bluuebunny/crossref_metadata_2025 huggingface dataset:
Redox regulation of mitochondrial sulfide oxidation in the lugworm,Arenicola marina
Authors: Hildebrandt Tatjana M. , Grieshaber Manfred K.
Published: August 2008

Sulfide oxidation in the lugworm, Arenicola marina (L.), is most likely localized in the mitochondria, which can either produce ATP with sulfide as a substrate or detoxify it via an alternative oxidase. The present study identified selective activators of the energy-conserving and the detoxifying sulfide oxidation pathways respectively. In the presence of the ROS scavengers glutathione (GSH) and ascorbate, isolated lugworm mitochondria rapidly oxidized up to 100 μmoll–1 sulfide with maximal oxygen consumption rates but did not produce any ATP in the process. Under these conditions, salicylhydroxamic acid (SHAM), which is an inhibitor of the alternative oxidase of plant mitochondria, completely blocked oxygen consumption whereas inhibitors of complex III and IV had hardly any effect. By contrast, dehydroascorbate (DHA) enabled the mitochondria to gain ATP from sulfide oxidation even if the sulfide concentration far exceeded the threshold for inhibition of cytochrome oxidase. In the presence of dehydroascorbate,respiratory rates were independent of sulfide concentrations, with a respiratory control ratio of 2.1±0.2, and both oxygen consumption and ATP production were completely inhibited by myxothiazol and sodium azide but only marginally by SHAM. The present data indicate that a redox mechanism may contribute to the regulation of sulfide oxidation in lugworm mitochondria in vivo. Thus, mitochondria are presumably much more sulfide resistant in a cellular context than previously thought.
Micromechanical properties of consecutive layers in specialized insect cuticle: the gula ofPachnoda marginata(Coleoptera, Scarabaeidae)and the infrared sensilla ofMelanophila acuminata(Coleoptera,Buprestidae)
Authors: Müller Martin , Olek Maciej , Giersig Michael , Schmitz Helmut
Published: August 2008

Insect cuticle is a highly adaptive material that fulfils a wide spectrum of different functions. Cuticle does not only build the exoskeleton with diverse moveable parts but is also an important component of a stunning variety of mechanosensory receptors. Therefore, the mechanical properties of these specialized cuticular systems are of crucial importance. We studied the different cuticular layers of the head part (gula) of the head-to-neck ball articulation of Pachnoda marginata and of the photomechanic infrared(IR) sensilla of Melanophila acuminata on the basis of cross sections. In our study, we combined histological methods (i.e. detection of the different types of cuticle by specific staining) with measurements of hardness (H) and reduced elastic modulus (Er) by nanoindentation technique. In the gula of Pachnoda we found an unusual aberrance from the well-known layering. Between the epi- and exocuticle, two meso- and one endocuticular layers are deposited which are softer and more elastic than the underlying exo- and mesocuticular layers. The hardest of all examined materials is the cuticle of the exocuticular shell of the internal sphere of the Melanophila IR sensillum with H=0.53GPa whereas the inner mesocuticular core of the sensillum represents the most elastic and softest layer with values of H=0.29GPa and Er=4.8GPa. Results are discussed with regard to the proposed functions.
Highly Multiplexed Genotyping of Thiopurine S-Methyltransferase Variants Using MALDI-TOF Mass Spectrometry: Reliable Genotyping in Different Ethnic Groups
Authors: Schaeffeler Elke , Zanger Ulrich M , Eichelbaum Michel , Asante-Poku Steven , Shin Jae-Gook , Schwab Matthias
Published: August 2008

Background: To avoid severe hematotoxicity in patients, determination of the TPMT (thiopurine S-methyltransferase) genotype before commencing thiopurine therapy has become accepted.

Methods: We used MALDI-TOF mass spectrometry (MS) based on Sequenom iPLEX® technology to develop novel multiplex assays for comprehensive testing of TPMT. Two assays, a 15-plex and a 7-plex assay, consisting of multiplex PCR, shrimp alkaline phosphatase treatment, primer extension, and MALDI-TOF MS analysis, allow detection of all currently known functionally relevant 24 TPMT alleles (TPMT*2 to *18, *20 to *23). Previously identified variant DNA samples and newly constructed synthetic templates were used as quality controls.

Results: Assay evaluation performed on a panel of 586 genomic DNA samples previously genotyped by other methods (denaturing HPLC, sequencing) resulted in 100% agreement. Analyses of the distribution of TPMT alleles in 116 samples from a Ghanaian population revealed a TPMT*8 allele frequency of 3.4%. In a Korean population of 118 unrelated individuals, we found a TPMT*6 allele frequency of 1.3%.

Conclusions: The newly developed multiplex MALDI-TOF MS assay allows efficient genotyping for all currently known functional TPMT variants. To achieve the most accurate prediction of TPMT phenotype, molecular diagnosis of TPMT should include all these variants.
High-Abundance Polypeptides of the Human Plasma Proteome Comprising the Top 4 Logs of Polypeptide Abundance
Authors: Hortin Glen L , Sviridov Denis , Anderson N Leigh
Published: August 2008

Background: Plasma contains thousands of proteins, but a small number of these proteins comprise the majority of protein molecules and mass.

