Studies on Plant Cover of Wadi Umm El-Rakham in The Northwestern Coast of Egypt

The present investigation was carried out to study the phytosociological characteristics of the range land in Wadi Umm El-Rakham, in Northwestern coast of Egypt during spring 2004 - fall 2005. Thirty eight plant species belong to 17 families were found in Wadi Umm El-Rakham. Eighteen species were annuals and 20 species were perennials. A total of 18 species were palatable, the rest were not. Among annulus, 11 species were palatable, whereas among perennials seven species only were palatable. Fresh and dry foliage yield, species density, frequency, herbage cover and the importance value as well as their relative values were determined in the different locations in the wadi (i.e. top, ridge and wadi bed).  All these traits recorded their highest value in the wadi bed location during spring season of both years 2004 and 2005. Meanwhile, the lowest values of all these traits were recorded in the wadi top location. Significant interaction was noticed among the studied factors i.e. year, location and season) in wadi bed location during spring season of both years.      ÂÂ

Passively Q-switched fiber lasers using a multi-walled carbon nanotube polymer composite based saturable absorber

We demonstrate a simple, compact and low cost Q-switched fiber lasers based on Erbium-doped fiber (EDF) and Thulium-doped fiber (TDF) to operate at 1534.5 nm and 1846.4 nm, respectively by exploiting a multi-walled carbon nanotubes (MWCNTs) polymer composite film based saturable absorber (SA). The composite is prepared by mixing the MWCNTs homogeneous solution into a dilute polyvinyl alcohol polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The EDF laser generates a stable pulse train with repetition rates ranging from 38.11 kHz to 48.22 kHz by varying the 980 nm pump power from 39.0 mW to 65.3 mW. At the 65.3 mW pump power, the pulse width and pulse energy were 5.3 μs and 99.75 nJ, respectively. The TDF laser generates a stable pulse train with 10.38 kHz repetition rate, 17.52 μs pulse width and 11.34 nJ pulse energy at 121.1 mW 800 nm pump power. A higher performance Q switching is expected to be achieved in both fiber lasers with the optimization of the SA and laser cavity

Soliton mode-locked erbium-doped fibre laser with mechanically exfoliated molybdenum disulphide saturable absorber

The authors demonstrate the generation of soliton mode-locked pulses from an erbium-doped fibre ring laser incorporating molybdenum disulphide (MoS2) saturable absorber (SA) with a net anomalous dispersion. The MoS2 SA is prepared by mechanically exfoliating MoS2 crystal and fixing the acquired MoS2 flakes onto the end surface of a standard FC/PC fibre connector. A self-started mode-locked soliton pulse is generated by fine-tuning the rotation of the polarisation controller at the threshold pump power of 50 mW. Its solitonic behaviour is verified by the presence of Kelly sidebands in the output spectrum. The central wavelength, 3 dB bandwidth, pulsewidth, and repetition rate of the laser are 1598.94 nm, 5.4 nm, 0.83 ps, and 17.1 MHz, respectively. The maximum pulse energy is 74 nJ at pump power of 110 mW with the output power of 1.26 mW. The MoS2 SA was constructed in a simple fabrication process and has a modulation depth of 11.3% to successfully produce the stable soliton mode-locked fibre laser

Femtosecond mode-locked erbium-doped fiber laser based on MoS2–PVA saturable absorber

We fabricate a free-standing few-layer molybdenum disulfide (MoS2)–polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a soliton mode-locked Erbium-doped fiber laser (EDFL). A stable self-started mode-locked soliton pulse is generated by fine-tuning the rotation of the polarization controller at a low threshold pump power of 25 mW. Its solitonic behavior is verified by the presence of Kelly sidebands in the output spectrum. The central wavelength, pulse width, and repetition rate of the laser are 1573.7 nm, 630 fs, and 27.1 MHz, respectively. The maximum pulse energy is 0.141 nJ with peak power of 210 W at pump power of 170 mW. This result contributes to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications

Tunable Q-switched erbium doped fiber laser with graphene oxide paper based saturable absorber

We demonstrate a tunable wavelength Q-switched erbium doped fiber laser (EDFL) using a graphene oxide (GO) saturable absorber (SA). The GO solution was prepared using the simplified Hummer’s method, which is then thinly spread into a petri-disk to make a paper-like material. The GO paper is sandwiched between two FC/PC fiber connectors and incorporated into a ring EDFL’s cavity for Q-switching operation. The wavelength tunable operation of the Q-switched laser was obtained with a band-pass filter. The stable Q-switched pulse with a tunable range from 1536 nm to 1563 nm was achieved, covering a wavelength range over ~28 nm. The Q-switched EDFL produced maximum pulse energy of 151 nJ at pump power of 80 mW

