bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of parameters affecting the calculation time of the image average colour
Authors: Proskuriakov N E , Yakovlev B S , Arkhangelskaia N N
Published: September 2019

Results of pilot studies of determination of average color when using the automated program systems provided. Experimental and analytical means revealed the critical parameters influencing the speed of process of determination of average color. As research showed, the most significant parameters are geometrical image sizes. Also the limit of change of image sizes for the TIF, JPG, PNG, BMP formats at which average color began is irreversible to change was set. The BMP format showed the highest resistance among all studied graphic formats to loss of average color depending on change of image sizes. Research of models of RGB and HSL color showed that the HSL model is not suitable for determination of average color of the image, because of the unpredictable sensitivity. The software capable automated computation of the image average color developed.
About One–Dimensional Space Allocation Problem with forbidden zones
Authors: Zabudsky G G , Veremchuk N S
Published: September 2019

This article discusses the One–Dimensional Space Allocation Problem (ODSAP) with the additional conditions. There are fixed objects (forbidden zones) and a partial order of placement objects on the line. You can not place objects in forbidden zones. The structure of connections between objects is determined using a directed graph. Situations of this type arise, for example, when designing the placement of technological equipment of some enterprise. Technological scheme of production determines the order of processing of raw materials. A polynomial–time algorithm for finding a local optimum for a special graph of connections between objects is proposed.
Encounters with predators fail to trigger predator avoidance in bumblebees, Bombus terrestris (Hymenoptera: Apidae)
Authors: Rodríguez-Gironés Miguel A , Jiménez Olga M
Published: September 2019

Many species must learn to identify their predators, but little is known about the effect of direct encounters on the development of predator avoidance. We asked whether bumblebees, Bombus terrestris, learn to avoid predators, whether learning depends on the conspicuousness of predators and whether bumblebees learn to identify predators or simply to avoid dangerous patches. To answer these questions, we allowed bumblebees to forage in an enclosed meadow of 15 artificial flowers containing a yellow female crab spider, Thomisus onustus. Flowers were yellow in half of the trials and white in the other half. Spiders could remain at the same flower throughout the experiment or swap flowers between bee foraging bouts. Of the 60 bees used in the experiment, eight were killed by the spiders and nine stopped foraging without finishing the trial. Death or refusal to forage typically occurred early in the trial. Regardless of the treatment, the probability of landing at the spider-harbouring flower increased with time. Previous encounters with heterospecific individuals can therefore be a poor source of information about their predatory nature.
Informing disease modelling with brain-relevant functional genomic annotations
Authors: Reynolds Regina H , Hardy John , Ryten Mina , Gagliano Taliun Sarah A
Published: September 2019

How can we best translate the success of genome-wide association studies for neurological and neuropsychiatric diseases into therapeutic targets? Reynolds et al. critically assess existing brain-relevant functional genomic annotations and the tools available for integrating such annotations with summary-level genetic association data.
Neural structures supporting spontaneous and assisted (entrained) speech fluency
Authors: Bonilha Leonardo , Hillis Argye E , Wilmskoetter Janina , Hickok Gregory , Basilakos Alexandra , Munsell Brent , Rorden Chris , Fridriksson Julius
Published: September 2019

Non-fluent speech is one of the most common impairments in post-stroke aphasia. The rehabilitation of non-fluent speech in aphasia is particularly challenging as patients are rarely able to produce and practice fluent speech production. Speech entrainment is a behavioural technique that enables patients with non-fluent aphasia to speak fluently. However, its mechanisms are not well understood and the level of improved fluency with speech entrainment varies among individuals with non-fluent aphasia. In this study, we evaluated the behavioural and neuroanatomical factors associated with better speech fluency with the aid of speech entrainment during the training phase of speech entrainment. We used a lesion-symptom mapping approach to define the relationship between chronic stroke location on MRI and the number of different words per second produced during speech entrainment versus picture description spontaneous speech. The behavioural variable of interest was the speech entrainment/picture description ratio, which, if ≥1, indicated an increase in speech output during speech entrainment compared to picture description. We used machine learning (shallow neural network) to assess the statistical significance and out-of-sample predictive accuracy of the neuroanatomical model, and its regional contributors. We observed that better assisted speech (higher speech entrainment/picture description ratio) was achieved by individuals who had preservation of the posterior middle temporal gyrus, inferior fronto-occipital fasciculus and uncinate fasciculus, while exhibiting lesions in areas typically associated with non-fluent aphasia, such as the superior longitudinal fasciculus, precentral, inferior frontal, supramarginal and insular cortices. Our findings suggest that individuals with dorsal stream damage but preservation of ventral stream structures are more likely to achieve more fluent speech with the aid of speech entrainment compared to spontaneous speech. This observation provides insight into the mechanisms of non-fluent speech in aphasia and has potential implications for future research using speech entrainment for rehabilitation of non-fluent aphasia.
To be or not to be pink(1): contradictory findings in an animal model for Parkinson’s disease
Authors: de Haas Ria , Heltzel Lisa C M W , Tax Denise , van den Broek Petra , Steenbreker Hilbert , Verheij Michel M M , Russel Frans G M , Orr Adam L , Nakamura Ken , Smeitink Jan A M
Published: September 2019

