bluuebunny/crossref_metadata_2025_split huggingface dataset:
The predominance of nucleotidyl activation in bacterial phosphonate biosynthesis
Authors: Rice Kyle , Batul Kissa , Whiteside Jacqueline , Kelso Jayne , Papinski Monica , Schmidt Edward , Pratasouskaya Alena , Wang Dacheng , Sullivan Rebecca , Bartlett Christopher , Weadge Joel T. , Van der Kamp Marc W. , Moreno-Hagelsieb Gabriel , Suits Michael D. , Horsman Geoff P. 
Published: August 2019

AbstractPhosphonates are rare and unusually bioactive natural products. However, most bacterial phosphonate biosynthetic capacity is dedicated to tailoring cell surfaces with molecules like 2-aminoethylphosphonate (AEP). Although phosphoenolpyruvate mutase (Ppm)-catalyzed installation of C-P bonds is known, subsequent phosphonyl tailoring (Pnt) pathway steps remain enigmatic. Here we identify nucleotidyltransferases in over two-thirds of phosphonate biosynthetic gene clusters, including direct fusions to ~60% of Ppm enzymes. We characterize two putative phosphonyl tailoring cytidylyltransferases (PntCs) that prefer AEP over phosphocholine (P-Cho) – a similar substrate used by the related enzyme LicC, which is a virulence factor in Streptococcus pneumoniae. PntC structural analyses reveal steric discrimination against phosphocholine. These findings highlight nucleotidyl activation as a predominant chemical logic in phosphonate biosynthesis and set the stage for probing diverse phosphonyl tailoring pathways.
A signal motif retains Arabidopsis ER-α-mannosidase I in the cis-Golgi and prevents enhanced glycoprotein ERAD
Authors: Schoberer Jennifer , König Julia , Veit Christiane , Vavra Ulrike , Liebminger Eva , Botchway Stanley W. , Altmann Friedrich , Kriechbaumer Verena , Hawes Chris , Strasser Richard 
Published: August 2019

AbstractThe Arabidopsis ER-α-mannosidase I (MNS3) generates an oligomannosidic N-glycan structure that is characteristically found on ER-resident glycoproteins. The enzyme itself has so far not been detected in the ER. Here, we provide evidence that in plants MNS3 exclusively resides in the Golgi apparatus at steady-state. Notably, MNS3 remains on dispersed punctate structures when subjected to different approaches that commonly result in the relocation of Golgi enzymes to the ER. Responsible for this rare behavior is an amino acid signal motif (LPYS) within the cytoplasmic tail of MNS3 that acts as a specific Golgi retention signal. This retention is a means to spatially separate MNS3 from ER-localized mannose trimming steps that generate the glycan signal required for flagging terminally misfolded glycoproteins for ERAD. The physiological importance of the very specific MNS3 localization is demonstrated here by means of a structurally impaired variant of the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1.
WHAMM initiates autolysosome tubulation by promoting actin polymerization on autolysosomes
Authors: Dai Anbang , Yu Li , Wang Hong-Wei 
Published: August 2019

AbstractWHAMM, a member of the Wiskott-Aldrich syndrome protein (WASP) family, is an actin nucleation promoting factor (NPF) that also associates with membranes and microtubules. Here we report that WHAMM is required for autophagic lysosome reformation (ALR). WHAMM knockout causes impairment of autolysosome tubulation, which results in accumulation of enlarged autolysosomes during prolonged starvation. Mechanistically, WHAMM is recruited to the autolysosome membrane through its specific interaction with PI(4,5)P2. WHAMM then works as an NPF which promotes assembly of an actin scaffold on the surface of the autolysosome to promote autolysosome tubulation. Our study demonstrates an unexpected role of the actin scaffold in regulating autophagic lysosome reformation.
Ca2+-regulated Ca2+ channels with an RCK gating ring control plant symbiotic associations
Authors: Kim Sunghoon , Zeng Weizhong , Bernard Shane , Liao Jun , Venkateshwaran Muthusubramanian , Ane Jean-Michel , Jiang Youxing 
Published: August 2019

