Positive Results Research Articles

Acoustic and vibrations measurments in an autonomous shuttle bus

In response to the ADEME's call for Autonomous Road Vehicle Experimentation projects, a consortium was created to propose the SAM project about Safety and Acceptability of Autonomous Driving and Mobility. It was composed of industrial and research teams, associated with local partners. SAM is a national project involving large-scale trials of autonomous driving and mobility on open roads. The assessments covered several topics, including environmental impacts, focusing on air pollution, noise and the life cycle of components. Cerema proposed a methodology to characterize acoustic and vibration levels for autonomous driving in the specific site near Paris. The tests consisted in instrumenting the interiors of an automated shuttle and a conventional car to determine the user's feelings. The vehicles were driven in a quiet area and in a high traffic area. The results displayed by Cerema are based on statistical studies on 20 vehicle passages for each experiment. The indicators were characterized for the entire route and by homogeneous sections. In fluid navigation situation, the measurements showed that the acoustic and vibration impacts are minimal. However, the tests have highlighted the effects of the lack of anticipation of an automated shuttle during specific events requiring rapid braking.

Cell type-specific epigenetic priming of gene expression in nucleus accumbens by cocaine.

A hallmark of addiction is the ability of drugs of abuse to trigger relapse after periods of prolonged abstinence. Here, we describe an epigenetic mechanism whereby chronic cocaine exposure causes lasting chromatin and downstream transcriptional modifications in the nucleus accumbens (NAc), a critical brain region controlling motivation. We link prolonged withdrawal from cocaine to the depletion of the histone variant H2A.Z, coupled with increased genome accessibility and latent priming of gene transcription, in D1 dopamine receptor-expressing medium spiny neurons (D1 MSNs) that relate to aberrant gene expression upon drug relapse. The histone chaperone ANP32E removes H2A.Z from chromatin, and we demonstrate that D1 MSN-selective Anp32e knockdown prevents cocaine-induced H2A.Z depletion and blocks cocaine's rewarding actions. By contrast, very different effects of cocaine exposure, withdrawal, and relapse were found for D2 MSNs. These findings establish histone variant exchange as an important mechanism and clinical target engaged by drugs of abuse to corrupt brain function and behavior.

Construction of superconducting dome and emergence of quantum critical region in holography

In this work, we investigate an extended model of holographic superconductor by a nonlinear electrodynamic interaction coupled to a complex scalar field. This nonlinear interaction term can make a quantum phase transition at zero temperature with finite charge carrier density. By solving full equations of motion, we can construct various shapes of the superconducting phase in the phase diagram. With a specific choice of interaction coefficients, we can construct a phase diagram with a superconducting dome. Also, we find a new geometric solution inside the superconducting dome, which turns out to be a Lifshitz-type geometry. This geometry is characterized by a dynamical critical exponent, which plays a crucial role near the quantum critical point. We refer to this region of the phase diagram as a quantum critical region. Published by the American Physical Society 2024

Spatial and Temporal Variations in Offshore Crude Oil Transportation: Insights From China's Coastal Ports

ABSTRACTAnalyzing the spatial and temporal variations of offshore crude oil transportation at China's coastal ports is critical for the country's energy security. The automatic identification system provides high‐resolution real‐time data on China's offshore crude oil transportation, offering more precise spatial and temporal insights than existing statistical studies. In this study, we propose a novel method for calculating offshore crude oil transportation volumes by considering the operational status of crude oil tankers as “empty” or “full.” This approach enhances reliability and provides detailed port‐level transport data. Our findings reveal notable similarities between the centrality measures of maritime oil transportation and oil tanker networks, but significant differences in community divisions. Specifically, in the tanker networks, Chinese ports are categorized into three regions, with one region being dominant and the other two regions containing only four ports. In contrast, the oil flow networks show China divided into two major regions and two minor ones. This study offers valuable contributions to strengthening energy security in China and supports informed policy development and implementation.

