bluuebunny/crossref_metadata_2025 huggingface dataset:
Børns adgange til legefællesskaber og legedeltagelse – set i en børnekulturel optik
Authors: Vilholm Fina , Schmidt Lene S.K.
Published: October 2024

I artiklen belyses de former for samspil, der opstår mellem legekulturer, udsathed og børns legedeltagelse i situationer, hvor børn befinder sig i periferien af et legefællesskab. Legefællesskaber henviser først og fremmest til, når det baserer sig på den selvorganiserede leg. Vi analyserer, hvordan det tager sig ud, når legedeltagelse i fællesskaber er udfordret set ud fra børne- og voksenperspektiver. Det sker med afsæt i to danske forskningsprojekter fra 2022. Artiklens empirinære analyser er baseret på et langvarigt etnografisk feltarbejde i en daginstitution (3- 6 år) og et etnografisk dybdeinterview med en forælder til et børnehavebarn fra en anden daginstitution. I daginstitutioner skabes pædagogisk institutionelle miljøer, hvor der udvikler sig forskellige former for kulturelle og sociale praksisser. Vi belyser med afsæt i to forskellige institutionelle miljøer, hvordan samspil mellem legekulturer, udsathed og børns adgange til legefællesskaber er kontekstuelle og situationelle. Når børn står i periferien af legefællesskaber, viser vi således, hvordan legedeltagelse ikke kan henføres til de enkelte børn alene. Derimod spiller det sammen med, i hvilken udstrækning der i de pædagogisk institutionelle miljøer er et blik for legens orden og børnekulturer i et givet fællesskab, og hvordan det opleves set fra voksen- og børneperspektiver.
Er der et hul i bogen? – om dramaleg, handlende fortolkning og (dør-)tærskler
Authors: Heiden Thomas Roed
Published: October 2024

Artiklens formål er at undersøge, hvad der sker i indskolingens litteraturundervisning, når (dør-)tærsklen mellem den »virkelige virkelighed« og den dramatiske fiktion overskrides i dramaleg. Det sker med udgangspunkt i to begivenheder, hvor eleverne i en 1.klasse og deres to lærere fortolker en billedbog om hekse med procesdrama og lærer-i-rolle, hvor eleven Mona får tårer i øjnene og hvor lærer Sif-i-rolle kaster op som-om. Begivenhederne er rammesat som kunstbaserede, autoetnografiske vignetter for at indfange de affektive påvirkninger, som griber eleverne, lærerne og mig som forsker i de betydningsskabende rum, som bliver til i sammenfiltringer af elever, lærere, tryllepinde, kapper, grøn plantesaft og en masse andre »ting og sager«. Artiklens centrale fund består i, hvordan lærerne selv leger med i den dramatiske fiktion og hvordan eleverne traderer og improviserer videre med oplevelser og erfaringer fra deres egen legekultur i handlende fortolkninger af billedbogen. Elevernes og lærernes leg med overskridelsen af virtuelle og stoflige tærskler i dramalegen engagerer og påvirker både dem selv og mig som forsker. Overskridelserne gør det muligt for eleverne gennem æstetiske formudtryk at gøre skolen til et mere autonomt rum, hvor de momentvis kan vende-op-og-ned på skolens institutionsdiskurs og formgive egne følelser og sansninger.
Brolopperne: Håbefulde fortællinger, om verdener der bliver til med teater, børn og pædagoger som skabende fællesskab
Authors: Sørensen Pernille Welent , Lund Mette Langeberg
Published: October 2024

Dagtilbuddet Brolopperne arbejder mod at blive en institution med kunst og kulturprofil i 2025. I 2022 indgik Brolopperne et partnerskab med Det Kongelige Teater, for blandt andet at udforske, hvordan scenekunst kan forankres i daginstitutionen gennem kontinuerlige møder. I denne artikel vil vi gerne vise nogle af mulighederne ved sådan et samarbejde. Muligheder for at børn, voksne og teater kan blive til i et børnekulturelt landskab.
Ved at anvende Donna Haraways forståelse om viden som situeret og om verden-skabelse i fællesskaber, ønsker vi at formidle nogle af de forskellige fortællinger der foregår i samarbejdet mellem Det Kongelige Teater og Dagtilbuddet Brolopperne. Fortællinger om, hvordan verden med teater, børn og pædagoger bliver til i konstante bevægelser og fortællinger, der forstyrrer ordner og modsætninger som stor/lille, barn/voksen, kunst/kultur, forsker/udforsket.
Fortællingerne om samarbejdet og dets betydning præsenteres i tre spor, det ene spor tager afsæt i pædagoger og ledelsens formuleringer, det andet tager afsæt i Det Kongelige Teaters (DKT) børneteams formuleringer, det tredje tager afsæt i forskerens teateroplevelse sammen med et barn fra Brolopperne. Vi ønsker ikke at fortolke og forklare de forskellige perspektiver, men snarere at invitere til at forbinde sig med de forskellige perspektiver og de muligheder de åbner op for.
Legemester – en digtsuite om at lege sammen med børn
Authors: Thestrup Klaus
Published: October 2024

– en digtsuite om at lege sammen med børn
The Poet-Creator of Philosophy: To the Methodology of Research in Philosophical Thought by Rabindranath Tagore
Authors: Skorokhodova Tatiana G.
Published: October 2024

