Anthropogenic modification of phosphorus sequestration in lake sediments during the Holocene: A global perspective

Human activity has fundamentally altered the global phosphorus (P) cycle. Yet our understanding of when and how humans influenced the P cycle has been limited by the scarcity of long-term P sequestration records, particularly outside Europe and North America. Lake sediments provide a unique archive of past P burial rates and allow the human-mediated disruption of the global P cycle to be examined. We compiled the first global-scale and continentally resolved reconstruction of lake-wide Holocene P burial rates using 108 lakes from around the world. In Europe, lake P burial rates started to increase noticeably after ∼4000 calendar years before 1950 CE (cal BP), whereas the increase occurred later in China (∼2000 cal BP) and in North America (∼550 cal BP), which is most likely related to different histories of population growth, land-use and associated soil erosion intensities. Anthropogenic soil erosion explains ∼86% of the observed changes in global lake P burial rates in pre-industrial times. We also provide the first long-term estimates of the global lake P sink over the Holocene (∼2686 Tg P). We estimate that the global mean lake sediment P sequestration since 1850 CE (100 cal BP) is ∼1.54 Tg P yr−1, representing approximately a six-fold increase above the mean pre-industrial value (∼0.24 Tg P yr−1; 11,500 to 100 cal BP) and around a ten-fold increase above the Early-Middle Holocene low-disturbance baseline of 0.16 Tg P yr−1. This study suggests that human activities have been affecting the global P cycle for millennia, with substantial alteration after industrial times (1850 CE)

Anthropogenic Activities Generate High-Refractory Black Carbon along the Yangtze River Continuum

12 pages, 7 figuresCombustion-driven particulate black carbon (PBC) is a crucial slow-cycling pool in the organic carbon flux from rivers to oceans. Since the refractoriness of PBC stems from the association of non-homologous char and soot, the composition and source of char and soot must be considered when investigating riverine PBC. Samples along the Yangtze River continuum during different hydrological periods were collected in this study to investigate the association and asynchronous combustion drive of char and soot in PBC. The results revealed that PBC in the Yangtze River, with higher refractory nature, accounts for 13.73 ± 6.89% of particulate organic carbon, and soot occupies 37.53 ± 11.00% of PBC. The preponderant contribution of fossil fuel combustion to soot (92.57 ± 3.20%) compared to char (27.55 ± 5.92%), suggested that fossil fuel combustion is a crucial driver for PBC with high soot percentage. Redundancy analysis and structural equation modeling confirmed that the fossil fuel energy used by anthropogenic activities promoting soot is the crucial reason for high-refractory PBC. We estimated that the Yangtze River transported 0.15–0.23 Tg of soot and 0.15–0.25 Tg of char to the ocean annually, and the export of large higher refractory PBC to the ocean can form a long-term sink and prolong the residence time of terrigenous carbonThis study was supported by grants from the National Natural Science Foundation of China (nos. 42277214, 42207256, and 41971286), major programs of the National Social Science Foundation of China (grant nos. 22&ZD136), the Special Science and Technology Innovation Program for Carbon Peak and Carbon Neutralization of Jiangsu Province (grant no. BE2022612)Peer reviewe

a computational approach to measure availability of networked software system

Due to networked software system's large scale, complex functional interaction and the complexity of the composition of the services, to solve the question of its availability is difficult to predict. The complex systems theory is introduced to the availability prediction method. The concept and availability measurement model of networked software system are defined here, and multi-agent based availability modeling and simulation methods of NSS are proposed in this paper. The networked software system is abstracted as a combination of service agent and connector agent, and a variety of other agents are used to establish the simulation. At last, the proposed approach's affectivity and feasibility are validated through taking advantage of an actual networked software system and the simulation result is analyzed.Due to networked software system's large scale, complex functional interaction and the complexity of the composition of the services, to solve the question of its availability is difficult to predict. The complex systems theory is introduced to the availability prediction method. The concept and availability measurement model of networked software system are defined here, and multi-agent based availability modeling and simulation methods of NSS are proposed in this paper. The networked software system is abstracted as a combination of service agent and connector agent, and a variety of other agents are used to establish the simulation. At last, the proposed approach's affectivity and feasibility are validated through taking advantage of an actual networked software system and the simulation result is analyzed

