bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐Potential Tomography of a Deep‐Sea Polymetallic Sulfide Deposit on Southwest Indian Ridge
Authors: Zhu Z. , Tao C. , Shen J. , Revil A. , Deng X. , Liao S. , Zhou J. , Wang W. , Nie Z. , Yu J. 
Published: October 2020

AbstractDeep‐sea polymetallic sulfides associated with hydrothermal systems are considered a potential viable resource for base and precious metals. The Southwest Indian Ridge (SWIR, Indian Ocean) hosts active and inactive hydrothermal systems. Inactive hydrothermal fields are more abundant than active fields but are difficult to remotely characterize. We report a deep‐sea self‐potential investigation to locate inactive ore deposits at the Yuhuang hydrothermal field on the ultraslow‐spreading SWIR. A horizontal array of six nonpolarizing AgCl electrodes are attached to a deep‐towed transient electromagnetic system to record the electrical field at a height of 40 m above the seafloor. The observed electrical field strength near a previously recognized sulfide deposits (verified by drilling) reaches an amplitude of 0.5 mV/m. Negative self‐potential anomalies (~ −27 mV) were observed by integrating the measured electrical field. The high electrical conductivities (up to 12 S/m) of sulfide samples measured in the laboratory and the oxidized sulfides recovered from the surface of the deposit suggest that the self‐potential anomalies are due to sulfide mineralization and corrosion of the polymetallic sulfides. Inversion of the self‐potential data reveals a localized body with a thickness of ~65 m, which is interpreted as the Yuhuang ore deposit. Our field data demonstrate that the self‐potential method is a useful exploration method to identify and image seafloor massive sulfide deposits hosted in inactive hydrothermal fields at mid‐ocean ridges.
A Floating Optical Buoy (FOBY) for Direct Measurement of Water‐Leaving Radiance Based on the Skylight‐Blocked Approach (SBA): An Experiment in Honghu Lake, China
Authors: Tian Liqiao , Li Sen , Li Yong , Sun Zhaohua , Song Qingjun , Zhao Jun 
Published: October 2020

AbstractWater‐leaving radiance (Lw), or remote sensing reflectance (Rrs), is a fundamental parameter of water color remote sensing. However, obtaining accurate and precise measurements of Lw is quite challenging. This study is intended to illustrate the design and implementation of a novel floating optical buoy (FOBY) to measure Lw directly in the field based on the skylight‐blocked approach (SBA). To assess the performance of FOBY, an experiment was conducted in Honghu Lake, China, a typical shallow turbid lake. FOBY‐derived Rrs can characterize the spectral features of different water types including water with kelp as substrate, relatively high chlorophyll‐a contents, and high amounts of suspended sediment (SS). FOBY‐derived Rrs is superior to that from a portable spectroradiometer (PSR 3500+, Spectral Evolution Inc.) based on the conventional above‐surface approach (ASA) in terms of data quality and stability. FOBY measurements had a quality assurance score (QAS) of 0.98 and a mean coefficient of variation (CV) of 3.6–7.0%, while the mean CV for PSR measurements is more than 2 times larger than that of FOBY in the visible domain. The measurement uncertainties may result from self‐shading, sensor tilt, and the immersed depth of the cone (IDC), which deserve further investigations. In the future, long‐term continuous floating observations of different aquatic environments can be conducted using the instrument with well‐refined data quality control.
Urbanization Impact on Regional Wind Stilling: A Modeling Study in the Beijing‐Tianjin‐Hebei Region of China
Authors: Wang Jun , Feng Jinming , Yan Zhongwei , Zha Jinlin 
Published: October 2020

AbstractProminent slowdown in near‐surface wind speed (NSWS) has been observed in the Beijing‐Tianjin‐Hebei (BTH) region of China, which has important implications for regional haze mitigation and wind energy production. Other than large‐scale climatic variation, this decline is suspected of being linked to the impact of urbanization. Based on nested high‐resolution simulations using the Weather Research and Forecasting model, we assessed quantitatively the respective roles of urban development and anthropogenic heat (AH) in regional NSWS change over the BTH region from a climatological perspective. The contribution of urbanization to station average annual NSWS over 1980–2018 was estimated to be approximately −0.37 m s−1, with the largest decline exceeding −1.0 m s−1 in some highly urbanized areas. The effect of urban development on NSWS was found partly offset by the AH effect. Urbanization‐induced NSWS decrease was most remarkable in spring and early in the night. Urbanization impacts on NSWS were more remarkable when regional prevailing winds were northeasterly and northwesterly. Further analysis showed that the simulated urbanization‐induced decreases in NSWS were highly correlated with the background regional NSWS levels. Our simulation results indicated that urbanization was an important but not a dominant cause of the observed regional wind stilling, even in such a rapidly urbanizing region, although it had remarkable influence on local NSWS in highly urbanized areas.
Importance of Shaded Leaf Contribution to the Total GPP of Canadian Terrestrial Ecosystems: Evaluation of MODIS GPP
Authors: Chen Bin , Arain M. Altaf , Chen Jing M. , Wang Shaoqiang , Fang Hongliang , Liu Zhenhai , Mo Gang , Liu Jane 
Published: October 2020

