bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusually strong electronic correlation and field-induced ordered phase in YbCo2
Authors: Valenta J , Tsujii N , Yamaoka H , Honda F , Hirose Y , Sakurai H , Terada N , Naka T , Nakane T , Koizumi T , Ishii H , Hiraoka N , Mori T
Published: April 2023

We report the first study of electrical resistivity, magnetization, and specific heat on YbCo2. The measurements on a single-phased sample of YbCo2 bring no evidence of magnetic ordering down to 0.3 K in a zero magnetic field. The manifestations of low Kondo temperature are observed. The specific heat value divided by temperature, C/T, keeps increasing logarithmically beyond 7 J/mol K2 with decreasing temperature down to 0.3 K without no sign of magnetic ordering, suggesting a very large electronic specific heat. Analysis of the magnetic specific heat indicates that the large portion of the low-temperature specific heat is not explained simply by the low Kondo temperature but is due to the strong intersite magnetic correlation in both the 3d and 4f electrons. Temperature-dependent measurements under static magnetic fields up to 7 T are carried out, which show the evolution of field-induced transition above 2 T. The transition temperature increases with increasing field, pointing to a ferromagnetic character. The extrapolation of the transition temperature to zero field suggests that YbCo2 is in the very proximity of the quantum critical point. These results indicate that in the unique case of YbCo2, the itinerant electron magnetism of Co 3d-electrons and the Kondo effect within the vicinity of quantum criticality of Yb 4f-local moments can both play a role.
Synergistic coupling of IrNi/Ni(OH)2 nanosheets with polypyrrole and iron oxyhydroxide layers for efficient electrochemical overall water splitting
Authors: Duan Zhongyao , Zhang Mei , Mao Qiqi , Deng Kai , Yu Hongjie , Wang Ziqiang , Xu You , Wang Liang , Wang Hongjing
Published: April 2023

The design of electrocatalysts with excellent activity and stability for overall water splitting is highly desirable, and remains a challenge. Constructing heterojunctions onto the same substrate is beneficial for the integration of a water-splitting reaction. Herein, self-supported IrNi/Ni(OH)2@PPy and IrNi/Ni(OH)2@FeOOH are fabricated by coupling polypyrrole (PPy) and iron oxyhydroxide (FeOOH) on IrNi/Ni(OH)2 nanosheets array, respectively. Benefiting from the nanosheet structure, composition, and heterogeneous interface, the as-constructed IrNi/Ni(OH)2@PPy and IrNi/Ni(OH)2@FeOOH catalysts can efficiently drive the hydrogen evolution reaction and oxygen evolution reaction, respectively. Moreover, the electrolyzer consisting of IrNi/Ni(OH)2@PPy and IrNi/Ni(OH)2@FeOOH for water splitting requires only a low cell voltage of 1.49 V to deliver 10 mA cm−2. This study provides a useful strategy for constructing efficient electrocatalysts by synergistic composition modulation and interface engineering.
An easy-to-build optical spectrometer for the Rayleigh scattering investigation of coffee solution
Authors: Dedeler Ayse Pelin , Ozturk Yavuz
Published: April 2023

Spectroscopy is an essential technique required in numerous analytical fields, yet spectrometers are often expensive instruments. In this study, we present an easy-to-build and low-cost optical spectrometer. The spectrometer is constructed from readily accessible materials including a white LED as the light source, a collimating lens, a cuvette, a slit, a DVD as the diffraction grating, and a webcam. This device is designed to measure the visible light spectra of liquid samples, which could then be processed into transmittance, absorbance, and spectral intensity graphs. We took measurements from several absorbing and scattering samples to evaluate the designed spectrometer. We chose solutions of food colouring as an absorbing medium and instant coffee as a scattering medium. We showed that instant coffee is a very good candidate for Rayleigh scattering experiments, and that the relative concentration of coffee can be investigated by these experiments.
Electron scattering cross sections from NH3: a comprehensive study based on R-matrix method
Authors: Chen Yingqi , Jiang Xianwu , Yao Lufeng , Jiang Wei , Liu Hainan , Zhang Ya
Published: April 2023

In this study, a comprehensive cross-sectional computation on the electron scattering from NH3 was performed using the frame of the R-matrix method. Cross section sets for total elastic, differential, momentum transfer, total ionization, and electronic excitation are presented. The electron-impact dissociation of NH3 to NH

2

+

H and NH+H2 was considered by summing up the cross sections for the molecular dissociative excitations to the correlated dissociation channels. The reported cross sections for vibrational excitation of NH3 remain controversial and are unable to distinguish the N–H symmetric and asymmetric stretching modes of close frequencies. Here, the excitation cross section for each vibrational mode of NH3 was computed by applying the theoretical approach combining the fixed-nuclei R-matrix method, normal mode approximation and the vibrational frame transformation. The uncertainties of the cross section sets computed in this study were estimated for convenience of use in the plasma modeling.
Formation of a lateral p–n junction light-emitting diode on an n-type high-mobility GaAs/Al0.33Ga0.67As heterostructure
Authors: Dobney C P , Nasir A , See P , Ford C J B , Griffiths J P , Chen C , Ritchie D A , Kataoka M
Published: April 2023

