Cross-Processing Fish Co-Products with Plant Food Side Streams or Seaweeds Using the pH-Shift Method - a new sustainable route to functional food protein ingredients stable towards lipid oxidation

The seafood value chain is highly inefficient as 50-60% of the fish weight end up as co-products in the filleting operation. Despite their abundance in high-quality proteins, fish co-products mainly go to low value products such as fodder. The pH-shift process, i.e., acid/alkaline solubilization followed by isoelectric precipitation, is an opportunity to instead recover these proteins in a food grade manner while maintaining their functionality. A challenge when subjecting hemoglobin-rich fish raw materials to pH-shift processing is however oxidation of polyunsaturated fatty acids (PUFAs).This thesis investigated, for the first time, cross-processing of fish co-products with antioxidant-containing support materials (\u27\u27helpers\u27\u27) to protect the fish protein isolates from lipid oxidation in a clean label and sustainable manner. The helpers, including locally sourced plant food side streams (press cakes from lingonberry (LPC) and apple, barley spent grain, oat fiber residues), shrimp shells, and seaweeds, were also expected to introduce new characteristics to the protein isolates.All helpers, except shrimp shells, reduced lipid oxidation in herring/salmon co-products when added at 30% (dw/dw) at start of the pH-shift process. LPC was the most effective, and even at 2.5% addition it prevented volatile aldehyde formation during production of herring protein isolates while at 10% addition, the isolates were also stable towards oxidation for ≥8 days on ice. When the 10% LPC instead was added during protein precipitation, the oxidation lag phase was extended to 21 days. The oxidative stability of protein isolates correlated with their total phenolic content, and the very high antioxidant ability of LPC\u27s was mainly attributed to anthocyanins, e.g., ideain and procyanidin A1.LPC also improved the water solubility, emulsifying activity, and gel-forming capabilities of herring protein isolates, expanding their potential applications in food products. The water solubility and emulsifying activity were also boosted by adding shrimp shells and Ulva, while the gel-forming ability was also enhanced by apple press cake. LPC-derived anthocyanins resulted in red isolates under acidic conditions and dark-colored isolates under neutral/alkaline conditions. Ulva resulted in green isolates due to the presence of chlorophyll. The color of protein isolates was also affected by oxidation of fish-derived pigments like Hb and astaxanthin. The addition of helpers also influenced the composition of protein isolates. LPC added at the start of the process reduced lipid content, while shrimp shells and LPC added during precipitation increased it. Seaweeds raised ash content by introducing minerals.Additionally, the organic acids of LPC saved the use of HCl in acid-aided protein solubilization and in isoelectric precipitation of alkali-solubilized proteins. During the latter, adding 30% LPC decreased HCl usage by as much as 61%. Opposite, alkaline protein solubilization in presence of LPC required more NaOH than the control, but this issue was naturally less pronounced at low LPC additions. Another challenge of introducing helpers was that they reduced total protein yield in the pH-shift process. This was however successfully mitigated by optimizing solubilization/precipitation pH, increasing water addition, and employing more powerful high shear homogenization and ultrasound techniques.In summary, this thesis introduced a completely new concept of cross-processing fish co-products with antioxidant-containing food materials, significantly reducing lipid oxidation and enhancing protein isolate techno-functionalities. Herring co-products paired with 10% LPC was particularly promising. Beyond its technical advantages, cross-processing can add economic value to side streams of both fish and other food industries, while stimulating circularity and industrial symbiosis. Altogether, these features reduce food chain losses and promote a more sustainable food system

Engineered antigen-presenting hydrogels: model platforms for studies of T cell mechanotransduction

