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Many real-life systems are dynamic, evolving, and intertwined. Examples of such systems displaying 'complexity', can be found in a wide variety of contexts ranging from economics to biology, to the environmental and physical sciences. The study of complex systems involves analysis and interpretation of vast quantities of data, which necessitates the application of many classical and modern tools and techniques from statistics, network science, machine learning, and agent-based modelling. Drawing from the latest research, this self-contained and pedagogical text describes some of the most important and widely used methods, emphasising both empirical and theoretical approaches. More broadly, this book provides an accessible guide to a data-driven toolkit for scientists, engineers, and social scientists who require effective analysis of large quantities of data, whether that be related to social networks, financial markets, economies or other types of complex systems.
Rhino-orbito-cerebral mucormycosis is a rapidly progressive disease with high mortality rates of about 60 per cent. The increasing incidence of rhino-orbito-cerebral mucormycosis in coronavirus disease 2019 patients in India and worldwide has become a matter of concern owing to the case fatality rate. This study explored the use of low dose aspirin in decreasing the mortality rate of coronavirus disease 2019 associated mucormycosis.
Method
This was a retrospective observational study. Patients suffering from post-coronavirus disease 2019 mucormycosis were included in the study. Each patient was treated with surgical debridement and systemic amphotericin B. Low dose aspirin was added, and mortality rates were compared with the patients who did not receive aspirin.
Results
The demographic data and rhino-orbito-cerebral mucormycosis staging between the two groups were not significantly different. There was a statistically significant difference in mortality outcomes between the two groups (p = 0.029) and a 1.77 times higher risk of dying for patients not receiving aspirin. Kaplan–Meier survival indicated that patients receiving aspirin had better survival rates (p = 0.04).
Background: Objective markers of disease progression are needed for patients with multiple sclerosis (MS). Increased randomness in neural networks is hypothesized to be an important cause of morbidity that can be objectified using graph theory. Methods: We use voxel-based structural similarity determined from T1-weighted MRI scans of 23 patients with MS receiving autologous stem cell transplant (ASCT) to compute cortical covariance network parameters. We examine associations between measures of cortical integration or segregation and biochemical/clinical measures of cortical health or function using Spearman correlation coefficients. P<0.05 was considered significant. Results: Path length increase was associated with markers of greater inflammation (ρ=0.56,P<.046) at baseline and reduced Naa/Cr ratio (P<.041) at 12 months. Reduced lambda was associated with markers of greater grey matter atrophy (ρ=0.55,P<.019) after 12 months and lower cognition (ρ=0.56,P<.008) at 12 months. Reduced clustering was associated with higher neurofilament (ρ=-0.68,P<.010) at baseline, greater white matter atrophy (ρ=0.62,P<.006) after 12 months, lower 2-second PASAT performance (ρ=0.56,P<.011) at baseline, and reduced Naa/Cr ratio (P<.001) at 12 months. Conclusions: Reduced cortical integration and segregation (random network features) co-occur with unfavourable markers of cortical health and function in patients with MS receiving ASCT. Network features show promise as important longitudinal markers of patient status and progression.
We consider a three-dimensional chemotaxis–convection–diffusion coupled system with the effect of surface tension at the deformed free surface. The novelty of this research is to explore the impact of surface tension on bioconvection. Our aim is to determine the nature of the instability at the onset of bioconvection in a chemotaxis–convection–diffusion system involving surface tension by performing a detailed linear stability analysis of steady-state cell and oxygen concentration distributions. The influence of the surface tension on the accumulated chemotaxis cells at the deformed free surface is studied analytically to illustrate its effect on the stability of the system. The Froude number, ${{Fr_\tau }}$, and capillary number, ${{Ca_\tau }}$, are two additional parameters introduced here. A detailed parametric study is undertaken to investigate the roles of the critical Rayleigh number, ${{Ra_\tau }}_c$, as well as ${{Fr_\tau }}$ and ${{Ca_\tau }}$, in the chemotaxis system. Linear stability results revealed that an increasing value of ${{Ra_\tau }}$ would stabilize the chemotaxis system. At a higher value of ${{Fr_\tau }}$, the motion of the cells is faster towards the free surface, and as the surface tension force increases, less accumulated cells are found at the free surface. A cluster of the cells can be observed mostly at the trough rather than on the crest of the wave profile. While experimental results for the present model are not yet available, the results of the linear stability analysis provide useful information about the system's stability.
