bluuebunny/crossref_metadata_2025 huggingface dataset:
Single and double scattering event analysis for ultraviolet communication channels
Authors: Borah Deva K. , Mareddy Vinay R. , Voelz David G.
Published: January 2021

This paper presents a channel analysis method for single and double scattering events in non-line-of-sight (NLOS) ultraviolet (UV) communication systems. In general, the calculations of path loss and impulse response of such systems require Monte Carlo random number generations. However, the high computational costs of Monte Carlo methods impose severe limitations on quick reliable evaluations of system performance under complex atmospheric conditions. This paper proposes a sample-based UV channel characterization approach that improves computational performance by multiple orders of magnitude. The proposed novel approach uses fixed probability-based sampling. The method focuses only on single and double scattering events which dominate the received signal. The effects of various fog and dust aerosols are discussed under non-planar realistic conditions. The results demonstrate reliable channel characterization with significantly lower complexity using the proposed approach.
ZCAM, a colour appearance model based on a high dynamic range uniform colour space
Authors: Safdar Muhammad , Hardeberg Jon Yngve , Ronnier Luo Ming
Published: January 2021

A colour appearance model based on a uniform colour space is proposed. The proposed colour appearance model, ZCAM, comprises of comparatively simple mathematical equations, and plausibly agrees with the psychophysical phenomenon of colour appearance perception. ZCAM consists of ten colour appearance attributes including brightness, lightness, colourfulness, chroma, hue angle, hue composition, saturation, vividness, blackness, and whiteness. Despite its relatively simpler mathematical structure, ZCAM performed at least similar to the CIE standard colour appearance model CIECAM02 and its revision, CAM16, in predicting a range of reliable experimental data.
Selection rule for cavity configurations to generate cylindrical vector beams with low beam quality factor
Authors: Chuang Chih-Hsiang , Ho Chen-Yu , Hsiao Yu-Chi , Chiu Chi-Pin , Wei Ming-Dar
Published: January 2021

Considering the birefringence of the gain medium, we propose a selection rule for designing cavity configurations that enable the generation of radially and azimuthally polarized laser beams with a low beam quality factor, i.e., high beam quality. Using this rule, all stable regions can support cylindrical vector (CV) beams by using the position of the end mirror as the tuning parameter to vary the cavity configuration. Such cavity configurations tend to sustain the fundamental or lowest-order CV beam, and radially or azimuthally polarized beams can be obtained simply by varying the tuning parameter. Based on experimental measurements of the beam quality factor and polarization characteristics, we verified our analyses and simulations for a four-element laser system.
Probe noise characteristics of the spin-exchange relaxation-free (SERF) magnetometer
Authors: Xing Bozheng , Sun Chang , Liu Ziao , Zhao Junpeng , Lu Jixi , Han Bangcheng , Ding Ming
Published: January 2021

In the spin-exchange relaxation-free (SERF) magnetometer, the probe noise is a consequential factor affecting the gradiometric measurement sensitivities. In this paper, we proposed a new characteristics model of the probe noise based on noise separation. Different from noise analysis on single noise source, we considered most of the noise sources influencing the probe system and realized noise sources level measurement experimentally. The results demonstrate that the major noise type changes with the signal frequency. Below 10 Hz, the probe noise mainly comes from the sources independent of light intensity such as the vibration, which accounts for more than 50%; while at 30 Hz, the photon shot noise and the magnetic noise are the main origins, with proportion about 43% and 32%, respectively. Moreover, the results indicate that the optimal probe light intensity with highest sensitivity appears when the response of the magnetic noise is equal to the sum of the electronic noise and half of the shot noise. The optimal intensity gets larger with higher signal frequency. The noise characteristics model could be applied in modulating or differential optical systems and helps sensitivity improvement in SERF magnetometer.
Maximum-likelihood parameter estimation in terahertz time-domain spectroscopy
Authors: Mohtashemi Laleh , Westlund Paul , Sahota Derek G. , Lea Graham B. , Bushfield Ian , Mousavi Payam , Dodge J. Steven
Published: January 2021

We present a maximum-likelihood method for parameter estimation in
terahertz time-domain spectroscopy. We derive the likelihood function
for a parameterized frequency response function, given a pair of
time-domain waveforms with known time-dependent noise amplitudes. The
method provides parameter estimates that are superior to other
commonly used methods and provides a reliable measure of the goodness
of fit. We also develop a simple noise model that is parameterized by
three dominant sources and derive the likelihood function for their
amplitudes in terms of a set of repeated waveform measurements. We
demonstrate the method with applications to material
characterization.
Improve optical properties by modifying Ag nanoparticles on a razor clam SERS substrate
Authors: Guo Liting , Cao Hongwen , Cao Lipeng , Li Na , Zhang Anqi , Shang Zubin , Jiao Tifeng , Liu H. L. , Wang Mingli
Published: January 2021