The Indian poet and educator Rabindranath Tagore was the creator of an original philosophy that gives additional meaning to the picture of the history of Indian philosophy in the 20th century. He usually emphasized his identity as a poet and an artist, not considering himself a philosopher. However, Tagore embodies the phenomenon of a poet-thinker who comprehends universal philosophical problems and, in the process of philosophizing, offers his own vision of them. Moreover, he owns a number of texts of a religious-philosophical and socio-philosophical nature, in addition to the content of poetry and fiction. The philosophy created by the poet requires a comprehensive holistic study, which, in turn, raises the problem of research methodology. The article proposes the author's methodology for the reconstruction of Rabindranath Tagore's philosophy, based on an understanding of his personality, the contexts of thought and the hermeneutics of texts. The methodological model of philosophy reconstruction includes three levels. The first involves analyzing the personality of R. Tagore using the categories "cross-cultural thinker" and "problematic thinker". The second is a description of the contexts of his philosophizing: external general civilizational, internal epochal and internal biographical. The third is the hermeneutics of texts, taking into account the poetic component and the philosophical problems of speeches and fiction. The novelty of the described methodological model is due to the possibilities and prospects of reconstructing Tagore's philosophical thought and concepts. 1. Description of the phenomenon of a poet and writer creating a philosophy in which the experience of artistic creation generates a universal religious and social meaning and actualizes humanistic issues. 2. Presentation of the process of formation of cross-cultural philosophy of the XX century on the material of a particular thinker. 3. The analysis of the contexts of the unfolding of philosophy helps to trace the continuity of the thinker and his ideas with the Indian philosophical tradition in a broad sense and at the same time identify innovation, not least due to his dialogue with Western culture and modernity. 4. Seeing Tagore's philosophy as a kind of quintessence of the Bengali Renaissance heritage, it is not difficult to notice its significance and relevance for modernity. 5. Reconstruction along the proposed methodological path will open up not only direct, but also comparative prospects for studying Tagore's philosophical thought in comparison with the reflections of philosophers from different cultural areas, primarily peripheral to the West and non-Western ones.
Location- and feature-based selection histories make independent, qualitatively distinct contributions to urgent visuomotor performance
Authors: Oor Emily E , Salinas Emilio , Stanford Terrence R
Published: October 2024

Attention mechanisms that guide visuomotor behaviors are classified into three broad types according to their reliance on stimulus salience, current goals, and selection histories (i.e., recent experience with events of many sorts). These forms of attentional control are clearly distinct and multifaceted, but what is largely unresolved is how they interact dynamically to determine impending visuomotor choices. To investigate this, we trained two macaque monkeys to perform an urgent version of an oddball search task in which a red target appears among three green distracters, or vice versa. By imposing urgency, performance can be tracked continuously as it transitions from uninformed guesses to informed choices, and this, in turn, permits assessment of attentional control as a function of time. We found that the probability of making a correct choice was strongly modulated by the histories of preceding target colors and target locations. Crucially, although both effects were gated by success (or reward), the two variables played dynamically distinct roles: whereas location history promoted an early motor bias, color history modulated the later perceptual evaluation. Furthermore, target color and location influenced performance independently of each other. The results show that, when combined, selection histories can give rise to enormous swings in visuomotor performance even in simple tasks with highly discriminable stimuli.
HIV-1 Vif disrupts phosphatase feedback regulation at the kinetochore, leading to a pronounced pseudo-metaphase arrest
Authors: Ghone Dhaval , Evans Edward L , Bandini Madison , Stephenson Kaelyn G , Sherer Nathan M , Suzuki Aussie
Published: October 2024

Virion Infectivity Factor (Vif) of the Human Immunodeficiency Virus type 1 (HIV-1) targets and degrades cellular APOBEC3 proteins, key regulators of intrinsic and innate antiretroviral immune responses, thereby facilitating HIV-1 infection. While Vif’s role in degrading APOBEC3G is well-studied, Vif is also known to cause cell cycle arrest, but the detailed nature of Vif’s effects on the cell cycle has yet to be delineated. In this study, we employed high-temporal single-cell live imaging and super-resolution microscopy to monitor individual cells during Vif-induced cell cycle arrest. Our findings reveal that Vif does not affect the G2/M boundary as previously thought. Instead, Vif triggers a unique and robust pseudo-metaphase arrest, distinct from the mild prometaphase arrest induced by Vpr. During this arrest, chromosomes align properly and form the metaphase plate, but later lose alignment, resulting in polar chromosomes. Notably, Vif, unlike Vpr, significantly reduces the levels of both Protein Phosphatase 1 (PP1) and 2A (PP2A) at kinetochores, which regulate chromosome-microtubule interactions. These results unveil a novel role for Vif in kinetochore regulation that governs the spatial organization of chromosomes during mitosis.
Dual role of FOXG1 in regulating gliogenesis in the developing neocortex via the FGF signaling pathway
Authors: Bose Mahima , Talwar Ishita , Suresh Varun , Mishra Urvi , Biswas Shiona , Yadav Anuradha , Suryavanshi Shital T , Hippenmeyer Simon , Tole Shubha
Published: October 2024