Two New Records of Orchid Species for the Flora of Iraq: Anacamptis papilionacea (L.) R.M. Bateman, Pridgeon & M.W. Chase and Dactylorhiza romana (Sebast.) Soó

The Orchidaceae is one of the most cosmopolitan flowering families however, the national floristic knowledge for Iraqi territories is restricted by the outdated and incomplete status of Flora of Iraq. We already recently add two new records of Orchid species for Iraq and the study objective was to pursue the dynamics on field studies and thus provide new contribution for Flora of Iraq. Two new Orchid species were recorded for the first time in Iraq: (i) Anacamptis papilionacea found on Silé waterfall locality (Dostaka mountain, Duhok governorate); and (ii) Dactylorhiza romana found in Hariké locality (Gara mountain, Duhok governorate). Field illustrations, infraspecific identification (A. papilionacea subsp. schirwanica; D. romana subsp. georgica), environment and geographical distribution, conservation status and a brief discussion about the new records are provided. This study highlights the importance of floristic surveys and their continuity over time as a first step towards the modern floristic knowledge including open databases

Fourier-transform infrared imaging spectroscopy and laser ablation -ICPMS new vistas for biochemical analyses of ischemic stroke in rat brain

Objective: Stroke is the main cause of adult disability in the world, leaving more than half of the patients dependent on daily assistance. Understanding the post-stroke biochemical and molecular changes are critical for patient survival and stroke management. The aim of this work was to investigate the photo-thrombotic ischemic stroke in male rats with particular focus on biochemical and elemental changes in the primary stroke lesion in the somatosensory cortex and surrounding areas, including the corpus callosum. Materials and Methods: FT-IR imaging spectroscopy and LA-ICPMS techniques examined stroke brain samples, which were compared with standard immunohistochemistry studies. Results: The FTIR results revealed that in the lesioned gray matter the relative distribution of lipid, lipid acyl and protein contents decreased significantly. Also at this locus, there was a significant increase in aggregated protein as detected by high-levels A?1-42. Areas close to the stroke focus experienced decrease in the lipid and lipid acyl contents associated with an increase in lipid ester, olefin, and methyl bio-contents with a novel finding of A?1-42 in the PL-GM and L-WM. Elemental analyses realized major changes in the different brain structures that may underscore functionality. Conclusion: In conclusion, FTIR bio-spectroscopy is a non-destructive, rapid, and a refined technique to characterize oxidative stress markers associated with lipid degradation and protein denaturation not characterized by routine approaches. This technique may expedite research into stroke and offer new approaches for neurodegenerative disorders. The results suggest that a good therapeutic strategy should include a mechanism that provides protective effect from brain swelling (edema) and neurotoxicity by scavenging the lipid peroxidation end products.Texas Biomedical Research Institute, Technische Universitat Wien, Qatar University, Monash University, Qatar Foundation, National Institutes of Health, Qatar National Research Fund, Qatar Foundatio

Application of FTIR and LA-ICPMS spectroscopies as a possible approach for biochemical analyses of different rat brain regions

Fourier Transform Infrared Spectroscopy (FTIR) is a non-destructive analytical technique that has been employed in this research to characterize the biochemical make-up of various rat brain regions. The sensorimotor cortex, caudate putamen, thalamus, and the hippocampus were found to have higher olefinic content-an indicator of a higher degree of unsaturated fatty acids-rich in short-chain fatty acids, and low in ester and lipid contents. While the regions of the corpus callosum, internal, and external capsule were found to contain long-chained and higher-esterified saturated fatty acids. These molecular differences may reflect the roles of the specific regions in information processing and can provide a unique biochemical platform for future studies on the earlier detection of pathology development in the brain, as a consequence of disease or injury. Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) is another vital analytical technique that was used in this work to analyze the elements' distribution patterns in various regions of the brain. The complementary data sets allowed the characterization of the brain regions, the chemical dominating groups, and the elemental composition. This set-up may be used for the investigation of changes in the brain caused by diseases and help create a deeper understanding of the interactions between the organic and elemental composition.Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Doha 34110, Qatar; [email protected] Department of Chemistry and Earth Sciences, Qatar University, Doha 2713, Qatar; [email protected] (F.R.); [email protected] (A.M.S.); [email protected] (K.A.-S.) Forschungszentrum J�lich GmbH, Zentralinstitut f�r Engineering, 52425 Elektronik und Analytik, Germany; [email protected] (V.N.); [email protected] (S.K.) Qatar Computing Research Institute (QCRI), Hamad Bin Khalifa University, Doha 34110, Qatar; [email protected] (E.U.); [email protected] (R.M.) Central Laboratories Unit, Qatar University, Doha 2713, Qatar; [email protected] Chemical Engineering Program, Texas A&M University at Qatar, Doha 23874, Qatar; [email protected] Centre for Biospectroscopy and the School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; [email protected] Correspondence: [email protected]