Bionics of the fish gill | Author : Shi-Min Yuan | Abstract | Full Text | Abstract :The physiological functions of the fish gill include gas exchange, ion regulation, water and acid-base
balances, hormone excretion, circulating metabolite activation and deactivation, and immune defense.
Inspired by these functions of the fish gill, several facilities, such as artificial membrane, "robot fish", shark gill
cooling hole, “artificial gill", and “breathing wall”, etc., have been invented and facilitated people’s daily work
and everyday life. Nevertheless, there not been any comprehensive reports concerning the bionic products in
terms of the structural and functional properties of the fish gill. The aim of this article is to give a brief review of
the bionic inventions of the fish gill. |
| Bollworms Eariasvittella (Fabricius) and Eariasinsulana (Lepidoptera: Noctuidae) Impairment in Cotton and Integrated Crop Management | Author : Muhammad Sarwar | Abstract | Full Text | Abstract :This article focuses on bollworms Eariasvittella (Fabricius) and Earias insulana Boisduval (Noctuidae: Lepidoptera), which
are primarily insect pests of cotton and can make cultivation of crop nearly impossible in some years. Initially, the
caterpillars tunnel into buds by destroying of vessels and growing points, and they cause adjacent blooms, young leaves and
eventually whole shoots to turn blackish-brown and die off, which can result in bunched growth of young plants.
Examination of the affected plant parts reveals a number of small holes either on or near to leaf, or flower buds. On cotton,
the damaged flower buds sometimes spread their bracteoles prematurely (flared squares). When fruiting starts, the larvae turn
towards the bolls, which as a result then become brown and fall off. Older bolls may stay on the plant, but are often so
damaged that they cannot be harvested. Secondary invasion by fungi and bacteria sometimes occurs, and ultimately damage
and excrement-filled tunnels in surviving fruit result in a low market price. Management of Eariasbollworms is becoming
increasingly difficult due to the development of their resistance to many chemical insecticides. In view of these facts, it is
needed to develop eco-friendly tactics such as Integrated Pest Management (IPM) program wherein all practicable tactics are
implemented. Setting of light trap or pheromone traps at 12 per ha effective for 40-45 days can commendably monitor adult’s
activity.Pheromone trapping data on bollworms give early warning of the infestation and also exhibit the density of the insect
population.Biological control and botanical pesticides are economical and safe to the environment. The egg parasitoid
Trichogramma chilonisis the most widely exploited hymenopteran parasitoid by releasing at 1, 25,000 perha three times in
crop is effectiveto control the bollworms. The infested fruits and shoots should be removed regularly and buried deep in the
soil. Spraying with quinalphos 25 EC (2 ml per liter of water) or carbaryl (4 g perliter of water) can effectively control the
pest. Before spraying all the affected plant parts should be removed.After harvest, cotton plants which can sprout from the
stump should be uprooted and destroyed in order to eliminate the food source for Earias spp., and thereby to interrupt
population build-up. |
| Seed Germination and Early Growth of Dacryodes Edulis as Influenced by Some Nursery Techniques | Author : Okunomo, K., Jacob, D. E., Ekpo, I. T. | Abstract | Full Text | Abstract :This study was aimed at assessing the effect of some nursery operations such as soil amendment, growing medium,
soaking time for both cold and warm water and sowing depth on seed germination of Dacryodes edulis. The parameters
assessed were germination rate, leaf area (cm), number of leaves, collar diameter (cm) and height (cm). The experiments
were carried out using complete randomized design (CRD) with three replication and data obtained were analyzed using
a two-way analysis (ANOVA) at 5% probability level. The result obtained indicated that top soil had the highest
germination rate (64%) for soil amendment, while sawdust was the best growing medium with 80% germination rate.
Soaking in warm water for 30 minutes produced the best germination rate (56%) for warm water and soaking for 24hrs
gave the best germination rate (40%) for cold water. In terms of depth of planting, 4cm depth had the highest rate (50%)
for germination. For growth parameters, wood ash had the highest collar diameter (0.39cm), top soil had the highest leaf
area (68.23cm), pig manure had the highest leaves number (10.83), while poultry dropping had the highest plant height
(982.85cm). This study recommend planting Dacryodes edulis should be grown on topsoil without any pretreatment as
this provides an optimum growth for the species at a lesser cost to the farmer.
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| Studies on Vegetation and Soil Characteristics of Karachi University Campus | Author : Jawayria A. Rab, Muhammad Zafar Iqbal,*Muhammad Shafiq, Mohammad Athar | Abstract | Full Text | Abstract :A survey of vegetation of Karachi University was conducted. Total numbers of nineteen species were recorded. Aeluropus lagopoides (Linn.) Trin. attained the highest importance value index (260.50) followed by Suaeda fruticosa (L.) 228.93, Zygophyllum simplex (L.) 223.15, Prosopis juliflora (Swartz) DC. 194.54, Salvia sentolinifolia L. 148.46 and Calotropis procera (Willd) 137. 95. Whereas, Digera muricata (L.) Mart attained the moderate importance value index 81.47. Senna holosericea (L.) attained further lower importance value index 27.34. P. juliflora attained the leading presence class IV. Four species viz. Aeluropus lagopoides, S. fruticosa, Z. simplex and A. javanica attained Class II. Whereas, fourteen species, A. fruticosum, C. trilocularis, S. holosericea, T. amplexicaule, C. depressus, T. terrestis, F. indica, A. aspera, H. europium, S. baryosma, S. sentolinifolia, C. procera and D. muricata attained presence class I.
The physical and chemical soil characteristics of the campus area were related with the vegetation of the areas. The campus area soil was alkaline in nature. The physical properties of Campus soil such as Maximum Water Holding Capacity (23.50 – 41.00 %), bulk density (1.30 – 1.60 g/cc) and porosity (40.60 – 47.60 %) were recorded. Chemical properties of soil for total dissolved salts (0.50 – 1.90 %), extractable sodium (150 - 3100 µg–g), extractable potassium (160 – 310 µg–g ), calcium carbonate (4.10 – 27.10 %), electrical conductivity of soil (0.80 - 2.80 mS cm-1), available sulphur (8.45 – 73.0 µg–g) and chloride (3.60 – 397.50 Meq. l-1) were determined.
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| Antibacterial Evaluation on Crude Bioactive Compounds of Tridax Procumbens Linn and Cardiospermum Halicacabum Linn | Author : A. Doss, T. P. Kumari, Pushpa Rani | Abstract | Full Text | Abstract :Crude extracts and flavonoids of leaves of Tridax procumbens L. (Asteraceae) and Cardiospermum halicacabum L. (Sapindaceae) have been studied for their antimicrobial activities using disc diffusion assay, against two Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis) and five Gram negative bacteria (Escherichia coli MTCC 2961, Salmonella typhi MTCC 733, Pseudomonas aeruginosa MTCC 4676, Klebsilla pneumoniae MTCC 432, Proteus mirabilis MTCC 425). Both plantsexhibited broad spectrum antimicrobial activity. Among the 5 extracts tested, the flavonoids of C. Halicacabum and T. Procumbens were foundto be more potent. Results of the present study indicate that T. Procumbent sand C. Halicacabumcan be exploited for future antimicrobial drugs. |
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