Modeling of Chlamydomonas reinhardtii motility in confinement

Microswimmers, such as bacteria or motile algae, which typically live in water and soil encounter boundaries very frequently. A wide range of dierent microswimmers seem to spend a signicant amount of time close to such boundaries as opposed to staying in the bulk. Dierent physical mechanisms have been proposed to explain these observations, such as hydrodynamic interactions or steric forces. While hydrodynamics are able to give a good explanation for pusher-type swimmers, its predictions for puller-type swimmers do not explain the trapping at walls. Here the \wall-hugging" eect of puller-type swimmers will be explained. A simple dumbbell model for the cell's shape will be introduced to model the steric wall interactions of Chlamydomonas reinhardtii in a quasi 2d environment. Simulations of this model will be performed and compared with experimental results

The STEMI phenomenon during the COVID-19 pandemic: what is beneath the tip of the iceberg?

Keywords: COVID-19; acute coronary syndrome

Effects of the use of control systems

This research explored the moderating effects of subordinate participation in decision making and subordinate job difficulty on their responses to different uses of control systems by their superiors. In a sample of managers from a moderately large U.S. organization, both of these factors were found to moderate the ways subordinates responded to the perceptions that their superiors used control systems for goal setting, evaluation, problem solving, and contingent reward allocations.The results of the study indicated that the use of control systems for contingent reward allocation produced defensive subordinate responses under all conditions, but also produced the functional response of effort when subordinate participation was low and job difficulty high. The use for goal setting appeared to result in functional responses when subordinate participation was high, and in dysfunctional responses when participation was low. The use for evaluation and the use for problem solving both seemed to be aspects of a collaborative developmental use of the control systems. This use pattern appeared to have primarily functional effects, although the results were more functional when the subordinate jobs were not difficult, and when they participated in decision making. Based on the results several propositions are formulated for future testing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21898/1/0000305.pd

The critical properties of the agent-based model with environmental-economic interactions

The steady-state and nonequilibrium properties of the model of environmental-economic interactions are studied. The interacting heterogeneous agents are simulated on the platform of the emission dynamics of cellular automaton. The model possess the discontinuous transition between the safe and catastrophic ecology. Right at the critical line, the broad-scale power-law distributions of emission rates have been identified. Their relationship to Zipf's law and models of self-organized criticality is discussed.Comment: 12 pages, 6 figures, published in Physica

Takotsubo Syndrome: Impact of endothelial dysfunction and oxidative stress

Takotsubo Syndrome (TTS) is characterized by a transient left ventricular dysfunction recovering spontaneously within days or weeks. Although the pathophysiology of TTS remains obscure, there is growing evidence suggesting TTS to be associated with increased production of reactive oxygen species (ROS), which may be involved in causing transient coronary and peripheral endothelial dysfunction leading to a transient impairment of myocardial contraction due to stunning (apical ballooning). Endothelial dysfunction is mainly caused by decreased vascular and myocardial nitric oxide bioavailability in response to increased ROS production. Accordingly, studies in humans and animal models demonstrated increased myocardial dihydroethidium staining of the myocardium in endomyocardial biopsy specimens, increased levels of hydrogen peroxide and malondialdehyde as well as reduced glutathione levels compatible with increased oxidative stress. As significant superoxide sources the mitochondria and the NADPH oxidase isoform NOX-4 and the NOX-2 regulating cytosolic subunit p67phox have been identified. Treatment with antioxidants such as sodium hydrosulfide reduced superoxide production in mitochondria and reduced expression of NOX-4 and p67phox, respectively. The presence of superoxide and nitric oxide also provides the basis for the concept of nitro-oxidative as well as nitrosative stress in TTS

Takotsubo Syndrome: Uncovering Myths and Misconceptions

PURPOSE OF REVIEW Takotsubo syndrome (TTS) was described in Japan 3 decades ago to affect predominately postmenopausal women after emotional stress. This history is the basis of commonly held beliefs which may contribute to the underdiagnosis and misperception of TTS. RECENT FINDINGS TTS affects not only women, but can be present in both sexes, and can appear in children as well as in the elderly. TTS is characterized by unique clinical characteristics with morphological variants, and incurs a substantial risk for recurrent events and adverse outcomes. Physical triggers are more common than emotional triggers and are major disease determinants. TTS seems not to be completely transient as patients report ongoing chest pain, dyspnea, or fatigue even after months of the acute event. Knowledge of the clinical features and outcomes of TTS patients has evolved substantially over the past decades. The heterogeneous appearance of TTS needs to be recognized in all medical disciplines to maximize therapy and improve outcomes

Spontaneous Coronary Artery Dissection: A Rare Event?

Spontaneous coronary artery dissection is an infrequent cause of acute coronary syndrome with comparable clinical features. Previously considered a rare disease, recent scientific interest has revealed spontaneous coronary artery dissection as an important differential diagnosis of acute coronary syndrome, especially in young women, during pregnancy or postpartum, and in patients with fibromuscular dysplasia or other arteriopathies. However, there remain many uncertainties regarding pathophysiology, risk factors, acute treatment, and optimal long-term management. The aim of this review is to summarize current scientific evidence on epidemiology, management, and outcomes

Metabolic reprogramming upon CD8 T cell activation

Otto-von-Guericke-Universität Magdeburg, Fakultät für Naturwissenschaften, Dissertation, 2016von Dipl.-Biochem. Clemens CammannLiteraturverzeichnis: Blatt 57-6

Artificial neural network (ANN) velocity better identifies benign prostatic hyperplasia but not prostate cancer compared with PSA velocity

<p>Abstract</p> <p>Background</p> <p>To validate an artificial neural network (ANN) based on the combination of PSA velocity (PSAV) with a %free PSA-based ANN to enhance the discrimination between prostate cancer (PCa) and benign prostate hyperplasia (BPH).</p> <p>Methods</p> <p>The study comprised 199 patients with PCa (n = 49) or BPH (n = 150) with at least three PSA estimations and a minimum of three months intervals between the measurements. Patients were classified into three categories according to PSAV and ANN velocity (ANNV) calculated with the %free based ANN "ProstataClass". Group 1 includes the increasing PSA and ANN values, Group 2 the stable values, and Group 3 the decreasing values.</p> <p>Results</p> <p>71% of PCa patients typically have an increasing PSAV. In comparison, the ANNV only shows this in 45% of all PCa patients. However, BPH patients benefit from ANNV since the stable values are significantly more (83% vs. 65%) and increasing values are less frequently (11% vs. 21%) if the ANNV is used instead of the PSAV.</p> <p>Conclusion</p> <p>PSAV has only limited usefulness for the detection of PCa with only 71% increasing PSA values, while 29% of all PCa do not have the typical PSAV. The ANNV cannot improve the PCa detection rate but may save 11–17% of unnecessary prostate biopsies in known BPH patients.</p