Abstract Vegetation composition and soil attributes in the lower tributaries of Wadi Qena in the Eastern Desert of Egypt are studied from fifty-one stands in three wadis, namely Wadi El-Ghuza, Wadi Naq El-Teir, and Wadi El-Atrash. Altogether, fifty-two species from twenty families and thirty-nine genera, mainly of the Saharo-Arabian focus of distribution, were recorded. Chamaephytes and therophytes constituted 73 % of the main bulk of life form the spectrum of the recorded flora. After the removal of unicates, the presence/absence datasets of thirty-six species and fifty-one stands were classified by TWINSPAN yielding four vegetation groups: Zygophyllum coccineum-Zilla spinosa-Calligonum polygonoides (group A) mainly in Wadi Naq El-Teir, Zygophyllum coccineum-Zilla spinosa (group B) in Wadi El-Ghuza, Morettia philaeana (group C) from the southern part of Wadi El-Atrash, and Zygophyllum coccineum-Morettia philaeana (group D) from the northern part of Wadi El-Atrash. These groups were clearly separated along the first two axes of DCA. Soil-vegetation correlations performed by Redundancy Analysis (RDA) indicated that axis 1 was shaped by calcium and organic matter, while axis two was controlled by pH and phosphate contents. Variations of species richness and Shannon diversity index within the separated TWINSPAN groups were highly significant.

Abstract Vegetation composition and soil attributes in the lower tributaries of Wadi Qena in the Eastern Desert of Egypt are studied from fifty-one stands in three wadis, namely Wadi El-Ghuza, Wadi Naq El-Teir, and Wadi El-Atrash. Altogether, fifty-two species from twenty families and thirty-nine genera, mainly of the Saharo-Arabian focus of distribution, were recorded. Chamaephytes and therophytes constituted 73 % of the main bulk of life form the spectrum of the recorded flora. After the removal of unicates, the presence/absence datasets of thirty-six species and fifty-one stands were classified by TWINSPAN yielding four vegetation groups: Zygophyllum coccineum-Zilla spinosa-Calligonum polygonoides (group A) mainly in Wadi Naq El-Teir, Zygophyllum coccineum-Zilla spinosa (group B) in Wadi El-Ghuza, Morettia philaeana (group C) from the southern part of Wadi El-Atrash, and Zygophyllum coccineum-Morettia philaeana (group D) from the northern part of Wadi El-Atrash. These groups were clearly separated along the first two axes of DCA. Soil-vegetation correlations performed by Redundancy Analysis (RDA) indicated that axis 1 was shaped by calcium and organic matter, while axis two was controlled by pH and phosphate contents. Variations of species richness and Shannon diversity index within the separated TWINSPAN groups were highly significant.

Abstract Vegetation composition and soil attributes in the lower tributaries of Wadi Qena in the Eastern Desert of Egypt are studied from fifty-one stands in three wadis, namely Wadi El-Ghuza, Wadi Naq El-Teir, and Wadi El-Atrash. Altogether, fifty-two species from twenty families and thirty-nine genera, mainly of the Saharo-Arabian focus of distribution, were recorded. Chamaephytes and therophytes constituted 73 % of the main bulk of life form the spectrum of the recorded flora. After the removal of unicates, the presence/absence datasets of thirty-six species and fifty-one stands were classified by TWINSPAN yielding four vegetation groups: Zygophyllum coccineum-Zilla spinosa-Calligonum polygonoides (group A) mainly in Wadi Naq El-Teir, Zygophyllum coccineum-Zilla spinosa (group B) in Wadi El-Ghuza, Morettia philaeana (group C) from the southern part of Wadi El-Atrash, and Zygophyllum coccineum-Morettia philaeana (group D) from the northern part of Wadi El-Atrash. These groups were clearly separated along the first two axes of DCA. Soil-vegetation correlations performed by Redundancy Analysis (RDA) indicated that axis 1 was shaped by calcium and organic matter, while axis two was controlled by pH and phosphate contents. Variations of species richness and Shannon diversity index within the separated TWINSPAN groups were highly significant.

