bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal variations in the infection of a population of Cerithidea cingulata by larval trematodes in Kuwait Bay
Authors: Al-Kandari W.Y. , Abdul-Salam J. , Meakins R.
Published: April 2024

The prosobranch gastropod Cerithidea cingulata (Gastropoda: Potamididae) in Kuwait Bay was examined for larval trematode infections over a 17-month period. A total of 2537 snails were examined and 1265 (49.9%) found to be infected with one or more species of trematodes. The component community in the snail comprised 12 species representing the families Cyathocotylidae (2), Echinostomatidae (2), Haplosplanchnidae (1), Heterophyidae (2), Microphallidae (1), Philophthalmidae (2), Plagiorchiidae (1) and Schistosomatidae (1). Cyathocotylid II (41.6%) was by far the most prevalent species followed by the microphallid (3.9%), the two species comprised 90% of the total trematode fauna. The prevalence of infection increased with shell size and was significantly higher in male (47%) than female (33%) snails. Multiple infections were observed in only 15 (1.2%) of the infected snails; cyathocotylid I and cyathocotylid II combination occurred 14 times and heterophyid I and the microphallid occurred once. Trematode species were more diverse and prevalent in winter, and cercarial shedding peaked in summer. Behaviour of the definitive host and snail population dynamics were probably the major contributors to the detected temporal pattern in the infections.
Intestinal helminths of spiny mice (Acomys cahirinus dimidiatus) from St Katherine's Protectorate in the Sinai, Egypt
Authors: Behnke J.M. , Barnard C.J. , Mason N. , Harris P.D. , Sherif N.E. , Zalat S. , Gilbert F.S.
Published: April 2024

Spiny mice,Acomys cahirinus dimidiatus, inhabiting the wadis close to St Katherine in the mountains of the Sinai peninsula, were trapped and their helminth parasites were studied. Sixty one mice provided faeces for analysis and 27 were killed and autopsied. Six species of helminths were recorded (the spirurid nematodes,Protospirura muricola(74.1%) andMastophorus muris(11.1%), the oxyuroid nematodes,Dentostomella kuntzi(59.3%),Aspiculuris africana(3.7%), andSyphacia minuta(3.7%) and the hymenolepidid cestodeRodentolepis negevi(18.5%)). The spirurids were the dominant species present, accounting for up to 0.87% of total host body weight. Analysis of worm weights and lengths suggested that transmission had been taking place in the months preceding our study. No sex difference in the prevalence or abundance of spirurids was detected. Significant differences were identified in the abundance of total nematode burdens and the mean helminth species richness between the three wadis which provided multiple captures of mice. There was also a marked effect of host age on both parameters. A highly significant positive correlation between spirurid egg counts and total worm biomass indicated that non-invasive techniques based on egg counts could be used to quantify worm burdens and when this technique was applied to a larger sample size (n= 61), a significant difference between sites but no host sex or age effects were detected for spirurid faecal egg counts. The data suggest that there are differences between helminth component communities infecting spiny mice in different neighbouring wadis, a hypothesis which will be explored further through our continuing studies in the Sinai.
Ultrastructure of the tegument of the metacercaria of Timoniella imbutiforme
Authors: El-Darsh H.E.M. , Whitfield P.J.
Published: April 2024

The spinous body tegument of the metacercaria of Timoniella imbutiforme (Molin, 1859) is described in detail and found to comprise an outer tegumental syncytium connected to subjacently situated subtegumentary ‘cells’. There are four types of secretory bodies in the outer syncytial layer as well as serrated overlapping spines and mitochondria. The subtegumentary ‘cells’ are characterized by the presence of four secretory body types as well as giant bodies which may be involved in the elaboration of the secretory bodies or spine material. The normal configuration of the somatic muscles of T. imbutiforme show that the muscular machinery necessary for activity once the larval stage becomes excysted is already in place. The sensory endings are found to be of the uniciliate type occurring in groups of up to eight in raised domes distributed over the body. Secretory gland cells are numerous and possess long ducts connected to the basal lamina of the outer syncytial layer via septate desmosomes.
Morphogenesis and distribution of Trichostrongylus retortaeformis in the intestine of the rabbit
Authors: Audebert F. , Cassone J. , Hoste H. , Durette-Desset M.C.
Published: April 2024

The morphogenesis and the distribution along the digestive tract of Trichostrongylus retortaeformis(Zeder, 1800) (Nematoda) were studied in detail in one of its natural hosts, Oryctolagus cuniculus. Worm-free rabbits were each infected with T. retortaeformis larvae and were killed at 12 h post-infection (HPI) and on each day from 1 to 15 days post-infection (DPI). The distribution of worm populations along the small intestine was assessed. At the different dates of infection, more than 80% of the population was recovered from the first third of the intestine with more than 50% occuring in the first 30 cm. For each date, morphological descriptions of the different stages of the life cycle were also provided. In addition, adult worms collected from naturally infected rabbits from France were redescribed.
Acquired resistance in rainbow trout against Gyrodactylus derjavini
Authors: Lindenstrøm T. , Buchmann K.
Published: April 2024

