bluuebunny/crossref_metadata_2025 huggingface dataset:
Lidar Overlap Function Determination Using the Raman Lidar Signals
Authors: Jaswant  , Singh Shishir Kumar , S.R. Radhakrishnan , Shukla Devesh , Sharma Chhemendra
Published: July 2020

The determination of vertical distribution of optical properties of clouds and aerosols using the lidar system is affected by the incomplete overlap between the field of view of transmitter i.e. laser beam & the receiver in the near‐field range. Thus, the study of vertical profiles of aerosol optical properties in the lower atmosphere is erroneous without the correction of lidar overlap function. Here we have analysed the effect of overlap using a simple technique proposed by Ansmann and Wandinger to determine overlap function. We have determined the overlap factor for 5 different days of June 2016 and then calculated the mean overlap profile and determined the relative deviation of each day with respect to mean overlap factor. Results reveal that the complete overlap was achieved beyond 300 meters.
Research on Non-Invasive Laser Doppler Current Measurement for Hydrothermal Vents Flow Rates Profile
Authors: Zhang Hongwei , Wu Songhua , Liu Jintao , Zhang Yuanshuai , Chen Xiaomin
Published: July 2020

Hydrothermal vents play important roles in the dynamic process of the stratosphere and the circulation of energy materials. Nowadays, invasive devices such as vane-type flow meter and turbine flow meter are commonly utilized to estimate the flow rates of hydrothermal vents. In- situ observation data obtained by LDCP system and CFD methods will be combined to solve the blind area of LDCP system during in-situ observation measurements. The flow rates profiles obtained in this project will improve the research on the circulation of energy materials and mineralization.
Assessing the Long Term Stability of the Depolarization Constant for the Cluj Station
Authors: Stefanie H. , Ajtai N. , Radovici A. , Ene D. , Belegante L.
Published: July 2020

The study aims to assess the additional systematic error caused by the assessment of the depolarization constant. Based on the long time assessment of this constant, a mean value and a standard deviation can be retrieved. A sensitivity study could assess the deviation of the depolarization value in high and low depolarizing atmospheric layers. Based on these deviations, the systematic error of the calibration is retrieved and included in the final depolarization products.
Impacts of Sinkholes on Salinity Level of Groundwater in Finegayan Area, Guam, USA
Authors: Wen Yuming , Jenson John
Published: July 2020

Guam is a strategic location for the United States of America, which is located in the western Pacific. Guam’s economy is mainly supported by tourism and military related activities. Because of buildup activities and increasing population of tourists in the following few years, much pressure has been imposed on water resources and water quality in Guam. With about 5,000 marines relocated to Guam from Okinawa in the next few years, the Finegayan area will be a concerned area for buildup activities. Therefore, the study area for the project is located in the Finegayan area, and the research concentrates on application of LiDAR data to figure out sinkholes in the Finegayan area, and application of GIS in evaluating salinity levels from drinking wells, and locating wells with problems with salinity in the study area. More concerns are focused on relationship between sinkholes and salinity, and whether sinkholes affect salinity levels in the study area.
Light Scattering by Particles with Arbitrary Shape in the Vicinity of the Backward Scattering Direction within Geometrical Optics Approximation
Authors: Shishko Victor , Konoshonkin Alexander , Kustova Natalia , Borovoi Anatoli , Timofeev Dmitry
Published: July 2020

The work presents the solution for the light scattering problem by arbitrarily-shaped particles in the vicinity of the backward scattering direction. The solution was obtained within the framework of the geometrical optics approximation. The refractive index was equal to 1.3116. It was shown that the general contribution of scattering light for arbitrarily-shaped particles in the vicinity of the backscattering direction consists of the specular reflection of the particles and two types of non-specular optical beams. It is shown that the optical characteristics of the ice particles with arbitrary shapes correspond to experimental data.
Simulation Effects of Surface Geometry and Water Optical Properties on Hydrographic Lidar Returns
Authors: Yang Song , Sun Qian , Zheng Yongchao
Published: July 2020

. Water LiDAR model was applied to simulate the returned waveforms of hydrographic LiDAR considering the effects of surface geometry and water optical properties. The signal to noise ratio(SNR) of bottom returned peak was considered as a criterion for performance of hydrographic LiDAR. The behavior of LiDAR was sensitive to water optical properties and it was insensitive to water surface roughness.
Surgical treatment of unusual osteoma associated with homolateral radicular cyst of the maxillary sinus
Authors: Cantone Elena , Torrisi Aldo , Romano Antonio , Cama Antonia , Foschi Giulia , Di Lullo Antonella Miriam , Cavaliere Michele , Motta Sergio , Califano Luigi , Iengo Maurizio
Published: July 2020

Introduction: We described a rare clinical case of osteoma associated with homolateral radicular cyst of the maxillary sinus. Observation: Imaging showed two different lesions in the right maxillary sinus. We performed a combined surgical approach to completely remove the lesions and used a plasma rich in growth factors membrane to repair dental roots. No relapse after a 2 years follow-up was observed. Commentaries: The simultaneous presence of two large lesions, a 23,7 mm osteoma and a 33,7 mm radicular cyst in the same maxillary sinus, has been rarely described in the literature. Although nasal endoscopy and imaging are mandatory to assess the diagnosis, the definitive diagnosis was obtained after histopathologic examination. A combined surgical approach allowed a complete removal of both lesions, ensuring, at same time, an optimal surgical field. Plasma rich in growth factors membrane due to its cohesive properties was particularly useful in improving bone neoformation and periodontal regeneration. Conclusion: Diagnostic assessment of maxillary lesions requires nasal endoscopy, imaging and histopathological examination. If these lesions are symptomatic, they should be completely removed and minimally invasive surgery is indicated. Plasma rich in growth factors membrane ensures a good postoperative recovery.
Posteriores kortikales Atrophie-Plus-Syndrom. Eine Kasuistik
Authors: Saleh Christian , Seidl Ulrich , Stegentritt Katharina , Schumacher Florian , Fehrenbach Rose A.
Published: July 2020

