12 research outputs found
Double-copy towards supergravity inflation with -attractor models
Key to the simplicity of supergravity alpha-attractor models of inflation are
Volkov-Akulov fermions, often in the form of nilpotent superfields. Here we
explore the possibility of using the double-copy to construct theories of
Dirac-Born-Infeld-Volkov-Akulov (DBIVA) coupled to supergravity. A color-dual
bootstrap admits scattering amplitudes involving pions and vectors through
five-point tree-level order by order in mass-dimension, but requires the
introduction of a tr(F^3) operator. Gauge theories with this operator were
recently found to require a tower of higher-derivative operators to be
compatible with the duality between color and kinematics. Adjoint-type
double-copy construction at its most conservative seems to require the UV
completion of DBVIA + pure Poincare supergravity scattering amplitudes to a
family of theories involving DBVIA-like particles coupled to Weyl-Einstein
supergravity. We also point out an alternative solution to color-dual gauged
pions that allows adjoint double-copy without a tower of higher derivative
corrections but at the cost of exchange symmetry between scalars.Comment: 40 pages, 3 figures, 4 tables, ancillary data available at this url:
https://github.com/drjjmc/colorDualPion
Immunodetection of nmt55/p54(nrb) isoforms in human breast cancer
BACKGROUND: We previously identified and characterized a novel 55 kDa nuclear protein, termed nmt55/p54(nrb), whose expression was decreased in a subset of human breast tumors. The objective of this study was to determine if this reduced expression in human breast tumors was attributed to the regulation of mRNA transcription or the presence of altered forms of this protein. RESULTS: Northern blot analysis and ribonuclease protection assay indicated that nmt55/p54(nrb) mRNA is expressed at varying levels in estrogen receptor positive (ER+) and estrogen receptor negative (ER-) human breast tumors suggesting that reduced expression of nmt55/p54(nrb) protein in ER- tumors was not due to transcriptional regulation. To determine if multiple protein isoforms are expressed in breast cancer, we utilized Western blot and immunohistochemical analyses, which revealed the expression of an nmt55/p54(nrb) protein isoform in a subset of ER+ tumors. This subset of ER+ human breast tumors expressed an altered form of nmt55/p54(nrb) that was undetectable with an amino-terminal specific antibody suggesting that this isoform contains alterations or modifications within the amino terminal domain. CONCLUSIONS: Our study indicates that nmt55/p54(nrb) protein is post-transcriptionally regulated in human breast tumors leading to reduced expression in ER- tumors and the expression of an amino terminal altered isoform in a subset of ER+ tumors. The potential involvement of nmt55/p54(nrb) in RNA binding and pre-mRNA splicing may be important for normal cell growth and function; thus, loss or alteration of protein structure may contribute to tumor growth and progression
Rethinking Stormwater: Analysis Using the Hydrosocial Cycle
Water management and governance continues to rely on the scientific and engineering principles of the hydrologic cycle for decision-making on policies and infrastructure choices. This over-reliance on hydrologic-based, technocratic, command-and-control management and governance tends to discount and overlook the political, social, cultural, and economic factors that shape water-society relationships. This paper utilizes an alternative framework, the hydrosocial cycle, to analyze how water and society shape each other over time. In this paper, the hydrosocial framework is applied to stormwater management in the United States. Two hydrosocial case studies centered on rain and stormwater are investigated to highlight how stormwater management can benefit from a hydrosocial approach. The insights and implications from these case studies are then applied to stormwater management by formulating key questions that arise under the hydrosocial framework. These key questions are significant to progressing stormwater management to more sustainable, resilient, and equitable outcomes for environmental and public safety and health. This paper frames a conversation for incorporating the hydrosocial framework into stormwater management and demonstrates the need for an interdisciplinary approach to water management and governance issues
Rethinking Stormwater: Analysis Using the Hydrosocial Cycle
Water management and governance continues to rely on the scientific and engineering principles of the hydrologic cycle for decision-making on policies and infrastructure choices. This over-reliance on hydrologic-based, technocratic, command-and-control management and governance tends to discount and overlook the political, social, cultural, and economic factors that shape water-society relationships. This paper utilizes an alternative framework, the hydrosocial cycle, to analyze how water and society shape each other over time. In this paper, the hydrosocial framework is applied to stormwater management in the United States. Two hydrosocial case studies centered on rain and stormwater are investigated to highlight how stormwater management can benefit from a hydrosocial approach. The insights and implications from these case studies are then applied to stormwater management by formulating key questions that arise under the hydrosocial framework. These key questions are significant to progressing stormwater management to more sustainable, resilient, and equitable outcomes for environmental and public safety and health. This paper frames a conversation for incorporating the hydrosocial framework into stormwater management and demonstrates the need for an interdisciplinary approach to water management and governance issues.https://doi.org/10.3390/w1205127
The color-dual fate of N=4 supergravity
We conjecture that the massless gauge theory of Yang-Mills deformed by a
higher-derivative Tr(F^3) operator will not be tree-level color-dual without an
infinite number of additional counterterms. The requirement of color-dual
kinematics and consistent factorization between four- and five-points induces a
tower of increasingly higher-dimensional operators. We find through explicit
calculation that their amplitudes are consistent with the alpha' expansion of
those generated by the (DF)^2+YM theory, a known color-dual theory where the
Tr(F^2) term has been given a mass squared proportional to 1/alpha'.