THE INFLUENCE OF A GENERATIVE LEARNING MODEL BASED ON WAVE MATERIAL COGNITIVE CONFLICT ON STUDENT LEARNING OUTCOMES AT SMAN 5 PAYAKUMBUH

Student learning outcomes in Physics subjects, especially in Wave material, are still low. This is caused by the learning model used in the Wave material not being being the process standards and characteristics of wave learning objectives. A generative learning model based on cognitive conflict is one approach to solving the aforementioned issue. The purpose of this study is to ascertain how student learning outcomes at SMAN 5 Payakumbuh are affected by the use of a generative learning model based on cognitive conflict in Wave content. The type of research is quasi-experimental research with a pretest-posttest Control Group Design. The participants in this study were all SMAN 5 Payakumbuh science class XI students. The information gathered reflects the attitudes, knowledge, and abilities of the pupils toward learning. Two averages are tested for equality as a data analysis technique. The study's findings demonstrate the notable distinctions between classrooms that employ the Problem-Based Learning model and those that employ the Generative learning model based on cognitive conflict. The average student learning outcome in classes that apply the Generative learning model is 83.14 and in classes that apply the Problem-Based Learning model is 77.26. The influence of the generative learning model based on cognitive conflict can be seen in the learning outcomes of students who have been analyzed and hypothesis tested. Based on the hypothesis test, the ttable is 2.006 and the tcount is 2.1. The condition for H0 to be rejected is if ttable < tcount. The tcount value is within the rejection of H0, so HI is accepted. Because all variables are controlled, except the learning model, it can be said that the application of the Generative learning model based on cognitive conflict in Wave material has a positive effect on student learning outcomes.

Insights into Thermal Conductivity at the MOF-Polymer Interface.

Understanding the thermal conductivity in metal-organic framework (MOF)-polymer composites is crucial for optimizing their performance in applications involving heat transfer. In this work, several UiO66-polymer composites (where the polymer is either PEG, PVDF, PS, PIM-1, PP, or PMMA) are examined using molecular simulations. Our contribution highlights the interface's impact on thermal conductivity, observing an overall increasing trend attributable to the synergistic effect of MOF enhancing polymer thermal conductivity. Flexible polymers such as PEG and PVDF exhibit increased compatibility with the MOF, facilitating their integration with the MOF lattice. However, this integration leads to a moderated enhancement in thermal conductivity compared to polymers that remain separate from the MOF structure, such as PS or PP. This effect can be attributed to alterations in phonon transport pathways and shifts in interfacial interactions between the polymer and MOF. Specifically, the infiltration of the polymer like PEG and PVDF into the MOF disrupted the MOF's ordered network, introducing defects or barriers that hindered phonon propagation. In contrast, nonpolar and rigid polymers like PP, PMMA, PS, and PIM-1 exhibited greater improvements in thermal conductivity when combined with MOFs compared to the flexible polymers PVDF and PEG. Most notably, our analysis identifies a critical interface region within approximately 30-50 Å that profoundly influences thermal conductivity. The interface region, as indicated by the density profile and radius of gyration, is notably shorter but plays a pivotal role in modulating the thermal properties. The sensitivity of the system to these interface characteristics underscores the crucial role of this particular interface area in dictating the thermal conductivity. Our findings emphasize the sensitivity of thermal conductivity in polymer matrices to interface characteristics and highlight the critical role of a specific interface region in modulating thermal properties.

Intelligent monitoring of marine vessel dynamics based on data mining

This study explores vessel navigation's universal characteristics and individual anomaly behavior from dispatch to destination. With the help of information technology, it introduces big data and machine learning technologies into the work of vessel traffic management and conducts statistical analysis and monitoring studies of vessel behavior from a data-driven perspective. The study was conducted by modeling vessel speed, position, course, and other navigational characteristics behavior through comprehensive statistical analysis of vessel AIS, radar, and VTS data. The study was based on the monitoring methods for anomalous behavior of vessel speed, position, and heading inconsistencies with the expected behavior identified by the model.