Content: We surveyed proteomic studies to identify candidates for high-abundance polypeptide chains. We searched the literature for information on the plasma concentrations of the most abundant components in healthy adults and for the molecular mass of the mature polypeptide chains in plasma. Because proteomic studies usually dissociate proteins into polypeptide chains or detect short peptide segments of proteins, we summarized data on individual peptide chains for proteins containing multiple subunits or polypeptides. We collected data on about 150 of the most abundant polypeptides in plasma. The abundant polypeptides span approximately the top 4 logs of concentration in plasma, from 650 to 0.06 μmol/L on a molar basis or from about 50 000 to 1 mg/L mass abundance.

Conclusions: Data on the concentrations of the high-abundance peptide chains in plasma assist in understanding the composition of plasma and potential approaches for clinical laboratory or proteomic analysis of plasma proteins. Development of more extensive databases regarding the plasma concentrations of proteins in health and diseases would promote diagnostic and proteomic advances.
Feedback Design for the Control of a Dynamic Multitasking System: Dissociating Outcome Feedback From Control Feedback
Authors: Neth Hansjörg , Khemlani Sangeet S. , Gray Wayne D.
Published: August 2008

Objective: We distinguish outcome feedback from control feedback to show that suboptimal performance in a dynamic multitasking system may be caused by limits inherent to the information provided rather than human resource limits. Background: Tardast is a paradigm for investigating human multitasking behavior, complex system management, and supervisory control. Prior research attributed the suboptimal performance of Tardast operators to poor strategic task management. Methods: We varied the nature of performance feedback in the Tardast paradigm to compare continuous, cumulative feedback (global feedback) on performance outcome with feedback limited to the most recent system state (local feedback). Results: Participants in both conditions improved with practice, but those with local feedback performed better than those with global feedback. An eye gaze analysis showed increased visual attention directed toward the feedback display in the local feedback condition. Conclusion: Predicting performance in the control of a dynamic multitasking system requires understanding the interactions between embodied cognition, the task being performed, and characteristics of performance feedback. In the current case, at least part of what had been diagnosed as a deficit caused by limited cognitive resources has been shown to be data limited. Application: Perfect outcome feedback can provide inadequate control feedback. Instances of suboptimal performance can be alleviated by better feedback design that takes into account the temporal dynamics of the human-system interaction.
Evaluation of Pictorial Assembly Instructions for Young Children
Authors: Martin Cortney V. , Smith-Jackson Tonya L.
Published: August 2008

Objective: We examined the usability of common formats of pictorial toy assembly instructions for 6- and 9-year-old children. Background: Interlocking building toys and models are increasingly prevalent and important for developing spatial abilities and fine motor skills among children. Little is known about how effectively the intended child users can interpret and carry out the instructions. Method: Twenty-four children used five sets of manufacturer-supplied pictorial toy assembly instructions. We evaluated the impact of toy instruction set, age, gender, and previous experience on usability problems, assembly speed and accuracy, instruction gaze time, and subjective ratings. Results: The children had difficulty with all but the simplest instructions and assemblies. As predicted, older participants assembled more quickly, with fewer errors and fewer instruction looks. However, the 6-year-old girls assembled the fewest parts correctly, and the 9-year-old girls reported having the least fun. Instruction look time and frequency revealed differences in instruction complexity and were correlated with subjective ratings of fun. Thirty-two usability problems were observed, and 10 are described in detail. Conclusion: Product age recommendations may not reflect developmentally appropriate instructions. Small design changes should contribute to improved instruction usability among young children. For instance, designers should avoid complex graphic syntax, depict colors accurately, select clear angles of view, and support natural tendencies to assemble top to bottom. Application: This research provides pictorial assembly instruction guidelines to inform instruction designers and describes performance and look-time benchmarks for future usability studies.
Environmental Support: An Integrative Framework
Authors: Morrow Daniel G. , Rogers Wendy A.
Published: August 2008

Objective: In this qualitative review, we develop an integrative framework to bring coherence to the concept of environmental support (ES) in the fields of human factors and cognitive aging. Background: The ES hypothesis, originally formulated to explain effects of retrieval support on age-related differences in memory by reducing need for self-initiated processing, has been applied to many domains, such that the concept now encompasses many manipulations and measures. We developed a framework in which different types of ES share a common function (external support of performance) but differ in how this function is accomplished. ES improves performance by reducing task demands on mental resources or promoting effective use of resources. Previous reviews show that ES can decrease age-related differences in performance (more benefit for older adults), provide equal benefit, or increase differences (more benefit for younger adults). We proposed that the outcome will depend on properties of the ES, task, and person. Method: We applied our framework to the domains of language comprehension and human-computer interaction, selecting studies representative of differing outcomes for ES. Results: In both domains, we found that outcomes depended on ES, task, and person. Age differences were more likely to be reduced by ES that imposed minimal prerequisites for use and targeted processes that needed support. Conclusion: Our review helps refine the ES concept by identifying conditions under which age differences in performance are reduced or magnified by ES. Applications: The framework provides guidance for human factors practitioners to design tasks and environments for older adults.
Effect of Task and Eccentricity of the Target on Detection Thresholds in Mesopic Vision: Implications for Road Lighting
Authors: Mayeur Anaïs , Brémond Roland , Bastien J.M. Christian
Published: August 2008

