bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social Isolation and Memory Decline in Later-life
Authors: Read Sanna , Comas-Herrera Adelina , Grundy Emily 
Published: November 2019

Abstract

Objectives
To investigate associations between level and changes in social isolation and in memory in older men and women.

Methods
The sample included 6,123 women and 5,110 men aged 50+ from the English Longitudinal Study of Aging (ELSA). Extended latent change score models from six measurement occasions every 2 years from 2002 were used to investigate associations between social isolation and memory. Models were adjusted for age, socioeconomic position, and health.

Results
Social isolation increased and memory decreased over time. Among men an initially high level of social isolation was associated with a somewhat greater decrease in memory. Among women a greater increase in social isolation predicted a greater decrease in memory and a larger change in social isolation was associated with further larger changes in isolation, although when social isolation reached a higher level it subsequently decreased.

Conclusions
Results suggest that the association between social isolation and memory decline arises because social isolation is associated with increased memory decline rather than poor memory leading to increases in social isolation. Men with high levels of social isolation and women with accumulated social isolation over time are especially affected as these patterns of isolation were associated with more profound memory decline.
Multi-objective waveform inversion of shallow seismic wavefields
Authors: Pan Yudi , Gao Lingli , Shigapov Renat 
Published: November 2019

SUMMARY
It has been increasingly popular to use shallow-seismic full-waveform inversion (FWI) to reconstruct near-surface structures. Conventional FWI tries to resolve the earth model by minimizing the difference between observed and synthetic seismic data using a certain criterion (conventionally, l2-norm of waveform difference). In this paper, we propose a multi-objective waveform inversion (MOWI) in which the similarity of data is quantified and minimized using multiple criteria simultaneously. By doing so, we expand the dimensionality of objective space as well as the mapping from data space to objective space, which provides MOWI higher freedom in exploring the model space compared to single-objective FWI. We combine three different scalar-valued objective functions into a vector-valued multi-objective function which measures the similarity of the waveform, the waveform envelope, and the amplitude spectra of the data, respectively. This multi-objective function takes not only trace-based waveform and wave packet similarity but also the dispersion characteristics of surface waves into account. Furthermore, the uncertainty in the inversion result could be estimated and analysed quantitatively by the variance of the optimal models. We propose a modified ϵ-constraint algorithm to solve the multi-objective optimization problem. Two synthetic examples are used to show the advantages of using MOWI compared to single-objective FWI. We also test the efficiency of MOWI by using two synthetic shallow-seismic examples, which confirm that MOWI can converge to a better result compared to the conventional single-objective FWI.
Depressed forehead scar: a case report and review of literature
Authors: Ozinko Mba O , Otei Otei O , Ekpo Rijami G , Isiwele Egi 
Published: November 2019

AbstractDepressed forehead scars are not frequently reported in the literature in the West African sub-region. Although they are not commonly reported, few cases were managed and are to be documented. We had seen a case of depressed forehead scar which was due to post frontal avulsion injury of the forehead with an intact posterior table of the frontal bone. He complained of aesthetic and psychological problems of the scar on presentation. The scar revision was done with polymethylmethacrylate bone cement with simple wound closure based on patient’s choice after counseling. The treatment outcome was satisfactory. We intend to highlight the use of polymethylmethacrylate bone cement and simple wound closure as an option in the revision of depressed forehead scars as well as add a report to the volume of literature from the sub-region.
Significant luminosity differences of two twin Type Ia supernovae
Authors: Foley Ryan J , Hoffmann Samantha L , Macri Lucas M , Riess Adam G , Brown Peter J , Filippenko Alexei V , Graham Melissa L , Milne Peter A 
Published: November 2019

