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Why did the human brain evolve? This study develops a Malthusian growth model with heterogeneous agents and natural selection to explore the evolution of human brain size. We find that if the cognitive advantage of a larger brain dominates its higher metabolic costs, then the average brain size increases over time, which is consistent with the rising trend in human brain size that started over 2 million years ago. Furthermore, an improvement in hunting-gathering productivity (e.g., the discovery of using stone tools and fire in hunting animals and cooking food) helps to trigger this human brain size evolution. As the average brain size increases, the average level of hunting-gathering productivity also rises over time. Quantitatively, our model is able to replicate the trend in hominin brain evolution over the last 10 million years.
Let G be a split connected reductive group defined over $\mathbb {Z}$. Let F and $F'$ be two non-Archimedean m-close local fields, where m is a positive integer. D. Kazhdan gave an isomorphism between the Hecke algebras $\mathrm {Kaz}_m^F :\mathcal {H}\big (G(F),K_F\big ) \rightarrow \mathcal {H}\big (G(F'),K_{F'}\big )$, where $K_F$ and $K_{F'}$ are the mth usual congruence subgroups of $G(F)$ and $G(F')$, respectively. On the other hand, if $\sigma $ is an automorphism of G of prime order l, then we have Brauer homomorphism $\mathrm {Br}:\mathcal {H}(G(F),U(F))\rightarrow \mathcal {H}(G^\sigma (F),U^\sigma (F))$, where $U(F)$ and $U^\sigma (F)$ are compact open subgroups of $G(F)$ and $G^\sigma (F),$ respectively. In this article, we study the compatibility between these two maps in the local base change setting. Further, an application of this compatibility is given in the context of linkage – which is the representation theoretic version of Brauer homomorphism.
The field of developmental psychopathology has grown broadly. Here, I draw upon lessons learned from Dante Cicchetti to highlight areas that show promise for continued disciplinary advancement. These include attention to equifinality and multifinality in the conceptualization of initial study designs, and more emphasis on specificity in accounting for developmental change. A shift from reliance on external events and towards greater diversity of research approaches will allow researchers to devote attention to the variety of ways that individuals come to understand and then respond to their own life experiences. The field of developmental psychopathology holds tremendous promise for advancing basic science about human development that can be applied to create interventions that improve the well-being of individuals and address significant societal issues.
The incidence of obesity-related glomerulopathy (ORG) is rising worldwide with very limited treatment methods. Paralleled with the gut–kidney axis theory, the beneficial effects of butyrate, one of the short-chain fatty acids (SCFA) produced by gut microbiota, on metabolism and certain kidney diseases have gained growing attention. However, the effects of butyrate on ORG and its underlying mechanism are largely unexplored. In this study, a mice model of ORG was established with a high-fat diet feeding for 16 weeks, and sodium butyrate treatment was initiated at the 8th week. Podocyte injury, oxidative stress and mitochondria function were evaluated in mice kidney and validated in vitro in palmitic acid-treated-mouse podocyte cell lines. Further, the molecular mechanisms of butyrate on podocytes were explored. Compared with controls, sodium butyrate treatment alleviated kidney injuries and renal oxidative stress in high-fat diet-fed mice. In mouse podocyte cell lines, butyrate ameliorated palmitic acid-induced podocyte damage and helped maintain the structure and function of the mitochondria. Moreover, the effects of butyrate on podocytes were mediated via the GPR43-Sirt3 signal pathway, as evidenced by the diminished effects of butyrate with the intervention of GPR43 or Sirt3 inhibitors. In summary, we conclude that butyrate has therapeutic potential for the treatment of ORG. It attenuates high-fat diet-induced ORG and podocyte injuries through the activation of the GPR43-Sirt3 signalling pathway.
The paper by Castaing et al. (J. Fluid Mech., vol. 204, 1989, pp. 1–30) on turbulent Rayleigh–Bénard convection has been one of the most impactful papers on the subject – not by giving the right and complete answers but by developing versatile concepts and by asking the right questions, namely: (i) What is the overall flow organization? (ii) What is the dependence of the Nusselt number ${\textit {Nu}}$ (the dimensionless heat transport) on the Rayleigh number ${\textit {Ra}}$ (the thermal driving strength)? (iii) What is the ultimate state of turbulence for extremely large ${\textit {Ra}}$? Thanks to Castaing et al. having asked the right questions, the field has made tremendous progress over the last 35 years.
We sought to examine the relative importance of surgical lesion complexity versus the presence of genetic/syndromic/extracardiac anomalies (GSAs) in determining survival, morbidity or need for reinterventions following repair for aortic arch hypoplasia.
