Hierarchical Stochastic Block Model for Community Detection in Multiplex Networks

Multiplex networks have become increasingly more prevalent in many fields, and have emerged as a powerful tool for modeling the complexity of real networks. There is a critical need for developing inference models for multiplex networks that can take into account potential dependencies across different layers, particularly when the aim is community detection. We add to a limited literature by proposing a novel and efficient Bayesian model for community detection in multiplex networks. A key feature of our approach is the ability to model varying communities at different network layers. In contrast, many existing models assume the same communities for all layers. Moreover, our model automatically picks up the necessary number of communities at each layer (as validated by real data examples). This is appealing, since deciding the number of communities is a challenging aspect of community detection, and especially so in the multiplex setting, if one allows the communities to change across layers. Borrowing ideas from hierarchical Bayesian modeling, we use a hierarchical Dirichlet prior to model community labels across layers, allowing dependency in their structure. Given the community labels, a stochastic block model (SBM) is assumed for each layer. We develop an efficient slice sampler for sampling the posterior distribution of the community labels as well as the link probabilities between communities. In doing so, we address some unique challenges posed by coupling the complex likelihood of SBM with the hierarchical nature of the prior on the labels. An extensive empirical validation is performed on simulated and real data, demonstrating the superior performance of the model over single-layer alternatives, as well as the ability to uncover interesting structures in real networks

Editorial: Remodeling Composition and Function of Microbiome by Dietary Strategies - Functional Foods Perspective

Microbes inhabiting the human gastrointestinal tract have been under the spotlight during the last decade, given the multiple associations detected between specific microbiota profiles and health status. Diet is widely recognized as the primary environmental variable shaping the intestinal microbiota in humans. Therefore, the study of diet-microbiota-host interactions deserves special attention to provide clues to several diseases, including cognitive, metabolic, and immune ones. In a similar manner, the investigation of the molecular cross-talk between host cells and microbes in a particular nutritional environment also serves as the foundation for design of innovative therapeutic strategies based on probiotics, prebiotics, and synbiotics. For instance, a recent investigation based on resistant starch suggests that discrete dietary fiber structures can be used to target the production of short-chain fatty acids (1), the major microbiota-derived effector molecules known to have a wide range of action on host health (2). On the other hand, the gut microbiota has been disclosed to modulate the effect of dietary fiber on host health, supporting the notion that there is no one-fits-all diet in the way to seek cost-effective nutritional strategies for health improvement and weight control (3). Anyhow, consensual benefits for human health in microbiota-targeted dietary interventions are still perceived, pointing out, for instance, fermented foods as attenuators of inflammation, and modulators of gut microbiota (4). The aim of the Frontiers in Nutrition Research Topic (RT) “Remodeling Composition and Function of Microbiome by Dietary Strategies—Functional Foods Perspective” was to assemble clinical and pre-clinical studies deciphering the microbiome-driven effects on human health of innovative functional foods based on probiotics, prebiotics or synbiotics, as well as dietary supplements. We provide an overview of this RT, including five original research articles and two review articles

Atomic Properties of Lu+^+

Singly ionised Lutetium has recently been suggested as a potential clock candidate. Here we report a joint experimental and theoretical investigation of \ce{Lu^+}. Measurements relevant to practical clock operation are made and compared to atomic structure calculations. Calculations of scalar and tensor polarizabilities for clock states over a range of wavelengths are also given. These results will be useful for future work with this clock candidate.Comment: 12 pages, 5 figure

Charge Symmetry Breaking in 500 MeV Nucleon-Trinucleon Scattering

Elastic nucleon scattering from the 3He and 3H mirror nuclei is examined as a test of charge symmetry violation. The differential cross-sections are calculated at 500 MeV using a microsopic, momentum-space optical potential including the full coupling of two spin 1/2 particles and an exact treatment of the Coulomb force. The charge-symmetry-breaking effects investigated arise from a violation within the nuclear structure, from the p-nucleus Coulomb force, and from the mass-differences of the charge symmetric states. Measurements likely to reveal reliable information are noted.Comment: 5 page

