基于改进YOLOv8模型的轻量化板栗果实识别方法

为实现自然环境下的板栗果实目标快速识别，该研究以湖北省种植板栗为研究对象，提出了一种基于改进YOLOv8模型的栗果识别方法YOLOv8-PBi。首先，将部分卷积（partial convolution，PConv）引入C2f模块中，缩减卷积过程中的浮点数和计算量；其次，引入加权双向特征金字塔网络（bidirectional feature pyramid network，BiFPN），增强多尺度特征融合性能，最后，更改边界框损失函数为动态非单调聚焦机制WIoU（wise intersection over union，WIoU），提高模型收敛速度，进一步提升模型检测性能。试验结果表明，改进YOLOv8-PBi模型准确率、召回率和平均精度分别为89.4%、74.9%、84.2%；相比原始基础网络YOLOv8s，模型权重减小46.22%，准确率、召回率和平均精度分别提升1.3、1.5、1.8个百分点。部署模型至边缘嵌入式设备上，经过TensorRT加速后，检测帧率达到43 帧/s。该方法可为板栗智能化收获过程中的栗果识别提供技术基础。     

The in vitro cytotoxicity of native and modified trichloroacetic acid-extracted antigens from Fusobacterium necrophorum for mouse peritoneal macrophages

A Boivin lipopolysaccharide-protein complex (LPS-P), Westphal LPS (W-LPS), Boivin LPS (B-LPS), and a lipid A-associated protein (LAP) were extracted from Fusobacterium necrophorum bov 5 strain and chemically analyzed for protein, total nitrogen, hydrolyzed hexosamine, and nucleic acid content. Dose and time effects on the in vitro cytotoxicity of these preparations for mouse peritoneal macrophages were determined. Macrophage monolayers were exposed to 2.0 ml of 10, 100, 250, 500, or 1000 μg/ml solutions of the individual preparations for 1, 2, 4, or 6 hr at 37°C, and relative toxicities were determined; B-LPS> LPS-P> LAP, W-LPS. The effects of heat, NaOH, and trypsin and pronase on the native antigens were determined. Heat treatment had no effect on the cytotoxicity of B-LPS, but increased the toxicity of LPS-P and LAP for macrophages. Alkaline treatment decreased the cytotoxicity of B-LPS and increased the toxicity of LPS-P and LAP for macrophages. Enzyme treatment had no effect on LPS-P toxicity. The relationship of lipid A and protein content to toxicity for macrophages is discussed. Lipid A appears to be important in the cytotoxicity of B-LPS, and the protein components of LPS-P and LAP may contribute to their toxic activity. The ability of these bacterial cellular antigens to destroy phagocytic cells may facilitate the establishment of necrotic abscesses in susceptible hosts.     

脊髓CGRP在大鼠实验性关节炎形成和发展中的作用

采用鞘内注射降钙素基因相关肽（ＣＧＲＰ）受体拮抗剂人ＣＧＲＰ片段８－３７（ｈＣＧＲＰ８－３７），探讨了佐剂性关节炎大鼠初级感觉系统中ＣＧＲＰ增多的意义。结果：佐剂前注射ｈＣＧＲＰ８－３７的动物，在注射佐剂后１～２０ｄ，患肢及健肢皮温均高于对照组（Ｐ＜０．０５）；患肢足容积明显大于对照组（Ｐ＜０．０５），并且在形成变态反应性佐剂性关节炎时（佐剂后１３～２０ｄ），健肢足容积也明显增加（Ｐ＜０．０５）；但双后肢的痛阈变化与对照组相比没有明显差异（Ｐ＞０．０５）。上述结果表明，佐剂前鞘内注射ｈＣＧＲＰ８－３７，使急性关节炎和多发性关节炎均有所加重。佐剂后１２ｄ注射ｈＣ－ＧＲＰ８－３７的动物，双后肢的肿胀积分均明显高于对照组（佐剂后１８～５０ｄ，Ｐ＜０．０５或０．０１），痛级别也明显高于对照组（佐剂后１４～５０ｄ，Ｐ＜０．０１），但痛阈的变化不明显（Ｐ＞０．０５）。因此佐剂后１２ｄ鞘内注射ＣＧＲＰ的拮抗剂也可加重关节炎的炎症反应。这进一步证明了脊髓ＣＧＲＰ可能具有抗炎和抑制免疫反应的作用。     

Comparison of various tests for the serological diagnosis of Trypanosoma equiperdum infection in the horse

Comparative tests such as FAT, ELISA, RIA, IEO and CF in the diagnosis of dourine in the horse have proved a satisfactory concordance ratio of the ELISA with CF, which seems to be the most reliable test. Discrepancies have been observed as to the other tests which appear less sensitive than CF test.     

One-cycle growth studies with Maedi—Progressive pneumonia—Visna viruses: Shorter latent periods revealed

The latent periods of Visna virus and of progressive pneumonia virus were demonstrated by one-cycle growth studies to end 14–16 hr after infection of sheep choroid plexus cell cultures. Maedi virus was demonstrated to have a 14–18-hr latent period.     

