bluuebunny/crossref_metadata_2025 huggingface dataset:
Superfast domain wall motion in lithium niobate single crystals. Analogy with crystal growth
Authors: Esin A. A. , Akhmatkhanov A. R. , Shur V. Ya.
Published: May 2019

In this paper, we studied the superfast domain walls that appear after domain merging during polarization reversal in congruent lithium niobate single crystals by in situ optical visualization with a high temporal resolution. The superfast domain walls were observed during the fast transformation of the domain shape from concave polygonal that appears after merging to the convex polygonal one with slow domain walls only. Orientations and velocities of superfast domain walls were measured during transformation of an artificial polygonal X-shaped domain (with all concave angles appearing after merging) to a hexagonal one. The “convex” growth of isolated hexagonal domains was governed by the slowest domain walls, while the “concave” growth after domain merging—by the superfast walls with three orders of magnitude higher velocity. We reconstructed experimentally the v-plot (kinetic Wulff plot) for domain wall motion by analysis of both convex and concave domain growth. The slowest walls (Y-walls) correspond to the v-plot deep cusps having six-fold symmetry, whereas the superfast walls correspond to the v-plot maxima having three-fold symmetry with a difference between Y+ and Y− crystallographic directions. The field dependences of the velocities of the superfast domain walls followed the activation law, taking into account the existence of the bias field.
Relationship between relaxation time and diffusion of magnetized two-dimensional Yukawa liquids
Authors: Lu Shaoyu , Wang Kang , Feng Yan
Published: May 2019

Structural relaxation and self-diffusion of magnetized two-dimensional (2D) Yukawa liquids are investigated using Langevin dynamical simulations. The structural relaxation time τα is obtained from the self-intermediate scattering function, while the self-diffusion coefficient D is calculated from the mean-squared displacement. It is discovered that, for the magnetized 2D Yukawa liquids with the coupling parameter of Γ, the relationship between τα and D can be expressed as D ∝ (1/ταΓ)ξ with two distinct values of the exponent ξ at low and high temperatures, respectively. At low temperatures, the exponent ξ decreases with the applied magnetic field, which is attributed to the dynamical heterogeneity caused by the magnetic field. At high temperatures, it is found that both D and ταΓ obey the Arrhenius behaviors, reasonably leading to the discovered D ∝ (1/ταΓ)ξ relationship.
The extreme acoustic anisotropy and fast sound velocities of cubic high-pressure ice polymorphs at Mbar pressure
Authors: Zhang Jin S. , Hao M. , Ren Z. , Chen B.
Published: May 2019

We presented the experimentally determined single-crystal elasticity model of ice up to 103(3) GPa, based on the sound velocity measurements of high-P ice polymorphs within multiple diamond anvil cells using Brillouin spectroscopy. We have not observed any discontinuities of the P-wave (Vp) or S-wave (Vs) velocities over the entire P range. The elastic moduli of high-P ice show a close to linear P dependence. In comparison with the high-P silicate minerals in terrestrial planetary bodies, the Vp and Vs values of ice exceed those of both bridgmanite and ferropericlase at P > 80–90 GPa, counter-intuitively indicating that the high-P ice, if existing in the deep terrestrial planets' interior, is not a slow phase. Instead, the high-P ice shows extremely strong elastic anisotropy, reaching 27% and 74% at 100 GPa for Vp and Vs, respectively. The presence of high-P ice in terrestrial planets' interior, even on a small scale may lead to the observable anisotropic signatures, such as the 25% Vs anisotropy in the deep earthquake-generating zone in subducting slabs. We anticipate our measurements to serve as an important base for explaining and modeling the geophysical observations for various types of planetary bodies.
Charging and dynamics of dust particles in lunar photoelectron sheath
Authors: Mishra S. K. , Misra S.
Published: May 2019

Sunlight scattering from electrostatically charged floating particles is considered accountable for the lunar twilight observations of horizon glow and streamers. In this work, the dynamics of the fine charged particles within the photoelectron sheath over the sunlit lunar surface has been investigated. Accounting for the influence of solar radiation, solar wind plasma, and lunar gravity, the present transport model consistently takes account of the coexisting phenomenon of particle charging, and characteristic photoelectron sheath screening in deriving the vertical motion of the particle. As novel features, half Fermi-Dirac statistics of the photoelectron velocity in determining the electron population and the sheath structure through the Poisson equation, and anisotropic photoelectron flux in evaluating the particle charge as it traverses through the sheath, have adequately been included in the analysis. In this framework, the electrostatic sheath features are observed to dominate over the lunar gravity in determining the dynamics of smaller (nanometer) size grains; for instance, ∼10 nm sized particles detached from the lunar regolith with a finite velocity are shown to loft up to the kilometer altitude. Depending on the initial particle velocity and size, a parametric regime defining the particle hopping over the lunar surface has been identified.
Stepwise propagation of a guided streamer along a DBD helium plasma jet fed by biased oscillating voltage
Authors: Pinchuk M. E. , Stepanova O. M. , Astafiev A. M. , Lazukin A. V. , Chen Zhaoquan
Published: May 2019