In the developing vertebrate central nervous system, neurons and glia typically arise sequentially from common progenitors. Here, we report that the transcription factor Forkhead Box G1 (
Foxg1
) regulates gliogenesis in the mouse neocortex via distinct cell-autonomous roles in progenitors and in postmitotic neurons that regulate different aspects of the gliogenic FGF signalling pathway. We demonstrate that loss of
Foxg1
in cortical progenitors at neurogenic stages causes premature astrogliogenesis. We identify a novel FOXG1 target, the pro-gliogenic FGF pathway component
Fgfr3
that is suppressed by FOXG1 cell-autonomously to maintain neurogenesis. Furthermore, FOXG1 can also suppress premature astrogliogenesis triggered by the augmentation of FGF signalling. We identify a second novel function of FOXG1 in regulating the expression of gliogenic cues in newborn neocortical upper-layer neurons. Loss of FOXG1 in postmitotic neurons non-autonomously enhances gliogenesis in the progenitors via FGF signalling. These results fit well with the model that newborn neurons secrete cues that trigger progenitors to produce the next wave of cell types, astrocytes. If FGF signalling is attenuated in
Foxg1
null progenitors, they progress to oligodendrocyte production. Therefore, loss of FOXG1 transitions the progenitor to a gliogenic state, producing either astrocytes or oligodendrocytes depending on FGF signalling levels. Our results uncover how FOXG1 integrates extrinsic signalling via the FGF pathway to regulate the sequential generation of neurons, astrocytes, and oligodendrocytes in the cerebral cortex.
Inhibitory basal ganglia nuclei differentially innervate pedunculopontine nucleus subpopulations and evoke opposite motor and valence behaviors
Authors: Fallah Michel , Udobi Kenea C , Swiatek Aleksandra E , Scott Chelsea B , Evans Rebekah C
Published: October 2024

The canonical basal ganglia model predicts that the substantia nigra
pars reticulata
(SNr) and the globus pallidus
externa
(GPe) will have specific effects on locomotion: the SNr inhibiting locomotion and the GPe enhancing it. In this manuscript, we use
in vivo
optogenetics to show that a projection-defined neural subpopulation within each structure exerts non-canonical effects on locomotion. These non-canonical subpopulations are defined by their projection to the pedunculopontine nucleus (PPN) and mediate opposing effects on reward. To understand how these structures differentially modulate the PPN, we use
ex vivo
whole-cell recording with optogenetics to comprehensively dissect the SNr and GPe connections to regionally– and molecularly-defined populations of PPN neurons. The SNr inhibits all PPN subtypes, but most strongly inhibits caudal glutamatergic neurons. The GPe selectively inhibits caudal glutamatergic and GABAergic neurons, avoiding both cholinergic and rostral cells. This circuit characterization reveals non-canonical basal ganglia pathways for locomotion and valence.
The conserved ATPase PCH-2 controls the number and distribution of crossovers by antagonizing crossover formation in C. elegans
Authors: Patel Bhumil , Grobler Maryke , Herrera Alberto , Logari Elias , Ortiz Valery , Bhalla Needhi
Published: October 2024

Meiotic crossover recombination is essential for both accurate chromosome segregation and the generation of new haplotypes for natural selection to act upon. While the conserved role of the ATPase, PCH-2, during meiotic prophase has been enigmatic, a universal phenotype that is observed when
pch-2
or its orthologs are mutated is a change in the number and distribution of meiotic crossovers. Here, we show that PCH-2 controls the number and distribution of crossovers by antagonizing crossover formation. This antagonism produces different effects at different stages of meiotic prophase: early in meiotic prophase, PCH-2 prevents double strand breaks from becoming crossovers, limiting crossovers at sites of initial DSB formation and homolog interactions. Later in meiotic prophase, PCH-2 winnows the number of crossover-eligible intermediates, contributing to the reinforcement of crossover-eligible intermediates, designation of crossovers and ultimately, crossover assurance. We also demonstrate that PCH-2 accomplishes this regulation through the meiotic HORMAD, HIM-3. Our data strongly support a model in which PCH-2’s conserved role is to remodel meiotic HORMADs throughout meiotic prophase to destabilize crossover-eligible precursors, coordinate meiotic recombination with synapsis, and contribute to the progressive implementation of meiotic recombination, guaranteeing crossover control.
De novo-designed minibinders expand the synthetic biology sensing repertoire
Authors: Weinberg Zara Y , Soliman Sarah S , Kim Matthew S , Shah Devan H , Chen Irene P , Ott Melanie , Lim Wendell A , El-Samad Hana
Published: October 2024

Synthetic and chimeric receptors capable of recognizing and responding to user-defined antigens have enabled “smart” therapeutics based on engineered cells. These cell engineering tools depend on antigen sensors which are most often derived from antibodies. Advances in the
de novo
design of proteins have enabled the design of protein binders with the potential to target epitopes with unique properties and faster production timelines compared to antibodies. Building upon our previous work combining a
de novo
-designed minibinder of the Spike protein of SARS-CoV-2 with the synthetic receptor synNotch (SARSNotch), we investigated whether minibinders can be readily adapted to a diversity of cell engineering tools. We show that the Spike minibinder LCB1 easily generalizes to a next-generation proteolytic receptor SNIPR that performs similarly to our previously reported SARSNotch. LCB1-SNIPR successfully enables the detection of live SARS-CoV-2, an improvement over SARSNotch which can only detect cell-expressed Spike. To test the generalizability of minibinders to diverse applications, we tested LCB1 as an antigen sensor for a chimeric antigen receptor (CAR). LCB1-CAR enabled CD8+ T cells to cytotoxically target Spike-expressing cells. We further demonstrate that two other minibinders directed against the clinically relevant epidermal growth factor receptor are able to drive CAR-dependent cytotoxicity with efficacy similar to or better than an existing antibody-based CAR. Our findings suggest that minibinders represent a novel class of antigen sensors that have the potential to dramatically expand the sensing repertoire of cell engineering tools.
Factors Influencing the Skill Level of Primary Healthcare Workers in Managing Paediatric Emergencies
Authors: PO Suberu , KO Obohwemu , VY Soyobi , MG Yakpir , K Henry , I Ndioho
Published: October 2024

