bluuebunny/crossref_metadata_2025 huggingface dataset:
APXS‐Derived Compositional Characteristics of Vera Rubin Ridge and Murray Formation, Gale Crater, Mars: Geochemical Implications for the Origin of the Ridge
Authors: Thompson L. M. , Berger J. A. , Spray J. G. , Fraeman A. A. , McCraig M. A. , O'Connell‐Cooper C. D. , Schmidt M. E. , VanBommel S. , Gellert R. , Yen A. , Boyd N. I.
Published: September 2020

The resistant ~50 m thick Vera Rubin ridge (VRR) situated near the base of Mount Sharp, Gale crater, Mars, has been deemed a high priority science target for the Mars Science Laboratory mission. This is because of (1) its position at the base of the 5 km layered strata of Mount Sharp and (2) the detection of hematite from orbit, indicating that it could be the site of enhanced oxidation. The compositional data acquired by the Alpha Particle X‐ray Spectrometer (APXS) during Curiosity's exploration of VRR help to elucidate questions pertaining to the formation of the ridge. APXS analyses indicate that VRR falls within the compositional range of underlying lacustrine mudstones, consistent with a continuation of that depositional environment and derivation from a similar provenance. Lower Fe concentrations for VRR compared to the underlying strata discounts the addition of large amounts of hematite to the strata, either as cement or as detrital input. Compositional trends are associated with VRR cross‐cut stratigraphy, indicating postdepositional processes. Higher Si and Al and lower Ti, Fe, and Mn than the underlying mudstone, particularly within distinct patches of gray/blue bedrock, are consistent with the addition of Si and Al. Lateral and vertical compositional variations suggest enhanced element mobility and fluid flow (possibly via multiple events) through VRR, increasing toward the top of the ridge, consistent with the action of warm (~50–100°C), locally acidic saline fluids as inferred from the mineralogy of drilled samples.
Morphometric Control on Dissolved Organic Carbon in Subarctic Streams
Authors: Mzobe P. , Yan Y. , Berggren M. , Pilesjö P. , Olefeldt D. , Lundin E. , Roulet N. T. , Persson A.
Published: September 2020

Climate change has the potential to alter hydrological regimes and to expand saturated areas in permafrost environments, which are important sources of organic carbon. The sources, transfer zones, and delivery mechanisms of carbon into the stream network are controlled by the morphometric properties of the catchment; however, the utility and limitations of these properties as predictors of dissolved organic carbon concentrations have rarely been systematically evaluated. This study tested the relationships between 18 morphometric indicators and observed dissolved organic carbon (DOC) concentrations in the Stordalen catchment, Sweden. Geospatial and explorative statistics were combined to assess the topographical, areal, and linear indicators influencing the distribution of DOC in the catchment. The results suggest that catchment morphometric indicators can be used as proxies to predict DOC concentrations along a longitudinal continuum in subarctic climate regions (R2 up to 0.52). Morphometry indicators that best served as predictors of DOC concentration in the model were as follows: relief, slope length and steepness factor (LS‐factor), sediment transport capacity, and catchment area. Due to the influence that catchment form exerts in DOC spatial patterns and processing, a morphometric approach can serve as a first approximation of DOC spatial patterns within a catchment. The initial step in identifying carbon sources based on the catchment topography has the potential to allow for quick and multilevel comparison within and between catchments.
Estuarine Forecasts at Daily Weather to Subseasonal Time Scales
Authors: Ross Andrew C. , Stock Charles A. , Dixon Keith W. , Friedrichs Marjorie A. M. , Hood Raleigh R. , Li Ming , Pegion Kathleen , Saba Vincent , Vecchi Gabriel A.
Published: September 2020

Most present forecast systems for estuaries predict conditions for only a few days into the future. However, there are many reasons to expect that skillful estuarine forecasts are possible for longer time periods, including increasingly skillful extended atmospheric forecasts, the potential for lasting impacts of atmospheric forcing on estuarine conditions, and the predictability of tidal cycles. In this study, we test whether skillful estuarine forecasts are possible for up to 35 days into the future by combining an estuarine model of Chesapeake Bay with 35‐day atmospheric forecasts from an operational weather model. When compared with both a hindcast simulation from the same estuarine model and with observations, the estuarine forecasts for surface water temperature are skillful up to about 2 weeks into the future, and the forecasts for bottom temperature, surface and bottom salinity, and density stratification are skillful for all or the majority of the forecast period. Bottom oxygen forecasts are skillful when compared to the model hindcast, but not when compared with observations. We also find that skill for all variables in the estuary can be improved by taking the mean of multiple estuarine forecasts driven by an ensemble of atmospheric forecasts. Finally, we examine the forecasts in detail using two case studies of extreme events, and we discuss opportunities for improving the forecast skill.
Intercomparison of XRF Core Scanning Results From Seven Labs and Approaches to Practical Calibration
Authors: Dunlea Ann G. , Murray Richard W. , Tada Ryuji , Alvarez‐Zarikian Carlos A. , Anderson Chloe H. , Gilli Adrian , Giosan Liviu , Gorgas Thomas , Hennekam Rick , Irino Tomohisa , Murayama Masafumi , Peterson Larry C. , Reichart Gert‐Jan , Seki Arisa , Zheng Hongbo , Ziegler Martin
Published: September 2020

