Roles of Chemokine Receptors in T Cell Accmulation in Omental Tumors

The omentum is an adipose tissue in the peritoneal cavity that contains immune aggregates termed milky spots. Functionally similar to conventional lymphoid tissues, these specialized leukocyte clusters harbor effector and suppressor cells, mount immune responses to antigens, and sustain peritoneal homeostasis. However, the pre-existing leukocytes fail to protect the tissue from tumor colonization. In fact, the omentum is frequently involved in peritoneal metastasis, during which the balance between effector and suppressor immune cells is compromised with the latter gaining dominance. Regulatory T cells (Tregs) represent a major immunosuppressive population in the omentum and rapidly accumulate after tumor implantation. The increased Treg abundance may be attributed to the local proliferation of pre-existing Tregs, peripheral Treg conversion, and/or cell recruitment from the circulation. Using T cell receptor (TCR) repertoire analysis, we show that tumor progression in the omentum does not promote Treg clonal expansion but leads to the influx of small Treg clonotypes. Naive CD4+ T cells poorly differentiate to Tregs in tumor-bearing omenta, suggesting a minimal contribution of peripheral conversion to the enlargement of the omental Treg pool. Parabiosis experiments reveal that circulating Tregs robustly migrate to the omentum as tumors progress, wherein they metabolically adapt to the environment and acquire the transcriptional signature of adipose-resident Tregs. We then find that CXCR3 is essential for Treg recruitment to omental tumors, and that CD4-specific CXCR3 ablation abrogates Treg accumulation and enhances tumor control. Interestingly, CXCR3 also supports effector CD8+ T cell responses, which mediate tumor control. Without this chemokine receptor, CD8+ T cells fail to undergo proper effector differentiation and maintain their numerical abundance in omental tumors. Therefore, our data reveal the mechanisms for the accumulation of Tregs and CD8+ T cells in omental tumors and uncover the pivotal roles of CXCR3 in this process

Launching a Robust Backdoor Attack under Capability Constrained Scenarios

As deep neural networks continue to be used in critical domains, concerns over their security have emerged. Deep learning models are vulnerable to backdoor attacks due to the lack of transparency. A poisoned backdoor model may perform normally in routine environments, but exhibit malicious behavior when the input contains a trigger. Current research on backdoor attacks focuses on improving the stealthiness of triggers, and most approaches require strong attacker capabilities, such as knowledge of the model structure or control over the training process. These attacks are impractical since in most cases the attacker's capabilities are limited. Additionally, the issue of model robustness has not received adequate attention. For instance, model distillation is commonly used to streamline model size as the number of parameters grows exponentially, and most of previous backdoor attacks failed after model distillation; the image augmentation operations can destroy the trigger and thus disable the backdoor. This study explores the implementation of black-box backdoor attacks within capability constraints. An attacker can carry out such attacks by acting as either an image annotator or an image provider, without involvement in the training process or knowledge of the target model's structure. Through the design of a backdoor trigger, our attack remains effective after model distillation and image augmentation, making it more threatening and practical. Our experimental results demonstrate that our method achieves a high attack success rate in black-box scenarios and evades state-of-the-art backdoor defenses.Comment: 9 pages, 6 figure

Self-Organized Fission Control for Flocking System

This paper studies the self-organized fission control problem for flocking system. Motivated by the fission behavior of biological flocks, information coupling degree (ICD) is firstly designed to represent the interaction intensity between individuals. Then, from the information transfer perspective, a “maximum-ICD” based pairwise interaction rule is proposed to realize the directional information propagation within the flock. Together with the “separation/alignment/cohesion” rules, a self-organized fission control algorithm is established that achieves the spontaneous splitting of flocking system under conflict external stimuli. Finally, numerical simulations are provided to demonstrate the effectiveness of the proposed algorithm

Monocyte chemoattractant protein-1/CCL2 produced by stromal cells promotes lung metastasis of 4T1 murine breast cancer cells