The PTEN-induced putative kinase 1 knockout rat (Pink1−/−) is marketed as an established model for Parkinson’s disease, characterized by development of motor deficits and progressive degeneration of half the dopaminergic neurons in the substantia nigra pars compacta by 8 months of age. In this study, we address our concerns about the reproducibility of the Pink1−/− rat model. We evaluated behavioural function, number of substantia nigra dopaminergic neurons and extracellular striatal dopamine concentrations by in vivo microdialysis. Strikingly, we and others failed to observe any loss of dopaminergic neurons in 8-month-old male Pink1−/− rats. To understand this variability, we compared key experimental parameters from the different studies and provide explanations for contradictory findings. Although Pink1−/− rats developed behavioural deficits, these could not be attributed to nigrostriatal degeneration as there was no loss of dopaminergic neurons in the substantia nigra and no changes in neurotransmitter levels in the striatum. To maximize the benefit of Parkinson’s disease research and limit the unnecessary use of laboratory animals, it is essential that the research community is aware of the limits of this animal model. Additional research is needed to identify reasons for inconsistency between Pink1−/− rat colonies and why degeneration in the substantia nigra is not consistent.
Plasma hsa_circ_0027089 is a diagnostic biomarker for hepatitis B virus-related hepatocellular carcinoma
Authors: Zhu Kai , Zhan Hao , Peng Yuanfei , Yang Liuxiao , Gao Qiang , Jia Hao , Dai Zhi , Tang Zhaoyou , Fan Jia , Zhou Jian
Published: September 2019

Circular RNAs (circRNAs) have recently been identified as a new member of endogenous noncoding RNAs. CircRNAs exhibit high stability and can thus can be used as valuable biomarkers for monitoring the occurrence and development of hepatocellular carcinoma (HCC). The present study sought to explore the diagnostic significance of plasma circRNAs in hepatitis B virus (HBV)-related HCC. Plasma circRNAs from 10 patients with hepatitis B (HBV)-related HCC and 5 patients with HBV-related liver cirrhosis were investigated by microarray to screen differentially expressed circRNAs, 157 upregulated and 161 downregulated circRNAs were found. Twenty-four circRNAs were further investigated via quantitative reverse-transcriptase–polymerase chain reaction assay in a training cohort (n = 48), hsa_circ_0027089 exhibited the highest significance and further distinguished 64 HCC patients from 40 cirrhosis patients and 72 healthy participants in a validation cohort. These results indicate that plasma hsa_circ_0027089 can serve as a new marker for the diagnosis of HBV-related HCC.
Diarrhea as a Potential Cause and Consequence of Reduced Gut Microbial Diversity Among Undernourished Children in Peru
Authors: Rouhani Saba , Griffin Nicholas W , Yori Pablo Peñataro , Gehrig Jeanette L , Olortegui Maribel Paredes , Salas Mery Siguas , Trigoso Dixner Rengifo , Moulton Lawrence H , Houpt Eric R , Barratt Michael J , Kosek Margaret N , Gordon Jeffrey I
Published: September 2019

Background

Detrimental effects of diarrhea on child growth and survival are well documented, but details of the underlying mechanisms remain poorly understood. Recent evidence demonstrates that perturbations to normal development of the gut microbiota in early life may contribute to growth faltering and susceptibility to related childhood diseases. We assessed associations between diarrhea, gut microbiota configuration, and childhood growth in the Peruvian Amazon.

Methods

Growth, diarrhea incidence, illness, pathogen infection, and antibiotic exposure were assessed monthly in a birth cohort of 271 children aged 0–24 months. Gut bacterial diversity and abundances of specific bacterial taxa were quantified by sequencing 16S rRNA genes in fecal samples collected at 6, 12, 18, and 24 months. Linear and generalized linear models were used to determine whether diarrhea was associated with altered microbiota and, in turn, if features of the microbiota were associated with the subsequent risk of diarrhea.

Results

Diarrheal frequency, duration, and severity were negatively associated with bacterial diversity and richness (P < .05). Children born stunted (length-for-age z-score [LAZ] ≤ −2) who were also severely stunted (LAZ ≤ −3) at the time of sampling exhibited the greatest degree of diarrhea-associated reductions in bacterial diversity and the slowest recovery of bacterial diversity after episodes of diarrhea. Increased bacterial diversity was predictive of reduced subsequent diarrhea from age 6 to 18 months.

Conclusions

Persistent, severe growth faltering may reduce the gut microbiota's resistance and resilience to diarrhea, leading to greater losses of diversity and longer recovery times. This phenotype, in turn, denotes an increased risk of future diarrheal disease and growth faltering.
Gut Microbiota Features Associated With Campylobacter Burden and Postnatal Linear Growth Deficits in a Peruvian Birth Cohort
Authors: Rouhani Saba , Griffin Nicholas W , Yori Pablo Peñataro , Olortegui Maribel Paredes , Siguas Salas Mery , Rengifo Trigoso Dixner , Moulton Lawrence H , Houpt Eric R , Barratt Michael J , Kosek Margaret N , Gordon Jeffrey I
Published: September 2019

Background

Campylobacter infection is associated with impaired growth of children, even in the absence of symptoms. To examine the underlying mechanisms, we evaluated associations between Campylobacter infection, linear growth, and fecal microbial community features in a prospective birth cohort of 271 children with a high burden of diarrhea and stunting in the Amazonian lowlands of Peru.

