bluuebunny/crossref_metadata_2025 huggingface dataset:
Erwartete Auswirkungen der Covid-19-Pandemie auf Angehörige Suchtkranker
Authors: Bischof Gallus , Velleman Richard , Bischof Anja , Orford Jim J.
Published: September 2020

Zusammenfassung. Fragestellung: Angehörige von Suchtkranken stellen eine belastete substantielle Gruppe dar, die in Forschung und Versorgung unzureichend repräsentiert ist. Es liegen bislang keine wissenschaftlichen Zahlen zu den Auswirkungen der durch die Covid-19 Pandemie verursachten sozialen Einschränkungen auf Belastungen und Versorgungsangebote für Angehörige vor. Methode: Internationale Expertenbefragung und Befragung von Mitarbeitenden des deutschen Suchthilfesystems. Ergebnisse: Während primär eine Zunahme von Belastungen durch Auswirkungen der Pandemie in Form von erhöhtem Risikoverhalten des suchtkranken Angehörigen und einer Zunahme interpersoneller Konflikte vermutet wird, ergaben sich auch Hinweise auf mögliche entlastende Auswirkungen bei Subgruppen von Angehörigen. Aus der Versorgung wurde ein Rückgang an Angeboten für Angehörige sowie ein tendenzieller Rückgang der Nachfrage berichtet. Schlussfolgerungen: Auswirkungen von Suchterkrankungen auf das soziale Umfeld sollten in Studien zu substanzbezogenen und affektiven Störungen sowie zu häuslicher Gewalt miterhoben werden. Evidenzbasierte Angebote für Angehörige Suchtkranker sollten flächendeckend und digital angeboten werden. Die Vernetzung mit weiteren psychosozialen Angeboten sollte optimiert werden.
Empfehlung zu Glücksspielwerbung während der Corona-Pandemie
Authors: Hayer Tobias , Füchtenschnieder Ilona , Hardeling Andrea , Landgraf Konrad , Rehbein Florian , Wulf Rüdiger , Rumpf Hans-Jürgen
Published: September 2020

Zusammenfassung. Theoretischer Hintergrund: Glücksspielwerbung steht in einem natürlichen Spannungsverhältnis zu besonders wichtigen Zielen der Suchtprävention sowie einer effektiven Abwehr von Suchtgefahren. Entsprechend besteht die grundsätzliche Notwendigkeit, Werbung für Glücksspiele aus Gründen des Jugend- und Spielerschutzes auf ein absolutes Minimum zu begrenzen. Aktuelle Situation: Die diversen Schutzbestimmungen im Zusammenhang mit COVID-19 dürften in Verbindung mit Prozessen der sozialen Isolation bei einem signifikanten Anteil der Bevölkerung zu deutlichen psychosozialen und finanziellen Belastungen führen. Mögliche Folgen: In der Konsequenz liegt die Vermutung nahe, dass das Glücksspielverhalten verstärkt internetgestützt aus den eigenen vier Wänden heraus erfolgt. Vor diesem Hintergrund ist die hierzulande aktuell zunehmend zu beobachtende Werbung für Online-Casinoanbieter aus suchtfachlicher Sicht scharf zu kritisieren. Diese Entwicklung steht im Widerspruch zu den Bemühungen anderer europäischer Ländern, die von einem temporären Komplettverbot von Glücksspielen bis zu erheblichen Werberestriktionen reichen. Schlussfolgerungen: Infolgedessen wird die Forderung abgeleitet, während der Corona-Krise jegliche Form der Werbung für Online-Glücksspiele auszusetzen und perspektivisch die grundsätzlich liberale Haltung zur Glücksspielwerbung im Rahmen des Glücksspielstaatsvertrages zu überdenken.
A Psychophysiological Examination of the Mutability of Type D Personality in a Therapeutic Trial
Authors: Hodgson Kirsty L. , Clayton Debbie A. , Carmi Michael A. , Carmi Louise H. , Ruden Ronald A. , Fraser William D. , Cameron Donnie
Published: September 2020

Abstract. Identifying the associations between health and personality has been a focus for psychophysiological research. Type D personality is associated with predisposition to physical and psychological ill-health. This statistician-blind parallel-group controlled trial (intervention group vs. waiting list control group) examined the impact of Havening Techniques on the Type D constituents of negative affect (NA) and social inhibition (SI). One hundred twenty-five adult (18+ years) participants in the United Kingdom (72 females, 53 males) completed the Type D Scale-14 (DS14) measure of Type D personality at baseline (T1), 24-hours (T2), and at 1-month (T3). Forty participants in the treatment group received additional stress biomarker assessment of heart rate, blood pressure, and salivary cortisol. Type D caseness remained stable in the waiting list participants ( n = 57). In the treatment group ( n = 68); NA, SI, and total scores decreased from T1 to T2 ( p < .001, p < .001, and p < .001, respectively), and from T2 to T3 ( p = .004, p < .001, and p < .001, respectively), significantly transmuting to non-caseness ( p < .001 for T1 to T2; p = .025 for T2 to T3). Between T1 and T2, decreases in cortisol ( p < .001), diastolic blood pressure ( p < .001), and systolic blood pressure ( p < .001) were demonstrated. Heart rate fell nonsignificantly between T1 and T2 ( p = .063), but significantly from T1 to T3 ( p = .048). The findings of this study indicate the potential mutability of the psychophysiological illness-prone characteristics of Type D personality.
Nowcasting and Validating Earth's Electric Field Response to Extreme Space Weather Events Using Magnetotelluric Data: Application to the September 2017 Geomagnetic Storm and Comparison to Observed and Modeled Fields in Scotland
Authors: Simpson Fiona , Bahr Karsten
Published: September 2020

