Malicious Agent Detection for Robust Multi-Agent Collaborative Perception

Recently, multi-agent collaborative (MAC) perception has been proposed and outperformed the traditional single-agent perception in many applications, such as autonomous driving. However, MAC perception is more vulnerable to adversarial attacks than single-agent perception due to the information exchange. The attacker can easily degrade the performance of a victim agent by sending harmful information from a malicious agent nearby. In this paper, we extend adversarial attacks to an important perception task -- MAC object detection, where generic defenses such as adversarial training are no longer effective against these attacks. More importantly, we propose Malicious Agent Detection (MADE), a reactive defense specific to MAC perception that can be deployed by each agent to accurately detect and then remove any potential malicious agent in its local collaboration network. In particular, MADE inspects each agent in the network independently using a semi-supervised anomaly detector based on a double-hypothesis test with the Benjamini-Hochberg procedure to control the false positive rate of the inference. For the two hypothesis tests, we propose a match loss statistic and a collaborative reconstruction loss statistic, respectively, both based on the consistency between the agent to be inspected and the ego agent where our detector is deployed. We conduct comprehensive evaluations on a benchmark 3D dataset V2X-sim and a real-road dataset DAIR-V2X and show that with the protection of MADE, the drops in the average precision compared with the best-case "oracle" defender against our attack are merely 1.28% and 0.34%, respectively, much lower than 8.92% and 10.00% for adversarial training, respectively

Aqua­bis(triphenyl­phosphine-κP)copper(I) tetra­fluoridoborate

In the title compound, [Cu(C18H15P)2(H2O)]BF4, the CuI atom is coordinated by two P atoms from triphenyl­phosphine ligands and one water mol­ecule in a distorted trigonal geometry. In the BF4 − anion, three F atoms are disordered over two sites around the B—F bond, the site-occupancy ratio being 0.67 (6):0.33 (6). The Cu⋯F distance of 2.602 (5) Å between the Cu atom and the ordered F atom may suggest a weak but genuine inter­action. O—H⋯F and weak C—H⋯F hydrogen bonding is present in the crystal structure

Secondary infection of Fasciola gigantica in buffaloes shows a similar pattern of serum cytokine secretion as in primary infection

BackgroundAs a natural host of Fasciola gigantica, buffalo is widely infected by F. gigantica. Its impact on buffalo production has caused great losses to the husbandry sector, and repeat infection is non-negligible. In buffaloes experimentally infected with F. gigantica, primary and secondary infection have yielded the same rate of fluke recovery, indicating a high susceptibility of buffalo to F. gigantica, which contributes to the high infection rate. Determining the immunological mechanism of susceptibility will deepen the understanding of the interaction between F. gigantica and buffalo. Here, we explored the immune response of buffaloes against primary and secondary F. gigantica infection, with a focus on cytokines’ dynamics explored through serum cytokine detection.MethodsBuffaloes were assigned to three groups: group A (noninfected, n = 4), group B (primary infection, n = 3), and group C (secondary infection, n = 3). Group B was infected via oral gavage with 250 viable F. gigantica metacercariae, and group C was infected twice with 250 metacercariae at an interval of 4 weeks. The second infection of group C was performed simultaneously with that of group B. Whole blood samples were collected pre-infection (0 weeks) and at 1–6, 10, and 12  weeks after that. The serum levels of seven cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-13, TGF-β, and IL-17) were simultaneously determined using ELISA and further analyzed.ResultsIn the present study, no significant changes in Th1-type cytokines production were detected in early infection, both in primary and secondary infections, while the Th2-type response was strongly induced. A comparison of primary and secondary infection showed no significant difference in the cytokine secretion, which may indicate that the re-infection at 4 weeks after primary infection could not induce a robust adaptive immune response. The full extent of interaction between buffalo and F. gigantica in re-infection requires further study

Metabolomics in the Development and Progression of Dementia: A Systematic Review

Dementia has become a major global public health challenge with a heavy economic burden. It is urgently necessary to understand dementia pathogenesis and to identify biomarkers predicting risk of dementia in the preclinical stage for prevention, monitoring, and treatment. Metabolomics provides a novel approach for the identification of biomarkers of dementia. This systematic review aimed to examine and summarize recent retrospective cohort human studies assessing circulating metabolite markers, detected using high-throughput metabolomics, in the context of disease progression to dementia, including incident mild cognitive impairment, all-cause dementia, and cognitive decline. We systematically searched the PubMed, Embase, and Cochrane databases for retrospective cohort human studies assessing associations between blood (plasma or serum) metabolomics profile and cognitive decline and risk of dementia from inception through October 15, 2018. We identified 16 studies reporting circulating metabolites and risk of dementia, and six regarding cognitive performance change. Concentrations of several blood metabolites, including lipids (higher phosphatidylcholines, sphingomyelins, and lysophophatidylcholine, and lower docosahexaenoic acid and high-density lipoprotein subfractions), amino acids (lower branched-chain amino acids, creatinine, and taurine, and higher glutamate, glutamine, and anthranilic acid), and steroids were associated with cognitive decline and the incidence or progression of dementia. Circulating metabolites appear to be associated with the risk of dementia. Metabolomics could be a promising tool in dementia biomarker discovery. However, standardization and consensus guidelines for study design and analytical techniques require future development

Continuous anaerobic digestion of food waste and design of digester with lipid removal

Separation of municipal solid waste has been implemented in many cities in China. As a major component of municipal solid waste, food waste can be treated by anaerobic digestion (AD) for energy production. To provide reference data for disposing of food waste through engineering applications, continuous AD was carried out under various organic loading rates (OLRs) at 27 +/- 2 degrees C in the laboratory. The anaerobic reactor was stable with pH 7.0-7.1, total volatile fatty acid (VFA) concentrations of 206-746mg/L, and NH4+ - N concentrations of 525-1293mg/L when the OLR was 1.118-5.588kg volatile solids (VS)/m(3)d. The maximum volumetric biogas production rate was 4.41L/Ld when the OLR was increased to 5.588kgVS/m(3)d with a hydraulic retention time of 30 d. When the OLR was increased to 6.706 and 8.382kgVS/m(3)d, biogas production was seriously inhibited by VFAs, with maximum total VFA and propionate concentrations of 8738mg/L and 2864mg/L, respectively. Due to the incomplete degradation of lipids, the specific methane production rate of 353-488L/kg VS accounted for 55.2-76.3% of the theoretical methane potential calculated based on the component composition. A retrofitted anaerobic digester with lipid removal was designed to improve the efficiency