MCP-1/CCL2 plays an important role in the initiation and progression of cancer. Since tumor cells produce MCP-1, they are considered to be the main source of this chemokine. Here, we examined whether MCP-1 produced by non-tumor cells affects the growth and lung metastasis of 4T1 breast cancer cells by transplanting them into the mammary pad of WT or MCP-1−/− mice. Primary tumors at the injected site grew similarly in both mice; however, lung metastases were markedly reduced in MCP-1−/− mice, with significantly longer mouse survival. High levels of MCP-1 mRNA were detected in tumors growing in WT, but not MCP-1−/− mice. Serum MCP-1 levels were increased in tumor-bearing WT, but not MCP-1−/− mice. Transplantation of MCP-1−/− bone marrow cells into WT mice did not alter the incidence of lung metastasis, whereas transplantation of WT bone marrow cells into MCP-1−/− mice increased lung metastasis. The primary tumors of MCP-1−/− mice consistently developed necrosis earlier than those of WT mice and showed decreased infiltration by macrophages and reduced angiogenesis. Interestingly, 4T1 cells that metastasized to the lung constitutively expressed elevated levels of MCP-1, and intravenous injection of 4T1 cells producing a high level of MCP-1 resulted in increased tumor foci in the lung of WT and MCP-1−/− mice. Thus, stromal cell-derived MCP-1 in the primary tumors promotes lung metastasis of 4T1 cells, but tumor cell-derived MCP-1 can also contribute once tumor cells enter the circulation. A greater understanding of the source and role of this chemokine may lead to novel strategies for cancer treatment

Modélisation de la déformation de transformateurs de puissance par approche magnéto-mécanique

Le but de ce travail est d'estimer la déformation d'un transformateur constitué de tôles empilées soumis à un chargement magnétique périodique. Il s'agit d'une approche numérique par éléments finis qui suppose le développement préalable et l'implémentation d'une loi de comportement multiéchelle magnéto-élastique anisotrope (modèle local, modèle d'empilement et modèle de structure). Les résultats numériques obtenus sont comparés à des mesures expérimentales obtenues sur transformateur réel

Rapid evolutionary divergence of Gossypium barbadense and G. hirsutum mitochondrial genomes

Background The mitochondrial genome from upland cotton, G. hirsutum, was previously sequenced. To elucidate the evolution of mitochondrial genomic diversity within a single genus, we sequenced the mitochondrial genome from Sea Island cotton (Gossypium barbadense L.). Methods Mitochondrial DNA from week-old etiolated seedlings was extracted from isolated organelles using discontinuous sucrose density gradient method. Mitochondrial genome was sequenced with Solexa using paired-end, 90 bp read. The clean reads were assembled into contigs using ABySS and finished via additional fosmid and BAC sequencing. Finally, the genome was annotated and analyzed using different softwares. Results The G. barbadense (Sea Island cotton) mitochondrial genome was fully sequenced (677,434-bp) and compared to the mitogenome of upland cotton. The G. barbadensemitochondrial DNA contains seven more genes than that of upland cotton, with a total of 40 protein coding genes (excluding possible pseudogenes), 6 rRNA genes, and 29 tRNA genes. Of these 75 genes, atp1, mttB, nad4, nad9, rrn5, rrn18, and trnD(GTC)-cp were each represented by two identical copies. A single 64 kb repeat was largely responsible for the 9 % difference in genome size between the two mtDNAs. Comparison of genome structures between the two mitochondrial genomes revealed 8 rearranged syntenic regions and several large repeats. The largest repeat was missing from the master chromosome in G. hirsutum. Both mitochondrial genomes contain a duplicated copy of rps3 (rps3-2) in conjunction with a duplication of repeated sequences. Phylogenetic and divergence considerations suggest that a 544-bp fragment of rps3 was transferred to the nuclear genome shortly after divergence of the A- and D- genome diploid cottons. Conclusion These results highlight the insights to the evolution of structural variation between Sea Island and upland cotton mitochondrial genomes

Design and processing test of eel automatic filleting machine

Objective: A special cutting mechanism for slicing elongated fish with smooth surface was designed. Methods: Taking the slimy eel as the research object, the mechanism of clamping and cutting operation was analyzed. Taking cutting quality and cutting time as test indexes, the influence of main parameters such as clamping wheel speed, cutting tool speed and clamping wheel surface geometry on cutting quality and cutting time were investigated. Results: The main factors affecting cutting quality were blade speed and clamping wheel limit height, and the most important factors affecting cutting time were clamping wheel speed. When the clamping wheel limit height was 5 mm, the blade speed was 1 350 r/min, and the clamping wheel speed wwas 167 r/min, the higher cutting quality score and cutting time could be obtained. Conclusion: The eel can be effectively transported by using the gripper wheel, and efficient and high-speed laparotomy can be achieved by adjusting the speed of the gripper wheel, the speed of the blade and the height of the limit

Improved collaborative optimization in multidisciplinary design optimization problems

This paper is about a new approach for concurrent design based on collaborative optimization, a distributed optimization method for multidisciplinary designs. The key idea of the proposed method is to consider the global objective in each subspace optimization problem with an additional interaction channel for coupling variables, while maintaining an easy coordination of design variables for system level problem. The improved collaborative optimisation is applied to two academic test cases to demonstrate its feasibility and validity