In the United Kingdom, geomagnetically induced currents (GICs) are calculated from thin‐sheet electrical conductivity models. In the absence of conductivity models, time derivatives of magnetic fields are sometimes used as proxies for GIC‐related electric fields. An alternative approach, favored in the United States, is to calculate storm time electric fields from time‐independent impedance tensors computed from an array of magnetotelluric (MT) sites and storm time magnetic fields recorded at geomagnetic observatories or assumed from line current models. A paucity of direct measurements of storm time electric fields has restricted validation of these different techniques for nowcasting electric fields and GICs. Here, we present unique storm time electric field data from seven MT sites in Scotland that recorded before, during, and after the September 2017 magnetic storm. By Fourier transforming electric field spectra computed using different techniques back to the time domain, we are able to make direct comparisons with these measured storm time electric field time series. This enables us to test the validity of different approaches to nowcasting electric fields. Our preferred technique involves frequency domain multiplication of magnetic field spectra from a regional site with a local impedance tensor that has been corrected for horizontal magnetic field gradients present between the local site and the regional site using perturbation tensors derived from geomagnetic depth sounding (GDS). Scatter plots of scaling factors between measured and nowcasted electric fields demonstrate the importance of coupling between the polarization of the storm time magnetic source field and Earth's direction‐dependent deep electrical conductivity structure.
Long‐Term Variations of Quasi‐Trapped and Trapped Electrons in the Inner Radiation Belt Observed by DEMETER and SAMPEX
Authors: Zhang Kun , Li Xinlin , Xiang Zheng , Khoo Leng Ying , Zhao Hong , Looper Mark D. , Temerin Michael A. , Sauvaud Jean‐André
Published: September 2020

Electrons in the Earth's radiation belts can be categorized into three populations: precipitating, quasi‐trapped, and trapped. We use data from the Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) and Solar, Anomalous, and Magnetospheric Particle Explorer satellite (SAMPEX) missions and from ground‐based neutron monitors (NM) and sunspot observations to investigate the long‐term variation of quasi‐trapped and trapped sub‐MeV electrons on different L shells in the inner belt. DEMETER and SAMPEX measurements span over 17 years and show that at L ≤ 1.14 the electron flux is anticorrelated with sunspot number, but proportional to the cosmic ray intensity represented by NM count rates, which suggests that electrons at the inner edge of the inner belt are produced by Cosmic Ray Albedo Neutron Decay (CRAND). The solar cycle variation of cosmic rays increased the electron flux at L ≤ 1.14 by a factor of 2 from solar maximum at 2001 to solar minimum at 2009. At L ≥ 1.2, both quasi‐trapped and trapped electrons are enhanced during geomagnetic storms and decay to a background level during extended quiet times. At L > 2, quasi‐trapped electrons resemble trapped electrons, with correlation coefficients as high as 0.97, indicating that pitch angle scattering is the dominant process in this region.
Measuring the Electron Density Roughness of the D‐Region Ionosphere
Authors: Higginson‐Rollins Marc A. , Cohen Morris B.
Published: September 2020

We present a method of characterizing the horizontal and vertical electron density roughness of the D‐region ionosphere using Nationwide Differential Global Position System (NDGPS) transmitters as low‐frequency (LF; 30–300 kHz) and medium‐frequency (MF; 300–3,000 kHz) signals of opportunity. The horizontal roughness is characterized using an amplitude cross‐correlation method, which yields the correlation length scale metric. The vertical roughness is characterized using a differential phase height, which is needed to mitigate the effects of transmitter phase instability. The ranges and typical values of roughness metrics are investigated using data from several field campaign measurements. Finally, the roughness metrics for an NDGPS transmitter and very low frequency (VLF) transmitter are compared. It is found that the roughness detected by the VLF transmitter is significantly smoother and demonstrates the utility of this method to complement traditional VLF measurements.
An FDTD Investigation of Orthogonality and the Backscattering of HF Waves in the Presence of Ionospheric Irregularities
Authors: Smith D. R. , Tan T. , Dao E. , Huang C. , Simpson J. J.
Published: September 2020

One of the most successful instruments used to investigate the Earth's ionosphere is coherent scatter radars such as the Super Dual Auroral Radar Network (SuperDARN). Their method of mapping plasma convection at high latitudes is contingent on irregularities that momentarily exist in the ionosphere and are elongated along the direction of the geomagnetic field. Under these conditions, SuperDARN transmits high‐frequency (HF) waves that are then backscattered from these plasma irregularities. In order for maximum backscatter to occur, the wave vector of the incident wave must be orthogonal to the magnetic field lines. This is called the “orthogonality condition.” Over the years, ray tracing results have generated many assumptions, where and how orthogonality occurs. However, since ray tracing only tracks the primary direction of energy flow and typically does not account for diffraction, it provides an incomplete understanding of the interaction of HF waves with small ionospheric irregularities. This work investigates the orthogonality assumptions by modeling at high‐resolution HF electromagnetic wave interactions with small‐scale irregularities in the ionosphere. Specifically, the finite‐difference time‐domain (FDTD) method is employed to determine where orthogonality occurs in the ionosphere and the number of times the condition is satisfied during the simulation. The results provide insights into the orthogonality condition as a function of source frequency and elevation angle for both unperturbed and perturbed ionospheres. From these results, small‐scale irregularities are observed to sometimes contribute significantly to the production of backscatter. A discussion is provided to highlight where three existing orthogonality condition assumptions are incorrect or misleading.
Kinetic Ballooning Instability of the Near‐Earth Magnetotail in Voigt Equilibrium
Authors: Khan Abdullah , Zhu Ping , Han Rui , Ali Ahmad
Published: September 2020