AbstractTerrestrial gross primary productivity (GPP) quantifies the photosynthetic uptake by vegetation and it is the largest component of the terrestrial carbon cycle. The separation of sunlit and shaded leaves has been shown to be an effective leaf‐to‐canopy upscaling method for modeling vegetation GPP. In this study, the performance of the Integrated Carbon‐Canadian Land Surface Scheme (IC‐CLASS) based on Farquhar's photosynthetic model and the two‐leaf approach was compared against that of Moderate Resolution Imaging Spectroradiometer (MODIS) GPP algorithm using the light use efficiency (LUE) approach, validated with eddy covariance (EC) measured GPP over a variety of terrestrial ecosystems in Canada. There were systematic differences between the IC‐CLASS simulated GPP and the MODIS GPP product in spatial distribution patterns. The differences were due to inherent shortcomings of the LUE modeling approach where a constant maximum LUE value is specified for each biome type, ignoring the variation of shaded leaf contribution to total GPP. The IC‐CLASS model separates the sunlit and shaded leaves and the bias in simulating GPP was minimized. The IC‐CLASS performed better than the MODIS GPP algorithm compared with monthly and annual GPP derived from EC flux data at 13 Canadian Carbon Program sites. The differences between the IC‐CLASS and the MODIS GPP estimates were larger in more clumped canopies (i.e. forests), because of the increase in the shaded leaf fraction. Different LUEs in sunlit and shaded portions of the canopy should be considered for effective and reliable estimation of GPP at regional scale.
STAT3 in the dorsal raphe gates behavioural reactivity and regulates gene networks associated with psychopathology
Authors: Reisinger Sonali N. , Sideromenos Spyros , Horvath Orsolya , Derdak Sophia , Cicvaric Ana , Monje Francisco J. , Bilban Martin , Häring Martin , Glat Micaela , Pollak Daniela D. 
Published: October 2020

AbstractThe signal transducer and activator of transcription 3 (STAT3) signalling pathway is activated through phosphorylation by Janus kinases in response to a diverse set of immunogenic and non-immunogenic triggers. Several distinct lines of evidence propose an intricate involvement of STAT3 in neural function relevant to behaviour in health and disease. However, in part due to the pleiotropic effects resulting from its DNA binding activity and the consequent regulation of expression of a variety of genes with context-dependent cellular consequences, the precise nature of STAT3 involvement in the neural mechanisms underlying psychopathology remains incompletely understood. Here, we focused on the midbrain serotonergic system, a central hub for the regulation of emotions, to examine the relevance of STAT3 signalling for emotional behaviour in mice by selectively knocking down raphe STAT3 expression using germline genetic (STAT3 KO) and viral-mediated approaches. Mice lacking serotonergic STAT3 presented with reduced negative behavioural reactivity and a blunted response to the sensitising effects of amphetamine, alongside alterations in midbrain neuronal firing activity of serotonergic neurons and transcriptional control of gene networks relevant for neuropsychiatric disorders. Viral knockdown of dorsal raphe (DR) STAT3 phenocopied the behavioural alterations of STAT3 KO mice, excluding a developmentally determined effect and suggesting that disruption of STAT3 signalling in the DR of adult mice is sufficient for the manifestation of behavioural traits relevant to psychopathology. Collectively, these results suggest DR STAT3 as a molecular gate for the control of behavioural reactivity, constituting a mechanistic link between the upstream activators of STAT3, serotonergic neurotransmission and psychopathology.
Novel MNZ-type microwave sensor for testing magnetodielectric materials
Authors: Jha Abhishek Kumar , Delmonte Nicolò , Lamecki Adam , Mrozowski Michal , Bozzi Maurizio 
Published: October 2020

