Multiple Processes Research Articles

A therapeutical insight into the correlation between circRNAs and signaling pathways involved in cancer pathogenesis.

Pre-messenger RNA molecules are back-spliced to create circular RNAs, which are non-coding RNA molecules. After a thorough investigation, it was discovered that these circRNAs have critical biological roles. CircRNAs have a variety of biological functions, including their ability to operate as microRNA sponges, interact with proteins to alter their stabilities and activities, and provide templates for the translation of proteins. Evidence supports a link between the emergence of numerous diseases, including various cancer types, and dysregulated circRNA expression. It is commonly known that a significant contributing element to cancer development is the disruption of numerous molecular pathways essential for preserving cellular and tissue homeostasis. The dysregulation of multiple biological processes is one of the hallmarks of cancer, and the molecular pathways linked to these processes are thought to be promising targets for therapeutic intervention. The biological and carcinogenic effects of circRNAs in the context of cancer are thoroughly reviewed in this article. Specifically, we highlight circRNAs' involvement in signal transduction pathways and their possible use as novel biomarkers for the early identification and prognosis of human cancer.

Neural specialization with generalizable representations underlies children's cognitive development of attention.

From childhood to adulthood, the human brain develops highly specialized yet interacting neural modules that give rise to nuanced attention and other cognitive functions. Each module can specialize over development to support specific functions, yet also coexist in multiple neurobiological modes to support distinct processes. Advances in cognitive neuroscience have conceptualized human attention as a set of cognitive processes anchored in highly specialized yet interacting neural systems. The underlying mechanisms of how these systems interplay to support children's cognitive development of multiple attention processes remain unknown. Leveraging developmental functional magnetic resonance imaging with attention network test paradigm, we demonstrate differential neurocognitive development of three core attentional processes from childhood to adulthood, with alerting reaching adult-like level earlier, followed by orienting and executive attention with more protracted development throughout middle and late childhood. Relative to adults, young children exhibit immature specialization with less pronounced dissociation of neural systems specific to each attentional process. Children manifest adult-like distributed representations in the ventral attention and cingulo-opercular networks, but less stable and weaker generalizable representations across multiple processes in the dorsal attention network. Our findings provide insights into the functional specialization and generalization of neural representations scaffolding cognitive development of core attentional processes from childhood to adulthood. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A Neuroanatomic and Pathophysiologic Framework for Novel Pharmacological Approaches to the Treatment of Post-traumatic Stress Disorder.

Post-traumatic stress disorder (PTSD) is a debilitating disorder inflicting high degrees of symptomatic and socioeconomic burdens. The development of PTSD results from a cascade of events with contributions from multiple processes and the underlying pathophysiology is complex, involving neurotransmitters, neurocircuitry, and neuroanatomical pathways. Presently, only two medications are US FDA-approved for the treatment of PTSD, both selective serotonin reuptake inhibitors (SSRIs). However, the complex underlying pathophysiology suggests a number of alternative pathways and mechanisms that may be targets for potential drug development. Indeed, investigations and drug development are proceeding in a number of these alternative, non-serotonergic pathways in an effort to improve the management of PTSD. In this manuscript, the authors introduce novel and emerging treatments for PTSD, including drugs in various stages of development and clinical testing (BI 1358894, BNC-210, PRAX-114, JZP-150, LU AG06466, NYV-783, PH-94B, SRX246, TNX-102), established agents and known compounds being investigated for their utility in PTSD (brexpiprazole, cannabidiol, doxasoin, ganaxolone, intranasal neuropeptide Y, intranasal oxytocin, tianeptine oxalate, verucerfont), and emerging psychedelic interventions (ketamine, MDMA-assisted psychotherapy, psilocybin-assisted psychotherapy), with an aim to examine and integrate these agents into the underlying pathophysiological frameworks of trauma-related disorders.

Electrochemical Signatures of Potassium Plating and Stripping

Alkali metal anodes can enable unmatched energy densities in next generation batteries but suffer from insufficient coulombic efficiencies. To deduce details about processes taking place during galvanostatic cycling, voltage profiles are commonly analyzed, however the interpretation is not straightforward as multiple processes can occur simultaneously. Here we provide a route to disentangle and interpret features of the voltage profile in order to build a mechanistic understanding on alkali metal stripping and deposition, by investigating potassium metal deposition as a model case where processes and reactions are exaggerated due to the high reactivity of potassium. In particular, the importance of separating SEI formation and nucleation to correctly estimate the energy barrier for nucleation is demonstrated. Further, we show how the native layer formed on alkali metal foils gives rise to strong features in the voltage profile and propose forming alkali metal electrode through electrodeposition to mitigate these effects.