For a long time, ballooning instabilities have been believed to be a possible triggering mechanism for the onset of substorm and current disruption initiation in the near‐Earth magnetotail. Yet the stability of the kinetic ballooning mode (KBM) in a global and realistic magnetotail configuration has not been well examined. In this paper, stability of the KBM is evaluated for the two‐dimensional Voigt equilibrium of the near‐Earth magnetotail based on an analytical kinetic theory of ballooning instability in the framework of kinetic magnetohydrodynamic (MHD) model, where the kinetic effects such as the finite gyroradius effect, wave‐particle resonances, and particle drifts motions are included usually through kinetic closures. The growth rate of the KBM strongly depends on the magnetic field line stiffening factor S, which is in turn determined by the effects of the trapped electrons, the finite ion gyroradius, and the magnetic drift motion of charged particles. The KBM is unstable in a finite intermediate range of equatorial βeq and only marginally unstable at higher βeq regime for higher Te/Ti values. The finite ion gyroradius and the trapped electron fraction enhance the stiffening factor that tends to stabilize the KBM in the magnetotail far away from Earth. On the other hand, the current sheet thinning destabilizes KBM in the lower βeq regime and stabilizes KBM in the higher βeq regime.
Ganymede's Far‐Ultraviolet Reflectance: Constraining Impurities in the Surface Ice
Authors: Molyneux P. M. , Nichols J. D. , Becker T. M. , Raut U. , Retherford K. D.
Published: September 2020

We present reflectance spectra of Ganymede's leading and trailing hemispheres in the wavelength range 138–215 nm, obtained by the Hubble Space Telescope Cosmic Origins Spectrograph (HST/COS) in 2014. The most notable feature of both spectra is the absence of a sharp water absorption edge at ~165 nm, seen in laboratory measurements of ice reflectivity and in previous observations of Saturn's icy moons and rings. Rather than displaying a sharp change in the reflectivity at the wavelength of the water ice absorption edge, Ganymede's reflectance gradually increases with wavelength at λ > 165 nm. We show that the observed shape of Ganymede's UV reflectance is inconsistent with intimate mixture models of pure ice with UV‐dark materials including tholins, amorphous carbon, graphite, and silicates. However, we find that intraparticle models, in which a small proportion of a UV‐absorbing contaminant is trapped as inclusions within the ice matrix, are able to suppress the 165 nm feature at contaminant concentrations of <1%. We show that models of ice with inclusions of silicates, Triton‐type tholin, or H2O2 are able to produce the observed gradual increase in reflectivity at λ > 165 nm, but additional absorbing surface materials are required to produce a good fit to Ganymede's previously observed near‐UV and visible reflectance.
Mesozoic Subduction Accretion History in Central Tibet Constrained From Provenance Analysis of the Mugagangri Subduction Complex in the Bangong‐Nujiang Suture Zone
Authors: Ma Anlin , Hu Xiumian , Kapp Paul , Lai Wen , Han Zhong , Xue Weiwei
Published: September 2020

The Mugagangri Complex in central Tibet provides a record of the subduction accretion history between the Lhasa and Qiangtang terranes and consists of coherent sedimentary sequences, strongly dismembered formations, and siliciclastic‐matrix block‐in‐matrix mélange. We identified three different groups of sandstone within the Mugagangri Complex. Group 1 is volcaniclastic lithic (Q41F19L40, Lm16Lv77Ls7) and exhibits youngest U‐Pb detrital zircon (YDZ) ages of 177–170 Ma. Group 2 is litho‐quartzose (Q67F6L27, Lm23Lv63Ls13) with YDZ ages of 237–213 Ma. Groups 1 and 2 show provenance affinity with the Qiangtang terrane to the north. Group 3 is similar to Group 2 in detrital mode (Q67F2L31) and U‐Pb detrital zircon age spectra but is distinguished by more sedimentary fragments (Lm17Lv24Ls59), a 1,200–1,100 Ma age peak that is possibly characteristic of the Lhasa terrane to the south and YDZ ages of 284–246 Ma. During (and possibly prior to) Late Triassic time, the recycled orogen‐derived sandstones, including Group 2 and possibly Group 3, were deposited on the ocean floor adjacent to the Qiangtang terrane. During the early Middle Jurassic, the arc‐derived sandstone (Group 1) was deposited and accreted through the northward subduction of Bangong‐Nujiang oceanic lithosphere. During the late Middle to Late Jurassic, Groups 2 and 3 may have been deposited in a trench or trench slope basin, with Group 3 receiving detritus from both the Lhasa and Qiangtang terranes. These three groups of sandstone and ocean plate stratigraphy were mixed in the mélange during the accretion between the Lhasa and Qiangtang terranes.
An Explicit Scheme to Represent the Bidirectional Hydrologic Exchanges Between the Vadose Zone, Phreatic Aquifer, and River
Authors: Hong M. , Mohanty B. P. , Sheng Z.
Published: September 2020