We have fabricated a device which includes two lateral p–n junctions on an n-type GaAs/Al0.33Ga0.67As heterostructure. A section of the n-type material has been converted to p-type by removing dopants and applying a voltage to a gate placed in this region. Controlled electroluminescence from both of the p–n junctions has been demonstrated by varying the applied bias voltages. An emission peak with a width of

∼

8

 nm is observed around 812 nm. The electroluminescence seen from both junctions is considered to originate from the GaAs quantum well layer in the device. The lithographic techniques that we have developed are compatible for further integration of gated quantum devices such as single-electron pumps to build on-demand single-photon sources.
Multi-segmented nanowires for vortex magnetic domain wall racetrack memory
Authors: Bahri M Al , Hinaai M Al , Harthy T Al
Published: April 2023

A vortex domain wall’s (VW) magnetic racetrack memory’s high performance depends on VW structural stability, high speed, low power consumption and high storage density. In this study, these critical parameters were investigated in magnetic multi-segmented nanowires using micromagnetic simulation. Thus, an offset magnetic nanowire with a junction at the center was proposed for this purpose. This junction was implemented by shifting one portion of the magnetic nanowire horizontally in the x-direction (l) and vertically (d) in the y-direction. The VW structure became stable by manipulating magnetic properties, such as magnetic saturation (M
s) and magnetic anisotropy energy (K
u). In this case, increasing the values of M
s ≥ 800 kA/m keeps the VW structure stable during its dynamics and pinning and depinning in offset nanowires, which contributes to maintenance of the storage memory’s lifetime for a longer period. It was also found that the VW moved with a speed of 500 m/s, which is desirable for VW racetrack memory devices. Moreover, it was revealed that the VW velocity could be controlled by adjusting the offset area dimensions (l and d), which helps to drive the VW by using low current densities and reducing the thermal-magnetic spin fluctuations. Further, the depinning current density of the VW (J
d) over the offset area increases as d increases and l decreases. In addition, magnetic properties, such as the M
s and K
u, can affect the depinning process of the VW through the offset area. For high storage density, magnetic nanowires (multi-segmented) with four junctions were designed. In total, six states were found with high VW stability, which means three bits per cell. Herein, we observed that the depinning current density (J
d) for moving the VW from one state to another was highly influenced by the offset area geometry (l and d) and the material’s magnetic properties, such as the M
s and K
u.
Analysis on the cation distribution of Mg
x
Ni1−x
Fe2O4 (x = 0, 0.25, 0.5, 0.75, 1) using Mössbauer spectroscopy and magnetic measurement
Authors: Xu 徐 Shiyu 诗语 , Mo 莫 Jiajun 家俊 , Liu 刘 Lebin 乐彬 , Liu 刘 Min 敏
Published: April 2023

Mg
x
Ni1−x
Fe2O4 (x = 0, 0.25, 0.5, 0.75, 1) spinel ferrite material was analyzed to determine its magnetic properties and structure. X-ray diffraction (XRD), Mössbauer spectroscopy, and vibrating sample magnetometer (VSM) characterization were performed on the samples prepared using the sol–gel method. The results from XRD confirmed the existence of the single-phase cubic spinel structures

F
d

3
¯

m

, as well as the evolution of the crystalline size (D), the lattice parameter (a) and cell volume in compounds. The Mössbauer spectra showed the distribution of cations and changes in the magnetic properties of the sample. VSM measurement revealed that the samples were room-temperature ferromagnetic. Moreover, the saturation magnetization (M
s) of the samples changed with the Mg2+ ion content x, and a maximum occured at x = 0.5. Doping with Mg2+ ions increased the transfer of Ni2+ ions to tetrahedral sites, thus increasing the magnetic moment difference between tetrahedral (A) and octahedral (B) sites. Specifically, doping NiFe2O4 with Mg2+ ions can enhance its magnetic properties and enhance its saturation magnetization.
Testing of the tungsten pin dump prototype at the JUDITH 2 testing facility
Authors: Weissman L. , Loewenhoff Th. , Pintsuk G. , Raz R. , Wirtz M.
Published: April 2023

A prototype of tungsten pins beam dump was tested with high
power electron beam at the JUDITH 2 facility. A maximum electron
beam power of 40 kW was applied on a nominal beam spot area of
4 × 4 cm2. This corresponds to the highest achieved
beam power density of 1.4 kW/cm2. Approximately 16% of the
deposited energy was removed by radiation at the highest beam power
values, corresponding to estimated surface temperature of
≈ 3100 K. The results of the irradiation test are
presented. The further improvements of the prototype are
discussed. This result provides an encouraging input for possible
design of a full power beam dump for SARAF Phase II.
Moisture origins of the Amazon carbon source region
Authors: Staal Arie , Koren Gerbrand , Tejada Graciela , Gatti Luciana V
Published: April 2023

