1,641 research outputs found
Preparando líderes para problemas wicked? Como os padrões revisados tratam da justiça e da justiça
The past 20 years have seen a shift in school leaders’ work that can best be characterized by an increasing complexity in expectations and greater demands for accountabilities. Educational leadership preparation programs and professional associations responded to these shifts, in part, with the development and proliferation of standards for both pre-service (ELCC and NELP) and practicing (ISLLC and PSEL) educational leaders. Both sets of standards have undergone significant revision in the last five years, largely in response to shifts in the work required of school administrators in today’s 21st century schools. However, what remains an open empirical question is whether the leadership standards are robust and pragmatic enough to tackle the various educational issues that school leaders face. In other words, do various school leadership standards prepare and assess school administrators appropriately? Using the wicked problems framework, we examine the extent to which the revised PSEL and NELP standards capture the challenging work required for school leaders to act as inclusive leaders and “equity-oriented change agents” (Maxwell, Locke, Scheurich, 2013, p. 1). We utilize qualitative content analysis (Weber, 1990) to analyze the content of the leadership standards, focusing in particular on the ways those standards represent evolving conceptions of equity and justice. These analyses suggest that although both sets of standards have changed considerably from their predecessors, they may not go far enough to help leaders determine how to implement the proper administrative authority to solve complex issues. This is particularly true as it relates to the persistent, wicked equity problems facing our schools.En los últimos 20 años, el trabajo del trabajo de los líderes escolares ha aumentado la complejidad en las expectativas y las mayores demandas de responsabilidad. Los programas de preparación para el liderazgo educativo y las asociaciones profesionales respondieron a estos cambios, en parte, con el desarrollo y la proliferación de estándares para todo tipo de líderes educativos en las escuelas actuales del siglo XXI. ¿Pero estos estándares preparan y evalúan a los administradores escolares de manera apropiada? Utilizando el marco de los problemas wicked, examinamos hasta qué punto los estándares revisados capturan el trabajo desafiante requerido para que los líderes escolares actúen como inclusivos y orientados a la equidad. Analizamos el contenido de los estándares de liderazgo y nos enfocamos en las formas en que esos estándares representan concepciones cambiantes de equidad y justicia. Estos análisis sugieren que, aunque los estándares han cambiado, es posible que no lleguen lo suficientemente lejos como para ayudar a los líderes a resolver problemas complejos, en particular los problemas de equidad persistentes y wicked en las escuelas de hoy.Nos últimos 20 anos, o trabalho dos líderes das escolas aumentou a complexidade das expectativas e as demandas por responsabilidades. Os programas de preparação para a liderança educacional e associações profissionais responderam a essas mudanças, em parte, com o desenvolvimento e a proliferação de padrões para todos os tipos de líderes educacionais nas escolas de hoje no século XXI. Mas esses padrões preparam e avaliam os administradores da escola adequadamente? Usando a estrutura de problemas wicked, examinamos até que ponto os padrões revisados capturam o trabalho desafiador necessário para os líderes das escolas agirem de maneira inclusiva e orientada para a equidade. Analisamos o conteúdo dos padrões de liderança e focamos nas maneiras pelas quais esses padrões representam concepções em mudança de justiça e justiça. Essas análises sugerem que, embora os padrões tenham mudado, eles podem não ir longe o suficiente para ajudar os líderes a resolver problemas complexos, particularmente problemas persistentes e wickedde equidade nas escolas de hoje.
