An investigation into the requirements for an efficient image transmission system over an ATM network

This thesis looks into the problems arising in an image transmission system when transmitting over an A TM network. Two main areas were investigated: (i) an alternative coding technique to reduce the bit rate required; and (ii) concealment of errors due to cell loss, with emphasis on processing in the transform domain of DCT-based images. [Continues.

Multi-label learning by Image-to-Class distance for scene classification and image annotation

In multi-label learning, an image containing multiple objects can be assigned to multiple labels, which makes it more chal-lenging than traditional multi-class classification task where an image is assigned to only one label. In this paper, we propose a multi-label learning framework based on Image-to-Class (I2C) distance, which is recently shown useful for image classification. We adjust this I2C distance to cater for the multi-label problem by learning a weight attached to each local feature patch and formulating it into a large margin optimization problem. For each image, we constrain its weighted I2C distance to the relevant class to be much less than its distance to other irrelevant class, by the use of a margin in the optimization problem. Label ranks are generated under this learned I2C distance framework for a query image. Thereafter, we employ the label correlation in-formation to split the label rank for predicting the label(s) of this query image. The proposed method is evaluated in the applications of scene classification and automatic image annotation using both the natural scene dataset and Mi-crosoft Research Cambridge (MSRC) dataset. Experiment results show better performance of our method compared to previous multi-label learning algorithms

Error concealment algorithms for an ATM videoconferencing system

The paper describes videoconferencing workstation using ATM for the transmission of all data and Motion-JPEG for compression of the video. Of particular interest is the work on algorithms to help conceal the errors that arise from transmission over an ATM network. Several methods are discussed and the results of some subjective assessments of typical images are presente

Comparison of antipsychotic dose equivalents for acute bipolar mania and schizophrenia

Are antipsychotic dose equivalents between acute mania and schizophrenia the same? Study selection and analysis Six databases were systematically searched (from inception to 17 September 2022) to identify blinded randomised controlled trials (RCTs) that used a flexible-dose oral antipsychotic drug for patients with acute mania. The mean and SD of the effective dose and the pre–post changes in manic symptoms were extracted. A network meta-analysis (NMA) under a frequentist framework was performed to examine the comparative efficacy between the antipsychotics. A classic mean dose method (sample size weighted) was used to calculate each antipsychotic dose equivalent to 1 mg/day olanzapine for acute mania. The antipsychotic dose equivalents of acute mania were compared with published data for schizophrenia. Findings We included 42 RCTs which enrolled 11 396 participants with acute mania. The NMA showed that risperidone was superior to olanzapine (reported standardised mean difference: −022, 95% CI −0.41 to –0.02), while brexpiprazole was inferior to olanzapine (standardised mean difference: 0.36, 95% CI 0.08 to 0.64). The dose equivalents to olanzapine (with SD) were 0.68 (0.23) for haloperidol, 0.32 (0.07) for risperidone, 0.60 (0.11) for paliperidone, 8.00 (1.41) for ziprasidone, 41.46 (5.98) for quetiapine, 1.65 (0.32) for aripiprazole, 1.23 (0.20) for asenapine, 0.53 (0.14) for cariprazine and 0.22 (0.03) for brexpiprazole. Compared with the olanzapine dose equivalents for schizophrenia, those of acute mania were higher for quetiapine (p<0.001, 28.5%) and aripiprazole (p<0.001, 17.0%), but lower for haloperidol (p<0.001, –8.1%) and risperidone (p<0.001, –15.8%). Conclusions Antipsychotic drugs have been considered first-line treatment for acute mania, warranting specific dose equivalence for scientific and clinical purposes

Variability and efficacy in treatment effects on manic symptoms with lithium, anticonvulsants, and antipsychotics in acute bipolar mania: A systematic review and meta-analysis