Die posteriore kortikale Atrophie (PCA) ist eine seltene neurodegenerative Erkrankung, die mit komplexen Sehstörungen einhergeht. Sie kann isoliert („PCA-pure“) oder zusammen mit anderen neurodegenerativen Störungen („PCA-plus“) auftreten. Die Diagnosestellung erfolgt meistens verzögert, da die Erkrankung wenig bekannt ist und oftmals initial eine ophthalmologische Ursache vermutet wird.
Hemostatic Adaptations to High Intensity Interval Training in Healthy
Adult Men
Authors: Sackett James R. , Farrell Dan P. , Nagelkirk Paul R.
Published: July 2020

Regular exercise is theorized to reduce cardiovascular risk by attenuating
coagulation and augmenting fibrinolysis. However, these adaptations have not
been consistently observed during traditional exercise programs. The purpose
of this study was to examine hemostatic adaptations in healthy men following
four (4W) and eight (8W) weeks of high intensity interval training.
Twenty-one men (age=25±1 y; body mass
index=26.5±6.4 kg/m2)
completed eight weeks, three days/week of high intensity interval
training on a cycle ergometer. Activated partial thromboplastin time,
prothrombin time, and plasma concentrations of thrombin-antithrombin III,
fibrinogen, tissue plasminogen activator, and plasminogen activator
inhibitor-1 were assessed at baseline (BL), 4W, and 8W. Repeated measures
ANOVA were used to determine potential effects of training. There were no
significant changes observed for activated partial thromboplastin time
(BL=43.3±5.5, 4W=43.2±5.1,
8W=44.2±6.4 s); prothrombin time
(BL=13.2±0.9, 4W=13.0±0.6,
8W=13.1±0.8 s); thrombin-antithrombin III
(BL=6.0±2.3, 4W=5.8±2.3,
8W=5.6±3.1 ng/mL); tissue plasminogen
activator (BL=9.7±3.3, 4W=9.4±3.2,
8W=8.7±2.8 ng/mL); and plasminogen activator
inhibitor-1 (BL=19.0±17.5, 4W=19.3±17.0,
8W=18.9±18.9 ng/mL) (all p>0.05).
Fibrinogen was significantly lower at 4W
(238.6±70.3 mg/dL) compared to BL
(285.0±82.1 mg/dL; p<0.05) and 8W
(285.3±83.2 mg/dL; p<0.05). These findings
indicate that eight weeks of high intensity interval training does not
influence coagulation potential and/or stimulate fibrinolysis.
Triggerpunkte lösen – Spray and Stretch nach Dr. Travell
Authors: Zumhasch Rainer
Published: July 2020

Myofasziale Triggerpunkte gelten als häufigste Ursache für muskuloskelettalen Schmerz. Sie bestehen aus punktuellen Verhärtungen in Muskeln und Muskelfaszien. Therapeuten können die Behandlungsmethode Spray and Stretch nutzen, um die Triggerpunkte zu lösen und dem Patienten so zu Schmerzfreiheit zu verhelfen.
Austausch zu Autismus – Psychoedukative Elterngruppen
Authors: Wild David
Published: July 2020

Eltern von Kindern mit Autismus-Spektrum-Störungen stellen sich oft ähnliche Fragen, beispielsweise zum Krankheitsbild, zu rechtlichen Aspekten oder zur Inklusion. David Wild hat eine Elternabend-Reihe entwickelt, die darauf abzielt, sie zu informieren und ihnen mit praktischen Tipps für den Alltag weiterzuhelfen.
Fatigue Increases in Resting Muscle Oxygen Consumption after a
Women’s Soccer Match
Authors: Bonilla Aldo Alfonso Vasquez , Timon Rafael , Camacho-Cardeñosa Alba , Camacho-cardeñosa Marta , Guerrero Samantha , Olcina Guillermo
Published: July 2020

Currently, near infrared spectroscopy has a clear potential to explain the
mechanisms of fatigue by assessing muscle oxygenation. The objective of the
study was to observe the changes in muscle oxygen consumption after an
official women’s soccer match. The sample was 14 players who
competing in the second division of Spain of women’s soccer. They
were evaluated before, immediately after and 24 h after the official
match. Biochemical parameters were measured in blood plasma (BUN, GOT, LDH,
CPK). The jumping in countermovement, perceived exertion and perceived
muscle pain were also assessed. The muscle oxygen consumption and muscle
oxygen saturation were evaluated in the gastrocnemius muscle with an
arterial occlusion test. ANOVA of repeated measures, Pearson’s
correlation and Hopkins’ statistics were applied to measure the
magnitudes of change and effect size. There was observed an increase in
kinetics of SmO2 at 24 h after the official match, using
arterial occlusion. In addition, it was found that the increase in muscle
oxygenation correlated with fatigue indicators, such as the increases in
LDH, perceived muscle pain and the decrease in countermovement. It is
confirmed that a women’s soccer match produced an increase of
resting muscle oxygenation in 24 h after the official match.
Surgical Experience of Video-Assisted Mediastinoscopy for Nonlung Cancer Diseases
Authors: Yazgan Serkan , Ucvet Ahmet , Gursoy Soner , Ceylan Kenan Can , Yıldırım Şener
Published: July 2020

Background Video-assisted mediastinoscopy (VAM) is a valuable method in the investigation of diseases with mediastinal lymphadenopathy or those localized in the mediastinum. The aim of this study was to determine the diagnostic value of VAM in the investigation of mediastinal involvement of nonlung cancer diseases and to describe our institutional surgical experience.

