Performance characteristics of an adaptive controller based on least-mean-square filters

A closed loop, adaptive control scheme that uses a least mean square filter as the controller model is presented, along with simulation results that demonstrate the excellent robustness of this scheme. It is shown that the scheme adapts very well to unknown plants, even those that are marginally stable, responds appropriately to changes in plant parameters, and is not unduly affected by additive noise. A heuristic argument for the conditions necessary for convergence is presented. Potential applications and extensions of the scheme are also discussed

Vaccination in liver diseases and liver Transplantation: Recommendations, implications and opportunities in the post-covid era

The interest in vaccination efficacy and toxicity has surged following the Covid-19 pandemic. Immune responses to several vaccines have been shown to be suboptimal in patients with chronic liver disease (CLD) or post-liver transplant (LT), as a consequence of cirrhosis-associated immune dysfunction (CAID) or post-LT immunosuppression respectively. Accordingly, vaccine-preventable infections may be more common or severe than in the general population. The Covid-19 pandemic has greatly accelerated research and development into vaccination technology and platforms, which will have spillover benefits for liver patients. The aims of this review are: (i) to discuss the impact of vaccine-preventable infections on CLD and post-LT patients, (ii) to appraise current evidence supporting vaccination strategies, and (iii) to provide some insight into recent developments relevant for liver patients

Retesting a Model of the Deming Management Method

Anderson et al. (1994) developed a model of the theory of quality management underlying the Deming management method; Anderson et al. (1995) tested that model using path analysis. They used data from an existing database collected from 41 manufacturing plants in the electronics, machinery, and transportation industries with 100 or more employees. In this study, which retests their model, data were gathered from over 100 manufacturing and service companies of all sizes across the US and Canada. The measures used in the original study were modified to apply to both service and manufacturing organizations. The data were analysed using similar statistical analysis procedures, and comparisons were made with the results of the Anderson et al. (1995) study. The results showed strong support for the model developed by Anderson et al. (1994) with the exception of one construct, Employee Fulfilment. The findings suggest that implementing a continuous improvement effort without first implementing Visionary Leadership, Cooperation, Learning, and Process Management is a recipe for failure

Pay Gap and Performance in China

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134150/1/abac12082.pd

Remote Cerebellar Haemorrhage: A Potential Iatrogenic Complication of Spinal Surgery

We report the case of a 51-year-old man with no significant past medical history, who underwent elective revision spinal surgery and subsequently developed intracranial hypotension, remote cerebellar haemorrhage (RCH), and mild hydrocephalus on the fourth postoperative day. Remote cerebellar haemorrhage is a known complication of supratentorial surgery. This iatrogenic phenomenon may also occur following spinal surgery, due to dural tearing and rapid cerebral spinal fluid (CSF) leakage, resulting in intracranial hypotension and cerebellar haemorrhage. This complication may result in severe permanent neurologic sequelae; hence, it is of pertinence to diagnose and manage it rapidly in order to optimise patient outcome

Remote Cerebellar Haemorrhage: A Potential Iatrogenic Complication of Spinal Surgery

We report the case of a 51-year-old man with no significant past medical history, who underwent elective revision spinal surgery and subsequently developed intracranial hypotension, remote cerebellar haemorrhage (RCH), and mild hydrocephalus on the fourth postoperative day. Remote cerebellar haemorrhage is a known complication of supratentorial surgery. This iatrogenic phenomenon may also occur following spinal surgery, due to dural tearing and rapid cerebral spinal fluid (CSF) leakage, resulting in intracranial hypotension and cerebellar haemorrhage. This complication may result in severe permanent neurologic sequelae; hence, it is of pertinence to diagnose and manage it rapidly in order to optimise patient outcome

SARS-CoV-2 infection and liver involvement

The COVID-19 pandemic is the largest public health challenge in living memory. Patients with underlying liver disease have been disproportionately affected, experiencing high morbidity and mortality. In addition, elevated liver enzymes appear to be a risk factor for disease progression, even in the absence of underlying liver disease. Nevertheless, the mechanism of liver injury in SARS-CoV-2 infection remains largely unknown. This review aims to provide an overview of the mechanisms by which SARS-CoV-2 induces liver injury, and the impact of COVID-19 on cirrhosis, alcohol-related liver disease, autoimmune liver disease, non-alcoholic fatty liver disease, hepatitis B and C virus infection, liver-transplant recipients and patients with hepatocellular carcinoma. Finally, emerging data on vaccination in liver diseases is discussed, to help inform public health policy

SARS-CoV-2: comparison of IgG levels at 9 months post second dose of vaccination in COVID-survivor and COVID-naïve healthcare workers

Background: Natural (asymptomatic/symptomatic COVID-19 infection) and artificial (vaccination) exposure to the pathogen represent two modes of acquiring active immunity. No definitive guidelines exist regarding whether COVID-survivors (with infection/re-infection/re-re-infection in the three COVID-19 waves) require a modified vaccination schedule. Most countries are offering a third vaccine dose and many are contemplating a fourth dose. Our aim was to gauge the IgG-antibody levels 9m post second vaccination in healthcare workers (HCW) and compare these with IgG-levels 1m post-vaccination in the same cohort for any decline, and to compare the post-vaccination IgG-levels in COVID-survivors and COVID-naïve HCW at 9m.Methods: This prospective observational single-centric cohort study included 63 HCW of either sex, aged 18-70y who completed 9m post-vaccination. The IgG-titre was tested at 9-10m post second vaccination in COVID-survivors and COVID-naïve HCW.Results: At 1m and 9m post-vaccination IgG-levels in COVID-survivors (23.097±4.58 and 15.103±4.367 respectively; p<0.0001) and COVID-naïve HCW (16.277±6.36 and 9.793±6.928 respectively; p=0.0013) had unequal variance (Welsch test; p=0.0022 at 9m). 9/31 COVID-naïve HCW but none of the 32 COVID-survivors tested COVID-positive in the second wave post second vaccination. 11/31 and 3/32 HCW belonging to the former and latter groups developed COVID-19 in the third wave consequently deferring their third/precautionary vaccination.Conclusions: Although HCW with IgG-levels in all brackets developed COVID-19, the severity of symptoms corresponded with the IgG-levels. COVID-19 is here to stay, but in peaceful co-existence in endemic proportions. Considering evidence that immunity acquired by vaccination/natural infection is ephemeral, re-invention of vaccines to match the ever-mutating virus is foreseen.

Spontaneous rupture of giant gastric stromal tumor into gastric lumen

BACKGROUND: Gastrointestinal stromal tumors (GIST) constitute a large majority of mesenchymal tumors of the gastrointestinal (GI) tract, which express the c-kit proto-oncogene protein, a cell membrane receptor with tyrosine kinase activity. GI stromal tumors of the stomach are usually associated with bleeding, abdominal pain or a palpable mass. CASE PRESENTATION: A 75-year-old male presented with upper abdominal pain and palpable mass. Computed tomographic (CT) scan of the abdomen showed a large mass arising in the posterior aspect of fundus, body, and greater curvature of the stomach. Second day after the admission, there was significant reduction in the size of the tumor, clinically as well as radiologically. Endoscopic biopsy showed large bulge in fundus and corpus of the stomach posteriorly with an opening in the posterior part of the corpus, and biopsy from the edge of the opening reveled GIST. Patient underwent curative resection. CONCLUSION: Spontaneous ruptured of giant gastric stromal tumor is very rare presentation of stomach GIST. Thorough clinical examination and timely investigation can diagnose rare complication