Analysis of Tourism Service Quality in Kołobrzeg Region by Means of Time Series Models

The undertaken study shows that methods that take into account time series can be successfully used in analysis of parameters of tourist comfort and in evaluation of hotel services.Przeprowadzone badania wskazują, że metody szeregów czasowych mogą być skutecznie zastosowane w badaniu wskaźników turystycznych i ocenie jakości usług hotelarskich

Rafał Biskup, Wolność gospodarcza w wymiarze podmiotowym, Wyd. Katolickiego Uniwersytetu Lubelskiego, Lublin 2011 (ss. 553)

recenzjaUniwersytet w Białymstok

From synaptic interactions to collective dynamics in random neuronal networks models: critical role of eigenvectors and transient behavior

The study of neuronal interactions is currently at the center of several neuroscience big collaborative projects (including the Human Connectome, the Blue Brain, the Brainome, etc.) which attempt to obtain a detailed map of the entire brain matrix. Under certain constraints, mathematical theory can advance predictions of the expected neural dynamics based solely on the statistical properties of such synaptic interaction matrix. This work explores the application of free random variables (FRV) to the study of large synaptic interaction matrices. Besides recovering in a straightforward way known results on eigenspectra of neural networks, we extend them to heavy-tailed distributions of interactions. More importantly, we derive analytically the behavior of eigenvector overlaps, which determine stability of the spectra. We observe that upon imposing the neuronal excitation/inhibition balance, although the eigenvalues remain unchanged, their stability dramatically decreases due to strong non-orthogonality of associated eigenvectors. It leads us to the conclusion that the understanding of the temporal evolution of asymmetric neural networks requires considering the entangled dynamics of both eigenvectors and eigenvalues, which might bear consequences for learning and memory processes in these models. Considering the success of FRV analysis in a wide variety of branches disciplines, we hope that the results presented here foster additional application of these ideas in the area of brain sciences.Comment: 24 pages + 4 pages of refs, 8 figure

The actin cortex at a glance.

Precisely controlled cell deformations are key to cell migration, division and tissue morphogenesis, and have been implicated in cell differentiation during development, as well as cancer progression. In animal cells, shape changes are primarily driven by the cellular cortex, a thin actomyosin network that lies directly underneath the plasma membrane. Myosin-generated forces create tension in the cortical network, and gradients in tension lead to cellular deformations. Recent studies have provided important insight into the molecular control of cortical tension by progressively unveiling cortex composition and organization. In this Cell Science at a Glance article and the accompanying poster, we review our current understanding of cortex composition and architecture. We then discuss how the microscopic properties of the cortex control cortical tension. While many open questions remain, it is now clear that cortical tension can be modulated through both cortex composition and organization, providing multiple levels of regulation for this key cellular property during cell and tissue morphogenesis

Biomaterials and Stem Cells: Promising Tools in Tissue Engineering and Biomedical Applications

Biomaterial sciences and tissue engineering approaches are currently fundamental strategies for the development of regenerative medicine. Stem cells (SCs) are a unique cell type capable of self‐renewal and reconstructing damaged tissues. At the present time, adult SCs isolated from postnatal tissues are widely used in clinical applications. Their characteristics such as a multipotent differentiation capacity and immunomodulatory activity make them a promising tool to use in patients. Modern material technologies allow for the development of innovative biomaterials that closely correspond to requirements of the current biomedical application. Biomaterials, such as ceramics and metals, are already used as implants to replace or improve the functionality of the damaged tissue or organ. However, the continuous development of modern technology opens new insights of polymeric and smart material applications. Moreover, biomaterials may enhance the SCs biological activity and their implementation by establishing a specific microenvironment mimicking natural cell niche. Thus, the synergistic advancement in the fields of biomaterial and medical sciences constitutes a challenge for the development of effective therapies in humans including combined applications of novel biomaterials and SCs populations

In Vitro

In our previous paper[1], we demonstrated that porcine follicles collected during the early stage of development are the most sensitive to the toxic action of polychlorinated biphenyl 153 (PCB 153). Follicles of this type were collected to test the effect of PCB 153 on cell steroidogenesis and viability. Cocultures of granulosa and theca cells were grown in M199 medium at 37ºC. Control cultures were maintained in that medium alone, while experimental ones were supplemented with PCB 153 at doses of 5, 10, 50, and 100 ng/ml. After 48, 96, and 144 h, media were collected for steroid analysis and cell viability was measured using an LDH (lactate dehydrogenase activity) cytotoxicity test. A 2-day exposure of follicular cells to all the investigated doses of PCB 153 caused a statistically significant decrease in progesterone (P4) secretion, while in doses of 50 and 100 ng/ml there was also a decrease in testosterone (T) secretion. No effect on estradiol (E2) secretion was observed. The observed decrease in P4 and T secretion, and lack of any statistically significant effect on E2 secretion by cells from small follicles exposed for 48 h to PCB, suggests that PCB 153 acts before P4 formation. Longer exposures caused an increase in P4 secretion, with a concomitant drastic decrease in T secretion and a tendency to decrease the E2 secretion, suggesting inhibition of P450 17α hydroxysteroid dehydrogenase, an enzyme that converts P4 to T. The observed PCB 153–induced increase in P4 secretion by cells collected from small antral follicles, with a concomitant decrease in E2 secretion, accounts for the induction of luteinization and, in this case, inhibition of aromatization process in the follicles. However, in all doses tested and at all times of exposure, PCB 153 had no effect on cell viability. These findings suggest different time of exposure–dependent action of PCB 153 on particular steps of steroidogenesis but not action on cell viability. These results should be considered preliminary, pending confirmation by other studies