Background: Acute mania is a psychiatric emergency requiring rapid management. However, randomised controlled trials (RCTs) have shown considerable individual differences in treatment effects on manic symptoms with antimanic drugs. Methods: We searched the MEDLINE, CENTRAL, EMBASE, PsycINFO, and ClinicalTrials.gov to identify RCTs without language restrictions from inception to April 19, 2022. We included double-blind RCTs of oral antimanic monotherapy versus placebo in adult patients. The primary outcome was variability in improvement of manic symptoms (assessed using the coefficient of variation ratio [CVR]). The secondary outcomes were overall improvement of manic symptoms and acceptability (i.e., discontinuation for any reason). The pooled effects of outcomes were calculated by random-effects meta-analyses using restricted maximum likelihood methods. The quality of the included studies was assessed using the Cochrane Risk of Bias (ROB) Assessment Tool. This study was registered with OSF (DOI:10.17605/OSF.IO/G4JNY). Findings: We included 39 RCTs (N=12150; mean age=39·9 years, interquartile range [IQR]=38·7-41·1; mean proportion of female=48·6%, IQR=42·3%-52·3%) and investigated 14 antimanic drugs. We found that eight antimanic drugs compared to placebo were associated with lower CVRs (95% confidence interval [CI]; I2), including risperidone (0·51; 0·37-0·70; 0%), haloperidol (0·54; 0·44-0·67; 4%), olanzapine (0·59; 0·44-0·79; 47%), ziprasidone (0·61; 0·53-0·71; 0%), lithium (0·63; 0·52-0·76; 0%), quetiapine (0·65; 0·48-0·87; 2%), aripiprazole (0·68; 0·56-0·84; 25%), and cariprazine (0·70; 0·49-0·99; 28%). There were nine antimanic drugs associated with greater efficacy than placebo, including risperidone (reported as standardised mean difference; 95% CI; I2: 0·64; 0·31-0·97; 15%), haloperidol (0·57; 0·29-0·85; 64%), cariprazine (0·51; 0·24-0·78; 0%), olanzapine (0·44; 0·30-0·58; 0%), lithium (0·42; 0·29-0·55; 0%), ziprasidone (0·42; 0·26-0·58; 0%), quetiapine (0·40; 0·13-0·67; 0%), asenapine (0·40; 0·13-0·67; 0%), and aripiprazole (0·32; 0·14-0·49; 53%). Ziprasidone (reported as risk ratio; 95% CI; I2: 0·83; 0·79-0·89; 0%) and olanzapine (0·63; 0·49-0·80; 35%) were associated with better acceptability relative to placebo. Among the 39 RCTs, none had a high ROB. Interpretation: We demonstrated that eight antimanic drugs were associated with lower variability and better efficacy than placebo, suggesting that these antimanic drugs were associated with more homogenous and predictable improvements of manic symptoms in patients with acute mania

Trial sequential analysis and updated meta-analysis of fluvoxamine on clinical deterioration in adult patients with symptomatic COVID-19 infection

Preliminary meta-analyses suggested that fluvoxamine was effective in treating COVID-19 infection. However, the reliability of this evidence has not yet been examined. MEDLINE, CENTRAL, EMBASE, PsycINFO, and ClinicalTrials.gov were searched to identify any randomized controlled trials (RCTs) from the inception of the databases to 5 February 2023. We used trial sequential analysis (TSA) to examine the reliability of the current existing evidence on the benefits of fluvoxamine on COVID-19 infection. The primary outcome was clinical deterioration, as defined in the original study (reported as odds ratio (OR), with 95% confidence intervals), and the secondary outcome was hospitalization. In the TSA, we used the relative risk reduction thresholds of 10, 20, and 30%. The updated meta-analysis of the five RCTs showed that fluvoxamine was not associated with lower odds of clinical deterioration when compared with a placebo (OR: 0.81; 0.59–1.11). The effect of fluvoxamine lay within the futility boundary (i.e., lack of effect) when using a 30% relative risk reduction threshold. The effect estimates lay between the superiority and futility boundary using the 10% and 20% threshold, and the required size of information was not reached for these two thresholds. The effect of fluvoxamine on the odds of hospitalization was not statistically significant (0.76; 0.56–1.03). In conclusion, there is no reliable evidence that fluvoxamine, when compared to a placebo, reduces the relative risk of clinical deterioration among adult patients with COVID-19 infection by 30%, and a relative risk reduction of 20% or 10% is still uncertain. The role of fluvoxamine as a COVID-19 treatment cannot be justified

Cognitive effects and tolerability of non-invasive brain stimulation on Alzheimer’s disease and mild cognitive impairment: a component network meta-analysis

Objectives: To compare cognitive effects and acceptability of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) in patients with Alzheimer’s disease (AD) or mild cognitive impairment (MCI), and to determine whether cognitive training (CT) during rTMS or tDCS provides additional benefits. Methods: Electronic search of PubMed, Medline, Embase, the Cochrane Library and PsycINFO up to 5 March 2020. We enrolled double-blind, randomised controlled trials (RCTs). The primary outcomes were acceptability and pre–post treatment changes in general cognition measured by Mini-Mental State Examination, and the secondary outcomes were memory function, verbal fluency, working memory and executive function. Durability of cognitive benefits (1, 2 and ≥3 months) after brain stimulation was examined. Results: We included 27 RCTs (n=1070), and the treatment components included high-frequency rTMS (HFrTMS) and low-frequency rTMS, anodal tDCS (atDCS) and cathodal tDCS (ctDCS), CT, sham CT and sham brain stimulation. Risk of bias of evidence in each domain was low (range: 0%–11.1%). HFrTMS (1.08, 9, 0.35–1.80) and atDCS (0.56, 0.03–1.09) had short-term positive effects on general cognition. CT might be associated with negative effects on general cognition (−0.79, –2.06 to 0.48) during rTMS or tDCS. At 1-month follow-up, HFrTMS (1.65, 0.77–2.54) and ctDCS (2.57, 0.20–4.95) exhibited larger therapeutic responses. Separate analysis of populations with pure AD and MCI revealed positive effects only in individuals with AD. rTMS and tDCS were well tolerated.\ud Conclusions: HFrTMS is more effective than atDCS for improving global cognition, and patients with AD may have better responses to rTMS and tDCS than MCI

