103 research outputs found

    Effects of Polyacrylamide on Rangeland Soils and Plants

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    The objectives of this study were to determine the effects of two forms of polyacrylamide (PAM) conditioners (Cross-linked and Non-cross-linked PAM) on evaporation, saturated hydraulic conductivity, water retention, crust and crack formation of soils, seed germination, and seedling and tubeling growth. The two PAM conditioners, 0.2% concentration by weight, were mixed with seven soils of different textures (sandy loam, silt, silty clay loam, silt loam, fine sand, medium sand, and coarse sand) to investigate the effects on evaporation, saturated hydraulic conductivity, and water retention. Soil samples of different textures were brought to field capacity and placed in a growth chamber for two weeks to measure evaporation under a controlled environment. A second experiment was carried out in the field to determine the effects of the two PAM conditioners on seedling emergence of crested wheatgrass, Agropyron desertorum, as well as on soil cracking, penetrometer resistance, and soil moisture. The two PAMs were mixed with a silt loam Xerollic Calciorthid at 0.2% concentration by weight. Seedling emergence was monitored directly for two weeks. Soil moisture was measured by TDR. Cracking was described by photographic means. Penetrometer resistance was measured by a hand-held. penetrometer. The third experiment was also carried out in the field, using the same soil texture as in experiment 2, to investigate the effects of the two PAMs on soil moisture at depths between 25 to 45 cm and on sagebrush (Artemisia tridentata) growth. Evaporation was found to be significantly lower in the fine-textured controls than under the two PAM treatments. The sandy loam and sandy soils experienced significantly higher evaporation from the controls. The two PAM conditioners significantly reduced saturated hydraulic conductivity on all soil textures. Water retention increased in the PAM-treated textures at the matric potential range used (0.0, 0.05, 0.1, 1.5 MPa) • The PAM application also did not improve grass seedling emergence or improve soil moisture, and did not have any significant affects on sagebrush growth. Larger cracks were found in the two plots treated with PAM than the controls. Lower penetrometer resistance occurred in the two PAM treatments compared to the untreated control. From this study, it can be concluded that the application of PAM conditioners, at relatively high concentrations used, could be more viable on sandy textures. Other researchers are advised to try lower application rates than used here, particularly with finer textured soils

    PEPTIDE BASED TARGETED RADIONUCLIDE THERAPIES; SCIENCE BEHIND THE SUCCESS.

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    The radionuclide therapies for solid and liquid malignancies are emerging field nowadays. The targeted radionuclide therapies have been in use since 1945. In the past 20 years, due to advancement in the nanotechnology and targeting cell receptors; radionuclide therapies have emerged as a subspecialty in nuclear medicine. Through this article, we would like to briefly describe the evolution of peptide-based radionuclide therapies, with a little emphasis on their clinical applications. Key words: Peptide-based radiopharmaceuticals, radionuclide therapy, somatostatin-receptor-positive neuroendocrine tumou

    Multicenter Study of Brucellosis in Egypt

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    Brucellosis causes appreciable economic losses in livestock. Examination of milk and tissues from animals in Egypt for Brucella spp. showed increased prevalence rates of serologically reactive animals. All isolates were B. melitensis biovar 3. One Brucella sp. was isolated from milk of serologically nonreactive buffaloes

    Nutritional Value, Mineral Composition, Secondary Metabolites, and Antioxidant Activity of Some Wild Geophyte Sedges and Grasses

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    Geophytes are plants with underground storage organs including bulbs, corms, tubers, and rhizomes, often physiologically active and able to survive during harsh environmental conditions. This study is conducted to assess the nutritive value, mineral composition, bioactive metabolites, and antioxidant activity of five wild geophytes (Cyperus capitatus, C. conglomeratus, Elymus farctus, Lasiurus scindicus, and Panicum turgidum) collected from the Nile Delta coast and inland desert. The proximate composition including dry matter, moisture content, ash content, fiber, fat, protein, sucrose, and glucose were determined. Also, total carbohydrates, total digestible nutrients (TDN), and nutritive values were calculated. Macro- and micro-minerals were also determined in the studied geophytes. Total phenolics, total flavonoids, alkaloids, saponins, and tannins were determined. Antioxidant activity was evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicle scavenging. Based on the nutritive value, the studied geophytes are ranked as follows: E. farctus > C. conglomeratus > L. scindicus > P. turgidum > C. capitatus. The mineral analysis reveals a sufficient amount of macro- and micro-elements in the studied geophytes while the microelements levels in the studied wild plants exist as Fe > Mn > Zn > Cu. Cyperus conglomeratus attained the highest concentrations of all determined secondary metabolites. On the other hand, C. conglomeratus, C. capitatus, and P. turgidum extracts showed strong scavenging activity (EC50 < 1 mg mL−1), while extracts of E. farctus and L. scindicus exhibited moderate scavenging activity (1 ≤ EC50 ≤ 2 mg mL−1). The present data reveal that geophytes under investigation could be used as good forage plants, especially in arid habitats. In addition, C. conglomeratus could be a potentially important candidate for natural antioxidants as it attained high contents of the bioactive constituents

    Epidemiological aspects of scorpion stings in Al-Jouf Province, Saudi Arabia

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    <b>Background: </b> Information on scorpion stings is available for many parts of Saudi Arabia, but not for Al-Jouf Province. <b> Methods: </b> We reviewed and analyzed 1449 cases of scorpion stings that presented to the emergency department of the hospitals and medical centers in Al-Jouf Province during a 2-year period (2005-2006). <b> Results: </b> The majority of patients (92.7&#x0025;) manifested class I envenomation with local pain at the sting site as the primary complaint. Systemic toxicity was noticed in 7.3&#x0025; of cases but no deaths were reported. Scorpion stings were recorded throughout the year with the highest seasonal incidence in the summer (64.3&#x0025;) and the lowest during the winter (10.6&#x0025;). The highest monthly incidence was in June (21.5&#x0025;) and the lowest in December (1.5&#x0025;). Most of the patients were male (77.3&#x0025;) and the age of 44.2&#x0025; of victims ranged between 15 to 30 years. Diurnal stings exceeded the nocturnal ones with a ratio of 3:2, and most of the stings were located mainly on the exposed limbs (88.6&#x0025;), especially the lower limbs (51.7&#x0025;). Leiurus quinquestriatus and Androctonus crassicc cauda were incriminated in most recorded cases. <b> Conclusions: </b> Our findings indicate that scorpion stings are common in Al-Jouf Province, especially during the summer. The overall threat to human health was found to be low

    Histology and histochemistry of the venom apparatus of the black scorpion Androctonus crassicauda (Olivier, 1807) (Scorpiones: Buthidae)

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    The venom apparatus of the black scorpion Androctonus crassicauda has been characterized histologically and histochemically in the present study. The results showed that this apparatus consists of paired venom glands, each of which initially presents its own canal and posteriorily both fuse into a single common one. Each gland is covered by a sheath of striated muscle and is lined with extensively folded secretory epithelium (formed of non-secretory and secretory venom-producing cells). The outcomes also revealed that the venom-producing cells of both glands produce neutral mucosubstances, sialomucins, sulfomucins and proteins, but are devoid of glycogen. Cysteine, tyrosine, tryptophan and arginine were also detected along with activities of acid and alkaline phosphatases, mitochondrial adenosine triphosphatase, aminopeptidase, cholinesterase and non-specific esterases. Structure and secretion of scorpion venom glands are discussed within the context of the present results
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