bluuebunny/crossref_metadata_2025_split huggingface dataset:
UV Photochemical Oxidation and Extraction of Marine Dissolved Organic Carbon at UC Irvine: Status, Surprises, and Methodological Recommendations
Authors: Walker Brett D , Beaupré Steven R , Griffin Sheila , Druffel Ellen R M 
Published: April 2019

ABSTRACTThe first ultraviolet photochemical oxidation (UVox) extraction method for marine dissolved organic carbon (DOC) as CO2 gas was established by Armstrong and co-workers in 1966. Subsequent refinement of the UVox technique has co-evolved with the need for high-precision isotopic (Δ14C, δ13C) analysis and smaller sample size requirements for accelerator mass spectrometry radiocarbon (AMS 14C) measurements. The UVox line at UC Irvine was established in 2004 and the system reaction kinetics and efficiency for isolating seawater DOC rigorously tested for quantitative isolation of ∼1 mg C for AMS 14C measurements. Since then, improvements have been made to sampling, storage, and UVox methods to increase overall efficiency. We discuss our progress, and key UVox system parameters for optimizing precision, accuracy, and efficiency, including (1) ocean to reactor: filtration, storage and preparation of DOC samples, (2) cryogenic trap design, efficiency and quantification of CO2 break through, and (3) use of isotopic standards, blanks and small sample graphitization techniques for the correction of DOC concentrations and Fm values with propagated uncertainties. New DOC UVox systems are in use at many institutions. However, rigorous assessment of quantitative UVox DOC yields and blank contributions, DOC concentrations and carbon isotopic values need to be made. We highlight the need for a community-wide inter-comparison study.
Can smartphone vibration provide a valid alternative to tuning forks for use on the ENT ward round?
Authors: Hopkins M E , Owens D 
Published: April 2019

AbstractBackgroundAll patients undergoing tympanomastoid surgery should be assessed post-operatively for a ‘dead ear’; however, tuning forks are frequently inaccessible.ObjectiveTo demonstrate that smartphone-based vibration applications provide equivalent accuracy to tuning forks when performing Weber's test.MethodsData were collected on lay participants with no underlying hearing loss. Earplugs were used to simulate conductive hearing loss. Both the right and left ears were tested with the iBrateMe vibration application on an iPhone and using a 512 Hz tuning fork.ResultsOccluding the left ear, the tuning fork lateralised to the left in 18 out of 20 cases. In 20 out of 20 cases, sound lateralised to the left with the iPhone (chi-square test, p = 0.147). Occluding the right ear, the tuning fork lateralised to the right in 19 out of 20 cases. In 19 out of 20 cases, sound lateralised to the right with the iPhone (chi-square test, p &gt; 0.999).ConclusionSmartphone-based vibration applications represent a viable, more accessible alternative to tuning forks when assessing for conductive hearing loss. They can therefore be utilised on the ward round, in patients following tympanomastoid surgery, for example.
A Sliding Mode Force and Position Controller Synthesis for Series Elastic Actuators
Authors: Sariyildiz Emre , Mutlu Rahim , Yu Haoyong 
Published: April 2019

SummaryThis paper deals with the robust force and position control problems of series elastic actuators (SEAs). It is shown that an SEA’s force control problem can be described by a second-order dynamic model which suffers from only matched disturbances. However, the position control dynamics of an SEA is of fourth order and includes matched and mismatched disturbances. In other words, an SEA’s position control is more complicated than its force control, particularly when disturbances are considered. A novel robust motion controller is proposed for SEAs by using disturbance observer (DOb) and sliding mode control. When the proposed robust motion controller is implemented, an SEA can precisely track desired trajectories and safely contact with an unknown and dynamic environment. The proposed motion controller does not require precise dynamic models of environments and SEAs. Therefore, it can be applied to many different advanced robotic systems such as compliant humanoids, industrial robots and exoskeletons. The validity of the proposed motion controller is experimentally verified.
The interplay of polygenic plasticity and adrenocortical activity as sources of variability in pathways among family adversity, youth emotional reactivity, and psychological problems
Authors: Davies Patrick T. , Cicchetti Dante , Thompson Morgan J. , Bascoe Sonnette M. , Cummings E. Mark 
Published: April 2019