Understanding groundwater storage variations as a result of effects from both the vadose zone and the river is of critical importance in the hydraulically connected surface‐subsurface system. In this study, we present a novel Bidirectional Exchange Scheme in Surface and Subsurface (BE3S) that represents bidirectional exchanges between the vadose zone, phreatic aquifer, and river. The approach enables explicit representations of each flow regime while conserving mass, and successfully yields solutions of the coupled system for multiple temporal resolutions. We test the scheme by comparing the BE3S‐derived outputs against other models and corresponding observational data. We apply the scheme to simulate hydrologic states in a reach of the Brazos River in Southeast Texas, such as soil moisture content, groundwater level, and river stage as well as net subsurface discharge fluxes. Good agreements between the simulated and observed data for all the components show the suitability of the proposed scheme in modeling the bidirectional flows and exchanges. We also assess how the bidirectional hydrologic exchanges are affected by adjacent flow domains. We find that vertical percolation is significantly affected by unsaturated soil thickness, resulting in the spatial variability of vertical percolation across sloping topography. Hilltop‐to‐valley convergent groundwater flow is also found to impede vertical percolation in river valleys due to shallow water table while facilitating percolation in the hilltops. The capability of the presented scheme that accounts for the topographically driven lateral groundwater flow and drainage dynamics provides the potential to enhance the representation of the surface‐subsurface system in Earth System Models (ESMs).
Flow and Entrainment Mechanisms Around a Freshwater Mussel Aligned With the Incoming Flow
Authors: Wu Hao , Constantinescu George , Zeng Jie
Published: September 2020

The paper uses information from eddy‐resolving simulations to characterize flow and turbulence around freshwater mussels at the organism scale. The focus is on the simplest case of a partially burrowed, isolated mussel aligned with the incoming flow in an open channel. The wake structure and the capacity of the flow to displace the mussel from the bed substrate and to induce local scour around the mussel are investigated as a function of the ratio between the height of the exposed part of the mussel, h, and the total mussel height, d, and as a function of the filtration velocity ratio (VR) between the incoming channel flow velocity, U0, and the mean velocity inside the excurrent siphon, Ue. As opposed to the flow past most surface‐mounted obstacles where the bed shear stresses are reduced in the wake of the body, the capacity of the flow to induce bed erosion behind isolated mussels aligned with the flow is relatively large because of strong downwelling motions inside the horizontal separated shear layers. These flow features are associated with the formation of counterrotating base vortices of unequal coherence that induce upwash behind the mussel. The total circulation of the base vortices increases with increasing h/d and VR. Though both symmetrical and antisymmetrical shedding are observed in the wake, the antisymmetrical mode dominates, and its strength increases with increasing VR. The nondimensional streamwise force acting on the emerged part of the mussel's shell increases with increasing h/d and VR. Finally, the paper discusses the effects of varying h/d and VR on the dynamics and dilution of the jet of filtered water originating in the excurrent siphon, which is important to understand how mussels affect mixing and water quality (e.g., nutrient availability and phytoplankton concentration) in natural streams.
Improved Prediction of Management‐Relevant Groundwater Discharge Characteristics Throughout River Networks
Authors: Barclay J. R. , Starn J. J. , Briggs M. A. , Helton A. M.
Published: September 2020

Groundwater discharge zones connect aquifers to surface water, generating baseflow and serving as ecosystem control points across aquatic ecosystems. The influence of groundwater discharge on surface flow connectivity, fate and transport of contaminants and nutrients, and thermal habitat depends strongly on hydrologic characteristics such as the spatial distribution, age, and depth of source groundwater flow paths. Groundwater models have the potential to predict spatial discharge characteristics within river networks, but models are often not evaluated against these critical characteristics and model equifinality with respect to discharge processes is a known challenge. We quantify discharge characteristics across a suite of groundwater models with commonly used frameworks and calibration data. We developed a base model (MODFLOW‐NWT) for a 1,570‐km2 watershed in the northeastern United States and varied the calibration data, control of river‐aquifer exchange directionality, and resolution. Most models (n = 11 of 12) fit similarly to calibration metrics, but patterns in discharge location, flow path depth, and subsurface travel time varied substantially. We found (1) a 15% difference in the percent of discharge going to first‐order streams, (2) threefold variations in flow path depth, and (3) sevenfold variations in the subsurface travel times among the models. We recalibrated three models using a synthetic discharge location data set. Calibration with discharge location data reduced differences in simulated discharge characteristics, suggesting an approach to improved equifinality based on widespread field‐based mapping of discharge zones. Our work quantifying variation across common modeling approaches is an important step toward characterizing and improving predictions of groundwater discharge characteristics.
Microbial carrying capacity and carbon biomass of plastic marine debris
Authors: Zhao Shiye , Zettler Erik R , Amaral-Zettler Linda A , Mincer Tracy J
Published: September 2020

