70 research outputs found

    Bayesian Regularized Neural Networks for Small n Big p Data

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    Artificial neural networks (ANN) mimic the function of the human brain and they have the capability to implement massively parallel computations for mapping, function approximation, classification, and pattern recognition processing. ANN can capture the highly nonlinear associations between inputs (predictors) and target (responses) variables and can adaptively learn the complex functional forms. Like other parametric and nonparametric methods, such as kernel regression and smoothing splines, ANNs can introduce overfitting (in particular with highly-dimensional data, such as genome wide association -GWAS-, microarray data etc.) and resulting predictions can be outside the range of the training data. Regularization (shrinkage) in ANN allows bias of parameter estimates towards what are considered to be probable. Most common techniques of regularizations techniques in ANN are the Bayesian regularization (BR) and the early stopping methods. Early stopping is effectively limiting the used weights in the network and thus imposes regularization, effectively lowering the Vapnik-Chervonenkis dimension. In Bayesian regularized ANN (BRANN), the regularization techniques involve imposing certain prior distributions on the model parameters and penalizes large weights in anticipation of achieving smoother mapping

    The effect of ovulatory follicle size at the time of insemination on pregnancy rate in lactating dairy cows

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    The aims of this study were to determine the factors that affect follicle size at the time of artificial insemination (AI) and to detect the relationship between ovulatory follicle size at the time of AI and pregnancy rate in dairy cows. A total of 1428 follicle size measurements were obtained from Holstein-Friesian (HF) and Swedish Red (SR) cows that were inseminated with the fixed-timed AI protocols used in this study. Follicle size was affected by breed (P - 0.0001), milk production (P - 0.01), parity (P - 0.05), and season (P = 0.04). Follicle size was greater (P = 0.0001) in the HF (15.55 mm) than the SR cows (14.88 mm). Multiparous cows had larger (P = 0.04) follicles (15.35 mm) than the primiparous cows (15.07 mm). Cows with follicle sizes between 13.5 and 17.5 mm were more likely to be pregnant than cows with other sizes follicles (P < 0.01). Embryonic loss was lower (P < 0.01) in cows with follicle sizes between 13.5 and 16.5 mm. Thus, the follicle size was affected by breed, milk production, parity, and season. Pregnancy and embryonic loss in lactating dairy cows were significantly related to follicle size

    Deep Learning for Subtyping and Prediction of Diseases: Long-Short Term Memory

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    The long short-term memory neural network (LSTM) is a type of recurrent neural network (RNN). During the training of RNN architecture, sequential information is used and travels through the neural network from input vector to the output neurons, while the error is calculated and propagated back through the network to update the network parameters. Information in these networks incorporates loops into the hidden layer. Loops allow information to flow multi-directionally so that the hidden state signifies past information held at a given time step. Consequently, the output is dependent on the previous predictions which are already known. However, RNNs have limited capacity to bridge more than a certain number of steps. Mainly this is due to the vanishing of gradients which causes the predictions to capture the short-term dependencies as information from earlier steps decays. As more layers in RNN containing activation functions are added, the gradient of the loss function approaches zero. The LSTM neural networks (LSTM-ANNs) enable learning long-term dependencies. LSTM introduces a memory unit and gate mechanism to enable capture of the long dependencies in a sequence. Therefore, LSTM networks can selectively remember or forget information and are capable of learn thousands timesteps by structures called cell states and three gates

    Use of Ultrasound-Guided Tendon Fenestration and Injection Procedures for Treatment of Tendinosis

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    Introduction. Overuse injuries such as tendinosis are a common complaint at sports medicine clinics. When conservative management for tendinosis has failed, ultrasound-guided tendon fenestration and injection procedures such as dry needling, needling tenotomy, autologous whole blood injections, and prolotherapy can be utilized for treatment. This study examined the effectiveness of these procedures for pain improvement and ability to return to activity for patients with tendinosis. Methods. This study included patients 15 years or older who underwent at least one treatment for tendinosis at a sports medicine clinic between January 1, 2014 through April 17, 2019. A CPT code query was used to screen patient charts for study inclusion. Results. In total, 680 patients’ data were reviewed, and 343 patients met inclusion criteria. Patients underwent a total of 598 unique procedures. Dry needling represented most procedures (62.8%, n=375). Most patients reported diminished pain at follow up (73.0%, n=268). Prolotherapy had the highest percentage of patients reporting diminished pain (81.0%, n=17). Most patients were able to return to activity (47.4%, n=172) at follow-up. A greater proportion of patients with autologous whole blood injection were able to return to activity (60.7%, n=85). Conclusions. Most patients with tendinosis who underwent tendon fenestration or injection procedures reported diminished pain at follow-up. Autologous whole blood injection may be more likely to diminish patient pain and allow return to activity than other procedure types. More research is needed across all anatomical sites to compare the generalized effectiveness of these procedures

