357 research outputs found

    Acute-on-chronic Liver Failure: MELD Score 30-day Mortality Predictability and Etiology in a Pakistani Population

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    Background: Cirrhosis is a pathological condition that ultimately leads to liver failure. Acute on chronic liver failure (ACLF) has a high short term mortality rate. Viral hepatitis is the most common cause of liver failure in our local population. We carried out this study to identity the 30-day mortality and etiology of patients presenting with ACLF using Model for End-Stage Liver Disease (MELD) score predictability. Methodology: This was a descriptive case series, conducted at Sheikh Zayed Hospital, Lahore, Pakistan from January 31, 2018 to July 30, 2018. One hundred and eighty five patients who met the inclusion criteria were enrolled using 95% confidence level and 4% margin of error. Data was entered and analyzed with SPSS version 23.0. Numerical variables including age was presented by Mean ± S.D. Categorical variables i.e. gender, etiology of acute-on-chronic liver failure and 30-day mortality were presented by frequency and percentage. Data was stratified for age, gender, duration of chronic liver disease and MELD grade to address the effect modifiers. Post-stratification chi-square test was calculated using 95% significance (p≤0.05). Results: Majority of the enrolled patients were male (74.6%) while only 25.4% of the patients were female. One hundred and thirty patients (70.3%) had underlying viral hepatitis while twelve patients (6.5%) and forty three patients (23.2%) presented with alcoholic liver disease and drug-induced ACLF, respectively. Eighty patients (43.2%) died within 30 days of admission.The 30-day mortality with respect to MELD grade was statistically significant (p<0.001) with the highest mortality noted in grade-IV and thirty five patients (43.8%) dying within 30 days of admission (p<0.001). Grade-II and III MELD scores also contributed to the 30-day mortality with twenty three patients (28.8%) and nineteen patients (23.8%) dying within 30 days of admission (p<0.001). Conclusion: MELD scores are able to accurately predict the short-term mortality in patients with ACLF and viral hepatitis was the most common etiology in our population. Early detection and use of appropriate prognostic models may alleviate mortality and morbidity in paitents with ACLF

    Vision and Learning for Deliberative Monocular Cluttered Flight

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    Cameras provide a rich source of information while being passive, cheap and lightweight for small and medium Unmanned Aerial Vehicles (UAVs). In this work we present the first implementation of receding horizon control, which is widely used in ground vehicles, with monocular vision as the only sensing mode for autonomous UAV flight in dense clutter. We make it feasible on UAVs via a number of contributions: novel coupling of perception and control via relevant and diverse, multiple interpretations of the scene around the robot, leveraging recent advances in machine learning to showcase anytime budgeted cost-sensitive feature selection, and fast non-linear regression for monocular depth prediction. We empirically demonstrate the efficacy of our novel pipeline via real world experiments of more than 2 kms through dense trees with a quadrotor built from off-the-shelf parts. Moreover our pipeline is designed to combine information from other modalities like stereo and lidar as well if available

    Geometric Reinforcement Learning For Robotic Manipulation

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    Reinforcement learning (RL) is a popular technique that allows an agent to learn by trial and error while interacting with a dynamic environment. The traditional Reinforcement Learning (RL) approach has been successful in learning and predicting Euclidean robotic manipulation skills such as positions, velocities, and forces. However, in robotics, it is common to encounter non-Euclidean data such as orientation or stiffness, and failing to account for their geometric nature can negatively impact learning accuracy and performance. In this paper, to address this challenge, we propose a novel framework for RL that leverages Riemannian geometry, which we call Geometric Reinforcement Learning (G-RL), to enable agents to learn robotic manipulation skills with non-Euclidean data. Specifically, G-RL utilizes the tangent space in two ways: a tangent space for parameterization and a local tangent space for mapping to a nonEuclidean manifold. The policy is learned in the parameterization tangent space, which remains constant throughout the training. The policy is then transferred to the local tangent space via parallel transport and projected onto the non-Euclidean manifold. The local tangent space changes over time to remain within the neighborhood of the current manifold point, reducing the approximation error. Therefore, by introducing a geometrically grounded pre- and post-processing step into the traditional RL pipeline, our G-RL framework enables several model-free algorithms designed for Euclidean space to learn from non-Euclidean data without modifications. Experimental results, obtained both in simulation and on a real robot, support our hypothesis that G-RL is more accurate and converges to a better solution than approximating non-Euclidean data.Comment: 14 pages, 14 figures, journa

