Estimating expected lifetime of revolving credit facilities in an IFRS 9 framework

This paper sets out to estimate expected lifetime of revolving credit facilities (e.g. credit card products) and is motivated by the introduction of the International Financial Reporting Standard 9 (IFRS 9) and its requirements for loan impairments. The reporting entity is required to estimate lifetime expected credit losses for certain nancial instruments. In practice, maximum contractual period for revolving credit facilities cannot be used in dening lifetime for the facility and credit risk mitigation actions need to be considered. A data set for a retail credit card portfolio was provided by a Nordic bank and for the lifetime denition derived, a model based on a conditional Markov chain was selected. Expected lifetime was estimated and an analytical expression for expected lifetime of revolving credit facilities was derived and validated.What period should credit losses be estimated over in IFRS 9? When the standard on how to account for credit losses moves to an expected loss approach, there is a need to find out how far into the future to look for losses. This is known as the expected lifetime, and I have dived into interpreting how the IFRS 9 standard can be implemented in a model for expected lifetime for credit cards and similar instruments. I propose and validate a model, along with a methodology for estimation. The Great Financial Crisis had a grand effect on most economies. Banks were assessed and it was recognized that in order to reduce effects of future downturns, provisions that were more forward-looking and higher were needed for credit losses. IFRS 9 is the answer to this (for reporting purposes) and the provisioning based on expected credit losses (rather than incurred) is the ingredient enabling this. A relevant consideration in this context is the expectation of lifetime for the instrument (e.g. a credit card) and since the phase of IFRS 9 concerning provisioning for loan losses is recently published, how to measure expected lifetime is not yet established. For this purpose, I introduce a concept called “End of lifetime event”. This concept brings together a common form of credit risk model for credit card portfolios and similar (where risk rating is based on how late the borrower is on a payment) with events related to expectations of how this type of instrument is managed. The result is a list of End of lifetime events that will function as absorbing states in the Markov chain implemented to estimate lifetimes. The Markov chain is a popular form of model, suitable for this task, both in its connection to common credit risk models and broad applicability. The selection methodology is based on testing if different candidate models possess the Markov property (that the distribution of future state depends on the past only in the present state), and finding a good trade-off between complexity (as low as possible) and accurate modelling of the data. For this, two statistical tests are used and a first-order Markov chain is selected, shown to be dependent on maximum historical risk of a borrower (which is reasonable, since this would explain a lot about a borrower beyond how late he or she currently is on a payment). The parameters for all allowed transitions in this extended model are estimated based on data from a portfolio of credit cards provided by a bank, where transitions between internal risk ratings (or states) were used for estimating the transition probabilities in the model. It is convenient at this point that a Markov chain is used, since expected lifetime now corresponds to what is known as expected absorption time, a straight-forward tool in analyzing absorbing Markov chains. There is a need to modify the way expected lifetime for this model is calculated, since the End of lifetime event for removal of what is known as the undrawn commitment component (the difference between the credit limit on e.g. a credit card and how much has been drawn) occurs with a delay from when the process reaches the corresponding absorbing state in the Markov chain. So, (expected) credit losses should be estimated over the period given by the following expression

COVID-19 lockdown reveals tourists as seabird guardians

The widespread lockdowns put in place to limit the spread of the new coronavirus disease (COVID-19) offers a rare opportunity in understanding how human presence influence ecosystems. Using data from long-term seabird monitoring, we reveal a previously concealed guarding effect by tourist groups on an iconic seabird colony in the Baltic Sea. The absence of tourists in 2020 lead to a sevenfold increase in presence of white-tailed eagles Haliaeetus albicilla, a sevenfold increase in their disturbance of breeding common murres Uria aalge and causing 26% lower murre productivity than the long-term average. Eagles did not prey on murres, but their frequent disturbances delayed egg laying and facilitated egg predation from herring gulls Larus argentatus and hooded crows Corvus cornix. Based on our findings, we suggest that human presence could be used as a strategic measure in guarding seabird colonies, and that a social-ecological systems perspective is vital for long-term success in protected area management

