bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benthic carbon cycling in Young Sound, Northeast Greenland
Authors: Thamdrup Bo , Glud Ronnie N. , Hansen Jens W. 
Published: January 2024

We present a synthesis of studies on benthic carbon cycling and related biogeochemical aspects performed in High Arctic Young Sound. Benthic carbon oxidation rates measured as the exchange of oxygen and DIC across the sediment/water interface increased rapidly from c. 5 to 10 mmol m-2 d-1 following the summer thaw in response to the settling of planktonic debris. Within few weeks, the exchange rates at 36 m depth returned to c. 5 mmol m-2 d-1. This background level was maintained throughout the rest of the annual cycle and found repeatedly over several years. The background activity was also maintained for 400 days in sediment cores incubated without external carbon sources, demonstrating that benthic carbon cycling was fuelled mainly by a large pool of relatively inert organic matter with a half-life >>1 yr.
Carbon oxidation rates decreased exponentially with water depth, the difference between 20 m and 163 m being approximately a factor of 6, while oxygen penetration increased from 7 to 16 mm over this range. Except for the shallowest sites, sulfate reduction was the most important carbon oxidation process, contributing 40–50%, while denitrification accounted for less than 5%. The remaining mineralization was shared equally between microbial iron reduction and aerobic respiration. Integrated over the entire outer Young Sound area, 1.3 Gg organic C was oxidized and 0.57 Gg organic C was buried. Thus, c. 30% of the organic carbon flux to the seafloor was preserved in the sedimentary record. Half of the carbon oxidation occurred at water depths shallower than 30 m, while burial was focused at the depths of around 80–100 m dominating the basin hypsometry. Sediment incubation experiments showed Q10 values of 2–3 for carbon oxidation rates, which agrees well with data from temperate sediments. Thus, patterns of carbon mineralization are qualitatively similar in Arctic and temperate sediments, but the low water temperature during settlement of spring and summer blooms leads to a less pronounced benthic-pelagic coupling in Arctic than in temperate coastal waters.
Benthic primary production in Young Sound, Northeast Greenland
Authors: Krause-Jensen Dorthe , Kühl Michael , Christensen Peter B. , Borum Jens 
Published: January 2024

The extreme and variable light climate of polar marine environments imposes a substantial limitation on benthic primary production and demands efficient adaptive capacities of the primary producers. This chapter reviews the composition, abundance, primary production and adaptive strategies of benthic primary producers in Young Sound. Benthic primary producers occurred in the 0-50 m depth range and the relative importance of microalgae, crustose coralline macroalgae and foliose macroalgae varied systematically with depth. On a summer day with optimal light conditions benthic primary production showed a maximum of c.
70 mmol O2 m-2 d-1 in shallow water. Production rates declined gradually to c. 20 mmol O2 m-2 d-1at 10–20 m depth and to 2.5 mmol O2 m-2 d-1 at 30 m depth.
Foliose macroalgae contributed markedly to primary production in shallow water but became insignificant at water depths >15 m, while benthic diatoms contributed most to primary production at intermediate water depths (5-30 m). At water depths greater than 30 m only coralline algae occurred, but their production was low because of their low abundance, low Pmax and the low ambient irradiance at those depths. All algal groups were well adapted to the ambient irradiance and could, within minutes, acclimate their photosynthetic performance to changing light conditions. The benthic primary production in Young Sound markedly surpassed the pelagic primary production down to water depths of 20 m and the results thereby underline the potential importance of benthic primary production in shallow-water Arctic ecosystems.
An estimation of walrus (Odobenus rosmarus) predation on bivalves in the Young Sound area (NE Greenland)
Authors: Born Erik W. , Acquarone Mario 
Published: January 2024