X‐ray fluorescence (XRF) scanning of marine sediment has the potential to yield near‐continuous and high‐resolution records of elemental abundances, which are often interpreted as proxies for paleoceanographic processes over different time scales. However, many other variables also affect scanning XRF measurements and convolute the quantitative calibrations of element abundances and comparisons of data from different labs. Extensive interlab comparisons of XRF scanning results and calibrations are essential to resolve ambiguities and to understand the best way to interpret the data produced. For this study, we sent a set of seven marine sediment sections (1.5 m each) to be scanned by seven XRF facilities around the world to compare the outcomes amidst a myriad of factors influencing the results. Results of raw element counts per second (cps) were different between labs, but element ratios were more comparable. Four of the labs also scanned a set of homogenized sediment pellets with compositions determined by inductively coupled plasma‐optical emission spectrometry (ICP‐OES) and ICP‐mass spectrometry (MS) to convert the raw XRF element cps to concentrations in two ways: a linear calibration and a log‐ratio calibration. Although both calibration curves are well fit, the results show that the log‐ratio calibrated data are significantly more comparable between labs than the linearly calibrated data. Smaller‐scale (higher‐resolution) features are often not reproducible between the different scans and should be interpreted with caution. Along with guidance on practical calibrations, our study recommends best practices to increase the quality of information that can be derived from scanning XRF to benefit the field of paleoceanography.
Tropical Indian Ocean Mediates ENSO Influence Over Central Southwest Asia During the Wet Season
Authors: Abid Muhammad Adnan , Ashfaq Moetasim , Kucharski Fred , Evans Katherine J. , Almazroui Mansour
Published: September 2020

El Niño–Southern Oscillation (ENSO) modulates wet season (November–April) precipitation over Central Southwest Asia (CSWA), however, intraseasonal characteristics of its influence are largely unknown, which can be important for its subseasonal to seasonal hydroclimate predictability. Here we show that the ENSO‐CSWA teleconnection varies intraseasonally and is a combination of direct and indirect positive influences. The direct influence is through a Rossby wave‐like pattern in the tail months. The indirect influence is through an atmospheric dipole of diabatic heating anomalies in the tropical Indian Ocean (TIO) as a result of ENSO‐forced response, which also generates a Rossby wave‐like forcing and persists throughout the wet season. ENSO exerts its strongest influence when both direct and indirect modes are in phase, while the relationship breaks down when the two modes are out of phase. The atmospheric teleconnection through the atmospheric diabatic heating anomalies in the TIO is reproducible in numerical simulations.
How Old Are Marshes on the East Coast, USA? Complex Patterns in Wetland Age Within and Among Regions
Authors: Braswell Anna E. , Heffernan James B. , Kirwan Matthew L.
Published: September 2020

Sea‐level dynamics, sediment availability, and marine energy are critical drivers of coastal wetland formation and persistence, but their roles as continental‐scale drivers remain unknown. We evaluated the timing and spatial variability of wetland formation from new and existing cores collected along the Atlantic and Gulf coasts of the United States. Most basal peat ages occurred after sea‐level rise slowed (after ~4,000 years before present), but predominance of sea‐level rise studies may skew age estimates toward older sites. Near‐coastal sites tended to be younger, indicating creation of wetlands through basin infilling and overwash events. Age distributions differed among regions, with younger wetlands in the northeast and southeast corresponding to European colonization and deforestation. Across all cores, wetland age correlated strongly with basal peat depth. Marsh age elucidates the complex interactions between sea‐level rise, sediment supply, and geomorphic setting in determining timing and location of marsh formation and future wetland persistence.
A Comprehensive Picture for Binary Interactions of Subaqueous Barchans
Authors: Assis W. R. , Franklin E. M.
Published: September 2020

We investigate experimentally the short‐range interactions occurring between two subaqueous barchans. The experiments were conducted in a water channel of transparent material where controlled grains were poured inside, and a camera placed on the top acquired images of the bedforms. We varied the grain types (diameter, density, and roundness), pile masses, transverse distances, water flow rates, and initial conditions. As a result, five different patterns were identified for both aligned and off‐centered configurations, and we propose interaction maps that depend basically on the ratio between the number of grains of each dune, Shields number, and alignment of barchans. In addition, we show experimental indications that an ejected barchan has roughly the same mass of the impacting one in some cases and that in wake‐dominated processes the asymmetry of the downstream dune is large. The present results shed light on the size regulation of barchans found on Earth and other planets.
Physical and Biogeochemical Drivers of Alongshore pH and Oxygen Variability in the California Current System
Authors: Cheresh Julia , Fiechter Jerome
Published: September 2020

In the California Current System (CCS), the nearshore environment experiences natural exposure to low pH and reduced oxygen in response to coastal upwelling. Anthropogenic impacts further decrease pH and oxygen below biological thresholds, making the CCS particularly vulnerable to ocean acidification and hypoxia. Results from a coupled physical‐biogeochemical model reveal a strongly heterogeneous alongshore pattern of nearshore pH and oxygen in the central CCS, both in their long‐term means and trends. This spatial structuring is explained by an interplay between alongshore variability in local upwelling intensity and subsequent primary production, modulated by nearshore advection and regional geostrophic currents. The model solution suggests that the progression of ocean acidification and hypoxia will not be spatially homogeneous, thereby highlighting the need to consider subregional processes when assessing natural and anthropogenic impacts on coastal ecosystems in eastern boundary current upwelling regions.
Radiosonde Observations of a Wintertime Meridional Convergence of Gravity Waves Around 60°S in the Lower Stratosphere
Authors: Moffat‐Griffin T. , Colwell S. R. , Wright C. J. , Hindley N. P. , Mitchell N. J.
Published: September 2020