Methods Clinical parameters such as age, sex, histological diagnosis, morbidity, and mortality of all patients who underwent VAM for the investigation of mediastinal involvement of diseases except lung cancer between January 2006 and July 2018 were retrospectively reviewed, and the diagnostic efficacy of VAM was determined statistically.

Results During the study period, 388 patients underwent VAM, and 536 lymph nodes were sampled for histopathological evaluation of mediastinum due to mediastinal lymphadenopathy or paratracheal lesions. The most common diagnoses were sarcoidosis (n = 178 [45.9%]), tuberculous lymphadenitis (n = 108 [27.8%]), lymphadenitis with anthracosis (n = 72 [18.6%]), and lymphoma (n = 15 [3.9%]).

Conclusion The results of the study show that VAM should be used because of its high diagnostic benefit in mediastinal lymphadenopathies, which are difficult to diagnose, or mediastinal lesions located in the paratracheal region. Despite the increase in the number of new diagnostic modalities, VAM is still the most effective method and a gold standard.
Comparison of Surgical Stabilization Time in Patients with Flail Chest
Authors: Çınar Hüseyin Ulaş , Çelik Burçin
Published: July 2020

Background This study aimed to compare the clinical outcomes of early and late surgical stabilization of rib fractures (SSRFs) in patients with flail chest.

Methods A retrospective analysis was performed on patients with flail chest according to surgical stabilization time of rib fractures (early [≤ 72 hours] and late [>72 hours]). Outcome measures included duration of mechanical ventilation, intensive care unit (ICU) stay, hospital stay, and morbidity and mortality rates. A correlation analysis was performed between the time from trauma to stabilization and the clinical outcomes after stabilization.

Results A total of 70 patients were evaluated (36 and 34 in the early and late groups, respectively). The demographics and indicators of injury severity were comparable in both groups. The early group had significantly shorter duration of mechanical ventilation (23.7 vs. 165.6 hours; p = 0.003), ICU stay (6.5 vs. 19.7 days; p = 0.003), hospital stay (9 vs. 22.5 days; p = 0.001), and lower rate of atelectasis (11 vs. 58%; p = 0.01), pneumonia (8.8 vs. 50%; p = 0.001), and empyema (2.8 vs. 20.6%; p = 0.019). According to the correlation analysis, it was found that early surgical stabilization had a positive significant effect on clinical outcomes after stabilization.

Conclusion Early SSRFs in patients with flail chest results in more favorable clinical outcomes. It should be performed as soon as possible in the presence of indication and if feasible.
Natural Occurrence, Biological Functions, and Analysis of D-Amino Acids
Authors: Gu Shuang-Xi , Wang Hai-Feng , Zhu Yuan-Yuan , Chen Fen-Er
Published: July 2020

This review covers the recent development on the natural occurrence, functional elucidations, and analysis of amino acids of the D (dextro) configuration. In the pharmaceutical field, amino acids are not only used directly as clinical drugs and nutriments, but also widely applied as starting materials, catalysts, or chiral ligands for the synthesis of active pharmaceutical ingredients. Earler belief hold that only L-amino acids exist in nature and D-amino acids were artificial products. However, increasing evidence indicates that D-amino acids are naturally occurring in living organisms including human beings, plants, and microorganisms, playing important roles in biological processes. While D-amino acids have similar physical and chemical characteristics with their respective L-enantiomers in an achiral measurement, the biological functions of D-amino acids are remarkably different from those of L-ones. With the rapid development of chiral analytical techniques for D-amino acids, studies on the existence, formation mechanisms, biological functions as well as relevant physiology and pathology of D-amino acids have achieved great progress; however, they are far from being sufficiently explored.
Performance evaluation of different solar collectors in building cooling, heating, and hot water supply
Authors: Xia Junbao , Li Yi , Li Chunmei , Wang Yi , Xie Lidong , Miao Yiran , Zhang Qi , Hao Chengming , Sun Guanyu
Published: July 2020

To evaluate the performance of parabolic trough solar collectors (PTCs) and flat plate solar collectors (FPCs) by different thermal utilization methods, including building cooling, heating, and hot water supply, this study adopted the indices of the primary energy ratio (PER) and unit cost of energy (UCE) and the operating ratio to compare the applicability of collector systems. First, the heat transfer models of FPCs and PTCs were constructed by a lumped parameter method and validated by experiments. Then, the performance of collectors and the operating modes of different thermal utilization methods were obtained. Finally, by inputting the meteorological parameters of Tianjin, the following conclusions can be drawn. (1) The evaluation indices of UCE and PER were consistent when evaluating different collector systems. The FPC system was more appropriate for hot water supply and heating, and the PTC system was more suitable for cooling and heating and cooling. (2) The hot water supply had the best energy saving and was economical compared to other solar thermal utilization methods with FPC and PTC systems, as its UCE was 0.19 RMB/kW h and 0.28 RMB/kW h and PER was 1.38 and 1.17, respectively. (3) The operating ratio of both the hot water supply and cooling was higher than 50% in both collector systems. The heating system had the lowest operating ratio, less than 40%, which was related to its load characteristics.
Near field scattering for samples under forced flow
Authors: Cremonesi Llorenç , Siano Mirko , Paroli Bruno , Potenza Marco A. C.
Published: July 2020

