bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of straying, reproductive strategies, and ocean distribution on the structure of American shad populations
Authors: Poulet Camille , Lassalle Géraldine , Jordaan Adrian , Limburg Karin E. , Nack Christopher C. , Nye Janet A. , O'Malley Andrew , O'Malley‐Barber Betsy , Stich Dan S. , Waldman John R. , Zydlewski Joseph , Lambert Patrick 
Published: December 2023

AbstractThe use of species distribution models has proliferated, providing insights for sustainable management of migratory species in a globally changing environment. However, many of these models are based on statistical relationships developed from historical conditions that may not perform well under changing or even analogous conditions caused by climate change. In this paper, we used a mechanistic species distribution model called GR3D (Global Repositioning Dynamics for Diadromous Fish Distribution) to examine the integrated dynamics of American shad (Alosa sapidissima) populations across their native range along the Eastern U.S. coast, where the species demonstrates latitudinal variations in life histories and reproductive strategies. The initial design of the model was adapted to incorporate region‐specific parameterization to fit the species ecology. Then, a sensitivity analysis was performed to test the influences of uncertain processes regarding American shad distribution at sea, straying and reproduction on key characteristics of the species distribution. The sensitivity analysis showed the influence of the Allee effect (i.e., “depensatory” process) and the homing rate (i.e., fidelity to the breeding sites) on the probability of presence and abundances among catchments and metapopulations estimated by the model. Contrary to the homing rate, the distance of straying did not change the estimated number of metapopulations or abundances. Homing strength, however, was quite influential. The integration of complex migration patterns during the marine phase (i.e., wintering and summering offshore areas) provided more likely estimates of the species' overall distribution. Overall, our study illustrated the utility of incorporating factors governing the large‐scale distribution of migratory species to improve local management.
Hidden in plain sight: The invasive macroalga Caulerpa prolifera evades detection by environmental DNA methods
Authors: Waters Tanner , Langlois Kylie , Gold Zachary , Theroux Susanna , Eagle Robert A. 
Published: December 2023

AbstractEnvironmental managers need a rapid and cost‐effective monitoring tool for tracking the spread of invasive species, particularly at the onset of introduction. The macroalgae Caulerpa prolifera is considered an invasive species outside its native range, colonizing large patches of seafloor, reducing native species, and altering ecosystem functioning. Here, we developed a droplet digital PCR assay for detection of C. prolifera from environmental DNA seawater samples using the internal transcribed spacer (ITS) region. While the assay itself was confirmed to be highly efficient, we discovered concentrations of C. prolifera eDNA were present below detectable levels in the water column surrounding an outbreak. To understand why, we conducted tank‐based experiments for two California invasive algae species, Caulerpa prolifera and Sargassum horneri. The steady‐state eDNA concentration (eDNA copies/ gram of biomass detected) of C. prolifera was found to be two orders of magnitude lower than S. horneri. A meta‐analysis of steady‐state concentrations reported in the literature showed a remarkable range from ~104–1011 (copies/g), revealing C. prolifera to have the lowest recorded steady‐state concentrations of eDNA of any known species. We attribute C. prolifera's low steady‐state eDNA concentration to its unique biology as a unicellular macroscopic algae which reduces the possible modes of eDNA release compared to similarly sized multicellular organisms. Critically our results demonstrate the potential limits of eDNA approaches, the influence of shedding rates in the reliability of species detections, and the vital importance of benchmarking and validating eDNA assays in both field and laboratory settings.
Study of the Mechanism of 7‐exo‐trig Cyclizations of Aryl, Vinyl, and Alkyl Radicals on Oxime Ethers
Authors: Bejarano Carlos A. , Díaz John E. , Camacho Jairo , Flores‐Bernal Gustavo G. , Miranda Luis D. , Mejía Sol M. , Loaiza Alix E. 
Published: December 2023