Abstract 119: Stroke Recovery and Genetic Variation: Main Results of the STRONG Study

Introduction: The STRONG (Stroke, sTress, RehabilitatiON, and Genetics) study performed detailed behavioral phenotyping to evaluate genetic variants in relation to stroke recovery and stress responses. Methods: Adults with a new stroke enrolled at 28 US sites were assessed 4 times over 1 year. Three pre-specified gene variants (ApoE-e4, rs6265 (BDNF), & a dopamine polygenic score) were examined for associations with change in grip strength, function (SIS-ADL), mood (PHQ8), and cognition (tMoCA). Seven candidate gene variants (HTTLPR, rs324420, rs4291, rs6265, rs4680, rs53576, rs1360780) were examined for associations with post-stroke trauma, mood, & PTSD. Data were Holm-Bonferroni corrected. Next, genome-wide association studies (GWAS) were performed to identify variants associated with 8 stroke outcomes of interest. Results: The 763 enrollees had age 63.1±14.9 yrs; initial NIHSS score 4 [2-9]; 41.2% Female; 69.4% White. Presence of the BDNF rs6265 polymorphism (in 27.1% of patients) was associated with a 0.9 point reduction in 1 yr tMoCA score (p=10^-5). Two of the 7 stress-related gene candidates [rs4291 (ACE) and rs4680 (COMT)] were risk factors linking increased post-stroke trauma with higher 1yr PHQ8 & PTSD scores (p<0.05). In GWAS, 4 of the 8 behavioral outcomes had significant (p<5x10^-8) associations with genetic variants. Change in grip strength (from acute to d90) had the largest number of genome-wide significant (147 at p<5x10^-8) and suggestive (2,541 at p<5x10^-6) associations; variants with p<5x10^-6 were then mapped to corresponding genes and their protein products to construct an interaction network, which had significant enrichment of protein-protein interactions (283 proteins, 69 edges, p=0.008) and which mapped (FDR<0.05) to multiple gene ontology biological processes pertaining to the nervous system, including nervous system development, neurogenesis, and neuron differentiation. Conclusions: Stroke recovery occurs across many dimensions and so benefits from detailed characterization over time. Building on such assessments, current results from candidate genetic variants and GWAS provide insights into the biology of stroke recovery and inform therapeutic targets for promoting improved stroke recovery.

A review of interaction mechanisms and microscopic simulation methods for CO2-water-rock system

This work systematically reviews the complex mechanisms of CO2-water-rock interactions, microscopic simulations of reactive transport (dissolution, precipitation and precipitate migration) in porous media, and microscopic simulations of CO2-water-rock system. The work points out the key issues in current research and provides suggestions for future research. After injection of CO2 into underground reservoirs, not only conventional pressure-driven flow and mass transfer processes occur, but also special physicochemical phenomena like dissolution, precipitation, and precipitate migration. The coupling of these processes causes complex changes in permeability and porosity parameters of the porous media. Pore-scale microscopic flow simulations can provide detailed information within the three-dimensional pore and throat space and explicitly observe changes in the fluid-solid interfaces of porous media during reactions. At present, the research has limitations in the decoupling of complex mechanisms, characterization of differential multi-mineral reactions, precipitation generation mechanisms and characterization (crystal nucleation and mineral detachment), simulation methods for precipitation-fluid interaction, and coupling mechanisms of multiple physicochemical processes. In future studies, it is essential to innovate experimental methods to decouple “dissolution–precipitation–precipitate migration” processes, improve the accuracy of experimental testing of minerals geochemical reaction-related parameters, build reliable characterization of various precipitation types, establish precipitation-fluid interaction simulation methods, coordinate the boundary conditions of different physicochemical processes, and, finally, achieve coupled flow simulation of “dissolution−precipitation−precipitate migration” within CO2-water-rock systems.

