bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and molecular determinants for the interaction of ExbB from Serratia marcescens and HasB, a TonB paralog
Authors: Biou Valérie , Adaixo Ricardo Jorge Diogo , Chami Mohamed , Coureux Pierre-Damien , Laurent Benoist , Enguéné Véronique Yvette Ntsogo , de Amorim Gisele Cardoso , Izadi-Pruneyre Nadia , Malosse Christian , Chamot-Rooke Julia , Stahlberg Henning , Delepelaire Philippe 
Published: April 2022

AbstractExbB and ExbD are cytoplasmic membrane proteins that associate with TonB to convey the energy of the proton-motive force to outer membrane receptors in Gram-negative bacteria for iron uptake. The opportunistic pathogen Serratia marcescens (Sm) possesses both TonB and a heme-specific TonB paralog, HasB. ExbBSm has a long periplasmic extension absent in other bacteria such as E. coli (Ec). Long ExbB’s are found in several genera of Alphaproteobacteria, most often in correlation with a hasB gene. We investigated specificity determinants of ExbBSm and HasB. We determined the cryo-EM structures of ExbBSm and of the ExbB-ExbDSm complex from S. marcescens. ExbBSm alone is a stable pentamer, and its complex includes two ExbD monomers. We showed that ExbBSm extension interacts with HasB and is involved in heme acquisition and we identified key residues in the membrane domain of ExbBSm and ExbBEc, essential for function and likely involved in the interaction with TonB/HasB. Our results shed light on the class of inner membrane energy machinery formed by ExbB, ExbD and HasB.
Structural and biochemical evidence that ATP inhibits the cancer biomarker human aldehyde dehydrogenase 1A3
Authors: Castellví Albert , Pequerul Raquel , Barracco Vito , Juanhuix Judith , Parés Xavier , Farrés Jaume 
Published: April 2022

AbstractHuman aldehyde dehydrogenase (ALDH) participates in the oxidative stress response and retinoid metabolism, being involved in several diseases, including cancer, diabetes and obesity. The ALDH1A3 isoform has recently elicited wide interest because of its potential use as a cancer stem cell biomarker and drug target. We report high-resolution three-dimensional ALDH1A3 structures for the apo-enzyme, the NAD+ complex and a binary complex with ATP. Each subunit of the ALDH1A3-ATP complex contains one ATP molecule bound to the adenosine-binding pocket of the cofactor-binding site. The ATP complex also shows a molecule, putatively identified as a polyethylene glycol aldehyde, covalently bound to the active-site cysteine. This mimics the thioacyl-enzyme catalytic intermediate, which is trapped in a dead enzyme lacking an active cofactor. At physiological concentrations, ATP inhibits the dehydrogenase activity of ALDH1A3 and other isoforms, with a Ki value of 0.48 mM for ALDH1A3, showing a mixed inhibition type against NAD+. ATP also inhibits esterase activity in a concentration-dependent manner. The current ALDH1A3 structures at higher resolution will facilitate the rational design of potent and selective inhibitors. ATP binding to ALDH1A3 enables activity modulation by the energy status of the cell and metabolic reprogramming, which may be relevant in several disease conditions.
Peripheral blood CD4+CCR6+ compartment differentiates HIV-1 infected or seropositive elite controllers from long-term successfully treated individuals
Authors: Svensson Akusjärvi Sara , Krishnan Shuba , Jütte Bianca B. , Ambikan Anoop T. , Gupta Soham , Rodriguez Jimmy Esneider , Végvári Ákos , Sperk Maike , Nowak Piotr , Vesterbacka Jan , Svensson J. Peter , Sönnerborg Anders , Neogi Ujjwal 
Published: April 2022