Objective: The aim of this work is to assess how adding a driving-related task affects the detection of objects in peripheral vision, under mesopic conditions. Background: The main index used to assess the quality of road lighting installations refers to simple detection tasks in foveal vision, which raises methodological and practical questions. Method: The experimental design consisted of a three-phase experiment. In the first phase, two groups (control and experimental) performed a peripheral detection task (simple task). Based on these results an individual detection threshold was computed for each participant and eccentricity. A tracking task was performed in Phase 2 for both groups (steering a tracking target along a circuit, on a screen). In the third phase, the control group performed the same task as in Phase 2. The experimental group performed a double task, with a tracking (primary) task and a peripheral detection (secondary) task. Results: The data show an effect of the tracking task and eccentricity on peripheral event detection. The tracking task caused detection performance to decrease from 84.2% to 67.5%, p < .001. Conclusion: The small target visibility model used in road lighting may be improved, taking into account the effects of task and eccentricity on target detection. Application: This study supports improved roadway lighting design by guiding consideration of sign eccentricity and task load.
Evaluation of Ecological Interface Design for Nuclear Process Control: Situation Awareness Effects
Authors: Burns Catherine M. , Skraaning Gyrd , Jamieson Greg A. , Lau Nathan , Kwok Jordanna , Welch Robin , Andresen Gisle
Published: August 2008

Objective: We determine whether an ecological interface display for nuclear power plant operations supports improved situation awareness over traditional and user-centered displays in a realistic environment. Background: Ecological interface design (EID) has not yet been fully evaluated with real operators facing realistic scenarios. Method: Ecological displays were evaluated alongside traditional and user-centered “advanced” displays in a full-scope nuclear power plant simulation. Licensed plant operators used the displays in realistic scenarios that either had procedural support or did not have procedural support. All three displays were evaluated for their ability to support operator situation awareness. Results: A significant three-way interaction effect was observed on two independent measures of situation awareness. For both measures, ecological displays improved situation awareness in scenarios that did not have procedural support, primarily in the detection phases of those scenarios. No other pronounced effects appeared across both measures. Conclusions: The observed improvement was sufficiently large to suggest that EID could improve situation awareness in situations where procedures are unavailable. However, the EID displays did not lead to improved situation awareness in the other conditions of the evaluation, and participants using these displays occasionally underperformed on single measures of situation awareness. This suggests that the approach requires further development, particularly in integrating EID with procedural support. Application: This research has important findings for the ongoing development of the EID approach, the design of industrial operator displays, and design to support situation awareness.
Racial Identity and the Civilizing Mission: Double-Consciousness at the 1895 Congress on Africa
Authors: Harris Paul W.
Published: August 2008

The Congress on Africa was held in Atlanta, Georgia, in December 1895 as part of a campaign to promote African American involvement in Methodist missions to Africa. Held in conjunction with the same exposition where Booker T. Washington delivered his famous Atlanta Compromise address, the Congress in some ways shared his accommodationist approach to racial advancement. Yet the diverse and distinguished array of African American speakers at the Congress also developed a complex rationale for connecting the peoples of the African diaspora through missions. At the same time that they affirmed the need for “civilizing” influences as an indispensable element for racial progress, they also envisioned a reinvigorated racial identity and a shared racial destiny emerging through the interactions of black missionaries and Africans. In particular, the most thoughtful participants in the Congress anticipated the forging of a black civilization that combined the unique gifts of their race with the progressive dynamics of Christian culture. These ideas parallel and likely influenced W. E. B. Du Bois's concept of double-consciousness. At a time when the missionary movement provided the most important source of awareness about Africa among African Americans, it is possible to discern in the proceedings of the Congress on Africa the glimmerings of a new pan-African consciousness that was destined to have a profound effect on African American intellectual life in the twentieth century.
“Terrible Laughing God”: Challenging Divine Justice in African American Antilynching Plays, 1916–1945
Authors: Prentiss Craig
Published: August 2008

In the early twentieth century, African Americans waged a propaganda war against the scourge of lynching. Theater was a vital element of this effort, and over two dozen plays were written with the intent of depicting the horror that accompanied these brutal acts of violence. These plays, though largely neglected by historians, have been studied as elements of an effort to promote antilynching legislation. Until now, however, their testimony to important religious currents in African American culture has been ignored. A closer look at these texts reveals them to be engaged in theological discourse that examines the role of God and the church in the face of evil. These plays reflect a burgeoning humanism in African American culture, particularly among the intelligentsia. By creating characters and constructing plot lines that explicitly challenged the goodness of God in light of African American suffering, or by exposing the hypocrisy and impotence of the church to bring about an end to violence and oppression, these playwrights were engaged in a form of vernacular theology. By observing their efforts, we add a fresh layer to our understanding of African American life during this time period.
“It Is a Day of Judgment”: The Peacemakers, Religion, and Radicalism in Cold War America
Authors: Danielson Leilah
Published: August 2008

