bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fundamental mechanisms of the stem cell regulation in land plants: lesson from shoot apical cells in bryophytes
Authors: Hata Yuki , Kyozuka Junko 
Published: February 2021

Abstract
Key message
This review compares the molecular mechanisms of stem cell control in the shoot apical meristems of mosses and angiosperms and reveals the conserved features and evolution of plant stem cells.

Abstract
The establishment and maintenance of pluripotent stem cells in the shoot apical meristem (SAM) are key developmental processes in land plants including the most basal, bryophytes. Bryophytes, such as Physcomitrium (Physcomitrella) patens and Marchantia polymorpha, are emerging as attractive model species to study the conserved features and evolutionary processes in the mechanisms controlling stem cells. Recent studies using these model bryophyte species have started to uncover the similarities and differences in stem cell regulation between bryophytes and angiosperms. In this review, we summarize findings on stem cell function and its regulation focusing on different aspects including hormonal, genetic, and epigenetic control. Stem cell regulation through auxin, cytokinin, CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) signaling and chromatin modification by Polycomb Repressive Complex 2 (PRC2) and PRC1 is well conserved. Several transcription factors crucial for SAM regulation in angiosperms are not involved in the regulation of the SAM in mosses, but similarities also exist. These findings provide insights into the evolutionary trajectory of the SAM and the fundamental mechanisms involved in stem cell regulation that are conserved across land plants.
Comparison Principle for Elliptic Equations with Mixed Singular Nonlinearities
Authors: Durastanti Riccardo , Oliva Francescantonio 
Published: February 2021

AbstractWe deal with existence and uniqueness of positive solutions of an elliptic boundary value problem modeled by
$$ \left \{\begin {array}{ll} \displaystyle -{\Delta }_{p} u= \frac {f}{u^{\gamma }} + g u^{q} & \text { in } {\Omega }, \\ u = 0 & \text {on } \partial {\Omega }, \end {array}\right . $$

−

Δ

p

u
=

f

u

γ

+
g

u

q

in

Ω
,

u
=
0

on

∂
Ω
,

where Ω is an open bounded subset of $\mathbb {R}^{N}$

ℝ

N

where Ω is an open bounded subset of $\mathbb {R}^{N}$

ℝ

N

, Δpu := ÷(|∇u|p− 2∇u) is the usual p-Laplacian operator, γ ≥ 0 and 0 ≤ q ≤ p − 1; f and g are nonnegative functions belonging to suitable Lebesgue spaces.
An Integrative Systems Approach to Enhancing Service Delivery for Individuals with Complex Needs
Authors: Pei Jacqueline , Poth Cheryl , Tremblay Melissa , Walker Meghan 
Published: February 2021

Abstract
Purpose of Review
There are a lack of system-wide integrative services for individuals with complex needs and a corresponding demand for advancing cross-disciplinary practices in community settings. This demand is especially acute for individuals with fetal alcohol spectrum disorder (FASD) and a gap we have sought to address.

Recent Findings
We present findings from a literature scan to guide service delivery for individuals and families affected by FASD and other complex needs: four overarching guiding principles for policy decision-makers, seven guiding practices for organizations, and 23 guiding practices for service providers.

Summary
These identified principles and practices bridge diverse perspectives, with potential for their implementation to provide consistent, evidence-based services to underserved populations with complex needs.
Estimating Changes in Forest Attributes and Enhancing Growth Projections: a Review of Existing Approaches and Future Directions Using Airborne 3D Point Cloud Data
Authors: Tompalski Piotr , Coops Nicholas C. , White Joanne C. , Goodbody Tristan R.H. , Hennigar Chris R. , Wulder Michael A. , Socha Jarosław , Woods Murray E. 
Published: February 2021