Insights into the Molecular Structure, Stability, and Biological Significance of Non-Canonical DNA Forms, with a Focus on G-Quadruplexes and i-Motifs

This article provides a comprehensive examination of non-canonical DNA structures, particularly focusing on G-quadruplexes (G4s) and i-motifs. G-quadruplexes, four-stranded structures formed by guanine-rich sequences, are stabilized by Hoogsteen hydrogen bonds and monovalent cations like potassium. These structures exhibit diverse topologies and are implicated in critical genomic regions such as telomeres and promoter regions of oncogenes, playing significant roles in gene expression regulation, genome stability, and cellular aging. I-motifs, formed by cytosine-rich sequences under acidic conditions and stabilized by hemiprotonated cytosine–cytosine (C:C+) base pairs, also contribute to gene regulation despite being less prevalent than G4s. This review highlights the factors influencing the stability and dynamics of these structures, including sequence composition, ionic conditions, and environmental pH. Molecular dynamics simulations and high-resolution structural techniques have been pivotal in advancing our understanding of their folding and unfolding mechanisms. Additionally, the article discusses the therapeutic potential of small molecules designed to selectively bind and stabilize G4s and i-motifs, with promising implications for cancer treatment. Furthermore, the structural properties of these DNA forms are explored for applications in nanotechnology and molecular devices. Despite significant progress, challenges remain in observing these structures in vivo and fully elucidating their biological functions. The review underscores the importance of continued research to uncover new insights into the genomic roles of G4s and i-motifs and their potential applications in medicine and technology. This ongoing research promises exciting developments in both basic science and applied fields, emphasizing the relevance and future prospects of these intriguing DNA structures.

Conceptual framework to incorporate drainage solutions in the urban open space system

Cities are increasingly dealing with challenges regarding the negative impact of rapid and mismanaged urbanization. Therefore, city planning must cope with the natural environment limitations, seeking a balance between the human activities and the well-functioning of the hydrologic cycle. This work aims to present a conceptual framework able to properly integrate the stormwater dynamics into the open spaces system in a functional way, establishing a Hydrological Interest Area, HIA, to structure urban expansion integrated into and respecting watershed natural processes. The initial step is to define a HIA, primarily consisting of open spaces that can be used for supporting urban drainage functions and to order land use in the urban expansion process. This delimitation offers the background for interpreting the watershed in three functional arches, especially covering the upstream, mid-reach and downstream areas of the basin, guiding the design of a set of flood mitigation interventions focusing on the use of Blue-Green Infrastructure. To illustrate and validate the proposed methodological framework, the design is evaluated by a flood modeling tool, using a hydrological-hydrodynamic cell-model. A case study was driven in the Bambu Watershed, a rapidly developing area in the municipality of Maricá, Rio de Janeiro, Brazil. The proposed intervention includes an urban expansion scenario for a low impact development on flood behavior alongside with four parks: an upstream park with reservoirs, two multifunctional floodable urban parks, and a park dedicated to lagoon restoration. This plan complements riverbed modifications designed to enhance water discharge. The simulation showed significant reduction of water depths with a consequent decrease in exposure of buildings and roads, especially in the most critical region of the watershed. This framework highlights the importance of a multifunctional approach in land use and serves as a robust foundation for controlling urban expansion and proposing projects.