Classical continuum-based liquid–vapour phase-change models typically assume continuity of temperature at phase interfaces along with a relation which describes the rate of evaporation at the interface (Hertz–Knudsen–Schrage, for example). However, for phase-transition processes at small scales, such as the evaporation of nanodroplets, the assumption that the temperature is continuous across the liquid–vapour interface leads to significant inaccuracies (McGaughey et al., J. Appl. Phys., vol. 91, issue 10, pp. 6406–6415; Rana et al., Phys. Rev. Lett., vol. 123, 154501), as might the adoption of classical constitutive relations that lead to the Navier–Stokes–Fourier (NSF) equations. In this paper, to capture the notable effects of rarefaction at small scales, we adopt an extended continuum-based approach utilising the coupled constitutive relations (CCRs). In CCR theory, additional terms are invoked in the constitutive relations of the NSF equations originating from the arguments of irreversible thermodynamics as well as being consistent with the kinetic theory of gases. The modelling approach allows us to derive new fundamental solutions for the linearised CCR model, to develop a numerical framework based upon the method of fundamental solutions (MFS) and enables three-dimensional multiphase micro-flow simulations to be performed at remarkably low computational cost. The new framework is benchmarked against classical results and then explored as an efficient tool for solving three-dimensional phase-change events involving droplets.
Background: Preliminary reports and subsequent immediate management decisions of radiological scans are often performed by emergency physicians and on-call radiology residents. Many academic hospitals have resident-only coverage for after-hour shifts. Generally, these preliminary reports are eventually reviewed by a staff radiologist, during which discrepancies may be identified. Depending on the severity of the discrepancy and the time taken to notify the treating physician, there is potential for significant impact on the patient's care. Aim Statement: In an attempt to identify and minimize errors in radiological readings, and to improve the communication of discrepancies, our project aims to retrospectively audit all radiological discrepancies that have occurred at The Ottawa Hospital's emergency departments from April 2018 to May 2019. Measures & Designs: A systematic review of all cases with noted radiological discrepancies was obtained from the Picture Archive and Communication System software and EPIC platform. Analysis of these cases will allow us to define when errors occur, what is the type and severity of the error, how long it took to relay the discrepancy to a treating physician, and what was the subsequent management impact. Evaluation/Results: We discovered 712 cases with radiological reading discrepancies, 168 major, 527 minor, and 17 incidentals. Interestingly, a significant portion of major (severely affecting care/life-threatning) discrepancies were reported from radiology residents, especially on CT images, although emergency physicians had the most discrepancies (mostly minor). Radiology residents were seen to have more discrepant reports during after-hour services while emergency physicians did not show any specific pattern of discrepant reporting. The average time to report a major discrepancy to a treating physician is 8.8 hours, where the maximum time taken was 104 hours and the minimum was 0.2 hours. 56% of reports with major discrepancies made no mention of who was notified. Discussion/Impact: By identifying weak points in radiological reporting, our results will allow us to provide suggestions at an administration and teaching level to minimize discrepancies. It is critical to create a workflow where mistakes are mitigated, and communication is efficient and standardized to prevent patient harm from delayed or incorrect diagnosis.
