bluuebunny/crossref_metadata_2025 huggingface dataset:
Sub‐seasonal correlation between growth and survival in three sympatric aquatic ectotherms
Authors: Kanno Yoichiro , Kim Seoghyun , Pregler Kasey C.
Published: November 2022

Animals experience seasonally changing conditions in temperate regions, thus population vital rates change seasonally. However, knowledge is lacking on patterns of seasonal correlation between growth and survival in sympatric ectotherms, and this knowledge gap limits our understanding of environmental change impacts on animal populations and communities. Here, we investigated sub‐seasonal (two‐month intervals) correlation between growth and survival in three stream fishes (bluehead chubNocomis leptocephalus, creek chubSemotilus atromaculatusand mottled sculpinCottus bairdii) in South Carolina, USA, via a mark–recapture survey over 28 months. We found that patterns of temporal correlation between the population vital rates differed among the sympatric species. Growth increased and survival decreased with water temperature in two eurythermal species, resulting in negative correlation between growth and survival. Growth peaked in sub‐seasons with an intermediate water temperature range in a third stenothermal species, while survival decreased with water temperature for this species too. Consequently, there was not significant negative or positive correlation between sub‐seasonal growth and survival in the stenothermal species. Body condition (weight at given length) decreased from May through November in all three species, providing a potential physiological explanation for why survival rates were lower during this period. Negative correlation among population vital rates stabilizes population size over time and buffers animal populations from environmental change because the vital rates are not affected simultaneously in the same direction, indicating some degree of resiliency in the face of climate changes in the two eurythermal species. However, such a demographic mechanism of resiliency could be maintained so long as climate warming does not exceed optimal growth temperature, above which negative correlation between growth and survival may no longer be maintained.
Characterization of FA1654: A putative DPS protein in Filifactor alocis
Authors: Mangar Malissa , Mishra Arunima , Yang Zhengrong , Deivanayagam Champion , Fletcher Hansel M.
Published: November 2022

The survival/adaptation of Filifactor alocis, a fastidious Gram‐positive asaccharolytic anaerobe, to the inflammatory environment of the periodontal pocket requires an ability to overcome oxidative stress. Moreover, its pathogenic characteristics are highlighted by its capacity to survive in the oxidative‐stress microenvironment of the periodontal pocket and a likely ability to modulate the microbial community dynamics. There is still a significant gap in our understanding of its mechanism of oxidative stress resistance and its impact on the virulence and pathogenicity of the microbial biofilm. Coinfection of epithelial cells with F. alocis and Porphyromonas gingivalis resulted in the upregulation of several genes, including HMPREF0389_01654 (FA1654). Bioinformatics analysis indicates that FA1654 has a “di‐iron binding domain” and could function as a DNA starvation and stationary phase protection (DPS) protein. We have further characterized the FA1654 protein to determine its role in oxidative stress resistance in F. alocis. In the presence of hydrogen peroxide‐induced oxidative stress, there was an ∼1.3 fold upregulation of the FA1654 gene in F. alocis. Incubation of the purified FA1654 protein with DNA in the presence of hydrogen peroxide and iron resulted in the protection of the DNA from Fenton‐mediated degradation. Circular dichroism and differential scanning fluorimetry studies have documented the intrinsic ability of rFA1654 protein to bind iron; however, the rFA1654 protein is missing the intrinsic ability to reduce hydrogen peroxide. Collectively, the data may suggest that FA1654 in F. alocis is involved in oxidative stress resistance via an ability to protect against Fenton‐mediated oxidative stress‐induced damage.
Perception of loneliness and life satisfaction in the elderly during the COVID‐19 pandemic process
Authors: Altay Birsen , Çalmaz Ayşe
Published: November 2022

This study was conducted to evaluate the perception of loneliness and life satisfaction among the elderly during the COVID‐19 pandemic process. A descriptive‐correlational study was carried out between July and October 2020. The study enrolled 216 individuals over the age of 65. A sociodemographic information form, the Loneliness Scale for the Elderly, and the Life Satisfaction Scale were used as data collection tools. Mann–Whitney U‐tests, Kruskal–Wallis H‐tests, and correlation analysis were used in the statistical processing of data. Ethics committee approval was obtained before the study started. It was found that 68.5% of the elderly in the study were female, their average age was 70.15 ± 5.48, 63.0% were married, the total average of the Loneliness Scale of the Elderly was at a moderate level (8.23 ± 4.90), and the total of the Life Satisfaction Scale at a low level (2.43 ± 1.10). Scores for the Loneliness Scale of the Elderly total and its emotional loneliness dimension were found to be significantly higher in the elderly who replied it was difficult to stay at home. It was found that the life satisfaction of the elderly who felt well, who did not feel partially lonely, who were satisfied with life, and who were not living alone was significantly higher (all P < 0.05). Isolation of the elderly under pandemic conditions affects their life satisfaction negatively. For the improvement of elderly health and life satisfaction, evaluation of the psychosocial determinants of health such as loneliness and life satisfaction is essential, and parallel to this evaluation, it is important for public health nurses to plan and implement appropriate interventions to reduce loneliness and increase life satisfaction.
The government behind insurance governance: Lessons for ransomware
Authors: Baker Tom , Shortland Anja
Published: November 2022