A stepwise propagation of a guided streamer along a helium atmospheric pressure plasma jet driven by a dielectric barrier discharge was recorded. To feed the plasma jet, we used a power supply generating an output voltage signal consisting of a superposition of 41.6 kHz bipolar square pulses and 300 kHz oscillating signals. At a positive half a period of the output voltage signal, a step-by-step propagation was observed for the ionization wave along the plasma jet. The streamer head stops with the decrease in voltage in the first cycle of oscillations and then restarts its motion at the voltage front of the next cycle of a voltage oscillation. The streamer propagation velocity and plasma jet length are likely to be controlled by varying the gas flow rate, bias voltage, voltage rise rate, frequency of oscillations in the pulse, and other parameters.
Terpene ligands in the coordination chemistry: synthesis of metal complexes, stereochemistry, catalytic properties and biological activity
Authors: Zalevskaya Olga A. , Gur’eva Yana A. , Kutchin Aleksandr V.
Published: May 2019

Published data on the synthesis and catalytic properties of metal complexes with chiral ligands containing a terpene moiety are integrated and systematized. The stereochemical features of transition metal complexes with terpene ligands are discussed. Structures of stable complexes of this type and the initial chiral ligands are presented. In view of the enormous structural diversity of the analyzed data, classification is based on the chemical functionality of terpene ligands. The results of application of terpene ligands in asymmetric transition metal catalysis are considered; the data are classified in terms of the type of chemical reaction. Data on the biological activity of some metal complexes with terpene ligands are presented.

The bibliography includes 228 references.
Weakly monotone sets and continuous selection in asymmetric spaces
Authors: Tsar’kov I. G.
Published: May 2019

Sets admitting a continuous selection from the set of near best approximations are studied. Applications of the geometric theory of approximation to the existence of continuous selections for the sets of

-link piecewise linear functions,

-link piecewise polynomial functions and generalizations thereof are also discussed.

Bibliography: 23 titles.
Corrigendum to: Controlling the trade-off between spikelet number and grain filling: the hierarchy of starch synthesis in spikelets of rice panicle in relation to hormone dynamics
Authors: Panigrahi Rashmi , Kariali Ekamber , Panda Binay Bhusan , Lafarge Tanguy , Mohapatra Pravat Kumar
Published: May 2019

The advent of dwarf statured rice varieties enabled a major breakthrough in yield and production, but raising the ceiling of genetically determined yield potential even further has been the breeding priority. Grain filling is asynchronous in the rice panicle; the inferior spikelets particularly on secondary branches of the basal part do not produce grains of a quality suitable for human consumption. Of the various strategies being considered, the control of ethylene production at anthesis has been a valuable route to potentially enhance genetic yield level of rice. The physiology underlying spikelet development has revealed spikelet position-specific ethylene levels determine the extent of grain filling, with higher levels resulting in ill-developed spikelet embodying poor endosperm starch content. To break the yield barrier, breeders have increased spikelet number per panicle in new large-panicle rice plants. However, the advantage of panicles with numerous spikelets has not resulted in enhanced yield because of poor filling of inferior spikelets. High spikelet number stimulates ethylene production and downgrading of starch synthesis, suggesting a trade-off between spikelet number and grain filling. High ethylene production in inferior spikelets suppresses expression of genes encoding endosperm starch synthesising enzymes. Hence, ethylene could be a retrograde signal that dictates the transcriptome dynamics for the cross talk between spikelet number and grain filling in the rice panicle, so attenuation of its activity may provide a solution to the problem of poor grain filling in large-panicle rice. This physiological linkage that reduces starch biosynthesis of inferior kernels is not genetically constitutive and amenable for modification through chemical, biotechnological, surgical and allelic manipulations. Studies on plant genotypes with different panicle architecture have opened up possibilities of selectively improving starch biosynthesis of inferior spikelets and thereby increasing grain yield through a physiological route.
The pragmatic use of ‘sort of’ in TV forums
Authors: Zhang Grace
Published: May 2019

This study discusses the pragmatic functions of four Chinese equivalents of the English ‘sort of’ based on a Chinese TV forum corpus:youdian(有点),yidian(一点),youyidian(有一点),keyishuo(可以说). It finds that the Chinese ‘sort of’ tends to cluster with verbs or adjectives rather than nouns. ‘Sort of’ is infrequent in the formal setting of this study and serves three pragmatic functions: mitigation, approximation and evasion, with the first two functions being much more frequent than the last one. ‘Sort of’ performs more of an interpersonal than an informational function. This study highlights the elasticity of ‘sort of’ in Mandarin Chinese in the form of fluidity, stretchability and strategy, contributing a fresh account of pragmatic markers. This study implies that elastic language use is a natural part of linguistic competence (particularly pragmatic competence) and forms a strong bond with effective linguistic communication.
Comparing French liaison acquisition in L1 children and L2 adults
Authors: Harnois-Delpiano Mylène , Cavalla Cristelle , Chevrot Jean-Pierre
Published: May 2019

In the study of liaison acquisition, a key line of inquiry has focused on potential differences and similarities between L1 and L2 French speakers. However, such a comparison encounters a number of difficulties such as matching learners in terms of language exposure, age, and learning abilities. This study addresses these issues based on the analysis of French liaison in a series of experimental tasks performed by L1 children aged two to six, and by adult Korean learners of French as a foreign language. Results show that, for both groups, acquisition of categorical liaison precedes acquisition of variable liaison. However, when L1 and L2 learners are matched individually based on the results of a production task, they differ in a judgment task involving the perception of liaison. More specifically, the ability to judge the correctness of liaison precedes the ability to produce it in L2 learners, but not in L1 children. The findings provide a strong indication that L2 learners follow a specific process when acquiring liaison.
Burla y risa en El celoso hasta la muerte de Alonso de Castillo Solórzano
Authors: Rodríguez Mansilla Fernando
Published: May 2019

