To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We define and develop two-level type theory (2LTT), a version of Martin-Löf type theory which combines two different type theories. We refer to them as the ‘inner’ and the ‘outer’ type theory. In our case of interest, the inner theory is homotopy type theory (HoTT) which may include univalent universes and higher inductive types. The outer theory is a traditional form of type theory validating uniqueness of identity proofs (UIP). One point of view on it is as internalised meta-theory of the inner type theory. There are two motivations for 2LTT. Firstly, there are certain results about HoTT which are of meta-theoretic nature, such as the statement that semisimplicial types up to level n can be constructed in HoTT for any externally fixed natural number n. Such results cannot be expressed in HoTT itself, but they can be formalised and proved in 2LTT, where n will be a variable in the outer theory. This point of view is inspired by observations about conservativity of presheaf models. Secondly, 2LTT is a framework which is suitable for formulating additional axioms that one might want to add to HoTT. This idea is heavily inspired by Voevodsky’s Homotopy Type System (HTS), which constitutes one specific instance of a 2LTT. HTS has an axiom ensuring that the type of natural numbers behaves like the external natural numbers, which allows the construction of a universe of semisimplicial types. In 2LTT, this axiom can be assumed by postulating that the inner and outer natural numbers types are isomorphic. After defining 2LTT, we set up a collection of tools with the goal of making 2LTT a convenient language for future developments. As a first such application, we develop the theory of Reedy fibrant diagrams in the style of Shulman. Continuing this line of thought, we suggest a definition of $(\infty,1)$-category and give some examples.
I discuss a contemporary solution to the dynamic problem of old evidence (POE), as proposed by Sprenger. Sprenger’s solution combines the Garber–Jeffrey–Niiniluoto (GJN) approach with Howson’s suggestion of counterfactually removing the old evidence from scientists’ belief systems. I argue that in the dynamic POE, the challenge is to explain how an insight under beliefs in which the old evidence E is known increased the credence of a scientific hypothesis. Therefore, Sprenger’s counterfactual solution, in which E has been artificially removed, does not resolve the problem. I consider several potential responses.
Misclassification of Clostridioides difficile colonization as hospital-onset C. difficile infection (HO-CDI) can lead to unnecessary treatment of patients and substantial financial penalties for hospitals. We successfully implemented mandatory C. difficile PCR testing approval as a strategy to optimize testing, which was associated with a significant decline in the monthly incidence of HO-CDI rates and lowering of our standardized infection ratio to 0.77 (from 1.03) 18 months after this intervention. Approval request served as an educational opportunity to promote mindful testing and accurate diagnosis of HO-CDI.
How does oral argument attendance impact public perceptions of the judiciary? Judicial independence is partly contingent on public support, but the conditions that generate institutional good will are not well understood. We examine how judicial outreach and court exposure inform public attitudes. Leveraging a field-experiment randomizing in-person attendance at oral arguments conducted by a federal circuit court of appeals on a university campus, we find that exposure increases perceptions of institutional legitimacy and the extent to which judicial decisions are motivated by law versus politics. The results have important implications for judicial politics and policy debates concerning reform initiatives involving circuit riding, courtroom cameras, and public outreach.
This article analyzes the effects on violence of electing law-and-order candidates at the local level. It argues that law-and-order politicians embedded in the police will divert resources to favor their constituency, which in violence-prone areas could generate more murders. Using ballot names of council candidates in thousands of local elections in Brazil to accurately classify law-and-order candidates, it shows that the election of police law-and-order candidates causes more homicides. Moreover, georeferenced data on police activity and homicides show neglect in areas that did not support a winning police law-and-order candidate, despite these areas being home to the majority of individuals vulnerable to violence. This favoritism, however, is not present in places where preexisting local institutions make policing more transparent. Instead of persecution directed against minorities or the incapacity to battle criminal gangs, this research shows that surges in violence can be the result of typical forms of democratic representation.