The Global Characteristics of Electrons Near the Inner Edge of the Inner Radiation Belt

AbstractEnergetic electrons around the inner edge of the inner radiation belt (L1.3) have not been studied to the extent of the rest of the inner belt and certainly not to that of the outer radiation belt. Yet, the behavior of electrons at the inner edge of the inner belt could improve our understanding of important dynamics deep within Earth's magnetosphere. Previous work has analyzed these electrons during either isolated events or via significantly limited statistical studies, and it remains unclear what the particular drivers of electron flux enhancements in this region may be. Here, we present a broad statistical study of electrons around the inner edge of the inner radiation belt, utilizing the 7‐year data set of the MagEIS particle detectors aboard both Van Allen Probes spacecraft. Moreover, we separate electron flux measurements into stably trapped and quasi‐trapped electrons and directly compare their behavior. We find both populations to be variable in L and energy, as well as showing a clear magnetic local time (MLT) asymmetry. Potential drivers are also explored, where we demonstrate an association between increased electron fluxes in this region and heightened solar wind speed, Sym‐H, dynamic pressure, southward IMF and most prominently with the AU and AL indices.

CDR identification, epitope mapping and binding affinity determination of novel monoclonal antibodies generated against human apolipoprotein B-100

In-house generated mAbs to apolipoprotein B-100 (apoB-100) clones hLDL-E8, hLDL-2D8 and hLDL-F5 were extensively studied to determine their complementarity-determining regions (CDRs), binding epitopes and affinity. RT-PCR revealed that all mAbs consisted of kappa light chains and gamma heavy chains. DNA sequencing and bioinformatic analysis showed that the variable gene and protein sequences of their CDRs shared over 50 % identity with the existing databases. The 3D structures of the mAb variable fragments (Fv) with a QSQE score above 0.7 were constructed using the SWISS-MODEL platform. The structural accuracy was confirmed by Ramachandran plots, with 99 % of amino acid residues falling within acceptable regions. Thrombolytic cleavage of apoB-100 and Western blot analysis demonstrated that hLDL-E8 and hLDL-F5 specifically bind to the T3 fragment (aa 1297–3249), whereas hLDL-2D8 binds to the T4 fragment (aa 1–1297). These findings were supported with epitope-binding assays using inhibition ELISA, which indicated that hLDL-E8 binds at different epitopes from hLDL-2D8 and has some overlap with hLDL-F5. Lastly, the binding affinity of the mAbs was examined by indirect ELISA. The average affinity constants (Kaff) for mAbs hLDL-2D8, hLDL-E8 and hLDL-F5 are 1.51 ± 0.69 × 109 Mol−1, 7.25 ± 3.56 × 108 Mol−1 and 4.39 ± 2.63 × 106 Mol−1, respectively. Additionally, the behavior of the antibodies in the dose-response curve revealed that hLDL-F5 may recognize two epitopes of apoB-100 or have very low binding affinity. In contrast, hLDL-2D8 and hLDL-E8 each recognize a single epitope. These findings provide information that will be useful when selecting mAbs for both laboratory and clinical research purposes.

Modulation effects of repetitive transcranial magnetic stimulation on target and indirect target nodes in patients with major depressive disorder

Clinical studies intensively highlight two critical brain regions, i,e, dorsal lateral prefrontal cortex (DLPFC) (target node) and subgenual anterior cingulate cortex (sgACC) (indirect target node) for the treatment of neuroimaging-guided repetitive transcranial magnetic stimulation (rTMS) in major depressive disorder (MDD). However, it remains unclear whether the clinical rTMS treatment could modulate the activity of the target and indirect target nodes in MDD patients. We aim to identify the rTMS-induced alteration of brain local and functional connectivity (FC) activities in the target and indirect target nodes. 38 patients with MDD were recruited for taking part in the 2-week rTMS treatment. We identified left DLPFC and right sgACC as the target and indirect target nodes for each participant, using the neuroimaging guided method, and further explored the rTMS-induced modulation on the brain functional activity of the two nodes. Ultimately, 28 patients were included in the analysis. We found that subjects had significant improvement in depressive symptoms, and their brain functional activities were reorganized. rTMS reduced the FC activity between the target and indirect target nodes, while the brain local activity in these nodes did not show rTMS-induced changes. The FC reduction was not associated with improvement in depressive symptoms. These results confirmed the clinical significance of the target node (DLPFC) and indirect target node (sgACC) in the rTMS treatment of MDD, and further shed light on the brain functional reorganization underpinning clinical practice of rTMS.

