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51.
Yasser Mattar 《Asia Pacific viewpoint》2004,45(2):165-179
Abstract: Ethnic entrepreneurs often concentrate in specific economic activities. Arab entrepreneurs in Singapore from the time of their first recorded arrivals in 1819 until the 1850s were concentrated in the consumer goods industry. The exit of the Arabs from consumer goods provision saw them moving into the real estate industry in the 1880s, where they remained concentrated until the 1940s. By the 1970s, however, no visible concentration of Arab entrepreneurs could be discerned. This paper argues that the entry and exit of Arab ethnic entrepreneurs into and out of consumer retail and real estate investments may be better explained with reference to political‐economic conditions which facilitate movement than embedded personal relations that enact a chain‐link pattern of industrial mobility. 相似文献
52.
S. Ben Romdhane M. E. Aouani M. Trabelsi P. De Lajudie R. Mhamdi 《Journal of Agronomy and Crop Science》2008,194(6):413-420
Inoculation of grain legumes with rhizobia may improve biological N2 fixation and crop yield. However, drought, high temperature and soil salinity constrain legume root-nodule formation and function. Here, two rhizobial strains nodulating Tunisian chickpea, Mesorhizobium ciceri strain CMG 6 and Mesorhizobium mediterraneum strain CTM 226 originating from semi-arid regions, were selected for their symbiotic performance and their salt stress tolerance (3 % NaCl). Both strains were then examined as inoculants in different soils and field conditions. Field experiments were conducted in four sites using four chickpea cultivars. Rhizobia occupying nodules in non-inoculated plots were isolated and characterized using 16S rDNA typing; to examine nodule occupancy by the inoculant strains we used polymerase chain reaction (PCR)-restriction fragment length polymorphism of 16S rDNA gene and repetitive extragenic palindromic PCR. The inoculant strains gave a significant increase in nodule number, shoot dry weight and grain yield in all the experimented fields for the four cultivars used, even in the non-irrigated soils. The improvement in plant production was equal to or better than nitrogen fertilization. Moreover, the monitoring of the nodule occupancy showed that inoculant strains competed well in the native populations of rhizobia. These results suggest that nodulation and yield of chickpea can be improved by inoculation with competitive and salt-tolerant rhizobia and is economically promising to increase chickpea production in water-limited regions. 相似文献
53.
Nemat Alla MM Shabana YM Serag MM Hassan NM El-Hawary MM 《Pest management science》2008,64(12):1237-1249
BACKGROUND: Orobanche spp. represent a serious threat to a wide range of crops. They are difficult targets for herbicides, and biological control could provide a possible solution. This work therefore aimed to formulate mycoherbicides of Fusarium with adequate shelf life and virulence against Orobanche but safe to faba bean and tomato. RESULTS: Only two isolates of Fusarium oxysporum Schlecht. (Foxy I and Foxy II) obtained from diseased Orobanche shoots were found to be pathogenic to Orobanche crenata Forsk. and Orobanche ramosa L. Conidial suspension of both isolates significantly decreased germination, attachments and tubercles of Orobanche. Microconidia and chlamydospores of both isolates were formulated as mycoherbicides encapsulated in a wheat flour–kaolin matrix (four different formulations). All formulations greatly diminished Orobanche emerged shoots, total shoot number, shoot height, attachment of emerged shoots, the germinated seeds that succeeded in emerging above the soil surface and dry weight. Meanwhile, disease incidence and disease severity of emerged shoots were enhanced. The shelf life was adequate, particularly for coarse, freshly prepared, low‐temperature‐stored, microconidia‐rich formulations. The induced growth reduction of Orobanche‐infected host plants seemed to be nullified by formulations, particularly at the highest dose. CONCLUSION: These formulations seemed to destroy Orobanche but appeared harmless to host plants. Hence, they could be efficiently used as mycoherbicides for biological control of Orobanche in faba bean and tomato. Copyright © 2008 Society of Chemical Industry 相似文献
54.
ABSTRACTThe objective of the current study was to determine the effects of chitosan (CH) coatings containing Mentha spicata essential oil (MSO; 0.2 and 0.4%) and zinc oxide nanoparticle (ZnO; 0.2 and 0.4%) on chemical (total volatile basic nitrogen (TVB-N), 2-thiobarbituric acid reactive substances (TBARS) and peroxide value (PV)), microbial (total viable count, psychrotrophic count, Pseudomonas spp., and Enterobacteriaceae) and sensory (odor, color, and overall acceptability) properties of raw rainbow trout fillets during 14 days of refrigerated storage. Final microbial population of CH + MSO 0.4% + ZnO 0.4% and CH + MSO 0.4% + ZnO 0.2% retarded approximately 3–5 log CFU/g as compared to control groups (P < 0.05). At the end of storage time in control samples, TVB-N, TBARS, and PV reached 49.3 mg N/100 g, 3.31 mg malonaldehyde/kg, and 2.04 meq peroxide/kg lipid, while the values for the treated samples with MSO (0.2 and 0.4%) in combination with ZnO (0.2 and 0.4%) remained lower than 25 mg N/100 g, 2 mg malonaldehyde/kg, and 1.1 meq peroxide/kg lipid, respectively. The results indicate a potential use of CH coating containing MSO and ZnO as an effective type of antimicrobial packaging to maintain quality of rainbow trout fillets. 相似文献
55.
