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We prove quantitative bounds for the inverse theorem for Gowers uniformity norms $\mathsf {U}^5$ and $\mathsf {U}^6$ in $\mathbb {F}_2^n$. The proof starts from an earlier partial result of Gowers and the author which reduces the inverse problem to a study of algebraic properties of certain multilinear forms. The bulk of the work in this paper is a study of the relationship between the natural actions of $\operatorname {Sym}_4$ and $\operatorname {Sym}_5$ on the space of multilinear forms and the partition rank, using an algebraic version of regularity method. Along the way, we give a positive answer to a conjecture of Tidor about approximately symmetric multilinear forms in five variables, which is known to be false in the case of four variables. Finally, we discuss the possible generalization of the argument for $\mathsf {U}^k$ norms.
This study investigates whether cross-linguistic differences affect how adult second language (L2) learners use different types of verb subcategorization information for prediction in real-time sentence comprehension. Using visual world eye-tracking, we tested if first language (L1) German and L1 Turkish intermediate-to-advanced learners of L2 English make use of categorical and gradient probabilistic selectional information of ditransitive verbs to predict whether the verbs would be followed by prepositional-object or double-object dative constructions. L1 German learners used both categorical (“pay/*donate the woman the money”) and gradient (“pay/#send the woman the money”) constraints for prediction in a target-like manner. In contrast, L1 Turkish learners were delayed in recruiting categorical verb information and were only selectively sensitive to gradient verb information. We argue that target-like predictive processing across categorical and gradient verb information is attainable for L2 learners, but differences in L1-L2 word order may curtail the utility of prediction by verb subcategorization information in L2 processing.
Indirect noise is a significant contributor to aircraft engine noise, which needs to be minimized in the design of aircraft engines. Indirect noise is caused by the acceleration of flow inhomogeneities through a nozzle. High-fidelity simulations showed that some flow inhomogeneities can be chemically reacting when they leave the combustor and enter the nozzle (Giusti et al., Trans. ASME J. Engng Gas Turbines Power, vol. 141, issue 1, 2019). The state-of-the-art models, however, are limited to chemically non-reacting (frozen) flows. In this work, first, we propose a low-order model to predict indirect noise in nozzle flows with reacting inhomogeneities. Second, we identify the physical sources of sound, which generate indirect noise via two physical mechanisms: (i) chemical reaction generates compositional perturbations, thereby adding to compositional noise; and (ii) exothermic reaction generates entropy perturbations. Third, we numerically compute the nozzle transfer functions for different frequency ranges (Helmholtz numbers) and reaction rates (Damköhler numbers) in subsonic flows with hydrogen and methane inhomogeneities. Fourth, we extend the model to supersonic flows. We find that hydrogen inhomogeneities have a larger impact on indirect noise than methane inhomogeneities. Both the Damköhler number and the Helmholtz number markedly influence the phase and magnitude of the transmitted and reflected waves, which affect sound generation and thermoacoustic stability. This work provides a physics-based low-order model which can open new opportunities for predicting noise emissions and instabilities in aeronautical gas turbines with multi-physics flows.
Roughly a thousand people are killed by American law enforcement officers each year, accounting for more than 5% of all homicides. We estimate the causal impact of these events on civic engagement. Exploiting hyperlocal variation in how close residents live to a killing, we find that exposure to police violence leads to significant increases in registrations and votes. These effects are driven entirely by Black and Hispanic citizens and are largest for killings of unarmed individuals. We find corresponding increases in support for criminal justice reforms, suggesting that police violence may cause voters to politically mobilize against perceived injustice.
CHDs correspond to 28% of all congenital anomalies, being the leading cause of infant mortality in the first year of life. Thus, it is essential to explore risk factors for CHDs presentation, allowing the detection of probable cases within a population.
Methods:
We identified newborns with CHDs within a cohort from the Program for the Prevention and Monitoring of Congenital Defects in Bogota and Cali, 2002–2020. Cases were classified as isolated, complex isolated, polymalformed, and syndromic. Variables were analysed by comparing case and control averages with Student’s t test using a 95% confidence level.
Results:
Prevalence obtained was 19.36 per 10 000 live births; non-specified CHD, ventricular septal defect, and atrial septal defect were the most prevalent. As risk factors were found: paternal and maternal age above 45 years, pregestational diabetes, mother’s body mass index above 25, low educational level, and socio-economic status. As protective factors: folic acid consumption within the first trimester and pregestational period.
Conclusion:
Different risk and protective factors associated with the presentation of CHDs have been described. We consider that public health strategies should be aimed to reduce risk factors exposure. Also, improving diagnosis and prognosis by having a close monitoring on high-risk patients.
