1,570 research outputs found
Coprecipitation of metal salts with organic coprecipitants
Coprecipitation studies were carried out for the more insoluble salts of six common metals and five anion systems. Three metal sulfides, namely, CuS, CdS and NiS, were the only metal salts studied that indicated nearly complete coprecipitation with phenolphthalein as carrier precipitate. The same salts showed almost no coprecipitation with B-naphthol as carrier precipitate. Solvent extraction of CuS with chloroform showed no significant amount of extraction had taken place. The data obtained in this work did not disclose any relationship between the extent of coprecipitation and the solubility product constant of the salt present. The main difficulty encountered at this stage in the work was the fact that high enough anion concentrations could not be obtained for systems other than the sulfide system due to the limitation of the solubilities of their anion sources. CuS, CdS, and NiS might have been coprecipitated by physical entrapments of their partially colloidal particles in the interstices of phenolphthalein --Abstract, page ii
The Rolodex model: understanding relationship complexity as a precursor to the design of organizational forms for chaotic environments
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
Smoking Behaviors among Adolescents in Foster Care: A Gender-Based Analysis
Background and objectives: Adolescents in foster care are at high risk for cigarette smoking. However, it is not clear how their smoking behaviors vary by gender. The present study examined lifetime and current smoking among males and females, and explored gender-specific risk factors for engagement in smoking behaviors. Method: Data from the Multi Site Evaluation of Foster Youth Programs was used to evaluate patterns of smoking among adolescents aged 12ā18 years (N = 1121; 489 males, 632 females). Results: Males and females did not differ significantly in rates of lifetime and current smoking, or in the age of smoking initiation and number of cigarettes smoked on a typical day. Gender-based analyses revealed that older age and placement in group homes or residential treatment facilities were associated with heightened risk of smoking among males. In contrast, sexual minority status (i.e., nonheterosexual orientation) and increased childhood victimization were associated with heightened risk of smoking among females. A history of running away was linked to smoking in both genders. Conclusion: Gender should be considered when designing intervention programs to address cigarette smoking among foster youth, as the stressors associated with smoking may differ for males and females
Interleukin-1 polymorphisms associated with increased risk of gastric cancer
Helicobacter pylori infection is associated with a variety of clinical outcomes including gastric cancer and duodenal ulcer disease. The reasons for this variation are not clear, but the gastric physiological response is influenced by the severity and anatomical distribution of gastritis induced by H. pylori. Thus, individuals with gastritis predominantly localized to the antrum retain normal (or even high) acid secretion, whereas individuals with extensive corpus gastritis develop hypochlorhydria and gastric atrophy, which are presumptive precursors of gastric cancer. Here we report that interleukin-1 gene cluster polymorphisms suspected of enhancing production of interleukin-1-beta are associated with an increased risk of both hypochlorhydria induced by H. pylori and gastric cancer. Two of these polymorphism are in near-complete linkage disequilibrium and one is a TATA-box polymorphism that markedly affects DNA-protein interactions in vitro. The association with disease may be explained by the biological properties of interleukin-1-beta, which is an important pro-inflammatory cytokine and a powerful inhibitor of gastric acid secretion. Host genetic factors that affect interleukin-1-beta may determine why some individuals infected with H. pylori develop gastric cancer while others do no
Investigation of Growth Inhibitory Effects of cyclo (NĪ±-pyrido)-bis-[(L-valinyl)-L-ornthenyl acid hydrazide] on Various Cancer Cells as well as in vitro VEGFR-2 Kinase Inhibition
328ā332During the current work, we synthesized a new peptide derivative; 4,13-diisopropyl-2,5,12,15-tetraoxo-3,6,11,14-tetraaza-1(3,5)-pyridinacyclopentadecaphane-7-carbohydrazide. The prepared hydrazide was investigated for its in vivo as well as in vitro anticancer effects. Results revealed that this derivative has a great potential against 6 cancerous cell lines. Furthermore, the highest effect was obtained against HT1080 and HeLa cells, where the compound showed 7.4- and 15.1-folds increased activity against them, respectively. Additionally, the compound seems to exert its potential anticancer effect by affecting the kinase enzyme VEGFR-2. Finally, the compound showed promising results when tested in in vivo against prostate cancer developed animal models
Anti-VEGFR-2 Kinase Effects of Cyclo (NĪ±-dinicotinoyl)-bis-[(L-valinyl)- L-lysine] and its Anticancer Activities Against Different Cancer Cell Lines
The current work aimed at preparing a cyclo (NĪ±-dinicotinoyl)-bis-[(L-valinyl)-L-lysine] from previously established synthetic routs. The derivative was investigated for its potential anticancer activities as well as its possible mechanism of action. The prepared compound showed variable anticancer activities against all tested cell lines. Furthermore, it showed very promising activities in terms of obtained IC50 values compared to known used drugs. The mechanism of action studies showed that the prepared tripeptide may act on cancerous cells through its inhibitory action on tyrosine kinase pathway. Animal model experiments proved the potential of the synthesized tripeptide as an anticancer agent against PC3 cancer cells
The TLR4 D299G and T399I SNPs Are Constitutively Active to Up-Regulate Expression of Trif-Dependent Genes
Peer reviewedPublisher PD
Panel 9: Problem Framing: Emerging Issues in DSS Research
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
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