ABSTRACT
The Type Ia supernovae (SNe Ia) 2011by, hosted in NGC 3972, and 2011fe, hosted in M101, are optical ‘twins,’ having almost identical optical light-curve shapes, colours, and near-maximum-brightness spectra. However, SN 2011fe had significantly more ultraviolet (UV; 1600 &lt; λ &lt; 2500 Å) flux than SN 2011by before and at peak luminosity. Several theoretical models predict that SNe Ia with higher progenitor metallicity should (1) have additional UV opacity and thus lower UV flux; (2) have an essentially unchanged optical spectral-energy distribution; (3) have a similar optical light-curve shape; and (4) because of the excess neutrons, produce more stable Fe-group elements at the expense of radioactive 56Ni and thus have a lower peak luminosity. Following these predictions, Foley and Kirshner suggested that the difference in UV flux between SNe 2011by and 2011fe was the result of their progenitors having significantly different metallicities. They also measured a large, but insignificant, difference between the peak absolute magnitudes of the SNe (ΔMV, peak = 0.60 ± 0.36 mag), with SN 2011fe being more luminous. We present a new Cepheid-based distance to NGC 3972, substantially improving the precision of the distance measurement for SN 2011by. With these new data, we determine that the SNe have significantly different peak luminosities (ΔMV, peak = 0.335 ± 0.069 mag). Consequently, SN 2011fe produced 38 per cent more 56Ni than SN 2011by, consistent with predictions for progenitor metallicity differences for these SNe, although alternative models may also explain this difference. We discuss how progenitor metallicity differences can contribute to the intrinsic scatter for light-curve-shape-corrected SN luminosities, the use of ‘twin’ SNe for measuring distances, and implications for using SNe Ia for constraining cosmological parameters.
The spatial distribution of circumstellar material of the wind-fed system GX 301-2
Authors: Zheng Xueying , Liu Jiren , Gou Lijun 
Published: November 2019

ABSTRACT
The distribution of the circumstellar material in systems of supergiant X-ray binaries (SgXBs) is complex and not well probed observationally. We report a detailed study of the spatial distribution of the Fe K α-emitting material in the wind-fed system GX 301-2, by measuring the time delay between the Fe K α line and the hard X-ray continuum (7.8–12 keV) using the cross-correlation method, based on XMM–Newton observation. We found that to obtain the true time delay, it is crucial to subtract the underlying continuum of the Fe K α line. The measured size of the Fe Kα-emitting region over the whole observation period is 40 ± 20 light-seconds. It is 5 times larger than the accretion radius estimated from a quasi-isotropic stellar wind, but consistent with the one estimated from a tidal stream, which could be the dominant mass-loss mechanism of GX 301-2 as inferred from the orbital distribution of the absorption column density previously. The measured time delay of the quiescent period is a little smaller than those of the flare periods, revealing the unsteady behaviour of the accretion flow in GX 301-2. Statistical and detailed temporal studies of the circumstellar material in SgXBs are expected for a large sample of SgXBs with future X-ray missions, such as Athena and eXTP.
Improving baryon acoustic oscillation measurement with the combination of cosmic voids and galaxies
Authors: Zhao Cheng , Chuang Chia-Hsun , Kitaura Francisco-Shu , Liang Yu , Pellejero-Ibanez Marcos , Tao Charling , Vargas-Magaña Mariana , Variu Andrei , Yepes Gustavo 
Published: November 2019

ABSTRACT
We develop a methodology to optimize the measurement of baryon acoustic oscillation (BAO) from a given galaxy sample. In our previous work, we demonstrated that one can measure BAO from tracers in underdense regions (voids). In this study, we combine the overdense and underdense tracers (galaxies and voids) to obtain better constraints on the BAO scale. To this end, we modify the de-wiggled BAO model with an additional parameter to describe both the BAO peak and the underlying exclusion pattern of void 2PCFs. We show that after applying BAO reconstruction to galaxies, the BAO peak scale of both galaxies and voids are unbiased using the modified model. Furthermore, we use a new 2PCF estimator for a multitracer analysis with galaxies and voids. In simulations, the joint sample improves by about 10 per cent the constraint for the post-reconstruction BAO peak position compared to the result from galaxies alone, which is equivalent to an enlargement of the survey volume by 20 per cent. Applying this method to the BOSS DR12 data, we have an 18 per cent improvement for the low-z sample (0.2 &lt; z &lt; 0.5), but a worse constraint for the high-z sample (0.5 &lt; z &lt; 0.75), which is consistent with statistical fluctuations for the current survey volume. Future larger samples will give more robust improvements due to less statistical fluctuations.
Constraining the magnetic field structure in collisionless relativistic shocks with a radio afterglow polarization upper limit in GW 170817
Authors: Gill Ramandeep , Granot Jonathan 
Published: November 2019