Satellite observations show that there is a wintertime hotspot of gravity wave activity, located mainly over the ocean, around 60°S in the stratosphere. However, the sources of the gravity waves making up this hotspot are varied and complex and remain unclear. Here we use radiosonde observations from 11 Antarctic stations and selected small islands close to 60°S to examine the horizontal directional pseudo‐momentum flux and energy density distributions of upward propagating gravity waves in the lower stratosphere. This paper shows, for the first time, that short vertical wavelength gravity waves in the lower stratosphere clearly propagate meridionally toward 60°S during the winter months. This result supports previous studies that show that this belt of gravity wave activity over the ocean is contributed to by wave sources outside 60°S.
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations
Authors: Dhital S. , Kaplan M. L. , Orza J. A. G. , Fiedler S.
Published: September 2020

We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multiscale observations and the Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust storm was initiated on the lee side of the Saharan Atlas Mountains (SAM) in Algeria on 10 November 2017. This dust storm was associated with a double Rossby wave break linked through nonlinear wave reflection. Two successive Rossby wave breaks contributed to the wave amplification over the Eastern North Atlantic Ocean which transported large magnitude potential vorticity air into the North African continent. The resulting coupled pressure surge was associated with cold air advected equatorward over the SAM which organized the strong near‐surface wind that ablated the dust. The simulation results indicate that the dust front was initially related to a density current‐like cold front which formed due to the downslope transport of cold airflow over the SAM and then triggered undular bores on the lee side. Each bore perturbed the dust loading and then the subsequent diurnal heating generated differential planetary boundary layer turbulence kinetic energy strengthening the dust frontogenesis. Dust became confined behind the cold surge and interacted with the daytime Saharan planetary boundary layer leading to increased dust loading, while the dust front propagated equatorward. Two distinct dust plumes arrived successively at low levels at Mindelo, Cape Verde Islands: (1) from the coasts of Mauritania and Senegal and (2) from the SAM southern flank.
Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen
Authors: Butler Ethan E. , Chen Ming , Ricciuto Daniel , Flores‐Moreno Habacuc , Wythers Kirk R. , Kattge Jens , Thornton Peter E. , Reich Peter B.
Published: September 2020

Transitioning across biological scales is a central challenge in land surface models. Processes that operate at the scale of individual leaves must be scaled to canopies, and this is done using dedicated submodels. Here, we focus on a submodel that prescribes how light and nitrogen are distributed through plant canopies. We found a mathematical inconsistency in a submodel implemented in the Community and Energy Land Models (CLM and ELM), which incorporates twigs, branches, stems, and dead leaves in nitrogen scaling from leaf to canopy. The inconsistency leads to unrealistic (physically impossible) values of the nitrogen scaling coefficient. The mathematical inconsistency is a general mistake, that is, would occur in any model adopting this particular submodel. We resolve the inconsistency by allowing distinct profiles of stems and branches versus living leaves. We implemented the updated scheme in the ELM and find that the correction reduces global mean gross primary production (GPP) by 3.9 Pg C (3%). Further, when stems and branches are removed from the canopy in the updated model (akin to models that ignore shading from stems), global GPP increases by 4.1 Pg C (3.2%), because of reduced shading. Hence, models that entirely ignore stem shading also introduce errors in the global spatial distribution of GPP estimates, with a strong signal in the tropics, increasing GPP there by over 200 g C m−2 yr−1. Appropriately incorporating stems and other nonphotosynthesizing material into the light and nitrogen scaling routines of global land models, will improve their biological realism and accuracy.
Structural Evolution of a 1.6 Ga Orogeny Related to the Final Assembly of the Supercontinent Nuna: Coupling of Episodic and Progressive Deformation
Authors: Volante S. , Collins W. J. , Pourteau A. , Li Z.‐X. , Li J. , Nordsvan A. R.
Published: September 2020

The poly‐deformed Georgetown Inlier (GTI) in NE Australia has recently been suggested to record a 1.60 Ga orogenic event related to final Nuna assembly. However, the structural evolution of the inlier has remained poorly constrained at the regional scale, and major tectono‐thermal events occurred at circa 1.55 Ga. The GTI is the type region for conceptualization of crenulation cleavage development and where the foliation intersection axes (FIAs) approach has been applied. We reevaluated both concepts by combining a multiscale petrostructural analysis with recent petrological and geochronological data. Three main deformation events (D1–D3) and associated composite fabrics (S1–S3) are identified in the GTI. The original NE orientation of 1.60 Ga D1 compressional structures is preserved in the low‐grade western domain, and the associated composite S1 fabric is retained as microstructural relicts within circa 1.55 Ga D2 low‐strain domains to the east. Extensional D2 structures, characterized by a pervasive, high‐grade, composite S2 foliation throughout the central and eastern domains, are interpreted as the footwall of a regional N‐S trending, W dipping crustal‐scale detachment zone. Syn‐D2 S‐type granites formed at 1.55 Ga as the detachment evolved. D1 stage was associated with Nuna assembly, whereas D2 represents postcollisional extension. Progressive foliation development occurred twice in the GTI, at 1.60 (D1) and 1.55 Ga (D2), but the previous FIA analysis only records the 1.60 Ga event and cannot be easily reconciled with the regional structural analysis. This study highlights that a multiscale and multidisciplinary approach is required to unravel the structural history of orogenic belts.
microRNA-25 as a novel modulator of circadian Period2 gene oscillation
Authors: Park Inah , Kim Doyeon , Kim Jeongah , Jang Sangwon , Choi Mijung , Choe Han Kyoung , Choe Youngshik , Kim Kyungjin
Published: September 2020