Irregular substrates are inappropriate for enhancing surface enhanced Raman scattering (SERS) due to their poor performances in terms of uniformity, enhancement performance, and polarization characteristics. However, in this work, we purposely employed a natural biological razor clam material with messy and irregular structures to improve the SERS. The rough surface was achieved by magnetron sputtering Ag nanoislands on the prism layer of the razor clams, and the Ag nanoparticles were treated using the method of oil-water interface self-assembly to form relatively uniform structures. Compared to the substrate without Ag nanoparticles, the presented substrate has better reproducibility, polarization-independence, and higher SERS intensity, and the detect limitation of R6G can be decreased from 10−12 M to 10−18 M. The ultrasensitive detection of thiram gives our structures potential for high sensitivity biosensors.
Raman pure quartic solitons in Kerr microresonators
Authors: Liu Kewei , Yao Shunyu , Yang Changxi
Published: January 2021

Pure quartic solitons (PQSs) are a unique class of solitons advantageous for developing promising applications due to their broad and flat-top spectrum, as well as the distinctive energy scaling law. Here we investigate the characteristics and dynamics of the PQS in the presence of the Raman effect based on Kerr microresonators. Stimulated Raman scattering leads to reduced pulse peak power, self-frequency shifts, and distortion of the symmetry pulse shape of the PQS. Besides, dynamical evolution of the Raman PQS, especially the breathing state, is investigated. We discover the appearance of an intermediate stable state between the existence region of breathers and chaos in the parameter space, which has not been discovered yet in other soliton regimes. A stability analysis is performed to investigate the spatial dynamics in the context of the Raman PQS.
Thin-disk laser system operating above 10  kW at near fundamental mode beam quality
Authors: Nagel Simon , Metzger Bernd , Bauer Dominik , Dominik Johanna , Gottwald Tina , Kuhn Vincent , Killi Alexander , Dekorsy Thomas , Schad Sven-Silvius
Published: January 2021

We report on a thin-disk laser system with more than 10 kW of output power and a beam quality of

M

2

=
1.76

at an overall optical-to-optical efficiency of 51%. The system consists of two thin-disk laser oscillators and a thin-disk multi-pass amplifier system. To reach high output powers while maintaining good beam quality, the output beams of two identical laser oscillators are polarization-combined. Subsequently, the beam is amplified in a multi-pass system. To the best of our knowledge, this is the highest output power achieved for a thin-disk laser system with a beam quality close to fundamental mode.
Nanostructure enabled lower on-state resistance and longer lock-on time GaAs photoconductive semiconductor switches
Authors: Liu Ruijia , Shang Annan , Chen Chang-Jiang , Lee Yun Goo , Yin Shizhuo
Published: January 2021

We report a new, to the best of our knowledge, type of SI-GaAs
photoconductive semiconductor switch (PCSS) with nanostructures. Since
light can enter from both the top and side surfaces of nanostructures,
the effective penetration depth is significantly increased. Lower
on-state resistance and a longer lock-on time have been achieved in
the nonlinear mode with this design, as well as a lower triggering
fluence in the linear mode. This could be highly useful for a variety
of applications that require lower on-state resistance and/or longer
lock-on time such as pulsed power systems and firing set switches.
Spectral broadening of 112  mJ, 1.3  ps pulses at 5  kHz in a LG10 multipass cell with compressibility to 37  fs
Authors: Kaumanns Martin , Kormin Dmitrii , Nubbemeyer Thomas , Pervak Vladimir , Karsch Stefan
Published: January 2021

The first-order helical Laguerre–Gaussian mode (also called donut mode) is used to improve the energy throughput of nonlinear spectral broadening in gas-filled multipass cells. The method proposed in this Letter enables, for the first time to the best of our knowledge, the nonlinear spectral broadening of pulses with energies beyond 100 mJ and is suitable for an average power of more than 500 W while conserving an excellent spatio-spectral homogeneity of

∼

98
%

and a Gaussian-like focus profile. Additionally compressibility from 1.3 ps to 37 fs is demonstrated.
Inverse design of multi-band and wideband waveguide crossings
Authors: Yi Dan , Zhou Wen , Zhang Yaojing , Tsang Hon Ki
Published: January 2021

Photonic integrated circuits for wideband and multi-band optical communications will need waveguide crossings that operate at all the wavelengths required by the system. In this Letter, we use the modified gradient decedent method to optimize the dual-wavelength band (DWB) crossings on both single- and double-level platforms. On the single-level platform, the simulation results show insertion losses (ILs) less than 0.07 and 0.11 dB for a crossing working at a DWB of 1.5–1.6 and 1.95–2.05 µm. ILs are less than 0.1 and 0.2 dB for a crossing operating in the DWB of 1.5–1.6 and 2.2–2.3 µm. On the double-layer platform, the simulated results show IL less than 0.08 dB across the wavelength range of 1.25–2.25 µm. We experimentally demonstrate the DWB crossing operating at 1.5–1.6 and 2.2–2.3 µm to have IL less than 0.3 and 0.4 dB and crosstalk of

−

28

and

−

26

d
B

in the two bands, respectively.
Threshold gain of coherently coupled aperiodic lattice Y lasers
Authors: Jiang Wei , Chakraborty Subhasish
Published: January 2021