Paediatric emergencies continue to be a significant public health concern in Nigeria, particularly in rural areas where primary healthcare centers (PHCs) often serve as the sole source of medical care. The ability of healthcare workers in these settings to effectively manage paediatric emergencies is crucial for improving child health outcomes. This study aimed to assess the factors influencing the skill level of primary healthcare workers in managing paediatric emergencies in Zaria, Nigeria. A cross-sectional descriptive study was conducted among 139 randomly selected healthcare workers in Sabon Gari and Zaria Local Government Areas. A pre-tested questionnaire was used to collect data on socio-demographic characteristics, work experience, and skills in managing paediatric emergencies. Data were analyzed using SPSS version 21. The results revealed that healthcare workers in PHCs in Zaria exhibited varying levels of skills in managing paediatric emergencies. Several factors were identified as influencing their skill levels. Healthcare workers with higher academic qualifications demonstrated significantly better skills in managing paediatric emergencies. This suggests that formal education plays a crucial role in developing the necessary competencies. While experience can be a valuable asset, the study did not find a strong association between years of experience and skill levels. This may indicate that experience alone is not sufficient for developing the necessary skills, and additional training and support may be required. Healthcare workers who had received recent training or participated in continuing medical education (CME) programs related to paediatric emergency management tended to have higher skill levels. This highlights the importance of ongoing professional development in maintaining and improving skills. The findings of this study suggest that a combination of factors influences the skill level of primary healthcare workers in managing paediatric emergencies. While academic qualifications are important, ongoing training and access to resources are also essential. It is crucial to address these factors through targeted interventions to improve the skills of healthcare workers and enhance the quality of care provided to children in need. This study highlights the critical need for targeted interventions to improve the skills of primary healthcare workers in managing paediatric emergencies in Zaria, Nigeria. By addressing factors such as academic qualifications, training, resource availability, and work environment, policymakers and healthcare providers can significantly enhance the quality of care provided to children in need.
Surgical Treatment of Haemorrhoids: Stapled Haemorrhoidopexy versus Conventional Excisional Haemorrhoidectomy - A Clinical Outcome Analysis
Authors: Lima Ismat Jahan
Published: October 2024

Background: Hemorrhoids are a common anorectal condition that often requires surgical intervention for thirddegree cases when conservative treatments fail. Although stapled haemorrhoidopexy and conventional excisional hemorrhoidectomy are widely used, uncertainty remains about which technique is superior. This study compares the short- and long-term outcomes of these procedures, focusing on recovery time, pain, and complications to clarify the optimal surgical approach. Materials and Methods: An open-label randomized controlled trial was conducted at Bangabandhu Sheikh Mujib Medical University (BSMMU) over 12 months. Eighty-two patients with third-degree hemorrhoids were randomly assigned to undergo either stapled haemorrhoidopexy or conventional excisional hemorrhoidectomy. Primary outcomes were operating time, postoperative pain, and recovery period, while secondary outcomes included symptom improvement and complications. Data analysis was performed using SPSS, with statistical significance at p < 0.05. Results: Group A had a significantly shorter operating time (16.5 vs. 25 minutes, p = 0.001) and less postoperative pain, with 42.9% reporting severe pain at 4 hours post-surgery compared to 95.2% in Group B (p = 0.001). By day 15, 95.2% of Group A experienced mild pain, while 64.3% of Group B reported moderate pain (p = 0.001). Group A also had a faster recovery, with a median pain-free defecation time of 7 days versus 18.5 days for Group B (p = 0.001). Urinary retention was more common in Group B (50% vs. 19%, p = 0.003), while recurrence of mucosal prolapse was lower in Group A (21.4% at 6 months, p < 0.01). Conclusion: Stapled haemorrhoidopexy provides faster recovery and less pain but has a lower recurrence of mucosal prolapse compared to conventional hemorrhoidectomy. Surgical decisions should balance short-term benefits with long-term risks.
miRNA‐mediated ‘tug‐of‐war’ model reveals ceRNA propensity of genes in cancers
Authors: Swain Arpit Chandan , Mallick Bibekanand
Published: March 2018

Competing endogenous RNA (ceRNA) are transcripts that cross‐regulate each other at the post‐transcriptional level by competing for shared microRNA response elements (MREs). These have been implicated in various biological processes impacting cell‐fate decisions and diseases including cancer. There are several studies that predict possible ceRNA pairs by adopting various machine‐learning and mathematical approaches; however, there is no method that enables us to gauge as well as compare the propensity of the ceRNA of a gene and precisely envisages which among a pair exerts a stronger pull on the shared miRNA pool. In this study, we developed a method that uses the ‘tug of war of genes’ concept to predict and quantify ceRNA potential of a gene for the shared miRNA pool in cancers based on a score represented by SoCeR (score of competing endogenous RNA). The method was executed on the RNA‐Seq transcriptional profiles of genes and miRNA available at TCGA along with CLIP‐supported miRNA‐target sites to predict ceRNA in 32 cancer types which were validated with already reported cases. The proposed method can be used to determine the sequestering capability of the gene of interest as well as in ranking the probable ceRNA candidates of a gene. Finally, we developed standalone applications (SoCeR tool) to aid researchers in easier implementation of the method in analysing different data sets or diseases.
Dynamics of Internal Tides Over a Shallow Ridge Investigated With a High‐Resolution Downscaling Regional Ocean Model
Authors: Masunaga Eiji , Uchiyama Yusuke , Suzue Yota , Yamazaki Hidekatsu
Published: March 2018