The insurance as governance literature focuses on the ability of private enterprises to collectively regulate, pool, and distribute risks. This paper analyzes how governments support insurance markets to maintain insurability and limit risks to society. We propose a new conceptual framework grouping government interventions into three dimensions: regulation of risky activity, public investment in risk reduction, and co‐insurance. We apply this framework to six case studies, describing insurance markets' reliance on public support in more analytically precise terms. We analyze how mature insurance markets overcame insurability challenges akin to those currently presented by extortive cybercrime. Private governance struggled when markets grew too big for informal coordination or when (tail) risks escalated. Government interventions vary widely. Some governments prioritize supporting economic activity while others concentrate on containing risks. Governments also choose between risk reduction and ex post socialization of losses. We apply these insights to the market for ransomware insurance, discussing the merits and potential hazards of current proposals for government intervention.
Environmental plastics and lung health: Increasing evidence for concern
Authors: Naidoo Rajen N.
Published: November 2022

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Small for gestational age at term and adult lung function
Authors: Wang Kimberley C. W. , James Alan L.
Published: November 2022

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A Venetian Secretary's Expertise. Marcantonio Donini and his Three Dialogues… on the Ottoman Empire and ‘Turkish’ Affairs
Authors: Chmiel Piotr
Published: November 2022

This article presents a text on the Ottoman Empire left by Marcantonio Donini – a career secretary with the Venetian diplomatic service, sent three times to Constantinople/Istanbul. After the death of his superior during his second stay in the Ottoman Empire, Donini was entrusted with temporarily heading the mission and with presenting the final mission report (relazione) after his return to Venice (1562). Most probably, he also wrote a much less formal text, composed of three dialogues on the Ottoman reality (signed 1591). Donini's writings attest to well‐developed rhetorical skills, manifested by the clear division of topics between the dialogues and relazione and by the ways used to present alleged Ottoman otherness. Some of the original traits in his writings are also attributable to Marcantonio's individual views and his social position as a secretary. By focusing on Donini and his dialogues, this paper aims to enrich discussion on the scope and content of texts on the Ottoman Empire produced by Venetian diplomats.
Estimation of Reproduction Numbers in Real Time: Conceptual and Statistical Challenges
Authors: Pellis Lorenzo , Birrell Paul J. , Blake Joshua , Overton Christopher E. , Scarabel Francesca , Stage Helena B. , Brooks-Pollock Ellen , Danon Leon , Hall Ian , House Thomas A. , Keeling Matt J. , Read Jonathan M. ,   JUNIPER Consortium, De Angelis Daniela
Published: November 2022

The reproduction number R has been a central metric of the COVID-19 pandemic response, published weekly by the UK government and regularly reported in the media. Here, we provide a formal definition and discuss the advantages and most common misconceptions around this quantity. We consider the intuition behind different formulations of R, the complexities in its estimation (including the unavoidable lags involved), and its value compared to other indicators (e.g. the growth rate) that can be directly observed from aggregate surveillance data and react more promptly to changes in epidemic trend. As models become more sophisticated, with age and/or spatial structure, formulating R becomes increasingly complicated and inevitably model-dependent. We present some models currently used in the UK pandemic response as examples. Ultimately, limitations in the available data streams, data quality and time constraints force pragmatic choices to be made on a quantity that is an average across time, space, social structure and settings. Effectively communicating these challenges is important but often difficult in an emergency.
A Statistical Test to Reject the Structural interpretation of a Latent Factor Model
Authors: VanderWeele Tyler J. , Vansteelandt Stijn
Published: November 2022

Factor analysis is often used to assess whether a single univariate latent variable is sufficient to explain most of the covariance among a set of indicators for some underlying construct. When evidence suggests that a single factor is adequate, research often proceeds by using a univariate summary of the indicators in subsequent research. Implicit in such practices is the assumption that it is the underlying latent, rather than the indicators, that is causally efficacious. The assumption that the indicators do not have effects on anything subsequent, and that they are themselves only affected by antecedents through the underlying latent is a strong assumption, effectively imposing a structural interpretation on the latent factor model. In this paper, we show that this structural assumption has empirically testable implications, even though the latent variable itself is unobserved. We develop a statistical test to potentially reject the structural interpretation of a latent factor model. We apply this test to data concerning associations between the Satisfaction with Life Scale and subsequent all-cause mortality, which provides strong evidence against a structural interpretation for a univariate latent underlying the scale. Discussion is given to the implications of this result for the development, evaluation and use of measures, and for the use of factor analysis itself.
Help‐seeking and Man Therapy: The impact of an online suicide intervention
Authors: Gilgoff Jon N. , Wagner Fernando , Frey Jodi J. , Osteen Philip J.
Published: November 2022

Introduction

Suicide is a leading cause of death for men in the United States. Men traditionally have been hesitant to seek help, based on masculine norms of stoicism and self‐reliance, among other factors. Man Therapy (MT) is an online suicide prevention and mental health initiative that provides promise for facilitating male help‐seeking.