Introduction: Suicide is the 9th leading cause of death in Canada, and a common reason for patients to present to Canadian emergency departments (ED). Little knowledge exists around Canadian emergency physicians (EPs) knowledge about the risk factors of completing suicide in patients presenting to the ED with suicidal thoughts. Methods: We developed a web-based survey on suicide knowledge, which was pilot tested by two emergency physicians and one psychiatrist for clarity and content. The survey was distributed via email to attending physician members of the Canadian Association of Emergency Physicians. Data were described using counts, means, medians and interquartile ranges. Results: 193 EPs responded to the survey (response rate 16%), with 42% of EPs practicing in Ontario. 35% of EPs were female, the mean age was 48 (95% CI 47.3-48.7), and mean years in practice was 17 (95% CI 16.3-17.7). Academic practice location was reported by 55% of EPs, and 81% reported access to an inpatient psychiatry service. Twenty four (12%) EPs had personally considered suicide, and 45% had experience with suicide in their personal lives. The top three risk factors for suicide identified by EPs were: intent for suicide (90%); a plan for suicide (89%); prior suicide attempt (88%). A majority of EPs were able to correctly identify the other risk factors for completion of suicide except for the following: diagnosis of anxiety disorder (25%), chronic substance use (43%), prior non-suicidal self-injury (37%), low socioeconomic status (34%). Conclusion: Canadian EPs have substantial personal experience with suicide. A majority of EPs were able to correctly identify known risk factors for suicide completion, yet important gaps in knowledge exist.
Introduction: Suicide is the 9th leading cause of death in Canada, and a common reason for patients to present to Canadian emergency departments (ED). Little knowledge exists around Canadian emergency physicians (EPs) attitudes toward and understanding of individuals who have attempted suicide. Methods: We developed a web-based survey on attitudes around suicide, which was pilot tested by two EPs and one psychiatrist for clarity and content. The survey was distributed via email to attending physician members of the Canadian Association of Emergency Physicians. Data were described using counts, means, medians and interquartile ranges. We used the Understanding of Suicidal Patients (USP) Scale, an 11-point questionnaire utilized in previous studies to assess healthcare providers’ attitudes toward individuals who have attempted suicide. Each question was graded as a five-point Likert, with a score of 1 indicating complete agreement and a 5 indicating complete disagreement. A total USP score is calculated by adding together the score from each question and ranges from 11 to 55; a lower score indicates greater empathy and understanding of individuals who have attempted suicide. Results: 193 EPs responded to the survey, with 42% of EPs practicing in Ontario. 35% of EPs were female, the mean age was 48 (95% CI 47.3-48.7), and mean years in practice was 17 (95% CI 16.3-17.7). Academic practice location was reported by 55% of EPs, and 81% reported access to an inpatient psychiatry service. The mean USP score was 21.8 (95% CI 21.1-22.5) with a Cronbach's alpha of 0.75, the median was 22 [IQR 14-29]. The item that had most agreement from EPs was “I would like to help a person who has attempted suicide” (1.58, 95% CI 1.50-1.67), while the item that had the least agreement was “patients who have attempted suicide are usually treated well in my work unit” (2.54, 95% CI 2.40-2.69). Conclusion: Canadian EPs have a generally positive attitude toward treating individuals who have attempted suicide. EPs scored highly on a scale that measured willingness to provide care for and empathize with suicidal patients, yet identified that overall care for these patients could be improved.
Introduction: Suicide is the 9th leading cause of death in Canada, and a common reason for patients to present to Canadian emergency departments (ED). Little knowledge exists around Canadian emergency physicians (EPs) current practices and barriers to screening for suicidal thoughts (ST). Methods: We developed a web-based survey on suicide knowledge, which was pilot tested by two emergency physicians and one psychiatrist for clarity and content. The survey was distributed via email to attending physician members of the Canadian Association of Emergency Physicians. Data were described using counts, means, medians and interquartile ranges. Results: 193 EPs responded to the survey (response rate 16%), with 42% of EPs practicing in Ontario. 35% of EPs were female, the mean age was 48 (95% CI 47.3-48.7), and mean years in practice was 17 (95% CI 16.3-17.7). Academic practice location was reported by 55% of EPs, and 81% reported access to an inpatient psychiatry service. 142 EPs (82%) reported no protocol for screening for ST in their ED. Of EPs reporting an existing protocol, the most common practice was routine screening at triage (43%). The most commonly identified screening tools were HEADS-ED (25%) and PHQ-9 (21%). 70% of EPs felt the ED was a good place for screening for ST, yet 66% identified slower clinical care as a potential barrier. A strong commitment to treatment and follow up was identified by 68% of EPs as a necessary requirement to implementing ST screening in their ED. A targeted 2-4 question screen was the preferred screening option for 62% of EPs responding. Conclusion: A majority of EPs report no protocol for screening for ST in their ED, yet identify the ED as a good place for screening efforts. Potential barriers to widespread ST screening in the ED include a strong commitment to patient treatment and follow up, and diminished clinical efficiency.