A series of novel quinones was synthesized by reacting tetrabromo-p-benzoquinone with amino oligoIJethylene glycol) dendrons of generation numbers g = 0–2. According to the performed shake-flask experiments, their aqueous solubility (S = 18 mg l−1 –1.6 g ml−1 ) and partition coefficients (logPoct/wat = 2.53–0.21) can be tuned in a wide range as a function of g. In vitro cytotoxicity assays of tetrabromo-pbenzoquinone and its derivatives against MCF-7 human breast cancer cells showed a concentration- and generation-specific biological activity with IC50-values as low as 0.8 μM. Further investigations revealed a considerable selectivity against cancer cells, as indicated by a weak cytotoxicity against human skin fibroblast cells (>80% survival) within the studied range of concentrations. The results demonstrate that these novel amino oligoIJethylene glycol) dendrons depict versatile tools to ameliorate physical and pharmacological characteristics of extremely hydrophobic molecules and make them susceptible to biological applications.

A series of novel quinones was synthesized by reacting tetrabromo-p-benzoquinone with amino oligoIJethylene glycol) dendrons of generation numbers g = 0–2. According to the performed shake-flask experiments, their aqueous solubility (S = 18 mg l−1 –1.6 g ml−1 ) and partition coefficients (logPoct/wat = 2.53–0.21) can be tuned in a wide range as a function of g. In vitro cytotoxicity assays of tetrabromo-pbenzoquinone and its derivatives against MCF-7 human breast cancer cells showed a concentration- and generation-specific biological activity with IC50-values as low as 0.8 μM. Further investigations revealed a considerable selectivity against cancer cells, as indicated by a weak cytotoxicity against human skin fibroblast cells (>80% survival) within the studied range of concentrations. The results demonstrate that these novel amino oligoIJethylene glycol) dendrons depict versatile tools to ameliorate physical and pharmacological characteristics of extremely hydrophobic molecules and make them susceptible to biological applications.

the sky is a basic component in outdoor images. Due to the low gradient values of the sky, it has high priority in seam removing for content aware image resizing and the result of enlarging image contributes obvious artificial pixels. The proportion of images which contains sky is over 40% of the daily recent explored images on Flickr (see section V). This paper presents a new technique for annotated outdoor image compression (AOIC) depending on sky replacing. We compress the outdoor images by replacing the sky region with the nearest sky in a predefined sky database to reduce image size. Our work is composed of two stages: encoding stage and decoding stage. In the encoding stage, we use sky annotation polygon to distinguish sky and non-sky regions. The sky features are extracted from the sky region (e.g. sky type, mean HSV, cloud type, and sun existence/relative position). These features are used to find the nearest sky feature from a predefined database of sky features. The sky ID and the sky polygon vertices are composed with non-sky region image. On the decoding stage, we use the sky ID to load the sky from the predefined sky database and compose the sky with the non-sky region (compressed image). Our method is tested using the standard outdoor images of LabelMe database which contain sky. Our method removes the sky and replaces it instead of shrinking the sky region in content aware image resize. Our AOIC can be used for reducing the file size of any image formats of outdoors that contains sky.

the sky is a basic component in outdoor images. Due to the low gradient values of the sky, it has high priority in seam removing for content aware image resizing and the result of enlarging image contributes obvious artificial pixels. The proportion of images which contains sky is over 40% of the daily recent explored images on Flickr (see section V). This paper presents a new technique for annotated outdoor image compression (AOIC) depending on sky replacing. We compress the outdoor images by replacing the sky region with the nearest sky in a predefined sky database to reduce image size. Our work is composed of two stages: encoding stage and decoding stage. In the encoding stage, we use sky annotation polygon to distinguish sky and non-sky regions. The sky features are extracted from the sky region (e.g. sky type, mean HSV, cloud type, and sun existence/relative position). These features are used to find the nearest sky feature from a predefined database of sky features. The sky ID and the sky polygon vertices are composed with non-sky region image. On the decoding stage, we use the sky ID to load the sky from the predefined sky database and compose the sky with the non-sky region (compressed image). Our method is tested using the standard outdoor images of LabelMe database which contain sky. Our method removes the sky and replaces it instead of shrinking the sky region in content aware image resize. Our AOIC can be used for reducing the file size of any image formats of outdoors that contains sky.