Circadian clock controls an organism’s biological rhythm and regulates its physiological processes in response to external time cues. Most living organisms have their own time-keeping mechanism that is maintained by transcriptional–translational autoregulatory feedback loops involving several core clock genes, such as Period. Recent studies have found the relevance between the modulation of circadian oscillation and posttranscriptional modifications by microRNAs (miRNAs). However, there are limited studies on candidate miRNAs that regulate circadian oscillation. Here, we characterize the functions of novel miRNA-25 regulating circadian Period2 (Per2) expression. Using several in silico algorithms, we identified novel miR-25-3p that, together with miR-24-3p, targets the Per2 gene. Luciferase reporter assays validated that miR-25-3p and miR-24-3p repressed Per2 expression and confirmed their predicted binding sites in the 3′-untranslated region (UTR) of Per2 mRNA. Real-time bioluminescence analyses using Per2::Luc mouse embryonic fibroblasts confirmed that PER2 protein oscillation patterns were responsive to miR-25-3p and miR-24-3. The overexpression of miR-25-3p or miR-24-3p resulted in the dampening and period shortening of the PER2::LUC oscillation, while inhibition of either miRNA increased the relative amplitude of the PER2::LUC oscillation. Notably, endogenous miR-25-3p expression in the suprachiasmatic nucleus (SCN) showed no circadian rhythmicity, but the expression levels differed in various brain regions and peripheral tissues. These results suggest that the posttranscriptional regulation of miR-25-3p and miR-24-3p may differ according to Per2 gene expression in different tissue regions. In summary, we found that novel miR-25-3p was involved in fine-tuning circadian rhythmicity by regulating Per2 oscillation at the posttranscriptional level and that it functioned synergistically with miR-24-3p to affect Per2 oscillation.
Independent iron and light limitation in a low-light-adapted Prochlorococcus from the deep chlorophyll maximum
Authors: Hawco Nicholas J , Fu Feixue , Yang Nina , Hutchins David A , John Seth G
Published: September 2020

Throughout the open ocean, a minimum in dissolved iron concentration (dFe) overlaps with the deep chlorophyll maximum (DCM), which marks the lower limit of the euphotic zone. Maximizing light capture in these dim waters is expected to require upregulation of Fe-bearing photosystems, further depleting dFe and possibly leading to co-limitation by both iron and light. However, this effect has not been quantified for important phytoplankton groups like Prochlorococcus, which contributes most of the productivity in the oligotrophic DCM. Here, we present culture experiments with Prochlorococcus strain MIT1214, a member of the Low Light 1 ecotype isolated from the DCM in the North Pacific subtropical gyre. Under a matrix of iron and irradiance matching those found at the DCM, the ratio of Fe to carbon in Prochlorococcus MIT1214 cells ranged from 10–40 × 10−6 mol Fe:mol C and increased with light intensity and growth rate. These results challenge theoretical models predicting highest Fe:C at lowest light intensity, and are best explained by a large photosynthetic Fe demand that is not downregulated at higher light. To sustain primary production in the DCM with the rigid Fe requirements of low-light-adapted Prochlorococcus, dFe must be recycled rapidly and at high efficiency.
A symbiotic nutrient exchange within the cyanosphere microbiome of the biocrust cyanobacterium,Microcoleus vaginatus
Authors: Nelson Corey , Giraldo-Silva Ana , Garcia-Pichel Ferran
Published: September 2020

Microcoleus vaginatus plays a prominent role as both primary producer and pioneer in biocrust communities from dryland soils. And yet, it cannot fix dinitrogen, essential in often nitrogen-limited drylands. But a diazotroph-rich “cyanosphere” has been described in M. vaginatus, hinting that there exists a C for N exchange between the photoautotroph and heterotrophic diazotrophs. We provide evidence for this by establishing such a symbiosis in culture and by showing that it is selective and dependent on nitrogen availability. In natural populations, provision of nitrogen resulted in loss of diazotrophs from the cyanosphere of M. vaginatus compared to controls, but provision of phosphorus did not. Co-culturing of pedigreed cyanosphere diazotroph isolates with axenic M. vaginatus resulted in copious growth in C and N-free medium, but co-culture with non-cyanosphere diazotrophs or other heterotrophs did not. Unexpectedly, bundle formation in M. vaginatus, diacritical to the genus but not seen in axenic culture, was restored in vitro by imposed nitrogen limitation or, even more strongly, by co-culture with diazotrophic partners, implicating this trait in the symbiosis. Our findings provide direct evidence for a symbiotic relationship between M. vaginatus and its cyanosphere and help explain how it can be a global pioneer in spite of its genetic shortcomings.
Determining dimensionalities and multiplicities of crystal nets
Authors: Gao Hao , Wang Junjie , Guo Zhaopeng , Sun Jian
Published: September 2020

