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ABSTRACTThe relationship between stand attributes and biomass accumulation pattern in a mangrove forest has been intensively studied in this study. We assessed above (AGM) and belowground mass (BGM) and examined the relationship between forest attributes and aboveground mass in the Sundarbans, Bangladesh. The study was conducted with 18 plots having total area of 1.08 ha. The mean AGM and BGM of the study sites were 234.08 and 132.85 Mg ha?1 respectively. H. fomes contributed the highest amount (82.9% of total AGM and 80.53% of total BGM) of above (193.56 Mg ha?1) and belowground mass (107.09 Mg ha?1) at the study site. Our study revealed structural attributes (tree diameter, height, and basal area) positively correlated with AGM. In contrast, species richness and species diversity negatively correlated with AGM. Our study indicated that lack of positive relationship between species diversity and AGM which may be attributable to high AGM of the dominant species (H. fomes) and may have a considerable consequence in AGM of the study area. Thus, maintaining large trees (DBH and height) rather than species diversity in the Sundarbans mangrove forest might be an effective approach for increasing aboveground mass. 相似文献
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Comparison of PCR and dot blot diagnostic techniques for detection of white spot syndrome virus (WSSV) was made on different tissues of infected Penaeus monodon including eye stalk, eye stalk with eye, gills, cuticle, pleopod, periopods, uropods and telson. Dot blots of crude DNA extracted from infected tissue samples showed positive reactions with all the samples; however, the sensitivity of the dot blot was reduced with the purification of DNA samples extracted from pleopod, telson and uropod. PCR was found to be more sensitive when compared to dot blot. Both crude DNA and purified DNA samples extracted from all the tissues except for eye stalk with eye showed single step nested PCR positive reaction. The amplification of all or either of the three bands of 941 bp, 525 bp and 204 bp size varied with the tissues analysed. The severity of infection assessed by PCR amplification was found to be maximum in cuticle and telson followed by gill. Other tissues such as eye stalk, pleopod, periopods and uropod were observed to have mild infection. The maximum intensity of the PCR product was for the smallest amplified product of 204 bp followed by 525 bp and the weakest intensity was observed for the 941 bp size. The limitation of PCR due to inhibiting factors present in tissues could be overcome with the use of dot blot which gave positive reaction from the DNA extracted from eye stalk including the eye but yielded no amplification by PCR. 相似文献
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An outbreak of pine lappet moth, Kunugia latipennis, in mid-altitude hills of Meghalaya state, India
D. M. Firake G. T. Behere P. D. Firake N. S. Azad Thakur Z. B. Dubal 《Phytoparasitica》2012,40(3):231-234
The pine lappet moth, Kunugia latipennis Walker (Lepidoptera: Lasiocampidae), is the major insect pest of pines found in the northeastern hilly region of India. Recently, an outbreak of lappet moths was observed in the mid-altitude hills of Meghalaya during May?CJune 2011. In this report, attempts are made to describe a recent outbreak of K. latipennis in the region. Females were found to be highly fecund and have the potential to cause severe damage to the pine forest. Incubation and pupal period were found to be 8?±?0.2?days and 16.1?±?0.3?days, respectively. However, many natural regulatory factors were observed during the course of time, which had substantial impact on their survival: these include mainly extreme weather fluctuations and natural enemies. Moths were found to be positively phototrophic; therefore, light traps could be the best option to manage the outbreak. 相似文献
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We investigated the morphology and germination of Tamarindus indica seeds in order to discover the effects of variation in seed sources and pre-sowing treatments on germination. The experiment was carried out in the nursery of the Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Seeds were collected from different but healthy trees from various locations in Bangladesh and subjected to four pre-sowing treatments, i.e., control, immersion in cold water (4°C for 24 h), immersion in hot water (80°C for 10 min) and scarification with sand paper. Seed germination was carried out in poly-bags with a mixture of topsoil and cow dung in the ratio of 3:1. The average length of the fresh seeds was 1.35±0.26 cm, their width 1.07 ±0.20 cm and thickness 0.69±0.11 cm. The results revealed that pre-sowing treatments affected the germination process of seeds, which significantly increased the germination percentage with the cold water (81.67%) and scarification with sand paper (82.33%) treatments, compared with those in the control (58.33%) and hot water treatment (59.00%). In all treatments germination started on average within 5 to 7 days after the start of the treatments and were completed from 13 to 19 days later. The greatest success in germination (82.33%) was found in scarification with sand paper, followed with 81.67% in the cold water treatment. The results of analyses of variance (ANOVA) showed significant differences (p<0.05) in germination closing dates, seed germination periods and germination percentages among the treatments but no significant difference among seed sources. However, the effect of the interaction between seed source variation and pre-treatment differed significantly in seed germination closing dates and germination percentages. We recommend cold water treatment (submersion of seed at a temperature of 4°C for a 24-h period) for seed germination of T. indica in rural Bangladesh. 相似文献