AbstractA family of plant nuclear ion channels, including DMI1 (Does not Make Infections 1) and its homologs CASTOR and POLLUX, are required for the establishment of legume-microbe symbioses by generating nuclear and perinuclear Ca2+ spiking. Here we show that CASTOR from Lotus japonicus is a highly selective Ca2+ channel whose activation requires cytosolic/nucleosolic Ca2+, contrary to the previous suggestion of it being a K+ channel. Structurally, the cytosolic/nucleosolic ligand-binding soluble region of CASTOR contains two tandem RCK (Regulator of Conductance for K+) domains, and four subunits assemble into the gating ring architecture, similar to that of large conductance, Ca2+-gated K+ (BK) channels despite the lack of sequence similarity. Multiple ion binding sites are clustered at two locations within each subunit, and three of them are identified to be Ca2+ sites. Our in vitro and in vivo assays also demonstrate the importance of these gating-ring Ca2+ binding sites to the physiological function of CASTOR as well as DMI1.
Synthesis of radiaannulene oligomers to model the elusive carbon allotrope 6,6,12-graphyne
Authors: Kilde Martin Drøhse , Murray Adrian H. , Andersen Cecilie Lindholm , Storm Freja Eilsø , Schmidt Katrin , Kadziola Anders , Mikkelsen Kurt V. , Hampel Frank , Hammerich Ole , Tykwinski Rik R. , Nielsen Mogens Brøndsted 
Published: August 2019

AbstractGraphyne allotropes of carbon are fascinating materials, and their electronic properties are predicted to rival those of the “wonder material” graphene. One allotrope of graphyne, having rectangular symmetry rather than hexagonal, stands out as particularly attractive, namely 6,6,12-graphyne. It is currently an insurmountable challenge, however, to design and execute a synthesis of this material. Herein, we present synthesis and electronic properties of molecules that serve as model compounds. These oligomers, so-called radiaannulenes, are prepared by iterative acetylenic coupling reactions. Systematic optical and redox studies indicate the effective conjugation length of the radiaannulene oligomers is nearly met by the length of the trimer. The HOMO-LUMO gap suggested by the series of oligomers is still, however, higher than that expected for 6,6,12-graphyne from theory, which predicts two nonequivalent distorted Dirac cones (no band gap). Thus, the radiaannulene oligomers present a suitable length in one dimension of a sheet, but should be expanded in the second dimension to provide a unique representation of 6,6,12-graphyne.
Plant circadian rhythms regulate the effectiveness of a glyphosate-based herbicide
Authors: Belbin Fiona E. , Hall Gavin J. , Jackson Amelia B. , Schanschieff Florence E. , Archibald George , Formstone Carl , Dodd Antony N. 
Published: August 2019

AbstractHerbicides increase crop yields by allowing weed control and harvest management. Glyphosate is the most widely-used herbicide active ingredient, with $11 billion spent annually on glyphosate-containing products applied to >350 million hectares worldwide, using about 8.6 billion kg of glyphosate. The herbicidal effectiveness of glyphosate can depend upon the time of day of spraying. Here, we show that the plant circadian clock regulates the effectiveness of glyphosate. We identify a daily and circadian rhythm in the inhibition of plant development by glyphosate, due to interaction between glyphosate activity, the circadian oscillator and potentially auxin signalling. We identify that the circadian clock controls the timing and extent of glyphosate-induced plant cell death. Furthermore, the clock controls a rhythm in the minimum effective dose of glyphosate. We propose the concept of agricultural chronotherapy, similar in principle to chronotherapy in medical practice. Our findings provide a platform to refine agrochemical use and development, conferring future economic and environmental benefits.
Memory-guided microsaccades
Authors: Willeke Konstantin F. , Tian Xiaoguang , Buonocore Antimo , Bellet Joachim , Ramirez-Cardenas Araceli , Hafed Ziad M. 
Published: August 2019

AbstractDespite strong evidence to the contrary in the literature, microsaccades are overwhelmingly described as involuntary eye movements. Here we show in both human subjects and monkeys that individual microsaccades of any direction can easily be triggered: (1) on demand, based on an arbitrary instruction, (2) without any special training, (3) without visual guidance by a stimulus, and (4) in a spatially and temporally accurate manner. Subjects voluntarily generated instructed “memory-guided” microsaccades readily, and similarly to how they made normal visually-guided ones. In two monkeys, we also observed midbrain superior colliculus neurons that exhibit movement-related activity bursts exclusively for memory-guided microsaccades, but not for similarly-sized visually-guided movements. Our results demonstrate behavioral and neural evidence for voluntary control over individual microsaccades, supporting recently discovered functional contributions of individual microsaccade generation to visual performance alterations and covert visual selection, as well as observations that microsaccades optimize eye position during high acuity visually-guided behavior.
Distinct microbial communities that differ by race, stage, or breast-tumor subtype in breast tissues of non-Hispanic Black and non-Hispanic White women
Authors: Smith Alana , Pierre Joseph F. , Makowski Liza , Tolley Elizabeth , Lyn-Cook Beverly , Lu Lu , Vidal Gregory , Starlard-Davenport Athena 
Published: August 2019