AbstractPurpose of ReviewThe increasing availability of three-dimensional point clouds, including both airborne laser scanning and digital aerial photogrammetry, allow for the derivation of forest inventory information with a high level of attribute accuracy and spatial detail. When available at two points in time, point cloud datasets offer a rich source of information for detailed analysis of change in forest structure.Recent FindingsExisting research across a broad range of forest types has demonstrated that those analyses can be performed using different approaches, levels of detail, or source data. By reviewing the relevant findings, we highlight the potential that bi- and multi-temporal point clouds have for enhanced analysis of forest growth. We divide the existing approaches into two broad categories— – approaches that focus on estimating change based on predictions of two or more forest inventory attributes over time, and approaches for forecasting forest inventory attributes. We describe how point clouds acquired at two or more points in time can be used for both categories of analysis by comparing input airborne datasets, before discussing the methods that were used, and resulting accuracies.SummaryTo conclude, we outline outstanding research gaps that require further investigation, including the need for an improved understanding of which three-dimensional datasets can be applied using certain methods. We also discuss the likely implications of these datasets on the expected outcomes, improvements in tree-to-tree matching and analysis, integration with growth simulators, and ultimately, the development of growth models driven entirely with point cloud data.
Why current quantitative serology is not quantitative and how systems immunology could provide solutions
Authors: Prechl József 
Published: February 2021

AbstractDetermination of the presence of antibodies against infectious agents, self-antigens, allogeneic antigens and environmental antigens is the goal of medical serology. Along with the standardization of these tests the community also started to use the expression “quantitative serology,” referring to the fact that arbitrary units are used for the expression of results. In this review I will argue against the use of the term quantitative serology for current tests. Because each test and each antibody isotype determination uses its own references, the term semiquantitative better describes these methods. The introduction of really quantitative serology could both benefit from and drive forward systems immunological approach to immunity.
Ketamine—50 years in use: from anesthesia to rapid antidepressant effects and neurobiological mechanisms
Authors: Kohtala Samuel 
Published: February 2021

AbstractOver the past 50 years, ketamine has solidified its position in both human and veterinary medicine as an important anesthetic with many uses. More recently, ketamine has been studied and used for several new indications, ranging from chronic pain to drug addiction and post-traumatic stress disorder. The discovery of the rapid-acting antidepressant effects of ketamine has resulted in a surge of interest towards understanding the precise mechanisms driving its effects. Indeed, ketamine may have had the largest impact for advancements in the research and treatment of psychiatric disorders in the past few decades. While intense research efforts have been aimed towards uncovering the molecular targets underlying ketamine’s effects in treating depression, the underlying neurobiological mechanisms remain elusive. These efforts are made more difficult by ketamine’s complex dose-dependent effects on molecular mechanisms, multiple pharmacologically active metabolites, and a mechanism of action associated with the facilitation of synaptic plasticity. This review aims to provide a brief overview of the different uses of ketamine, with an emphasis on examining ketamine’s rapid antidepressant effects spanning molecular, cellular, and network levels. Another focus of the review is to offer a perspective on studies related to the different doses of ketamine used in antidepressant research. Finally, the review discusses some of the latest hypotheses concerning ketamine’s action.
Challenges for the management of the invasive blackberry (Rubus niveus) in the restoration of the Scalesia forest in the Galapagos Islands
Authors: Renteria Jorge L. , Atkinson Rachel , Crespo Claudio , Gardener Mark R. , Grosholz Edwin D. 
Published: February 2021

