Order-of-magnitude speedup for steady states and traveling waves via Stokes preconditioning in Channelflow and Openpipeflow

Steady states and traveling waves play a fundamental role in understanding hydrodynamic problems. Even when unstable, these states provide the bifurcation-theoretic explanation for the origin of the observed states. In turbulent wall-bounded shear flows, these states have been hypothesized to be saddle points organizing the trajectories within a chaotic attractor. These states must be computed with Newton's method or one of its generalizations, since time-integration cannot converge to unstable equilibria. The bottleneck is the solution of linear systems involving the Jacobian of the Navier-Stokes or Boussinesq equations. Originally such computations were carried out by constructing and directly inverting the Jacobian, but this is unfeasible for the matrices arising from three-dimensional hydrodynamic configurations in large domains. A popular method is to seek states that are invariant under numerical time integration. Surprisingly, equilibria may also be found by seeking flows that are invariant under a single very large Backwards-Euler Forwards-Euler timestep. We show that this method, called Stokes preconditioning, is 10 to 50 times faster at computing steady states in plane Couette flow and traveling waves in pipe flow. Moreover, it can be carried out using Channelflow (by Gibson) and Openpipeflow (by Willis) without any changes to these popular spectral codes. We explain the convergence rate as a function of the integration period and Reynolds number by computing the full spectra of the operators corresponding to the Jacobians of both methods.Comment: in Computational Modelling of Bifurcations and Instabilities in Fluid Dynamics, ed. Alexander Gelfgat (Springer, 2018

Characterizing the morbid genome of ciliopathies

Background Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. Results We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their “mutation load” beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. Conclusions Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies

Toward Enhanced State of Charge Estimation of Lithium-ion Batteries Using Optimized Machine Learning Techniques.

State of charge (SOC) is a crucial index used in the assessment of electric vehicle (EV) battery storage systems. Thus, SOC estimation of lithium-ion batteries has been widely investigated because of their fast charging, long-life cycle, and high energy density characteristics. However, precise SOC assessment of lithium-ion batteries remains challenging because of their varying characteristics under different working environments. Machine learning techniques have been widely used to design an advanced SOC estimation method without the information of battery chemical reactions, battery models, internal properties, and additional filters. Here, the capacity of optimized machine learning techniques are presented toward enhanced SOC estimation in terms of learning capability, accuracy, generalization performance, and convergence speed. We validate the proposed method through lithium-ion battery experiments, EV drive cycles, temperature, noise, and aging effects. We show that the proposed method outperforms several state-of-the-art approaches in terms of accuracy, adaptability, and robustness under diverse operating conditions

An Atypical Seizure Onset and Re-Emergence in a Refugee with an Undiagnosed Sturge-Weber Syndrome: A Case Report from a Limited Setting

Awab H Saad,1,* Saeed Mohammed Omar,2,* Abeir Abbas Elgilli,2,* Ibtehal Abdalwahid Abdalmjeed Omer,2,* Morouj Hussein Jalaleldeen2,* 1Department of Internal Medicine, University of Medical Sciences and Technology, Khartoum, Khartoum State, Sudan; 2Department of Internal Medicine, University of Gadarif, Gadarif, Gadarif State, Sudan*These authors contributed equally to this workCorrespondence: Awab H Saad, Tel +249961162550 ; +966535911050, Email [email protected]: Sturge-Weber syndrome (SWS) is a complex rare genetic neuro-cutaneous disorder characterized by the presence of a port-wine stain, ophthalmic and intracranial angiomatosis leading to seizures, ocular, and oral abnormalities.Case Presentation: We report a 39-year-old, non-diabetic, non-hypertensive female refugee who presented initially with heart failure due to anemia for which she received blood transfusions. Later on admission, she developed multiple focal to bilateral seizures, severe irritability, aphasia, and right-sided hemiplegia, leading to admission to the ICU. A repeat medical history and examination revealed a faint left-sided ophthalmic port-wine stain that was initially unnoticed and a remote history of unprovoked seizures 20 years ago. Imaging revealed parietal calcifications and confirmed the diagnosis of SWS. Thus, a multidisciplinary approach was taken to fully understand the patient’s diagnosis and determine a treatment strategy, involving consultations with the neurology, ophthalmology, otolaryngology, and physiotherapy departments. Successful seizure control was achieved by administering IV phenytoin for 3 days and the up-titrating of oral carbamazepine to 1g daily through a nasogastric tube. Unfortunately, due to the unavailability of personnel or resources, other important assessments for patients with SWS, such as advanced neuroimaging, psychiatric, plastic and neuro-surgery evaluations, as well as dentistry reviews, could not be conducted.Conclusion: This case highlights the rare occurrence of adult-onset seizures in an undiagnosed SWS and their re-emergence after almost two decades without anti-seizure medications. It also highlights the importance of a comprehensive history and clinical examination, as this patient’s diagnosis of SWS could have been missed if she had not experienced seizures on admission. Our study also demonstrates the challenges associated with managing such a complex condition in settings with limited resources.Keywords: genetic, angioma, seizure, glaucoma, port-wine stai

