This paper engages with recent work on formalization in economics to develop a new perspective on mathematization. Boylan and O’Gorman draw on foundations of mathematics to argue that classical mathematics is inappropriate for economics; intuitionistic foundations and constructive mathematics should be used instead. The use of real analysis would be blocked and equilibrium results undermined. I argue that their line of thought faces several challenges; however, I then draw on their analyses and the philosophy of applied mathematics to propose a novel approach in which questions about mathematization are properly understood as questions about the contextual aptness of relevant idealizations.

Obsessive–compulsive disorder (OCD) is often missed and misdiagnosed. This Editorial reminds the reader to screen for obsessions and compulsions; how OCD can be distinguished from other disorders characterised by recurrent thoughts and repetitive behaviours; and to facilitate better access to effective treatments for this often distressing and disabling disorder.

In this article, we investigate the higher topological complexity of oriented Seifert fibred manifolds that are Eilenberg–MacLane spaces $K(G,1)$ with infinite fundamental group $G$. We first refine the cohomological lower bounds for higher topological complexity by introducing the notion of higher topological complexity weights. As an application, we show that the $r^{\text{th}}$ topological complexity of these manifolds lies in $\{3r-1, 3r, 3r+1\}$, and characterize large families where the value is $3r$ or $3r+1$. Additionally, we establish a sufficient condition for higher topological complexity to be exactly $3r$ when the base surface is orientable and aspherical. Finally, we show that the higher topological complexity of the wedge of finitely many closed, orientable, aspherical $3$-manifolds is exactly $3r+1$.

Transnational anti-trans actors fall into two camps: traditionally conservative actors who pursue transphobia to extend patriarchy and feminists who pursue transphobia to challenge patriarchy. This article investigates how shared language and practices of anti-trans feminist and traditionalist coalitions enact opposing sex/gender orders. I explain this alliance through grounded theory generated from a critical discourse analysis of my dataset of 1016 anti-trans texts from 175 organizations. I develop my Affective Orientation Threat Structure, which explains the affective governing process of this coalition, and then apply this framework to anti-trans discourses about trans threats to womanhood. I find that anti-trans feminists and traditionalists generate fear via shared threat constructions but frame threat differently in order to mobilize affective energy in service of diverging regulative regimes and sex/gender orders. I argue that the illogics produced by contradictions within this incompatible coalition benefit both camps by maximizing affective disorientation and generating momentum through paradox.

This paper studies the transition to high inflation during the COVID-19 pandemic, using a behavioral version of the New Keynesian model, which replaces the conventional assumption of rational expectations with subjective and heterogeneous expectations. Different shares of agents in the economy form expectations based on alternative views regarding future economic variables: (1) a share of agents forecasts that inflation and output will rapidly revert to steady state; (2) another share forms forecasts based on a model resembling the MSV solution under rational expectations; (3) a third share of agents uses an under-specified model that captures trend-following, adaptive, or extrapolative behavior. Agents learn over time the parameters of their perceived model and they can also shift across different views based on past forecasting performance. The macroeconomic model is estimated using Bayesian methods to fit realized macroeconomic variables and data on expectations from surveys. The results document an additional channel that operates through switches in agents’ perceptions and amplifies the impact of the original inflationary shocks. In response to rising inflation after COVID, agents begin shifting from the mean reversion model to the trend-following specification (with a belief about perceived inflation persistence that is simultaneously revised upward). Consequently, the impact of inflationary shocks is magnified and the effects of monetary policy attenuated.