AbstractGrowing evidence highlights an association between an imbalance in the composition and abundance of bacteria in the breast tissue (referred as microbial dysbiosis) and breast cancer in women. However, studies on the breast tissue microbiome have not been conducted in non-Hispanic Black (NHB) women. We investigated normal and breast cancer tissue microbiota from NHB and non-Hispanic White (NHW) women to identify distinct microbial signatures by race, stage, or tumor subtype. Using 16S rRNA gene sequencing, we observed that phylum Proteobacteria was most abundant in normal (n = 8), normal adjacent to tumor (normal pairs, n = 11), and breast tumors from NHB and NHW women (n = 64), with fewer Firmicutes, Bacteroidetes, and Actinobacteria. Breast tissues from NHB women had a higher abundance of genus Ralstonia compared to NHW tumors, which could explain a portion of the breast cancer racial disparities. Analysis of tumor subtype revealed enrichment of family Streptococcaceae in TNBC. A higher abundance of genus Bosea (phylum Proteobacteria) increased with stage. This is the first study to identify racial differences in the breast tissue microbiota between NHB and NHW women. Further studies on the breast cancer microbiome are necessary to help us understand risk, underlying mechanisms, and identify potential microbial targets.
Oral Administration of Clinically Relevant Antimalarial Drugs Does Not Modify the Murine Gut Microbiota
Authors: Denny Joshua E. , Schmidt Nathan W. 
Published: August 2019

AbstractMalaria is an infectious disease responsible for the death of around 450,000 people annually. As an effective vaccine against the parasite that causes malaria is not available, antimalarial drug treatments are critical in fighting the disease. Previous data has shown that the gut microbiota is important in modulating the severity of malaria. Although it is well appreciated that antibiotics substantially alter the gut microbiota, it is largely unknown how antimalarial drugs impact the gut microbiota. We show here that the two commonly used artemisinin combination therapies of artesunate plus amodiaquine and artemether plus lumefantrine do not change the gut microbiota. The overall relative species abundance and alpha diversity remained stable after treatment, while beta diversity analysis showed minimal changes due to drug treatment, which were transient and quickly returned to baseline. Additionally, treatment with antimalarial drugs did not change the kinetics of later Plasmodium infection. Taken together, antimalarial drug administration does not affect the gut microbiota.
Overexpression of the Rieske FeS protein of the Cytochrome b6f complex increases C4 photosynthesis in Setaria viridis
Authors: Ermakova Maria , Lopez-Calcagno Patricia E. , Raines Christine A. , Furbank Robert T. , von Caemmerer Susanne 
Published: August 2019

AbstractC4 photosynthesis is characterised by a CO2 concentrating mechanism that operates between mesophyll and bundle sheath cells increasing CO2 partial pressure at the site of Rubisco and photosynthetic efficiency. Electron transport chains in both cell types supply ATP and NADPH for C4 photosynthesis. Cytochrome b6f is a key control point of electron transport in C3 plants. To study whether C4 photosynthesis is limited by electron transport we constitutively overexpressed the Rieske FeS subunit in Setaria viridis. This resulted in a higher Cytochrome b6f content in mesophyll and bundle sheath cells without marked changes in the abundances of other photosynthetic proteins. Rieske overexpression plants showed better light conversion efficiency in both Photosystems and could generate higher proton-motive force across the thylakoid membrane underpinning an increase in CO2 assimilation rate at ambient and saturating CO2 and high light. Our results demonstrate that removing electron transport limitations can increase C4 photosynthesis.
The Effect of Working Memory Training on a Clinical Marker of French-Speaking Children With Developmental Language Disorder
Authors: Stanford Emily , Durrleman Stephanie , Delage Hélène 
Published: August 2019

Purpose

Our work investigates the production of 3rd-person accusative clitic pronouns in French-speaking typically developing (TD) children and children with developmental language disorder (DLD) following a novel working memory (WM) training program (12 hrs of effective training) that specifically targets the components of WM that have been shown to be impaired in children with DLD and to be directly related to the mastery of clitics (
Delage & Frauenfelder, submitted for publication
;
Durrleman & Delage, 2016
).

