Current Profile Research Articles

In-situ profiling of glycosylation on single cells with surface plasmon resonance imaging

Cellular glycosylation is crucial for cell recognition, signal transduction, and the development of various diseases, especially in tumor initiation, progression, and metastasis. Current glycosylation profiling methods normally involve laborious sample processing and labeling and lack in-situ quantitative analysis. Here, we present a direct optical method to investigate and quantify the glycan expression on single cells based on lectin-glycan kinetic quantification with plasmonic imaging. Three unlabeled lectins (WGA, SBA, ConA) are employed as probes to bind with specific glycans, and binding kinetics are assessed to determine glycosylation profiles. The result reveals cell-to-cell heterogeneity in glycosylation patterns. To demonstrate the capability of our method, the glycosylation profiling of four distinct cell lines is explored, showing obvious alterations in glycan expression related to tumor initiation, progression, and metastasis. This approach enables direct quantification of glycosylation and binding kinetics, providing insights into tumor cell glycosylation mechanisms and potential applications in disease diagnosis and treatment.

What influences the distribution of microplastics in the marine environment? An interdisciplinary study reveals key factors driving microplastic in the North Sea.

Microplastics (MP) are known to be ubiquitous. The pathways and fate of these contaminants in the marine environment are receiving increasing attention, but still knowledge gaps exist. In particular, the link between mass-based MP quantification and oceanographic parameters is often lacking. In this study, we aim to interconnect different parameters for the first time through in-situ measurements with an autonomous surface vehicle in the German Bight. It simultaneously sampled air, sea surface microlayer, and underlying water for analysis of MP and additionally, extracellular polymeric substances (only in water). These compounds, secreted by microorganisms, can interact with particulate matter, influencing their transport dynamics and aggregation behavior in the environment. During the entire sampling, a weather station and conductivity, temperature, and depth sensors were installed on the vehicle. Depth profiles were taken with an accompanying research vessel to learn more about the stratification and horizontal processes of MP in the marine environment. Additionally, an acoustic Doppler current profiler recorded water current velocities and flow direction. A relationship was found between wind direction and the presence of MP in the atmosphere. Furthermore, wind speeds may seem to increase heterogeneity in both the composition and concentration of MP in the water. A tentative correlation between extracellular polymeric substances and MP was documented. Investigating horizontal and vertical velocities of currents within the surface and the water column helped to explain the distribution of MP. Up- and downwelling processes corresponded to the accumulation of MP along density fronts and across depth profiles.

Streamflow and sediment simulation in the Song River basin using the SWAT model

This study assesses the performance of the Soil and Water Assessment Tool (SWAT) in simulating streamflow and sediment for the Song River watershed, with a focus on calibration, validation, and sensitivity analysis. Thirteen parameters were selected for calibration, with eight identified as highly sensitive, reflecting key hydrological processes of the area. The model was calibrated for the period 1974–1995 and validated from 1996 to 2004, with additional testing using field data collected in 2022–2023 through Acoustic Doppler Current Profiler (ADCP) measurements. Key model adjustments, such as the baseflow recession constant (ALPHA_BF) and channel roughness coefficient (CH_N2), were set to 0.05 and 0.04, respectively, to capture the area’s groundwater dynamics and channel characteristics. The calibration results indicated a strong fit, with R2 values of 0.77, NSE of 0.70, and PBIAS of 17.06, demonstrating good agreement between observed and simulated streamflow. Validation showed slightly lower but acceptable performance, with R2 of 0.75 and NSE of 0.68. Further ADCP validation from field data showed R2 values of 0.79 and 0.78 for two monitoring sites, confirming the model’s reliability. Sediment yield simulations at site-2 yielded R2 values of 0.70 and 0.59 for calibration and validation, with NSE values of 0.53 and 0.52, indicating the model’s capability to simulate both streamflow and sediment accurately. These results demonstrate SWAT’s practical utility for water resource management in similar data-limited regions.