This study investigates the dynamics of tidally induced internal waves over a shallow ridge, the Izu‐Ogasawara Ridge off the Japanese mainland, using a downscaled high‐resolution regional ocean numerical model. Both the Kuroshio and tides contribute to the field of currents in the study area. The model results show strong internal tidal energy fluxes over the ridge, exceeding 3.5 kW m−1, which are higher than the fluxes along the Japanese mainland. The flux in the upstream side of the Kuroshio is enhanced by an interaction of internal waves and currents. The tidal forcing induces 92% of the total internal wave energy flux, exhibiting the considerable dominance of tides in internal waves. The tidal forcing enhances the kinetic energy, particularly in the northern area of the ridge where the Kuroshio Current is not a direct influence. The tidal forcing contributes to roughly 30% of the total kinetic energy in the study area.
Pore‐Scale Reconstruction and Simulation of Non‐Darcy Flow in Synthetic Porous Rocks
Authors: Zhao Yixin , Zhu Guangpei , Zhang Cun , Liu Shimin , Elsworth Derek , Zhang Tong
Published: March 2018

We image synthetic porous rocks of varied porosity and pore size by micro–computed tomography with pore‐scale finite element modeling representing the pore space for single‐phase fluid flow. The simulations quantify the key features of microscale flow behavior in the synthetic cores. The smaller the permeability, the greater the critical pressure gradient required for the onset of non‐Darcy fluid flows, and the easier the emergence of nonlinear seepage within the tested cores. The relationship between permeability and porosity from different methods shows a power law correlation with pressure. Structural heterogeneity and anisotropy of the pore systems are shown to have a significant impact on transport through the three‐dimensional pore model—exhibiting irregular flow fields. The simulated permeabilities of the tested cores vary by a factor of 2–5 depending on the fluid flow directions. With the increase of flow seepage velocity, the flow regime deviates from Darcy linear relationship and non‐Darcy behavior (inertia) leads to a reduction in the effective permeability of the core. Both experiments and modeling demonstrate that the larger the porosity and permeability, the stronger the non‐linear phenomenon of the seepage within the pore space. A method is proposed to estimate the non‐Darcy coefficient β based on simulation results, which provides a good prediction for all the tested cores. A new equation is established to predict the transition of flow patterns as a function of the apparent permeability K* and Reynolds number Re. The K*‐Re model provides a theoretical approach to dynamically describe the transition from Darcy to Forchheimer flow.
Quantifying the Impacts of Subpixel Reflectance Variability on Cloud Optical Thickness and Effective Radius Retrievals Based On High‐Resolution ASTER Observations
Authors: Werner F. , Zhang Z. , Wind G. , Miller D. J. , Platnick S.
Published: March 2018

Recently, Zhang et al. (2016, https://doi.org/10.1002/2016JD024837) presented a mathematical framework based on a second‐order Taylor series expansion in order to quantify the plane‐parallel homogeneous bias (PPHB) in cloud optical thickness (τ) and effective droplet radius (reff) retrieved from the bispectral solar reflective method. This study provides observational validation of the aforementioned framework, using high‐resolution reflectance observations from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) over 48 marine boundary layer cloud scenes. ASTER reflectances at a horizontal resolution of 30 m are aggregated up to a scale of 1,920 m, providing retrievals of τ and reff at different spatial resolutions. A comparison between the PPHB derived from these retrievals and the predicted PPHB from the mathematical framework reveals a good agreement with correlation coefficients of r > 0.97 (for Δτ) and r > 0.79 (for Δreff). To test the feasibility of PPHB predictions for present and future satellite missions, a scale analysis with varying horizontal resolutions of the subpixel and pixel‐level observations is performed, followed by tests of corrections with only limited observational high‐resolution data. It is shown that for reasonably thick clouds with a mean subpixel τ larger than 5, correlations between observed and predicted PPHB remain high, even if the number of available subpixels decreases or just a single band provides the information about subpixel reflectance variability. Only for thin clouds the predicted Δreff become less reliable, which can be attributed primarily to an increased retrieval uncertainty for reff.
Temporal Coupling of Subsurface and Surface Soil CO2 Fluxes: Insights From a Nonsteady State Model and Cross‐Wavelet Coherence Analysis
Authors: Samuels-Crow Kimberly E. , Ryan Edmund , Pendall Elise , Ogle Kiona
Published: March 2018