Methods

This study draws on data from a randomized controlled trial which examined effects of MT on a sample of men residing in Michigan aged 25–64. The current study utilized logistic regression to test MT's effect on nonprofessional and professional help‐seeking, controlling for marital status, education, and sexual orientation.

Results

A statistically significant positive association was found between MT and professional help‐seeking (OR = 1.55, p = 0.049). A significant inverse association was also found with marital status, with partnered men less likely to seek professional help (OR = 0.53, p = 0.007). There was no significant association between MT and nonprofessional help‐seeking.

Conclusion

Man Therapy demonstrates the promise of web‐based suicide prevention efforts to reach men who typically do not engage in help‐seeking, providing a gateway to vital professional support. As technology continues to emerge, further suicide research is needed on use of this modality with working‐age men from diverse backgrounds.
Development of de novo donor‐specific antibodies in renal transplant recipients with BK viremia managed with immunosuppression reduction
Authors: Hod‐Dvorai Reut , Lee Ryan , Muluhngwi Penn , Raijmakers Mariella , Shetty Aneesha , Tambur Anat R. , Ison Michael G.
Published: November 2022

Background

Reduction of immunosuppression (IS) upon detection of Polyomavirus (BK) viremia is widely used to prevent BK virus nephropathy. This retrospective case‐control study assesses the frequency of de novo donor‐specific antibodies (dnDSA) in renal transplant recipients with IS modulation due to BK viremia and the associated risk of antibody mediated rejection.

Methods

Our cohort included recipients of kidney transplantation between 2007 and 2017 with clinical, HLA antibody, and biopsy data. BK positivity was defined as viremia >10 000 c/ml or biopsy proven BK nephropathy. A total of 190 BK cases matched our inclusion criteria, each case was matched with two controls based on gender, donor type, and transplant within 1 year (N = 396).

Results

Despite lower number of HLA antigen mismatches (mean = 3.5 vs. 4.4, p < .001), dnDSA rates were higher in BK cases than in control group (22.1% vs. 13.9%, p = .02), with the majority detected following IS reduction for BK infection, and arising earlier posttransplant compared with no BK infection (294d vs. 434d, p < .001). Antibody mediated rejection rates were similar between cases and controls (8.9% and 8.3%, respectively), but rejection was more likely to occur earlier posttransplant in the BK cases (354d vs. 602d, p = .03).

Conclusion

Our data suggest a link between IS reduction and the generation of dnDSA and/or rejection, supporting close monitoring for DSA in patients with reduced IS due to BK infection given their increased risk to develop dnDSA.

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Effective CMV prophylaxis with high‐dose valaciclovir in allogeneic hematopoietic stem‐cell recipients at a high risk of CMV infection
Authors: Douglas Genevieve , Yong Michelle K. , Tio Shio Yen , Chau Maggie , Prabahran Ashvind , Sasadeusz Joe , Slavin Monica , Ritchie David , Chee Lynette
Published: November 2022

Background

Cytomegalovirus (CMV) infection increases mortality and morbidity following allogeneic hematopoietic stem‐cell transplantation (alloHSCT). Universal antiviral prophylaxis with letermovir is effective but unsubsidized in Australia. Valaciclovir demonstrates anti‐CMV activity in high doses, but few current real‐world studies explore its use as primary prophylaxis in high‐risk patients post‐alloHSCT.

Methods

We performed a retrospective analysis of alloHSCT recipients at high risk of clinically significant CMV infection (cs‐CMVi), defined as a plasma CMV DNA viral load of >400 IU/ml requiring preemptive therapy, or CMV disease. High‐risk recipients were CMV seropositive and underwent T‐cell depleted, haploidentical or umbilical cord stem‐cell transplants. Consecutive patients transplanted from July 2018 to January 2020, treated with valaciclovir 2 g TDS from day +7 to +100 (HD‐VALA), were compared to a historical cohort (July 2017–June 2018) who only received preemptive CMV therapy, and standard valaciclovir (SD‐VALA) for varicella/herpes prophylaxis. We compared incidence of and time to cs‐CMVi.

Results

In the SD‐VALA cohort (n = 27, median CMV follow‐up duration 259 days), 23/27 (85%) developed cs‐CMVi at a median of 39 days. For the HD‐VALA cohort (n = 35, median CMV follow‐up duration 216 days), 19/35 (54%) developed cs‐CMVi, at a median of 68 days. Time to cs‐CMVi was significantly longer in HD‐VALA cohort (p < .0001). On multivariate analysis, HD VALA reduced the risk of cs‐CMVi (HR 0.32, p = .0005).