AbstractIn this work, we conducted a study of 7‐exo‐trig cyclizations mechanism involving aryl, vinyl, and alkyl radicals on oxime ethers. Initially, the reaction of brominated oxime ether 9 a with (TMS)3SiH and AIBN gave rise to aryl radicals that underwent a 7‐exo‐trig cyclization on the oxime ether, yielding dibenzoxepine 10 a, and the ipso reaction and reduction products were obtained as well. Approximate rate constants at 80 °C for the 7‐exo‐trig (1.0×108 s−1) and the ipso cyclization (4.3×107 s−1) were determined by competition experiments. DFT calculations showed good agreement with the experimental results. The reduction rate constant of the N‐alkoxyaminyl radical with (TMS)3SiH was calculated to be 4.1×10−1 M−1 s−1; while the rate constants for the 7‐exo‐trig cyclizations of vinyl and alkyl radicals on the oxime ether were estimated in the ranges of 106 s−1–108 s−1 and 103 s−1–108 s−1, respectively. The 7‐exo‐trig cyclization reactions involving aryl, vinyl, and alkyl radicals with oxime ethers were found to be an exothermic and irreversible process, with the oximic carbon showing a preference for nucleophilic alkyl radicals. This kinetic study contributes to the deeper understanding of radical‐mediated cyclizations, enabling the efficient design of complex synthetic routes.
Sequenced‐based Rwanda population provides insights into demographic history
Authors: Miao Xinyao , Gong Xiaojuan , Paul Gasana , Shen Yuesheng , Gao Jiayang , Li Bowen , Yu Huiyun , Chang Liao , Li Shengbin , Liang Zuhuan , Yan Chunxia , Ma Tao , Zhang Bao 
Published: December 2023

AbstractRwanda is known as the heart of Africa, reflecting the history of the world. Colonization and genocide have led to Rwanda's existing genetic structure. Herein, we used massively parallel sequencing to analyze 296 loci in 185 Rwandans and constructed a database for Rwandan forensic data for the first time. We found the following results: First, forensic parameters demonstrated that all loci were highly informative and could be used for forensic identification and paternity tests in Rwandans. Second, we found that the differences in genetic background between Rwandans and other African populations were similar but slight, as indicated by the massively parallel sequencing panel. Rwandans belonged to the African population and were inseparable from populations from neighboring countries. Also, Rwandans were closer to the European and American populations because of colonization, war, and other reasons. There was no scientific basis for racial classification established by colonization. Further research still needs to be carried out on more loci and larger Rwandan samples.
Exploration of heterogeneous catalyst for molecular hydrogen ortho‐para conversion
Authors: Abe Hideki , Mizoguchi Hiroshi , Eguchi Ryuto , Hosono Hideo 
Published: December 2023

AbstractMolecular hydrogen (H2) ortho‐para conversion (O/P conversion) proceeds slowly at low temperatures accompanying a heat release. Thus, catalysts for accelerating this conversion rate are highly demanded in terms of the storage and utilization of liquid H2. The catalysts for this purpose are experimentally screened by examining a broad range of materials covering magnetic, non‐magnetic, metallic, and nonmetallic oxides. The primary conclusions obtained are summarized below. (1) active materials are required to be non‐metallic and to bear the cations with ionic radii smaller than the bond length of H2. (2) Metallic materials have almost no activity irrespective of with or without magnetism (3) The activity of materials belonging to (1) is largely enhanced when the constituting cation has a magnetic moment. In addition, there is a class of materials for which the activity is distinctly enhanced just upon substitution by the foreign ions.
Racial differences in the effect of APOE‐ε4 genotypes on trail making test B in Alzheimer's disease: A longitudinal study
Authors: Xu Chun , Acevedo Priscila , Lu Yongke , Su Brenda Bin , Ozuna Kaysie , Padilla Victoria , Karithara Annu , Mao ChunXiang , Navia R. Osvaldo , Piamjariyakul Ubolrat , Wang Kesheng ,   The Alzheimer's Disease Neuroimaging Initiative
Published: December 2023