Ethics are important in psychiatry since psychiatrydeals mainly with human conduct and behaviour. Ethics are principles, notlaws but standards of conduct, which define the essentials of honourablebehaviour for the physician. Indian Psychiatric Society approved ethical guideline in 1989Cuttack conference.
Hypothesis-
Ethical issues depend on the following theories –
Utilitarian Theory– A fundamental obligation in making decision and is to try to producethe greatest possible happiness for the greatest benefit.
Parentalism-A person performing actions for another benefit without the person's consent.
Autonomy Theory –It is based on writing of Imanuel Kant. Relationship between a physician and anadult patient is conceived as relationship between two responsible persons.
Observation –
Some common causes of malpractice in psychiatry seen in India arei) Negligence in diagnosis ii) Overlooking basic human rights iii) Consent nottaken from patient iv) Risk of suicide v) Experimentation by doctor vi)Negligence in physical methods of treatment vii) Seaxual relation with clientand Exploitation.
Conclusion –
Now a days following forces are to be considered as new ethical challenges a)Rapidly increasing cost of mental health care b) Influence of new technologies likeMRI, CT SCAN Brain c) Societal reengineering for better mental health d)Increasing pressure by patient party e) Current market forces are demandinghigh quality health care.
Discussion–
Apracticing psychiatrist has to take more responsibility in management of mentaldisorders. One has to take it as normal inevitable professionalhazards.
High-pressure-temperature (P-T) experiments were conducted in an attempt to determine the diffusion rates of C atoms in diamond, and the possibility of changes in the isotope compositions of diamond at high P-T in the Earth’s mantle. The starting material consisted of a polished plate of natural diamond (very largely 12C), which had been coated with 13C diamond by chemical-vapourdeposition to form a sharp interface between 12C and 13C diamond. Three experiments were performed at 1800, 2000 and 2300ºC, all at 7.7 GPa, for0.5 –20 h. Isotopic profiles obtained by ion microprobe before and after each experiment showed no evidence of relaxation of the sharp interface between 12C and 13C, and so diffusion must have been on a scale less than the ~32 nm depth resolution for this technique. Using 32 nm as the maximum length scale of diffusion across the interface, the maximum ln D (diffusion coefficient) values for the experiments were calculated to be in the range –38 to –42. Unlike previous experimental data, these results show that changes in the isotopic compositions of diamond on long time scales in the Earth’s upper mantle are unlikely. Furthermore, the results support empirical evidence from mapping of C isotope distributions in natural diamonds that C isotope compositions reflect diamond growth compositions.
Pikeperch (Sander lucioperca) is a highly valuable fish in Europe. However, development of aquaculture of pikeperch is highly limited due to seasonality of production. This can be overcome by the controlled reproduction of domesticated fish. The first steps of domestication process may induce changes at anatomical, physiological and molecular levels, thereby affecting a variety of biological functions. While there is abundant literature on their effects on stress and growth for example, these effects on reproduction received limited attention notably in pikeperch, a promising candidate for the development of aquaculture. To answer the question of this life-history effect on pikeperch’s reproduction, we compared two groups (weight: 1 kg) originated from Czech Republic and with the same domestication level (F0). The first group was a recirculating aquatic system cultured one (2 years, previously fed with artificial diet, never exposed to natural changes in temperature/photoperiod conditions) and the second one was a pond cultured group (3 to 4 years, bred under natural feeding and temperature/photoperiod). The wild group successfully spawned, while the farmed one did not spawn at all. During the program, gonadosomatic indexes of both males and females were significantly higher for the wild fish, as well as the sexual steroids. Gene expression analysis revealed significantly lower LH transcript levels at the pituitary level for the farmed females and lower FSH transcript levels at the pituitary level for the males. In conclusion this study showed that the previous rearing conditions (e.g. culture system, age, diet, etc.) alter the further progress of gametogenesis and the reproductive performances in response to controlled photothermal program for both sexes in pikeperch.
