116 research outputs found

    Rhizofiltration of heavy metals from the tannery sludge by the anchored hydrophyte, Hydrocotyle umbellata L.

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    The anchored hydrophyte, Hydrocotyle umbellata L., was employed for the removal of toxic metals from tannery sludge concentrations (w/v) from a tanneries wastewater treatment plant. Differentconcentrations of wet tannery sludge were prepared and plants of H. umbellata showed a good tolerance for all the prepared concentrations. Plants were retrieved after 30, 60 and 90 days and thesludge concentrations showed reduction in sodium chloride, chlorides and chemical oxygen demand (COD). The accumulation of toxic metals in the plants was significantly increased, with increasing exposure time of plants. A higher amount was accumulated in the roots than in the shoots. The bioconcentration factor of Cr was higher than that of Zn and Cu at the same exposure time, indicating a higher accumulation potential of Cr by H. umbellata. The order of uptake efficiency was Cr > Zn > Na > Cu and the maximum metal uptake was observed after 90 days of exposure of H. umbellata, being 18,200 mg kg -1 for chromium, 15,560 mg kg -1 for zinc 7,692 mg kg -1 for sodium and 6,660 mg kg -1 for copper in the roots. These plants not only tolerated up to 60% concentration of tannery sludge but also reduced chromium content of sludge to a considerable extent

    Bioaccumulation of metals from tannery sludge by Typha angustifolia L.

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    The metal bioaccumulation capability of a common anchored hydrophyte, Typha angustifolia L. was studied in a green house trial. The plants could absorb significant amounts of the heavy metals likechromium, copper and zinc from tannery sludge. DifferentĀ  concentrations of tannery sludge were prepared in water and plants of T. angustifolia were exposed to the sludge for 30, 60 and 90 days. Asignificant reduction in sodium chloride percentage, chlorides and chemical oxygen demand (COD) was observed. The percentage reduction in all metals was significant. Cadmium and lead were found to be totally absent. A greater reduction of metals was observed in 30% concentration of sludge. A maximum reduction of 62% for Na, 42% for Cr, 38% for Cu and 36% for Zn was observed in 30% sludge after 90days exposure of T. angustifolia. The bioaccumulation potential of T. angustifolia was greater for the heavy metals especially for Cr. The maximum metal uptake, observed after 90 days exposure of T.angustifolia, was 6,698 mg kg-1 for sodium, 20,210 mg kg -1 for chromium, 16,325 mg kg -1 for zinc and 7,022 mg kg -1 for copper in the roots. In shoots, the uptake was 3,745 mg kg-1 for sodium, 10,150 mg kg- 1 for chromium, 3,509 mg kg-1.for copper and 7,025 mg kg -1 for zinc. Aerial parts of T. angustifolia accumulated less heavy metal than the corresponding roots. T. angustifolia is suitable for thedecontamination of most of the harmful metals from tannery sludge

    Significance of cytogenetic abnormalities in acute myeloid leukaemia

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    Objective: To evaluate the role of karyotype in acute myeloid leukaemia (AML) as a predictor of response to induction chemotherapy. Methods: A cross-sectional study was carried out at the department of Pathology and Oncology, Aga Khan University Karachi from January 2003 to January 2005. Newly diagnosed patients with denovo AML admitted to the hospital were included in the study. Diagnosis of AML was based on FAB criteria, immunophenotyping and cytogenetic studies. They were treated according to standard protocols (combination of anthracycline and cytarabine -3+7) and those who had acute promyelocytic leukaemia additionally received all- trans retinoic acid (ATRA). Results: A total of 56 patients were enrolled, 4 were excluded due to inadequate cytogenetic analysis and the remaining patients entered the study protocol. There were 32 males and 20 females with mean age of 31.3 years (range 9 months to 73 years). Thirty-five (67.3%) patients had normal karyotype while 17 (32.7%) were found to have cytogenetic abnormalities. Eleven patients did not receive treatment at our hospital. Half of the (51.2%) patients out of remaining 41 achieved complete remission on bone marrow examination after receiving induction chemotherapy. In favourable risk group 3/3 (100%) achieved complete remission (CR) while 15/32 (46.9%) in intermediate risk group and 3/6 (50%) in unfavourable risk group. There was low CR rate in patients with high white cell counts. Conclusion: The frequency of cytogenetic abnormalities in AML and response to induction chemotherapy was low when compared with international data possibly due to the small sample size. However, there was a clear difference in CR rates between favourable and unfavourable risk group