AbstractThis study examined the interplay between a polygenic composite and cortisol activity as moderators of the mediational pathway among family adversity, youth negative emotional reactivity to family conflict, and their psychological problems. The longitudinal design contained three annual measurement occasions with 279 adolescents (Mean age = 13.0 years) and their parents. Latent difference score analyses indicated that observational ratings of adversity in interparental and parent–child interactions at Wave 1 predicted increases in a multimethod, multi-informant assessment of youth negative emotional reactivity to family conflict from Waves 1 to 2. Changes in youth negative emotional reactivity, in turn, predicted increases in a multi-informant (i.e., parents, adolescent, and teacher) assessment of psychological problems from Waves 1 to 3. Consistent with differential susceptibility theory, the association between family adversity and negative emotional reactivity was stronger for adolescents who carried more sensitivity alleles in a polygenic composite consisting of 5-HTTLPR, DRD4 VNTR, and BDNF polymorphisms. Analyses of adolescent cortisol in the period surrounding a family disagreement task at Wave 1 revealed that overall cortisol output, rather than cortisol reactivity, served as an endophenotype of the polygenic composite. Overall cortisol output was specifically associated with polygenic plasticity and moderated the association between family adversity and youth negative emotional reactivity in the same for better or for worse manner as the genetic composite. Finally, moderator-mediated-moderation analyses indicated that the moderating role of the polygenic plasticity composite was mediated by the moderating role of adolescent cortisol output in the association between family adversity and their emotional reactivity.
Judging clinical competence using structured observation tools: A cautionary tale
Authors: Roth Anthony D. , Myles-Hooton Pamela , Branson Amanda 
Published: April 2019

AbstractBackground:One method for appraising the competence with which psychological therapy is delivered is to use a structured assessment tool that rates audio or video recordings of therapist performance against a standard set of criteria.Aims:The present study examines the inter-rater reliability of a well-established instrument (the Cognitive Therapy Scale – Revised) and a newly developed scale for assessing competence in CBT.Method:Six experienced raters working independently and blind to each other’s ratings rated 25 video recordings of therapy being undertaken by CBT therapists in training.Results:Inter-rater reliability was found to be low on both instruments.Conclusions:It is argued that the results represent a realistic appraisal of the accuracy of rating scales, and that the figures often cited for inter-rater reliability are unlikely to be generalizable outside the specific context in which they were achieved. The findings raise concerns about the use of these scales for making summative judgements of clinical competence in both educational and research contexts.
Associations among serum folate, waist-to-hip ratio, lipid profile, and eating habits with homocysteine in an elderly Thai population
Authors: Paratthakonkun Chirawat , Kaewprasert Sarunya , Arthan Dumrongkiet , Soonthornworasiri Ngamphol , Tungtrongchitr Rungsunn , Prangthip Pattaneeya , Wongsutthilerd Alisara , Pooudoung Somchai , Chantaranipapong Yaovamarn , Nakosiri Wanyarat , Aroonnual Amornrat , Chupeerach Chaowanee , Chanchai Siriporn , Nana Arth 
Published: April 2019