The total consumption of bivalve prey by walruses (Odobenus rosmarus) in the important inshore summer feeding area Young Sound (about 74° N) in Northeast Greenland was estimated. To determine relative area use, the movement and activity of three adult male walruses carrying satellite transmitters were studied during the open-water season in 1999 and 2001. Because one of the animals was tracked during both years the study covered a total of four “walrus seasons”.
Overall, the animals spent c. 30% of their time in the water inshore in Young Sound between Sandøen and Zackenberg. The remaining time was spent along the coast north and south of Young Sound and offshore in the Greenland Sea. The total amount of bivalve food consumed in Young Sound by the walruses during a total of 1620 “walrus feeding days” was calculated from information on the total number of walruses using the area (n=60), occupancy in the study area, and estimates obtained from satellite telemetry on the number of daily feeding dives (118-181/24 h at sea). Depending on the applied estimator of number of feeding dives, the estimated consumption by walruses of shell-free (SF) bivalve wet weight (WW) during the open-water period ranged between 111 and 171 tons.
Based on estimates of mean total body mass (TBM: 1000 kg) of walruses using the area and daily per capita gross food intake (6% of TBM), the corresponding estimate of consumption by walruses is c. 97 tons SF WW. It is suggested that the two lowest estimates of total consumption are the most plausible.
The annual organic carbon budget of Young Sound, NE Greenland
Authors: Glud Ronnie N. , Rysgaard Søren 
Published: January 2024

On the basis of data presented in the previous chapters a carbon budget for the respective compartments of the outer region of Young Sound (76 km2) was established. The average and maximum water depth of the region was 76 m and 177 m, respectively. Primary production was mainly related to the activity of phytoplankton (65%), benthic macrophytes (21%) and benthic microphytes (13%), while the contribution sea-ice algae and corallines was negligible (<1%). The pelagic grazing community was completely dominated by copepods, which were capable of consuming 87% of the pelagic primary production.
The benthic carbon demand was almost balanced by the measured sedimentation of POC and the benthic primary production. The organic carbon collected in the sediment traps was estimated to consist of 40% terrestrial carbon, 20% fecal pellets, while the rest was poorly defined marine detritus. The benthic sink for settling organic material was dominated by microbial respiration (59%) and only to a minor extent related to macrofauna respiration (15%) and carbon preservation (26%).
The total primary production in the region (1119 t C yr-1) only sustained c. 40% the estimated organic carbon demand (2850 t C yr-1). Thus, the independently determined input of TOC (990 t C yr-1) imported to Region 1 from land via freshwater runoff and the TOC import of 1446 t C yr-1 from the Greenland Sea are required to balance the carbon sinks of the net heterotrophic region. A complete balance between the respective compartments cannot be expected, as the various components of the carbon budget are determined independently. The microbial and viral loops remain poorly constrained, as does the carbon demand of the top predators. Only the importance of walrus was quantitatively assessed.
Effects of climate variation on the breeding ecology of Arctic shorebirds
Authors: Meltofte Hans , Piersma Theunis , Boyd Hugh , McCaffery, Brian , Ganter Barbara , Golovnyuk Viktor V. , Graham Katherine , Gratto-Trevor Cheri L. , Morrison R.I.G. , Nol Erica , Rösner Hans-Ulrich , Schamel Douglas , Schekkerman Hans , Soloviev Mikhail Y. , Tomkovich Pavel S. , Tracy Diane M. , Tulp Ingrid , Wennerberg Liv 
Published: January 2024

About 50 species of shorebirds breed in the Arctic, where they constitute the most characteristic component of the tundra avifauna. Here, we review the impact of weather and climate on the breeding cycle of shorebirds based on extensive studies conducted across the Arctic. Conditions for breeding shorebirds are highly variable among species, sites and regions, both within and between continents.
Weather effects on breeding are most moderate in the Low Arctic of northern Europe and most extreme in the Siberian High Arctic. The decision of whether or not to breed upon arrival on the breeding grounds, the timing of egg-laying and the chick-growth period are most affected by annual variation in weather. In large parts of the Arctic, clutch initiation dates are highly correlated with snowmelt dates and in regions and years where extensive snowmelt occurs before or soon after the arrival of shorebirds, the decision to breed and clutch initiation dates appear to be a function of food availability for laying females. Once incubation is initiated, adult shorebirds appear fairly resilient to variations in temperature with nest abandonment primarily occurring in case of severe weather with new snow covering the ground. Feeding conditions for chicks, a factor highly influenced by weather, affects juvenile production in most regions.
Predation has a very strong impact on breeding productivity throughout the Arctic and subarctic, with lemming Dicrostonyx spp. and Lemmus spp. fluctuations strongly influencing predation rates, particularly in the Siberian Arctic.
The fate of Arctic shorebirds under projected future climate scenarios is uncertain, but High Arctic species and populations appear particularly at risk. Climatic amelioration may benefit Arctic shorebirds in the short term by increasing both survival and productivity, whereas in the long term habitat changes both on the breeding grounds and in the temperate and tropical non-breeding areas may put them under considerable pressure and may bring some of them near to extinction. Their relatively low genetic diversity, which is thought to be a consequence of survival through past climatically-driven population bottlenecks, may also put them more at risk to anthropogenic-induced climate variation than other avian taxa.
Short Interpregnancy Intervals Among Women Experiencing Homelessness in Colorado
Authors: Sakai-Bizmark Rie , Jackson Nicholas J. , Wu Frank , Marr Emily H. , Kumamaru Hiraku , Estevez Dennys , Gemmill Alison , Moreno Jessica C. , Henwood Benjamin F. 
Published: January 2024

