-flow scale-up. The assumptions inherent to this technique will introduce a bias toward three-parameter models that will be carried through the scale-up process, if not isolated and minimized during error determination. Data Acquisition Data for scale-up are normally acquired in the laboratory with capillary-, tube- and extrusional-type rheometers or parallel-plate, cone-and-plate, and concentric-cylinder rotational-type rheometers. When crosslinked gels are measured, each measurement technique suffers from the effects of the viscoelastic nature1 of the gels. Slip at the wall in capillary- and tube-type rheometers makes data obtained with this type of measurement difficult to reproduce. Slip at the wall and the Weissenberg effect complicate the interpretation of data derived from the steady-shear mode of rotational-type viscometers. The method of dynamic testing1 avoids many of those problems and provides reproducible data for the next step in the scale-up process. Analysis and Data Reduction The first step in the data analysis process is the conversion of the experimental measurements - i.e., pressure drop and pump rate or torque and angular velocity - into estimates of shear stress and shear rate. Three methods of conversion can be used:equivalent (apparent) Newtonian shear rate or viscosity,model-dependent conversions, andmodel-independent conversions. Method 1 is specified by API as the method of reporting fluid data. The shear rate, computed as if the fluid were a Newtonian liquid, is used to estimate parameters for non-Newtonian fluid models. It can be shown that this technique is adequate for certain two-parameter models, provided that restrictions are applied to the range of scale-up shear rates and that the rheological parameters are used without modification in generalized methods of scale-up. This method is inadequate, however, if the object of the experiment is both fluid-model optimization and fluid-flow scale-up. The assumptions inherent to this technique will introduce a bias toward three-parameter models that will be carried through the scale-up process, if not isolated and minimized during error determination.
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Swimm, Lindy Lee. "EMDR Intervention for a 17-Month-Old Child to Treat Attachment Trauma: Clinical Case Presentation." Journal of EMDR Practice and Research 12, no. 4 (November 2018): 269–81. http://dx.doi.org/10.1891/1933-3196.12.4.269.
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This article explores the effectiveness of treating a 17-month-old male diagnosed with posttraumatic stress disorder (PTSD) and a disrupted secure attachment utilizing eye movement desensitization reprocessing (EMDR) and an integrative family therapy approach. The child experienced a life-threatening choking incident requiring hospitalization. Pretreatment, the child was inconsolable by his parents when distressed and could not tolerate anything touching his throat. Posttreatment, the child accepts comfort from his parents and allows his mother to kiss his throat. Results demonstrate a reduction or elimination of PTSD symptoms and a return to a secure attachment. This case study underscores Shapiro’s Adaptive Information Processing (AIP) model (2001). Application and customization of the eight phases of EMDR therapy are highlighted along with the Integrative Attachment Trauma Protocol for Children (IATP-C). Treatment consisted of five sessions. Customization included caregiver psychoeducation; EMDR resource development, focused on strengthening attachment and regulating emotion; and facilitating caregiver co-regulation throughout EMDR. The use of EMDR therapy with customization through the IATP-C protocol shows promise as an effective intervention for treating posttraumatic stress symptoms and repairing attachment in very young children.
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Birch, Colin J., David Thornby, Steve Adkins, Bruno Andrieu, and Jim Hanan. "Architectural modelling of maize under water stress." Australian Journal of Experimental Agriculture 48, no. 3 (2008): 335. http://dx.doi.org/10.1071/ea06105.