Investigations were conducted on the host response in rainbow trout and the associated changes in mucous cell density during infection with the skin monogenean Gyrodactylus derjavini. Parasite populations increased on all naive hosts and peaked 4–5 weeks p.i. after which infection levels decreased. Introduction of naive fish into responding host populations resulted in heavy infections of the naive fish, whereas parasite expulsion continued in the responding host groups showing an acquired, non-sterile immunity. This non-sterile immunity lasted at least a month as these hosts were refractory to reinfection despite being exposed to a high infection pressure. Mucous cell hyperplasia was seen in some groups during the intermediary phase of infection, but at the termination of the study a significant depletion was evident. Passive immunization of naive host (with sera from immune hosts) did not confer protection. This indicates differences between host responses to G. derjavini compared to responses against other pathogens where such a passive immunity has been described.
The occurrence of two opecoeliid digeneans in Mullus barbatus and M. surmuletus
Authors: Martínez-Vicaria A. , Martín-Sánchez J. , Illescas P. , Lara A.M. , Jiménez-Albarrán M. , Valero A.
Published: April 2024

The infection by Opecoeloides furcatus and Poracanthium furcatum (Opecoeliidae) was studied in 121 Mullus barbatus and 113 M. surmuletus collected from the Spanish south-eastern Mediterranean. The prevalence of infection was most frequent in M. surmuletus with values of 81.42% for O. furcatus and 38.05% for P. furcatum. In M. barbatus the prevalences of O. furcatus and P. furcatum were 54.54% and 14.88% respectively. Statistically significant differences were found between the infection of the two hosts with P. furcatum. No significant differences in worm burdens could be attributable to host size or to seasonal changes, although a lower infection of M. barbatus by O. furcatus occurred in the autumn. Furthermore, the electrophoretic mobility of the enzyme malic dehydrogenase (MDH) was also studied and both digeneans presented different patterns, corresponding in both cases to homozygotic genotypes.
Localization of a 24-kDa collagenase in the Gymnorhynchus gigas plerocercoid
Authors: Vázquez-López C. , de Armas-Serra C. , Pérez-Serrano J. , Giménez-Pardo C. , Rodríguez-Caabeiro F.
Published: April 2024

A 24-kDa collagenase was localized in the Gymnorhynchus gigas plerocercoid immunohistochemically by peroxidase complex staining using polyclonal antibodies from NMRI mouse sera immunized with purified enzyme. Immunoreactivity was determined at different parts of the body (scolex, vesicle and caudal region) and mainly localized in microtriches and parenchymal tissues of the scolex and vesicle. These results, along with the absence of the enzyme in the plerocercoid excretion–secretion products, suggest that the 24-kDa collagenase is produced by parenchymal cells in the anterior region and transported to the outer regions of the worm It is possible that the enzyme plays an important role in degrading parasite tissues during the moulting process.
Immune responses of the argasid tick Ornithodoros moubata moubata induced by infection with the filarial worm Acanthocheilonema viteae
Authors: Hutton D. , Reid A.P. , Townson S.
Published: April 2024

Investigations were undertaken to determine whether the tick Ornithodoros moubatamoubata mounted a detectable immune response to primary and secondary infections with Acanthocheilonema viteae. Uninfected control tick survival rate was 70%, but only 45% in the primary infection group. Post-secondary infection survival rate (82%) was comparable to controls, indicating that these selected ticks had some protective advantage. Mean A. viteae infective larvae recovery from ticks with secondary infections was 31.4% lower than expected, suggesting the development of immunity. SDS–PAGE of haemolymph for proteins induced post-primary infection yielded a stronger signal at 45 kDa than controls, which was further elevated post-secondary infection. Proteins at 48, 22 and 16 to 18 kDa were detected in haemolymph from infected ticks but not seen from controls. The direct effect of haemolymph on microfilarial viability was examined using a novel in vitro assay; in these preliminary trials no differences were observed in parasite viability when exposed to haemolymph from infected or uninfected groups of ticks.
In vitro antifilarial activity of extracts of the medicinal plant Cardiospermum halicacabum against Brugia pahangi
Authors: Khunkitti W. , Fujimaki Y. , Aoki Y.
Published: April 2024

The in vitro effects of ethanol and aqueous extracts of the medicinal plant Cardiospermum halicacabum on adult worms and microfilariae of Brugia pahangi were investigated. With or without the plant extracts in culture medium, the motility of adult worms, microfilariae and microfilarial release from female worms were monitored daily. After 7 days of culture, viability or tissue damage of adult worms was assessed using the MTT assay. At > 500 μg ml-1, the aqueous extract significantly reduced motility of adult females after 24 h of exposure and adult males after 3 days. The aqueous extract, at > 500 μg ml-1, also significantly reduced microfilarial release from female worms, starting on day 2. The reduction in the motility of adult worms and the pattern of microfilarial release from female worms were concentration and time dependent. The MTT assay results revealed that adult worms cultured in the presence of aqueous extracts at > 500 μg ml-1 were damaged. However, the aqueous extract did not affect the motility of microfilariae with the exception of those in higher concentration extracts. Higher concentrations of ethanol extracts (2 mg ml-1) inhibited both the motility of adult worms and the release of microfilariae from females. Little effect of ethanol extracts was detected by the MTT assay, as only slight damage was caused to worms exposed only to the highest concentration (2 mg ml-1). However, ethanol extract at 500 μg ml-1 rapidly reduced the motility of microfilariae on day 2. The present study revealed that an aqueous extract of C. halicacabum has mild but definite direct macrofilaricidal action on B. pahangi.
Monoamine oxidase in amphistomes and its role in worm motility
Authors: Abidi S.M.A. , Nizami W.A.
Published: April 2024

