Topological phase transition in a RNA model in the de Gennes regime

We study a simplified model of the RNA molecule proposed by G. Vernizzi, H. Orland and A. Zee in the regime of strong concentration of positive ions in solution. The model considers a flexible chain of equal bases that can pairwise interact with any other one along the chain, while preserving the property of saturation of the interactions. In the regime considered, we observe the emergence of a critical temperature T_c separating two phases that can be characterized by the topology of the predominant configurations: in the large temperature regime, the dominant configurations of the molecule have very large genera (of the order of the size of the molecule), corresponding to a complex topology, whereas in the opposite regime of low temperatures, the dominant configurations are simple and have the topology of a sphere. We determine that this topological phase transition is of first order and provide an analytic expression for T_c. The regime studied for this model exhibits analogies with that for the dense polymer systems studied by de GennesComment: 15 pages, 4 figure

Cfd simulations of thermal comfort in naturally ventilated primary school classrooms

The purpose of thermal comfort is to speck the combinations of indoor space environment and personal factors that will produce thermal environment conditions acceptable to 80% or more of the occupants within a space. Naturally ventilated indoors has a very complex air movement, which depends on numerous variables such as: outdoor interaction, intensity of infiltration, the number of openings, the thermal inertia of walls, occupant behaviors, etc. The most important mechanism for naturally ventilated indoors is the intensity of infiltration and thermal buoyancy mechanism. In this study the objective was to determine indicators of thermal comfort for children, by the CFD model based on experimental measurements with modification on turbulent and radiant heat transfer mathematical model. The case study was selected on school children of 8 and 9 years in "France Presern" primary school in Belgrade. The purpose was to evaluate the relationships between the indoor environment and the subjective responses. Also there was analysis of infiltration and stack effect based on meteorological data on site. The main parameters that were investigated are: operative temperature, radiant temperature, concentration of CO2, and air velocity. The new correction of turbulence and radiative heat transfer models has been validated by comparison with experimental data using additional statistical indicators. It was found that both turbulence model correct and the new radiative model of nontransparent media have a significant influence on CFD data set accuracy

Cfd simulations of thermal comfort in naturally ventilated primary school classrooms

The purpose of thermal comfort is to speck the combinations of indoor space environment and personal factors that will produce thermal environment conditions acceptable to 80% or more of the occupants within a space. Naturally ventilated indoors has a very complex air movement, which depends on numerous variables such as: outdoor interaction, intensity of infiltration, the number of openings, the thermal inertia of walls, occupant behaviors, etc. The most important mechanism for naturally ventilated indoors is the intensity of infiltration and thermal buoyancy mechanism. In this study the objective was to determine indicators of thermal comfort for children, by the CFD model based on experimental measurements with modification on turbulent and radiant heat transfer mathematical model. The case study was selected on school children of 8 and 9 years in "France Presern" primary school in Belgrade. The purpose was to evaluate the relationships between the indoor environment and the subjective responses. Also there was analysis of infiltration and stack effect based on meteorological data on site. The main parameters that were investigated are: operative temperature, radiant temperature, concentration of CO2, and air velocity. The new correction of turbulence and radiative heat transfer models has been validated by comparison with experimental data using additional statistical indicators. It was found that both turbulence model correct and the new radiative model of nontransparent media have a significant influence on CFD data set accuracy

Comparative evaluation of antimutagenic and antimitotic effects of Morchella esculenta extracts and protocatechuic acid

Morchella esculenta (L.) Pers. methanolic extracts, obtained from fruiting bodies growing wild in Serbia and Portugal, were screened for their antimutagenic properties and compared to protocatechuic acid, previously identified in both species. Salmonella typhimurium TA100 reversion assay was used for the antimutagenic properties. Methanolic extracts expressed important antimutagenic potency towards S. typhimurium, which was documented by index of antimutagenicity (I). Sample from Serbia expressed slightly higher antimutagenic properties with inhibition rate of 58.7%. Sample from Portugal gave inhibition rate of 51.7%. Protocatechuic acid had inhibition rate I of his+ revertants of 72.4%. Cell viability in the presence of extracts was also documented. M. esculenta samples from Serbia and Portugal possessed novel biological potential for the studied species, as well as its phenolic compound – protocatechuic acid, identified in both samples. Genotoxic effect, regarding mitotic index and chromosomal aberration score, was also assessed by using Allium cepa L. assay. Protocatechuic acid showed the most significant decrease in mitotic index, as well as decrease in chromosomal aberration score.Serbian Ministry of Education, Science and Technological Development; FCT Portugal; COMPETE/QREN/EU, PTDC/AGR-ALI/110062/2009 PEst-OE/AGR/UI0690/201

