Simulated impact trauma and osteoarthritis: the role of cell volume and mechanotransduction

Health and emotional benefits are linked to participation in exercise, however single-impact load (e.g. trauma) and altered joint loading can cause bone fracture(s) resulting in permanent cartilage damage and increased risk of osteoarthritis (OA). This study investigated the role of single mechanical load and the effects of chondroprotective agents over short periods of time (2-30 min) post impact. Mechanical load (force 1.14 N) induced by a drop tower device caused cell death from as early as 2 min. Pre-incubation in hypertonic media protected chondrocytes from cell death, whereby at 30 min, death was decreased from 9.22 % to 3.42 % (p<0.01), thus implicating volume regulatory changes as a potential key mechanism for chondroprotection, with in situ chondrocytes altering their cell volume in response to hypertonicity by 20 %. Investigation of the cell cytoskeleton, showed that hypertonicity increased cortical actin by 29 % within the superficial zone (SZ) only (p<0.01). Volume and actin polymerisation regulation are governed by intracellular Ca2+ and the regulatory volume decrease (RVD) inhibitor REV5901 has been linked to both and was therefore tested for its potential chondroprotective properties. Impact led to cell death, which was significantly reduced by REV5901 from 10.92 % to 5.44 % (p<0.001) and initial cell volume was reduced by 25%. Cortical actin staining was increased by 20 % within the SZ of articular cartilage only (p<0.01). GdCl3 (blocker for stretch-activated calcium channels), uridine-5’-triphosphate (uridine; calcium mobilizing mediator) and the phosphoinositide 3-kinases (PI3K) inhibitor wortmannin were used to determine its mechanism of action. Wortmannin alone increased cell death and inhibited REV5901 chondroprotective effects with no alteration in cell volume compared to REV5901 alone. Whilst uridine reduced cell volume with 20 % (p<0.05) it did not reduce cell death significantly from 10.92 % to 8.10 % (p>0.05) compared to control. GdCl3 inhibited REV5901 chondroprotective effects by increasing cell death by ~ 5 % compared to control (p<0.05), F-actin staining appeared reduced 72.84 AU and not significantly different from control (p>0.05). The role of the cell cytoskeleton is important for cell mechanotransduction and for maintaining integrity as actin microfilaments are recognized to bear tension therefore, alterations of the actin-binding proteins responsible for actin treadmilling cofilin, profilin and gelsolin mRNA was compared to untreated chondrocytes. REV5901 was observed to reduce cofilin (known actin depolymerizing factor) with 30 % (p<0.05) and increase profilin significantly by 75 % (p<0.001) respectively. Western blot analysis showed that only cofilin and gelsolin were expressed in all samples with no detection of profilin. REV5901 was observed to significantly reduce cofilin by 28 % (p<0.05). This data highlights that REV5901 exhibits chondroprotective properties in part due to the polymerisation of the actin cytoskeleton via PI3Ks pathway. This could offer a novel therapeutic opportunity for perention of irreversible cartilagedamage following acute impact trauma

ECONOMIC ASPECTS AND CHARACTERISTICS OF AGE INEQUALITY IN THE NEW REALITY

The aim of article is to present the contemporary development of society and related economic inequality. Emphasis is placed on age inequality due to its economic aspects and characteristics. The main focus of the article is on the new reality of economic slowdown and its adverse effect on another contemporary trend – the growing number of retired persons. The results of the study identified a trend which is similar across most EU member states - population aging and inequality of the retired people. Unlike the other member states, old-age inequality in Bulgaria is affected by additional factors, such as the ongoing economic transition, social reforms, and European integration processes

