Singular stochastic integral operators

In this paper we introduce Calder\'on-Zygmund theory for singular stochastic integrals with operator-valued kernel. In particular, we prove $L^p$-extrapolation results under a H\"ormander condition on the kernel. Sparse domination and sharp weighted bounds are obtained under a Dini condition on the kernel, leading to a stochastic version of the solution to the $A_2$-conjecture. The results are applied to obtain $p$-independence and weighted bounds for stochastic maximal $L^p$-regularity both in the complex and real interpolation scale. As a consequence we obtain several new regularity results for the stochastic heat equation on $\mathbb{R}^d$ and smooth and angular domains.Comment: typos corrected. Accepted for publication in Analysis & PD

Vector-valued extensions of operators through multilinear limited range extrapolation

We give an extension of Rubio de Francia's extrapolation theorem for functions taking values in UMD Banach function spaces to the multilinear limited range setting. In particular we show how boundedness of an $m$-(sub)linear operator $$T:L^{p_1}(w_1^{p_1})\times\cdots\times L^{p_m}(w_m^{p_m})\to L^p(w^p)$$ for a certain class of Muckenhoupt weights yields an extension of the operator to Bochner spaces $L^{p}(w^p;X)$ for a wide class of Banach function spaces $X$, which includes certain Lebesgue, Lorentz and Orlicz spaces. We apply the extrapolation result to various operators, which yields new vector-valued bounds. Our examples include the bilinear Hilbert transform, certain Fourier multipliers and various operators satisfying sparse domination results.Comment: 21 pages. Minor modification

Fourier multipliers in Banach function spaces with UMD concavifications

We prove various extensions of the Coifman-Rubio de Francia-Semmes multiplier theorem to operator-valued multipliers on Banach function spaces. Our results involve a new boundedness condition on sets of operators which we call $\ell^{r}(\ell^{s})$-boundedness, which implies $\mathcal{R}$-boundedness in many cases. The proofs are based on new Littlewood-Paley-Rubio de Francia-type estimates in Banach function spaces which were recently obtained by the authors

Vector-valued extensions of operators through multilinear limited range extrapolation

We give an extension of Rubio de Francia's extrapolation theorem for functions taking values in UMD Banach function spaces to the multilinear limited range setting. In particular we show how boundedness of an $m$-(sub)linear operator $$T:L^{p_1}(w_1^{p_1})\times\cdots\times L^{p_m}(w_m^{p_m})\to L^p(w^p)$$ for a certain class of Muckenhoupt weights yields an extension of the operator to Bochner spaces $L^{p}(w^p;X)$ for a wide class of Banach function spaces $X$, which includes certain Lebesgue, Lorentz and Orlicz spaces. We apply the extrapolation result to various operators, which yields new vector-valued bounds. Our examples include the bilinear Hilbert transform, certain Fourier multipliers and various operators satisfying sparse domination results.Comment: 21 pages. Minor modifications. To appear in Journal of Fourier Analysis and Application

On the ℓs\ell^s-boundedness of a family of integral operators

In this paper we prove an $\ell^s$-boundedness result for integral operators with operator-valued kernels. The proofs are based on extrapolation techniques with weights due to Rubio de Francia. The results will be applied by the first and third author in a subsequent paper where a new approach to maximal $L^p$-regularity for parabolic problems with time-dependent generator is developed.Comment: Minor revision. Accepted for publication in Rev. Mat. Iberoamerican

Effects of Reapeated Doses of Caffeine on Performance and Alertness: New Data and Secondary Analyses

