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In this paper, we consider multi-state coherent systems that can be regarded as a series/parallel/recurrent connection of multi-state modules with binary/multi-state components. The multi-state (survival) signatures of such systems are presented in terms of multi-state (survival) signatures of related modules based on the structures. For a recurrent structure, the multi-state survival signature of the structure is also needed. The results established here are finally illustrated with a number of examples.
Conduit stenosis is a major, albeit rare, complication following the Fontan palliation. A single-baffle conduit with polytetrafluoroethylene is widely used for an extracardiac type Fontan palliation. A polyethylene terephthalate conduit (Dacron) is sometimes used for the conduit when more flexibility is required. A Y-shaped conduit is rarely used, but it may reduce the energy loss and achieve better hepatic flow distribution. Data on the long-term patency and complications when using a Y-shaped Dacron conduit is lacking. We report a case of a severely stenotic Y-shaped Dacron conduit in a patient who underwent extracardiac Fontan palliation.
To investigate the effect of atmospheric density and jet-fluid density during supersonic jet-induced cratering on a granular particle bed, large eddy simulation (LES) for the fluid phase coupled with a granular flow model based on kinetic theory is used. Coupling accounts for momentum and energy interaction between particles and fluid. Several simulations are conducted that enable discriminating between the crater characteristics which depend on the atmospheric (or jet) density, and those which depend on the ratio between jet-fluid density and atmospheric density. The crater cross-sectional shapes are controlled by the density ratio between jet fluid and atmosphere. For large such ratios, the craters have a parabolic cross-section shape, are relatively shallow, have large diameters and have subdued ejecta. In contrast, for ratios close to unity, the craters have a conical cross-section, are relatively deep, have relatively small diameters and have substantial ejecta; these craters also display ripples on their walls. The physics leading to these differences is explained. Considerations of particle momentum flux indicate that at same fraction of the crater depth and same radial distance from the jet axis, the radial and vertical components have larger magnitudes for conical craters than for parabolic craters. The spatial distribution of the ratio between the drag force and the force due to the particles resistance to compaction are compared and it is found to be dependent on the jet-to-atmospheric fluid density ratio. A few features of the crater, in particular its depth, only depend on the atmospheric (or jet) fluid density.
Emergency Medicine being a young specialty in India, we aimed to assess the level of disaster preparedness and planning strategies among various academic Emergency Departments (EDs) across India during the COVID-19 pandemic.
A cross-sectional multicentric survey was developed and disseminated online to various academic EDs in India and followed up over a period of 8 weeks. All results were analysed using descriptive statistics.
28 Academic Emergency Medicine Departments responded to the study. Compared to Pre-COVID period, COVID-19 pandemic has led to 90% of centres developing separate triage system with dedicated care areas for COVID suspect/infected in 78.6% centres with nearly 70% utilizing separate transportation pathways. Strategizing and executing the Institutional COVID-19 treatment protocol in 80% institutes were done by Emergency Physicians. Training exercises for airway management and PPE usage were seen in 93% and 80% centres respectively. Marked variation in recommended PPE usage were observed across EDs in India.
Our study highlights the high variance in the level of preparedness response among various EDs across India during the pandemic. Preparedness for different EDs across India needs to be individually assessed and planned according to the needs and resources available.
Inaccuracy and information measures based on cumulative residual entropy are quite useful and have attracted considerable attention in many fields including reliability theory. Using a point process martingale approach and a compensator version of Kumar and Taneja's generalized inaccuracy measure of two nonnegative continuous random variables, we define here an inaccuracy measure between two coherent systems when the lifetimes of their common components are observed. We then extend the results to the situation when the components in the systems are subject to failure according to a double stochastic Poisson process.
In this paper, we consider finite mixture models with components having distributions from the location-scale family. We then discuss the usual stochastic order and the reversed hazard rate order of such finite mixture models under some majorization conditions on location, scale and mixing probabilities as model parameters.