Trillions of plastic debris fragments are floating at sea, presenting a substantial surface area for microbial colonization. Numerous cultivation-independent surveys have characterized plastic-associated microbial biofilms, however, quantitative studies addressing microbial carbon biomass are lacking. Our confocal laser scanning microscopy data show that early biofilm development on polyethylene, polypropylene, polystyrene, and glass substrates displayed variable cell size, abundance, and carbon biomass, whereas these parameters stabilized in mature biofilms. Unexpectedly, plastic substrates presented lower volume proportions of photosynthetic cells after 8 weeks, compared to glass. Early biofilms displayed the highest proportions of diatoms, which could influence the vertical transport of plastic debris. In total, conservative estimates suggest 2.1 × 1021 to 3.4 × 1021 cells, corresponding to about 1% of the microbial cells in the ocean surface microlayer (1.5 × 103 to 1.1 × 104 tons of carbon biomass), inhabit plastic debris globally. As an unnatural addition to sea surface waters, the large quantity of cells and biomass carried by plastic debris has the potential to impact biodiversity, autochthonous ecological functions, and biogeochemical cycles within the ocean.
SH003 activates autophagic cell death by activating ATF4 and inhibiting G9a under hypoxia in gastric cancer cells
Authors: Kim Tae Woo , Cheon Chunhoo , Ko Seong-Gyu
Published: September 2020

In gastric cancer (GC), hypoxia is one of the greatest obstacles to cancer therapy. In this present study, we report that SH003, an herbal formulation, induces ER stress via PERK-ATF4-CHOP signaling in GC. SH003-mediated ER stress inhibits G9a, a histone methyltransferase, by reducing STAT3 phosphorylation and activates autophagy, indicating to the dissociation of Beclin-1 and autophagy initiation from Bcl-2/Beclin-1 complex. However, the inhibition of PERK and CHOP inhibited SH003-induced cell death and autophagy activation. Moreover, targeting autophagy using specific siRNAs of LC3B or p62 or the autophagy inhibitor 3-MA also inhibited SH003-induced cell death in GC. Interestingly, SH003 induces BNIP3-mediated autophagic cell death under hypoxia than normoxia in GC. These findings reveal that SH003-induced ER stress regulates BNIP3-induced autophagic cell death via inhibition of STAT3-G9a axis under hypoxia in GC. Therefore, SH003 may an important tumor therapeutic strategy under hypoxia-mediated chemo-resistance.
Dietary diversity is associated with longitudinal changes in hippocampal volume among Japanese community dwellers
Authors: Otsuka Rei , Nishita Yukiko , Nakamura Akinori , Kato Takashi , Iwata Kaori , Tange Chikako , Tomida Makiko , Kinoshita Kaori , Nakagawa Takeshi , Ando Fujiko , Shimokata Hiroshi , Arai Hidenori
Published: September 2020

Background/Objectives

Dietary habits are known to affect health, including the rate of brain ageing and susceptibility to diseases. This study examines the longitudinal relationship between dietary diversity and hippocampal volume, which is a key structure of memory processing and is known to be impaired in dementia.

Subjects/Methods

Subjects were aged 40–89 years (n = 1683, men: 50.6%) and participated in a 2-year follow-up study of the National Institute for Longevity Sciences-Longitudinal Study of Aging. Dietary intake was calculated from 3-day dietary records, and dietary diversity was determined using the Quantitative Index for Dietary Diversity at baseline. Longitudinal changes in hippocampal and total grey matter volumes were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. Estimated mean brain volume change in relation to dietary diversity score quintiles was assessed by the general linear model, adjusted for age, sex, education, smoking status, alcohol intake, physical activity, and comorbidities.

Results

The mean (± standard deviation) % decreases in hippocampal and total grey matter volume during the 2-year follow-up were 1.00% (±2.27%) and 0.78% (±1.83%), respectively. Multivariate-adjusted decreases in total grey matter volume were associated with dietary diversity score (p = 0.065, p for trend = 0.017), and the % decrease in hippocampal volume was more strongly associated with the dietary diversity score: the estimated mean (± standard error) values were 1.31% (±0.12%), 1.07% (±0.12%), 0.98% (±0.12%), 0.81% (±0.12%), and 0.85% (±0.12%), according to dietary diversity quintiles in ascending order (p = 0.030, p for trend = 0.003).

Conclusions

Among community dwellers, increased dietary diversity may be a new nutritional strategy to prevent hippocampal atrophy.
Sex-biased patterns shaped the genetic history of Roma
Authors: García-Fernández C. , Font-Porterias N. , Kučinskas V. , Sukarova-Stefanovska E. , Pamjav H. , Makukh H. , Dobon B. , Bertranpetit J. , Netea M. G. , Calafell F. , Comas D.
Published: September 2020

The Roma population is a European ethnic minority characterized by recent and multiple dispersals and founder effects. After their origin in South Asia around 1,500 years ago, they migrated West. In Europe, they diverged into ethnolinguistically distinct migrant groups that spread across the continent. Previous genetic studies based on genome-wide data and uniparental markers detected Roma founder events and West-Eurasian gene flow. However, to the best of our knowledge, it has not been assessed whether these demographic processes have equally affected both sexes in the population. The present study uses the largest and most comprehensive dataset of complete mitochondrial and Y chromosome Roma sequences to unravel the sex-biased patterns that have shaped their genetic history. The results show that the Roma maternal genetic pool carries a higher lineage diversity from South Asia, as opposed to a single paternal South Asian lineage. Nonetheless, the European gene flow events mainly occurred through the maternal lineages; however, a signal of this gene flow is also traceable in the paternal lineages. We also detect a higher female migration rate among European Roma groups. Altogether, these results suggest that sociocultural factors influenced the emergence of sex-biased genetic patterns at global and local scales in the Roma population through time.
Identification of 12 immune-related lncRNAs and molecular subtypes for the clear cell renal cell carcinoma based on RNA sequencing data
Authors: Zhong Weimin , Chen Bin , Zhong Hongbin , Huang Chaoqun , Lin Jianqiong , Zhu Maoshu , Chen Miaoxuan , Lin Ying , Lin Yao , Huang Jiyi
Published: September 2020

