DNA flexibility on short length scales probed by atomic force microscopy

Unusually high bending flexibility has been recently reported for DNA on short length scales. We use atomic force microscopy (AFM) in solution to obtain a direct estimate of DNA bending statistics for scales down to one helical turn. It appears that DNA behaves as a Gaussian chain and is well described by the worm-like chain model at length scales beyond 3 helical turns (10.5nm). Below this threshold, the AFM data exhibit growing noise because of experimental limitations. This noise may hide small deviations from the Gaussian behavior, but they can hardly be significant.Comment: 5 pages, 5 figures; to appear in PR

The Middle Atlas Geological karsts forms: Towards Geosites characterization

International audienceRich limestone Jurassic formations and huge water reservoir are natural characteristics of the Middle Atlas Chain in Morocco, which, therefore, offers geodiversity of karst geosystems. The geological, tectonic and hydro-geo-morphological nature of the history of Atlas orogeny has affected the eastern part of the Middle, ensuring the evolution of karst features on various sites of this zone. This study presents some touristic offers specific to the Middle Atlas, particularly in terms of genesis, structures, and functions that could develop and promote public tourism offers. It argues that this development depends on future geological funds identification and classification as Geosites. On the basis of the patrimonial process characterising the Middle Atlas, this study suggests the creation of a Geopark in the Middle Atlas, within the framework of the evaluation criteria of the UNESCO. The implementation of this suggestion would contribute to the socioeconomic development of this region of Morocco

Plackett–Burman randomization method for Bacterial Ghosts preparation form E. coli JM109

AbstractPlackett–Burman randomization method is a conventional tool for variables randomization aiming at optimization. Bacterial Ghosts (BGs) preparation has been recently established using methods other than the E lysis gene. The protocol has been based mainly on using critical concentrations from chemical compounds able to convert viable cells to BGs. The Minimum Inhibition Concentration (MIC) and the Minimum Growth Concentration (MGC) were the main guide for the BGs preparation. In this study, Escherichia coli JM109 DEC has been used to produce the BGs following the original protocol. The study contained a detail protocol for BGs preparation that could be used as a guide

The Middle Atlas Geological karsts forms: Towards Geosites characterization

Rich limestone Jurassic formations and huge water reservoir are natural characteristics of the Middle Atlas Chain in Morocco, which, therefore, offers geodiversity of karst geosystems. The geological, tectonic and hydro-geo-morphological nature of the history of Atlas orogeny has affected the eastern part of the Middle, ensuring the evolution of karst features on various sites of this zone. This study presents some touristic offers specific to the Middle Atlas, particularly in terms of genesis, structures, and functions that could develop and promote public tourism offers. It argues that this development depends on future geological funds identification and classification as Geosites. On the basis of the patrimonial process characterising the Middle Atlas, this study suggests the creation of a Geopark in the Middle Atlas, within the framework of the evaluation criteria of the UNESCO. The implementation of this suggestion would contribute to the socioeconomic development of this region of Morocco

Utjecaj toplinske obrade na fizička svojstva tankih slojeva antimon trisulfida

The influence of isochronal and isothermal annealing for 0 to 180 minutes and at 27 to 250°C, respectively, on the optical and electrical properties of thin films of Sb2S3 have been investigated. The films deposited on glass substrate by thermal vacuum evaporation have amorphous structure, but after annealing at temperatures above 200°C for 3 hours, they change to polycrystalline structure. The optical absorption coefficient becomes higher for subgap absorption at higher annealing temperatures. The value of the optical Tauc gap and direct band gap changed with the annealing temperature. The dark electrical resistivity showed a decrease by about an order of magnitude when increasing both the isochronal and isothermal annealing treatment.Ispitivao se je utjecaj izotermičkog toplinskog otpuštanja na optička i električna svojstva tankih slojeva Sb2S3 na temperaturama 27 do 250° C i u vremenima od 0 do 180 minuta. Tanki slojevi dobiveni vakuumskim naparavanjem na staklenu podlogu imaju amorfnu strukturu, ali nakon otpuštanja iznad 200° C kroz 3 sata oni mijenjaju strukturu u polikristaliničnu. Optički apsorpcijski koeficijent raste za podprocijepnu apsorpciju s povišenjem temperature otpuštanja. Vrijednost optičkog Taucovog procijepa i izravni procijep mijenjali su se s temperaturom otpuštanja. Tamna električna otpornost se je smanjila za red veličine kada se je povećalo vrijeme otpuštanja i temperatura

