Application of projection-based interpolation algorithm for non-stationary problem

In this paper we present a solver for non-stationary problems using L2 projection and h-adaptations. The solver utilizes the Euler time integration scheme for time evolution mixed with the projection based interpolation techniques for solving the L2 projections problem at every time step. The solver is tested on the model problem of the heat transfer in L-shape domain. We show that our solver delivers linear computational cost at every time step

Alternating directions parallel hybrid memory iGRM direct solver for non-stationary simulations

The three-dimensional isogeometric analysis (IGA-FEM) is a modern method for simulation. The idea is to utilize B-splines or NURBS basis functions for both computational domain descriptions and the engineering computations. Refined isogeometric analysis (rIGA) employs a mixture of patches of elements with B-spline basis functions, and $C^0$ separators between them. It enables a reduction of the computational cost of direct solvers. Both IGA and rIGA come with challenging sparse matrix structure, that is expensive to generate. In this paper, we show a hybrid parallelization method to reduce the computational cost of the integration phase using hybrid-memory parallel machines. The two-level parallelization includes the partitioning of the computational mesh into sub-domains on the first level (MPI), and loop parallelization on the second level (OpenMP). We show that hybrid parallelization of the integration reduces the contribution of this phase significantly. Thus, alternative algorithms for fast isogeometric integration are not necessary

Parallel Fast Isogeometric Solvers for Explicit Dynamics

This paper presents a parallel implementation of the fast isogeometric solvers for explicit dynamics for solving non-stationary time-dependent problems. The algorithm is described in pseudo-code. We present theoretical estimates of the computational and communication complexities for a single time step of the parallel algorithm. The computational complexity is O(p^6 N/c t_comp) and communication complexity is O(N/(c^(2/3)t_comm) where p denotes the polynomial order of B-spline basis with Cp-1 global continuity, N denotes the number of elements and c is number of processors forming a cube, t_comp refers to the execution time of a single operation, and t_comm refers to the time of sending a single datum. We compare theoretical estimates with numerical experiments performed on the LONESTAR Linux cluster from Texas Advanced Computing Center, using 1 000 processors. We apply the method to solve nonlinear flows in highly heterogeneous porous media

Vacuum – assisted closure in neurosurgery as treatment option for purulent wounds after spinal implants procedures – short preliminary report

We present a short preliminary report about the use of vacuum - assisted closure in infected and purulent wounds treatment after neurosurgical spinal procedures. Our report is based on the currently treated patients and points out to other neurosurgeons this therapeutic possibility. We are currently treating two severely injured patients in bad functional state. These patients had severe spine injuries and were therefore treated surgically by decompression and fusion. Patient No. 1 had C5 burst fracture treated by anterior and posterior stabilization, while patient No. 2 had Th4 burst fracture treated with posterior transpedicular stabilization. The patients developed purulent surgical site infection. Revision and wounds irrigation were ineffective. Desire to leave titanium implants in patient’s spines (which is important for future rehabilitation), it was decided to use V.A.C® in wounds healing. We find that vacuum - assisted closure appears to be of significant benefit in such treatment. It is a good therapeutic option in the management of such patients; however, this issue requires more extensive research in the future

Relationship between fiscal instruments and investments of industrial SMEs and LEs in Poland

The authors used statistical tools to analyze the relationship of fiscal support instruments and the level of the investment of industrial micro, small, and medium–sized enterprises in comparison to large companies in Poland in the years 2006–2014. The results revealed that there is a significant relationship between the level of investment in micro–, small–, and medium–sized enterprises and the majority of tax instruments. There is a negative relationship between the instruments and some of other factors that should influence on the investments of enterprises

Simultaneous occurrence of C5 vertebral angioma and C5-C6 discopathy and stenosis - case report

Introduction. Vertebral angioma is a benign tumor of blood vessels. Since they usually do not cause any pain, they are usually diagnosed by accident while diagnosing other conditions within the spine. In case when pain occurs and persists or even intensifies a vertebroplasty should be performed. Case presentation. A 50-year-old patient admitted to the Neurosurgery Department for surgical treatment of C5 vertebral angioma and C5-C6 stenosis and discopathy. In physical examinations on admission: general condition good, back pain at the lower part of the cervical spine, neck pain radiating to the left upper limb, no sensory disturbance. Based on the clinical symptoms and the MRI image, the patient was qualified for simultaneous surgical decompression of C5-C6 stenosis and C5 vertebroplasty. Because of the C5 vertebral angioma shown in MRI, administration of PMMA was performed in a first step, for vascular coagulation and restoration of C5 vertebral strength, and a discectomy with decompression and implantation of cage at C5-C6 level in a second step. After the surgery the patient's condition improved, pain ailments regressed. Conclusion. The decision and choice of vertebral angiomas treatment must be based both on the clinical symptoms and the MRI image. In case of surgical management of simultaneous occurrence of vertebral angioma and discopathy and stenosis, vertebroplasty should be performed first, followed by decompression and cage implantation

