bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct evidence of increased natural mortality of a wild fish caused by parasite spillback from domestic conspecifics
Authors: Vollset Knut Wiik , Lennox Robert J. , Skoglund Helge , Karlsen Ørjan , Normann Eirik Straume , Wiers Tore , Stöger Elisabeth , Barlaup Bjørn T.
Published: January 2023

Parasite spillback from domestic animals can distort the balance between host and parasites in surrounding wildlife, with potential detrimental effects on wild populations. In aquatic environments, parasite spillback from aquaculture to wild salmon is one of the most contentious sustainability debates. In a 19 year time series of release group studies of Atlantic salmon, we demonstrated that (i) the effect of subjecting out-migrating salmon smolts to parasite treatment on marine survival has been reduced over a time, (ii) the relation between salmon lice levels in the out-migration route of the salmon and effect of treatment against the parasite is weak, but also (iii) the return rates in both treated and untreated groups of salmon are negatively correlated with salmon lice levels, and (iv) returns of wild salmon to the region are similarly negatively correlated with salmon lice levels during the out-migration year. Our study suggests that salmon lice can have a large effect on wild salmon populations that is not revealed with randomized control trials using antiparasitic drugs. This should be better accounted for when considering the impacts of farms on wild salmon populations.
Ants act as olfactory bio-detectors of tumours in patient-derived xenograft mice
Authors: Piqueret Baptiste , Montaudon Élodie , Devienne Paul , Leroy Chloé , Marangoni Elisabetta , Sandoz Jean-Christophe , d'Ettorre Patrizia
Published: January 2023

Early detection of cancer is critical in medical sciences, as the sooner a cancer is diagnosed, the higher are the chances of recovery. Tumour cells are characterized by specific volatile organic compounds (VOCs) that can be used as cancer biomarkers. Through olfactory associative learning, animals can be trained to detect these VOCs. Insects such as ants have a refined sense of smell, and can be easily and rapidly trained with olfactory conditioning. Using urine from patient-derived xenograft mice as stimulus, we demonstrate that individual ants can learn to discriminate the odour of healthy mice from that of tumour-bearing mice and do so after only three conditioning trials. After training, they spend approximately 20% more time in the vicinity of the learned odour than beside the other stimulus. Chemical analyses confirmed that the presence of the tumour changed the urine odour, supporting the behavioural results. Our study demonstrates that ants reliably detect tumour cues in mice urine and have the potential to act as efficient and inexpensive cancer bio-detectors.
The evolution of age-specific resistance to infectious disease
Authors: Buckingham Lydia J. , Bruns Emily L. , Ashby Ben
Published: January 2023

Innate, infection-preventing resistance often varies between host life stages. Juveniles are more resistant than adults in some species, whereas the opposite pattern is true in others. This variation cannot always be explained by prior exposure or physiological constraints and so it has been hypothesized that trade-offs with other life-history traits may be involved. However, little is known about how trade-offs between various life-history traits and resistance at different life stages affect the evolution of age-specific resistance. Here, we use a mathematical model to explore how trade-offs with natural mortality, reproduction and maturation combine to affect the evolution of resistance at different life stages. Our results show that certain combinations of trade-offs have substantial effects on whether adults or juveniles are more resistant, with trade-offs between juvenile resistance and adult reproduction inherently more costly than trade-offs involving maturation or mortality (all else being equal), resulting in consistent evolution of lower resistance at the juvenile stage even when infection causes a lifelong fecundity reduction. Our model demonstrates how the differences between patterns of age-structured resistance seen in nature may be explained by variation in the trade-offs involved and our results suggest conditions under which trade-offs tend to select for lower resistance in juveniles than adults.
Trophic strategies explain the ocean niches of small eukaryotic phytoplankton
Authors: Edwards Kyle F. , Li Qian , McBeain Kelsey A. , Schvarcz Christopher R. , Steward Grieg F.
Published: January 2023

A large fraction of marine primary production is performed by diverse small protists, and many of these phytoplankton are phagotrophic mixotrophs that vary widely in their capacity to consume bacterial prey. Prior analyses suggest that mixotrophic protists as a group vary in importance across ocean environments, but the mechanisms leading to broad functional diversity among mixotrophs, and the biogeochemical consequences of this, are less clear. Here we use isolates from seven major taxa to demonstrate a tradeoff between phototrophic performance (growth in the absence of prey) and phagotrophic performance (clearance rate when consuming
Prochlorococcus
). We then show that trophic strategy along the autotrophy-mixotrophy spectrum correlates strongly with global niche differences, across depths and across gradients of stratification and chlorophyll
a
. A model of competition shows that community shifts can be explained by greater fitness of faster-grazing mixotrophs when nutrients are scarce and light is plentiful. Our results illustrate how basic physiological constraints and principles of resource competition can organize complexity in the surface ocean ecosystem.
Deficiency of complement C3a and C5a receptors does not prevent angiotensin II–induced hypertension and hypertensive end-organ damage
Authors: Bode Marlies , Herrnstadt Georg Rudolf , Dreher Leonie , Ehnert Nicolas , Kirkerup Pia , Lindenmeyer Maja T. , Meyer-Schwesinger Catherine , Ehmke Heimo , Köhl Jörg , Huber Tobias B. , Wiech Thorsten , Wenzel Ulrich O.
Published: January 2023

Abstract

Complement activation may drive the pathology of hypertension through its effects on innate and adaptive immune responses, aside from direct effects on tissue integrity. Recently it was suggested that hypertension is a disease characterized by a decreased number of forkhead box protein 3 (Foxp3)+regulatory T cells (Tregs) and that combined deficiency of the anaphylatoxin receptors C3aR (complement component 3a receptor) and C5aR1 (complement component 5a receptor) upregulates Tregs and heals hypertension and hypertensive end-organ damage.