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Two field experiments using maize (Pioneer 31H50) and three watering regimes [(i) irrigated for the whole crop cycle, until anthesis, (ii) not at all (experiment 1) and (iii) fully irrigated and rain grown for the whole crop cycle (experiment 2)] were conducted at Gatton, Australia, during the 2003–04 season. Data on crop ontogeny, leaf, sheath and internode lengths and leaf width, and senescence were collected at 1- to 3-day intervals. A glasshouse experiment during 2003 quantified the responses of leaf shape and leaf presentation to various levels of water stress. Data from experiment 1 were used to modify and parameterise an architectural model of maize (ADEL-Maize) to incorporate the impact of water stress on maize canopy characteristics. The modified model produced accurate fitted values for experiment 1 for final leaf area and plant height, but values during development for leaf area were lower than observed data. Crop duration was reasonably well fitted and differences between the fully irrigated and rain-grown crops were accurately predicted. Final representations of maize crop canopies were realistic. Possible explanations for low values of leaf area are provided. The model requires further development using data from the glasshouse study and before being validated using data from experiment 2 and other independent data. It will then be used to extend functionality in architectural models of maize. With further research and development, the model should be particularly useful in examining the response of maize production to water stress including improved prediction of total biomass and grain yield. This will facilitate improved simulation of plant growth and development processes allowing investigation of genotype by environment interactions under conditions of suboptimal water supply.
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Chen, Meng-Hsiang, Pei-Chin Chen, Cheng-Hsien Lu, Hsiu-Ling Chen, Yi-Ping Chao, Shau-Hsuan Li, Yi-Wen Chen, and Wei-Che Lin. "Plasma DNA Mediate Autonomic Dysfunctions and White Matter Injuries in Patients with Parkinson’s Disease." Oxidative Medicine and Cellular Longevity 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/7371403.
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Background. Cardiovascular autonomic dysfunction is well known in Parkinson’s disease (PD) presentation and it produces hypoperfusion of vital organs. The association between cardiovascular autonomic dysfunction and oxidative stress was examined in previous animal models. Oxidative stress and neuroinflammation were thought to have roles in PD pathogenesis. Owing to the relative low intrinsic antioxidative properties, brain white matter (WM) is vulnerable to the oxidative stress. This study is conducted to examine possible relationships by using a hypothesis-driven mediation model. Methods. Twenty-nine patients with PD and 26 healthy controls participated in this study, with complete examinations of cardiac autonomic parameters, plasma DNA level, and WM integrity. A single-level three-variable mediation model was used to investigate the possible relationships. Results. The elevated serum oxidative stress biomarkers include plasma nuclear DNA and mitochondrial DNA, and poorer cardiac autonomic parameters and multiple regional microstructural WM changes are demonstrated. Further mediation analysis shows that plasma nuclear DNA served as the mediators between poorer baroreflex sensitivity and mean diffusivity changes in cingulum. Conclusions. These results provide a possible pathophysiology for how the poor baroreflex sensitivity and higher oxidative stress adversely impacted the WM integrity. This model could provide us with a piece of the puzzle of the entire PD pathogenesis.
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Luckett, Tim, Jane Phillips, Miriam Johnson, Maja Garcia, Priyanka Bhattarai, Virginia Carrieri-Kohlman, Anne Hutchinson, et al. "Insights from Australians with respiratory disease living in the community with experience of self-managing through an emergency department ‘near miss’ for breathlessness: a strengths-based qualitative study." BMJ Open 7, no. 12 (December 2017): e017536. http://dx.doi.org/10.1136/bmjopen-2017-017536.
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ObjectivesBreathlessness ‘crises’ in people with chronic respiratory conditions are a common precipitant for emergency department (ED) presentations, many of which might be avoided through improved self-management and support. This study sought insights from people with experience of ED ‘near misses’ where they considered going to the ED but successfully self-managed instead.Design and methodsA qualitative approach was used with a phenomenological orientation. Participants were eligible if they reported breathlessness on most days from a diagnosed respiratory condition and experience of ≥1 ED near miss. Recruitment was through respiratory support groups and pulmonary rehabilitation clinics. Semistructured interviews were conducted with each participant via telephone or face-to-face. Questions focused on ED-related decision-making, information finding, breathlessness management and support. This analysis used an integrative approach and independent coding by two researchers. Lazarus and Cohen’s Transactional Model of Stress and Coping informed interpretive themes.ResultsInterviews were conducted with 20 participants, 15 of whom had chronic obstructive pulmonary disease. Nineteen interviews were conducted via telephone. Analysis identified important factors in avoiding ED presentation to include perceived control over breathlessness, self-efficacy in coping with a crisis and desire not to be hospitalised. Effective coping strategies included: taking a project management approach that involved goal setting, monitoring and risk management; managing the affective dimension of breathlessness separately from the sensory perceptual and building three-way partnerships with primary care and respiratory services.ConclusionsIn addition to teaching non-pharmacological and pharmacological management of breathlessness, interventions should aim to develop patients’ generic self-management skills. Interventions to improve self-efficacy should ensure this is substantiated by transfer of skills and support, including knowledge about when ED presentation is necessary. Complementary initiatives are needed to improve coordinated, person-centred care. Future research should seek ways to break the cyclical relationship between affective and sensory-perceptual dimensions of breathlessness.