This article explores the function of mockery and laughter in the short novel El celoso hasta la muerte by Alonso de Castillo Solórzano. I interpret this text as a “novela de burlas” or comic novella, a specific type of narrative in which mockery is a central device. The analysis pays close attention to the mechanism of the “canned laughter” that reveals the function of ridicule and the role of both the victim as scapegoat and his victimizers. At the end, this short novel reflects the literary sensitivity of the aristocratic audience to whom it is addressed: a small group of noble families and friends that the author met during his stay in Valencia.
miR-655-3p inhibits cell migration and invasion by targeting pituitary tumor-transforming 1 in non-small cell lung cancer
Authors: Wang Wei , Cao Ranhua , Su Wuyun , Li Yulian , Yan Haicheng
Published: May 2019

miR-655-3p functions as a tumor suppressor in tumor metastases; however, its role and mechanism in regulating cell migration and invasion of non-small cell lung cancer (NSCLC) remain unclear. Here, we found that miR-655-3p expression was markedly decreased in the NSCLC cell lines A549, NCI-H1650, PC14/b, NCI-H1299, and HPAEpiC compared to levels observed in normal human lung fibroblasts. miR-655-3p overexpression significantly inhibited migration and invasion of A549 and PC14/b cells, and pituitary tumor-transforming 1 (PTTG1) expression was up-regulated in the NSCLC cells. Luciferase reporter assays indicated that PTTG1 was a direct target of miR-655-3p. Additionally, PTTG1 overexpression alleviated the inhibitory effect of miR-655-3p on migration and invasion abilities in A549 and PC14/b cells. In conclusion, miR-655-3p inhibits NSCLC migration and invasion by targeting PTTG1, suggesting that miR-655-3p may serve as a therapeutic target to provide a new approach for the clinical treatment of NSCLC.
Effects of the FIFA 11+ on ankle evertors latency time and knee muscle strength in amateur futsal players
Authors: Lopes Mário , Rodrigues João Manuel , Monteiro Pedro , Rodrigues Mário , Costa Rui , Oliveira José , Ribeiro Fernando
Published: May 2019

Background: The FIFA 11+ has shown to increase muscle strength and reduce injury risk. The purpose of this study was to assess the short and long‐term effects of the FIFA 11+ on knee strength, and muscle latency after sudden inversion of amateur futsal players.

Methods: Seventy‐one male futsal players were recruited and randomized to a FIFA 11+ (n = 37, age: 27.0 ± 5.1 years) and a control group (n = 34, age: 26.0 ± 5.1 years). The FIFA 11+ programme was executed twice a week, for 10 weeks, followed‐up after 10 weeks where both groups executed regular warm‐ups. Concentric and eccentric isokinetic knee muscle strength was tested and latency time of the evertor muscles after sudden inversion of the ankle was executed with a trapdoor mechanism following an EMG protocol of selected leg muscles (peroneus brevis and peroneus longus).

Results: No significant difference were observed between groups for short‐term changes in isokinetic strength after adjustment for baseline differences. At long‐term, significant gains were obtained after adjustment for baseline differences in eccentric strength for both lower limbs as for the H/Q ratios for the dominant limb. No changes between groups were observed in the peroneus brevis and peroneus longus latency time.

Conclusions: Performing FIFA 11+ did not have short‐term effects on knee strength and muscle latency after sudden inversion in amateur futsal players. However, significant long‐term benefits were observed for eccentric strength and H/Q ratios.
Non-linear optical response of edible oils by means of the Z-scan technique
Authors: Marbello O , Valbuena S , Racedo F J
Published: May 2019

Oils of vegetable origin are classified as organic compounds, which have become the object of study in the field of photonics and non-linear optics, because they have a characteristic chemical bond with the presence of delocalized electrons, which gives them a high non-linear response. In the food industry, non-destructive or invasive studies are required to establish the quality and conservation indices of the chemical, physical and nutritional properties of edible products. The non-linear optic response of different oils of vegetable origin was evaluated: extra virgin olive oil, extra virgin sesame oil, extra refined linseed oil and virgin avocado oil using the Z-scan technique. The absorption and transmission spectra were taken to establish the coefficient of linear absorption of the sample as a function of the wavelength. For each compound, the variations of the nonlinear optical properties were analyzed as a function of the excitation power, using the closed cell and open cell configurations; where the third-order electrical susceptibility (χ
3), the non-linear refraction index (η
2) and the non-linear absorption coefficient (β) were determined. Subsequently, a comparison of the non-linear response was made according to the type of oil and the degree of refinement. It was found that extra virgin olive oil and virgin avocado oil presented a better non-linear response at low laser power as a consequence of the low thermal influence, which makes them possible candidates in the development of photonic devices.
Analysis of deviations in wavelength measurements with a diffraction grating monochromator with respect to a certified reference spectral lamp
Authors: Arcón G , Álvarez J , Sogamoso L , Sarmiento R
Published: May 2019