The quantitative assay of mitochondrial monoamine oxidase (MAO) activity revealed a higher enzyme level in Explanatum explanatum than Gastrothylax crumenifer. The specific MAO inhibitors, chlorgyline, pargyline, deprenyl and nialamide produced different degrees of interspecific inhibition. The differential effects on enzyme activity of chlorgyline and deprenyl suggests the possible existence of polymorphic forms of the enzyme, MAO-A and MAO-B, in amphistomes. These specific inhibitors also had a differential influence on the in vitro motility of amphistomes, further indicating the involvement of different forms of MAO in the oxidative deamination of biogenic monoamines which might be partly responsible for neuromuscular coordination in amphistomes. The experimental procedures used in this study could be conveniently used for quick screening and evaluation of some of the qualitative effects of anthelmintic drugs under in vitro conditions.
The life-cycle of the flatfish nematode Cucullanus heterochrous
Authors: Køie M.
Published: April 2024

Mature specimens of Cucullanus heterochrous Rudolphi, 1802 (Nematoda: Cucullanidae) were obtained from the intestine of the flounder, Platichthys flesus, from Danish waters. Eggs embryonate in seawater but do not hatch. Fully developed larvae pressed out of eggs are 430 μm long with amphids and dereids and enclosed within the cuticle of a previous larval stage. Infective larvae are believed to be in their third stage. Experimental studies showed that the polychaetes, Nereis spp., Scoloplos armiger, Brada villosa and Capitella sp., may act as intermediate hosts. In N. diversicolor the larvae increase their length to 1 mm within four weeks (15°C) without moulting. Experimental infections showed that larvated eggs are not infective to fish, whereas >550 μm long larvae from polychaetes survived in 4–24 cm long flounders and plaice, Pleuronectes platessa. Third-stage larvae 550 μm to 1.1 mm long were found in the submucosa of the intestine one week post infection. At a length of about 800 μm to 1.4 mm they moult to fourth-stage larvae. Fourth-stage larvae, immature and mature worms occur in the intestine and rectum. Fourth-stage larvae and adults survived experimental transfer from one flounder to another. Similar developmental stages survived for two weeks in the intestine of experimentally infected cod, Gadus morhua.
Neutral lipids in cercariae, encysted metacercariae, and rediae of Echinostoma caproni
Authors: Marsit C.J. , Fried B. , Sherma J.
Published: April 2024

High performance thin-layer chromatography (HPTLC) was used to analyse the neutral lipids in the rediae, cercariae, and encysted metacercariae of Echinostoma caproni from Biomphalaria glabrata snails. Visual observations of the chromatograms showed that the most abundant lipid fraction in all stages was free sterol. Quantification of the free sterol revealed mean weights of 2.7 ± 0.64 ng per redia, 0.53 ± 0.023 ng per cercaria, and 0.081 ± 0.0098 ng per encysted metacercaria. Oil Red O staining of the larval stages confirmed the presence of lipids within the rediae and cercariae but did not show lipids in the encysted metacercariae. The dimunition in neutral lipids from the cercarial to the encysted metacercarial stage does not support a previous observation that fat increases in successive phases of the digenean life cycle.
Metacercarial aggregation in Digenea (Fasciola hepatica and Paramphistomum daubneyi): environmental or species determinism?
Authors: Abrous M. , Vareille-Morel C. , Rondelaud D. , Dreyfuss G. , Cabaret J.
Published: April 2024

Metacercarial aggregation of Fasciola hepatica and Paramphistomum daubneyi was studied under experimental conditions to determine if the formation of these aggregates was influenced by environmental factors, or it was a characteristic of trematode species. This process was studied using the confinement of infected snails on the bottom of Petri dishes (diameter, 14 cm) for 3 days. The formation of metacercarial aggregates of F. hepatica was not significantly modified by environmental factors such as intensity and duration of lighting, quality and volume of water. Metacercariae of F. hepatica were more numerous on the Petri dish walls and 63.9% of them constituted aggregates. In contrast, most metacercariae of P. daubneyi were found on the Petri dish bottoms and 78.3% of them were isolated or in groups of two metacercariae each. The mean number of metacercariae per aggregate ranged from 6.7 to 12.2 in the case of F. hepatica, and from 2.7 to 4.5 in the case of P. daubneyi. However, these mean numbers were independent of the site of cercarial attachment. The tendency of cercariae to form metacercarial aggregations was a characteristic of F. hepatica and was species determined.
Prevalence of anthelmintic resistance in gastrointestinal nematodes of dairy goats under extensive management conditions in southwestern France
Authors: Chartier C. , Soubirac F. , Pors I. , Silvestre A. , Hubert J. , Couquet C. , Cabaret J.
Published: April 2024