Using data from the European Renal cDNA Bank, renal single cell sequencing data and immunohistochemistry we found increased expression of C3aR, C5aR1 and Foxp3 in kidney biopsies of patients with hypertensive nephropathy. Expression of C3aR and C5aR1 was mainly found in myeloid cells and almost absent in lymphocytes. Next we aimed to determine whether C3aR or C3aR/C5aR1 double deficiency decreases blood pressure and hypertensive injury in Ang II infused mice.

However, no difference was found for blood pressure, renal injury (albuminuria, glomerular and tubulointerstitial injury, inflammation) and cardiac injury (cardiac fibrosis, heart weight, gene expression) between C3aR KO and WT mice as well as C3aR/C5aR1 double KO respectively. Ang II as well as DOCA salt induced hypertension resulted in an increased number of Tregs in the kidney. This was valid in mice of the Balb/c and C57black strain.

In summary, hypertensive nephropathy in patients is characterized by an increased expression of anaphylatoxin receptors and Tregs. However, deficiency of C3aR alone or C3aR and C5aR1 combined does not influence blood pressure or hypertensive end-organ damage in Ang II induced hypertension. Targeting the anaphylatoxin receptors C3aR alone or in combination with C5aR1 is not useful to treat cardiovascular disease in hypertension.
Endothelial tissue remodeling induced by intraluminal pressure enhances paracellular solute transport
Authors: Cacheux Jean , Bancaud Aurélien , Alcaide Daniel , Suehiro Jun-ichi , Akimoto Yoshihiro , Sakurai Hiroyuki , Matsunaga Yukiko T.
Published: January 2023

The endothelial layers of the microvasculature regulate the transport of solutes to the surrounding tissues. It remains unclear how this barrier function is affected by blood flow-induced intraluminal pressure. Using a 3D microvessel model, we compare the transport of macromolecules through endothelial tissues at mechanical rest or with intraluminal pressure, and correlate these data with electron microscopy of endothelial junctions. Upon application of an intraluminal pressure of 100 Pa, we demonstrate that the flow through the tissue increases by 135%. This increase is associated with a 25% expansion of microvessel diameter, which leads to tissue remodeling and thinning of the paracellular junctions. We recapitulate these data with the deformable monopore model, in which the increase in paracellular transport is explained by the augmentation of the diffusion rate across thinned junctions under mechanical stress. We therefore suggest that the deformation of microvasculatures contributes to regulate their barrier function.
A conserved, non-canonical insert in FIS1 is required for mitochondrial fission and recruitment of DRP1 and TBC1D15
Authors: Ihenacho UK , Toro R , Mansour RH , Hill RB
Published: January 2023

Mitochondrial fission protein 1 (FIS1) is conserved in all eukaryotes yet its activity in metazoans is thought divergent from lower eukaryotes like fungi. To address this discrepancy, structure-based sequence alignments revealed a conserved but non-canonical, three-residue insert in a turn of FIS1, suggesting conserved activity. In vertebrate FIS1 this insert is serine (S45), lysine (K46), and tyrosine (Y47). To determine the biological role of this “SKY insert”, three variants were evaluated for their fold, and tested in HCT116 cells for altered mitochondrial morphology and recruitment of effectors, DRP1 and TBC1D15. Substitution of the SKY insert with three alanine residues (AAA), or deletion of the insert (ΔSKY), did not substantially alter the fold or thermal stability of the protein. Replacing SKY with a canonical turn (ΔSKYD49G) introduced significant conformational heterogeneity by NMR that was removed upon deletion of a known regulatory region, the FIS1 arm. Expression of AAA fragmented mitochondria into perinuclear clumps associated with increased mitochondrial DRP1 similar to the wild-type protein. In contrast, expression of ΔSKY variants elongated mitochondrial networks and reduced mitochondrial DRP1. Co-expression of YFP-TBC1D15 partially rescued mitochondrial morphology and DRP1 recruitment for ΔSKY variants, although ΔSKY variants were markedly unable to support TBC1D15 assembly into punctate structures found upon co-expression with wildtype FIS1 or the AAA variant. Collectively these results show that FIS1 activity can be modulated by conserved residues supporting a generalized model whereby FIS1 is governed by intramolecular interactions between the regulatory FIS1 arm and SKY insert that may be conserved across species.
Evaluating the solubility of compounds intended for intramammary infusion based upon tests conducted across a range of milk products using cephapirin sodium and benzathine as model drugs
Authors: Martinez Marilyn N. , Zhao Fang , Longstaff David G. , Gabriel Justin J. , Coffey Martin J.
Published: January 2023