Conclusions

In alloHSCT recipients at high risk for cs‐CMVi, HD‐VALA resulted in lower cumulative reactivation, and delayed reactivation, reducing requirement for preemptive CMV therapy in the early post‐engraftment period.

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AP2S1 regulates APP degradation through late endosome–lysosome fusion in cells and APP/PS1 mice
Authors: Wen Qi‐Xin , Luo Biao , Xie Xiao‐Yong , Zhou Gui‐Feng , Chen Jian , Song Li , Liu Yue , Xie Shi‐Qi , Chen Long , Li Kun‐Yi , Xiang Xiao‐Jiao , Chen Guo‐Jun
Published: November 2022

AP2S1 is the sigma 2 subunit of adaptor protein 2 (AP2) that is essential for endocytosis. In this study, we investigated the potential role of AP2S1 in intracellular processing of amyloid precursor protein (APP), which contributes to the pathogenesis of Alzheimer disease (AD) by generating the toxic β‐amyloid peptide (Aβ). We found that knockdown or overexpression of AP2S1 decreased or increased the protein levels of APP and Aβ in cells stably expressing human full‐length APP695, respectively. This effect was unrelated to endocytosis but involved lysosomal degradation. Morphological studies revealed that silencing of AP2S1 promoted the translocalization of APP from RAB9‐positive late endosomes (LE) to LAMP1‐positive lysosomes, which was paralleled by the enhanced LE‐lysosome fusion. In support, silencing of vacuolar protein sorting‐associated protein 41 (VPS41) that is implicated in LE‐lyso fusion prevented AP2S1‐mediated regulation of APP degradation and translocalization. In APP/PS1 mice, an animal model of AD, AAV‐mediated delivery of AP2S1 shRNA in the hippocampus significantly reduced the protein levels of APP and Aβ, with the concomitant APP translocalization, LE‐lyso fusion and the improved cognitive functions. Taken together, these data uncover a LE‐lyso fusion mechanism in APP degradation and suggest a novel role for AP2S1 in the pathophysiology of AD.
Grand Challenges in Membrane Distillation for Desalination and Water Recovery
Authors: Kaleekkal Noel Jacob , John Juliana
Published: November 2022

Seawater desalination and water recovery from wastewater are potential solutions to meet the ever-growing water demand. Membrane distillation (MD) is a next-generation membrane technology that can be harnessed for sustainable water production. The advantages of the MD process and the various operating configurations are discussed. The challenges in membrane development are highlighted, and the various state-of-the-art approaches for improving membrane performance, fouling resistance, anti-wetting character, and minimizing concentration/temperature polarisations are included. The process design is another crucial aspect of the successful implementation of the MD. Response surface methodology and Analysis of Variance (ANOVA) have been explored to identify the optimal operating conditions. Machine learning and computational fluid dynamics analysis (CFD) that have been used to predict the performance and influence of the process parameters are discussed. The energetics and economics of the MD process have also been discussed. The MD process could become sustainable if it utilizes renewable energy sources (solar, geothermal) for bulk heating of the feed. This article highlights the various challenges associated with MD technology and provides an overview of the strategies researched to overcome them.
Grand Challenges in Fabrication of Nanocomposite Hollow Fiber Membranes
Authors: Subramaniam M. N. , Wu Z.
Published: November 2022

Membrane processes allow scalable and energy-efficient separation of gas and liquid, advance low-carbon purifications in various industrial and environmental applications and enable more resilient economy and society. In pursuit of developing more advanced membranes with continuously improved separating performances, nanofillers have been commonly incorporated into membranes to upgrade membrane properties such as mechanical robustness, antifouling ability, and permeability etc., across all types of popular membrane geometries from flat sheet and spiral wound to hollow fiber. Nanofillers inside hollow fibre membranes have received more attentions due to the unique structural advantages such as a large surface area/volume ratio and compact module designs. The resultant nanocomposite hollow fiber membranes thus combine the structural superiority with specific functions of nanomaterials such as superhydrophilicity or catalytic activity, whereas the development of dual layer hollow fiber membrane allowed further design of both the inner and outer membrane layers with innovative functions. On the other hand, greener and more environmentally friendly membranes fabrication are increasingly important to sustainable membrane technology, for example topics of using natural polymers, solvent free membrane fabrication and nano-pollutions are fervently investigated.
Evolution of Membrane Surface Properties for Membrane Distillation: A Mini Review
Authors: Chiam Chel-Ken , Sarbatly Rosalam
Published: November 2022