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Samuel, Shikaa, and Vinod Gill. "Diffusion-Chemotaxis Model of Effects of Cortisol on Immune Response to Human Immunodeficiency virus." Nonlinear Engineering 7, no. 3 (September 25, 2018): 207–27. http://dx.doi.org/10.1515/nleng-2017-0018.
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AbstractIn quest to contain and subsequently eradication Human Immunodeficiency virus (HIV) in the society, mathematical modelling remains an important research tool. In this paper, we formulated a mathematical model to study the effects of cortisol on immune response to HIV capturing the roles played by dendritic cells, T helper cells, regulatory T cells and cytotoxic T cells in the virus replication dynamics. The primary source of concentration of cortisol in this work is through psychological stress. Numerical experiments are performed to examine the effect of cortisol on selective inhibition of antigen presentation activities and up-regulation of naive cytotoxic T cells activation in the case of acute and persistent stressful conditions.
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van Donselaar, Wilma, Mariëtte Koster, and Anne Cutler. "Exploring the Role of Lexical stress in Lexical Recognition." Quarterly Journal of Experimental Psychology Section A 58, no. 2 (February 2005): 251–73. http://dx.doi.org/10.1080/02724980343000927.
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Three cross-modal priming experiments examined the role of suprasegmental information in the processing of spoken words. All primes consisted of truncated spoken Dutch words. Recognition of visually presented word targets was facilitated by prior auditory presentation of the first two syllables of the same words as primes, but only if they were appropriately stressed (e.g., OKTOBER preceded by okTO-); inappropriate stress, compatible with another word (e.g., OKTOBER preceded by OCto-, the beginning of octopus), produced inhibition. Monosyllabic fragments (e.g., OC-) also produced facilitation when appropriately stressed; if inappropriately stressed, they produced neither facilitation nor inhibition. The bisyllabic fragments that were compatible with only one word produced facilitation to semantically associated words, but inappropriate stress caused no inhibition of associates. The results are explained within a model of spoken-word recognition involving competition between simultaneously activated phonological representations followed by activation of separate conceptual representations for strongly supported lexical candidates; at the level of the phonological representations, activation is modulated by both segmental and suprasegmental information.
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Michaud, H., Jean Michel Sprauel, and F. Galzy. "The Residual Stresses Generated by Deep Rolling and their Stability in Fatigue & Application to Deep-Rolled Crankshafts." Materials Science Forum 524-525 (September 2006): 45–50. http://dx.doi.org/10.4028/www.scientific.net/msf.524-525.45.
Full textAbstract:
In this work, the effect of steel grade on the fatigue resistance of deep-rolled crankshafts is analysed. In the first part of this paper, the mechanisms leading to the increase of the fatigue resistance brought by the deep rolling treatment, is presented. This reinforcement is mainly linked to crack arrest due both to a decrease of the in-depth stress concentration factor and to remaining compressive residual stresses induced by the deep rolling. In a second part, an analytical model of residual stresses generation by deep-rolling and fatigue is presented. In this model the low cyclic fatigue behaviour of the steel is taken into account, and the residual stress stability with bending fatigue cycling can be predicted. After a presentation of the experimental validation on two different microstructures (baintic and ferrito- perlitic), this model is used for analysing the main parameters of the deep-rolling process and fatigue resistance.
