Environmentally specific servant leadership and voluntary pro-environmental behavior in the context of green operations: A serial mediation path.

Green operations of organizations and enhancement of corporate social responsibility hinges upon leaders. This study investigated the influential role performed by environmentally specific servant leadership in provoking voluntary pro-environmental behavior of employees. The findings illuminate a serial chain mediation model that originates as a result of environmentally specific servant leadership and leads toward psychological empowerment, and organizational identity, ultimately leading toward voluntary pro-environmental behavior. Data from the textile sector of Pakistan uncovered that environmentally specific servant leadership prompted the voluntary pro-environmental behavior of employees. Moreover, environmentally specific servant leadership was significantly linked with voluntary pro-environmental behavior through psychological empowerment. The study supports the serial mediation of psychological empowerment and organizational identity in stirring voluntary pro-environmental behavior. An organizational psychological mechanism has been unraveled that can help organizations achieve a high level of sustainability and can serve as a catalyst for organizational green operations.

Dominant role of αIIbß3 in platelet interactions with cross-linked fibrin fragment D-dimer.

Although much is known about the interaction of fibrinogen with αIIbß3, much less is known about the interaction of platelets with cross-linked fibrin. Fibrinogen residue Lys406 plays a vital role in the interaction of fibrinogen with αIIbß3, but because it participates in fibrin cross-linking, it is not available for interacting with αIIbß3. We studied the adhesion of platelets and HEK cells expressing normal and constitutively active αIIbß3 to both immobilized fibrinogen and D-dimer, a proteolytic fragment of cross-linked fibrin, as well as platelet-mediated clot retraction. Nonactivated platelets and HEK cells expressing normal αIIbß3 adhered to fibrinogen but not D-dimer, whereas activated platelets as well as HEK cells expressing activated αIIbß3 both bound to D-dimer. Small-molecule antagonists of the αIIbß3 RGD (Arg-Gly-Asp) binding pocket inhibited adhesion to D-dimer, and an Asp119Ala mutation that disrupts the ß3 metal ion-dependent adhesion site inhibited αIIbß3-mediated adhesion to D-dimer. D-dimer and a polyclonal antibody against D-dimer inhibited clot retraction. The monoclonal antibody (mAb) 10E5, directed at αIIb and a potent inhibitor of platelet interactions with fibrinogen, did not inhibit the interaction of activated platelets with D-dimer or clot retraction, whereas the mAb 7E3, directed at ß3, inhibited both phenomena. We conclude that activated, but not nonactivated, αIIbß3 mediates interactions between platelets and D-dimer, and by extrapolation, to cross-linked fibrin. Although the interaction of αIIbß3 with D-dimer differs from that with fibrinogen, it probably involves contributions from regions on ß3 that are close to, or that are affected by, changes in the RGD binding pocket.

Empirical estimation of suspended solids concentration in the Indus Delta Region using Landsat-7 ETM+ imagery.

Suspended Solids Concentration (SSC) in water is related to its quality and transparency. Satellite remote sensing has proven to be an efficient means of monitoring water quality in large deltas because in situ sampling methods are costly, laborious, time consuming, and spatially constrained. In this study, the potential of Landsat's Enhanced Thematic Mapper Plus (ETM+) sensor was explored to develop a model for remote sensing-based quantification of SSC within the large, turbid Indus Delta Region (IDR, south of Pakistan). Six scenes were atmospherically corrected using the Dark Object Subtraction (DOS) method, to formulate a model for monitoring water quality of the IDR. An empirical model was developed and validated using in situ SSC measurements (9.4-761.4 mg/L) from several data collection campaigns coinciding (within an 11-day window) with satellite overpasses. It was found that using Band 1 (blue: 450-520 nm), Band 2 (green: 520-600 nm), Band 3 (red: 630-690 nm), and Band 5 (shortwave infrared: 1550-1750 nm) of Landsat-7 ETM + along with the Normalized Difference Suspended Sediment Index (NDSSI) can help in precise and accurate estimation of SSC, resulting in a relatively small Root Mean Square Error of 67.24 mg/L, Mean Absolute Error of 54.75 mg/L, and coefficient of determination of 0.88. Further, it was also evident that residuals do not increase with an increasing time window (0-11 days) between the satellite overpass and in situ data collection. Therefore, the established algorithm can potentially be used for frequent (after 8 days) synoptic mapping of SSC in the IDR and other similar estuarine environments.

αIIbß3 binding to a fibrinogen fragment lacking the γ-chain dodecapeptide is activation dependent and EDTA inducible.