    Antimicrobial activity analysis of extracts of Acacia modesta, Artimisia absinthium, Nigella sativa and Saussurea lappa against Gram positive and Gram negative microorganisms

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    Antimicrobial activity of extracts of certain herbs including Acacia modesta (leaf and stem), Artimisia absinthium (leaf and stem), Nigella sativa (seeds) and i (root) was evaluated against three Gram positive and two Gram negative microorganisms. The Gram positive organisms included Bacillus subtalis (ATCC 6633), Entereococcus faecalis (ATCC 14506) and Staphylococcus aureus (ATCC 6538) and the Gram negative organisms included Pseudomonas aeruginosa (ATCC 27853) and Salmonella typhi (ATCC 14028). Methanolic, hot water and cold water extracts of these plants were taken for antibacterial assay through Discs agar diffusion technique using commercial filter paper discs applied on inoculated Muellar Hinton agar plates. The objective of this study was to explore the curative powers of these herbs that exist in nature as a tool to counter disease causing agents. The maximum zone of inhibition of 18 mm of methanolic extract of N. sativa was observed against B. subtalis and S. aureus. Similarly, the maximum zone of inhibition of 18 mm of cold water extract of N. sativa against S. aureus and methanolic extract of Saussurea lappa against S. aureus and Pseudomonas aeruginosa was also observed. The antibacterial action was compared with the effect of ceftriaxone, ceftriaxone sodium, cefuroxine, ciprofloxacin, gentamycine, levofloxacin, metronidazole and tranexamic acid that were used as standered drugs. Based on the results obtained in this study, it may be concluded that plant extracts of A. modesta, A. absinthium, N. sativa and Saussurea lappa have a stronger and broader spectrum of antimicrobial activity against a number of food borne bacteria.Key words: Herbs, methanolic extract, Acacia modesta, Bacillus subtalis, gentamycine, gram negative, gram positive

    Ontogenic development of corticotrophs in fetal buffalo (Bubalus bubalis) pituitary gland

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    To evaluate the subpopulation of corticotrophs in developing buffalo (Bubalus bubalis) fetus, recovered pituitary glands (n=6 per group) from late first, second and third gestational female buffalo dams. The corticotrophs were identified by using specific antibodies against proopiomelanocortin (POMC) and adrenocorticotrophic hormone (ACTH) through immunohistochemistry. There was a significant (Pā‰¤0.05) increase of immunoreactive (ir) ir-ACTH cells during late 2nd trimester while, ir-POMC cells were more (Pā‰¤0.05) at late 3rd trimester of gestation as compared to other age groups. The quantity of co-localized cells for POMC and ACTH was significantly (Pā‰¤0.05) greater at the end of 1st gestation rather than 2nd and 3rd gestational fetal adenohypophyseal cells. This study is the first to demonstrate co-localization of POMC+ACTH and the affect of gestational age on the expression of these cells in buffalo fetus adenohypophysis

    Sialylated N-glycans mediate monocyte uptake of extracellular vesicles secreted from Plasmodium falciparum-infected red blood cells