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Mateescu, Raluca G., Kaitlyn M. Sarlo Davila, Serdal Dikmen, Andrea Nunez, Eduardo Rodriguez, and Pascal Oltenacu. "74 President Oral Presentation Pick: Phenotypic plasticity of heat tolerance in beef cattle." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 51. http://dx.doi.org/10.1093/jas/skaa278.091.
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Abstract Bos taurus indicus cattle have superior ability for regulation of body temperature during heat stress due to a number of physiological and cellular level adaptive traits. The objectives of this study were to quantify the change in body temperature in heifers with various proportions of Brahman genes per unit increase in heat stress as measured by THI and to assess the impact of skin properties on the phenotypic plasticity. A total of 299 two-year old heifers from six breed groups ranging from 100% Angus to 100% Brahman were evaluated under hot and humid conditions during 2017 and 2018 summer days. The plasticity in body temperature of breed groups in response to environmental challenges was estimated using a random regression mixed model. Six mm skin biopsies were collected from the right side of sixth thoracic bone of each heifer. Cross-sections of biopsy samples with a thickness of 7 µm were stained with Hematoxilin–Eosin technique. The number and area of sweat and sebaceous glands and the thickness of dermis and epidermis were determined using the ImageJ program. The 100% Brahman group had the lowest intercept and slope (38.66 and 0.18) representing the body temperature under the low THI conditions and the increase in body temperature for 2 units of THI, respectively. Except for the 100% Angus group, which had a slightly higher intercept (38.68), all other breed groups had lower intercepts. Body temperature in the 100% Angus heifers increases by 0.42 for every 2 units of THI. There was a significant linear effect of Brahman percentage on the sweat gland size, with the 100% Brahman having the largest sweat gland size (203.57µm2) and purebred Angus the smallest (94.31µm2). Effective strategies will require the identification of the genes conferring the superior thermotolerance in Brahman cattle.
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Desai, Geetha, and Santosh K. Chaturvedi. "Idioms of Distress." Journal of Neurosciences in Rural Practice 08, S 01 (August 2017): S094—S097. http://dx.doi.org/10.4103/jnrp.jnrp_235_17.
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ABSTRACTThe presentations of psychosocial distress and cultural conflicts are often bodily symptoms, especially in traditional societies and village backgrounds. These might not meet the criteria of the current psychiatric diagnostic systems. Sociocultural milieu contributes to the unique presentations of the stress in the form of idioms of distress. The latter are alternative modes of expressing distress and indicate manifestations of distress in relation to personal and cultural meaning. Health professionals often consider these as hysterical, functional or having functional overlays, and abnormal illness behaviors. Management of idioms of distress would need cultural competence and sensitivity. This article highlights the common idioms of distress in India with specific focus on bodily symptoms.
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Andrew, Martin Benedict, and Le Hong Tran. "Using Weekly Group Political Presentations to Enhance the Phonological Learning of Second-Year English Major Students at a University in Vietnam." International Journal of Language Education 3, no. 2 (October 31, 2019): 115. http://dx.doi.org/10.26858/ijole.v3i2.9611.
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Studies about the learning value of group presentations in ESL and EFL have become increasingly common, particularly in relation to spoken fluency. However, few studies have explored their impact on students’ intelligible pronunciation. In a Vietnamese context, recent changes in teaching and learning strategies set by the government have shifted attention to students’ ability to communicate effectively in today’s increasingly globalized environment. This inevitably turns the spotlight on pronunciation, an aspect of EFL long ignored in Vietnam. Qualitatively describing a case where group presentations were a key mode of teaching, learning and assessment for 17 second-year students majoring in English for Political Discipline at the Institute of International Studies in Hanoi over the course of one semester, this study suggests that monitored and transcribed group presentations may be one rational answer.
