Computer-Supported Collaborative Negotiation Methodology

The development of large-scale civil engineering projects requires the collaboration of experts from different specialties. However, conflicts and disputes occur regularly during the entire life cycle of large-scale projects due to the complex structure of organization and the different types of expertise involved. If these disputes or conflicts cannot be resolved or addressed quickly and effectively, the collaborative mode of the participants can be affected, creating a hostile environment in which progress of the project will slow to a halt. Therefore, better methodologies are needed to improve the collaborative process and to create more effective, efficient, and sustainable solutions to conflicts. This paper presents a methodology for facilitating the negotiation of conflicts during the development of large-scale civil engineering projects. Two fundamental theories are used in this methodology: (1) game theory, which is the study of players' actions based on the premise that the decision of any player can affect the payoff of all players; and (2) negotiation theory, which is the study of the interactions between parties, designed to reconcile their differences and produce a settlement. The strong support given by these two theories to negotiators is highlighted in the following observations. First, people need to negotiate because of their conflicting interests. From the negotiator's point of view, expressing the interests of all participants is very important in conflict resolution and can be accomplished by following the principles outlined in negotiation theory. Once the interests have been expressed correctly, the influence of positions or of conflicting interests on the overall negotiation outcome is evaluated using game theory. Based on these two fundamental theories, this paper presents a collaborative negotiation methodology and a computer agent named CONVINCER, which incorporates that methodology to facilitate or mediate the negotiation of conflicts in large-scale civil engineering projects. Hypothetical case studies and resolution processes demonstrate the effectiveness of the CONVINCER agent in conflict resolution. Results of applying the methodology to different scenarios also show that the CONVINCER agent provides efficient, effective, and sustainable solutions, thus improving the conflict resolution paradigm in the A∕E∕C industry.     

Purification and characterization of a Synechococcus sp. strain PCC 7942 polypeptide structurally similar to the stress-induced Dps/PexB protein of Escherichia coli

A stable DNA/protein complex having an apparent molecular mass of approximately 150 kDa was purified from nitrate-limited cultures of the cyanobacterium Synechococcus sp. strain PCC 7942. Amino-terminal peptide sequencing indicated that the polypeptide was structurally similar to the Dps protein of Escherichia coli; Dps is also known as the product of the starvation- and stationary-phase-inducible gene, pexB. The 150-kDa complex dissociated into a 22-kDa protein monomer after boiling in 2% SDS. The 150-kDa complex preparation had approximately a 10% nucleic acid content and upon dissociation released DNA fragments that were sensitive to S1 nuclease digestion. Immunoblot data indicated that the complex accumulates during stationary phase and during nitrogen, sulfur, and phosphorus limitation. DNA-binding assays indicated that the protein nonspecifically binds both linear and supercoiled DNA. Circular dichroism spectroscopy revealed that the Synechococcus sp. Dps-like protein contains extensive regions of alpha-helical secondary structure. We propose that the 150-kDa complex represents a hexameric aggregate of the Dps-like protein complexed with single-stranded DNA and serves to bind a portion of the chromosomal DNA under nutrient-limited conditions.     

Electrochemical fixation techniques. II. Electrochemical dog body fixation. Histological study

BACKGROUND: Cervical lymph node metastasis in differentiated thyroid carcinoma has mostly been found to have little relationship to prognosis. However, some studies report nodal involvement to be an adverse factor, while others have found it to be favorable. We have undertaken a matched-pair analysis of previously untreated patients, with and without ipsilateral neck metastasis, to examine the significance of nodal spread in patients with otherwise equivalent prognostic factors for differentiated thyroid cancer. METHOD: From a database of 931 patients, treated from 1930 to 1980, we used a computer to match patients with confirmed lateral neck metastasis (N1) to those who were stage NO, and had the following identical prognostic factors: no distant metastasis, age (within 4 years), and tumor size, histology, and intrathyroidal extent. When possible, matches were also made for gender, multifocality, and extent of thyroid surgery. Survival and treatment failures were analyzed, with and without stratification for age. RESULTS: We were able to select 100 N1 patients with corresponding NO patients, sharing the major prognostic risk factors as listed. Overall, there was no difference in survival, although N1 patients more often had recurrence. Mortality increased with age. Analysis at high-risk age (45 years and older) showed significantly more recurrences in N1 patients (p = .008). Twenty-year survival in N1 patients over the age of 45 was lower than that of NO patients. On the other hand, under the age of 45, N1 patients had better survival. These differences, however, did not reach statistical significance. CONCLUSION: Nodal involvement in older patients with thyroid cancer increases the risk of recurrence, although no significant difference in survival is observed in relation to age.     