Synthesis and characterization of hierarchical suspended carbon fiber structures decorated with carbon nanotubes

Carbon nanotubes (CNTs) and carbon microfibers (CMFs) have received significant attention due to their exceptional mechanical and electrical properties, which make them promising materials for various applications. This study introduces a novel approach to integrate CNTs and CMFs into a unified architecture by simultaneously conducting pyrolysis and chemical vapor deposition (CVD). The localized CVD of CNTs on suspended CMFs was achieved by utilizing Fe–Co nanoparticles (NPs) embedded in polyacrylonitrile (PAN) fibers as catalysts. Scanning electron microscopy and elemental analysis confirmed the formation of needle-like carbon structures on the pyrolyzed fiber surface, where carbon gases released from the pyrolyzing PAN fiber acted as the carbon source for the localized CVD. The incorporation of an additional carbon source, such as camphor vapor, significantly enhanced the growth and density of CNTs on the CMF. Various characterization techniques, including transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Atomic Force Microscopy, were employed to analyse the properties of the synthesized materials. The substantial increase in electrical conductivity upon incorporating CNTs highlights their positive influence on electrical properties and defect reduction. These characterization results highlight the potential applications of the fabricated structures in various fields, including sensors, lithium-ion electrodes, and microfabrication. In addition, the economic advantages of optimizing the process by integrating CVD with pyrolysis were assessed, revealing decreased operation time, lower energy consumption, and reduced chemical costs in comparison to conventional methods involving multiple intermediate processing steps.Graphical

Arabidopsis retromer subunit AtVPS29 is involved in SLY1-mediated gibberellin signaling

Key messageRetromer protein AtVPS29 upregulates the SLY1 protein and downregulates the RGA protein, positively stimulating the development of the root meristematic zone, which indicates an important role of AtVPS29 in gibberellin signaling.In plants, the large retromer complex is known to play roles in multiple development processes, including cell polarity, programmed cell death, and root hair growth in Arabidopsis. However, many of its roles in plant development remain unknown. Here, we show that Arabidopsis trimeric retromer protein AtVPS29 (vacuolar protein sorting 29) modulates gibberellin signaling. The SLEEPY1 (SLY1) protein, known as a positive regulator of gibberellic acid (GA) signaling, exhibited lower abundance in vps29-3 mutants compared to wild-type (WT) plants. Conversely, the DELLA repressor protein, targeted by the E3 ubiquitin ligase SCF (Skp, Cullin, F-box) complex and acting as a negative regulator of GA signaling, showed increased abundance in vps29-3 mutants compared to WT. The vps29-3 mutants exhibited decreased sensitivity to exogenous GA supply in contrast to WT, despite an upregulation in the expression of GA receptor genes within the vps29-3 mutants. In addition, the expression of the GA synthesis genes was downregulated in vps29-3 mutants, implying that the loss of AtVPS29 causes the downregulation of GA synthesis and signaling. Furthermore, vps29-3 mutants exhibited a reduced meristematic zone accompanied by a decreased cell number. Together, these data indicate that AtVPS29 positively regulates SLY1-mediated GA signaling and plant growth.

Identification of genetic features that are associated with amplitude of low-frequency fluctuation changes in schizophrenia using omics analysis.

Genetic risk for schizophrenia is thought to trigger variation in clinical features of schizophrenia, but biological processes associated with neuronal activity in brain regions remain elusive. In this study, gene expression features were mapped to various sub-regions of the brain by integrating low-frequency amplitude features and gene expression data from the schizophrenia brain and using gene co-expression network analysis of the Allen Transcriptome Atlas of the human brain from six donors to identify genetic features of brain regions and important associations with neuronal features. The results indicate that changes in the dynamic amplitude of low-frequency fluctuation (dALFF) are mainly associated with transcriptome signature factors such as cortical layer synthesis, immune response, and expanded membrane transport. Further modular disease enrichment analysis revealed that the same set of signature genes associated with dALFF levels was enriched for multiple neurological biological processes. Finally, genetic profiling of individual modules identified multiple core genes closely related to schizophrenia, also potentially associated with neuronal activity. Thus, this paper explores genetic features of brain regions in the schizophrenia closely related to low-frequency amplitude ratio levels based on imaging genetics, which suggests structural endophenotypes associated with schizophrenia.

Organized abandonment under racial capitalism: Measuring accountable actors of structural racism for public health research and action