The occurrence of benzimidazole (BZ) and levamisole resistance was investigated in 18 randomly selected dairy goat herds located in southwestern France and characterized by extensive management. On each of the 18 farms, 45 adult goats were randomly allocated into three groups of 15 animals each: an untreated control group, a group that was orally administered fenbendazole (10 mg kg-1 body weight) and a group that received orally a levamisole drench (12 mg kg-1 body weight). Individual faecal egg counts and pooled larval cultures were done 10 days after anthelmintic treatment. Naive lambs were infected with larvae obtained from control and fenbendazole treated groups and were necropsied 35 days after infection for worm recovery. Faecal egg count reductions (FERC) were calculated for fenbendazole and levamisole and, when less than 95 per 100, were considered as indicative of anthelmintic resistance. An in vitro egg hatch test (EHT) was conducted with thiabendazole on eggs isolated from pooled faeces of fenbendazole treated goats in nine farms. Faecal egg count reductions indicated the occurrence of benzimidazole resistance in 15 out of 18 farms. Among these farms, nine had EHT values above 0.1 μg thiabendazole ml-1 confirming the benzimidazole resistance status. Levamisole resistance was detected in two farms through FECR. Based on necropsy results, the prevalence of benzimidazole resistance was higher in Trichostrongylus colubriformis, medium in Haemonchus contortus and lower in Teladorsagia circumcincta. In nine farms the benzimidazole resistance was monospecific whereas multispecific resistance was found in the six remaining farms. A negative relationship was found between FECR for fenbendazole and the average number of anthelmintic treatments given per year on the farm. Despite extensive management including a low number of treatments, the prevalence of benzimidazole resistance was very high suggesting that the repeated and sometimes exclusive use of benzimidazole drugs, even at low frequency, is probably the main cause in developing nematode resistance in dairy goat herds. The importance of other factors such as under-dosing or buying animals already carrying resistant nematodes are discussed.
Associations and interactions among intestinal helminths of the brown trout, Salmo trutta, in northern Italy
Authors: Dezfuli B.S. , Giari L. , Biaggi S. De , Poulin R.
Published: April 2024

Species co-occurrences and interspecific associations between intensity of infection were studied in helminth communities of three populations of brown trout, Salmo trutta, from northern Italy. Of the eight helminth species, only four were common enough to be included in the analyses: Pomphorhynchus laevis, Acanthocephalus anguillae, Echinorhynchus truttae and Cyathocephalus truncatus. The observed frequencies of co-occurrences of the different species, based on presence/absence data, did not differ from those predicted by a null model derived from prevalence data. However, the intensity of infection (number of individuals per fish) of different helminth species were generally, but not always significantly, negatively correlated in tests of pairwise associations. Variation in fish sizes and its effect on infection levels, and whether or not two helminth species used the same or different intermediate hosts, had no influence on these findings. Of the few significant negative associations found between pairs of helminth species, none was found in more than one fish population. This suggests that interspecific associations may be condition-dependent: even in apparently similar localities, the same combinations of helminth species show different associations. Without evidence of replicability, it is almost impossible to conclude to the consistent role of competition between any pair of helminth species in the field.
Abomasal and small intestinal nematodes from captive gazelles in Spain
Authors: Ortiz J. , Ruiz de Ybáñez M.R. , Garijo M.M. , Goyena M. , Espeso G. , Abáigar T. , Cano M.
Published: April 2024

The abomasal and small intestinal helminth fauna of three species of captive gazelles (Gazella dama mhorr, G. cuvieri and G. dorcas neglecta) kept in captivity in Almería (southeast Spain) have been studied, and the following species were identified: Nematodirus spathiger, N. filicollis, N. helvetianus, Camelostrongylus mentulatus, Trichostrongylus vitrinus, T. probolurus, T. colubriformis, Ostertagia ostertagi, O. harrisi, Teladorsagia (Ostertagia) circumcincta, and T. (Ostertagia) davtiani. Camelostrongylus mentulatus and N. spathiger were the most prevalent and abundant parasites. Ostertagia ostertagi, O. harrisi, N. helvetianus, and T. (Ostertagia) davtiani were identified for the first time in the genus Gazella. In addition, O. harrisi and Trichostrongylus probolurus are new records for Spain.
Effect of drilling on otolithic organ functions in mastoidectomy
Authors: Karakuzu Ahmet Taha , Özel Halil Erdem , Temir Hümeyra , Özdoğan Fatih , Genç Selahattin , Çalışkan Sebla
Published: April 2024

Objective

This study aimed to assess the effect of drilling during mastoidectomy on otolithic organ functions and development of benign paroxysmal positional vertigo using objective vestibular tests.

Materials and methods

The study included 45 adult patients diagnosed with chronic otitis media who underwent mastoidectomy with drilling. Pre-operative and post-operative assessments included tests for subjective visual vertical deviation and videonystagmography.

Results

Subjective visual vertical deviation was significantly higher in post-operative periods. On the third day, the subjective visual vertical deviation was at its maximum (1.4 degrees). Post-operatively, benign paroxysmal positional vertigo was detected in 14 patients (31.1 per cent). The most common type was ipsilateral lateral canal benign paroxysmal positional vertigo (57.1 per cent).