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

The Outcomes of Delayed Revascularization in Lower Extremity Vascular Injury: A Retrospective Cohort Study

Introduction: There is no consensus yet whether delayed limb salvage procedures with an “ischemic time” of more than 6 hours are worthwhile, as these repairs are often complicated by reperfusion injury. Our study aims to determine the outcomes of delayed revascularization to validate our current treatment approach and assess areas for future improvement. Materials and methods: We performed a retrospective cohort study on a highly selected group of patients who underwent delayed revascularization surgery for lower extremity traumatic vascular injuries in our institution from January 2008 to June 2018. Exclusion criteria include the presence of a terminal non-salvageable ischemic limb; defined as a gangrenous extremity evident by non-blanchable, mottled skin with complete limb paralysis, renal trauma, known renal impairment, and those with an ischemic time less than 6 hours. The demographic data, type and level of vascular, type of injuries, duration of ischemia, MESS score, and the need for secondary amputation were assessed. Result: Fifty-nine patients were identified and included in the analysis. Fifty patients (84.7%) were male, while 9 patients (15.3%) were female. The mean age was 28.1 years. The most injured vessel was the popliteal artery (n=41, 69.5%). The commonest injury pattern was contusion with thrombosis (n=31, 52.5%). Revascularizations were mainly achieved by interposition saphenous vein graft (n=40, 67.8%). The mean duration of delayed was 14.1 hours. A total of 83.1% of patients (n=49) had a Mangled Extremity Severity Scoring (MESS) of 7 and above. The limb salvage rate in this study was 89.8%, with only 6 patients (12.2%) requiring secondary amputations. Thirty-one patients developed rhabdomyolysis, with 6 cases (19.4%) requiring temporary inpatient renal replacement therapy (RRT). Out of the six, only one patient required lifelong RRT. Conclusions: Limb salvage in those with the duration of delayed of more than 6 hours should be attempted after careful assessment and a high rate of limb salvage, minimal renal complication and acceptable functional (mobility) outcomes can be achieved, despite the reperfusion injury that accompanies

The role of gut-liver axis in the restriction of intrauterine growth in a model of experimental gastroschisis

PURPOSE: To evaluate the intrauterine growth restriction (IUGR) by the expression of IR-&#946;, IRS-1, IRS-2, IGF-IR&#946; and Ikappa&#946; in experimental model of gastroschisis. METHODS: Pregnant rats at 18.5 days of gestation were submitted to surgery to create experimental fetal gastroschisis (term = 22 days) were divided in three groups: gastroschisis (G), control (C) and sham (S). Fetuses were evaluated for body weight (BW), intestinal (IW), liver (LW) and their relations IW/BW and LW/BW. IR-&#946; and IGF-IR&#946; receptors, IRS-1 and IRS-2 substrates and Ikappa&#946; protein were analyzed by western blotting. RESULTS: BW was lower in G, the IW and IW / BW were greater than C and S (p<0.05) groups. The liver showed no differences between groups. In fetuses with gastroschisis, compared with control fetuses, the expression of IGF-IR&#946; (p<0.001) and Ikappa&#946; (p<0.001) increased in the liver and intestine, as well as IR-&#946; (p<0.001) which decreased in both. In contrast to the intestine, IRS-1 (p<0.001) increased in the liver and IRS-2 decreased (p<0.01). CONCLUSION: The axis of the intestine liver has an important role in inflammation, with consequent changes in the metabolic pathway of glucose can contribute to the IUGR in fetuses with gastroschisis

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112