    Composition and Characteristic of the Surficial Sediments in the Southern Corniche of Jeddah, Red Sea Coast

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    This work discusses the composition and characteristic of the surficial sediments in the southern corniche of Jeddah, Saudi Red Sea coast, in an attempt to infer the surficial distribution pattern of minerals and provenance of sediments. Twenty-six superficial sediments samples were collected from backreef and forereef areas and were analyzed for grain size, CaCO3 content, and mineralogy. The textural of grain size range from gravel to mud fraction. The mud-dominated substrates (<63 µm) occur generally in the back-reef area near the shoreline (sheltered area) and in the lagoon. Gravel rich-sediments are mostly found in forereef regions. The highest content of aragonite and Mg-calcite occur in the forereef area, probably because to suitability the forereef region for chemical and biochemical precipitation of these minerals. High Mg-calcite and Dolomite are low in both the regions. The pyrite occurs in lagoon; this indicates the reductive conditions in this part. However, on the contrary the percentage of carbonate minerals were low in the backreef-flat area, which could be attributed to the supply of non-carbonate terrigenous materials. The terrigenous material contains quartz, k-feldspar, plagioclase and amphibole minerals and are dominant in backreef-flat area with averages of 12.7%, 7.13%, 2.93% and 0.65%, respectively. Their abundance could be attributed to the supply of terrigenous materials by Aeolian deposits and intermittent Wadis

    Application of a new grading scale for tear ferning in non-dry eye and dry eye subjects

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    The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.clae.2014.09.007 © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Purpose: To apply the Masmali tear ferning (TF) grading scale on non-dry eye (NDE) and dry eye (DE) subjects to test the validity of the grading scale in practice, and to describe the grading scale range for NDE and DE. Method: Forty NDE subjects (20 males, 20 females) and 40 DE subjects (23 males, 17 females) ranging in age from 19 to 53 years (mean ± SD: 25.3 ± 5.5) with no other ocular disease, no contact lens wear, and not pregnant or breastfeeding were recruited. McMonnies scores were used for subject grouping. Phenol red thread (PRT) and slit-lamp test were used. A tear sample was collected from right eye, which was then dried to produce a ferning pattern, that was observed using a digital microscope, and graded. Results: Mean McMonnies, PRT and TF grade in NDE subjects were 7.1 ± 3.8, 27.4 ± 4.3 mm and 0.78 ± 0.40, respectively. Median McMonnies, PRT and TF grade in DE subjects were 16.5 ± 3.0, 9.0 ± 2.0 mm and 2.3 ± 1.48, respectively. In NDE subjects, grades 0.0–1.8 were observed (82.5% Grade 0.0–1.00). Grades 2.0–4.0 were observed in DE subjects (72.5% Grades 2.0–3.0). For all subjects, there were large correlations between TF grade and PRT (r = −0.79), PRT and McMonnies (r = −0.60), and TF and McMonnies (r = 0.73). Conclusions: The Masmali TF grading scale showed good validity in describing the TF patterns. Grades ≥2 can be classified as abnormal patterns. The TF test has the potential to be used in the clinic

    Stress monitoring using wearable sensors:a pilot study and stress-predict dataset

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    With the recent advancements in the field of wearable technologies, the opportunity to monitor stress continuously using different physiological variables has gained significant interest. The early detection of stress can help improve healthcare and minimizes the negative impact of long-term stress. This paper reports outcomes of a pilot study and associated stress-monitoring dataset, named the “Stress-Predict Dataset”, created by collecting physiological signals from healthy subjects using wrist-worn watches with a photoplethysmogram (PPG) sensor. While wearing these watches, 35 healthy volunteers underwent a series of tasks (i.e., Stroop color test, Trier Social Stress Test and Hyperventilation Provocation Test), along with a rest period in-between each task. They also answered questionnaires designed to induce stress levels compatible with daily life. The changes in the blood volume pulse (BVP) and heart rate were recorded by the watch and were labelled as occurring during stress-inducing tasks or a rest period (no stress). Additionally, respiratory rate was estimated using the BVP signal. Statistical models and personalised adaptive reference ranges were used to determine the utility of the proposed stressors and the extracted variables (heart rate and respiratory rate). The analysis showed that the interview session was the most significant stress stimulus, causing a significant variation in heart rate of 27 (77%) participants and respiratory rate of 28 (80%) participants out of 35. The outcomes of this study contribute to the understanding the role of stressors and their association with physiological response and provide a dataset to help develop new wearable solutions for more reliable, valid, and sensitive physio-logical stress monitoring