This article argues that Christian beliefs and concerns shaped the political culture of anti-nuclear activism in the early years of the Cold War. It focuses in particular on the origins of the Peacemakers, a group founded in 1948 by a mostly Protestant group of radical pacifists to oppose conscription and nuclear proliferation. Like others who came of age in the interwar years, the Peacemakers questioned the Enlightenment tradition, with its emphasis on reason and optimism about human progress, and believed that liberal Protestantism had accommodated itself too easily to the values of modern, secular society. But rather than adopt the “realist” framework of their contemporaries, who gave the United States critical support in its Cold War with the Soviet Union, radicals developed a politics of resistance rooted in a Christian framework in which repentance for dropping atomic bombs on Hiroshima and Nagasaki was the first step toward personal and national redemption. Although they had scant influence on American policymakers or the public in the early years of the Cold War, widespread opposition to nuclear testing and U.S. foreign policy in the late 1950s and 1960s launched them into leadership roles in campaigns for nuclear disarmament and peace.
Application of recombinant, activated Factor VII in the treatment and prevention of the bleeding complication of two female patients suffering from congenital XI factor deficiency during orthopedic and traumatology intervention
Authors: Moravcsik Bence , Nemes László , Zsiros Lajos
Published: August 2008

A szerzők ritka veleszületett vérzékenységben, XI-es faktorhiányban szenvedő nőbetegek ortopéd sebészeti, illetve traumatológiai műtét után jelentkező, keringésmegingást okozó vérzéses szövődményének kezelését, illetve a vérzéses szövődmény kivédését ismertetik aktivált, rekombinált VII-faktor (NovoSeven
®
, Novo Nordisk, Bagsvaerd, Denmark) alkalmazásával. Az első esetben előrehaladott, bal csípőízületi arthrosis miatt csípőízületi teljes arthroplasticát végeztek. Az ismert vérzékenység tükrében, a friss fagyasztott plazma adása ellenére, súlyos fokú utóvérzés lépett fel. A szerzők ismertetik a műtét után kialakult vérzéses epizódok időbeli dinamikáját, az újbóli feltárás dilemmáját és az alkalmazott aktivált rekombinált VII-faktor- (rFVIIa-) terápiával szerzett kedvező tapasztalataikat. A második esetben egy ismerten FXI-hiányos beteg esés során elszenvedett jobb oldali pertrochantertörésének műtéti megoldását ismertetik. A beteg korábbi műtétei során jelentős vérzékenységet tapasztaltak, ami az alkalmazott friss fagyasztott plazma adásával nehezen volt uralható, ezért a vérzéses szövődmény elkerülése érdekében a műtétet rVIIa-faktor védelmében végezték.
The safety of COX-2 inhibitors
Authors: Lakatos Gábor , Herszényi László , Tulassay Zsolt
Published: August 2008

A nemszteroid gyulladáscsökkentők (NSAID) a leggyakrabban alkalmazott gyógyszerek közé tartoznak világszerte. Az NSAID-ok súlyos emésztőszervi mellékhatásokat okozhatnak, a szerek a tápcsatorna bármely szakaszát károsíthatják. A ciklooxigenáz-2- (COX-2-) gátlók (coxibok) kifejlesztésétől változatlan gyulladáscsökkentő hatás mellett kedvezőbb emésztőszervi tulajdonságokat vártak. Számos tanulmány igazolta, hogy a coxibok alkalmazása csökkenti a gastroduodenalis fekélybetegség és a fekélyeredetű szövődmények gyakoriságát a hagyományos szerekkel összehasonlítva. Kevesebb adat ismert a coxibok vékony- és vastagbelet érintő mellékhatásairól. A COX-2 konstitutívan expresszálódik a tápcsatornában, és fontos szerepet játszik a bél integritásában. Mind több adat igazolja, hogy a coxibok növelik a szív- és érrendszeri szövődmények gyakoriságát. Az összefoglaló a coxibok biztonságosságával kapcsolatos újabb eredményeket tekinti át.
Psychosocial factors determining life expectancy of patients undergoing open heart surgery
Authors: Cserép Zsuzsanna , Losoncz Eszter , Malik Anikó , Székely Andrea , Balog Piroska , Kopp Mária
Published: August 2008

A nyitott szívműtét kimenetelét, a műtét utáni felépülést nem csupán a beteg fizikai állapota és a klinikai változók határozzák meg. Ebben a kérdésben egyre nagyobb hangsúlyt kapnak a szocioökonómiai és a pszichoszociális tényezők. Az utóbbi évtizedekben a revascularisatio eredményeinek értékelésekor előtérbe került a beteg egészségi állapotának, az egészséggel kapcsolatos életminőségének önértékelése, önbecslése (self-perceived health related quality of life). Az eddigi eredmények alapján valószínű, hogy az egészségi állapot önbecslése, a depressziós tünetegyüttes és a szorongás rövid és hosszú távon is befolyásolja a coronaria-bypassműtétet követő felépülést. Az egyedül élők, a szociálisan elszigeteltek körében szintén magasabb morbiditási és mortalitási kockázattal kell számolnunk. Az alacsonyabb iskolázottság és a rossz szociális háttér szintén szerepet játszhat a magasabb halálozási arányok alakulásában. Összefoglaló tanulmányunkban megpróbálunk áttekintést adni a szívműtét kimenetelét befolyásoló pszichoszociális tényezőkről.
Endoscopic saphenic vein harvesting during coronary artery bypass operations
Authors: Vígh András , Rashed Aref , Alotti Nasri , Sipos József
Published: August 2008