Les projets de nature intergénérationnelle sont aujourd’hui hautement valorisés par les décideurs publics et les responsables académiques. La pandémie de COVID-19 a fait ressurgir l’importance des relations entre les générations et des projets intergénérationnels ancrés dans la communauté. Cet article présente les résultats d’une étude visant à faire travailler ensemble des personnes aînées et des jeunes adultes au sein d’un projet intergénérationnel ancré dans la communauté. La particularité dans cette étude c’est qu’elle utilise une démarche méthodologique co-constructive, c’est-à-dire qu’elle jumelle des chercheurs et des chercheures académiques de différents horizons et des personnes aînées citoyennes tout au long du processus de recherche. Les résultats portent particulièrement sur les attentes des personnes participantes au projet intergénérationnel, la description du déroulement du projet (sur une période de dix mois) et les perceptions des relations intergénérationnelles au cours du projet. Nous terminons l’article par une discussion autour des constats centraux de notre étude et de notre expérience dans le cadre d’une recherche co-constructive.
During the operation of automatic navigation rice transplanter, the accuracy of path tracking is influenced by whether the transplanter can enter the stable state of linear path tracking quickly, thus affecting the operation quality and efficiency. To reduce the time to enter the path tracking stable state and improve the tracking accuracy and stability for the rice transplanter, path tracking control method based on variable universe fuzzy control (VUFC) and improved beetle antenna search (BAS) is proposed in this paper. VUFC is applied to achieve adaptive adjustment of the fuzzy universe by dynamically adjusting the quantization and scaling factors according to the variations of errors by the contraction–expansion factor. To solve the problem of setting the contraction–expansion factor in VUFC and real-time performance, an offline parameter optimization method is presented to calculate the optimal contraction–expansion factor by an iterative optimization algorithm in a path tracking simulation model, where the iterative optimization algorithm is the BAS algorithm improved by the isolated niching technique and adaptive step size strategy in this paper. To verify the effectiveness of the proposed path tracking control method, simulation and field linear path tracking experiments were carried out. Experimental results indicate that the proposed method reduces the time of entering the stable state of linear path tracking and improves the accuracy and stability of path tracking compared with the pure pursuit control method.
Anaemia is characterised by low hemoglobin (Hb) concentration. Despite being a public health concern in Ethiopia, the role of micronutrients and non-nutritional factors as a determinant of Hb concentrations has been inadequately explored. This study focused on the assessment of serum micronutrient and Hb concentrations and a range of non-nutritional factors, to evaluate their associations with the risk of anaemia among the Ethiopian population (n 2046). It also explored the mediation effect of Zn on the relation between se and Hb. Bivariate and multivariate regression analyses were performed to identify the relationship between serum micronutrients concentration, inflammation biomarkers, nutritional status, presence of parasitic infection and socio-demographic factors with Hb concentration (n 2046). Sobel–Goodman test was applied to investigate the mediation of Zn on relations between serum se and Hb. In total, 18·6 % of participants were anaemic, 5·8 % had iron deficiency (ID), 2·6 % had ID anaemia and 0·6 % had tissue ID. Younger age, household head illiteracy and low serum concentrations of ferritin, Co, Cu and folate were associated with anaemia. Serum se had an indirect effect that was mediated by Zn, with a significant effect of se on Zn (P < 0·001) and Zn on Hb (P < 0·001). The findings of this study suggest the need for designing a multi-sectorial intervention to address anaemia based on demographic group.
On all Bergman–Besov Hilbert spaces on the unit disk, we find self-adjoint weighted shift operators that are differential operators of half-order whose commutators are the identity, thereby obtaining uncertainty relations in these spaces. We also obtain joint average uncertainty relations for pairs of commuting tuples of operators on the same spaces defined on the unit ball. We further identify functions that yield equality in some uncertainty inequalities.
Hypotheses based on allocation theory and herbivore selection offer opposite predictions about how defence levels against herbivores change as the plant tissue grows. The growth differentiation balance hypothesis (GDBH) assumes that defences will be resource-limited in immature tissues and predict that defence levels increase as the plant tissue grows. Conversely, the optimal defence hypothesis (ODH) proposes that plants would have the highest level of defences in the parts that have the highest value in terms of fitness and/or are more frequently attacked by herbivores, such as young tissues. We examine whether spinescence in the shrub Rubus adenotrichos (blackberry) change as the leaf grows, and if this change is consistent with the GDBH or the ODH. We compare the petiole area occupied by prickles, the prickles density and the individual prickle area in mature versus young petioles from Rubus adenotrichos. Our results show that, in R. adenotrichos, young tissues are more protected than mature tissues. Prickles density and the petiole area occupied by prickles were up to 25% higher in young petioles than in mature ones. These results support the ODH, reinforcing the idea that extrinsic factors such as herbivores pressure might drive the change of structural defences level across leaf ontogeny.