To date, the membrane development for membrane distillation (MD) application is growing in line with the increasing volume of various types of wastewaters discharged into environment. MD is a liquid-vapor separation process and a hydrophobic membrane is used to retain the liquid. Theoretically, the hydrophobic membrane can achieve 100% rejection of non-volatile components that dissolved in feed liquids. As a result, MD has received significant attention in water recovery from saline water as well as wastewaters. Nevertheless, in addition to the scaling problem due to salts, the hydrophobicity property of membrane becomes a concern when dealing with challenging wastewaters which contain various types of low surface tension components such as oils, grease, alcohols, organics and surfactants. The membrane pore wetting due to salts deposition fouling and low surface tension components subsequently reduces the flux and even fails the liquid-vapor separation process. This article briefly discusses the transformation of MD membrane from hydrophobic to superhydrophobic and omniphobic which purposely to enhance the flux and eliminate the membrane pore wetting.
Examining the Performance of Software Defined Virtual Local Area Network
Authors: Abubakar Ibrahim Adamu , Abdulkadir Ahmed Mohamud
Published: November 2022

For more than three decades, the Virtual Local Area Network (VLAN) has been one of the most popular systems virtualization groups of users on both local and corporate networks. Because of the advantages that VLAN provides, network managers and operators have continued to use it in the creation of their networks and have even extended its use to include cloud computing networking. Previous research studies have established a lot of issues associated with VLAN architecture. Typically, it was revealed that it is difficult to set up a complex VLAN, and even it is successful, it leads to computational time-consuming, and prone to error to process majority of complex VLAN. Considering this, the current research examines the performance of “Software Defined- VLAN”. This is because Software-Defined Network (SDN) is a viable alternative network architecture that allows the separation of information and control functions on devices. It appears to be a promising optimized option VLAN administration. The SDN-enabled VLAN testbed was set out and implemented using OpenFlow. SDN-Enabled VLAN and a conventional VLAN. The finding revealed that SDN-enabled VLAN offers higher network performance, lower packet transfer delay, and a more efficient configuration.
The Imperative of Technical Skilled Staff in Legacy Information System Management
Authors: Edegbe Glory Nosawaru , Onianwa Charles Uche
Published: November 2022

Technical skilled personnel and information systems are important for the success of contemporary firms as they face intense rivalry, globalization, and time-to-market pressures. They are an essential element that plays a critical role in an organisation’s ability to sense environmental change and respond efficiently and effectively to that change. Besides the technology components of an information system and the fast pace of technological innovation, the people involved in the design, operation and maintenance are essential elements of information systems. Most of the research work on deciding whether or not to continue with legacy information systems has been centred mainly on intrinsic agility factors. Extrinsic agility factors like technical skilled personnel have largely been overlooked. But, as information systems age or in the case of highly rigid processes, extrinsic agility factors like technical skilled personnel will start playing an important role in deciding whether to prolong the life cycle of the information system. However, human skills obsolescence is a growing problem for organizations that must support legacy systems. The technical skilled staff are either ageing out or upgrading their skills to a non-procedural programming paradigm due to market demand. It is, therefore, imperative to regularly assess the technical skilled personnel competency level of a legacy information system. This study evaluates and classifies the technical knowledge of skilled personnel using a developed online assessment system with test questions based on the legacy information system application program. The result obtained indicates that the technical skilled staff can still operate and maintain the case study information system.
Long COVID: mechanisms, risk factors and recovery
Authors: Astin Rónan , Banerjee Amitava , Baker Mark R. , Dani Melanie , Ford Elizabeth , Hull James H. , Lim Phang Boon , McNarry Melitta , Morten Karl , O'Sullivan Oliver , Pretorius Etheresia , Raman Betty , Soteropoulos Demetris S. , Taquet Maxime , Hall Catherine N.
Published: November 2022

Long COVID, the prolonged illness and fatigue suffered by a small proportion of those infected with SARS‐CoV‐2, is placing an increasing burden on individuals and society. A Physiological Society virtual meeting in February 2022 brought clinicians and researchers together to discuss the current understanding of long COVID mechanisms, risk factors and recovery. This review highlights the themes arising from that meeting. It considers the nature of long COVID, exploring its links with other post‐viral illnesses such as myalgic encephalomyelitis/chronic fatigue syndrome, and highlights how long COVID research can help us better support those suffering from all post‐viral syndromes. Long COVID research started particularly swiftly in populations routinely monitoring their physical performance – namely the military and elite athletes. The review highlights how the high degree of diagnosis, intervention and monitoring of success in these active populations can suggest management strategies for the wider population. We then consider how a key component of performance monitoring in active populations, cardiopulmonary exercise training, has revealed long COVID‐related changes in physiology – including alterations in peripheral muscle function, ventilatory inefficiency and autonomic dysfunction. The nature and impact of dysautonomia are further discussed in relation to postural orthostatic tachycardia syndrome, fatigue and treatment strategies that aim to combat sympathetic overactivation by stimulating the vagus nerve. We then interrogate the mechanisms that underlie long COVID symptoms, with a focus on impaired oxygen delivery due to micro‐clotting and disruption of cellular energy metabolism, before considering treatment strategies that indirectly or directly tackle these mechanisms. These include remote inspiratory muscle training and integrated care pathways that combine rehabilitation and drug interventions with research into long COVID healthcare access across different populations. Overall, this review showcases how physiological research reveals the changes that occur in long COVID and how different therapeutic strategies are being developed and tested to combat this condition.
Petrophysical Characterization of Shaly Sand Reservoirs in Well UK-05 Eastern Niger Delta Basin, Nigeria
Authors: Victor Wotanie Ligbwah , Mbaringong Christopher Agyingi , Anatole Djieto-Lordon
Published: November 2022