By incorporating a holographically designed aperiodic photonic lattice within one of the arms of a Y-coupled Fabry–Perot quantum cascade laser architecture, it has been demonstrated that the multiband mode control exerted by the photonic lattice on emission spectra can, owing to the mutual optical coupling between the arms, be transferred to the second unpatterned arm. However, the underlying theoretical mechanism on how the lattice influences the threshold gain spectral properties of the Y architecture has, until now, remained unstudied. Here, we use the transfer matrix formalism, originally developed for studying aperiodic lattice lasers, to investigate this. A detailed threshold gain spectral study revealed that although the effects of facet feedback of the Y-coupled laser chip are present, due to the enhanced photonic density-of-states at user-specified frequencies, the aperiodic lattice has remarkable control over the Y architecture laser spectra, under the mutual optical coupling between the arms. Finally, indicated by the fringe patterns akin to double-slit interference, of the measured far-field beam profiles, phase-locked terahertz emissions from the Y architecture are demonstrated.
Simultaneous generation of the second- and third-order OAM modes by using a high-order helical long-period fiber grating
Authors: Detani Taishu , Zhao Hua , Wang Peng , Suzuki Taiga , Li Hongpu
Published: January 2021

An all-fiber orbital angular momentum (OAM) mode generator enabling simultaneous generation of the second- and the third-order OAM modes with conversion efficiencies larger than 95% has been proposed and experimentally demonstrated, which is realized by using a high-order helical long-period fiber grating (HLPG) written in a thinned four-mode fiber. This is the first time, to the best of our knowledge, that two such OAM modes have been simultaneously obtained at wavelengths ranging from 1450 to 1620 nm by using only one fiber component, i.e., the HLPG. The proposed method provides a new way to simultaneously generate different orders of the OAM modes, which would further expand the OAM’s applications to the fields of the optical tweezers, microscopy, and fiber communication, etc.
The evolution of group differences in changing environments
Authors: Harpak Arbel , Przeworski Molly
Published: January 2021

The selection pressures that have shaped the evolution of complex traits in humans remain largely unknown, and in some contexts highly contentious, perhaps above all where they concern mean trait differences among groups. To date, the discussion has focused on whether such group differences have any genetic basis, and if so, whether they are without fitness consequences and arose via random genetic drift, or whether they were driven by selection for different trait optima in different environments. Here, we highlight a plausible alternative: that many complex traits evolve under stabilizing selection in the face of shifting environmental effects. Under this scenario, there will be rapid evolution at the loci that contribute to trait variation, even when the trait optimum remains the same. These considerations underscore the strong assumptions about environmental effects that are required in ascribing trait differences among groups to genetic differences.
Physicochemical and metabolic constraints for thermodynamics-based stoichiometric modelling under mesophilic growth conditions
Authors: Tomi-Andrino Claudio , Norman Rupert , Millat Thomas , Soucaille Philippe , Winzer Klaus , Barrett David A. , King John , Kim Dong-Hyun
Published: January 2021

Metabolic engineering in the post-genomic era is characterised by the development of new methods for metabolomics and fluxomics, supported by the integration of genetic engineering tools and mathematical modelling. Particularly, constraint-based stoichiometric models have been widely studied: (i) flux balance analysis (FBA) (in silico), and (ii) metabolic flux analysis (MFA) (in vivo). Recent studies have enabled the incorporation of thermodynamics and metabolomics data to improve the predictive capabilities of these approaches. However, an in-depth comparison and evaluation of these methods is lacking. This study presents a thorough analysis of two differentin silicomethods tested against experimental data (metabolomics and13C-MFA) for the mesophileEscherichia coli. In particular, a modified version of the recently published matTFA toolbox was created, providing a broader range of physicochemical parameters. Validating against experimental data allowed the determination of the best physicochemical parameters to perform the TFA (Thermodynamics-based Flux Analysis). An analysis of flux pattern changes in the central carbon metabolism between13C-MFA and TFA highlighted the limited capabilities of both approaches for elucidating the anaplerotic fluxes. In addition, a method based on centrality measures was suggested to identify important metabolites that (if quantified) would allow to further constrain the TFA. Finally, this study emphasised the need for standardisation in the fluxomics community: novel approaches are frequently released but a thorough comparison with currently accepted methods is not always performed.
PASA: Proteomic analysis of serum antibodies web server
Authors: Avram Oren , Kigel Aya , Vaisman-Mentesh Anna , Kligsberg Sharon , Rosenstein Shai , Dror Yael , Pupko Tal , Wine Yariv
Published: January 2021

Motivation

A comprehensive characterization of the humoral response towards a specific antigen requires quantification of the B-cell receptor repertoire by next-generation sequencing (BCR-Seq), as well as the analysis of serum antibodies against this antigen, using proteomics. The proteomic analysis is challenging since it necessitates the mapping of antigen-specific peptides to individual B-cell clones.