Statistic Experience Based Adaptive One-Shot Detector (EAO) for Camera Sensing System

Object detection in a camera sensing system has been addressed by researchers in the field of image processing. Highly-developed techniques provide researchers with great opportunities to recognize objects by applying different algorithms. This paper proposes an object recognition model, named Statistic Experience-based Adaptive One-shot Detector (EAO), based on convolutional neural network. The proposed model makes use of spectral clustering to make detection dataset, generates prior boxes for object bounding and assigns prior boxes based on multi-resolution. The model is constructed and trained for improving the detection precision and the processing speed. Experiments are conducted on classical images datasets while the results demonstrate the superiority of EAO in terms of effectiveness and efficiency. Working performance of the EAO is verified by comparing it to several state-of-the-art approaches, which makes it a promising method for the development of the camera sensing technique

Intubation and Ventilation amid the COVID-19 Outbreak: Wuhan's Experience.

The COVID-19 outbreak has led to 80,409 diagnosed cases and 3,012 deaths in mainland China based on the data released on March 4, 2020. Approximately 3.2% of patients with COVID-19 required intubation and invasive ventilation at some point in the disease course. Providing best practices regarding intubation and ventilation for an overwhelming number of patients with COVID-19 amid an enhanced risk of cross-infection is a daunting undertaking. The authors presented the experience of caring for the critically ill patients with COVID-19 in Wuhan. It is extremely important to follow strict self-protection precautions. Timely, but not premature, intubation is crucial to counter a progressively enlarging oxygen debt despite high-flow oxygen therapy and bilevel positive airway pressure ventilation. Thorough preparation, satisfactory preoxygenation, modified rapid sequence induction, and rapid intubation using a video laryngoscope are widely used intubation strategies in Wuhan. Lung-protective ventilation, prone position ventilation, and adequate sedation and analgesia are essential components of ventilation management

Preparation of a Cellulosic Photosensitive Hydrogel for Tubular Tissue Engineering

Since the concept of tissue engineering was proposed, biocompatible hydrogel materials have attracted the attention of researchers. With the help of three-dimensional (3D) printing technology, precise shaping of hydrogels can be realized. In this paper, we synthesized a cellulosic photosensitive acrylamide (AM)/N,N-methylenebisacrylamide (MBA) hydrogel. With the high-efficiency water-soluble photoinitiator TPO@Tw developed by our research group, the efficient photocuring cross-linking process of the hydrogel can be realized under 405 nm visible light. In consideration of the viscosity, curing mass, curing depth, and break distance of the hydrogel, we screened out hydroxypropyl cellulose (HPC) as the preferred tackifier of the material. The addition of HPC greatly improved the mechanical properties of the hydrogel. The compressive modulus of the optimal sample AM-HPC-5 increased by 709.2% and the tensile strength increased by 76.7% compared with the blank control group. By adding a PEGDA shell to the surface of the material, the water retention capacity of the hydrogel was effectively improved. The water loss rate was greatly reduced. The 3D wooden-pile structure model was printed by a DIW 3D printer. Further, through coaxial extrusion, the microtubule structure that may be applied in tissue engineering was obtained. Cell experiment results showed high biocompatibility of the hydrogel. NIH 3T3 cells could adhere and grow on the surface of microtubules

Spatiotemporal response of dissolved organic matter diversity to natural and anthropogenic forces along the whole mainstream of the Yangtze River [Poster]

