Phytosociology and pedological characteristics of selected beats of Durgapur Forest Range, West Bengal, India

The aim of the investigation was to analyze phytosociological characteristics and diversity pattern of five selected beats of tropical dry deciduous forest of Durgapur Forest Range, Burdwan, West Bengal, India. The present investigation was carried out through quadrat method for analysis of phytosociological aspect of vegetation. The soil of the different study sites were analyzed by following standard methodology. The results reflect dominancy of dicotyledons over monocotyledons in the five studied sites. Basudha (61) and Shibpur (58) beats represents higher number of species among the five studied sites. Maximum IVI value was recorded by Shorea robusta followed by Madhuka longifolia among all the beats except Shibpur. The study represents overall dominance of Sal forest over the entire region. Therefore Basudha and Shibpur beat needs prior conservative measure for protection of bioresources in those two forest region. The soil characteristics of the four study sites revealed acidic nature of soil in all the studied sites of Durgapur Forest Division. The range of organic carbon % was found to be higher in amount in comparison to conventional soil samples reflecting higher soil fertility of the studied sites. Therefore, proper management and conservative measures needs to be implemented for conservation of bioresources in different sites of Durgapur Forest Division, West Bengal, India

Deactivation and regeneration of Ni catalyst during steam reforming of model biogas: An experimental investigation

his paper presents detailed study of biogas reforming. Model biogas with different levels of H2S is subjected to reforming reaction over supported Ni catalyst in a fixed bed reactor at 700 °C and 800 °C. In order to understand the poisoning effects of H2S the reactions have been initially carried out without H2S in the feed stream. Three different H2S concentrations (20, 50 and 100 ppm) have been considered in the study. The H2O to CH4 ratio is maintained in such as way that CO2 also participates in the reforming reaction. After performing the poisoning studies, regeneration of the catalyst has been studied using three different techniques i) removal of H2S from the feed stream ii) temperature enhancement and iii) steam treatment. Poisoning at low temperature is not recoverable just by removal of H 2S from the feed stream. However, poisoning at high temperature is easily reversed just by removal of H2S from the feed stream. Unlike some previous reports by Li et al. (2010) and Rostrup-nielsen (1971) [1,2], catalyst regeneration is achieved in shorter time frames for all the regeneration techniques attempte

The Strangeness of Knowledge-based Injustices against Children

This paper explores a particular kind of epistemic injustice against children. Following Fricker and Dotson’s ideas on epistemic injustice and testimonial smothering respectively, I use the terminology offered by them to examine the Christchurch Civic Creche case (1993

A detailed kinetic model for biogas steam reforming on Ni and catalyst deactivation due to sulfur poisoning

This paper deals with the development and validation of a detailed kinetic model for steam reforming of biogas with and without H2S. The model has 68 reactions among 8 gasphase species and 18 surface adsorbed species including the catalytic surface. The activation energies for various reactions are calculated based on unity bond index-quadratic exponential potential (UBI-QEP) method. The whole mechanism is made thermodynamically consistent by using a previously published algorithm. Sensitivity analysis is carried out to understand the influence of reaction parameters on surface coverage of sulfur. The parameters describing sticking and desorption reactions of H2S are the most sensitive ones for the formation of adsorbed sulfur. The mechanism is validated in the temperature range of 873-1200 K for biogas free from H 2S and 973-1173 K for biogas containing 20-108 ppm H2S. The model predicts that during the initial stages of poisoning sulfur coverages are high near the reactor inlet; however, as the reaction proceeds further sulfur coverages increase towards the reactor exit. In the absence of sulfur, CO and elemental hydrogen are the dominant surface adsorbed species. High temperature operation can significantly mitigate sulfur adsorption and hence the saturation sulfur coverages are lower compared to low temperature operation. Low temperature operation can lead to full deactivation of the catalyst. The model predicts saturation coverages that are comparable to experimental observatio

Physico-chemical changes during fruit growth and developmental stages in yellow type passion fruit (Passiflora edulis f. flavicarpa Degener) accessions

Physiological and biochemical changes during fruit growth, development and maturity of six yellow type passion fruit (Passiflora edulis f. flavicarpa Degener) accessions were studied at weekly interval after fruit set from 21 days to 91 days after fruit set and after dropping from vine also. Fruit growth of passion fruit followed a single sigmoid growth curve. Fruit length (cm), diameter (cm) and weight (g) increased continuously (25.24%, 33.13% and 75.08% respectively) (from the initial stage till maturity up to 84 days), which slightly declined at ripening stage. Fruits developed acceptable physico-chemical qualities with good colour, when harvested at 84 to 91 days after fruit set (DAF). The study further revealed that the days taken from fruit set to maturity and ripening, colour change, total soluble solids and acidity may be considered as the most reliable maturity indices for taking harvest decision in pas-sion fruit

Effect Of Nanoclay On The Toughness Of Epoxy And Mechanical, Impact Properties Of E-glass-epoxy Composites