Identification, characterization, and In situ detection of a fruit-body-specific hydrophobin of Pleurotus ostreatus

Hydrophobins are small (length, about 100 +/- 25 amino acids), cysteine-rich, hydrophobic proteins that are present in large amounts in fungal cell walls, where they form part of the outermost layer (rodlet layer); sometimes, they can also be secreted into the medium. Different hydrophobins are associated with different developmental stages of a fungus, and their biological functions include protection of the hyphae against desiccation and attack by either bacterial or fungal parasites, hyphal adherence, and the lowering of surface tension of the culture medium to permit aerial growth of the hyphae. We identified and isolated a hydrophobin (fruit body hydrophobin 1 [Fbh1]) present in fruit bodies but absent in both monokaryotic and dikaryotic mycelia of the edible mushroom Pleurotus ostreatus. In order to study the temporal and spatial expression of the fbh1 gene, we determined the N-terminal amino acid sequence of Fbh1. We also synthesized and cloned the double-stranded cDNA corresponding to the full-length mRNA of Fbh1 to use it as a probe in both Northern blot and in situ hybridization experiments. Fbh1 mRNA is detectable in specific parts of the fruit body, and it is absent in other developmental stages.     

A new type of intraocular prosthesis for dogs

A simple technique is described in which sterile silicone oil (viscosity 350 cSt) was injected into the globe of an eviscerated eye with an intact cornea and sclera; the volume injected was calculated from the formula 3/4 pi r3 where 'r' was the horizontal corneal diameter. After induction of general anaesthesia and routine preparation of the surgical site, the globe was eviscerated by using a transscleral or transcorneal approach. The procedure was carried out in five dogs with follow-ups ranging between 19 and 27 months. None of the eyes developed postoperative complications. In one dog, more silicone oil had to be injected 10 days after surgery to increase the size of the globe to match the other eye. The intraocular contents were removed more easily by using the transcorneal approach, which also resulted in a perfect adjustment and virtually eliminated the possibility of leakage of silicone oil, than by a transscleral approach. The dogs responded extremely well and their owners were satisfied with the cosmetic appearance of their pets.     

Myotrophic effects of muscle extracts obtained at different intervals after denervation

BACKGROUND: The assessment of return of function within dysfunctional myocardium after acute myocardial infarction (MI) using contractile reserve has been primarily qualitative. Magnetic resonance (MR) myocardial tagging is a novel noninvasive method that measures intramyocardial function. We hypothesized that MR tagging could be used to quantify the intramyocardial response to low-dose dobutamine and relate this response to return of function in patients after first MI. METHODS AND RESULTS: Twenty patients with a first reperfused MI (age, 53+/-12 years; 16 male; 11 inferior MIs) were studied. Patients underwent breath-hold MR-tagged short-axis imaging on day 4+/-2 after MI at baseline and during dobutamine infusion at 5 and 10 microg x kg(-1) x min(-1). At 8+/-1 weeks after MI, patients returned for a follow-up MR tagging study without dobutamine. Quantification of percent intramyocardial circumferential segment shortening (%S) was performed. Low-dose dobutamine MRI was well tolerated. Overall, mean %S was 15+/-11% at baseline (n=227 segments), increased to 16+/-10% at 5 microg x kg(-1) x min(-1) dobutamine (P=NS), 21+/-10% at peak (P<0.0001 versus baseline and 5 microg x kg(-1) x min(-1), and 18+/-10% at 8 weeks (P<0.004 versus baseline and peak). The increase in %S with peak dobutamine was greater in dysfunctional myocardium (103 segments, +9+/-10%) than in normal tissue (124 segments, +4+/-12%, P<0.0001). In dysfunctional regions, %S also increased from 6+/-7% at baseline to 14+/-10% at 8 weeks after MI (P<0.0001). In dysfunctional regions that responded normally to peak dobutamine (> or =5% increase in %S), the increase in %S from baseline to 8 weeks after MI (+9+/-9%) was greater than in those regions that did not respond normally (+5+/-9%, P<0.04). Midmyocardial and subepicardial response to dobutamine were predictive of functional recovery, but the subendocardial response was not. CONCLUSIONS: The response of intramyocardial function to low-dose dobutamine after reperfused MI can be quantified with MR tagging. Dysfunctional tissue after MI demonstrates a larger contractile response to dobutamine than normal myocardium. A normal increase in shortening elicited by dobutamine within dysfunctional midwall and subepicardium predicts greater functional recovery at 8 weeks after MI, but the response within the subendocardium is not predictive.     

On the logical development of statistical models

Resumen This pager presents a classification of statistical models using a simple and logical framework. Some remarks are made about the historical appearance of each type of model and the practical problems that motivated them. It is argued that the current stages of the statistical methodology for model building have arisen in response to the needs of more sophisticated procedures for building dynamic-explicative types of models. Some potentially important topics for future research are included.     

The optimization of penicillin biosynthesis in fungi

Penicillin production by Penicillium chrysogenum is not only commercially important but arguably the most intensively investigated secondary-metabolic pathway in fungi. Isolation of the structural genes encoding the three main penicillin-biosynthetic enzymes has stimulated the use of molecular approaches to optimize yield and permitted genetic analysis of current production strains, which are themselves the products of 50 years of strain and process improvement. Parallel studies on the penicillin-producing genetic model organism Aspergillus nidulans are now addressing questions about the genetic regulation of primary and secondary metabolism, the compartmentalization of biosynthesis and the excretion of the end products.