316 research outputs found

    The Rolodex model: understanding relationship complexity as a precursor to the design of organizational forms for chaotic environments

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    The emerging business environment is increasingly complex, characterized by hypercompetition, compound interdependence, and electronic webs This heightened complexity is triggering a slew of new organizational forms and shifts in the underlying logics of organizational forms These new organizational forms are not only more complex, but they have new kinds of complexity - increasingly hybrid and heterarchical, more flexible, and dynamically reconfigurable. The report argues that in such new conditions we need to rethink how we conceive the structural dimensions of organizational form and base them on a process model of inter-organizational relationships. This report examines relationship complexity as a structural topology that underlies organizational form It identifies three structural dimensions of relationship complexity reach, range, and reciprocity and combines them in a model that allows dynamic reconfigurability. The model is based on the primacy of perspective of practicing managers and we have termed it the Rolodex Model as it has overtones of an organizational version of a manager's card file of contacts. Using the concepts of energy and phase space from physics to enrich the Rolodex Model, the report shows how it can be used to explain existing archetypes of organizational forms, to identity new organizational forms, and to provide insights for organizational design The report then argues that further elaboration of energy concepts and relationship complexity may be necessary before we can fully respond to, and anticipate, the complex, dynamic, hypercompetitive organizational environment of today , much less that likely to exist tomorrow.Approved for public release; distribution is unlimited

    Panel 9: Problem Framing: Emerging Issues in DSS Research

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    Decision support systems (DSS) are commonly understood to be interactive computer-based systems that are designed to help managers cope with ill-defined situations. In the past, most DSSs have helped decision makers deal with issues that have been relatively easy to structure. These have not always been the issues that have been of most interest to them. This panel will address various research issues related to isolating and structuring the problems in which effective problem framing accounts for a large part of the performance variance in problem solving. While the members of the panel agree that DSS must be extended in order to help managers formulate problems, they differ in their perceptions of the criticality of issues to be considered. Joyce Elam is convinced that initial research efforts should be directed toward methods and feasibility of supporting decision makers in the task of framing multiple problem representations. She believes that ill-defined situations require creative problem formulations. In other words, asking the right questions can be more important than answering them. She has found that problem formulation appears to grow in importance as the need for alternative solutions increases. She will argue that the key to creative thinking in ill-defined situations is the manager\u27s ability to develop and explore alternative problem formulations and that DSS must facilitate this process. Omar El Sawy believes that successful problem framing is critically dependent on initially enlarging the problem space through effective environmental scanning and multiple scenario generation, similar to what is practiced in futures research. He will discuss the features of DSS that have divergent rather than convergent support capabilities and are suitable for problem framing. He will address the types of DSS capabilities and underlying technologies that can be used to support How about? and What else? as well as the more traditional What if? Benn Konsynski\u27s position is that research into problem-framing DSS must begin with an investigation of dialogue management. He will propose an approach that begins by exploring the human computer dialogue through which decision makers frame problems. Convinced that, for the most part, DSS dialogues are static and offer little help in structuring problems, he will discuss the proper apportionment of the cognitive responsibilities between manager and system. Charles Stabell suggests that, in order to develop more effective support for problem framing, we need to have a better understanding of how managers frame problems. In particular, he believes that to develop active support for problem framing, we need to consider and understand under what conditions, in what context, and for what purpose a manager might choose to use such a tool. He will address the issue by reviewing some ongoing research on key determinants of problem framing. In particular, he will discuss the operational code approach to studying managerial choice behavior; the approach considers the manager\u27s fundamental beliefs about life in organizations, the role of managers, and the basis for effective decision making. Sue Weber believes that we can best help managers frame problems in ill-structured situations by providing them with pattern- matching tools. These tools would help a manager gradually to accumulate patterns, extract the invariant features from these patterns, and map patterns and relations. Recognizing and then accepting a new problem formulation often requires considerable time and practice. Consequently, she calls for a problem-framing DSS that would support a manager in storing, retrieving, and modifying different mappings over many sessions until understanding and confidence in the formulation is developed

    Efficacy of plant extracts in controlling wheat leaf rust disease caused by Puccinia triticina