Az ischaemiás szívbetegség gyógyításában meghatározó jelentőségű coronaria-bypassműtétek során a szerzők leggyakrabban vena saphena magna graftot használnak az áthidalásokhoz. Tekintettel a betegek növekvő életkorára, a több társbetegségre, a rosszabb általános állapotra, alapvető jelentőségű a lehető legkisebb sebfelület kialakítása az ilyen műtétek alatt.
Célkitűzés:
A vizsgálatok célja az endoszkópos saphenakivétel által adott lehetőségek felmérése, illetve az így nyert saphenagraft minőségének megítélése volt.
Módszer:
A szerzők 24 betegnél használtak endoszkópos technikát a vena saphena kivételére coronaria-bypassműtét vagy kombinált billentyű-coronaria bypassműtét során. A kivett vénából szövettani vizsgálatra 10 alkalommal küldtek mintát a vena-endothel megítélésére.
Eredmények:
Sebszövődmény a módszer alkalmazása után nem volt. A kivett vénaszakaszokat a műtétek során felhasználták, két esetet kivéve, amikor a véna kis kaliberűnek bizonyult. A szövettani vizsgálat minden esetben a véna ép endothelrétegét igazolta.
Következtetés:
Az endoszkópos technika jól alkalmazható a vena saphena eltávolítására bypassműtétek során. Alkalmazásának a szerzők jelenlegi gyakorlatában határt szab az egyelőre hosszabb műtéti idő (amely a későbbiekben remélhetőleg rövidülni fog).
The serotonin transporter gene and personality: association of the 5-HTTLPR s allele, anxiety, depression and affective temperaments
Authors: Gonda Xénia
Published: August 2008

Az 5-HTTLPR-polimorfizmus kiemelt szerepet játszik a hangulatzavarok és a neuroticismus hátterében. Vizsgálatunk célja az 5-HTTLPR és a neuroticismus komponensei közül a szorongásra és a depresszióra való hajlam és az affektív labilitás összefüggésének vizsgálata volt pszichiátriailag egészséges populációban. A vizsgálat résztvevői a Spielberger-féle vonás- és állapotszorongás kérdőívet (STAI), a Zung-féle önértékelő depresszióskálát (ZSDS), valamint a TEMPS-A kérdőívet töltötték ki. Az 5-HTTLPR genotípust PCR segítségével határoztuk meg. A pontszámokat a különböző csoportokban ANOVA segítségével hasonlítottuk össze. Az s allélt hordozók szignifikánsan magasabb pontszámot kaptak a ZSDS és a STAI állapotszorongás-skálán, valamint a depresszív komponenst hordozó affektívtemperamentum-skálákon is. Eredményeink szerint a neuroticismus komponensei önállóan is összefüggést mutatnak az 5-HTTLPR-polimorfizmussal, ami a vonás egységességét támasztja alá. Eredményeink rámutatnak további kutatások szükségességére az egészséges populációban megfigyelhető vonások genetikai hátterének feltárásával kapcsolatban, mivel ezek a neuropszichiátriai betegségek endofenotípusaiként a jövőbeli kutatások alapvető építőkövei lehetnek.
Differentiation of Neural Stem Cells into Oligodendrocytes: Involvement of the Polycomb Group Protein Ezh2
Authors: Sher Falak , Rößler Reinhard , Brouwer Nieske , Balasubramaniyan Veerakumar , Boddeke Erik , Copray Sjef
Published: August 2008

The mechanisms underlying the regulation of neural stem cell (NSC) renewal and maintenance of their multipotency are still not completely understood. Self-renewal of stem cells in general implies repression of genes that encode for cell lineage differentiation. Enhancer of zeste homolog 2 (Ezh2) is a Polycomb group protein involved in stem cell renewal and maintenance by inducing gene silencing via histone methylation and deacetylation. To establish the role of Ezh2 in the maintenance and differentiation of NSCs, we have examined the expression of Ezh2 in NSCs isolated from embryonic (embryonic day 14) mice during proliferation and differentiation in vitro. Our results show that Ezh2 is highly expressed in proliferating NSCs. In accordance with its suggested role as a transcription repressor, the expression of Ezh2 decreased when the NSCs differentiated into neurons and was completely suppressed during differentiation into astrocytes. Surprisingly, Ezh2 remained highly expressed in NSCs that differentiated into an oligodendrocytic cell lineage, starting from oligodendrocyte precursor cells (OPCs) up to the immature (premyelinating) oligodendrocyte stage. To further establish the role of Ezh2 in NSC differentiation, we silenced and induced overexpression of the Ezh2 gene in NSCs. High levels of Ezh2 in differentiating NSCs appeared to be associated with an increase in oligodendrocytes and a reduction in astrocytes, whereas low levels of Ezh2 led to completely opposite effects. The increase in the number of oligodendrocytes induced by enhanced expression of Ezh2 could be ascribed to stimulation of OPC proliferation although stimulation of oligodendrocyte differentiation cannot be excluded.

