Urban Concentration and Poverty in Developing Countries          下载免费PDF全文

Khalid Sekkat 《Growth and change》2017,48(3):435-458

We investigate the impacts of urban concentration (share of the population living in large cities) on poverty in developing countries. We use instrumental variables to estimate a system linking urban concentration, growth and urban and rural poverty. The results show that the importance of the population living in (small) cities (less than 0.5 million inhabitants) or very large cities (beyond 5 million inhabitants) has no impact on poverty. The importance of cities of 1 to 5 million inhabitants is poverty reducing. We conclude that developing countries with a large share of the population living in very big cities could reduce poverty by deconcentrating their urbanization toward cities of between 1 and 5 million inhabitants.  相似文献   

Bacillus thuringiensis CHGP12 uses a multifaceted approach for the suppression of Fusarium oxysporum f. sp. ciceris and to enhance the biomass of chickpea plants     

Rida Fatima  Tahir Mahmood  Anam Moosa  Muhammad Naveed Aslam  Muhammad Taimoor Shakeel  Ambreen Maqsood  Muhammad Umar Shafiq  Tanvir Ahmad  Mahmoud Moustafa  Mohammad Al-Shehri 《Pest management science》2023,79(1):336-348

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Optimization of Agrobacterium-mediated transformation parameters for Melastomataceae spp. using green fluorescent protein (GFP) as a reporter     

Wilson Thau Lym Yong  Janna Ong Abdullah  Maziah Mahmood 《Scientia Horticulturae》2006

Agrobacterium-mediated transformation for both Melastoma malabathricum and Tibouchina semidecandra were optimized using green fluorescent protein (GFP) as a reporter. The binary vector pCAMBIA1304 harboring the modified green fluorescent protein (mgfp) gene driven by the CaMV 35S promoter was used. Parameters optimized were bacterial strain, bacterial concentration, pre-culture period, co-cultivation period, immersion time, acetosyringone concentration and wounding type. Results obtained were based on the percentage of GFP expression which was observed 3 days post-transformation. Agrobacterium tumefaciens strain LBA4404 and EHA105 at concentration 1 × 10⁷ cfu ml⁻¹ (OD_600nm 0.8) showed the highest virulence on M. malabathricum and T. semidecandra, respectively. Four days of pre-culture and 2 days of co-cultivation were optimum for M. malabathricum transformation, while 3 days of pre-culture and co-cultivation for T. semidecandra. Result also showed that 60 min of immersion and addition of 200 μM acetosyringone gave the highest percentage of positive transformants for both M. malabathricum and T. semidecandra. Mild wounding also significantly increased the efficiency of M. malabathricum transformation.  相似文献   

Effect of exogenous putrescine on post-harvest life of strawberry (Fragaria ananassa Duch.) fruit,cultivar Selva     

Mohammad Reza Zokaee Khosroshahi  Mahmood Esna-AshariAhmad Ershadi 《Scientia Horticulturae》2007

Effect of different concentrations of putrescine on post-harvest life of strawberry (Fragaria ananassa Duch.) fruit, cultivar Selva at 5 °C was studied. Fruits were immerged in 0.3, 0.5, 1 and 2 mM putrescine as well as distilled water (control) for 5 min, then transferred into the fridge (5 °C) together with untreated fruits (dry treatment). The rate of weight loss, ethylene production, flesh firmness, soluble solids content, titratable acidity and pH of fruits were determined 5, 9 and 13 days after the beginning of storage. Flesh firmness, appearance, color change and taste of fruits were also determined in the same intervals using a taste panel. Storage life of the strawberry fruits was significantly increased by the use of putrescine, so that the untreated and control fruits had 6 and 8 days storage life, respectively, while the immerged fruits in 1 and 2 mM putrescine were still suitable to be exposed in the market 12 and 14 days after the beginning of storage, respectively. No significant weight losses were observed in treated fruits compared to controls and dry treatment at all determination times. Ethylene production was decreased significantly by the use of putrescine. Untreated fruits (dry treatment) had the highest rate of ethylene production and the lowest rate was occurred in 2 mM putrescine treatment at all determination times (5, 9 and 13 days after the beginning of storage). The use of putrescine also prevented the softening of fruit flesh during the storage and kept their firmness, so that, the 2 mM putrescine treatment caused the highest fruit firmness at all determination times. Distilled water treatment (control) had the lowest fruit firmness 5 and 9 days after storage, while this occurred for the dry treatment 13 days after storage. Soluble solids content, pH and titratable acidity of the fruits were not significantly affected by the use of putrescine, but the highest and lowest rate of titratable acidity were related to the 2 mM putrescine and dry treatment, respectively, at the three determination times. Overall, the quality of fruits was improved by the use of 2 mM putrescine in terms of properties evaluated by the taste panel.  相似文献   