Populations of the White-rumped Vulture Gyps bengalensis, Indian Vulture G. indicus and Slender-billed Vulture G. tenuirostris declined rapidly during the mid-1990s all over their ranges in the Indian subcontinent because of poisoning due to veterinary use of the non-steroidal anti-inflammatory drug diclofenac. This paper reports results from the latest in a series of road transect surveys conducted across northern, central, western and north-eastern India since the early 1990s. Results from the seven comparable surveys now available were analysed to estimate recent population trends. Populations of all three species of vulture remained at a low level. The previously rapid decline of White-rumped Vulture has slowed and may have reversed since the ban on veterinary use of diclofenac in India in 2006. A few thousand of this species, possibly up to the low tens of thousands, remained in India in 2015. The population of Indian Vulture continued to decline, though probably at a much slower rate than in the 1990s. This remains the most numerous of the three species in India with about 12,000 individuals in 2015 and a confidence interval ranging from a few thousands to a few tens of thousands. The trend in the rarest species, Slender-billed Vulture, which probably numbers not much more than 1,000 individuals in India, cannot be determined reliably.
Persistence of the embryonic “fifth aortic arch” in postnatal life is a rare, enigmatic – and at times controversial – condition, with variable anatomical forms and physiological consequences. First described in humans over 40 years ago by Van Praagh, the condition was labelled the “great pretender” by Gerlis 25 years later, because of its apparent propensity to mimic anatomically similar structures. Despite many subsequent case reports citing the condition, the true developmental origin of these structures remains unresolved, and has been the subject of debate among embryologists for more than a century. A persistent fifth aortic arch has been defined as an extrapericardial structure, arising from the ascending aorta opposite or proximal to the brachiocephalic artery, and terminating in the dorsal aorta or pulmonary arteries via a persistently patent arterial duct. This description may therefore encompass various anatomical forms, such as a unilateral double-lumen aortic arch, an unrestrictive aortopulmonary shunt, or a critical vascular channel for either the systemic or pulmonary circulation. The physiological properties of these vessels, such as their response to prostaglandins, may also be unpredictable. In this article, we demonstrate a number of cases that fulfil the contemporary definition of “persistent fifth aortic arch” while acknowledging the embryological controversies associated with this term. We also outline the key diagnostic features, particularly with respect to the use of new cross-sectional imaging techniques.
Vortex-induced vibration (VIV) is an important physical phenomenon as one design a riser or a cylindrical structure in ocean. As the riser or the cylindrical structure is adjacent to a seabed, the boundary effect on VIV is not fully understood yet. The direct-forcing immersed boundary (DFIB) method is used to investigate a two-degree-of-freedom VIV of a flexible supported circular cylinder adjacent to a plane boundary in this study. Furthermore, the effect of the VIV of cylinder on skin friction of the plane boundary is investigated. The effects of varying reduced velocity and gap ratio on VIV are discussed. Only a single vortex street is found when the cylinder is close to plane boundary. Hydrodynamic coefficients of the freely vibrating cylinder are analyzed in time and spectral domains. Furthermore, nearly round oval-shaped motion is observed as the so-called lock-in phenomenon occurs. The skin friction of the plane boundary is predicted by the DFIB model. Results show that the vibrating cylinder in the boundary layer flow can reduce the friction effectively. This proposed DFIB model can be useful for the investigation of VIV of the structures under the plane boundary effect even for a small gap between the cylinder and the boundary.