We describe a light scattering technique for characterizing colloidal samples under constant flow. It exploits the properties of speckles in the deep Fresnel region—the so-called near field speckles—providing absolute scattering measurements of the static form factor of the sample, as described extensively by Mazzoni et al. [Rev. Sci. Instrum. 84, 043704 (2013)] for static samples. We exploit a strongly astigmatic beam for illuminating the scattering volume with a light sheet a few microns thick. This largely improves the sensitivity of the method to small signals. Moreover, by flowing the sample in the direction perpendicular to the light sheet, the transit times are reduced to a minimum, allowing for fast measurements. We tested the instrument with suspensions of calibrated colloidal polystyrene spheres with a size comparable to the light wavelength. In particular, we recovered the static form factors of suspensions of spherical particles and the phase lag of the zero-angle scattering amplitude, which both compare well to Mie theory predictions. We then applied the method to colloidal fractal aggregates of sub-wavelength particles and measured their fractal dimension. The instrument is designed to be operational in continuous flow analysis systems.
Nonlinear ablative Rayleigh–Taylor growth experiments on Shenguang–II
Authors: Wang L. F. , Wu J. F. , Ye W. H. , Dong J. Q. , Fang Z. H. , Jia G. , Xie Z. Y. , Huang X. G. , Fu S. Z. , Zou S. Y. , Ding Y. K. , Zhang W. Y. , He X. T.
Published: July 2020

Nonlinear evolution of the ablative Rayleigh–Taylor instability (ARTI) is investigated on the Shenguang-II laser facility using a target specifically designed for this purpose. The evolution of the excited bubbles and spikes is tracked and their displacement amplitudes are quantitatively measured with the help of a Kirkpatrick–Baez microscope coupled with an x-ray framing camera. Radiation-hydrodynamic simulations are qualitatively in agreement with the experiments and demonstrate the phenomenon of bubble acceleration predicted by Betti and Sanz [Phys. Rev. Lett. 97, 205002 (2006)] in the nonlinear evolution of the ARTI.
Lock-in frequency measurement with high precision and efficiency
Authors: Lu Jun
Published: July 2020

This paper describes a new method of frequency measurement based on lock-in amplifiers (LIAs). In contrast to other frequency measurement methods, such as fast Fourier transformation (FFT), zero crossing, and scanning autocorrelation, this method is based on an adaptable LIA design for high-precision determination of not only the frequency but also the amplitude and phase of periodic signals, even when they are buried in heavy noise with low signal-to-noise ratios. Mathematical derivation of the local spectrum around the center frequency is performed, and the local frequency spectrum waveform of the sinusoidal signal, regardless of whether it is pure or noisy, is found to be exactly of a bell shape that can be described by a three-parameter sine function. Based on the principle of LIAs, the correct frequency can produce a peak amplitude in the local spectrum. As a result, the amplitudes of three frequency points around the target frequency can be used to precisely determine the peak frequency via sinusoidal fitting. The efficiency of the proposed method is log2(N) times that of FFT. Simulation results show that the new algorithm can reach the theoretical Cramer–Rao lower bound and remain below a lock-in upper bound. The new frequency measurement method has been implemented in an field-programmable gate array (FPGA)-based device and systematically tested for its dependence on the frequency, amplitude, and signal-to-noise ratio with typical noise types. Theoretical and experimental results show that the new method can be used in fine determination of the frequency if the user has prior knowledge of the approximate location of the frequency.
System-level performance and degradation of 21 GWDC of utility-scale PV plants in the United States
Authors: Bolinger Mark , Gorman Will , Millstein Dev , Jordan Dirk
Published: July 2020

We assess the performance of a fleet of 411 utility-scale (i.e., >5 MWAC and ground-mounted) photovoltaic (PV) projects totaling 21.1 GWDC (16.3 GWAC) of capacity, which achieved commercial operations in the United States from 2007 to 2016. This fleet of projects contributed more than 50% of all solar electricity generated in the United States in 2017. Using detailed information on individual project characteristics, in conjunction with modeled irradiance data, we assess the extent to which actual first-year performance has lived up to both modeled and stated expectations. We then analyze system-level performance degradation in subsequent years by employing a “fixed effects” regression model to statistically isolate the impact of age on system performance. We find that this fleet of utility-scale PV projects has generally lived up to ex ante expectations for first-year performance but that subsequent system-level degradation—found to be −1.3%/year (±0.2%)—has, on average, been worse than both ex ante expectations (commonly −0.5%/year) and results from past studies (ranging from −0.8%/year to −1.0%/year). We emphasize that −1.3%/year is a system-level estimate that captures more than just module degradation (e.g., including soiling, balance of plant degradation, and downtime for maintenance and/or other events). A side analysis of a variety of project characteristics suggests that system-level degradation rates tend to be of lower magnitude among newer projects and larger projects and at sites with lower long-term average temperatures.
Laser-produced plasma soft x-ray source based on an aerosol target
Authors: Węgrzyński Łukasz , Bartnik Andrzej , Wachulak Przemysław , Fok Tomasz , Fiedorowicz Henryk
Published: July 2020

