1,099 research outputs found

    The community college presidency in the new millennium: gender differences in leadership preparation

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    Community colleges educate nearly half of all students in higher education. With the majority of presidents, upper-level administrators and faculty nearing retirement, community colleges are in the midst of a serious leadership shortage, and a potential leadership crisis. In addition, the community college presidency is changing nationwide to meet 21st century challenges of higher education, requiring a different set of traits, skills, and abilities for effective leadership. Given the complex, changing role of community colleges and their leaders and dwindling numbers of qualified candidates to meet the need for new leaders, the purpose of this study was to develop a profile of the characteristics and competencies of current male and female community college presidents and examine whether gender differences exists in the preparation of transformational leadership skills as delineated by the American Association of Community Colleges\u27 (AACC) Competencies for Community College Leaders.;A survey was administered to a sample of current presidents from public, non-profit community colleges to draw inferences based on background characteristics, professional development, competencies, and leadership skills of the total population of individuals serving as community college presidents. Because this study intended to contribute to an existing body of knowledge, an original survey instrument was created so that new data could be collected as it relates to background characteristics, educational and leadership preparation, career pathways, faculty, staff, and public relations, and perceptions about the AACC Competencies for Community College Leaders (2005).;Descriptive and inferential statistics were used to analyze the data. By looking through the lens of a female researcher, this study adds to the limited research on gender differences in community college leadership from a woman\u27s perspective. There were statistically significant gender differences in all of the variables addressing mentor-protege relationships. There was a surprising result of this study; yet, with consideration, males and females think differently, act differently, communicate differently and, thus, learn and lead differently. Thus, one gender is not superior or inferior to the other; rather, they are different. Future research should be conducted to ascertain how this uniqueness can be maximized and potential barriers eliminated to prepare new community college presidents in the new millennium

    Detection of water molecules on the radical transfer pathway of ribonucleotide reductase by 17O electron–nuclear double resonance spectroscopy

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    The role of water in biological proton-coupled electron transfer (PCET) is emerging as a key for understanding mechanistic details at atomic resolution. Here we demonstrate 17O high-frequency electron–nuclear double resonance (ENDOR) in conjunction with H217O-labeled protein buffer to establish the presence of ordered water molecules at three radical intermediates in an active enzyme complex, the α2β2E. coli ribonucleotide reductase. Our data give unambiguous evidence that all three, individually trapped, intermediates are hyperfine coupled to one water molecule with Tyr-O···17O distances in the range 2.8–3.1 Å. The availability of this structural information will allow for quantitative models of PCET in this prototype enzyme. The results also provide a spectroscopic signature for water H-bonded to a tyrosyl radical

    Inactivation of pollen and other effects of genome-plastome incompatibility in Oenothera

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    A series of strains of the homozygous species Oenothera grandiflora (characterized by the genome BB and plastome III) were combined with plastome IV from O. parviflora (BC-IV) by means of appropriate crosses. An incompatibility between genome B and plastome IV is expressed in the haplo- and diplophase: (1) B-IV pollen, though normally developed, is largely inactive. The extent of the inactivation varies between different strains and shows a seasonal fluctuation as determined by seed set in outcrossing and selfing experiments. (2) In most of the strains lethality of BB-IV embryos is the rule, leading to empty seeds. This can be ameliorated by including another plastome in the zygotes and developing embryos on account of the biparental plastid transmission in Oenothera. It can best be demonstrated in crosses with a seed parent having normal green plastids of plastome IV and mutated chlorophyll deficient plastids from a different plastome in the pollen parent, leading to variegated progeny as well as a remainder of empty seeds. (3) In about one-half of the strains the BB-IV plants exhibit a temporary bleaching of the virescens type. The incompatibily between genome B and plastome IV does not support the earlier assumption that plastome IV is the ancestor of plastomes II, III, and V. Instead, a precursor plastome is postulated from which plastomes II, III, and IV are descended. While plastome I can be derived from II, only plastome V can be descended from plastome IV.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41640/1/606_2004_Article_BF00984370.pd