ImportanceShort interpregnancy intervals (SIPIs) are associated with increased risk of adverse maternal and neonatal outcomes. Disparities exist across socioeconomic status, but there is little information on SIPIs among women experiencing homelessness.ObjectiveTo investigate (1) differences in rates and characteristics of SIPIs between women experiencing homelessness and domiciled women, (2) whether the association of homelessness with SIPIs differs across races and ethnicities, and (3) whether the association between SIPIs of less than 6 months (very short interpregnancy interval [VSIPIs]) and maternal and neonatal outcomes differs between participant groups.Design, Setting, and ParticipantsThis cohort study used a Colorado statewide database linking the Colorado All Payer Claims Database, Homeless Management Information System, death records, and infant birth records. Participants included all women who gave birth between January 1, 2016, and December 31, 2021. Data were analyzed from September 1, 2022, to May 10, 2023.ExposuresHomelessness and race and ethnicity.Main Outcomes and MeasuresThe primary outcome consisted of SIPI, a binary variable indicating whether the interval between delivery and conception of the subsequent pregnancy was shorter than 18 months. The association of VSIPI with maternal and neonatal outcomes was also tested.ResultsA total of 77 494 women (mean [SD] age, 30.7 [5.3] years) were included in the analyses, of whom 636 (0.8%) were women experiencing homelessness. The mean (SD) age was 29.5 (5.4) years for women experiencing homelessness and 30.7 (5.3) years for domiciled women. In terms of race and ethnicity, 39.3% were Hispanic, 7.3% were non-Hispanic Black, and 48.4% were non-Hispanic White. Associations between homelessness and higher odds of SIPI (adjusted odds ratio [AOR], 1.23 [95% CI, 1.04-1.46]) were found. Smaller associations between homelessness and SIPI were found among non-Hispanic Black (AOR, 0.59 [95% CI, 0.37-0.96]) and non-Hispanic White (AOR, 0.57 [95% CI, 0.39-0.84]) women compared with Hispanic women. A greater association of VSIPI with emergency department visits and low birth weight was found among women experiencing homelessness compared with domiciled women, although no significant differences were detected.Conclusions and RelevanceIn this cohort study of women who gave birth from 2016 to 2021, an association between homelessness and higher odds of SIPIs was found. These findings highlight the importance of conception management among women experiencing homelessness. Racial and ethnic disparities should be considered when designing interventions.
A comparative analysis of two century‐old historical map and satellite images for assessing land use transformation and preservation of the historical monuments of the Ahmad Shahi old city, Kandahar
Authors: Farooqi Javed Ahmad , Ono Hiroko 
Published: January 2024

AbstractThis study evaluates land use transformation in Kandahar's old city, also known as Ahmad Shahi city, the birthplace and first capital of modern Afghanistan. The city consists of four rectangular quarters and is surrounded by a high strong mud wall, entrance gates, and a moat. In the early 20th century, the city experienced significant and arbitrary expansion, which certainly affected the urban fabric of the area, the streets were widened, and the city wall, towers, and gates were demolished, and the area was added to the construction of new government buildings, commercial establishments, and residential plots. This study aims to evaluate the alterations in the old city's urban morphology, culture, and sociology by conducting a comparative analysis of three maps from different time periods and considering various factors within the target area.
Commissioning and clinical evaluation of a novel high‐resolution quality assurance digital detector array for SRS and SBRT
Authors: Zhou Yang , Liu Yimei , Chen Meining , Fang Jianlan , Xiao Liangjie , Huang Shaomin , Qi Zhenyu , Deng Xiaowu , Zhang Jun , Peng Yinglin 
Published: January 2024

