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Seed treatments with thiamine reduce the performance of generalist and specialist aphids on crop plants

Research Abstract
Thiamine is a vitamin that has been shown to act as a trigger to activate plant defence and reduce pathogen and nematode infection as well as aphid settling and reproduction. We have here investigated whether thiamine treatments of seeds (i.e. seed dressing) would increase plant resistance against aphids and whether this would have different effects on a generalist than on specialist aphids. Seeds of wheat, barley, oat and pea were treated with thiamine alone or in combination with the biocontrol bacteria Pseudomonas chlororaphis MA 342 (MA 342). Plants were grown in climate chambers. The effects of seed treatment on fecundity, host acceptance and life span were studied on specialist aphids bird cherry-oat aphid (Rhopalosiphum padi L.) and pea aphid (Acyrthosiphon pisum Harris) and on the generalist green peach aphid (Myzus persicae, Sulzer). Thiamine seed treatments reduced reproduction and host acceptance of all three aphid species. The number of days to reproduction, the length of the reproductive life, the fecundity and the intrinsic rate of increase were found reduced for bird cherry-oat aphid after thiamine treatment of the cereal seeds. MA 342 did not have any effect in any of the plant-aphid combinations, except a weak decrease of pea aphid reproduction on pea. The results show that there are no differential effects of either thiamine or MA 342 seed treatments on specialist and generalist aphids and suggest that seed treatments with thiamine has a potential in aphid pest management.
Research Authors
Hamada A.F., Fatehi J., Jonsson L.M.V.
Research Journal
Bulletin of Entomological Research
Research Pages
1-9
Research Publisher
Cambridge core
Research Rank
1
Research Vol
5
Research Website
arch/article/seed-treatments-with-thiamine-reduce-the-performance-of-generalist-and-specialist-aphids-on-crop-plants
Research Year
2017

Physiological responses to excess boron in wheat cultivars.

Research Abstract
This study investigates the response of two wheat cultivars to boron toxicity stress. Plants were cultivated in sand culture and boron was applied to the culture for 10-day. Symptoms, tiller number, boron concentration, soluble sugars, proteins and other free amino acids than proline were studied. The differences between the cultivars were apparent from higher boron and the chlorosis in tolerant cultivar was about 7% compared to the sensitive one 70%. Tiller number gradual decreased in tolerantcultivar, while in sensitive one a dramatic reduction was exhibited by increasing boron level in culture media. In most boron levels, although the accumulation of soluble carbohydrates was significantly stimulated in shoot of B-sensitive cultivar (Gemmeza 9; S), there were no appreciable differences in the production of carbohydrates in shoot of B-tolerant cultivar (Sakha 93; T). However, the soluble proteins production did not affect by most boron levels in both cultivars. The presence of boron at various concentrations induced a production of free amino acids in shoots of each of the two test cultivars. Tiller number (yield index) decreased in the two test cultivars and was in range 50-59 and 84-92% less than control plants for tolerant and sensitive cultivar, respectively.
Research Authors
Ashraf M. Metwally, Rasha M. El-Shazoly and Afaf M. Hamada
Research Journal
European Journal of Biological Research
Research Pages
1-8
Research Publisher
ISSN: 2449-8955
Research Rank
1
Research Vol
7 (1):
Research Website
http://www.journals.tmkarpinski.com
Research Year
2017

Physiological responses to excess boron in wheat cultivars.

Research Abstract
This study investigates the response of two wheat cultivars to boron toxicity stress. Plants were cultivated in sand culture and boron was applied to the culture for 10-day. Symptoms, tiller number, boron concentration, soluble sugars, proteins and other free amino acids than proline were studied. The differences between the cultivars were apparent from higher boron and the chlorosis in tolerant cultivar was about 7% compared to the sensitive one 70%. Tiller number gradual decreased in tolerantcultivar, while in sensitive one a dramatic reduction was exhibited by increasing boron level in culture media. In most boron levels, although the accumulation of soluble carbohydrates was significantly stimulated in shoot of B-sensitive cultivar (Gemmeza 9; S), there were no appreciable differences in the production of carbohydrates in shoot of B-tolerant cultivar (Sakha 93; T). However, the soluble proteins production did not affect by most boron levels in both cultivars. The presence of boron at various concentrations induced a production of free amino acids in shoots of each of the two test cultivars. Tiller number (yield index) decreased in the two test cultivars and was in range 50-59 and 84-92% less than control plants for tolerant and sensitive cultivar, respectively.
Research Authors
Ashraf M. Metwally, Rasha M. El-Shazoly and Afaf M. Hamada
Research Journal
European Journal of Biological Research
Research Pages
1-8
Research Publisher
ISSN: 2449-8955
Research Rank
1
Research Vol
7 (1):
Research Website
http://www.journals.tmkarpinski.com
Research Year
2017