AbstractObjectivesThe trail making test part B (TMT‐B) evaluates executive functions, memory, and sensorimotor functions. No previous study was found to examine the longitudinal effect of APOE‐ε4 genotypes on the TMT‐B scores in Alzheimer's disease (AD) across racial groups.MethodsThis study used the data from Alzheimer's Disease Neuroimaging Initiative (ADNI): 382 participants with AD, 503 with cognitive normal (CN), 1293 with mild cognitive impairment (MCI) at baseline and follow‐up of four years. The multivariable linear mixed model was used to investigate the effect of APOE‐ε4 genotypes on changes in TMT‐B scores.ResultsCompared with Whites, African Americans (AA) and Hispanics had higher TMT‐B scores (poor cognitive function). Furthermore, Whites subjects with 1 or 2 APOE‐ε4 alleles had significantly higher TMT‐B scores compared with individuals without APOE‐ε4 allele at baseline and four follow‐up visits; however, no differences in TMT‐B were found between APOE‐ε4 alleles in the Hispanic and AA groups. No APOE‐ε4 by visit interactions was found for 3 racial groups. Stratified by AD diagnosis, the APOE‐ε4 allele was associated with TMT‐B scores only in the MCI group, while there were significant interactions for visit by education, APOE‐ε4 allele, and the Mini Mental State Examination (MMSE) score in the MCI group. In addition, TMT‐B was significantly correlated with the MMSE, AD Assessment Scale‐cognitive subscale 13 (ADAS13), tTau, pTau, Aβ42, and hippocampus.ConclusionsAPOE‐ɛ4 allele is associated with TMT‐B scores in Whites subjects, but not in the Hispanic and AA groups. APOE‐ε4 showed interaction with visit in the MCI group.
Hippocampal parvalbumin and perineuronal nets: Possible involvement in anxiety‐like behavior in rats
Authors: Fan Zhixin , Gong Xiayu , Xu Hanfang , Qu Yue , Li Bozhi , Li Lanxin , Yan Yuqi , Wu Lili , Yan Can 
Published: December 2023

AbstractThe excitatory‐inhibitory imbalance has been considered an important mechanism underlying stress‐related psychiatric disorders. In the present study, rats were exposed to 6 days of inescapable foot shock (IFS) to induce stress. The open field test and elevated plus maze test showed that IFS‐exposed rats exhibited increased anxiety‐like behavior. Immunofluorescence showed that IFS rats had a decreased density of GAD67‐immunoreactive interneurons in the dorsal hippocampal CA1 region, while no significant change in the density of CaMKIIα‐immunoreactive glutamatergic neurons was seen. We investigated the expression of different interneuron subtype markers, including parvalbumin (PV), somatostatin (SST), and calretinin (CR), and noted a marked decline in the density of PV‐immunoreactive interneurons in the dorsal CA1 region of IFS rats. The perineuronal net (PNN) is a specialized extracellular matrix structure primarily around PV interneurons. We used Wisteria floribunda agglutinin lectin to label the PNNs and observed that IFS rats had an increased proportion of PNN‐coated PV‐positive interneurons in CA1. The number of PSD95‐positive excitatory synaptic puncta on the soma of PNN‐free PV‐positive interneurons was significantly higher than that of PNN‐coated PV‐positive interneurons. Our findings suggest that the effect of IFS on the hippocampal GABAergic interneurons could be cell‐type‐specific. Loss of PV phenotype in the dorsal hippocampal CA1 region may contribute to anxiety in rats. The dysregulated PV‐PNN relationship in CA1 after traumatic stress exposure might represent one of the neurobiological correlates of the observed anxiety‐like behavior.
Heterogeneity and dynamics in network models
Authors: D'Innocenzo Enzo , Lucas André , Opschoor Anne , Zhang Xingmin 
Published: December 2023

SummaryWe propose an empirical spatial modeling framework that allows for both heterogeneity and dynamics in economic network connections. We establish the model's stationarity and ergodicity properties and show that the model's implied filter is invertible. While highly flexible, the model is straightforward to estimate by maximum likelihood. We apply the model to three datasets for Eurozone sovereign credit risk over the period Dec‐2009 to Dec‐2022. Accounting for both heterogeneity and time‐variation turns out to be empirically important both in‐sample and out‐of‐sample. The new model uncovers intuitive patterns that would go unnoticed in either homogeneous and/or static spatial financial network models.
How delocalized are the polyacenes?
Authors: Mrovec Martin , Gill Peter M. W. 
Published: December 2023

AbstractIn an attempt to quantify electron delocalization in polyacenes with up to 50 carbon atoms, we have performed self‐consistent field calculations in which the electrons are constrained to occupy highly localized molecular orbitals (HILOs) centered on a maximum of two, six or ten adjacent carbon atoms. We have also performed similar calculations on simple polyacene analogs consisting only of hydrogen atoms and exhibiting electron delocalization in the framework. We find that the energetic cost of localizing the electrons in the polyacenes is roughly 60, 5 or 0.1 kJ/mol per ring atom for the two‐, six‐ and ten‐atom HILOs, respectively, and the use of these localized models overestimates the predicted hydrogenation energies of the acenes by roughly 50%, 4% and 0.1%, respectively. We conclude that the chemistry of polyacenes can be modeled well using highly localized descriptions of the electrons.
Extraction of enzymes produced by endophytic fungi isolated from mangroves
Authors: Paliga Letícia Raquel , Bonatto Charline , Camargo Aline Frumi , Cadamuro Rafael Dorighello , da Silveira Bastos Isabela Maria Agustini , de Freitas Ana Claudia Oliveira , da Silva Rosa Marilene , Silva Izabella Thaís , Robl Diogo , Stoco Patrícia Hermes , Sandjo Louis Pergaud , Steindel Mário , Fongaro Gislaine , Treichel Helen 
Published: December 2023

