Multi-Resolution and Asymmetric Implementation of Attention in Transformers

Transformers are the state-of-the-art for machine translation and grammar error correction. One of the most important components of transformers are the attention layers, but they require significant computational power. We suggest a new way of looking at the “mixing” mechanisms of tokens by doing a multi-resolution implementation of attention, which maintains inference results while also improving training and inference speed, thus getting the best of both worlds. This approximation can be applied in symmtrical and asymmetrical manner within and across attention layers. We also suggest an interesting alternative for the softmax layer in attention. We also analyzed some other hyperparameters in detail. For example, our experiments indicate that we can have asymmetry among the attention layers w.r.t. number of heads, while still achieving similar results. In many cases, reducing the number of heads improves inference results. We also explored the role of weighting matrices for query, key, and value vectors; and show that in case of self-attention, absence of these matrices results in the collapse of the attention layers to an identity matrix

Hypoglossal nerve paraganglioma depicting as glomus tumor of neck

Introduction: Paraganglioma are infrequent neuroendocrine tumors that are most commonly found in the carotid body, ganglia of the vagus, jugular and tympanic nerve. Very rarely they can involve other cranial nerves outside the cranial cavity, we present one such case of hypoglossal nerve paraganglioma in neck.Case report: A 48 years old male presented with 1-month history of right sided stroke and aphasia. Ultrasonography of neck revealed a highly vascular mass on the right side of the neck. CT angiogram confirmed a highly vascular mass arising above the carotid bifurcation. With the working diagnosis of Glomus tumor, he underwent right sided neck exploration, however, intra-operatively tumor was found to be arising from the hypoglossal nerve instead. Surgery was abandoned on basis of the available literature, with only 6 reported cases in the past 54 years. Patient had no immediate post op complications and was sent for cyber knife treatment. After completion of 5 cycles of cyber knife there was a total of 45% reduction in the size of the paraganglioma with the resolution of the patient\u27s symptoms after a follow up of 6 months.Conclusion: Hypoglossal nerve paraganglioma is an uncommon tumor of the neck and can be misdiagnosed with the other tumors in this region especially chemodectoma and glomus tumor. The diagnostic criteria and appropriate treatment modalities have not been established due to the rare presentation hence hypoglossal paraganliomas should be kept in mind when Highly vascular neck mass is encountered

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

An Artificial-Neural-network Method for the Identification of Saturated Turbogenerator Parameters Based on a Coupled Finite-element/State-space Computational Algorithm

An artificial neural network (ANN) is used in the identification of saturated synchronous machine parameters under diverse operating conditions. The training data base for the ANN is generated by a time-stepping coupled finite-element/state-space (CFE-SS) modeling technique which is used in the computation of the saturated parameters of a 20-kV, 733-MVA, 0.85 PF (lagging) turbogenerator at discrete load points in the P-Q capability plane for three different levels of terminal voltage. These computed parameters constitute a learning data base for a multilayer ANN structure which is successfully trained using the backpropagation algorithm. Results indicate that the trained ANN can identify saturated machine-reactances for arbitrary load points in the P-Q plane with an error less than 2% of those values obtained directly from the CFE-SS algorithm. Thus, significant savings in computational time are obtained in such parameter computation tasks

Coupled Finite-element/State-space Modeling of Turbogenerators in the ABC Frame of Reference--the Short-circuit and Load Cases Including Aaturated Parameters

