Let $H_n$ be the minimal number such that any n-dimensional convex body can be covered by $H_n$ translates of the interior of that body. Similarly $H_n^s$ is the corresponding quantity for symmetric bodies. It is possible to define $H_n$ and $H_n^s$ in terms of illumination of the boundary of the body using external light sources, and the famous Hadwiger’s covering conjecture (illumination conjecture) states that $H_n=H_{n}^s=2^n$. In this note, we obtain new upper bounds on $H_n$ and $H_{n}^s$ for small dimensions n. Our main idea is to cover the body by translates of John’s ellipsoid (the inscribed ellipsoid of the largest volume). Using specific lattice coverings, estimates of quermassintegrals for convex bodies in John’s position, and calculations of mean widths of regular simplexes, we prove the following new upper bounds on $H_n$ and $H_n^s$: $H_5\le 933$, $H_6\le 6137$, $H_7\le 41377$, $H_8\le 284096$, $H_4^s\le 72$, $H_5^s\le 305$, and $H_6^s\le 1292$. For larger n, we describe how the general asymptotic bounds $H_n\le \binom {2n}{n}n(\ln n+\ln \ln n+5)$ and $H_n^s\le 2^n n(\ln n+\ln \ln n+5)$ due to Rogers, Shephard and Roger, Zong, respectively, can be improved for specific values of n.

By constraining organic carbon (OC) turnover times and ages, radiocarbon (14C) analysis has become a crucial tool to study the global carbon cycle. However, commonly used “bulk” measurements yield average turnover times, masking age variability within complex OC mixtures. One method to unravel intra-sample age distributions is ramped oxidation, in which OC is oxidized with the aid of oxygen at increasing temperatures. The resulting CO2 is collected over prescribed temperature ranges (thermal fractions) and analyzed for 14C content by accelerator mass spectrometry (AMS). However, all ramped oxidation instruments developed to date are operated in an “offline” configuration and require several manual preparation steps, hindering sample throughput and reproducibility. Here we describe a compact, online ramped oxidation (ORO) setup, where CO2 fractions are directly collected and transferred for 14C content measurement using an AMS equipped with a gas ion source. Our setup comprises two modules: (i) an ORO unit containing two sequential furnaces, the first of which holds the sample and is ramped from room temperature to ∼900°C, the second of which is maintained at 900°C and holds catalysts (copper oxide and silver) to ensure complete oxidation of evolved products to CO2; and (ii) a dual-trap interface (DTI) collection unit containing two parallel molecular sieve traps, which alternately collect CO2 from a given fraction and handle its direct injection into the AMS. Initial results for well-characterized samples indicate that 14C content uncertainties and blank background values are like those obtained during routine gas measurements at ETH, demonstrating the utility of the ORO-DTI setup.

In recent decades, analysing the progression of mortality rates has become very important for both public and private pension schemes, as well as for the life insurance branch of insurance companies. Traditionally, the tools used in this field were based on stochastic and deterministic approaches that allow extrapolating mortality rates beyond the last year of observation. More recently, new techniques based on machine learning have been introduced as alternatives to traditional models, giving practitioners new opportunities. Among these, neural networks (NNs) play an important role due to their computation power and flexibility to treat the data without any probabilistic assumption. In this paper, we apply multi-task NNs, whose approach is based on leveraging useful information contained in multiple related tasks to help improve the generalized performance of all the tasks, to forecast mortality rates. Finally, we compare the performance of multi-task NNs to that of existing single-task NNs and traditional stochastic models on mortality data from 17 different countries.

Several breast microwave sensing (BMS) systems have shown encouraging results as a potential breast cancer detection tool. The existing systems in the literature have diverse designs, equipment, measurement protocols, and analysis methods. However, there is relatively little investigation on the impact and performance of varying system designs. This work compares the impact of system design parameters on three existing BMS systems. The first system, a bed-based system, was designed for use in a permanent clinic. The second system, a bench-top system, was created for laboratory research. The third system, a portable system, was designed for use in low-income and remote communities. The bed-based system had the highest resolving capabilities, achieving a spatial resolution of 12.4 ± 0.5 mm. Additionally, the bed system had the highest signal-to-noise ratio of 26 ± 1 dB. The portable system had the least intensity dependence on polar positions within the imaging chamber. The bed system had the highest contrast between tumor- and adipose-mimicking materials. However, the contrast of tumor- and fibroglandular-mimicking materials was similar for each system. By comparing and evaluating the performance of multiple BMS systems, we improve our understanding of system design, allowing for potential studies into an ideal BMS system.