AbstractBACKGROUNDThis work aimed to study different methodologies for extracting enzymes produced by the endophytic fungi isolated from mangrove Neofusicoccum parvum, Penicillium glabra series and Bjerkandera sp. grown on organic rice. The enzymatic activities of amylase, cellulase, laccase, lipase, peroxidase, protease and keratinase were evaluated for future applications in biotechnology and enzymology. The evaluation of the extraction was carried out using the design of experiments methodology, where variations were made in pH (4–8), temperature (20–36 °C) and agitation (150–200 rpm), in times of 1, 6 and 12 h.RESULTSAmong the enzymes analyzed, promising activities were found for amylase, cellulase, lipase, protease, peroxidase and especially keratinase, presenting activities of up to 7049.47 U g−1 in the fermentation carried out with the fungus Neofusicoccum parvum, 3538.52 U g−1 with the fungus Penicillium glabra series and 5068.20 U g−1 with the fungus Bjerkandera sp. This indicates that the fungi are promising for the production of multienzyme cocktails.CONCLUSIONIt should be emphasized that the microorganisms and extraction conditions evaluated resulted in a series of promising results, that is, in the case of aiming to obtain different enzymes by other extraction conditions, after fermentation of various microorganisms on rice, several options of situations are presented and validated in this work, which allows the choice of the same, depending on the future application potential of these biocatalysts. © 2023 Society of Chemical Industry (SCI).
Investigation of layered glazes coloured with carbon‐based pigments using micro spatially‐offset Raman spectroscopy
Authors: Bouvier Caroline , Elliott Stephen R. 
Published: December 2023

AbstractNon‐invasive and non‐destructive Raman spectroscopic techniques have been used to detect the stratigraphic variation of tints in semi‐translucent films, comprising stacked layers with varying low concentrations of carbon‐black pigment dispersed in a painting varnish imitating historical artist materials, as in the ‘Sfumato’ technique often associated with Leonardo da Vinci's works of art. Understanding the structures behind this effect could help to conserve such paintings. Micro‐Raman spectroscopy is one of the analytical techniques usually applied to painting materials that has proved suitable for tackling the challenging detection and characterization of carbon‐based pigments in organic‐rich paintings. Model transparent samples have been fabricated following a selected recipe from historical sources and analysed using Raman‐scattering‐based experimental techniques, including micro‐spatially offset Raman spectroscopy (micro‐SORS). Single glaze layers spanning a range of concentrations, and multilayer systems mimicking the resulting stratigraphy of the Sfumato glaze technique, have been studied. Raman‐spectroscopy performance to detect the pigment was assessed on the single layers; the spectral behaviour was characterized according to the concentration of pigment. The micro‐SORS technique was tested on the multilayer systems and appears to be able to distinguish between different stratigraphic samples, varying in concentration of the same carbon‐based pigment, and the order of layers. This proof‐of‐concept observation is promising. It calls for further studies to be undertaken to obtain comprehensive results about an increased number of model painting materials, especially for carbon‐based materials mixed with other pigments.
Tracheal A‐frame deformity and suprastomal collapse after pediatric tracheostomy
Authors: Suresh Rishi , Dabbous Helene , Alahari Swapnika , Kou Yann‐Fuu , Johnson Romaine F. , Chorney Stephen R. 
Published: December 2023