Mortality rates in Alzheimer's disease and non-Alzheimer's dementias: a systematic review and meta-analysis

Background People with dementia die prematurely. Identifying differences in mortality rates between different types of dementia might aid in the development of preventive interventions for the most vulnerable populations. The aim of this study was to compare the difference in mortality rates between individuals without dementia and individuals with various types of dementia. Methods For this systematic review and meta-analysis, we did a systematic search of MEDLINE, PubMed, Embase, and Cochrane Library from inception to July 11, 2020, for cross-sectional or cohort studies that assessed mortality and survival-related outcomes among people with different types of dementia compared with people without dementia. Single-arm studies without comparison groups and autopsy studies or family studies that used a selected sample were excluded. The Newcastle-Ottawa Scale was used by two authors (D-JL and C-SC) independently to measure the methodological quality of included studies, and two authors (F-CY and P-TT) independently extracted data. We assessed differences in all-cause mortality rate and survival time from dementia diagnosis between individuals without dementia, individuals with Alzheimer's disease, and individuals with non-Alzheimer's disease dementias. The secondary outcomes were age at death and survival time from disease onset. Random-effects meta-analyses were done. Effect sizes included hazard ratios (HRs) and mean differences (MDs) with 95% CIs. Potential moderators, including age-associated moderators, were identified through meta-regression and subgroup analyses. This study is registered with PROSPERO, CRD42020198786. Findings Our database search identified 11 973 records, and we included 78 eligible studies in our analyses, encompassing 63 125 individuals with dementia and 152 353 controls. Individuals with any type of dementia had a higher mortality rate than individuals without dementia (HR 5·90, 95% CI 3·53 to 9·86), and the HR for all-cause mortality was highest for Lewy body dementia (17·88, 5·87 to 54·46). After diagnosis, the mean survival time for people with Alzheimer's disease was 5·8 years (SD 2·0). Compared with people with Alzheimer's disease, a diagnosis of any non-Alzheimer's disease dementia was associated with a higher risk of all-cause mortality (HR 1·33, 1·21 to 1·46), a shorter survival time from diagnosis (MD −1·12 years, 95% CI −1·52 to −0·72), and a younger age at death (−1·76 years, −2·66 to −0·85). Survival time from disease onset was also shorter in people with non-Alzheimer's dementia, across types, compared with people with Alzheimer's disease, but the subgroup analysis revealed that this difference was only significant for vascular dementia (MD −1·27 years, −1·90 to −0·65) and dementia with Lewy bodies (MD −1·06 years, −1·68 to −0·44). The interactions between age and several survival-related outcomes were significant. 39 (50%) of the 78 included studies were rated as good quality, and large heterogeneity (I2>75%) was observed for most of the study outcomes. Interpretation Alzheimer's disease is the most common type of dementia and one of the major causes of mortality worldwide. However, the findings from the current study suggest that non-Alzheimer's disease dementias were associated with higher morality rates and shorter life expectancy than Alzheimer's disease. Developing tailored treatment and rehabilitation programmes for different types of dementia is important for mental health providers, patients, and their families

Treatment efficacy and acceptability of pharmacotherapies for dementia with lewy bodies: a systematic review and network meta-analysis

Introduction We investigated the efficacy and acceptability of pharmacotherapy for dementia with Lewy bodies (DLB) while simultaneously considering the neuropsychiatric symptoms (NPS), cognitive function, motor symptoms, and acceptability. Methods Electronic databases were searched from inception through June 5, 2019, for randomized controlled trials (RCTs) and open-label trials (OLTs) in patients with DLB. We performed a pairwise conventional meta-analysis (PWMA) and network meta-analysis (NMA) within a frequentist framework. The main outcomes were mean change scores in NPS, general cognition, motor symptoms and acceptability. The effect sizes and odds ratios with 95% confidence intervals (CIs) were calculated. This study was registered with PROSPERO (CRD42018096996). Results In total, we included 29 studies (9 RCTs and 20 OLTs). In the NMA with 9 RCTs, both high- (mean difference [MD] 2.00, 95% CIs, 0.69 to 3.31) and low-dose (1.86, 0.58 to 3.15) donepezil were associated with a greater cognitive improvement than placebo. High-dose zonisamide was associated with greater motor symptom improvement ( -4.10, -7.03 to -1.17]). No medications reached statistical significance regarding improving neuropsychiatric symptoms or developing intolerable adverse effects as compared to placebo. In the second NMA, with 29 studies as an exploratory analysis, aripiprazole and yokukansan may be effective for neuropsychiatric symptoms, while levodopa may be associated with cognitive impairment. Conclusions We report the most comprehensive evidence for the selection of pharmacotherapy for treating different clusters of DLB-related symptoms. Due to the limited availability of RCTs on DLB, more well-conducted RCTs are needed for MMA to warrant clinical efficacy in the future