Disclosure of potential conflicts of interest is found at the end of this article.
Bone Marrow-Derived Mesenchymal Stromal Cells Express Cardiac-Specific Markers, Retain the Stromal Phenotype, and Do Not Become Functional Cardiomyocytes In Vitro
Authors: Rose Robert A. , Jiang Huijie , Wang Xinghua , Helke Simone , Tsoporis James N. , Gong Nanling , Keating Stephanie C.J. , Parker Thomas G. , Backx Peter H. , Keating Armand
Published: August 2008

Although bone marrow-derived mesenchymal stromal cells (MSCs) may be beneficial in treating heart disease, their ability to transdifferentiate into functional cardiomyocytes remains unclear. Here, bone marrow-derived MSCs from adult female transgenic mice expressing green fluorescent protein (GFP) under the control of the cardiac-specific α-myosin heavy chain promoter were cocultured with male rat embryonic cardiomyocytes (rCMs) for 5–15 days. After 5 days in coculture, 6.3% of MSCs became GFP+ and stained positively for the sarcomeric proteins troponin I and α-actinin. The mRNA expression for selected cardiac-specific genes (atrial natriuretic factor, Nkx2.5, and α-cardiac actin) in MSCs peaked after 5 days in coculture and declined thereafter. Despite clear evidence for the expression of cardiac genes, GFP+ MSCs did not generate action potentials or display ionic currents typical of cardiomyocytes, suggesting retention of a stromal cell phenotype. Detailed immunophenotyping of GFP+ MSCs demonstrated expression of all antigens used to characterize MSCs, as well as the acquisition of additional markers of cardiomyocytes with the phenotype CD45−-CD34+-CD73+-CD105+-CD90+-CD44+-SDF1+-CD134L+-collagen type IV+-vimentin+-troponin T+-troponin I+-α-actinin+-connexin 43+. Although cell fusion between rCMs and MSCs was detectable, the very low frequency (0.7%) could not account for the phenotype of the GFP+ MSCs. In conclusion, we have identified an MSC population displaying plasticity toward the cardiomyocyte lineage while retaining mesenchymal stromal cell properties, including a nonexcitable electrophysiological phenotype. The demonstration of an MSC population coexpressing cardiac and stromal cell markers may explain conflicting results in the literature and indicates the need to better understand the effects of MSCs on myocardial injury.

Disclosure of potential conflicts of interest is found at the end of this article.
Functional and size typology of the village settlements in the city of Nis territory
Authors: Mitkovic Petar , Vasilevska Ljiljana , Bogdanovic Ivana , Dinic Milena
Published: August 2008

The paper gives an analysis of the functional and size typology of the village settlements in the city of Nis territory. It also presents the review of the development and demographic tendencies of the spatial distribution of the village settlements, as well as the categorization of the village settlements in the city of Nis territory. The paper was done in the framework of the scientific and research project "Sustainahle development of the village settlements in the city of Nis territory" at the Faculty of Civil Engineering and Architecture of Nis.
Modeling conoid surfaces
Authors: Velimirovic Ljubica , Stankovic Mica , Radivojevic Grozdana
Published: August 2008

In tins paper we consider conoid surfaces as frequently used surfaces in building techniques, mainly as daring roof structures. Different types of conoids are presented using the programme package Mathematica. We describe the generation of conoids and by means of parametric representation we get their graphics. The geometric approach offers a wide range of possibilities in the research of complicated spatial surface systems.
Determination of intersecting curve between two surfaces of revolution with parallel axes by use of auxiliary planes and auxiliary spheres
Authors: Obradovic Ratko
Published: August 2008

In this paper the space intersecting curve between two surfaces of revolution with parallel axes of surfaces have been determined. Two mathematical models for determination of intersecting curve between two surfaces of revolution have been formed: auxiliary planes have been used in the first mathematical model and auxiliary spheres have been used in the second model (Obradovic 2000). In the first case each auxiliary plane intersected with each surface of revolution on circle and two points of intersecting curve are obtained as intersecting points between these two circles. In the second case centres of two locks of auxiliary spheres are put on axes of surfaces of revolution (centre of first lock is on axis of the first surface of revolution and centre of second lock is on axis of the second surface of revolution) on saine z coordinate (when axes of surfaces of revolution are parallel with z axis of coordinate system). First lock sphere intersects the first surface of revolution on w1 parallels and second lock corresponding sphere intersects the second surface of revolution on w2 circles. It is possible to find a relationship that for selected radius of the first lock sphere can determine the radius of second lock sphere and real points of intersecting curve have been determined by use of these two spheres. The points of intersecting curve between two surfaces of revolution are obtained by intersection between w1 circles from the first surface with w2 circles from the second surface (Obradovic 2000).
Some relevant aspects of footbridge vibrations
Authors: Spasojevic Ana , Djordjevic Djordje , Spasojevic Marija , Spasojevic Novak
Published: August 2008