Conclusion

The effect of drilling on otolithic organ functions in mastoidectomy seems to be temporary and subclinical; however, it potentially could be a risk factor for the development of benign paroxysmal positional vertigo.
The relationship between childhood trauma, psychotic symptoms, and cognitive schemas in patients with schizophrenia, their siblings, and healthy controls: results from the EU-GEI study
Authors: Üçok Alp , Noyan Handan , Gülöksüz Sinan , Saka Meram Can , Alptekin Köksal , Atbaşoğlu Cem , Akturan Elçin , Karadayı Gülşah , Baran Tatar Zeynep , Akdede Berna , Binbay Tolga , Altınyazar Vesile , Ulaş Halis , Yalınçetin Berna , Gümüş-Akay Güvem , Cihan Burçin , Soygür Haldun , Şahin Cankurtaran Eylem , Ulusoy Kaymak Semra , Rutten Bart P.F. , van Os Jim
Published: April 2024

Background

The relationship between childhood trauma (CT) and psychotic symptoms in patients with schizophrenia (SCZ), and subthreshold psychotic experiences in non-clinical populations is well-established. However, little is known about the relationship between subtypes of trauma and specific symptoms in patients, their siblings, and controls. It is also not clear which variables mediate the relationship between trauma and psychotic symptoms.

Methods

Seven hundred and forty-two patients with SCZ, 718 of their unaffected siblings and 1039 controls from three EU-GEI sites were assessed for CT, symptom severity, and cognitive schemas about self/others. CT was assessed with the Childhood Trauma Questionnaire, and cognitive schemas were assessed by The Brief Core Schema Scale.

Results

Patients with psychosis were affected by CT more than their siblings and controls in all domains. Childhood emotional abuse and neglect were more common in siblings than controls. CT was related to negative cognitive schemas toward self/others in patients, siblings, and controls. We found that negative schemas about self-mediated the relationship between emotional abuse and thought withdrawal and thought broadcasting. Approximately 33.9% of the variance in these symptoms was explained by the mediator. It also mediated the relationship between sexual abuse and persecutory delusions in SCZ.

Conclusions

Our findings suggest that childhood abuse and neglect are more common in patients with schizophrenia than their siblings and healthy controls, and have different impacts on clinical domains which we searched. The relationship between CT and positive symptoms seems to be mediated by negative cognitive schemas about self in schizophrenia.
Intergenerational Justice and Freedom from Deprivation
Authors: Timmer Dick
Published: April 2024

Almost everyone believes that freedom from deprivation should have significant weight in specifying what justice between generations requires. Some theorists hold that it should always trump other distributive concerns. Other theorists hold that it should have some but not lexical priority. I argue instead that freedom from deprivation should have lexical priority in some cases, yet weighted priority in others. More specifically, I defend semi-strong sufficientarianism. This view posits a deprivation threshold at which people are free from deprivation, and an affluence threshold at which people can live an affluent life, even though their lives may be even further improved beyond that point. I argue that freedom from deprivation in one generation lexically outweighs providing affluence in another generation; in all other cases, freedom from deprivation does not have lexical priority.
The distribution of the maximum protection number in simply generated trees
Authors: Heuberger Clemens , Selkirk Sarah J. , Wagner Stephan
Published: April 2024

The protection number of a vertex
$v$
in a tree is the length of the shortest path from
$v$
to any leaf contained in the maximal subtree where
$v$
is the root. In this paper, we determine the distribution of the maximum protection number of a vertex in simply generated trees, thereby refining a recent result of Devroye, Goh, and Zhao. Two different cases can be observed: if the given family of trees allows vertices of outdegree
$1$
, then the maximum protection number is on average logarithmic in the tree size, with a discrete double-exponential limiting distribution. If no such vertices are allowed, the maximum protection number is doubly logarithmic in the tree size and concentrated on at most two values. These results are obtained by studying the singular behaviour of the generating functions of trees with bounded protection number. While a general distributional result by Prodinger and Wagner can be used in the first case, we prove a variant of that result in the second case.
From bias to black boxes: understanding and managing the risks of AI – an actuarial perspective
Authors: du Preez Valerie , Bennet Shaun , Byrne Matthew , Couloumy Aurelién , Das Arijit , Dessain Jean , Galbraith Richard , King Paul , Mutanga Victor , Schiller Frank , Zaaiman Stefan , Moehrke Patrick , van Heerden Lara
Published: April 2024

We explore some of the risks related to Artificial Intelligence (AI) from an actuarial perspective based on research from a transregional industry focus group. We aim to define the key gaps and challenges faced when implementing and utilising modern modelling techniques within traditional actuarial tasks from a risk perspective and in the context of professional standards and regulations. We explore best practice guidelines to attempt to define an ideal approach and propose potential next steps to help reach the ideal approach. We aim to focus on the considerations, initially from a traditional actuarial perspective and then, if relevant, consider some implications for non-traditional actuarial work, by way of examples. The examples are not intended to be exhaustive. The group considered potential issues and challenges of using AI, related to the following key themes:

Ethical

○

Bias, fairness, and discrimination

○

Individualisation of risk assessment

○

Public interest

Professional

○

Interpretability and explainability

○

Transparency, reproducibility, and replicability

○

Validation and governance

Lack of relevant skills available

Wider themes

This paper aims to provide observations that could help inform industry and professional guidelines or discussion or to support industry practitioners. It is not intended to replace current regulation, actuarial standards, or guidelines. The paper is aimed at an actuarial and insurance technical audience, specifically those who are utilising or developing AI, and actuarial industry bodies.
Association between abdominal obesity and depressive symptoms in Peruvian women aged 18–49 years: a sub-analysis of the Demographic and Family Health Survey 2018–2019
Authors: Leon-Zamora Sharon , Villarreal-Zegarra David , Bellido-Boza Luciana
Published: April 2024

Objective:

Abdominal obesity (AO) is characterised by excess adipose tissue. It is a metabolic risk that affects the physical and mental health, particularly in women since they are more prone to mental health problems like depression. This study investigated the association between AO and depressive symptoms in Peruvian women of reproductive age (18–49 years).