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Hridam Deb Shili Xiao Mohammad Neaz Morshed Shamim Al Azad 《Fibers and Polymers》2018,19(8):1715-1725
We report a facile approach to fabrication and characterization of cationic titanium dioxide (TiO2+) on poly (vinyl alcohol)/poly (acrylic acid) (PVA/PAA) composite electro-spun nanofibrous mat. The aim of this study is to develop a “functional electrospun nanofibrous mat” as a sustainable approach to superior photocatalytic degradation of organic colorants. For that, the PVA/PAA nanofibrous mat was prepared by electrospinning of PVA and PAA solution according to an aspect ratio of 1:1 and later water stability was induced by the thermal cross linking at an elevated temperature of 145 °C for 30 minute. By means of electrostatic layer-by-layer (LbL) assembly, cationic titanium dioxide (TiO2+, ~19 nm) was immobilized on the surface of the water stable nanofibrous mat. As functionalized composited nanofibrous mat was characterized by using scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis and thermogravimetric analysis (TGA). Superior competency of the functionalized nanofibrous mat towards photocatalytic degradation of organic dye (methyl blue) in aqueous solution was observed by using UV-visible spectrophotometer with quantitative measuring method. The result indicates a complete degradation of methyl blue within 40 mins and superior reusability upto 5 cycles application. The study signifies the prospect of using electrospun nanofibers to manipulate the catalytic activity, which could be a foundation for further rational design of various composite nanofibrous materials. 相似文献
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Effects of commonly used disinfectants on bacterial load,hatchability and survival of Bluefin Sea bream (Sparidentex hasta) eggs 
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下载免费PDF全文 The efficacy of four chemical reagents, iodophor, formalin, hydrogen peroxide and bronopol as fish egg surface disinfectants were evaluated in bluefin sea bream (Sparidentex hasta). Fertilized eggs were counted and subjected to a static bath dip treatment in different concentrations of the above chemicals for 4 min before being incubated at 20 ± 0.5°C for 40 h. Treatment efficacy of the different disinfectants was evaluated by assessing the bactericidal activity, egg hatch percentage and survival of larvae up to 3 days post hatch. Results showed that iodophor at medium concentrations (75 and 100 ppm) was the best of all tested disinfectants in bacterial killing ability (12% reduction in the bacterial counts), egg hatching per cent (99.8% and 99.6% respectively) and larval survival up to 3 days post hatch (50.8% and 54.8% respectively). Formalin was the second best disinfectant at levels of 100 and 150 ppm. Hydrogen peroxide gave good results compared with the control while, bronopol showed discouraging results. In conclusion, iodophor appeared to be suitable for bluefin sea bream eggs disinfection with a 4 min exposure to 75–100 ppm when applied 14–16 h after egg fertilization. 相似文献
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Mansourian AR 《Pakistan journal of biological sciences: PJBS》2010,13(14):664-673
This literature review was conducted to summarize the main points of maternal thyroid function tests, with particular attention in the first trimester of pregnancy which accompanied with significant biochemical and metabolic alteration. The evaluation of thyroid function of either hyperthyroidism and hypothyroidism should be assessed by determination of serum Thyroid Stimulating Hormone (TSH), Thyroxine (T4), Triiodothyronine (T3), Iodine and Thyroid Autoantibodies. Glomerular filtration rate is increased during pregnancy; therefor iodine deficiency should be evaluated during the pregnancy to prevent hypothyroidism. The role which can be played by Human Chronic Gonadotropin (hCG) on stimulating the thyroid gland to become over-active was investigated. Serum level ofthyroglobulin (Tg) and Thyroxin Binding Globulin (TBG) should be assessed for proper assessments of thyroid gland during pregnancy. Thyroid function tests during first-trimester of pregnancy and particularly the reference interval for thyroid function tests for pregnant women in each region has to be established, to prevent mis-diagnosis and irreversible mental and physical adverse affect for growing fetus. 相似文献