Considering consistent double-copy construction as a physical principle would
suggest that a Tr(F^3)-based attempt at a color-dual resolution of the UV
divergence of N=4 supergravity may be able to tame the bad ultraviolet behavior
of the theory, but at the cost of field-theoretic locality.Comment: 6 pages, 1 figur
Double-copy towards supergravity inflation with α-attractor models
Abstract Key to the simplicity of supergravity α-attractor models of inflation are Volkov-Akulov fermions, often in the form of nilpotent superfields. Here we explore the possibility of using the double-copy to construct theories of Dirac-Born-Infeld-Volkov-Akulov (DBIVA) coupled to supergravity. A color-dual bootstrap admits scattering amplitudes involving pions and vectors through five-point tree-level order by order in mass-dimension, but requires the introduction of a Tr(F 3) operator. Gauge theories with this operator were recently found to require a tower of higher-derivative operators to be compatible with the duality between color and kinematics. Adjoint-type double-copy construction at its most conservative seems to require the UV completion of DBIVA + pure Poincaré supergravity scattering amplitudes to a family of theories involving DBIVA-like particles coupled to Weyl-Einstein supergravity. We also point out an alternative solution to color-dual gauged pions that allows adjoint double-copy without a tower of higher derivative corrections but at the cost of exchange symmetry between scalars
The color-dual fate of N=4 supergravity
We conjecture that the massless gauge theory of Yang-Mills deformed by a higher-derivative Tr(F^3) operator will not be tree-level color-dual without an infinite number of additional counterterms. The requirement of color-dual kinematics and consistent factorization between four- and five-points induces a tower of increasingly higher-dimensional operators. We find through explicit calculation that their amplitudes are consistent with the alpha' expansion of those generated by the (DF)^2+YM theory, a known color-dual theory where the Tr(F^2) term has been given a mass squared proportional to 1/alpha'. Considering consistent double-copy construction as a physical principle would suggest that a Tr(F^3)-based attempt at a color-dual resolution of the UV divergence of N=4 supergravity may be able to tame the bad ultraviolet behavior of the theory, but at the cost of field-theoretic locality
Computational Study of CO Reactivity with Nb3X Heteronuclear Clusters
© CSIRO 2008Density functional calculations were performed to determine the equilibrium structures, ionization potentials, and electron affinities of Nb3X clusters (X = Na, Al, Sc, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd). Pseudo-tetrahedral geometries were preferred for all Nb3X clusters except Nb3Cd. The equilibrium structures and binding energies of the associatively and dissociatively bound products of the Nb3X + CO reaction were calculated at the same level of theory. All clusters were found to thermodynamically dissociate CO. Only Nb3Al and Nb3Cd reduced the enthalpy of dissociation relative to Nb4, whereas all other heteroatoms increased it.Matthew A. Addicoat and Gregory F. Meth
Dosage, Intensity, and Frequency of Language Therapy for Aphasia: A Systematic Review-Based, Individual Participant Data Network Meta-Analysis
BACKGROUND AND PURPOSE: Optimizing speech and language therapy (SLT) regimens for maximal aphasia recovery is a clinical research priority. We examined associations between SLT intensity (hours/week), dosage (total hours), frequency (days/week), duration (weeks), delivery (face to face, computer supported, individual tailoring, and home practice), content, and language outcomes for people with aphasia. METHODS: Databases including MEDLINE and Embase were searched (inception to September 2015). Published, unpublished, and emerging trials including SLT and >= 10 individual participant data on aphasia, language outcomes, and time post-onset were selected. Patient-level data on stroke, language, SLT, and trial risk of bias were independently extracted. Outcome measurement scores were standardized. A statistical inferencing, one-stage, random effects, network meta-analysis approach filtered individual participant data into an optimal model examining SLT regimen for overall language, auditory comprehension, naming, and functional communication pre-post intervention gains, adjusting for a priori-defined covariates (age, sex, time poststroke, and baseline aphasia severity), reporting estimates of mean change scores (95% CI). RESULTS: Data from 959 individual participant data (25 trials) were included. Greatest gains in overall language and comprehension were associated with >20 to 50 hours SLT dosage (18.37 [10.58-26.16] Western Aphasia Battery-Aphasia Quotient; 5.23 [1.51-8.95] Aachen Aphasia Test-Token Test). Greatest clinical overall language, functional communication, and comprehension gains were associated with 2 to 4 and 9+ SLT hours/week. Greatest clinical gains were associated with frequent SLT for overall language, functional communication (3-5+ days/week), and comprehension (4-5 days/week). Evidence of comprehension gains was absent for SLT <= 20 hours, <3 hours/week, and <= 3 days/week. Mixed receptive-expressive therapy, functionally tailored, with prescribed home practice was associated with the greatest overall gains. Relative variance was <30%. Risk of trial bias was low to moderate; low for meta-biases. CONCLUSIONS: Greatest language recovery was associated with frequent, functionally tailored, receptive-expressive SLT, with prescribed home practice at a greater intensity and duration than reports of usual clinical services internationally. These exploratory findings suggest critical therapeutic ranges, informing hypothesis-testing trials and tailoring of clinical services. Registration: URL: ; Unique identifier: CRD42018110947.N