AbstractPurposeWe aimed to perform the commissioning and clinical evaluation of myQA SRS detector array for patient‐specific quality assurance (PSQA) of stereotactic radiosurgery (SRS)/ stereotactic body radiotherapy (SBRT) plans.MethodsTo perform the commissioning of myQA SRS, its dose linearity, dose‐rate dependence, angular dependence, and field‐size dependence were investigated. Ten SBRT plans were selected for clinical evaluation: 1) Common clinical deviations based on the original SBRT plan (Plan0), including multileaf collimator (MLC) positioning deviation and treatment positioning deviation were introduced. 2) Compared the performance of the myQA SRS and a high‐resolution EPID dosimetry system in PSQA measurement for the SBRT plans. Evaluation parameters include gamma passing rate (GPR) and distance‐to‐agreement (DTA) pass rate (DPR).ResultsThe dose linearity, angle dependence, and field‐size dependence of myQA SRS system exhibit excellent performance. The myQA SRS is highly sensitive in the detection of MLC deviations. The GPR of (3%/1 mm) decreases from 90.4% of the original plan to 72.7%/62.9% with an MLC outward/inward deviation of 3 mm. Additionally, when the setup error deviates by 1 mm in the X, Y, and Z directions with the GPR of (3%/1 mm) decreasing by an average of −20.9%, −25.7%, and −24.7%, respectively, and DPR (1 mm) decreasing by an average of −33.7%, −32.9%, and −29.8%. Additionally, the myQA SRS has a slightly higher GPR than EPID for PSQA, However, the difference is not statistically significant with the GPR of (3%/1 mm) of (average 90.4%% vs. 90.1%, p = 0.414).ConclusionDosimetry characteristics of the myQA SRS device meets the accuracy and sensitivity requirement of PSQA for SRS/SBRT treatment. The dose rate dependence should be adequately calibrated before its application and a more stringent GPR (3%/1 mm) evaluation criterion is suggested when it is used for SRS/SBRT QA.
Robust Super‐Lubricity for Novel Cartilage Prototype Inspired by Scallion Leaf Architecture
Authors: Liu Hui , Zhao Weiyi , Zhang Yunlei , Zhao Xiaoduo , Ma Shuanhong , Scaraggi Michele , Zhou Feng 
Published: January 2024

AbstractThe simultaneous achievement ‐under physiologically high contact pressures‐ of ultra‐low friction, nearly zero surface wear, and long lifetime in the development of human cartilage prosthetics is still a big challenge. In this work, inspired by the unique lubrication mechanism of scallion leaves resulting from the synergy of oriented surface micro‐topography and mucus hydration, a novel layered soft hydrogel as cartilage prototype is developed by chemically embedding thick hydrophilic polyelectrolyte brush chains into the sub‐surface of a high strength anisotropic hydrogel bulk. It exhibits an anisotropic polymer network with unique mechanical properties (tensile strength: 8.3 to 23.7 MPa; elastic modulus 20.0 to 30.0 MPa), anisotropic hydrated surface texture, super‐lubricity, and excellent wear resistance. Thydrogel architecture can exhibit low coefficient of friction (COF) less than ≈0.01 under a wide range of contact stresses (0.2 to 2.4 MPa) and maintain cartilage‐like long‐lasting (50k sliding cycles) robust super‐lubricity (COF ≈ 0.006) and nearly‐zero wear under high contact pressure (≈2.4 MPa) condition. Theoretical underpinning reveals how multiscale surface anisotropy, mechanics, and hydration regulate super‐low friction generation. This work provides a novel design paradigm for the fabrication of robust soft materials with extraordinary lubricity as implantable prototypes and coatings.
A Versatile Passivated Protein‐Adsorption Platform for Rapid Healing of Vascular Stents by Modulating the Microenvironment
Authors: Li Linhua , Cao Zhengjiang , Zhang Chunle , Li Li , Li Qingying , Liu Chang , Qu Chao , Luo Rifang , Fu Ping , Wang Yunbing 
Published: January 2024