Inferences about subsurface CO2 fluxes often rely on surface soil respiration (Rsoil) estimates because directly measuring subsurface microbial and root respiration (collectively, CO2 production, STotal) is difficult. To evaluate how well Rsoil serves as a proxy for STotal, we applied the nonsteady state DEconvolution of Temporally varying Ecosystem Carbon componenTs model (0.01‐m vertical resolution), using 6‐hourly data from a Wyoming grassland, in six simulations that cross three soil types (clay, sandy loam, and sandy) with two depth distributions of subsurface biota. We used cross‐wavelet coherence analysis to examine temporal coherence (localized linear correlation) and offsets (lags) between STotal and Rsoil and fluxes and drivers (e.g., soil temperature and moisture). Cross‐wavelet coherence revealed higher coherence between fluxes and drivers than linear regressions between concurrent variables. Soil texture and moisture exerted the strongest controls over coherence between CO2 fluxes. Coherence between CO2 fluxes in all soil types was strong at short (~1 day) and long periods (>8 days), but soil type controlled lags, and rainfall events decoupled the fluxes at periods of 1–8 days for several days in sandy soil, up to 1 week in sandy loam, and for a month or more in clay soil. Concentrating root and microbial biomass nearer the surface decreased lags in all soil types and increased coherence up to 10% in clay soil. The assumption of high temporal coherence between Rsoil and STotal is likely valid in dry, sandy soil, but may lead to underestimates of short‐term STotal in semiarid grasslands with fine‐grained and/or wet soil.
A Fourier Method for Sidelobe Reduction in Equally Spaced Linear Arrays
Authors: Safaai‐Jazi Ahmad , Stutzman Warren L.
Published: March 2018

Uniformly excited, equally spaced linear arrays have a sidelobe level larger than −13.3 dB, which is too high for many applications. This limitation can be remedied by nonuniform excitation of array elements. We present an efficient method for sidelobe reduction in equally spaced linear arrays with low penalty on the directivity. The method involves the following steps: construction of a periodic function containing only the sidelobes of the uniformly excited array, calculation of the Fourier series of this periodic function, subtracting the series from the array factor of the original uniformly excited array after it is truncated, and finally mitigating the truncation effects which yields significant increase in sidelobe level reduction. A sidelobe reduction factor is incorporated into element currents that makes much larger sidelobe reductions possible and also allows varying the sidelobe level incrementally. It is shown that such newly formed arrays can provide sidelobe levels that are at least 22.7 dB below those of the uniformly excited arrays with the same size and number of elements. Analytical expressions for element currents are presented. Radiation characteristics of the sidelobe‐reduced arrays introduced here are examined, and numerical results for directivity, sidelobe level, and half‐power beam width are presented for example cases. Performance improvements over popular conventional array synthesis methods, such as Chebyshev and linear current tapered arrays, are obtained with the new method.
GITM‐Data Comparisons of the Depletion and Enhancement During the 2017 Solar Eclipse
Authors: Wu Chen , Ridley A. J. , Goncharenko Larisa , Chen Gang
Published: March 2018

The total solar eclipse of 21 August 2017 was simulated with the Global Ionosphere‐Thermosphere Model (GITM), and the results were compared with the total electron content (TEC) measurements provided by the Global Navigation Satellite System, as well as F2 layer peak electron density (NmF2) derived from six ionosondes. TEC decreased over North America by ~54.3% in the model and ~57.6% in measurements, and NmF2 decreased by ~20–50% in the model and ~40–60% in the measurements. GITM predicted a posteclipse enhancement of ~10% in TEC and NmF2, consistent with observations which suggested an increase of ~10–25% in TEC and ~10–40% in NmF2. GITM showed that the divergence of horizontal winds drove the increase in Oxygen after the eclipse allowing an increase in the ionization rate. The slower charge exchange due to both the decreased ion temperature and N2 density allowed an increase of O+ density in the F region also.
Depth‐Resolved Physicochemical Characteristics of Active Layer and Permafrost Soils in an Arctic Polygonal Tundra Region
Authors: Wu Yuxin , Ulrich Craig , Kneafsey Timothy , Lopez Robin , Chou Chunwei , Geller Jil , McKnight Katie , Dafflon Baptiste , Soom Florian , Peterson John , Hubbard Susan
Published: March 2018

Permafrost physicochemical parameters play a key role in controlling the response of permafrost carbon to climate change. We studied the physicochemical parameters of permafrost in an Arctic tundra region to evaluate (1) how soil parameters vary with depth and whether and how they are interrelated, (2) whether and how permafrost soil differs from its overlaying active layer, and (3) whether soil property‐depth relationships are different across geomorphic features (e.g., low, flat, and high centered polygons). We also explored the possible biogeochemical processes that led to these soil characteristics and how they may affect biogeochemical reactions upon permafrost thaw. We observed (1) consistent relationships between soil property and depth and between major parameters, (2) large contrasts of key soil parameters between active layer and permafrost, indicative of potentially different response of the permafrost carbon to warming when compared to the active layer, and (3) a correlation between soil hydraulic conductivity and topographic features that impacts soil hydrologic processes. Our analysis suggests that the permafrost has a marine‐derived chemical signature that differs from the active layer and shapes the physicochemical fingerprints of the different geomorphic features. Specifically, we revealed the unique signatures of the high center polygons, indicative of possible microbial activity at depth (>1 m). Our study suggested consistent key soil parameter‐depth correlations while demonstrating complex lateral and vertical variabilities. These results are valuable for identifying approaches to upscale point‐based measurements and for improving model parameterization to predict permafrost carbon behavior and feedback under future climate.
Anticancer activity of the protein kinase C modulator HMI‐1a3 in 2D and 3D cell culture models of androgen‐responsive and androgen‐unresponsive prostate cancer
Authors: Jäntti Maria H. , Talman Virpi , Räsänen Kati , Tarvainen Ilari , Koistinen Hannu , Tuominen Raimo K.
Published: March 2018

