144 research outputs found
Changing the Landscape: Toward Equitable Programming Highlighting Choral Works by Women Composers
Changing the Landscape advocates for increased programming of choral compositions by women composers. Progress toward equitable programming is being realized especially for twenty-first century women composers; however, when surveying which pieces are selected within major genres of the choral canon, works by men are represented disproportionately. It is my view that this gap perpetuates not for lack of feminist research or artistic output, but for lack of an established tradition and lack of exposure (e.g., choral literature texts, choral conference concert programming, reading sessions). Conductors have more access than ever before to a myriad of high quality choral works by women in every genre performed in concert. This document analyzes choral works for eight varied genres and highlights the composer as a guide for conductors who feel compelled, as I do, to do their part in lessening this disparity. The compositions I use as exemplars are âBaciai per aver vitaâ from Ghirlanda de madrigali a quatro voci (1593) by Vittoria Aleotti and for which I include a new performance edition, âAbendfeier in Venedigâ from Drei Gemischte ChĂśre (1848) by Clara Schumann, âPeace I Leave with Youâ from Three Choral Responses, Op. 8 (1891) by Amy Beach, âDaniel, Daniel, Servant of the Lordâ (1953) arranged by Undine Smith Moore, âThe Crucifixionâ from Simon Bore the Cross (1964) by Margaret Bonds, âBenedictusâ from amass (2007) by Jocelyn Hagen, âRing Out, Ye Bells!â (2013) by Dale Trumbore, âGoinâ Across the Mountainâ (2016) by Ellen Gilson Voth, and âEven After All This Time...â (2016) by Reena Esmail. I append interviews with Jocelyn Hagen, Dale Trumbore and Ellen Gilson Voth
Coronal lines and the importance of deep core-valence correlation in Ag-like ions
We report on large-scale and critically evaluated {\em ab initio} MCDHF
calculations of the wavelength of the "coronal", M1 transition $4f\
^2\mathrm{F}_{5/2}^o-^2\mathrm{F}_{7/2}^oZ
\ge 62^{23+}^{27+}Z = 5094n=3$ shell in the theoretical model is emphasized. The
results show close to spectroscopic accuracy for these forbidden lines.Comment: 10 pages, 5 figures, 3 table
The effect of an external magnetic field on the determination of E1M1 two-photon decay rates in Be-like ions
In this work we report on ab initio theoretical results for the magnetic
field induced 2s2p ^3P_0 - 2s^2 ^1S_0 E1 transition for ions in the beryllium
isoelectronic sequence between Z=5 and 92. It has been proposed that the rate
of the E1M1 two-photon transition 2s2p ^3P_0 - 2s^2 ^1S_0 can be extracted from
the lifetime of the ^3P_0 state in Be-like ions with zero nuclear spin by
employing resonant recombination in a storage-ring. This experimental approach
involves a perturbing external magnetic field. The effect of this field needs
to be evaluated in order to properly extract the two-photon rate from the
measured decay curves. The magnetic field induced transition rates are
carefully evaluated and it is shown that, with a typical storage-ring field
strength, it is dominant or of the same order as the E1M1 rate for low- and
mid-Z ions. Results for several field strengths and ions are presented and we
also give a simple Z-dependent formula for the rate. We estimate the
uncertainties of our model to be within 5% for low- and mid-Z ions, and
slightly larger for more highly charged ions. Furthermore we evaluate the
importance of including both perturber states, ^3P_1 and ^1P_1, and it is shown
that excluding the influence of the ^1P_1 perturber overestimates the rate by
up to 26% for the mid-Z ions.Comment: 21 pages, 5 figure
A first spectroscopic measurement of the magnetic field strength for an active region of the solar corona
For all involved in astronomy, the importance of monitoring and determining
astrophysical magnetic field strengths is clear. It is also a well-known fact
that the corona magnetic fields play an important part in the origin of solar
flares and the variations of space weather. However, after many years of solar
corona studies, there is still no direct and continuous way to measure and
monitor the solar magnetic field strength. We will here present a scheme which
allows such a measurement, based on a careful study of an exotic class of
atomic transitions known as magnetic induced transitions in Fe. In this
contribution we present a first application of this methodology and determine a
value of the coronal field strength using the spectroscopic data from HINODE
Attentional Load and Sensory Competition in Human Vision: Modulation of fMRI Responses by Load at Fixation during Task-irrelevant Stimulation in the Peripheral Visual Field