5-HT2A receptor signalling through phospholipase D1 associated with its C-terminal tail
The 5-HT2AR (5-hydroxytryptamine-2A receptor) is a GPCR (G-protein-coupled receptor) that is implicated in the actions of hallucinogens and represents a major target of atypical antipsychotic agents. In addition to its classical signalling though PLC (phospholipase C), the receptor can activate several other pathways, including ARF (ADP-ribosylation factor)-dependent activation of PLD (phospholipase D), which appears to be achieved through a mechanism independent of heterotrimeric G-proteins. In the present study we show that wild-type and inactive constructs of PLD1 (but not PLD2) respectively facilitate and inhibit ARF-dependent PLD signalling by the 5-HT2AR. Furthermore we demonstrate that PLD1 specifically co-immunoprecipitates with the receptor and binds to a distal site in GST (glutathione transferase) fusion protein constructs of its C-terminal tail which is distinct from the ARF-interaction site, thereby suggesting the existence of a functional ARF-PLD signalling complex directly associated with this receptor. This reveals the spatial co-ordination of an important GPCR, transducer and effector into a physical complex that is likely to reinforce the impact of receptor activation on a heterotrimeric G-protein-independent signalling pathway. Signalling of this receptor through such non-canonical pathways may be important to its role in particular disorders
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Precision measurement of violation in decays
The time-dependent asymmetry in decays is
measured using collision data, corresponding to an integrated luminosity
of fb, collected with the LHCb detector at centre-of-mass energies
of and TeV. In a sample of 96 000 decays, the
-violating phase is measured, as well as the decay widths
and of the light and heavy mass eigenstates of the
system. The values obtained are rad, ps, andps, where the first uncertainty is
statistical and the second systematic. These are the most precise single
measurements of those quantities to date. A combined analysis with decays gives rad. All
measurements are in agreement with the Standard Model predictions. For the
first time the phase is measured independently for each polarisation
state of the system and shows no evidence for polarisation
dependence.Comment: 6 figure
Observation of resonances consistent with pentaquark states in decays
Observations of exotic structures in the channel, that we refer to
as pentaquark-charmonium states, in decays are
presented. The data sample corresponds to an integrated luminosity of 3/fb
acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude
analysis is performed on the three-body final-state that reproduces the
two-body mass and angular distributions. To obtain a satisfactory fit of the
structures seen in the mass spectrum, it is necessary to include two
Breit-Wigner amplitudes that each describe a resonant state. The significance
of each of these resonances is more than 9 standard deviations. One has a mass
of MeV and a width of MeV, while the second
is narrower, with a mass of MeV and a width of MeV. The preferred assignments are of opposite parity, with one
state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after
referee's comments, now 19 figure
Search for the rare decays and
A search for the rare decay of a or meson into the final
state is performed, using data collected by the LHCb experiment
in collisions at and TeV, corresponding to an integrated
luminosity of 3 fb. The observed number of signal candidates is
consistent with a background-only hypothesis. Branching fraction values larger
than for the decay mode are
excluded at 90% confidence level. For the decay
mode, branching fraction values larger than are excluded at
90% confidence level, this is the first branching fraction limit for this
decay.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-044.htm
First observation and amplitude analysis of the decay
The decay is observed in a data sample
corresponding to of collision data recorded by the LHCb
experiment during 2011 and 2012. Its branching fraction is measured to be
where the uncertainties are statistical, systematic and from
the branching fraction of the normalisation channel , respectively. An amplitude analysis of the resonant
structure of the decay is used to measure the
contributions from quasi-two-body ,
, and
decays, as well as from nonresonant sources. The
resonance is determined to have spin~1.Comment: 39 pages, 10 figures, submitted to Phys. Rev. D. Updated following
erratum 10.1103/PhysRevD.93.11990
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Study of and decays and determination of the CKM angle
We report a study of the suppressed and favored
decays, where the neutral meson is detected
through its decays to the and CP-even and
final states. The measurement is carried out using a proton-proton
collision data sample collected by the LHCb experiment, corresponding to an
integrated luminosity of 3.0~fb. We observe the first significant
signals in the CP-even final states of the meson for both the suppressed
and favored modes, as well as
in the doubly Cabibbo-suppressed final state of the decay. Evidence for the ADS suppressed decay , with , is also presented. From the observed
yields in the , and their
charge conjugate decay modes, we measure the value of the weak phase to be
. This is one of the most precise
single-measurement determinations of to date.Comment: 22 pages, 9 figures; All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-020.htm
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