T cells apply forces and eventually sense and then respond to the mechanical properties of their surroundings, including those of antigen presenting cells (APC) when they form the immunological synapse (IS). The identification of the mechanosensitive receptors and time scales at which they sense and actuate is experimentally difficult at the natural cell-cell interface. Inspired by the tools used in cell-matrix mechanobiology, this thesis presents synthetic, hydrogel-based models of APCs to study T cell mechanotransduction, focusing on the early T cell activation. Polyacrylamide (PAAm) hydrogels (1-50 kPa) were micropatterned with streptavidin and APC ligands (antibody against CD3 co-receptor (anti-CD3) and intercellular cell adhesion molecule-1 (ICAM-1)) at controlled ligand density and in geometries with defined dimensions. The anti-CD3 patterned hydrogels were used to study the interplay between hydrogel stiffness and CD3-mediated early T cell activation markers. In the last chapter, the regulatory role of ICAM-1 coupled to anti-CD3 and hydrogel stiffness in early T cell activation was studied on hydrogels with patterned anti-CD3 microdots surrounded by a background of ICAM-1. The results contribute to the understanding of the factors involved in T cell mechanotransduction, providing useful information for the future design of immunomodulatory materials.T-Zellen üben auf ihre Umgebung Kräfte aus und erfassen und reagieren auf die mechanischen Eigenschaften ihrer Umgebung, insbesondere auf Antigen-präsentierende Zellen (APC), wenn sie die immunologische Synapse (IS) bilden. Die Identifizierung der mechanosensitiven Rezeptoren und der Zeitskalen, in denen sie aktiviert werden, ist an der natürlichen Zell-Zell-Grenzfläche experimentell schwierig. Inspiriert von Werkzeugen aus der Zellmatrix-Mechanobiologie werden in dieser Arbeit synthetische hydrogelbasierte Modelle der IS entwickelt, um die T-Zell-Mechanotransduktion zu untersuchen, wobei der Schwerpunkt auf der frühen T-Zell-Aktivierung liegt. Dazu wurden Polyacrylamid (PAAm)-Hydrogele (1-50 kPa) hergestellt und mit Streptavidin- und APC-Liganden (Antikörper gegen CD3-Co-Rezeptor (Anti-CD3) und interzelluläres Zelladhäsionsmolekül-1 (ICAM-1)) mikrostrukturiert. Anhand von Hydrogelen mit Anti-CD3-Mustern wurde die Korrelation zwischen der CD3-vermittelten frühen T-Zell-Aktivierung und der Steifigkeit des Hydrogels untersucht. Anschließend wurde die zusätzliche regulatorische Rolle von ICAM-1 an Hydrogelen mit strukturierten Anti-CD3-Mikropunkten auf einem ICAM-1 Hintergrund untersucht. Die Ergebnisse tragen zum Verständnis der Faktoren bei, die an der T-Zell-Mechanotransduktion beteiligt sind, und liefern nützliche Informationen für das zukünftige Design immunmodulatorischer Materialien

Motor Noise and Vibration Test Research

Some factors, such as friction, vibration, and so on, can result in the fault and abnormal noise in the motor. Based on the detection and analysis of noise and vibration, we can identify and eliminate the faults of the motor. This is helpful not only to ensure the completion of production tasks, but also to prevent accidents. In this paper, we briefly introduce the motor noise generation principle. A laptop computer and LabVIEW software are used to design the experiment system to detect and analysis the noise and vibration of motor. External microphone and computer with sound card constitute noise detection system hardware. Vibration sensor and the data acquisition card constitute vibration detection system hardware. LabVIEW software combined with FFT analysis is used to realize the noise signal acquisition, recording and spectral analysis. Detecting and analyzing the noise of the permanent magnet DC motor and three-phase asynchronous motor proves that the motor noise and vibration detecting experimental platform is fully meet the requirements of motor test and research. This detection and analysis system has a good man-machine interface and strong operability

Cross-processing herring and salmon co-products with agricultural and marine side-streams or seaweeds produces protein isolates more stable towards lipid oxidation

Herring and salmon filleting co-products were pH-shift processed together with seven antioxidant-containing raw materials (“helpers”) including lingonberry-, apple-, oat-, barley- and shrimp-co-products, and two seaweeds (Saccharina latissima, Ulva fenestrata) to produce protein isolates stable towards lipid oxidation. Malondialdehyde (MDA) and 4-hydroxy-(E)-2-hexenal (HHE) levels revealed that all helpers, except shrimp shells, to different extents retarded lipid oxidation both during pH-shift-processing and ice storage. The three helpers performing best were: lingonberry press-cake > apple pomace ∼ Ulva. Color of protein isolates was affected by helper-derived pigments (e.g., anthocyanins, carotenoids, chlorophyll) and lipid oxidation-induced changes (e.g., metHb-formation, pigment-bleaching). In conclusion, combining fish co-products with other food side-streams or seaweeds during pH-shift processing appears a promising new tool to minimize lipid oxidation of protein isolates, both during their production and subsequent storage. Lingonberry press-cake was the most efficient helper but provided dark color which may narrow product development possibilities, something which requires further attention

Lingonberry (Vaccinium vitis-idaea) press-cake as a new processing aid during isolation of protein from herring (Clupea harengus) co-products

High acid-consumption and lipid oxidation are challenges when recovering functional proteins from herring co-products via pH-shift-processing. Here, lingonberry press-cake (LP), which is abundant in organic acids and phenolics, was added to alkali-solubilized herring-co-product-proteins (2.5–30 % LP per dry weight) aiming to aid protein precipitation, save hydrochloric acid (HCl) and provide oxidative stability. The results revealed 5–30 % LP addition reduced HCl-consumption by 13–61 % and 19–79 % when precipitating proteins at pH 5.5 and 6.5, respectively. Higher LP% decreased protein content and lightness of protein isolates but raised the lipid content. Precipitation at pH 6.5 used less acid, reduced total protein yield and raised moisture content and darkness of isolates. Contrary to controls, lipid oxidation-derived volatiles did not develop in protein isolates precipitated with 10 % and 30 % LP, neither during the process itself nor during 21 days on ice. Altogether, LP was identified as a promising all-natural processing-aid to use during herring protein isolation