In this paper, a coupled finite-element/state space modeling technique is applied in the determination of the steady-state parameters of a 733 MVA turbogenerator in the abc frame of reference. In this modeling environment, the forward rotor stepping-finite element procedure described in a companion paper is used to obtain the various machine self and mutual inductances under short-circuit and load conditions. A fourth-order state-space model of the armature and field winding flux linkages in the abc frame of reference is then used to obtain the next set of flux linkages and forcing function currents for the finite-element model. In this process, one iterates between the finite-element and state-space techniques until the terminal conditions converge to specified values. This method is applied to the determination of the short-circuit, and reduced- and rated-voltage load characteristics, and the corresponding machine inductances. The spatial harmonics of these inductances are analyzed via Fourier analysis to reveal the impact of machine geometry and stator-to-rotor relative motion, winding layout, magnetic saturation, and other effects. In the full-load infinite-bus case, it is found that, while the three-phase terminal voltages are pure sinusoidal waveforms, the steady-state armature phase currents are nonsinusoidal and contain a substantial amount of odd harmonics which cannot be obtained using the traditional two-axis analysis

Coupled Finite-element/State-space Modeling of Turbogenerators in the ABC Frame of Reference-the No-load Case

This first of two companion papers centers on applying a coupled finite-element/state-space technique to the determination of self and mutual winding inductances of a 733 MVA turbogenerator and computing its open-circuit characteristic, in the natural abc frame of reference. In this method, the apparent self and mutual inductance profiles of the armature and field windings, expressed as functions of rotor position angle, are computed from a series of magnetic field solutions performed at uniformly-distributed samples of rotor positions covering the entire 360/spl deg/ electrical cycle, using the energy perturbation method. These inductances, which are obtained at no-load for three different excitation levels, include the full effect of space harmonics introduced by the magnetic circuit geometry, winding layouts and magnetic circuit saturation. The abc-frame/finite-element computed open-circuit characteristic is in excellent agreement with the test results. This computed no-load set of parameters forms the initial data for simulation of the full-load performance given in the companion paper, including the full impact of space harmonics and saturation on the flux linkage, current and voltage waveforms, and other performance parameters

Predictors of early postoperative voiding dysfunction and other complications following a midurethral sling.

BACKGROUND: The rates reported for postoperative urinary retention following midurethral sling procedures are highly variable. Determining which patients have a higher likelihood of failing a voiding trial will help with preoperative counseling prior to a midurethral sling. OBJECTIVE: The objective of the study was to identify preoperative predictors for failed voiding trial following an isolated midurethral sling. STUDY DESIGN: A retrospective, multicenter, case-control study was performed by including all isolated midurethral sling procedures performed between Jan. 1, 2010 to June 30, 2015, at 6 academic centers. We collected demographics, medical and surgical histories, voiding symptoms, urodynamic evaluation, and intraoperative data from the medical record. We excluded patients not eligible for attempted voiding trial after surgery (eg, bladder perforation requiring catheterization). Cases failed a postoperative voiding trial and were discharged with an indwelling catheter or taught intermittent self-catheterization; controls passed a voiding trial. We also recorded any adverse events such as urinary tract infection or voiding dysfunction up to 6 weeks after surgery. Bivariate analyses were completed using Mann-Whitney and Pearson χ RESULTS: A total of 464 patients had an isolated sling (70.9% retropubic, 28.4% transobturator, 0.6% single incision); 101 (21.8%) failed the initial voiding trial. At follow-up visits, 90.4% passed a second voiding trial, and 38.5% of the remainder passed on the third attempt. For the bivariate analyses, prior prolapse or incontinence surgery was similar in cases vs controls (31% vs 28%, P = .610) as were age, race, body mass index, and operative time. Significantly more of the cases (32%) than controls (22%) had a Charlson comorbidity index score of 1 or greater (P = .039). Overactive bladder symptoms of urgency, frequency, and urgency incontinence were similar in both groups as was detrusor overactivity in those with a urodynamic evaluation (29% vs 22%, P = .136), but nocturia was reported more in the cases (50% vs 38%, P = .046). Mean (SD) bladder capacity was similar in both groups (406 [148] mL vs 388 [122] mL, P = .542) as was maximum flow rate with uroflowmetry and pressure flow studies. Cases were significantly more likely to have a voiding type other than detrusor contraction: 37% vs 25%, P = .027, odds ratio, 1.79 (95% confidence interval, 1.07-3.00). There was no difference in voiding trial failures between retropubic and transobturator routes (23.1% vs 18.9%, P = .329). Within 6 weeks of surgery, the frequency of urinary tract infection in cases was greater than controls (20% vs 6%, P \u3c .001; odds ratio, 3.51 [95% confidence interval, 1.82-6.75]). After passing a repeat voiding trial, cases were more likely to present with acute urinary retention (10% vs 3%, P = .003; odds ratio, 4.00 [95% confidence interval, 1.61-9.92]). For multivariable analyses, increasing Charlson comorbidity index increased the risk of a voiding trial failure; apart from this, we did not identify other demographic information among the patients who did not undergo urodynamic evaluation that reliably forecasted a voiding trial failure. CONCLUSION: The majority of women will pass a voiding trial on the first attempt after an isolated midurethral sling. Current medical comorbidities are predictive of a voiding trial failure, whereas other demographic/examination findings are not. Patients failing the initial voiding trial are at an increased risk of postoperative urinary tract infection or developing acute retention after passing a subsequent voiding trial