Comparative evaluation of antimutagenic and antimitotic effects of Morchella esculenta extracts and protocatechuic acid

Morchella esculenta (L.) Pers. methanolic extracts, obtained from fruiting bodies growing wild in Serbia and Portugal, were screened for their antimutagenic properties and compared to protocatechuic acid, previously identified in both species. Salmonella typhimurium TA100 reversion assay was used for the antimutagenic properties. Methanolic extracts expressed important antimutagenic potency towards S. typhimurium, which was documented by index of antimutagenicity (I). A sample from Serbia expressed slightly higher antimutagenic properties with an inhibition rate of 58.7%. A sample from Portugal gave an inhibition rate of 51.7%. Protocatechuic acid had an inhibition rate I of his(+) revertants of 72.4%. Cell viability in the presence of extracts was also documented. M. esculenta samples from Serbia and Portugal possessed novel biological potential for the studied species, as well as its phenolic compound - protocatechuic acid, identified in both samples. Genotoxic effect, regarding mitotic index and chromosomal aberration score, was also assessed by using the Allium cepa L. assay. Protocatechuic acid showed the most significant decrease in mitotic index, as well as decrease in chromosomal aberration score

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Observation of Associated Near-Side and Away-Side Long-Range Correlations in sqrt[s_{NN}]=5.02 TeV Proton-Lead Collisions with the ATLAS Detector.

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in sqrt[s_{NN}]=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb^{-1} of data as a function of transverse momentum (p_{T}) and the transverse energy (ΣE_{T}^{Pb}) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) "near-side" (Δϕ∼0) correlation that grows rapidly with increasing ΣE_{T}^{Pb}. A long-range "away-side" (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣE_{T}^{Pb}, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣE_{T}^{Pb} dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣE_{T}^{Pb} ranges and particle p_{T}

Implementation of Dual Quaternion-based Robot Forward Kinematics Algorithm in ROS

This paper presents a method for the implementation of a robot forward kinematics algorithm that complies with the Denavit-Hartenberg (DH) convention in Robot Operating System (ROS). The integration of the algorithm in ROS is based on the representation of DH parameters in dual quaternion space. The main motivation for the presented research is to make use of ROS powerful visualization tools available in tasks that require robot forward kinematics calculation while keeping the principles of DH robot modeling convention. Implementation of the dual quaternion-based robot forward kinematics algorithm in ROS is demonstrated using a serial 6DoFs robot as an example

First Report of Anthracnose on Alfalfa Caused by Colletotrichum linicola in Serbia