The ability to evaluate drug solubility in milk and milk-related products has relevance both to human and veterinary medicine. Model compounds explored in a previous investigation focused on drug solubility assessments when delivered in milk-associated vehicles for administration to human patients. In the current investigation, we focus on the solubility of drugs intended for delivery via intramammary infusion to cattle. Because there are logistic challenges typically associated with obtaining raw milk samples for these tests, there is a need to determine potential alternative media as a substitute for raw bovine milk. Given the complexity of the milk matrix, aqueous media do not reflect the range of factors that could impact these solubility assessments. This led to the current effort to explore the magnitude of differences that might occur when substituting raw bovine milk with off-the-shelf milk products such as whole milk, skim milk, or reconstituted whole milk powder. We considered conclusions based upon the solubility assessments derived from the use of the model compounds studied in our previous report and compared them to conclusions obtained when testing two drugs with differing physicochemical characteristics that are approved for administration via bovine intramammary infusion: cephapirin benzathine and cephapirin sodium. Based upon these results, we recommend that whole milk or reconstituted whole milk can substitute for bovine raw milk for the solubility assessment of compounds intended for administration via intramammary infusion. However, unlike the human drug situation, these tests should be conducted at 38°C.
The impact of tone management on investor judgments: evidence from ICFR reports
Authors: Starliper Matthew
Published: January 2023

Purpose

In preparing company financial statements, management is required to evaluate internal controls and disclose any material weaknesses in the internal control over financial reporting (ICFR) report. This study aims to examine how the tone of the details management provides to describe a material weakness in its ICFR report impacts investors’ perceptions of the severity of the material weakness and the desirability of the company as a potential investment.

Design/methodology/approach

This study uses an experimental design that manipulates whether the company’s ICFR report includes a negatively-toned detail to describe a material weakness disclosed in the report. Participants read the report and answer questions concerning their perceptions of the desirability of the company as an investment and the severity of the material weakness.

Findings

This study finds that using negatively-toned details to describe a material weakness, as opposed to an absence of those details, decreases investment desirability due to an increase in the perceived severity and number of distinct problems in ICFR.

Originality/value

This study extends prior research by showing that the tone of details used to describe a material weakness, not just the quantity of details, impacts investors’ decision-making. This study shows that management can carefully construct their ICFR report to avoid tone and potentially mitigate the negative effect of disclosing ineffective ICFR.
The impact of operational risk on performance in supply chains and the moderating role of integration
Authors: Pham Hai Thanh , Testorelli Raffaele , Verbano Chiara
Published: January 2023

Purpose

This study aims to empirically investigate the impact of operational risk (i.e. supply, manufacturing and demand risks) on supply chain performance and the moderating role of integration (i.e. supplier, internal and customer integrations) in mitigating the impact of these risks, respectively.

Design/methodology/approach

A research framework of hypotheses is tested by structural equation modeling with data collected from the fourth round of the high-performance manufacturing project.

Findings

It is revealed that manufacturing and demand risks negatively impact operational performance, and more importantly, internal and customer integrations help to reduce the impact of these two risks. Additionally, the effects of both supply risk and supplier integration are only significant for large firms.

Practical implications

Supply chain managers need to appropriately develop the levels of integration to mitigate the adverse impact of operational risk.

Originality/value

Operational performance is always threatened by different types of risk that adversely affect the supply, production and demand sides of manufacturing firms. Despite this fact, large-scale data-based empirical research on the impact of operational risk on the performance of supply chains has been scarce. This study aims to fill this literature gap.
Phenotypic evolution of agricultural crops
Authors: Milla Rubén
Published: January 2023

Food crops are a vital source of nutrition for humans and domestic animals, with an estimated 4 billion metric tons of food produced per year. Crops do not only provide yields, but their traits also play a significant role in regulating the ecosystem processes of croplands, affecting local biotas, water balance, nutrient and carbon cycling. Domestication has led to significant changes in crop traits, making it important to understand the recent evolution of crops and how they differ from wild plants.

In this paper I review the evidence on how the ecological traits of herbaceous crops have evolved during and after domestication. Loss of seed dispersal mechanisms, increased plant and organ sizes, high rates of consumption by herbivores and fast decomposition of residues by decomposer microbes in the soil, all have evolved independently in domestication processes of different crops.

I also point out types of traits for which we have not identified common responses to domestication, be it because domestication processes of the different crop species are disparate, or because of lack of strong evidence. Those traits include resource acquisition rates of leaves and roots, and whole‐plant growth rates. Then, I discuss research gaps in the field, including how to advance knowledge for those traits that show apparently idiosyncratic responses to domestication.

Finally, I emphasize the importance of understanding the interactions of crops with other organisms and the environment to breed crops that deliver yield and other services required from croplands. To this end, I introduce an ideotype for sustainable agriculture, which might inspire the breeding of multipurpose herbaceous crops, in the same way than the ideotypes of the Green Revolution inspired the breeding of elite varieties to foster yields under conventional agriculture.

