6,678 research outputs found
Saturation in “nonmagnetic” stainless steel
Scientific equipment often uses “nonmagnetic” stainless steel, relying on the steel’s nonmagnetic behavior to leave external magnetic fields unaltered. However, stainless steel’s permeability can rise significantly when it is welded or machined, possibly perturbing an external field. Such perturbations will diminish well above the stainless steel’s saturation point. The authors measured the permeability of both welded and machined 304 stainless steel as a function of an external magnetic field, and found that both saturate at fields of approximately 0.25 T
Can Auditors Be Independent? - Experimental Evidence
The Sarbanes-Oxley Act of 2002 has transformed the institutional environment in the US by making the audit committee responsible for the appointment, compensation and oversight of the auditor. We examine whether this institutional change successfully resolves the alleged problem of an unconscious favoring of the management (Bazerman et al. 1997, 2002, 2006) by changing the effects of auditors’ economic incentives and psychological pressure. In our experimental design, we make use of the particular features of the German institutional setting as it enables us to manipulate the client of the auditor in a realistic and clear-cut way. 72 German auditors with at least two years of job experience participated in our experiment. Following Turner (2001), we distinguish in our analyses between belief tasks (e.g. evidence evaluation) and action tasks (e.g. audit opinion). Our findings imply that certain institutional features seem to be helpful in ensuring auditor independence. First, we find that auditors demonstrate professional scepticism in belief tasks. This seems to counteract any potentially negative effect of the acceptability heuristic in actions tasks. Second, experience helped auditors in coping with psychological pressure. Third, making the auditor accountable to a supervisory board was helpful in reducing the risk that financial considerations would impair auditor independence.
Improvement of Onsite Wastewater Treatment By Use of Electrically Conductive Carbon Cloth
The purpose of this research is primarily focused on carbon oxidation in domestic septic systems. Small-scale septic waste reactors utilizing electrically conductive carbon cloth were assessed for improving carbon oxidation and therefore the overall efficiency of on-site wastewater treatment systems. A bioelectrochemical system was developed to enhance carbon oxidation in septic systems using electrically conductive carbon cloth as an anode/cathode bridge to transfer electrons from strictly anoxic septic wastewater to an oxic system outside of the septic reactor. This \u27septic snorkel\u27 (so named since the system \u27breathes\u27 via the carbon cloth extends into an aerobic zone) was designed to lower the carbon loading on the leach field, while being simple to deploy at the field level, which would be necessary for regulatory and stakeholder approval. The concept is predicated on previously published work that demonstrated Fe(III) amendment to septic wastewater increased carbon mineralization. Data with Fe(III) amendment (an analogous system) demonstrated that mineralization of 14C-labeled acetate, lactate, propionate, starch, glucose, and oleic acid increased by as much as 100%, while completely suppressing methane production. Bench scale results using different carbon cloth setups suggested that complete and open circuit configurations improved soluble COD removal by 25% and 23% respectively. Select 14C-labeled compounds were also tested using the carbon cloth system. Interestingly, reactors with carbon cloth alone (no circuitry) showed the highest mineralization for all 14C-labeled compounds. Increases in mineralization ranged from 16% to 82%
Multiple Conserved Enhancers of the Osteoblast Master Transcription Factor, Runx2, Integrate Diverse Signaling Pathways to Direct Expression to Developing Bone
The vertebrate skeleton forms via two distinct modes of ossification, membranous and endochondral. Osteoblasts are also heterogeneous in embryonic origin; bone formed by either mode can be derived from neural crest cells or mesoderm. In contrast, all bone develops via a common genetic pathway regulated by the transcription factor Runx2. Runx2 is required for bone formation, and haploinsufficiency in humans causes the skeletal syndrome cleidocranial dysplasia, demonstrating the importance of gene dosage. Despite the central role of Runx2 in directing bone formation, little is understood about how its expression is regulated in development. We took an unbiased approach to identify direct regulatory inputs into Runx2 transcription by identifying cis-regulatory elements associated with the human gene. We assayed conserved non-coding elements in a 1 Mb interval surrounding the gene for their ability to direct osteoblast expression in transgenic zebrafish. We identified three enhancers spaced out across the interval. Within each we identified conserved transcription factor binding sites required for their activity, and further showed distinct and specific regulation of each. The enhancer in the last intron of RUNX2 itself is positively regulated by the FGF signaling pathway, an enhancer in the last intron of the adjacent gene, SUPT3H, is regulated by canonical Wnt signaling, and a distant downstream enhancer requires a conserved Dlx binding site for its activity. While all of these pathways and factors have been previously implicated in bone formation, our results provide the first direct links to the common genetic pathway regulating osteogenesis, transcription of Runx2. These findings further illustrate the integration of multiple regulatory inputs at the level of transcription of a key developmental gene, and highlight the role of Runx2 as the gatekeeper for changes in skeletal morphology achieved through alterations in gene expression