Understanding the shifting nature of structural racism historically and across institutions is vital for effective action towards racial health equity. While public health research on structural racism is rapidly increasing, most studies are missing the interdependence of policies and institutional practices over time that shape power imbalances and lead to entrenched health inequities. Here, we discuss Ruth Wilson Gilmore's concept of organized abandonment — the intentional disinvestment in communities which, in turn, creates opportunities for extraction, revenue generation, and carceral enforcement to fill the cracks of a compromised social infrastructure — to encourage action-oriented public health research that is grounded in history and an understanding of racial capitalism. We present a case example using publicly-available data on redlining, gentrification and policing in Seattle, Washington. We mapped the intersections of redlining and gentrification and estimated their neighborhood-level association with police activity using Bayesian spatial Poisson regression models. We found that histories of racist housing policies like redlining and processes of gentrification are interdependent and shape contemporary neighborhood racial and economic segregation and police activity. Compared to structurally advantaged neighborhoods, police stops were higher in neighborhoods that were 1) historically disinvested (i.e. redlined) and remain low-income and structurally disadvantaged and 2) formerly industrial and business districts that were not redlined and are now gentrified. Notably, we found that policing practices were significantly more intensive in neighborhoods that were both high redlined and gentrified. Together, these findings illustrate how the place-based racialized processes of dispossession, displacement and policing are deeply intertwined to maintain racial capitalism. Our findings also highlight the importance of examining multiple racialized processes simultaneously to fill critical gaps in the existing literature that are necessary for sustainable solutions to address structural racism.

Individual word representations dissociate from linguistic context along a cortical unimodal to heteromodal gradient.

Language comprehension involves multiple hierarchical processing stages across time, space, and levels of representation. When processing a word, the sensory input is transformed into increasingly abstract representations that need to be integrated with the linguistic context. Thus, language comprehension involves both input-driven as well as context-dependent processes. While neuroimaging research has traditionally focused on mapping individual brain regions to the distinct underlying processes, recent studies indicate that whole-brain distributed patterns of cortical activation might be highly relevant for cognitive functions, including language. One such pattern, based on resting-state connectivity, is the 'principal cortical gradient', which dissociates sensory from heteromodal brain regions. The present study investigated the extent to which this gradient provides an organizational principle underlying language function, using a multimodal neuroimaging dataset of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) recordings from 102 participants during sentence reading. We found that the brain response to individual representations of a word (word length, orthographic distance, and word frequency), which reflect visual; orthographic; and lexical properties, gradually increases towards the sensory end of the gradient. Although these properties showed opposite effect directions in fMRI and MEG, their association with the sensory end of the gradient was consistent across both neuroimaging modalities. In contrast, MEG revealed that properties reflecting a word's relation to its linguistic context (semantic similarity and position within the sentence) involve the heteromodal end of the gradient to a stronger extent. This dissociation between individual word and contextual properties was stable across earlier and later time windows during word presentation, indicating interactive processing of word representations and linguistic context at opposing ends of the principal gradient. To conclude, our findings indicate that the principal gradient underlies the organization of a range of linguistic representations while supporting a gradual distinction between context-independent and context-dependent representations. Furthermore, the gradient reveals convergent patterns across neuroimaging modalities (similar location along the gradient) in the presence of divergent responses (opposite effect directions).

Electron beam melting efficiency at multiple hafnium e-beam processing

The method of electron beam melting and vacuum refining has clear advantages over other metallurgical methods since it enables manufacturing of refractory and chemically active metals. This study focuses on the efficiency of removing impurities from technogenic hafnium under multiple electron beam melting. Assessments are performed on the efficiency of double and triple e-beam melting processing of refractory metal hafnium. The influence of different e-beam melting technological modes on the refining effectiveness is investigated. A highest hafnium purity of 99.2% was achieved after double and triple e-beam refinements of the investigated materials, with the highest process efficiency reaching 61.58% and 51.07%, respectively.

RTCB deficiency triggers colitis in mice by influencing the NF-κB and Wnt/β-catenin signaling pathways.

RNA terminal phosphorylase B (RTCB) has been shown to play a significant role in multiple physiological processes. However, the specific role of RTCB in the mouse colon remains unclear. In this study, we employ a conditional knockout mouse model to investigate the effects of RTCB depletion on the colon and the potential molecular mechanisms. We assess the efficiency and phenotype of Rtcb knockout using PCR, western blot analysis, histological staining, and immunohistochemistry. Compared with the control mice, the Rtcb-knockout mice exhibit compromised colonic barrier integrity and prominent inflammatory cell infiltration. In the colonic tissues of Rtcb-knockout mice, the protein levels of TNF-α, IL-8, and p-p65 are increased, whereas the levels of IKKβ and IκBα are decreased. Moreover, the level of GSK3β is increased, whereas the levels of Wnt3a, β-catenin, and LGR5 are decreased. Collectively, our findings unveil a close association between RTCB and colonic tissue homeostasis and demonstrate that RTCB deficiency can lead to dysregulation of both the NF-κB and Wnt/β-catenin signaling pathways in colonic cells.