Abstract. A lower serum folate level is common in older populations and is associated with increased serum homocysteine concentration. In turn, an elevated homocysteine level is associated with increased risk of cardiovascular disease and age-related diseases. Contemporary studies of folate and dietary risk factors for cardiovascular disease among the elderly population in Thailand are lacking. This cross-sectional study aimed to investigate the relationships among serum folate, homocysteine level, and nutritional status in the elderly Thai. Three hundred individuals, aged 60 years and over, underwent anthropometric and physiological measurements, and biochemical parameters, and eating habits were also determined. Folate insufficiency was found in approximately 35% of subjects. Folate and homocysteine showed a significant inverse correlation. Serum homocysteine levels rose with increasing age. Folate deficiency and high waist-to-hip ratio were associated with 7-fold and 2.5-fold increased risk for hyperhomocysteinemia, respectively. There were positive correlations between homocysteine and waist-to-hip ratio and systolic blood pressure, but a negative correlation between homocysteine and high-density lipoprotein ( r = −0.239, p < 0.01), which are markers for cardiovascular disease risk. Folate negatively correlated with body mass index, waist-to-hip ratio, and diastolic blood pressure, but positively with high-density lipoprotein ( r = 0.162, p < 0.01). Investigation of eating habits showed that low consumption of green leafy vegetables and high consumption of sugary foods were associated with high homocysteine levels. Given associations between nutritional status and cardiovascular disease confirmed in this study, nutrition education, holistic health promotion, and appropriate behavioral modification of eating habits represent important measures for preventing premature cardiovascular disease in the elderly Thai population.
China's Urban Methane Emissions From Municipal Wastewater Treatment Plant
Authors: Zhao X. , Jin X. K. , Guo W. , Zhang C. , Shan Y. L. , Du M. X. , Tillotson M. R. , Yang H. , Liao X. W. , Li Y. P. 
Published: April 2019

AbstractThe increased number and capacity of municipal wastewater treatment plants (WWTPs) in China has driven the emission of methane (CH4). Few studies have focused on quantification of CH4 emissions from municipal WWTPs of different cities and analysis of socioeconomic factors influencing the quantity of emissions. Here we estimated CH4 emissions from WWTPs in China for 229 prefectural‐level cities, based on data from 2,019 working municipal WWTPs. The results show the total CH4 emissions to be 1,169.8 thousand tons (29.2 MtCO2e) in 2014, which is over three times that of the municipal WWTPs in the United States in 2016. Large cities along the east coast regions had larger CH4 emissions in absolute and per capita terms. Correlation analysis shows that cities with higher gross domestic product, household food consumption expenditure, or household consumption expenditure produced more degradable organics in wastewater, thus more CH4 emissions. Measures to control the sources of degradable organics and regulate WWTP processes with less emission factor are key to mitigate CH4 emissions. In addition to aerobic or anaerobic wastewater treatment systems, factors such as wastewater temperature, length of sewer, and the addition of nitrate that influencing emission factor are suggested to be involved in CH4 emission modeling.
The UT Variation of the Polar Ionosphere Based on COSMIC Observations
Authors: Wu Ye‐Wen , Liu Rui‐Yuan , Zhang Bei‐Chen , Wang Wen‐Bin , Zhang Shun‐Rong , Zhang Qing‐He , Hu Hong‐Qiao , Lu Jian‐Yong 
Published: April 2019

AbstractMean polar electron content (mPEC) is used to analyze the polar ionosphere in both the Antarctic and Arctic. The mPEC is calculated over the polar region covering geographic latitudes higher than 60° from the global distributed vertical total electron contents based on electron density profiles observed by Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Using this parameter, the universal time (UT) variation of the polar ionosphere is quantitatively characterized. This UT variation exists an opposite phase (i.e., a 12‐hr phase difference) between them. The mPEC standard deviation (SD) in the Antarctic is larger in summer and autumn (being 1.37 and 0.78 TECu, respectively) and smaller in winter (0.29 TECu) and spring (0.61 TECu). The SD in the Arctic, however, is the largest in winter (0.14 TECu). In other seasons, the SD is less than 0.1 TECu. (being 0.07 TECu in spring, 0.05 TECu in summer, and 0.08 TECu in autumn, respectively). We use SD over the mean value to describe relative intensity of mPEC variations. This relative intensity is larger in winter for both Antarctic and Arctic regions. The UT variation in intensity is much stronger in the Antarctic than in the Arctic. These characteristics are attributed to the fact that the separation of the geomagnetic pole and geographic pole is dihedral and the angle is larger in the Antarctic. The larger angle causes more electrons transported into the polar region when the geomagnetic pole is on the dayside and fewer electrons transported into the polar region when the geomagnetic pole is on the nightside.
Multidecadal Wind Variability Drives Temperature Shifts on the Agulhas Bank
Authors: Malan Neil , Durgadoo Jonathan V. , Biastoch Arne , Reason Chris , Hermes Juliet 
Published: April 2019