Professor and student travel to Chile to track an asteroid that may really be a comet
As Linda French and her student Gautham Narayan sit in front of a computer in the Center for Natural Sciences, meticulously studying photos of findings from a recent research trip, it is hard to believe that only a few months earlier the two astronomers had taken these same pictures halfway across the globe
Fascination with extraterrestrial life extends into IWU classroom
French, an astronomer by trade, is teaching a semester-long course this spring that focuses on the depiction of human-alien encounters in science fiction and popular culture
Crisis in the American courts: Greylord and the destruction of fiduciary bonds between the justice system and society
Includes bibliographical references.While it is commonly accepted and agreed upon that judges ought not to be partial, which (for reasons which will be discussed later) in the case of the judge necessarily implies corrupt, very seldom is there a reason given as to why the judge ought not to be partial to one litigant or the other. Perhaps this is because the judiciary is considered, as it was by the Founding Fathers, to be the weakest branch of government and therefore the least able to do harm, or perhaps it is because the answer to this question is considered too obvious and therefore uninteresting. Nevertheless, with the ever-expanding role of the judicial system into the policy-making role that was traditionally reserved solely for the legislature (such as can be seen in recent cases involving affirmative action, busing, and abortion, just to name a few) it is time to re-examine the role of the judge in the judicial system and his position in, responsibility to, and relationship with the rest of society
Ultrafast investigation and control of Dirac and Weyl semimetals
Ultrafast experiments using sub-picosecond pulses of light are poised to play an important role in the study and use of topological materials and, particularly, of the three-dimensional Dirac and Weyl semimetals. Many of these materials’ characteristic properties—their linear band dispersion, Berry curvature, near-vanishing density of states at the Fermi energy, and sensitivity to crystalline and time-reversal symmetries—are closely related to their sub- and few-picosecond response to light. Ultrafast measurements offer the opportunity to explore excitonic instabilities and transient photocurrents, the latter depending on the Berry curvature and possibly quantized by fundamental constants. Optical pulses may, through Floquet effects, controllably and reversibly move, split, merge, or gap the materials’ Dirac and Weyl nodes; coherent phonons launched by an ultrafast pulse offer alternate mechanisms for similar control of the nodal structure. This Perspective will briefly summarize the state of research on the ultrafast properties of Dirac and Weyl semimetals, emphasizing important open questions. It will describe the challenges confronting each of these experimental opportunities and suggest what research is needed for ultrafast pulses to achieve their potential of controlling and illuminating the physics of Dirac and Weyl semimetals
Essential Fish Habitat project status report
: Groundfish that associate with rugged seafloor types are difficult to assess with bottom-trawl sampling gear. Simrad ME70 multibeam echosounder (MBES) data and video imagery were collected to characterize trawlable and untrawlable areas, and to ultimately improve efforts to determine habitat-specific groundfish biomass. The data were collected during two acoustic-trawl surveys of the Gulf of Alaska (GOA) during 2011 and 2012 by NOAA Alaska Fisheries Science Center (AFSC) researchers. MBES data were collected continuously along the trackline, which included parallel transects (1-20 nmi spacing) and fine-scale survey locations in 2011. Video data were collected at camera stations using a drop camera system. Multibeamderived seafloor metrics were overlaid with the locations of previously conducted AFSC bottomtrawl (BT) survey hauls and 2011 camera stations. Generalized linear models were used to identify the best combination of multibeam metrics to discriminate between trawlable and untrawlable seafloor for the region of overlap between the camera stations or haul paths and the MBES data. The most discriminatory models were chosen based on the Akaike information criterion (AIC). The two best models were developed using data collected at camera stations with either oblique incidence backscatter strength (Sb) or mosaic Sb in combination with bathymetric position index and seafloor ruggedness and described over 54% of the variation between trawlable and untrawlable seafloor types. A map of predicted seafloor trawlability produced from the model using mosaic Sb and benthic-terrain metrics demonstrated that 58% of the area mapped (5,987 km2 ) had \u3e 50% probability of being trawlable and 42% of being untrawlable. The model predicted 69% of trawlable and untrawlable haul locations correctly. Successful hauls occurred in areas with 62% probability of being trawlable and haul locations with gear damage occurred in areas with a 38% probability of being trawlable. This model and map produced from multibeamderived seafloor metrics may be used to refine seafloor interpretation for the AFSC BT surveys and to advance efforts to develop habitat-specific biomass estimates for GOA groundfish populations
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