Hotspots of Biased Nucleotide Substitutions in Human Genes

Genes that have experienced accelerated evolutionary rates on the human lineage during recent evolution are candidates for involvement in human-specific adaptations. To determine the forces that cause increased evolutionary rates in certain genes, we analyzed alignments of 10,238 human genes to their orthologues in chimpanzee and macaque. Using a likelihood ratio test, we identified protein-coding sequences with an accelerated rate of base substitutions along the human lineage. Exons evolving at a fast rate in humans have a significant tendency to contain clusters of AT-to-GC (weak-to-strong) biased substitutions. This pattern is also observed in noncoding sequence flanking rapidly evolving exons. Accelerated exons occur in regions with elevated male recombination rates and exhibit an excess of nonsynonymous substitutions relative to the genomic average. We next analyzed genes with significantly elevated ratios of nonsynonymous to synonymous rates of base substitution (dN/dS) along the human lineage, and those with an excess of amino acid replacement substitutions relative to human polymorphism. These genes also show evidence of clusters of weak-to-strong biased substitutions. These findings indicate that a recombination-associated process, such as biased gene conversion (BGC), is driving fixation of GC alleles in the human genome. This process can lead to accelerated evolution in coding sequences and excess amino acid replacement substitutions, thereby generating significant results for tests of positive selection

Detailed evaluation of topographical effects of Hirtisation post-processing on electron beam powder bed fusion (PBF-EB) manufactured Ti-6Al-4V component

Metal additive manufacturing surface topographies are complex and challenging to characterise due to e.g. steep local slopes, re-entrant features, varying reflectivity and features of interest in vastly different scale ranges. Nevertheless, average height parameters such as Ra or Sa are commonly used as sole parameters for characterisation. In this paper, a novel method for selecting relevant parameters for evaluation is proposed and demonstrated using a case study where the smoothing effects after three processing steps of the electro chemical post-process Hirtisation of a metal AM surface are quantified. The method uses a combination of conventional areal texture parameters, multiscale analysis and statistics and can be used to efficiently achieve a detailed and more relevant surface topography characterisation. It was found that the three process steps have different effects on the surface topography regarding the types and sizes of features that were affected. In total, Sdq was reduced by 97 %, S5v was reduced by 81 % and Sa was reduced by 78 %. A surface texture with much lower average roughness, less deep pits and less steep slopes was produced, which is expected to be beneficial for improved fatigue properties

Exposure to drinking water chlorination by-products and fetal growth and prematurity: A nation wide register-based prospective study

Background: Chlorination is globally used to produce of safe drinking water. Chlorination by-products are easily formed, and there are indications that these are associated with adverse reproductive outcomes. Objectives: We conducted a nationwide register-based prospective study to assess whether gestational exposure to the four most common chlorination by-products [total trihalomethanes (TTHMs)] via tap water was associated with risk of small for gestational age (SGA), preterm delivery, and very preterm delivery. To date, this is one of the largest studies assessing drinking water TTHM-associated adverse reproductive outcomes. Methods: We included all singleton births 2005–2015 (live and stillbirths) of mothers residing in Swedish localities having >10,000 inhabitants, ≤2 operating waterworks, adequate information on chlorination treatment, and a sufficient number of routine TTHM measurements in tap water. Individual maternal second and third trimester exposure was obtained by linking TTHM measurements to residential history, categorized into no chlorination, 15μg TTHM/L. Outcomes and covariates were obtained via the linkage to Swedish health and administrative registers. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression using inverse probability weighting. We stratified the analyses by chlorination treatment (chloramine, hypochlorite). Results: Based on approximately 500,000 births, we observed a TTHM dose-dependent association with increased risk of SGA, confined to treatment with hypochlorite, corresponding to a multivariable-adjusted OR=1.20 (95% CI: 1.08, 1.33) comparing drinking water TTHM >15μg to the unexposed. Similar results were obtained when, instead of unexposed, the lowest exposure category (<5μg/L TTHM) was used as reference. No clear associations were observed for preterm delivery and very preterm delivery. Discussion: Chlorination by-products exposure via drinking water was associated with increased risk of SGA in areas with hypochlorite treatment. https://doi.org/10.1289/EHP6012This study was funded by the Swedish Research Council Formas (grant 942-2015-425