In this article, using an Halpern extragradient method, we study a new iterative scheme for finding a common element of the set of solutions of multiple set split equality equilibrium problems consisting of pseudomonotone bifunctions and the set of fixed points for two finite families of Bregman quasi-nonexpansive mappings in the framework of p-uniformly convex Banach spaces, which are also uniformly smooth. For this purpose, we design an algorithm so that it does not depend on prior estimates of the Lipschitz-type constants for the pseudomonotone bifunctions. Furthermore, we present an application of our study for finding a common element of the set of solutions of multiple set split equality variational inequality problems and fixed point sets for two finite families of Bregman quasi-nonexpansive mappings. Finally, we conclude with two numerical experiments to support our proposed algorithm.
Effective doctor–patient communication is a core competency for healthcare professionals. With the pivot to online clinical education and assessment due to the COVID-19 pandemic, there was a need to explore the views of psychiatric trainees and examiners on assessment of communication skills during online high stakes postgraduate examinations.
Methods:
The study was designed as descriptive qualitative research. All candidates and examiners of the September and November 2020 sitting of online Basic Specialist Training exam (a clinical Objective Structured Clinical Examination exam completed in the first 4 years of psychiatry training) were invited to participate. The respondents were interviewed by Zoom which was transcribed verbatim. Data were analyzed by NVivo20 pro and various themes and subthemes were drawn using Braun and Clarke thematic analysis.
Results:
A total of seven candidates and seven examiners were interviewed with an average duration of 30 minutes and 25 minutes, respectively. Four main themes emerged: Communication, Screen optimization, Continuation postpandemic and Overall experience. All candidates preferred to continue an online format post pandemic for practical reasons e.g., avoiding travel and overnight stay, while all examiners preferred to go back to in-person Objective Structured Clinical Examination. However, continuation of online Clinical Formulation and Management Examination was agreed by both groups.
Conclusion:
The participants were largely satisfied with the online examination but did not consider it equal to face-to-face for picking up nonverbal cues. Overall minimal technical issues were reported. These findings may be helpful to modify current psychiatry membership examinations or similar assessments in other countries and specialties.
We present pore-resolved compressible direct numerical simulations of turbulent flows grazing over perforated plates, that closely resemble the acoustic liners found on aircraft engines. Our direct numerical simulations explore a large parameter space including the effects of porosity, thickness and viscous-scaled diameter of the perforated plates, at friction Reynolds numbers $\textit {Re}_\tau = 500\unicode{x2013}2000$, which allows us to develop a robust theory for estimating the added drag induced by acoustic liners. We find that acoustic liners can be regarded as porous surfaces with a wall-normal permeability and that the relevant length scale characterizing their added drag is the inverse of the wall-normal Forchheimer coefficient. Unlike other types of porous surfaces featuring Darcian velocities inside the pores, the flow inside the orifices of acoustic liners is fully turbulent, with a magnitude of the wall-normal velocity fluctuations comparable to the peak in the near-wall cycle. We provide clear evidence of a fully rough regime for acoustic liners, also confirmed by the increasing relevance of pressure drag. Once the fully rough asymptote is reached, canonical acoustic liners provide an added drag comparable to that of sand-grain roughness with viscous-scaled height matching the inverse of the viscous-scaled Forchheimer permeability of the plate.
We develop the theory of relative regular holonomic $\mathcal {D}$-modules with a smooth complex manifold $S$ of arbitrary dimension as parameter space, together with their main functorial properties. In particular, we establish in this general setting the relative Riemann–Hilbert correspondence proved in a previous work in the one-dimensional case.
Assume that f is a real ρ-harmonic function of the unit disk $\mathbb{D}$ onto the interval $(-1,1)$, where $\rho(u,v)=R(u)$ is a metric defined in the infinite strip $(-1,1)\times \mathbb{R}$. Then we prove that $|\nabla f(z)|(1-|z|^2)\le \frac{4}{\pi}(1-f(z)^2)$ for all $z\in\mathbb{D}$, provided that ρ has a non-negative Gaussian curvature. This extends several results in the field and answers to a conjecture proposed by the first author in 2014. Such an inequality is not true for negatively curved metrics.
In this Modern Asian Studies book symposium, scholars of South Asia analyse the political, ethical, and epistemic aspects of market life. They build on the 2020 Cambridge volume, Rethinking Markets in Modern India: Embedded Exchange and Contested Jurisdiction, edited by Ajay Gandhi, Barbara Harriss-White, Douglas Haynes, and Sebastian Schwecke. This interdisciplinary conversation approaches transactional realms from the disciplines of history, anthropology, development studies, and political economy. The symposium’s contributors examine a range of pertinent issues that encompass customary forms of exchange and capitalist aspects of trade. Among the topics discussed are those of market fetishism, bazaar knowledge, social embeddedness, forms of transactional representation and translation, and institutional and regulatory contexts for commerce.