Methods

Campylobacter was identified using a broadly reactive, genus-specific enzyme-linked immunosorbent assay. 16S rRNA-based analyses were used to identify bacterial taxa in fecal samples at ages 6, 12, 18, and 24 months (N = 928). Associations between infection, growth, and gut microbial community composition were investigated using multiple linear regression adjusting for within-child correlations, age, and breastfeeding. Indicator species analyses identified taxa specifically associated with Campylobacter burden.

Results

Ninety-three percent (251) of children had Campylobacter present in asymptomatic fecal samples during the follow-up period. A 10% increase in the proportion of stools infected was associated with mean reductions of 0.02 length-for-age z scores (LAZ) at 3, 6, and 9 months thereafter (P < .01). We identified 13 bacterial taxa indicative of cumulative Campylobacter burden and 14 taxa significantly associated with high or low burden of enteroaggregative Escherichia coli, norovirus, or Giardia.

Conclusions

Campylobacter infection is common in this cohort and associated with changes in microbial community composition. These results support the notion that disruptions to the fecal microbiota may help explain the observed effects of asymptomatic infections on growth in early life.
Comparison of outcomes in infected cardiovascular implantable electronic devices between complete, partial, and failed lead removal: an ESC-EHRA-EORP ELECTRa (European Lead Extraction ConTrolled) registry
Authors: Nof Eyal , Bongiorni Maria Grazia , Auricchio Angelo , Butter Christian , Dagres Nikolaos , Deharo Jean-Claude , Rinaldi Christopher A , Maggioni Aldo P , Kutarski Andrzej , Kennergren Charles , Laroche Cécile , Milman Anat , Beinart Roy , Bogdan Stefan , Mortsell David , Calvi Valeria , Desiron Quentin , Mansourati Jacques , Blomstrom Lundqvist Carina , Glikson Michael ,   On behalf of the ELECTRa Investigators
Published: September 2019

Aims

The present study sought to determine predictors for success and outcomes of patients who underwent cardiac implantable electronic devices (CIED) extraction indicated for systemic or local CIED related infection in particular where complete lead removal could not be achieved.

Methods and results

ESC-EORP ELECTRa (European Lead Extraction ConTRolled Registry) is a European prospective lead extraction registry. Out of the total cohort, 1865/3510 (52.5%) patients underwent removal due to CIED related infection. Predictors and outcomes of failure were analysed. Complete removal was achieved in 1743 (93.5%) patients, partial (<4 cm of lead left) in 88 (4.7%), and failed (>4 cm of lead left) in 32 (1.8%) patients. Removal success was unrelated to type of CIED infection (pocket or systemic). Predictors for failure were older leads and older patients [odds ratio (OR) 1.14 (1.08–1.19), P < 0.0001 and OR 2.68 (1.22–5.91), P = 0.0146, respectively]. In analysis by lead, predictors for failure were: pacemaker vs. defibrillator removal and failure to engage the locking stylet all the way to the tip [OR 0.20 (0.04–0.95), P = 0.03 and OR 0.32 (0.13–0.74), P = 0.008, respectively]. Significantly higher complication rates were noted in the failure group (40.6% vs. 15.9 for partial and 8.7% for success groups, P < 0.0001). Failure to remove a lead was a strong predictor for in hospital mortality [hazard ratio of 2.05 (1.01–4.16), P = 0.046].

Conclusion

A total of 6.5% of infected CIED patients failed attempted extraction. Only were >4 cm of lead remained resulted in higher procedural complications and mortality rates.
Protein expression profiles in methicillin-resistant Staphylococcus aureus (MRSA) under effects of subminimal inhibitory concentrations of imipenem
Authors: Wang Jichun , Wang Junrui , Wang Yanyan , Sun Peng , Zou Xiaohui , Ren Luo , Zhang Chunxia , Liu Enmei
Published: September 2019

Imipenem is a beta-lactam antibiotic mainly active against gram-negative bacterial pathogens and also could cause cell wall impairment in methicillin-resistant Staphylococcus aureus(MRSA). However, related antibacterial mechanisms of imipenem on MRSA and mixed infections of MRSA and gram-negative bacteria are relatively poorly revealed. This study was to identify proteins in the MRSA response to subminimal inhibitory concentrations (sub-MICs) of imipenem treatment. Our results showed that 240 and 58 different expression proteins (DEPs) in sub-MICs imipenem-treated S3 (a standard MRSA strain) and S23 (a clinical MRSA strain) strains were identified through the isobaric tag for relative and absolute quantitation method when compared with untreated S3 and S23 strains, respectively, which was further confirmed by multiple reactions monitoring. Our result also demonstrated that expressions of multiple DEPs involved in cellular proliferation, metabolism and virulence were significantly changed in S3 and S23 strains, which was proved by gene ontology annotations and qPCR analysis. Further, transmission electron microscopy and scanning electron microscopy analysis showed cell wall deficiency, cell lysis and abnormal nuclear mitosis on S23 strain. Our study provides important information for understanding the antibacterial mechanisms of imipenem on MRSA and for better usage of imipenem on patients co-infected with MRSA and other multidrug-resistant gram-negative bacteria.
Identification and characterization of FtsH mediating in vivo colonization and stress adaptation in the fish pathogen Edwardsiella piscicida
Authors: Ma Ruiqing , Huang Jianchang , Zhang Yuanxing , Wang Qiyao
Published: September 2019