AbstractHIV-1 infection induces a chronic inflammatory environment not restored by suppressive antiretroviral therapy (ART). As of today, the effect of viral suppression and immune reconstitution in people living with HIV-1 (PLWH) has been well described but not completely understood. Herein, we show how PLWH who naturally control the virus (PLWHEC) have a reduced proportion of CD4+CCR6+and CD8+CCR6+cells compared to PLWH on suppressive ART (PLWHART) and HIV-1 negative controls (HC). Expression of CCR2 was reduced on both CD4+, CD8+and classical monocytes in PLWHECcompared to PLWHARTand HC. Longer suppressive therapy, measured in the same patients, decreased number of cells expressing CCR2 on all monocytic cell populations while expression on CD8+T cells increased. Furthermore, the CD4+CCR6+/CCR6−cells exhibited a unique proteomic profile with a modulated energy metabolism in PLWHECcompared to PLWHARTindependent of CCR6 status. The CD4+CCR6+cells also showed an enrichment in proteins involved in apoptosis and p53 signalling in PLWHECcompared to PLWHART, indicative of increased sensitivity towards cell death mechanisms. Collectively, this data shows how PLWHEChave a unique chemokine receptor profile that may aid in facilitating natural control of HIV-1 infection.
Perspective on pros and cons of microlearning in health education
Authors: Sozmen Eser Yıldırım 
Published: April 2022

Abstract
Recently, digital technology and digital materials have started to be widely used in education from primary school to college worldwide. Microlearning is one of the innovative teaching techniques that use digital technologies. In this review, benefits and disadvantages of microlearning is discussed. Many studies show that microlearning facilitated learning by dividing into smaller pieces encourages students to study. A wide range of activities might be used in this technique and it can be easily integrated into daily routine, it allows on-demand learning for the students. On the other hand, the success of microlearning techniques is closely related to the personal characteristics of learners, teachers’ prone to use digital technology and the external factors such as access to learning materials. Its effectiveness on behavior and outcome which were defined in the third and fourth levels of Kirkpatrick’s learning model is still obscure.
In the light of the literature, it should be decided which microlearning method will be used for which educational subjects.
Fuzzy linear extended states observer‐based iteration learning fault‐tolerant control for autonomous underwater vehicle trajectory‐tracking system
Authors: Hou Chao , Li XiaoGang , Wang Hongbo , Zhai Peng , Lu Hao 
Published: April 2022

AbstractTo deal with thrusters’ faults of autonomous underwater vehicle (AUV), an iterative learning algorithm fault‐tolerant control (FTC) based on the linear extended states observer (LESO) is proposed. In this control scheme, the non‐linear feedback mechanism of the LESO is transplanted into iterative learning processes to estimate fault. Compared to our previous work, LESO is used to substitute classic non‐linear extended state observer to make the establishment of the whole system more structured; moreover, the number of parameters need to be tuned can be reduced by the conception of observer bandwidth of LESO. To enhance the controllability and robustness of whole scheme, a new saturated sliding mode controller is proposed based on the Lyapunov theory. Then to achieve online parameter self‐tuning for the control system, fuzzy logic controllers are introduced to find optimal relationship between LESO's parameter and tracking errors. The performance of the proposed controller is tested by some comparison experiments on Zhuhai A18D AUV; the results show that the proposed control scheme can ensure better stability than classical control and our previous control scheme when AUV suffers faults.
Classification of hyperspectral images via improved cycle‐MLP
Authors: Gong Na , Zhang Chunlei , Zhou Heng , Zhang Kai , Wu Zhongyuan , Zhang Xin 
Published: April 2022

AbstractPixel‐wise classification of hyperspectral image (HSI) is a hot spot in the field of remote sensing. The classification of HSI requires the model to be more sensitive to dense features, which is quite different from the modelling requirements of traditional image classification tasks. Cycle‐Multilayer Perceptron (MLP) has achieved satisfactory results in dense feature prediction tasks because it is an expert in extracting high‐resolution features. In order to obtain a more stable receptive field and enhance the effect of feature extraction in multiple directions, we propose an MLP‐like model called DriftNet for HSI classification inspired by Cycle‐MLP and deformable convolution. Besides, the proposed DriftNet uses a unique ladder‐like fully connected structure to achieve progressive activation of neurons and facilitates the fusion of spatial and spectral information, thereby obtaining more sensitive location information for better classification results. Experimental results on three public hyperspectral datasets demonstrate the effectiveness and generalisation of DriftNet.
Ground glass opacity detection and segmentation using CT images: an image statistics framework
Authors: Banday S.A. , Nahvi Rafia , Mir A.H. , Khan S. , AlGhamdi Ahmad Saeed , Alshamrani Sultan S. 
Published: April 2022

