933 research outputs found

    From Revolutionary to Palace Guard: The Role and Requirements of Intermediaries Under Proposed Regulation Crowdfunding

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    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 Engineers’ Interdisciplinary Competence

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    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 students’ development of generic cognitive skills but not the development of interdisciplinary competencies.Purpose/HypothesisThis study sought to explore how engineering students’ characteristics, college experiences, and engineering faculty beliefs relate to students’ 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 students’ curricular and co‐curricular experiences and faculty beliefs regarding interdisciplinarity in engineering education on students’ reports of interdisciplinary competence.ResultsThis study found that a curricular emphasis on interdisciplinary topics and skills, as well as co‐curricular activities, specifically, participating in nonengineering clubs and organizations, study abroad, and humanitarian engineering projects, significantly and positively relate to engineering students’ reports of interdisciplinary skills. Faculty members’ beliefs regarding interdisciplinarity in engineering education moderated the relationships between particular co‐curricular experiences and students’ interdisciplinary skills, as well as between curricular emphasis and students’ interdisciplinary skills.ConclusionsThis study identified a small set of experiences that are related to students’ 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 co‐curricular 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

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    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)

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    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 017–characterization, evolution and epidemiology of the dominant strain in Asia

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    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

    Bridging Physics and Biology Teaching through Modeling

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    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

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    We study the stellar population properties of the IRAC-detected 6â‰Čzâ‰Č106 \lesssim z \lesssim 10 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 6â‰Čzâ‰Č106 \lesssim z \lesssim 10 with S/N≄3S/N \geq 3 in at least one of the IRAC 3.6ÎŒ3.6\mum and 4.5ÎŒ4.5\mum bands. According to the best mass models available for the surveyed galaxy clusters, these IRAC-detected galaxy candidates are magnified by factors of ∌1.2\sim 1.2--5.55.5. We find that the IRAC-detected 6â‰Čzâ‰Č106 \lesssim z \lesssim 10 sample is likely not a homogeneous galaxy population: some are relatively massive (stellar mass as high as 4×109 M⊙4 \times 10^9\,M_{\odot}) and evolved (age â‰Č500\lesssim 500 Myr) galaxies, while others are less massive (Mstellar∌108 M⊙M_{\text{stellar}}\sim 10^8\,M_{\odot}) and very young (∌10\sim 10 Myr) galaxies with strong nebular emission lines that boost their rest-frame optical fluxes. We identify two Lyα\alpha emitters in our sample from the Keck DEIMOS spectra, one at zLyα=6.76z_{\text{Ly}\alpha}=6.76 (in RXJ1347) and one at zLyα=6.32z_{\text{Ly}\alpha}=6.32 (in MACS0454). We show that IRAC [3.6]−[4.5][3.6]-[4.5] 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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