Edwardsiella piscicida is an important pathogenic enteric bacterium of fish. FtsH is a unique membrane-anchored AAA + protease that regulates protein homeostasis in bacteria. In cooperation with modulators HflK and HflC, FtsH is essential in enteric bacteria and controls the response to environmental stresses. Here, we used in vivo pattern analysis of conditional essentiality (PACE) and identified that ftsH and hflK/C were associated with impaired in vivo colonization in Edw. piscicida and attenuated internalization ability of ZF4 cells. The ftsH mutant displayed increased survival during prolonged treatment of starvation and high osmotic stresses in Edw. piscicida. Further analysis showed that the disruption of ftsH resulted in the overproduction of the established substrate LpxC, which is responsible for the synthesis of LPS (lipopolysaccharide), as well as the substrate YfgM, which is involved in high osmolality tolerance during stationary phase. However, the inconsistency in the abilities of the ftsH and hflK/C mutants to achieve YfgM-based osmotic resistance indicated that there might be multiple, while distinctive, pathways controlled by FtsH and the associated modulator proteins HflK/C. This investigation revealed the unique functions of FtsH and its modulator HflK/C in Edw. piscicida.
Land seismic multiparameter full waveform inversion in elastic VTI media by simultaneously interpreting body waves and surface waves with an optimal transport based objective function
Authors: He Weiguang , Brossier Romain , Métivier Ludovic , Plessix René-Édouard
Published: September 2019

Land seismic multiparameter full waveform inversion in anisotropic media is challenging because of high medium contrasts and surface waves. With a data-residual least-squares objective function, the surface wave energy usually masks the body waves and the gradient of the objective function exhibits high values in the very shallow depths preventing from recovering the deeper part of the earth model parameters. The optimal transport objective function, coupled with a Gaussian time-windowing strategy, allows to overcome this issue by more focusing on phase shifts and by balancing the contributions of the different events in the adjoint-source and the gradients. We first illustrate the advantages of the optimal transport function with respect to the least-squares one, with two realistic examples. We then discuss a vertical transverse isotropic (VTI) example starting from a quasi 1-D isotropic initial model. Despite some cycle-skipping issues in the initial model, the inversion based on the windowed optimal transport approach converges. Both the near-surface complexities and the variations at depth are recovered.
Exploiting the emergent nature of mixed methods designs: insights from a mixed methods impact evaluation in Malawi
Authors: De Allegri Manuela , Brenner Stephan , Kambala Christabel , Mazalale Jacob , Muula Adamson S , Chinkhumba Jobiba , Wilhelm Danielle , Lohmann Julia
Published: September 2019

The application of mixed methods in Health Policy and Systems Research (HPSR) has expanded remarkably. Nevertheless, a recent review has highlighted how many mixed methods studies do not conceptualize the quantitative and the qualitative component as part of a single research effort, failing to make use of integrated approaches to data collection and analysis. More specifically, current mixed methods studies rarely rely on emergent designs as a specific feature of this methodological approach. In our work, we postulate that explicitly acknowledging the emergent nature of mixed methods research by building on a continuous exchange between quantitative and qualitative strains of data collection and analysis leads to a richer and more informative application in the field of HPSR. We illustrate our point by reflecting on our own experience conducting the mixed methods impact evaluation of a complex health system intervention in Malawi, the Results Based Financing for Maternal and Newborn Health Initiative. We describe how in the light of a contradiction between the initial set of quantitative and qualitative findings, we modified our design multiple times to include additional sources of quantitative and qualitative data and analytical approaches. To find an answer to the initial riddle, we made use of household survey data, routine health facility data, and multiple rounds of interviews with both healthcare workers and service users. We highlight what contextual factors made it possible for us to maintain the high level of methodological flexibility that ultimately allowed us to solve the riddle. This process of constant reiteration between quantitative and qualitative data allowed us to provide policymakers with a more credible and comprehensive picture of what dynamics the intervention had triggered and with what effects, in a way that we would have never been able to do had we kept faithful to our original mixed methods design.
Concrete Examples of Abstract Others: Testing Exemplar Availability as an Additional Explanation for Third-Person Perceptions
Authors: Schmierbach Mike , Boyle Michael P
Published: September 2019

Explanations for the third-person phenomenon generally hinge on either self-favoring biases or cognitive mechanisms. While controlling for common perceptual factors, we demonstrate an additional cognitive component: exemplar availability, using a 2-study design. The first considers the third-person perception in the context of media-generated stereotypes. The second considers 3 distinct types of advertisements meant to evoke varied third- and first-person perceptions. Results of both studies showed that the ability to think of examples serves as the most consistent predictor, even after accounting for the influence of perceived exposure and similarity.
Cefepime/sulbactam as an enhanced antimicrobial combination therapy for the treatment of MDR Gram-negative infections
Authors: Wareham David W , Momin M H F Abdul , Phee Lynette M , Hornsey Michael , Standing Joseph F
Published: September 2019

Background

β-Lactam (BL)/β-lactamase inhibitor (BLI) combinations are widely used for the treatment of Gram-negative infections. Cefepime has not been widely studied in combination with BLIs. Sulbactam, with dual BL/BLI activity, has been partnered with very few BLs. We investigated the potential of cefepime/sulbactam as an unorthodox BL/BLI combination against MDR Gram-negative bacteria.

