Seasonal fluctuation in primary production in relation to the physicochemical parameters of two weed-infested ponds of Kalyani, West Bengal

Kalyani lake (P sub(1)), a weed infested recreational water body and a weed chocked derelict water body (P sub(2)) in the heart of Kalyani city of West Bengal were studied for a period of one year for their primary productivity and other physicochemical parameters. Very low primary productivity (GPP=360-1237mg C m super(-2) d super(-1); NPP=157-787 mg C m super(-2) d super(-1)) was recorded in P sub(2) in spite of having a high concentration of nutrients (PO sub(4)–P=0.052-0.260mg l super(- 1); NO sub(3)-N=0.110-0.412mg l super(-1)). On the other hand, moderate primary productivity (GPP=1687-3195mg C m super(-2) d super(-1); NPP=900-2700mg C m super(-2) d super(-1)) was found in P sub(1) with comparatively low range of nutrients (P0 sub(4)-P =0.010-0.058mg l super(-1); NO sub(3)-N=0.032-0.118mg l super(-1)). After studying the other physicochemical parameters (temperature, transparency, dissolved oxygen, free carbon dioxide, pH, alkalinity and macrophytic biomass), it was found that the overall hydro-biological conditions of the weed-chocked derelict water body (P sub(2)) is not congenial for biological production as compared to Kalyani Lake (P sub(1)). Kalyani Lake may be used for fish culture with proper management practices

Study of cyclic bursting loading on needle-punched nonwovens: Part II – Change in air permeability and compression behavior

Efforts have been made to investigate the physical properties of needle-punched nonwovens, such as compression and air permeability, before and after the application of cyclic bursting pressure. It is observed that the structural parameters, such as areal density, needling density and fibre fineness, have significant effect on the aforementioned fabric characteristics. More compression is observed in a sample with low mass density. Sample made of coarser fibre shows lower compression as compared to finer fibre samples. The air permeability decreases with increase in mass density. On conducting cyclic bursting test on a sample, the values of air permeability and compression change significantly. The cyclic parameters, such as pressure magnitude and rest time at cyclic peak pressure, cause significant structural changes and reorientation of the fibre during deformation. Increase in pressure and rest time causes increase in compression parameter (α) and air permeability. Nevertheless, at low cyclic pressure level (10% of bursting pressure), the network becomes compact due to fibrous reorientation, and therefore both the values of compression parameter (α) and air permeability show initial drop. On examining the samples made of coarser and finer fibres, the variation is observed in the extent of change in the air permeability

Cyclic bursting loading on needle-punched nonwovens: Part I – Distention behavior

The present study aims at examining different needle-punched polypropylene nonwovens under different cyclic bursting pressure. Various fabric parameters including mass density, punch density and fibre fineness have been investigated. For the cyclic test, the distension is measured at different cyclic bursting pressures proportionate to the bursting strength of the fabric. Other parameters including the cyclic pressure magnitude, the number of cycles, and the rest time at peak pressure have also been investigated. It has been found that the bursting strength and distension of fabric increase with an increase in mass density, while they show opposite trend with punch density and fibre denier (p < 0.01). The distension value of each sample increases with an increase in the cyclic parameters i.e. number of loading cycle, rest time and pressure peak

Long-term impacts of integrated nutrient management with equivalent nutrient doses to mineral fertilization on soil organic carbon sequestration in a sub-tropical Alfisol of India

Limited evidence is available on carbon sequestration potential of long-term integrated nutrient management (INM) versus mineral fertilization, when equivalent amounts of nutrients were added. Hence, this study was carried out to understand the impact of 60 years of INM with adjusted nutrient doses and mineral fertilization in an Alfisol in a maize (Zea maysL.)-wheat (Triticum aestivumL.) system on soil organic carbon (SOC) sequestration in surface (0-30 cm) and deep (30-60 cm) soil layers. Conventional tillage was done twice before sowing of both maize and wheat using a spade. In farmyard manure (FYM) and lime treated plots (FYMP'K'L: plots with nitrogen (N) applied in terms of FYM; additional dose of phosphorus (P) and potassium (K) and lime) total SOC concentration was nearly 83% higher than unfertilized control plots. The FYMP'K'L plots had similar to 11% more total SOC concentration than plots treated with mineral fertilizer and lime (NPKL: recommended dose of N, P, K and lime) in the 0-30 cm soil layer. Labile C, including KMnO4-C, was more in plots with FYM than NPKL plots, whereas the recalcitrant C stock was more in NPKL than FYM treated plots. In the 0-60 cm soil layer, the labile C stock was highest in FYMP'K'L plots, but the recalcitrant C stock was highest in NPKL. Total SOC accumulation rate (over unfertilized control plots) was highest for FYMP'K'L plots (0.38 Mg ha(-1 )year(-1)) in the surface soil layer, whereas SOC sequestration rate was highest in NPKL plots (0.18 Mg ha(-1 )year(-1)) in the deep layer and in the 0-60 cm layer. Overall, although NPKL management practice had the highest C sequestration in the 0-60 cm layer, FYMP'K'L had the best CMI and labile C pools. Thus, resource poor farmers need not to use full doses of NPK and FYM for soil C management in the region

Pattern of regional metastasis in papillary thyroid cancer: our experience of 86 cases

Background: Papillary thyroid cancer (PTC) have a high propensity for regional metastasis which ranges from 30- 80%. The objective of the study is to assess the pattern of lymph node metastasis and to plan the extent of neck dissection accordingly. Though central neck dissection (CND) is routinely done in PTC but the indication of extent of  neck dissection is still controversial.Methods: The medical records of   86 patients with PTC  who underwent total thyroidectomy (TT) and neck dissection at Dr. B. Borooah Cancer Institute(BBCI) from January 2010 to  December 2014 were retrospectively reviewed.Results: Out of 86 patients 22 were males and 64 were females. The median age of presentation was 40.0 years. 43 out of 86 patients (50%) had cervical lymph node metastasis. Ipsilateral nodal metastasis was found in 37 patients (43.0%) and contralateral metastasis was found in only 6 patients (7.0%).Tumors with size more than 3cm had ipsilateral nodal metastasis in 21(56.7%) patients which is statistically significant (p 0.03).A strong association was found between level VI and the ipsilateral group of lymph nodes involving level II,III,IV and V.Conclusions: Majority of patients present with multiple level nodal metastasis, with the central compartment commonly involved. In view of the high incidence of metastatic lymph nodes in levels II, III, IV and level VI ,our study  supports the recommendation  for posterolateral  and anterior  neck dissection in patients with clinically positive neck  nodes and tumor with aggressive criteria