Experimental Study: How fast is the Children's Reaction Times for Different Heights of Traffic Signs - Ergonomic Principles and Traffic Safety Aspect

Touchscreen devices have dramatically increased the accessibility and usage of technology, causing escalating usage, especially by very young children. Although the effects of screen time have been shown to produce serious (negatively effects on executive functioning, attention problems, school difficulties, sleep and eating disorders, and obesity) and even life-threatening consequences (due to radiation emission), technology can be beneficial if it is carefully used. Child-centered technology is especially designed to be as entertaining and captivating as possible. In order to examine how touchscreen devices, influence the acquisition of some important spatial concepts and provide exciting opportunities for learning new abilities, an experimental research was conducted aimed to determine whether the type of device used (computers or tablets) in the natural kindergarten environment influences young children performances. For the purpose of this work, geometrical symbols on traffic signs were used to test spatial relationships – left/right, and longer/shorter relations. The test was carried out on a sample of 30 pre-school children. The results show significant differences between the two-testing media for identifying the longer vs. shorter relationships in favor of Tablet PC. Based on the results obtained, it can be concluded that the kinesthetic characteristics of tablets, the novelty factor and the opportunity to learn through playing, provide a positive approach to the early childhood education. Besides, the interactive environment created in a kindergarten by using tablets contributes to introduce new teaching methods which are expected to amplify the pedagogical capacity, changing the way of spatial concepts acquisition, as well as, children traffic education take place within.

Effects of soy isoflavones on the hypothalamic-pituitary system in rats: a morphofunctional study