AbstractA novel microwave sensor with the mu-near-zero (MNZ) property is proposed for testing magnetodielectric material at 4.5 GHz. The sensor has a double-layer design consisting of a microstrip line and a metal strip with vias on layers 1 and 2, respectively. The proposed sensor can detect a unit change in relative permittivity and relative permeability with a difference in the operating frequency of 45 MHz and 78 MHz, respectively. The MNZ sensor is fabricated and assembled on two layers of Taconic RF-35 substrate, with thicknesses of 0.51 mm and 1.52 mm, respectively, for the measurement of the sample under test using a vector network analyzer. The dielectric and magnetic properties of two standard dielectric materials (Taconic CER-10 and Rogers TMM13i) and of yttrium–gadolinium iron garnet are measured at microwave frequencies. The results are found to be in good agreement with the values available in the literature, which shows the applicability of the prototype for sensing of magnetodielectric materials.
Modeling Posidonia oceanica shoot density and rhizome primary production
Authors: Catucci Elena , Scardi Michele 
Published: October 2020

AbstractPosidonia oceanica meadows rank among the most important and most productive ecosystems in the Mediterranean basin, due to their ecological role and to the goods and services they provide. Estimations of crucial ecological process such as meadows productivity could play a major role in an environmental management perspective and in the assessment of P. oceanica ecosystem services. In this study, a Machine Learning approach, i.e. Random Forest, was aimed at modeling P. oceanica shoot density and rhizome primary production using as predictive variables only environmental factors retrieved from indirect measurements, such as maps. Our predictive models showed a good level of accuracy in modeling both shoot density and rhizome productivity (R2 = 0.761 and R2 = 0.736, respectively). Furthermore, as shoot density is an essential parameter in the estimation of P. oceanica productivity, we proposed a cascaded approach aimed at estimating the latter using predicted values of shoot density rather than observed measurements. In spite of the complexity of the problem, the cascaded Random Forest performed quite well (R2 = 0.637). While direct measurements will always play a fundamental role, our estimates could support large scale assessment of the expected condition of P. oceanica meadows, providing valuable information about the way this crucial ecosystem works.
A comprehensive examination of the local- and long-range structure of Sb6O13 pyrochlore oxide
Authors: Mayer S. F. , Rodrigues J. E. , Marini C. , Fernández-Díaz M. T. , Falcón H. , Asensio M. C. , Alonso J. A. 
Published: October 2020

AbstractThe crystal structure of the Sb6O13oxide, exhibiting a defect pyrochlore crystal structure with atomic vacancies, has been studied using a complete set of state-of-the-art techniques. The degree of antimony disproportionation in Sb3+and Sb5+valence states has been directly determined around 36% and 64%, respectively, using X-ray absorption near edge structure (XANES). These findings are in excellent agreement with our Rietveld analysis of synchrotron X-ray (SXRD) and neutron powder diffraction (NPD) results. Moreover, the highly distorted Sb3+coordination due to its lone electron pair has been critically revisited. The bonding distances and coordination of Sb3+and Sb5+species closely agree with an extensive dynamic and crystallographic determination using the Extended X-ray Absorption Fine Structure (EXAFS) technique. Most importantly, the specific local disorder of the two distinctive Sb ions has been crosschecked monitoring their unusual Debye–Waller factors.
Assessment of conbercept therapy for high myopia macular neovascularization by optical coherence tomography angiography
Authors: Cheng Lu-Na , Lin Yu-Xi , Liu Lei , Zhang Xu-He , Xue Yan-Qi , Zhou Sheng-Di , Liu Zhe-Li , Zhang Han 
Published: October 2020