In this paper, we discuss stochastic orderings of lifetimes of two heterogeneous parallel and series systems with heterogeneous dependent components having generalized Birnbaum–Saunders distributions. The comparisons presented here are based on the vector majorization of parameters. The ordering results are established in some special cases for the generalized Birnbaum–Saunders distribution based on the multivariate elliptical, normal, t, logistic, and skew-normal kernels. Further, we use these results by considering Archimedean copulas to model the dependence structure among systems with generalized Birnbaum–Saunders components. These results have been used to derive some upper and lower bounds for survival functions of lifetimes of parallel and series systems.
To evaluate the patterns of recurrence following postoperative conformal radiotherapy (RT) for intracranial meningioma.
Materials and methods:
Eighty-six patients who received conformal RT for intracranial meningiomas from 2014 to 2017 were retrospectively analysed. For documented recurrences, recurrence imaging was deformably co-registered to planning CT scan. In-field recurrence was defined as recurrence within the 90% isodose line, and out-of-field recurrences were those that occurred outside the 90% isodose line. We present the demographic details, surgical and RT details, outcomes and patterns of recurrence.
The median age was 46 years (range 17–72); 82·6% underwent surgery [46·5% had subtotal resection (STR), 43·7% gross tumour resection (GTR), 5·6% biopsy] and 17·4% had no surgery. Among these, 53·5% were WHO grade 2; 27·9% grade 1; and 1·2% grade 3 meningioma. Fifty per cent received stereotactic RT (SRT), 46·5% 3D conformal RT (3DCRT) and 3·5% intensity-modulated RT (IMRT). The mean clinical target volume (CTV) and planning target volume (PTV) margins were 4·5 mm (range 0–15) and 3·9 mm (range 1–5), respectively. The doses ranged from 54 to 59·4 Gy. The median follow-up after RT was 1·7 years (range 0·2–4·7). 17·4% were lost to follow-up, 5·4% had recurrence, and the median time to recurrence after completion of RT was 2 years (range 0·7–2·9). The 3-year recurrence-free rate was 81·5%. Three patients had in-field and two had in-field and out-of-field recurrence. Among the cases with recurrence, three received SRT, one 3DCRT and one IMRT. Four were grade 2 and one was grade 3 tumour, and the CTV margin ranged from 0 to 5 mm, and the PTV margin ranged from 3 to 5 mm.
Local recurrence was seen in grade 2 and 3 meningiomas. SRT probably had more recurrence as they had lesser CTV margin. Increased CTV margin, escalated dose up to 59·4 Gy and 3DCRT/IMRT may be helpful in preventing local recurrences in grade 2 and grade 3 meningiomas.
In this paper we state the original identity proved by Euler, and we provide an alternative proof of this result. We then extend the approach to derive a further identity for the sum of reciprocals of squares, along with two other related identities. We conclude by obtaining yet another extension of the identity, and this is accomplished by means of a probability density function, or pdf.
The coronavirus disease (COVID-19) pandemic is bound to put tremendous pressure on the existing healthcare system. This aim of this technical note is to help in triaging patients with brain tumours who are sent for radiotherapy during this pandemic and to provide safe and evidence-based care.
Materials and Methods:
Published data for this review were identified by systematically searching PubMed database from November 2007 onwards with the following Medical Subject Heading (Mesh) terms ‘Brain tumours’, ‘COVID-19’, ‘coronavirus’, ‘SARS-nCoV-2’, ‘Radiotherapy’, ‘Guidelines’ ‘hypofractionation’ using Boolean search algorithm. Articles in English language were reviewed.
We tried to apply the as low as reasonable achievable (ALARA) principle in triaging and management of patients for radiotherapy. We identified protocols which have hypofractionated regimens (reducing patient visits to hospital, time spent in treatment console) with similar outcomes when compared to conventional fractionated regimens and not overburdening the healthcare facility. We also identified the tumours for which we could safely avoid or delay the initiation of radiotherapy.
Treatment decisions made during the COVID-19 pandemic rely on the safety first/do no harm principle and evidence-based prioritisation of cases for triage. This article is a tool to aid in triaging and prioritising brain tumour patient management. This is for consideration during the pandemic only and certainly not as a strategy for permanent practice change.