The southeastern Amazon has recently been shown to be a net carbon source, which is partly caused by drying conditions. Drying depends on a number of factors, one of which is the land cover at the locations where the moisture has originated as evaporation. Here we assess for the first time the origins of the moisture that precipitates in the Amazon carbon source region, using output from a Lagrangian atmospheric moisture tracking model. We relate vegetation productivity in the Amazon carbon source region to precipitation patterns and derive land-cover data at the moisture origins of these areas, allowing us to estimate how the carbon cycle and hydrological cycle are linked in this critical part of the Amazon. We find that, annually, 13% of the precipitation in the Amazon carbon source region has evaporated from that same area, which is half of its land-derived moisture. We further find a moisture-recycling-mediated increase in gross primary productivity of roughly 41 Mg carbon km−2 yr−1 within the Amazon carbon source region if it is fully forested compared to any other land cover. Our results indicate that the parts of the Amazon forest that are already a net carbon source, still help sustain their own biomass production. Although the most degraded parts of the Amazon depend mostly on oceanic input of moisture, further degradation of this region would amplify carbon losses to the atmosphere.
Quantifying airborne fraction trends and the destination of anthropogenic CO2 by tracking carbon flows in a simple climate model
Authors: Pressburger Leeya , Dorheim Kalyn , Keenan Trevor F , McJeon Haewon , Smith Steven J , Bond-Lamberty Ben
Published: April 2023

Atmospheric carbon dioxide (CO2) concentrations have increased as a direct result of human activity and are at their highest level over the last 2 million years, with profound impacts on the Earth system. However, the magnitude and future dynamics of land and ocean carbon sinks are not well understood; therefore, the amount of anthropogenic fossil fuel emissions that remain in the atmosphere (the airborne fraction) is poorly constrained. This work aims to quantify the sources and controls of atmospheric CO2, the fate of anthropogenic CO2 over time, and the likelihood of a trend in the airborne fraction. We use Hector v3.0, a coupled simple climate and carbon cycle model with the novel ability to explicitly track carbon as it flows through the Earth system. We use key model parameters in a Monte Carlo analysis of 15 000 model runs from 1750 to 2300. Results are filtered for physical realism against historical observations and CMIP6 projection data, and we calculate the relative importance of parameters controlling how much anthropogenic carbon ends up in the atmosphere. Modeled airborne fraction was roughly 52%, consistent with observational studies. The overwhelming majority of model runs exhibited a negative trend in the airborne fraction from 1960–2020, implying that current-day land and ocean sinks are proportionally taking up more carbon than the atmosphere. However, the percentage of atmospheric CO2 derived from anthropogenic origins can be much higher because of Earth system feedbacks. We find it peaks at over 90% between 2010–2050. Moreover, when looking at the destination of anthropogenic fossil fuel emissions, only a quarter ends up in the atmosphere while more than half of emissions are taken up by the land sink on centennial timescales. This study evaluates the likelihood of airborne fraction trends and provides insights into the dynamics of anthropogenic CO2 in the Earth system.
Optical properties of PVDF-TrFE and PVDF-TrFE-CTFE films in terahertz band
Authors: Kalel Sudarshan , Wang Wei-Chih
Published: April 2023

Polymers have enormous potential in the optoelectronic and biomedical fields due to flexibility, biocompatibility, and ease of fabrication. Recent developments in the use of terahertz (THz) waves for biomedical and security applications demand information on the optical properties of the polymers and polymer composites in this region. In the present work, transmission, refractive index (n), and extinction coefficient (k) of PVDF-TrFE (75/25 mol.) copolymer and PVDF-TrFE-CTFE (73/23/4 mol.) terpolymer films with different thicknesses (40 μm, 60 μm, 80 μm) are measured by the THz-TDS system (up to 1 THz). PVDF copolymer and terpolymer films show average transmission of more than 90% irrespective of thickness. The average refractive index of PVDF-TrFE (75/25 mol.) copolymer and PVDF-TrFE-CTFE (73/23/4 mol.) terpolymer films are 1.50 ± 0.04 and 1.45 ± 0.05 respectively. The estimated extinction coefficient is considerably low for both polymer films for frequencies less than 0.6 THz. The average indices for PVDF-TrFE and PVDF-TrFE-CTFE films are close, however, the loss in PVDF-TrFE films is larger than the PVDF-TrFE-CTFE films. High transmission, low loss and ferroelectric properties make these PVDF based polymers highly desirable in light-wave manipulation, flexible electronic and solar devices.
Copper and silver doped in CdTe quantum dots: C. albicans and C. tropicalis antifungal nanomaterials
Authors: Tirado-Guizar Antonio , Pina-Luis Georgina E , Trujillo-Navarrete Balter , Paraguay-Delgado Francisco
Published: April 2023

Quantum dots based on CdTe and Copper or Silver doped CdTe were used for antifungal against C. albicans and C. tropicalis by microdilution method protocol by CLSI. Pure and doped QDs were characterized by UV–vis and fluorescence spectroscopy, x-ray diffraction and transmission electron microscopy which showed sizes between 7.1 and 15.9 nm. Energy dispersive x-ray spectroscopy was carried out to determinate the metal doping in the QDs. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was obtained. The pure QDs fungicidal effect at 500 mg l−1 but 10 mg l−1 of 10% Copper doped QDs show fungicidal for both yeast.
A lab-on-chip solution for the detection and suppression of COVID-19 severity
Authors: Laxmi Vijai , Joshi Suhas S , Agrawal Amit
Published: April 2023

