五种培养液对萱藻丝状体生长发育的影响

提要 本文以实验室保存的萱藻丝状体为材料,采用实验生态学方法,探讨了L1、PES、F1、f/2以及ESNW等五种培养液对萱藻丝状体生长发育的影响,并以去除氮或磷成分的L1培养液为基础,研究了不同外加浓度氮和磷对萱藻丝状体生长发育的影响。结果显示:(1)五种培养液中,L1培养液最有利于萱藻丝状体的生长发育,培养28天后,丝状体生物量增重倍比可达560.48%,孢子囊枝比例高达46.88%,孢子囊直径为18.95μm;(2)萱藻丝状体生长发育最适添加NO3--N浓度为6.00mg/L,在此NO3--N浓度条件下,萱藻丝状体生长速度最快,培养20天后,孢子囊枝比例高达46.78%,孢子囊直径可达18.78μm。在添加NO3--N浓度为0.00mg/L和高氮(96.00mg/L、192.00mg/L)条件下,萱藻丝状体生长速度均相对较慢,培养20天后,孢子囊枝比例分别仅为0.00%、9.06%和7.65%,孢子囊直径仅9.00~10.00μm;(3)萱藻丝状体生长发育的最适外加PO43--P浓度为1.32mg/L,在此PO43--P浓度条件下,萱藻丝状体生长速度最快,培养20天后,孢子囊枝比例高达47.12%,孢子囊直径可达18.89μm。外加PO43--P为0.00mg/L时,培养20天后,孢子囊枝比例仅为10.12%,孢子囊直径仅有9.78μm。外加PO43--P高于15.84mg/L时,均没有孢子囊枝的形成。研究证明,在萱藻丝状体的生长发育过程中,选择一种合适的培养液以及适时地控制硝酸盐与磷酸盐的浓度,使其维持在一定范围内,从而促进萱藻丝状体的快速生长,提高其孢子囊枝比例、增大孢子囊直径。     

Flavonoids from stem and leaf of Scutellaria baicalonsis Georgi inhibit PHF abnormality and regulatory mechanism of protein phosphatase in rats' brain induced by okadaic acid

AIM: To investigate the effect of flavonoids from stem and leaf of Scutellaria baicalonsis Georgi (SSF) on paired helical filament (PHF) abnormality and the regulatory mechanism of protein phosphatase (PP) in rats' brain induced by okadaic acid (OA). METHODS: Male Sprague-Dawley (SD) rats were microinjected with OA (200 ng/kg) by the lateral ventricle to establish a memory impairment model. Morris water maze was used to screen the memory impairment model. The successful model rats were continuous intragastric infusion (ig) SSF for 36 days. The relative protein expression of PHF, PP1, PP2A-Cα, PP2A-Cβ, PP2CA and PP2CB in the rat cerebral cortex and hippocampus were detected by Western blot. GinKgo biloba leaf flavonoids (GLF) were used as positive control drug. RESULTS: Compared with the sham-operated rats, the relative protein expression of PHF in the cerebral cortex and hippocampus and PP1 in cortex of model rats were significantly increased (P<0.01), and the protein expression of PP2A-Cα, PP2A-Cβ in the cerebral cortex and hippocampus and PP2CB in the hippocampus were decreased (P<0.05), while the relative protein expression of PP2CA and PP2CB in the cortex were significantly increased (P<0.01). SSF reversed the abnormality in the protein expression of PHF, PP2A-Cα and PP2A-Cβ in rat cortex and hippocampus and PP1 in rat cortex induced by OA (P<0.01), which had no significant effect on the relative protein expression of PP2CA and PP2CB. GLF also showed similar results to SSF. CONCLUSION: SSF significantly reduces the abnormal formation of PHF in rats' brain induced by OA, which may be related to the regulation of PP1, PP2A-Cα and PP2A-Cβ expression, but not with PP2CA and PP2CB expression.     