Results

The PASA web server provides a robust computational platform for the analysis and integration of data obtained from proteomics of serum antibodies. PASA maps peptides derived from antibodies raised against a specific antigen to corresponding antibody sequences. It then analyzes and integrates proteomics and BCR-Seq data, thus providing a comprehensive characterization of the humoral response. The PASA web server is freely available at https://pasa.tau.ac.il and open to all users without a login requirement.
Mitochondrial depolarization promotes calcium alternans: Mechanistic insights from a ventricular myocyte model
Authors: Pandey Vikas , Xie Lai-Hua , Qu Zhilin , Song Zhen
Published: January 2021

Mitochondria are vital organelles inside the cell and contribute to intracellular calcium (Ca2+) dynamics directly and indirectly via calcium exchange, ATP generation, and production of reactive oxygen species (ROS). Arrhythmogenic Ca2+alternans in cardiac myocytes has been observed in experiments under abnormal mitochondrial depolarization. However, complex signaling pathways and Ca2+cycling between mitochondria and cytosol make it difficult in experiments to reveal the underlying mechanisms of Ca2+alternans under abnormal mitochondrial depolarization. In this study, we use a newly developed spatiotemporal ventricular myocyte computer model that integrates mitochondrial Ca2+cycling and complex signaling pathways to investigate the mechanisms of Ca2+alternans during mitochondrial depolarization. We find that elevation of ROS in response to mitochondrial depolarization plays a critical role in promoting Ca2+alternans. Further examination reveals that the redox effect of ROS on ryanodine receptors and sarco/endoplasmic reticulum Ca2+-ATPase synergistically promote alternans. Upregulation of mitochondrial Ca2+uniporter promotes Ca2+alternans via Ca2+-dependent mitochondrial permeability transition pore opening. Due to their relatively slow kinetics, oxidized Ca2+/calmodulin-dependent protein kinase II activation and ATP do not play significant roles acutely in the genesis of Ca2+alternans after mitochondrial depolarization, but their roles can be significant in the long term, mainly through their effects on sarco/endoplasmic reticulum Ca2+-ATPase activity. In conclusion, mitochondrial depolarization promotes Ca2+alternans acutely via the redox effect of ROS and chronically by ATP reduction. It suppresses Ca2+alternans chronically through oxidized Ca2+/calmodulin-dependent protein kinase II activation.
Are Melanoides tuberculata and Tarebia granifera (Gastropoda, Thiaridae), suitable first intermediate hosts of Clonorchis sinensis in Vietnam?
Authors: Nguyen Hung Manh , Van Hien Hoang , Ho Loan Thi , Tatonova Yulia V. , Madsen Henry
Published: January 2021

Background

Two thiarid snail species,Melanoides tuberculataandTarebia graniferahave been reported as first intermediate hosts of the liver flukeClonorchis sinensis; however, their role as true first intermediate hosts has not been verified. Thus, the present study aimed to clarify the suitability of these two snail species as first intermediate hosts ofC.sinensis. This was accomplished by collecting snails from a highly endemic area forC.sinensisin Vietnam, the Thac Ba reservoir, and identifying shed cercariae using molecular techniques. We also conducted experimental infections of five snail species includingM.tuberculataandT.graniferawith eggs ofC.sinensis.

Methodology/Principal findings

A total of 11,985 snails, representing 10 species were sampled. Five snail species,M.tuberculata,T.granifera,Lymnaea swinhoei,Parafossarulus manchouricus, andBithynia fuchsianawere found shedding cercariae with an overall prevalence of infection ranging from 0.7% to 11.5%. Seven cercarial types were recorded. Cercariae ofC.sinensiswere only found inParafossarulus manchouricus. Using a multiplex PCR approach for detectingC.sinensisinfection, the prevalence inP.manchouricuswas 4.2%. Additionally, all five snail species were experimentally exposed toC.sinensiseggs, however onlyP.manchouricuswas successfully infected with an infection rate of 7.87%.

Conclusions/Significance

We confirmed that in the Thac Ba reservoir, Vietnam, the two thiarids,M.tuberculataandT.graniferaare not suitable first intermediate hosts ofC.sinensis. OnlyP.manchouricuswas found infected byC.sinensisin nature, and was the only species that became infected experimentally.
The contribution of stimulating multiple body parts simultaneously to the illusion of owning an entire artificial body
Authors: O’Kane Sophie H. , Ehrsson H. Henrik
Published: January 2021