tA novel electrochemical sensor based on the use of boron doped CeO2nanocubes modified glassy carbonmicrospheres paste electrode (B-CeO2NCs/GCPE) was prepared and applied for selective and sensitivedetermination of xanthine (XA) and hypoxanthine (HXA) individually and simultaneously. The mor-phology, composition and structural properties of the undoped and B doped CeO2nanocubes werecharacterized by X-ray diffraction, energy-dispersed X-ray spectrometry (EDS) and transmission elec-tron microscopy (TEM). Electrochemical activities and the surface analysis of the modified electrodewere investigated using scanning electron microscopy (SEM) and cyclic voltammetry (CV). From the B-CeO2NCs/GCPE, well oxidation peaks and enhanced peak currents of XA and HXA were observed owingto the excellent catalytic activity of B-CeO2NCs. For individual detection, the linear responses of XAand HXA were in the concentration range of 5.42 × 10−8–1.31 × 10−5M and 3.98 × 10−7–6.01 × 10−5Mwith detection limits of 3.02 and 6.17 nM, respectively. For simultaneous detection by synchronouschange of the concentration of XA and HXA, the linear ranges were 1.98 × 10−7–9.45 × 10−6M and3.98 × 10−7–1.28 × 10−5M with detection limits of 3.65 and 8.17 nM, respectively. The practical appli-cation of the modified electrode was demonstrated by simultaneously determining the concentrationsof XA and HXA in human biological fluids and in fish meat samples with satisfactory results.

tA novel electrochemical sensor based on the use of boron doped CeO2nanocubes modified glassy carbonmicrospheres paste electrode (B-CeO2NCs/GCPE) was prepared and applied for selective and sensitivedetermination of xanthine (XA) and hypoxanthine (HXA) individually and simultaneously. The mor-phology, composition and structural properties of the undoped and B doped CeO2nanocubes werecharacterized by X-ray diffraction, energy-dispersed X-ray spectrometry (EDS) and transmission elec-tron microscopy (TEM). Electrochemical activities and the surface analysis of the modified electrodewere investigated using scanning electron microscopy (SEM) and cyclic voltammetry (CV). From the B-CeO2NCs/GCPE, well oxidation peaks and enhanced peak currents of XA and HXA were observed owingto the excellent catalytic activity of B-CeO2NCs. For individual detection, the linear responses of XAand HXA were in the concentration range of 5.42 × 10−8–1.31 × 10−5M and 3.98 × 10−7–6.01 × 10−5Mwith detection limits of 3.02 and 6.17 nM, respectively. For simultaneous detection by synchronouschange of the concentration of XA and HXA, the linear ranges were 1.98 × 10−7–9.45 × 10−6M and3.98 × 10−7–1.28 × 10−5M with detection limits of 3.65 and 8.17 nM, respectively. The practical appli-cation of the modified electrode was demonstrated by simultaneously determining the concentrationsof XA and HXA in human biological fluids and in fish meat samples with satisfactory results.

A surface-enhanced Raman scattering (SERS) substrate composed of silver nanoparticles (Ag NPs) was synthesized by spark discharge deposition (SDD). The spark-ablated species were directly deposited on a copper substrate at room temperature and atmospheric pressure. Sharp and reproducible SERRS signals from the model molecule Rhodamine B (Rh B) were observed from the prepared substrates. Under optimized deposition conditions, the detection limit of Rh B reached the single molecular level (1.0 × 10−16 M) with an enhancement factor of 3.9 × 1012. This substrate also provided excellent SERS activity toward crystal violet molecule and the representative biomolecule adenine. We were further interested to find that the activity of the prepared substrate responded very sensitively when we changed the morphology of the deposited NPs by adjusting the operating parameters. An increase in the spark time to 20 min increased the particle size and filling factor, which induced the particles to grow into self-assembled dendrite-like structures. We observed the highest intensity in an Ag NP film with an average particle size of 45 nm and filling factor of 0.57. We speculate that the high sensitivity of this substrate may have derived from the high electromagnetic field produced by the tuning of the particle size and the formation of nanogaps (hot spots) between adjacent particles. This method offers a simple, cost effective, eco-friendly route to the synthesis of highly sensitive, reproducible SERS substrates.