Laser produced plasma (LPP) soft x-ray and extreme ultraviolet sources utilize various types of targets. Some of them are based on gaseous targets. The most important disadvantage of such targets is the very limited number of elements that can be used in the gaseous form under normal conditions, including chemical compounds in the gaseous state. In this paper, the authors propose a new type of target, constituting an extension of the gaseous target, namely aerosol target, based on solutions of solid chemical compounds in liquids. Unlike previous attempts to produce aerosol targets from overheated liquids, in our system, the target is created by injection of a mist, preformed in a dedicated cell, into the vacuum chamber. Such targets have many advantages: the emission spectra can be adjusted by choosing proper chemical compounds, the aerosol target is elongated, hence, the laser focus can be positioned at a relatively long distance from the nozzle outlet, its average density can be higher compared to gaseous targets. In this work, such a target and its usefulness for the LPP soft x-ray source was demonstrated. The target was investigated by the soft x-ray backlighting method. Its density distribution at the position of the laser focus was determined. The emission spectra from the soft x-ray range, corresponding to multiple charged ions, originating from the solvent and the diluted salt were measured. Based on numerical simulations of the spectra, an ionic composition of the resulting plasmas was determined.
Kantorovich–Rubinstein–Wasserstein distance between overlapping attractor and repeller
Authors: Chigarev Vladimir , Kazakov Alexey , Pikovsky Arkady
Published: July 2020

We consider several examples of dynamical systems demonstrating overlapping attractor and repeller. These systems are constructed via introducing controllable dissipation to prototypic models with chaotic dynamics (Anosov cat map, Chirikov standard map, and incompressible three-dimensional flow of the ABC-type on a three-torus) and ergodic non-chaotic behavior (skew-shift map). We employ the Kantorovich–Rubinstein–Wasserstein distance to characterize the difference between the attractor and the repeller, in dependence on the dissipation level.
A novel Rauch–Tung–Streibel smoothing scheme based on the factor graph for autonomous underwater vehicles
Authors: Ma Xiaoshuang , Liu Xixiang , Li Chenlong , Liu Jianwei , Wu Xiaoqiang
Published: July 2020

In submarine surveying and mapping applications, a novel Rauch–Tung–Streibel smoothing (RTSS) scheme based on the factor graph for autonomous underwater vehicles is presented to gain a better offline navigation solution in this paper. The factor graph method is applied to optimally use observation information of multi-sensors with the asynchronous and short-term failure problems to overcome deficiencies of the federal Kalman filter in information fusion processing. Furthermore, the revised RTSS as a post-mission smoothing algorithm is performed by combining the results of the factor graph and one backward data processing through recursively updating the smoothed state and its covariance. From the simulation analysis, it is found that the factor graph mainly owns plug and play capability and contributes to the real-time navigation accuracy over the federal Kalman filtering. The RTSS provides better accuracy and smoothness for the position, velocity, and attitude at the same time compared to the corresponding real-time navigation solution, especially when signals are lost or sensors fail for a short time. With the best of both methods, a novel smoothing scheme combining the factor graph with the RTSS is built. Semi-physical experiment results verify the reliability and effectiveness of the proposed method.
A mathematical model for the numerical simulations of traveling ionospheric disturbances/atmospheric gravity waves generated by the Joule heating
Authors: Nijimbere V.
Published: July 2020

Traveling ionospheric disturbances (TIDs) and atmospheric gravity waves (AGWs) generated by the Joule heating produced from intensified auroral electrojet and/or intense particle precipitation in the auroral and subauroral regions during geomagnetic storms and which propagate downward toward the lower (neutral) atmosphere are numerically simulated using a simple two-dimensional mathematical model for internal gravity waves propagating in the lower atmosphere. An explicit expression for the Joule heating is obtained, and the characteristics of the simulated TIDs/AGWs (e.g., buoyancy frequency, wavenumbers, cutoff wavelength, speed, structures) are also examined and compared with the results obtained from observations. As may be seen in the observations, small-scale TIDs/AGWs with wavelengths shorter than 100 km, medium-scale TIDs/AGWs with wavelengths of several hundred kilometers, and large-scale TIDs/AGWs with wavelengths longer than 1000 km generated by the Joule heating were modeled and numerically simulated. For example, observations have revealed that the Joule heating can generate TID/AGW pairs. The developed numerical model was used to simulate medium-scale TID/AGW wave packet pairs, and the results (wavelength, speed, structure) are in agreement with SuperDARN observations reported by Sofko and Huang, 2000. TIDs/AGWs with shorter horizontal wavelengths are more trapped than those with longer wavelengths (medium- and large-scale TIDs/AGWs). Their cutoff horizontal wavelength was approximated using the linear stability theory of AGWs. The approximated cutoff horizontal wavelength suggests that not all simulated small-scale disturbances with horizontal wavelengths shorter than 100 km are traveling as may be seen in the observations.
Toward clinical elastography of dermal tissues: A medical device to probe skin’s elasticity through suction, with subsurface imaging via optical coherence tomography
Authors: Bartolini Luca , Feroldi Fabio , Slaman Martin , Weda Jelmer J. A. , de Boer Johannes F. , van Zuijlen Paul , Iannuzzi Davide
Published: July 2020