Considering the contemporary structural inaterials that are becoming more resistant, having higher strength to weight ratio, and the fact that live load of footbridges is low, the design based on static analysis only, respecting ultimate limit states requirements, leads to slender bridge structures for pedestrian and cycle track use. As a consequence, stiffness and masses decrease, facing lively, easy to excite structures, with smaller natural frequencies. The excitation of a footbridge by a pedestrian passing over it can be unpleasant for a person walking or standing on the bridge, but usually not destructive for the structure itself. Recent experiences regarding dynamic behavior of slender footbridges have especially shown that vibration serviceability limit states are very important requirements in any structural design. We are presenting a general algorithm for analytical testing of dynamic parameters of structures, calculation of deflection, thus speed and acceleration of superstructure under human-induced excitation, as predicted by Eurocode, British and Canadian standards in use, since no Yugoslav code deals with the problem. The evaluated system is a footbridge in a system of a simply supported concrete girder. The presented model is used to show correspondence of results, obtained by the algorithm, with the results obtained using the simplified methods suggested by the Codes of Practice, since the latter exists only for certain structural systems.
Geometry of straight lines pencils
Authors: Janic Milan , Tanikic Dejan
Published: August 2008

This paper considers a pencil of straight Unes in the Euclidean plane as well as the same pencil of straight lines in the projective plane where the projective geometry model M" is defined with its points forming the sets of (n-l) collinear points, whose supporting straight lines belong to the considered pencil of straight lines.
Application of Petri nets for transport streams modeling
Authors: Filipova Krasimira , Stojadinova Tanja , Hadjiatanasova Vihra
Published: August 2008

One of the possible methods for transport stream modeling is by using Petri's nets [1,2]. This approach turns out to be very convenient for achieving the desired tasks because of the following reasons: the Petri's nets [3] are based on causal-consequence connections found in abundance in transport problems and the graphical representation by means of the net elements is easily percieved by man, i.e. there an easy way of visualisation of the transport problem under consideration. Examples will be given of how transport problems are modeled.
Reactive loading function on tunnel excavation contour in rock mass
Authors: Lukic Dragan , Anagnosti Petar
Published: August 2008

Investigation of the stress field around the cavity that is loaded or partially loaded at the inner surface by the rotationally symmetric loading is still the contemporary problem in the theory of elasticity. As the contribution to the similar investigations, the paper introduces the new function of loading in the form of the infinite sine series. Besides the definition of the mentioned loading function as the boundary condition on inner surface of the cavity, the paper presents the comparative analysis of the new function with the previously used ones. The said loading function at the inner surface of a cavity is internal loading between rock mass and supporting structure, for the case of homogeneous isotropic elastic medium as the first approximation of the real situation.
Design methods of a timber-concrete T-cross-section
Authors: Cvetkovic Radovan , Stojic Dragoslav
Published: August 2008

This paper deals with the composite timber-concrete structures. By combining timber and concrete in a new type of composite material and using the best properties of both materials (the high tensile strength of timber and the high compressive strength of concrete) a new type of composite structure is obtained, which can have many applications, depending on the different building conditions, due to the certain advantages it has over concrete or steel structures. Here, the design procedures according to the theory of elasticity based on the exact method and approximate method are given in order, and particularly according to the regulations and recommendations of the modern concept for design of timber structures and concrete structures given in Eurocode 5 and based on the limit states of bearing capacity and usability of structures.
Models for the choice of the most favorable contractor for construction of the thermal insulation systems
Authors: Zlatanovic Milorad , Trajkovic Dima
Published: August 2008

The paper considers the multi-criterion models of the choice of the most favorable contractor for construction of the thermal insulation system at the previously constructed buildings. The paper is a contribution to the consideration of the most favorable contractor, as it is one of the very important decisions of the investor. A large number of variant solutions is proposed. Firstly, the criteria for the choice of the most favorable contractor of these works are formed. Then, a methodology for the choice of the contractor for the construction of the facade thermal insulation system is presented, that is the mathematical models for the solution of such problem are presented, with a purpose to determine the optimal solution that is, make a choice of the most favorable contractor of these works.
Design of the vapor diffusion characteristics of the exterior facing of the facade thermal insulation systems
Authors: Bogdanovic Veliborka , Milanovic Danijela
Published: August 2008

Various facade facings - systems made of thermal insulation materials with the finishing facade renders which are directly applied to the facade walls are simple for construction and are applied in the newly built structures and they are also suitable for the application in the cases of the energy revitalization of the existing buildings. The exterior walls, and especially their outer layers, are exposed to various atmospheric influences. They cause different effects in the walls, one of them being the occurrence of the water vapor condensation. In the walls with the facade thermal insulation systems, the occurrence of the water vapor condensation may be caused by the vapor diffusion characteristics of the exterior render. At certain temperatures and humidity of the external and internal air, there are several conditions for the occurrence of the water vapor condensation in the wall with the facade thermal insulation system, when the exterior render is of higher relative resistance to the water vapor diffusion. Therefore, it is useful to determine the vapor diffusion characteristics, that is, highest values of the relative resistance to the water vapor diffusion of the exterior renders which will not cause the condensation of the water vapor in the wall, or at least those that will not cause the impermissible dampening of the wall material, and will allow for the possibility of moisture drying.
Implications of Robert Venturi's theory of architecture
Authors: Hearn Fil
Published: August 2008