Methods

In vitro activity of cefepime/sulbactam (1:1, 1:2 and 2:1) was assessed against 157 strains. Monte Carlo simulation was used to predict the PTA with a number of simulated cefepime combination regimens, modelled across putative cefepime/sulbactam breakpoints (≤16/≤0.25 mg/L).

Results

Cefepime/sulbactam was more active (MIC50/MIC90 8/8–64/128 mg/L) compared with either drug alone (MIC50/MIC90 128 to >256 mg/L). Activity was enhanced when sulbactam was added at 1:1 or 1:2 (P < 0.05). Reduction in MIC was most notable against Acinetobacter baumannii and Enterobacterales (MIC 8/8–32/64 mg/L). Pharmacokinetic/pharmacodynamic modelling highlighted that up to 48% of all isolates and 73% of carbapenem-resistant A. baumannii with a cefepime/sulbactam MIC of ≤16/≤8 mg/L may be treatable with a high-dose, fixed-ratio (1:1 or 1:2) combination of cefepime/sulbactam.

Conclusions

Cefepime/sulbactam (1:1 or 1:2) displays enhanced in vitro activity versus MDR Gram-negative pathogens. It could be a potential alternative to existing BL/BLI combinations for isolates with a cefepime/sulbactam MIC of 16/8 mg/L either as a definitive treatment or as a carbapenem-sparing option.
Antimicrobial anaphylaxis: the changing face of severe antimicrobial allergy
Authors: Hall Victoria , Wong Micah , Munsif Maitri , Stevenson Brittany R , Elliott Katie , Lucas Michaela , Baird Ashleigh J , Athan Eugene , Young Melissa , Pickles Robert , Cheng Allen C , Stewardson Andrew J , Aung Ar K , Trubiano Jason A
Published: September 2019

Objectives

The epidemiology, clinical characteristics and outcomes of antimicrobial-associated anaphylaxis remain ill-defined. We sought to examine antimicrobial anaphylaxis with regard to: (i) the frequency of implicated antimicrobials; (ii) attributable mortality; and (iii) referral for definitive allergy assessment.

Methods

This was conducted through a national retrospective multicentre cohort study at five Australian tertiary hospitals (January 2010 to December 2015). Cases of antimicrobial anaphylaxis were identified from ICD-10 coding and adverse drug reaction committee databases.

Results

There were 293 participants meeting the case definition of antimicrobial anaphylaxis and 310 antimicrobial anaphylaxis episodes. Of 336 implicated antimicrobials, aminopenicillins (62/336, 18.5%) and aminocephalosporins (57/336, 17%) were implicated most frequently. ICU admission occurred in 43/310 (13.9%) episodes; however, attributable mortality was low (3/310, 1%). The rate of anaphylaxis to IV antibiotics was 3.5 (95% CI = 2.9–4.3) per 100 000 DDDs and the rate of hospital-acquired anaphylaxis was 1.9 (95% CI = 2.1–3.3) per 100 000 occupied bed-days. We observed overall low rates of hospital discharge documentation (222/310, 71.6%) and follow-up by specialist allergy services (73/310, 23.5%), which may compromise medication safety and antimicrobial prescribing in future.

Conclusions

This study demonstrated that a high proportion of severe immediate hypersensitivity reactions presenting or acquired in Australian hospitals are secondary to aminopenicillins and aminocephalosporins. Overall rates of hospital-acquired anaphylaxis, predominantly secondary to cephalosporins, are low, and also associated with low inpatient mortality.
Overexpression of HvCslF6 in barley grain alters carbohydrate partitioning plus transfer tissue and endosperm development
Authors: Lim Wai Li , Collins Helen M , Byrt Caitlin S , Lahnstein Jelle , Shirley Neil J , Aubert Matthew K , Tucker Matthew R , Peukert Manuela , Matros Andrea , Burton Rachel A
Published: September 2019

Overexpression of the HvCslF6 gene in hull-less barley grain perturbs sucrose uptake and allocation, and impairs transfer tissue and endosperm development
The wheat LLM-domain-containing transcription factor TaGATA1 positively modulates host immune response to Rhizoctonia cerealis
Authors: Liu Xin , Zhu Xiuliang , Wei Xuening , Lu Chungui , Shen Fangdi , Zhang Xuewen , Zhang Zengyan
Published: September 2019

A wheat LLM-domain-containing B-GATA transcription factor positively regulates the host immune response to the important pathogen Rhizoctonia cerealis.
Tests of acoustic scale shifts in halo-based mock galaxy catalogues
Authors: Duan Yutong , Eisenstein Daniel
Published: September 2019