At present, the conventional method for detecting COVID-19 infection is reverse transcription-polymerase chain reaction (RT-PCR) performed on nasopharyngeal and pharyngeal swabs. In addition, other detection techniques such as isothermal nucleic acid amplification, enzyme-linked immunosorbent assay (ELISA) have also been proposed and are being used. However, these techniques are limited to central hospitals and pathologies. Point-of-care solutions may play an important role in rapid and timely detection by an individual at their doorstep. In addition, the disease adversely affects the functioning of various constituents of human blood. For example, it reduces the platelets count, increases production of proinflammatory cytokine which results in cytokine storm, and increases level of various plasma proteins with the severity of the disease. Therefore, monitoring and transfusion of blood plasma and platelets may play an essential role in detection and suppression of severity of COVID-19 infection. In this regard, we propose evolution of our existing microdevice for the detection and suppression of severity of COVID-19 infection. We propose modification of our microdevice in the following ways (i) as a platelet-rich plasma separation unit, (ii) as an on-chip device to study inter-cellular properties of platelets, and (iii) for on-chip detection of infection by separating plasma. The integration of these microdevices with lateral flow assays, flow-virometry reader (FVR), direct serological biosensor assay along with proprietary technology based on plasmonic, place these microdevices in an advantageous position. Moreover, coupling of the microdevices with machine leaning application for rapid detection of the severity of COVID-19 and platelets related disorders makes these microdevices as a complete unit for point-of-care application.
Stretching mode deformation analysis for an elastomeric encapsulation-assisted stable flexible electronic substrate
Authors: Tripathy Kamalesh , Bhattacharjee Mitradip
Published: April 2023

The substrate plays an important role in flexible devices and sensors. In this direction, it is observed that elastomeric encapsulation assists the sensor system to deform successfully under stretching. The encapsulation not only makes it flexible but also protects it from environmental factors and mechanical damage. In this paper, a finite element method analysis is used to study the mechanical effects on the encapsulated system, which provides insight into the design of a stretchable substrate for flexible electronic systems. Here, a serpentine silver electrode is designed on a polyethylene terephthalate substrate, which is then encapsulated by polydimethylsiloxane. With the variation in the ratio of top-to-bottom encapsulation thickness i.e. T
en1: T
en2, the interfacial stress was studied. The mismatch in T
en1 and T
en2 may result in compressive bending strain, which can be avoided by making T
en1 = T
en2. It is observed from the simulation that, there is a spike in von-Mises stress at the interface of the substrate and the encapsulation when stretching mode deformation is applied. Also, this maximum stress varies with the variation in encapsulation thickness. For a range of total encapsulation thickness i.e. T
EN = T
en1 + T
en2 = 30 μm to 100 μm, the optimum thickness is found to be 55 μm, for which the spike in interfacial von-Mises stress is minimum.
System model of neuromorphic sequence learning on a memristive crossbar array
Authors: Siegel Sebastian , Bouhadjar Younes , Tetzlaff Tom , Waser Rainer , Dittmann Regina , Wouters Dirk J
Published: April 2023

Machine learning models for sequence learning and processing often suffer from high energy consumption and require large amounts of training data. The brain presents more efficient solutions to how these types of tasks can be solved. While this has inspired the conception of novel brain-inspired algorithms, their realizations remain constrained to conventional von-Neumann machines. Therefore, the potential power efficiency of the algorithm cannot be exploited due to the inherent memory bottleneck of the computing architecture. Therefore, we present in this paper a dedicated hardware implementation of a biologically plausible version of the Temporal Memory component of the Hierarchical Temporal Memory concept. Our implementation is built on a memristive crossbar array and is the result of a hardware-algorithm co-design process. Rather than using the memristive devices solely for data storage, our approach leverages their specific switching dynamics to propose a formulation of the peripheral circuitry, resulting in a more efficient design. By combining a brain-like algorithm with emerging non-volatile memristive device technology we strive for maximum energy efficiency. We present simulation results on the training of complex high-order sequences and discuss how the system is able to predict in a context-dependent manner. Finally, we investigate the energy consumption during the training and conclude with a discussion of scaling prospects.
On a singular Lifshitz-Slyozov-Wagner model
Authors: Eichenberg C. , Niethammer B. , Velázquez J.
Published: April 2023

We investigate the well-posedness of the classical Lifshitz-Slyozov-Wagner mean-field model for Ostwald ripening with singular coefficients, as they appear, for example in two-dimensional diffusion controlled growth. For Hölder-continuous initial data we prove the existence and uniqueness of a global solution with bounded mean-field. If the data are only in

L

l
o
c

q

(
[
0
,
∞
)
)

L^q_{loc}([0,\infty ))

for some

q
>
1

q>1

we establish global existence of a solution with a mean-field that is in general unbounded but in

L
r

(
0
,
T
)

L^r(0,T)

for some

r
>
1

r>1

that depends on the coefficients in the model.
Chemical Pollution and Regulatory Choices at the Start of Industrialization: Comparing France and Great Britain
Authors: Morag-Levine Noga
Published: April 2023

In both Britain and France, pollution from emergent chemical manufacturing during the early industrial era presented a choice between two regulatory approaches. One option, consistent with longstanding restrictions in both countries on the location of malodorous trades, insisted on the separation of chemical plants from (upper-class) residences. The alternative approach allowed polluting firms to operate near residences, subject to incremental technology-based mitigation. By 1810, France issued a decree that conferred on most chemical manufacturers the right to operate inside cities, subject to permitting requirements. For residents of working-class industrial neighborhoods, who never stood a realistic chance of removing polluters, a regulatory regime geared at incremental mitigation held the potential for modest environmental improvement. For wealthy landowners, however, partial technological mitigation was far inferior to the complete relief obtainable through the removal of pollution sources.