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    AbstractThe efficacy of eight plant extracts (garlic, clove, garden quinine, Brazilian pepper, anthi mandhaari, black cumin, white cedar and neem) in controlling leaf rust disease of wheat was investigated in vitro and in vivo. In vitro, all treatments inhibited spore germination by more than 93%. Neem extract recorded 98.99% inhibition of spore germination with no significant difference from the fungicide Sumi-8 (100%). Under greenhouse conditions, seed soaking application in neem extract (at concentration of 2ml/L) resulted in 36.82% reduction in the number of pustules/leaf compared with the untreated control. Foliar spraying of plant extracts on wheat seedlings decreased the number of pustules/leaf. Foliar spraying of plant extracts four days after inoculation led to the highest resistance response of wheat plants against leaf rust pathogen. Spray application of wheat seedlings with neem, clove and garden quinine extracts, four days after inoculation with leaf rust pathogen completely prevented rust development (100% disease control) and was comparable with the fungicide Sumi-8. Foliar spray application of wheat plants at mature stage with all plant extracts has significantly reduced the leaf rust infection (average coefficient of infection, ACI) compared with the untreated control and neem was the most effective treatment. This was reflected on grain yield components, whereas the 1000-kernel weight and the test weight were improved whether under one- or two-spray applications, with two-spray application being more effective in this regard. Thus, it could be concluded that plant extracts may be useful to control leaf rust disease in Egypt as a safe alternative option to chemical fungicides

    Early administration of oral oseltamivir increases the benefits of influenza treatment

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    Our objective was to evaluate the benefit of early treatment of influenza illness using oral oseltamivir. This open-label, multicentre international study investigated the relationship between the interval from illness onset to first dose (time-to-treatment) and illness duration in the intent-to-treat infected population using accelerated failure time (AFT) modelling. A total of 1426 patients (12-70 years) presenting within 48 h of the onset of influenza symptoms were treated with oseltamivir 75 mg twice a day for 5 days during the 1999-2000 influenza season; 958 (67%) had laboratory-confirmed influenza virus infection. Earlier intervention was associated with shorter illness duration (P < 0.0001). Initiation of therapy within the first 12 h after fever onset reduced the total median illness duration by 74.6 h (3.1 days; 41%) more than intervention at 48 h. Intermediate interventions reduced the illness proportionately compared with 48 h. In addition, the earlier administration of oseltamivir further reduced the duration of fever, severity of symptoms and the times to return to baseline activity and health scores. Oseltamivir was well tolerated. The most common adverse events were nausea and vomiting, which were transient and generally occurred only with first dosing. When oseltamivir was taken with food, the tolerability was enhanced. The overall discontinuation rate was low (1.8%). In conclusion, the IMPACT study demonstrated that earlier initiation of oral oseltamivir therapy increased its therapeutic effects, which were seen at every time point of intervention and were progressive. Thus, early presentation, diagnosis and treatment of patients with influenza maximized the benefits of oseltamivir therap

    Sinteza i biološko djelovanje novih 1-benzil i 1-benzoil 3-heterocikličkih derivata indola

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    Starting from 1-benzyl- (2a) and 1-benzoyl-3-bromoacetyl indoles (2b) new heterocyclic, 2-thioxoimidazolidine (4a,b), imidazolidine-2,4-dione (5a,b), pyrano(2,3-d)imidazole (8a,b and 9a,b), 2-substituted quinoxaline (11a,b–17a,b) and triazolo(4,3-a)quinoxaline derivatives (18a,b and 19a,b) were synthesized and evaluated for their antimicrobial and anticancer activities. Antimicrobial activity screening performed with concentrations of 0.88, 0.44 and 0.22 g mm2 showed that 3-(1-substituted indol-3-yl)quinoxalin-2(1H)ones (11a,b) and 2-(4-methyl piperazin-1-yl)-3-(1-substituted indol-3-yl) quinoxalines (15a,b) were the most active of all the tested compounds towards P. aeruginosa, B. cereus and S. aureus compared to the reference drugs cefotaxime and piperacillin, while 2-chloro-3-(1-substituted indol-3-yl)quinoxalines (12a,b) were the most active against C. albicans compared to the reference drug nystatin. On the other hand, 2-chloro-3-(1-benzyl indol-3-yl) quinoxaline (12a) display potent efficacy against ovarian cancer xenografts in nude mice with tumor growth suppression of 100 0.3 %.U radu je opisana sinteza, antimikrobno i antitumorsko djelovanje heterocikličkih derivata indola. Polazeći iz 1-benzil- i 1-benzoil-3-bromacetil indola (2a i 2b) sintetizirani su novi heterociklički spojevi 2-tioksoimidazolidini (4a,b), imidazolidin-2,4-dioni (5a,b), pirano(2,3-d)imidazoli (8a,b i 9a,b), 2-supstituirani kinoksalini (11a,b–17a,b) i triazolo(4,3-a)kinoksalini (18a,b i 19a,b). Sintetizirani spojevi testirani su na antimikrobno i antitumorsko djelovanje. Ispitivanje antimikrobnog djelovanja provedeno je s koncentracijama otopina 0,88, 0,44 i 0,22 g mm2 i uspoređeno s referentnim lijekovima cefotaksimom i piperacilinom. Rezultati pokazuju da su 3-(1-supstituirani indol-3-il)kinoksalin-2(1H)oni (11a,b) i 2-(4-metil piperazin-1-il)-3-(1-supstituirani indol-3-il) kinoksalini (15a,b) najaktivniji spojevi na sojeve P. aeruginosa, B. cereus i S. aureus, dok su 2-klor-3-(1-supstituirani indol-3-il)kinoksalini (12a,b) najaktivniji na C. albicans (usporedba s nistatinom). Osim toga, 2-klor-3-(1-benzil indol-3-il) kinoksalin (12a) pokazuje veliku učinkovitost na tumore ovarija miševa (supresija rasta tumora 100 0,3 %)