Read the free Plain Language Summary for this article on the Journal blog.
d‐amino acid auxotrophic Escherichia coli strain for in vivo functional cloning of novel d‐amino acid synthetic enzyme
Authors: Ito Tomokazu , Muto Natsumi , Sakagami Haruna , Tanaka Miho , Hemmi Hisashi , Yoshimura Tohru
Published: January 2023

Various d‐amino acids have been found in a wide range of organisms, including mammals. Although the physiological functions of various d‐amino acids have been reported or suggested, the molecular basis of these biological functions has been elucidated in only a few cases. The identification of a d‐amino acid biosynthetic enzyme is a critical step in understanding the mechanism of the physiological functions of d‐amino acids. While in vivo functional screening can be a powerful tool for identifying novel metabolic enzymes, none of the existing organisms exhibit growth dependent on d‐amino acid other than d‐Ala and d‐Glu. Here, we report the first organism that exhibits non‐canonical d‐amino acid auxotrophy. We found that an Escherichia coli strain lacking the major d‐Ala and d‐Glu biosynthetic enzymes, alr, dadX, and murI, and expressing the mutated d‐amino acid transaminase (DAAT) gene from Bacillus sp. YM‐1 (MB3000/mdaat+) grew well when supplemented with certain d‐amino acid. A multicopy suppression study with plasmids encoding one of the 51 PLP‐dependent enzymes of E. coli showed that MB3000/mdaat+ could detect weak and moonlighting racemase activity, such from cystathionine β‐lyase (MetC) and a negative regulator of MalT activity/cystathionine β‐lyase (MalY)—these exhibit only a few tenths to a few thousandths of the racemization activity of canonical amino acid racemases. We believe that this unique platform will contribute to further research in this field by identifying novel d‐amino acid‐metabolizing enzymes.
Economic evaluation of fluoride varnish application in preschoolers: A systematic review
Authors: Dhyppolito Izabel Monteiro , Nadanovsky Paulo , Cruz Laís Rueda , de Oliveira Branca Heloisa , dos Santos Ana Paula Pires
Published: January 2023

Background

Fluoride varnish (FV) is a convenient way of professionally applying fluoride in preschoolers. However, its modest anticaries effect highlights the need for economic evaluations.

Aim

To assess economic evaluations reporting applications of FV to reduce caries incidence in preschoolers.

Design

We included full economic evaluations with preschool participants, in which the intervention was FV and the outcome was related to dentin caries. We searched in CENTRAL; MEDLINE via PubMed; WEB OF SCIENCE; EMBASE; SCOPUS; LILACS; BBO; and BVS Economia em saúde, OpenGrey, and EconoLit. Clinical trial registers, thesis and dissertations, and meeting abstracts were hand searched, as well as 11 dental journals. Risk of bias in the included studies was assessed using the Philips' and Drummond's (full and simplified) tools.

Results

Titles and abstracts of 2871 articles were evaluated, and 200 were read in full. Eight cost‐effectiveness studies were included: five modeling and three within‐trial evaluations. None of the studies gave sufficient information to allow a thorough assessment using the bias tools. We did not combine the results of the studies due to the great heterogeneity among them. Four studies reported that FV in preschool children was a cost‐effective measure, but in one of these studies, sealants and fluoride toothpaste were more cost‐effective measures than the varnish, and three studies used limited data that compromised the generalizability of their results. The other four studies showed a large increase in costs due to the application of varnish and/or low cost‐effectiveness.

Conclusion

We did not find convincing overall evidence that applying FV in preschoolers is an anticaries cost‐effective measure. The protocol of this systematic review is available at Open Science Framework (https://osf.io/xw5va/).
Trends in incidence rates of childhood type 1 diabetes mellitus: A retrospective study in Isfahan province, Iran
Authors: Hashemipour Mahin , Maracy Mohammadreza , Javanmard Shaghayegh Haghjooy , Zamaneh Farzane , Mostofizadeh Neda , Hovsepian Silva
Published: January 2023

Aims/Introduction

We aimed to determine the incidence trend of childhood type 1 diabetes mellitus in Isfahan province over a period of 12 years.

Materials and Methods

In this retrospective study, children aged <20 years at the time of type 1 diabetes mellitus diagnosis, from March 2007 to March 2019, were included. The crude and adjusted incidence rate of type 1 diabetes mellitus is calculated as the number of cases per 100,000 person‐years by the period. The cumulative, age‐ and sex‐specific incidence rates were also calculated. Age‐specific incidence rates were calculated for age and sex groups.

Results

A total of 1,954 (983 boys and 971 girls) cases of type 1 diabetes mellitus were identified. The mean age at diagnosis in all studied populations was 9.89 (standard deviation 4.76). There were no significant differences between the proportion of boys and girls in different years (P = 0.12) and different age groups (P = 0.19). The average annual percent change of incidence rate for the total population, for girls and boys, was 6.9%, 6.7% and 6.3% respectively. The type 1 diabetes mellitus incidence rate had a significant trend to be increased from 2007 to 2019 (P < 0.001,t = 3.6).