Optimizing stability and characteristics of a vibrating rigid body pendulum with energy harvesting device

The focus of this paper is on reducing vibrations and capturing energy from a three degrees-of-freedom (3DOF) dynamical system. The system consists of a damped spring-pendulum with an elliptical pivot path at a constant angular velocity and a connected rigid body experiencing external harmonic forces and moments. An independent electromagnetic energy harvesting system has been integrated into the structure, utilizing the motion of a magnet within a coil. The optimization efforts target both energy harvesting (EH) and vibration reduction capabilities. The second kind of Lagrange’s equations are used to formulate the governing kinematic equations, which are then solved asymptotically using the multiple-scales technique (MST), producing novel and precise results up to the third approximation. Various resonance cases are identified, with three examined concurrently. The time evolution of the solutions, as well as the modified phases and amplitudes, are analyzed through graphical representations, taking into account the influential parameters of the system. Graphical plots of phase portraits successfully depicted the system’s stable dynamics. The power output and current time profiles of the electromagnetic device are presented to demonstrate the impact of various parameters on system behavior. Analysis of stability and instability areas reveals that the system exhibits stable performance across a wide range of parameters. This model is gaining significance in contemporary applications, especially in control sensors used across various sectors such as industry, construction, automotive, transportation, and infrastructure.

TCAD-Based Analysis on the Impact of AlN Interlayer in Normally-off AlGaN/GaN MISHEMTs with Buried p-Region

With the growing demand for more efficient power conversion and silicon reaching its theoretical limit, wide bandgap semiconductor devices are emerging as a potential solution. For instance, Gallium Nitride (GaN)-based high-electron-mobility transistors (HEMTs) are getting more attention, and several structures for the normally off operation have been proposed. Adding an AlN interlayer in conventional AlGaN/GaN normally on HEMT structures is known to enhance the current density. In this work, the effect of an AlN interlayer in the normally off AlGaN/GaN MISHEMT with a buried p-region was investigated using a TCAD simulation from Silvaco. The added AlN interlayer increases the two-dimensional electron gas density, requiring a higher p-doping concentration to achieve the same threshold voltage. The simulation results show that the overall effect is a reduction in the device’s current density and peak transconductance by 21.83% and 44.4%, respectively. Further analysis of the current profile shows that because of the buried p-region and at high gate voltages, the current flows near the AlGaN/GaN interface and along the insulator/AlGaN interface. Adding an AlN interface blocks the migration of channel electrons to the insulator/AlGaN interface, resulting in a lower current density.

Intensification of sediment flux by wind-induced residual currents in a heavily contaminated, micro-tidal bay.

Wind-induced currents are the major forces responsible for sediment resuspension and transport in micro-tidal bays. To reveal the impact of wind-induced residual currents on the sediment flux, in-situ measurements using acoustic Doppler current profilers (ADCPs) were conducted at two mooring stations in a heavily contaminated, micro-tidal Onsan Bay. During the mooring period, the suspended sediments at both stations were transported seaward (landward) at the surface (bottom) layer mainly through the residual currents (mean-flow flux Fmean: > 70% of the total flux). Under northerly winds, the landward bottom residual currents at both stations strengthened, resulting in the "intensification" of landward Fmean. This suggests that the northerly winds might be a primary factor intensifying the landward sediment fluxes, potentially resulting in the increased sediment deposition into the bay. The findings provide insights into managing sedimentation in contaminated coastal bays and highlight the importance of wind effects on sediment transport in micro-tidal bays.

Overcoming Shifting Baselines: Paleo-Behaviour Reveals Industrial Revolution as Tipping Point.

Human activities have significantly altered coastal ecosystems worldwide. The phenomenon of shifting baselines syndrome (SBS) complicates our understanding of these changes, masking the true scale of human impacts. This study investigates the long-term ecological effects of anthropogenic activities on New Zealand's coastal ecosystems over 800 years using fish otolith microchemical profiling and dynamic time warping across an entire stock unit. Results reveal a shift in snapper (Chrysophrys auratus; Sparidae) habitat-use behaviour, transitioning from low-salinity estuarine environments to higher-salinity habitats, correlating with ongoing land-use changes. This shift coincided with New Zealand's localised Industrial Revolution, which served as a tipping point for widespread ecosystem transformation. By comparing current coastal fish movement profiles with historical baselines, we provide evidence to address SBS and guide conservation strategies. Re-establishing pre-industrial habitat-use behaviours in snapper will indicate successful habitat restoration, promoting overall ecosystem connectivity and resilience. Our findings enable more effective habitat restoration measures and sustainable management practices, informing policies for maintaining coastal biodiversity and ecosystem function.