We prove that there exists a universal constant D such that if p is a prime divisor of the index of the Fitting subgroup of a finite group G, then the number of conjugacy classes of G is at least $Dp/\log_2p$. We conjecture that we can take $D=1$ and prove that for solvable groups, we can take $D=1/3$.
This paper proposes an infrastructure analytic for exploring the urbanizing landscapes of China's “national new areas.” In an effort to develop a less city-centred approach to the transformations underway in these spaces, I consider the new area as an “infrastructure space” in which the conventional distinctions between rural and urban have become increasingly meaningless. Such an approach draws our attention to the ways large-scale infrastructures of connectivity are driving a decentred form of urban development in which the livelihoods of residents are shaped by access to networks more than proximity to city centres. Based on case-study research of urbanizing villages and the rapid transformation of rural livelihoods in Gui'an New Area in Guizhou province, I suggest that an infrastructure analytic sheds light on the ways national new areas can be understood as particular events in an unfolding regime of circulation that has come to dominate urban forms worldwide.
Diaphus fulgens is a diel vertical migrant myctophid, occurring abundantly in the Kuroshio waters of the East China Sea. They are multiple batch spawners with a short interspawn period, resulting in high egg productivity. Multiple spawning would be supported by feeding during their spawning season; however, there is no information on the feeding habits of this species. The present study examined the diet composition, diel feeding periodicity and daily ration of mature adult D. fulgens collected at different periods of the day during February to March. The most prevalent item was appendicularians and their mucus houses, which dominated the stomach contents in both number and weight. Additionally, various species of copepods were predated, with a prevalence, by weight, of the large-sized Pleuromamma piseki. Diaphus fulgens feeds actively in the epipelagic layer at night and moves down to the mesopelagic layer in the early morning, and digests most of the consumed food by the late afternoon, showing a typical nocturnal feeding pattern. Based on diel changes in the stomach content index and instantaneous gastric evacuation rate estimated in this study (0.118–0.129 h−1), the daily ration was calculated to be 4.0–4.2% of body weight, equivalent to a daily caloric intake of 21.2–22.3 cal day−1. Since the caloric value to produce a batch of oocytes was estimated to be 8.2–11.5 cal day−1, on an energetic basis, D. fulgens can maintain the multiple spawning at a cost of approximately 37–54% of its daily caloric intake.
Acquired Brain Injury (ABI) can lead to the need to plan for housing, assistive technology and support to meet a person’s goals. Recent Australian policy reforms have brought about opportunities for person-centred approaches to assistive technology (AT) product selection, and the opportunity for users of supports such as assistive technology and environmental adaptations to describe and measure their own outcomes. My AT Outcomes Framework (MyATOF) is an Australian tool designed for use by AT users and their support networks to articulate supports, outcomes, costs, and service delivery experiences. This article aims (i) report on use of MyATOF in a case study of ABI and AT-enabled housing and (ii) critically evaluate MyATOF tools and administration for this use case from the perspectives of the MyATOF author, an occupational therapist, and a lived experience expert with an ABI. An iterative development and test design was used to adapt the MyATOF administration procedures and conduct a case report evaluation. Results support the relevance of MyATOF conceptual domains, and detailed data about outcomes made possible by an AT-enabled home was captured. Recommendations are made to further refine the questions for ease of use by persons with ABI including simplifying the costing tool and enabling staggered administration. This case report suggests MyATOF can ‘measure what matters’ for ABI and AT-enabled housing and is worthy of further evaluation.
The analysis of food using a perspective centred on nutrients seems inadequate for understanding the dietary transition and its impact on the growth of obesity and chronic diseases. Industrial food processing is now proposed as the key to explain the relationship between food and health. The NOVA food classification considers the degree and the purpose of food processing, which includes physical, biological and chemical processes used after foods are separated from nature, and before being consumed or prepared as dishes and meals. NOVA has four food groups: (1) unprocessed and minimally processed foods; (2) processed culinary ingredients; (3) processed foods and (4) ultra-processed foods, which are formulations made mostly or entirely from substances derived from group 1 foods and additives, with little if any intact group 1 food. Many investigations linking high ultra-processed food consumption with deterioration of diets and adverse health outcomes are reinforced by prospective studies, systematic reviews and meta-analyses. There are various plausible explanations of why diets high in ultra-processed foods are harmful. Their production and consumption continue to rise worldwide. Efficient and effective public policies and actions that reduce production and consumption of ultra-processed products are needed, to protect human health now and in future.