Method
Sixteen TD children aged 5–12 years and 26 age-matched children with DLD completed our 8-week WM training program. Furthermore, an age-matched control group of 16 TD children and 17 children with DLD followed a scholastic training regime matched for intensity and frequency. Syntax and WM were assessed prior to and following the WM/scholastic training.

Results
Significant posttraining WM gains were found in TD children and children with DLD who took part in the WM training, and the production rate of 3rd-person accusative clitics significantly increased in children with DLD following the WM training. No significant WM or syntax gains were observed in the control group.

Conclusion

These findings are noteworthy as
Melby-Lervåg and Hulme's (2013)
meta-analysis concluded that existing WM training programs show short-lived generalized effects to other comparable measures of WM, but that there is no evidence that such training generalizes to less directly related tasks. That our study led to gains in skills that were not trained (i.e., syntax) suggests that a WM training regime that is firmly grounded in theory and that targets the specific mechanisms shown to underpin the acquisition of syntax may indeed provide effective remediation for children with DLD.
Facilitator Behaviors Leading to Engagement and Disengagement in Aphasia Conversation Groups
Authors: Lee Jaime B. , Azios Jamie H. 
Published: August 2019

PurposeResearchers have identified features of successful aphasia conversation groups and clinician behaviors leading to engagement and group cohesion. There has been less focus in the literature on facilitator behaviors that hinder participation or result in disengagement. This study aims to explore the behaviors of graduate student facilitators that contribute to and detract from engagement in aphasia conversation groups.MethodData were drawn from 4 conversation group sessions from 2 different university settings. Groups included 1 graduate student facilitator and 3 or more persons with aphasia. Sociolinguistic discourse analysis was applied to transcripts of group sessions.ResultsThree broad patterns detailing facilitator behaviors were identified. Several facilitator actions contributing to engagement were noted, including strategic use of topic elicitors, multimodal communication supports, and techniques to avoid interactional asymmetry. Behaviors associated with participant disengagement were also noted across sessions, including restricted discourse behaviors and difficulty managing the competing needs of participants. Engagement and disengagement were the product of several coordinating actions of the facilitator and group members that together influenced participation in conversation.ConclusionResults suggest that novice facilitators exhibit behaviors that contribute to and detract from participant engagement in aphasia conversation groups. Findings, discussed within the context of the literature on well-managed groups, highlight the skill required in managing the needs of participants with aphasia and knowing how and when to employ clinician-led strategies.
Treatment Fidelity Procedures for an Aphasia Intervention Within a Randomized Controlled Trial: Design, Feasibility, and Results
Authors: Conlon Elissa L. , Braun Emily J. , Babbitt Edna M. , Cherney Leora R. 
Published: August 2019

Purpose
This study reports on the treatment fidelity procedures implemented during a 5-year randomized controlled trial comparing intensive and distributed comprehensive aphasia therapy. Specifically, the results of 1 treatment, verb network strengthening treatment (VNeST), are examined.

Method
Eight participants were recruited for each of 7 consecutive cohorts for a total of 56 participants. Participants completed 60 hr of aphasia therapy, including 15 hr of VNeST. Two experienced speech-language pathologists delivered the treatment. To promote treatment fidelity, the study team developed a detailed manual of procedures and fidelity checklists, completed role plays to standardize treatment administration, and video-recorded all treatment sessions for review. To assess protocol adherence during treatment delivery, trained research assistants not involved in the treatment reviewed video recordings of a subset of randomly selected VNeST treatment sessions and completed the fidelity checklists. This process was completed for 32 participants representing 2 early cohorts and 2 later cohorts, which allowed for measurement of protocol adherence over time. Percent accuracy of protocol adherence was calculated across clinicians, cohorts, and study condition (intensive vs. distributed therapy).

Results
The fidelity procedures were sufficient to promote and verify a high level of adherence to the treatment protocol across clinicians, cohorts, and study condition.