    Beaver Research in the Uvs Nuur Region

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    In 1985, 1988, and 2002 Castor fiber birulai was introduced to the Tes Gol of the Uvs Nuur basin in North-western Mongolia. The beavers migrated through the Republic of Tyva and settled in the middle part of Tes Gol near the Tyvinian-Mongolian border. About 10 colonies were recorded in this region in 2002. Strict protection of Castor fiber birulai has to be ensured in Mongolia and the Republic of Tyva in future

    An analysis of teachers’ instructions and feedback at a contemporary dance university

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    Background: Given the demands posed by excessive practice quantities in modern dance, physical and mental health can be compromised. Therefore, there is a need to consider how quality of practice may be improved and possibly even reduce training times. Sports literature has shown that instructions and feedback given by coaches can have an effect on the quality of training and influence self-regulation and the performance of athletes. However, currently little is known about the use of instructions and feedback by dance teachers. The aim of the current study was, therefore, to examine the type of instructions and feedback given by dance teachers during various dance classes. Methods: A total of six dance teachers participated in this study. Video and audio recordings were made of six dance classes and two rehearsals at a contemporary dance university. The dance teacher’s coaching behavior was analyzed using the modified Coach Analysis and Intervention System (CAIS). Additionally, feedback and instructions were also examined in terms of their corresponding focus of attention. Absolute numbers, as well as times per minute (TPM) rates were calculated for each behavior before, during, and after an exercise. Absolute numbers were also used to calculate ratios of positive-negative feedback and open-closed questions. Results: Most feedback comments were given after an exercise (472 out of 986 total observed behaviors). Improvisation had the highest positive-negative feedback ratio (29) and open-closed questions ratio (1.56). Out of the focus of attention comments, internal focus of attention comments were used most frequently (572 out of 900). Discussion/conclusion: The results make clear that there is a large variability in instructions and feedback over teachers and classes. Overall, there is room for improvement toward a higher positive-negative feedback ratio, a higher open-closed question ratio and producing more comments eliciting an external focus of attention.</p

    19F Electron-nuclear double resonance reveals interaction between redox-active tyrosines across the α/β interface of E. coli ribonucleotide reductase

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    Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, thereby playing a key role in DNA replication and repair. Escherichia coli class Ia RNR is an α2β2 enzyme complex that uses a reversible multistep radical transfer (RT) over 32 Å across its two subunits, α and β, to initiate, using its metallo-cofactor in β2, nucleotide reduction in α2. Each step is proposed to involve a distinct proton-coupled electron-transfer (PCET) process. An unresolved step is the RT involving Y356(β) and Y731(α) across the α/β interface. Using 2,3,5-F3Y122-β2 with 3,5-F2Y731-α2, GDP (substrate) and TTP (allosteric effector), a Y356• intermediate was trapped and its identity was verified by 263 GHz electron paramagnetic resonance (EPR) and 34 GHz pulse electron–electron double resonance spectroscopies. 94 GHz 19F electron-nuclear double resonance spectroscopy allowed measuring the interspin distances between Y356• and the 19F nuclei of 3,5-F2Y731 in this RNR mutant. Similar experiments with the double mutant E52Q/F3Y122-β2 were carried out for comparison to the recently published cryo-EM structure of a holo RNR complex. For both mutant combinations, the distance measurements reveal two conformations of 3,5-F2Y731. Remarkably, one conformation is consistent with 3,5-F2Y731 within the H-bond distance to Y356•, whereas the second one is consistent with the conformation observed in the cryo-EM structure. The observations unexpectedly suggest the possibility of a colinear PCET, in which electron and proton are transferred from the same donor to the same acceptor between Y356 and Y731. The results highlight the important role of state-of-the-art EPR spectroscopy to decipher this mechanism

    Determination of the light curve of the Rosetta target asteroid (2867) Steins by the OSIRIS cameras onboard Rosetta

