Metachronal propulsion of a magnetized particle-fluid suspension in a ciliated channel with heat and mass transfer

Biologically inspired pumping systems are of great interest in modern engineering since they achieve enhanced efficiency and circumvent the need for moving parts and maintenance. Industrial applications also often feature two-phase flows. In this article, motivated by these applications, the pumping of an electrically conducting particle-fluid suspension due to metachronal wave propulsion of beating cilia in a two-dimensional channel with heat and mass transfer under a transverse magnetic field is investigated theoretically. The governing equations for mass and momentum conservation for fluid- and particle-phases are formulated by ignoring the inertial forces and invoking the long wavelength approximation. The Jeffrey viscoelastic model is employed to simulate non-Newtonian characteristics. The normalized resulting differential equations are solved analytically. Symbolic software is employed to evaluate the results and simulate the influence of different parameters on flow characteristics. Results are visualized graphically with carefully selected and viable data

TEMPORALITIES IN ETHNOGRAPHIC FIELDWORK: DEALING WITH PAST AND FUTURE IN THE EUROPEAN CRISIS

The panel addresses the theme of the “familiar/strange” from the spatial and temporal perspectives as it emerges in crisisridden Europe. Many people in Europe had incorporated the expectations of economic growth and welfare as the political expression of a postWorld War II expansion of citizenship entitlements superseding violent confrontation between nations and classes. The aftermath of the 2008 financial crisis and the intensification of structural adjustment policies have resulted in an ambivalent understanding of the present experience. While some perceive it as a breakdown of political, social and economic promises and expectations, stressing the “strangeness” of the new situation, others perceive it as the continuation of past relationships that have never disappeared, stressing their “familiarity.” The latter may refer to the memories of past job loss, national humiliation, repression, corruption, etc. This panel focuses on the temporalities of the crisis. Presenters explore the modes in which the past and the future are interpreted and used in order to make sense of continuity and change, and as discursive weapons by European social actors in the wake of the crisis. Particular practices of resilience or accommodation are often justified in terms of remembrance of “familiar” past events and actions. Conversely, some forms of mobilization and social creativity stress their total rupture with past political practices and present themselves as exclusively oriented toward a future, willfully different. Often we observe this happening simultaneously. How can we understand these tensions? What structural and lived incoherencies are they pointing at? This panel also seeks to address ethnographic encounters as they select to stress one or the other of these realities. It poses reflexivity at the center of the understanding of crisis in Europe. Why do we choose to focus on the “familiar” or the “strange” aspects of people’s practices and discourses? Why do our informants and collaborators choose to underscore breakdown or continuity? Is it a matter of methodological choice on our part or of ideological positioning on theirs? Or is it, rather, the inescapable presence of historical facts? As we penetrate the spaces of crisis through the concrete ethnographic experience we are driven to embrace the logics and reasons of the people we share our lives with, for the time being. How do we need to negotiate them as we pause to analyze and explain?https://scholarworks.umass.edu/chess_panels/1001/thumbnail.jp

Intramural haematoma of the thoracic aorta: who's to be alerted the cardiologist or the cardiac surgeon?

This review article is written so as to present the pathophysiology, the symptomatology and the ways of diagnosis and treatment of a rather rare aortic disease called Intra-Mural Haematoma (IMH). Intramural haematoma is a quite uncommon but potentially lethal aortic disease that can strike as a primary occurrence in hypertensive and atherosclerotic patients to whom there is spontaneous bleeding from vasa vasorum into the aortic wall (media) or less frequently, as the evolution of a penetrating atherosclerotic ulcer (PAU). IMH displays a typical of dissection progress, and could be considered as a precursor of classic aortic dissection. IMH enfeebles the aortic wall and may progress to either outward rupture of the aorta or inward disruption of the intima layer, which ultimately results in aortic dissection. Chest and back acute penetrating pain is the most commonly noticed symptom at patients with IMH. Apart from a transesophageal echocardiography (TEE), a tomographic imaging such as a chest computed tomography (CT), a magnetic resonance (MRI) and most lately a multy detector computed tomography (MDCT) can ensure a quick and accurate diagnosis of IMH. Similar to type A and B aortic dissection, surgery is indicated at patients with type-A IMH, as well as at patients with a persistent and/or recurrent pain. For any other patient (with type-B IMH without an incessant pain and/or without complications), medical treatment is suggested, as applied in the case of aortic dissection. The outcome of IMH in ascending aorta (type A) appears favourable after immediate (emergent or urgent) surgical intervention, but according to international bibliography patients with IMH of the descending aorta (type B) show similar mortality rates to those being subjected to conservative medical or surgical treatment. Endovascular surgery and stent-graft placement is currently indicated in type B IMH