The purpose of this study is to further investigate the relationship between sweetener exposure and the risk of endometrial cancer (EC). Up until December 2022, a literature search in an electronic database was carried out utilizing PubMed, Web of Science, Ovid, and Scopus. The odds ratio (OR) and 95 % confidence interval (CI) were used to evaluate the results. Sweeteners were divided into nutritional sweeteners (generally refers to sugar, such as sucrose and glucose) and non-nutritional sweeteners (generally refers to artificial sweeteners, such saccharin and aspartame). Ten cohort studies and two case-control studies were eventually included. The study found that in 12 studies, compared with the non-exposed group, the incidence rate of EC in the sweetener exposed group was higher (OR = 1·15, 95 % CI = [1·07, 1·24]). Subgroup analysis showed that in 11 studies, the incidence rate of EC in the nutritional sweetener exposed group was higher than that in the non-exposed group (OR = 1·25, 95 % CI = [1·14, 1·38]). In 4 studies, there was no difference in the incidence rate of EC between individuals exposed to non-nutritional sweeteners and those who were not exposed to non-nutritional sweeteners (OR = 0·90, 95 % CI = [0·81, 1·01]). This study reported that the consumption of nutritional sweeteners may increase the risk of EC, whereas there was no significant relationship between the exposure of non-nutritional sweeteners and the incidence of EC. Based on the results of this study, it is recommended to reduce the intake of nutritional sweeteners, but it is uncertain whether use of on-nutritional sweeteners instead of nutritional sweetener.
In the coronavirus disease 2019 (COVID-19) pandemic, child and adolescent psychiatry wards face the risk of severe acute respiratory coronavirus 2 (SARS-CoV-2) introduction and spread within the facility. In this setting, mask and vaccine mandates are hard to enforce, especially for younger children. Surveillance testing may detect infection early and enable mitigation measures to prevent viral spread. We conducted a modeling study to determine the optimal method and frequency of surveillance testing and to analyze the effect of weekly team meetings on transmission dynamics.
Design and setting:
Simulation with an agent-based model reflecting ward structure, work processes, and contact networks from a real-world child and adolescent psychiatry clinic with 4 wards, 40 patients, and 72 healthcare workers.
Methods:
We simulated the spread of 2 SARS-CoV-2 variants over 60 days under surveillance testing with polymerase chain reaction (PCR) tests and rapid antigen tests in different scenarios. We measured the size, peak, and the duration of an outbreak. We compared medians and percentage of spillover events to other wards from 1,000 simulations for each setting.
Results:
The outbreak size, peak, and duration were dependent on test frequency, test type, SARS-CoV-2 variant, and ward connectivity. Under surveillance conditions, joint staff meetings and therapists shared between wards did not significantly change median outbreak size under surveillance conditions. With daily antigen testing, outbreaks were mostly confined to 1 ward and median outbreak sizes were lower than with twice-weekly PCR testing (1 vs 22; P < .001).
Conclusion:
Modeling can help to understand transmission patterns and guide local infection control measures.
The presence of thermocapillary (Marangoni) convection in microgravity may help to enhance the heat transfer rate of phase change materials (PCMs) in space applications. We present a three-dimensional numerical investigation of the nonlinear dynamics of a melting PCM placed in a cylindrical container filled with n-octadecane and surrounded by passive air. The heat exchange between the PCM and ambient air is characterized in terms of the Biot number, when the air temperature has a linear profile. The effect of thermocapillary convection on heat transfer and the topology of the melting front is studied by varying the applied temperature difference between the circular supports and the heat transfer through the interface. The evolution of Marangoni convection during the PCM melting leads to the appearance of hydrothermal instabilities. A new mathematical approach for the nonlinear analysis of emerging hydrothermal waves (HTWs) is suggested. Being applied for the first time to the examination of PCMs, this procedure allows us to explore the nature of the coupling between HTWs and heat gain/loss through the interface, and how it changes over time. We observe a variety of dynamics, including standing and travelling waves, and determine their dominant and secondary azimuthal wavenumbers. Coexistence of multiple travelling waves with different wavenumbers, rotating in the same or opposite directions, is among the most fascinating observations.