Fluid theory of coherent magnetic vortices in high-beta space plasmas

In-situ observations in the Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfv\'en vortices as intermittent structures in the range of scales from fluid lengths down to few ion lengths. The density and the magnetic field associated with them appear to be compressible for higher plasma betas. Until now, only incompressible Alfv\'en vortices have been known. Motivated by space plasma observations we develop a new model of magnetic vortices in high-beta plasmas with anisotropic temperature, possessing compressible density and magnetic field, whose typical size ranges from fluid to ion scales. At magneto-fluid scales we find novel non-propagating field-aligned cylindrical monopoles and inclined propagating dipoles. Their transverse magnetic and velocity fluctuations are aligned, but not identical, {and they exhibit density and compressible magnetic field fluctuations $\delta n$ and $\delta B_\Vert$ localized inside the vortex core. In the presence of thermal anisotropy and acoustic effects, they may be correlated or anti-correlated $\delta n/\delta B_\Vert={\rm constant}\gtrless 0$; fluctuations whose velocity along the magnetic field is below the ion thermal speed are always correlated.} At ion or kinetic scales (with the smallest radii $\sim c/\omega_{pi}, \rho_{L i}$) {and in the absence of acoustic perturbations}, only dipolar Alfv\'en vortices survive with similar properties as those at fluid scales, except for their $\delta n/n_0$ that reaches the level of $\delta B_\Vert/B_0$. At kinetic scales we find also pressure balanced dipolar structures, possessing finite parallel electric field $E_\Vert$ and purely compressional magnetic field perturbation

Increased il-33 and il-17 in colorectal carcinoma patients with severe disease

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Colorectal cancer (CRC) represents one of the most common cancers. It is frequently diagnosed at advanced stages, indicating on need for new diagnostic markers. The aim of this study was to determine systemic and fecal values of IL-17 and IL-33 in patients with CRC and the relationship with clinicopathological aspects of disease. The blood samples and feces liquid fraction of 50 patients with CRC were analyzed. Serum and fecal levels of IL-33 and IL-17 were measured using sensitive enzyme-linked immu-nosorbent assay (ELISA) kits. Fecal levels of Il-33 and IL-17 were increased in CRC patients with poor tumor tissue differentiation. Serum IL-33 and fecal IL-17 were increased in patients with presence of lung/liver metastasis or peritoneal carcinomatosis, respec-tively, while enhanced fecal IL-33 was detected only in patients with peritoneal carcinomatosis. Positive correlation between IL-33 and IL-17 values in sera and feces, respectively was also observed. We believe that increased local values of IL-33 and IL-17, reflected trough higher fecal concentration, in CRC patients with poor tumor tissue differentiation and with presence of lung/liver metastasis or peritoneal carcinomatosis may be considered as a sign of the tumor’s malignant progression and, consequently, of a poor prognosis for patients

Teaching Introduction to Welding in Undergraduate and Graduate Engineering Technology Programs

Recent trends in the industry have led to an increased need for engineers with welding training. Not many universities in the U.S.A. offer welding courses at undergraduate level. Engineers that do not receive education about this complex process, sometimes they make a very costly and dangerous mistake. More profound understanding of the welding process that expands beyond the basic comprehension of technology use is needed for the advanced manufacturing sector. Welding related courses, as it involves the complex interplay of the four states of matter (solid, liquid, gas and plasma) as governed by the laws of physics, need topics such as material science, phase diagrams, phase transformation, heat treatment, and possible failure modes of welds and working with special alloys and material that are difficult to weld. This paper will present two such courses at two different universities, both offered in mechanical engineering technology programs. These courses cover various welding processes, heat flow, residual stress, design, problems, codes, standards, and most importantly metallography

Improved ACO Algorithm with Pheromone Correction Strategy for the Traveling Salesman Problem

A new, improved ant colony optimization (ACO) algorithm with novel pheromone correction strategy is introduced. It is implemented and tested on the traveling salesman problem (TSP). Algorithm modification is based on undesirability of some elements of the current best found solution. The pheromone values for highly undesirable links are significantly lowered by this a posteriori heuristic. This new hybridized algorithm with the strategy for avoiding stagnation by leaving local optima was tested on standard benchmark problems from the TSPLIB library and superiority of our method to the basic ACO and also to the particle swarm optimization (PSO) is shown. The best found solutions are improved, as well as the mean values for multiple runs. The computation cost increase for our modification is negligible

Viral Infection in Renal Transplant Recipients

Viruses are among the most common causes of opportunistic infection after transplantation. The risk for viral infection is a function of the specific virus encountered, the intensity of immune suppression used to prevent graft rejection, and other host factors governing susceptibility. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses have also affected outcomes. In some cases, preventive measures such as pretransplant screening, prophylactic antiviral therapy, or posttransplant viral monitoring may limit the impact of these infections. Recent advances in laboratory monitoring and antiviral therapy have improved outcomes. Studies of viral latency, reactivation, and the cellular effects of viral infection will provide clues for future strategies in prevention and treatment of viral infections. This paper will summarize the major viral infections seen following transplant and discuss strategies for prevention and management of these potential pathogens

Etiology and mechanisms of ulnar and median forearm nerve injuries

© 2015, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved. Bacgraund/Aim. Most often injuries of brachial plexus and its branches disable the injured from using their arms and/or hands. The aim of this study was to investigate the etiology and mechanisms of median and ulnar forearm nerves injuries. Methods. This retrospective cohort study included 99 patients surgically treated in the Clinic of Neurosurgery, Clinical Center of Serbia, from January 1st, 2000 to December 31st, 2010. All data are obtained from the patients' histories. Results. The majority of the injured patients were male, 81 (81.8%), while only 18 (18.2%) were females, both mainly with nerve injuries of the distal forearm – 75 (75.6%). Two injury mechanisms were present, transection in 85 patients and traction and contusion in 14 of the patients. The most frequent etiological factor of nerve injuries was cutting, in 61 of the patients. Nerve injuries are often associated with other injuries. In the studied patients there were 22 vascular injuries, 33 muscle and tendon injuries and 20 bone fractures. Conclusion. The majority of those patients with peripheral nerve injuries are represented in the working age population, which is a major socioeconomic problem. In our study 66 out of 99 patients were between 17 and 40 years old, in the most productive age. The fact that the majority of patients had nerve injuries of the distal forearm and that they are operated within the first 6 months after injury, promises them good functional prognosis