DNA repair kinetics in SCID mice Sertoli cells and DNA-PKcs-deficient mouse embryonic fibroblasts

Research Abstract
Noncycling and terminally differentiated (TD) cells display differences in radiosensitivity and DNA damage response. Unlike other TD cells, Sertoli cells express a mixture of proliferation inducers and inhibitors in vivo and can reenter the cell cycle. Being in a G1-like cell cycle stage, TD Sertoli cells are expected to repair DSBs by the error-prone nonhomologous end-joining pathway (NHEJ). Recently, we have provided evidence for the involvement of Ku-dependent NHEJ in protecting testis cells from DNA damage as indicated by persistent foci of the DNA double-strand break (DSB) repair proteins phospho-H2AX, 53BP1, and phospho-ATM in TD Sertoli cells of Ku70-deficient mice. Here, we analyzed the kinetics of 53BP1 foci induction and decay up to 12 h after 0.5 Gy gamma irradiation in DNA-PKcs-deficient (Prkdc scid) and wild-type Sertoli cells. In nonirradiated mice and Prkdc scid Sertoli cells displayed persistent DSBs foci in around 12 % of cells and a fivefold increase in numbers of these DSB DNA damage-related foci relative to the wild type. In irradiated mice, Prkdc scid Sertoli cells showed elevated levels of DSB-indicating foci in 82 % of cells 12 h after ionizing radiation (IR) exposure, relative to 52 % of irradiated wild-type Sertoli cells. These data indicate that Sertoli cells respond to and repair IR-induced DSBs in vivo, with repair kinetics being slow in the wild type and inefficient in Prkdc scid. Applying the same dose of IR to Prdkc −/− and Ku −/− mouse embryonic fibroblast (MEF) cells revealed a delayed induction of 53BP1 DSB-indicating foci 5 min post-IR in Prdkc −/− cells. Inefficient DSB repair was evident 7 h post-IR in DNA-PKcs-deficient cells, but not in Ku −/− MEFs. Our data show that quiescent Sertoli cells repair genotoxic DSBs by DNA-PKcs-dependent NEHJ in vivo with a slower kinetics relative to somatic DNA-PKcs-deficient cells in vitro, while DNA-PKcs deficiency caused inefficient DSB repair at later time points post-IR in both conditions. These observations suggest that DNA-PKcs contributes to the fast and slow repair of DSBs by NHEJ.
Research Authors
Emad A. Ahmed, Eukene Vélaz, Michael Rosemann, Klaus-P. Gilbertz, and Harry Scherthan
Research Department
Research Journal
Chromosoma
Research Pages
PP.287–298.
Research Publisher
NULL
Research Rank
1
Research Vol
Vol.126,No.2
Research Website
NULL
Research Year
2016

Influence of annealing temperature on the structural and optical properties of As30Te70 thin films

Research Abstract
Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.
Research Authors
Alaa Abd-Elnaiem, Mansour Mohamed, Rashed Hassan, A. Abu-Sehly, M. Abdel-Rahim,Mohamed Hafiz
Research Department
Research Journal
Materials Science-Poland
Research Pages
335-345
Research Publisher
De Gruyter Open
Research Rank
1
Research Vol
35(2)
Research Website
https://www.degruyter.com/view/j/msp.ahead-of-print/msp-2017-0052/msp-2017-0052.xml
Research Year
2017

Influence of annealing temperature on the structural and optical properties of As30Te70 thin films

