1,650 research outputs found
Acoustic analysis of aft noise reduction techniques measured on a subsonic tip speed 50.8 cm (twenty inch) diameter fan
Sound data which were obtained during tests of a 50.8 cm diameter, subsonic tip speed, low pressure ratio fan were analyzed. The test matrix was divided into two major investigations: (1) source noise reduction techniques; and (2) aft duct noise reduction with acoustic treatment. Source noise reduction techniques were investigated which include minimizing second harmonic noise by varying vane/blade ratio, variation in spacing, and lowering the Mach number through the vane row to lower fan broadband noise. Treatment in the aft duct which includes flow noise effects, faceplate porosity, rotor OGV treatment, slant cell treatment, and splitter simulation with variable depth on the outer wall and constant thickness treatment on the inner wall was investigated. Variable boundary conditions such as variation in treatment panel thickness and orientation, and mixed porosity combined with variable thickness were examined. Significant results are reported
Comparison of Aspergillus species-complexes detected in different environmental settings
Purpose: Samples from different environmental sources were screened for the presence of Aspergillus, and the distribution of the different species-complexes was determined in order to understand differences among that distribution in the several environmental sources and which of these species complexes are present in specific environmental settings. Methods: Four distinct environments (beaches, poultries, swineries and hospital) were studied and analyzed for which Aspergillus complexes were present in each setting. After plate incubation and colony isolation, morphological identification was done using macro- and microscopic characteristics. The universal fungal primers ITS1 and ITS4 were used to amplify DNA from all Aspergillus isolates, which was sequenced for identification to species complex level. SPSS v15.0 for Windows was used to perform the statistical analysis. Results: Thirty-nine isolates of Aspergillus were recovered from both the sand beach and poultries, 31 isolates from swineries, and 80 isolates from hospital environments, for a total 189 isolates. Eleven species complexes were found total. Isolates belonging to the Aspergillus Versicolores species-complex were the most frequently found (23.8%), followed by Flavi (18.0%), Fumigati (15.3%) and Nigri (13.2%) complexes. A significant association was found between the different environmental sources and the distribution of the several species-complexes (p<0.001); the hospital environment had a greater variability of species-complexes than other environmental locations (10 in hospital environment, against nine in swine, eight in poultries and seven in sand beach). Isolates belonging to Nidulantes complex were detected only in the hospital environment, whereas the other complexes were identified in more than one setting. Conclusion: Because different Aspergillus complexes have different susceptibilities to antifungal drugs, and different abilities in producing mycotoxins, knowledge of the species-complex epidemiology for each setting may allow preventive or corrective measures to be taken toward decreasing professional workers or patient exposure to those agents
Organization theory and military metaphor: time for a reappraisal?
A ‘conventional’ use of military metaphor would use it to convey attributes such as hierarchical organization, vertical communication and limited autonomy. This is often used in contrast to a looser form of organization based on the metaphor of the network. However, this article argues that military practice is more complex, with examples of considerable autonomy within the constraints of central direction. It is suggested that not only might this be a more useful metaphor for many contemporary organizations, but also that simplistic uses of military metaphor divert our attention away from the functions that management hierarchies play. The discussion is embedded within a critical realist account of metaphor, arguing for both its value and the need for its further development
A practical synthesis of a novel DPAGT1 inhibitor, aminouridyl phenoxypiperidinbenzyl butanamide (APPB) for in vivo studies
Immunotherapy that targets N-linked glycans has not yet been developed due in large part to the lack of specificity of N-linked glycans between normal and malignant cells. N-Glycan chains are synthesized by the sequential action of glycosyl transferases in the Golgi apparatus. It is an overwhelming task to discover drug-like inhibitors of glycosyl transferases that block the synthesis of specific branching processes in cancer cells, killing tumor cells selectively. It has long been known that N-glycan biosynthesis can be inhibited by disruption of the first committed enzyme, dolichyl-phosphate N-acetylglucosaminephosphotransferase 1 (DPAGT1). Selective DPAGT1 inhibitors have the promising therapeutic potential for certain solid cancers that require increased branching of N-linked glycans in their growth progressions. Recently, we discovered that an anti-Clostridium difficile molecule, aminouridyl phenoxypiperidinbenzyl butanamide (APPB) showed DPAGT1 inhibitory activity with the IC_(50) value of 0.25 μM. It was confirmed that APPB inhibits N-glycosylation of β-catenin at 2.5 nM concentration. A sharp difference between APPB and tunicamycin was that the hemolytic activity of APPB is significantly attenuated (IC_(50) > 200 μM RBC). Water solubility of APPB is >350-times greater than that of tunicamycin (78.8 mg/mL for APPB, 60 min) for in vivo studies (PK/PD, safety profiles, and in vivo efficacy) using animal models. We have refined all steps in the previously reported synthesis for APPB for larger-scale. This article summarizes protocols of gram-scale synthesis of APPB and its physicochemical data, and a convenient DPAGT1 assay
Patient perceptions and expectations regarding imaging for metastatic disease in early stage breast cancer
Abstract
Purpose
The probability of detecting radiologically evident metastatic disease in asymptomatic women with newly diagnosed operable breast cancer is low. Despite the recommendations of most practice guidelines imaging is still frequently performed. Relatively little is known about what patients believe is important when it comes to radiologic staging.