Izoflavoni soje, genistein i daidzein, se sve više koriste u preventivi i alternativnoj terapiji različitih patoloških stanja. Uticaj izoflavona soje na neuroendokrini sistem bio je, a i danas je, predmet istraživanja različitih studija. Veliki broj literaturnih podataka govori o uticaju izoflavona soje na reproduktivni sistem, s obzirom na njihovu estogensku i anti-estrogensku aktivnost. Ipak, podaci o njihovom uticaju na somatotropni i adrenokortikotropni sistem oskudni su, a neophodni, imajuću u vidu značaj ovih sistema za normalan razvoj i funkcionisanje organizma. Takoñe, mnogobrojne in vitro studije obezbeñuju samo limitirane informacije o potencijalnim efektima in vivo. Cilj ove studije je bio da se ispita uticaj hroničnih tretmana estradioldiproprionatom, genisteinom i daidzeinom na histološke, stereološke i biohemijske parametre somatotropnog i adrenokortikotropnog sistema orhidektomisanih adultnih pacova. Na početku eksperimenta adultni pacovi Wistar soja, stari 3 meseca, su podeljeni u dve eksperimentalne grupe: lažno orhidektomisanu (Sham) i orhidektomisanu (Orx) grupu. Dve nedelje nakon sham operacije ili orhidektomije pacovi su podeljeni u sedam eksperimentalnih grupa. Prvu (Sham1) grupu su sačinjavale sham operisane životinje subkutano (s.c.) tretirane odgovarajućom zapreminom sterilnog maslinovog ulja, medijumom estradiol-diproprionata (medijum I). Drugu (Orx1) grupu su sačinjavale orhidektomisane životinje s.c. tretirane odgovarajućom zapreminom medijuma I. U trećoj (Orx1+E) grupi orhidektomisane životinje su s.c. tretirane estradioldipropionatom u medijumu I (0,6 mg/kg t.m.). Četvrta (sham operisana - Sham2) i peta (orhidektomisana - Orx2) grupa s.c. su tretirane odgovarajućom zapreminom mešavine alkohola i sterilnog maslinovog ulja, medijumom genisteina i daidzeina (u odnosu 1:2; medijum II). Šestu (Orx2+G) grupu su sačinjavale orhidektomisane životinje s.c. tretirane genisteinom u medijumu II (30 mg/kg t.m.), dok je sedma (Orx2+D) grupa orhidektomisanih pacova s.c. tretirana daidzeinom u istom medijumu (30 mg/kg t.m.). Sve grupe životinja su dobijale tretman tokom tri nedelje (hroničan tretman), a žrtvovane su 24 h nakon poslednje primljene doze. Pre početka i nakon završenog tretmana izmerene su telesne mase životinja svih eksperimentalnih grupa, dok su mase hipofiza izmerene nakon žrtvovanja. Za lokalizaciju arkuatnog (Arc) i periventrikularnog (Pe) jedra, paravenrikularnog jedra (PVN) i eminencije medijane (ME) korišćeno je histološko bojenje krezil-ljubičastom bojom. Za obeležavanje oslobañajućih hormona hipotalamusa (oslobañajućeg hormona hormona rasta–GHRH, somatostatina-SS, kortikotropnog oslobañajućeg hormona-CRH) i ćelija adenohipofize (somatotropnih–GH i adrenokortikotropnih-ACTH) korišćeno je imunohistohemijsko bojenje. Histološki i imunohistohemijski obojeni preseci hipotalamusa, kao i imunohistohemijski obojeni preseci hipofiza stereološki su analizirani, uz pomoć newCAST stereološkog softverskog paketa. Dobijene su vrednosti: volumena Arc i Pe jedra i PVN, volumenske gustine SS neurona, volumena hipofize, volumenske i numeričke gustine GH i ACTH ćelija, apsolutnog broja i volumena GH i ACTH ćelija. Koncentracija GH i ACTH u cirkulaciji odreñena je biohemijskim metodama. Dobijeni podaci su statistički obrañeni...The soy isoflavones genistein and daidzein are being used increasingly as preventive or alternative therapeutics in various pathological conditions. The effects of soy isoflavones on the neuroendocrine system were, and still are, the subject of numerous studies. Literature data predominantly focus on their effects on the gonadotrophic axis, considering the soy isoflavones established estrogenic and antiestrogenic mode of action. However, data about their potential effects on the somatotrophic and adrenocorticotrophic systems are rather scarce, but nevertheless very meaningful, considering the importance of these systems for the normal development and function of an organism. Furthermore, in vitro studies provide only limited data, that cannot be fully extrapolated to in vivo conditions. The aim of this study was to investigate the effects of chronically applied estradiol dipropionate, genistein and daidzein on the histological, stereological and biochemical parameters of somatotrophic and adrenocorticotrophic systems in orchidectomized adult rats. Initially, adult (three months old) Wistar rats were divided into two groups: sham operated (Sham) and orchidectomized (Orx). Two weeks after the surgery, the rats were subdivided into seven experimental groups. The first group (Sham1) included sham operated rats subcutaneously (s.c.) treated with an adequate volume of sterile olive oil, the medium for estradiol dipropionate (medium I). In the second group (Orx1) were orchidectomized rats s.c. treated with an adequate volume of medium I. The third group (Orx1+E) was comprised of orchidectomized rats s.c. treated with estradiol dipropionate in medium I (0.6 mg/kg b.w.). The fourth (sham operated – Sham2) and fifth (orchidectomized – Orx2) group of rats were s.c. treated with adequate volumes of absolute ethanol and sterile olive oil mixture, the medium for genistein or daidzein (mixing ratio was 1:2; medium II). In the sixth group (Orx2+G) were orchidectomized rats s.c. treated with genistein in medium II (30 mg/kg b.w.), while the seventh group (Orx2+D) included orchidectomized rats s.c. treated with daidzein in the same medium (30 mg/kg b.w.). All the groups of animals received the treatment during three weeks (chronic treatment), and were sacrificed 24 h after the last injected dose. All the animals were weighed before and after the treatment, while the pituitary weights were measured after sacrificing. For the localization of arcuate (Arc), periventricular (Pe) and paraventricular (PVN) nuclei, as well as for median eminence (ME) cresyl violet histochemical staining was used. Hypothalamic releasing hormones (growth hormone releasing hormone – GHRH, somatostatin – SS, corticotrophin releasing hormone – CRH) and pituitary cells (somatotrophic – GH and adrenocorticotrophic – ACTH) were immunohistochemically (peroxidase-antiperoxidase) labeled. Histochemically stained and immunohistochemically labeled hypothalamic sections, as well as immunohistochemically labeled pituitary sections were stereologically analysed, using newCast stereological software package. The following values were obtained: the Arc, Pe and PVN nuclei volumes, volume density of SS neurones, volumes of the pituitaries, the volume and numerical density of GH and ACTH cells, as well as the absolute numbers and volumes of GH and ACTH cells. The circulating GH and ACTH were determined biochemically. The obtained data were statistically processed..