The pre-emptive effect of epidural ketamine on wound sensitivity in horses tested by using von Frey filaments

Objective To evaluate the pre‐emptive analgesic effect of pre‐incisional epidural ketamine. Study Design A blinded, randomized experimental study. Animals Sixteen mixed breed mares, 7.6 ± 2.8 years old, weighing 352 ± 32 kg. Methods In a pilot study, an incision was made on one lateral thigh using a lidocaine block and no further analgesics, and it was verified that the nociceptive threshold was lower on the incised side than nonincised side (p ≤ 0.05), and that von Frey filaments evoked a pain response. The 16 animals were divided into group A (ketamine, n = 9) and B (saline, n = 7). An epidural catheter was inserted 24 hours before the trials. The thigh was shaved bilaterally, and the right side was blocked (incised side) using lidocaine. Twenty‐five minutes later, ketamine (A) or saline (B) was administered epidurally. Five minutes later, a 10‐cm skin incision was made on the right side, and then sutured. Nociceptive threshold was determined with von Frey filaments at 1, 3, and 5 cm around the incision at 15‐minute intervals for 2 hours, then at 4, 6, and 8 hours. Behavioral alterations, heart and respiratory rates were recorded. Nociceptive thresholds from these points were averaged to obtain mean values at each time, converted to a logarithmic scale, and submitted to a nonparametric analysis (Mann–Whitney and one‐way repeated measures anova test, p ≤ 0.05). Results After 8 hours, the global range score revealed reduced hyperalgesia (p < 0.01) around the incision in 92% (4.65–4.27) of evaluated intervals in group A (ketamine). There were no significant changes in behavior, heart and respiratory rates. Conclusions It was concluded that pre‐emptive epidural ketamine reduced post‐incisional pain in the horse, and that von Frey filaments were able to quantify cutaneous sensitivity after tissue damage. Clinical relevance Epidural ketamine injection can reduce post‐incisional sensitivity in the horse.     

Characterization of Interstitial Cells of Cajal in Bowel of Cattle (Bos taurus)

Interstitial cells of Cajal (ICC) have been described in the gastrointestinal tract of different mammals including humans, horses, pigs, rats, dogs, mice and guinea-pigs. In the present study, ICC were identified in the jejunum of Bos taurus using polyclonal anti-c-Kit antibodies in immunohistochemical assays. Vimentin and desmin intermediate filaments were also determined using monoclonal antibodies. ICC were found in the tunica muscularis either in a palisade distribution pattern between the outer longitudinal and the inner circular layers (ICC-MP) or freely distributed in clusters in the longitudinal layer (ICC-LM). Morphometric studies determined that ICC have a fusiform shape presenting cytoplasmic prolongations. ICC were positive to c-Kit and vimentin antigens but negative to desmin. We have observed and described for the first time the presence of ICC in a ruminant. As observed in the aforementioned mammals, bovine ICC were associated with the myenteric plexus. Nevertheless, the presence of widespread ICC in the longitudinal muscular layer of the jejunum differs from previously described studies of other mammals.     

Larval fish abundance and distribution during the late winter bloom off Gran Canaria Island, Canary Islands

The species composition, distribution and abundance of fish larvae off Gran Canaria (Canary Islands), an oceanic island in the NE Atlantic, were studied from January to August 2005. Weekly samplings were carried out at six stations in the eastern and southern flanks of the island, at the edge of the island shelf, in order to analyze the fluctuations of the planktonic community. The highest chlorophyll a values were recorded in March, coinciding with the lowest values of temperature in the mixed layer, which gave rise to the 'late winter bloom'. Mesozooplankton biomass peaked with only a week-lag to phytoplankton, and its average value (13.5 ± 10.9 SD mg dry weight m⁻³) was typical for the area. A clear windward-leeward distribution pattern was found for small mesozooplankton and neritic larvae, showing higher values in two stagnation points, upstream and downstream of the island. A total of 128 taxa of fish larvae were identified. Neritic and oceanic larvae appeared in quite similar proportions. Only three families accounted for half of the total larval fish collected: Myctophidae (24.9%), Sparidae (12.7%) and Clupeidae (11.9%). Sardinella aurita (8% of total larvae collected) was the most abundant species, appearing during the whole period of study and at each of the six sampled stations. Sardina pilchardus larvae were rarely captured but were always encountered with the arrival of NW African upwelling filaments to the island coast, suggesting that these larvae were transported in those mesoscale structures.     