Conclusion
Treatment fidelity strategies and monitoring are feasible when incorporated into the study design. Treatment fidelity monitoring should be completed at regular intervals during the course of a study to ensure that high levels of protocol adherence are maintained over time and across conditions.
Broadband two‐thirds photonic microwave frequency divider
Authors: Zhou Hongzhen , Liu Shifeng , Kang Xiaochen , Zhu Nan , Lv Kailin , Zhang Yamei , Pan Shilong 
Published: August 2019

A broadband two‐thirds frequency divider based on two cascaded carrier‐suppressed double sideband (CS‐DSB) modulators is proposed and experimentally demonstrated. The first CS‐DSB modulator is aimed to introduce an RF signal under frequency division to the system, and the second one is employed in an optoelectronic oscillator (OEO) loop to avoid the OEO from free running. By mixing the injection frequency and the oscillation frequency in the OEO loop, oscillation of a signal with its frequency equal to two‐thirds of the injection frequency is established. An experiment is carried out, RF signals with frequencies from 12.3 to 17.7 GHz are successfully divided into 8.2 to 11.8 GHz. The maximum power ripple is 2.79 dB and the harmonic components suppression ratio is larger than 36.13 dB.
Driving white dwarf metal pollution through unstable eccentric periodic orbits
Authors: Antoniadou Kyriaki I. , Veras Dimitri 
Published: August 2019

Context. Planetary debris is observed in the atmospheres of over 1000 white dwarfs, and two white dwarfs are now observed to contain orbiting minor planets. Exoasteroids and planetary core fragments achieve orbits close to the white dwarf through scattering with major planets. However, the architectures that allow for this scattering to take place are time-consuming to explore with N-body simulations lasting ∼1010 yr; these long-running simulations restrict the amount of phase space that can be investigated.
Aims. Here we use planar and three-dimensional (spatial) elliptic periodic orbits, as well as chaotic indicators through dynamical stability maps, as quick scale-free analytic alternatives to N-body simulations in order to locate and predict instability in white dwarf planetary systems that consist of one major and one minor planet on very long timescales. We then classify the instability according to ejection versus collisional events.
Methods. We generalized our previous work by allowing eccentricity and inclination of the periodic orbits to increase, thereby adding more realism but also significantly more degrees of freedom to our architectures. We also carried out a suite of computationally expensive 10 Gyr N-body simulations to provide comparisons with chaotic indicators in a limited region of phase space.
Results. We compute dynamical stability maps that are specific to white dwarf planetary systems and that can be used as tools in future studies to quickly estimate pollution prospects and timescales for one-planet architectures. We find that these maps also agree well with the outcomes of our N-body simulations.
Conclusions. As observations of metal-polluted white dwarfs mount exponentially, particularly in the era of Gaia, tools such as periodic orbits can help infer dynamical histories for ensembles of systems.
Pseudoexfoliationssyndrom und Glaukom
Authors: Nobl Matthias , Mackert Marc 
Published: August 2019

ZusammenfassungDas Pseudoexfoliationssyndrom (PEX-Syndrom) ist eine häufige, mit dem Alter zunehmende und weltweit auftretende Erkrankung. Charakteristisch ist die Produktion und Ablagerung von extrazellulärem, fibrillärem Material im Bereich der vorderen Augenkammer. Mit einem breiten Spektrum potenzieller Komplikationen ist die Relevanz sowohl für die konservative als auch die operative Ophthalmologie groß.
Skabies und andere Infestationen durch Milben
Authors: Fölster-Holst Regina 
Published: August 2019

ZusammenfassungEktoparasitosen sind häufig und werden im Wesentlichen durch Insekten und Milben, seltener durch Larven von Würmern hervorgerufen. Während der Mensch für Läuse (Kopf-, Kleider- und Filzläuse) und Skabiesmilben auch der eigentliche und der einzige Wirt ist, stellt er für die temporären Ektoparasiten wie beispielsweise Flöhe, Wanzen und tropische Rattenmilben einen Fehlwirt dar.Als diagnostische Kriterien der Infestationen zählen sowohl das klinische Bild (Morphologie, Prädilektionsstellen) als auch anamnestische Angaben (Kontaktpersonen betroffen, Kontakt zu Tieren). Therapeutisch werden zur Abtötung der permanenten Parasiten chemisch definierte Mittel oder Dimeticone (zur Behandlung der Pediculosis capitis) eingesetzt, während die Hautreaktionen durch die temporären Parasiten symptomatisch behandelt werden. Die Quelle der Parasiten ist zu beachten und erfordert die Behandlung der Tiere und die der Umgebung, die von Tierärzten bzw. Schädlingsbekämpfern durchgeführt wird. Im Folgenden werden Dermatitiden hervorgerufen durch Milben fokussiert.