170 research outputs found
An improved wrapper-based feature selection method for machinery fault diagnosis
A major issue of machinery fault diagnosis using vibration signals is that it is over-reliant on personnel knowledge and experience in interpreting the signal. Thus, machine learning has been adapted for machinery fault diagnosis. The quantity and quality of the input features, however, influence the fault classification performance. Feature selection plays a vital role in selecting the most representative feature subset for the machine learning algorithm. In contrast, the trade-off relationship between capability when selecting the best feature subset and computational effort is inevitable in the wrapper-based feature selection (WFS) method. This paper proposes an improved WFS technique before integration with a support vector machine (SVM) model classifier as a complete fault diagnosis system for a rolling element bearing case study. The bearing vibration dataset made available by the Case Western Reserve University Bearing Data Centre was executed using the proposed WFS and its performance has been analysed and discussed. The results reveal that the proposed WFS secures the best feature subset with a lower computational effort by eliminating the redundancy of re-evaluation. The proposed WFS has therefore been found to be capable and efficient to carry out feature selection tasks
EVALUATING WATER QUALITY INDEX OF AL HAMMAR MARSH, SOUTH OF IRAQ WITH THE APPLICATION OF GIS TECHNIQUE
This study concerns the water quality index of the Al Hammar marsh. The water quality of station M1, also termed Al-Hamedy, located in the middle of the marsh and related to the Al-Basra governorate, was evaluated from 2011 to 2015, using 12 selected parameters. The parameters include pH, Phosphate (PO4), Nitrate (NO3), Magnesium (Mg), Calcium (Ca), Total hardness (TH), Sodium (Na), Sulphate (SO4), Chloride (Cl), Total dissolved solids (TDS), Alkalinity (Alk.) and Electrical conductivity (EC). The Arithmetic Weighted Index was employed to ascertain the water quality index (WQI) in the Al-Hammar marsh. The findings from this research have been linked to the ArcGIS 10.4.1 software, to produce layers that represent the nature of the spatial distribution of the WQIs, as coloured maps. The results revealed that the marsh quality fell below the class of poor water quality, and the marsh water was brackish due to the high concentration of totally dissolved solids flowing in from the estuaries of the feeding channels coming from the river Euphrates, as well as from the tidal phenomenon via river Shatt Al-Arab
Magnetic resonance imaging findings in children with Parry-Romberg syndrome and en coup de sabre
BACKGROUND: The aim of this study was to: (i) describe the abnormalities seen on brain imaging in a group of children with en coup de sabre (EDCS) with/without Parry-Romberg syndrome (PRS); and (ii) identify clinical predictors of brain imaging abnormalities. METHODS: This was a single centre (Great Ormond Street Hospital, London) retrospective case series of patients with ECDS/PRS seen from 2000 to 2018. We identified patients with cutaneous manifestations consistent with the clinical descriptions of ECDS/PRS. Presenting clinical, laboratory, and radiological brain findings are described. Results are expressed as medians and ranges or frequencies and percentages. Fisher's exact test was used to identify clinical associations with magnetic resonance imaging (MRI) abnormalities. RESULTS: Fourteen patients were studied: 6 males and 8 females; median age 14 years (range 3-20). We observed neuroimaging abnormalities in 2/6 ECDS and 5/8 ECDS/PRS patients. White matter signal abnormality, dystrophic calcification, leptomeningeal enhancement, and sulcal crowding were the typical findings on brain imaging. A total of 50% of patients had no MRI abnormality despite some of these patients having neurological symptoms. The presence of seizures was significantly associated with ipsilateral enhanced white matter signalling on MRI (p < 0.05). CONCLUSIONS: In summary, we observed several distinct radiographic patterns associated with ECDS/PRS. Seizure disorder was strongly associated with the presence of ipsilateral enhanced white matter signalling. Improved neuroimaging techniques that combine morphological with functional imaging may improve the detection rate of brain involvement in children with ECDS/PRS in the future