France’s example loomed large over chemical pollution debates in nineteenth-century Britain. Manufacturers hoped the courts would remove locational restrictions on chemical plants, while the near absence of pollution mitigation within working-class areas alarmed liberal reformers. The road to a compromise solution patterned after France’s was impeded in Britain, however, by a deep-seated aversion to uniform, centralized pollution control. This reticence was rooted in common-law-inspired understandings of nuisance law as the sole and inviolable constitutional means for the regulation of land use. By the 1860s, through the combined impact of St. Helens v. Tipping (1865) and the Alkali Act of 1863, Britain moved towards the French approach. Nevertheless, compared with France, British law remained more protective of landowners, more reactive in its implementation, and more willing to vary required mitigation based on sociodemographic factors. Beyond its contribution to comparative environmental history, in revealing the legal-ideological underpinnings of the Franco-British divide over the regulation of early chemical pollution, this Article also seeks to shine a light on the lingering role of legal ideology within contemporary cross-national divisions over the efficacy and legitimacy of centralized technology-based regulatory instruments
Populations of unlabelled networks: graph space geometry and generalized geodesic principal components
Authors: Calissano Anna , Feragen Aasa , Vantini Simone
Published: April 2023

Statistical analysis for populations of networks is widely applicable, but challenging, as networks have strongly non-Euclidean behaviour. Graph space is an exhaustive framework for studying populations of unlabelled networks that are weighted or unweighted, uni- or multilayered, directed or undirected. Viewing graph space as the quotient of a Euclidean space with respect to a finite group action, we show that it is not a manifold, and that its curvature is unbounded from above. Within this geometrical framework we define generalized geodesic principal components, and we introduce the align-all-and-compute algorithms, all of which allow for the computation of statistics on graph space. The statistics and algorithms are compared with existing methods and empirically validated on three real datasets, showcasing the potential utility of the framework. The whole framework is implemented within the geomstats Python package.
Maximizing the benefits from sharing cyber threat intelligence by government agencies and departments
Authors: Dykstra Josiah , Gordon Lawrence A , Loeb Martin P , Zhou Lei
Published: April 2023

The primary objective of the current study is to analytically examine the economic benefits an organization can obtain by receiving and processing cyber threat intelligence (CTI) shared by the US government. Our results show that the benefits from receiving CTI are closely associated with the difference between the threat level indicated by the CTI and the receiving organization’s prior belief of the threat level. In addition, for the same difference between the threat levels indicated by the CTI and the organization’s prior belief, our analyses show that the magnitude of adjustments to an organization’s cybersecurity investments is inversely related to the organization’s prior belief of the threat level. Thus, larger benefits can be obtained when the receiving organization’s prior belief of a threat level is lower. Taken together, our results suggest that the common belief that it is optimal for a federal government agency or department to focus on sharing CTI related to vulnerabilities with the highest threat level is misguided. More generally, the benefits from CTI sharing can be improved if producers of CTI could develop a clearer understanding of the prior beliefs that organizations have concerning their threat level and focus on sharing CTI that is significantly different from those prior beliefs.
The genome sequence and demographic history of Przewalskia tangutica (Solanaceae), an endangered alpine plant on the Qinghai–Tibet Plateau
Authors: Wu Ying , Yang Jiao , Yang Yongzhi , Liu Jianquan
Published: April 2023

To adapt to high-altitude habitats, many alpine plants develop self-compatible breeding systems from outcrossing. The genetic bases for this shift and the resulting demographic consequences remain largely unexplored. Here, we present a high-quality, chromosome-level genome assembly of the monotypic and endangered alpine perennial Przewalskia tangutica (Solanaceae) occurring on the Qinghai–Tibet Plateau (QTP). Our assembled genome is approximately 3 Gb, with a contig N50 size of 17 Mb, and we identified one lineage-specific whole-genome duplication. We found that the gametophytic self-incompatibility (GSI) syntenic locus to the other obligate outcrossing Solanaceae species was broken by the inserted the long terminal repeats, and changes in the flower-specific expression of the homologous genes, and the linked GSI genes in this species. Such changes may have led to its self-compatibility. We identified three deeply diverged lineages in the central distribution of this species, and the gene flow between them was weak but continuous. All three lineages diverged and decreased their population sizes since the largest glaciations occurred in the QTP approximately 720–500 thousand years ago. In addition, we identified one obvious hybrid population between two lineages, suggesting that genetic exchanges between and within lineages still occur. Our results provide insights into evolutionary adaptation through facultative self-pollination and demographic consequences of this alpine rare species in arid habitats.
An enhanced recovery programme significantly improves postoperative outcomes after surgical aortic valve replacement
Authors: Giger Albane , Schneider Clément , Marguerite Sandrine , Ramlugun Dharmesh , Maechel Anne-Lise , Collange Olivier , Mertes Paul-Michel , Mazzucotelli Jean-Philippe , Kindo Michel
Published: April 2023

OBJECTIVES

Evidence regarding the benefits of an enhanced recovery after cardiac surgery (ERACS) programme is lacking. The aim of this study was to analyse the impact of a systematic standardized ERACS programme for patients undergoing isolated elective surgical aortic valve replacement (SAVR) for aortic stenosis in terms of hospital mortality and morbidity, patient blood management and length of stay.