Awatef Trabelsi Andrzej Jaworski Ewa Kamler Jean-Noël Gardeur Fabrice Teletchea Habib Ayadi Pascal Fontaine 《Fish physiology and biochemistry》2016,42(2):593-606
Size, caloric value and chemical composition were measured separately in the progeny of two northern pike (Esox lucius) females at 3-day intervals during the endogenous feeding period from hatching to final yolk resorption. Tissue, yolk and entire larvae were analysed separately in three groups of larvae that hatched at different times (between 88 and 106 degree-days post-fertilization). An integrated approach with the Gompertz model was used to compute the yolk conversion efficiency and time to maximum tissue size in early, mid and late hatched larvae. At hatching, unresorbed yolk of early hatched larvae contained more energy (39.20 J) and more protein (0.99 mg) compared to the yolk of larvae that hatched later (38.13 J and 0.92 mg protein for late hatched larvae, p < 0.05). In contrast, a significant reduction in tissue weight (?0.7 mg DW) and protein content (?0.5 mg) was found in early hatched larvae compared to those which hatched later (p < 0.05). Between days 9 and 12 post-hatching (108 and 144 degree-days post-hatching), close to the final yolk resorption, late hatched larvae stopped growing and their tissue began to be resorbed. This tissue resorption time was delayed in early hatched larvae which presented at the end of the experiment a greater tissue weight than late hatched ones. Yolk conversion efficiency in term of energy from hatching to complete yolk resorption stage was significantly higher for early and mid hatched larvae (51 %) compared to late hatched ones (44 %) (p = 0.004). Furthermore, the time to maximum tissue size was found to be negatively related to hatching time which implies that early hatched larvae take longer time to switch from one developmental stage to the next. The maximum tissue dry weight and energy content were found to be reached at approximately the same age post-fertilization for both early hatched and late hatched larvae, suggesting that the principal steps in a fish’s lifespan are better correlated with time of fertilization than hatching time. 相似文献
56.
Al-Majali AM Al-Qudah KM Al-Tarazi YH Al-Rawashdeh OF 《Tropical animal health and production》2008,40(3):193-200
During the period between February, 2004 and December, 2006, a cross-sectional study was performed to investigate some epidemiological
aspects related to camel brucellosis in Jordan. Four hundred twelve camel sera from 37 herds were randomly collected and analyzed
using Rose Bengal plate test and complement fixation test. A structured pre-tested questionnaire was administered to collect
information on camel herd health and management. A multivariable logistic regression model was constructed to investigate
risk factors associated with seropositivity to Brucella antigens. Moreover, the incidence of Brucella-specific abortion was investigated in 7 camel herds located in different locations in Southern Jordan. The true prevalence
of Brucella-seropositive in camels was 12.1%. Thirteen (35.1%) herds had at least one positive camel. The seroprevalence of brucellosis
in camels was significantly higher in the southern part of Jordan than that in central or northern Jordan. The multivariable
logistic regression model on both individual and herd levels revealed large herds and contact with small ruminants as risk
factors for Brucella seropositivity. On the other hand, using disinfectants was identified as a protective factor (OR = 0.8; 95% CI: 0.1, 0.9)
only on the camel herd level. The incidence of Brucella-caused abortion was 1.9%. Brucella melitensis biotype 3 was isolated from 4 aborted camel fetuses. 相似文献
57.
Ghanem Yasser M. El-Khodery Sabry A. Saad Ashraf A. Abdelkader Ahemd H. Heybe Ahemd Musse Yasin A. 《Tropical animal health and production》2009,41(8):1779-1786
The present study was delineated to investigate the prevalence and risk factors of camel brucellosis in Northern Somalia (Somaliland).
The study was carried out at three main districts of camel-rearing regions of Somaliland (Awdal, Waqoyi Galbed and Togdheer)
in the period from July to November, 2008. A total of 1246 camel blood sera were randomly collected from 42 sporadic small
scale camel herds. Two serological tests were used to screen all serum samples, Rose Bengal Plate Test (RBPT) and indirect
ELISA (I-ELISA). Multivariate logistic regression was constructed to study the risk factors associated with Brucella seropositive cases. The overall prevalence of camel brucellosis in districts under investigation was 3.9% by RBPT and 3.1%
by (I-ELISA). Multivariate logistic regression on animal level showed that locality (P < 0.05; OR: 6.254; CI, 1.186–32.976),
herd size (P < 0.001; OR: 5.493; CI, 2.956-10–207), rearing with other ruminants (P < 0.001; OR: 12.433; CI, 3.957–39.060),
and contact with other camels (P < 0.05; OR: 5.311; CI, 1.093–25.800) were the potential risk factors. However, herd size
(P < 0.05; OR: 5.425; CI, 1.181–24.932), and rearing with other ruminants (P < 0.05; OR: 20.466; CI, 1.456–28.638) were recorded
as risk factors on the herd level. The results of the present investigation indicate that the Brucella spp. exists within the camel herds in Somaliland. Further studies need to be done on Brucella infection in the other ruminants to determine which measure should be followed for control of brucellosis. 相似文献
58.
Yasser Mahmoud Awad Johanna Pausch Yong Sik Ok Yakov Kuzyakov 《Journal of Soils and Sediments》2017,17(3):621-631