An ensemble based approach using a combination of clustering and classification algorithms to enhance customer churn prediction in telecom industry.

Mobile communication has become a dominant medium of communication over the past two decades. New technologies and competitors are emerging rapidly and churn prediction has become a great concern for telecom companies. A customer churn prediction model can provide the accurate identification of potential churners so that a retention solution may be provided to them. The proposed churn prediction model is a hybrid model that is based on a combination of clustering and classification algorithms using an ensemble. First, different clustering algorithms (i.e. K-means, K-medoids, X-means and random clustering) were evaluated individually on two churn prediction datasets. Then hybrid models were introduced by combining the clusters with seven different classification algorithms individually and then evaluations were performed using ensembles. The proposed research was evaluated on two different benchmark telecom data sets obtained from GitHub and Bigml platforms. The analysis of results indicated that the proposed model attained the highest prediction accuracy of 94.7% on the GitHub dataset and 92.43% on the Bigml dataset. State of the art comparison was also performed using the proposed model. The proposed model performed significantly better than state of the art churn prediction models.

Suspected intra-articular soft-tissue tumours and tumour-like lesions: Performance of image-guided core needle biopsy.

PURPOSE: To determine the efficacy of image-guided core needle biopsy (IGCNB) in patients presenting with suspected intra-articular soft tissue tumours or tumour-like lesions. METHODS: Retrospective study of patients referred to a musculoskeletal oncology service between January 2019 and May 2020 with a suspected intra-articular soft tissue tumour over a 16-month period. Data collected included patient age, gender, joint involved and maximal lesion size. Type of image-guidance (ultrasound or computed tomography), type of needle and type of anaesthesia, general anaesthetic (GA) or local anaesthetic (LA), were recorded, as was the histological diagnosis. For patients who proceeded to surgical excision, the IGCNB histology result was correlated with resection histology. Descriptive statistics were used and complications were also noted. RESULTS: By the termination of data collection 91 patients underwent IGCNB, 32 (35.2 %) males and 59 (64.8 %) females with a mean age of 41.4 years (age range 3-86 years). The joints involved were the knee (n = 73; 80.2 %), ankle (n = 12; 13.2 %), hip (n = 3; 3.3 %), shoulder (n = 1; 1.1 %), elbow (n = 1; 1.1 %) and wrist (n = 1; 1.1 %). Biopsy types were as follows: US-guided GA (n = 29; 31.9 %), US-guided LA (n = 37; 40.7 %), CT-guided GA, (n = 23; 25.3 %), CT-guided LA (n = 2; 2.2 %). Mean maximal tumour dimension for 76 focal lesions was 36.5 mm (range 18-113 mm). IGCNB yielded a definitive histological result in 85 of 91 cases (93.4 %), 44 of whom went on to surgical resection. Concordance between IGCNB and resection histology was achieved in 42 of 44 cases (95.5 %). The commonest diagnosis was tenosynovial giant cell tumour, with only a single malignant lesion identified. There were no recorded immediate or delayed complications. CONCLUSIONS: IGCNB of suspected intra-articular tumours or tumour-like lesions is a highly effective and safe technique.

Evaluation of 30-day mortality for 500 patients undergoing non-emergency surgery in a COVID-19 cold site within a multicentre regional surgical network during the COVID-19 pandemic

BackgroundTwo million non-emergency surgeries are being cancelled globally every week due to the COVID-19 pandemic, which will have a major impact on patients and healthcare systems. ObjectiveTo determine whether it is feasible and safe to continue non-emergency surgery in the COVID-19 pandemic Design, setting and participantsThis is a cohort study of 500 consecutive patients undergoing non-emergency surgery in a dedicated COVID-19 cold site following the first case of COVID-19 that was reported in the institution. The study was carried out during the peak of the pandemic in the United Kingdom, which currently has one of the highest number of cases and deaths from COVID-19 globally. We set up a hub-and-spoke surgical network amongst 14 National Health Service institutions during the pandemic. The hub was a cancer centre, which was converted into a COVID-19 cold site, performing urological, thoracic, gynaecological and general surgical operations. OutcomesThe primary outcome was 30-day mortality from COVID-19. Secondary outcomes included all-cause mortality and post-operative complications at 30-days. Results500 patients underwent surgery with median age 62.5 (IQR 51-71). 65% were male and 60% had a known diagnosis of cancer. 44% of surgeries were performed with robotic or laparoscopic assistance and 61% were considered complex or major operations. None of the 500 patients undergoing surgery died from COVID-19 at 30-days. 30-day allcause mortality was 3/500 (1%). 10 (2%) patients were diagnosed with COVID-19, 4 (1%) with confirmed laboratory diagnosis and 6 (1%) with probable COVID-19. 33/500 (7%) of patients developed Clavien-Dindo grade 3 or higher complications, with 1/33 (3%) occurring in a patient with COVID-19. ConclusionIt is safe to continue non-emergency surgery during the COVID-19 pandemic with appropriate service reconfiguration. Patient summaryNo patients died from COVID-19 when undergoing non-emergency surgery during the pandemic in one of the worst affected world regions.

