Simultaneous Clustering and Model Selection for Multinomial Distribution: A Comparative Study

International audienceIn this paper, we study different discrete data clustering methods, which use the Model-Based Clustering (MBC) framework with the Multinomial distribution. Our study comprises several relevant issues, such as initialization, model estimation and model selection. Additionally, we propose a novel MBC method by efficiently combining the partitional and hierarchical clustering techniques. We conduct experiments on both synthetic and real data and evaluate the methods using accuracy, stability and computation time. Our study identifies appropriate strategies to be used for discrete data analysis with the MBC methods. Moreover, our proposed method is very competitive w.r.t. clustering accuracy and better w.r.t. stability and computation time

Evolutionary clustering for categorical data using parametric links among multinomial mixture models

International audienceIn this paper, we propose a novel evolutionary clustering method for temporal categorical data based on parametric links among multinomial mixture models. Besides clustering, our main goal is to interpret the evolutions of clusters over time. To this aim, first we propose the formulation of a generalized model that establishes parametric links among two multinomial mixture. Afterward, different parametric sub-models are defined in order to model typical evolutions of the clustering structure. Model selection criteria allow to select the best sub-models and thus to guess the clustering evolution.For the experiments, first we evaluate the proposed method with synthetic temporal data. Next, we apply it to analyze the annotated social media data. Results show that the proposed method is better than the state-of-the-art based on the common evaluation metrics. Additionally, it can provide interpretation about the temporal evolution of the clusters

Evaluation of Arthroscopic Repair to Pan-Labral Lesions of the Glenoid: A Retrospective Review of Patient Outcomes Over a Ten-Year Period and Matched Cohort Analysis

Introduction: Most shoulder labral tears are partial and treated with surgery, but rarely they are “panlabral” around the entire shoulder. Due to infrequency panlabral tears aren’t well understood, and thus this study compares outcomes between panlabral and more common SLAP tears. We hypothesize no difference in outcomes based on surgeon experiences. Methods: This is a retrospective cohort study of shoulder labrum repairs at Rothman Institute from 2006-2016. All patients received arthroscopic repair and were categorized to compare panlabral to SLAP tears. The primary outcome is return-to-activity rate at six months post-surgery and secondary outcomes include post-operative range of motion, strength, and identifying the incidence of this rare injury. Chart abstraction into Excel and patient phone calls/emails for return-to-activity rates will be analyzed via Independent T-tests and Chi-squared tests. Results: The panlabral tear incidence was 3.9%. Currently the primary outcome (return-to-activity rate) lacks enough panlabral patients for analysis with 140 patients (60 SLAP, 3 panlabral, 77 other) of 739 total (350 SLAP, 29 panlabral, 360 other) answering phone calls/emails. Secondary outcome analysis indicated no difference in range of motion, strength, or complications between SLAP and panlabral repairs. Discussion: Compared to existing reports of 2.4% incidence, using one of (if not) the largest cohorts we suggest the true incidence of panlabral tears is higher at 3.9%. Though primary outcome analysis is ongoing, secondary outcomes demonstrate that, as hypothesized, panlabral repairs perform as well as SLAP repairs. This may represent the highest level of evidence support yet for current treatment of this rare injury

Maternal effects on anogenital distance in a wild marmot population

Peer reviewedPublisher PD

Mfn2 downregulation in excitotoxicity causes mitochondrial dysfunction and delayed neuronal death.

Mitochondrial fusion and fission is a dynamic process critical for the maintenance of mitochondrial function and cell viability. During excitotoxicity neuronal mitochondria are fragmented, but the mechanism underlying this process is poorly understood. Here, we show that Mfn2 is the only member of the mitochondrial fusion/fission machinery whose expression is reduced in in vitro and in vivo models of excitotoxicity. Whereas in cortical primary cultures, Drp1 recruitment to mitochondria plays a primordial role in mitochondrial fragmentation in an early phase that can be reversed once the insult has ceased, Mfn2 downregulation intervenes in a delayed mitochondrial fragmentation phase that progresses even when the insult has ceased. Downregulation of Mfn2 causes mitochondrial dysfunction, altered calcium homeostasis, and enhanced Bax translocation to mitochondria, resulting in delayed neuronal death. We found that transcription factor MEF2 regulates basal Mfn2 expression in neurons and that excitotoxicity-dependent degradation of MEF2 causes Mfn2 downregulation. Thus, Mfn2 reduction is a late event in excitotoxicity and its targeting may help to reduce excitotoxic damage and increase the currently short therapeutic window in stroke

Invasive hemodynamic parameters in patients with hepatorenal syndrome.

Background: Hepatorenal syndrome (HRS), a form of kidney dysfunction frequent in cirrhotic patients, is characterized by low filling pressures and impaired kidney perfusion due to peripheral vasodilation and reduced effective circulatory volume. Cardiorenal syndrome (CRS), driven by renal venous hypertension and elevated filling pressures, is a separate cause of kidney dysfunction in cirrhotic patients. The two entities, however, have similar clinical phenotypes. To date, limited invasive hemodynamic data are available to help distinguish the primary forces behind worsened kidney function in cirrhotic patients. Objective: Our aim was to analyze invasive hemodynamic profiles and kidney outcomes in patients with cirrhosis who met criteria for HRS. Methods: We conducted a single center retrospective study among cirrhotic patients with worsening kidney function admitted for liver transplant evaluation between 2010 and 2020. All met accepted criteria for HRS and underwent concurrent right heart catheterization (RHC). Results: 127 subjects were included. 79 had right atrial pressure \u3e10 mmHg, 79 had wedge pressure \u3e15 mmHg, and 68 had both. All patients with elevated wedge pressure were switched from volume loading to diuretics resulting in significant reductions between admission and post diuresis creatinine values (2.0 [IQR 1.5-2.8] vs 1.5 [IQR 1.2-2.2]; p = 0.003). Conclusion: 62% of patients diagnosed with HRS by clinical criteria have elevated filling pressures. Improvement of renal function after diuresis suggests the presence of CRS physiology in these patients. Invasive hemodynamic data profiling can lead to meaningful change in management of cirrhotic patients with worsened kidney function, guiding appropriate therapies based on filling pressures