bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating elephant density using motion‐sensitive cameras: challenges, opportunities, and parameters for consideration
Authors: Morrison Jacqueline , Omengo Fred , Jones Martin , Symeonakis Elias , Walker Susan L. , Cain Bradley 
Published: March 2022

AbstractWith extinction rates far exceeding the natural background rate, reliable monitoring of wildlife populations has become crucial for adaptive management and conservation. Robust monitoring is often labor intensive with high economic costs, particularly in the case of those species that are subject to illegal poaching, such as elephants, which require frequent and accurate population estimates over large spatial scales. Dung counting methods are commonly employed to estimate the density of elephants; however, in the absence of a full survey calibration, these can be unreliable in heterogeneous habitats where dung decay rates may be highly variable. We explored whether motion‐sensitive cameras offer a simple, lower cost, and reliable alternative for monitoring in challenging forest environments. We estimated the density of African savanna elephants (Loxodanta africana) in a montane forest using the random encounter model and assessed the importance of surveying parameters for future survey design. We deployed motion‐sensitive cameras in 65 locations in the Aberdare Conservation Area in Kenya during June to August in 2015 to 2017, for a survey effort of 967 days, and a mean encounter rate of 0.09 ± 0.29 (SD) images/day. Elephants were captured in 16 locations. Density estimates varied between vegetation types, with estimates ranging from 6.27/km2 in shrub, 1.1/km2 in forest, 0.53/km2 in bamboo (Yushania alpine), and 0.44/km2 in the moorlands. The average speed of animal movement and the camera detection zone had the strongest linear associations with density estimates (R = −0.97). The random encounter model has the potential to offer an alternative, or complementary method within the active management framework for monitoring elephant populations in forests at a relatively low cost.
A Wearable Strain Sensor Based on Electroconductive Hydrogel Composites for Human Motion Detection
Authors: Fraser Stephanie A. , Van Zyl Werner E. 
Published: March 2022

AbstractHydrogels are becoming the default platform for flexible electronic applications—specifically, strain sensors. But the simultaneous realization of compliance, robustness, and strain sensitivity required, using environmentally friendly materials, remains challenging. Here a series of poly(vinyl alcohol) (PVA)‐based biocomposite hydrogels, comprising variable quantities of nanocellulose and sodium alginate formed by freeze/thaw cycling, is reported. The results indicate that a hybrid hydrogel is prepared via the incorporation of conductive polypyrrole/bacterial nanocellulose composite material into the optimized PVA‐based hydrogel matrix (yield strength = 6.0 MPa, elastic modulus = 2.4 MPa, stretchability >384%). The resulting hybrid material exhibits remarkable toughness, nonlinear conformability, and piezoresistivity and demonstrates good strain sensitivity over a considerable range of deformation (<≈200% elongation, maximum gauge factor = 0.96). Moreover, the hybrid hydrogel is assembled into a wearable piezoresistive sensor capable of detecting large‐range human motion with high sensitivity, stability, and repeatability over a few repeated loading cycles. Thus, there is potential for the application of the conductive hybrid hydrogel in flexible electronics, such as wearable devices for health monitoring, soft robotics, and biomedical implants. Furthermore, the implementation of biocompatible polymers and renewable materials, amongst other green design principles, provides scope for the design of sustainable high performance materials.
Finite element analysis of newly developed hip prosthesis
Authors: Namasivayam D. , Andriyana A. , Arifin N. 
Published: March 2022

AbstractThe present study focuses on the design and finite element analysis of a novel hip prosthesis comprising truss structures intended to equally distribute the stress along the prosthesis. The prosthesis is designed to suit three different inclination angles of 20°, 40° and 60°. The three designs were subjected to loading conditions that emulate walking, jogging, and cycling activities via finite element simulations. Using the von Mises yield criterion and Goodman relation for fatigue, it is found that the safety factor and the life cycle of the proposed prosthesis design was within the acceptable range. Furthermore, the truss structures incorporated in the prosthesis appear to reduce the stress levels in the femur.
Effect of graphene filler on mechanical properties of cotton/viscose hybrid composite
Authors: Arunkumar K. , Raghu R. , LetaTesfaye J. , Krishnaraj R. 
Published: March 2022