Poster.-- ASLO Aquatic Sciences Meeting 2023, Resilience and Recovery in Aquatic Systems, 4–9 June 2023, Palma de Mallorca, SpainLarge rivers provide crucial linkages between continental and oceanic ecosystems. We investigated dissolved organic matter (DOM) at elemental, optical and molecular levels along the whole mainstream of the Yangtze River that is the largest river in Asia at highly spatial resolution in the dry and early wet seasons. Compared with other worldwide larger rivers, both concentration and flux of dissolved organic carbon (DOC) in the Yangtze River was much lower. The distribution of δ13CDOC and higher abundance of humic-like fluorescent component and highly unsaturated and phenolics (HUPs) compound reflected a prominent contribution of allochthonous DOM. Microbial and terrestrial humic-like fluorescent components tended to be coupled with CHO molecules and HUPs compound with higher aromatic, unsaturated, molecular weight and stable characteristics in up-midstream. With increasing agricultural and urban land downstream, there were more heteroatomic formulae and labile aliphatic and protein-like compounds derived from human activities and in situ primary production. Besides, chemical sulfurization, hydrogenation and oxidation were found during molecular cycling processes in different reaches. Weaker solar radiation and water dilution during the dry/cold season left highly aromatic, oxygenated and unsaturated DOM composition. Conversely, increased discharge during the wet/warm season contributed to dilute the terrestrial DOM but warm temperatures could promote phytoplankton growth that releases freshly aliphatic DOMN

Spatiotemporal response of dissolved organic matter diversity to natural and anthropogenic forces along the whole mainstream of the Yangtze River

12 pages, 9 figuresThe Yangtze River, the largest river in Asia, plays a crucial role in linking continental and oceanic ecosystems. However, the impact of natural and anthropogenic disturbances on composition and transformation of dissolved organic matter (DOM) during long-distance transport and seasonal cycle is not fully understood. By using a combination of elemental, isotopic and optical techniques, as well as Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), we investigated DOM abundance and composition along the whole mainstream at highly spatial resolution in the dry and early wet seasons. Our findings showed that the concentration and flux of dissolved organic carbon (DOC) in the Yangtze River was much lower compared with other worldwide larger rivers. The distribution of δ13CDOC and higher abundance of humic-like fluorescent component and highly unsaturated and phenolics (HUPs) compound reflected a prominent contribution of allochthonous DOM. Further optical and molecular analysis revealed humic-like fluorescent components were coupled with CHO molecules and HUPs compound with higher aromatic, unsaturated, molecular weight and stable characteristics between upstream and midstream reaches. With increasing agricultural and urban land downstream, there were more heteroatomic formulae and labile aliphatic and protein-like compounds which were derived from human activities and in situ primary production. Meanwhile, DOM gradually accumulates with slow water flow and additional autochthonous organics. Weaker solar radiation and water dilution during the dry/cold season favours highly aromatic, unsaturated and oxygenated DOM compositions. Conversely, higher discharge during the wet/warm season diluted the terrestrial DOM, but warm temperatures could promote phytoplankton growth that releases labile aliphatic and protein-like DOM. Besides, chemical sulfurization, hydrogenation and oxygenation were found during molecular cycling processes. Our research emphasizes the active response of riverine DOM to natural and anthropogenic controls, and provides a valuable preliminary background to better understand the biogeochemical cycling of DOM in a larger riverThis study was financially supported by the National Natural Science Foundation of China [Grant Nos. 41971286, 42277214, and 42207256], Major programs of the National Social Science Foundation of China [Grant No. 22&ZD136], Special Science and Technology Innovation Program for Carbon Peak and Carbon Neutralization of Jiangsu Province [Grant No. BE2022612], Postgraduate Research Innovation Project of Jiangsu Province [Grant No. KYCX21_1338], China Scholarship Council [Grant No. 202006860045] and the Youth Top Talent funded by Nanjing Normal University. The Ion Cyclotron Resonance user facility at the National High Magnetic Field Laboratory at Florida State University is supported by the National Science Foundation Division of Materials Research and Division of Chemistry through DMR 16–44779, and the State of FloridaPeer reviewe