A geographical analysis of industry in Libya, with special reference to industrial location

This study will, it is hoped, provide a contribution to the knowledge of the industrial geography of a small third world country, Libya, by shedding light on the location and development of its industries. Particular attention has been given to the role of the government in industrial development and industrial location, and the changes which have taken place in Libya's industrial structure and problems. The study proper begins in part one, chapter two, by examining industrial structure and location from the late Turkish period to the mid- nineteen fifties. In chapter three an attempt is made to analyse the characteristics, location and growth of the oil industry, while the main developments and changes in the industrial structure and spatial patterns from 1964 to 1971 are discussed in chapter four. The roles of the private industrialist and the government, including the latter's measures of encouragement and industrial finance, as well as its direct participation, are critically examined in chapter five. In part two, chapter six is a geographical analysis of the nature, location and regional distribution of industrial activities as they existed in Libya in 1971. Chapter seven deals primarily with the main factors which affect present industrial location as well as the relationship between industrial location in Libya and some theories of industrial location. The areal distribution and character of industry in the main cities (Tripoli and Benghazi) has been examined very closely in chapter eight. Finally, in part three, chapter nine deals with the main industrial problems, whilst some important indicators for the industrial future and concluding statements are presented in chapter ten

Selenium Hyperaccumulators Facilitate Selenium-Tolerant Neighbors via Phytoenrichment and Reduced Herbivory

SummaryBackgroundSoil surrounding selenium (Se) hyperaccumulator plants was shown earlier to be enriched in Se, impairing the growth of Se-sensitive plant species. Because Se levels in neighbors of hyperaccumulators were higher and Se has been shown to protect plants from herbivory, we investigate here the potential facilitating effect of Se hyperaccumulators on Se-tolerant neighboring species in the field.ResultsWe measured growth and herbivory of Artemisia ludoviciana and Symphyotrichum ericoides as a function of their Se concentration and proximity to hyperaccumulators Astragalus bisulcatus and Stanleya pinnata. When growing next to hyperaccumulators, A. ludoviciana and S. ericoides contained 10- to 20-fold higher Se levels (800–2,000 mg kg−1 DW) than when growing next to nonaccumulators. The roots of both species were predominantly (70%–90%) directed toward hyperaccumulator neighbors, not toward other neighbors. Moreover, neighbors of hyperaccumulators were 2-fold bigger, showed 2-fold less herbivory damage, and harbored 3- to 4-fold fewer arthropods. When used in laboratory choice and nonchoice grasshopper herbivory experiments, Se-rich neighbors of hyperaccumulators experienced less herbivory and caused higher grasshopper Se accumulation (10-fold) and mortality (4-fold).ConclusionsEnhanced soil Se levels around hyperaccumulators can facilitate growth of Se-tolerant plant species through reduced herbivory and enhanced growth. This study is the first to show facilitation via enrichment with a nonessential element. It is interesting that Se enrichment of hyperaccumulator neighbors may affect competition in two ways, by reducing growth of Se-sensitive neighbors while facilitating Se-tolerant neighbors. Via these competitive and facilitating effects, Se hyperaccumulators may affect plant community composition and, consequently, higher trophic levels

Experimental evaluation of anti-inflammatory, antinociceptive and antipyretic activities of clove oil inmice