Methods:
A single-centre, retrospective cohort study of infants undergoing biventricular aortic arch repair via sternotomy from 2010 to 2021 was conducted. Survival analysis was performed using Kaplan–Meier methods, with additional Bayesian survival modelling for subgroups. Composite morbidity comprised respiratory, renal, neurologic, or sepsis-related complications.
Results:
Of 83 included infants, n = 13/83 (15.7%) had complex repairs; 27/83 (32.5%) were GSA+. Operative mortality was significantly higher in GSA+ versus GSA− patients (18.5% vs. 1.8%; p = 0.01), though not for complex versus non-complex repairs. Overall 10-year Kaplan–Meier survival was 86.7%. Bayesian modelling suggested equivalent post-discharge attrition in non-complex/GSA+ and complex/GSA− patients, with the poorest outcomes in complex/GSA+ patients; non-complex/GSA− patients had 100% survival. GSA+ patients exhibited higher composite morbidity (44.4% vs. 7.1% in GSA− p < 0.001), with their mode of death seemingly related to a high incidence of respiratory and neurological morbidity, notably in Dandy–Walker syndrome. The 10-year freedom from arch reinterventions was 87.7%; neither complexity, GSA status, nor post-repair peak arch velocity predicted the need for arch reinterventions.
Conclusions:
Whilst anatomic complexity may have been somewhat neutralised as a risk factor for operative mortality, in contrast to GSA+ status, there is further post-discharge attrition attributable to complexity or GSA+ status, with additive risk effects. Morbidity directly related to certain syndromes underlies some of this risk. Non-anatomic substrates represent a persistent limitation to outcomes of surgical aortic arch repair in infants.
In a two-dimensional plane, entire solutions of the Allen–Cahn type equation with a finite Morse index necessarily have finite ends. In the case that the nonlinearity is a sine function, all the finite-end solutions have been classified. However, for the classical Allen–Cahn nonlinearity, the structure of the moduli space of these solutions remains unknown. We construct in this paper new finite-end solutions to the Allen–Cahn equation, which will be called fence of saddle solutions, by gluing saddle solutions together. Our construction can be generalized to the case of gluing multiple four-end solutions, with some of their ends being almost parallel.
A long-standing issue in pipe flow physics is whether the friction of the fluid follows a logarithmic or an algebraic decay. In 2005, McKeon et al. (J. Fluid Mech., vol. 538, 2005, pp. 429–443) published a detailed analysis of new measurements in the Princeton facility, and apparently settled the debate by showing that ‘the log is the law’. Almost 20 years later, no better data are presently available to reinforce their statement. Still, the story may not be totally over, and this is bad news for mathematicians who were hoping to get a long awaited final answer to one of their most elusive questions.
The nanoscale is the new frontier of fluid dynamics and its phenomenology can echo at the macroscale as in the canonical example of drop impact on a planar substrate. Unprecedented advances in measurement technology have recently equipped fluid dynamicists with the ability to probe nanoscale effects. The paper by Li et al. (J. Fluid Mech., vol. 785, 2015, R2) uses ultrafast imaging at the hundreds of nanoseconds scale to resolve the first contact between the drop and the substrate and thereby reveal the effect of prescribed nano-roughness on contact line motion.
This article looks again at the history of British migration policy in the 1940s and 1950s by centering international and imperial politics, and by drawing on archives related to shipping. These sources suggest that the British government sought to reactivate a system of race-segregated mobility across the Empire-Commonwealth after the Second World War. This involved subsidizing fares for emigrants bound for Australia, transporting migrants from Europe to the UK, and withdrawing shipping from routes that connected the Caribbean to the UK. Very soon, however, these policies came under strain. There were not enough deep-sea ships to meet demand for berths to Australia or to bring over recruited European migrants. Then the Australian government found new ways to ship migrants from continental Europe by signing a deal with the International Refugee Organization, challenging UK policy to keep Australian immigration British. Meanwhile, new routes were opened up from the Caribbean and South Asia to the UK. These trends raised a host of dilemmas for policymakers and all related to transport infrastructure. Thinking about transport can deepen our understanding of migration history, and the article's conclusion suggests some of the ways that taking such an approach can contribute to existing explanations for the government's fateful decision to amend the UK's nationality and citizenship legislation during the 1960s.
Depicting transgender persons in comics without falling into visual caricature and thereby perpetuating harmful stereotypes can be a delicate task. In this discussion, I draw upon the notion of picture-reading to argue that, despite this fact, comics as a medium is particularly well-suited—both formally and in terms of production-relevant factors—toward capturing and communicating the complexities of transgender experience.