Piecewise Convex Curves and their Integral Representation

2000 Mathematics Subject Classification: 52A10.A convex arc in the plane is introduced as an oriented arc G satisfying the following condition: For any three of its points c1 < c2 < c3 the triangle c1c2c3 is counter-clockwise oriented. It is proved that each such arc G is a closed and connected subset of the boundary of the set FG being the convex hull of G. It is shown that the convex arcs are rectifyable and admit a representation in the natural parameter by the Riemann-Stieltjes integral with respect to an increasing, nonnegative and continuous from the right function s+. Further it is shown that the obtained representation relates to the support function of the set FG. Concerning the reverse question, namely what can be said for the curves that admit such representation, it is shown that they are exactly the curves that can be decomposed into finitely many convex arcs. This result suggests the name piecewise convex curves. In particular, the class of piecewise convex curves contains the convex curves being boundary sets of convex figures, therefore the results from the paper can be used as a tool for studying convex curves

Visual Prediction of Rover Slip: Learning Algorithms and Field Experiments

Perception of the surrounding environment is an essential tool for intelligent navigation in any autonomous vehicle. In the context of Mars exploration, there is a strong motivation to enhance the perception of the rovers beyond geometry-based obstacle avoidance, so as to be able to predict potential interactions with the terrain. In this thesis we propose to remotely predict the amount of slip, which reflects the mobility of the vehicle on future terrain. The method is based on learning from experience and uses visual information from stereo imagery as input. We test the algorithm on several robot platforms and in different terrains. We also demonstrate its usefulness in an integrated system, onboard a Mars prototype rover in the JPL Mars Yard. Another desirable capability for an autonomous robot is to be able to learn about its interactions with the environment in a fully automatic fashion. We propose an algorithm which uses the robot's sensors as supervision for vision-based learning of different terrain types. This algorithm can work with noisy and ambiguous signals provided from onboard sensors. To be able to cope with rich, high-dimensional visual representations we propose a novel, nonlinear dimensionality reduction technique which exploits automatic supervision. The method is the first to consider supervised nonlinear dimensionality reduction in a probabilistic framework using supervision which can be noisy or ambiguous. Finally, we consider the problem of learning to recognize different terrains, which addresses the time constraints of an onboard autonomous system. We propose a method which automatically learns a variable-length feature representation depending on the complexity of the classification task. The proposed approach achieves a good trade-off between decrease in computational time and recognition performance.</p

"Leader" - Catalyst of Ideas and Opportunities for Improving the Quality of Life in Rural Areas in Bulgaria

Policy for rural development and improving the quality of life in their part of the Common Agricultural Policy (CAP) and Bulgaria's accession to the EU has gained wide popularity with its focus on addressing the socio - economic, environmental, infrastructure and others. problems in order to reduce inequalities in rural areas in Bulgaria than in other European countries. One of the tools and innovative approach to the implementation of EU policy for sustainable rural development approach is "Leader". Keywords: politics, 'Leader', rural, sustainable development, economi

Glagolski prefiks o(b)- u hrvatskome i bugarskome: semantička mreža i izazovi korpusno utemeljena istraživanja

This study compares the verbal prefix o(b)– in two South Slavic languages, Croatian and Bulgarian, from a cognitive linguistic perspective. We focus on the problems arising when constructing the semantic network of this polysemous prefix, particularly on 1) isolating the prefix’s meaning from the meaning of the base verb and 2) identifying core/dominant sub–meanings for all verbs and giving them corresponding semantic labels. Our approach to morphology is based on extensive databases of verbs collected from dictionaries and a few corpora. However, our work with corpora led to a number of challenges. This study thus has two aims: a) presenting challenges encountered in working out semantic networks of prefixes, and b) presenting challenges related to obtaining reliable (quantitative) results from the corpora.U analizi se iz komparativne perspektive razmatra glagolski prefiks o(b)– u hrvatskome i bugarskome jeziku. Teorijski je okvir kognitivna lingvistika. Prva je tema na koju se osvrćemo značenjska mreža ovoga prefiksa u svjetlu polisemije. U tom sklopu posebno razmatramo sljedeća pitanja: 1) kako odvojiti značenje prefiksa od značenja osnovnih glagola, 2) kako identificirati središnje značenje i osnovna podznačenja i kako ih imenovati. Analiza se temelji na opsežnom inventaru prefigiranih glagola prikupljenom u rječnicima i korpusima. U radu s korpusima bilo je nekih izazova, pa se analiza stoga (uz spomenutu problematiku povezanu s razradom semantičke mreže) osvrće i na pitanje kako doći do kvantitativno relevantnih rezultata na temelju korpusa koji su ili ograničena opsega ili imaju druge vrste ograničenja