AbstractBiodegradable stents have paved the way to treat coronary artery disease. However, rapid reendothelialization is required to solve the problems of mismatched degradation rates, localized inflammation, and insufficient biocompatibility. Herein, a novel passivated protein‐adsorption coating is synthesized by coordination chelation, oxidation, cross‐linking, polymerization, and deposition of dopamine, (‐)‐epigallocatechin gallate (EGCG), and copper ions (Cu2+) using two‐electron oxidation. This coating exhibits hierarchical functionality, that is, at the macroscale, its superhydrophilicity conveys antifouling ability; whereas at the microscale, the active groups (quinone‐, amino‐, hydroxyphenyl groups and aromatic ring) facilitate protein adsorption. Antifouling ability prevents acute thrombosis and inflammation and maintains initial microenvironment stability post‐implantation. The active groups facilitate gradual endothelial cells (ECs) adhesion. Meanwhile, the decomposition of nitric oxide (NO) donors to release NO is catalyzed by Cu2+, and EGCG alleviates or prevents oxidative stress damage, inflammatory responses, thrombosis formation, and excessive smooth muscle cells proliferation in the stent microenvironment. This provides favorable conditions for the rapid and healthy growth of ECs. This study proposes a novel strategy for rapid neointima formation comprising healthy ECs on the surfaces of biodegradable stents by depositing a passivated protein‐adsorption coating (polydopamine/EGCG/Cu), opening new possibilities for the efficient treatment of coronary artery disease.
Stroking through Electrolyte: Liquid Metal Droplet Propulsion through Pulse Time Modulation
Authors: Fuchs Richard , Abdoli Shiva , Kilani Mohamed , Nor‐Azman Nur‐Adania , Yu Ruohan , Tang Shi‐Yang , Dickey Michael D. , Mao Guangzhao , Kalantar‐Zadeh Kourosh , Tang Jianbo 
Published: January 2024

AbstractActive droplets play important roles in microfluidics, robotics, and micro‐electromechanical systems. As a special class of active droplets that are conductive, reactive, and of high surface tension, liquid metal droplets (LMDs) can be driven by electric‐field‐induced surface (Marangoni) flows to function as reconfigurable components in actuators, sensors, catalytic reactors, and antennas. Stimulating LMDs using an electric field induces concurrent electro‐hydrodynamic flows and electrochemical surface oxidation (passivation). It is however difficult to decouple these two effects which brings complexity in controlling LMD motions. To address this challenge, pulse time modulation (PTM) signals are used. PTM enables controlled LMD displacement by propelling the droplets forward during the voltage‐on phases and facilitating surface recovery from oxidation during the voltage‐off phases. Counterintuitively, by taking such intermittent “rests”, the LMDs effectively inhibit the unfavorable impact of oxidation, granting high motion controllability. Combining high‐speed imaging, motion tracking, machine learning, and electrochemical analysis, the study reveals how electro‐hydrodynamic flows and surface oxide formation/dissolution interplay to generate well‐defined motion regimes. The study further develops a quasi‐analytical model to describe droplet motions and designs a rotary LMD motor to showcase the versatility of the approach. This work provides the fundamental framework and viable strategy for designing innovative liquid metal‐based systems.
Exploiting the Mechanical Bond Effect for Enhanced Molecular Recognition and Sensing
Authors: Wilmore Jamie T. , Beer Paul D. 
Published: January 2024

AbstractThe ubiquity of charged species in biological and industrial processes has resulted in ever‐increasing interest in their selective recognition, detection, and environmental remediation. Building on the established coordination chemistry principles of the chelate and macrocyclic effects, and host preorganization, supramolecular chemists seek to construct specific 3D binding cavities reminiscent of biotic systems to enhance host‐guest binding affinity and selectivity. Mechanically interlocked molecules (MIMs) present a wholly unique platform for synthetic host design, wherein topologies afforded by the mechanical bond enable the decoration of 3D cavities for non‐covalent interactions with a range of target guest geometries. Notably, MIM host systems exhibit mechanical bond effect augmented affinities and selectivities for a variety of charged guest species, compared to non‐interlocked acyclic and macrocycle host analogs. Furthermore, the modular nature of MIM synthesis facilitates incorporation of optical and electrochemical reporter groups, enabling fabrication of highly sensitive and specific molecular sensors. This review discusses the development of recognition and sensing MIMs, from the first reports in the late 20th century through to the present day, delineating how their topologically preorganized and dynamic host cavities enhance charged guest recognition and sensing, demonstrating the mechanical bond effect as a potent tool in future chemosensing materials.