42 research outputs found
Mitigating Hallucination in Large Multi-Modal Models via Robust Instruction Tuning
Despite the promising progress in multi-modal tasks, current large
multi-modal models (LMMs) are prone to hallucinating inconsistent descriptions
with respect to the associated image and human instructions. This paper
addresses this issue by introducing the first large and diverse visual
instruction tuning dataset, named Large-scale Robust Visual (LRV)-Instruction.
Our dataset comprises 400k visual instructions generated by GPT4, covering 16
vision-and-language tasks with open-ended instructions and answers. Unlike
existing studies that primarily focus on positive instruction samples, we
design LRV-Instruction to include both positive and negative instructions for
more robust visual instruction tuning. Our negative instructions are designed
at three semantic levels: (i) Nonexistent Object Manipulation, (ii) Existent
Object Manipulation and (iii) Knowledge Manipulation. To efficiently measure
the hallucination generated by LMMs, we propose GPT4-Assisted Visual
Instruction Evaluation (GAVIE), a stable approach to evaluate visual
instruction tuning like human experts. GAVIE does not require human-annotated
groundtruth answers and can adapt to diverse instruction formats. We conduct
comprehensive experiments to investigate the hallucination of LMMs. Our results
demonstrate existing LMMs exhibit significant hallucinations when presented
with our negative instructions, particularly Existent Object and Knowledge
Manipulation instructions. Moreover, we successfully mitigate hallucination by
finetuning MiniGPT4 and mPLUG-Owl on LRV-Instruction while improving
performance on several public datasets compared to state-of-the-art methods.
Additionally, we observed that a balanced ratio of positive and negative
instances in the training data leads to a more robust model.Comment: 40 pages, 32 figures. Under Revie
Optimization of Inorganic Ceramic Membrane Filtration Process for Tea Enzymes
In order to enhance the clarity of tea enzymes while maximizing the preservation of their functional components during the clarification process, this experiment utilized tea enzymes derived from summer and autumn tea fermentation as the primary material. Through both single-factor and response surface experiments, the effects of inorganic ceramic membrane pore size, transmembrane power, transmembrane pressure, and transmembrane temperature on the content of functional components, membrane flux, transmittance, and soluble solids content of the enzyme solution after membrane filtration were examined. The objective was to determine the optimal conditions for ceramic membrane filtration of tea enzymes. The results showed that, the ideal conditions for ceramic membrane filtration of tea enzymes were as follows: Membrane pore size of 400 nm, transmembrane power of 47 Hz, transmembrane pressure of 0.28±0.02 MPa, and transmembrane temperature of 15±2 ℃. Under these conditions, the retention rates of tea polyphenols, theanine, zinc, selenium, and soluble solids content in tea enzymes were 95.28%, 82.91%, 90.48%, 91.67%, and 84.46% respectively. The transmittance reached 85.10%±0.12% with 2.5-fold improvement compared to before membrane filtration. Additionally, the membrane flux achieved 123.25±2.68 m3/(m2·h). These optimal conditions not only maximized the retention of functional components in tea enzymes, but also ensured their transparency and uniformity. Therefore, employing these conditions for the filtration and clarification of tea enzymes was a viable approach
Insect anal droplets contain diverse proteins related to gut homeostasis
Abstract Background Insects share similar fundamental molecular principles with mammals in innate immunity. For modulating normal gut microbiota, insects produce phenoloxidase (PO), which is absent in all vertebrates, and reactive nitrogen species (ROS) and antimicrobial proteins (AMPs). However, reports on insect gut phagocytosis are very few. Furthermore, most previous studies measure gene expression at the transcription level. In this study, we provided proteomic evidence on gut modulation of normal microorganisms by investigating the anal droplets from a weevil, Cryptorhynchus lapathi. Results The results showed that the anal droplets contained diverse proteins related to physical barriers, epithelium renewal, pattern recognition, phenoloxidase activation, oxidative defense and phagocytosis, but AMPs were not detected. According to annotations, Scarb1, integrin βν, Dscam, spondin or Thbs2s might mediate phagocytosis. As a possible integrin βν pathway, βν activates Rho by an unknown mechanism, and Rho induces accumulation of mDia, which then promotes actin polymerization. Conclusions Our results well demonstrated that insect anal droplets can be used as materials to investigate the defense of a host to gut microorganisms and supported to the hypothesis that gut phagocytosis occurs in insects
Construction of eGFP-Tagged Senecavirus A for Facilitating Virus Neutralization Test and Antiviral Assay
Senecavirus A (SVA), also known as Seneca Valley virus, is an emerging virus that causes vesicular disease in pigs. This virus belongs to the genus Senecavirus in the family Picornaviridae. The SVA CH-LX-01-2016 was isolated from Guangdong Province of China in 2016. In this study, a recombinant SVA CH-LX-01-2016 was constructed using reverse genetics, and proven to be able to express efficiently an enhanced green fluorescent protein (eGFP) in vitro. This eGFP-tagged recombinant SVA (rSVA-eGFP) exhibited a high capacity for viral replication. Its fluorescence-tracked characteristics greatly facilitated both virus neutralization test (VNT) and antiviral assay. The rSVA-eGFP-based VNT was used to detect eight porcine serum samples, out of which four were determined to be neutralization titer-positive. Subsequently, two antiviral drugs, ribavirin and apigenin, were assayed for evaluating both effects against the rSVA-eGFP in vitro. The result showed that only the ribavirin exhibited an anti-SVA activity