This paper shows the analysis of the deviations in the wavelength measurements made with a DK-480 monochromator of diffraction grating respect to the values reported for a certified calibration spectral lamp. The radiation emitted by the calibration lamp was dispersed using diffraction gratings of 300, 1200 and 2400 grooves/mm provided in the monochromator. The emitted spectrum contains neutral Mercury and neutral Argon lines, which was registered with a photomultiplier tube coupled to an amplifier circuit. In this study it was applied the method of least squares to the results of the spectral measurements, and it was obtained for each diffraction grating, the linear model or linear fitting of the comparison with respect to the values of the wavelengths of the reference lamp. With the general model of the propagation of the uncertainty, the uncertainty function was obtained for each diffraction grating, in order to estimate the uncertainty of wavelengths interpolated in each spectral range, which are useful for measuring wavelengths of any other spectral source.
Level control loop design for a test-rig flotation column
Authors: Piñeres J , Mendoza M. , Tellez M , Jiménez F
Published: May 2019

During the last years, there has been a great advance in the instrumentation to improve the performance of industrial processes, this has allowed important advances in the control processes. In this work, we analysed the control of the froth layer height (level) of a flotation column to improve its performance. A level control loop was designed, selected and assembled, finally it was adjusted through NB Omron Designer interface that allows the communication between the measure element, controller and control valve, establishing a pressure (Set Point) to control froth layer height (level) and make sure it is stable operating. Tests were carried out with water, water-air and water-air-frother. This was done to analyse the behaviour of the column and subsequently verify the results using drift flux analysis. Once the results were obtained, the parameters that showed the optimal performance of the column were analysed. An overshoot was obtained in the range of 1 % to 12 %, stabilization time in the range of 90 s to 97 s and the tailing velocity which was maintained between 0.72 cm/s - 0.76 cm/s. Analysing the results, the experimental error was in the range of 0 % to 6 %.
Electric polarizability of type-II semiconductor nanocone induced by magnetoexciton
Authors: Mercado A M , Sierra-Ortega J , Garcia L F , Mikhailov I D
Published: May 2019

We present a theoretical analysis of the possibility of formation of a permanent electric dipole moment in the presence of the electric and magnetic fields, which are simultaneously applied along the symmetry axis of a CdS/ZnSe type II nanocone, induced by a trapped exciton. We show that the external magnetic field applied along the cone’s axis increases the electric dipole moment forcing the electron to climb along the cone’s border via the diamagnetic confinement, meanwhile the electric field may cause either growth or reduction of the electric dipole moment.
Nonlinear encryption system based on the fractional Fourier operators and truncation operations
Authors: Vilardy J M , Perez R , Jimenez C
Published: May 2019

In this paper, the fractional Fourier operators, the random phase masks and the nonlinear operations of amplitude and phase truncations are utilized to encrypt and decrypt images. We use the following fractional Fourier operators in the image encryption-decryption system: the fractional Fourier transform, the fractional traslation and the fractional correlation. The proposed encryption system uses nonlinear operations, such as phase encoding and truncation operations, in order to increase the security of the encrypted image. The encryption-decryption system has the following security keys: one fractional order of the fractional Fourier transform, two random phase masks and two pseudorandom code images. When all the proper security keys are used in the decryption system, the obtained decrypted image is a replica of the image to encrypt.
A DFT study about the effects of exchange-correlation functional on the structural and electronic properties of Anatase
Authors: González Ramirez I A , Alcalá Varilla L A , Montoya J A
Published: May 2019

A comparative study is presented, based on Density Functional Theory, of the influence that the different approximations of the exchange-correlation functional have on the structural and electronic properties of titanium dioxide in the anatase phase. In this work, the method of plane waves and pseudopotentials, as implemented in the Quantum Espresso package was used. The approximations to the correlation-exchange functional that were considered are the local density approximation, the generalized gradient approximation in the form of Perdew-Burke-Ernzerhof, the Perdew-Burke-Ernzerhof for solids, and the Perdew-Wang 91. For each case, the effects due to the inclusion of spin (spin polarization), and the correction of Hubbard (U=4.2 eV for Ti) were also studied. We found that the Perdew-Burke-Ernzerhof for solids functional offers the best results for the calculation of the lattice parameters and bond lengths, followed by the local density approximation with the Hubbard correction included. For the bond angles, the best description was obtained with the local density approximation. The inclusion of the U term increases the errors associated with the mentioned structural parameters when the following functionals are used: Perdew-Burke-Ernzerhof, Perdew-Burke-Ernzerhof for solids and Perdew-Wang 91. The Perdew-Burke-Ernzerhof and Perdew-Wang 91 functionals show the largest errors when the Hubbard correction is used; while the local density approximation shows significant improvement when the Hubbard correction is included. Regarding the energy gap, we found that the introduction of the U term improves the estimation of this property for all the approximations included in this work.
Efficacy of black carbon aerosols: the role of shortwave cloud feedback
Authors: Modak Angshuman , Bala Govindasamy
Published: May 2019