This research investigates the tone system of an understudied language, Du’an Zhuang and its interaction with duration. Cross-linguistically, tones tend to be less complex in shorter duration contexts. In Du’an Zhuang, syllable type provides these contexts: There are six contrastive tones among unchecked syllables with longer rhyme duration, but this is reduced to four tones in shorter duration checked syllables. Acoustic analyses of f0 and duration from six native speakers were performed to check whether tonal complexity is reduced in the shorter duration checked syllables. The results showed this was true with some exceptions. The two tones in CVVO syllables corresponded to the two least complex tones; however, one of the two CVO tones included a more complex rising tone. This rising tone exhibited a reduced f0 excursion though. Finally, there is a two-way phonological vowel length contrast in Du’an Zhuang, which necessarily interacts with syllable type via its effect on rhyme duration. However, based on our vowel duration measurements, this vowel length contrast only exists in unchecked syllables with sonorant codas, the only syllable type where rhyme duration and vowel duration could possibly differ. In this context, a sonorant coda contributes to the syllable’s rhyme duration, but not to vowel duration, allowing syllable type and vowel length to contrast independently, only in this phonological context.

An area-preserving homeomorphism isotopic to the identity is said to have rational rotation direction if its rotation vector is a real multiple of a rational class. We give a short proof that any area-preserving homeomorphism of a compact surface of genus at least two, which is isotopic to the identity and has rational rotation direction, is either the identity or has periodic points of unbounded minimal period. This answers a question of Ginzburg and Seyfaddini and can be regarded as a Conley conjecture-type result for symplectic homeomorphisms of surfaces beyond the Hamiltonian case. We also discuss several variations, such as maps preserving arbitrary Borel probability measures with full support, maps that are not isotopic to the identity and maps on lower genus surfaces. The proofs of the main results combine topological arguments with periodic Floer homology.

Delphi studies allow for the generation of a consensus among experts. This has historically been professional experts in their field. This study aimed to obtain a consensus regarding the most important components of cognitive behavioural therapy (CBT) for depression not only for professional experts (therapists) but also for adult experts by experience. Perceptions of importance between therapists and experts by experience differed in multiple areas including content components such as behavioural activation and experiments, psychoeducation, and homework, which the latter did not agree were important. Experts by experience found several components relating to delivery process important which therapists did not, such as delivery method and session length. The strongest agreement from both groups involved the importance of positive therapist factors such as being non-judgemental, knowledgeable, understanding, and trustworthy. Both groups were in agreement on the importance of cognitive restructuring. Neither experts by experience nor therapists met consensus agreement on the inclusion of mindfulness as part of a wider CBT intervention for depression, being rated among the lowest components for both groups. Findings highlight several aspects of CBT content and delivery which may benefit from review in order to increase acceptability for recipients.

Key learning aims

1. (1) To identify what recipients and deliverers feel are the most important parts of a CBT intervention for depression.

2. (2) To compare these responses, and consider reasons why these similarities and differences may exist.

3. (3) To discuss ways in which these differences could impact acceptability and perceived efficacy of cognitive behavioural therapy.

4. (4) To reflect on ways gained knowledge could be used to consider ways to improve the delivery of cognitive behavioural therapy.

Adults rate the speech of children assigned male at birth (AMAB) and assigned female at birth (AFAB) as young as 2.5 years of age differently on a scale of definitely a boy to definitely a girl (Munson et al., 2022), despite the lack of consistent sex dimorphism in children’s speech production mechanisms. This study used longitudinal data to examine the acoustic differences between AMAB and AFAB children and the association between the acoustic measures and perceived gender ratings of children’s speech. We found differences between AMAB and AFAB children in two acoustic parameters that mark gender in adult speech: the spectral centroid of /s/ and the overall scaling of resonant frequencies in vowels. These results demonstrate that children as young as 3 years old speak in ways that reflect their sex assigned at birth. We interpret this as evidence that children manipulate their speech apparatus volitionally to mark gender through speech.

Neoliberal forces have increased the use of English as a medium of instruction (MOI) in higher education globally. The status of English has shifted from being a curricular subject to the primary language of instruction, particularly in private higher education institutions. Drawing on Baldauf (2006), Kaplan and Baldauf (2003), and Spolsky (2009), and conducting a multi-level policy document analysis, this study set out to investigate the use of English as an MOI in Bangladeshi higher education. At the macro level, we analysed language-related policy documents, such as the National Education Policy (NEP), the Bangladesh National Qualifications Framework (BNQF), and University Grant Commission (UGC) policies. At the meso level, we examined various publicly available policy documents of a private university, including MOI statements, purpose and vision statements, admission requirements, curriculum, assessment, textbook recommendations, and advertisements for faculty positions. The findings revealed that while macro-level MOI policies are left open for meso-level interpretation, private universities have adopted an MOI policy that shifted from a nationalist Bangla-only ideology to a neoliberal English-only one, as evidenced in their practices and management initiatives. This shift has essentially served a covert colonial agenda under the guise of internationalisation and adoption of the American higher education model.