Pityriasis lichenoides-like secondary syphilis and neurosyphilis in a HIV-infected patient

Papulo- and vesiculo-necrotic lesions are rare manifestations of secondary syphilis. Until now it has been described only in HIV-infected patients with advanced stages of immunosuppression. This case report describes an unusual case of PLEVA-like syphilis in a 33-year-old man with newly diagnosed HIV infection. Despite that the CD4 cells level and viral load did not indicate the advance stage of immunosuppression, the unusual manifestation of syphilis and neurosyphilis occurred. The presented case indicates the need for HIV screening in every patient with syphilis especially when the clinical manifestation is unusual. Importance of syphilis testing in every case with atypical rashes should be also highlighted

Microvessels in tumor tissue in patients with central nervous system tumors

Angiogenesis plays an essential role in the development of a tumor. The most preferred histological evaluation method of this process is the determination of microvessel density (MVD) in the biopsy. Numerous studies report the possibility of using various MRI techniques for imaging the network of neoplastic vessels and determining the angiogenesis in them, as well as the subsequent analysis of the obtained images. In this study, a classic MRI imaging with intravenous contrast agent administration was used, and in order to ensure objectification and repeatability, and to eliminate human error that may occur in classic MRI image analysis, an automatic evaluation algorithm was used to determine the degree of angiogenesis, which was then presented in the form of a statistical pixels analysis. The study involved 48 adult patients of both sexes, treated surgically at the Department of Neurosurgery, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, due to a solid brain tumor. The highest mean density of MVD microvessels in tumor tissue was observed in high-grade gliomas. The high level of MVD expression in tumors of the central nervous system showed a positive correlation with the high degree of tumor malignancy. Based on the conducted research, it was concluded that the determination of the level of MVD expression in the tumor tissue is an additional prognostic factor in neoplasms of the central nervous system. The comparison of the results obtained with the tests performed routinely translates into a more accurate selection of treatment and assessment of the prognosis for survival

Relationships between macroeconomics indicators and investments of enterprises : evidence from Poland

PURPOSE: The paper aims to analyze the impact of macroeconomics factors, including their delay on investments of enterprises in Poland in the years 2005-2018.DESIGN/METHODOLOGY/APPROACH: The authors use statistical analysis to verify the hypotheses. First, the test of KPSS was done to check the stationarity of the variables. The next step was to calculate coefficients of linear correlation of Pearson between two subgroups of variables. After that, the causality of Granger was done.FINDINGS: There is a relationship between actual investment spending of enterprises and the value of economic growth and its components but only in some cases. Moreover, past investments have a negative impact on investment spending of medium and large-sized companies. However, there is no evidence that inventory investments influence the investment spending of enterprises, and fiscal preferences positively impact on changes in the value of actual investment spending of companies.PRACTICAL IMPLICATIONS: The findings could change the rules of preparing predictions for investment spending in Poland. Furthermore, it may affect the changes in fiscal preferences.ORIGINALITY/VALUE: The paper contributes to the macroeconomics theory in the area of economic growth. Furthermore, it also makes insights into the theory of incentives, particularly in fiscal preferences.peer-reviewe

Extensive ossifications of falx cerebri – literature review based on own experience and case report

Extensive ossification of the falx cerebri occur rarely however are described in the world literature references. Ossifications may concern both cerebral falx and other dural structures: tentorium. They are most often incidental findings and occurrence frequency in the population is remains unclear. The authors of the study are reviewing references on this subject, based on a case of extensive falx ossification. Manuscript describes the case of incidental detected of extensive calcification of the anterior brain sickle in a patient after head injury. Computed tomography revealed no pathology, but extensive ossification of falx was described. The patient did not complain of any significant complaints or neurological symptoms. The described calcification constituted a median and sagittal bone or calcium plate separating the frontal lobes of the brain. Analyzing references did not identify such extensive ossification of falx cerebri in human, however dural ossifications are reported in the references