ABSTRACT
Gamma-ray burst (GRB) afterglow arises from a relativistic shock driven into the ambient medium, which generates tangled magnetic fields and accelerates relativistic electrons that radiate the observed synchrotron emission. In relativistic collisionless shocks the post-shock magnetic field $\boldsymbol {B}$ is produced by the two-stream and/or Weibel instabilities on plasma skin-depth scales (c/ωp), and is oriented predominantly within the shock plane (B⊥; transverse to the shock normal, $\hat{\boldsymbol {n}}_{\rm {sh}}$), and is often approximated to be completely within it ($B_\parallel \equiv \hat{\boldsymbol {n}}_{\rm {sh}}\, \cdot \, \boldsymbol {B}=0$). Current 2D/3D particle-in-cell simulations are limited to short time-scales and box sizes ≲104(c/ωp) ≪ R/Γsh much smaller than the shocked region’s comoving width, and hence cannot probe the asymptotic downstream $\boldsymbol {B}$ structure. We constrain the latter using the linear polarization upper limit, $\vert \Pi \vert \lt 12{{\ \rm per\ cent}}$, on the radio afterglow of GW $170817$ / GRB 170817A. Afterglow polarization depends on the jet’s angular structure, our viewing angle, and the $\boldsymbol {B}$ structure. In GW $170817$ / GRB 170817A the latter can be tightly constrained since the former two are well-constrained by its exquisite observations. We model $\boldsymbol {B}$ as an isotropic field in 3D that is stretched along $\hat{\boldsymbol {n}}_{\rm {sh}}$ by a factor ξ ≡ $B_\parallel $/B⊥, whose initial value ξf ≡ $B_\parallel,$f/B⊥, f describes the field that survives downstream on plasma scales ≪R/Γsh. We calculate Π(ξf) by integrating over the entire shocked volume for a Gaussian or power-law core-dominated structured jet, with a local Blandford-McKee self-similar radial profile (used for evolving ξ downstream). We find that independent of the exact jet structure, $\boldsymbol {B}$ has a finite, but initially sub-dominant, parallel component: 0.57 ≲ ξf ≲ 0.89, making it less anisotropic. While this motivates numerical studies of the asymptotic $\boldsymbol {B}$ structure in relativistic collisionless shocks, it may be consistent with turbulence amplified magnetic field.
Twenty Years of Wage Inequality in Latin America
Authors: Messina Julian , Silva Joana 
Published: November 2019

AbstractThis article documents an inverse U-shape in the evolution of wage inequality in Latin America since 1995, with a sharp reduction starting in 2002. The Gini coefficient of wages increased from 42 to 44 between 1995 and 2002 and declined to 39 by 2015. Between 2002 and 2015, the 90/10 log hourly earnings ratio decreased by 26 percent. The decline since 2002 was characterized by rising wages across the board, but especially at the bottom of the wage distribution in each country. Triggered by a rapid expansion of educational attainment, the wages of college and high school graduates fell relative to the wages of workers with only primary education. The premium for labor market experience also fell significantly. However, the compression of wages was not entirely driven by changes in the wage structure across skill groups. Two-thirds of the decline in the variance of wages took place within skill groups. Changes in the sectoral, occupational, and formal/informal composition of jobs matter for the process of reduction in inequality, but they do not fully account for the fall in within-skill variance. Evidence based on longitudinal matched employer-employee administrative data suggests that an important driver was falling wage dispersion across firms.
Can we predict early 7-day readmissions using a standard 30-day hospital readmission risk prediction model?
Authors: Saleh Sameh N. , Makam Anil N. , Halm Ethan A. , Nguyen Oanh Kieu 
Published: November 2019