AbstractObjectivesTo determine the incidence of A‐frame deformity and suprastomal collapse after pediatric tracheostomy.Study designRetrospective cohort.MethodsAll patients (<18 years) that had a tracheostomy placed at a tertiary institution between 2015 and 2020 were included. Children without a surveillance bronchoscopy at least 6 months after tracheostomy were excluded. Operative reports identified tracheal A‐frame deformity or suprastomal collapse.ResultsA total of 175 children met inclusion with 18% (N = 32) developing A‐frame deformity within a mean of 35.8 months (SD: 19.4) after tracheostomy. For 18 children (18/32, 56%), A‐frame developed within a mean of 11.3 months (SD: 15.7) after decannulation. There were 96 children developing suprastomal collapse (55%) by a mean of 17.7 months (SD: 14.2) after tracheostomy. All suprastomal collapse was identified prior to decannulation. Older age at tracheostomy was associated with a lower likelihood of collapse (OR: 0.92, 95% CI: 0.86–0.99, p = .03). The estimated 5‐year incidence of A‐frame deformity after tracheostomy was 32.8% (95% CI: 23.0–45.3) and the 3‐year incidence after decannulation was 36.1% (95% CI: 24.0–51.8). Highly complex children had an earlier time to A‐frame development (p = .04). At 5 years after tracheostomy, the estimated rate of suprastomal collapse was 73.7% (95% CI: 63.8–82.8).ConclusionsTracheal A‐frame deformity is estimated to occur in 36% of children within 3 years after tracheostomy decannulation. Suprastomal collapse, which approaches 74% at 5 years after tracheostomy, is more common when tracheostomy is placed at a younger age. Surgeons caring for tracheostomy‐dependent children should recognize acquired airway obstruction and appropriately monitor these outcomes.Level of evidence3.
Specific and rapid guanidinium CEST imaging using double saturation power and QUASS analysis in a rodent model of global ischemia
Authors: Zhou Iris Y. , Ji Yang , Zhao Yu , Viswanathan Malvika , Sun Phillip Zhe , Zu Zhongliang 
Published: December 2023

AbstractPurposeGuanidinium CEST is sensitive to metabolic changes and pH variation in ischemia, and it can offer advantages over conventional pH‐sensitive amide proton transfer (APT) imaging by providing hyperintense contrast in stroke lesions. However, quantifying guanidinium CEST is challenging due to multiple overlapping components and a close frequency offset from water. This study aims to evaluate the applicability of a new rapid and model‐free CEST quantification method using double saturation power, termed DSP‐CEST, for isolating the guanidinium CEST effect from confounding factors in ischemia. To further reduce acquisition time, the DSP‐CEST was combined with a quasi‐steady state (QUASS) CEST technique to process non‐steady‐state CEST signals.MethodsThe specificity and accuracy of the DSP‐CEST method in quantifying the guanidinium CEST effect were assessed by comparing simulated CEST signals with/without the contribution from confounding factors. The feasibility of this method for quantifying guanidinium CEST was evaluated in a rat model of global ischemia induced by cardiac arrest and compared to a conventional multiple‐pool Lorentzian fit method.ResultsThe DSP‐CEST method was successful in removing all confounding components and quantifying the guanidinium CEST signal increase in ischemia. This suggests that the DSP‐CEST has the potential to provide hyperintense contrast in stroke lesions. Additionally, the DSP‐CEST was shown to be a rapid method that does not require the acquisition of the entire or a portion of the CEST Z‐spectrum that is required in conventional model‐based fitting approaches.ConclusionThis study highlights the potential of DSP‐CEST as a valuable tool for rapid and specific detection of viable tissues.
Registered nurses' perceptions and experience of working in aged care: A qualitative approach
Authors: Sun Yong‐Jhu , Wang Shou‐Yu , Tsai Yvette , Wei Wenxi , Chang Hui‐Chen 
Published: December 2023

AbstractAimTo understand and report on the perceptions and experiences of registered nurses in the aged care sector.DesignAn exploratory qualitative study.MethodsSemi‐structured telephone interviews were utilised as the primary data collection method. Fifteen registered nurses were interviewed. All interviews were recorded, transcribed verbatim and analysed using conventional content analysis. Participants were quoted verbatim to ensure authenticity.ResultsThe results indicated a demand for increased administrative and staffing support in the aged care workplace. Poor morale and unethical practices contributed to negative perceptions and attitudes among nurses towards aged care. Managing and communicating with older people was reported as challenging, which impacts nursing staff recruitment and retention. Future work is needed to ensure that outstanding clinical role models and leadership support nursing staff recruitment and retention. Incorporating aged care content into the nursing curriculum and providing professional development opportunities to aged care professionals would be the foundation towards solutions, as the study primarily explored nurses' perspectives.