Abstract WP32: A Dissection of Spinal Cord Infarction: Cases With Rare Features and Innovative Treatments

Spinal cord infarction (SCI) poses a unique set of diagnostic and therapeutic challenges to clinicians. The condition carries high risk for severe disability if not promptly addressed, yet there is no consensus on the threshold for patients to be screened with emergent MRI or receive acute interventions such as IV-thrombolysis or endovascular therapy, in large part due to limited case data and a lack of statistically powered trials or formal guidelines. Moreover, multiple distinct pathologic processes can cause SCI, and there remains limited understanding of which patient cohorts may be most susceptible to each stroke mechanism or respond favorably to the various possible treatments. Here, we present an in-depth analysis of a series of 11 SCI cases presenting to a network of 3 hospitals at a large academic center in New York City over a 5-year period to compare presenting symptoms, etiology, acute treatment strategy, and clinical outcome. We review the results of 9 patients who were evaluated with digital subtraction angiography (DSA), including 2 patients receiving different multiple drug regimens of acute intra-arterial therapies. One patient was also found eligible and treated with IV-thrombolysis. In these data we also identify multiple patients who experienced SCI in the setting of sickle cell disease and track their functional outcomes after being treated with exchange transfusion or anticoagulation, as well as 2 young patients with apparent heritable causes of hypercoagulability leading to their ischemic events. These preliminary data suggest that underlying conditions of hypercoagulability and arterial dissection are more predominant drivers of SCI than traditional mechanisms of cerebral ischemic stroke such as large vessel atherosclerosis or cardioembolism, and that heritable causes may be more prevalent in patients with SCI compared to other stroke patients. We propose these findings as a basis for designing a larger scale study for result confirmation.

Interpersonal and intrapersonal factors contributing to women's posttraumatic growth following perinatal loss.

Despite the high prevalence of perinatal loss and its potential for negative impact on mental health, specific risk and resilience factors contributing to adjustment following perinatal loss have not been fully explored. This study investigated the relationship between attachment security, dyadic coping, and posttraumatic growth (PTG). Women who had experienced miscarriage or stillbirth (n = 244) were recruited via social media and completed an online survey that assessed their attachment security, dyadic coping, and PTG. Loss context factors and demographics were also collected. Hypotheses were tested via hierarchical multiple regression and PROCESS macro. Attachment security was related to couples' relational functioning. Dyadic coping mediated the relationship between attachment anxiety, attachment avoidance and PTG. This study contributes to the literature by providing evidence that relational security and ability to utilize a partner to reduce distress following perinatal loss is an important factor contributing to positive psychological change. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Advances in the co-production of biosurfactant and other biomolecules: statistical approaches for process optimization.

An efficient microbial conversion for simultaneous synthesis of multiple high-value compounds, such as biosurfactants and enzymes, is one of the most promising aspects for an economical bioprocess leading to a marked reduction in production cost. Although biosurfactant and enzyme production separately have been much explored, there are limited reports on the predictions and optimization studies on simultaneous production of biosurfactants and other industrially important enzymes, including lipase, protease, and amylase. Enzymes are suited for an integrated production process with biosurfactants as multiple common industrial processes and applications are catalysed by these molecules. However, the complexity in microbial metabolism complicates the production process. This study details the work done on biosurfactant and enzyme co-production and explores the application and scope of various statistical tools and methodologies in this area of research. The use of advanced computational tools is yet to be explored for the optimization of downstream strategies in the co-production process. Given the complexity of the co-production process and with various new methodologies based on artificial intelligence (AI) being invented, the scope of AI in shaping the biosurfactant-enzyme co-production process is immense and would lead to not only efficient and rapid optimization, but economical extraction of multiple biomolecules as well.

Abstract PR016: Topology of the tumor microenvironment: Integrating imaging, modeling, and topological data analysis

Abstract Cancer evolution involves multiple stochastic processes across many scales. In addition to genomic and transcriptomic changes, hallmarks of cancer within solid tumors include the malignant co-evolution of the tumor microenvironment. Although the evaluation of tissue architecture plays a key role in pathologist staging, the automated extraction of additional structural features remains far from translation to the clinic. However, one particularly effective novel methodology for extracting patterns from these clinical images is topological data analysis(TDA). TDA is a field that studies the shape of data and its connectedness using concepts from geometric and algebraic topology. Recent work using topological data analysis has allowed the extraction of image features. Such features have been associated with clinical outcomes in both the analysis of H&E images in prostate cancer and CT images in lung cancer. We set out to question how the topological features of tissues, including tumor and stromal composition, evolve during treatment and between original sites and metastasis. To analyze this we use a combination of tissue sections, imaging, and cell-automata models and persistent homology and cubical persistence techniques from TDA. We apply certain topological methods for the first time to tissue images (H&E) and to the output of spatial simulations. We focus specifically on analyzing the evolution of topological features in ovarian and lung cancer and compare our features to 2D and 3D simulations (HAL) with varying game theoretical interactions as well as comparing features across tissues from matched primary and metastatic sites. We find that several topological features are conserved between primary and metastatic sites and some feature evolution is replicated in simulation. Citation Format: Rowan Barker-Clarke, Jason M. Gray, Jacob G. Scott. Topology of the tumor microenvironment: Integrating imaging, modeling, and topological data analysis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr PR016.

