5,438 research outputs found
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Using Technology to Develop Ethical Choice in Engineering Students
This paper describes the interactive technology that we have added to an undergraduate course titled “Engineering Ethics and Impact on Society.” The purpose of this technology is to develop students’ awareness of cultural differences in engineers’ approaches to ethical practice, and to develop students’ abilities to communicate in a global workplace. These goals are being pursued through a website that is publicly available, titled Reflective Choices http://ReflectiveChoices.ttu.edu. We describe the development of the website and results from the first several months of implementation. A major purpose of this paper is to make our colleagues aware of this website and to encourage them to contribute featured articles related to engineering ethics and professional practice.Cockrell School of Engineerin
Is venture capital a local business? : A test of the proximity and local network hypotheses
Venture capital (VC) investment has long been conceptualized as a local business , in which the VC’s ability to source, syndicate, fund, monitor, and add value to portfolio firms critically depends on their access to knowledge obtained through their ties to the local (i.e., geographically proximate) network. Consistent with the view that local networks matter, existing research confirms that local and geographically distant portfolio firms are sourced, syndicated, funded, and monitored differently. Curiously, emerging research on VC investment practice within the United States finds that distant investments, as measured by “exits” (either initial public offering or merger & acquisition) out-perform local investments. These findings raise important questions about the assumed benefits of local network membership and proximity. To more deeply probe these questions, we contrast the deal structure of cross-border VC investment with domestic VC investment, and contrast the deal structure of cross-border VC investments that include a local
partner with those that do not. Evidence from 139,892 rounds of venture capital financing in the period 1980-2009 suggests that cross-border investment practice, in terms of deal sourcing, syndication, and performance indeed change with proximity, but that monitoring practices do not. Further, we find that the inclusion of a local partner in the investment syndicate yields surprisingly few benefits. This evidence, we argue, raises important questions about VC investment practice as well as the ability of firms to capture and lever the presumed benefits of network membership
Entry into Winner-Take-All and Proportional-Prize Contests: An Experimental Study
This experiment compares the performance of two contest designs: a standard winnertake- all tournament with a single fixed prize, and a novel proportional-payment design in which that same prize is divided among contestants by their share of total achievement. We find that proportional prizes elicit more entry and more total achievement than the winner-take-all tournament. The proportional-prize contest performs better by limiting the degree to which heterogeneity among contestants discourages weaker entrants, without altering the performance of stronger entrants. These findings could inform the design of contests for technological and other improvements, which are widely used by governments and philanthropic donors to elicit more effort on targeted economic and technological development activities.performance pay, tournament, piece rate, tournament design, contest, experiments, risk aversion, feedback, gender
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Do Engineering Students Learn Ethics From an Ethics Course?
The goal of the present research is to develop machine-assisted methods that can assist in the analysis of students’ written compositions in ethics courses. As part of this research, we analyzed Social Impact Assessment (SIA) papers submitted by engineering undergraduates in a course on engineering ethics. The SIA papers required students to identify and discuss a contemporary engineering technology (e.g., autonomous tractor trailers) and to explicitly discuss the ethical issues involved in that technology. Here we describe the ability of three machine tools to discriminate differences in the technical compared to ethical portions of the SIA papers. First, using LIWC (Language Inquiry and Word Count) we quantified differences in analytical thinking, expertise and self-confidence, disclosure, and affect, in the technical and ethical portions of the papers. Next, we applied MEH (Meaning Extraction Helper) to examine differences in critical concepts in the technical and ethical portions of the papers. Finally, we used LDA (Latent Dirichlet Allocation) to examine differences in the topics in the technical and ethical portions of the papers. The results of these three tests demonstrate the ability of machine-based tools to discriminate conceptual, affective, and motivational differences in the texts that students compose that relate to engineering technology and to engineering ethics. We discuss the utility and future directions for this research.Cockrell School of Engineerin
Digitalis for treatment of heart failure in patients in sinus rhythm
<b>Background</b><p></p>
Digitalis glycosides have been in clinical use for the treatment of heart failure (HF) for longer than 200 years. In recent years, several trials have been conducted to address concerns about their efficacy and toxicity.<p></p>
<b>Objectives</b><p></p>
To examine the effectiveness of digitalis glycosides in treating HF in patients with normal sinus rhythm. To examine the effects of digitalis in patients taking diuretics and angiotensin-converting enzyme inhibitors; in patients with varying severity and duration of disease; in patients with prior exposure to digitalis versus no prior exposure; and in patients with "HF due to systolic dysfunction" versus "HF with preserved ejection fraction."<p></p>
<b>Search methods</b><p></p>
Searches on the following databases were updated in May 2013: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Dissertation Abstracts. Annual meeting abstracts of the American Heart Association, the American College of Cardiology, and the European Society of Cardiology were searched from 1996 to March 2013. In addition, reference lists provided by the pharmaceutical industry (GlaxoSmithKline and Covis Pharma) were searched.<p></p>
