Optimum structure for a uniform load over multiple spans

This paper presents a new half-plane Michell structure that transmits a uniformly distributed load of infinite horizontal extent to a series of equally-spaced pinned supports. Full kinematic description of the structure is obtained for the case when the maximum allowable tensile stress is greater than or equal to the allowable compressive stress. Although formal proof of optimality of the solution presented is not yet available, the proposed analytical solution is supported by substantial numerical evidence, involving the solution of problems with in excess of 10 billion potential members. Furthermore, numerical solutions for various combinations of unequal allowable stresses suggest the existence of a family of related, simple, and practically relevant structures, which range in form from a Hemp-type arch with vertical hangers to a structure which strongly resembles a cable-stayed bridge

Brendan meets Columbus: A more commodious islescape

This paper proposes that we can reimagine insular literatures and medieval islescapes as commodious seas of cultural and intellectual loci that span time, culture, and text alike. By moving beyond the rhetoric of insular separation or connectivity, we can see that islands connect even when medieval minds saw separation. The essay focuses on the Brendan legend and the commodious cultural ‘sea of islands’ that it inhabits, a space that connects the modern reader to a history of other connections, fact to fancy, and the real and the imaginary. When sailing in this sea, Brendan meets Columbus, and the late medieval idea of a lost island spreads though space and time

Queer Touch Between Holy Women: Julian of Norwich, Margery Kempe, Birgitta of Sweden, and the Visitation

Under embargo until: 2021-12-17This essay takes a new approach to the well-known meeting between two late-medieval English visionary women, Margery Kempe and the anchoress Julian of Norwich, as described in The Book of Margery Kempe. In this analysis their conversation subtly evokes a long history of women concentrating their subversive power through intimate, spiritual exchange, a history reaching back to the Biblical Visitation scene and expressed in its medieval artistic and literary instantiations. A queer reading illuminates the way that such female same-sex relationships challenge patriarchal systems by offering a privileged access to God outside clerical supervision. By examining Margery and Julian’s encounter, Luke’s Visitation passage, its depiction in a late-medieval Book of Hours, and comparing two different Middle English translations of a Visitation vision in Birgitta of Sweden’s Revelations, the full transgressive effect of queer touch between women—or even its unspoken possibility—emerges.acceptedVersio

On the edge: Chaucer and Gower’s queer glosses

In this article Diane Watt and I focus on a number of manuscript glosses accompanying the tale of Constance in Chaucer's The Man of Law's Tale and in Gower's Tale of Constance in Confessio Amantis. By applying queer theory to the paratextual apparatus of these manuscripts, we shed new light on the anxieties about authority and authorship shared by Chaucer and Gower (and their circles of collaborators). We also reevaluate the role of error and manuscripts variants, and argue for the queer pleasure provided by misprision and misinterpretation. This helps us to move away from patriarchal constructs on canon formation and manuscript transmission

On transmissible load formulations in topology optimization

Transmissible loads are external loads defined by their line of action, with actual points of load application chosen as part of the topology optimization process. Although for problems where the optimal structure is a funicular, transmissible loads can be viewed as surface loads, in other cases such loads are free to be applied to internal parts of the structure. There are two main transmissible load formulations described in the literature: a rigid bar (constrained displacement) formulation or, less commonly, a migrating load (equilibrium) formulation. Here, we employ a simple Mohr’s circle analysis to show that the rigid bar formulation will only produce correct structural forms in certain specific circumstances. Numerical examples are used to demonstrate (and explain) the incorrect topologies produced when the rigid bar formulation is applied in other situations. A new analytical solution is also presented for a uniformly loaded cantilever structure. Finally, we invoke duality principles to elucidate the source of the discrepancy between the two formulations, considering both discrete truss and continuum topology optimization formulations

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Prevalence and progression of diabetic nephropathy in South Asian, white European and African Caribbean people with type 2 diabetes: A systematic review and meta-analysis

AIMS: To conduct a systematic review and meta-analysis of published observational evidence to assess the difference in the prevalence and progression of diabetic nephropathy, and the development of end-stage renal disease (ESRD) in people from three different ethnic groups with type 2 diabetes (T2DM). MATERIALS AND METHODS: Relevant studies were identified in a literature search of MEDLINE, EMBASE and reference lists of relevant studies published up to May 2018. We decided a priori that there were no differences in the prevalence and progression of diabetic nephropathy, and the development of ESRD in the three ethnicities with T2DM. Pooled relative risks of microalbuminuria by ethnicity were estimated by fitting three random effects meta-analyses models. A narrative synthesis of the nephropathy progression in the studies was carried out. The review was registered in PROSPERO (CRD42018107350). RESULTS: Thirty-two studies with data on 153 827 unique participants were eligible for inclusion in the review. The pooled prevalence ratio of microalbuminuria in South Asian compared with white European participants was 1.14 (95% confidence interval [CI] 0.99, 1.32; P = 0.065), while for African Caribbean vs South Asian participants the pooled prevalence ratio was 1.08 (95% CI 0.93, 1.24; P = 0.327). Results for renal decline were inconsistent, with preponderance towards a high rate of disease progression in South Asian compared with white participants. The estimated pooled incidence rate ratio (IRR) for ESRD was significantly higher in African Caribbean vs white European participants: 2.75 (95% CI 2.01, 3.48; P < 0.001). CONCLUSION: The results of this review did not show a significant link between ethnicity (South Asian, white European and African Caribbean) and the prevalence of microalbuminuria; however, the IRR for ESRD in African Caribbean compared with white European participants was significantly higher. Further research is needed to explore the potential non-albuminuric pathways of progression to ESRD