Perceptual suppression of distractors may depend on both endogenous and exogenous factors, such as attentional load of the current task and sensory competition among simultaneous stimuli, respectively. We used functional magnetic resonance imaging (fMRI) to compare these two types of attentional effects and examine how they may interact in the human brain. We varied the attentional load of a visual monitoring task performed on a rapid stream at central fixation without altering the central stimuli themselves, while measuring the impact on fMRI responses to task-irrelevant peripheral checkerboards presented either unilaterally or bilaterally. Activations in visual cortex for irrelevant peripheral stimulation decreased with increasing attentional load at fixation. This relative decrease was present even in V1, but became larger for successive visual areas through to V4. Decreases in activation for contralateral peripheral checkerboards due to higher central load were more pronounced within retinotopic cortex corresponding to âinner' peripheral locations relatively near the central targets than for more eccentric âouter' locations, demonstrating a predominant suppression of nearby surround rather than strict âtunnel vision' during higher task load at central fixation. Contralateral activations for peripheral stimulation in one hemifield were reduced by competition with concurrent stimulation in the other hemifield only in inferior parietal cortex, not in retinotopic areas of occipital visual cortex. In addition, central attentional load interacted with competition due to bilateral versus unilateral peripheral stimuli specifically in posterior parietal and fusiform regions. These results reveal that task-dependent attentional load, and interhemifield stimulus-competition, can produce distinct influences on the neural responses to peripheral visual stimuli within the human visual system. These distinct mechanisms in selective visual processing may be integrated within posterior parietal areas, rather than earlier occipital corte
Assessing the cost of global biodiversity and conservation knowledge
Knowledge products comprise assessments of authoritative information supported by stan-dards, governance, quality control, data, tools, and capacity building mechanisms. Considerable resources are dedicated to developing and maintaining knowledge productsfor biodiversity conservation, and they are widely used to inform policy and advise decisionmakers and practitioners. However, the financial cost of delivering this information is largelyundocumented. We evaluated the costs and funding sources for developing and maintain-ing four global biodiversity and conservation knowledge products: The IUCN Red List ofThreatened Species, the IUCN Red List of Ecosystems, Protected Planet, and the WorldDatabase of Key Biodiversity Areas. These are secondary data sets, built on primary datacollected by extensive networks of expert contributors worldwide. We estimate that US116â204 million), plus 293 person-years of volunteer time (range: 278â308 person-years) valued at US12â16 million), were invested inthese four knowledge products between 1979 and 2013. More than half of this financingwas provided through philanthropy, and nearly three-quarters was spent on personnelcosts. The estimated annual cost of maintaining data and platforms for three of these knowl-edge products (excluding the IUCN Red List of Ecosystems for which annual costs were notpossible to estimate for 2013) is US6.2â6.7 million). We esti-mated that an additional US12 million. These costs are much lower than those tomaintain many other, similarly important, global knowledge products. Ensuring that biodi-versity and conservation knowledge products are sufficiently up to date, comprehensiveand accurate is fundamental to inform decision-making for biodiversity conservation andsustainable development. Thus, the development and implementation of plans for sustain-able long-term financing for them is critical
Sanitation and Health
As one article in a four-part PLoS Medicine series on water and sanitation, David Trouba and colleagues discuss the importance of improved sanitation to health and the role that the health sector can play in its advocacy
Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model
Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 Âľg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures
Has land use pushed terrestrial biodiversity beyond the planetary boundary? A global assessment
Land use and related pressures have reduced local terrestrial biodiversity, but it is unclear how the magnitude of change relates to the recently proposed planetary boundary (âsafe limitâ). We estimate that land use and related pressures have already reduced local biodiversity intactnessâthe average proportion of natural biodiversity remaining in local ecosystemsâbeyond its recently proposed planetary boundary across 58.1% of the worldâs land surface, where 71.4% of the human population live. Biodiversity intactness within most biomes (especially grassland biomes), most biodiversity hotspots, and even some wilderness areas is inferred to be beyond the boundary. Such widespread transgression of safe limits suggests that biodiversity loss, if unchecked, will undermine efforts toward long-term sustainable development
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