<b>Selection criteria</b><p></p>
Included were randomized placebo-controlled trials of 20 or more adult participants of either sex with symptomatic HF who were studied for seven weeks or longer. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of HF such as acute ischemic heart disease or myocarditis was present.<p></p>
<b>Data collection and analysis</b><p></p>
Articles selected from the searches described above were evaluated in a joint effort of the review authors. The staff of the Cochrane Heart Group ran searches on the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE.<p></p>
<b>Main results</b><p></p>
No new studies were identified in the updated searches. Thirteen studies (7896 participants) are included, and major endpoints of mortality, hospitalization, and clinical status, based respectively on 8, 4, and 12 of these selected studies, were recorded and analyzed. The data show no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with lower rates of both hospitalization and clinical deterioration. The largest study, in which most participants were taking angiotensin-converting enzyme inhibitors, showed a significant rise in “other cardiac” deaths, possibly due to arrhythmias. However collectively, these findings were based on studies done before beta-blockers, as well as angiotensin receptor blockers and aldosterone antagonists, became widely used to treat HF.<p></p>
<b>Authors' conclusions</b><p></p>
The literature indicates that digitalis may have a useful role in the treatment of patients with HF who are in normal sinus rhythm. New trials are needed to elucidate the importance of the dosage of digitalis and its usefulness in the era of beta-blockers and other agents shown to be effective in treating HF.<p></p>
Turbulent fluid acceleration generates clusters of gyrotactic microorganisms
The motility of microorganisms is often biased by gradients in physical and
chemical properties of their environment, with myriad implications on their
ecology. Here we show that fluid acceleration reorients gyrotactic plankton,
triggering small-scale clustering. We experimentally demonstrate this
phenomenon by studying the distribution of the phytoplankton Chlamydomonas
augustae within a rotating tank and find it to be in good agreement with a new,
generalized model of gyrotaxis. When this model is implemented in a direct
numerical simulation of turbulent flow, we find that fluid acceleration
generates multi-fractal plankton clustering, with faster and more stable cells
producing stronger clustering. By producing accumulations in high-vorticity
regions, this process is fundamen- tally different from clustering by
gravitational acceleration, expanding the range of mechanisms by which
turbulent flows can impact the spatial distribution of active suspensions.Comment: 5 pages, 4 figure
Binding between the neural cell adhesion molecules axonin-1 and Nr- CAM/Bravo is involved in neuron-glia interaction
Neural cell adhesion molecules of the immunoglobulin superfamily mediate cellular interactions via homophilic binding to identical molecules and heterophilic binding to other family members or structurally unrelated cell-surface glycoproteins. Here we report on an interaction between axonin-1 and Nr-CAM/Bravo. In search for novel ligands of axonin-1, fluorescent polystyrene microspheres conjugated with axonin-1 were found to bind to peripheral glial cells from dorsal root ganglia. By antibody blockage experiments an axonin-1 receptor on the glial cells was identified as Nr-CAM. The specificity of the interaction was confirmed with binding studies using purified axonin-1 and Nr-CAM. In cultures of dissociated dorsal root ganglia antibodies against axonin-1 and Nr-CAM perturbed the formation of contacts between neurites and peripheral glial cells. Together, these results implicate a binding between axonin-1 of the neuritic and Nr-CAM of the glial cell membrane in the early phase of axon ensheathment in the peripheral nervous system
Bravo/Nr-CAM Is Closely Related to the Cell Adhesion Molecules L1 and Ng-CAM and Has a Similar Heterodimer Structure
Diverse cell-surface molecules of the nervous system play an important role in specifying cell interactions during development. Using a method designed to generate mAbs against neural surface molecules of defined molecular weight, we have previously reported on the surface protein, Bravo, found in the developing avian retinotectal system. Bravo is immunologically detected on developing optic fibers in the retina, but absent from distal regions of the same fibers in the tectum. We have isolated cDNA clones encompassing the entire coding region of Bravo, including clones containing five alternative sequences of cDNA. These putative alternatively spliced sequences encode stretches of polypeptide ranging in length from 10-93 amino acids and are predicted to be both extra- and intracellular. The deduced primary structure of Bravo reveals that, like the cell adhesion molecules (CAMs) chicken Ng- CAM and mouse L1, Bravo is composed of six Ig-like domains, five fibronectin type III repeats, a transmembrane domain, and a short cytoplasmic region. Recently, the cDNA sequence of a related molecule, Nr-CAM, was reported and its possible identity with Bravo discussed (Grumet, M., V. Mauro, M. P. Burgoon, G. E. Edelman, and B. A. Cunningham. 1991. J. Cell Biol. 113:1399-1412). Here we confirm this identity and moreover show that Bravo is found on Muller glial processes and end-feet in the developing retina. In contrast to the single polypeptide chain structure of Nr-CAM reported previously, we show that Bravo has a heterodimer structure composed of an alpha chain of M(r) 140/130 and a beta chain of 60-80 kD. As with L1 and Ng-CAM, the two chains of Bravo are generated from an intact polypeptide by cleavage at identical locations and conserved sites within all three molecules (Ser-Arg/Lys-Arg). The similar domain composition and heterodimer structure, as well as the 40% amino acid sequence identity of these molecules, defines them as an evolutionarily related subgroup of CAMs. The relationship of Bravo to molecules known to be involved in cell adhesion and process outgrowth, combined with its pattern of expression and numerous potential isoforms, suggests a complex role for this molecule in cell interactions during neural development
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