Experimental investigation on validation of the mini wave gauge for ocean wave measurements in comparison to an acoustic doppler current profiler and HOBO

Experimental investigation on validation of the mini wave gauge for ocean wave measurements in comparison to an acoustic doppler current profiler and HOBO

Physics‐Informed Estimation of Tidal and Subtidal Flow Fields From ADCP Repeat Transect Data

AbstractAcoustic Doppler current profilers (ADCPs) are a global standard in observing flow fields in rivers, estuaries and the coastal ocean. To date, it remains a labor intensive challenge to isolate mean flow fields governed by river discharge, tides and atmospheric forcing on the one hand, from small‐scale turbulence, positioning imprecision, Doppler noise and erroneous backscatter, on the other hand. Here, we introduce a generic, new method of combining raw shipborne ADCP transect data with continuity and smoothness constraints to obtain better estimates of turbulence‐averaged three‐dimensional flow velocities in any type of open water body. The physical constraints are enforced with variable relative importance via generalized Tikhonov regularization. We demonstrate that in complex estuarine flow, this procedure allows for more reliable estimates of tidal amplitudes, phases and their gradients than what is possible with a purely data‐based approach, by testing the method's generalization capabilities and robustness to turbulence and measurement noise on a data set retrieved at a tidal channel junction. The increased adherence to mass conservation and robustness to noise of various kinds allows for more reliable and verifiable estimates of Reynolds‐averaged flow components, and subsequently, of terms in the Navier‐Stokes equations.

Mapping River Flow from Thermal Images in Approximately Real Time: Proof of Concept on the Sacramento River, California, USA

Image velocimetry has become an effective method of mapping flow conditions in rivers, but this analysis is typically performed in a post-processing mode after data collection is complete. In this study, we evaluated the potential to infer flow velocities in approximately real time as thermal images are being acquired from an uncrewed aircraft system (UAS). The sensitivity of thermal image velocimetry to environmental conditions was quantified by conducting 20 flights over four days and assessing the accuracy of image-derived velocity estimates via comparison to direct field measurements made with an acoustic Doppler current profiler (ADCP). This analysis indicated that velocity mapping was most reliable when the air was cooler than the water. We also introduced a workflow for River Velocity Measurement in Approximately Real Time (RiVMART) that involved transferring brief image sequences from the UAS to a ground station as distinct data packets. The resulting velocity fields were as accurate as those generated via post-processing. A new particle image velocimetry (PIV) algorithm based on staggered image sequences increased the number of image pairs available for a given image sequence duration and slightly improved accuracy relative to a standard PIV implementation. Direct, automated geo-referencing of image-derived velocity vectors based on information on the position and orientation of the UAS acquired during flight led to poor alignment with vectors that were geo-referenced manually by selecting ground control points from an orthophoto. This initial proof-of-concept investigation suggests that our workflow could enable highly efficient characterization of flow fields in rivers and might help support applications that require rapid response to changing conditions.

Active and passive organic carbon fluxes during a bloom in the Southern Ocean (South Georgia)

The Controls Over Mesopelagic Interior Carbon Storage (COMICS) cruise DY086 took place aboard the RRS Discovery in the South Atlantic during November and December, 2017. Physical, chemical, biogeochemical and biological data were collected during three visits to ocean observatory station P3, off the coast of South Georgia, during an austral spring bloom. A diverse range of equipment including CTD-rosette, Acoustic Doppler Current Profiler (ADCP), net deployments, marine snow catchers (MSCs), Stand Alone Pump System (SAPS) and PELAGRA Sediment Traps were used to produce a comprehensive, high-quality dataset. The data can provide excellent insight into regional biological carbon pump (BCP) processes; it is recommended for use by observational scientists and modellers to enhance understanding of ecosystem interactions relating to mesopelagic carbon storage.

