Discrete modelling of capillary mechanisms in multi-phase granular media

A numerical study of multi-phase granular materials based upon micro-mechanical modelling is proposed. Discrete element simulations are used to investigate capillary induced effects on the friction properties of a granular assembly in the pendular regime. Capillary forces are described at the local scale through the Young-Laplace equation and are superimposed to the standard dry particle interaction usually well simulated through an elastic-plastic relationship. Both effects of the pressure difference between liquid and gas phases and of the surface tension at the interface are integrated into the interaction model. Hydraulic hysteresis is accounted for based on the possible mechanism of formation and breakage of capillary menisci at contacts. In order to upscale the interparticular model, triaxial loading paths are simulated on a granular assembly and the results interpreted through the Mohr-Coulomb criterion. The micro-mechanical approach is validated with a capillary cohesion induced at the macroscopic scale. It is shown that interparticular menisci contribute to the soil resistance by increasing normal forces at contacts. In addition, more than the capillary pressure level or the degree of saturation, our findings highlight the importance of the density number of liquid bonds on the overall behaviour of the material

Separate and concentrate: accounting for patient complexity in general hospitals

Scholars have recently suggested the reorganization of general hospitals into organizationally separate divisions for routine and non-routine services to overcome operational misalignments between the two types of services. We provide empirical evidence for this proposal from a quality perspective, using over 250,000 patient discharge records from 60 German hospitals across 39 high-mortality disease segments, and focusing on in-hospital mortality as outcome. Disentangling the effects of high absolute and relative hospital volumes in a disease group, our analysis suggests that both routine and complex patients would benefit from a hospital organization with a multi-specialty hub for emergency and non-routine elective services at its core, complemented by organizationally separate disease-focused hospitals-within-hospitals for routine services. We also provide evidence that the hub hospital can further improve service quality for complex patients by adopting a disease-based rather than medical specialty-based departmental routing strategy for newly arriving patients. A counterfactual analysis, based on a simultaneous equations probit model that controls simultaneously for endogeneity of volume, focus, and routing strategy, suggests that the proposed reorganization could have reduced mortality in the sample by 13.43% (95% CI [6.87%; 18.95%]) for routine patients and by 11.67% (95% CI [6.13%; 16.86%]) for the most complex patients

Impact of cooperative learning strategies upon mathematics achievement: An application of STAD in seventh grade mathematics

Cooperation is a key to success today in our work and personal relationships as adults, yet the traditional classroom, that prepares children for adulthood, has been found to be more competitive than cooperative (Johnson & Johnson, 1975). Traditionally, students have spent their day working individually or receiving instruction in large groups through lecture or class discussion with students being expected to outperform or compete with their peers (Johnson & Johnson, 1975). It has been estimated that over 85 percent of the instruction in schools consists of lectures, seat work, or competition, where students are isolated from one another (Johnson, Johnson, Holubec, & Roy, 1984)

Pain, Physical and Social Functioning, and Quality of Life in Individuals with Multiple Hereditary Exostoses in the Netherlands

Background: This study aimed to assess pain and quality of life in a large cohort of patients with multiple hereditary exostoses. Methods: All 322 known patients with multiple hereditary exostoses in the Netherlands were asked to participate. An age-specific questionnaire was sent to children (less than eighteen years old) and adults. The questionnaire focused on pain, daily activities, and school and/or professional situation. Adults also filled out the RAND-36 questionnaire.Results were statistically analyzed with use of the SPSS 15.0 software and with the chi-square test and multiple logistic regression. A p value of <0.05 was regarded as significant. Results: Two hundred and eighty-three patients (88%), including 184 adults (65%) and ninety-nine children (35%), completed the questionnaire. Multiple hereditary exostoses resulted in various physical and social consequences. The majority of adults (119) were employed; however, thirty-three (28%) had changed jobs because of the symptoms of multiple hereditary exostoses and twenty-five (21%) required adjustments in their working environment. Of the sixty-five adults who were not employed, thirteen were medically unfit to work. Of eighty-five children attending school, forty-five (53%) experienced problems at school. The symptoms of multiple hereditary exostoses caused twenty-seven children (27%) and eighty-five adults (46%) to stop participating in sporting activities. Pain was the greatest problem, with sixty-two children (63%) and 152 adults (83%) who reported recent pain. On multivariate analysis, pain in adults was correlated most significantly with age and problems at work, and pain in children was correlated with the perception of the disease and problems at school. Adult patients with multiple hereditary exostoses had a lower quality of life than the Dutch reference groups, with lower scores on six of eight RAND-36 subscales. Conclusions: Our study confirms that multiple hereditary exostoses is a chronic disease causing a profound impact on quality of life. The results suggest that pain is not the only problem associated with multiple hereditary exostoses, as it has an extensive influence on daily activities, as well as on social and psychological well-being, causing significant disability