Ensuring the successful treatment of tuberculosis (TB) is an essential public health responsibility of national TB programs. This case study describes how the Department of Health and Family Welfare, Kerala state, successfully prevented the disruptions in TB treatment when an unprecedented massive flood, declared as “a calamity of severe nature,” completely disrupted normal operations in the state during August 2018. Unanticipated floods led to the displacement and relocation of more than 1.5 million citizens. The state has ensured continuity of TB treatment for all notified drug sensitive and drug-resistant TB patients (9608 and 434, respectively), including those who were displaced and relocated. A real-time web-enabled, case-based patient management information system has helped preserve the entire patient information, available at multiple levels. Routine strength of the program, including good rapport with patients, frontline multipurpose health workers and treatment supporters, high literacy rate of general population, and well-integrated primary health care system delivering TB services, enabled ensuring continuity of care during the disaster situation. The success of the post-flood TB control measures in Kerala affirms the importance of maintaining an integrated and strong TB control component with general health system ownership.
To analyse the presentation, diagnosis and patterns of care of extraosseous Ewing sarcoma treated at our institution between 2008 and 2018.
Electronic medical records of extraosseous Ewing sarcoma patients treated at our institution between January 2008 and April 2018 were reviewed. Kaplan–Meier curves were plotted to assess the overall and disease-free survival with 95% confidence intervals. A univariate analysis was carried out to assess the impact of variables such as surgical excision, completeness of surgery, completeness of chemotherapy and addition of radiation therapy on the survivorship.
The records of 65 patients treated at our institution were available for review. The mean age was 26·4 years. The most frequent sites of extraosseous Ewing tumour were kidney—9/65 (13·8%) and brain—10/65 (15·4%). Sixteen (24·6%) patients presented with inoperable/metastatic disease at diagnosis. The other 49 (75·4%) had localised disease at presentation. The median overall survival of the 49 non-metastatic patients was 46 months, and the disease-free survival was 45 months.
Extraosseous Ewing sarcoma is a rare and aggressive tumour diagnosed by molecular techniques. Multi-modality treatment including surgical resection with wide margins, adjuvant radiation when indicated and completion of systemic chemotherapy results in optimum outcomes.
In this paper, the signature of a multi-state coherent system with binary-state components is discussed, and then it is extended to the case of ordered system lifetimes arising from a life-test on coherent multi-state systems with the same multi-state system signature. Some properties of the multi-state system signature and the ordered multi-state system signature are also studied. The results established here are finally explained through some illustrative examples.
Contrary to the belief that prisons never predated colonial rule in Africa, this article traces their emergence in the Gold Coast after the abolition of the Atlantic slave trade. During the era of ‘legitimate commerce’, West African merchants required liquidity to conduct long-distance trade. Rather than demand human pawns as interest on loans, merchants imprisoned debtors’ female relatives because women's sexual violation in prison incentivized kin to repay loans. When British colonists entered the Gold Coast, they discovered how important the prisons were to local credit. They thus allowed the institutions to continue, but without documentation. The so-called ‘native prisons’ did not enter indirect rule — and the colonial archive — until the 1940s. Contrary to studies of how Western states used prisons to control black labour after emancipation, this article excavates a ‘debt genealogy’ of the prison. In the Gold Coast, prisons helped manage cash flow after abolition by holding human hostages.
Obesity is a modifiable, independent risk factor for mortality and morbidity after cardiovascular surgery in adults. Our objective was to evaluate the impact of obesity on short-term outcomes in adolescents undergoing surgery for congenital heart disease (CHD).
This retrospective chart review included patients 10–18 years of age who underwent CHD surgery. Our exclusion criteria were patients with a known genetic syndrome, heart transplantation, and patients with incomplete medical records. The clinical data collected included baseline demographics and multiple perioperative variables. Charting the body mass index in the Centers for Disease Control and Prevention growth curves, the entire cohort was divided into three categories: obese (>95th percentile), overweight (85th–95th percentile), and normal weight (<85th percentile). The composite outcome included survival, arrhythmias, surgical wound infection, acute neurologic injury, and acute kidney injury.