Using idealized climate model simulations, we investigate the effectiveness of black carbon (BC) aerosols in warming the planet relative to CO2 forcing. We find that a 60-fold increase in the BC aerosol mixing ratio from the present-day levels leads to the same equilibrium global mean surface warming (∼4.1 K) as for a doubling of atmospheric CO2 concentration. However, the radiative forcing is larger (∼5.5 Wm−2) in the BC case relative to the doubled CO2 case (∼3.8 Wm−2) for the same surface warming indicating the efficacy (a metric for measuring the effectiveness) of BC aerosols to be less than CO2. The lower efficacy of BC aerosols is related to the differences in the shortwave (SW) cloud feedback: negative in the BC case but positive in the CO2 case. In the BC case, the negative SW cloud feedback is related to an increase in the tropical low clouds which is associated with a northward shift (∼7°) of the Intertropical Convergence Zone (ITCZ). Further, we show that in the BC case fast precipitation suppression offsets the surface temperature mediated precipitation response and causes ∼8% net decline in the global mean precipitation. Our study suggests that a feedback between the location of ITCZ and the interhemispheric temperature could exist, and the consequent SW cloud feedback could be contributing to the lower efficacy of BC aerosols. Therefore, an improved representation of low clouds in climate models is likely the key to understand the global climate sensitivity to BC aerosols.
Domesticating Colonizers: Domesticity, Indigenous Domestic Labor, and the Modern Settler Colonial Nation
Authors: Haskins Victoria
Published: May 2019

The placement of Indigenous girls and young women in white homes to work as servants was a key strategy of official policy and practice in both the United States and Australia. Between the 1880s and the Second World War, under the outing programs in the U.S. and various apprenticeship and indenturing schemes in Australia, the state regulated and constructed relations between Indigenous and white women in the home. Such state intervention not only helped to define domesticity in a modern world, but was integral to the formation of the modern settler colonial nation in its claims to civilizing authority in the United States and Australia. In the context of settler colonialism, domesticity was not hegemonic in this period, but rather was precarious and uncertain. By prescribing and demanding from employers demonstrations of domesticity, the state was engaged in perfecting white women as well as Indigenous women, the latter as the colonized, to be domesticated, and the former as the colonizer, to domesticate.
Distributional consistency of the lasso by perturbation bootstrap
Authors: Das Debraj , Lahiri S N
Published: May 2019

The lasso is a popular estimation procedure in multiple linear regression. We develop and establish the validity of a perturbation bootstrap method for approximating the distribution of the lasso estimator in a heteroscedastic linear regression model. We allow the underlying covariates to be either random or nonrandom, and show that the proposed bootstrap method works irrespective of the nature of the covariates. We also investigate finite-sample properties of the proposed bootstrap method in a moderately large simulation study.
A unified method for improved inference in random effects meta-analysis
Authors: Sugasawa Shonosuke , Noma Hisashi
Published: May 2019

Random effects meta-analyses have been widely applied in evidence synthesis for various types of medical studies. However, standard inference methods (e.g. restricted maximum likelihood estimation) usually underestimate statistical errors and possibly provide highly overconfident results under realistic situations; for instance, coverage probabilities of confidence intervals can be substantially below the nominal level. The main reason is that these inference methods rely on large sample approximations even though the number of synthesized studies is usually small or moderate in practice. In this article, we solve this problem using a unified inference method based on Monte Carlo conditioning for broad application to random effects meta-analysis. The developed method provides improved confidence intervals with coverage probabilities that are closer to the nominal level than standard methods. As specific applications, we provide new inference procedures for three types of meta-analysis: conventional univariate meta-analysis for pairwise treatment comparisons, meta-analysis of diagnostic test accuracy, and multiple treatment comparisons via network meta-analysis. We also illustrate the practical effectiveness of these methods via real data applications and simulation studies.
Returns to livestock disease control – a panel data analysis in Togo
Authors: Weyori Alirah Emmanuel , Liebenehm Sabine , Waibel Hermann
Published: May 2019

This paper investigates whether – and to what extent – a veterinary intervention programme lead to improvements in small-scale cattle farmers’ welfare using a unique panel data set of 443 households from northern Togo. Our results show a positive impact of the interventions on improving farmers’ knowledge and husbandry practices that translates into improved livestock health and productivity. In addition, these positive effects trigger improvements in terms of poverty and vulnerability. The results highlight the important role of targeted interventions that aim to improve livestock health – a key asset among rural households in sub-Saharan Africa.
Evolutionary and functional analysis of RBMY1 gene copy number variation on the human Y chromosome
Authors: Shi Wentao , Louzada Sandra , Grigorova Marina , Massaia Andrea , Arciero Elena , Kibena Laura , Ge Xiangyu Jack , Chen Yuan , Ayub Qasim , Poolamets Olev , Tyler-Smith Chris , Punab Margus , Laan Maris , Yang Fengtang , Hallast Pille , Xue Yali
Published: May 2019