Laparoscopic Cholecystectomy in Situs Inversus Totalis.

Situs inversus is a rare condition. It is characterised by reverse handed positioning of the internal viscera. Laparoscopic cholecystectomy is the standard procedure for cholelithiasis, but it may lead to technical difficulties in case of situs inversus, especially to right-handed surgeons. A 40-year female presented to the department with epigastric pain and bloating usually after fatty meals. Diagnosis of symptomatic gall bladder stone was made. She was a known case of situs inversus. Laparoscopic cholecystectomy was performed by right-handed surgeon with uneventful recovery.

Femtosecond Time-Resolved Raman Spectroscopy Reveals Structural Evidence for meta Effect in Stilbenols.

The meta effect in substituted aromatics plays a crucial role in their excited-state photophysical properties. Meta-substituted hydroxyarenes such as naphthols, stilbenols, and chromophoric constituents of green fluorescent proteins show unusual photoacidity and enhanced fluorescence lifetime and quantum yield when compared to their para-derivatives. Variation in the excited state features of the meta-derivatives when compared to the para-derivatives in stilbenols has been attributed to the enhanced torsional barrier for interconversion between the planar and the twisted perpendicular forms. Herein, we employed femtosecond time-resolved Raman spectroscopy to provide the direct structural evidence for the enhanced torsional barrier in meta-stilbenol. The Raman band profiles of the olefinic C═C stretch related to the torsional motion are found to decay with time constants of ∼750 and ∼13 ps in meta-stilbenol and para-stilbenol respectively, unraveling the structural evidence for the observed enhanced photoacidity originating from enhanced rates of excited-state proton transfer. Further, time-resolved fluorescence measurements are performed to elucidate the relaxation pathways of the excited states of the stilbenols.

Burnout among surgical residents in a lower-middle income country - Are we any different?

OBJECTIVE: To assess the presence of burnout among surgical residents working at various public sector hospitals in Pakistan. DESIGN: A survey based on MBI was used to assess the presence of burnout. Residents were grouped into Group A (Burn out) or Group B (No burn out). Pearson Test was used to see any correlation between different variables and burn out. A p value of <0.05 was taken as significant. SETTING/PARTICIPANTS: A cross sectional survey of all the surgical residents at various public sector hospitals in Lahore was done. RESULTS: A total of 133 residents responded to our questionnaire. 74% respondents were male and 26% were female. All residents showed a very high level of burnout. 50.4% residents had high levels of burn out on the EE category, 49.6% in the DP category and 53.4% residents had low levels on the PA scale. When assessed for overall burn out 57.9% residents had overall burnout. Males were more prone to develop burnout. Job dissatisfaction was the most prevalent reason for burn out. Owning a smartphone was significantly associated with development of burnout. Awareness regarding the burnout syndrome and having children were two factors which had a protective effect against burnout syndrome. Marriage, working hours, financial conditions, smoking and consumption of coffee/tea had no effect on development of burnout syndrome. CONCLUSION: There is high prevalence of burnout among the surgical residents in our hospitals. Unsatisfactory training is the number one reason for development of this syndrome.

Blind modulation format identification for digital coherent receivers.

In this paper, a simple novel digital modulation format identification (MFI) scheme for coherent optical systems is proposed. The scheme is based on the evaluation of the peak-to-average-power ratio (PAPR) of the incoming data samples after analog-to-digital conversion (ADC), chromatic dispersion (CD) and polarization mode demultiplexing (PMD) compensation at the receiver (Rx). Since at a particular optical-signal-to-noise ratio (OSNR) value different modulation formats have distinct PAPR values, it is possible to identify them. The proposed scheme and the results are analyzed both experimentally and through numerical simulations. The results demonstrate successful identification among four modulation formats (MF) commonly used in digital coherent systems.