Quantum computing has been studied over the past four decades based on two computational models of quantum circuits and quantum Turing machines. To capture quantum polynomial-time computability, a new recursion-theoretic approach was taken lately by Yamakami [J. Symb. Logic 80, pp. 1546–1587, 2020] by way of recursion schematic definition, which constitutes six initial quantum functions and three construction schemes of composition, branching, and multi-qubit quantum recursion. By taking a similar approach, we look into quantum polylogarithmic-time computability and further explore the expressing power of elementary schemes designed for such quantum computation. In particular, we introduce an elementary form of the quantum recursion, called the fast quantum recursion, and formulate $EQS$ (elementary quantum schemes) of “elementary” quantum functions. This class $EQS$ captures exactly quantum polylogarithmic-time computability, which forms the complexity class BQPOLYLOGTIME. We also demonstrate the separation of BQPOLYLOGTIME from NLOGTIME and PPOLYLOGTIME. As a natural extension of $EQS$, we further consider an algorithmic procedural scheme that implements the well-known divide-and-conquer strategy. This divide-and-conquer scheme helps compute the parity function, but the scheme cannot be realized within our system $EQS$.
Antenna arrays are a main driver of next generation millimeter-wave communication and radar systems as shrinking antenna sizes leverage larger arrays to compensate for reduced link budget. However, conventional phase controlled arrays exhibit a frequency dependent scan angle that appears as loss to a fixed counterpart. Bandwidth limitations introduced by the so-called beam squint effect hinder larger array sizes and data rates thereby generating a demand for timed arrays as a solution. This paper gives a quantified overview of the beam squint phenomenon, different hardware architectures as well as evaluation parameters and common shortcomings of true-time delay (TTD) elements. A broad variety of TTD realizations from literature are compared by their operational principles and performance. Finally, the delay interpolation principle, its non-idealities, and their impact on a hierarchically time delay controlled D-band antenna array are described. Extended content on a previously published, continuously tunable TTD implementation at a center frequency of 144 GHz with a bandwidth of 26 GHz and a delay range of 1.75 ps that requires only 0.53 × 0.3 mm2 of core chip area is presented. Measurement results have been obtained from a demonstrator manufactured in 130 nm BiCMOS technology.
Consider a flow in $\mathbb{R}^3$ and let K be the biggest invariant subset of some compact region of interest $N \subseteq \mathbb{R}^3$. The set K is often not computable, but the way the flow crosses the boundary of N can provide indirect information about it. For example, classical tools such as Ważewski’s principle or the Poincaré–Hopf theorem can be used to detect whether K is non-empty or contains rest points, respectively. We present a criterion that can establish whether K has a non-trivial homology by looking at the subset of the boundary of N along which the flow is tangent to N. We prove that the criterion is as sharp as possible with the information it uses as an input. We also show that it is algorithmically checkable.
This paperpresents the measurement procedure as well as the calculations and theoretical background for the estimation of particle sizes with the help of a dual-frequency measurement setup. For the measurement, two fully integrated radar sensors are implemented which offer advantages over typically used technologies at high frequencies. The first sensor has a constant transmitting frequency of 90 GHz while the second sensor offers a possibility to vary the transmitting frequency over the entire D-band with frequencies between 110 and 180 GHz. With these frequencies, different sizes can be determined. The presented approach makes use of the different transitions between the linear increasing Rayleigh scattering regime and the Mie regime. With a fitting indoor measurement setup that resembles an industrial duct, the approach is verified for spheroid glass particles with a diameter of 0.875 mm. The results show a slight deviation from the expected value of particle sizes overall.
The agency of a person with young onset dementia (YOD) changes owing to individual symptoms, uncertainty about the speed of progression and the severity of YOD. Dementia usually greatly interrupts life and reduces agency. Previous studies show that some people and families integrate and cope with dementia better than others. This study aimed to find out how YOD changes the agency of the person who has it and what family members’ role is in forming their agency. The data were collected in Finland in semi-structured interviews with 14 people with YOD and 15 family members, about a year after the diagnosis. These two data sets were analysed with a narrative method, actantial analysis. A wide variety of elements, both human and non-human factors, were found to promote and undermine agency. It was found that people with YOD need both integrity and flexibility to reconstruct their own agency. Resources support them in this process of reconstruction, and hinderers interrupt the process. This combination of integrity and flexibility, resources and hinderers, generates how people with YOD recount the future, the aims they set and how they reconstruct their agency. Other people, especially family members, are part of this dynamic process and when their relationship is cohesive, the agency of both parties increases. The participants used ideal and burdensome storylines to narrate factors that supported or interrupted their agency. Based on our findings, narrating one’s situation is, for coping, not only a means but its very basis.