Human RBMY1 genes are located in four variable-sized clusters on the Y chromosome, expressed in male germ cells and possibly associated with sperm motility. We have re-investigated the mutational background and evolutionary history of the RBMY1 copy number distribution in worldwide samples and its relevance to sperm parameters in an Estonian cohort of idiopathic male factor infertility subjects. We estimated approximate RBMY1 copy numbers in 1218 1000 Genomes Project phase 3 males from sequencing read-depth, then chose 14 for valid ation by multicolour fibre-FISH. These fibre-FISH samples provided accurate calibration standards for the entire panel and led to detailed insights into population variation and mutational mechanisms. RBMY1 copy number worldwide ranged from 3 to 13 with a mode of 8. The two larger proximal clusters were the most variable, and additional duplications, deletions and inversions were detected. Placing the copy number estimates onto the published Y-SNP-based phylogeny of the same samples suggested a minimum of 562 mutational changes, translating to a mutation rate of 2.20 × 10−3 (95% CI 1.94 × 10−3 to 2.48 × 10−3) per father-to-son Y-transmission, higher than many short tandem repeat (Y-STRs), and showed no evidence for selection for increased or decreased copy number, but possible copy number stabilizing selection. An analysis of RBMY1 copy numbers among 376 infertility subjects failed to replicate a previously reported association with sperm motility and showed no significant effect on sperm count and concentration, serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone levels or testicular and semen volume. These results provide the first in-depth insights into the structural rearrangements underlying RBMY1 copy number variation across diverse human lineages.
Challenges in IBD Research: Novel Technologies
Authors: Dhyani Manish , Joshi Nitin , Bemelman Willem A , Gee Michael S , Yajnik Vijay , D’Hoore André , Traverso Giovanni , Donowitz Mark , Mostoslavsky Gustavo , Lu Timothy K , Lineberry Neil , Niessen Heiko G , Peer Dan , Braun Jonathan , Delaney Conor P , Dubinsky Marla C , Guillory Ashley N , Pereira Maria , Shtraizent Nataly , Honig Gerard , Polk David Brent , Hurtado-Lorenzo Andrés , Karp Jeffrey M , Michelassi Fabrizio
Published: May 2019

This section is focused on prioritizing unmet clinical needs that will benefit from novel technologies applied to non-invasive detection and monitoring of active inflammation and assessment of treatment response, mucosal targeted drug delivery systems, and prevention of post-operative septic complications and treatment of fistulizing complications.
Comparative Incidence of Inflammatory Bowel Disease in Different Age Groups in the United States
Authors: Keyashian Kian , Dehghan Melody , Sceats Lindsay , Kin Cindy , Limketkai Berkeley N , Park K T
Published: May 2019

Background

Data on the incidence of inflammatory bowel disease (IBD) by age group are available in countries outside of the United States or localized populations within the United States. We aimed to estimate the incidence rates (IRs) of IBD by age group using a US multiregional data set.

Methods

We used the Optum Research Database to identify incident IBD patients with a disease-free interval of 1.5 years between 2005 and 2015. Overall and age-specific IRs were calculated for 4 different age groups: pediatric (0–17 years), young adult (18–25 years), adult (26–59 years), elderly (>60 years). Time trends of incidence were evaluated in each age group. Perianal phenotype (in Crohn’s disease [CD]) was also compared.

Results

The mean IR for the cohort (n = 60,247) from 2005 to 2015 was 37.5/100,000. The IR was highest in adult and elderly cohorts (36.4 and 36.7/100,000 respectively). In the adult and elderly groups, the IR for UC was higher than that for CD, whereas the opposite was true in the pediatric and young adult groups. The IR increased over the 10-year study period for all age groups (time trends P < 0.001). The elderly group had less perianal disease than the adult group (20.8 vs 22.3%, respectively; P < 0.05).

Conclusions

In one of the most comprehensive evaluations of the incidence of IBD in the United States, we found an incidence rate similar to those of other national populations. We also confirmed differences of specific IBD phenotypes based on age groups, with lower rates of perianal disease in the elderly.
Mitochondrial Mechanisms Underlying Tolerance to Fluctuating Oxygen Conditions: Lessons from Hypoxia-Tolerant Organisms
Authors: Sokolova Inna M , Sokolov Eugene P , Haider Fouzia
Published: May 2019

Oxygen (O2) is essential for most metazoan life due to its central role in mitochondrial oxidative phosphorylation (OXPHOS), which generates >90% of the cellular adenosine triphosphate. O2 fluctuations are an ultimate mitochondrial stressor resulting in mitochondrial damage, energy deficiency, and cell death. This work provides an overview of the known and putative mechanisms involved in mitochondrial tolerance to fluctuating O2 conditions in hypoxia-tolerant organisms including aquatic and terrestrial vertebrates and invertebrates. Mechanisms of regulation of the mitochondrial OXPHOS and electron transport system (ETS) (including alternative oxidases), sulphide tolerance, regulation of redox status and mitochondrial quality control, and the potential role of hypoxia-inducible factor (HIF) in mitochondrial tolerance to hypoxia are discussed. Mitochondrial phenotypes of distantly related animal species reveal common features including conservation and/or anticipatory upregulation of ETS capacity, suppression of reactive oxygen species (ROS)-producing electron flux through ubiquinone, reversible suppression of OXPHOS activity, and investment into the mitochondrial quality control mechanisms. Despite the putative importance of oxidative stress in adaptations to hypoxia, establishing the link between hypoxia tolerance and mitochondrial redox mechanisms is complicated by the difficulties of establishing the species-specific concentration thresholds above which the damaging effects of ROS outweigh their potentially adaptive signaling function. The key gaps in our knowledge about the potential mechanisms of mitochondrial tolerance to hypoxia include regulation of mitochondrial biogenesis and fusion/fission dynamics, and HIF-dependent metabolic regulation that require further investigation in hypoxia-tolerant species. Future physiological, molecular and genetic studies of mitochondrial responses to hypoxia, and reoxygenation in phylogenetically diverse hypoxia-tolerant species could reveal novel solutions to the ubiquitous and metabolically severe problem of O2 deficiency and would have important implications for understanding the evolution of hypoxia tolerance and the potential mitigation of pathological states caused by O2 fluctuations.
Natural Heteroplasmy and Mitochondrial Inheritance in Bivalve Molluscs
Authors: Ghiselli Fabrizio , Maurizii Maria Gabriella , Reunov Arkadiy , Ariño-Bassols Helena , Cifaldi Carmine , Pecci Andrea , Alexandrova Yana , Bettini Simone , Passamonti Marco , Franceschini Valeria , Milani Liliana
Published: May 2019