AbstractLung cancer is one of the most profound causes of cancer‐related deaths in the world. Early detection is known to significantly improve the chances of survival. Several detection and diagnostic methods are used for this purpose. CT is one of the most widely used non‐invasive medical imaging modalities in this domain. The biggest challenge faced by radiologists in this case is detection and diagnosis of cancerous lung nodules. The growth of ground glass opacity (GGO) lesions is an indication of malignancy. However, GGO is difficult to capture for physicians as it manifests in the form of tiny, faint shadows. This research paper proposes an approach for aiding GGO identification in CT lung images for improved lung cancer prognosis. In the proposed approach, morphological reconstruction is used for segmentation. Once the region of interest (ROI) is extracted, statistical analysis using mean, standard deviation, variance, entropy, skewness, kurtosis, minimum grey scale value, maximum grey scale value and range is performed. The same statistical measures are determined for normal lung and distribution plot is drawn for comparison. It is observed that maximum grey‐scale value demonstrates minimum overlap of approximately 7.4%. To reduce this, a joint feature by summing values of feature mean, skewness, and maximum grey‐scale value was used. This approach reduced the overlap to approximately 1.32%. Lastly, ANN was used for classification of GGO and non‐GGO lung tissue with an achieved accuracy of 99.5%.
The dark matter halo masses of elliptical galaxies as a function of observationally robust quantities
Authors: Sonnenfeld Alessandro , Tortora Crescenzo , Hoekstra Henk , Asgari Marika , Bilicki Maciej , Heymans Catherine , Hildebrandt Hendrik , Kuijken Konrad , Napolitano Nicola R. , Roy Nivya , Valentijn Edwin , Wright Angus H. 
Published: April 2022

Context. The assembly history of the stellar component of a massive elliptical galaxy is closely related to that of its dark matter halo. Measuring how the properties of galaxies correlate with their halo mass can therefore help to understand their evolution.
Aims. We investigate how the dark matter halo mass of elliptical galaxies varies as a function of their properties, using weak gravitational lensing observations. To minimise the chances of biases, we focus on the following galaxy properties that can be determined robustly: the surface brightness profile and the colour.
Methods. We selected 2409 central massive elliptical galaxies (log M*/M⊙ ≳ 11.4) from the Sloan Digital Sky Survey spectroscopic sample. We first measured their surface brightness profile and colours by fitting Sérsic models to photometric data from the Kilo-Degree Survey (KiDS). We fitted their halo mass distribution as a function of redshift, rest-frame r-band luminosity, half-light radius, and rest-frame u − g colour, using KiDS weak lensing measurements and a Bayesian hierarchical approach. For the sake of robustness with respect to assumptions on the large-radii behaviour of the surface brightness, we repeated the analysis replacing the total luminosity and half-light radius with the luminosity within a 10 kpc aperture, Lr, 10, and the light-weighted surface brightness slope, Γ10.
Results. We did not detect any correlation between the halo mass and either the half-light radius or colour at fixed redshift and luminosity. Using the robust surface brightness parameterisation, we found that the halo mass correlates weakly with Lr, 10 and anti-correlates with Γ10. At fixed redshift, Lr, 10 and Γ10, the difference in the average halo mass between galaxies at the 84th percentile and 16th percentile of the colour distribution is 0.00 ± 0.11 dex.
Conclusion. Our results indicate that the average star formation efficiency of massive elliptical galaxies has little dependence on their final size or colour. This suggests that the origin of the diversity in the size and colour distribution of these objects lies with properties other than the halo mass.
Covariances of density probability distribution functions. Lessons from hierarchical models
Authors: Bernardeau Francis 
Published: April 2022