AbstractStrong competitive ability of introduced plant species has been frequently stated as a key factor promoting successful invasion. The dynamics of invasive species may depend on their abilities to compete for resources and exploit disturbances relative to native species. This study compares the growth performance of the invasive blackberry (Rubus niveusThunb.) with four of the most common woody native species of the Scalesia forest in the Galapagos Islands. Using a series of greenhouse and field studies, the growth rate and biomass production of native species alone and in competition withR. niveuswas compared under different water and light stress conditions.Rubus niveusshowed a faster growth rate and biomass production than the native species as well as a broad tolerance to light and water stress conditions. Competitive ability was also assessed by looking at the seedbank and regeneration processes after herbicide control in the field. Although the number ofR. niveusseedlings that germinated from the soil samples was considerably larger than that of native species, recruitment of the invasive on the experimental plots was limited. Overall,R. niveusshowed superior competitive ability over native species with comparable growth forms, suggesting a possible mechanism that enablesR. niveusto successfully invade a wide range of habitats in the Galapagos Islands. Implementing an integrated management strategy including biological control, seedbank reduction, and active revegetation, should improve the efficiency ofR. niveusmanagement, enabling the restoration of degraded vegetation in the Galapagos.
Investigation of Small‐Scale Electron Density Irregularities Observed by the Arase and Van Allen Probes Satellites Inside and Outside the Plasmasphere
Authors: Thomas Neethal , Shiokawa Kazuo , Miyoshi Yoshizumi , Kasahara Yoshiya , Shinohara Iku , Kumamoto Atsushi , Tsuchiya Fuminori , Matsuoka Ayako , Kasahara Satoshi , Yokota Shoichiro , Keika Kunihiro , Hori Tomoaki , Asamura Kazushi , Wang Shiang‐Yu , Kazama Yoichi , Tam Sunny Wing‐Yee , Chang Tzu‐Fang , Wang Bo‐Jhou , Wygant John , Breneman Aaron , Reeves Geoffrey 
Published: February 2021

AbstractIn situ electron density profiles obtained from Arase in the night magnetic local time (MLT) sector and from RBSP‐B covering all MLTs are used to study the small‐scale density irregularities present in the plasmasphere and near the plasmapause. Electron density perturbations with amplitudes >10% from background density and with time‐scales less than 30‐min are investigated here as the small‐scale density irregularities. The statistical survey of the density irregularities is carried out using nearly 2 years of density data obtained from RBSP‐B and 4 months of data from Arase satellites. The results show that density irregularities are present globally at all MLT sectors and L‐shells both inside and outside the plasmapause, with a higher occurrence at L > 4. The occurrence of density irregularities is found to be higher during disturbed geomagnetic and interplanetary conditions. The case studies presented here revealed: (1) The plasmaspheric density irregularities observed during both quiet and disturbed conditions are found to coexist with the hot plasma sheet population. (2) During quiet periods, the plasma waves in the whistler‐mode frequency range are found to be modulated by the small‐scale density irregularities, with density depletions coinciding well with the decrease in whistler intensity. Our observations suggest that different source mechanisms are responsible for the generation of density structures at different MLTs and geomagnetic conditions.
Towards a Multi‐Platform Assimilative System for North Sea Biogeochemistry
Authors: Skákala Jozef , Ford David , Bruggeman Jorn , Hull Tom , Kaiser Jan , King Robert R. , Loveday Benjamin , Palmer Matthew R. , Smyth Tim , Williams Charlotte A. J. , Ciavatta Stefano 
Published: February 2021

AbstractOceanography has entered an era of new observing platforms, such as biogeochemical‐Argo floats and gliders, some of which will provide three‐dimensional maps of essential ecosystem variables on the North‐West European (NWE) Shelf. In a foreseeable future operational centers will use multi‐platform assimilation to integrate those valuable data into ecosystem reanalysis and forecast systems. Here we address some important questions related to glider biogeochemical data assimilation (DA) and introduce multi‐platform DA in a preoperational model of the NWE Shelf sea ecosystem. We test the impact of the different multi‐platform system components (glider vs. satellite, physical vs. biogeochemical) on the simulated biogeochemical variables. To characterize the model performance, we focus on the period around the phytoplankton spring bloom, since the bloom is a major ecosystem driver on the NWE Shelf. We found that the timing and magnitude of the phytoplankton bloom is insensitive to the physical DA, which is explained in the study. To correct the simulated phytoplankton bloom one needs to assimilate chlorophyll observations from glider or satellite Ocean Color (OC) into the model. Although outperformed by the glider chlorophyll assimilation, we show that OC assimilation has mostly desirable impact on the sub‐surface chlorophyll. Since the OC assimilation updates chlorophyll only in the mixed layer, the impact on the sub‐surface chlorophyll is the result of the model dynamical response to the assimilation. We demonstrate that the multi‐platform assimilation combines the advantages of its components and always performs comparably to its best performing component.
Paleoecology of Late Cretaceous Coccolithophores: Insights From the Shallow‐Marine Record
Authors: Püttmann Tobias , Mutterlose Jörg 
Published: February 2021

