724 research outputs found
BCJ relations in and the double-trace spectrum of super gluons
We revisit the four-point function of super gluons in in
the spirit of the large formalism and show how the integrand of a
generalised Mellin transform satisfies various non-trivial properties such as
decoupling identity, BCJ relations and colour-kinematic duality, in a
way that directly mirrors the analogous relations in flat space. We unmix the
spectrum of double-trace operators at large and find all anomalous
dimensions at leading order. The anomalous dimensions follow a very simple
pattern, resembling those of other theories with hidden conformal symmetries.Comment: 9 page
Introduction: ‘Women as Wives and Workers: Marking Fifty Years of The Feminine Mystique’ Special Issue
A Heat Loss Sensitivity Index to Inform Housing Retrofit Policy in the UK
A substantial number of dwellings in the UK have poor building fabric, leading to higher carbon emissions, fuel expenses, and the risk of cold homes. To tackle these challenges, domestic energy efficiency policies are being implemented. One effective approach is the use of energy models, which enable sensitivity analysis to provide valuable insights for policymakers. This study employed dynamic thermal simulation models for 32 housing archetypes representative of solid-walled homes in the UK to calculate the heat loss and the sensitivity coefficient per building fabric feature, after which a metric Heat Loss Sensitivity (HLS) index was established to guide the selection of retrofit features for each archetype. The building fabric features’ inputs were then adjusted to establish both lower and upper bounds, simulating low and high performance levels, to predict the how space heating energy demand varies. The analysis was extended by replicating the process with various scenarios considering climates, window-to-wall ratios, and overshadowing. The findings highlight the external wall as the primary consideration in retrofitting due to its high HLS index, even at high window-to-wall ratios. It was also established that dwelling type is important in retrofit decision-making, with floor and loft retrofits having a high HLS index in bungalows. Furthermore, the analysis underlines the necessity for Standard Assessment Procedure assessors to evaluate loft U-value and air permeability rates prior to implementing retrofit measures, given the significance of these factors in the lower and upper bounds analysis. Researchers globally can replicate the HLS index approach, facilitating the implementation of housing retrofit policies worldwide
"I'm not an investigator and I'm not a police officer" : a faculty's view on academic integrity in an undergraduate nursing degree
In nursing, expectations of honesty and integrity are clearly stipulated throughout professional standards and codes of conduct, thus the concept of academic integrity has even more impetus in preparing students for graduate practice. However, a disparity between policy and practice misses the opportunity to instil the principles of academic integrity, and at its core honesty, a pivotal trait in the nursing profession. This study draws upon the experience of the nursing faculty to explore how academic integrity policy of deterrence operate in nursing education. While participants deplored cheating behaviours, they expressed frustration in having to ‘police’ large numbers of students who had little awareness of the academic standards to meet policy requirements. In addition, they were cynical because of a perceived lack of severity in sanctions for students who repeatedly breached integrity. Participants expressed a moral obligation as educators to meet student learning needs and preferred to engage with students in a more meaningful way to uphold academic integrity. The ambivalence to detect and report breaches in integrity undermines the effectiveness of policy. Therefore, faculty must recognise the importance of their role in detecting and escalating cases of dishonesty and execute deterrence in a more consistent way. To do this, greater support at an institutional level, such as smaller class sizes, inclusion in decision making around sanctions and recognition of additional workload, will enable faculty to uphold policy. Although policing was not their preferred approach, the role of faculty in detecting and reporting cases of misconduct is crucial to increase the certainty of students getting caught, which is essential if policy is to be effective in deterring dishonest behaviour
Nutritional Factors Associated with Anaemia in Pregnant Women in Northern Nigeria
This study was conducted to assess the relative contribution of iron, folate, and B12 deficiency to anaemia in pregnant women in sub-Saharan Africa. In total, 146 pregnant women, who attended two antenatal clinics in Gombe, Nigeria, were recruited into the study. The majority (54%) of the women were in the third trimester. Blood samples were obtained for determination of haematocrit and for measurement of serum iron, total iron-binding capacity, ferritin, folate, vitamin B12, and homocysteine. Malaria was present in 15 (9.4%) women. Based on a haemoglobin value of <105 g/L, 44 (30%) women were classified as anaemic. The major contributing factor to anaemia was iron deficiency based on the serum concentration of ferritin (<10 ng/mL). The mean homocysteine concentration for all subjects was 14.1 μmol/L, and homocysteine concentrations were inversely correlated with concentrations of folate and vitamin B12. The serum homocysteine increased markedly at serum vitamin B12 levels below 250 pmol/L. The most common cause of anaemia in the pregnant women in northern Nigeria was iron deficiency, and the elevated concentrations of homocysteine were most likely due to both their marginal folate and vitamin B12 status
Evaluating Floor Losses in the Context of QUB Measurements of a Passivhaus Dwelling
Measuring the performance of building fabric is increasingly important as stakeholders wish to compare as-built performance with design expectations. When measuring whole house performance (Heat Transfer Coefficient) heat losses through the floor in slab-on-ground type constructions are intractable and introduce uncertainty into measurements. As such efforts are often made to isolate them from measurements. The QUB method is a practical method of measuring whole house building performance. Previous work has shown floor losses can successfully be isolated from measurement through use of heat flux measurements and additional calculation steps. To further test this isolation procedure, three QUB tests were performed on a slab-on-ground Passivhaus dwelling. Whilst the whole house performance measurements agree with the design performance (all results within 11% of the design) the floor losses measured appear unrealistically high. The conditions of the tests, conducted in late summer and in a highly insulated property, are likely causing the heat flux measurements to capture heat being stored in the floor construction rather than heat being lost from the property. Follow up measurements in more preferable conditions are planned which will assist in determining the cause of these observations