Surface integrity investigations for prediction of fatigue properties after machining of alloy 718

Fatigue performance is crucial for gas turbine components, and it is greatly affected by the manufacturing processes. Ability to predict the expected fatigue life of a component based on surface integrity has been the objective in this work, enabling new processing methods. Alloy 718 samples were prepared by different machining setups, evaluated in fatigue testing and surface integrity investigations. These results generated two predictive statistical multi-variate regression models. The fatigue correlated well with roughness, residual stresses and deformation. The two models showed great potential, which encourages further exploration to fine-tune the procedure for the particular case.The results from this work was granted from the research project G5Demo-2 [2013-04666] and SWE DEMO MOTOR [2015-06047] financed by VINNOVA, Sweden’s innovation agency. Special thanks to GKN Aerospace Sweden AB. The authors also would like to thank the KK- foundation and the SiCoMaP research school

Typing of Borrelia Relapsing Fever Group Strains

Partial sequencing of the 16S-23S rDNA intergenic spacer showed two to four genotypes each for Borrelia hermsii and B. turicatae, both relapsing fever agents transmitted by argasid ticks, and for B. miyamotoi and B. lonestari, transmitted by ixodid ticks. Field surveys of Ixodes ticks in Connecticut and Sweden showed limited local diversity for B. miyamotoi

Breeding failures and reduced nest attendance in response to heat stress in a high-latitude seabird

Climate change research on seabirds has so far focused mainly on indirect effects acting via impacts at lower trophic levels. However, seabirds that breed in exposed sites may also be vulnerable to direct impacts from extreme weather events such as heatwaves, which are projected to increase in both severity and frequency with climate change. Yet there are relatively few field studies of how breeding seabirds respond to heatwaves. Here, we used video footage from a breeding colony of common guillemots Uria aalge in the Baltic Sea over 4 consecutive breeding seasons (2019−2022) to explore responses to air temperature and sun exposure. We found a positive relationship between temperature and 2 thermoregulatory behaviours: panting and postural changes. In addition, we show that as temperatures increase, breeding partners spend less time together at the colony. At the highest temperatures, some birds even temporarily abandon their eggs and chicks. Of 48 breeding failures recorded on video over 4 breeding seasons, we documented 13 cases directly associated with heat stress (corresponding to ca. 9% of all 150 breeding attempts recorded); 11 of these occurred during 2 periods with sunshine and particularly high temperatures in 2020 and 2022. Using a larger data set (>500 breeding attempts over 12 seasons), we also identified a clear increase in the probability of egg loss at higher temperatures. As such, the responses of breeding seabirds to heatwaves could have important demographic consequences in some populations, especially as heatwaves continue to increase in frequency and magnitude

Nanostructurally Controllable Strong Wood Aerogel toward Efficient Thermal Insulation

Eco-friendly materials with superior thermal insulation and mechanical properties are desirable for improved energy- and space-efficiency in buildings. Cellulose aerogels with structural anisotropy could fulfill these requirements, but complex processing and high energy demand are challenges for scaling up. Here we propose a scalable, nonadditive, top-down fabrication of strong anisotropic aerogels directly from wood with excellent, near isotropic thermal insulation functions. The aerogel was obtained through cell wall dissolution and controlled precipitation in lumen, using an ionic liquid (IL) mixture comprising DMSO and a guanidinium phosphorus-based IL [MTBD][MMP]. The wood aerogel shows a unique structure with lumen filled with nanofibrils network. In situ formation of a cellulosic nanofibril network in the lumen results in specific surface areas up to 280 m2/g and high yield strengths >1.2 MPa. The highly mesoporous structure (average pore diameter ∼20 nm) of freeze-dried wood aerogels leads to low thermal conductivities in both the radial (0.037 W/mK) and axial (0.057 W/mK) directions, showing great potential as scalable thermal insulators. This synthesis route is energy efficient with high nanostructural controllability. The unique nanostructure and rare combination of strength and thermal properties set the material apart from comparable bottom-up aerogels. This nonadditive synthesis approach is believed to contribute significantly toward large-scale design and structure control of biobased aerogels.Peer reviewe