    Glycemic Control and Awareness of Insulin Therapy

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    Introduction: Glycemic control is associated with better health outcomes among patients with diabetes. No previous research has examined the relationship between knowledge of one’s insulin dose and glycemic control. This study sought to determine if patients who accurately recalled their insulin dose achieved better glycemic control than patients who could not remember their dose. Methods: Interviews were conducted with 106 patients. Data were collected during patients’ appointments at two endocrinology clinics in Wichita, Kansas from May 29, 2018 to February 15, 2019. Adequate glycemic control was defined as an HbA1c of less than 7.5%.  A multiple logistic regression model was developed to identify factors associated with glycemic control.    Results: Of the 109 patients asked to participate, 105 agreed to participate in the study. About half (45%, n = 48) were male. Patients’ mean age was 50 years (SD = 17). Seventy-seven percent (n = 81) were overweight (body mass index (BMI) of 25 to 29.9) or obese (BMI &gt;30). Patients who correctly stated their insulin dose had a mean Hemoglobin A1c (HbA1c) of 6.9% (SD = 0.98), whereas those who incorrectly stated their dose had a mean HbA1c of 9.5% (SD = 1.9; p &lt;0.0001).   Conclusions: There was a significant relationship between knowledge of one’s insulin dose and adequate glycemic control

    Guideline Adherence in Dyspepsia Investigation and Treatment

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    Introduction: The impact of dyspepsia guidelines on clinical practice may be poor. Provider adherence with dyspepsia guidelines was examined to determine their impact on clinical practice. Methods: Provider adherence with the 2005 American College of Gastroenterology Guidelines for the Management of Dyspepsia and the 2017 American College of Gastroenterology and Canadian Association of Gastroenterology joint Dyspepsia Management Guidelines was assessed on a national level using data from the National Ambulatory Medical Care Survey (NAMCS). Patient visit data, including reason for visit of dyspepsia, diagnosis of dyspepsia, or diagnosis of H. pylori infection from NAMCS years 2012 through 2015, were used. Provider adherence with dyspepsia management guidelines was determined based upon provision of at least one recommended test or treatment for dyspepsia. Results: Providers appeared to adhere to the 2005 ACG guidelines for 49.7% of patient visits. Providers appeared to adhere to the 2017 ACG/CAG guidelines for 51.0% of patient visits. Conclusions: Provider adherence with the 2005 ACG and the 2017 ACG/CAG Dyspepsia Management Guidelines was determined to be low in this study, highlighting the need to increase evidence-based medical treatment and efficient resource use for dyspepsia

    Recent Evolution in the Management of Lymph Node Metastases in Melanoma

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    Introduction. Based upon two large randomized international clinical trials (German Dermatologic Cooperative Oncology Group (DeCOG-SLT) and Multicenter Selective Lymphadenectomy Trial II (MSLT-II)) which were published in 2016 and 2017, respectively, active surveillance has been demonstrated to have equivalent survival outcomes to completion lymphadenectomy (CLND) for a subset of patients who have microscopic lymph node disease. In this study, we examined the changes in national practice patterns regarding the utilization of CLND after positive sentinel lymph node biopsy (SLNB). Methods. Using the National Cancer Database, we examined CLND utilization in SLN-positive patients diagnosed with melanoma between 2012 and 2016. A hierarchal logistical regression model with hospital-level random intercepts was constructed to examine the factors associated with SLNB followed by observation vs. SLNB with CLND. Results. Of the 148,982 patients identified, 43% (n = 63,358) underwent SLNB, and 10.3% (n = 6,551) had a SLNB with microscopic disease. CLND was performed for 57% (n = 2,817) of these patients. Patients were more likely to undergo CLND if they were &lt; 55 years of age (OR, 0.687; &nbsp;p = &lt;0.0001), ages 56 - 65 (OR, 0.886; p = 0.0237), Charlson Deyo Score = 0 (OR, 0.859; p = 0.0437), or were diagnosed with melanoma in 2012 (OR, 0.794, p = &lt;0.0001). Conclusions. We found the utilization of CLND among patients with microscopic nodal melanoma to be significantly lower in 2016 compared to 2012. Younger age, lack of comorbidities, and primary tumor location on the trunk or head/neck were associated with higher utilization of CLND
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