METHODS

Patients undergoing isolated elective SAVR for aortic stenosis between 2015 and 2020 were identified from our database (n = 941). The standardized systematic ERACS programme was implemented in November 2018. Propensity score matching indicated that 259 patients would receive standard perioperative care (control group) and 259 patients would receive the ERACS programme (ERACS group). The primary outcome was hospital mortality. The secondary outcomes were hospital morbidity, patient blood management and length of stay.

RESULTS

Both groups had similar hospital mortality rates (0.4%). The ERACS group had a significantly lower troponin I peak level (P < 0.001), a larger proportion of improved perioperative left ventricular ejection fractions (P = 0.001), a lower incidence of bronchopneumonia (P = 0.030), a larger proportion of patients with mechanical ventilation <6 h (P < 0.001), a lower incidence of delirium (P = 0.028) and less acute renal failure (P = 0.013). The ERACS group had a significantly lower rate of red blood cell transfusions (P = 0.002). The intensive care unit stay was significantly shorter in the ERACS group than in the control group (P = 0.039).

CONCLUSIONS

The standardized systematic ERACS programme significantly improved postoperative outcomes and should become the reference for the perioperative care pathway for patients undergoing SAVR.
Proteomic cardiovascular risk assessment in chronic kidney disease
Authors: Deo Rajat , Dubin Ruth F , Ren Yue , Murthy Ashwin C , Wang Jianqiao , Zheng Haotian , Zheng Zihe , Feldman Harold , Shou Haochang , Coresh Josef , Grams Morgan , Surapaneni Aditya L , Bhat Zeenat , Cohen Jordana B , Rahman Mahboob , He Jiang , Saraf Santosh L , Go Alan S , Kimmel Paul L , Vasan Ramachandran S , Segal Mark R , Li Hongzhe , Ganz Peter
Published: April 2023

Aims

Chronic kidney disease (CKD) is widely prevalent and independently increases cardiovascular risk. Cardiovascular risk prediction tools derived in the general population perform poorly in CKD. Through large-scale proteomics discovery, this study aimed to create more accurate cardiovascular risk models.

Methods and results

Elastic net regression was used to derive a proteomic risk model for incident cardiovascular risk in 2182 participants from the Chronic Renal Insufficiency Cohort. The model was then validated in 485 participants from the Atherosclerosis Risk in Communities cohort. All participants had CKD and no history of cardiovascular disease at study baseline when ∼5000 proteins were measured. The proteomic risk model, which consisted of 32 proteins, was superior to both the 2013 ACC/AHA Pooled Cohort Equation and a modified Pooled Cohort Equation that included estimated glomerular filtrate rate. The Chronic Renal Insufficiency Cohort internal validation set demonstrated annualized receiver operating characteristic area under the curve values from 1 to 10 years ranging between 0.84 and 0.89 for the protein and 0.70 and 0.73 for the clinical models. Similar findings were observed in the Atherosclerosis Risk in Communities validation cohort. For nearly half of the individual proteins independently associated with cardiovascular risk, Mendelian randomization suggested a causal link to cardiovascular events or risk factors. Pathway analyses revealed enrichment of proteins involved in immunologic function, vascular and neuronal development, and hepatic fibrosis.

Conclusion

In two sizeable populations with CKD, a proteomic risk model for incident cardiovascular disease surpassed clinical risk models recommended in clinical practice, even after including estimated glomerular filtration rate. New biological insights may prioritize the development of therapeutic strategies for cardiovascular risk reduction in the CKD population.
COVID-19 vaccination and changes in preventive behaviours: findings from the 2021 vaccine roll-out in Switzerland
Authors: Hitchman Sara C , Geber Sarah , Tribelhorn Lukas , Friemel Thomas N
Published: April 2023

Background

Behavioural, environmental, social and systems interventions (BESSIs) remain important for controlling the COVID-19 pandemic in addition to vaccination. However, people’s adoption of BESSIs may decrease as vaccination rates increase due to reductions in the perceived threat of disease, and changes in risk perceptions of behaviours that increase the chance of infection. Thus, we examined predictors of and changes over time in reports of mask wearing and physical distancing and whether changes in mask wearing and physical distancing differed by vaccination status during the main 2021 COVID-19 vaccine roll-out period in Switzerland.

Methods

Weekly online cross-sectional surveys (26 April 2021 to 1 August 2021) among people 18–79 years old in Switzerland, N = 6308 observations and 5511 cases. Logistic regression models using generalized estimating equations.

Results

Reports of being vaccinated increased, while mask wearing and physical distancing decreased over time. This decrease was similar regardless of vaccination status. However, the level of reported mask wearing and physical distancing remained higher among vaccinated people. Older, female, and Italian language region respondents also had higher odds of reporting mask wearing and physical distancing.

