1,081 research outputs found
Citizen Engagement through Design Space Exploration Integrating citizen knowledge and expert design in computational urban planning
A common understanding exists that citizens should become more involved in thedesign, planning, and governance of the city. Due to a lack of common platformsand difficulties in the meaningful integration of the participatory input, however,the tools and methods currently employed in citizen engagement are often illconnected to the design and governance tools and processes used by experts. Inthis paper we describe a Grasshopper and Rhino based approach, which allowsdesigners to share a subset of the design space formed by parametric designvariants with citizens via the online interface Beta.Speckle. In a user study weevaluated the usability of the tool as well as studied the design choices ofparticipants, which were found to be influenced by preferences for visual orderand underlying economic, social, and environmental values. For the futuredesign of participatory exercises, it was concluded that indicators relating tocitizens' values and preferences will allow for a more effective exploration of thedesign space and increase the meaningfulness of results
Geometric approach to condensates in holographic QCD
An SU(Nf)xSU(Nf) Yang-Mills theory on an extra-dimensional interval is
considered, with appropriate symmetry-breaking boundary conditions on the IR
brane. UV-brane to UV-brane correlators at high energies are compared with the
OPE of two-point functions of QCD quark currents. Condensates correspond to
departure from AdS of the (different) metrics felt by vector and axial
combinations, away from the UV brane. Their effect on hadronic observables is
studied: the extracted condensates agree with the signs and orders of magnitude
expected from QCD.Comment: References added: published version plus misprints correction
Pseudo scalar contributions to light-by-light correction of muon g-2 in AdS/QCD
We have performed a holographic calculation of the hadronic contributions to
the anomalous magnetic moment of the muon, using the gauge/gravity duality. We
study a model of holographic QCD in the five dimensional AdS background with a
hard-wall cutoff. Both 5D SU(2) and U(3) flavor gauge symmetries are considered
for the neutral pion, eta and eta' contributions to the hadronic corrections.
We find the total light-by-light contributions of pseudo scalars to the muon
anomalous magnetic moment, a_mu=10.7 x 10^(-10), which is consistent with
previous estimates, based on other approaches.Comment: v3. 13 pages, 6 figures, slightly expanded and reorganized for
clarit
Produção de (in)visibilidades: mulheres negras e políticas públicas de saúde
As mulheres negras estão em um lugar desfavorecido na sociedade, expostas a diferentes tipos de violência, incluindo o que diz respeito ao acesso à saúde. Partindo deste pressuposto, realizou-se uma análise das políticas públicas de saúde voltadas para as mulheres negras, visando compreender de que forma busca-se dar conta das demandas especificas dessa população. Como metodologia, analisaram-se três documentos elaborados pelo Ministério da Saúde, onde se observou o contexto em que as palavras “mulheres negras”, “mulheres brancas”, “população negra”, “raça” e “cor”, se inserem. Problematizou-se, a partir dos estudos culturais, sobre se as políticas públicas de saúde estão produzindo visibilidade ou invisibilidade em relação às mulheres negras, partindo do entendimento de que, quando um determinado grupo é mais vulnerável em relação aos outros, não nomeá-lo tende a ser mais uma forma de exclusão. Através da análise dos documentos, elencaram-se duas categorias de análise, onde, na primeira, buscou-se discutir sobre identidade, diferença e branquitude, visto que a identidade branca, nos documentos, permanece invisível. Após, reflete-se sobre a relação da cor com o conceito de vulnerabilidade social
Chiral symmetry breaking from five dimensional spaces
Based on the AdS/CFT correspondence we study the breaking of the chiral
symmetry in QCD using a simple five dimensional model. The model gives definite
predictions for the spectrum of vector mesons, their decay constants and
interactions as a function of one parameter related to the quark condensate. We
calculate the coefficients of the low-energy QCD chiral lagrangian, as
well as other physical quantities for the pions. All the predictions are shown
to be in good agreement with the experimental data. We also show that they are
robust under modifications of the 5D metric in the IR, and that some of them
arise as a consequence of the higher-dimensional gauge symmetry. For example,
at the tree-level, we find ,
and BR(.Comment: 20 pages, 5 figure
Spin-1 Correlators at Large NC: Matching OPE and Resonance Theory up to O(alpha_s)
The relation between the quark-gluon description of QCD and the hadronic
picture is studied up to order alpha_s. The analysis of the spin-1 correlators
is developed within the large NC framework. Both representations are shown to
be equivalent in the euclidean domain, where the Operator Product Expansion is
valid. By considering different models for the hadronic spectrum at high
energies, one is able to recover the alpha_s running in the correlators, to fix
the rho(770) and a1(1260) couplings, and to produce a prediction for the values
of the condensates. The Operator Product Expansion is improved by the large NC
resonance theory, extending its range of validity. Dispersion relations are
employed in order to study the minkowskian region and some convenient sum
rules, specially sensitive to the resonance structure of QCD, are worked out. A
first experimental estimate of these sum rules allows a cross-check of former
determinations of the QCD parameters and helps to discern and to discard some
of the considered hadronical models. Finally, the truncated resonance theory
and the Minimal Hadronical Approximation arise as a natural approach to the
full resonance theory, not as a model.Comment: 36 pages, 19 figures. Minor changes (added reference,...). Paper as
finally appeared in pres
Epidemiological associations between brachycephaly and upper respiratory tract disorders in dogs attending veterinary practices in England