The full-body ownership illusion exploits multisensory perception to induce a feeling of ownership of an entire artificial body. Although previous research has shown that synchronous visuotactile stimulation of a single body part is sufficient for illusory ownership of the whole body, the effect of combining multisensory stimulation across multiple body parts remains unknown. Therefore, 48 healthy adults participated in a full-body ownership illusion with conditions involving synchronous (illusion) or asynchronous (control) visuotactile stimulation to one, two, or three body parts simultaneously (2×3 design). We used questionnaires to isolate illusory ownership of five specific body parts (left arm, right arm, trunk, left leg, right leg) from the full-body ownership experience and sought to test not only for increased ownership in synchronous versus asynchronous conditions but also for potentially varying degrees of full-body ownership illusion intensity related to the number of body parts stimulated. Illusory full-body ownership and all five body-part ownership ratings were significantly higher following synchronous stimulation than asynchronous stimulation (p-values < .01). Since non-stimulated body parts also received significantly increased ownership ratings following synchronous stimulation, the results are consistent with an illusion that engages the entire body. Furthermore, we noted that ownership ratings for right body parts (which were often but not always stimulated in this experiment) were significantly higher than ownership ratings for left body parts (which were never stimulated). Regarding the effect of stimulating multiple body parts simultaneously on explicit full-body ownership ratings, there was no evidence of a significant main effect of the number of stimulations (p= .850) or any significant interaction with stimulation synchronicity (p= .160), as assessed by linear mixed modelling. Instead, median ratings indicated a moderate affirmation (+1) of an illusory full-body sensation in all three synchronous conditions, a finding mirrored by comparable full-body illusion onset times. In sum, illusory full-body ownership appears to be an ‘all-or-nothing’ phenomenon and depends upon the synchronicity of visuotactile stimulation, irrespective of the number of stimulated body parts.
Venues and segregation: A revised Schelling model
Authors: Silver Daniel , Byrne Ultan , Adler Patrick
Published: January 2021

This paper examines an important but underappreciated mechanism affecting urban segregation and integration: urban venues. The venue- an area where urbanites interact- is an essential aspect of city life that tends to influence residential location. We study the venue/segregation relationship by overlaying venues onto Schelling’s classic (1971) [1] agent-based segregation model. We show that a simulation world with venues makes segregation less likely among relatively tolerant agents and more likely among the intolerant. We also show that multiple venues can create spatial structures beyond their catchment areas and that the initial location of venues shapes later residential patterns. Finally, we demonstrate that the social rules governing venue participation alter their impacts on segregation. In the course of our study, we compile techniques for advancing Schelling-style studies of urban environments and catalogue a set of mechanisms that operate in this environment.
Isolating, identifying and evaluating of oil degradation strains for the air-assisted microbial enhanced oil recovery process
Authors: Cheng Mingming , Yu Long , Gao Jianbo , Lei Guanglun , Zhang Zaiwang
Published: January 2021

Due to the inefficient reproduction of microorganisms in oxygen-deprived environments of the reservoir, the applications of microbial enhanced oil recovery (MEOR) are restricted. To overcome this problem, a new type of air-assisted MEOR process was investigated. Three compounding oil degradation strains were screened using biochemical experiments. Their performances in bacterial suspensions with different amounts of dissolved oxygen were evaluated. Water flooding, microbial flooding and air-assisted microbial flooding core flow experiments were carried out. Carbon distribution curve of biodegraded oil with different oxygen concentration was determined by chromatographic analysis. The long-chain alkanes are degraded by microorganisms. A simulation model was established to take into account the change in oxygen concentration in the reservoir. The results showed that the optimal dissolved oxygen concentration for microbial growth was 4.5~5.5mg/L. The main oxygen consumption in the reservoir happened in the stationary and declining phases of the microbial growth systems. In order to reduce the oxygen concentration to a safe level, the minimum radius of oxygen consumption was found to be about 145m. These results demonstrate that the air-assisted MEOR process can overcome the shortcomings of traditional microbial flooding techniques. The findings of this study can help for better understanding of microbial enhanced oil recovery and improving the efficiency of microbial oil displacement.
Next of kin participation in the care of older persons in nursing homes: A pre–post non-randomised educational evaluation, using within-group and individual person-level comparisons
Authors: Westergren Albert , Ahlström Gerd , Persson Magnus , Behm Lina
Published: January 2021

Background

Next of kin participation in care is a cornerstone of palliative care and is thus important in nursing homes, and outcomes following interventions need to be evaluated using robust methods.

Objective

To use within-group and within-individual analytical approaches to evaluate the participation of next of kin in care following an intervention and to compare the outcome between the intervention and control groups.

Methods

A pre–post intervention/control group study design was used. The educational intervention, directed towards staff members, focused on palliative care. The Next of Kin Participation in Care scale comprises the Communication and Trust subscale and the Collaboration in Care subscale, with nine items each. In total, 203 persons (intervention group: n = 95; control group: n = 108) were included. Three different analytical approaches were used: 1) traditional within-group comparison of raw ordinal scores and linearly transformed interval scores; 2) modern within-individual (person-level) interval score comparisons; 3) comparisons between the intervention group and control group based on individual person-level outcomes.

Results

Within-group comparisons of change revealed no change in any of the groups, whether based on raw or transformed scores. Despite this, significant improvements at the individual level were found in 32.9% of the intervention group and 11.6% of the control group for the total scale (p = 0.0024), in 25% of the intervention group and 10.5% of the control group for the Communication and Trust subscale (p = 0.0018), and in 31.2% of the intervention group and 10.5% of the control group for the Collaboration in Care subscale (p = 0.0016). However, a significant worsening at the individual level in Collaboration in Care was found in 35.1% of the intervention group but only among 8.4% of the control group (p < 0.0005).

Conclusion

The intervention seems to have a positive impact on next of kin participation in care in nursing homes, especially for communication and trust. However, some next of kin reported decreased participation in care after the intervention. Modern individual person-level approaches for the analysis of intervention outcomes revealed individual significant changes beyond traditional group-level comparisons that would otherwise be hidden. The findings are relevant for future outcome studies and may also necessitate a re-evaluation of previous studies that have not used individual person-level comparisons.