Context. Statistical properties of the cosmic density fields are to a large extent encoded in the shape of the one-point density probability distribution functions (PDF) as measured in surveys. In order to successfully exploit such observables, a detailed functional form of the covariance matrix of the one-point PDF is needed.Aims. The objectives are to model the properties of this covariance for general stochastic density fields and for stochastic fields that reproduce the properties expected in cosmology. The accuracy of the proposed forms is evaluated in specific cases.Methods. The study was conducted in a cosmological context and determined whether the density is defined absolutely or relatively to the sample mean density. Leading and subleading contributions were identified within a large class of models, the so-called hierarchical models. They come from either large or short separation contributions. The validity of the proposed forms for the covariance matrix was assessed with the help of a toy model, the minimum tree model, for which a corpus of exact results could be obtained (forms of the one- and two-point PDF, large-scale density-bias functions, and full covariance matrix of the one-point PDF).Results. It is first shown that the covariance matrix elements are directly related to the spatial average of the two-point density PDF within the sample. The dominant contribution to this average is explicitly given for hierarchical models (coming from large scale contribution), which leads to the construction of specific density-bias functions. However, this contribution alone cannot be used to construct an operational likelihood function. Subdominant large-scale effects are found to provide corrective terms, but also a priori lead to limited information on the covariance matrix. Short distance effects are found to be more important but more difficult to derive as they depend more on the details of the model. However, a simple and generic form of these contributions is proposed. Detailed comparisons in the context of the Rayleigh-Levy flight model show that the large-scale effects capture the bulk of the supersample effects and that, by adding the short-distance contributions, a qualitatively correct model of the likelihood function can be obtained.
Finite-amplitude sound propagation effects in volume backscattering measurements for fish abundance estimation
Authors: Pedersen Audun O. , Lunde Per , Tichy Frank E. , Korneliussen Rolf J. 
Published: April 2022

Scientific advice for governmental management of marine resources relies on acoustical observation methods. Quantification and identification of fish and plankton species are often achieved using multi-frequency acoustic data. Accurate measurements of backscattering cross-sections and volume backscattering coefficients are essential. Systematic errors from finite-amplitude sound propagation are demonstrated in experimental survey measurements on Atlantic mackerel using 120 kHz and 200 kHz echosounders and high power settings. Finite-amplitude signal distortion causes excess transmission loss that is not accounted for in fisheries acoustics today, other than by fixed limits on the maximum transmitted power. The demonstrated errors are of a magnitude that can seriously bias abundance estimation and species identification. It is shown how the finite-amplitude effects can be modelled and predicted quantitatively, within a framework of electroacoustic power budget equations. A method is provided to calculate related errors in echosounder calibration and oceanic measurement of acoustic volume backscattering. When accounting for finite-amplitude effects in echosounder signal processing, higher transmit powers can be used when needed to improve signal-to-noise ratio or extend measurement range. The results indicate that historical survey data can be adjusted for such errors using numerical simulations. The echosounder characteristics relevant to finite-amplitude effects can be determined by laboratory measurements.
17.8.5 Porphyrins (Update 2022)
Authors: Jux N. , Montforts F.-P. , Haake E. 
Published: April 2022

AbstractThis chapter covers methods for the synthesis and transformations of porphyrins, and is an update to the earlier Science of Synthesis contribution Section 17.8.1. The focus is on the literature published in the period 2000–2021. The basic principles and strategies for the construction and modification of the porphyrin core are examined, with an emphasis on the most useful approaches reported in the past two decades.
17.8.8 Contracted, Isomeric, and Expanded Porphyrins and Carba and Hetero Analogues (Update 2022)
Authors: Jux N. , Montforts F.-P. , Haake E. 
Published: April 2022

AbstractIn this chapter, a range of porphyrinoid analogues and related macrocyclic structures are described and the key literature covering these types of compounds has been collated.
44.2.6.11 Applications of Allenes in Organic Synthesis (Update 2022)
Authors: Tius M. A. 
Published: April 2022

AbstractThis chapter is an update to the earlier Science of Synthesis article (Section 44.2.6) that described the applications of allenes in organic synthesis. An attempt has been made to cover the literature from the end of 2005 through to approximately the end of June 2020. Allenes generally participate in the same reactions as alkenes, but their strain and the presence of the sp-hybridized carbon atom enable additional pathways. Advances in transition-metal-mediated asymmetric catalysis, especially involving gold and rhodium, have led to the development of many of the novel highly enantioselective processes that are discussed.
Effectiveness of biochar- and boron-coated diammonium phosphate for improving boron availability to sunflower (
Authors: Samreen Tayyaba , Kanwal Nafeesa , Nadeem Faisal , Farooq Muhammad , Noreen Saima , Nazir Muhammad Zulqernain , Bashir Muhammad Asaad , Naveed Muhammad , Zahir Zahir Ahmad 
Published: April 2022