Low-dimensional materials have attracted significant attention over the past decade. To discover new low-dimensional materials, high-throughput screening methods for structures with target dimensionality have been applied in different materials databases. For this purpose, the reliability of dimensionality identification is therefore highly important. In this work, we find that the existence of self-penetrating nets may lead to incorrect results by previous methods. Instead of this, we use the quotient graph to analyse the topologies of structures and compute their dimensionalities. Based on the quotient graph, we can calculate not only the dimensionality but also the multiplicity of self-penetrating structures. As a demonstration, we screened the Crystallography Open Database using the method and find hundreds of structures with different dimensionalities and high multiplicities up to 11. Some of the self-penetrating materials may have application values in gas storage, selective catalysis or photocatalysis because of their high gas sorption capacities and various electronic structures.
Author Correction: Activation of SIRT6 by DNA hypomethylating agents and clinical consequences on combination therapy in leukemia
Authors: Carraway Hetty E. , Malkaram Sridhar A. , Cen Yana , Shatnawi Aymen , Fan Jun , Ali Hamdy E. A. , Abd Elmageed Zakaria Y. , Buttolph Thomm , Denvir James , Primerano Donald A. , Fandy Tamer E.
Published: September 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Tick populations from endemic and non-endemic areas in Germany show differential susceptibility to TBEV
Authors: Liebig Katrin , Boelke Mathias , Grund Domenic , Schicht Sabine , Springer Andrea , Strube Christina , Chitimia-Dobler Lidia , Dobler Gerhard , Jung Klaus , Becker Stefanie
Published: September 2020

Tick-borne encephalitis virus (TBEV) is endemic in twenty-seven European countries, transmitted via the bite of an infected tick. TBEV is the causative agent of one of the most important viral diseases of the central nervous system (CNS). In Germany, 890 human cases were registered between the years 2018–2019. The castor bean tick, Ixodes ricinus, is the TBEV vector with the highest importance in Central Europe, including Germany. Despite the nationwide distribution of this tick species, risk areas of TBEV are largely located in Southern Germany. To increase our understanding of TBEV-tick interactions, we collected ticks from different areas within Germany (Haselmühl/Bavaria, Hanover/Lower Saxony) and infected them via an in vitro feeding system. A TBEV isolate was obtained from an endemic focus in Haselmühl. In two experimental series conducted in 2018 and 2019, ticks sampled in Haselmühl (TBEV focus) showed higher artificial feeding rates, as well as higher TBEV infections rates than ticks from the non-endemic area (Hanover). Other than the tick origin, year and month of the infection experiment as well as co-infection with Borrelia spp., had a significant impact on TBEV Haselmühl infection rates. Taken together, these findings suggest that a specific adaptation of the tick populations to their respective TBEV virus isolates or vice versa, leads to higher TBEV infection rates in those ticks. Furthermore, co-infection with other tick-borne pathogens such as Borrelia spp. can lower TBEV infection rates in specific populations.
Long-term cognitive impairment after ICU treatment: a prospective longitudinal cohort study (Cog-I-CU)
Authors: Müller Annekatrin , von Hofen-Hohloch Judith , Mende Meinhard , Saur Dorothee , Fricke Christopher , Bercker Sven , Petros Sirak , Classen Joseph
Published: September 2020

In this prospective cohort study we aimed to investigate the trajectory of the cognitive performance of patients after discharge from an intensive care unit (ICU). Special consideration was given to patients with suspected premorbid cognitive impairment who might be at risk for the development of dementia. Clinical characteristics were collected until discharge. The premorbid cognitive state was estimated by a structured interview with a close relative. Cognitive outcome was assessed using the Consortium to Establish a Registry of Alzheimer’s Disease (CERAD) Plus battery and the Stroop Color and Word Test at the time of discharge from ICU and 9 months later. The results of the study group were compared to an established healthy control group and to normative data. A total number of 108 patients were finally included. At the time of discharge, patients underperformed the healthy control group. In linear regression models, delirium during the ICU stay and the factor premorbid cognitive impairment were associated with poorer cognitive outcome (p = 0.047 and p = 0.001). After 9 months, in 6% of patients without evidence of premorbid cognitive impairment long-lasting deficits were found. In patients with suspected premorbid cognitive impairment, performance in tests of executive function failed to improve.
Hepatic lipocalin 2 promotes liver fibrosis and portal hypertension
Authors: Chen Jiegen , Argemi Josepmaria , Odena Gemma , Xu Ming-Jiang , Cai Yan , Massey Veronica , Parrish Austin , Vadigepalli Rajanikanth , Altamirano Jose , Cabezas Joaquin , Gines Pere , Caballeria Juan , Snider Natasha , Sancho-Bru Pau , Akira Shizuo , Rusyn Ivan , Gao Bin , Bataller Ramon
Published: September 2020