Heteroplasmy is the presence of more than one type of mitochondrial genome within an individual, a condition commonly reported as unfavorable and affecting mitonuclear interactions. So far, no study has investigated heteroplasmy at protein level, and whether it occurs within tissues, cells, or even organelles. The only known evolutionarily stable and natural heteroplasmic system in Metazoa is the Doubly Uniparental Inheritance (DUI)—reported so far in ∼100 bivalve species—in which two mitochondrial lineages are present: one transmitted through eggs (F-type) and the other through sperm (M-type). Because of such segregation, mitochondrial oxidative phosphorylation proteins reach a high amino acid sequence divergence (up to 52%) between the two lineages in the same species. Natural heteroplasmy coupled with high sequence divergence between F- and M-type proteins provides a unique opportunity to study their expression and assess the level and extent of heteroplasmy. Here, for the first time, we immunolocalized F- and M-type variants of three mitochondrially-encoded proteins in the DUI species Ruditapes philippinarum, in germline and somatic tissues at different developmental stages. We found heteroplasmy at organelle level in undifferentiated germ cells of both sexes, and in male soma, whereas gametes were homoplasmic: eggs for the F-type and sperm for the M-type. Thus, during gametogenesis, only the sex-specific mitochondrial variant is maintained, likely due to a process of meiotic drive. We examine the implications of our results for DUI proposing a revised model, and we discuss interactions of mitochondria with germ plasm and their role in germline development. Molecular and phylogenetic evidence suggests that DUI evolved from the common Strictly Maternal Inheritance, so the two systems likely share the same underlying molecular mechanism, making DUI a useful system for studying mitochondrial biology.
Level and source of fat in the diet of gestating beef cows. II. Effects on the postpartum performance of the dam and the progeny1
Authors: Añez-Osuna Federico , Penner Gregory B , Campbell John , Dugan Michael E R , Fitzsimmons Carolyn J , Jefferson Paul G , Lardner Herbert A , McKinnon John J
Published: May 2019

A study was conducted to evaluate the effects of level and source of fat in the diet of gestating beef cows on the postpartum performance of the dam and the progeny. Each year, 75 mature pregnant (183 ± 4.8 d until calving) Angus cows with similar BW (663 ± 21.5 kg) and BCS (2.6 ± 0.12; 1 to 5 scale) were randomly assigned to 1 of 15 outdoor pens. Each pen was assigned to 1 of 3 iso-caloric and iso-nitrogenous treatments: a low-fat diet (LF; 1.4 ± 0.12% EE) and two high-fat diets (HF; 3.3 ± 0.20% EE) including a canola seed- (CAN) or a flaxseed (FLX)-based pelleted feed. Diets were formulated to meet the requirements of pregnant beef cows and fed until calving. Data were analyzed as a randomized complete block design with contrasts for the effects of level (LF vs. HF) and source (CAN vs. FLX) of fat. No differences (P ≥ 0.21) were found for BW or calving to weaning ADG of cows. The average BCS during the first 42 d of lactation was greater (P<0.01) for LF compared with HF (2.63 vs. 2.51) with no difference (P = 0.35) for CAN vs. FLX cows. Subcutaneous fat thickness over the ribs was greater (P ≤ 0.01) for LF compared with that of HF cows at calving (5.7 vs. 4.3 mm) and at weaning (4.3 vs. 3.7 mm) with no difference (P ≥ 0.11) for CAN vs. FLX cows. Over the first 42 d of lactation, no difference (P ≥ 0.23) was observed for 12-h milk yield. Milk protein concentration was greater (P = 0.03) for CAN compared with FLX (3.11 vs. 3.01%) cows, whereas no difference (P ≥ 0.28) was observed for any other milk component. Milk fat from FLX cows had greater (P < 0.01) CLA and CLnA concentrations than that of CAN cows during the first 42 d of lactation. Pregnancy rate of HF cows tended (P = 0.07) to be greater than that of LF cows with no difference (P = 0.77) for CAN vs. FLX cows. Calves from HF cows were heavier (P ≤ 0.01) at birth (42.9 vs. 40.2 kg) than those from LF cows. From calving to weaning, ADG of calves born to CAN cows was greater (P = 0.03) that that of calves born to FLX cows (1.19 vs. 1.13 kg/d) with no difference (P = 0.18) for calves born to LF vs. HF cows. At slaughter, progeny of HF cows had greater (P ≤ 0.03) shrunk BW (605 vs. 579 kg) and HCW (355 vs. 339 kg) compared with those from LF cows with no difference (P ≥ 0.16) for progeny of CAN vs. FLX cows. These results show that feeding a HF diet over gestation results in heavier calves at birth and at slaughter, and superior calf gains from birth to slaughter as well as heavier carcasses, possibly due to a developmental programming effect.
Screening Aedes aegypti (Diptera: Culicidae) Populations From Pernambuco, Brazil for Resistance to Temephos, Diflubenzuron, and Cypermethrin and Characterization of Potential Resistance Mechanisms
Authors: de Araújo Ana Paula , Paiva Marcelo Henrique Santos , Cabral Amanda Maria , Cavalcanti Antônio Emanuel Holanda Dias , Pessoa Luiz Fernando Freitas , Diniz Diego Felipe Araujo , Helvecio Elisama , da Silva Ellyda Vanessa Gomes , da Silva Norma Machado , Anastácio Daniela Bandeira , Pontes Claudenice , Nunes Vânia , de Souza Maria de Fátima Marinho , Magalhães Fernando Jorge Rodrigues , de Melo Santos Maria Alice Varjal , Ayres Constância Flávia Junqueira
Published: May 2019