Conclusion

Our findings showed that currently our region is considered a region with a high incidence rate of type 1 diabetes mellitus. Although we have had fluctuations in the incidence rate over the 12 years, the overall trend is increasing.
Nipple eczema: A systematic review and practical recommendations
Authors: Reynaert V. , Gutermuth J. , Wollenberg A.
Published: January 2023

The nipple is the focal point of the human breast and serves important physiological, sexual, and aesthetic purposes. It can be affected by atopic, irritant, and allergic contact eczema, which often reduce the patient's quality of life. The objective of this article is to discuss the different types of nipple eczema and highlight relevant differential diagnoses and treatment options. A systematic search of PubMed was conducted to identify and critically appraise the existing literature on the topic. All articles on nipple eczema were considered eligible, regardless of publication date, language or study design. A final of 33 manuscripts on nipple eczema remained. The scarce literature and the limited number of high‐quality manuscripts impedes provision of structured data on nipple eczema. To securely reach the educative value of this manuscript, the systematic review was combined with a manual databank search and selected manual search of textbooks. The differential diagnosis of nipple eczema encompasses among others nipple psoriasis, nipple candidiasis and Paget's disease. In case of diagnostic uncertainty, swabs or biopsies are indicated. Treatment of nipple eczema needs to rapidly control the signs and symptoms of the disease, since it can have a negative effect on quality of life and can lead to premature arrest of breastfeeding. The key treatment step is starting with topical corticosteroids or calcineurin inhibitors, both of which are considered safe during lactation. Avoidance of provoking factors, such as repetitive friction, chemical agents, or allergens, can help. The use of nipple protection devices can be proposed for nursing women and sometimes adjusting of latch/suck positioning during breastfeeding is needed. Furthermore, patients should be advised to moisturize the nipple intensively and to switch to emollient wash products. Warm water compresses, black tea compresses or commercially available tannin containing topicals can provide comfort.
The association of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage in patients with chronic hepatitis B
Authors: Lian Mingjian , Wang Qianming , Chen Shidong , Yang Yuanyuan , Hong Guolin
Published: January 2023

The utility of measurement of serum immunoglobulin and complement in chronic hepatitis B (CHB) patients remains controversial. This study aimed to investigate the association of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage in CHB patients. A total of 687 patients with CHB who underwent liver biopsy were enrolled. Serum immunoglobulin and complement were measured before liver biopsy, and liver pathological results were recorded. Associations of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage were analysed. C3, C4, IgG and IgG1 had statistically significant differences among different fibrosis and different inflammation groups. Both C3 and C4 negatively correlated with fibrosis and inflammation stage, but IgG and IgG1 showed opposite results. C3, C4, IgG and IgG1 had statistical significance to predict ≥S2, ≥S3 and S4, and also had statistical significance to predict ≥G2, ≥G3 and G4. The area under curve (AUC) of the combination of C3, C4 and IgG (C3 + C4 + IgG) for predicting ≥S2, ≥S3 and S4 was 0.640 (95% CI: 0.603, 0.676), 0.674 (95% CI: 0.638, 0.709) and 0.744 (95% CI: 0.710, 0.776), respectively. The AUC of C3 + C4 + IgG for predicting ≥G2, ≥G3 and G4 was 0.723 (95% CI: 0.688, 0.756), 0.674 (95% CI: 0.638, 0.709) and 0.771 (95% CI: 0.738, 0.802), respectively. C3, C4, IgG and IgG1 are correlated with liver fibrosis and inflammation stage in CHB patients. C3, C4, IgG and IgG1 have diagnostic value for liver fibrosis and inflammation. C3 + C4 + IgG may improve diagnostic accuracy.
“The Volunteering Days is Gone”: All‐Hazard Incarcerated Firefighters and Rural Disinvestment☆
Authors: Purdum J. Carlee
Published: January 2023

After decades of economic restructuring, many rural communities are struggling to provide adequate fire and emergency services across their communities. Subsequent population loss, the destabilization of local tax‐bases, and an increased demand from work and family have left local fire departments at a loss for personnel and support. In this context, rural Georgia communities look to nearby prisons to provide incarcerated persons to work as local firefighters and emergency medical technicians (EMTs) to stabilize rural emergency services. In this paper, I examine the narrative accounts that officials who employ, manage, or work alongside incarcerated workers who are trained to respond locally as firefighters and EMTs and ask why incarcerated workers are looked to for this type of work in spite of the challenges associated with the program. Officials describe turning to the state prison system as the only viable option to make their communities and fire departments safe. These findings further illuminate the relationship between racial capitalism, carceral infrastructure, and emergency services as rural communities turn to the false promise of prisons and all‐hazard incarcerated firefighters to keep their communities safe.
¿Qué pasó con el rendimiento académico en Ingeniería Química?: un estudio en tiempos de COVID-19
Authors: Monsalve-Silva Santiago , Vera-Monroy Sulma Paola
Published: January 2023

