There is direct evidence for the spread of infectious diseases such as influenza, SARS, measles, and norovirus in locations where large groups of people gather at high densities e.g. theme parks, ...airports, etc. The mixing of susceptible and infectious individuals in these high people density man-made environments involves pedestrian movement which is generally not taken into account in modeling studies of disease dynamics. We address this problem through a multiscale model that combines pedestrian dynamics with stochastic infection spread models. The pedestrian dynamics model is utilized to generate the trajectories of motion and contacts between infected and susceptible individuals. We incorporate this information into a stochastic infection dynamics model with infection probability and contact radius as primary inputs. This generic model is applicable for several directly transmitted diseases by varying the input parameters related to infectivity and transmission mechanisms. Through this multiscale framework, we estimate the aggregate numbers and probabilities of newly infected people for different winding queue configurations. We find that the queue configuration has a significant impact on disease spread for a range of infection radii and transmission probabilities. We quantify the effectiveness of wall separators in suppressing the disease spread compared to rope separators. Further, we find that configurations with short aisles lower the infection spread when rope separators are used.
Wernicke’s encephalopathy (WE) is a severe and life-threatening illness resulting from vitamin B1 (thiamine) deficiency. The prevalence of WE has been estimated from 0.4 to 2.8%. If not treated ...properly, severe neurologic disorders such as Korsakoff psychosis and even death may occur. The classical triad of clinical symptoms (abnormal mental state, ataxia, and ophthalmoplegia) is found in only 16–33% of patients on initial examination. The originally described underlying condition of WE is alcoholism, but it accounts for about 50% of causes of WE. Nonalcoholic patients are also affected by WE and likely to present symptoms and radiological imaging findings different from patients with alcoholism, which further complicates the diagnosis of WE. Being familiar with predisposing causes, symptoms and radiological imaging findings of WE is important for radiologists and clinicians when making the diagnosis to start immediate treatment. This review discusses pathophysiologies, underlying causes, clinical symptoms, imaging findings and their mimics.
A major function of T helper (Th) 17 cells is to induce the production of factors that activate and mobilize neutrophils. Although Th17 cells have been implicated in the pathogenesis of multiple ...sclerosis (MS) and the animal model experimental autoimmune encephalomyelitis (EAE), little attention has been focused on the role of granulocytes in those disorders. We show that neutrophils, as well as monocytes, expand in the bone marrow and accumulate in the circulation before the clinical onset of EAE, in response to systemic up-regulation of granulocyte colony-stimulating factor (G-CSF) and the ELR(+) CXC chemokine CXCL1. Neutrophils comprised a relatively high percentage of leukocytes infiltrating the central nervous system (CNS) early in disease development. G-CSF receptor deficiency and CXCL1 blockade suppressed myeloid cell accumulation in the blood and ameliorated the clinical course of mice that were injected with myelin-reactive Th17 cells. In relapsing MS patients, plasma levels of CXCL5, another ELR(+) CXC chemokine, were elevated during acute lesion formation. Systemic expression of CXCL1, CXCL5, and neutrophil elastase correlated with measures of MS lesion burden and clinical disability. Based on these results, we advocate that neutrophil-related molecules be further investigated as novel biomarkers and therapeutic targets in MS.
The diagnosis of vascular lesions of the head and neck should be directed by classifying the lesions as tumors or malformations and by determining their flow characteristics. Location of the lesion ...is key when differentiating between vascular neoplasms. Ultrasonography is an appropriate screening tool; MRI is often used to confirm the diagnosis. Computed tomography can be used for further characterization of the lesion, particularly when there is bony involvement. In many cases, vascular lesions grow to be extensive. In these cases, percutaneous sclerotherapy or embolization therapy can be employed to aid in surgical resection.
The goals of our study were to evaluate dual-energy CT (DECT) differences between benign posttreatment changes and primary or recurrent head and neck malignancies in terms of spectral Hounsfield ...units for virtual monochromatic series at 40 keV and iodine concentration and compare their utility with that of spectral Hounsfield units at 70 keV.
A retrospective review of patients with a history of head and neck malignancy evaluated with DECT of the neck from November 2012 through December 2014 revealed 16 patients with benign posttreatment changes and 24 with malignancies (17 primary tumors and seven recurrent tumors). One reader placed ROIs within benign posttreatment changes or malignant tumors in each patient to generate spectral Hounsfield units at 40 keV, iodine concentration, and spectral Hounsfield units at 70 keV, and the Wilcoxon rank sum test was used to evaluate the differences between the two cohorts. ROC curves were also generated, and AUC and partial AUC were calculated at the three following specificities: 75%, 80%, and 90%.
Malignant tissues were significantly different from benign posttreatment changes in spectral Hounsfield units at 40 keV (p < 0.0001), iodine concentration (p < 0.0001), and spectral Hounsfield units at 70 keV (p = 0.0001). The AUCs were 0.949, 0.943, and 0.858 for spectral Hounsfield units at 40 keV, iodine concentration, and spectral Hounsfield units at 70 keV, respectively. Both spectral Hounsfield units at 40 keV and iodine concentration had statistically higher partial AUCs than spectral Hounsfield units at 70 keV at 90% specificity (p = 0.0133 and 0.0063, respectively) but were not significantly different from each other.