We utilize mock catalogues from high-accuracy cosmological N-body simulations to quantify shifts in the recovery of the acoustic scale that could potentially result from galaxy clustering bias. The relationship between galaxies and dark matter haloes presents a complicated source of systematic errors in modern redshift surveys, particularly when aiming to make cosmological measurements to sub-per cent precision. Apart from a scalar, linear bias parameter accounting for the density contrast ratio between matter tracers and the true matter distribution, other types of galaxy bias, such as assembly and velocity biases, may also significantly alter clustering signals from small to large scales. We create mocks based on generalized halo occupation populations of 36 periodic boxes from the abacus cosmosrelease, and test various biased models along with an unbiased base case in a total volume of $48 \, h^{-3} \, {\rm Gpc}^{3}$. Two reconstruction methods are applied to galaxy samples and the apparent acoustic scale is derived by fitting the two-point correlation function multipoles. With respect to the baseline, we find a 0.3 per cent shift in the line-of-sight acoustic scale for one variation in the satellite galaxy population, and we find a 0.7 per cent shift for an extreme level of velocity bias of the central galaxies. All other bias models are consistent with zero shift at the 0.2 per cent level after reconstruction. We note that the bias models explored are relatively large variations, producing sizeable and likely distinguishable changes in small-scale clustering, the modelling of which would further calibrate the baryon acoustic oscillations standard ruler.
Dynamical interactions in the planetary system GJ4276
Authors: Horrobin Fergus , Rein Hanno
Published: September 2019

GJ4276 is an M4.0 dwarf star with an inferred Neptune mass planet from radial velocity (RV) observations. We re-analyse the RV data for this system and focus on the possibility of a second, super-Earth mass, planet. We compute the time-scale for fast resonant librations in the eccentricity to be $\sim \!2000 \, \mathrm{d}$. Given that the observations were taken over $700\, \mathrm{d}$, we expect to see the effect of these librations in the observations. We perform a fully dynamical fit to test this hypothesis. Similar to previous results, we determine that the data could be fit by two planets in a 2:1 mean motion resonance. However, we also find solutions near the 5:4 mean motion resonance that are not present when planet–planet interactions are ignored. Using the mean exponential growth of nearby orbits indicator, we analyse the stability of the system and find that our solutions lie in a stable region of parameter space. We also find that though out-of-resonance solutions are possible, the system favours a configuration that is in a first-order mean motion resonance. The existence of mean motion resonances has important implications in many planet formation theories. Although we do not attempt to distinguish between the one- and two-planet models in this work, in either case, the predicted orbital parameters are interesting enough to merit further study. Future observations should be able to distinguish between the different scenarios within the next 5 yr.
Optical transient from an explosion close to the stellar surface
Authors: Yalinewich Almog , Matzner Christopher D
Published: September 2019

We study the hydrodynamic evolution of an explosion close to the stellar surface, and give predictions for the radiation from such an event. We show that such an event will give rise to a multiwavelength transient. We apply this model to describe a precursor burst to the peculiar supernova iPTF14hls, which occurred in 1954, 60 yr before the supernova. We propose that the new generation of optical surveys might detect similar transients, and that they can be used to identify supernova progenitors well before the explosion.
Multifilter time-series observations of three short period ATLAS variable stars
Authors: Koen Chris
Published: September 2019

The ‘Asteroid Terrestrial-impact Last Alert System’ discovered hundreds of thousands of new candidate variable stars. Follow-up observations of three of these are reported in this paper. The targets were selected on the basis of having high probability of being periodic (false alarm probability for period detection smaller than 10−5), short periods (P < 0.2 d), and being relatively bright (g′ < 17). The targets were also chosen to be either very blue (g′ − i′ < −0.4, r′ − z′ < −0.4) or very red (g′ − i′ > 2.2, r′ − z′ > 1.5) as periodic variables with these colours are relatively rare. Two of the stars are hot subdwarfs, both of which are likely reflection effect binaries. In both cases simple models suggest that the companions may have masses very close to or below 0.1 $\, \mathrm{M}_\odot$. The third star is also a binary, which appears to consist of two M dwarfs in a near contact configuration. At 0.12 d its period is one of the shortest known for M-type binaries.
An interpretable machine-learning framework for dark matter halo formation
Authors: Lucie-Smith Luisa , Peiris Hiranya V , Pontzen Andrew
Published: September 2019

We present a generalization of our recently proposed machine-learning framework, aiming to provide new physical insights into dark matter halo formation. We investigate the impact of the initial density and tidal shear fields on the formation of haloes over the mass range 11.4 ≤ log (M/M⊙) ≤ 13.4. The algorithm is trained on an N-body simulation to infer the final mass of the halo to which each dark matter particle will later belong. We then quantify the difference in the predictive accuracy between machine-learning models using a metric based on the Kullback–Leibler divergence. We first train the algorithm with information about the density contrast in the particles’ local environment. The addition of tidal shear information does not yield an improved halo collapse model over one based on density information alone; the difference in their predictive performance is consistent with the statistical uncertainty of the density-only based model. This result is confirmed as we verify the ability of the initial conditions-to-halo mass mapping learnt from one simulation to generalize to independent simulations. Our work illustrates the broader potential of developing interpretable machine-learning frameworks to gain physical understanding of non-linear large-scale structure formation.
Controlling systematics in ground-based CMB surveys with partial boresight rotation
Authors: Thomas Daniel B , McCallum Nialh , Brown Michael L
Published: September 2019