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    Glycoconjugates on extracellular vesicles (EVs) play a vital role in internalization and mediate interaction as well as regulation of the host immune system by viruses, bacteria, and parasites. During their intraerythrocytic life-cycle stages, malaria parasites, Plasmodium falciparum (Pf) mediate the secretion of EVs by infected red blood cells (RBCs) that carry a diverse range of parasitic and host-derived molecules. These molecules facilitate parasite-parasite and parasite-host interactions to ensure parasite survival. To date, the number of identified Pf genes associated with glycan synthesis and the repertoire of expressed glycoconjugates is relatively low. Moreover, the role of Pf glycans in pathogenesis is mostly unclear and poorly understood. As a result, the expression of glycoconjugates on Pf-derived EVs or their involvement in the parasite life-cycle has yet to be reported. Herein, we show that EVs secreted by Pf-infected RBCs carry significantly higher sialylated complex N-glycans than EVs derived from healthy RBCs. Furthermore, we reveal that EV uptake by host monocytes depends on N-glycoproteins and demonstrate that terminal sialic acid on the N-glycans is essential for uptake by human monocytes. Our results provide the first evidence that Pf exploits host sialylated N-glycans to mediate EV uptake by the human immune system cells

    Explicitly searching for useful inventions: dynamic relatedness and the costs of connecting versus synthesizing

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    Inventions combine technological features. When features are barely related, burdensomely broad knowledge is required to identify the situations that they share. When features are overly related, burdensomely broad knowledge is required to identify the situations that distinguish them. Thus, according to my first hypothesis, when features are moderately related, the costs of connecting and costs of synthesizing are cumulatively minimized, and the most useful inventions emerge. I also hypothesize that continued experimentation with a specific set of features is likely to lead to the discovery of decreasingly useful inventions; the earlier-identified connections reflect the more common consumer situations. Covering data from all industries, the empirical analysis provides broad support for the first hypothesis. Regressions to test the second hypothesis are inconclusive when examining industry types individually. Yet, this study represents an exploratory investigation, and future research should test refined hypotheses with more sophisticated data, such as that found in literature-based discovery research

    The mediating role of discrete emotions in the relationship between injustice and counterproductive work behaviors:a study in Pakistan

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    Purpose: Our study explores the mediating role of discrete emotions in the relationships between employee perceptions of distributive and procedural injustice, regarding an annual salary raise, and counterproductive work behaviors (CWBs). Design/Methodology/Approach: Survey data were provided by 508 individuals from telecom and IT companies in Pakistan. Confirmatory factor analysis, structural equation modeling, and bootstrapping were used to test our hypothesized model. Findings: We found a good fit between the data and our tested model. As predicted, anger (and not sadness) was positively related to aggressive CWBs (abuse against others and production deviance) and fully mediated the relationship between perceived distributive injustice and these CWBs. Against predictions, however, neither sadness nor anger was significantly related to employee withdrawal. Implications: Our findings provide organizations with an insight into the emotional consequences of unfair HR policies, and the potential implications for CWBs. Such knowledge may help employers to develop training and counseling interventions that support the effective management of emotions at work. Our findings are particularly salient for national and multinational organizations in Pakistan. Originality/Value: This is one of the first studies to provide empirical support for the relationships between in/justice, discrete emotions and CWBs in a non-Western (Pakistani) context. Our study also provides new evidence for the differential effects of outward/inward emotions on aggressive/passive CWBs

    Do you get what you pay for? Sales incentives and implications for motivation and changes in turnover intention and work effort

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    This study investigated relations between pay-for-performance incentives designed to vary in instrumentality (annual pay-for-performance, quarterly pay-for-performance, and base pay level) and employee outcomes (self-reported work effort and turnover intention) in a longitudinal study spanning more than 2Ā years. After controlling for perceived instrumentality, merit pay increase, and the initial values of the dependent variables, the amount of base pay was positively related to work effort and negatively related to turnover intention, where both relationships were mediated by autonomous motivation. The amounts of quarterly and annual pay-for-performance were both positively related to controlled motivation, but were differently related to the dependent variables due to different relations with autonomous motivation
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