Conclusions

Adoption of COVID-19 preventive behaviours is associated with demographics and vaccination status. Further research is needed to understand the reasons why people who are not vaccinated are less likely to adopt preventive behaviours, including that they may have fewer social and environmental opportunities to do so.
Comparative study of GBP recruitment on two cytosol-dwelling pathogens, Francisella novicida and Shigella flexneri highlights differences in GBP repertoire and in GBP1 motif requirements
Authors: Valeva Stanimira V , Degabriel Manon , Michal Fanny , Gay Gabrielle , Rohde John R , Randow Felix , Lagrange Brice , Henry Thomas
Published: April 2023

Guanylate-Binding Proteins are interferon-inducible GTPases that play a key role in cell autonomous responses against intracellular pathogens. Despite sharing high sequence similarity, subtle differences among GBPs translate into functional divergences that are still largely not understood. A key GBP feature is the formation of supramolecular GBP complexes on the bacterial surface. Such complexes are observed when GBP1 binds lipopolysaccharide (LPS) from Shigella and Salmonella and further recruits GBP2-4. Here, we compared GBP recruitment on two cytosol-dwelling pathogens, Francisella novicida and S. flexneri. Francisella novicida was coated by GBP1 and GBP2 and to a lower extent by GBP4 in human macrophages. Contrary to S. flexneri, F. novicida was not targeted by GBP3, a feature independent of T6SS effectors. Multiple GBP1 features were required to promote targeting to F. novicida while GBP1 targeting to S. flexneri was much more permissive to GBP1 mutagenesis suggesting that GBP1 has multiple domains that cooperate to recognize F. novicida atypical LPS. Altogether our results indicate that the repertoire of GBPs recruited onto specific bacteria is dictated by GBP-specific features and by specific bacterial factors that remain to be identified.
Seismic stratigraphy and attenuation of gas-hydrate zones within Hikurangi and Gondwana margins, eastern New Zealand
Authors: Wang Yichuan , Bedle Heather , Marfurt Kurt J
Published: April 2023

Gas hydrates that occur on many continental margins have received global attention. In reflection seismic imaging, the bottom-simulating reflector (BSR) is a common indicator of gas hydrates. However, it is difficult to identify gas hydrates and quantify their amounts through the BSR alone. For gas-hydrate characterization, it is therefore useful to measure seismic stratigraphic and attenuation attributes. Short-scale patterns of layering that contain information about the amount and mechanism of gas hydrates can be identified through stratigraphic and attenuation attributes. We measure the complete time-variant spectra by using sparse strongest peaks, and the spectral differences at different times through attenuation parameters Q–1 and γ. The traditional Q–1 is associated with the attenuation of the frequency-dependent part of wavefield, and the γ characterizes the frequency-independent attenuation. The measurement approach is straightforward and requires no sophisticated inverse algorithm and is applied to surface seismic data acquired over the Hikurangi and Gondwana margins, eastern New Zealand. High-quality spectral and attenuation images are obtained. Spectral attributes correlate with BSRs and large positive Q–1 and negative γ-values are below and above the BSRs, which are interpreted as being related to free-gas and gas-hydrate accumulations. These results will aid the quantification of gas hydrates and the assessment of their roles as an energy resource, as a potential geological hazard, and in climate change and ocean warming.
Substrate specificity and transglycosylation capacity of α-L-fucosidases across GH29 assessed by bioinformatics-assisted selection of functional diversity
Authors: Perna Valentina N , Barrett Kristian , Meyer Anne S , Zeuner Birgitte
Published: April 2023

Glycoside hydrolase family 29 (GH29) encompasses α-L-fucosidases, i.e. enzymes that catalyze the hydrolytic release of fucose from fucosylated glycans, including N- and O-linked glycans on proteins, and these α-L-fucosidases clearly play important roles in biology. GH29 enzymes work via a retaining exo-action mechanism, and some can catalyze transfucosylation. There is no formal subfamily division of GH29 α-L-fucosidases, but they are nonetheless divided into two subfamilies: GH29A having a range of substrate specificities and GH29B having narrower substrate specificity. However, the sequence traits that determine the substrate specificity and transglycosylation ability of GH29 enzymes are not well characterized. Here, we present a new functional map of family GH29 members based on peptide-motif clustering via CUPP (conserved unique peptide patterns) and compare the substrate specificity and transglycosylation activity of 21 representative α-L-fucosidases across the 53 CUPP groups identified. The 21 enzymes exhibited different enzymatic rates on 8 test substrates, CNP-Fuc, 2’FL, 3FL, Lewisa, Lewisx, Fuc-α1,6-GlcNAc, Fuc-α1,3-GlcNAc, and Fuc-α1,4-GlcNAc. Certain CUPP groups clearly harbored a particular type of enzymes, e.g. the majority of the enzymes having activity on Lewisa or Lewisx categorized in the same CUPP clusters. In general, CUPP was useful for resolving GH29 into functional diversity subgroups when considering hydrolytic activity. In contrast, the transglycosylation capacity of GH29 α-L-fucosidases was distributed across a range of CUPP groups. Transglycosylation thus appears to be a common trait among these enzymes and not readily predicted from sequence comparison.
Dissection of a Down syndrome-associated trisomy to separate the gene dosage-dependent and -independent effects of an extra chromosome
Authors: Xing Zhuo , Li Yichen , Cortes-Gomez Eduardo , Jiang Xiaoling , Gao Shuang , Pao Annie , Shan Jidong , Song Yinghui , Perez Amanda , Yu Tao , Highsmith Max R , Boadu Frimpong , Conroy Jeffrey M , Singh Prashant K , Bakin Andrei V , Cheng Jianlin , Duan Zhijun , Wang Jianmin , Liu Song , Tycko Benjamin , Yu Y Eugene
Published: April 2023