Enhancing crop production in the Haihe Basin while addressing challenges related to water quantity and quality

To tackle the challenge of ensuring food security while managing water availability and quality constraints in the Haihe Basin, a critical grain-producing region in China with a dense population and severe water degradation issues, we have developed a comprehensive spatial optimization (CSO) strategy. This approach integrates various crop and soil management practices, land consolidation, and cutting-edge breeding technologies. It also uses a spatial planning model based on linear programming, considering water quantity and quality constraints. Our research shows that crop yields may drop by 14 % (3780 Kt) compared to levels in 2017 due to restrictions on groundwater extraction and nitrogen (N) concentrations in leaching or runoff. However, by strategically maximizing overall crop yields through the integrated CSO strategy without changing the crop production structure, the total crop yield could potentially increase by 81 % (21,817 Kt) while using 3.0 % (86 Kha) less cultivated land than in 2017. This would help to fulfill the projected food demand in 2050. If the integrated aims to minimize the sown area after fulfilling the demand for crops in 2050, around 28 % of the sown area, or 820 Kha cropland, could be reduced compared with 2017. This reduction may save more land for natural conversation. Furthermore, total N losses, including ammonia, nitrous oxide emissions, runoff, and leaching, could be reduced by 23 %–43 % (139–252 Kt), depending on the specific optimization strategy goals. The stepwise integrated optimization strategy provides a feasible framework for the Haihe Basin, enabling the maintenance or even enhancing current crop yields while safeguarding water quality and quantity.

Complete analysis of G-quadruplex forming sequences in the gapless assembly of human chromosome Y

Recent advancements have finally delivered a complete human genome assembly, including the elusive Y chromosome. This accomplishment closes a significant knowledge gap. Prior efforts were hampered by challenges in sequencing repetitive DNA structures such as direct and inverted repeats. We used the G4Hunter algorithm to analyze the presence of G-quadruplex forming sequences (G4s) within the current human reference genome (GRCh38) and the new telomere-to-telomere (T2T) Y chromosome assemblies. This analysis served a dual purpose: identifying the location of potential G4s within the genomes and exploring their association with functionally annotated sequences. Compared to GRCh38, the T2T assembly exhibited a significantly higher prevalence of G-quadruplex forming sequences. Notably, these repeats were abundantly located around precursor RNA, exons, genes, and within protein binding sites. This remarkable co-occurrence of G4-forming sequences with these critical regulatory regions suggests their role in fundamental DNA regulation processes. Our findings indicate that the current human reference genome significantly underestimated the number of G4s, potentially overlooking their functional importance.

Structural feature of RrGGP2 promoter and functional analysis of RrNAC56 regulating RrGGP2 expression and ascorbate synthesis via stress-inducible cis-elements in Rosa roxburghii Tratt

Rosa roxburghii Tratt is a well-known horticultural crop that produces fruits with extremely high l-ascorbic acid (AsA) levels, and GDP-l-galactose phosphorylase2 (RrGGP2) encodes a major enzyme operating in AsA biosynthesis. This study aims to elucidate the transcriptional mechanism of RrGGP2 underlying AsA overproduction under abiotic stress. Herein, the sequence of RrGGP2 promoter (PRrGGP2) was isolated. The analysis of the PRrGGP2 detected an upstream open reading frame encoding a 64-amino acid peptide as well as a number of cis-acting elements responsive to environmental factors and hormones. Several truncated promoter fragments were constructed for dual-luciferase assays which revealed a critical promoter region (−1949 to −2089 bp) for PRrGGP2 activity. Overexpressing β-glucuronidase (GUS) and RrGGP2 under the control of PRrGGP2 in transgenic Arabidopsis thaliana increased the GUS activity and AsA content, respectively. Furthermore, the extent of the increases was significantly influenced by temperature and abscisic acid. Yeast one-hybrid and dual-luciferase assays indicated that RrNAC56 could activate PRrGGP2. Cold stress significantly increased the transcription of RrNAC56 and RrGGP2 in R. roxburghii fruits, which resulted in AsA accumulation. These findings offer a theoretical foundation for understanding the transcriptional regulation of RrGGP2, while also uncover a novel mechanism of RrNAC56-RrGGP2 module-mediated abiotic stress response via regulating AsA synthesis.