Prostate cancer is one of the most common cancers in men. Although it has a relatively high 5‐year survival rate, development of resistance to standard androgen‐deprivation therapy is a significant clinical problem. Therefore, novel therapeutic strategies are urgently needed. The protein kinase C (PKC) family is a putative prostate cancer drug target, but so far no PKC‐targeting drugs are available for clinical use. By contrast to the standard approach of developing PKC inhibitors, we have developed isophthalate derivatives as PKC agonists. In this study, we have characterized the effects of the most potent isophthalate, 5‐(hydroxymethyl)isophthalate 1a3 (HMI‐1a3), on three prostate cancer cell lines (LNCaP, DU145, and PC3) using both 2D and 3D cell culture models. In 2D cell culture, HMI‐1a3 reduced cell viability or proliferation in all cell lines as determined by the metabolic activity of the cells (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide assay) and thymidine incorporation. However, the mechanism of action in LNCaP cells was different to that in DU145 or PC3 cells. In LNCaP cells, HMI‐1a3 induced a PKC‐dependent activation of caspase 3/7, indicating an apoptotic response, whereas in DU145 and PC3 cells, it induced senescence, which was independent of PKC. This was observed as typical senescent morphology, increased β‐galactosidase activity, and upregulation of the senescence marker p21 and downregulation of E2F transcription factor 1. Using a multicellular spheroid model, we further showed that HMI‐1a3 affects the growth of LNCaP and DU145 cells in a 3D culture, emphasizing its potential as a lead compound for cancer drug development.
A noncanonical function of histidyl‐tRNA synthetase: inhibition of vascular hyperbranching during zebrafish development
Authors: Ni Rui , Luo Lingfei
Published: March 2018

Histidyl‐tRNA synthetase (Hars) catalyzes the ligation of histidine residues to cognate tRNA. Here, we demonstrate a noncanonical function of Hars in vascular development in zebrafish. We obtained a novel zebrafish cq34 mutant which exhibited hyperbranching of cranial and intersegmental blood vessels 48 h after fertilization. The gene responsible for this phenotype was identified as hars. We found the increased expression of cdh5 and vegfa in the harscq34 mutant. Knockdown of cdh5 in the mutant reduced disordered connections of the hindbrain capillaries. Inhibition of vascular endothelial growth factor signaling suppressed the abnormal vascular branching observed in the mutant. Moreover, the human HARS mRNA rescued the vascular defects in the cq34 mutant. Thus, the noncanonical function of Hars regulates vascular development, mainly by modulating expression of cdh5 and vegfa.
Redox properties of Cys2His2 and Cys4 zinc fingers determined by electrospray ionization mass spectrometry
Authors: Smirnova Julia , Kabin Ekaterina , Tõugu Vello , Palumaa Peep
Published: March 2018

Zinc finger (ZF) protein motifs, stabilized by binding of Zn(II), typically function as interaction modules that bind nucleic acids, proteins and other molecules. The elucidation of the redox states of ZF proteins in cellular conditions, which depend on their midpoint redox potentials, is important for understanding of ZF functioning. In the present study we determined the midpoint redox potentials for representatives of Cys2His2 and Cys4 types of ZF proteins in apo and Zn(II)‐bound forms using electrospray ionization mass spectrometry. The midpoint redox potentials of the apo forms of Cys2His2 and Cys4 ZF proteins were −326 and −365 mV (pH 7.5), respectively. These values are close to the cytosolic redox potential of approx. −350 mV (pH 7.5) and thus we can conclude that the apo form of Cys2His2‐type ZF proteins is predominantly reduced but apo forms of Cys4‐type ZF proteins should be substantially oxidized in the cytoplasm. As expected, Zn(II) binding stabilized the reduced forms of both ZF proteins: the corresponding redox potential values were −284 and −301 mV, respectively. Consequently, binding of Zn(II) ions to ZF motifs can act as a sensitive switch that activates the functioning of the ZF motifs within the cell, and also protects them from oxidation and can function as part of a redox‐sensitive regulation mechanism of cellular functions.
Improved Conventional PCR Assay for Detecting Tetracapsuloides bryosalmonae DNA in Fish Tissues
Authors: Hutchins Patrick R. , Sepulveda Adam J. , Martin Renee M. , Hopper Lacey R.
Published: March 2018

Conventional PCR is an established method to detect Tetracapsuloides bryosalmonaeDNA in fish tissues and to confirm diagnosis of proliferative kidney disease (PKD) caused by T. bryosalmonae. However, the commonly used PKX5f-6r primers were designed with the intention of obtaining sequence information and are suboptimal for determining parasite DNA presence. A new PCR assay to detect T. bryosalmonae 18s rDNA, PKX18s1266f-1426r, is presented that demonstrates specificity, repeatability, and enhanced sensitivity over the PKX5f-6r assay. The limit of detection of the PKX18s1266f-1426r assay at 95% confidence was 100 template copies, and the new primers detected parasite DNA more consistently at template concentrations below 100 copies than did PKX5f-6r. The PKX18s1266f-1426r also achieved 100% detection at sample DNA concentrations one order of magnitude lower than PKX5f-6r. Out of 127 salmonid fish with unknown T. bryosalmonae infection status, PKX5f-6r detected 35 positive samples, while the new assay detected 43. The discrepancy in T. bryosalmonae detection between the two primer sets may be attributed to several differences between the assays, including oligonucleotide melting temperatures, the use of a touchdown PCR thermal cycle, and amplicon length.
Comparison of measured electron energy spectra for six matched, radiotherapy accelerators
Authors: McLaughlin David J. , Hogstrom Kenneth R. , Neck Daniel W. , Gibbons John P.
Published: March 2018

This study compares energy spectra of the multiple electron beams of individual radiotherapy machines, as well as the sets of spectra across multiple matched machines. Also, energy spectrum metrics are compared with central‐axis percent depth‐dose (PDD) metrics.