Environmental and genotypic effects on bulb development in onion – a review     

Khalid Mahmud Khokhar 《The Journal of Horticultural Science and Biotechnology》2017,92(5):448-454

Environmental and genetic factors influence growth and bulb development of onions by affecting their physiology. Photoperiod plays critical a role in bulb development and determines the suitability of a cultivar for a particular region. Long days and high temperatures promote onion bulbing. Bulbing is regulated more by temperature than photoperiod, as determined by growing degree days. Far-red light promotes bulbing most effectively. High-temperature storage of sets (above 20–25°C) results in increased total bulb yields, while very high temperature (25.5–31°C) or temperature below 0°C depresses yield. Plant density has an impact on bulb size: the higher the plant density the smaller the bulb size. Onion is more sensitive to water stress during bulb formation and enlargement than during the vegetative stage. Nitrogen improves bulb development, but too much nitrogen promotes excessive vegetative growth and delays maturity. Growth hormones (gibberellins and ethrel) promote the growth and development of bulbs. Flowering and bulb formation in onion is regulated by different (Flowering Locus T) FT genes. Two antagonistic FT-like genes regulate bulb formation. AcFT1 promotes bulb formation, while AcFT4 prevents AcFT1 up-regulation and inhibits bulbing. There is a need to link our research with the genetics and physiology of onions, to enhance bulb yield.  相似文献   

Effect of set-size and storage temperature on bolting,bulbing and seed yield in two onion cultivars     

Khalid Mahmud Khokhar 《Scientia Horticulturae》2009

The effects of three set-sizes (12.5, 17.5 and 22.5 mm in diameter) and seven storage temperatures (0, 5, 10, 15, 20, 25 and 30 °C) on bolting, bulbing and seed yield in two onion (Allium cepa L.) cultivars ‘Hygro’ and ‘Delta’ were investigated. The incidence of bolting increased linearly with set-size and curvi-linearly with decreasing storage temperature. Time to inflorescence emergence and floret opening showed a curvi-linear response to storage temperature with the earliest inflorescence emergence and floret opening occurring at 5 °C and the latest at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’. Seed yield per umbel also showed a curvi-linear response to storage temperature with the lowest seed yield occurring at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’ and the highest seed yield at 5 °C. For a seed crop, storage of large sets (22.5 mm) of these cultivars at 5 °C for 120 days appeared to be optimum with 5–12% higher seed yield per umbel than that of 90 days storage. Bulb yield showed a curvi-linear response to storage temperature with the highest bulb yield occurring at 25 °C and the lowest at 5 °C.  相似文献   

Early heat acclimation during incubation improves Japanese quail performance under summer conditions     

Farghly  Mohamed  Mahrose  Khalid  Abougabal  Mohammed  Taboosha  Mossad  Ali  Reham 《Veterinary research communications》2022,46(1):93-100

Effects of exposing quail eggs to high temperature on the heat tolerance ability and productivity of birds were investigated. Four groups of 600 fertile eggs were randomly selected; the first group was incubated under 37.5 °C and the hatched chicks were reared under a gradual decrease in temperature from 35 to 24 °C (Control). The second group was exposed to 39.1 °C for 2 h/day during 4–14 days of embryogenesis and the hatched chicks were reared under a gradual decrease in temperature from 35 to 24 °C. The third group was incubated under 37.5 °C and the hatched chicks were exposed to 39?±?1 °C for 2 h/day during 4–14 days of age. The fourth group was exposed to 39?±?1 °C for 2 h during 4–14 days of embryogenesis and the hatched chicks were exposed to 39?±?1 °C for 2 h/day during 4–14 days of age. The temperature applied changed (P?<?0.01) embryo weight and incubation period. Birds exposed to high temperature during brooding had superior growth performance, dressed carcass, body temperature and health traits. Birds subjected to 39?±?1 °C during brooding exhibited decreased feed consumption and body weight gain. Finally, this work suggests that thermal acclimation during embryogenesis might offer a practical method for easing heat stress.