AbstractThis work addresses the preparation of cotton/viscose fabric reinforced hybrid composite with graphene as a filler material by a compression moulding process and investigation on their mechanical properties such as tensile strength, flexural strength, impact strength, and hardness. The graphene filler was taken in different proportions such as 1.5 weight percentage (wt. %), 3 wt. %, and 4.5 wt. %, which was mixed with the matrix material. It was observed that the addition of filler improved the mechanical properties of the composite. The hybrid composite with 4.5 wt. % of graphene was observed with an enhanced tensile strength of 73.9 MPa and flexural strength of 406.2 MPa. An improvement of 21.7 % in tensile strength and 284.2 % in flexural strength was noticed for the addition of 4.5 wt. % of graphene filler. The addition of filler during the preparation of hybrid composite improved the bonding of the epoxy matrix with the cotton/viscose fabric and thereby mechanical properties were enhanced due to better load carrying capacity of the composites.
Fatigue properties of wood at different load ratios tested at 50 Hz and 20 kHz
Authors: Schönbauer B.M. , Killinger M. , Karr U. , Fitzka M. , Müller U. , Teischinger A. , Mayer H. 
Published: March 2022

AbstractFatigue properties of sycamore maple (Acer pseudoplatanus) under cyclic tension, cyclic compression and tension‐compression loading at 50 Hz are investigated. Furthermore, for the first time, fatigue test results of wood generated with the ultrasonic fatigue testing technique at 20 kHz under tension‐compression loading are presented. Cyclic properties are in line with the static properties – with the tensile strength being more than two times the compressive strength. Mean lifetimes of 106 cycles are found if the maximum tensile stress for cyclic tension is 69 %±8 % of the tensile strength and if the maximum compressive stresses for cyclic compression and tension‐compression are 75 %±7 % and 54 %±4 % of the compressive strength, respectively. Tension‐compression loading at 20 kHz delivers lifetimes comparable to servo‐hydraulic tests at 50 Hz, and no pronounced frequency effect on fatigue lifetime is found. Ultrasonic fatigue testing is therefore, in principle, appropriate for accelerated fatigue testing of wood up to the very high cycle fatigue regime. Tests up to 109 cycles show no evidence of a fatigue limit for sycamore maple.
Oxygen detection system based on TDLAS–WMS and a compact multipass gas cell
Authors: Chang Jvqiang , He Qixin , Li Jiakun , Feng Qibo 
Published: March 2022

AbstractIn this paper, a sensitive oxygen monitoring system was demonstrated using tunable diode laser absorption spectroscopy and wavelength modulation spectroscopy. Light from a distributed feedback laser near 760.8 nm was coupled into a compact Herriott cell with a 3.3 m optical path. A LabVIEW‐based orthogonal lock‐in amplifier was developed to extract the gas concentration information from the absorption signal, which can achieve baseline fitting, background deduction, filtering, and harmonic extraction. Oxygen measurement experiments were conducted, and the performance of the system was obtained. Based on an Allan deviation analysis, the minimum detection limit of the system was 0.247% at an averaging time of 1 s and could improve to 0.022% when the averaging time was 40 s.
Wideband asymmetric coplanar waveguide antenna using composite right/left‐handed transmission line
Authors: Shi Yuan , Zeng Qingsheng , Wang Zhefei , Si Qingqing , Zhang Yandong , Qiu Tian , Shang Yuqiu , Wu Yong 
Published: March 2022

AbstractA broadband asymmetric coplanar waveguide antenna is designed. In this design, two periodical composite right/left‐handed transmission line (CRLH‐TL) unit cells were chosen to generate three resonating modes. The broadband characteristic of this antenna can be achieved by combining the first‐negative‐order resonance, zeroth‐order resonance, and first‐positive‐order resonance of CRLH‐TL. A prototype structure of our proposed antenna has been fabricated and tested. The dimensions of the antenna are 30.0 × 40.0 × 1.6 mm3, which corresponds to 0.19  × 0.25  × 0.01 , where is the free‐space wavelength at 1.88 GHz. The measured band in which S11 is below −10 dB ranges from 1.80 to 3.75 GHz with the fractional bandwidth of 70.27%. The radiation patterns of the proposed antenna are highly consistent throughout the operating band, which covers the band of WiMAX, with the measured average peak gain of 2.77 dBi and radiation efficiency of 86.63%.
Dynamic response of large diameter, concrete‐lined vertical shafts under external and seismic excitation
Authors: Guerra Conrado S. , Labaki Josué , Barros Pérsio L. A. 
Published: March 2022