Contrasting two major Arctic coastal polynyas: the role of sea ice in driving diel vertical migrations of zooplankton in the Laptev and Beaufort seas

Abstract. The diel vertical migration (DVM) of zooplankton is one of the largest species migrations to occur globally and is a key driver of regional ecosystems and the marine carbon pump. Previously thought to be hampered by the extreme light regime prevailing in the Arctic Ocean, observations have revealed that DVM does occur in ice-covered Arctic waters and suggest the decline in Arctic sea ice may thereby impact DVM and its role in the Arctic ecosystem. However, coastal polynyas present a unique environment where open water or thin, nearly translucent, ice prevail when offshore winds advect the ice pack away from the coast, allowing light into the surface waters and potentially disrupting DVM. Here, four yearlong time series of acoustic backscatter collected by moored acoustic Doppler current profilers at two opposite sides of the circumpolar polynya system at the Laptev Sea shelf (2007–2008) and the Beaufort Sea shelf (2005–2006) were used to examine the annual cycle of acoustic scattering and therefore the annual cycle of DVM in these areas. The acoustic time series were used along with atmospheric and oceanic reanalysis and satellite data to interpret the results. Our observations show that DVM started to occur once the ice-free surface or under-ice layer irradiance exceeds a certain threshold (from ∼0.3 to 3.3 lx), which is about 2 to 10 times lower in the Beaufort Sea compared to the Laptev Sea. In the Laptev Sea, based on our data and methodology, DVM could not be detected during polar night. In contrast, civil twilight in the Beaufort Sea is sufficient to trigger DVM through polar night. This difference in DVM between the Laptev and Beaufort seas is not entirely assigned to the 3° difference in latitude between the mooring positions as it is also due to the different light threshold required to trigger DVM, different zooplankton communities' composition, and potentially different depths and predation pressures. We find examples in both the Laptev and Beaufort seas where the formation of polynyas and large leads caused DVM to abruptly cease or be disrupted, which we attribute to predator avoidance by the zooplankton in response to higher polar cod (Boreogadus saida) abundance near the open water. Finally, light attenuation by sea ice in the Beaufort Sea caused DVM to extend onto the polar day until the summer solstice. Overall, our results highlight the role of sea ice in disrupting synchronized DVM, the spatial variability in the relationship between sea ice and DVM, and the potential ecological impact of significant trends toward a more extensive circumpolar Arctic coastal polynya as part of changing ice conditions in the Arctic Ocean.

MASCS 1.0: synchronous atmospheric and oceanic data from a cross-shaped moored array in the northern South China Sea during 2014–2015

Abstract. This work presents a cross-shaped moored array dataset (MASCS 1.0) comprising five buoys and four moorings with synchronous atmospheric and oceanic data in the northern South China Sea during 2014–2015. The atmospheric data are observed by two meteorological instruments at the buoys. The oceanic data consist of sea surface waves measured using a wave recorder, temperature, and salinity from the surface to a depth of 400 m and at 10 and 50 m above the ocean bottom using conductivity, temperature, and depth recorders. They also include currents from the surface to a depth of 850 m measured using acoustic Doppler current profilers and measured at 10, 50, and 100 m above the floor using current meters. Additional measurements were taken for sea surface radiation, air visibility, chlorophyll, turbidity, and chromophoric dissolved organic matter at buoy 3 located at the center of the moored array. The data reveal air–sea interactions and oceanic processes in the upper and bottom ocean, especially the transition of the air–sea interface and ocean conditions from summer to winter monsoon and the effects of six tropical cyclones on the moored array. Multiscale processes were also recorded, such as air–sea fluxes, tides, internal waves, and low-frequency flows. The data are valuable and have many potential applications, including analyzing the phenomena and mechanisms of air–sea interactions and ocean dynamics and validating and improving numerical model simulations, data reanalysis, and assimilations. All the data described here are made publicly available at https://doi.org/10.5281/zenodo.14039870 (Zhang et al., 2024a).

Cancer Nursing Frameworks to Guide Clinical Capability, Education and Careers: A Scoping Review of the International Literature.