Resistance to chemical insecticides detected in Aedes aegypti (L.) mosquitoes has been a problem for the National Dengue Control Program (PNCD) over the last years. In order to provide deeper knowledge of resistance to xenobiotics, our study evaluated the susceptibility profile of temephos, diflubenzuron, and cypermethrin insecticides in natural mosquito populations from the Pernambuco State, associating these results with the local historical use of such compounds. Furthermore, mechanisms that may be associated with this particular type of resistance were characterized. Bioassays with multiple temephos and diflubenzuron concentrations were performed to detect and quantify resistance. For cypermethrin, diagnostic dose assays were performed. Biochemical tests were carried out to quantify the activity of detoxification enzymes. In addition, a screening of mutations present in the voltage-gated sodium channel gene (NaV) was performed in samples previously submitted to bioassays with cypermethrin. The populations under study were resistant to temephos and showed a positive correlation between insecticide consumption and the resistance ratio (RR) to the compound. For diflubenzuron, the biological activity ratio (BAR) ranged from 1.3 to 4.7 times, when compared to the susceptible strain. All populations showed resistance to cypermethrin. Altered enzymatic profiles of alpha, p-nitrophenyl acetate (PNPA) esterases and glutathione-S-transferases were recorded in most of these samples. Molecular analysis demonstrated that Arcoverde was the only population that presented the mutated form 1016Ile/Ile. These findings show that the situation is critical vis-à-vis the effectiveness of mosquito control using chemical insecticides, since resistance to temephos and cypermethrin is widespread in Ae. aegypti from Pernambuco.
Vasectomy and Prostate Cancer Risk: A 38-Year Nationwide Cohort Study
Authors: Husby Anders , Wohlfahrt Jan , Melbye Mads
Published: May 2019

Background

A man’s risk of prostate cancer has been linked to his prior reproductive history, with low sperm quality, low ejaculation frequency, and a low number of offspring being associated with increased prostate cancer risk. It is, however, highly controversial whether vasectomy, a common sterilization procedure for men, influences prostate cancer risk.

Methods

We established a cohort of all Danish men (born between 1937 and 1996) and linked information on vasectomy, doctor visits, socioeconomic factors, and cancer from nationwide registries using unique personal identification numbers. Incidence risk ratios for prostate cancer by time since vasectomy and age at vasectomy during the follow-up were estimated using log-linear Poisson regression.

Results

Overall, 26 238 cases of prostate cancer occurred among 2 150 162 Danish men during 53.4 million person-years of follow-up. Overall, vasectomized men had an increased risk of prostate cancer compared with nonvasectomized men (relative risk = 1.15, 95% confidence interval = 1.10 to 1.20). The increased risk of prostate cancer following vasectomy persisted for at least 30 years after the procedure and was observed regardless of age at vasectomy and cancer stage at diagnosis. Adjustment for the number of visits to the doctor and socioeconomic factors did not explain the association.

Conclusions

Vasectomy is associated with a statistically significantly increased long-term risk of prostate cancer. The absolute increased risk following vasectomy is nevertheless small, but our finding supports a relationship between reproductive factors and prostate cancer risk.
Systematic Review of the Role of Stereotactic Radiotherapy for Bone Metastases
Authors: Spencer Katie L , van der Velden Joanne M , Wong Erin , Seravalli Enrica , Sahgal Arjun , Chow Edward , Verlaan Jorrit-Jan , Verkooijen Helena M , van der Linden Yvette M
Published: May 2019

Background

Stereotactic radiotherapy (SBRT) might improve pain and local control in patients with bone metastases compared to conventional radiotherapy, although an overall estimate of these outcomes is currently unknown.

Methods

A systematic review was carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pubmed, Embase, and Cochrane databases were systematically searched to identify studies reporting pain response and local control among patients with bone metastases from solid-organ tumors who underwent SBRT in 1–6 fractions. All studies prior to April 15, 2017, were included. Study quality was assessed by predefined criteria, and pain response and local control rates were extracted.

Results

A total of 2619 studies were screened; 57 were included (reporting outcomes for 3995 patients) of which 38 reported pain response and 45 local control rates. Local control rates were high with pain response rates above those previously reported for conventional radiotherapy. Marked heterogeneity in study populations and delivered treatments were identified such that quantitative synthesis was not appropriate. Reported toxicity was limited. Of the pain response studies, 73.7% used a retrospective cohort design and only 10.5% used the international consensus endpoint definitions of pain response. The median survival within the included studies ranged from 8 to 30.4 months, suggesting a high risk of selection bias in the included observational studies.

Conclusions

This review demonstrates the potential benefit of SBRT over conventional palliative radiotherapy in improving pain due to bone metastases. Given the methodological limitations of the published literature, however, large randomized trials are now urgently required to better quantify this benefit.