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A parametric simulation on the effect of the rejected brine temperature on the performance of multieffect distillation with thermal vapour compression desalination process and its environmental impacts
YesMultieffect distillation with thermal vapour compression (MED–TVC) is one of the most attractive thermal desalination technologies for the production of freshwater. Several mathematical models were presented in the open literature to analyse the steady-state performance of such process. However, these models have several limitations and assumptions. Therefore, there remains the challenge of having a reliable model to accurately predict the performance of the MED process. Thus, this research attempts to resolve this challenge by rectifying the shortcomings of the models found in the literature and create a new one. The robustness of the developed model is evaluated against the actual data of Umm Al-Nar commercial plant situated in UAE. In seawater desalinisation, a large amount of high-salinity stream (brine) is rejected back into the sea. This paper investigates the influence of the rejected (exit) brine temperature on the system performance parameters of MED–TVC process. Specifically, these parameters are considered as total heat consumption, gain output ratio, freshwater production, heat transfer area and performance ratio. Also, the particular parameters of TVC section of the entrainment ratio, compression ratio and expansion ratio are also addressed. Moreover, a critical evaluation of the influence of the rejected brine temperature on the seawater is also embedded
Systemic juvenile idiopathic arthritis: The Great Ormond Street Hospital experience (2005–2021)
Systemic juvenile idiopathic arthritis (sJIA) is a complex, systemic inflammatory disorder driven by both innate and adaptive immunity. Improved understanding of sJIA pathophysiology has led to recent therapeutic advances including a growing evidence base for the earlier use of IL-1 or IL-6 blockade as first-line treatment. We conducted a retrospective case notes review of patients diagnosed with sJIA over a 16-year period (October 2005-October 2021) at Great Ormond Street Hospital for Children. We describe the clinical presentation, therapeutic interventions, complications, and remission rates at different timepoints over the disease course. We examined our data, which spanned a period of changing therapeutic landscape, to try and identify potential therapeutic signals in patients who received biologic treatment early in the disease course compared to those who did not. A total of 76-children (female n = 40, 53%) were diagnosed with sJIA, median age 4.5 years (range 0.6-14.1); 36% (27/76) presented with suspected or confirmed macrophage activation syndrome. A biologic disease-modifying anti-rheumatic drug (bDMARD) alone was commenced as first-line treatment in 28% (n = 21/76) of the cohort; however, at last review, 84% (n = 64/76) had received treatment with a bDMARD. Clinically inactive disease (CID) was achieved by 88% (n = 67/76) of the cohort at last review; however, only 32% (24/76) achieved treatment-free CID. At 1-year follow-up, CID was achieved in a significantly greater proportion of children who received treatment with a bDMARD within 3 months of diagnosis compared to those who did not (90% vs. 53%, p = 0.002). Based on an ever-increasing evidence base for the earlier use of bDMARD in sJIA and our experience of the largest UK single-centre case series described to date, we now propose a new therapeutic pathway for children diagnosed with sJIA in the UK based on early use of bDMARDs. Reappraisal of the current National Health Service commissioning pathway for sJIA is now urgently required
Testicular ischemia in deficiency of adenosine deaminase 2 (DADA2)
Background: Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive autoinflammatory
condition. Recognised features include vasculitis predominantly affecting medium sized vessels, livedoid skin rash,
central and peripheral nervous system involvement, variable degrees of immunodeficiency, and marrow failure,
amongst other clinical presentations. We present the case of a six year old male with DADA2 who presented with
acute testicular ischaemia secondary to vasculitis, the first such description in DADA2.
