3,110 research outputs found

    Research and assessment methods for leadership development in practice

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    While the field of leadership education continues to grow in terms of number of programs, students, and associated professional educators, our rigorous understanding of the impact of these programs has continued to lag behind such growth. Many postsecondary leadership educators work on campuses and have graduated from masters-level preparatory programs that do not focus extensively on rigorous research/assessment methods and may, therefore, lack the background necessary for high-level work (Brachle et al., 2021; Rosch et al., 2017; Teig, 2018). As a result, researchers and program assessment staff often recognize the need to take their methodological development “into their own hands” to increase their knowledge and maintain the high standards of rigor required in well-developed fields. Advancements in leadership education have afforded the opportunity to facilitate leadership learning better today than 20 years ago or even 10 years ago. For example, advancements in leadership education have taught us the critical importance of undergirding leader/leadership development (LD) programs in leadership theory and research that match learner needs (Avolio et al., 2009; Day & Liu, 2019) – this is what separates leadership education from expensive leadership development consultations that lack depth and involve programs based on popular fads. Advancements in leadership education have taught us that leadership is an active and dynamic process, where leadership is not singularly about the leader (Day et al., 2014; Komives et al., 2013). Those who are not in formal leadership roles are not passive recipients of whatever the leader does, but rather have important voice and are an active and essential part of the leadership process. Thus, we are learning that LD programs must be multi-level (Day et al., 2014; DeRue & Myers, 2014; O’Connell, 2014) – LD cannot focus on individual leader development and expect the team to get better, but rather team leadership capacity must also be enhanced

    Infiltration and short-term movement of nitrogen in a silt-loam soil typical of rice cultivation in Arkansas

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    Rice production in Arkansas is one of the top three crop commodities in terms of cash receipts. Researchers and farmers report that nitrogen (N) needs to be managed according to a variety of factors with two important ones being soil and fertilizer type. The objectives of this experiment were to determine: 1) the degree to which floodwater-incorporated N applied as urea or as ammonium sulfate infiltrates intact cores (7.2-cm dia., 10-cm depth) containing DeWitt siltloam soil, and 2) the distribution of N during 12 h of ponding. Inorganic-N concentrations were analyzed at 2-cm depth intervals in cores following removal of the flood. Nitrogen from applied fertilizer was recovered as ammonium. Ammonium sulfate-N remained in the top 4 cm of soil with concentrations of 375 ”g N g-1 in the surface 2 cm and 300 ”g N g-1 at the 2 - 4 cm depth after 12 hr of ponding. At all depth intervals below 4 cm, ammonium sulfate-N remained below 30 ”g N g-1. In contrast, after 12 h of ponding, N in soil receiving urea was 105 ”g N g-1 in the top 2 cm and 173 ”g N g-1 at 2-4 cm. At 4-6, 6-8, and 8-10 cm, N was 109, 108, and 35 ”g N g-1, respectively, after 12 h of ponding. These results demonstrate immediate and deeper movement of ammonium into silt loam soil receiving urea as compared to ammonium sulfate, demonstrating how the form of N in fertilizer affects its movement into the soil profile

    NuSTAR hard X-ray observation of a sub-A class solar flare

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    We report a NuSTAR observation of a solar microflare, SOL2015-09-01T04. Although it was too faint to be observed by the GOES X-ray Sensor, we estimate the event to be an A0.1 class flare in brightness. This microflare, with only 5 counts per second per detector observed by RHESSI, is fainter than any hard X-ray (HXR) flare in the existing literature. The microflare occurred during a solar pointing by the highly sensitive NuSTAR astrophysical observatory, which used its direct focusing optics to produce detailed HXR microflare spectra and images. The microflare exhibits HXR properties commonly observed in larger flares, including a fast rise and more gradual decay, earlier peak time with higher energy, spatial dimensions similar to the RHESSI microflares, and a high-energy excess beyond an isothermal spectral component during the impulsive phase. The microflare is small in emission measure, temperature, and energy, though not in physical size; observations are consistent with an origin via the interaction of at least two magnetic loops. We estimate the increase in thermal energy at the time of the microflare to be 2.4x10^27 ergs. The observation suggests that flares do indeed scale down to extremely small energies and retain what we customarily think of as "flarelike" properties.Comment: Status: Accepted by the Astrophysical Journal, 2017 July 1

    America Unbound: The Bush Revolution in Foreign Policy

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    NuSTAR detection of X-ray heating events in the quiet Sun

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    The explanation of the coronal heating problem potentially lies in the existence of nanoflares, numerous small-scale heating events occurring across the whole solar disk. In this Letter, we present the first imaging spectroscopy X-ray observations of three quiet Sun flares during the Nuclear Spectroscopic Telescope ARray (NuSTAR) solar campaigns on 2016 July 26 and 2017 March 21, concurrent with the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) observations. Two of the three events showed time lags of a few minutes between peak X-ray and extreme ultraviolet emissions. Isothermal fits with rather low temperatures in the range 3.2–4.1 MK and emission measures of (0.6–15) × 1044 cm−3 describe their spectra well, resulting in thermal energies in the range (2–6) × 1026 erg. NuSTAR spectra did not show any signs of a nonthermal or higher temperature component. However, as the estimated upper limits of (hidden) nonthermal energy are comparable to the thermal energy estimates, the lack of a nonthermal component in the observed spectra is not a constraining result. The estimated Geostationary Operational Environmental Satellite (GOES) classes from the fitted values of temperature and emission measure fall between 1/1000 and 1/100 A class level, making them eight orders of magnitude fainter in soft X-ray flux than the largest solar flares

    A quantitative empirical directing group scale for selectivity in iridium-catalysed hydrogen isotope exchange reactions

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    A palette of commonly used directing groups, including various pharmaceutically relevant nitrogen-containing heterocycles, are quantitatively ranked based on the results of intermolecular hydrogen isotope exchange competition reactions using two iridium complexes: [Ir(COD)(IMes)(PPh3)][BArF24] and [IrCl(COD)(IMes)]. The directing group power scales that have been constructed from these data reveal a wide range of reactivity covering four orders of magnitude. Intramolecular competition experiments have demonstrated that the obtained reactivity scale provides accurate predictions of regioselectivity within molecules with multiple competing directing groups. This work contributes to our understanding and control of regioselectivity in metal-catalysed C-H activation reactions

    Quantitative prediction of selectivity in iridium-catalysed hydrogen isotope exchange reactions

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    A pallette of commonly used directing groups, including various pharmaceutically relevant nitrogen-containing heterocycles, are quantitatively ranked based on the results of intermolecular hydrogen isotope exchange competition reactions using two iridium complexes: [Ir(COD)(IMes)(PPh3)][BArF24] and [IrCl(COD)(IMes)]. The directing group power scales that have been constructred from these data reveal a wide range of reactivity covering four orders of magnitude. Intramolecular competition experiments have demonstrated that the obtained reactivity scale provides accurate predictions of regioselectivity within molecules with multiple competing directing groups. This work contributes to our understanding and control of regioselectivity in metal-catalysed C-H activation reactions
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