Action Without Awareness: Reaching to an Object You Do Not Remember Seeing

BACKGROUND: Previous work by our group has shown that the scaling of reach trajectories to target size is independent of obligatory awareness of that target property and that "action without awareness" can persist for up to 2000 ms of visual delay. In the present investigation we sought to determine if the ability to scale reaching trajectories to target size following a delay is related to the pre-computing of movement parameters during initial stimulus presentation or the maintenance of a sensory (i.e., visual) representation for on-demand response parameterization. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed immediate or delayed (i.e., 2000 ms) perceptual reports and reaching responses to different sized targets under non-masked and masked target conditions. For the reaching task, the limb associated with a trial (i.e., left or right) was not specified until the time of response cuing: a manipulation that prevented participants from pre-computing the effector-related parameters of their response. In terms of the immediate and delayed perceptual tasks, target size was accurately reported during non-masked trials; however, for masked trials only a chance level of accuracy was observed. For the immediate and delayed reaching tasks, movement time as well as other temporal kinematic measures (e.g., times to peak acceleration, velocity and deceleration) increased in relation to decreasing target size across non-masked and masked trials. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that speed-accuracy relations were observed regardless of whether participants were aware (i.e., non-masked trials) or unaware (i.e., masked trials) of target size. Moreover, the equivalent scaling of immediate and delayed reaches during masked trials indicates that a persistent sensory-based representation supports the unconscious and metrical scaling of memory-guided reaching

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Bacteremia and infective endocarditis in patients on hemodialysis.

The number of patients with end-stage renal disease (ESRD) has risen dramatically over the last decade. There are 300,000 patients in the United States with ESRD who are receiving hemodialysis (HD), and the incidence is increasing at a rate of 6% to 8% per year. Bacteremia, a prerequisite for infective endocarditis (IE), occurs at a rate of 0.7 to 1.4 episodes per 100 patient-care months. Few other medical conditions, except for chemotherapy-induced neutropenia, immunosuppression, and intravenous drug abuse, are associated with higher rates of bacteremia. IE occurs in approximately 2% to 6% of patients receiving HD. The aim of this article is to review the pathogenesis, diagnosis, current therapeutic options, and determinants of prognosis of IE in patients receiving HD

Epidemiology and outcome of infective endocarditis in hemodialysis patients.

BACKGROUND: Survival in patients with infective endocarditis (IE) ranges from 4 to 50% depending on the type of organism, the type of valve involvement and the type of treatment. METHODS: We conducted a retrospective analysis of data in hemodialysis (HD) patients at our center from 1990 to 2000. Demographics, risk factors, and outcome data were extracted in the subgroup of patients with first-episode IE diagnosed primarily by echocardiography. RESULTS: A total of 2239 patients underwent HD at our center. Thirty-two (1.4%) had IE defined using the Duke Criteria. Permanent and temporary venous dialysis catheters, arteriovenous (AV) grafts, and AV fistulae were used in 19 (59%), 12 (38%), and 1 (3%) patient respectively. Mean access duration was 7.6 +/- 7.9 months. Thirty (94%) patients had positive blood cultures, with the majority having Staphylococcus aureus bacteremia. Two (7%) patients had positive echocardiographic findings but negative blood cultures due to the commencement of empiric antibiotic therapy prior to blood cultures. The mitral valve was mainly affected. Transesophageal echocardiography was performed in 23 (72%) patients and detected an intracardiac mass in all 23 patients. One-year mortality was 56.3%. A poor 1-year prognosis was associated with presenting features of low hemoglobin, elevated leukocyte count, hypoalbuminemia, severe aortic and mitral regurgitation, and annular calcification in mitral valve IE. CONCLUSION: The prevalence of IE in HD patients is 1.4%. One-year mortality was 56.3%. Close observation is required during the first year when patients with severe valvular regurgitation and hematological abnormalities have a high mortality