AbstractThis study aimed to evaluate the efficacy and safety of the intravitreal injection of conbercept in the treatment of macular neovascularization (MNV) secondary to high myopia and to observe the application of optical coherence tomography angiography (OCTA) in the treatment follow-up. We reviewed the medical records of 20 patients (21 eyes) with MNV secondary to high myopia who were enrolled in the Department of Ophthalmology of the First Hospital of China Medical University between May 2018 and January 2020. Each patient received one or more intravitreal injections of conbercept (0.5 mg/0.05 mL). The treatment was conducted according to a 1 + PRN (pro re nata) regimen. The changes of best corrected visual acuity (BCVA), central macular thickness (CMT), and selected MNV and flow areas measured by OCTA were observed over a 6-month follow-up period. The mean logarithm of the minimum angle of resolution (logMAR) BCVA was 1.03 ± 0.61 before treatment and improved to 0.83 ± 0.59 (P = 0.007), 0.78 ± 0.62 (P = 0.001), 0.81 ± 0.73 (P = 0.027), and 0.79 ± 0.72 (P = 0.023) at 1 month, 2 months, 3 months, and 6 months after treatment, respectively. The mean CMT was 358.16 ± 206.11 μm before treatment and decreased to 295.38 ± 178.70 μm (P = 0.003), 288.34 ± 165.60 μm (P = 0.004), 284.36 ± 163.07 μm (P = 0.005), and 283.00 ± 160.32 μm (P = 0.004) at 1 month, 2 months, 3 months, and 6 months after treatment, respectively. Nineteen eyes (90.5%) had stable or improved vision at 6 months of follow-up. One month after conbercept injection, in OCTA images, the small-diameter blood vessels of the MNV decreased, the intertwined small blood vessels decreased or even disappeared, and the main or larger-diameter blood vessels were still present. The mean selected MNV and blood flow areas were 0.62 ± 0.81 and 0.22 ± 0.27 mm2, respectively, before treatment and decreased to 0.23 ± 0.33 and 0.07 ± 0.08 mm2(P = 0.04 for both), respectively, 1 month after treatment. No drug-related systemic or ocular adverse effects were observed. Our results suggest that conbercept can effectively and safely improve BCVA and reduce CMT in patients with myopic MVN (mMNV). OCTA can be used to observe MNV area, blood flow area, and MNV morphological changes after treatment with conbercept, thus providing a reference for treatment follow-up.
Acute respiratory muscle unloading improves time-to-exhaustion during moderate- and heavy-intensity cycling in obese adolescent males
Authors: Alemayehu Hailu Kinfu , Salvadego Desy , Tringali Gabriella , De Micheli Roberta , Caccavale Mara , Sartorio Alessandro , Grassi Bruno 
Published: October 2020

AbstractObesity significantly impairs breathing during exercise. The aim was to determine, in male obese adolescents (OB), the effects of acute respiratory muscle unloading, obtained by switching the inspired gas from ambient air (AIR) to a normoxic helium + oxygen gas mixture (HeO2) (AIR → HeO2) during moderate [below gas exchange threshold (GET)] and heavy [above GET] constant work rate cycling. Ten OB [age 16.0 ± 2.0 years (mean ± SD); body mass index (BMI) 38.9 ± 6.1 kg/m2] and ten normal-weight age-matched controls (CTRL) inspired AIR for the entire exercise task, or underwent AIR → HeO2 when they were approaching volitional exhaustion. In OB time to exhaustion (TTE) significantly increased in AIR → HeO2 vs. AIR during moderate [1524 ± 480 s vs. 1308 ± 408 (P = 0.024)] and during heavy [570 ± 306 s vs. 408 ± 150 (P = 0.0154)] exercise. During moderate exercise all CTRL completed the 40-min task. During heavy exercise no significant differences were observed in CTRL for TTE (582 ± 348 s [AIR → HeO2] vs. 588 ± 252 [AIR]). In OB, but not in CTRL, acute unloading of respiratory muscles increased TTE during both moderate- and heavy-exercise. In OB, but not in CTRL, respiratory factors limit exercise tolerance during both moderate and heavy exercise.
A systematic review of employment outcomes from youth skills training programmes in agriculture in low- and middle-income countries
Authors: Maïga W. H. Eugenie , Porgo Mohamed , Zahonogo Pam , Amegnaglo Cocou Jaurès , Coulibaly Doubahan Adeline , Flynn Justin , Seogo Windinkonté , Traoré Salimata , Kelly Julia A. , Chimwaza Gracian 
Published: October 2020

AbstractEngagement of youth in agriculture in low- and middle-income countries may offer opportunities to curb underemployment, urban migration, disillusionment of youth and social unrest, as well as to lift individuals and communities from poverty and hunger. Lack of education or skills training has been cited as a challenge to engage youth in the sector. Here we systematically interrogate the literature for the evaluation of skills training programmes for youth in low- and middle-income countries. Sixteen studies—nine quantitative, four qualitative and three mixed methods—from the research and grey literature documented the effects of programmes on outcomes relating to youth engagement, including job creation, income, productivity and entrepreneurship in agriculture. Although we find that skills training programmes report positive effects on our chosen outcomes, like previous systematic reviews we find the topic to chronically lack evaluation. Given the interest that donors and policymakers have in youth engagement in agriculture, our systematic review uncovers a gap in the knowledge of their effectiveness.
Accelerated discovery of high-strength aluminum alloys by machine learning
Authors: Li Jiaheng , Zhang Yingbo , Cao Xinyu , Zeng Qi , Zhuang Ye , Qian Xiaoying , Chen Hui 
Published: October 2020