A petrophysical evaluation of Well UK-05 in the eastern Niger Delta Basin was carried out in order to determine reservoir zones, their porosity, permeability, fluid saturation and the effect of shaliness on the petrophysical parameters. Using interactive petrophysics software version 3.5, twenty five (25) reservoir zones were identified. The porosity values range from 15.77- 4.66% and permeability from 2.76-546.54 mD. The Archie’s, Simandoux, Dual-porosity, Waxman and Smith, and the Indonesian models were used to determine the fluid saturation. The water and hydrocarbon saturation values using the Indonesian model are 21.67-50.49% and 49.51-78.33% respectively. They slightly differ from the ones obtained using Simandoux, Dual Water and Waxman and Smith model (20.72-49.88% and 50.12- 9.22%, 18.26-50.49% and 49.51-81.74%, 14.67-48.26% and 51.74-5.33% for water and hydrocarbon saturation respectively). The interpreted lithology shows that the formation penetrated by the Well UK-05 is dominated by alternating sands and shales with the sand being the dominant lithology. These lithostratigraphic characteristics correspond to those of the parallic Agbada Formation. The effective porosity values obtained range from 14.93 to 34.66%, which are lower than 0.013% to 94.08% obtained by other authors since they did not take into consideration the effect of shaliness. This shows that the more the shale volume, the higher the uncertainty of actual porosity of the reservoir.
Cervical Spine Finite Element Models for Healthy Subjects: Development and Validation
Authors: Tahmid Shadman , Love Brittany M. , Liang Ziyang , Yang James
Published: November 2022

Finite element modeling is a popular method for predicting kinematics and kinetics in spine biomechanics. With the advancement of powerful computational equipment, more detailed finite element models have been developed for the various spine segments. In this study, five detailed finite element models of the cervical spine are developed and validated. The geometric boundaries of the vertebrae are determined from computed tomography (CT) scans of five female subjects. The models include the C2–C7 vertebrae, intervertebral discs, nuclei, endplates, and five major ligaments (anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), ligamentum flavum (LF), interspinous ligament (ISL), and capsular ligament (CL)). The ligaments follow nonlinear stress–strain curves whereas all other parts adopt linear material properties. All the material properties are taken from existing literature. The mesh convergence test is performed under flexion/extension. For flexion/extension motion, a pure moment is applied at the top surface of the odontoid process of the C2 vertebra while nodes at the bottom surface of the C7 vertebra are fixed in all directions. The models are extensively validated in flexion/extension, lateral bending, and axial rotation against experimental and finite element studies in the literature. Intervertebral rotation and range of motion are studied under different loading conditions found in the literature. This research also investigates intersubject variability for the cervical spine among five finite element models from five different subjects. Predicted angular displacements and ranges of motion of the current models are consistent with the literature. The validated models are expected to be applicable to simulate neck-related trauma like whiplash and high-g acceleration, among other scenarios.
Reinforcement Learning for Efficient Design Space Exploration With Variable Fidelity Analysis Models
Authors: Agrawal Akash , McComb Christopher
Published: November 2022

Reinforcement learning algorithms can autonomously learn to search a design space for high-performance solutions. However, modern engineering often entails the use of computationally intensive simulation, which can lead to slower design timelines with highly iterative approaches such as reinforcement learning. This work provides a reinforcement learning framework that leverages models of varying fidelity to enable an effective solution search while reducing overall computational needs. Specifically, it utilizes models of varying fidelity while training the agent, iteratively progressing from low- to high fidelity. To demonstrate the effectiveness of the proposed framework, we apply it to two multimodal multi-objective constrained mixed integer nonlinear design problems involving the components of a ground and aerial vehicle. Specifically, for each problem, we utilize a high-fidelity and a low-fidelity deep neural network surrogate model, trained on performance data generated from underlying ground truth models. A tradeoff between solution quality and the proportion of low-fidelity surrogate model usage is observed. Specifically, high-quality solutions are achieved with substantial reductions in computational expense, showcasing the effectiveness of the framework for design problems where the use of just a high-fidelity model is infeasible. This solution quality-computational efficiency tradeoff is contextualized by visualizing the exploration behavior of the design agents.
Characterization and Modeling of the System Behavior of High Load SMA Actuators
Authors: Maiwald Daniel , Trittler Toennis , Bucht André , Pagel Kenny , Drossel Welf-Guntram
Published: November 2022

Actuators are key elements in almost every production plant and machine. Thermal shape memory alloys (SMA) have an enormous energy density and can be used as a structural component of the machine. The technology therefore represents an interesting alternative to conventional actuator technologies. Wire-based SMA actuators are already established in industrial applications but are limited to low forces (N-range) at small strokes (mm-range). However, there are also applications and demands for compact SMA actuators with higher forces (kN-range). They require more massive geometries and new integration concepts of the shape memory components. This can significantly change the thermal system behavior, knowledge of which is required for design and optimization, as well as for dynamic control of the actuators.