As an aneuploidy, trisomy is associated with mammalian embryonic and postnatal abnormalities. Understanding the underlying mechanisms involved in mutant phenotypes is broadly important and may lead to new strategies to treat clinical manifestations in individuals with trisomies, such as trisomy 21 [Down syndrome (DS)]. Although increased gene dosage effects because of a trisomy may account for the mutant phenotypes, there is also the possibility that phenotypic consequences of a trisomy can arise because of the presence of a freely segregating extra chromosome with its own centromere, i.e. a ‘free trisomy’ independent of gene dosage effects. Presently, there are no reports of attempts to functionally separate these two types of effects in mammals. To fill this gap, here we describe a strategy that employed two new mouse models of DS, Ts65Dn;Df(17)2Yey/+ and Dp(16)1Yey/Df(16)8Yey. Both models carry triplications of the same 103 human chromosome 21 gene orthologs; however, only Ts65Dn;Df(17)2Yey/+ mice carry a free trisomy. Comparison of these models revealed the gene dosage-independent impacts of an extra chromosome at the phenotypic and molecular levels for the first time. They are reflected by impairments of Ts65Dn;Df(17)2Yey/+ males in T-maze tests when compared with Dp(16)1Yey/Df(16)8Yey males. Results from the transcriptomic analysis suggest the extra chromosome plays a major role in trisomy-associated expression alterations of disomic genes beyond gene dosage effects. This model system can now be used to deepen our mechanistic understanding of this common human aneuploidy and obtain new insights into the effects of free trisomies in other human diseases such as cancers.
Providing more effective kangaroo care during the COVID-19 pandemic: A quality improvement project in a Lebanese neonatal intensive care unit
Authors: Abi Farraj Farida , Masri Saadieh , Maalouf Faouzi I , Charafeddine Lama
Published: April 2023

Background

Kangaroo care has become the standard in caring for preterm infants; however, its application still faces many barriers due to insufficient staff or parental education or participation and most recently visitation restrictions after the COVID-19 pandemic.

Methods

This quality improvement project (QIP) took place in a tertiary center’s neonatal intensive care unit in Lebanon from September 2018 to March 2021. It aimed to increase kangaroo care practice and maternal milk use among admitted infants. Nurses and parents received education and hands-on training about kangaroo care and skin-to-skin contact. Nurses’ and parents’ knowledge, attitude, and behavior toward kangaroo care were evaluated pre- and post-intervention. Balancing measures included hypothermia, central line infection, catheter dislodgement, and babies being dropped. COVID-19 visitation restrictions during QIP cycles were documented.

Results

A total of 143 infants received kangaroo care during the project period and 105 (73%) were ≤34 weeks of gestation. By the end of the QIP, kangaroo care practice increased from 2.5 to 7 h per infant stay (from a median of 45 min per session to 60 min per session). Infants receiving more than five kangaroo care sessions had higher maternal milk use (71.3% vs. 52.8%; P = 0.002) and growth velocity (12.1 vs. 2.0 g/kg/day; P < 0.001). Parents’ perceived behavior and frequency of performing kangaroo care–related tasks improved significantly (P < 0.005) compared to before QIP. Thirty-seven of 44 participating nurses reported more perceived behavior transferring ventilated babies (P = 0.049).

Conclusion

This QIP successfully increased kangaroo care practice and maternal milk use in a resource-limited environment, despite COVID-19 restrictions. More work is needed to ensure sustainability and replicability.
Weight loss increases skeletal muscle mitochondrial energy efficiency in obese mice
Authors: Ferrara Patrick J , Lang Marisa J , Johnson Jordan M , Watanabe Shinya , McLaughlin Kelsey L , Alan Maschek John , Verkerke Anthony R P , Siripoksup Piyarat , Chaix Amandine , Cox James E , Fisher-Wellman Kelsey H , Funai Katsuhiko
Published: April 2023

Weight loss from an overweight state is associated with a disproportionate decrease in whole-body energy expenditure that may contribute to the heightened risk for weight regain. Evidence suggests that this energetic mismatch originates from lean tissue. Although this phenomenon is well documented, the mechanisms have remained elusive. We hypothesized that increased mitochondrial energy efficiency in skeletal muscle is associated with reduced expenditure under weight loss. Wildtype (WT) male C57BL6/N mice were fed with high-fat diet for 10 weeks, followed by a subset of mice that were maintained on the obesogenic diet (OB) or switched to standard chow to promote weight loss (WL) for additional 6 weeks. Mitochondrial energy efficiency was evaluated using high-resolution respirometry and fluorometry. Mass spectrometric analyses were employed to describe the mitochondrial proteome and lipidome. Weight loss promoted ~50% increase in the efficiency of oxidative phosphorylation (ATP produced per O2 consumed, or P/O) in skeletal muscle. However, Weight loss did not appear to induce significant changes in mitochondrial proteome, nor any changes in respiratory supercomplex formation. Instead, it accelerated the remodeling of mitochondrial cardiolipin (CL) acyl-chains to increase tetralinoleoyl CL (TLCL) content, a species of lipids thought to be functionally critical for the respiratory enzymes. We further show that lowering TLCL by deleting the CL transacylase tafazzin was sufficient to reduce skeletal muscle P/O and protect mice from diet-induced weight gain. These findings implicate skeletal muscle mitochondrial efficiency as a novel mechanism by which weight loss reduces energy expenditure in obesity.