Uso de progesterona y sales de estradiol para mejorar la eficiencia reproductiva de vacas con cría

El objetivo del trabajo fue evaluar la eficiencia reproductiva de un rodeo de vacas con cría ante la administración de un dispositivo intravaginal con 1 g de progesterona (DISP) más una inyección de benzoato de estradiol (BE) combinado o no con la administración de cipionato de estradiol (CPE) al retirar el DISP. Se utilizaron 196 vacas Angus negro de primera parición (condición corporal: 2 a 2,5 – escala 1 a 5), post parto ≥ a 90 días y mayoritariamente en anestro. Las vacas fueron divididas al azar para recibir tres tratamientos: 1) Grupo BEDISP (n=65): el día 0 recibieron un DISP más 2 mg de BE permaneciendo colocado 8 días. 2) Grupo BEDISPCPE (n=65): ídem al grupo BEDISP sumando una inyección de CPE (1 mg) al retirar el DISP. 3) Grupo control (n=66): no recibieron tratamiento hormonal. El servicio comenzó el día 8, utilizando un 4% de toros Angus (duración: 90 días). El diagnóstico de gestación se realizó por ultrasonografía, a los 59 días de retirado los DISP para determinar el porcentaje de preñez en los primeros 21 días de servicio y a los 50 días del retiro de los toros para determinar la preñez final. Se evaluaron los efectos de los tratamientos sobre el porcentaje de preñez en 21 días de servicio, final y distribución de la preñez. El grupo BEDISPCPE tuvo el mayor porcentaje de preñez en los primeros 21 días de servicio (BEDISP: 36,9%, BEDISPCPE: 53,8% y control: 36,4%, p<0,05), no difiriendo la preñez final (91,3%; p>0,05); además tuvo el mayor porcentaje de preñez cabeza. Se concluye que el uso de un DISP combinado con una inyección de BE al momento de colocarlo y una de CPE al momento de retirarlo, mejoran la eficiencia reproductiva de vacas con cría que están mayoritariamente en anestro

Impact of the COVID-19 pandemic on emergency department CT for suspected diverticulitis: A natural experiment to explain patients’ and clinicians’ assessment of risk and willingness to undergo CT scanning? [preprint]

Purpose: This study examined the impact of the COVID-19 pandemic on emergency department CT use for acute non-traumatic abdominal pain, to better understand why imaging volume so drastically decreased during the COVID-19 pandemic. Methods: This was a retrospective review of emergency imaging volumes from January 5 to May 30, 2020. Weekly volume data were collected for total imaging studies, abdominopelvic CT, and abdominopelvic CTs positive for common causes of acute non-traumatic abdominal pain. Two emergency radiology attendings scored all diverticulitis cases independently and weekly volume data for uncomplicated and complicated diverticulitis cases was also collected. Volume data prior to and during the COVID-19 pandemic was compared, using 2019 volumes as a control. Results: During the COVID-19 pandemic, overall emergency imaging volume decreased 30% compared to 2019 (p = 0.002). While the number of emergency abdominopelvic CTs positive for appendicitis and small bowel obstruction did not significantly change during the COVID-19 pandemic, the number of cases of diverticulitis decreased significantly compared to 2019 (p = 0.001). This reduction can be specifically attributed to decreased uncomplicated diverticulitis cases, as the number of uncomplicated diverticulitis cases dropped significantly (p = 0.002) while there was no significant difference in the number of complicated diverticulitis cases (p = 0.09). Conclusions: Reduced emergency abdominopelvic CT volume during the COVID-19 pandemic can partially be explained by decreased imaging of lower acuity patients. This data may help formulate future strategies for imaging resource utilization with an improved understanding of the relationship between perceived imaging risk and symptom acuity