This paper describes the thermal system characterization and simulation methods for bulk actuators based on SMA. First, a technology demonstrator is presented, which is the basis for the measurements and models discussed. Next, two connected models for the thermal system behavior are presented: A thermal FE model and a lumped-parameter model with significantly reduced complexity to simulate dynamic behavior in real time and for optimization. Both models are validated with measurement data. In the end, the benefits and limitations of both models are discussed.
Electromechanical Model of Dielectric Elastomer Transducers
Authors: Bakardjiev Petko , Marschner Uwe , Richter Andreas , Altinsoy Ercan M.
Published: November 2022

Dielectric Elastomers (DE) considered as smart materials have increasing popularity in the scientific community. Despite a multitude of presented applications and devises based on DE, there is no standard model to describe them as transducers. Thus, their design is in general often time-consuming. To describe the operational behavior, mostly material equations describing the materials energy state through strain and stress are utilized. The driving mechanism is expressed through the commonly known Maxwell-pressure which is the result of the energy balance. This often-used approach is sufficient for quasi-static applications. Yet when considering the dynamic regime, a description of the locally effective directional forces is necessary.

We propose an expansion to the existing modelling approach. Deepening the view on force mechanisms of electrostatic actuators and incorporating the solid body properties of elastomers into consideration. Thus, we gain a network description for dielectric elastomers as reversible electromechanical transducers near an operating point. The network model, allows for a sped-up design and simulation process, especially in the development of dynamic applications. Our findings are supported findings from previous literature and FEM-simulations.
Micro Laser Welding of NiTi Shape Memory Wires and Printed Circuit Boards
Authors: Schuleit Marvin , Theren Benedict , Maaß Burkhard , Kuhlenkötter Bernd , Esen Cemal
Published: November 2022

Integration of shape memory alloys (SMA) into actuator systems is still challenging, since mechanically and electrically anchoring are needed to provide stroke and trigger the shape memory effect (SME) in a controlled manner. A direct connection of SMA wires with printed circuit boards (PCBs) would offer many advantages. No additional material (e.g. crimps, clamp connections) and no additional steps for the electrical connection would be required. This would facilitate the engineering for new actuator systems because key integration challenges would be addressed through the use of the nickel-titanium (NiTi) PCB assembly. Soldering is traditionally used for bonding components with PCBs, but due to the poor wettability of the natural passivation layer, NiTi can only be soldered by using aggressive fluxes. In addition, soldered connections withstand mechanical loads to a limited extent. A stronger connection can be achieved using micro laser welding to create a joint, which provides mechanical and electrical connection for actuators. Controlling the heat input yield by laser radiation is especially important for this purpose. On the one hand, too intense heat input causes delamination processes due to excessive temperatures at the interface layer between copper layer and the PCB substrate. On the other hand, insufficient heat input leads to a weak connection that lacks mechanical strength, most importantly tensile and cyclic strength. In this work, the influence of laser power on the welded joint is investigated. In this context, tensile tests, lifetime tests, and microsections of the joint area are used for characterisation.
Practical guide on chemometrics/informatics in x-ray photoelectron spectroscopy (XPS). II. Example applications of multiple methods to the degradation of cellulose and tartaric acid
Authors: Avval Tahereh G. , Haack Hyrum , Gallagher Neal , Morgan David , Bargiela Pascal , Fairley Neal , Fernandez Vincent , Linford Matthew R.
Published: November 2022