Background: Clove oil of Eugenia caryophyllata (Myrtaceae) is a light yellowish fluid obtained from dried flower buds. Clove oil is used traditionally to relieve toothache.Aim: The aim of the present work was to study the anti-inflammatory, antinociceptive and antipyretic potential of clove oil in mice.Methods: Analgesic activity was examined using acetic-acid-induced abdominal constrictions and the hot plate test. Carrageenan-induced paw edema and brewer’s-yeast-induced pyrexia were used to investigate the anti-inflammatory activity and the antipyretic effects, respectively. The oil was administered intraperitoneally (i.p.) at a dose of 33 mg/kg body weight and the effects were compared with reference drugs.Results: In the antinociceptive test, mice treated with clove oil exhibited significantly decreased acetic-acidinducedwrithing movements by a maximum of 87.7% (p<0.01) compared with a decrease of 77.7% (p<0.01) in response to aspirin injection (100 mg/kg, intraperitoneal, i.p.). Similarly, in the hot plate test, clove oil significantly increased the reaction latency to pain after 60 min by 82.3% (p<0.05) compared with morphine value of 91.7% (p<0.01). In addition, clove oil and indomethacin produced anti-inflammatory effects, as demonstrated by respectively 50.6% (p<0.05) and 70.4% (p<0.01) inhibition of mouse paw edema induced by carrageenan. Furthermore, clove oil significantly attenuated the hyperthermia induced by yeast at ΔT-max by 2.7oC (p<0.001), and time of peak effects was 30-180 min compared with a paracetamol value ΔT-max of 3.2oC (p<0.001). The estimated i.p. LD50 of clove oil was 161.9 mg/kg. Phytochemical screening of the oil showed the presence of eugenol.Conclusion: The present findings demonstrate the potential pharmacological properties of clove oil and provide further a support for its reported use in folk medicine.Keywords: Eugenia caryophyllata; clove oil; eugenol; antinociceptive; anti-inflammatory; antipyretic; mic

Influence of sulfate supply on selenium uptake dynamics and expression of sulfate/selenate transporters in selenium hyperaccumulator and nonhyperaccumulator Brassicaceae

Summary Stanleya pinnata not only hyperaccumulates selenium (Se) to 0.5% of its dry weight, but also exhibits higher tissue Se‐to‐sulfur (S) ratios than other species and its surroundings. To investigate the mechanisms underlying this Se enrichment, we compared S. pinnata with the nonhyperaccumulators S. elata and Brassica juncea for selenate uptake in long‐ (9 d) and short‐term (1 h) assays, using different concentrations of selenate and competitor sulfate. Different sulfate pre‐treatments (0, 0.5, 5 mM, 3 d) were also tested for effects on selenate uptake and sulfate transporters' expression. Relative to nonhyperaccumulators, S. pinnata showed higher rates of root and shoot Se accumulation and less competitive inhibition by sulfate or by high‐S pretreatment. The selenate uptake rate for S. pinnata (1 h) was three‐ to four‐fold higher than for nonhyperaccumulators, and not significantly affected by 100‐fold excess sulfate, which reduced selenate uptake by 100% in S. elata and 40% in B. juncea. Real‐time reverse transcription PCR indicated constitutive upregulation in S. pinnata of sulfate transporters SULTR1;2 (root influx) and SULTR2;1 (translocation), but reduced SULTR1;1 expression (root influx). In S. pinnata, selenate uptake and translocation rates are constitutively elevated and relatively sulfate‐independent. Underlying mechanisms likely include overexpression of SULTR1;2 and SULTR2;1, which may additionally have evolved enhanced specificity for selenate over sulfate

A preliminary study of the role of nickel in enhancing flowering of the nickel hyperaccumulating plant Alyssum inflatum Nyár. (Brassicaceae)

Alyssum inflatum is a native of serpentine soils and is able to hyperaccumulate nickel (Ni), but the importance of Ni to reproduction in the species is unknown. We investigated if reproductive fitness is enhanced by Ni in the growth medium, and included a treatment involving a relatively high level of Mg to provide a comparison with elevated levels of another metal. Seedlings were grown in a modified Hoagland solution culture in an inertmediumof Perlite andwere treatedwith Ni (100 μM), a high concentration ofMg (5mM), or under control conditions (solution culture without Ni or the addition of high Mg) for 14 months.We documented survival, as well as the proportion of individuals that flowered.We also quantified flower production as an indicator of plant fitness. Survival was not affected by treatment (87–90% for all treatments), but significantly more Ni-treated plants (63%) flowered compared with Mg-treated (19%) or control plants (12%). In addition, inflorescences per plant, inflorescence length, and number of open flowers per inflorescence were all significantly greater for Nitreated plants relative to plants fromthe other treatments. Although high levels of Ni are not essential for growth and reproduction of the species, we suggest that Ni stimulates flowering in A. inflatum and may result in greater fitness for the species on serpentine soils