AbstractThis article proposes a novel numerical model of the dynamic response of large diameter, concrete‐lined circular shafts, embedded in transversely isotropic soils. Excitation is given as time‐harmonic external loads applied to the base of the shaft, or vertically propagating, time‐harmonic pressure waves. The concrete lining is modeled with finite annular plate and cylindrical‐shell finite elements, while the contact tractions at the shaft–soil interface are modeled within a boundary elements framework. The response of the coupled system is obtained by imposing rigorous continuity and equilibrium conditions at the interface. The model yields accurate representation of the energy exchange between shaft and soil, as well as energy propagation through the soil as an unbounded medium. Original numerical results are presented on the response of the shaft and lining for selected geometric and constitutive parameters, frequencies and type of excitation, and anisotropic soil constitutions.
Impact of COVID‐19 on life experiences reported by a diverse cohort of older adults with diabetes and obesity
Authors: Wagenknecht Lynne E. , Chao Ariana M. , Wadden Thomas A. , McCaffery Jeanne M. , Hayden Kathleen M. , Laferrère Blandine , Clark Jeanne M. , Johnson Karen C. , Howard Marjorie J. , Yanovski Susan Z. , Wing Rena R. ,   the Look AHEAD Research Group
Published: March 2022

AbstractObjectiveThis study aimed to measure the impact of the COVID‐19 pandemic on self‐reported life experiences in older adults with diabetes and obesity.MethodsParticipants were surveyed in 2020 regarding negative and positive impacts of the pandemic across domains of personal, social, and physical experiences. A cumulative negative risk index (a count of all reported negative impacts of 46 items) and a positive risk index (5 items) were characterized in relation to age, sex, race/ethnicity, BMI, and multimorbidity.ResultsResponse rate was high (2950/3193, 92%), average age was 76 years, 63% were women, and 39% were from underrepresented populations. Women reported more negative impacts than men (6.8 vs. 5.6; p < 0.001 [of 46 items]) as did persons with a greater multimorbidity index (p < 0.001). Participants reporting African American/Black race reported fewer negative impacts than White participants. Women also reported more positive impacts than men (1.9 vs. 1.6; p < 0.001 [of 5 items]).ConclusionsOlder adults with diabetes and obesity reported more positive impacts of the pandemic than negative impacts, relative to the number of positive (or negative) items presented. Some subgroups experienced greater negative impacts (e.g., for women, a greater multimorbidity index). Efforts to reestablish personal, social, and physical health after the pandemic could target certain groups.
Macroscopic membranes self‐assembled by alginate and a cationic and amphiphilic peptide for cell culture
Authors: Levi Topaz , Yosefi Gal , Bitton Ronit , Rapaport Hanna 
Published: March 2022

AbstractPeptides self‐assembly systems have been explored over the past years in the context of various biological applications, such as tissue engineering and drug delivery. Here we present the development of hierarchically ordered planar and spherical macroscopic membranes constructed by an amphiphilic and cationic β‐sheet peptide that spontaneously assembles with the negatively charged alginate biopolymer. These two components generate a condensed film that developed to exhibit perpendicularly oriented fibers under specific conditioning over days. Here we examined the suitability of these spherical and planar membranes to serve as substrates for cell culture applications. Planar and spherical membranes were stable in the cell culture Dulbecco's modified eagle medium, at 37°C, over days. Breast‐cancer cells seeded on the peptide and alginate sides of fully developed and non‐fully developed planar membrane were viable for more than 2 weeks. In addition, cells were injected into spherical membranes and detected viable close to the rim even at 3 weeks. These results demonstrate the suitability of planar and spherical membranes to serve as a platform, for example, in studying cancer cells in unique niches and alternatively in potential allogeneic cell therapies.
Mechanical behavior and damage kinetics of a unidirectional carbon/epoxy laminated composite under dynamic compressive loading
Authors: Xie Wenbo , Zhang Wei , Yang Hongbin , Jiang Xiongwen , Wang Lina , Gao Yubo , Cai Xuanming 
Published: March 2022