Social networking and Internet use among pelvic floor patients: a multicenter survey.

BACKGROUND: Internet resources are becoming increasingly important for patients seeking medical knowledge. It is imperative to understand patient use and preferences for using the Internet and social networking websites to optimize patient education. OBJECTIVES: The purpose of this study was to evaluate social networking and Internet use among women with pelvic floor complaints to seek information for their conditions as well as describe the likelihood, preferences, and predictors of website usage. STUDY DESIGN: This was a cross-sectional, multicenter study of women presenting to clinical practices of 10 female pelvic medicine and reconstructive surgery fellowship programs across the United States, affiliated with the Fellows\u27 Pelvic Research Network. New female patients presenting with pelvic floor complaints, including urinary incontinence, pelvic organ prolapse, and fecal incontinence were eligible. Participants completed a 24 item questionnaire designed by the authors to assess demographic information, general Internet use, preferences regarding social networking websites, referral patterns, and resources utilized to learn about their pelvic floor complaints. Internet use was quantified as high (≥4 times/wk), moderate (2-3 times/wk), or minimal (≤1 time/wk). Means were used for normally distributed data and medians for data not meeting this assumption. Fisher\u27s exact and χ 2 tests were used to evaluate the associations between variables and Internet use. RESULTS: A total of 282 surveys were analyzed. The majority of participants, 83.3%, were white. The mean age was 55.8 years old. Referrals to urogynecology practices were most frequently from obstetrician/gynecologists (39.9%) and primary care providers (27.8%). Subjects were well distributed geographically, with the largest representation from the South (38.0%). Almost one third (29.9%) were most bothered by prolapse complaints, 22.0% by urgency urinary incontinence, 20.9% by stress urinary incontinence, 14.9% by urgency/frequency symptoms, and 4.1% by fecal incontinence. The majority, 75.0%, described high Internet use, whereas 8.5% moderately and 4.8% minimally used the Internet. Women most often used the Internet for personal motivations including medical research (76.4%), and 42.6% reported Google to be their primary search engine. Despite this, only 4.9% primarily used the Internet to learn about their pelvic floor condition, more commonly consulting an obstetrician-gynecologist for this information (39.4%). The majority (74.1%) held a social networking account, and 45.9% visited these daily. Nearly half, 41.7%, expressed the desire to use social networking websites to learn about their condition. Women(83.4% vs 68.8%, P = .018) and to desire using social networking websites to learn about their pelvic floor complaint (P = .008). The presenting complaint was not associated with Internet use (P = .905) or the desire to use social networking websites to learn about pelvic floor disorders (P = .201). CONCLUSION: Women presenting to urogynecology practices have high Internet use and a desire to learn about their conditions via social networking websites. Despite this, obstetrician-gynecologists remain a common resource for information. Nonetheless, urogynecology practices and national organizations would likely benefit from increasing their Internet resources for patient education in pelvic floor disorders, though patients should be made aware of available resources