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma (RCC). Despite the existing extensive research, the molecular and pathogenic mechanisms of ccRCC are elusive. We aimed to identify the immune-related lncRNA signature and molecular subtypes associated with ccRCC. By integrating 4 microarray datasets from Gene Expression Omnibus database, we identified 49 immune-related genes. The corresponding immune-related lncRNAs were further identified in the TCGA dataset. 12-lncRNAs prognostic and independent signature was identified through survival analysis and survival difference between risk groups was further identified based on the risk score. Besides, we identified 3 molecular subtypes and survival analysis result showed that cluster 2 has a better survival outcome. Further, ssGSEA enrichment analysis for the immune-associated gene sets revealed that cluster 1 corresponded to a high immune infiltration level. While cluster 2 and cluster 3 corresponded to low and medium immune infiltration level, respectively. In addition, we validated the 12-lncRNA prognostic signature and molecular subtypes in an external validation dataset from the ICGC database. In summary, we identified a 12-lncRNA prognostic signature which may provide new insights into the molecular mechanisms of ccRCC and the molecular subtypes provided a theoretical basis for personalized treatment by clinicians.
Novel miRNA signature for predicting the stage of hepatocellular carcinoma
Authors: Yerukala Sathipati Srinivasulu , Ho Shinn-Ying
Published: September 2020

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide. Recently, microRNAs (miRNAs) are reported to be altered and act as potential biomarkers in various cancers. However, miRNA biomarkers for predicting the stage of HCC are limitedly discovered. Hence, we sought to identify a novel miRNA signature associated with cancer stage in HCC. We proposed a support vector machine (SVM)-based cancer stage prediction method, SVM-HCC, which uses an inheritable bi-objective combinatorial genetic algorithm for selecting a minimal set of miRNA biomarkers while maximizing the accuracy of predicting the early and advanced stages of HCC. SVM-HCC identified a 23-miRNA signature that is associated with cancer stages in patients with HCC and achieved a 10-fold cross-validation accuracy, sensitivity, specificity, Matthews correlation coefficient, and area under the receiver operating characteristic curve (AUC) of 92.59%, 0.98, 0.74, 0.80, and 0.86, respectively; and test accuracy and test AUC of 74.28% and 0.73, respectively. We prioritized the miRNAs in the signature based on their contributions to predictive performance, and validated the prognostic power of the prioritized miRNAs using Kaplan–Meier survival curves. The results showed that seven miRNAs were significantly associated with prognosis in HCC patients. Correlation analysis of the miRNA signature and its co-expressed miRNAs revealed that hsa-let-7i and its 13 co-expressed miRNAs are significantly involved in the hepatitis B pathway. In clinical practice, a prediction model using the identified 23-miRNA signature could be valuable for early-stage detection, and could also help to develop miRNA-based therapeutic strategies for HCC.
Centers of endemism of freshwater protists deviate from pattern of taxon richness on a continental scale
Authors: Olefeld Jana L. , Bock Christina , Jensen Manfred , Vogt Janina C. , Sieber Guido , Albach Dirk , Boenigk Jens
Published: September 2020

Here, we analyzed patterns of taxon richness and endemism of freshwater protists in Europe. Even though the significance of physicochemical parameters but also of geographic constraints for protist distribution is documented, it remains unclear where regional areas of high protist diversity are located and whether areas of high taxon richness harbor a high proportion of endemics. Further, patterns may be universal for protists or deviate between taxonomic groups. Based on amplicon sequencing campaigns targeting the SSU and ITS region of the rDNA we address these patterns at two different levels of phylogenetic resolution. Our analyses demonstrate that protists have restricted geographical distribution areas. For many taxonomic groups the regions of high taxon richness deviate from those having a high proportion of putative endemics. In particular, the diversity of high mountain lakes as azonal habitats deviated from surrounding lowlands, i.e. many taxa were found exclusively in high mountain lakes and several putatively endemic taxa occurred in mountain regions like the Alps, the Pyrenees or the Massif Central. Beyond that, taxonomic groups showed a pronounced accumulation of putative endemics in distinct regions, e.g. Dinophyceae along the Baltic Sea coastline, and Chrysophyceae in Scandinavia. Many other groups did not have pronounced areas of increased endemism but geographically restricted taxa were found across Europe.
Spectral dynamics on saturable absorber in mode-locking with time stretch spectroscopy
Authors: Suzuki Masayuki , Boyraz Ozdal , Asghari Hossein , Jalali Bahram
Published: September 2020