Methods
Patients with early stage breast cancer who had completed their definitive breast surgery were surveyed about their personal experiences, perceptions, and expectations on the issue of perioperative imaging for distant metastatic disease.
Results
Over a 3 month period, 245 women with primary operable breast cancer completed the questionnaire (87.0% response rate) and 80.8% indicated having had at least one imaging test for distant metastatic disease. These were either of the thorax (72.2%), abdomen (55.9%) or skeleton (65.3%) with a total of 701 imaging tests (average of 3.5 tests per patient imaged) performed. Overall, 57.1% indicated that they would want imaging done if the chance of detecting metastases was ≤10%. Although 80.0% of patients indicated that, “doing whatever their doctor recommended” was important to them, 70.4% also noted that they would be uncomfortable if their physician did not order imaging, even if this was in keeping with practice guidelines.
Conclusions
Most patients with early stage breast cancer recall having imaging tests for distant metastases. Given the choice, most would prefer having imaging performed, even if this is not in line with current guidelines. If patient expectations are, in part, driving excessive imaging, new strategies addressing this are required
Expanding the model of consumer satisfaction and dissatisfaction : the Means-End Disconfirmation Model of CS/D
The importance of consumer satisfaction and dissatisfaction (CS/D) as a component of the marketing concept is well documented. However, a replete understanding of CS/D and its related evaluative processes is yet to be realized. This dissertation examines the current knowledge of CS/D, and identifies several unresolved issues. In an attempt to resolve some of these issues and better the understanding of CS/D, a new model is proposed which incorporates the means-end theory of evaluation with the currently dominant disconfirmation paradigm of CS/D. Using data collected in a field survey, the Means-End Disconfirmation Model of Consumer (Dis)Satisfaction is tested as a Linear Structural Relations model. The results indicate that the proposed model improves upon both the explanation and understanding of consumer (dis)satisfaction. Implications and suggestions for future research are also offered
A Human Islet Cell-Culture System for High-Throuput screening.
A small-molecule inducer of beta-cell proliferation in human islets represents a potential regeneration strategy for treating type 1 diabetes. However, the lack of suitable human beta cell lines makes such a discovery a challenge. Here, we adapted an islet cell culture system to high-throughput screening to identify such small molecules. We prepared microtiter plates containing extracellular matrix from a human bladder carcinoma cell line. Dissociated human islets were seeded onto these plates, cultured for up to 7 days, and assessed for proliferation by simultaneous Ki67 and C-peptide immunofluorescence. Importantly, this environment preserved beta-cell physiological function, as measured by glucose-stimulated insulin secretion. Adenoviral overexpression of cdk-6 and cyclin D(1), known inducers of human beta cell proliferation, was used as a positive control in our assay. This induction was inhibited by cotreatment with rapamycin, an immunosuppressant often used in islet transplantation. We then performed a pilot screen of 1280 compounds, observing some phenotypic effects on cells. This high-throughput human islet cell culture method can be used to assess various aspects of beta-cell biology on a relatively large number of compounds
An Exploration Of The Relationship Between Transformational Leadership Characterististics And Multicultural Education Practices In Teacher Educators
This exploration focused on the relationship of transformational leadership in teacher educators and their multicultural education practices as an avenue to prepare and produce more teachers for the increasingly diverse student population in P-12 Schools. This research was a two-phase sequential mixed method design including quantitative and qualitative data of 21 teacher educators at one Historically Black College and University (Kameron Carolina State University). The data were collected through questionnaires, content analysis, interviews and observations. The two questionnaires utilized were the Multifactor Leadership Questionnaire developed by Bass and Avolio (1995) and the Multicultural Education Questionnaire developed by Johnson and Inoue (2001). Descriptive analyses and the Spearman‟s Rank Correlation Coefficient statistic test was used to analyzed the data. The findings suggest from the quantitative results that there is a moderate positive correlation (Rho=.48) in regards to the relationship between HBCU teacher educator‟s transformational leadership characteristics and multicultural education practices. The qualitative findings suggest underlying factors such as the gender, ethnicity and professional ranking along with the collaboration of faculty members influence the development of HBCUs teacher educators‟ practices in multicultural education
A VALUE PLATFORM ANALYSIS PERSPECTIVE ON CUSTOMER ACCESS INFORMATION TECHNOLOGY
Customer access information technologies (CAITs) provide a link between a
firm and its customers. Firms invest in CAITs to reduce costs, increase revenues
and market share, lock in existing customers and capture new ones. These benefits,
however, are notoriously difficult to measure. This paper proposes an evaluative
method for CAlT deployment called value platform analysis, that is based on a
conceptual model drawn from the theory of retail outlet deployment in marketing
science. The model focuses on the impact of CAIT features and environmental
features on transactions generated by the CAIT. Specific econometric models are
developed for deployment. Hypotheses regarding the likely impact of automated
teller machine (ATM) location design choices and environmental features on ATM
transactions are evaluated. The results indicate that there are a number of key
features influencing ATM performance. Two distinct ATM deployment scenarios
emerge: one for servicing a bank's own customers, and another for providing
transaction services for customers for a fee.Information Systems Working Papers Serie
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