Organically modified montimorillonite nanoclay was added to the epoxy and E-glass-epoxy composites. The influence of nanoclay content (varied between 0 to 5wt %) on the relative crosslink density and the fracture toughness of the epoxy matrix was studied. Differential scanning calorimetry (DSC) indicated that the amino functional groups present on the nanoclay react with the epoxy matrix to increase the crosslink density of about 13 and 18% at 3 and 5wt% addition, respectively. The toughness of the epoxy composites increased by 25% at 3wt% addition of nanoclay, whereas, it decreases at 5wt%. Flexural strength and tensile strength of the E-glass-epoxy composites were found to increase by 12% and 11% respectively at 3wt% addition of nanoclay, while at 5wt% addition these properties decreased due to the matrix embrittlement. Interestingly matrix embrittlement is found to be beneficial in increasing the impact resistance due to spallation of embrittled matrix that ensures the dissipation of the impact energy. 5wt% nanoclay addition increases the impact strength by 29% and reduces the back face bulge of composite by 31%. These results may lead to the design and realization of glass-epoxy composites with better impact strength

Anti-tumor effect of fruit rind of Myristica malabarica in an Ehrlich ascites carcinoma model

Background: Among the various modalities of anti-cancer treatment, cancer chemotherapy plays a very vital role. The alarming side effects being its main drawback leads to relentless research for newer agents. A new natural agent with promising anti-cancer properties from in-vitro studies leads to this study. Here we have evaluated the anti-tumor activity of a crude extract of fruit rind of Myristica malabarica in an Ehrlich ascites carcinoma model in mice.Methods: A murine model of cancer was established with i.p. inoculation of Ehrlich Ascites carcinoma (EAC) cells; animals were divided into five groups (including normal control) to observe the inhibitory effect of a crude extract of the fruit rind of Myristica malabarica/rampatri (0-100mg/kg b.w. i.p.) as compared with methotrexate (0.4mg/kg bw., i.p.). Blood and ascitic fluid were collected on the 10th day for analysis.Results: In the EAC model, there was an increase in tumor volume, tumor weight, and tumor packed cell volume, which was decreased by rampatri (50 and 100mg/kg bw) along with an increase in the mean survival time (MST). Rampatri caused minimal alterations in hematological parameters, renal functions remained unchanged but an increase in hepatic SGOT was demonstrated.Conclusions: The crude extract of rampatri (containing Malabaricones) exhibited significant anti-tumor activity with minimal effect on hematological and renal functions

Effectiveness of malabaricone-A in P-glycoprotein over-expressing cancer cell lines

Background: A major impediment in treatment for cancers is resistance to chemotherapy and is primarily attributed to over-expression of efflux pumps. This study aimed to establish the cytotoxicity of malabaricone-A (MAL-A) in P-glycoprotein/multidrug resistance (P-gp/MDR) over-expressing hematopoietic cancer cell lines.Methods: Leukemia and multiple myeloma cell lines were indirectly evaluated for their P-gp/MDR status by examining Calcein-AM fluorescence and cell viability was assessed by the MTS-PMS assay.Results: The fluorescence of calcein was significantly decreased in three cell lines LP-1, RPMI-8226 and CEM-ADR 5000 and reversal with verapamil endorsed their P-gp/MDR activity. The mean IC50 of MAL-A in these MDR+ cell lines (5.40±1.41 to 12.33±0.78 µg/ml) was comparable with the MDR- leukemic (9.72±1.08 to 19.26±0.75 µg/ml) and multiple myeloma cell lines (9.65±0.39 to 18.05±0.17 μg/ml).Conclusions: Irrespective of their P-gp activity, the cytotoxicity of MAL-A was comparable, making it worthy of future pharmacological consideration in multidrug resistance

Malabaricone-A Induces A Redox Imbalance That Mediates Apoptosis in U937 Cell Line

BACKGROUND: The 'two-faced' character of reactive oxygen species (ROS) plays an important role in cancer biology by acting both as secondary messengers in intracellular signaling cascades and sustaining the oncogenic phenotype of cancer cells, while on the other hand, it triggers an oxidative assault that causes a redox imbalance translating into an apoptotic cell death. PRINCIPAL FINDINGS: Using a tetrazolium [{3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl}-2H-tetrazolium] based cell viability assay, we evaluated the cytotoxicity of a plant derived diarylnonanoid, malabaricone-A on leukemic cell lines U937 and MOLT-3. This cytotoxicity hinged on its ability to cause a redox imbalance via its ability to increase ROS, measured by flow cytometry using 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate and by decreasing glutathione peroxidase activity. This redox imbalance mediated apoptosis was evident by an increase in cytosolic [Ca(2+)], externalization of phosphatidyl serine as also depolarization of the mitochondrial membrane potential as measured by flow cytometry. There was concomitant peroxidation of cardiolipin, release of free cytochrome c to cytosol along with activation of caspases 9, 8 and 3. This led to cleavage of the DNA repair enzyme, poly (ADP-ribose) polymerase that caused DNA damage as proved by labeling with 4',6-diamidino-2-phenylindole (DAPI); furthermore, terminal deoxy ribonucleotide transferase catalysed incorporation of deoxy uridine triphosphate confirmed DNA nicking and was accompanied by arrest of cell cycle progression. CONCLUSIONS: Taken together, compounds like MAL-A having pro-oxidant activity mediate their cytotoxicity in leukemic cells via induction of oxidative stress triggering a caspase dependent apoptosis