Alfalfa (Medicago sativa L.) is economically the most important forage crop in Serbia. In July 2009, alfalfa plants showed symptoms characteristic of anthracnose disease (“shepherd's crook”) including wilting and death of the upper portion of the stems. Anthracnose of alfalfa has been reported to be caused by Colletotrichum trifolii or C. destructivum (2). Alfalfa plants with anthracnose symptoms were collected in Srpska Crnja, South Banat District, Serbia. Infected tissue samples were surface disinfected with 5% sodium hypochlorite for 2 min and washed three times for 5 min in sterile distilled water. Surface sterilized tissue was transferred to sterile filter paper and placed on potato dextrose agar (PDA), and incubated at 24°C in the dark for 10 days (1). Developing colonies were light to dark olive green. In cultures on PDA medium, acervuli were formed. Conidia from acervuli were released in mucous masses that were orange to cream-pink in color. Conidia were hyaline, aseptate, straight with one end pointed and the other slightly rounded, measuring 12.5 to 25.0 × 2.5 to 7.5 μm (mean 19.83 × 4.42 μm). After 5 days, numerous setae were formed. The setae were slightly darker at the bottom and lighter at the top, septate with 3 septa. Setae dimensions were 100 to 185.5 × 2.5 to 5 μm (average 160.9 × 3.12 μm). The isolated fungus was designated Coll-44. Stems of 30 7-week-old plants were spray-inoculated in the laboratory with an aqueous suspension of conidia (106 spores per ml; 10 ml per plant) harvested from 7-day-old cultures grown on PDA. The plants and two non-inoculated check plants were placed in a greenhouse and a covered with plastic bags at 25°C in darkness. After 48 h, plastic bags were removed from the all plants. All plants were watered once a day. Symptoms were observed 10 days after inoculation. No symptoms were observed on non-inoculated plants. In the greenhouse, all 30 inoculated plants became diseased with anthracnose symptoms after 10 days. Coll-44 was consistently re-isolated from diseased stem tissue. Koch's postulates were fulfilled by re-isolation from inoculated alfalfa plants. Pure culture of the Coll-44 isolate was deposited in the public collection of CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands (specimen no. CBS 3263). Partial sequences of the internal transcribed spacer regions-ITS (GenBank Accession No. JX908364) and betatubulin-TUB2 gene (KJ556347) were amplified and sequenced from extracted fungal DNA with primer pairs ITS1-ITS4 (4) and T1-Bt2b (3), respectively. ITS sequence of the Coll-44 isolate showed 100% nucleotide identity to the GenBank accessions JQ005765 and AB046609 of C. linicola. TUB2 sequence of isolate Coll-44 showed 99.6% nucleotide identity with the GenBank accession JQ005849 of C. linicola isolate CBS 172.51. To our knowledge, this is the first report of C. linicola causing alfalfa anthracnose in Serbia. References: (1) A. P. Baxter et al. S. Afr. J. Bot. 2:259, 1983. (2) K. D. Hyde et al. Fungal Divers. 39:1, 2009. (3) K. O'Donnell and E. Cigelnik. Mol. Phylogenet. Evol. 7:103, 1997. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. </jats:p

Sorbus sp - New host of Erwinia amylovora in Serbia

In 1989 Erwinia amylovora was confirmed to be a pathogen of pear and quince in Serbia. Subsequently, apple, firethorn, hawthorn, Mespilus spp., Cotoneaster horisontalis and Cheanotneles spp. were confirmed as hosts of the pathogen. During the summer 2005, fire blight symptoms were observed on Sorbus spp. for the first time in the south-eastern Serbia, near Nis. Disease symptoms included leaf and shoot blight and cankers with purple-brown colouration of necrotic tissue on mature branches. The diseased tissue was macerated and the suspension was streaked on nutrient sucrose agar (NAS) and King's medium B. Typical light grey, levan-positive colonies developed on NAS medium after two day incubation at 25 degrees C. Colonies on King's medium B were white and nonfluorescent. The results of physiological and biochemical tests of the bacterium were as follows: gram negative, oxidative and fermentative metabolism of glucose; oxidase negative, gelatin hydrolysis positive, aesculin hydrolysis negative and acid produced from most carbon sources. In pathogenicity tests, all isolates induced HR in tobacco leaves and necrosis on artificially inoculated pear fruits followed by appearence of bacterial ooze. After inoculation of petioles and shoots of the host plant (Sorbus spp.) initial symptoms were dark green, watersoaked, eliptical spots on inoculated tissues. Leaf and shoot blight resembling the natural infection appeared five to six days after inoculation. The investigated strains reacted positively with antisera specific to E. amylovora in DASI ELISA test. Identity of isolated strains also was confirmed by polymerase chain reaction (PCR). According to the biochemical and physiological characteristics, pathogenicity tests, results of PCR analyses and ELISA test, strains isolated from Sorbus spp. plants were identified as E. amylovora. This is the first report of E. amylovora on Sorbus spp. plants in Serbia