Background: Brachycephalic dog breeds are increasingly common. Canine brachycephaly has been associated with upper respiratory tract (URT) disorders but reliable prevalence data remain lacking. Using primary-care veterinary clinical data, this study aimed to report the prevalence and breed-type risk factors for URT disorders in dogs. Results: The sampling frame included 170,812 dogs attending 96 primary-care veterinary clinics participating within the VetCompass Programme. Two hundred dogs were randomly selected from each of three extreme brachycephalic breed types (Bulldog, French Bulldog and Pug) and three common small-to medium sized breed types (moderate brachycephalic: Yorkshire Terrier and non-brachycephalic: Border Terrier and West Highland White Terrier). Information on all URT disorders recorded was extracted from individual patient records. Disorder prevalence was compared between groups using the chi-squared test or Fisher’s test, as appropriate. Risk factor analysis used multivariable logistic regression modelling. During the study, 83 (6.9 %) study dogs died. Extreme brachycephalic dogs (median longevity: 8.6 years, IQR: 2.4-10.8) were significantly younger at death than the moderate and non-brachycephalic group of dogs (median 12.7 years, IQR 11.1-15.0) (P \u3c 0.001). A higher proportion of deaths in extreme brachycephalic breed types were associated with URT disorders (4/24 deaths, 16.7 %) compared with the moderate and non-brachycephalic group (0/59 deaths, 0.0 %) (P = 0.001). The prevalence of having at least one URT disorder in the extreme brachycephalic group was higher (22.0 %, 95 % confidence interval (CI): 18.0-26.0) than in the moderate and non-brachycephalic group (9.7 %, 95 % CI: 7.1-12.3, P \u3c 0.001). The prevalence of URT disorders varied significantly by breed type: Bulldogs 19.5 %, French Bulldogs 20.0 %, Pugs 26.5 %, Border Terriers 9.0 %, West Highland White Terriers 7.0 % and Yorkshire Terriers 13.0 % (P \u3c 0.001). After accounting for the effects of age, bodyweight, sex, neutering and insurance, extreme brachycephalic dogs had 3.5 times (95 % CI: 2.4-5.0, P \u3c 0.001) the odds of at least one URT disorder compared with the moderate and non-brachycephalic group. Conclusions: In summary, this study reports that URT disorders are commonly diagnosed in Bulldog, French Bulldog, Pug, Border Terrier, WHWT and Yorkshire Terrier dogs attending primary-care veterinary practices in England. The three extreme brachycephalic breed types (Bulldog, French Bulldog and Pug) were relatively short-lived and predisposed to URT disorders compared with three other small-to-medium size breed types that are commonly owned (moderate brachycephalic Yorkshire Terrier and non-brachycephalic: Border Terrier and WHWT). Conclusions: In summary, this study reports that URT disorders are commonly diagnosed in Bulldog, French Bulldog, Pug, Border Terrier, WHWT and Yorkshire Terrier dogs attending primary-care veterinary practices in England. The three extreme brachycephalic breed types (Bulldog, French Bulldog and Pug) were relatively short-lived and predisposed to URT disorders compared with three other small-to-medium size breed types that are commonly owned (moderate brachycephalic Yorkshire Terrier and non-brachycephalic: Border Terrier and WHWT)
Genetic Engineering of Dictyostelium discoideum Cells Based on Selection and Growth on Bacteria
Dictyostelium discoideum is an intriguing model organism for the study of cell differentiation processes during development, cell signaling, and other important cellular biology questions. The technologies available to genetically manipulate Dictyostelium cells are well-developed. Transfections can be performed using different selectable markers and marker re-cycling, including homologous recombination and insertional mutagenesis. This is supported by a well-annotated genome. However, these approaches are optimized for axenic cell lines growing in liquid cultures and are difficult to apply to non-axenic wild-type cells, which feed only on bacteria. The mutations that are present in axenic strains disturb Ras signaling, causing excessive macropinocytosis required for feeding, and impair cell migration, which confounds the interpretation of signal transduction and chemotaxis experiments in those strains. Earlier attempts to genetically manipulate non-axenic cells have lacked efficiency and required complex experimental procedures. We have developed a simple transfection protocol that, for the first time, overcomes these limitations. Those series of large improvements to Dictyostelium molecular genetics allow wild-type cells to be manipulated as easily as standard laboratory strains. In addition to the advantages for studying uncorrupted signaling and motility processes, mutants that disrupt macropinocytosis-based growth can now be readily isolated. Furthermore, the entire transfection workflow is greatly accelerated, with recombinant cells that can be generated in days rather than weeks. Another advantage is that molecular genetics can further be performed with freshly isolated wild-type Dictyostelium samples from the environment. This can help to extend the scope of approaches used in these research areas
Vector-axial vector correlators in weak electric field and the holographic dynamics of the chiral condensate
The transverse part of the vector-axial vector flavor current correlator in
the presence of weak external electric field is studied using holography. The
correlator is calculated using a bottom-up model arxiv:1003.2377 {proposed
recently}, that includes the non-linear dynamics of the chiral condensate. It
is shown that for low momenta the result agrees with the relation proposed by
arXiv:1010.0718 {Son and Yamamoto} motivated by a simpler holographic model.
For large Euclidean momenta however, the two results diverge. In the process,
the difference of the vector and axial vector two point functions is also
calculated. At large Euclidean momenta it is found that the first
non-perturbative contribution, decreases as as expected from QCD.Comment: 17 pages, 5 figures, typos correcte
Weinberg like sum rules revisited
The generalized Weinberg sum rules containing the difference of isovector
vector and axial-vector spectral functions saturated by both finite and
infinite number of narrow resonances are considered. We summarize the status of
these sum rules and analyze their overall agreement with phenomenological
Lagrangians, low-energy relations, parity doubling, hadron string models, and
experimental data.Comment: 31 pages, noticed misprints are corrected, references are added, and
other minor corrections are mad
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