This review aimed to provide a current global profile of all existing cancer nursing competency, capability, education and career frameworks and map capabilities and competencies to the clinical, facilitation of education, management and research pillars of practice. Scoping review. Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Epistemonikos, Google Scholar, Medline, and PubMed. Gray literature searches and reference list searches were also performed. This review was guided by Arksey and O'Malley's method and followed PRISMA guidelines for reporting. Screening and data extraction was conducted independently by two or more authors. The quality of frameworks were assessed using The Joanna Briggs Institute (JBI) critical appraisal checklist for textual evidence: policy/consensus guidelines. Data were analyzed and narratively synthesized by experienced cancer nurse researchers. Thirty-four articles were included, comprising of 29 cancer nursing frameworks. Frameworks were categorized as competency frameworks, career and education frameworks, education/learning pathways, and career/professional development frameworks. Competencies and capabilities described in the frameworks were mapped to the four pillars of practice including clinical (n = 27), facilitation of learning (n = 20), leadership and management (n = 23), and research and scholarship (n = 24). Comprehensive cancer nursing frameworks are pivotal in enabling nurse leaders to grow and develop the cancer nursing workforce globally. They are also integral to support cancer nurses in providing high-quality, effective, and safe care for patients and their families across the cancer continuum. This is the first review to comprehensively capture and synthesize the capabilities, educational components, and career pathways outlined in existing cancer nursing frameworks worldwide and highlights where areas of improvement are needed to support professional growth, job satisfaction and retention of cancer nurses. This article is a review of frameworks and does not include patient or public contribution.

Darcy–Forchheimer gravity currents in porous media

We theoretically and experimentally study gravity currents of a Newtonian fluid advancing in a two-dimensional, infinite and saturated porous domain over a horizontal impermeable bed. The driving force is due to the density difference between the denser flowing fluid and the lighter, immobile ambient fluid. The current is taken to be in the Darcy–Forchheimer regime, where a term quadratic in the seepage velocity accounts for inertial contributions to the resistance. The volume of fluid of the current varies as a function of time as $\sim T^{\gamma }$ , where the exponent parameterizes the case of constant volume subject to dam break ( $\gamma =0$ ), of constant ( $\gamma =1$ ), waning ( $\gamma <1$ ) and waxing inflow rate ( $\gamma >1$ ). The nonlinear governing equations, developed within the lubrication theory, admit self-similar solutions for some combinations of the parameters involved and for two limiting conditions of low and high local Forchheimer number, a dimensionless quantity involving the local slope of the current profile. Another parameter $N$ expresses the relative importance of the nonlinear term in Darcy–Forchheimer's law; values of $N$ in practical applications may vary in a large interval around unity, e.g. $N\in [10^{-5},10^{2}]$ ; in our experiments, $N\in [2.8,64]$ . Sixteen experiments with three different grain sizes of the porous medium and different inflow rates corroborate the theory: the experimental nose speed and current profiles are in good agreement with the theory. Moreover, the asymptotic behaviour of the self-similar solutions is in excellent agreement with the numerical results of the direct integration of the full problem, confirming the validity of a relatively simple one-dimensional model.

Genetic algorithm‐based approach for torque control and increased efficiency across an optimised speed range in switched reluctance drives

AbstractThis paper presents a novel genetic algorithm (GA) design for current profiling in switched reluctance machines that eliminates torque ripple (TR) while inherently guaranteeing minimal RMS currents across the machines speed range. Minimising RMS current provides an increase to machine efficiency and the elimination of TR is required for potential SRM applications such as traction vehicles. This paper proposes a novel method for intentional greater‐than‐two‐phase overlap in the algorithm design. This allows any SRM configuration capable of three or more phase conduction to utilise its full speed range with zero torque ripple, in the case where it is limited using two‐phase torque sharing. An optimal set of current profiles is created using the algorithm across the full speed range of an exemplary 8/6 SRM and these are analysed. A current profiling‐based control scheme using these results is then proposed and simulated for the 8/6 SRM. This is then compared to classical and recently published SRM control methods to highlight the merits of the overall GA design and its resultant control scheme.