Trial registration

This study is part of the intervention project registered under Clinical Trials Registration NCT02708498.
Manganese exposure in juvenile C57BL/6 mice increases glial inflammatory responses in the substantia nigra following infection with H1N1 influenza virus
Authors: Bantle Collin M. , French C. Tenley , Cummings Jason E. , Sadasivan Shankar , Tran Kevin , Slayden Richard A. , Smeyne Richard J. , Tjalkens Ronald B.
Published: January 2021

Infection with Influenza A virus can lead to the development of encephalitis and subsequent neurological deficits ranging from headaches to neurodegeneration. Post-encephalitic parkinsonism has been reported in surviving patients of H1N1 infections, but not all cases of encephalitic H1N1 infection present with these neurological symptoms, suggesting that interactions with an environmental neurotoxin could promote more severe neurological damage. The heavy metal, manganese (Mn), is a potential interacting factor with H1N1 because excessive exposure early in life can induce long-lasting effects on neurological function through inflammatory activation of glial cells. In the current study, we used a two-hit model of neurotoxin-pathogen exposure to examine whether exposure to Mn during juvenile development would induce a more severe neuropathological response following infection with H1N1 in adulthood. To test this hypothesis, C57BL/6 mice were exposed to MnCl2in drinking water (50 mg/kg/day) for 30 days from days 21–51 postnatal, then infected intranasally with H1N1 three weeks later. Analyses of dopaminergic neurons, microglia and astrocytes in basal ganglia indicated that although there was no significant loss of dopaminergic neurons within the substantia nigra pars compacta, there was more pronounced activation of microglia and astrocytes in animals sequentially exposed to Mn and H1N1, as well as altered patterns of histone acetylation. Whole transcriptome Next Generation Sequencing (RNASeq) analysis was performed on the substantia nigra and revealed unique patterns of gene expression in the dual-exposed group, including genes involved in antioxidant activation, mitophagy and neurodegeneration. Taken together, these results suggest that exposure to elevated levels of Mn during juvenile development could sensitize glial cells to more severe neuro-immune responses to influenza infection later in life through persistent epigenetic changes.
Estimation of forage biomass and vegetation cover in grasslands using UAV imagery
Authors: Théau Jérôme , Lauzier-Hudon Étienne , Aubé Lydiane , Devillers Nicolas
Published: January 2021

Grasslands are among the most widespread ecosystems on Earth and among the most degraded. Their characterization and monitoring are generally based on field measurements, which are incomplete spatially and temporally. The recent advent of unmanned aerial vehicles (UAV) provides data at unprecedented spatial and temporal resolutions. This study aims to test and compare three approaches based on multispectral imagery acquired by UAV to estimate forage biomass or vegetation cover in grasslands. The study site is composed of 30 pasture plots (25 × 50 m), 5 bare soil plots (25 x 50), and 6 control plots (5 × 5 m) on a 14-ha field maintained at various biomass levels by grazing rotations and clipping over a complete growing season. A total of 14 flights were performed. A first approach based on structure from motion was used to generate a volumetric-based biomass estimation model (R2 of 0.93 and 0.94 for fresh biomass [FM] and dry biomass [DM], respectively). This approach is not very sensitive to low vegetation levels but is accurate for FM estimation greater than 0.5 kg/m2 (0.1 kg DM/m2). The Green Normalized Difference Vegetation Index (GNDVI) was selected to develop two additional approaches. One is based on a regression biomass prediction model (R2 of 0.80 and 0.66 for FM and DM, respectively) and leads to an accurate estimation at levels of FM lower than 3 kg/m2 (0.6 kg DM/m2). The other approach is based on a classification of vegetation cover from clustering of GNDVI values in four classes. This approach is more qualitative than the other ones but more robust and generalizable. These three approaches are relatively simple to use and applicable in an operational context. They are also complementary and can be adapted to specific applications in grassland characterization.
Intestinal parasites may be associated with later behavioral problems in internationally adopted children
Authors: Heikkilä Anna-Riitta , Elovainio Marko , Raaska Hanna , Matomäki Jaakko , Sinkkonen Jari , Lapinleimu Helena
Published: January 2021

Aim

At arrival in new home country, internationally adopted children often have intestinal parasites. International adoptees also exhibit more behavioral problems than their biological peers. We examined whether intestinal parasite infections in international adoptees on arrival in Finland are associated with their later behavioral and emotional problems.

Methods

Data for this study were sourced from the Finnish Adoption Study (FinAdo) based on parental questionnaires for all internationally adopted children under 18 years (n= 1450) who arrived in Finland from 1985 to 2007. A total of 1293 families provided sufficient information on the adoptee’s background, parasitic status on arrival, and behavioral symptoms at the median time of 5 years after arrival (mean age = 7.8 years). Behavioral and emotional disorders were evaluated with the Child Behavior Checklist (CBCL). Statistical analyses were conducted using linear regression.