Case presentation: A six year old male presented acute right-sided testicular pain. His history included transient
infantile neutropenia, resolved hepatosplenomegaly, and longstanding livedo racemosa, leading to screening and
confirmation of DADA2 caused by homozygous c.139G > C (p.G47R) mutation of ADA2. As his only clinical feature
was that of mild livedo racemosa with normal laboratory parameters at diagnosis, he was being actively monitored
prior to starting any treatment. At a routine clinic follow-up a 24 h history of testicular pain was noted on systems
review. He was afebrile, and his only physical signs were that of moderate livedo racemosa, and tenderness of the
right testicle. Laboratory parameters revealed C-reactive protein (CRP) 8 mg/L (reference range [RR] < 20 mg/L);
erythrocyte sedimentation rate (ESR) 28 mm/hr. (RR < 10); and serum amyloid A (SAA)5 mg/L (RR < 10). Ultrasoundscan of the scrotum revealed significantly reduced perfusion of the right testes, without torsion. Surgical scrotal
exploration confirmed testicular ischaemia without torsion. Histology demonstrated ischaemic seminiferous tubules
with intervening haemorrhage and acute inflammatory cells, consistent with vasculitis of the testis as the cause. He
was treated with high dose intravenous methyl-prednisolone followed by a weaning course of oral prednisolone,
and subcutaneous adalimumab (anti-tumour necrosis factor alpha, anti-TNFα). Repeat ultrasound-scan 3 weeks later
revealed good testicular perfusion, with a small area of focal infarction. At last follow-up (11 months post-event) he
remained asymptomatic, on treatment with adalimumab.
Conclusion: The phenotype of DADA2 continues to expand, and we add testicular infarction to the features of
DADA2. CRP and SAA cannot be relied on as reliable biomarkers to predict tissue ischaemia and hence who to
target for anti-TNFα therapy in DADA2, since these remained steadfastly normal before, during, and after testicular
infarction in this case
Observations of changes in acoustic emission parameters for varying corrosion defect in reciprocating compressor valves
Acoustic Emission (AE) technology is probably one of the most recent entries in the field of machinery condition monitoring. This paper investigates the application of AE parameters for valve faults detection in reciprocating compressor. The defective valves were designed by emulating the actual valve corrosion with varying sizes such that defects could be applied onto the reciprocating compressor. A set of experiments was performed to acquire the AE signal. The primary source of AE signal was verified using waveform analysis. The AE parameters versus different operational and valve condition were illustrated individually. In addition, the significance of the change and sensitivity of AE parameters versus different experimental conditions was verified using MANOVA and coefficient of variance analysis. It is concluded that the AE signal parameters can be used to detect the valve faults in the reciprocating compressor with the consideration of the variation in the AE parameters sensitivity
Aquaporin-4 IgG antibody-related disorders in patients with juvenile systemic lupus erythematosus
Objective
The aim of this study was to: (a) screen a large group of unselected patients with juvenile systemic lupus erythematosus for anti-aquaporin 4 antibodies (AQP4-Ab); (b) identify clinical and laboratory predictors of the presence of AQP4-Ab positivity in juvenile systemic lupus erythematosus.
Methods
Sera from 90 patients with juvenile systemic lupus erythematosus were tested for the presence of AQP4-Ab using a cell-based assay. Demographics, clinical and immunological features, treatment received were summarized. Fisher’s exact test was used to identify clinical predictors of positivity for AQP4-Ab.
Results
Five of 90 (5.5%) patients tested positive for AQP4-Ab, all of which had neurological involvement, mainly transverse myelitis and optic neuritis. AQP4-Ab-positive patients were more likely to have neurological symptoms (P = 0.002), less likely to experience dermatological manifestations (P = 0.045), and less likely to have detectable anti-dsDNA antibodies (P = 0.022). These patients were also more likely to have received anti-epileptic (P = 0.023) and anti-coagulant (P = 0.007) drugs.
Conclusions
The findings of this study indicate that some patients with juvenile systemic lupus erythematosus develop antibodies against aquaporin-4 and may be at risk of developing a neurological clinical phenotype. We suggest that all juvenile systemic lupus erythematosus patients should be systematically screened for the presence of AQP4-Ab and this may help identify a high risk for neurological involvement in juvenile systemic lupus erythematosus
The pipeline for drugs for control and elimination of neglected tropical diseases : 2. Oral anti-infective drugs and drug combinations for off-label use
In its ‘Road map for neglected tropical diseases 2021–2030’, the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for ‘off-label’ use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with ‘off-label’ treatment of diseases with insufficient treatment options as pursued by the ‘CURE ID’ initiative. Graphical abstract: [Figure not available: see fulltext.]
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