El COVID-19 obligó a que las Instituciones de Educación Superior tuvieran que cambiar el ambiente de aprendizaje de presencial a asistido por ordenador, para poder continuar y asegurar la calidad educativa. Objetivo: Este estudio se evaluó el efecto del cambio de ambiente sobre el rendimiento académico de estudiantes de Ingeniería Química. Participaron estudiantes de Química General I e Ingeniería de Fenómenos de Transporte, reconocidos como aprendices y conocedores, respectivamente. Materiales y métodos: Se diseñaron y validaron dos instrumentos tipo likert para evaluar la percepción en términos de variables académicas y sociales, en dos momentos, iniciando el aislamiento y al finalizar el semestre, además se compararon las notas de los estudiantes que participaron en el estudio, llamados aprendices y conocedores, de primero y sexto semestre, respectivamente, con las notas de estudiantes que vieron las asignaturas en otros periodos. Resultados y discusión: Aprendices disminuyeron su rendimiento al experimentar un nuevo contexto de aprendizaje que afectó fuertemente el componente social, mientras que conocedores mejoraron su rendimiento por tener una adaptación escolar, producto de su experiencia y madurez mental. La comunicación y el bienestar formativo fueron reconocidas como las variables que identifican la presencialidad, favoreciendo la apropiación del conocimiento y el desarrollo de competencias. La modalidad remota, condiciona la metodología afectando el aprendizaje, y finalmente, la evaluación no cambia al modificar el entorno, ya que, por ser una declaración institucional, no depende del espacio de aprendizaje. Conclusiones: El ambiente de aprendizaje incide en el rendimiento de los estudiantes, negativamente a los aprendices y positivamente a los conocedores, quienes por tener experiencia universitaria manifiestan capacidad de adaptación. De otro lado, la presencialidad favorece el bienestar mejorando la comunicación asertiva y el desarrollo de competencias transversales.
Tree-Based Ensemble Learning Models for Wall Temperature Predictions in Post-Critical Heat Flux Flow Regimes at Subcooled and Low-Quality Conditions
Authors: Liu Qingqing , Liu Yang , Burak Adam , Kelly Joseph , Bajorek Stephen , Sun Xiaodong
Published: January 2023

Accurately predicting post-critical heat flux (CHF) heat transfer is an important but challenging task in water-cooled reactor design and safety analysis. Although numerous heat transfer correlations have been developed to predict post-CHF heat transfer, these correlations are only applicable to relatively narrow ranges of flow conditions due to the complex physical nature of the post-CHF heat transfer regimes. In this paper, a large quantity of experimental data is collected and summarized from the literature for steady-state subcooled and low-quality film boiling regimes with water as the working fluid in vertical tubular test sections. A low-quality water film boiling (LWFB) database is consolidated with a total of 22,813 experimental data points, which cover a wide flow range of the system pressure from 0.1 to 9.0 MPa, mass flux from 25 to 2750 kg/m2 s, and inlet subcooling from 1 to 70 °C. Two machine learning (ML) models, based on random forest (RF) and gradient boosted decision tree (GBDT), are trained and validated to predict wall temperatures in post-CHF flow regimes. The trained ML models demonstrate significantly improved accuracies compared to conventional empirical correlations. To further evaluate the performance of these two ML models from a statistical perspective, three criteria are investigated and three metrics are calculated to quantitatively assess the accuracy of these two ML models. For the full LWFB database, the root-mean-square errors between the measured and predicted wall temperatures by the GBDT and RF models are 5.7% and 6.2%, respectively, confirming the accuracy of the two ML models.
Development of a Three-Mobile-Robot System for Cooperative Transportation
Authors: Fan Changxiang , Zeng Fan , Shirafuji Shouhei , Ota Jun
Published: January 2023

The transportation of large-scale objects in a narrow space is a challenging, but useful application for mobile robots. We have developed a three-mobile-robot system to cooperatively lift, support, and transport a large object on a mobile robot system. To facilitate the manipulation involved with loading an object onto the robots, where the robots must maintain firm contact with the object and anchor at its location, we designed an adaptable mechanism for the object-loading platform and a liftable brake to ensure that the robot remains stationary when necessary. Furthermore, each robot is designed to act as an omnidirectional wheel; therefore, all three robots can work as an omnidirectional block when collectively loading an object. The kinematic constraints of the object–robot system and forward kinematics of the robots’ cooperative motion are proposed, and experiments are conducted to confirm the designed mechanisms and confirm that the robots can load an object and cooperatively transport it along the expected trajectory.
Optimised Shear Horizontal Guided Wave Inspection Set-Up for Titanium Welds.
Authors: Peyton Christian , Dixon Steve , Dutton Ben , Vesga Wilson , Edwards Rachel S.
Published: January 2023