Demonstration of inflammatory cell population changes in rat lungs in response to intratracheal instillation of spring wheat dust using lung enzymatic digestion and centrifugal elutriation

The inhalation of grain dust by grain workers is responsible for a large number of pulmonary pathophysiologies. These problems may be acute or chronic and may be mediated by the chronic activation of the immune system. Constant inflammatory states in the lung may eventually lead to tissue damage and respiratory deficit. This study was designed to measure the changes in the relative number of inflammatory cells in peripheral blood, bronchoalveolar spaces, and lung interstitium that occur in response to intratracheally instilled airborne spring wheat dust in rats. It was found that 6h after instillation with dust, neutrophils were present in greater numbers in the blood and bronchoalveolar spaces than in lung interstitium. After 24h, there appeared to be a larger number of neutrophils in the lung interstitium in dust-instilled animals than in saline-instilled controls. These results indicate that intratracheal instillation of grain dust initiates an acute inflammatory reaction, and that there is an initial influx of neutrophils into the air spaces of the lung followed by transit of these cells into the lung interstitium.     

Evaluation of an Electrolyte Analyser for Measurement of Concentrations of Ionized Calcium and Magnesium in Cats

The goal of this study was to evaluate the Nova CRT 8 electrolyte analyser for determination of concentrations of ionized calcium (Ca_i) and magnesium (Mg_i) in cats, todetermine the effects of sample handling and storage and to establish reference ranges. The precision and analytical accuracy of the Nova CRT 8 analyser were good. The concentrations of Ca_i and Mg_i were significantly lower in aerobically handled serum samples than in those handled anaerobically. The concentrations of Ca_i and Mg_i differed significantly among whole blood, plasma and serum. In anaerobically handled serum, the concentration of Ca_i was stable for 8 h at 22°C, for 5 days at 4°C and for 1 week at −20°C. The concentration of Mg_i was stable for 4 h at 22°C but for less than 24 h at 4°C and for less than 1 week at −20°C. In serum from 36 cats, the reference ranges were 1.20–1.35 mmol/L for Ca_i and 0.47–0.59 mmol/L for Mg_i. The Nova CRT 8 electrolyte analyser is suitable for determination of Ca_i and Mg_i concentrations in cats. Anaerobically handled serum samples are recommended and, stored at room temperature, they yield accurate results when analysed within 4 h.     

Urinary tract infections-microbial virulence determinants and reactive oxygen species

The human urinary tract is able to combat with the microbial invasion under normal circumstances. To cause urinary tract infection the organism has to evade the host defense mechanisms by possessing distinct properties which contribute to the virulence of the organism hence called virulence determinants Ninety percent of uncomplicated urinary tract infections are caused by Escherichia coli, hence the knowledge of the virulence determinants of this organism can be extrapolated to other uropathogenic organism as well. Virulence determinants of uropathogenic E. coli include adhesins, siderophore production, polysaccharide coating, hemolysin production, outer membrane proteins etc. The intestinal E. coli, which are the reservoir of E. coli for causing UTI, lack these virulence determinants. On the other hand these virulence determinants enable the organism to colonize and invade the urinary tract. In addition these are important in acquiring the nutrients in other wise nutrient deficient environment. Further, they also help the organisms in triggering an inflammatory response and hence bringing about pathological changes which leads to symptomatic UTI. Severity of symptomatic infections and tissue damage during the infective process depends upon the magnitude of the inflammatory response triggered by the uropathogen which in turn is dependent upon the amount of extrcellular release of reactive oxygen species by the phagocytic cells; hence role of antioxidants as an adjunct to antibiotics in the treatment of infective process needs to be evaluated further.     

Pseudotuber culosis in man: Possible epidemiological role of the cats

Human infection by Malassez and Vignal's bacillus (Yersinia pseudotuberculosis) can take many clinical aspects, the most frequent of which is mesenteric adenitis with pseudo-appendicular syndrome, but occasionally also appearing as a tumor of the right lower abdominal quadrant.

In a subsequent stage this mesenteric adenitis is often accompanied by erythema nodosum. There also exist some septicemia-like forms, which have become more and more frequent of late, always appearing on a particular terrain (predisposed persons).

These various forms all correspond to contamination via the digestive route. Other, more exceptional modes of contamination may result in much rarer forms, such as ocular or pulmonary forms.

Diagnosis is based on: (a) demonstrating the presence of Yersinia pseudotuberculosis, (b) serodiagnosis, (c) a positive intradermal reaction, (d) the characteristic aspect of lymph node lesions.

Pseudotuberculosis is extremely frequent in animals. Many species, most of them rodents or birds, can serve as healthy carriers. This is how cats, through their access to this natural “reservoir”, get contaminated and thus act as a “conveyor belt” in transmitting the disease to man.     

Prolonged elevated atmospheric CO2 does not affect decomposition of plant material

Prolonged elevated atmospheric CO₂ might alter decomposition. In a 90-day incubation study, we determined the long-term (9 years) impact of elevated CO₂ on N mineralization of Lolium perenne and Trifolium repens plant material grown at ambient and elevated CO₂ and low- and high-¹⁵N fertilizer additions. No significant differences were observed in recovery rates between any of the treatments, except an N addition effect was observed for L. perenne (0.4 versus 0.5% day⁻¹ in high versus low N). The results suggest that elevated CO₂ did not change plant N mineralization in any of the soils, because of a surplus of available N in the fertilized and leguminous systems, and because of insignificant plant responses to elevated CO₂ in the low soil N availability systems.