Rationale The effects of caffeine on mood and performance are well established. Some authors suggest that caffeine merely reverses effects of caffeine withdrawal rather than having direct behavioural effects. It has also been suggested that withdrawal may be removed by a first dose of caffeine and further doses have little subsequent effect. These issues were examined here. Objectives The present study aimed to determine whether caffeine withdrawal influenced mood and performance by comparing regular consumers who had been withdrawn from caffeine overnight with non-consumers. Following this repeated caffeine doses were administered to test the claim that repeated dosing has no extra effect on mood or performance. Secondary analyses of a data collected by Christopher et al. (2003) were also carried out to examine some alternative explanations of their results which showed effects of caffeine after a day of normal caffeine consumption. Methods One hundred and twenty volunteers participated in the study. Regular caffeine consumption was assessed by questionnaire and this showed that thirty six of the sample did not regularly consume caffeinated beve rages. Volunteers were instructed to abstain from caffeine overnight and then completed a baseline session measuring mood and a range of cognitive functions at 08.00 the next day. Following this volunteers were given 0, or 1mg/kg caffeine in a milkshake, glucose solution or water (at 09:00), followed by a second 0 or 1mg/kg caffeine dose (at 09:40) and the test battery repeated at 10:00. Results The baseline data showed no effect of overnight caffeine withdrawal on mood or performance. In contrast, caffeine challenge improved vigilance performance and prevented decreases in alertness induced by completion of the task battery. The magnitude of these effects increased as a function of the number of doses of caffeine given. Secondary analyses of data from Christopher et al. (2003) also confirmed that effects of caffeine did not depend on length of withdrawal. Conclusions The present findings show no effect of overnight caffeine withdrawal on mood and performance. Caffeine challenge did have the predicted effect on alertness and vigilance, with the size of the effects increasing with caffeine dose. These findings suggest that the effects of caffeine are not due to reversal of effects of withdrawal, a view confirmed by secondary analyses of data collected after a day of normal caffe ine consumption

The fluidity of patriarchy:Resisting Dutch gender interventions in Uganda and Zambia

In this PhD thesis, Jeroen Lorist explores how a new category for intervention, the ‘good African man,’ has emerged and proliferated within Dutch development thinking and practice in the first decades of the 21st century. It critiques the morally superior stance and elided racialist norms of such interventions, but also examines how gender and sexual and reproductive health and rights (SRHR) interventions are adapted, circumvented, and navigated by different groups in Uganda and Zambia, often to their own benefit. The fluidity of patriarchy refers to processes in which traditions are dynamically adapted by powerful big men to stay in power, but also to the multiplicity of patriarchy. For example, masculinist leadership can also be practiced by powerful women in the Dutch development space. Patriarchy, therefore, exists in many dynamic shapes and forms in different places within the international gender equality assemblage. With the current major cuts in Dutch development funding and the global anti-gender movement, insight into the fluidity of patriarchy within global SRHR could inform the building of new, more equitable SRHR futures when the progressive wind starts blowing once again

The fluidity of patriarchy:Resisting Dutch gender interventions in Uganda and Zambia

In this PhD thesis, Jeroen Lorist explores how a new category for intervention, the ‘good African man,’ has emerged and proliferated within Dutch development thinking and practice in the first decades of the 21st century. It critiques the morally superior stance and elided racialist norms of such interventions, but also examines how gender and sexual and reproductive health and rights (SRHR) interventions are adapted, circumvented, and navigated by different groups in Uganda and Zambia, often to their own benefit. The fluidity of patriarchy refers to processes in which traditions are dynamically adapted by powerful big men to stay in power, but also to the multiplicity of patriarchy. For example, masculinist leadership can also be practiced by powerful women in the Dutch development space. Patriarchy, therefore, exists in many dynamic shapes and forms in different places within the international gender equality assemblage. With the current major cuts in Dutch development funding and the global anti-gender movement, insight into the fluidity of patriarchy within global SRHR could inform the building of new, more equitable SRHR futures when the progressive wind starts blowing once again

Banach function spaces done right

In this survey, we discuss the definition of a (quasi-)Banach function space. We advertise the original definition by Zaanen and Luxemburg, which does not have various issues introduced by other, subsequent definitions. Moreover, we prove versions of well-known basic properties of Banach function spaces in the setting of quasi-Banach function spaces.FJC2021-046837-