The mechanical behavior of dermal tissues is unarguably recognized for its diagnostic ability and in the last decades received a steadily increasing interest in dermatology practices. Among the various methods to investigate the mechanics of skin in clinical environments, suction-based ones are especially noteworthy, thanks to their qualities of minimal invasiveness and relative simplicity of setups and data analysis. In such experiments, structural visualization of the sample is highly desirable, both in its own right and because it enables elastography. The latter is a technique that combines the knowledge of an applied mechanical stimulus and the visualization of the induced deformation to result in a spatially resolved map of the mechanical properties, which is particularly important for an inhomogeneous and layered material such as skin. We present a device, designed for clinical trials in dermatology practices, that uses a handheld probe to (1) deliver a suction-based, controlled mechanical stimulus and (2) visualize the subsurface structure via optical coherence tomography. We also present a device-agnostic data-analysis framework, consisting of a Python library, released in the public domain. We show the working principle of the setup on a polymeric model and on a volunteer’s skin.
Herders and livestock professionals’ experiences and perceptions on developments and challenges in yak farming in Bhutan
Authors: Dorji Nedup , Derks Marjolein , Dorji Phub , Groot Koerkamp Peter W. G. , Bokkers Eddie A. M.
Published: July 2020

Context
The yak-based transhumant system is influenced by socioeconomic developments, regulations and environmental changes. Little is known about the impact of this on yak farming practices among different regions in Bhutan.

Aim and methods
The experienced changes in yak farming practices over the years and perceptions on developments were assessed through interviews with yak herders in three regions (west, n = 22; central, n = 20; east, n = 25) and with livestock extensionists (n = 28).

Key results
At present, forage shortage in the rangeland, yak mortality mainly due to (endangered) wild predators and, to a lesser extent, labour availability are the main concerns in all yak farming regions. These concerns have increased due to socioeconomic developments (e.g. education and other sources of income) and strong conservation policy, which affects the living environment of the yaks. Overall, the market to sell yak products and livestock extension services has improved, but forage shortage and yak mortality has increased over the years. However, some factors causing forage shortage are more specific to certain regions, e.g. competition with the horse population (west), cattle and cattle–yak hybrids (east), cordyceps collection (west and central) and prohibited burning of rangelands (central and east). Family labour available to herd yaks has slightly decreased, and the number of young family members (successors) to take over yak farming has decreased over the years.

Conclusions
On the basis of the experiences and perceptions of yak herders and extensionists, we conclude that increasing forage shortage in the rangelands, decreasing numbers of successors, and increasing yak predation by wild animals are the major threats to yak farming.

Implications
This study demonstrates that yak farming in Bhutan experiences an increasing pressure to sustain. Differences between regions make clear that a one blanket-policy will not be effective to preserve yak farming for the future.
Performance of broilers and layers supplemented with Moringa stenopetala leaf meal under hot humid tropical conditions
Authors: Tamiru Metekia , Ashagrie Shiferaw , Alkhtib Ashraf , Getachew Minyehun , Demeke Solomon , Hassen Waseyehun , Worku Zemene , Burton Emily
Published: July 2020

Context Heat stress poses a major limit to poultry production. Moringa stenopetala leaf meal (MSL) could be a promising feed additive for poultry raised under heat stress, as it is rich in antioxidants. Aims To determine the effect of (MSL) supplementation on the production and quality of broilers under heat-stress conditions. Methods In the broiler performance trial, 156 1-day old Cobb 500 broilers were assigned to four groups, with each containing three replicates of 13 chicks. For the egg production trial, 108 Bovan Brown layers aged 20 weeks were allocated to four groups, with each containing three replicates of nine hens. The four groups of broiler and layer chicken were supplemented with MSL at a level of 0% (control), 1% (MSL1), 1.5% (MSL1.5) and 2% (MSL2). Relative humidity, and minimum and maximum temperatures were 82%, 13°C and 23°C respectively. The effects of MSL supplementation on growth performance, characteristics of digestive organs, carcass traits, egg production and egg quality were analysed with one-way ANOVA. Key results Moringa stenopetala-leaf supplementation at a level up to 2% (MSL2) did not significantly affect feed intake, weight gain or feed conversion ratio of the birds. Supplemented broilers had a significantly longer large intestine (24% for MSL1, 37% for MSL1.5 and 49% for MSL2) and a heavier pancreas (82% for MSL1, 67% for MSL1.5, and 57% for MSL2) than did the control broilers. Hot and cold carcass weights, dressing yield, dressing percentage, breast-meat weight, drumstick and thigh-meat weights, wing-meat weight, back weight and meat pH were not significantly affected by MSL supplementation. Ash content of meat of the MSL2-fed birds was significantly higher than that of the control birds (3.51% vs 2.74% respectively). Egg production, feed conversion ratio and interior and exterior egg-quality parameters were not significantly affected by MSL supplementation. Intensity of yolk colour was significantly and linearly enhanced due to MSL supplementation (by ~5–8 times compared with the control). Conclusions Supplementation with MSL at a level up to 2% improved yolk colour of Bovan Brown layer eggs, with no effect on meat and egg production. Implications Yolk colour of eggs of layers raised under heat stress can be improved by MSL supplementation at 1%, with there being a minimum increase in the diet cost.
The influence of heat load on Merino sheep. 1. Growth, performance, behaviour and climate
Authors: Lees A. M. , Sullivan M. L. , Olm J. C. W. , Cawdell-Smith A. J. , Gaughan J. B.
Published: July 2020

Context
Annually, millions of sheep are exported from Australia to the Middle East, typically during the southern hemisphere winter to the northern hemisphere summer. During these voyages, sheep can be exposed to relatively rapid changes in ambient conditions within a short period of time (≤29 days); therefore, excessive heat load concerns can arise.

Aims
The aim of this study was to define the responses of sheep to incremental heat load under simulated live export conditions. The study herein describes (1) the heat load imposed, and (2) the effect of this heat load on the growth, performance and behavioural responses of sheep during periods of incremental heat load.