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Integrated pest management of Tuta absoluta: practical implementations across different world regions     

Desneux  Nicolas  Han  Peng  Mansour  Ramzi  Arn&#;  Judit  Br&#;vault  Thierry  Campos  Mateus R.  Chailleux  Anais  Guedes  Raul N. C.  Karimi  Javad  Konan  Kouassi Arthur J.  Lavoir  Anne-violette  Luna  Mar&#;a G.  Perez-Hedo  Meritxell  Urbaneja  Alberto  Verheggen  Fran&#;ois J.  Zappal&#;  Lucia  Abbes  Khaled  Ali  Abid  Bayram  Yunus  Cantor  Fernando  Cuthbertson  Andrew G. S.  De Vis  Raf  Erler  Fedai  Firake  Dnyaneshwar M.  Haddi  Khalid  Hajjar  M. Jamal  Ismoilov  Khasan  Jaworski  Coline C.  Kenis  Marc  Liu  Hao-tian  Madadi  Hossein  Martin  Thibaud  Mazih  Ahmed  J. Messelink  Gerben  Mohamed  Samira A.  Nofemela  Robert S.  Oke  Abiola  Ramos  C&#;sar  Ricupero  Michele  Roditakis  Emmanouil  Shashank  Pathour R.  Wan  Fang-Hao  Wang  Ming-hui  Wang  Su  Zhang  Yi-Bo  Biondi  Antonio 《Journal of pest science》2022,95(1):17-39

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...  相似文献   

The effect of feeding three anabolic steroids in different combinations on the growth,food conversion efficiency and protein and nucleic acid levels of liver,kidney, brain and muscle of mirror carp (Cyprinus carpio)     

Khalid P. Lone 《Fish physiology and biochemistry》1989,6(3):149-156

A study on the effect of three different anabolic-androgenic steroids on the growth, food conversion efficiency and nucleic acid contents of liver, kidney, brain and muscle of carp,Cyprinus carpio was undertaken. The three steroids, methyltestosterone (MT), ethylestrenol (EE) and oxandrolone (ON), were fed in different combinations at final concentrations of 5 or 6 mg/kg diet for 60 days. No effect on the growth was observed in any of the experimental groups. A decrease in the specific growth rate (11–21%) and food conversion efficiency (20–29%) was noted. Feeding of drugs increased the cranio-somatic and reno-somatic index in all except one group. Hepatosomatic (ON+MT) and viscero-somatic (ON+MT; EE+MT+ON) indices decreased. Protein increased and RNA/DNA decreased in only one group while a decrease in protein/DNA was observed in the liver of all experimental groups. RNA/DNA increased and protein/RNA decreased only in one group while no effect was seen in protein and protein/DNA contents in any of the treated kidneys. Proteins, protein/RNA and protein/DNA decreased in certain groups in brain tissue. In muscle, no effect was seen in proteins or protein/DNA. Protein/RNA decreased in all but one group while RNA/DNA was higher only in the group fed all the three steroids together.  相似文献   

Morphological studies of peripheral blood cells of the Chinese sturgeon, <Emphasis Type="Italic">Acipenser sinensis</Emphasis>     

Gao Zexia  Wang Weimin  Yang Yi  Khalid Abbas  Li Dapeng  Zou Guiwei  James S. Diana 《Fish physiology and biochemistry》2007,33(3):213-222

The peripheral blood cells of one-year-old Chinese sturgeon (Acipenser sinensis) have been studied by light microscopy and transmission electron microscopy. The erythrocyte count was 84.86 × 10⁴ cell mm⁻³ in the peripheral blood of the fish and that of leukocytes was 2.24 × 10⁴ cell mm⁻³. The erythrocytes and four main types of leucocyte—thrombocytes, lymphocytes, granulocytes (including neutrophils and eosinophils), and monocytes, were identified in the peripheral blood. In addition to normal erythrocytes, reticulocytes and division of erythrocytes were observed. Thrombocytes were the most numerous among the leukocytes, and the number of neutrophils with lobated nuclei was larger than for other fish. The structures of the erythrocytes, lymphocytes, monocytes, granulocytes, and thrombocytes of the fish were studied. The erythrocytes were almost completely devoid of organelles, except for some mitochondria and granules. A large number of vacuoles and a few organelles were observed in cytoplasm of the monocytes. There were many microvilli on the membrane and pseudopodia-like cytoplasm bulge in the lymphocytes. The neutrophils were round or oval in shape with bilobed, trilobed, or multilobed nuclei whereas the eosinophils had big special granules, dark stained. There were many vesicles in some thrombocytes, which were related to its phagocytosis; some thrombocytes had almost no cytoplasm or organelles.  相似文献