A mode-locked laser that can produce a broadband spectrum and ultrashort pulse has been applied for many applications in an extensive range of scientific fields. To obtain stable mode-locking during a long time alignment-free, a semiconductor saturable absorber is one of the most suitable devices. Dynamics from noise to a stable mode-locking state in the spectral-domain are known as complex and a non-repetitive phenomenon with the time scale from nanoseconds to milliseconds. Thus, a conventional spectrometer, which is composed of a grating and line sensor, cannot capture the spectral behavior from noise to stable mode-locking. As a powerful spectral measurement technique, a time-stretch dispersive Fourier transformation (TS-DFT) has been recently used to enable a successive single-shot spectral measurement over a couple of milliseconds time span. Here, we experimentally demonstrate real-time spectral evolution of femtosecond pulse build-up in a homemade passive mode-locked Yb fiber laser with a semiconductor saturable absorber mirror using TS-DFT. Capturing 700 consecutive spectra (~ 17 µs time window) in real-time using the time-stretch technique, we are able to resolve the transient dynamics that lead to stable mode-locking. Before setting stable mode-locking, an oscillating or shifting fringe pattern in the consecutive spectra was detected. This signature proves the existence of multiple pulses (including a soliton molecule) which is temporally separated with a different relative phase. The dynamics on multiple pulses is originated from a fast relaxation time of the saturable absorption effect. This study provides novel insights into understanding the pulse behavior during the birth of an ultrafast mode-locked laser pulse and the stable single-pulse operation which is highly stabilized.
Eye-background contrast as a quantitative marker for pupal age in a forensically important carrion beetle Necrodes littoralis L. (Silphidae)
Authors: Novák M. , Frątczak-Łagiewska K. , Mądra-Bielewicz A. , Matuszewski S.
Published: September 2020

Insect pupae sampled at a death scene may be used to estimate the post-mortem interval. The pupal age is however difficult to estimate, as there are no good quantitative markers for the age of a pupa. We present a novel method for pupal age estimation based on the quantification of contrast in intensity between the eyes of a pupa and the middle grey photography card as a standard background. The intensity is measured on a standardized scale from 0 (perfect black) to 255 (perfect white) using computer graphical software and pictures of the eye and the background taken with a stereomicroscope. Eye-background contrast is calculated by subtracting the average intensity of the eye from the average intensity of the background. The method was developed and validated using pupae of Necrodes littoralis (Linnaeus, 1758) (Coleoptera: Silphidae), one of the most abundant beetle species on human cadavers in Central Europe. To develop the model, pupae were reared in 17, 20 and 23 °C, with a total of 120 specimens. The method was validated by three raters, using in total 182 pupae reared in 15, 17, 20, 23 and 25 °C. We found a gradual increase in eye-background contrast with pupal age. Changes followed generalized logistic function, with almost perfect fit of the model. Using our method pupal age was estimated with the average error of 8.1 accumulated degree-days (ADD). The largest error was 27.8 ADD and 95% of age estimates had errors smaller than 20 ADD. While using the method, different raters attained similar accuracy. In conclusion, we have demonstrated that eye-background contrast is a good quantitative marker for the age of N. littoralis pupae. Contrast measurements gave accurate estimates for pupal age. Our method is thus proven to be a candidate for a reliable approach to age insect pupae in forensic entomology.
Increased levels of histidine-rich glycoprotein are associated with the development of post-thrombotic syndrome
Authors: Siudut Jakub , Natorska Joanna , Son Maksim , Plens Krzysztof , Undas Anetta
Published: September 2020

Denser fibrin networks which are relatively resistant to lysis can predispose to post-thrombotic syndrome (PTS). Histidine-rich glycoprotein (HRG), a blood protein displaying antifibrinolytic properties, is present in fibrin clots. We investigated whether HRG may affect the risk of PTS in relation to alterations to fibrin characteristics. In venous thromboembolism (VTE) patients, we evaluated plasma HRG levels, plasma clot permeability, maximum absorbance, clot lysis time and maximum rate of increase in D-dimer levels released from clots after 3 months of the index event. We excluded patients with cancer and severe comorbidities. After 2 years of follow-up, 48 patients who developed PTS had 18.6% higher HRG at baseline. Baseline HRG positively correlated with clot lysis time, maximum absorbance, and thrombin-activatable fibrinolysis inhibitor (TAFI) activity but was inversely correlated with plasma clot permeability and maximum rate of increase in D-dimer levels released from clots. On multivariate regression model adjusted for age, fibrinogen and glucose, independent predictors of PTS were recurrent VTE, baseline HRG level, and TAFI activity. VTE recurred in 45 patients, including 30 patients with PTS, and this event showed no association with elevated HRG. Our findings suggest that increased HRG levels might contribute to the development of PTS, in part through prothrombotic fibrin clot properties.
Robustness and rich clubs in collaborative learning groups: a learning analytics study using network science
Authors: Saqr Mohammed , Nouri Jalal , Vartiainen Henriikka , Tedre Matti
Published: September 2020

Productive and effective collaborative learning is rarely a spontaneous phenomenon but rather the result of meeting a set of conditions, orchestrating and scaffolding productive interactions. Several studies have demonstrated that conflicts can have detrimental effects on student collaboration. Through the application of network science, and social network analysis in particular, this learning analytics study investigates the concept of group robustness; that is, the capacity of collaborative groups to remain functional despite the withdrawal or absence of group members, and its relation to group performance in the frame of collaborative learning. Data on all student and teacher interactions were collected from two phases of a course in medical education that employed an online learning environment. Visual and mathematical analysis were conducted, simulating the removal of actors and its effect on the group’s robustness and network structure. In addition, the extracted network parameters were used as features in machine learning algorithms to predict student performance. The study contributes findings that demonstrate the use of network science to shed light on essential elements of collaborative learning and demonstrates how the concept and measures of group robustness can increase understanding of the conditions of productive collaborative learning. It also contributes to understanding how certain interaction patterns can help to promote the sustainability or robustness of groups, while other interaction patterns can make the group more vulnerable to withdrawal and dysfunction. The finding also indicate that teachers can be a driving factor behind the formation of rich clubs of well-connected few and less connected many in some cases and can contribute to a more collaborative and sustainable process where every student is included.
Hybrid Harris hawks optimization with cuckoo search for drug design and discovery in chemoinformatics
Authors: Houssein Essam H. , Hosney Mosa E. , Elhoseny Mohamed , Oliva Diego , Mohamed Waleed M. , Hassaballah M.
Published: September 2020