Sunflower (Helianthus annuus L.) growth and yield are severely compromised by boron (B) deficiency in alkaline calcareous soils of Pakistan. Biochar produced through low-temperature pyrolysis helps to maintain acidic functional groups in such soils. The aim of this study was to enhance B availability in biochar-amended alkaline calcareous soils in order to improve morpho-physiological and yield attributes of sunflower. In a pot experiment, sunflower was grown with three fertiliser treatments: diammonium phosphate (DAP) alone; simple B + DAP; and DAP coated with biochar and B (BC-BDAP). All treatments were grown in soil receiving no biochar, and the BC-BDAP treatment was also applied in soil amended with wheat straw biochar at 2% and 4%. Preparation with wheat straw biochar improved soil properties such that soil with 4% biochar showed highest levels of organic matter (0.97%), total nitrogen (0.08%), available phosphorus (6.21 mg/kg), extractable potassium (93.4 mg/kg) and available B (0.41 mg/kg). Furthermore, compared with DAP alone and B + DAP, BC-BDAP in 4% biochar-amended soil enhanced the concentrations of shoot B (by 64% and 35%) and root B (by 41% and 26%), respectively. This indicated sufficient B availability in soil for root absorption, which subsequently increased sunflower achene weight per plant (by 33% and 17%), protein content (by 29% and 18%) and oil content (by 17% and 10%). Thus, application of BC-BDAP fertiliser in 4% biochar-amended soil can be an efficient strategy for enhancing B availability in alkaline calcareous soils and increasing sunflower growth and yield.
Plio-Pleistocene environmental variability in Africa and its implications for mammalian evolution
Authors: Cohen Andrew S. , Du Andrew , Rowan John , Yost Chad L. , Billingsley Anne L. , Campisano Christopher J. , Brown Erik T. , Deino Alan L. , Feibel Craig S. , Grant Katharine , Kingston John D. , Lupien Rachel L. , Muiruri Veronica , Owen R. Bernhart , Reed Kaye E. , Russell James , Stockhecke Mona 
Published: April 2022

Significance
We have developed an Africa-wide synthesis of paleoenvironmental variability over the Plio-Pleistocene. We show that there is strong evidence for orbital forcing of variability during this time that is superimposed on a longer trend of increasing environmental variability, supporting a combination of both low- and high-latitude drivers of variability. We combine these results with robust estimates of mammalian speciation and extinction rates and find that variability is not significantly correlated with these rates. These findings do not currently support a link between environmental variability and turnover and thus fail to corroborate predictions derived from the variability selection hypothesis.
Hamilton’s rule in economic decision-making
Authors: Levy Moshe , Lo Andrew W. 
Published: April 2022

Significance
Kin selection—helping genetically related individuals even at a cost to oneself—can be evolutionarily advantageous. This is the main theoretical explanation for altruism in the natural world. Hamilton’s rule provides a simple algebraic relationship that captures this profound idea. While behavior consistent with Hamilton’s rule has been observed in many species, a direct and sharp test of this rule has not yet been performed. In this paper, we employ techniques borrowed from experimental economics to test the predictions of Hamilton’s rule. We find strong support for the rule. This result sheds light on the dominant role played by evolutionary biology in explaining human behavior.
Human shoulder development is adapted to obstetrical constraints
Authors: Kawada Mikaze , Nakatsukasa Masato , Nishimura Takeshi , Kaneko Akihisa , Ogihara Naomichi , Yamada Shigehito , Coudyzer Walter , Zollikofer Christoph P. E. , Ponce de León Marcia S. , Morimoto Naoki 
Published: April 2022

Significance
During human birth, the risk of complications is relatively high because of the comparatively large dimensions of the fetal head and shoulders relative to the maternal birth canal. Here we show that humans exhibit a developmental mode of the shoulders that likely contributes to mitigating obstetrical problems. Human shoulder growth is decelerated before birth but accelerated after birth, which stands in contrast to the more uniform shoulder growth trajectories of chimpanzees and macaques. This indicates that fetal developmental modifications were required during human evolution not only in the head but also in the shoulders to compensate obstetrical constraints.