AbstractThe Agulhas Bank is an important area for the spawning of small pelagic fish and other species. Here, within a NEMO ocean model, we investigate changes in temperature over the Bank on multidecadal time scales. In agreement with previous observational studies, a shift to colder temperatures is found in 1997. The model also simulates an earlier shift from colder to warmer temperatures in 1966. These shifts are coastally confined and shown, using a climatologically forced model run as a control, to be driven by a north‐south migration in the large‐scale wind belts, rather than by changes in downward heat fluxes or changes in the Agulhas Current itself. The zonal wind changes on the Agulhas Bank show a significant relationship with the Southern Annular Mode, showing some promise for future predictability of cold and warm regimes on the Agulhas Bank. Thus, while the Agulhas Current has been shown in previous work to have a large impact on intra‐annual and interannual temperature variability, this work shows that multidecadal variability in temperature on the shelf is likely to be wind forced.
Submesoscale Surface Tidal, Vortical, and Residual Circulations in a Semienclosed Bay
Authors: Won Sang In , Kim Sung Yong , Kim Kyeong Ok 
Published: April 2019

AbstractWe scrutinize three different components of submesoscale surface tidal, vortical, and residual circulations in a semienclosed bay using (1) observations of high‐frequency radar‐derived surface current maps and (2) numerical model simulations run under realistic vertical stratification and boundary conditions at O(1)‐km spatial and 1‐hourly temporal resolutions over a 2‐year period (2013‐2014). The tidal circulation is characterized by (1) the tidal ellipses and spectral contents having more baroclinic motions at the M2 and S2 frequencies and more barotropic motions at the K1 frequency and (2) the temporal and spatial variability in the tidal fronts appearing as tidal ellipses with clustered shapes and opposite rotational directions. The regional vortical circulation is presented with the submesoscale eddies at diameters ranging from 3 to 12 km and normalized vorticity magnitudes of 0.2 to 2 for both clockwise and counterclockwise rotations. Based on the spatial statistics of the identified submesoscale eddies and eddy kinetic energy budget analysis, the submesoscale eddies are primarily generated by the detachment of shoreline‐following tidal currents at the coastal boundaries, persist for less than 1.5 days, and are dissipated dominantly via vertical buoyancy fluxes associated with bottom bathymetric interactions of the tidal currents. The residual circulation is clearly shown with the nontidal geostrophic currents associated with the pressure gradients generated by wind‐driven Ekman transports against the coast and the ageostrophic low‐frequency currents.
Detection of Mixed‐Phase Convective Clouds by a Binary Phase Information From the Passive Geostationary Instrument SEVIRI
Authors: Coopman Q. , Hoose C. , Stengel M. 
Published: April 2019

AbstractBetween −37 and 0 °C, clouds are liquid, ice, or mixed phase. Nearly all retrieval algorithms for passive instruments provide binary phase information—ice or liquid—making it difficult to retrieve mixed‐phase cloud properties. Based on measurements from the geostationary space‐based instrument Spinning Enhanced Visible and InfraRed Imager (SEVIRI), we show that the retrieved ice crystal effective radius is smaller than the liquid droplet effective radius for 48% of 230 analyzed cloud thermodynamic phase transitions—phase transition from liquid to ice of rising convective clouds—while ice crystals are expected to be larger than cloud droplets. We simulate mixed‐phase cloud radiances with the numerical model Santa Barbara DISORT Atmospheric Radiative Transfer for which we compare simulated effective radius retrievals with observations. The phase retrieval algorithm from SEVIRI does not represent well mixed‐phase clouds, and categorizing clouds by only ice and liquid is not enough to accurately represent mixed‐phase cloud optical properties. We conclude that the mixed‐phase nature of clouds explains that retrieved cloud droplet radii are larger than ice crystal radii directly before and after the phase transition. However, from a cloud tracking algorithm perspective, the variation of the effective radius enables the detection of mixed‐phase convective clouds from binary phase information.
Distinct Source Water Chemistry Shapes Contrasting Concentration‐Discharge Patterns
Authors: Zhi Wei , Li Li , Dong Wenming , Brown Wendy , Kaye Jason , Steefel Carl , Williams Kenneth H. 
Published: April 2019