Methods
A total of 144 Merino wethers (44.02 ± 0.32 kg) were included in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral and (2) hot (HOT). Ambient temperature (°C) and relative humidity (%) for the HOT treatment were modelled from live export voyages from Australia to the Middle East in July. Climatic conditions within the climate control chambers were recorded at 10-min intervals, then used to calculate a temperature humidity index. Sheep posture, rumination, eating, drinking and demeanour (calm, agitated or depressed) were observed four times daily at 3-h intervals between 0800 hours and 1700 hours. Feed intake was recorded daily and water intake was measured using an automated meter. Sheep were weighed on Day 0 and then at 7-day intervals. Sheep were weighed at slaughter and carcass weights were obtained, these data were used to determine carcass dressing percentage. Data were analysed using a repeated measures model, with a compound symmetry covariance structure.

Key results
Climatic conditions in the HOT treatment increased incrementally between Day 1 (temperature humidity index ≥19) and Day 29 (temperature humidity index ≤34.7). Behaviour, feed intake, average daily gain (g/day), carcass weight (kg) and dressing percentage were not influenced by treatment (P > 0.05). Sheep in the HOT treatment group showed a 137% increase in water intake (P < 0.01) and on average consumed 2.15 L/sheep.day, whereas the thermoneutral group consumed 1.67 L/sheep.day.

Conclusions
These results suggest that these sheep were capable of maintaining feed intake and growth despite exposure to heat load, albeit with a 137% increase in water intake.

Implications
These results highlight the resilience of the Australian Merino genotype, as these sheep were capable of maintaining feed intake and growth during exposure to heat load. As the climatic conditions in this study were modelled based on typical live export vessel conditions, these results may suggest that the climatic conditions experienced by sheep during voyages may not be as critical as previously thought.
Out-of-plane carrier spin in transition-metal dichalcogenides under electric current
Authors: Li Xiao , Chen Hua , Niu Qian
Published: July 2020

Significance

Although out-of-plane current-induced spin polarization (CISP) is important for perpendicular-magnetization reorientation, and it has been realized by the crystalline symmetry breaking, its material examples are relatively fewer compared with in-plane CISP in Rashba systems. With the help of intrinsic spin–orbit coupling, an intriguing out-of-plane CISP is designed in transition-metal dichalcogenides by the symmetry breaking in the spin space, which provides opportunities for out-of-plane magnetization rotation and electric control of valley splitting. Moreover, the spin polarization is associated with valley-dependent responses to electric current and adds a dimension, valley degree of freedom, to the study of CISP. The symmetry argument and non-Rashba effective model also helps to illuminate these physics and broaden the scope of the CISP.
A partially disordered region connects gene repression and activation functions of EZH2
Authors: Jiao Lianying , Shubbar Murtada , Yang Xin , Zhang Qi , Chen Siming , Wu Qiong , Chen Zhe , Rizo Josep , Liu Xin
Published: July 2020

Significance

Enhancer of Zeste Homolog 2 (EZH2) is the catalytic subunit of Polycomb Repressive Complex 2, mediating trimethylation of histone H3K27, a hallmark of gene silencing. Paradoxically, accumulating evidence indicates that EZH2 also dictates a unique gene activation program to promote cancer development. The molecular mechanism underlying the functional conversion of EZH2 from a gene repressor to an activator is unclear. In the current study, we report an unexpected finding that EZH2 contains a hidden, partially disordered transactivation domain (TAD), which directly binds to the transcriptional coactivator p300 and activates gene expression in cancer cells. Structural analysis suggests a “lock-and-release” mechanism of the functional control of the EZH2 TAD by cancer-specific EZH2 phosphorylation.
Inhibition of impulsive action by projection-defined prefrontal pyramidal neurons
Authors: Li Bing , Nguyen Thao Phuong , Ma Chenyan , Dan Yang
Published: July 2020

Significance

The prefrontal cortex (PFC) has long been recognized as a crucial region for suppressing impulsive behavior, but the specific neurons mediating the effect remained elusive. Using projection-specific labeling of PFC neurons for imaging and optogenetic manipulation in mice performing a go/no-go task, we showed that the subset of layer 5 pyramidal neurons projecting to the subthalamic nucleus, but not those projecting to the lateral hypothalamus or visual cortex, play a critical role in inhibiting impulsive responses. Our demonstration of a distinct functional property of a projection-defined PFC pyramidal neuron population provides an important entry point for delineating the PFC circuit underlying impulse control.
Dynamic and asymmetric fluctuations in the microtubule wall captured by high-resolution cryoelectron microscopy
Authors: Debs Garrett E. , Cha Michael , Liu Xueqi , Huehn Andrew R. , Sindelar Charles V.
Published: July 2020

Significance

The dynamic behavior of microtubules, a tubular polymer, is essential for numerous processes throughout the cell. Cryoelectron microscopy (cryo-EM) has provided high-resolution snapshots of the microtubule during its GTP hydrolysis cycle, which regulates assembly and depolymerization. However, the dynamic structural properties of microtubules remain less well understood, due to limitations in cryo-EM analysis methods. Here we present a method to subdivide the microtubule wall into elemental components during cryo-EM refinement. This method substantially enhances the quality of 3D cryo-EM reconstructions, and reveals stochastic fluctuations in the geometry of the microtubule wall. Distinct microtubule subpopulations were identified that exhibit large and systematic deviations from helical symmetry, with potential implications for microtubule assembly/disassembly and other dynamic behaviors that remains incompletely understood.
A frameshift variant in specificity protein 1 triggers superactivation of Sp1-mediated transcription in familial bone marrow failure
Authors: Tummala Hemanth , Walne Amanda J. , Bewicke-Copley Findlay , Ellison Alicia , Pontikos Nikolas , Bridger Maria G. , Rio-Machin Ana , Sidhu Jasmin K. , Wang Jun , Hasle Henrik , Fitzgibbon Jude , Vulliamy Tom , Dokal Inderjeet
Published: July 2020