The fossil record of medusozoan cnidarians is relatively sparse and, in some cases, contentious. Here, we describe a new genus and species of a well-preserved, soft-bodied, tubicolous polyp, Paleocanna tentaculum n. gen. n. sp., from the Upper Ordovician (Katian) Neuville Formation in Québec. These fossils, preserved as carbonaceous compressions, were found in association with typical shelly assemblages. Fifteen slabs of shaly limestone containing ~ 135 specimens of Paleocanna tentaculum n. gen. n. sp. were examined. Individual polyps occupied upright tubes, which occur either solitarily or in clusters. Some tubes exhibit a striated periderm near their base. The polyp is elongated, with a rounded aboral end and a consistent ring of tentacles protruding distally from the tube. A phylogenetic analysis of 69 taxa and 236 discrete morphological characters indicated that the species is more closely related to the crown clade including Staurozoa, Cubozoa, Scyphozoa than to other fossil medusozoans, e.g., conulariids and carinachitids. The uniform orientation of specimens on single slabs suggests rapid burial. Paleocanna tentaculum n. gen. n. sp. represents an exceptionally preserved member of an Ordovician deposit exhibiting Burgess Shale-type soft-tissue preservation.

UUID: http://zoobank.org/12d03d82-1925-4578-873e-2e9c23db635f

Vitamin A deficiency (VAD) is common among pregnant women (PW) and has been associated with anaemia and adverse birth outcomes. However, in the Free State Province of South Africa, evidence regarding this is limited. Hence, this cross-sectional study investigated the vitamin A (vitA) intake and status of PW in Bloemfontein and its association with anaemia, iron status and birth outcomes. Blood was taken from 427 PW to assess the status of vitA (retinol-binding protein 4 (RBP4)), iron (ferritin, soluble transferrin receptor (sTfR)) and anaemia (Hb). Sociodemographic, HIV, birth outcomes (birthweight and gestational age) and dietary vitA intake data were obtained using a questionnaire in an interview and medical records. Descriptive statistics and linear regression were used to describe variables and the association between vitA and iron status and birth outcomes. Median vitA intake was 1007 µgRAE/d with 19 % of participants’ intake below the estimated average requirement of 550 µgRAE/d. Median (IQR) RBP4 was 1·51 (0·78) µmol/l. Insufficient vitA status and VAD prevalence were 12·2 % and 1·2 %, respectively. VitA intake was positively associated with RBP4 (β = 0·068; 95 % CI 0·020, 0·116; P = 0·006). RBP4 was positively associated with Hb (β = 0·363; 95 % CI 0·186, 0·539; P < 0·001) and ferritin (β = 0·359; 95 % CI 0·139, 0·579; P = 0·001) but negatively with sTfR (β = −0·125; 95 % CI −0·246, −0·005; P = 0·041). No significant association between plasma RBP4 and birth weight, as well as preterm birth, was observed. There was a low prevalence of VAD in the study population. Nonetheless, the positive association between RBP4 and Hb and ferritin highlights the importance of optimal vitA status in preventing anaemia in pregnancy.

We compute the Galois groups of the reductions modulo a prime number p of the generating series of Apéry numbers, Domb numbers and Almkvist–Zudilin numbers. We observe in particular that their behaviour is governed by congruence conditions on p.

The notion of $\theta $-congruent numbers generalises the classical congruent number problem. A positive integer n is $\theta $-congruent if it is the area of a rational triangle with an angle $\theta $ whose cosine is rational. Das and Saikia [‘On $\theta $-congruent numbers over real number fields’, Bull. Aust. Math. Soc. 103(2) (2021), 218–229] established criteria for numbers to be $\theta $-congruent over certain real number fields and concluded their work by posing four open questions regarding the relationship between $\theta $-congruent and properly $\theta $-congruent numbers. In this work, we provide complete answers to those questions. Indeed, we remove a technical assumption from their result on fields with degrees coprime to six, provide a definitive answer for real cubic fields without congruence restrictions, extend the analysis to fields of degree six and examine the exceptional cases $n=1, 2, 3$ and $6$.

The set of sums of two squares plays a significant role in number theory. We establish the existence of several rich monochromatic configurations in the natural numbers by exploiting algebraic structures induced by the set of sums of two squares. The proofs rely on algebraic properties arising from the induced structures on the Stone–Čech compactification of the natural numbers.