Direct Numerical Simulation (DNS) results are presented for high speed nonreacting mixing layer in a confined test section. The hyper-velocity mixing layer experiment of Erdos et al with H2/N2 stream is simulated by discretizing two dimensional Navier Stokes equation using a higher order (fourth order spatial and second order temporal) compact numerical algorithm. A favourable comparison of the computation with experimentally measured wall static pressure forms the basis of further analysis. Instantaneous flow picture and the mean profiles of various flow variables were examined to determine the development and general characteristics of the confined mixing layer. It has been found that the growth of the mixing layer is towards the high speed side of the layer. Various turbulence quantities were derived from the stored time series data of the DNS calculation and the results were compared with the experimental results of supersonic free shear layer as no experimental results of turbulence statistics are available for the confined hypervelocity mixing layer. The increasing Reynolds stress data with the flow direction indicate that the turbulence is sustained by transferring the energy from the mean flow to the fluctuating field as the shear layer develops. Although the Reynolds stress is negligible in the most portion of the wall boundary layers, effect of counter gradient effect is observed in the far downstream location of the lower wall boundary layer. The general conclusion that for the supersonic mixing layer, various turbulence quantities like Reynolds stress, turbulence intensities (both streamwise and transverse) decrease with the increase in the convective Mach number is also confirmed by our results.
The ability of a CFD technique to evaluate the performance of a heat shield separation system has been demonstrated. The evolution of the differential pressure across the heat shield surface has been estimated. The results of the analysis have been compared with the data from the separation test of the heat shield of an Indian launch vehicle. The pressure on the heat shield surface was estimated by solving the Navier Stokes equations using the Eulerian Lagrangian formulation. The results, which show good agreement with the observed results of a heat shield separation test on the ground, were found to be adequate for design purposes.
Quasi-one-dimensional (quasi-1D) tools developed for capturing flow and acoustic dynamics in non-segmented solid rocket motors are evaluated using multi-dimensional computational fluid dynamic simulations and used to characterise damping of modal perturbations. For motors with high length-to-diameter ratios (of the order of 10), remarkably accurate estimates of frequencies and damping rates of lower modes can be obtained using the the quasi-1D approximation. Various grain configurations are considered to study the effect of internal geometry on damping rates. Analysis shows that lower cross-sectional area at the nozzle entry plane is found to increase damping rates of all the modes. The flow-turning loss for a mode increases if the more mass addition due to combustion is added at pressure nodes. For the fundamental mode, this loss is, therefore, maximum if burning area is maximum at the centre. The insights from this study in addition to recommendations made by Blomshield(1) based on combustion considerations would be very helpful in realizing rocket motors free from combustion instability.
Synonymous codons are used with different frequencies, a phenomenon known as codon bias, which exists in many genomes and is mainly resolute by mutation and selection. To elucidate the genetic characteristics and evolutionary relationship of Wucheraria bancrofti and Schistosoma haematobium we examined the pattern of synonymous codon usage in nuclear genes of both the species. The mean overall GC contents of W. bancrofti and S. haematobium were 43.41 and 36.37%, respectively, which suggests that genes in both the species were AT rich. The value of the High Effective Number of Codons in both species suggests that codon usage bias was weak. Both species had a wide range of P3 distribution in the neutrality plot, with a significant correlation between P12 and P3. The codons were closer to the axes in correspondence analysis, suggesting that mutation pressure influenced the codon usage pattern in these species. We have identified the more frequently used codons in these species, most codons ending with an A or T. The nucleotides A/T and C/G were not proportionally used at the third position of codons, which reveals that natural selection might influence the codon usage patterns. The regression equation of P12 on P3 suggests that natural selection might have played a major role, while mutational pressure played a minor role in codon usage pattern in both species. These results form the basis of exploring the evolutionary mechanisms and the heterologous expression of medically important proteins of W. bancrofti and S. haematobium.