Design:

This is a cross-sectional observational study.

Setting:

Peruvian women population of reproductive age.

Participants:

We used data from the Peruvian Demographic and Family Health Survey (DHS) for 2018 and 2019 to assess 17 067 women for the presence of depressive symptoms (using the Patient Health Questionnaire (PHQ-9): cut-off score ≥ 10) and AO (measured by abdominal circumference; cut-off score ≥88 cm).

Results:

We observed a 64·55 % prevalence of AO and 7·61 % of depressive symptoms in the study sample. Furthermore, 8·23 % of women with AO had depressive symptoms (P < 0·05). Initially, women with AO appeared to have a 26 % higher risk of depressive symptoms compared with women without AO (P = 0·028); however, after adjustment for covariates, no statistically significant association was observed.

Conclusions:

Therefore, although both conditions are common in women of this age group, no significant association was found between AO and depressive symptoms.
Dual-Action Costs and Benefits in a Uni-Modal Single-Onset Paradigm
Authors: Raettig Tim , Huestegge Lynn
Published: April 2024

Abstract: While performing two actions at the same time has mostly been associated with reduced performance, several recent studies have observed the opposite effect, that is, dual-action benefits. Previous evidence suggests that dual-action benefits result from single-action inhibitory costs – more specifically, it appears that under certain circumstances, single-action representations are derived from dual-action representations by removing (i.e., inhibiting) one of the component actions. In the present paper, we investigated if this is tied to the presence of multi-modal response demands (i.e., responses making use of two different effector systems). We implemented a very simple experimental paradigm where participants responded to a single stimulus with zero, one, or two uni-modal responses. As predicted, we did not observe dual-action benefits, but rather significant dual-action costs. Furthermore, a trial-by-trial sequence analysis revealed that alternations between both single-action responses were associated with significantly better performance than all other types of action switches. This can be accounted for by assuming that actions are represented as “feature bundles” and that switching a single, binary distinctive feature of an action to its opposite is relatively easy.
Transformer Versus LSTM: A Comparison of Deep Learning Models for Karst Spring Discharge Forecasting
Authors: Pölz Anna , Blaschke Alfred Paul , Komma Jürgen , Farnleitner Andreas H. , Derx Julia
Published: April 2024

Karst springs are essential drinking water resources, however, modeling them poses challenges due to complex subsurface flow processes. Deep learning models can capture complex relationships due to their ability to learn non‐linear patterns. This study evaluates the performance of the Transformer in forecasting spring discharges for up to 4 days. We compare it to the Long Short‐Term Memory (LSTM) Neural Network and a common baseline model on a well‐studied Austrian karst spring (LKAS2) with an extensive hourly database. We evaluated the models for two further karst springs with diverse discharge characteristics for comparing the performances based on four metrics. In the discharge‐based scenario, the Transformer performed significantly better than the LSTM for the spring with the longest response times (9% mean difference across metrics), while it performed poorer for the spring with the shortest response time (4% difference). Moreover, the Transformer better predicted the shape of the discharge during snowmelt. Both models performed well across all lead times and springs with 0.64–0.92 for the Nash–Sutcliffe efficiency and 10.8%–28.7% for the symmetric mean absolute percentage error for the LKAS2 spring. The temporal information, rainfall and electrical conductivity were the controlling input variables for the non‐discharge based scenario. The uncertainty analysis revealed that the prediction intervals are smallest in winter and autumn and highest during snowmelt. Our results thus suggest that the Transformer is a promising model to support the drinking water abstraction management, and can have advantages due to its attention mechanism particularly for longer response times.
Non‐Linear Climate Change Impacts on Crop Yields May Mislead Stakeholders
Authors: Ruane Alex C. , Phillips Meridel , Jägermeyr Jonas , Müller Christoph
Published: April 2024

We utilize a global warming level (GWL) lens to evaluate global and regional patterns of agricultural impacts as global surface temperature increases, providing a unique perspective on the experience of stakeholders with continued warming in the 21st century. We analyze crop productivity outputs from 11 crop models simulating 5 climate models under 3 emissions scenarios across 4 crops within the AgMIP/ISIMIP Phase 3 ensemble. We categorize regional productivity changes (without adaptation) into 9 characteristic climate change response patterns, identifying consistent increases and decreases as well as non‐linear (peak or dip) responses indicative of inflection points reversing trends as GWLs increase. Many maize regions and pockets of wheat, rice and soybean show peak decrease patterns where initial increases may lull stakeholders into complacency or maladaptation before productivity shifts to losses at higher GWLs. Although the GWL perspective has proven useful in connecting diverse climate models and emissions scenarios, we identify multiple pitfalls that recommend proceeding with caution when applying this approach to climate impacts. Chief among these is that carbon dioxide (CO2) concentrations at any GWL depend on a climate model's transient climate response (TCR). Higher CO2 concentrations generally benefit crop productivity, so this leads to more pessimistic agricultural projections for so‐called “hot” models and can skew multi‐model ensemble results as models with high TCR are disproportionately likely to reach higher GWLs. While there are strong connections between many climatic impact‐drivers and GWLs, vulnerability and exposure components of food system risk are strongly dependent on development pathways.
Fluorescence in situ hybridization reveals the evolutionary biology of minor clone of gain/amp(1q) in multiple myeloma
Authors: Cui Jian , Liu Yuntong , Lv Rui , Yan Wenqiang , Xu Jingyu , Li Lingna , Du Chenxing , Yu Tengteng , Zhang Shuaishuai , Deng Shuhui , Sui Weiwei , Hao Mu , Yi Shuhua , Zou Dehui , Qiu Lugui , Xu Yan , An Gang
Published: April 2024