Advanced fibrosis and portal hypertension influence short-term mortality. Lipocalin 2 (LCN2) regulates infection response and increases in liver injury. We explored the role of intrahepatic LCN2 in human alcoholic hepatitis (AH) with advanced fibrosis and portal hypertension and in experimental mouse fibrosis. We found hepatic LCN2 expression and serum LCN2 level markedly increased and correlated with disease severity and portal hypertension in patients with AH. In control human livers, LCN2 expressed exclusively in mononuclear cells, while its expression was markedly induced in AH livers, not only in mononuclear cells but also notably in hepatocytes. Lcn2−/− mice were protected from liver fibrosis caused by either ethanol or CCl4 exposure. Microarray analysis revealed downregulation of matrisome, cell cycle and immune related gene sets in Lcn2−/− mice exposed to CCl4, along with decrease in Timp1 and Edn1 expression. Hepatic expression of COL1A1, TIMP1 and key EDN1 system components were elevated in AH patients and correlated with hepatic LCN2 expression. In vitro, recombinant LCN2 induced COL1A1 expression. Overexpression of LCN2 increased HIF1A that in turn mediated EDN1 upregulation. LCN2 contributes to liver fibrosis and portal hypertension in AH and could represent a new therapeutic target.
Visual-reward driven changes of movement during action execution
Authors: Marti-Marca Angela , Deco Gustavo , Cos Ignasi
Published: September 2020

Motor decision-making is often described as a sequential process, beginning with the assessment of available options and leading to the execution of a selected movement. While this view is likely to be accurate for decisions requiring significant deliberation, it would seem unfit for choices between movements in dynamic environments. In this study, we examined whether and how non-selected motor options may be considered post-movement onset. We hypothesized that a change in reward at any point in time implies a dynamic reassessment of options, even after an initial decision has been made. To test this, we performed a decision-making task in which human participants were instructed to execute a reaching movement from an origin to a rectangular target to attain a reward. Reward depended on arrival precision and on the specific distribution of reward presented along the target. On a third of trials, we changed the initial reward distribution post-movement onset. Our results indicated that participants frequently change their initially selected movements when a change is associated with an increase in reward. This process occurs quicker than overall, average reaction times. Finally, changes in movement are not only dependent on reward but also on the current state of the motor apparatus.
The structure of first-cousin marriages in Brazil
Authors: Otto Paulo A. , Lemes Renan B. , Farias Allysson A. , Weller Mathias , Lima Shirley O. A. , Albino Victor Alves , Marques-Alves Yanna K. , Pardono Eliete , Bocangel Magnolia A. P. , Santos Silvana
Published: September 2020

This paper deals with the frequency and structure of first-cousin marriages, by far the most important and frequent type of consanguineous mating in human populations. Based on the analysis of large amounts of data from the world literature and from large Brazilian samples recently collected, we suggest some explanations for the asymmetry of sexes among the parental sibs of first-cousin marriages. We suggest also a simple manner to correct the method that uses population surnames to assess the different Wright fixation indexes FIS, FST and FIT taking into account not only alternative methods of surname transmission, but also the asymmetries that are almost always observed in the distribution of sexes among the parental sibs of first-cousins.
Correlated chromosomal periodicities according to the growth rate and gene expression
Authors: Liu Liu , Kurokawa Masaomi , Nagai Motoki , Seno Shigeto , Ying Bei-Wen
Published: September 2020

Linking genetic information to population fitness is crucial to understanding living organisms. Despite the abundant knowledge of the genetic contribution to growth, the overall patterns/features connecting genes, their expression, and growth remain unclear. To reveal the quantitative and direct connections, systematic growth assays of single-gene knockoutEscherichia colistrains under both rich and poor nutritional conditions were performed; subsequently, the resultant growth rates were associated with the original expression levels of the knockout genes in the parental genome. Comparative analysis of growth and the transcriptome identified not only the nutritionally differentiated fitness cost genes but also a significant correlation between the growth rates of the single-gene knockout strains and the original expression levels of these knockout genes in the parental strain, regardless of the nutritional variation. In addition, the coordinated chromosomal periodicities of the wild-type transcriptome and the growth rates of the strains lacking the corresponding genes were observed. The common six-period periodicity was somehow attributed to the essential genes, although the underlying mechanism remains to be addressed. The correlated chromosomal periodicities associated with the gene expression-growth dataset were highly valuable for bacterial growth prediction and discovering the working principles governing minimal genetic information.
Electromagnetic surface waves supported by a resistive metasurface-covered metamaterial structure
Authors: Yaqoob M. Z. , Ghaffar A. , Alkanhal Majeed A. S. , Naz M. Y. , Alqahtani Ali H. , Khan Y.
Published: September 2020

This study examines the analytical and numerical solution of electromagnetic surface waves supported by a resistive metasurface-covered grounded metamaterial structure. To simulate the metamaterial, the Kramers–Kronig relation based on the causality principle is used, while the modeling of the resistive metasurface has been done by implementing the impedance boundary conditions. The analytical expressions for the field phasors of surface waves are developed for the transverse magnetic (TM) polarized mode and transverse electric (TE) polarized mode. The characteristic equations are computed for both modes, and the unknown propagation constant is evaluated numerically in the kernel. After computation, the dispersion curves, electric field profiles, effective mode index ($$N_{eff}$$