The inspection of welds in thin titanium sheets is vital to ensure that all components meet their required criteria. Shear horizontal (SH) guided waves may offer particular benefits for defect detection, especially the fundamental mode (SH0), which is non-dispersive. Electromagnetic acoustic transducers (EMATs) are efficient generators of SH waves. However, titanium is traditionally a difficult material to inspect using EMATs. Through finite element analysis and experiments, this work proposes an inspection set-up using a 6 mm wavelength SH0 mode as the incident wave. When the SH0 mode interacts with a defect, reflections occur. The primary reflection is the SH0 mode, but mode conversions occurring at the defect result in the reflection of a mode converted Lamb wave. The Lamb guided wave mode reflected in our work is the S0 mode. The weld inspection approach presented uses both of these guided wave modes. The intention of detecting multiple wave modes is to provide more information about the inspected region, improving the reliability of the results by providing an increased probability of detection and a reduced likelihood of false positives. The results show initial testing and validation of the proposed set-up, highlighting how the SH0 mode reflection is sensitive to the weld quality. The positioning of the transducers sensitive to the S0 mode is also presented, showing the defect size's effect on the angle of reflection.
Non-Destructive Testing of Underwater Concrete Structures Using Remotely Controlled Drones
Authors: Venkatesh Vishnu , Ashish Anthony Jacob , Gupta Sanchit , Sangani Abhijeet , Jhunjhunwala Tanuj , Upadhyay Vineet , Rajagopal Prabhu , Balasubramanian Krishnan
Published: January 2023

Concrete is a fundamental component in civil, commercial, and industrial infrastructure. Periodic inspection is mandated to ensure safe operation during the structure’s lifetime. Recent innovations in inspection technology have enabled rapid characterization of the interior of a concrete specimen with techniques like ground penetrating radar and phased array ultrasonic tomography. A universal limitation of these conventional methods is that they are best documented for in-air application, with comparatively scant literature available for underwater deployment. Visual inspections and diver deployed semi-destructive tests are the main modes of underwater concrete inspection. Underwater, concrete structures encounter harsher conditions and larger weathering effects compared to those above. Underwater inspections sites often have poor visibility, strong currents and debris, making manned inspections risky. Divers also have limited inspection time and depth, decreasing scope and increasing asset downtime. To overcome those limitations, this paper proposes the use of remotely operated underwater vehicles (ROVs) to perform quantitative non-destructive tests on underwater concrete structures. ROVs developed by Planys Technologies are compact, lightweight, and versatile. They are capable of extended inspection times, and operational depths of up to 200 m. These ROVs can be deployed by a crew of 2-3 personnel and are remotely controlled from a safe location above water. One of the most well-known techniques, ultrasonic pulse velocimetry, was adapted for the marine environment. While foundational when compared to the state-of-the-art in-air techniques, it is still capable of providing a quantitative measure of a concrete structure’s integrity. The paper describes experimental results from in-lab and in-field testing, as well as limitations to practical applications.
A Study on the Influence of Wave Scattering in Metamaterial-Based Super-Resolution Imaging of Defects in Materials
Authors: Chandran Loheshwaran , Akbar Ali Mohamed Subair Syed , Saini Abhishek , Fan Zheng , Rajagopal Prabhu
Published: January 2023

Recently there is much interest in metamaterial based super resolution imaging. Several demonstrations have been reported using sources or slits as targets for imaging. However, in the context of non-destructive evaluation, imaging of defects and discontinuities within a sample are of more interest. Such defects, unlike sources or slits, induce wave scattering which could potentially impact image generation. This paper studies the effects of wave scattering by subwavelength spaced defects in holey structured metamaterial based super resolution imaging using numerical (finite element) models. In these models, the ultrasonic waves are assumed to impinge on the defects in a normal incidence through transmission configuration, and a line-scan image at the receiver location is generated based on the captured waves past the metamaterial. The influence of defect position within the specimen sample (object plane) and the receiver location (image plane) with respect to the metamaterial on the output images are investigated. The results show that the defect-induced wave scattering processes produce intensity and spatial artefacts that have a signature on imaging. For various parametric cases, the changes in the output images are quantified and discussed in the context of metamaterial based super resolution imaging in the field of non-destructive evaluation and non-invasive diagnostics.
Magnetic Inspection Platform for Teleoperated Remote Inspections of Complex Geometry
Authors: Jackson William , Zhang Dayi , McMillan Ross , Tabatabaeipour Morteza , Hampson Rory , Gilmour Adam , MacLeod Charles , Dobie Gordon
Published: January 2023

The NDE industry is under constant pressure to increase inspection speeds, while simultaneously reducing costs to keep up with the ever-expanding demands of providing robust inspection for new infrastructure as well as ongoing inspections for currently operating facilities, and the increasing rise in the need for extensions in the planned life of existing plants.

Currently, setting up an automated phased array ultrasonic inspection requires significant manpower, especially on components with complex geometry, this often exposes operators to hazardous environments. This is a particular problem with conventional ultrasonic NDT where operators must regularly exchange probes (an ‘intervention’). Furthermore, inspections are often carried out during planned outages, and the necessary installation time of rigging can represent a significant part of the inspection cost.

To alleviate these challenges, several specialised robotic systems have been developed in industry for performing NDE in areas with well-defined geometries. However, these systems are often limited by a high degree of manual intervention, a lack of general-purpose design, and unsophisticated brute-force data acquisition with little to no data interpretation.

The development of next generation, automated NDE solutions present considerable improvements to the current state of design such as reduced inspection time, greater separation of data capture and analysis, data localization – data are intrinsically encoded with the position they were captured. These benefits lead to a reduction in plant downtime & operator dosage.