AbstractIn this work, mechanical behavior and damage kinetics of a unidirectional carbon/epoxy laminated composite (CFRP) under dynamic compressive loading were investigated. An Instron testing machine and a pulse‐shaped split Hopkinson pressure bar (SHPB) apparatus were employed to test the quasi‐static and dynamic mechanical properties of the material, respectively. Digital image correlation (DIC) combined with ultra high‐speed photography was used to study the deformation and failure process of the specimen under dynamic loading. The results show that the failure modes of the material along the main direction were strain‐rate sensitive. The failure mode along the fiber direction was observed to change from crushing followed by fiber kink banding to predominantly interlaminar delamination, longitudinal cracking and fiber buckling delamination as the strain rate increases from quasi‐static to high strain rates. Furthermore, an empirical formula for dynamic compression strength was established based on the test data. Model predictions and experimental data are in very good agreement. Finally, a simplified Zhu‐Wang‐Tang (ZWT) nonlinear visco‐hyperelastic constitutive model ZWT nonlinear viscoelastic model was developed to predict the mechanical behaviors of CFRP under dynamic impact loading. The predicted values are observed to essentially match the trends of the experimental results. This research will further improve the design of CFRP composites subjected to high‐speed impact loads during service.
Extending the prenatal Noonan's phenotype by review of ultrasound and autopsy data
Authors: Lamouroux Audrey , Dauge Coralie , Wells Constance , Mousty Eve , Pinson Lucile , Cavé Hélène , Capri Yline , Faure Jean‐Michel , Grosjean Frédéric , Sauvestre Fanny , Attié‐Bitach Tania , Pelluard Fanny , Geneviève David 
Published: March 2022

AbstractObjectivesThe antenatal phenotypic spectrum of Noonan Syndrome (NS) requires better characterization.MethodsThis multicenter retrospective observational included 16 fetuses with molecularly confirmed NS admitted for fetopathological examination between 2009 and 2016.ResultsAmong 12 pathogenic variants (PV) in PTPN11 (80%), 5 (42%) fell between position c.179 and c.182. Ultrasound showed increased nuchal translucency (n = 13/16, 93%), increased nuchal fold after 15 weeks of gestation (n = 12/16, 75%), pleural effusions (n = 11/16, 69%), polyhydramnios (n = 9/16, 56%), hydrops (n = 7/16, 44%), cardiovascular (n = 6/16, 38%) and cerebral (n = 4/16, 25%) anomalies. Fetopathological examination found dysmorphic features in all cases, cardiovascular anomalies (n = 12/15, 80%), pulmonary hypoplasia (n = 10/15, 67%), effusions (n = 7/15, 47%) and neuropathological anomalies (n = 5/15, 33%). Hydrops was significantly (p = 0.02) more frequent in the four fetuses with RIT1, NRAS and RAF1 PV versus the 12 fetuses with PTPN11 PV.ConclusionsIncreased nuchal translucency and nuchal fold is common in NS. Noonan Syndrome antenatal phenotype showed high in utero fetal death, hydrops, prenatal pleural effusion and pulmonary hypoplasia, although the inclusion of only deceased fetuses will have selected more severe phenotypes. Non‐specific cardiovascular and neurological abnormalities should be added to NS antenatal phenotype. Next generation sequencing will help detect more genotypes, clarifying the prenatal phenotype and identifying genotype‐phenotype correlations.
Time‐varying response of fine root growth to soil temperature and soil moisture in cypress and deciduous oak forests
Authors: Nakahata Ryo 
Published: March 2022

AbstractFine root phenology is controlled by complex mechanisms associated with aboveground phenological events and environmental conditions, and therefore, elucidating fine root responses to changing environments remains difficult without considering the dynamics within and among years. This study evaluated the response of fine root growth at variable time scales to the surrounding environments of soil temperature and moisture at ecosystem scales. Optical scanners were used to measure fine root production over 4 years in two forests dominated by either cypress or deciduous oak trees. Correlations between fine root production and soil temperature and moisture were analyzed using the state‐space model. Fine root phenology varied among years in the cypress stand and showed stable growth patterns in the oak stand as production peaked in spring every year. Soil temperature had a dominant influence on fine root production, while soil moisture enhanced fine root growth especially in the oak stand. Fine root responses to both soil temperature and moisture peaked during the early growing season, indicating its own temperature hysteresis that means different responses under same temperature within a year. The time‐varying response of fine root growth to external factors is a key perspective to explain fine root growth mechanisms, and whether evergreen or deciduous habits differentiates the fine root phenology due to a linkage between above‐ and belowground resource dynamics.
Predicted Melt Curve and Liquid Shear Viscosity of RDX up to 30 GPa
Authors: Kroonblawd Matthew P. , Springer H. Keo 
Published: March 2022