    Sinteza, antimikrobno i antitumorsko djelovanje nekoliko novih N-etil, N-benzil i N-benzoil-3-indolil heterocikličkih spojeva

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    A series of 1-(N-substituted-1H-indol-3-yl)-3-arylprop-2-ene-1-ones (2a,b-4a,b) were prepared and allowed to react with urea, thiourea or guanidine to give pyrimidine derivatives 5a,b–13a,b. Reaction of 2a,b-4a,b with ethyl acetoacetate in the presence of a base gave cyclohexanone derivatives 14a,b-16a,b. Reaction of the latter compounds with hydrazine hydrate afforded indazole derivatives 17a,b-19a,b. On the other hand, reaction of 2a,b-4a,b with some hydrazine derivatives, namely hydrazine hydrate, acetyl hydrazine, phenyl- hydrazine and benzylhydrazine hydrochloride, led to the formation of pyrazole derivatives 20a,b-31a,b. Moreover, reaction of 2a,b-4a,b with hydroxylamine hydrochloride gave isoxazole derivatives 32a,b-34a,b. The newly synthesized compounds were tested for their antimicrobial activity and showed that 4-(N-ethyl-1H-indol-3-yl)-6-(p-chlorophenyl)-pyrimidine-2-amine (11b) was the most active of all the test compounds towards Candida albicans compared to the reference drug cycloheximide. Eighteen new compounds, namely pyrimidin-2(1H)-ones 5a,b-7a,b, pyrimidin-2(1H)-thiones 8a,b-10a,b and pyrimidin-2-amines 11a,b-13a,b derivatives, were tested for their in vitro antiproliferative activity against HEPG2, MCF7 and HCT-116 cancer cell lines. 4-(N-ethyl-1H-indol-3-yl)-6-(p-methoxyphenyl)-pyrimidin-2-amine (11a) was found to be highly active with IC50 of 0.7 µmol L1.Sintetizirana je serija 1-(N-supstituiranih-1H-indol-3-il)-3-arilprop-2-en-1-ona (2a,b-4a,b) i podvrgnuta reakciji s ureom, tioureom ili gvanidinom, pri čemu su nastali derivati pirimidina 5a,b–13a,b. Reakcijom 2a,b-4a,b s etil-acetoacetatom u prisutnosti baze nastali su derivati cikloheksanona 14a,b-16a,b. Njihovom reakcijom s hidrazin hidratom dobiveni su derivati indazola 17a,b-19a,b. S druge strane, reakcijom 2a,b-4a,b s određenim derivatima hidrazina, tj. s hidrazin hidratom, acetil hidrazinom, fenilhidrazinom i benzilhidrazin hidrokloridom, nastali su derivati pirazola 20a,b-31a,b. Nadalje, reakcijom 2a,b-4a,b s hidroksilamin hidrokloridom dobiveni su derivati izoksazola 32a,b-34a,b. Pripravljeni spojevi ispitani su na antimikrobno djelovanje. Pokazalo se da je 4-(N-etil-1H-indol-3-il)-6-(p-klorfenil)-pirimidin-2-amin (11b) najaktivniji spoj za Candida albicans (ATCC 10231) uz cikloheksimid kao poredbeni lijek. Testirano je antitumorsko djelovanje in vitro osamnaest novih spojeva, tj. pirimidin-2(1H)-ona 5a,b-7a,b, pirimidin-2(1H)-tiona 8a,b-10a,b i pirimidin-2-amina 11a,b-13a,b na tumorske stanice HEPG2, MCF7 i HCT-116. Najaktivniji spoj bio je 4-(N-etil-1H-indol-3-il)-6-(p-metoksifenil)-pirimidin-2-amin (11a) uz IC50 0,7 µmol L1