N

eff

), and phase speeds ($$v_{p}$$

v
p

) are presented for both the TM and TE polarized modes. To study the tunability of surface waves, the influence of the thickness of the metamaterial slab ($$d$$
d
), effective permittivity of the metamaterial ($$\varepsilon_{1}$$

ε
1

), thickness of the resistive metasurface ($$t$$
t
), and effective permittivity of the metasurface ($$\varepsilon_{r}$$

ε
r

) on all the numerical results has been studied. However, the geometrical parameters are found to be more sensitive to the effective mode index ($$N_{eff}$$

N

eff

) and phase speed ($$v_{p}$$

v
p

) of the surface waves. The results are consistent with the published results, which reflects the accuracy of the work. It is concluded that the appropriate choice of parameters can be used to achieve surface waves with the desired characteristics in the GHz range. The present work may have potential applications in surface waveguide design, surface wave speed controllers, surface communication devices, and light trapping configurations.
Ancestral sequence reconstruction produces thermally stable enzymes with mesophilic enzyme-like catalytic properties
Authors: Furukawa Ryutaro , Toma Wakako , Yamazaki Koji , Akanuma Satoshi
Published: September 2020

Enzymes have high catalytic efficiency and low environmental impact, and are therefore potentially useful tools for various industrial processes. Crucially, however, natural enzymes do not always have the properties required for specific processes. It may be necessary, therefore, to design, engineer, and evolve enzymes with properties that are not found in natural enzymes. In particular, the creation of enzymes that are thermally stable and catalytically active at low temperature is desirable for processes involving both high and low temperatures. In the current study, we designed two ancestral sequences of 3-isopropylmalate dehydrogenase by an ancestral sequence reconstruction technique based on a phylogenetic analysis of extant homologous amino acid sequences. Genes encoding the designed sequences were artificially synthesized and expressed in Escherichia coli. The reconstructed enzymes were found to be slightly more thermally stable than the extant thermophilic homologue from Thermus thermophilus. Moreover, they had considerably higher low-temperature catalytic activity as compared with the T. thermophilus enzyme. Detailed analyses of their temperature-dependent specific activities and kinetic properties showed that the reconstructed enzymes have catalytic properties similar to those of mesophilic homologues. Collectively, our study demonstrates that ancestral sequence reconstruction can produce a thermally stable enzyme with catalytic properties adapted to low-temperature reactions.
The conservation value of admixed phenotypes in a critically endangered species complex
Authors: Sadanandan Keren R. , Low Gabriel W. , Sridharan Sheeraja , Gwee Chyi Yin , Ng Elize Y. X. , Yuda Pramana , Prawiradilaga Dewi M. , Lee Jessica G. H. , Tritto Anaïs , Rheindt Frank E.
Published: September 2020

In today’s environmental crisis, conservationists are increasingly confronted with terminally endangered species whose last few surviving populations may be affected by allelic introgression from closely related species. Yet there is a worrying lack of evidence-based recommendations and solutions for this emerging problem. We analyzed genome-wide DNA markers and plumage variability in a critically endangered insular songbird, the Black-winged Myna (BWM, Acridotheres melanopterus). This species is highly threatened by the illegal wildlife trade, with its wild population numbering in the low hundreds, and its continued survival urgently depending on ex-situ breeding. Its three subspecies occur along a geographic gradient of melanism and are variably interpreted as three species. However, our integrative approach revealed that melanism poorly reflects the pattern of limited genomic differentiation across BWM subspecies. We also uncovered allelic introgression into the most melanistic subspecies, tertius, from the all-black congeneric Javan Myna (A. javanicus), which is native to the same islands. Based on our results, we recommend the establishment of three separate breeding programs to maintain subspecific traits that may confer local adaptation, but with the option of occasional cross-breeding between insurance populations in order to boost genetic diversity and increase overall viability prospects of each breeding program. Our results underscore the importance of evidence-based integrative approaches when determining appropriate conservation units. Given the rapid increase of terminally endangered organisms in need of ex-situ conservation, this study provides an important blueprint for similar programs dealing with phenotypically variable species.
Automated thermal imaging for the detection of fatty liver disease
Authors: Brzezinski Rafael Y. , Levin-Kotler Lapaz , Rabin Neta , Ovadia-Blechman Zehava , Zimmer Yair , Sternfeld Adi , Finchelman Joanna Molad , Unis Razan , Lewis Nir , Tepper-Shaihov Olga , Naftali-Shani Nili , Balint-Lahat Nora , Safran Michal , Ben-Ari Ziv , Grossman Ehud , Leor Jonathan , Hoffer Oshrit
Published: September 2020

Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of progressive liver pathologies, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. A liver biopsy is currently required to stratify high-risk patients, and predicting the degree of liver inflammation and fibrosis using non-invasive tests remains challenging. Here, we sought to develop a novel, cost-effective screening tool for NAFLD based on thermal imaging. We used a commercially available and non-invasive thermal camera and developed a new image processing algorithm to automatically predict disease status in a small animal model of fatty liver disease. To induce liver steatosis and inflammation, we fed C57/black female mice (8 weeks old) a methionine-choline deficient diet (MCD diet) for 6 weeks. We evaluated structural and functional liver changes by serial ultrasound studies, histopathological analysis, blood tests for liver enzymes and lipids, and measured liver inflammatory cell infiltration by flow cytometry. We developed an image processing algorithm that measures relative spatial thermal variation across the skin covering the liver. Thermal parameters including temperature variance, homogeneity levels and other textural features were fed as input to a t-SNE dimensionality reduction algorithm followed by k-means clustering. During weeks 3,4, and 5 of the experiment, our algorithm demonstrated a 100% detection rate and classified all mice correctly according to their disease status. Direct thermal imaging of the liver confirmed the presence of changes in surface thermography in diseased livers. We conclude that non-invasive thermal imaging combined with advanced image processing and machine learning-based analysis successfully correlates surface thermography with liver steatosis and inflammation in mice. Future development of this screening tool may improve our ability to study, diagnose and treat liver disease.
A novel coupled RPL/OSL system to understand the dynamics of the metastable states
Authors: Jain M. , Kumar R. , Kook M.
Published: September 2020

Metastable states form by charge (electron and hole) capture in defects in a solid. They play an important role in dosimetry, information storage, and many medical and industrial applications of photonics. Despite many decades of research, the exact mechanisms resulting in luminescence signals such as optically/thermally stimulated luminescence (OSL or TL) or long persistent luminescence through charge transfer across the metastable states remain poorly understood. Our lack of understanding owes to the fact that such luminescence signals arise from a convolution of several steps such as charge (de)trapping, transport and recombination, which are not possible to track individually. Here we present a novel coupled RPL(radio-photoluminescence)/OSL system based on an electron trap in a ubiquitous, natural, geophotonic mineral called feldspar (aluminosilicate). RPL/OSL allows understanding the dynamics of the trapped electrons and trapped holes individually. We elucidate for the first time trap distribution, thermal eviction, and radiation-induced growth of trapped electron and holes. The new methods and insights provided here are crucial for next generation model-based applications of luminescence dating in Earth and environmental sciences, e.g. thermochronometry and photochronometry.
Evaluation of plant growth promotion properties and induction of antioxidative defense mechanism by tea rhizobacteria of Darjeeling, India
Authors: Bhattacharyya Chandrima , Banerjee Srimoyee , Acharya Udita , Mitra Aroni , Mallick Ivy , Haldar Anwesha , Haldar Shyamalina , Ghosh Anupama , Ghosh Abhrajyoti
Published: September 2020

A total of 120 rhizobacteria were isolated from seven different tea estates of Darjeeling, West Bengal, India. Based on a functional screening of in vitro plant growth-promoting (PGP) activities, thirty potential rhizobacterial isolates were selected for in-planta evaluation of PGP activities in rice and maize crops. All the thirty rhizobacterial isolates were identified using partial 16S rRNA gene sequencing. Out of thirty rhizobacteria, sixteen (53.3%) isolates belong to genus Bacillus, five (16.6%) represent genus Staphylococcus, three (10%) represent genus Ochrobactrum, and one (3.3%) isolate each belongs to genera Pseudomonas, Lysinibacillus, Micrococcus, Leifsonia, Exiguobacterium, and Arthrobacter. Treatment of rice and maize seedlings with these thirty rhizobacterial isolates resulted in growth promotion. Besides, rhizobacterial treatment in rice triggered enzymatic [ascorbate peroxidase (APX), catalase (CAT), chitinase, and phenylalanine ammonia-lyase (PAL)], and non-enzymatic [proline and polyphenolics] antioxidative defense reactions indicating their possible role in the reduction of reactive oxygen species (ROS) burden and thereby priming of plants towards stress mitigation. To understand such a possibility, we tested the effect of rhizobacterial consortia on biotic stress tolerance of rice against necrotrophic fungi, Rhizoctonia solani AG1-IA. Our results indicated that the pretreatment with rhizobacterial consortia increased resistance of the rice plants towards the common foliar pathogen like R. solani AG1-IA. This study supports the idea of the application of plant growth-promoting rhizobacterial consortia in sustainable crop practice through the management of biotic stress under field conditions.
Independent evolution of cutaneous lymphoma subclones in different microenvironments of the skin
Authors: Iyer Aishwarya , Hennessey Dylan , O’Keefe Sandra , Patterson Jordan , Wang Weiwei , Wong Gane Ka-Shu , Gniadecki Robert
Published: September 2020

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma. Lesions of MF are formed by hematogenous seeding the skin with polyclonal (clonotypically diverse) neoplastic T-cells which accumulate numerous mutations and display a high degree of mutational, intratumoral heterogeneity (ITH). A characteristic but poorly studied feature of MF is epidermotropism, the tendency to infiltrate skin epithelial layer (epidermis) in addition to the vascularized dermis. By sequencing the exomes of the microdissected clusters of lymphoma cells from the epidermis and the dermis, we found that those microenvironments comprised different malignant clonotypes. Subclonal structure witnessed the independent mutational evolution in the epidermis and dermis. Thus, the epidermal involvement in MF could not be explained by gradual infiltration from the dermis but was caused by a separate seeding process followed by a quasi-neutral, branched evolution. In conclusion, tissue microenvironments shape the subclonal architecture in MF leading to “ecological heterogeneity” which contributes to the total ITH. Since ITH adversely affects cancer prognosis, targeting the microenvironment may present therapeutic opportunities in MF and other cancers.