    Glyoxalase 1 copy number variation in patients with well differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET)

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    Background: The glyoxalase-1 gene (GLO1) is a hotspot for copy-number variation (CNV) in human genomes. Increased GLO1 copy-number is associated with multidrug resistance in tumour chemotherapy, but prevalence of GLO1 CNV in gastro-entero-pancreatic neuroendocrine tumours (GEP-NET) is unknown. Methods: GLO1 copy-number variation was measured in 39 patients with GEP-NET (midgut NET, n = 25; pancreatic NET, n = 14) after curative or debulking surgical treatment. Primary tumour tissue, surrounding healthy tissue and, where applicable, additional metastatic tumour tissue were analysed, using real time qPCR. Progression and survival following surgical treatment were monitored over 4.2 ± 0.5 years. Results: In the pooled GEP-NET cohort, GLO1 copy-number in healthy tissue was 2.0 in all samples but significantly increased in primary tumour tissue in 43% of patients with pancreatic NET and in 72% of patients with midgut NET, mainly driven by significantly higher GLO1 copy-number in midgut NET. In tissue from additional metastases resection (18 midgut NET and one pancreatic NET), GLO1 copy number was also increased, compared with healthy tissue; but was not significantly different compared with primary tumour tissue. During mean 3 - 5 years follow-up, 8 patients died and 16 patients showed radiological progression. In midgut NET, a high GLO1 copy-number was associated with earlier progression. In NETs with increased GLO1 copy number, there was increased Glo1 protein expression compared to non-malignant tissue. Conclusions: GLO1 copy-number was increased in a large percentage of patients with GEP-NET and correlated positively with increased Glo1 protein in tumour tissue. Analysis of GLO1 copy-number variation particularly in patients with midgut NET could be a novel prognostic marker for tumour progression

    The relationship between kidney function and body mass index before and after bariatric surgery in patients with chronic kidney disease

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    Background: Improvements in kidney function post-bariatric surgery may be related to weight loss-independent effects. Objectives: To characterize the dynamic relationship between body mass index (BMI) and estimated glomerular filtration rate (eGFR) before and after bariatric surgery in patients with chronic kidney disease (CKD). Setting: Kaiser Permanente Southern California (KPSC) health system. Methods: We conducted an observational, retrospective cohort study of patients with CKD stage 3 or higher who received bariatric surgery at the KPSC health system between 2007-2015. Bariatric surgery procedures included primary Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) procedures. Outcomes consisted of mean trajectory estimates and correlations of BMI and eGFR taken between 2 years before and 3 years after surgery. Multivariate functional mixed models were used to estimate how BMI and eGFR trajectories evolved jointly. Results: A total of 619 RYGB and 474 SG patients were included in the final analytic sample. The measurements were available before surgery for a median time of 1.9 years for SG and 1.8 years for RYGB patients. Median follow-up times after surgery were 2.8 years for both SG and RYGB patients. The mean age at the time of surgery was 58 years; 77% of patients were women; 56% of patients were non-Hispanic White; the mean BMI was 44 kg/m2; 60% of patients had diabetes mellitus; and 84% of patients had hypertension. Compared to the presurgery eGFR declines, the postsurgery declines in eGFR were 57% slower (95% credible interval [CrI], 33%-81%) for RYGB patients and 55% slower (95% CrI, 25%-75%) for SG patients. The mean correlation between BMI and eGFR was negligible at all time points. Conclusion: Though bariatric surgery slowed declines in eGFR up to 3 years after surgery, changes in eGFR tracked poorly with changes in BMI. This study provides evidence that the kidney-related benefits of bariatric surgery may be at least partly independent of weight loss. Confirming this hypothesis could lead to mechanistic insights and new treatment options for CKD
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