Growing evidence suggests that gain or amplification [gain/amp(1q)] accumulates during disease progression of multiple myeloma (MM). Previous investigations have indicated that small gain/amp(1q) subclones present at the time of diagnosis may evolve into dominant clones upon MM relapse. However, the influence of a minor clone of gain/amp(1q) on MM survival, as well as the correlation between different clonal sizes of gain/amp(1q) and the chromosomal instability (CIN) of MM, remains poorly understood. In this study, we analyzed fluorescence in situ hybridization (FISH) results of 998 newly diagnosed MM (NDMM) patients. 513 patients were detected with gain/amp(1q) at diagnosis. Among these 513 patients, 55 had a minor clone (≤20%) of gain/amp(1q). Patients with a minor clone of gain/amp(1q) displayed similar survival outcomes compared to those without gain/amp(1q). Further analysis demonstrated patients with a minor clone of gain/amp(1q) exhibited a clonal architecture similar to those without gain/amp(1q). Lastly, our results showed a significant increase in the clonal size of the minor clone of gain/amp(1q), frequently observed in MM. These findings suggested that a minor clone of gain/amp(1q) might represent an earlier stage in the pathogenesis of gain/amp(1q) and propose a “two-step” process in the clonal size changes of gain/amp(1q) in MM.
RUVBL1 ubiquitination by DTL promotes RUVBL1/2-β-catenin-mediated transcriptional regulation of NHEJ pathway and enhances radiation resistance in breast cancer
Authors: Tian Jie , Wen Mingxin , Gao Peng , Feng Maoxiao , Wei Guangwei
Published: April 2024

Radiotherapy effectiveness in breast cancer is limited by radioresistance. Nevertheless, the mechanisms behind radioresistance are not yet fully understood. RUVBL1 and RUVBL2, referred to as RUVBL1/2, are crucial AAA+ ATPases that act as co-chaperones and are connected to cancer. Our research revealed that RUVBL1, also known as pontin/TIP49, is excessively expressed in MMTV-PyMT mouse models undergoing radiotherapy, which is considered a murine spontaneous breast-tumor model. Our findings suggest that RUVBL1 enhances DNA damage repair and radioresistance in breast cancer cells both in vitro and in vivo. Mechanistically, we discovered that DTL, also known as CDT2 or DCAF2, which is a substrate adapter protein of CRL4, promotes the ubiquitination of RUVBL1 and facilitates its binding to RUVBL2 and transcription cofactor β-catenin. This interaction, in turn, attenuates its binding to acetyltransferase Tat-interacting protein 60 (TIP60), a comodulator of nuclear receptors. Subsequently, ubiquitinated RUVBL1 promotes the transcriptional regulation of RUVBL1/2-β-catenin on genes associated with the non-homologous end-joining (NHEJ) repair pathway. This process also attenuates TIP60-mediated H4K16 acetylation and the homologous recombination (HR) repair process. Expanding upon the prior study’s discoveries, we exhibited that the ubiquitination of RUVBL1 by DTL advances the interosculation of RUVBL1/2-β-catenin. And, it then regulates the transcription of NHEJ repair pathway protein. Resulting in an elevated resistance of breast cancer cells to radiation therapy. From the aforementioned, it is evident that targeting DTL-RUVBL1/2-β-catenin provides a potential radiosensitization approach when treating breast cancer.
Kinetic trapping organizes actin filaments within liquid-like protein droplets
Authors: Chandrasekaran Aravind , Graham Kristin , Stachowiak Jeanne C. , Rangamani Padmini
Published: April 2024

Several actin-binding proteins (ABPs) phase separate to form condensates capable of curating the actin network shapes. Here, we use computational modeling to understand the principles of actin network organization within VASP condensate droplets. Our simulations reveal that the different actin shapes, namely shells, rings, and mixture states are highly dependent on the kinetics of VASP-actin interactions, suggesting that they arise from kinetic trapping. Specifically, we show that reducing the residence time of VASP on actin filaments reduces degree of bundling, thereby promoting assembly of shells rather than rings. We validate the model predictions experimentally using a VASP-mutant with decreased bundling capability. Finally, we investigate the ring opening within deformed droplets and found that the sphere-to-ellipsoid transition is favored under a wide range of filament lengths while the ellipsoid-to-rod transition is only permitted when filaments have a specific range of lengths. Our findings highlight key mechanisms of actin organization within phase-separated ABPs.
Introgression and disruption of migration routes have shaped the genetic integrity of wildebeest populations
Authors: Liu Xiaodong , Lin Long , Sinding Mikkel-Holger S. , Bertola Laura D. , Hanghøj Kristian , Quinn Liam , Garcia-Erill Genís , Rasmussen Malthe Sebro , Schubert Mikkel , Pečnerová Patrícia , Balboa Renzo F. , Li Zilong , Heaton Michael P. , Smith Timothy P. L. , Pinto Rui Resende , Wang Xi , Kuja Josiah , Brüniche-Olsen Anna , Meisner Jonas , Santander Cindy G. , Ogutu Joseph O. , Masembe Charles , da Fonseca Rute R. , Muwanika Vincent , Siegismund Hans R. , Albrechtsen Anders , Moltke Ida , Heller Rasmus
Published: April 2024