Characterization of Selenium Accumulation, Localization and Speciation in Buckwheat–Implications for Biofortification

Buckwheat is an important crop species in areas of selenium (Se) deficiency. To obtain better insight into their Se metabolic properties, common buckwheat (Fagopyrum esculentum) and tartary buckwheat (F. tataricum) were supplied with different concentrations of Se, supplied as selenate, selenite, or Astragalus bisulcatus plant extract (methyl-selenocysteine). Se was supplied at different developmental stages, with different durations, and in the presence or absence of potentially competing ions, sulfate, and phosphate. The plants were analyzed for growth, Se uptake, translocation, accumulation, as well as for Se localization and chemical speciation in the seed. Plants of both buckwheat species were supplied with 20 μM of either of the three forms of Se twice over their growth period. Both species accumulated 15–40 mg Se kg−1 DW in seeds, leaves and stems, from all three selenocompounds. X-ray microprobe analysis showed that the Se in seeds was localized in the embryo, in organic C-Se-C form(s) resembling selenomethionine, methyl-selenocysteine, and γ-glutamyl-methylselenocysteine standards. In short-term (2 and 24 h) Se uptake studies, both buckwheat species showed higher Se uptake rate and shoot Se accumulation when supplied with plant extract (methyl-selenocysteine), compared to selenite or selenate. In long-term (7 days) uptake studies, both species were resistant to selenite up to 50 μM. Tartary buckwheat was also resistant to selenate up to 75 μM Se, but >30 μM selenate inhibited common buckwheat growth. Selenium accumulation was similar in both species. When selenite was supplied, Se levels were 10–20-fold higher in root (up to 900 mg Se kg−1 DW) than shoot, but 4-fold higher in shoot (up to 1,200 mg Se kg−1 DW) than root for selenate-supplied plants. Additionally, sulfate and phosphate supply affected Se uptake, and conversely selenate enhanced S and P accumulation in both species. These findings have relevance for crop Se biofortification applications

Variation in the angiosperm ionome

The ionome is defined as the elemental composition of a subcellular structure, cell, tissue, organ or organism. The subset of the ionome comprising mineral nutrients is termed the functional ionome. A ‘standard functional ionome’ of leaves of an ‘average’ angiosperm, defined as the nutrient composition of leaves when growth is not limited by mineral nutrients, is presented and can be used to compare the effects of environment and genetics on plant nutrition. The leaf ionome of a plant is influenced by interactions between its environment and genetics. Examples of the effects of the environment on the leaf ionome are presented and the consequences of nutrient deficiencies on the leaf ionome are described. The physiological reasons for (1) allometric relationships between leaf nitrogen and phosphorus concentrations and (2) linear relationships between leaf calcium and magnesium concentrations are explained. It is noted that strong phylogenetic effects on the mineral composition of leaves of angiosperm species are observed even when sampled from diverse environments. The evolutionary origins of traits including (1) the small calcium concentrations of Poales leaves, (2) the large magnesium concentrations of Caryophyllales leaves, and (3) the large sulfur concentrations of Brassicales leaves are traced using phylogenetic relationships among angiosperm orders, families and genera. The rare evolution of hyperaccumulation of toxic elements in leaves of angiosperms is also described. Consequences of variation in the leaf ionome for ecology, mineral cycling in the environment, strategies for phytoremediation of contaminated land, sustainable agriculture, and the nutrition of livestock and humans are discussed

An analysis of the Libyan oil industry with special emphasis on its growth and economic implications

An examination of available research finds little significant material on the Libyan oil industry. This being the case it is important that a study be attempted in order to shad some light on the important economic Interest as well as effects on the development of the nation. The importance of the industry on the Libyan economy is sometimes under estimated by western observers. This study will attempt to organize available data as well as add now Libyan studies in developing or give an overview of the implication of the oil industry. The problem is to analyze the growth and development of the oil industry. The question of available suppliant manpower, geology of the area, all operation as well as the economic aspect will be stressed.Thesis (M.A.