Methods

A lightweight, permanent magnet spectrometer was used to measure energy spectra for seven electron beams (7–20 MeV) on six matched Elekta Infinity accelerators with the MLCi2 treatment head. PDD measurements in the distal falloff region provided R50 and R80–20 metrics in Plastic Water®, which correlated with energy spectrum metrics, peak mean energy (PME) and full‐width at half maximum (FWHM).

Results

Visual inspection of energy spectra and their metrics showed whether beams on single machines were properly tuned, i.e., FWHM is expected to increase and peak height decrease monotonically with increased PME. Also, PME spacings are expected to be approximately equal for 7–13 MeV beams (0.5‐cm R90 spacing) and for 13–16 MeV beams (1.0‐cm R90 spacing). Most machines failed these expectations, presumably due to tolerances for initial beam matching (0.05 cm in R90; 0.10 cm in R80–20) and ongoing quality assurance (0.2 cm in R50). Also, comparison of energy spectra or metrics for a single beam energy (six machines) showed outlying spectra. These variations in energy spectra provided ample data spread for correlating PME and FWHM with PDD metrics. Least‐squares fits showed that R50 and R80–20 varied linearly and supralinearly with PME, respectively; however, both suggested a secondary dependence on FWHM. Hence, PME and FWHM could serve as surrogates for R50 and R80–20 for beam tuning by the accelerator engineer, possibly being more sensitive (e.g., 0.1 cm in R80–20 corresponded to 2.0 MeV in FWHM).

Conclusions

Results of this study suggest a lightweight, permanent magnet spectrometer could be a useful beam‐tuning instrument for the accelerator engineer to (a) match electron beams prior to beam commissioning, (b) tune electron beams for the duration of their clinical use, and (c) provide estimates of PDD metrics following machine maintenance. However, a real‐time version of the spectrometer is needed to be practical.
Modeling of the metallic port in breast tissue expanders for photon radiotherapy
Authors: Yoon Jihyung , Xie Yibo , Heins David , Zhang Rui
Published: March 2018

The purpose of this study was to model the metallic port in breast tissue expanders and to improve the accuracy of dose calculations in a commercial photon treatment planning system (TPS). The density of the model was determined by comparing TPS calculations and ion chamber (IC) measurements. The model was further validated and compared with two widely used clinical models by using a simplified anthropomorphic phantom and thermoluminescent dosimeters (TLD) measurements. Dose perturbations and target coverage for a single postmastectomy radiotherapy (PMRT) patient were also evaluated. The dimensions of the metallic port model were determined to be 1.75 cm in diameter and 5 mm in thickness. The density of the port was adjusted to be 7.5 g/cm3 which minimized the differences between IC measurements and TPS calculations. Using the simplified anthropomorphic phantom, we found the TPS calculated point doses based on the new model were in agreement with TLD measurements within 5.0% and were more accurate than doses calculated based on the clinical models. Based on the photon treatment plans for a real patient, we found that the metallic port has a negligible dosimetric impact on chest wall, while the port introduced significant dose shadow in skin area. The current clinical port models either overestimate or underestimate the attenuation from the metallic port, and the dose perturbation depends on the plan and the model in a complex way. TPS calculations based on our model of the metallic port showed good agreement with measurements for all cases. This new model could improve the accuracy of dose calculations for PMRT patients who have temporary tissue expanders implanted during radiotherapy and could potentially reduce the risk of complications after the treatment.
Mechanical Considerations for Electrospun Nanofibers in Tendon and Ligament Repair
Authors: Brennan David A. , Conte Adriano A. , Kanski Gregory , Turkula Stefan , Hu Xiao , Kleiner Matthew T. , Beachley Vince
Published: March 2018

Electrospun nanofibers possess unique qualities such as nanodiameter, high surface area to volume ratio, biomimetic architecture, and tunable chemical and electrical properties. Numerous studies have demonstrated the potential of nanofibrous architecture to direct cell morphology, migration, and more complex biological processes such as differentiation and extracellular matrix (ECM) deposition through topographical guidance cues. These advantages have created great interest in electrospun fibers for biomedical applications, including tendon and ligament repair. Electrospun nanofibers, despite their nanoscale size, generally exhibit poor mechanical properties compared to larger conventionally manufactured polymer fiber materials. This invites the question of what role electrospun polymer nanofibers can play in tendon and ligament repair applications that have both biological and mechanical requirements. At first glance, the strength and stiffness of electrospun nanofiber grafts appear to be too low to fill the rigorous loading conditions of these tissues. However, there are a number of strategies to enhance and tune the mechanical properties of electrospun nanofiber grafts. As researchers design the next‐generation electrospun tendon and ligament grafts, it is critical to consider numerous physiologically relevant mechanical criteria and to evaluate graft mechanical performance in conditions and loading environments that reflect in vivo conditions and surgical fixation methods.