Foundation Work of High TV Tower in Collapsible Loess

The TV tower in Rousse city is the highest in the Balkan area with its 198 m height. It is built up on loess with thickness of the collapsible zone about 15-16 m. The collapsibility has been overcome by excavation deepening up to 14.50 m, dynamic compaction of the excavation bottom with 7.0 tons tamper and building of a 4.5 m soil-cement cushion. A comparison between the calculated and measured settlement and of the soil base moisture content before and after TV tower construction is presented. Geodetic measurements have been made during and after the tower construction. Several calculation methods were used for settlement prediction: Soviet building code for large-size foundations and restricted active zone, the corrected Burmister formula, the method of Kushner and the finite element method. For the load of 146 kPa of the tower, the total settlement in 2005 reached 5.75 cm. The calculated settlement using the finite element method is 6.85 cm, and according to Burmister – 6.75 cm. After 10 years of operation of the tower, increased water content was established in the backfill around it and some increasing of the facility settlement. The next measures were applied: drying of the backfill with quicklime columns, injection of cement-sand mortar in the cavities under the concrete sidewalk, repair of the water & sewerage installations, performance of new vertical planning

Student Community As An Educational Factor

The question of clarifying the influence of the major factors that have the greatest impact on the education of school-age children is a traditional one in the pedagogical literature. There is an undoubted opinion that school, along with family, has a leading role among these factors. School itself is a kind of community that stands out with its specific culture and environment. It is called upon to give not only knowledge to the younger generation, but also to instill a sense of belonging to the educational and cultural traditions of the people, responsibility to oneself and to the others, respect for the institutions, etc. Evidence of this can be found in various types of research according to which school education and upbringing are a kind of system comprising several subsystems: a teacher and teaching community, a student and student community, a community of the service staff, the school board. The most valuable asset of the Bulgarian educational system is the child (the student). That is why every idea for development of the Bulgarian school education is assessed precisely through the prism of this “asset” a student should feel as an artist in the school environment, should be involved in the successes and failures of the people with whom s/he communicates, should build and form his/her own opinion that will stimulate his/her participation in the forms of self-organization and self-management, should get to know himself/herself using his/her evolving reflection, i.e. the interest in what the others think of him/her, how they feel about him/her, how s/he sees herself/himself, what s/he really is like, and so on. All this can be achieved mostly in an environment of peers. That is why the student community is defined and considered as an important factor for the upbringing of the children in the educational (school) environment

Plants traditionally used to make brooms in several European countries

<p>Abstract</p> <p>Background</p> <p>The research was carried out within the course of two years (2005–2006) in four countries from southern, southeast and eastern parts of Europe: Bulgaria, Italy, Macedonia and Romania. The data are collected mainly from Bulgaria and Italy and are compared with those from Macedonia and Romania.</p> <p>Methods</p> <p>The information was gathered largely from literature as well as field collected data and interviewed informants. A brief questionnaire, referring to the vernacular name, plant description, providing specimens from the plants and brooms, details on their use has been prepared and applied.</p> <p>Results</p> <p>The total number of species as brooms in the study areas is about 108. The list includes two fungi taxa which caused the so-called "Witches' brooms". A high species diversity of 106 taxa of vascular plants, belonging to 37 families and 74 genera, is established in the research area. The investigation includes data about scientific name, family, vernacular name, life form, status (wild or cultivated), used parts and place of use. The relations between the plant characteristics and broom specific shape and working qualities, details of the traditionally broom planting and making, the broom as a part of folklore, traditions and religious rituals are discussed.</p> <p>Conclusion</p> <p>Collected data show how ecological, geographical features and different cultures are related with the variety of plants traditionally used as brooms as well as details for their uses. The data about the variety of plants traditionally used to make brooms and the ways in which they are used according to the specific characteristics of the areas are important for ethnobotanical knowledge.</p