Towards a Unified Analysis of Kernel-based Methods Under Covariate Shift

Covariate shift occurs prevalently in practice, where the input distributions of the source and target data are substantially different. Despite its practical importance in various learning problems, most of the existing methods only focus on some specific learning tasks and are not well validated theoretically and numerically. To tackle this problem, we propose a unified analysis of general nonparametric methods in a reproducing kernel Hilbert space (RKHS) under covariate shift. Our theoretical results are established for a general loss belonging to a rich loss function family, which includes many commonly used methods as special cases, such as mean regression, quantile regression, likelihood-based classification, and margin-based classification. Two types of covariate shift problems are the focus of this paper and the sharp convergence rates are established for a general loss function to provide a unified theoretical analysis, which concurs with the optimal results in literature where the squared loss is used. Extensive numerical studies on synthetic and real examples confirm our theoretical findings and further illustrate the effectiveness of our proposed method.Comment: Poster to appear in Thirty-seventh Conference on Neural Information Processing System

Indocyanine Green-Loaded Polydopamine-Reduced Graphene Oxide Nanocomposites with Amplifying Photoacoustic and Photothermal Effects for Cancer Theranostics

Photoacoustic (PA) imaging and photothermal therapy (PTT) as light-induced theranostic platforms have been attracted much attention in recent years. However, the development of highly efficient and integrated phototheranostic nanoagents for amplifying PA imaging and PTT treatments poses great challenges. Here, we report a novel phototheranostic nanoagent using indocyanine green-loaded polydopamine-reduced graphene oxide nanocomposites (ICG-PDA-rGO) with amplifying PA and PTT effects for cancer theranostics. The results demonstrate that the PDA layer coating on the surface of rGO could effectively absorb a large number of ICG molecules, quench ICG's fluorescence, and enhance the PDA-rGO's optical absorption at 780 nm. The obtained ICG-PDA-rGO exhibits stronger PTT effect and higher PA contrast than that of pure GO and PDA-rGO. After PA imaging-guided PTT treatments, the tumors in 4T1 breast subcutaneous and orthotopic mice models are suppressed completely and no treatment-induced toxicity being observed. It illustrates that the ICG-PDA-rGO nanocomposites constitute a new class of theranostic nanomedicine for amplifying PA imaging and PTT treatments

Fish beyond fillets: Life cycle assessment of cross-processing herring and lingonberry co-products into a food product

The food industry generates side streams that can be used as sources of valuable compounds. We carried out a life cycle assessment of a protein ingredient obtained by pH-shift processing co-products of herring (Clupea harengus) and lingonberry (Vaccinium vitis-idaea) pomace. The assessment was based on a combination of primary and literature data to assess climate change, cumulative energy demand, land occupation, and depleted stock fraction impacts of marine resources. We analyzed the environmental profile of the fish protein ingredient on its own and as a consumable fish ball preparation. The potential impacts of the protein ingredient fish ball were compared with a benchmark fish ball and with salmon fillets. The results were generally favorable for the protein ingredient fish ball produced via cross-processing herring co-products and lingonberry pomace. This analysis supports the idea of further investment in cross-processing food sidestreams into a protein ingredient for food products

FF-LINS: A Consistent Frame-to-Frame Solid-State-LiDAR-Inertial State Estimator

Most of the existing LiDAR-inertial navigation systems are based on frame-to-map registrations, leading to inconsistency in state estimation. The newest solid-state LiDAR with a non-repetitive scanning pattern makes it possible to achieve a consistent LiDAR-inertial estimator by employing a frame-to-frame data association. In this letter, we propose a robust and consistent frame-to-frame LiDAR-inertial navigation system (FF-LINS) for solid-state LiDARs. With the INS-centric LiDAR frame processing, the keyframe point-cloud map is built using the accumulated point clouds to construct the frame-to-frame data association. The LiDAR frame-to-frame and the inertial measurement unit (IMU) preintegration measurements are tightly integrated using the factor graph optimization, with online calibration of the LiDAR-IMU extrinsic and time-delay parameters. The experiments on the public and private datasets demonstrate that the proposed FF-LINS achieves superior accuracy and robustness than the state-of-the-art systems. Besides, the LiDAR-IMU extrinsic and time-delay parameters are estimated effectively, and the online calibration notably improves the pose accuracy. The proposed FF-LINS and the employed datasets are open-sourced on GitHub (https://github.com/i2Nav-WHU/FF-LINS)

A Comparative Study of Perceptual Quality Metrics for Audio-driven Talking Head Videos

The rapid advancement of Artificial Intelligence Generated Content (AIGC) technology has propelled audio-driven talking head generation, gaining considerable research attention for practical applications. However, performance evaluation research lags behind the development of talking head generation techniques. Existing literature relies on heuristic quantitative metrics without human validation, hindering accurate progress assessment. To address this gap, we collect talking head videos generated from four generative methods and conduct controlled psychophysical experiments on visual quality, lip-audio synchronization, and head movement naturalness. Our experiments validate consistency between model predictions and human annotations, identifying metrics that align better with human opinions than widely-used measures. We believe our work will facilitate performance evaluation and model development, providing insights into AIGC in a broader context. Code and data will be made available at https://github.com/zwx8981/ADTH-QA