Research Abstract
Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.
Research Authors
Alaa Abd-Elnaiem, Mansour Mohamed, Rashed Hassan, A. Abu-Sehly, M. Abdel-Rahim,Mohamed Hafiz
Research Department
Research Journal
Materials Science-Poland
Research Pages
335-345
Research Publisher
De Gruyter Open
Research Rank
1
Research Vol
35(2)
Research Website
https://www.degruyter.com/view/j/msp.ahead-of-print/msp-2017-0052/msp-2017-0052.xml
Research Year
2017

Influence of annealing temperature on the structural and optical properties of As30Te70 thin films

Research Abstract
Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.
Research Authors
Alaa Abd-Elnaiem, Mansour Mohamed, Rashed Hassan, A. Abu-Sehly, M. Abdel-Rahim,Mohamed Hafiz
Research Department
Research Journal
Materials Science-Poland
Research Member
Research Pages
335-345
Research Publisher
De Gruyter Open
Research Rank
1
Research Vol
35(2)
Research Website
https://www.degruyter.com/view/j/msp.ahead-of-print/msp-2017-0052/msp-2017-0052.xml
Research Year
2017

Influence of annealing temperature on the structural and optical properties of As30Te70 thin films

Research Abstract
Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.
Research Authors
Alaa Abd-Elnaiem, Mansour Mohamed, Rashed Hassan, A. Abu-Sehly, M. Abdel-Rahim,Mohamed Hafiz
Research Department
Research Journal
Materials Science-Poland
Research Pages
335-345
Research Publisher
De Gruyter Open
Research Rank
1
Research Vol
35(2)
Research Website
https://www.degruyter.com/view/j/msp.ahead-of-print/msp-2017-0052/msp-2017-0052.xml
Research Year
2017

Fast inversion of logging-while-drilling resistivity measurements acquired in multiple wells,

Research Abstract
We have developed a new method for the fast inversion of borehole resistivity measurements acquired in multiple wells using logging-while-drilling instruments. There are two key novel contributions. First, we approximate general 3D transversely isotropic (TI) formations with a sequence of several “stitched” 1D planarly layered TI sections. This allows us to approximate the solution of rather complex 3D formations using only 1.5D simulations. Second, the developed method supports the simultaneous inversion of measurements acquired in different neighboring wells and/or with different logging instruments. Numerical experiments performed with realistic 3D synthetic formations confirm the flexibility of the method and the reliability of the inversion products. The method yields relative errors of less than 5% on the model space, and it enables the interpretation of resistivity measurements acquired in multiple wells (e.g., an exploratory, an offset, and a geosteering well) and with any combination of coaxial and/or triaxial commercial logging measurements acquired with known antennae configurations. Numerical results also indicate that thinly bedded resistive formations are very sensitive to the presence of noise on the measurements and/or to possible errors on bed-boundary locations, whereas conductive layers are only weakly sensitive to those effects.
Research Authors
S.A. Bakr, D. Pardo, Carlos Torres-Verdin
Research Department
Research Journal
Geophysics
Research Member
Research Pages
E111-E120
Research Publisher
NULL
Research Rank
1
Research Vol
82 (3)
Research Website
10.1190/GEO2016-0292.1
Research Year
2017

A multi-domain decomposition-based Fourier finite element
method for the simulation of 3D marine CSEM
measurements

Research Abstract
We introduce a multi-domain decomposition Fourier finite element (MDDFFE) method for the simulation of three-dimensional (3D) marine controlled source electromagnetic measurement (CSEM). The method combines a 2D finite element (FE) method in two spatial dimensions with a hybrid discretization based on a Fourier FE method along the third dimension. The method employs a secondary field formulation rather than the total field formulation. We apply the MDDFFE method to several synthetic marine CSEM examples exhibiting bathymetry and/or multiple 3D subdomains. Numerical results show that the use of the MDDFFE method reduces the problem size by as much as 87 % in terms of the number of unknowns, without any sacrifice in accuracy.
Research Authors
Shaaban A. Bakr and David Pardo
Research Department
Research Journal
Computational Geosciences
Research Member
Research Pages
345-357
Research Publisher
Springer International Publishing Switzerland 2017
Research Rank
1
Research Vol
21 (3)
Research Website
DOI 10.1007/s10596-017-9615-6
Research Year
2017
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