AbstractAluminum alloys are attractive for a number of applications due to their high specific strength, and developing new compositions is a major goal in the structural materials community. Here, we investigate the Al-Zn-Mg-Cu alloy system (7xxx series) by machine learning-based composition and process optimization. The discovered optimized alloy is compositionally lean with a high ultimate tensile strength of 952 MPa and 6.3% elongation following a cost-effective processing route. We find that the Al8Cu4Y phase in wrought 7xxx-T6 alloys exists in the form of a nanoscale network structure along sub-grain boundaries besides the common irregular-shaped particles. Our study demonstrates the feasibility of using machine learning to search for 7xxx alloys with good mechanical performance.
Superplastic Behaviour of Ti54M and Ti64
Authors: Mandal Paranjayee , Gomez-Gallegos Ares , Gonzalez Diego , Elrakayby Hosam , Blackwell Paul 
Published: October 2020

Even though TIMETAL-54M (Ti-5Al-4V-0.6Mo-0.4Fe or Ti54M) has been commercially available for over 10 years, further study of its superplastic properties is still required in order to assess its applicability within the aerospace industry as a potential replacement for other commercial titanium alloys such as Ti-6Al-4V (Ti64). Ti54M is expected to obtain superplastic characteristics at a lower temperature than Ti64 due to its lower beta-transus temperature. The superplastic forming (SPF) capability of alloys that can be formed at lower temperatures has always attracted the interest of industry as it reduces the grain growth and alpha-case formation, leading to longer life for costly high temperature resistant forming tools.
In this work, the SPF characteristics of both Ti54M and Ti64 have been examined by conducting tensile tests according to the ASTM E2448 standard within a range of temperatures and strain values at a fixed strain rate of 1 × 10-4/S. A high strain rate sensitivity and uniform deformation at high strains are key indicators in selecting the optimum superplastic temperature. This was observed at 815˚C and 925˚C for Ti54M and Ti64 respectively. The tensile samples were water quenched to freeze their respective microstructure evolution following superplastic deformation and SEM images were captured for grain size and volume fraction of alpha-phase analyses. A slightly higher alpha-grain growth rate was observed during superplastic deformation of Ti64. The initial fine-grain microstructure of Ti54M (~1.6 micron) resulted in a final microstructure with an average grain size of ~3.4 micron and optimum the alpha/beta ratio. Both the fine-grained microstructure and increased amount of beta-volume fraction promotes the superplastic behaviour of Ti54M by grain boundary sliding (GBS). Thus superplastic properties were observed for Ti54M at a lower temperature (~100˚C) than for Ti64.
“Microstructure and mechanical characterisation of titanium alloy linear friction welds”
Authors: Flipo Bertrand , Beamish Kathryn , Humphreys Bryan , Wood Martin 
Published: October 2020

The increasing use of composite materials in new aircraft builds leads to a significant demand for titanium alloy structural parts. The increasing costs and popularity of this material, together with restrictions in supply and processing, are driving the aerospace industry to make increasingly efficient use of available material.
Linear Friction Welding (LFW) is a rapid, high integrity, solid-state forging process that has the potential to decrease the buy-to-fly ratio, production time and time to market of aerostructure components. Its dependability has already been proven for the production of key components in some of the latest generation aero engines.
The LFW process is yet to be used for aerostructures. This is primarily due to the LFW process not being widely known, but also due to a lack of performance data on aerostructures manufactured by LFW being available to the supply chain and design community.
To address this issue, a large series of titanium alloy weldments was produced and assessed via metallographic examinations and mechanical testing in both as-welded and post-weld heat-treated condition. The matrix of experiments was able to capture the LFW process window of this titanium alloy, and to measure the impact of the parametric conditions.
Metallographic examination revealed a high integrity weld free from contaminants and oxides at the weld interface; with a characteristic recrystallised Widmanstätten martensitic Beta weld centre zone microstructure, in as welded condition, and a finegrained equiaxed recrystallised to alpha-beta microstructure in post-weld heat-treated condition.
As-welded joints were tested under tensile and alternating fatigue conditions to provide an extended set of joint performance data. Joints demonstrated tensile performance equivalent to that of the parent material in all cases, with near-parent fatigue properties and improved (reduced) fatigue scatter in the post-weld heat-treated condition.