AbstractDespite focus on preventing 30-day readmissions, early readmissions (within 7 days of discharge) may be more preventable than later readmissions (8-30 days). We assessed how well a previously validated 30-day readmission prediction model predicts 7-day readmissions. We re-derived model coefficients for the same predictors as in the original 30-day model to optimize prediction of 7-day readmissions. We compared model performance and compared differences in strength of model factors between the 7-day model to the 30-day model. While there was no substantial change in model performance between the original 30-day and the re-derived 7-day model, there was significant change in strength of predictors. Characteristics at discharge were more predictive of 7-day readmissions, while baseline characteristics were less predictive. Improvements in predicting early 7-day readmissions will likely require new risk factors proximal to the day of discharge.
Individual differences in the course of youth depression: The importance of renitence and reversion
Authors: Hawrilenko Matthew J. , Masyn Katherine E. , Cerutti Janine , Dunn Erin C. 
Published: November 2019

AbstractStudies of developmental trajectories of depression are important for understanding its etiology. Existing studies have been limited by short time frames and no studies have explored a key factor: differential patterns of responding to life events. This paper introduces a novel analytic technique, growth mixture modeling with structured residuals, to examine the course of youth depression symptoms in a large, prospective cohort (N=11,641, ages 4-16.5). Age-specific critical points were identified at ages 10 and 13 where depression symptoms spiked for a minority of children. However, most depression risk was due to dynamic responses to environmental events, drawn not from a small pool of persistently depressed children, but a larger pool of children who varied across higher and lower symptom levels.
Statistical considerations for drawing conclusions about recovery
Authors: Lohse Keith R. , Hawe Rachel L. , Dukelow Sean P. , Scott Stephen H. 
Published: November 2019

AbstractBackgroundNumerous studies have found associations when change scores are regressed onto initial impairments in people with stroke (slopes ≈ 0.7). However, there are important statistical considerations that limit the conclusions we can draw about recovery from these studies.ObjectiveTo provide an accessible “check-list” of conceptual and analytical issues on longitudinal measures of stroke recovery. Proportional recovery is an illustrative example, but these considerations apply broadly to studies of change over time.MethodsUsing a pooled dataset of N = 373 Fugl-Meyer Assessment (FMA) upper extremity scores, we ran simulations to illustrate three considerations: (1) how change scores can be problematic in this context; (2) how “nil” and non-zero null-hypothesis significance tests can be used; and (3) how scale boundaries can create the illusion of proportionality, while other analytical procedures (e.g., post-hoc classifications) can augment this problem.ResultsOur simulations highlight several limitations of common methods for analyzing recovery over time. Critically, we find that uniform recovery (in the population) leads to similar group-level statistics (regression slopes) and individual-level classifications (into fitters and non-fitters) that have been claimed as evidence for the proportional recovery rule.ConclusionsOur results highlight that one cannot identify whether proportional recovery is true or not based on commonly used methods. We illustrate how these techniques (regressing change scores onto baseline values), measurement tools (bounded scales), and post-hoc classifications (e.g., “non-fitters”) can create spurious results. Going forward the field needs to carefully consider the influence of these factors on how we measure, analyze, and conceptualize recovery.
Sort-purification of human CD34+CD90+cells reduces target cell population and improves lentiviral transduction for gene therapy
Authors: Radtke Stefan , Pande Dnyanada , Cui Margaret , Perez Anai M. , Chan Yan-Yi , Enstrom Mark , Schmuck Stefanie , Berger Andrew , Eunson Tom , Adair Jennifer E. , Kiem Hans-Peter 
Published: November 2019

ABSTRACTHematopoietic stem cell (HSC) gene therapy has the potential to cure many genetic, malignant and infectious diseases. We have shown in a nonhuman primate (NHP) HSC gene therapy and transplantation model that the CD34+CD90+cell fraction was exclusively responsible for multilineage engraftment and hematopoietic reconstitution. Here we show the translational potential of this HSC-enriched CD34 subset for lentivirus-mediated gene therapy. Alternative HSC-enrichment strategies include the purification of CD133+cells or CD38low/-subsets of CD34+cells from human blood products. We directly compared these strategies to the isolation of CD90+cells using a GMP-grade flow-sorting protocol with clinical applicability. We show that CD90+cell selection results in 40-fold fewer target cells in comparison to CD133+or CD38low/-CD34 subsets without compromising the engraftment potentialin vivo. Single cell RNA sequencing confirmed nearly complete depletion of lineage committed progenitor cells in CD90+fractions compared to alternative selections. Importantly, lentiviral transduction efficiency in purified CD90+cells resulted in up to 3-fold higher levels of engrafted gene-modified blood cells. These studies should have important implications for the manufacturing of patient-specific HSC gene therapy and genome editing products.
Electrode pooling: boosting the yield of extracellular recordings with switchable silicon probes
Authors: Lee Kyu Hyun , Ni Yu-Li , Colonell Jennifer , Karsh Bill , Putzeys Jan , Pachitariu Marius , Harris Timothy D. , Meister Markus 
Published: November 2019