    Synthesis and Biocidal Activity of Some Naphthalene-Based Cationic Surfactants

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    In this study, different cationic surfactants were prepared by reacting dodecyl bromide with tertiary amines to produce a series of quaternary ammonium salts that were converted subsequently to stannous and cobalt cationic complexes via complexing them with stannous (II) or cobalt (II) ions. Surface properties such as surface- and interfacial-tension, and the emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, minimum surface area, tension lowering efficiency and effectiveness were studied. The free energy of micellization and adsorption were calculated. Antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which was measured against six strains of a representative group of microorganisms. The antimicrobial activity of some of the prepared surfactants against sulfate reducing bacteria was determined by the dilution method. FTIR spectra, elemental analysis and a H1 NMR spectrum were examined to confirm compound structure and purity. The results obtained indicate that these compounds have good surface properties and good biocidal effect on broad spectrum of micro organisms

    Evolutionary Conservation of the Functional Modularity of Primate and Murine LINE-1 Elements

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    LINE-1 (L1) retroelements emerged in mammalian genomes over 80 million years ago with a few dominant subfamilies amplifying over discrete time periods that led to distinct human and mouse L1 lineages. We evaluated the functional conservation of L1 sequences by comparing retrotransposition rates of chimeric human-rodent L1 constructs to their parental L1 counterparts. Although amino acid conservation varies from ∼35% to 63% for the L1 ORF1p and ORF2p, most human and mouse L1 sequences can be functionally exchanged. Replacing either ORF1 or ORF2 to create chimeric human-mouse L1 elements did not adversely affect retrotransposition. The mouse ORF2p retains retrotransposition-competency to support both Alu and L1 mobilization when any of the domain sequences we evaluated were substituted with human counterparts. However, the substitution of portions of the mouse cys-domain into the human ORF2p reduces both L1 retrotransposition and Alu trans-mobilization by 200–1000 fold. The observed loss of ORF2p function is independent of the endonuclease or reverse transcriptase activities of ORF2p and RNA interaction required for reverse transcription. In addition, the loss of function is physically separate from the cysteine-rich motif sequence previously shown to be required for RNP formation. Our data suggest an additional role of the less characterized carboxy-terminus of the L1 ORF2 protein by demonstrating that this domain, in addition to mediating RNP interaction(s), provides an independent and required function for the retroelement amplification process. Our experiments show a functional modularity of most of the LINE sequences. However, divergent evolution of interactions within L1 has led to non-reciprocal incompatibilities between human and mouse ORF2 cys-domain sequences

    Genetic and epigenetic variations contributed by Alu retrotransposition

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    <p>Abstract</p> <p>Background</p> <p><it>De novo </it>retrotransposition of Alu elements has been recognized as a major driver for insertion polymorphisms in human populations. In this study, we exploited Alu-anchored bisulfite PCR libraries to identify evolutionarily recent Alu element insertions, and to investigate their genetic and epigenetic variation.</p> <p>Results</p> <p>A total of 327 putatively recent Alu insertions were identified, altogether represented by 1,762 sequence reads. Nearly all such <it>de novo </it>retrotransposition events (316/327) were novel. Forty-seven out of forty-nine randomly selected events, corresponding to nineteen genomic loci, were sequence-verified. Alu element insertions remained hemizygous in one or more individuals in sixteen of the nineteen genomic loci. The Alu elements were found to be enriched for young Alu families with characteristic sequence features, such as the presence of a longer poly(A) tail. In addition, we documented the occurrence of a duplication of the AT-rich target site in their immediate flanking sequences, a hallmark of retrotransposition. Furthermore, we found the sequence motif (TT/AAAA) that is recognized by the ORF2P protein encoded by LINE-1 in their 5'-flanking regions, consistent with the fact that Alu retrotransposition is facilitated by LINE-1 elements. While most of these Alu elements were heavily methylated, we identified an Alu localized 1.5 kb downstream of TOMM5 that exhibited a completely unmethylated left arm. Interestingly, we observed differential methylation of its immediate 5' and 3' flanking CpG dinucleotides, in concordance with the unmethylated and methylated statuses of its internal 5' and 3' sequences, respectively. Importantly, TOMM5's CpG island and the 3 Alu repeats and 1 MIR element localized upstream of this newly inserted Alu were also found to be unmethylated. Methylation analyses of two additional genomic loci revealed no methylation differences in CpG dinucleotides flanking the Alu insertion sites in the two homologous chromosomes, irrespective of the presence or absence of the insertion.</p> <p>Conclusions</p> <p>We anticipate that the combination of methodologies utilized in this study, which included repeat-anchored bisulfite PCR sequencing and the computational analysis pipeline herein reported, will prove invaluable for the generation of genetic and epigenetic variation maps.</p
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