The blue wildebeest (Connochaetes taurinus) is a keystone species in savanna ecosystems from southern to eastern Africa, and is well known for its spectacular migrations and locally extreme abundance. In contrast, the black wildebeest (C. gnou) is endemic to southern Africa, barely escaped extinction in the 1900s and is feared to be in danger of genetic swamping from the blue wildebeest. Despite the ecological importance of the wildebeest, there is a lack of understanding of how its unique migratory ecology has affected its gene flow, genetic structure and phylogeography. Here, we analyze whole genomes from 121 blue and 22 black wildebeest across the genus’ range. We find discrete genetic structure consistent with the morphologically defined subspecies. Unexpectedly, our analyses reveal no signs of recent interspecific admixture, but rather a late Pleistocene introgression of black wildebeest into the southern blue wildebeest populations. Finally, we find that migratory blue wildebeest populations exhibit a combination of long-range panmixia, higher genetic diversity and lower inbreeding levels compared to neighboring populations whose migration has recently been disrupted. These findings provide crucial insights into the evolutionary history of the wildebeest, and tangible genetic evidence for the negative effects of anthropogenic activities on highly migratory ungulates.
Precision ion separation via self-assembled channels
Authors: Hong Shanshan , Di Vincenzo Maria , Tiraferri Alberto , Bertozzi Erica , Górecki Radosław , Davaasuren Bambar , Li Xiang , Nunes Suzana P.
Published: April 2024

Selective nanofiltration membranes with accurate molecular sieving offer a solution to recover rare metals and other valuable elements from brines. However, the development of membranes with precise sub-nanometer pores is challenging. Here, we report a scalable approach for membrane fabrication in which functionalized macrocycles are seamlessly oriented via supramolecular interactions during the interfacial polycondensation on a polyacrylonitrile support layer. The rational incorporation of macrocycles enables the formation of nanofilms with self-assembled channels holding precise molecular sieving capabilities and a threshold of 6.6 ångström, which corresponds to the macrocycle cavity size. The resulting membranes provide a 100-fold increase in selectivity for Li+/Mg2+ separation, outperforming commercially available and state-of-the-art nanocomposite membranes for lithium recovery. Their performance is further assessed in high-recovery tests under realistic nanofiltration conditions using simulated brines or concentrated seawater with various Li+ levels and demonstrates their remarkable potential in ion separation and Li+ recovery applications.
Collective relational inference for learning heterogeneous interactions
Authors: Han Zhichao , Fink Olga , Kammer David S.
Published: April 2024

Interacting systems are ubiquitous in nature and engineering, ranging from particle dynamics in physics to functionally connected brain regions. Revealing interaction laws is of fundamental importance but also particularly challenging due to underlying configurational complexities. These challenges become exacerbated for heterogeneous systems that are prevalent in reality, where multiple interaction types coexist simultaneously and relational inference is required. Here, we propose a probabilistic method for relational inference, which possesses two distinctive characteristics compared to existing methods. First, it infers the interaction types of different edges collectively by explicitly encoding the correlation among incoming interactions with a joint distribution, and second, it allows handling systems with variable topological structure over time. We evaluate the proposed methodology across several benchmark datasets and demonstrate that it outperforms existing methods in accurately inferring interaction types. The developed methodology constitutes a key element for understanding interacting systems and may find application in graph structure learning.
Tension activation of mechanosensitive two-pore domain K+ channels TRAAK, TREK-1, and TREK-2
Authors: Sorum Ben , Docter Trevor , Panico Vincent , Rietmeijer Robert A. , Brohawn Stephen G.
Published: April 2024

TRAAK, TREK-1, and TREK-2 are mechanosensitive two-pore domain K+ (K2P) channels that contribute to action potential propagation, sensory transduction, and muscle contraction. While structural and functional studies have led to models that explain their mechanosensitivity, we lack a quantitative understanding of channel activation by membrane tension. Here, we define the tension response of mechanosensitive K2Ps using patch-clamp recording and imaging. All are low-threshold mechanosensitive channels (T10%/50% 0.6-2.7 / 4.4-6.4 mN/m) with distinct response profiles. TRAAK is most sensitive, TREK-1 intermediate, and TREK-2 least sensitive. TRAAK and TREK-1 are activated broadly over a range encompassing nearly all physiologically relevant tensions. TREK-2, in contrast, activates over a narrower range like mechanosensitive channels Piezo1, MscS, and MscL. We further show that low-frequency, low-intensity focused ultrasound increases membrane tension to activate TRAAK and MscS. This work provides insight into tension gating of mechanosensitive K2Ps relevant to understanding their physiological roles and potential applications for ultrasonic neuromodulation.