Future CMB experiments will require exquisite control of systematics in order to constrain the B-mode polarization power spectrum. One class of systematics that requires careful study is instrumental systematics. The potential impact of such systematics is most readily understood by considering analysis pipelines based on pair differencing. In this case, any differential gain, pointing or beam ellipticity between the two detectors in a pair can result in intensity leakage into the B-mode spectrum, which needs to be controlled to a high precision due to the much greater magnitude of the total intensity signal as compared to the B-mode signal. One well-known way to suppress such systematics is through careful design of the scan-strategy, in particular making use of any capability to rotate the instrument about its pointing (boresight) direction. Here, we show that the combination of specific choices of such partial boresight rotation angles with redundancies present in the scan strategy is a powerful approach for suppressing systematic effects. This mitigation can be performed in analysis in advance of map-making and, in contrast to other approaches (e.g. deprojection or filtering), results in no signal loss. We demonstrate our approach explicitly with time ordered data simulations relevant to next-generation ground-based CMB experiments, using deep and wide scan strategies appropriate for experiments based in Chile. These simulations show a reduction of multiple orders of magnitude in the spurious B-mode signal arising from differential gain and differential pointing systematics.
Search for RR Lyrae stars in DES ultrafaint systems: Grus I, Kim 2, Phoenix II, and Grus II
Authors: Martínez-Vázquez C E , Vivas A K , Gurevich M , Walker A R , McCarthy M , Pace A B , Stringer K M , Santiago B , Hounsell R , Macri L , Li T S , Bechtol K , Riley A H , Kim A G , Simon J D , Drlica-Wagner A , Nadler E O , Marshall J L , Annis J , Avila S , Bertin E , Brooks D , Buckley-Geer E , Burke D L , Carnero Rosell A , Carrasco Kind M , da Costa L N , De Vicente J , Desai S , Diehl H T , Doel P , Everett S , Frieman J , García-Bellido J , Gaztanaga E , Gruen D , Gruendl R A , Gschwend J , Gutierrez G , Hollowood D L , Honscheid K , James D J , Kuehn K , Kuropatkin N , Maia M A G , Menanteau F , Miller C J , Miquel R , Paz-Chinchón F , Plazas A A , Sanchez E , Scarpine V , Serrano S , Sevilla-Noarbe I , Smith M , Soares-Santos M , Sobreira F , Swanson M E C , Tarle G , Vikram V ,   (DES Collaboration)
Published: September 2019

This work presents the first search for RR Lyrae stars (RRLs) in four of the ultrafaint systems imaged by the Dark Energy Survey using SOAR/Goodman and Blanco/DECam imagers. We have detected two RRLs in the field of Grus I, none in Kim 2, one in Phoenix II, and four in Grus II. With the detection of these stars, we accurately determine the distance moduli for these ultrafaint dwarf satellite galaxies; μ0 = 20.51 ± 0.10 mag (D⊙ = 127 ± 6 kpc) for Grus I and μ0 = 20.01 ± 0.10 mag (D⊙ = 100 ± 5 kpc) for Phoenix II. These measurements are larger than previous estimations by Koposov et al. and Bechtol et al., implying larger physical sizes; 5 per cent for Grus I and 33 per cent for Phoenix II. For Grus II, of the four RRLs detected, one is consistent with being a member of the galactic halo (D⊙ = 24 ± 1 kpc, μ0 = 16.86 ± 0.10 mag), another is at D⊙ = 55 ± 2 kpc (μ0 = 18.71 ± 0.10 mag), which we associate with Grus II, and the two remaining at D⊙ = 43 ± 2 kpc (μ0 = 18.17 ± 0.10 mag). Moreover, the appearance of a subtle red horizontal branch in the colour–magnitude diagram of Grus II at the same brightness level of the latter two RRLs, which are at the same distance and in the same region, suggests that a more metal-rich system may be located in front of Grus II. The most plausible scenario is the association of these stars with the Chenab/Orphan Stream. Finally, we performed a comprehensive and updated analysis of the number of RRLs in dwarf galaxies. This allows us to predict that the method of finding new ultrafaint dwarf galaxies using two or more clumped RRLs will work only for systems brighter than MV ∼ −6 mag.
A nitrogen-enhanced metal-poor star discovered in the globular cluster ESO280−SC06
Authors: Simpson Jeffrey D , Martell Sarah L
Published: September 2019

We report the discovery of the only very nitrogen-enhanced metal-poor star known in a Galactic globular cluster. This star, in the very metal-poor cluster ESO280−SC06 , has $[\textrm{N}/\textrm{Fe}]\, \gt +2.5$, while the other stars in the cluster show no obvious enhancement in nitrogen. Around 80 NEMP stars are known in the field, and their abundance patterns are believed to reflect mass transfer from a binary companion in the asymptotic giant branch phase. The dense environment of globular clusters is detrimental to the long term survival of binary systems, resulting in a low observed binary fraction among red giants and the near absence of NEMP stars. We also identify the first known horizontal branch members of ESO280−SC06 , which allow for a much better constraint on its distance. We calculate an updated orbit for the cluster based on our revised distance of 20.6 ± 0.5 kpc, and find no significant change to its orbital properties.
Super-giant pulses from the Crab pulsar: energy distribution and occurrence rate
Authors: Bera Apurba , Chengalur Jayaram N
Published: September 2019