Lip lift with advancement flap as nasal columella reconstruction

Basocellular carcinomas are characterized by their non-deep spread neoplastic nature. Although treatment typically proceeds without complication, excision in critical facial regions can lead to aesthetically undesirable defects. Furthermore, elderly patients often express aesthetic concerns, particularly regarding the thinning of the upper lip over time. This article presents the case of a 75-year-old patient with a basocellular carcinoma located on the tip of the nose, amidst a history of multiple neoplastic conditions. To address the defect, an inferiorly-based philtral advancement flap was employed, accompanied by a lip lift procedure, resulting in favorable aesthetic and functional outcomes.

Increased Maternal BMI at Time of Delivery Associated with Poor Maternal and Neonatal Outcomes.

Current literature on the risks and outcomes of obesity in pregnancy almost exclusively utilizes prepregnancy body mass index (BMI). Given the rising obesity rate across the United States along with a paucity of available information on the relationship between delivery BMI and maternal and neonatal outcomes, our study aimed to determine the association of maternal BMI at delivery with antepartum, intrapartum, and neonatal complications at an academic referral hospital. This study is a secondary analysis of data collected for a prospective cohort study of Coronavirus Disease-2019 (COVID-19) in pregnancy. This analysis included all patients who delivered term singleton infants between May 1, 2020, and April 30, 2021, at the University of Iowa Hospitals and Clinics. Demographic and clinical data were obtained from the electronic medical record. The relationship between maternal BMI and maternal and neonatal characteristics of interest was assessed using logistic regression models. A statistical significance threshold of 0.05 was used for all comparisons. There were 1,996 women who delivered term singleton infants during the study period. The median BMI at delivery was 31.7 kg/m2 (interquartile range: 27.9, 37.2), with 61.1% of women having a BMI ≥ 30.0 kg/m2. Increasing BMI was significantly associated with nonreassuring fetal status, unscheduled cesarean birth, overall cesarean birth rate, postpartum hemorrhage, prolonged postpartum stay, hypertensive diseases of pregnancy, neonatal hypoglycemia, neonatal intensive care unit admission, decreased APGAR score at 1 minute, and increasing neonatal birth weight. Even when controlling for preexisting hypertension in a multivariate model, increasing BMI was associated with gestational hypertension and preeclampsia. Increased maternal BMI at delivery was associated with adverse perinatal outcomes. These findings have implications for clinical counseling regarding risks of pregnancy and delivery for overweight and obese patients and may help inform future studies to improve safety, especially by examining reasons for high cesarean rates. · Sixty-one percent of delivering patients had a BMI330 kg/m2 at delivery.. · There was a higher cesarean rate with increasing delivery BMI.. · For every 5-unit increase in maternal BMI, neonatal weight increased by 0.47 g..

Comparing performances of different statistical models and multiple threshold methods in a nested association mapping population of wheat.