The platform presented will achieve these improvements through a set of universal automated deployment tools, implemented through hardware and software advances. By creating a platform consisting of a motorised magnetic base paired with a miniature robotic arm, a very capable and adaptable system is formed. This allows for different sensing modalities with an initial focus on phased array ultrasonics to be delivered accurately and repeatably to the target inspection site. Furthermore, by introducing additional perceptual sensors such as cameras, laser scanners, & a force-torque sensor the system can understand the environment in which it is operating. Through these sensors the user may guide the robot through the plant remotely in a safe and controlled manner. In addition to this these sensors may be used to generate scan paths of critical areas with unknown geometry on the fly as well as adapt the path in a conformable manner.
Evaluation and Comparison of Two Deep-Learning Strategies for On-Line X-Ray Computed Tomography
Authors: Vo Romain , Escoda Julie , Vienne Caroline , Decencière Étienne
Published: January 2023

X-ray Computed Tomography (CT) has been increasingly used in many industrial domains for its unique capability of controlling both the integrity and dimensional conformity of parts. Still, it fails to be adopted as a standard technique for on-line monitoring due to its excessive cost in terms of acquisition time. The reduction of the number of projections, leading to the so-called sparse-view CT strategy, while maintaining a sufficient reconstruction quality is therefore one of the main challenges in this field. This work aims to evaluate and compare the performances of two deep learning strategies for the sparse-view reconstruction problem. As such, we propose an extensive study of these methods, both in terms of data regime and angular sparsity during training. The two strategies present quantitative improvements over a classical FBP/FDK approach with a PSNR improvement varying between 11 and 16 dB (depending on the angular sparsity) ; showing that efficient CT inspection can be performed from only few dozens of images
Corrosion Detection in Storage Tank Bottoms via Omni-Directional Magnetostrictive Guided Wave Inspection System
Authors: Chen Xin , Cobb Adam , Vinogradov Sergey
Published: January 2023

Storage tanks are ubiquitous in various industries, and corrosion in tank bottoms is a major threat to their normal operation. A variety of nondestructive testing (NDT) methods have been proposed for corrosion detection, of which the ultrasonic guided wave (UGW) technique is widely considered efficient due to the large propagation distance and high sensitivity to defects. To obtain complete mapping of tank bottom defects, UGW tomography is usually preferred; however, the requirement to place transducers at fine angular increments can cause the measurements to be time consuming. In this paper, we report the usage of a newly designed omni-directional magnetostrictive guided wave system for tank bottom corrosion detection. Different from existing omni-directional system designs, which are typically based on sparse array elements, the system proposed here excites guided waves using a single probe in a single predominant direction that covers the area determined by its beam characteristics. The omni-directional coverage is achieved by rotating the probe with a servo motor and acquiring data at predefined angles. In this fashion, the beam directionality is improved due to a larger transducer aperture compared with those based on a sparse array of small elements, and the beam directionality remains the same at every angle. The performance of the proposed omni-directional system for corrosion inspection is evaluated experimentally by introducing drilled holes of different depths and locations in the bottom of a mock-up tank. The system was placed at several locations along the tank bottom chime plate edge (skirt), where triangulation using appropriate angular measurements can be applied to locate corrosion in the tank bottom.
The health service impact of an occupational therapy practice placement model: Student-resourced service delivery of groups
Authors: Pigott Amanda , Patterson Freyr , Birch Stephen , Oakley Padrig , Doig Emmah , Project team "Impact of SRSD of groups placement"
Published: January 2023

Introduction: Student-resourced service delivery of groups is a practice education placement model in which students deliver therapy to groups, with graded supervision. This study examined an application of this model in occupational therapy to determine its costs to the health service and impact on hospital rehabilitation throughput and patient outcomes.
Methods: Retrospectively collected data were compared between periods when groups were student-resourced and staff-resourced. Patient data were analysed separately to group data.
Results: Seventeen patients received staff-resourced group therapy, and 52 patients received student-resourced group therapy, with no statistically significant differences identified in the characteristics of patients between group types. There was no evidence student-resourced therapy was associated with change in patient rehabilitation outcomes or length of rehabilitation stay.
Student-resourced therapy groups had an average duration of 10.8 minutes per session shorter (95% CI: 3.7, 18.0 P: 0.002) than staff-resourced groups. Under the student-resourced groups placement model, mean clinician time per group—both direct patient time and time spent on group facilitation—was not adversely affected and was reduced for occupational therapy assistants’ direct time (mean difference -7.6 minutes, 95% CI: 0.8, -16.0 P: 0.04) and for occupational therapists’ indirect time (mean difference -30.28 minutes 95% CI: -1.0, -59.6 P:0.02). Despite an implied mean cost savings per group of $49.61 under the student-resourced model, there was no evidence of any statistically significant impact on overall costs.
Conclusions: Student-resourced service delivery of rehabilitation groups provide an opportunity for student practice education placements and do not appear to negatively impact occupational therapists’ time, costs or patient outcomes.