Climate change resilient strategies for greener Africa: The perspectives of energy efficiency and eco-complexities

The far-reaching effects of climate change on the environment are particularly pronounced in developing countries, with the African continent facing the highest risks. Ironically, there is a scarcity of empirical research addressing the perspectives of African nations regarding climate change mitigation strategies. In alignment with the "African We Want" agenda, this study investigates energy efficiency within the KAYA identity framework as a strategic pathway toward a greener Africa. The empirical findings, derived from feasible generalized least squares (FGLS) and panel-corrected standard errors (PCSE), indicate that Africa's current energy and carbon intensity profiles are detrimental to sustainable growth. The results reveal a heavy reliance on traditional energy sources rather than cleaner alternatives. The validation of the Environmental Kuznets Curve (EKC) hypothesis suggests that economic activities could contribute to cleaner environments in the long term. While eco-complexities and population growth are significant drivers of pollution, the role of ICT has shown substantial climate resilience effects. As a policy recommendation, the continent must reduce its dependence on traditional energy sources and shift towards more environmentally friendly modern energy options. Embracing modern manufacturing techniques and facilitating economic transformations will be crucial for achieving the continent's climate change resilience goals by 2060.

Analysis of biofluid metabolomic profiles to the discovery of biomarkers in age-related macular degeneration.

Age-related macular degeneration (AMD) is one of the leading causes of irreversible visual impairment and blindness in the elderly. As AMD is a multifactorial disease, it is critical to explore useful biomarkers and pathological pathways underlying it. The purpose of this study is to summarise current metabolic profiles and further identify potential metabolic biomarkers and therapeutic targets in AMD, which could facilitate clinical diagnosis and treatment. Relevant metabolomics studies published before 10 December 2021 were generally reviewed from online resources by two investigators. Studies with sufficient information and data were included in this systematic review and repeatedly identified metabolites were extracted. Pathway and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analyses were performed. The public Gene Expression Omnibus (GEO) database was used for coanalysis with differential metabolites to construct a pathway network via MetaboAnalyst V.5.0. 16 studies were included in our analysis. 24 metabolites were repeatedly detected and regarded as potential biomarkers for AMD. Pathway analysis implied a major role of phenylalanine, tyrosine and tryptophan pathways in AMD pathology. 11 KEGG pathways were enriched, meanwhile, 11 metabolic pathway clusters were identified by coanalysing the differential metabolites and gene profiles using the GEO database. In this study, we summarised 16 metabolomic studies on AMD, and 24 metabolites were identified as potential biofluid biomarkers. This provided novel insights into the pathogenic mechanisms underlying AMD. Further studies are warranted to validate and expand an effective pattern for AMD diagnosis and treatment.

A Kinematic Approach for Rip Current Identification from ADCP Observation Data at Haeundae Beach, Korea

In May 2023, direct observations of rip currents were conducted at Haeundae Beach, Korea, over a two-day period at six different stations using upward-facing Acoustic Doppler Current Profilers (ADCPs). The depth-averaged cross-shore velocity data were low-pass filtered with a 30-s cutoff period to eliminate wave-related motions. By applying 15-min boxcar averages, correlation analyses were performed to examine the relationship between three types of flow (cross-shore, onshore, and offshore) and three environmental factors (tide, wave, and wind). The analysis revealed that only one (R2-3) of the six stations had a high likelihood of rip current occurrence. Rip currents were defined as regions of offshore flow within the low-pass filtered time series of cross-shore velocities. For each identified rip current, three key kinematic features—maximum speed, duration, and distance—were estimated. Using specific thresholds for these features, hazardous rip currents were determined. Station R2-3 was the only station where hazardous rip currents were observed, which is consistent with the findings of the correlation analysis. Additionally, swells with a 15-s period were detected exclusively at R2-3 during the period of the hazardous rip currents, suggesting their significant role in the development of the observed rip currents. Furthermore, both Rip Index from the Rip Current Monitoring and Warning System and the CCTV Score from the Rip Current Checklist exceeded threshold values during this period, reinforcing the reliability of the method used. The potential influence of bound infragravity waves on the duration and variability of these rip currents was discussed. The rip currents observed at Haeundae Beach could be categorized as the "focused" type.

Influence of the Shape of the Pump Current Profile on Stabilization of the Dynamics of a Broad-Area Vertical-Cavity Surface-Emitting Laser

Influence of the Shape of the Pump Current Profile on Stabilization of the Dynamics of a Broad-Area Vertical-Cavity Surface-Emitting Laser