We present macrobotanical, starch, and phytolith data from artifacts and sediments from Middle Formative La Blanca (1000–600 cal BC) and Late Formative El Ujuxte (600 cal BC–cal AD 115 ) in the Soconusco region in Guatemala. Potential economic plants identified included palm (cf. Arecaceae), two varieties of maize (Zea mays), guava (Psidium guajava), bean (Phaseolus), chili peppers (Capsicum), squash (Cucurbitaceae), custard apple (Annonaceae), coco plum (Chrysobalanaceae), lerén (Calathea), arrowroot (Maranta), and bird-of-paradise (Heliconia). The results suggest that control of food production and consumption was critical for the transition from complex chiefdoms during the Middle Formative to the archaic state in the Late Formative. The arrival of a more productive South American variety of maize at El Ujuxte (about 2549 BP) allowed elites to exploit an already existing broad-based economic system and to use the maize-based religious system to increase control over maize agricultural practices and maintain power through ideology and disciplinary power. These data suggest that the arrival of fully domesticated South American maize likely influenced the overall development of Mesoamerican state-level societies.
From the ‘real’ stage performance in the late 1980s to the ‘virtual’ stage performance in April 2020, when China, after months of being locked down due to the COVID-19 pandemic, was gingerly reopening for life again, Chinese theatre artists have persisted in their efforts to adapt the Beckettian play for their sociocultural, artistic and existential needs in the Beckettian spirit of ‘Try again. Fail again. Fail better’.
Premature birth, bronchopulmonary dysplasia or restrictive nutrition in the first weeks of postnatal life may have repercussions on lung development and affect long-term lung function outcomes. This prospective observational study is based on a cohort of 313 very low birth weight (VLBW) neonates, born between 1 January 2008 and 1 December 2016. The daily intake of calories, protein, fat and carbohydrates during the first week of life and evidence of inadequate weight gain (Δwt) until week 36 of gestational age (GA) were recorded. FEV1, FEF25–75 %, forced vital capacity (FVC) and the FEV1/FVC ratio were determined. The relations between these parameters were determined by regression analysis. Spirometric parameters were obtained for 141 children with a mean age of 9 years (95 % CI 7, 11); 69 of them (48·9 %) had presented wheezing episodes on more than three occasions. In addition, 60 (42·5 %) had a history of bronchopulmonary dysplasia. Of these, n 40 (66·6 %) had a history of wheezing. Significant association between protein/energy intake in the first week of life and the lung function parameters analysed was observed. Poor Δwt to GA week 36 was significantly associated with decreased mean pulmonary flow. Inadequate protein/energy intake in the first week of life of VLBW newborns and poor Δwt to week 36 of GA is associated with a significant worsening of lung function parameters.
Greenhouses are inflated structures with transparent covering that are used to grow crops under controlled climatic conditions. Crops are protected from extreme climate-related events by being enclosed. Furthermore, the greenhouse design ratio impacts the temperature and humidity distribution profile uniformity as well as the greenhouse. As a result, by effectively designing the greenhouse structure, building materials, dimensions, and shapes, the cost of cooling management strategies can be reduced. Structures with changed arch shapes showed to be more effective at reducing greenhouse cooling demands in hot areas. To demonstrate the tropical region’s inherent capabilities for generating a proper atmosphere for plant development, the optimal temperature, humidity, light, and PH for greenhouse production of crops were supplied. Greenhouse cooling systems are dominated by local environmental characteristics that have an immediate impact on their indoor climatic conditions. Photovoltaic systems in greenhouses have proven technological capacity in real-world settings in this area. This could increase the energy efficiency of some agrivoltaic greenhouse design options.
Two kinetic models are proposed for high-temperature rarefied (or non-equilibrium) gas flows with internal degrees of freedom and radiation. One of the models uses the Boltzmann collision operator to model the translational motion of gas molecules, which has the ability to capture the influence of intermolecular potentials, while the other adopts the relaxation time approximations, which has higher computational efficiency. In our kinetic model equations, not only the transport coefficients such as the shear/bulk viscosity and thermal conductivity but also their underlying relaxation processes are recovered. The non-equilibrium dynamics of gas flow and radiation are tightly coupled, where the transport properties of gas molecules and photons are correlatively dependent. The proposed kinetic models are validated by the direct simulation Monte Carlo method in several non-radiative rarefied gas flows (e.g. the normal shock wave, Fourier flow, Couette flow and the creep flow driven by the Maxwell demon), and the experimental data of planar heat transfer and normal shock waves in nitrogen. Then, the rarefied gas flows with strong radiation are studied based on the kinetic models, not only in the above one-dimensional gas flows, but also in the two-dimensional radiative hypersonic flow passing a cylinder. The characteristics of heat transfer in the tightly coupled fields of gas and radiation are systematically investigated, particularly the influence of the non-equilibrium photon transport and their interactions with gas molecules are revealed. It is found that the radiation makes a profound contribution to the total heat transfer in radiative hypersonic flow at an intermediate photon Knudsen number.