Plasma-enhanced chemical vapor deposition of thick silicon nitride films with low stress on InP

We have developed a low-temperature plasma-enhanced chemical vapor deposition process that facilitates the deposition of silicon nitride films with controlled stress by using periodically alternating high- and low-frequency power sources. Very thick films of 3 mu m with low stress were deposited on InP substrates. Suitable sidewall profiles for metallization are obtained at 250 degrees C deposition temperature. A 3- mu m-thick low-stress nitride film was successfully applied to reduce the capacitance of bond pad for an array of four InP based photodetectors, that were integrated with a four channel phased-array wavelength demultiplexer. The capacitance of the detectors was below 0.5 pF at -5 V bia

A methodology for setting practice criteria in healthcare

Practice criteria are an important part of health care and have taken a new prominence in the trend to address quality-of-care issues. Once an organisation makes a commitment to addressing its quality-of- care, it must define 'quality' in operational terms. Practice criteria do just that. The organisation ensures consistent, high-quality services through the correct application of practice criteria. This paper outlines a methodology that has been used in at least three countries to date. Early indications are that it is useful for helping an organisation begin its quality improvement 'journey'.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Sampling of temporal networks: methods and biases

Temporal networks have been increasingly used to model a diversity of systems that evolve in time; for example, human contact structures over which dynamic processes such as epidemics take place. A fundamental aspect of real-life networks is that they are sampled within temporal and spatial frames. Furthermore, one might wish to subsample networks to reduce their size for better visualization or to perform computationally intensive simulations. The sampling method may affect the network structure and thus caution is necessary to generalize results based on samples. In this paper, we study four sampling strategies applied to a variety of real-life temporal networks. We quantify the biases generated by each sampling strategy on a number of relevant statistics such as link activity, temporal paths and epidemic spread. We find that some biases are common in a variety of networks and statistics, but one strategy, uniform sampling of nodes, shows improved performance in most scenarios. Given the particularities of temporal network data and the variety of network structures, we recommend that the choice of sampling methods be problem oriented to minimize the potential biases for the specific research questions on hand. Our results help researchers to better design network data collection protocols and to understand the limitations of sampled temporal network data

Probing empirical contact networks by simulation of spreading dynamics

Disease, opinions, ideas, gossip, etc. all spread on social networks. How these networks are connected (the network structure) influences the dynamics of the spreading processes. By investigating these relationships one gains understanding both of the spreading itself and the structure and function of the contact network. In this chapter, we will summarize the recent literature using simulation of spreading processes on top of empirical contact data. We will mostly focus on disease simulations on temporal proximity networks -- networks recording who is close to whom, at what time -- but also cover other types of networks and spreading processes. We analyze 29 empirical networks to illustrate the methods

An awkward fishing expedition

We report the case of a patient, among a group of five, in a small outbreak of histamine fish poisoning (HFP). The epidemic character of the ailment led us to the correct diagnosis. In this case, the diagnosis was also associated with a Kounis syndrome (KS). Literature concerning this subject is reviewed, reporting recent physiopathological data