Nested association mapping (NAM) populations emerged as a multi-parental strategy that combines the high statistical power of biparental linkage mapping with greater allelic richness of association mapping. Several statistical models have been developed for marker-trait associations (MTAs) in genome-wide association studies (GWAS), which ranges from simple to increasingly complex models. These statistical models vary in their performance for detecting real association with the avoidance of false positives and false negatives. Furthermore, significant threshold methods play an equally important role for controlling spurious associations. In this study, we compared the performance of seven different statistical models ranging from single to multi-locus models on eight different simulated traits with varied genetic architecture for a NAM population of spring wheat (Triticum aestivum L.). The best identified model was further used to identify MTAs for 11 different agronomic and spectral reflectance traits, which were collected on the NAM population between 2014 and 2016. The "Bayesian information and linkage disequilibrium iteratively nested keyway (BLINK)" model performed better than all other models observed based on QQ plots and detection of real association in a simulated data set. The results from model comparison suggest that BLINK controls both false positives and false negatives under the different genetic architecture of simulated traits. Comparison of multiple significant threshold methods suggests that Bonferroni correction performed superior for controlling false positives and false negatives and complements the performance of GWAS models. BLINK identified 45 MTAs using Bonferroni correction of 0.05 for 11 different phenotypic traits in the NAM population. This study helps identify the best statistical model and significant threshold method for performing association analysis in subsequent NAM population studies.

How Can Revitalizing Traditional Handicraft And Cottage Industries In Rural India Contribute To Sustainable Economic Growth And Employment Generation In The 21st Century?

There exists tremendous potential for the growth of sustainable economic growth and employment generation in the traditional handicraft and cottage industry of rural India. Although these industrial activities are of cultural importance and have collectively contributed to local economies, they are disappearing as a result of rapid industrialization, globalization, and competition from mass production. This research investigates how these sectors can be revitalized to help India achieve sustainable development in the 21st century, by creating employment, reducing poverty, and preserving cultural heritage. This study draws on statistical data, case studies, and successful global examples to identify key barriers including lack of infrastructure, marketing challenges, lack of access to finance, and competition from mass-produced goods. It also provides strategies to cope with these challenges such as skill development, opening up of microcredit access, market diversification, export promotion, and regulatory reforms. The research shows that government policies play a critical role in subsidizing and incentivizing, promoting geographical indications for handicrafts, and simplifying business regulations. It encourages inclusive entrepreneurship in rural areas, empowering artisans and entrepreneurs (women and youth), along with creatively co-creating livelihood and business opportunities. Revitalizing traditional industries can help achieve multiple Sustainable Development Goals (SDGs) such as decent work, economic growth, and responsible consumption and production, according to the findings. This study offers a roadmap for policymakers, entrepreneurs, and other stakeholders to enable the sustainable growth of traditional industries across the villages of rural India while maintaining economic growth and cultural preservation for long-term resilience and prosperity

Paleomagnetic Field Variability and Revised Chronostratigraphy of Bering Sea (IODP Expedition 323) Deep‐Sea Sediments During MIS 6–7 (130–144 ka)

AbstractWe have developed replicate paleomagnetic secular variation (PSV) records for MIS 6–7 (130–244 ka) from IODP Ex. 3 23 Sites 1,343, 1,344, and 1,345 (Bering Sea). We can correlate the PSV at all three sites and identify 90 inclination features and 64 declination features. We have developed relative paleointensity records for all three sites by normalizing the demagnetized natural remanence to magnetic susceptibility. Paleointensity highs/lows can be tied to the PISO‐1500 global oxygen‐isotope‐dated paleointensity record. This provides a significant increase in chronostratigraphic resolution for these sites. Only one excursion is recorded in the MIS 6–7 sediments of the Bering Sea—the Iceland Basin Excursion (∼196 ± 3 ka). Replicate records of the inclinations and declinations both flip quickly to reversed polarity directions, stay there for several hundred years and then flip quickly back to normal polarity directions. However, the inclination flips occur without significant declinations changes and visa versa. A statistical PSV study was carried out by averaging the data in 3 ky and 9 ky windows. There is a distinctive bimodal pattern to the angular dispersions with most time spent with low angular dispersion values (∼10°–15°), but there is an interval of more than 30 ky (185–220 ka) with angular dispersions averaging two to three times higher amplitudes (∼25°–35°). This interval also has low paleointensities and the Iceland Basin Excursion. This same, coupled pattern of high angular dispersion, low paleointensity, and excursions is noted synchronously in the central North Atlantic Ocean and may indicate a global pattern to the geomagnetic field.