Reduced growth of the adrenal zona glomerulosa after neonatal treatment of female rats with SRIH-14

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The Morpho-Functional Parameters of Rat Pituitary Hormone Producing Cells after Genistein Treatment

Phytoestrogens are a diverse group of steroid-like compounds that occur naturally in many plants. There are various types of phytoestrogens, including the best-researched isoflavones which are commonly found in soy. The consumption of soy products has many health benefits, including protection against breast cancer, prostate cancer, menopausal symptoms, heart disease and osteoporosis. In contrast, use of hormonally active compounds-isoflavones may unfortunately interfere with the endocrine system and can have far-reaching consequences. Genistein, the most abundant soy-bean derived isoflavone, possesses a ring system similar to estrogens and acts through an estrogen receptor (ER)-mediated mechanism, by increasing or decreasing the transcription of ER-dependent target genes. Also, genistein can act on cells through ER non-dependent mechanisms, such as tyrosine kinase inhibitor. The neuroendocrine systems are responsible for the control of homeostatic processes in the body, including reproduction, growth, metabolism and energy balance, and stress responsiveness. It is well known, that estrogen is important for development of the neuroendocrine system in both sexes. At the pituitary level, estrogen is known to affect the regulation of all hormone producing (HP) cells, by direct and/or indirect mechanisms. Due to structural and functional resemblance to estrogen, the question may arise of whether and how genistein affects the morphofunctional features of pituitary HP cells. This review deals with the consequences of genistein’s effects on morphological, stereological and hormonal features of HP cells within the anterior pituitary gland. Transparency on this issue is needed because isoflavones are presently highly consumed. Inter alia, genistein as well as other isoflavones, are present in various dietary supplements and generally promoted as an accepted alternative to estrogen replacement therapy. Potential isoflavone biomedical exploitation is not only limited to estrogen replacement therapy, so it should be treated in a wider context of different ageing symptoms remediation

The importance of ergonomic principles in design of the traffic signs for childeren

Children represent a vulnerable population from the standpoint of traffic safety. A modern traffic poses complex and high requirements to all its participants, and among them, particularly to young children. Children have a higher risk of pedestrian injuries. Children are experiencing experience traffic differently from adults. How do children view the world? What helps them to link with their environment? How do children imagine traffic signs? To address these questions, this study examines how fast the children (between 6 and 10 years of age) react to traffic signs mounted at different heights. The analysis of the results indicated that there were differences in mean reaction time for traffic signs of different heights. Children best perceive a traffic sign when it is mounted at 1.9 m. The research highlights the importance of ergonomic principles in choosing the appropriate height of traffic signs for children

An algebraic approach to Harder-Narasimhan filtrations

It is a well-known fact that a stability condition $\phi: Obj^* \mathcal{A} \to \mathcal{I}$ over an abelian length category $\mathcal{A}$ induces a chain of torsion classes $\eta_\phi$ indexed by the totally ordered set $\mathcal{I}$. Inspired by this fact, in this paper we study all chains of torsion classes $\eta$ indexed by a totally ordered set $\mathcal{I}$ in $\mathcal{A}$. Our first theorem says that every chain of torsion classes $\eta$ indexed by $\mathcal{I}$ induces a Harder-Narasimhan filtration to every nonzero object of $\mathcal{A}$. Building on this, we are able to generalise several of the results showed by Rudakov in \cite{Rudakov1997}. Moreover we adapt the definition of slicing introduced by Bridgeland in \cite{Bridgeland2007} and we characterise them in terms of indexed chain of torsion classes. Finally, we follow ideas of Bridgeland to show that all chains of torsion classes of $\mathcal{A}$ indexed by the set $[0,1]$ form a metric space with a natural wall and chamber structure. Moreover we show a one to one correspondence between the chambers of this metric space and the maximal green sequences of $\mathcal{A}$.Comment: Typos and minor corrections were mad