AbstractState-of-the-art silicon probes for electrical recording from neurons have thousands of recording sites. However, due to volume limitations there are typically many fewer wires carrying signals off the probe, which restricts the number of channels that can be recorded simultaneously. To overcome this fundamental constraint, we propose a novel method called electrode pooling that uses a single wire to serve many recording sites through a set of controllable switches. Here we present the framework behind this method and an experimental strategy to support it. We then demonstrate its feasibility by implementing electrode pooling on the Neuropixels 1.0 electrode array and characterizing its effect on signal and noise. Finally we use simulations to explore the conditions under which electrode pooling saves wires without compromising the content of the recordings. We make recommendations on the design of future devices to take advantage of this strategy.
All talk? Left temporal alpha oscillations are not specific to verbal-analytical processing during conscious motor control
Authors: Parr Johnny V. V. , Gallicchio Germano , Harrison Neil R. , Johnen Ann-Kathrin , Wood Greg 
Published: November 2019

AbstractThe present study tested the validity of inferring verbal-analytic motor processing from EEG left-temporal alpha activity. Participants (n = 20) reached for and transport a jar under three conditions: one control condition and two self-talk conditions aimed at eliciting either task-unrelated verbal processing or task-related conscious control, while 32-channel EEG and kinematics were recorded. Compared to the control condition, both self-talk conditions elicited greater self-reported levels of verbal processing, but only the task-related self-talk condition was accompanied by greater left temporal activity (i.e., EEG alpha power decreased) during movement production. However, this increase was not localised to the left temporal region but was rather evident over all scalp regions examined, suggesting an interpretation more consistent with diminished neural efficiency. No effects for left temporal-frontal (T7-Fz) connectivity were detected across conditions. Our results failed to endorse left-temporal EEG alpha activity as valid index of verbal-analytic processing during motor tasks.
Successful mating and hybridisation in two closely related flatworm species despite significant differences in reproductive morphology and behaviour
Authors: Singh Pragya , Ballmer Daniel , Laubscher Max , Schärer Lukas 
Published: November 2019

AbstractSpeciation is usually a gradual process, in which reproductive barriers between two species accumulate over time. Reproductive traits, like genital morphology and mating behaviour, are some of the fastest diverging characters and can serve as reproductive barriers. The free-living flatworm Macrostomum lignano, an established model for studying sex in hermaphrodites, and its congener M. janickei are closely related, but differ substantially in their male intromittent organ (stylet) morphology. Here, we examine whether these morphological differences are accompanied by differences in behavioural traits, and whether these could represent barriers to successful mating and hybridization between the two species. Our data shows that the two species differ in many aspects of their mating behaviour, with M. janickei having a five-fold longer copulation duration, copulating less frequently, and having a longer and more delayed suck behaviour (a postcopulatory behaviour likely involved in sexual conflict). Interestingly, and despite these significant morphological and behavioural differences, the two species mate readily with each other in heterospecific pairings, often showing behaviours of intermediate duration. Although both species have similar fecundity in conspecific pairings, the heterospecific pairings revealed clear postmating barriers, as only few heterospecific pairings produced F1 hybrids. These hybrids had a stylet morphology that was intermediate between that of the parental species, and they could successfully backcross to both parental species. Finally, in a mate choice experiment we tested if the worms preferentially mated with conspecifics over heterospecifics, since such a preference could represent a premating barrier. Interestingly, the experiment showed that the nearly two-fold higher mating rate of M. lignano caused it to mate more with conspecifics, leading to assortative mating, while M. janickei ended up mating more with heterospecifics. Thus, while the two species can hybridize, the mating rate differences could possibly lead to higher fitness costs for M. janickei compared to M. lignano.