Chemometrics/informatics, and data analysis in general, are increasingly important in x-ray photoelectron spectroscopy (XPS) because of the large amount of information (spectra/data) that is often collected in degradation, depth profiling, operando, and imaging studies. In this guide, we present chemometrics/informatics analyses of XPS data using a summary statistic (pattern recognition entropy), principal component analysis, multivariate curve resolution (MCR), and cluster analysis. These analyses were performed on C 1s, O 1s, and concatenated (combined) C 1s and O 1s narrow scans obtained by repeatedly analyzing samples of cellulose and tartaric acid, which led to their degradation. We discuss the following steps, principles, and methods in these analyses: gathering/using all of the information about samples, performing an initial evaluation of the raw data, including plotting it, knowing which chemometrics/informatics analyses to choose, data preprocessing, knowing where to start the chemometrics/informatics analysis, including the initial identification of outliers and unexpected features in data sets, returning to the original data after an informatics analysis to confirm findings, determining the number of abstract factors to keep in a model, MCR, including peak fitting MCR factors, more complicated MCR factors, and the presence of intermediates revealed through MCR, and cluster analysis. Some of the findings of this work are as follows. The various chemometrics/informatics methods showed a break/abrupt change in the cellulose data set (and in some cases an outlier). For the first time, MCR components were peak fit. Peak fitting of MCR components revealed the presence of intermediates in the decomposition of tartaric acid. Cluster analysis grouped the data in the order in which they were collected, leading to a series of average spectra that represent the changes in the spectra. This paper is a companion to a guide that focuses on the more theoretical aspects of the themes touched on here.
Charging a supercapacitor through a lamp: A power-law RC decay
Authors: Storms Michelle L. , Trees Brad R.
Published: November 2022

A circuit involving a charging supercapacitor in series with a non-Ohmic tungsten lamp displays a wealth of interesting behavior. Most notably, the current through the lamp decreases in time according to a power-law function as opposed to the exponential time dependence observed in RC circuits with Ohmic resistors. We use a combination of computational and analytical techniques to model this power-law behavior as well as the behavior of the filament's temperature and resistance as the supercapacitor charges. Our results agree well with experiment, and the experiment described here can be modified to be appropriate for physics courses at a wide range of levels.
Graphical analysis of an oscillator with constant magnitude sliding
friction
Authors: Roitberg V. , Drory Alon
Published: November 2022

We treat a horizontal oscillator damped by constant-magnitude sliding friction by extending the analogy between the simple harmonic motion of a mass on a spring and the uniform circular motion of a mass attached to the end of a string. In the presence of sliding friction, the motion of the mass on a spring becomes the horizontal projection of the path of a mass attached to a string winding around two nails separated by a well-defined distance; this path is a spiral consisting of connected semi-circles of diminishing radii. This graphical analysis is very simple and pedagogically useful. It can also be generalized to any oscillation affected by other forces of constant magnitude but not necessarily constant direction.
Persistence and
In Vivo
Evolution of Vaginal Bacterial Strains over a Multiyear Time Period
Authors: France Michael , Ma Bing , Ravel Jacques
Published: November 2022

The stability of strains within the vaginal microbiota is largely uncharacterized. Should these strains be capable of persisting for extended periods of time, they could evolve within their host in response to selective pressures exerted by the host or by other members of the community.
Supplemental Material: Large-scale submarine landslide drives long-lasting regime shift in slope sediment deposition
Authors: Dottore Stagna Marina , al. et
Published: November 2022

Supplemental Figures S1–S6. 
Supplemental Material: Deep magma mobilization years before the 2021 CE Fagradalsfjall eruption, Iceland
Authors: Kahl M. , al. et
Published: November 2022

Geological background, sampling and analytical methodology, modeling constraints, compositional data, standard checks, orientation data, and diffusion time scales. 
Poor psychological health and 8-year mortality: a population-based prospective cohort study stratified by gender in Scania, Sweden
Authors: Fridh Maria , Pirouzifard Mirnabi , Rosvall Maria , Lindstrom Martin
Published: November 2022

Objectives

We investigated gender differences in the association between mortality and general psychological distress (measured by 12-item General Health Questionnaire, GHQ-12), as an increased mortality risk has been shown in community studies, but gender differences are largely unknown.

Setting

We used data from a cross-sectional population-based public health survey conducted in 2008 in the Swedish region of Skåne (Scania) of people 18–80 years old (response rate 54.1 %). The relationship between psychological distress and subsequent all-cause and cause-specific mortality was examined by logistic regression models for the total study population and stratified by gender, adjusting for age, socioeconomic status, lifestyle (physical activity, smoking, alcohol consumption), and chronic disease.

Participants

Of 28 198 respondents, 25 503 were included in analysis by restrictive criteria.

Outcome measures

Overall and cause-specific mortality by 31 December 2016.

Results

More women (20.2 %) than men (15.7 %) reported psychological distress at baseline (GHQ ≥3). During a mean follow-up of 8.1 years, 1389 participants died: 425 (30.6%) from cardiovascular diseases, 539 (38.8%) from cancer, and 425 (30.6%) from other causes. The overall association between psychological distress and mortality risk held for all mortality end-points except cancer after multiple adjustments (eg, all-cause mortality OR 1.8 (95 % CI 1.4 to 2.2) for men and women combined. However, stratification revealed a clear gender difference as the association between GHQ-12 and mortality was consistently stronger and more robust among men than women.

Conclusion

More women than men reported psychological distress while mortality was higher among men (ie, the morbidity-mortality gender paradox). GHQ-12 could potentially be used as one of several predictors of mortality, especially for men. In the future, screening tools for psychological distress should be validated for both men and women. Further research regarding the underlying mechanisms of the gender paradox is warranted.