Elucidation of the infection process of Ustilaginoidea virens (teleomorph: Villosiclava virens) in rice spikelets

This study reports an efficient inoculation protocol that allowed cytological analysis of the infection process of the rice false smut pathogen Ustilaginoidea virens. Examination of serial semithin and ultrathin sections of infected spikelets showed that the primary infection sites for the pathogen were the upper parts of the three stamen filaments located between the ovary and the lodicules. The stigma and lodicules were also occasionally infected to a limited extent. The pathogen infected the filaments intercellularly and extended intercellularly along the filament base. The host cells were degraded gradually. The pathogen did not penetrate host cell walls directly and did not form haustoria. In the balls the ovary remained alive and was never infected. This suggests that the pathogen is a biotrophic parasite that grows intercellularly in vivo.     

Reproduction of landlocked Aplochiton zebra Jenyns (Pisces, Galaxiidae)

Abstract –  Life-history studies comparing landlocked versus diadromous populations reveal factors associated with life-history evolution under different scenarios. We describe several aspects of spawning and development of landlocked Aplochiton zebra in Patagonia (Argentina) based on the presence of eggs, the gonadal development, the analysis of otolith daily growth increments validated by tetracycline marking experiments, and the analysis of standard length frequencies. Among Patagonian galaxiids, A. zebra showed intermediate size and age at first maturity and high fecundity, with vitellogenic oocytes covered with short chorionic filaments. Free embryos of A. zebra were larger than those of Galaxias maculatus and Galaxias platei . This information is particularly significant for conservational purposes when we consider the reduced distribution of landlocked populations of the species and the risks imposed by salmonid introduction.     

不同类型糯玉米自交系花丝活力比较

选用不同类型的5个糯玉米自交系,测定了其花丝伸长速度、花丝抽出苞叶数目以及吐丝后不同时期授粉结实数,结果表明:无秃尖类型自交系花丝伸长速度较一致,花丝抽出苞叶的时间较早、集中,花丝伸长1 cm后的第3天,花丝就全部抽出苞叶;第2天授粉结实数就显著增加,第3天授粉结实数接近于最大值;第5天、第6天后结实数开始显著下降。有秃尖、长穗型自交系的花丝伸长速度在试验的6 d中缓慢提高,抽出苞叶的花丝数目较少,持续时间长,前7 d的结实数缓慢升高,后逐渐降低。因此,在糯玉米组合选配时,选择少秃尖自交系作母本,制种时尽可能使父本盛花期在母本吐丝后的第3天至第5天,从而提高制种产量。     

改进YOLOv3的复杂环境下红花丝检测方法

天气变化、光照变化、枝叶遮挡等复杂环境给红花丝的快速、准确检测带来挑战,影响红花采摘机器人的作业效率,该研究基于改进YOLOv3提出了一种目标检测算法（GSC-YOLOv3）。首先GSC-YOLOv3采用轻量级网络幻影结构GhostNet替换主干特征提取网络,并在保证良好检测精度的前提下,最大限度压缩算法参数,提高算法速度,从而使用少量参数生成红花丝有效特征;其次使用空间金字塔池化结构（spatial pyramid pooling,SPP）实现特征增强,弥补提取红花丝特征过程中的信息损失;最后将卷积块注意力模块（convolutional block attention module,CBAM）融入特征金字塔结构,以解决特征融合过程中的干扰问题,提高算法的检测效率和精度。检测结果表明：GSC-YOLOv3算法在测试集下的平均精度均值达到91.89%,比FasterR-CNN、YOLOv3、YOLOv4、YOLOv5、YOLOv6、YOLOv7算法分别高12.76、2.89、6.35、3.96、1.87、0.61个百分点;在GPU下的平均检测速度达到51.1帧/s,均比其他6种算法高。...