AbstractRecent grain‐scale simulations of HMX and TATB have shown that predictions for hot spot formation in high explosives are particularly sensitive to accurate determinations of the pressure‐dependent melt curve and the shear viscosity of the liquid phase. These physics terms are poorly constrained beyond ambient pressure for the explosive RDX. We adopt an all‐atom modeling approach using molecular dynamics (MD) simulations to predict the melt curve of RDX near to detonation conditions (30 GPa) and determine the shear viscosity of the liquid as a function of temperature and pressure above the melt curve. Phase‐coexistence simulations were used to determine the melt curve, which is predicted to vary by almost 1100 K as the pressure increases from 0 GPa to 30 GPa. Equilibrium MD simulations and the Green‐Kubo formalism were used to obtain the pressure‐temperature‐dependent shear viscosity. The shear viscosity of RDX is predicted to be of similar magnitude to the viscosity of TATB at low GPa‐range pressures, and to be roughly an order of magnitude lower than the viscosity of HMX. The temperature dependence of the shear viscosity is Arrhenius at a given pressure, and the exponential pre‐factor and activation term exhibit a strong, yet complicated, pressure dependence. An empirical pressure‐temperature dependent function for RDX shear viscosity is developed that simultaneously captures a wide range of MD predictions while taking an analytic form that extrapolates smoothly beyond the fitted regime. The relative strength of the pressure and temperature dependencies of these two physics terms is found to be of similar magnitude for RDX, HMX, and TATB, which motivates incorporating these results in future RDX grain‐scale modeling.
Clinical and pathological features associated with circulating tumor DNA content in real‐world patients with metastatic prostate cancer
Authors: Antonarakis Emmanuel S. , Tierno Marni , Fisher Virginia , Tukachinsky Hanna , Alexander Sonja , Hamdani Omar , Hiemenz Matthew C. , Huang Richard S.P. , Oxnard Geoffrey R. , Graf Ryon P. 
Published: March 2022

AbstractBackgroundLiquid biopsy is a powerful tool that can enable treatment decisions for metastatic prostate cancer patients with difficult‐to‐biopsy tumors. However, the detection of genomic alterations via liquid biopsy is limited by the fraction (tumor fraction [TF]) of circulating tumor DNA (ctDNA) within the total cell‐free DNA content. While prior work has preliminarily correlated TF with clinical features of prostate cancer, we sought to validate and provide additional resolution, such that a clinical practitioner might anticipate the probability of successful liquid biopsy profiling leveraging commonly assessed clinical and laboratory features.MethodsA total of 813 liquid biopsy specimens were assessable, with 545 associated with a PSA prostate specific antigen measurement, collected in standard‐of‐care settings across approximately 280 US academic or community‐based cancer clinics from September 2018 to July 2021. Deidentified data were captured into a real‐world clinico‐genomic database (CGDB). Comprehensive genomic profiling (CGP) was performed on extracted cell‐free DNA from liquid biopsy samples.ResultsIn multivariable models, higher PSA level, lower hemoglobin, lower albumin, higher alkaline phosphatase (all p < 0.001), and collection of liquid biopsy blood draw within 60 days of new treatment initiation (p = 0.002) were the most strongly associated features with higher TF. At PSA levels of <5 ng/ml, 43% of patients had a TF of <1% indicating an increased likelihood of unevaluable results. Conversely, at PSA levels of >5 ng/ml, 78% of patients had a TF of at least 1% and 46% had a TF of ≥10%, suggesting improved sensitivity for detection of targetable alterations.ConclusionsUniversal genomic profiling of prostate cancers will require complementary use of liquid biopsy and tumor tissue profiling for suitable patients. The likelihood of adequate ctDNA shedding into plasma is one consideration when deciding whether to pursue CGP via liquid biopsy versus tumor profiling. Our real‐world data suggest that PSA < 5 ng/ml is associated with lower ctDNA yield on liquid biopsy, potentially increasing the incidence of negative results or a need for confirmation with tissue testing.