AbstractCoccolithophores, common primary producers in Mesozoic, Cenozoic, and present oceans, are significant components of the earth’s biogeochemical cycles. Being the most productive calcifying organism on earth, their carbonate oozes play a major role in fixing CO2, thereby forming the most important long‐term CO2 sink throughout the last 100 Ma. Our understanding of their fossil ancestors is mainly based on data from chalk sequences. Generally, the Cretaceous chalks were deposited at water depths of ≥200 m under stable, pelagic conditions. Here we report on remarkably diverse fossil coccolithophore assemblages from Cenomanian‐Campanian (100‐72 Ma) nearshore deposits, with estimated water depths of ≤40 m. For interpreting the findings in a broader paleoenvironmental context, we additionally analyzed contemporaneous chalk material from the Santonian‐Campanian (86‐72 Ma) interval. Highly diverse coccolithophore associations (50–81 species/sample) characterize the nearshore setting, while the contemporaneous chalk samples are less diverse (43–54 species/sample). The absolute abundances of coccoliths from the nearshore setting are by a factor 2–10 lower than those from the chalk, diversity indices are by 20%–30% higher (Shannon Index = 2.94–3.46) in the nearshore sediments. The presence of highly diverse coccolithophore communities in nearshore settings provides new insights into their paleoecology and evolution and the paleoceanography of the Late Cretaceous. Our data revise the traditional view of coccolithophores being typical open ocean dwellers. Extreme nearshore settings of the Late Cretaceous greenhouse world were characterized by environmental conditions equating those of the hemipelagic realm but supplying a larger variety of ecological niches.
Unbiased Estimates and Confidence Intervals for Riverine Loads
Authors: Tada Akio , Tanakamaru Haruya 
Published: February 2021

AbstractEstimating the uncertainty in annual riverine constituent loads, which is the mass that passes through a river cross‐section into a receiving water body, using infrequent water quality (WQ) observations is a difficult and unsolved task. Therefore, we propose an unbiased point estimation method and interval estimation method for river loads based on the rating curve (RC) method using importance sampling and the bootstrap method, respectively. In this paper, we first statistically explain the unbiasedness of load estimates using the proposed method. Second, the effectiveness of point and interval estimates by the proposed method is demonstrated for river loads from a small catchment and from large watersheds based on discharge and WQ data of solutes, nutrients, and suspended sediments with 10‐min to daily intervals. The results show that the proposed method provides unbiased estimates and appropriate coverage of confidence intervals regardless of the RC model used. The results also reveal that the dominant cause of bias in load estimates based on ordinary RC methods, such as the Loadest model, is not due to the poor simulation of observed loading rates by the RCs or because of the nonnormality of the regression residuals but rather improper sampling strategies. The proposed method is currently not feasible for WQ monitoring sites in large rivers due to the unmanageability of missing observations or censored data and an inefficient sampling strategy, although the requirement of unbiased estimation explained here can aid in scheduling high‐flow sampling for monitoring sites.
A modular hierarchical array camera
Authors: Yuan Xiaoyun , Ji Mengqi , Wu Jiamin , Brady David J. , Dai Qionghai , Fang Lu 
Published: February 2021