One of the major drawbacks of cheminformatics is a large amount of information present in the datasets. In the majority of cases, this information contains redundant instances that affect the analysis of similarity measurements with respect to drug design and discovery. Therefore, using classical methods such as the protein bank database and quantum mechanical calculations are insufficient owing to the dimensionality of search spaces. In this paper, we introduce a hybrid metaheuristic algorithm called CHHO–CS, which combines Harris hawks optimizer (HHO) with two operators: cuckoo search (CS) and chaotic maps. The role of CS is to control the main position vectors of the HHO algorithm to maintain the balance between exploitation and exploration phases, while the chaotic maps are used to update the control energy parameters to avoid falling into local optimum and premature convergence. Feature selection (FS) is a tool that permits to reduce the dimensionality of the dataset by removing redundant and non desired information, then FS is very helpful in cheminformatics. FS methods employ a classifier that permits to identify the best subset of features. The support vector machines (SVMs) are then used by the proposed CHHO–CS as an objective function for the classification process in FS. The CHHO–CS-SVM is tested in the selection of appropriate chemical descriptors and compound activities. Various datasets are used to validate the efficiency of the proposed CHHO–CS-SVM approach including ten from the UCI machine learning repository. Additionally, two chemical datasets (i.e., quantitative structure-activity relation biodegradation and monoamine oxidase) were utilized for selecting the most significant chemical descriptors and chemical compounds activities. The extensive experimental and statistical analyses exhibit that the suggested CHHO–CS method accomplished much-preferred trade-off solutions over the competitor algorithms including the HHO, CS, particle swarm optimization, moth-flame optimization, grey wolf optimizer, Salp swarm algorithm, and sine–cosine algorithm surfaced in the literature. The experimental results proved that the complexity associated with cheminformatics can be handled using chaotic maps and hybridizing the meta-heuristic methods.
Sylvian fissure development is linked to differential genetic expression in the pre-folded brain
Authors: Mallela Arka N. , Deng Hansen , Brisbin Alyssa K. , Bush Alan , Goldschmidt Ezequiel
Published: September 2020

The mechanisms by which the human cerebral cortex folds into its final form remain poorly understood. With most of the current models and evidence addressing secondary folds, we sought to focus on the global geometry of the mature brain by studying its most distinctive feature, the Sylvian fissure. A digital human fetal brain atlas was developed using previously obtained MRI imaging of 81 healthy fetuses between gestational ages 21 and 38 weeks. To account for the development of the Sylvian fissure, we compared the growth of the frontotemporal opercula over the insular cortex and compared the transcriptome of the developing cortices for both regions. Spatiotemporal mapping of the lateral hemispheric surface showed the highest rate of organized growth in regions bordering the Sylvian fissure of the frontal, parietal and temporal lobes. Volumetric changes were first observed in the posterior aspect of the fissure moving anteriorly to the frontal lobe and laterally in the direction of the temporal pole. The insular region, delineated by the limiting insular gyri, expanded to a much lesser degree. The gene expression profile, before folding begins in the maturing brain, was significantly different in the developing opercular cortex compared to the insula. The Sylvian fissure forms by the relative overgrowth of the frontal and temporal lobes over the insula, corresponding to domains of highly expressed transcription factors involved in neuroepithelial cell differentiation.
Tryptophan-galactosylamine conjugates inhibit and disaggregate amyloid fibrils of Aβ42 and hIAPP peptides while reducing their toxicity
Authors: Paul Ashim , Frenkel-Pinter Moran , Escobar Alvarez Daniela , Milordini Giulia , Gazit Ehud , Zacco Elsa , Segal Daniel
Published: September 2020

Self-assembly of proteins into amyloid fibrils is a hallmark of various diseases, including Alzheimer’s disease (AD) and Type-2 diabetes Mellitus (T2DM). Aggregation of specific peptides, like Aβ42 in AD and hIAPP in T2DM, causes cellular dysfunction resulting in the respective pathology. While these amyloidogenic proteins lack sequence homology, they all contain aromatic amino acids in their hydrophobic core that play a major role in their self-assembly. Targeting these aromatic residues by small molecules may be an attractive approach for inhibiting amyloid aggregation. Here, various biochemical and biophysical techniques revealed that a panel of tryptophan-galactosylamine conjugates significantly inhibit fibril formation of Aβ42 and hIAPP, and disassemble their pre-formed fibrils in a dose-dependent manner. They are also not toxic to mammalian cells and can reduce the cytotoxicity induced by Aβ42 and hIAPP aggregates. These tryptophan-galactosylamine conjugates can therefore serve as a scaffold for the development of therapeutics towards AD and T2DM.