Incidence of otolaryngological symptoms in patients with temporomandibular joint dysfunctions

The functional disorders of the masticatory organ are the third stomatological disease to be considered a populational disease due to its chronicity and widespread prevalence. Otolaryngological symptoms are a less common group of dysfunction symptoms, including sudden hearing impairment or loss, ear plugging sensation and earache, sore and burning throat, difficulties in swallowing, tinnitus, and vertigo. The diagnostic and therapeutic problems encountered in patients with the functional disorders of the masticatory organ triggered our interest in conducting retrospective studies with the objective of assessing the incidence of otolaryngological symptoms in patients subjected to prosthetic treatment of the functional disorders of masticatory organ on the basis of the analysis of medical documentation containing data collected in medical interviews. Material and Methods. Retrospective study was conducted by analyzing the results of medical interviews of 1208 patients, who had reported for prosthetic treatment at the Functional Disorders Clinic of the Department of Dental Prosthetics of Jagiellonian University Medical College in Cracow between 2008 and March 14, 2014. Results. Otolaryngological symptoms were observed in 141 patients. The most common symptoms in the study group were earache and sudden hearing impairment; no cases of sudden hearing loss were experienced

Constitutional reforms processes

This chapter analyse the different constitutional reform processes that have taken place in the Maghreb (Algeria, Morocco and Tunisia) and the Middle East (Egypt, Jordan, Syria, Yemen, Oman and Bahrain) since the uprisings in 2011. The purpose of this study is to examine and compare the latest constitutional reform processes in the aforementioned nine countries in order to offer key insights into these processes and to propose a typology of the dynamics of constitutional reform, and its scope in the Arab world. The aspects for analysis include procedures, consensus and dissent during the course of the constitutional process, and the content of the constitutional reforms. The emphasis is placed on the most important elements of the processes of constitutional change and of the content of the new constitutions, while paying particular attention to aspects related with the power of heads of state, the most frequently-debated reforms and the advancement of gender equality and women’s rights.En este capítulo se analizan los diferentes procesos de las reformas constitucionales que se han producido en el Magreb (Argelia, Marruecos y Túnez) y en el Oriente Medio (Egipto, Jordania, Siria, Yemen, Omán y Bahrein) tras las revueltas de 2011. El propósito de este trabajo es conocer y comparar los últimos procesos de reforma constitucional en los diez países mencionados con el objetivo de ofrecer las claves explicativas de estos procesos y proponer una tipología de las dinámicas de reforma constitucional y de su alcance en el mundo árabe. Las dimensiones de análisis incluyen los procedimientos (las instituciones y las normas), el consenso y el disenso a lo largo del proceso constitucional y el contenido de dichas reformas constitucionales (dispositivos democráticos y dispositivos autoritarios). El énfasis se pone en los elementos más relevantes de los procesos de cambio constitucional y de los contenidos de las nuevas constituciones, prestando una atención particular a los aspectos relacionados con el poder de los jefes de Estado, las reformas más debatidas y las mejoras concedidas a las mujeres, siendo éste uno de los grupos principales del movimiento pro-democrático en las revueltas árabes

Educating a New Generation of Library and Information Science Professionals: A United States Perspective

This article examines the U.S model of library and information science (LIS) education in light of the changes brought about by information and communication technology. The accepted model of professional preparation in the United States has emphasized graduate education on a Master’s level from LIS programs accredited by the American Library Association (ALA). The authors trace the historical development of this approach and provide an overview of the ALA accreditation process. Furthermore, they examine the strategies of LIS programs in adjusting to the changing information environment, present the debate about the iSchool movement, and discuss the evolution of the core curriculum. In addition, the article explores the relationship between LIS education and the field of practice and presents a practitioner’s perspective on educating library professionals. The authors conclude that the model of advanced professional preparation for librarianship is still relevant in the digital environment, but it requires greater flexibility and close cooperation with the field of practice