DECT-derived spectral Hounsfield units at 40 keV and iodine concentration may be superior to spectral Hounsfield units at 70 keV, which is similar to MDCT, in differentiating benign posttreatment changes from primary or recurrent head and neck malignancies.
Pedestrian dynamics models the walking movement of individuals in a crowd. It has recently been used in the analysis of procedures to reduce the risk of disease spread in airplanes, relying on the ...SPED model. This is a social force model inspired by molecular dynamics; pedestrians are treated as point particles, and their trajectories are determined in a simulation. A parameter sweep is performed to address uncertainties in human behavior, which requires a large number of simulations. The SPED model's slow speed is a bottleneck to performing a large parameter sweep. This is a severe impediment to delivering real-time results, which are often required in the course of decision meetings, especially during emergencies. We propose a new model, called CALM, to remove this limitation. It is designed to simulate a crowd's movement in constrained linear passageways, such as inside an aircraft. We show that CALM yields realistic results while improving performance by two orders of magnitude over the SPED model.
Background and Purpose
Diffuse hemispheric gliomas, H3 G34‐mutant (DHGs‐G34m), are newly recognized malignant brain tumors characterized by histone gene mutations. However, the neuroradiologic ...characteristics of these tumors require elucidation. We reviewed the demographic, clinical, and neuroradiological features of DHGs‐G34m.
Methods
Data were extracted using a database search in MEDLINE, SCOPUS, and Google Scholar in June 2021. Studies assessing pathologically proven DHGs‐G34m with each patient's information and neuroradiological findings were included. After screening and reviewing 332 s, 12 articles including 56 cases met the criteria. We also added the findings for three patients evaluated in our hospital. Two board‐certified radiologists reviewed all demographic, clinical, and neuroradiological findings of each study. One board‐certified pathologist reviewed all pathological data of each study. Kaplan–Meier analyses with log‐rank tests were performed to compare the survival between patients with different tumor margin characteristics (well‐delineated and ill‐defined).
Results
The median patient age at diagnosis was 19 years (range, 6–66 years), and 31/59 patients (52.5%) were men. Supratentorial tumors were observed in all patients (59/59, 100%). Frequent contact with leptomeninges (92.3%) and ependymal regions (87.5%) was observed. The 1‐ and 2‐year survival rates after initial surgery were 66.7% and 40.0%, respectively. DHGs‐G34m with ill‐defined and well‐delineated margins showed significant differences in survival (p = .04).
Conclusions
DHGs‐G34m occur most often in the supratentorial regions of adolescents. Prognosis varies among patients. Evaluation of tumor margins may provide prognostic value.
Differentiating pseudoprogression from true tumor progression has become a significant challenge in follow-up of diffuse infiltrating gliomas, particularly high grade, which leads to a potential ...treatment delay for patients with early glioma recurrence. In this study, we proposed to use a multiparametric MRI data as a sequence input for the convolutional neural network with the recurrent neural network based deep learning structure to discriminate between pseudoprogression and true tumor progression. In this study, 43 biopsy-proven patient data identified as diffuse infiltrating glioma patients whose disease progressed/recurred were used. The dataset consists of five original MRI sequences; pre-contrast T1-weighted, post-contrast T1-weighted, T2-weighted, FLAIR, and ADC images as well as two engineered sequences; T1post-T1pre and T2-FLAIR. Next, we used three CNN-LSTM models with a different set of sequences as input sequences to pass through CNN-LSTM layers. We performed threefold cross-validation in the training dataset and generated the boxplot, accuracy, and ROC curve, AUC from each trained model with the test dataset to evaluate models. The mean accuracy for VGG16 models ranged from 0.44 to 0.60 and the mean AUC ranged from 0.47 to 0.59. For CNN-LSTM model, the mean accuracy ranged from 0.62 to 0.75 and the mean AUC ranged from 0.64 to 0.81. The performance of the proposed CNN-LSTM with multiparametric sequence data was found to outperform the popular convolutional CNN with a single MRI sequence. In conclusion, incorporating all available MRI sequences into a sequence input for a CNN-LSTM model improved diagnostic performance for discriminating between pseudoprogression and true tumor progression.
This paper considers network supply chains with price dependent demand by modelling them as large acyclic networks. Such large networks are common in the automobile and apparel industries. We develop ...a model to analyze the effect of these large-scale problems involving long sequences of contracts, and show that contract leadership, as well as leader position in the network, affect the performance of the entire supply chain. We generalize Spengler (Spengler, J. 1950. Vertical integration and anti-trust policy. J. Political Econom. 58 347–352) to a game on a "contract tree" for a particular supply chain and extend the concept of double marginalization so that it can be applied in the form of a transformation to each contract that is offered by one member to another in the "contract tree." We construct an algorithm to find the equilibrium solution, and derive the optimal location of the leader ("optimal" being the leader location that maximizes total supply chain profits). Our work formalizes many intuitive insights; for example, member profits are determined by systemwide rather than individual costs. Finally, we model Cournot competition between competing supply chains (both two heterogeneous trees and multiple identical trees) and show the effect of changes in leader position as well as cost structure on the equilibrium.
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