AbstractUnderstanding concentration‐discharge (C‐Q) relationships are essential for predicting chemical weathering and biogeochemical cycling under changing climate and anthropogenic conditions. Contrasting C‐Q relationships have been observed widely, yet a mechanistic framework that can interpret diverse patterns remains elusive. This work hypothesizes that seemingly disparate C‐Q patterns are driven by switching dominance of end‐member source waters and their chemical contrasts arising from subsurface biogeochemical heterogeneity. We use data from Coal Creek, a high‐elevation mountainous catchment in Colorado, and a recently developed watershed reactive transport model (BioRT‐Flux‐PIHM). Sensitivity analysis and Monte‐Carlo simulations (500 cases) show that reaction kinetics and thermodynamics and distribution of source materials across depths govern the chemistry gradients of shallow soil water and deeper groundwater entering the stream. The alternating dominance of organic‐poor yet geo‐solute‐rich groundwater under dry conditions and organic‐rich yet geo‐solute‐poor soil water during spring melt leads to the flushing pattern of dissolved organic carbon and the dilution pattern of geogenic solutes (e.g., Na, Ca, and Mg). In addition, the extent of concentration contrasts regulates the power law slopes (b) of C‐Q patterns via a general equation. At low ratios of soil water versus groundwater concentrations (Cratio = Csw/Cgw < 0.6), dilution occurs; at high ratios (Cratio > 1.8), flushing arises; chemostasis occurs in between. This equation quantitatively interpretsbvalues of 11 solutes (dissolved organic carbon, dissolved P, NO3−, K, Si, Ca, Mg, Na, Al, Mn, and Fe) from three catchments (Coal Creek, Shale Hills, and Plynlimon) of differing climate, geologic, and land cover conditions. This indicates potentially broad regulation of subsurface biogeochemical heterogeneity in determining C‐Q patterns and wide applications of this equation in quantifyingbvalues, which can have broad implications for predicting chemical weathering and biogeochemical transformation at the watershed scale.
Seismic Evidence for Lithospheric Thinning and Heat in the northern Canadian Cordillera
Authors: Audet Pascal , Currie Claire A. , Schaeffer Andrew J. , Hill Alexander M. 
Published: April 2019

AbstractGeophysical and geological data indicate that the lithosphere in the northern Canadian Cordillera (NCC) is thin and hot. However, lack of direct constraints on mantle structure is fueling debates on the origin and nature of this lithosphere. Here we image the crust and uppermost mantle beneath the NCC and resolve the Moho at ~35‐km depth, the lithosphere‐asthenosphere boundary ~15 km deeper, and a westward dipping structure in the mantle below the eastern NCC. We examine end‐member tectonic models where the thin lithosphere is either long‐lived or has been rejuvenated by gravitational removal. In the long‐lived model, steady state thermal calculations indicate a Moho at ~1,000 °C; alternatively, time‐dependent calculations suggest that a removal event 5–25 Myr ago reproduces the seismic constraints. Combined with geologic evidence, these results suggest that the mantle lithosphere beneath the NCC is either exotic or the result of progressive thickening and cooling since the Miocene.
Quasi Thermal Noise Spectroscopy for Van Allen Probes
Authors: Yoon Peter H. , Hwang Junga , Kim Hyangpyo , Seough Jungjoon 
Published: April 2019

AbstractQuasi thermal fluctuations in the Langmuir/upper‐hybrid frequency range are pervasively observed in space plasmas including the radiation belt and the ring current region of inner magnetosphere as well as the solar wind. The quasi thermal noise spectroscopy may be employed in order to determine the electron density and temperature as well as to diagnose the properties of energetic electrons when direct measurements are not available. However, when employing the technique, one must carefully take the spacecraft orientation into account. The present paper takes the upper‐hybrid and multiple harmonic—or (n + 1/2)fce—emissions measured by the Van Allen Probes as an example in order to illustrate how the spacecraft antenna geometrical factor can be incorporated into the theoretical interpretation. This method can in principle be applied to other spacecraft, including the Parker Solar Probe.