The study cohort (n = 149) had a mean standard deviation (SD), body mass index (BMI) of 22.6 ± 6.5 g/m2, and 65% were male. There were 27 obese (18.1%), 24 overweight (16.1%), and 98 normal weight (65.8%) patients. Twenty-seven (18%) patients had composite adverse outcomes. Overweight and obese patients had significantly higher adverse outcomes compared with normal weight patients (odds ratio (OR): 2.9; confidence interval (CI): 1–8.5, p = 0.04 and OR: 3; CI: 1–8.5, p = 0.03, respectively). In multivariate analysis, obesity was an independent predictor of adverse outcome in our cohort (p = 0.04).
Obesity is associated with short-term adverse outcome and increased health resource utilisation in adolescents following surgery for CHD. Further studies should evaluate if intervention in the preoperative period can improve outcomes in this population.
The Chabauty–Kim method allows one to find rational points on curves under certain technical conditions, generalising Chabauty’s proof of the Mordell conjecture for curves with Mordell–Weil rank less than their genus. We show how the Chabauty–Kim method, when these technical conditions are satisfied in depth 2, may be applied to bound the number of rational points on a curve of higher rank. This provides a non-abelian generalisation of Coleman’s effective Chabauty theorem.
To compare nasal mucociliary clearance in adult non-smokers, cigarette smokers and bidi smokers using the methylene blue dye test.
The study sample consisted of 20 non-smokers, 20 cigarette smokers and 20 bidi smokers (age range, 20–40 years). A single drop of the methylene blue dye was placed at the anterior end of the inferior turbinate of the participants’ nasal cavity. The distance travelled by the methylene blue in 15 minutes inside the nasal cavity was measured. Nasal mucociliary clearance of the three groups was compared using the Kruskal Wallis test.
Nasal mucociliary clearance was significantly decreased in bidi smokers as compared to cigarette smokers and non-smokers (p < 0.05). Multivariate analysis revealed a significant association between nasal mucociliary clearance and bidi smoking, number of cigarettes or bidis smoked per day, and pack-years (all p < 0.05).
Nasal mucociliary clearance measurement is a simple and useful index for assessing the effect of smoking on the mucociliary activity of nasal mucosa.
Sequential order statistics can be used to describe the ordered lifetimes of components of a system when the failure of a component may affect the reliability of the remaining components. After a reliability system consisting of n components fails, some of its components may still be alive. In this paper we first establish some univariate stochastic orderings and ageing properties of the residual lifetimes of the live components in a sequential (n-r+1)-out-of-n system. We also obtain a characterizing result for the exponential distribution based on uncorrelated residual lifetimes of live components. Finally, we provide some sufficient conditions for comparing vectors of residual lifetimes of the live components from two sequential (n-r+1)-out-of-n systems. The results established here extend some well-known results in the literature.
Seedling vigour is an important indicator of crop establishment, subsequent crop growth and yield. Initial seedling vigour is most vital in case of water-limited conditions and in environments where the crop is exposed to different stresses at the early growth stage. Wild and weedy species are well known for their vigour and survival in adverse environmental conditions. Seedling vigour traits of backcross introgression lines (BILs) derived from Swarna × Oryza nivara IRGC81848(S) (accession from Uttar Pradesh, India) and IRGC81832 (K) (accession from Bihar, India) were studied in wet (Kharif) and dry (Rabi) seasons. Seedling vigour was estimated in terms of plant height and tiller number at 30 and 60 d after transplanting under field conditions. In both the seasons, 148S showed highest seedling vigour for plant height. The highest number of tillers were produced by 7K in Kharif and 248S in Rabi season. 75S showed the highest percentage increase in tiller number consistently. High yielding BILs 166S, 14S and 148S showed higher seedling vigour indices compared with checks Tulasi and Sahbhagidhan. Seedling vigour was also evaluated using paper roll method and shoot length, root length and dry weight were used to estimate vigour index. Season-wise association studies were conducted to determine the relative contribution of seedling vigour to yield traits. Seedling vigour was significantly correlated with yield traits. Markers RM217 and RM253 on chromosome 6 differentiated lines with high seedling vigour from those with low seedling vigour and have the potential for use in marker-assisted breeding.