Beginning with a functional program, the rational design method adopted by modernist architects took cognizance of neither cultural meaning nor context. Although criticized for these shortcomings by post-modern theorists, no means of introducing such concerns into the planning process has ever been proposed. This essay sets out a possible procedure ? based on the ancient theory of rhetoric ? that addresses these matters first, before turning to functional considerations. Its virtue is that it can be employed while otherwise leaving intact the prevailing method of design development.
The check of important monuments with topographical methodologies
Authors: Bezoari Giorgio
Published: August 2008

The static control of architectural monuments has some important and impressive applications in topographical methodologies. Two interesting examples of the topographic control methods concern the very famous Byzantine S. Marco Basilica in Venice and the Cathedral of Como, situated in the North of Italy. The measurements carried out in the static control field are in reference to the: lengths variation, transversal variation according to a specific direction and height variation. In the paper, one can find the description of the instruments and of the methodologies employed in the static control.
The criteria for the evaluation of the existing schools in the rural area in the city of Nis territory
Authors: Stankovic Danica , Bogdanovic Ivana , Tanic Milan
Published: August 2008

After the announced first phase of the recorded material collecting and the information on the existing schools in the rural areas in the administrative are of the City of Nis, the data base on the schools in 68 villages was created. In this paper, the possible systematization models for the existing schools have been presented, and the criteria for the analysis and its evaluation in respect to the determined set of parameters have been defined. The conducted classifications make further research possible and gives the guidelines for the concrete action in the revitalization of the education and the village development.
Implementation of computer technologies in descriptive geometry teaching: Surfaces of revolution
Authors: Stulic Radovan , Atanackovic Jelena
Published: August 2008

The proper estimation of computer technologies is very important when computers are to be implemented in the educational process. Otherwise, if not implemented properly, the quality of students' education may be seriously imperiled. This is crucial when Descriptive geometry (DG) is the matter; the discipline that develops and improves the students' spatial visualization ability (SVA). Unfortunately, nowadays, there is a tendency that some educators, mostly non- geometricians, being destitute of profound knowledge of DG, and not fully understanding the fundamental importance of DG, find themselves involved in computerization of DG, using various CAD programs and thus, force students to (computer aided ? CA) draw already well known standardized objects and consequently train their capabilities typical for draughtsman. In this paper we, propose how and to which extent the computerization of DG should be carried out. The previous has been governed by the criteria of facilitating students' comprehension of spatial relationships, orientation and visualization. We have developed the procedure for the representation of surfaces of revolution (SOR) and their shades and shadows on planes. What is to be emphasized on the matter is that each CA approach to DG teaching should follow the traditional DG reasoning and the step-by-step acquisition of fine solution, offering students the possibility of gradual process of visualization.
Identical appended series of points as invariants in the collocal general-colinear fields
Authors: Krasic Sonja
Published: August 2008

In order to bring the collocal collinear fields from the general into the perspective position, it is required to determine the identical appended series of points. Because of the properties depending on the projectivity that is given by the four appended points (straight lines) the appended identical series of the points and types are ranked among the invariants of general-collinear and perspectively-collinear fields. The procedure of determination of appended identical series of points is comprised of the following: in the set of ?1 of perspectively similar series in one field (whose center of perspective is a point on the vanishing line), find those that are identical to all the series in the set ?1 of perspective identical series of points in the other field (whose center of perspective is the point on the infinitely distant straight line). In the procedure, one begins from the appended similar methods obtained by the general method. The procedure is simplified by the introduction of the specially given similar series of points.
Foundations of Byzantine late middle ages architecture thoughtfulness
Authors: Milosevic Predrag
Published: August 2008

Only in the recent few years have a number of facsimile publications on architecture offered a possibility of studying the original texts from different time periods. Those, already rare studies on the theory of architecture in the western civilization, almost regularly completely omit the Byzantine achievements in the so-called entirety of thoughtfulness (enkyklios paideia), that was a main characteristic of Byzantine learning. This learning, based on the ancient Greek and Hellenistic foundations, in many ways concern architecture, especially the architectural theory. That is why writing a good account of the architectural theory of this, historically such an important country as Byzantium, in such a long historical period (since 312 till 1453), has been a difficult task (this contribution is just the initial part of the study). One should not be disregarded that the architectural theories are never completely independent of historical geographical or even personal prejudices of their authors. In this sense, a subject matter of this treatise is just one 1141 year long part of the architectural theory of the West (West - in civilizational terms, not a political West), the part that rests on Christian foundations that is the Orthodox, Roman Catholic and Protestant ones, mainly. It is all treated in order, from ancient pagan Greece and Rome, ancient and Middle Ages Orthodox Byzantium, until Middle Ages and New Age Europe, altogether, Orthodox, Roman Catholic and Protestant Europe, and then those parts of the world in which the said civilizational circle managed to take root in: parts of Asia, North and South America, parts of Africa and Australia.
A constructive model of orthogonal axonometry
Authors: Dicheva-Kirilova Natasha , Jivkova-Todorova Jaklina
Published: August 2008

A new method for object representation in arbitrary orthogonal axonometry is suggested. Constructions for a point drawing are shown, using two rotations - a rotation of the coordinate plane Oxy to the profile plane and a rotation of the profile plane to the projection plane. Using these simple constructions, an object can be projected on arbitrary plane. Plane figures (circles and polygons) can be pictured, too.