933 research outputs found
The Sandbox Paradox: Balancing the Need to Facilitate Innovation with the Risk of Regulatory Privilege
From Revolutionary to Palace Guard: The Role and Requirements of Intermediaries Under Proposed Regulation Crowdfunding
Intermediaries in securities crowdfunding face significant requirements as a result of the statutory mandates of Title III of the JOBS Act. The SEC, in its proposed rules, provided structure to these requirements. The proposed rules would create strict requirements for intermediaries regarding their relationships with investors and how they undertake crowdfunding transactions under Section 4(a)(6) of the Securities Act. The proposed rules would also create and establish the guidelines for funding portals, a new type of limited purpose securities broker. While some commentators decry the SEC for placing undue burdens and legal liabilities on intermediaries in securities crowdfunding, the SEC had limited discretion in the proposed rules in regards to those issues. It is unclear what type of market will develop as a result of these rules as market participants work through the challenges and opportunities of securities crowdfunding
Supporting the Development of Engineersâ Interdisciplinary Competence
BackgroundAlthough interdisciplinarity has been a subject of interest and debate for decades, few investigations of interdisciplinary education exist. Existing studies examine the effects of interdisciplinary experiences on studentsâ development of generic cognitive skills but not the development of interdisciplinary competencies.Purpose/HypothesisThis study sought to explore how engineering studentsâ characteristics, college experiences, and engineering faculty beliefs relate to studentsâ reports of interdisciplinary competence.Design/MethodThe study used a nationally representative survey sample of 5,018 undergraduate students and 1,119 faculty members in 120 U.S. engineering programs at 31 institutions. Using hierarchical linear modeling, we investigated the relationships among studentsâ curricular and coâcurricular experiences and faculty beliefs regarding interdisciplinarity in engineering education on studentsâ reports of interdisciplinary competence.ResultsThis study found that a curricular emphasis on interdisciplinary topics and skills, as well as coâcurricular activities, specifically, participating in nonengineering clubs and organizations, study abroad, and humanitarian engineering projects, significantly and positively relate to engineering studentsâ reports of interdisciplinary skills. Faculty membersâ beliefs regarding interdisciplinarity in engineering education moderated the relationships between particular coâcurricular experiences and studentsâ interdisciplinary skills, as well as between curricular emphasis and studentsâ interdisciplinary skills.ConclusionsThis study identified a small set of experiences that are related to studentsâ reported development of interdisciplinary competence. The study points to the critical role of the curriculum in promoting interdisciplinary thinking and habits of mind, as well as the potential of coâcurricular opportunities that bring engineering students together with nonmajors to build interdisciplinary competence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135983/1/jee20155_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135983/2/jee20155.pd
Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions
Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe
Student, instructor, and observer agreement regarding frequencies of scientific teaching practices using the Measurement Instrument for Scientific Teaching-Observable (MISTO)
Background: The Scientific Teaching (ST) pedagogical framework encompasses many of the best practices recommended in the literature and highlighted in national reports. Understanding the growth and impact of ST requires instruments to accurately measure the extent to which practitioners implement ST in their courses. Researchers have typically relied on students, instructors, or observers to document course teaching practices, but it remains unclear whether and how these perspectives differ from each other. To address this issue, we modified our previously published instrument to generate the Measurement Instrument for Scientific Teaching-Observable (MISTO), which can be completed by students, instructors, and observers, and we investigated the degree of similarity between these three perspectives across 70 undergraduate science courses at seven different institutions in the USA.
Results: We found that the full MISTO and Active Learning subcategory scores showed the highest correlations among the three perspectives, but the degree of correlation between perspectives varied for the other subcategories. Match scores between students and instructors were significantly higher than observer matches for the full MISTO and for the Active Learning, Inclusivity, and Responsiveness subcategories.
Conclusions: We find that the level and type of agreement between perspectives varies across MISTO subcategories and that this variation likely stems from intrinsic differences in the course access and scoring decisions of the three perspectives. Building on this data, we recommend MISTO users consider their research goals, available resources, and potential artifacts that may arise when deciding which perspective best fits their needs in measuring classroom teaching practices
Clostridium difficile ribotype 017âcharacterization, evolution and epidemiology of the dominant strain in Asia
Clostridium difficile ribotype (RT) 017 is an important toxigenic C. difficile RT which, due to a deletion in the repetitive region of the tcdA gene, only produces functional toxin B. Strains belonging to this RT were initially dismissed as nonpathogenic and circulated largely undetected for almost two decades until they rose to prominence following a series of outbreaks in the early 2000s. Despite lacking a functional toxin A, C. difficile RT 017 strains have been shown subsequently to be capable of causing disease as severe as that caused by strains producing both toxins A and B. While C. difficile RT 017 strains can be found in almost every continent today, epidemiological studies suggest that the RT is endemic in Asia and that the global spread of this MLST clade 4 lineage member is a relatively recent event. C. difficile RT 017 transmission appears to be mostly from human to human with only a handful of reports of isolations from animals. An important feature of C. difficile RT 017 strains is their resistance to several antimicrobials and this has been documented as a possible factor driving multiple outbreaks in different parts of the world. This review summarizes what is currently known regarding the emergence and evolution of strains belonging to C. difficile RT 017 as well as features that have allowed it to become an RT of global importance
Delivery of high energy Er:YAG pulsed laser light at 2.94Ăm through a silica hollow core photonic crystal fibre
Bridging Physics and Biology Teaching through Modeling
As the frontiers of biology become increasingly interdisciplinary, the
physics education community has engaged in ongoing efforts to make physics
classes more relevant to life sciences majors. These efforts are complicated by
the many apparent differences between these fields, including the types of
systems that each studies, the behavior of those systems, the kinds of
measurements that each makes, and the role of mathematics in each field.
Nonetheless, physics and biology are both sciences that rely on observations
and measurements to construct models of the natural world. In the present
theoretical article, we propose that efforts to bridge the teaching of these
two disciplines must emphasize shared scientific practices, particularly
scientific modeling. We define modeling using language common to both
disciplines and highlight how an understanding of the modeling process can help
reconcile apparent differences between the teaching of physics and biology. We
elaborate how models can be used for explanatory, predictive, and functional
purposes and present common models from each discipline demonstrating key
modeling principles. By framing interdisciplinary teaching in the context of
modeling, we aim to bridge physics and biology teaching and to equip students
with modeling competencies applicable across any scientific discipline.Comment: 10 pages, 2 figures, 3 table
Spitzer UltRa Faint SUrvey Program (SURFS UP). II. IRAC-Detected Lyman-Break Galaxies at 6 < z < 10 Behind Strong-Lensing Clusters
We study the stellar population properties of the IRAC-detected galaxy candidates from the Spitzer UltRa Faint SUrvey Program
(SURFS UP). Using the Lyman Break selection technique, we find a total of 16
new galaxy candidates at with in at
least one of the IRAC m and m bands. According to the best mass
models available for the surveyed galaxy clusters, these IRAC-detected galaxy
candidates are magnified by factors of --. We find that the
IRAC-detected sample is likely not a homogeneous
galaxy population: some are relatively massive (stellar mass as high as ) and evolved (age Myr) galaxies, while
others are less massive () and very
young ( Myr) galaxies with strong nebular emission lines that boost
their rest-frame optical fluxes. We identify two Ly emitters in our
sample from the Keck DEIMOS spectra, one at (in
RXJ1347) and one at (in MACS0454). We show that IRAC
color, when combined with photometric redshift, can be used to
identify galaxies likely with strong nebular emission lines within certain
redshift windows.Comment: ApJ in pres
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