Travel accounts provide both benefits and challenges to survey archaeologists. This article presents a case study, generated by the Vayots Dzor Silk Road Survey, which aims to reconstruct the medieval (tenth to fifteenth centuries ad) landscape of Vayots Dzor in the Republic of Armenia, ‘excavating’ literary accounts of its landscape. Knowledge of this region in the Middle Ages is dominated by a core text written in the thirteenth century by Bishop Step’anos Orbelyan. From the mid-nineteenth century onwards, the region was visited by travellers who found links between the places they visited, the inscriptions they recorded, and the events and locations attested in Orbelyan’s text. Through examples from the site list of the Vayots Dzor Silk Road Survey, the authors explore how these and other sources accumulate, creating local knowledge about places that inform archaeologists and heritage professionals. They argue for reflection on the ways that local memory, archaeology, and the physical landscape inform complex makings of place.

Retrograde amnesia for autobiographical memories is a commonly self-reported cognitive side-effect of electroconvulsive therapy (ECT), but it is unclear to what extent objective performance differs between ECT-exposed and ECT-unexposed patients with depression. We investigated the association between exposure to brief-pulse (1.0 ms) bitemporal or high-dose right unilateral ECT and retrograde amnesia at short- and long-term follow-up, compared with inpatient controls with moderate-to-severe depression without lifetime exposure to ECT and receiving psychotropic pharmacotherapy and other aspects of routine inpatient care. In propensity score analyses, statistically significant reductions in autobiographical memory recall consistency were found in bitemporal and high-dose right unilateral ECT within days of an ECT course and 3 months following final ECT session. The reduction in autobiographical memory consistency was substantially more pronounced in bitemporal ECT. Retrograde amnesia for items recalled before ECT occurs with commonly utilised ECT techniques, and may be a persisting adverse cognitive effect of ECT.

According to a recent move in social epistemology, certain types of epistemic wrongs require distinctively epistemic reparations. For instance, if you have been wrongfully convicted of murder, you have not only the right to various kinds of economic and social reparations but also the ‘right to be known’ (Lackey 2022) – crudely, the right to tell the true story about yourself and be listened to. In this paper, I extend this framework to the context of epistemic decolonisation. I argue that the key decolonial epistemic reparations are reparations for the undermined epistemic authority of the colonised. I call these ‘decolonial epistemic authority reparations’ and develop five constraints on a plausible account of them. If the argument is compelling, it will advance both the epistemic reparations framework (which does not talk to the decolonisation literature at present) and the project of epistemic decolonisation (which does not yet canvass epistemic reparations).

Minimizing an adversarial surrogate risk is a common technique for learning robust classifiers. Prior work showed that convex surrogate losses are not statistically consistent in the adversarial context – or in other words, a minimizing sequence of the adversarial surrogate risk will not necessarily minimize the adversarial classification error. We connect the consistency of adversarial surrogate losses to properties of minimizers to the adversarial classification risk, known as adversarial Bayes classifiers. Specifically, under reasonable distributional assumptions, a convex surrogate loss is statistically consistent for adversarial learning iff the adversarial Bayes classifier satisfies a certain notion of uniqueness.

‘Living well’ is an important concept across national dementia strategies. Qualitative research has contributed to understanding of living well for people with dementia. Longitudinal qualitative approaches, though fewer, can explore potential changes in accounts of living well, psychological coping and adapting to dementia, and if/how people with dementia maintain continuity in their lives. This longitudinal qualitative study aims to gauge what is important for ‘living well’ with mild-to-moderate dementia and whether this changes over time in a group of older people with mild-to-moderate dementia living at home. Semi-structured, qualitative interviews with 20 people with dementia from the IDEAL cohort study were conducted in 2017 and again one year later then thematically analysed. The overarching narrative was largely that of continuity and adaptation, with incremental not disruptive change. Continuing participation and meaningful occupation were important to maintaining living well over time; individuals pursued new as well as previous interests. As a key psychological coping strategy to support continuity in their lives, individuals emphasised their capabilities to maintain activities in spite of dementia, compartmentalising areas that had become more challenging. Maintaining social networks and accommodating changes in social relationships were also central to living well, including managing the psychological impacts of changes in spousal relationships. People in the earlier stages of dementia emphasise continuity and their capabilities, reporting change over time only in certain aspects of their lives. However, small, incremental changes in their social relationships and opportunities for meaningful occupation may still afford key areas for supporting capability to ‘live well’.

We consider a family of cyclic presentations and show that, subject to certain conditions on the defining parameters, they are spines of closed 3-manifolds. These are new examples where the reduced Whitehead graphs are of the same type as those of the Fractional Fibonacci presentations; here the corresponding manifolds are often (but not always) hyperbolic. We also express a lens space construction in terms of a class of positive cyclic presentations that are spines of closed 3-manifolds. These presentations then furnish examples where the Whitehead graphs are of the same type as those of the positive cyclic presentations of type $\mathfrak {Z}$, as considered by McDermott.