Results

Of the 1293 families, parents of 206 adoptive children reported intestinal parasites in their adopted children on arrival. Parasite-infected children had subsequently higher CBCL problem scores than the children without parasites (p< 0.001). The association between intestinal parasites and later behavioral problems was stronger than that between intestinal parasites and any other factors measured in this study, except disability.

Limitations

The control group was naturally provided by the adopted children without parasite infections, but we could not compare the adopted children to non-adopted children without a defined parasite infection. We were unable to specify the effects associated with a specific parasite type. It was not possible either to include multiple environmental factors that could have been associated with behavioral problems in the models, which indicated only modest explanatory values.

Conclusions

In this study, intestinal parasite infections in early childhood may be associated with children’s later psychological wellbeing, even in children who move to a country with a low prevalence of parasites. Our findings may support further developments pertaining to the gut-brain theory.
Effects of whole-body electromyostimulation on function, muscle mass, strength, social participation, and falls-efficacy in older people: A randomized trial protocol
Authors: de Oliveira Túlio Medina Dutra , Felício Diogo Carvalho , Filho José Elias , Durigan João Luiz Quagliotti , Fonseca Diogo Simões , José Anderson , Oliveira Cristino Carneiro , Malaguti Carla
Published: January 2021

Background

Resistance training has a positive impact on functional capacity and muscle mass in the elderly. However, due to physical limitations or a simple aversion against regular exercise, a majority of the elderly do not reach the recommended exercise doses. This led us to evaluate the effect of whole-body electromyostimulation (WB-EMS), a novel, time-efficient, and smooth training technology on physical function, fat-free mass, strength, falls-efficacy, and social participation of the elderly.

Methods

The present study is a randomized, parallel group clinical trial approved by the Ethics Committee of our Institution. Sixty-six volunteers (age ≥ 60 years) will be recruited from the geriatric outpatient department in a tertiary hospital and primary care units and randomized into two groups: WB-EMS group or active control group (aCG). The WB-EMS or aCG protocol will consist of 16 sessions for 8 consecutive weeks, twice per week. The primary outcomes will be maximal isometric knee extension (IKE), functional lower extremity strength, fat-free mass, gait speed, and risk of falls measured before and after intervention. The secondary outcomes will be social participation and falls-efficacy assessed before and after the intervention and at three and six months of follow-up. Participant’s satisfaction with and awareness of electrical stimulation therapy will also be assessed immediately after the 8-week intervention.

Discussion

Patients receiving WB-EMS exercises are believed to have better outcomes than those receiving conventional, more time-consuming resistance exercises. Hence, innovative, time-efficient, joint-friendly, and highly individualized exercise technologies (such as WB-EMS) may be a good choice for the elderly with time constraints, physical limitations, or little enthusiasm, who are exercising less than the recommended amounts for impact on muscle mass, strength, and function.
Elevated serum 4HNE plus decreased serum thioredoxin: Unique feature and implications for acute exacerbation of chronic obstructive pulmonary disease
Authors: Liu Jia , Huang Jin , Liu Hu , Chen Chang , Xu Jianying , Zhong Liangwei
Published: January 2021

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a global problem with high mortality. Its pathogenesis is not fully understood. To reveal new serum feature of AECOPD and their potential implications, we have analyzed 180 serum samples, and found that in the serum of AECOPD patients, 4-hydroxy-2-nonenal (4HNE)-protein adducts are dynamically increased as partial pressure of oxygen (PaO2) drops, which is accompanied by progressively decreasing thioredoxin reductase (TrxR1) and thioredoxin (Trx1), as compared with those of healthy people. This phenomenon is unique, because acute hypoxia patients have 1.1-fold or 1.7-fold higher serum TrxR1 or Trx1 activity, respectively, than healthy people, in keeping with low 4HNE level. Moreover, serum 4HNE-protein adducts may form disulfide-linked complexes with high-molecular-weight, the amount of which is significantly increased during AECOPD. Serum 4HNE-protein adducts include 4HNE-Trx1 adduct and 4HNE-TrxR1 adduct, but only the former is significantly increased during AECOPD. Through cell biology, biochemistry and proteomics methods, we have demonstrated that extracellular 4HNE and 4HNE-Trx1 adduct affect human bronchial epithelial cellsviadifferent mechanisms. 4HNE-Trx1 adduct may significantly alter the expression of proteins involved mainly in RNA metabolism, but it has no effect on TrxR1/Trx1 expression and cell viability. On the other hand, low levels of 4HNE promote TrxR1/Trx1 expression and cell viability, while high levels of 4HNE inhibit TrxR1/Trx1 expression and cell viability, during which Trx1, at least in part, mediate the 4HNE action. Our data suggest that increasing serum 4HNE and decreasing serum Trx1 in AECOPD patients are closely related to the pathological processes of the disease. This finding also provides a new basis for AECOPD patients to use antioxidant drugs.
Development of a porcine model of phenylketonuria with a humanized R408W mutation for gene editing
Authors: Kaiser Robert A. , Carlson Daniel F. , Allen Kari L. , Webster Dennis A. , VanLith Caitlin J. , Nicolas Clara T. , Hillin Lori G. , Yu Yue , Kaiser Catherine W. , Wahoff William R. , Hickey Raymond D. , Watson Adrienne L. , Winn Shelley R. , Thöny Beat , Kern Douglas R. , Harding Cary O. , Lillegard Joseph B.
Published: January 2021