Significance

Bone marrow failure (BMF) syndromes are inherited life-threatening conditions characterized by low blood cell production and predisposition to cancer. In this study we report a germ line frameshift variant in the Sp1 transcription factor in a family of patients with BMF and acute leukemia. Sp1 is ubiquitously expressed in human tissues and regulates transcription for blood cell lineage specification. Dissecting the molecular function of this
SP1
variant revealed a hypermorphic effect, triggering superactivation of Sp1-mediated transcription in the patients’ blood. To our knowledge, this is the first report of a naturally occurring germ line variant in
SP1
that alters transcriptional networks and disrupts hematopoiesis in humans.
Symmetry breaking in particle-forming diblock polymer/homopolymer blends
Authors: Cheong Guo Kang , Bates Frank S. , Dorfman Kevin D.
Published: July 2020

Significance

Frank–Kasper phases are low-symmetry packings of particles, originally discovered in metals and alloys and now observed in a wide range of soft matter. Understanding how such low-symmetry phases arise in soft materials is an outstanding challenge, as they tend to form high-symmetry, close-packed structures. This work uncovers a mechanism for generating Frank–Kasper phases in diblock copolymers with soft matrices that prefer to form a body-centered cubic structure in the neat-melt state. As homopolymer is loaded into the core of the particles, the system selects a series of Frank–Kasper phases with increasing particle volume asymmetry until eventually the homopolymer phase separates from the block polymer.
Hyponastic Leaves 1 protects pri-miRNAs from nuclear exosome attack
Authors: Gao Shuai , Wang Jingyu , Jiang Ning , Zhang Shiting , Wang Yuan , Zhang Jun , Li Ning , Fang Yixiao , Yang Lin , Chen Susu , Yan Bingbing , Huang Tian , Kuai Benke , Wang Yingxiang , Chang Fang , Ren Guodong
Published: July 2020

Significance

MicroRNAs (miRNAs) are indispensable regulators of gene expression. Hyponastic Leaves 1 (HYL1) is a core component of the microprocessor that processes primary miRNAs (pri-miRNAs) into mature miRNAs. Here we report a noncanonical function of HYL1 in protecting pri-miRNAs from unwanted nuclear exosome activities during processing. Our observations also suggest that HYL1 may contribute differently to the Dicer-like 1 (DCL1)-mediated maturation of loop-to-base– and base-to-loop–processed pri-miRNAs. This study thus integrates the RNA surveillance system to the miRNA biogenesis pathway and sheds light on the multifaced roles of HYL1 in miRNA biogenesis.
Rubisco accumulation factor 1 (Raf1) plays essential roles in mediating Rubisco assembly and carboxysome biogenesis
Authors: Huang Fang , Kong Wen-Wen , Sun Yaqi , Chen Taiyu , Dykes Gregory F. , Jiang Yong-Liang , Liu Lu-Ning
Published: July 2020

Significance

Cyanobacteria are keystone organisms in global carbon fixation. Their great carbon-assimilation capability arises from a specialized virus-like protein organelle, the carboxysome, which comprises hundreds of proteins that form a shell to encapsulate the CO
2
-fixing enzymes Rubisco and carbonic anhydrase. How do these proteins self-assemble to construct the defined architecture? Here we explore the significance of one assembly factor, Raf1, in Rubisco assembly and carboxysome formation. We show that Raf1 mediates Rubisco assembly; without Raf1, carboxysome proteins are prone to form intermediate assemblies and small carboxysome-like structures rather than intact carboxysomes. Our results suggest a model of the Raf1-mediated biogenesis of carboxysomes and provide advanced knowledge of carboxysome assembly and function, informing synthetic engineering of functional CO
2
-fixing organelles for biotechnological applications.
The implications of silent transmission for the control of COVID-19 outbreaks
Authors: Moghadas Seyed M. , Fitzpatrick Meagan C. , Sah Pratha , Pandey Abhishek , Shoukat Affan , Singer Burton H. , Galvani Alison P.
Published: July 2020

Since the emergence of coronavirus disease 2019 (COVID-19), unprecedented movement restrictions and social distancing measures have been implemented worldwide. The socioeconomic repercussions have fueled calls to lift these measures. In the absence of population-wide restrictions, isolation of infected individuals is key to curtailing transmission. However, the effectiveness of symptom-based isolation in preventing a resurgence depends on the extent of presymptomatic and asymptomatic transmission. We evaluate the contribution of presymptomatic and asymptomatic transmission based on recent individual-level data regarding infectiousness prior to symptom onset and the asymptomatic proportion among all infections. We found that the majority of incidences may be attributable to silent transmission from a combination of the presymptomatic stage and asymptomatic infections. Consequently, even if all symptomatic cases are isolated, a vast outbreak may nonetheless unfold. We further quantified the effect of isolating silent infections in addition to symptomatic cases, finding that over one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population. Our results indicate that symptom-based isolation must be supplemented by rapid contact tracing and testing that identifies asymptomatic and presymptomatic cases, in order to safely lift current restrictions and minimize the risk of resurgence.