AbstractArray cameras removed the optical limitations of a single camera and paved the way for high-performance imaging via the combination of micro-cameras and computation to fuse multiple aperture images. However, existing solutions use dense arrays of cameras that require laborious calibration and lack flexibility and practicality. Inspired by the cognition function principle of the human brain, we develop an unstructured array camera system that adopts a hierarchical modular design with multiscale hybrid cameras composing different modules. Intelligent computations are designed to collaboratively operate along both intra- and intermodule pathways. This system can adaptively allocate imagery resources to dramatically reduce the hardware cost and possesses unprecedented flexibility, robustness, and versatility. Large scenes of real-world data were acquired to perform human-centric studies for the assessment of human behaviours at the individual level and crowd behaviours at the population level requiring high-resolution long-term monitoring of dynamic wide-area scenes.
Physiological dead space and alveolar ventilation in ventilated infants
Authors: Williams Emma , Dassios Theodore , Dixon Paul , Greenough Anne 
Published: February 2021

Abstract
Background
Dead space is the volume not taking part in gas exchange and, if increased, could affect alveolar ventilation if there is too low a delivered volume. We determined if there were differences in dead space and alveolar ventilation in ventilated infants with pulmonary disease or no respiratory morbidity.

Methods
A prospective study of mechanically ventilated infants was undertaken. Expiratory tidal volume and carbon dioxide levels were measured. Volumetric capnograms were constructed to calculate the dead space using the modified Bohr–Enghoff equation. Alveolar ventilation (VA) was also calculated.

Results
Eighty-one infants with a median (range) gestational age of 28.7 (22.4–41.9) weeks were recruited. The dead space [median (IQR)] was higher in 35 infants with respiratory distress syndrome (RDS) [5.7 (5.1–7.0) ml/kg] and in 26 infants with bronchopulmonary dysplasia (BPD) [6.4 (5.1–7.5) ml/kg] than in 20 term controls with no respiratory disease [3.5 (2.8–4.2) ml/kg, p < 0.001]. Minute ventilation was higher in both infants with RDS or BPD compared to the controls. VA in infants with RDS or BPD was similar to that of the controls [p = 0.54].

Conclusion
Prematurely born infants with pulmonary disease have a higher dead space than term controls, which may influence the optimum level during volume-targeted ventilation.

Impact

Measurement of the dead space was feasible in ventilated newborn infants.

The physiological dead space was a significant proportion of the delivered volume in ventilated infants.

The dead space (per kilogram) was higher in ventilated infants with respiratory distress syndrome or evolving bronchopulmonary dysplasia compared to term controls without respiratory disease.

The dead space volume should be considered when calculating the most appropriate volume during volume-targeted ventilation.
PLA2R1 promotes DNA damage and inhibits spontaneous tumor formation during aging
Authors: Huna Anda , Griveau Audrey , Vindrieux David , Jaber Sara , Flaman Jean-Michel , Goehrig Delphine , Azzi Lamia , Médard Jean-Jacques , Djebali Sophia , Hernandez-Vargas Hector , Dante Robert , Payen Léa , Marvel Jacqueline , Bertolino Philippe , Aubert Sébastien , Dubus Pierre , Bernard David 
Published: February 2021

AbstractAlthough aging is a major risk factor for most types of cancers, it is barely studied in this context. The transmembrane protein PLA2R1 (phospholipase A2 receptor) promotes cellular senescence, which can inhibit oncogene-induced tumor initiation. Functions and mechanisms of action of PLA2R1 during aging are largely unknown. In this study, we observed that old Pla2r1 knockout mice were more prone to spontaneously develop a wide spectrum of tumors compared to control littermates. Consistently, these knockout mice displayed increased Parp1, a master regulator of DNA damage repair, and decreased DNA damage, correlating with large human dataset analysis. Forced PLA2R1 expression in normal human cells decreased PARP1 expression, induced DNA damage and subsequent senescence, while the constitutive expression of PARP1 rescued cells from these PLA2R1-induced effects. Mechanistically, PARP1 expression is repressed by a ROS (reactive oxygen species)-Rb-dependent mechanism upon PLA2R1 expression. In conclusion, our results suggest that PLA2R1 suppresses aging-induced tumors by repressing PARP1, via a ROS–Rb signaling axis, and inducing DNA damage and its tumor suppressive responses.