The study investigates the impacts on participants’ pronunciation of sounds and word stress and considers their attitude towards this method. The results reveal that students acknowledged the benefits of group presentations and experienced improvements in pronunciation, confidence and range of political vocabulary. These changes were diverse depending on each participant’s attitude. The article concludes with reflective evaluations of the lessons and explores the pedagogical implications for future projects on implementing research into presentations among Vietnamese students of foreign languages.
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Kelly, Brendan D., Frank Rawlinson, and Ben Ogburn. "Herbal mania: a diagnostic dilemma?" Irish Journal of Psychological Medicine 18, no. 3 (September 2001): 108–9. http://dx.doi.org/10.1017/s0790966700006522.
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AbstractA case of affective psychosis and cognitive impairment is described. The patient had a history of cerebrovascular disease and had been ingesting large quantities of a complex herbal tonic prior to presentation. Diagnostic issues are discussed. Relevant literature on cerebrovascular disease and herbal remedies is reviewed. We propose a stress-diathesis model to account for this patient's illness and we advise caution in the use of complementary therapies in patients with compromised cerebrovascular status. Appropriate practice guidelines are outlined.
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BOUZID, DJ AMAR, P. A. VERMEER, B. TILIOUINE, and M. MIR. "AN EFFICIENT PSEUDO THREE-DIMENSIONAL FINITE ELEMENT MODEL: PRESENTATION AND ANALYSIS OF TWO SOIL/FOUNDATION INTERACTION PROBLEMS." International Journal of Computational Methods 02, no. 02 (June 2005): 231–53. http://dx.doi.org/10.1142/s0219876205000454.
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A pseudo-three-dimensional numerical model has been developed for the analysis of full 3D soil problems under combined loading. The procedure called Vertical Slices Model takes advantage of finite element (FE) 2D numerical solutions in plane stress for building approximate 3D solutions by replacing the inter-slice interactions by fictitious body forces. Continuum slices are successively analyzed by the combination of the explicit 2D finite element (FE) method and finite difference (FD) method in iterative process. The three-dimensional aspect of the considered problem is preserved by satisfying the continuity of shear stresses developed at the inter-slices. The theory of the vertical slices model is developed first, and then encoded in a Fortran computer program. Next, the prediction capabilities of this program are illustrated with two classical geotechnical applications, namely; the laterally and the axially loaded single piles embedded in homogeneous and non-homogeneous elastic soils. Although approximate, the model proved its ability to capture the behavior of the two boundary value problems. Then, in terms of stiffness factors the approach is used to predict the behavior of an embedded rigid square footing and a pile under combined loading in a half-space where the stiffness shows a power law variation with depth.
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Messner, Mark, Armand Beaudoin, and Robert Dodds. "Consistent crystal plasticity kinematics and linearization for the implicit finite element method." Engineering Computations 32, no. 6 (August 3, 2015): 1526–48. http://dx.doi.org/10.1108/ec-05-2014-0107.
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Purpose – The purpose of this paper is to describe several novel techniques for implementing a crystal plasticity (CP) material model in a large deformation, implicit finite element framework. Design/methodology/approach – Starting from the key kinematic assumptions of CP, the presentation develops the necessary CP correction terms to several common objective stress rates and the consistent linearization of the stress update algorithm. Connections to models for slip system hardening are isolated from these processes. Findings – A kinematically consistent implementation is found to require a correction to the stress update to include plastic vorticity developed by slip deformation in polycrystals. A simpler, more direct form for the algorithmic tangent is described. Several numerical examples demonstrate the capabilities and computational efficiency of the formulation. Research limitations/implications – The implementation assumes isotropic slip system hardening. With simple modifications, the described approach extends readily to anisotropic coupled or uncoupled hardening functions. Practical implications – The modular formulation and implementation support streamlined development of new models for slip system hardening without modifications of the stress update and algorithmic tangent computations. This implementation is available in the open-source code WARP3D. Originality/value – In the process of developing the CP formulation, this work realized the need for corrections to the Green-Naghdi and Jaumann objective stress rates to account properly for non-zero plastic vorticity. The paper describes fully the consistent linearization of the stress update algorithm and details a new scheme to implement the model with improved efficiency.