Platelet integrin receptor αIIbß3 supports platelet aggregation by binding fibrinogen. The interaction between the fibrinogen C-terminal γ-chain peptide composed of residues γ-404-411 (GAKQAGDV) and the Arg-Gly-Asp (RGD) binding pocket on αIIbß3 is required for fibrinogen-mediated platelet aggregation, but data suggest that other ancillary binding sites on both fibrinogen and αIIbß3 may lead to higher-affinity fibrinogen binding and clot retraction. To identify additional sites, we analyzed the ability of platelets and cells expressing normal and mutant αIIbß3 to adhere to an immobilized fibrinogen plasmin fragment that lacks intact γ-404-411 ('D98'). We found the following: (1) Activated, but not unactivated, platelets adhere well to immobilized 'D98.' (2) Cells expressing constitutively active αIIbß3 mutants, but not cells expressing normal αIIbß3 or αVß3, adhere well to 'D98.' (3) Monoclonal antibodies 10E5 and 7E3 inhibit the adhesion to 'D98' of activated platelets and cells expressing constitutively active αIIbß3, as do small-molecule inhibitors that bind to the RGD pocket. (4) EDTA paradoxically induces normal αIIbß3 to interact with 'D98.' Because molecular modeling and molecular dynamics simulations suggested that the αIIb L151-D159 helix may contribute to the interaction with 'D98,' we studied an αIIbß3 mutant in which the αIIb 148-166 loop was swapped with the corresponding αV loop; it failed to bind to fibrinogen or 'D98.' Our data support a model in which conformational changes in αIIbß3 and/or fibrinogen after platelet activation and the interaction between γ-404-411 and the RGD binding pocket make new ancillary sites available that support higher-affinity fibrinogen binding and clot retraction.

Synthesis and characterization of Schiff base octaazamacrocyclic complexes and their biological studies.

A condensation reaction between 1,2-diphenylethane-1,2-dione dihydrazone (DPEDDH) and dimethyl or diethyloxalate in methanol resulted in a novel Schiff base octaazamacrocyclic ligand, (L): (6,7,14,15-tetraoxa-2,3,10,11-tetraphenyl-1,4,5,8,9,12,13,16-octaazacyclohexadecane-1,3,9,11-tetraene). Subsequently metal complexes of the type [MLX2] and [CuL]X2; (M=Mn(II), Co(II), Ni(II) and Zn(II); X=Cl or NO3) were synthesized by the reaction of the free macrocyclic ligand (L) with the corresponding metal salts in 1:1 molar ratio. These complexes were characterized on the basis of analytical data, molar conductivity and magnetic susceptibility measurements, ESI-mass, IR, NMR ((1)H and (13)C), EPR and electronic spectral studies. The thermal stability of the complexes was also studied by TGA and DTA analyses. These studies show that all the complexes have octahedral arrangement around the metal ions except copper complexes which are square planar. The ligand and its complexes were screened for their antibacterial activity in vitro against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and were also studied for their anticancer activity against the human cancer cells lines: HeLa (Human cervical carcinoma), MCF7 (Human breast adenocarcinoma) and Hep3B (Human Hepatocellular carcinoma). The recorded IC50 values for the tested compounds show moderate to good cytotoxicity against these cancer cell lines. The copper complex, [CuL]Cl2, showed excellent antimicrobial activity against tested microorganisms which is almost equivalent to the standard drug ciprofloxacin.

Distinct tmRNA sequence elements facilitate RNase R engagement on rescued ribosomes for selective nonstop mRNA decay.

trans-Translation, orchestrated by SmpB and tmRNA, is the principal eubacterial pathway for resolving stalled translation complexes. RNase R, the leading nonstop mRNA surveillance factor, is recruited to stalled ribosomes in a trans-translation dependent process. To elucidate the contributions of SmpB and tmRNA to RNase R recruitment, we evaluated Escherichia coli-Francisella tularensis chimeric variants of tmRNA and SmpB. This evaluation showed that while the hybrid tmRNA supported nascent polypeptide tagging and ribosome rescue, it suffered defects in facilitating RNase R recruitment to stalled ribosomes. To gain further insights, we used established tmRNA and SmpB variants that impact distinct stages of the trans-translation process. Analysis of select tmRNA variants revealed that the sequence composition and positioning of the ultimate and penultimate codons of the tmRNA ORF play a crucial role in recruiting RNase R to rescued ribosomes. Evaluation of defined SmpB C-terminal tail variants highlighted the importance of establishing the tmRNA reading frame, and provided valuable clues into the timing of RNase R recruitment to rescued ribosomes. Taken together, these studies demonstrate that productive RNase R-ribosomes engagement requires active trans-translation, and suggest that RNase R captures the emerging nonstop mRNA at an early stage after establishment of the tmRNA ORF as the surrogate mRNA template.