Phenylketonuria (PKU) is a metabolic disorder whereby phenylalanine metabolism is deficient due to allelic variations in the gene for phenylalanine hydroxylase (PAH). There is no cure for PKU other than orthotopic liver transplantation, and the standard of care for patients is limited to dietary restrictions and key amino acid supplementation. Therefore, Pah was edited in pig fibroblasts for the generation of PKU clone piglets that harbor a common and severe human mutation, R408W. Additionally, the proximal region to the mutation was further humanized by introducing 5 single nucleotide polymorphisms (SNPs) to allow for development of gene editing machinery that could be translated directly from the pig model to human PKU patients that harbor at least one classic R408W allele. Resulting piglets were hypopigmented (a single Ossabaw piglet) and had low birthweight (all piglets). The piglets had similar levels of PAH expression, but no detectable enzymatic activity, consistent with the human phenotype. The piglets were fragile and required extensive neonatal care to prevent failure to thrive and early demise. Phenylalanine levels rose sharply when dietary Phe was unrestricted but could be rapidly reduced with a low Phe diet. Fibroblasts isolated from R408W piglets show susceptibility to correction using CRISPR or TALEN, with subsequent homology-directed recombination to correct Pah. This pig model of PKU provides a powerful new tool for development of all classes of therapeutic candidates to treat or cure PKU, as well as unique value for proof-of-concept studies for in vivo human gene editing platforms in the context of this humanized PKU allele.
Association of low back pain with muscle weakness, decreased mobility function, and malnutrition in older women: A cross-sectional study
Authors: Kato Satoshi , Demura Satoru , Shinmura Kazuya , Yokogawa Noriaki , Kabata Tamon , Matsubara Hidenori , Kajino Yoshitomo , Igarashi Kentaro , Inoue Daisuke , Kurokawa Yuki , Oku Norihiro , Tsuchiya Hiroyuki
Published: January 2021

Background

Low back pain (LBP) and decreased mobility function are common problem among older people. Muscle weakness has been reported as a risk factor for these conditions, and exercise therapy can improve them. We created a novel exercise device that also measures abdominal trunk muscle strength. Malnutrition has also emerged as a major problem among older people. Muscle is a direct key linking decreased mobility function and malnutrition. This study aimed to examine the associations of LBP with not only decreased physical function and muscle weakness but also nutritional status of older people.

Methods

We examined the associations of LBP with muscle weakness, decreased mobility function (locomotive syndrome [LS]), and malnutrition among older women. The study included 101 female patients aged 60 years or older scheduled to undergo surgery for degenerative lower extremity diseases. Preoperatively, physical tests including abdominal trunk muscle strength assessment using the device and laboratory tests were conducted. Subjects with LBP (numerical rating scale ≥2; range, 0–4) during the preceding month were allocated to the LBP group (n = 36). Other subjects were allocated to the non-LBP group (n = 65).

Results

The LBP group had lower abdominal trunk and knee extensor muscle strength, lower serum albumin, and hemoglobin levels as blood biomarkers associated with malnutrition risk, and higher LS test scores than the non-LBP group. A multivariate analysis showed that abdominal trunk muscle weakness and advanced LS were associated with LBP. LBP intensity was negatively correlated with abdominal trunk and knee extensor muscle strength and positively correlated with the LS test score. The serum hemoglobin level was negatively correlated with the LS test score.

Conclusion

Abdominal trunk muscle weakness and decreased mobility function were associated with LBP among older women.
Have FDI quantity and quality promoted the low-carbon development of science and technology parks (STPs)? The threshold effect of knowledge accumulation
Authors: Zhang Shujing , Hu Beibei , Zhang Xiufeng
Published: January 2021

In recent times, China has emphasized five major development concepts to promote high-quality development: coordination, green, innovation, openness, and sharing. As a metamorphosis of these ideas, Chinese science and technology parks (STPs) are gathering areas of high-tech industries and represent advanced productive forces. Their greenness, openness, and innovative developments herald the future development trends of China. Based on the data of 52 STPs in China from 2011 to 2018, this study analyzes the impact of foreign direct investment (FDI) quantity and quality on the low-carbon development of the STPs. We use Hansen’s nonlinear panel threshold regression model with knowledge accumulation as the threshold variable. The results show the following: First, there are complex nonlinear relationships between FDI quantity, FDI quality, and the low-carbon development of the STPs. Second, FDI quantity has a significant positive impact on the low-carbon development of the STPs only when the level of knowledge accumulation is below a certain threshold. Beyond this threshold the effect is no longer significant. Third, FDI quality has a significant positive impact on the low-carbon development of STPs only when the level of knowledge accumulation is lower than a certain threshold; beyond which, the impact is no longer significant. These results can serve as a reference for China to effectively promote economic low-carbon growth of STPs and achieve green, open, and innovative development.