We present statistical analysis of a fluence-limited sample of over 1100 giant pulses from the Crab pulsar, with fluence > 130 Jy ms at ∼1330 MHz. These were detected in ∼260 h of observation with the National Centre for Radio Astrophysics (NCRA) 15 m radio telescope. We find that the pulse-energy distribution follows a power law with index $\rm \alpha \approx -3$ at least up to a fluence of ∼5 Jy s. The power-law index agrees well with that found for lower-energy pulses in the range 3–30 Jy ms. The fluence distribution of the Crab pulsar hence appears to follow a single power law over ∼3 orders of magnitude in fluence. We do not see any evidence for the flattening at high fluences reported by earlier studies. We also find that, at these fluence levels, the rate of giant-pulse emission varies by as much as a factor of ∼5 on time-scales of a few days, although the power-law index of the pulse-energy distribution remains unchanged. The slope of the fluence distribution for Crab giant pulses is similar to that recently determined for the repeating FRB 121102. We also find an anti-correlation between the pulse fluence and the pulse width, so that more energetic pulses are preferentially shorter.
Flow Diversion for Intracranial Aneurysm Treatment: Trials Involving Flow Diverters and Long-Term Outcomes
Authors: Chancellor Bree , Raz Eytan , Shapiro Maksim , Tanweer Omar , Nossek Erez , Riina Howard A , Nelson Peter Kim
Published: September 2019

Flow diverters (FDs) have changed the management of brain aneurysms; not only for complex aneurysms (giant, fusiform and blister) refractory to conventional therapies, but also for unruptured lesions previously managed by traditional surgical or coil-based endovascular methods. Since 2011 when the PipelineTM Embolization Device (Medtronic) was cleared by the Food and Drug Administration for adults with large or giant wide-neck intracranial aneurysms of the internal carotid artery proximal to the posterior communicating segment, the role of flow diversion for aneurysm treatment has expanded—supported by favorably low complication and high cure rates compared with alternative treatments. Here we review the key clinical trials and the long term outcomes that have demonstrated safety and efficacy of minimized porosity endoluminal devices in the treatment of cerebral aneurysms.
Single-Arm, Open-Label, Multicenter Study to Evaluate the Safety and Performance of Dura Sealant Patch in Reducing Cerebrospinal Fluid Leakage Following Elective Cranial Surgery: The ENCASE Trial Study Protocol
Authors: van Doormaal Tristan P C , Germans Menno R , Sie Mariska , Brouwers Bart , Fierstra Jorn , Depauw Paul R A M , Robe Pierre A , Regli Luca
Published: September 2019

BACKGROUND

Cerebrospinal fluid (CSF) leakage is one of the most common neurosurgical complications, occurring in 4% to 32% of surgical cases, with a higher incidence in complicated skull base surgery, intradural spine surgery, and the surgery of the posterior fossa. Our group developed a Dural Sealant Patch (DSP) for watertight dural closure after cranial surgery.

OBJECTIVE

To clinically study for the first time the safety and performance of the DSP as a means of reducing CSF leakage in patients undergoing elective cranial intradural surgery with a dural closure procedure.

METHODS

We will conduct an open-label, single-arm, multicenter study with a 360 d (12 mo) follow-up. A total of 40 patients will be enrolled at 3 sites. The primary endpoint is a combination of occurrences of one of the following events: postoperative percutaneous CSF leakage, intraoperative leakage at 20 cm H2O, or postoperative wound infection. The secondary endpoints are pseudomeningocele and thickness of dura + DSP.

EXPECTED OUTCOMES

Not more than 3 patients will meet the primary endpoint suggesting safety and efficacy.

DISCUSSION

As a next step, a randomized controlled trial against the best current practice will follow to evaluate if DSP reduces CSF leakage while its safety is noninferior.
Interrater and Intrarater Reliability of the Colloid Cyst Risk Score
Authors: Alford Elizabeth N , Rotman Lauren E , Lepard Jacob R , Agee Bonita S , Markert James M
Published: September 2019

BACKGROUND

The Colloid Cyst Risk Score (CCRS) was developed to identify symptomatic patients and stratify risk of hydrocephalus among patients with colloid cysts. Its components consider patient age, cyst diameter, presence/absence of headache, fluid-attenuated inversion recovery (FLAIR) hyperintensity, and location within the third ventricle.

OBJECTIVE

To independently evaluate the inter- and intrarater reliability of the CCRS.

METHODS

Patients with a colloid cyst were identified from billing records and radiology archives. Three independent raters reviewed electronic medical records to determine age, presence/absence of headache, cyst diameter (mm), FLAIR hyperintensity, and risk zone location. Raters made 53 observations, including 5 repeat observations.

Fleiss’ generalized kappa (κ) was calculated for all of the nominal criteria, whereas Kendall's coefficient of concordance (W) and the intraclass correlation coefficient (ICC) were calculated for the overall score.

RESULTS

Total CCRS score demonstrated extremely strong agreement (W = 0.83) using Kendall's W coefficient and good agreement (ICC = 0.74) using the ICC (P < .001). For interrater reliability of individual criteria, age (κ = 1.00) and FLAIR hyperintensity (κ = 0.89) demonstrated near perfect agreement. Axial diameter (κ = 0.63) demonstrated substantial agreement, whereas agreement was moderate for risk zone (κ = 0.51) and fair for headache (κ = 0.26). Intrarater reliability for total CCRS score was extremely strong using Kendall's W, good to excellent using ICC, and fair to substantial using weighted kappa.

CONCLUSION

The CCRS has good inter- and intrarater reliability when tested in an independent sample of patients, though strength of agreement varies among individual criteria. The validity of the CCRS requires independent evaluation.