Boron inhibits the proliferating cell nuclear antigen index, molybdenum containing proteins and ameliorates oxidative stress in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common malignancy and the main cause of mortality in patients with chronic liver diseases. This study reports the inhibitory effect of boron on HCC induced in rats by administering thioacetamide (TAA) (0.03%) in drinking water for 400days. Boron (4mg/kg body weight) was administered orally after induction of carcinoma. Treatment was continued for 122days, and cell proliferation, histology and biochemistry of treated and control group of rats were studied. Proliferating cell nuclear antigen (PCNA), and [(3)H]-thymidine incorporation, which increased in rats exposed to carcinogen, significantly decreased after boron treatment. PCNA index decreased from 80 in HCC rats to 32 after boron treatment. In the control group, it was 20. Boron caused a dose-dependent decrease in carcinogen-induced [(3)H]-thymidine uptake by the rat hepatocyte. It could partially reverse the activity of selected biochemical indicators of hepatic damage, oxidative stress, selenium and serum retinol, which are depleted in liver cancer, and improved overall health of animal. The study implicates the elevated levels of mammalian molybdenum Fe-S containing flavin hydroxylases, which increase the free radical production and oxidative stress, consequently causing increased hepatic cell proliferation in HCC, and reports boron to ameliorate these changes in liver cancer.

Role of mammalian cytosolic molybdenum Fe-S flavin hydroxylases in hepatic injury.

The study was designed to investigate the role of molybdenum iron-sulfur flavin hydroxylases in the pathogenesis of liver injuries induced by structurally and mechanistically diverse hepatotoxicants. While carbon tetrachloride (CCl4), thioacetamide (TAA) and chloroform (CHCl3) inflict liver damage by producing free radicals, acetaminophen (AAP) and bromobenzene (BB) exert their effects by severe glutathione depletion. Appropriate doses of these compounds were administered to induce liver injury in rats. The activities of the Mo-Fe-S flavin hydroxylases were measured and correlated with the biochemical markers of hepatic injury. The activity levels of the anti-oxidative enzymes and glutathione redox cycling enzymes were also determined. The treatment of rats with the hepatotoxins that inflict liver injury by generating free radicals (CCl4, TAA, CHCl3) had elevated activity levels of hepatic Mo-Fe-S flavin hydroxylases (p<0.05). Specific inhibition of these hydroxylases by their common inhibitor, sodium tungstate, suppresses biochemical and oxidative stress markers of hepatic tissue damage. On the contrary, Mo-Fe-S flavin hydroxylases did not show any change in animals receiving AAP and BB. Correspondingly, sodium tungstate could not attenuate damage in AAP and BB treated groups of rats. The study concludes that Mo-Fe-S hydroxylases contribute to the hepatic injury inflicted by free radical generating agents and does not play any role in hepatic injury produced by glutathione depleting agents. The study has implication in understanding human liver diseases caused by a variety of agents, and to investigate the efficacy of the inhibitors of Mo-Fe-S flavin hydroxylases as potential therapeutic agents.

Critical evaluation of the claims made by pharmaceutical companies in drug promotional material in Pakistan.

BACKGROUND: In Pakistan, there is no mechanism to monitor the drug promotional campaign by pharmaceutical industry despite the fact that there is enough evidence that irrational pharmacotherapy is increasingly encountered even in the developed countries due to unethical practices of pharmaceutical promotion. Objectives. To audit the drug promotional claims made by the pharmaceutical companies in Pakistan. METHODS: Drug promotional pamphlets and brochures containing claims for the drugs, which were circulated by the pharmaceutical representatives were collected from 122 general practitioners (GPs) from Karachi and Larkana cities of the Sindh Province. The claims were critically analyzed and audited with the help of currently available evidence in the medical literature. RESULTS: 345 distinct advertisements covering 182 drugs from different manufacturers were critically analyzed for information content. Sixty two out of 345 (18%) of the reviewed advertisements were adjudged to be misleading / unjustifiable, which were again classified as, exaggerated (32%), ambiguous (21%), false (26%), and controversial (21%). The primary source of information (approximately 78%) about the newly launched drugs for the GPs was found to be the pharmaceutical representatives followed by hospital doctors (5%) and colleagues (5%). Furthermore, 110 (90%) GPs were of the view that the drug promotion has definitely an influence on their prescribing pattern. CONCLUSIONS: Since GPs in Pakistan rate pharmaceutical companies as their primary source of information regarding drugs, it can be anticipated that inappropriate advertisement claims would lead to irrational prescribing if physicians had no any other information to follow.