An empirical evaluation of temporal overheating in an assisted living Passivhaus dwelling in the UK
Global concern around energy use and anthropogenic climate change have resulted in an increased effort to reduce the energy demand and CO2 emissions attributable to buildings. This has led to the development of a number of low energy building standards, one of which is the internationally recognised Passivhaus Standard. The Passivhaus Standard aims to reduce the space heating energy demand of a building by adopting a ‘fabric first’ approach, thus ensuring the thermal envelope is highly insulated and airtight whilst also maximising passive solar heat gains. However, adopting such an approach does present a risk of overheating; a situation that is of particular concern when the occupants have additional healthcare requirements. This study uses 21 months of in-use monitored data to consider the overheating risk in a UK Passivhaus dwelling with vulnerable occupants using both static and adaptive thermal comfort assessment methods. The analysis of the data suggests the occurrence of substantial overheating according to PHPP, CIBSE Guide A and CIBSE TM52 criteria. The analysis was then expanded to consider a novel composite method to overcome the limitations of existing approaches, allowing overheating to be assessed during non-typical periods i.e. the heating season. This revealed apparent overheating during colder months, in addition to substantial night-time overheating. This has implications for the thermal comfort assessment of low energy dwellings and the design and operation of Passivhaus buildings, particularly those with vulnerable occupants
Party Wall Behaviour and Impact in QUB and Coheating Tests
In situ measurement can enable accurate evaluation of a building’s as-built performance. However, when measuring whole house performance, party walls introduce measurement uncertainty. Subsequently, it is common to “adjust” measurements to isolate heat transfer through party walls. This study explores the behaviour and impact of party walls in QUB and coheating measurements of a semi-detached house, presenting empirical evidence on the validity of these measurements where a party wall is present. Two different party wall heat transfer behaviours were observed through heat flux density measurements. Thermal charging is apparent in QUB tests and the initial stages of coheating. After 48 h of coheating, the party wall has become heat saturated and exhibits stable heat transfer. Consequently, using heat flux density measurements to isolate party wall heat transfer in QUB tests, where thermal saturation has not been achieved, can result in misleading inferences. The coheating and QUB measurements without party wall adjustment are in close agreement, irrespective of differing heating patterns in the neighbouring property. The generalisation of these findings is problematic since they describe the impact of the case study-specific built form and the test conditions. Future work to explore the impact of built form and test conditions is needed
Evolución de los ácidos grasos en el mesocarpo del níspero (Mespilus germanica. L.) a diferentes estados de maduración
The fatty acid composition of medlar (Mespilus germanica L.) varied significantly among the ripening stages sampled at 157, 172 and 187 DAFs (days after full bloom). Twenty-one different fatty acids were detected in preclimacteric fruit and 17 when the climacteric began. Principal fatty acids, determined in medlar fruit harvested from October (157 and 172 DAFs) to November (187 DAF) were mainly palmitic acid (16:0), linoleic acid (18:2n-6), and a-linolenic acid (18:3n-3). While the content of saturated fatty acids [palmitic acid (16:0) and stearic acid (18:0)] increased, the content of the essential polyunsaturated fatty acids [linoleic acid (18:2n-6) and linolenic acid (18:3n-3)] decreased through ripening, in parallel with pulp darkening. The percentage of linoleic acid and a-linolenic acid in ripe, hard fruits was 60.0 and 13.5 % of dry wt at 157 DAF which decreased throughout ripening, remaining at 28.7 and 5.6 % of dry wt, respectively, in the fully softened and darkened pulp. A marked decreases in the double bond index, percentage of unsaturation and the ratio of unsaturation/saturation were also seen throughout the medlar ripening. The contribution of unsaturated fatty acid to the total fatty acid content decreased markedly as the medlar fruit became progressively softer and darkened.La composición en ácidos grasos del níspero (Mespilus germanica L.) varió significativamente entre los estados de maduración muestreados a los 157, 172 y 187 DAFs (días después de la floración). Veinte y un ácidos grasos diferentes fueron detectados en el fruto preclimatérico y 17 cuando comenzó el climaterio. Los ácidos grasos principales encontrados en nísperos, recolectados desde Octubre (157 y 172 DAFs) hasta Noviembre (187 DAF), fueron principalmente ácido palmítico (16:0), ácido linoléico (18:2n-6), y ácido a-linolénico (18:3n-3). En tanto que el contenido en ácidos grasos saturados (ácido palmítico (16:0) y ácido esteárico (18:0)) aumentó, el contenido en ácidos grasos esenciales (ácido linoleico (18:2n-6) y ácido linolénico (18:3n-6)) disminuyó durante la maduración, en paralelo con el oscurecimiento de la pulpa. El porcentaje de ácido linoleico y de ácido a-linolénico en frutos maduros sin reblandecer fue de 60.0 y 13.5 % del peso seco a 157 DAF, disminuyendo durante la maduración, y permaneciendo a 28.7 y 56 % del peso seco, respectivamente, en la pulpa completamente blanda y oscura. También se observó durante la maduración del níspero una marcada disminución en el número de dobles enlaces, en el tanto por ciento de instauración y en la relación instauración / saturación. La contribución de los ácidos grasos insaturados al contenido de ácidos grasos totales disminuyó marcadamente cuando el níspero comenzó progresivamente a reblandecerse y oscurecerse
- …