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    7 pp.-- Article published by EDP Sciences and available at http://www.aanda.org or http://dx.doi.org/10.1051/0004-6361:20066694.-- Table 2 is only available in electronic form at http://www.aanda.org.[Context] In 2004 asteroid (2867) Steins has been selected as a flyby target for the Rosetta mission. Determination of its spin period and the orientation of its rotation axis are essential for optimization of the flyby planning.[Aims] Measurement of the rotation period and light curve of asteroid (2867) Steins at a phase angle larger than achievable from ground based observations, providing a high quality data set to contribute to the determination of the orientation of the spin axis and of the pole direction.[Methods] On March 11, 2006, asteroid (2867) Steins was observed continuously for 24 h with the scientific camera system OSIRIS onboard Rosetta. The phase angle was 41.7 degrees, larger than the maximum phase angle of 30 degrees when Steins is observed from Earth. A total of 238 images, covering four rotation periods without interruption, were acquired.[Results] The light curve of (2867) Steins is double peaked with an amplitude of ≈0.23 mag. The rotation period is 6.052 ± 0.007 h. The continuous observations over four rotation periods exclude the possibility of period ambiguities. There is no indication of deviation from a principal axis rotation state. Assuming a slope parameter of G = 0.15, the absolute visual magnitude of Steins is 13.05 ± 0.03.The OSIRIS imaging system on board Rosetta is managed by the Max-Planck-Intitute for Solar System Research in Katlenburg-Lindau (Germany), thanks to an International collaboration between Germany, France, Italy, Spain, and Sweden. The support of the national funding agencies DLR, CNES, ASI, MEC, and SNSB is gratefully acknowledged. We acknowledge the work of the Rosetta Science Operations Centre at ESA/ESTEC and of the Rosetta Mission Operations Centre at ESA/ESOC who made these observations possible on short notation and operated the spacecraft. S.C.L. acknowledges support from the Leverhulme Trust. This research made use of JPL’s online ephemeris generator (HORIZONS).Peer reviewe

    An analysis of teachers’ instructions and feedback at a contemporary dance university

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    BackgroundGiven the demands posed by excessive practice quantities in modern dance, physical and mental health can be compromised. Therefore, there is a need to consider how quality of practice may be improved and possibly even reduce training times. Sports literature has shown that instructions and feedback given by coaches can have an effect on the quality of training and influence self-regulation and the performance of athletes. However, currently little is known about the use of instructions and feedback by dance teachers. The aim of the current study was, therefore, to examine the type of instructions and feedback given by dance teachers during various dance classes.MethodsA total of six dance teachers participated in this study. Video and audio recordings were made of six dance classes and two rehearsals at a contemporary dance university. The dance teacher’s coaching behavior was analyzed using the modified Coach Analysis and Intervention System (CAIS). Additionally, feedback and instructions were also examined in terms of their corresponding focus of attention. Absolute numbers, as well as times per minute (TPM) rates were calculated for each behavior before, during, and after an exercise. Absolute numbers were also used to calculate ratios of positive-negative feedback and open-closed questions.ResultsMost feedback comments were given after an exercise (472 out of 986 total observed behaviors). Improvisation had the highest positive-negative feedback ratio (29) and open-closed questions ratio (1.56). Out of the focus of attention comments, internal focus of attention comments were used most frequently (572 out of 900).Discussion/conclusionThe results make clear that there is a large variability in instructions and feedback over teachers and classes. Overall, there is room for improvement toward a higher positive-negative feedback ratio, a higher open-closed question ratio and producing more comments eliciting an external focus of attention

    Phase transition in the collisionless regime for wave-particle interaction

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    Gibbs statistical mechanics is derived for the Hamiltonian system coupling self-consistently a wave to N particles. This identifies Landau damping with a regime where a second order phase transition occurs. For nonequilibrium initial data with warm particles, a critical initial wave intensity is found: above it, thermodynamics predicts a finite wave amplitude in the limit of infinite N; below it, the equilibrium amplitude vanishes. Simulations support these predictions providing new insight on the long-time nonlinear fate of the wave due to Landau damping in plasmas.Comment: 12 pages (RevTeX), 2 figures (PostScript
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