Utjecaj toplinske obrade na fizička svojstva tankih slojeva antimon trisulfida

The influence of isochronal and isothermal annealing for 0 to 180 minutes and at 27 to 250°C, respectively, on the optical and electrical properties of thin films of Sb2S3 have been investigated. The films deposited on glass substrate by thermal vacuum evaporation have amorphous structure, but after annealing at temperatures above 200°C for 3 hours, they change to polycrystalline structure. The optical absorption coefficient becomes higher for subgap absorption at higher annealing temperatures. The value of the optical Tauc gap and direct band gap changed with the annealing temperature. The dark electrical resistivity showed a decrease by about an order of magnitude when increasing both the isochronal and isothermal annealing treatment.Ispitivao se je utjecaj izotermičkog toplinskog otpuštanja na optička i električna svojstva tankih slojeva Sb2S3 na temperaturama 27 do 250° C i u vremenima od 0 do 180 minuta. Tanki slojevi dobiveni vakuumskim naparavanjem na staklenu podlogu imaju amorfnu strukturu, ali nakon otpuštanja iznad 200° C kroz 3 sata oni mijenjaju strukturu u polikristaliničnu. Optički apsorpcijski koeficijent raste za podprocijepnu apsorpciju s povišenjem temperature otpuštanja. Vrijednost optičkog Taucovog procijepa i izravni procijep mijenjali su se s temperaturom otpuštanja. Tamna električna otpornost se je smanjila za red veličine kada se je povećalo vrijeme otpuštanja i temperatura

STUDY THE EFFECT OF MYCOPLASMA CONTAMINATION OF EGGS USED IN VIRUS TITRATION AND EFFICACY OF SOME LIVE ATTENUATED POULTRY VIRAL VACCINES

Objective: The study of Mycoplasma gallisepticum (MG) infection is needed, not only to understand the disease process but also to understand theinterference with the evaluation of some live viral poultry vaccines. This study aims to investigate the titration and potency of some live attenuatedpoultry viral vaccines; Newcastle disease, infectious bronchitis, infectious bursal disease, and Reo in both specific pathogen-free (SPF) embryonatedchicken eggs (ECEs) and chickens.Methods: Titration of live attenuated viral poultry vaccines in ECEs was carried out by dividing the inoculated eggs into four groups; the pre-,simultaneously-, post-, and non-MG contaminated. MG effect on the potency test was carried out using seventeen groups of SPF chickens (25 chicken/group) placed into separate isolators. Each live attenuated viral poultry vaccine was inoculated into 4 groups.Results: The highest titer of these vaccines that appeared in MG pre- contaminated ECEs were 1011, 107.5, 107.9, and 10, respectively. The lowest vaccinetiters that appeared in non-MG contaminated ECEs were 108, 106, 106.8, and 1067.5, respectively. Although the potency of these previous vaccines indicated thatthe highest antibodies titer that appeared in MG pre-infected vaccinated chickens were 7.5 log, 36 enzyme-linked immunosorbent assay unit (EU), and42 EU, respectively; the lowest antibodies titer that appeared in non-MG infected vaccinated chickens were 6.5 log22, 12 EU, 17 EU, and 10 EU, respectively.Conclusion: The present study findings underline the importance of using Mycoplasma -free eggs or chicken for the production of virus vaccines.Keywords: Mycoplasma gallisepticum, Newcastle disease virus, Infectious bronchitis virus, Infectious bursal disease virus, Reo virus, Chicken, Specificpathogen-free eggs. Keywords: Mycoplasmagallisepticum,Newcastlediseasevirus,Infectiousbronchitisvirus,Infectiousbursaldiseasevirus,Reovirus,Chicken,Specific pathogen-free eggs.Â

Enhanced piezoelectric properties of PVdF-HFP/PZT nanocomposite for energy harvesting application

The use of piezoelectric nanocomposite in detection and actuation applications for the development of electromechanical microsystems (MEMS) has become quite common over the last decade. In this paper, we present a flexible piezoelectric nanocomposite films, composed of lead zirconate titanate (PZT) nanoparticles, embedded in poly(vinylidene-difluoride hexafluoro propylene) (PVdF-HFP) matrix. Piezoelectric and ferroelectric properties evolution is proportional to the evolution of the crystalline β-phase. The evaluation of the interactions between PZT and PVdF- HFP, performed by Fourier transform infrared spectroscopy (FTIR), revealed a dramatic improvement in these characteristics over pure PVdF-HFP, and attributed to a better crystallinity of the PVdF-HFP matrix and uniform distribution of nanoparticles. These films nanocomposites were done by solvent casting method, with various concentrations of PZT. Results of these experiments indicate that the investigated thin films nanocomposites are appropriate for various applications in energy storage and energy harvesting application