Shortwave radiation balance modulates potential evapotranspiration over China
Shortwave radiation is an influential driver of global hydrological cycle, as its variation will alter evapotranspiration (ET). While climate change discussion extensively examined ET response to temperature, wind speed and land use/cover variations, little is known about the contribution of shortwave radiation balance on ET partly because of data availability. In this study, we applied the newly-released Global LAnd Surface Satellite (GLASS) products to detect changes in shortwave radiation and albedo for 2003–2018 over China, and quantified their contributions on potential evapotranspiration (PET) which is the upper limit of ET and generally the basis to estimate it. The results showed that downward shortwave radiation declined, together with a slight decrease in albedo, causing a decrease of net shortwave radiation. While climate change affected PET, the decreased net shortwave radiation reduced PET during the period. We identified a hotspot area in the north China plain that is one of the main agricultural production regions, as the radiation balance induced a contrasting effect on PET for the warm and the cold seasons. Our study indicates that it is important to consider shortwave radiation balance when estimating PET and ET to make reliable evaluation of climate change on hydrological cycle and ecosystem response
Surface water expansion due to increasing water demand on the Loess Plateau
Study region: The Loess Plateau in China Study focus: Land surface water bodies are important to ensure water security for agricultural, industrial, domestic, and environmental sectors. In the Loess Plateau, changes in land surface water due to climate change and human activities are a concern. Dam and reservoir constructions are effective to combat erosion and water scarcity, but the impact on surface water dynamics is unclear. In this study, we employ a long-term satellite water product to detect the spatial-temporal variability in surface water at the regional scale on the Loess Plateau and identify the potential cause of climate change and human activities.New hydrological insights for the region: Over the past two decades, the area of permanent water has increased by approximately 800Â km2. Surface water expansion is primarily associated with small water bodies (< 1Â km2), as their number has roughly doubled, while the number and area of large water bodies have remained stable. This expansion has little correlation with precipitation variation but is highly correlated with water withdrawal for agricultural, industrial, and other sectors. Thus, it is primarily contributed by hydraulic project construction as a response to the increasing water demand. The above findings imply the positive role of hydraulic projects, but it is essential to note that the continuous expansion of surface water might not be sustainable because of natural constraints
The Magnetic Properties and Magnetocaloric Effect of Pr<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub> Thin Film Grown on SrTiO<sub>3</sub> Substrate
The magnetic behaviors and magnetocaloric effect (MCE) of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate by a pulsed laser deposition (PLD) were studied in this paper. X-ray diffraction with a high resolution (HRXRD) measurement shows that PSMO-7 film is grown with a (001) single orientation. The magnetic properties and the MCE related to the ferromagnetic (FM) phase transition of the PSMO-7 film are investigated using the temperature dependence of magnetization M(T) and the magnetic field dependence of magnetization M(H). The M(T) data suggest that with decreasing temperatures, the PSMO-7 film goes through the transition from the paramagnetic (PM) state to the FM state at around the Curie temperature (TC). The TC (about 193 K) can be obtained by the linear fit of the Curie law. Magnetic hysteresis loop measurements show that the PSMO-7 film exhibits the FM feature at temperatures of 10, 100, and 150 K (low magnetic hysteresis can be found), while the film reveals the PM feature with the temperature increased up to 200 and/or 300 K. The research results of M(H) data are consistent with the M(T) data. Furthermore, the magnetic entropy change (−ΔSM) of the PSMO-7 film was studied. It was found that the maximum value of (−ΔSM) near TC reaches about 4.7 J/kg·K under the applied field change of 20 kOe, which is comparable to that of metal Gd (−ΔSM of 2.8 J/kg K under 10 kOe), indicating the potential applications of PSMO-7 film in the field of magnetic refrigeration
Complete chloroplast genome of green alga Caulerpa serrulata (Forsskål) J.Agardh, 1837
The complete chloroplast genome of Caulerpa serrulata from South China Sea has been assembled and characterized for the first time. The circular chloroplast genome was 177,848 bp in length, with a GC content of 33.80%. It contained 117 genes, which included 78 protein-coding genes, 37 tRNA genes, and 2 ribosomal RNA genes. Like other species in Caulerpa, the chloroplast genome of C. serrulata did not demonstrate a typical quadripartite structure. A total of 35 microsatellites (SSRs) were identified in the genome using MISA. Phylogenetic analysis showed that C. serrulata was closer to Caulerpa cupressoides, which further clarified the phylogenetic relationships of species in Caulerpa
Complete chloroplast genome of red seaweed Halymenia maculata (J. Agardh, 1885)
In this study, we first assembled and characterized the complete chloroplast genome of red seaweed Halymenia maculata. It is 190,431 bp in length, with an AT content of 70.56%. In total, 122 genes were identified, and they consisted of 87 protein-coding genes, 33 tRNA genes, and two rRNA genes. The chloroplast genome of H. maculata did not show an obvious quadripartite structure. A total of five microsatellites (SSRs) were identified in the genome using MISA. Phylogenetic analysis revealed that H. maculata was first clustered with Grateloupia filicina and Grateloupia taiwanensis in a monophyletic clade that provides useful data for the phylogeny and taxonomy of Rhodymeniophycidae