Glycerol Metabolic Repressor GlpR Contributes to Streptococcus suis Oxidative Stress Resistance and Virulence

Bacterial DeoR family transcription regulators regulate multiple physiological processes. Little is known about the function of DeoR family regulators in streptococci. Here, we identified a novel DeoR family regulator, GlpR, from Streptococcus suis, a pathogen causing severe diseases in pigs and humans. GlpR was involved in glycerol utilization and exhibited specific signature residues at positions 30-31 (KV) which are crucial for DNA binding. Deletion of glpR (ΔglpR) showed a significant increase in relative growth rate in glycerol medium compared to the wild-type (WT) and complementary strains (CΔglpR). Employing RNA-seq analysis, β-galactosidase activity analysis, and electrophoretic mobility shift assay, we discovered that GlpR directly represses the expression of glycerol metabolism-related genes pflB2, pflA1, and fsaA, encoding pyruvate formate-lyase and its activating enzyme, and fructose-6-phosphate aldolase, respectively. Compared to WT and CΔglpR, ΔglpR showed a reduced survival rate under oxidative stress and in murine macrophages and attenuated virulence in mice. GlpR probably enhances oxidative stress resistance and virulence in S. suis by functioning as a glycerol metabolic repressor decreasing energy consumption. These findings contribute to a better understanding of S. suis pathogenesis and enrich our knowledge of the biological functions of DeoR family regulators in streptococci.

Fatigue Life Assessment of Automotive Leaf Springs

The creation of a new mechanical component, such as a high-performance leaf spring, is a very challenging procedure that consists of many stages over a long timeframe from concept to production. High performance leaf springs are components with high complexity at the areas of failure. This complexity is derived from the multiple manufacturing processes that the raw material undergoes to reach its final geometrical and microstructural form. The paper shows the assessment of fatigue life of high-performance leaf springs, from different manufacturers with different geometrical and loading parameters. The assessment uses the fatigue life calculations which are described at the FKM Guideline as a basis. Limitations of the FKM Guideline, concerning the material’s ultimate tensile strength and the exclusion of the stress shot peening process, are restricting the fatigue life calculations of such components, therefore, a new theoretical tool is needed for more accurate calculations.

Identifying drivers of demographic rates in an at‐risk population of marine mammals using integrated population models

AbstractEffective conservation of threatened populations requires identification of the processes limiting recovery. When multiple population processes are potentially limiting, they are sometimes analyzed independently, often using different datasets. Analytically, this is suboptimal, as processes are often correlated, which can lead to biased estimates of parameters and quantities of interest. Integrated population models (IPMs) can synthesize several data streams in the same probabilistic framework to circumvent these issues. Lack of prey was identified as one of the primary threats to recovery of critically endangered southern resident killer whales (SRKWs), Orcinus orca. Previous studies have correlated SRKW demographic rates with indices of Chinook salmon Oncorhynchus tshawytscha abundance, but these approaches have modeled reproduction and survival independently. We developed an IPM for SRKWs that models both processes simultaneously, as a function of Chinook salmon abundance along the west coast of North America. We used this model to evaluate the relationship between Chinook salmon abundance and demographic rates of SRKWs, with the goal of updating our understanding of a potential causal relationship between prey availability and SRKW population dynamics, and how these relationships may have changed over time. Results suggest that SRKW mortality rates are more strongly associated with Chinook salmon abundance than birth rates. Our analysis also suggests northern resident killer whale abundance could also be affecting SRKW carrying capacity, possibly through competition over shared prey resources. The IPM fit observed total abundance data well and predicted temporal changes in population demographics with reasonable accuracy, but small sample size may have opacified model selection. Our approach offers a valuable tool for predicting the response of the SRKW population to alternative management strategies involving the recovery of Chinook salmon stocks in the eastern Pacific.