Participation Traders Separating Waste In Pasar Baru Tampan Sub District Pekanbaru City

Garbage is defined as something that is not used anymore, unused, or something that is thrown away, which is derived from human activities and does not happen by itself. The market is one of the human activities that produce large amounts of garbage every day, when the waste sorting system is not good, it will make it difficult to carry out waste management and will have an impact on health directly or indirectly. This study aims to determine the factors associated with the participation of traders in waste sorting in Tampan Sub district  Pasar Baru  Pekanbaru.This study is quantitative research with cross sectional design. This research was conducted April 2015, sample in this study is 79 merchants. Data were collected by using questionnaires and observation. Data analysis for bivariate with chi-square test with 95% confidence level with α = 0.05. The results showed that there is a relationship between education (OR = 2,60  ; CI: 1,08-3,67),  socialization  (OR = 3,10; CI: 2,58-5,99) availability of trash waste (OR = 8,25 ; CI: 2,98-7,55 with waste sorting participation

Mechanism of strand displacement synthesis by DNA replicative polymerases

Replicative holoenzymes exhibit rapid and processive primer extension DNA synthesis, but inefficient strand displacement DNA synthesis. We investigated the bacteriophage T4 and T7 holoenzymes primer extension activity and strand displacement activity on a DNA hairpin substrate manipulated by a magnetic trap. Holoenzyme primer extension activity is moderately hindered by the applied force. In contrast, the strand displacement activity is strongly stimulated by the applied force; DNA polymerization is favoured at high force, while a processive exonuclease activity is triggered at low force. We propose that the DNA fork upstream of the holoenzyme generates a regression pressure which inhibits the polymerization-driven forward motion of the holoenzyme. The inhibition is generated by the distortion of the template strand within the polymerization active site thereby shifting the equilibrium to a DNA-protein exonuclease conformation. We conclude that stalling of the holoenzyme induced by the fork regression pressure is the basis for the inefficient strand displacement synthesis characteristic of replicative polymerases. The resulting processive exonuclease activity may be relevant in replisome disassembly to reset a stalled replication fork to a symmetrical situation. Our findings offer interesting applications for single-molecule DNA sequencing

Asymmetric DNA requirements in Xer recombination activation by FtsK

In bacteria with circular chromosomes, homologous recombination events can lead to the formation of chromosome dimers. In Escherichia coli, chromosome dimers are resolved by the addition of a crossover by two tyrosine recombinases, XerC and XerD, at a specific site on the chromosome, dif. Recombination depends on a direct contact between XerD and a cell division protein, FtsK, which functions as a hexameric double stranded DNA translocase. Here, we have investigated how the structure and composition of DNA interferes with Xer recombination activation by FtsK. XerC and XerD each cleave a specific strand on dif, the top and bottom strand, respectively. We found that the integrity and nature of eight bottom-strand nucleotides and three top-strand nucleotides immediately adjacent to the XerD-binding site of dif are crucial for recombination. These nucleotides are probably not implicated in FtsK translocation since FtsK could translocate on single stranded DNA in both the 5′–3′ and 3′–5′ orientation along a few nucleotides. We propose that they are required to stabilize FtsK in the vicinity of dif for recombination to occur because the FtsK–XerD interaction is too transient or too weak in itself to allow for XerD catalysis

DNA mechanics as a tool to probe helicase and translocase activity

Helicases and translocases are proteins that use the energy derived from ATP hydrolysis to move along or pump nucleic acid substrates. Single molecule manipulation has proved to be a powerful tool to investigate the mechanochemistry of these motors. Here we first describe the basic mechanical properties of DNA unraveled by single molecule manipulation techniques. Then we demonstrate how the knowledge of these properties has been used to design single molecule assays to address the enzymatic mechanisms of different translocases. We report on four single molecule manipulation systems addressing the mechanism of different helicases using specifically designed DNA substrates: UvrD enzyme activity detection on a stretched nicked DNA molecule, HCV NS3 helicase unwinding of a RNA hairpin under tension, the observation of RecBCD helicase/nuclease forward and backward motion, and T7 gp4 helicase mediated opening of a synthetic DNA replication fork. We then discuss experiments on two dsDNA translocases: the RuvAB motor studied on its natural substrate, the Holliday junction, and the chromosome-segregation motor FtsK, showing its unusual coupling to DNA supercoiling

Structural plasticity of single chromatin fibers revealed by torsional manipulation

Magnetic tweezers are used to study the mechanical response under torsion of single nucleosome arrays reconstituted on tandem repeats of 5S positioning sequences. Regular arrays are extremely resilient and can reversibly accommodate a large amount of supercoiling without much change in length. This behavior is quantitatively described by a molecular model of the chromatin 3-D architecture. In this model, we assume the existence of a dynamic equilibrium between three conformations of the nucleosome, which are determined by the crossing status of the entry/exit DNAs (positive, null or negative). Torsional strain, in displacing that equilibrium, extensively reorganizes the fiber architecture. The model explains a number of long-standing topological questions regarding DNA in chromatin, and may provide the ground to better understand the dynamic binding of most chromatin-associated proteins.Comment: 18 pages, 7 figures, Supplementary information available at http://www.nature.com/nsmb/journal/v13/n5/suppinfo/nsmb1087_S1.htm

Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics

Quelques expériences entre physique, chimie, biologie :<br />formations de boucles dans l'ADN, moteurs moléculaires et<br />ségrégation chromosomique, excitation biphotonique,<br />spectroscopie de corrélation de fluorescence...

In the first part, we describe the use of the single DNA micromanipulationtechnique called magnetic tweezers to study the loop formationkinetics and thermodynamics in DNA caused by the GalR repressor.We alsostudied the properties of the DNA translocase FtsK involved in chromosomesegregation in E. coli. In a second part we present experiments using twophotons excitation. In a first set of experiments we did built an apparatus toperform two photons cross section absorption for molecules synthesized inthe laboratory. Then we used fluorescence correlation spectroscopy to measurediffusion coefficents and kinetics constants.Dans une première partie nous avons utilisé des techniques demicromanipulations de molécules d'ADN uniques avec des pinces magnétiquespour étudier la cinétique et thermodynamique de formation de bouclessur l'ADN par le répresseur GalR. Nous avons également étudié les propriétésde la translocase à ADN FtsK impliquée dans la ségrégation des chromosomeschez E. coli. Dans une seconde partie nous avons mis en place différentesexpériences utilisant l'excitation biphotonique. Tout d'abord nousavons construit un dispositif pour mesurer les sections efficaces d'absorptionà deux photons de molécules synthétisées au laboratoire.Nous avons ensuitemis en place la technique de corrélation de fluctuations de fluorescence pourmesurer des coefficients de diffusion et des constantes cinétiques