Pump RIN-induced impairments in unrepeatered transmission systems using distributed Raman amplifier.

High spectral efficiency modulation format based unrepeatered transmission systems using distributed Raman amplifier (DRA) have attracted much attention recently. To enhance the reach and optimize system performance, careful design of DRA is required based on the analysis of various types of impairments and their balance. In this paper, we study various pump RIN induced distortions on high spectral efficiency modulation formats. The vector theory of both 1st and higher-order stimulated Raman scattering (SRS) effect using Jones-matrix formalism is presented. The pump RIN will induce three types of distortion on high spectral efficiency signals: intensity noise stemming from SRS, phase noise stemming from cross phase modulation (XPM), and polarization crosstalk stemming from cross polarization modulation (XPolM). An analytical model for the statistical property of relative phase noise (RPN) in higher order DRA without dealing with complex vector theory is derived. The impact of pump RIN induced impairments are analyzed in polarization-multiplexed (PM)-QPSK and PM-16QAM-based unrepeatered systems simulations using 1st, 2nd and 3rd-order forward pumped Raman amplifier. It is shown that at realistic RIN levels, negligible impairments will be induced to PM-QPSK signals in 1st and 2nd order DRA, while non-negligible impairments will occur in 3rd order case. PM-16QAM signals suffer more penalties compared to PM-QPSK with the same on-off gain where both 2nd and 3rd order DRA will cause non-negligible performance degradations. We also investigate the performance of digital signal processing (DSP) algorithms to mitigate such impairments.

Treatment of malignant triton tumor in zygomatic region.

Malignant triton tumor (MTT) is extremely rare and supposed to be highly aggressive because of high propensity for local recurrence and metastasis. To date, only about 170 cases were reported in various body locations including trunks, maxillary sinus, neck, extremities, retroperitoneal, and so on. We present a case of MTT in the zygoma with good outcome. A 27-year-old male patient with progressive swelling and pain in the right zygoma was proved to have an MTT by biopsy. Radical resection accompanying postoperative radiotherapy was adopted, and then the soft and hard tissue defects were repaired by prosthesis. The patient recovered well and was satisfied with the facial contour. At 45-month follow-up, there was no recurrence or metastasis that occurred. According to literature review, one third of MTTs appeared in the head and neck regions and seem to have a better prognosis. Radical resection is the most important remedy, and adjuvant radiotherapy could be helpful. With early finding and effective treatments, satisfactory outcome could be achieved.

Effectiveness and safety of vaginal misoprostol for induction of labour in unfavourable cervix in 3rd trimester.

BACKGROUND: The use of prostaglandin preparations with or without oxytocin infusion, is widely recognized and accepted as a standard method of induction of labour. It has been shown to reduce induction time and the risk of failed induction. The objective of this quasi-experimental observational study was to determine the effectiveness and safety of Misoprostol administered vaginally for induction of labour to achieve vaginal delivery. METHODS: This study was conducted from October 2004 to October 2007. The study was conducted at Shaheena Jamil Teaching Hospital, Frontier Medical College, Abbottabad and Women and Children Hospital Abbottabad. A total of 6299 obstetric patients were received for delivery and 946 patients had to undergo induction of labour. Primary outcome measures were to address clinical effectiveness (delivery within 24-hours) and safety (uterine hyper-stimulation, Caesarean Section and serious Maternal Morbidity). Secondary outcome measures included neonatal outcome. RESULTS: Out of 946 cases, successful vaginal deliveries were achieved in 843 (89.1%) cases. Time interval between induction and delivery was 4-24 hours. Oxytocin was required in 107 (12%) patients. Caesarean Section had to be done in 103 (10.8%) cases. The indications for Caesarean Section were foetal distress in 42 (40%), occipito-posterior position in 8 (7.7%), abruptioplacentae 2 (1.9%), cord around the neck 9 (7%), uterine hyperstimulation 6 (5.8%) and failure to progress in 20 (19%) cases. Admission to NICU was 28 (3.3%) and Neonatal deaths were 5 (0.5%). Postpartum Haemorrhage (PPH) was observed in 22 (2.3%) patients. There was no case of rupture uterus. CONCLUSION: Vaginal Misoprostol appears to be safe and effective for cervical ripening in 3rd Trimester. It helps vaginal delivery within 24 hours, does not increase incidence of Caesarean Section and has no adverse effect on foetal outcome. It could also be used in circumstances where extensive monitoring techniques are not available though close observation and vigilance is mandatory.