Augmented reality application in engineering students spatial abilities assessment

Expanding technology, augmented reality (AR), where the customer/user can obtain various information about 3D digital model of an object in real time virtual presentation, has a wide range of applications. One of the fields of interest is cultural heritage preservation. Combined with 3D modeling, mostly based on 3D laser scanning data, AR enables a common user to visualize the object, i.e. cultural heritage monument in its' real surroundings. This is especially important in the cases when the monument is in ruined or devastated state. If reconstructed 3D model would give the clear visual impression about the monument and its historical value. This topic is especially interesting for engineering students, whose further professional activities would be involved in the tasks of cultural heritage protection. Augmented reality applications, among other, are available through android phones, i-phones and tablets by 3D model upload and its real time presentation. AR applications aimed for architectural objects require certain manipulation skills regarding object's positioning on the mobile device's screen, as well as, geometry knowledge for obtaining correctness. In this research, a testing was performed regarding spatial abilities of the engineering students, which had a task to incorporate the 3D model of the cultural heritage monument into several variants of 2D and 3D scene, as well as decomposition and recognition of elements of the structure. 3D digital Auto CAD model (geometric model) of reconstructed one nave church in Serbia, in monastery complex Kastaljan, on the mountain Kosmaj, was used for the testing purposes

Some epidemiological characteristics of malignant fibrous histiocytoma in the Province of Vojvodina

BACKGROUND: Malignant fibrous histiocytoma is most common soft tissue sarcoma occurring in late adult life, most in the extremities and in the retroperitoneum, usually developing in deep fascia or skeletal muscle. Because of the aggressive nature of the tumor early and complete surgical removal is indicated. The overall survival rate of patients with malignant fibrous histiocytoma ranges from 36% to 58% at 5 years. Malignant fibrous histiocytoma in Vojvodina is still rare malignancy either in incidence or in mortality in both sexes. The population of Vojvodina is about 2 100 000. METHODS: We used a descriptive epidemiological method to analyze incidence and mortality from malignant fibrous histiocytoma in Vojvodina. This study is based on the Cancer Registry data for the ten-year period from 1993 to 2002. RESULTS: During the observed period 37 cases of malignant fibrous histiocytoma were reported (19 men and 18 women). The average age of patients was 50 years. The body site distribution differed between sexes and malignant fibrous histiocytoma was more common on the trunk (retroperitoneum) in men and on the lower limbs in women. The average annual incidence rate for the observed period was 1.82 per 1 000 000 for both sexes. The incidence rate changed irregularly over the observed period with the peak of 9 cases (4.55 per 1 000 000) in 2001. The overall linear trends of incidence and of mortality showed a slight increasing tendency in both sexes, but not significantly. Concerning mortality, the similar patterns were noticed. The mortality rate was 0.83 per 1 000 000. CONCLUSION: According to epidemiological data we obtained it can be concluded that Province of Vojvodina is not a region with an important risk for malignant fibrous histiocytoma; however, the increase of incidence appearing in both men and women should be taken into account very seriously in future

Segmental cavernous carotid ectasia in a patient with cluster-like headache

Introduction Cluster headache (CH) is a primary headache with severe, unilateral periorbital or temporal pain lasting 15–180min, accompanied with various cranial autonomic features. A diagnosis of cluster-like headache can be made whenever underlying cause of CLH is present. Methods and results We report a case where an ectatic cavernous segment of the internal carotid artery triggered CHL, most probably due to compression of the ophthalmic nerve within cavernous sinus. The pathological substrate of a vessel ectasia is degeneration of the tunica intima as a consequence of atherosclerosis and hypertension. On the other hand, cavernous sinus is unique space where parasympathetic, sympathetic and nociceptive fibers are in intimate relationship which is of great importance for understanding of CH pathophysiology. Conclusion Magnetic resonance imaging and MR angiography are mandatory imaging tools used for precise localization of pathological changes in the cavernous sinus, especially in the group of secondary headaches attributed to vascular disorders

Reduced growth of the adrenal zona glomerulosa after neonatal treatment of female rats with SRIH-14

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