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31.
Identifying inbreeding depression early in small and declining populations is essential for management and conservation decisions. Correlations between heterozygosity and fitness (HFCs) provide a way to identify inbreeding depression without prior knowledge of kinship among individuals. In Northern Quebec and Labrador, the size of two herds of migratory caribou (Rivière‐George, RG and Rivière‐aux‐Feuilles, RAF) has declined by one to two orders of magnitude in the last three decades. This raises the question of a possible increase in inbreeding depression originating from, and possibly contributing to, the demographic decline in those populations. Here, we tested for the association of genomic inbreeding indices (estimated with 22,073 SNPs) with body mass and survival in 400 caribou sampled in RG and RAF herds between 1996 and 2016. We found no association of individual heterozygosity or inbreeding coefficient with body mass or annual survival. Furthermore, those genomic inbreeding indices remained stable over the period monitored. These results suggest that the rapid and intense demographic decline of the herds did not cause inbreeding depression in those populations. Although we found no evidence for HFCs, if demographic decline continues, it is possible that such inbreeding depression would be triggered.  相似文献   
32.
Abstract The effects of two commercial chitin synthesis inhibitors, dimilin and polyoxin D, on chitin fiber formation and cell sedimentation for the diatoms Thalassiosira fluviatilis and Cyclotella cryptica (Bacillariophyceae) were investigated. Dimilin treatments for both diatom species were indistinguishable from controls in terms of chitin fiber productions, cell density and sedimentation. Polyoxin D-treated cells of both diatom species completely lacked the characteristic chitin fibers. Polyoxin D cultures were also characterized by a significant decrease in population density, increased sedimentation rates and a strong tendency to clump in comparison with control and dimilin treatments. It was concluded that (1) dimilin does not directly inhibit chitin synthesis in diatoms; (2) polyoxin-D inhibits β-chitin fibril formation, and (3) chitin fibers play an important role in cell separation and cell buoyancy.  相似文献   
33.
摘要 目的:探讨高压氧联合高频重复经颅磁刺激(rTMS)对重型颅脑损伤后意识障碍(DOC)患者促醒作用、神经电生理和脑损伤标志物的影响。方法:选取2021年6月~2023年6月期间安徽中医药大学附属六安医院收治的的80例重型颅脑损伤后DOC患者。根据随机数字表法分为对照组(n=40,高压氧治疗)和观察组(n=40,高压氧联合高频rTMS治疗)。对比两组疗效、促醒作用、神经电生理和脑损伤标志物水平变化情况。结果:观察组的临床总有效率高于对照组(P<0.05)。两组治疗4周后修订的昏迷恢复量表(CRS-R)、格拉斯哥昏迷量表(GCS)评分升高,观察组高于对照组(P<0.05)。两组治疗4周后脑干听觉诱发电位(BAFP)、四肢体感诱发电位(SEP)、脑电图(EEG)分级有所改善,观察组改善效果优于对照组(P<0.05)。两组治疗4周后髓鞘碱蛋白(MBP)、神经元特异性烯醇化酶(NSE)、S100β蛋白下降,观察组低于对照组(P<0.05)。结论:高压氧联合高频rTMS治疗可有效促醒重型颅脑损伤后DOC患者,还可改善神经电生理活动,减轻脑损伤程度。  相似文献   
34.
摘要 目的:探讨经会阴实时三维超声评估生物反馈电刺激联合盆底肌锻炼治疗产后盆底功能障碍的临床疗效。方法:选择2020年9月至2022年9月我院收治的96例产后盆底功能障碍患者,根据随机数字表法将患者分为两组,对照组(48例)采用盆底肌锻炼治疗,研究组(48例)采用生物反馈电刺激联合盆底肌锻炼治疗。治疗前后采用经会阴实时三维超声检查,对比两组治疗前后的盆底功能障碍调查表(PFDI-20)、盆底障碍影响简易问卷7(PFIQ-7)评分、静息和Valsalva动作状态下的肛提肌超声参数。分析肛提肌超声参数与PFDI-20、PFIQ-7评分的相关性。结果:两组治疗后PFDI-20、PFIQ-7评分,静息和Valsalva动作状态下肛提肌裂孔前后径、肛提肌裂孔左右径、肛提肌裂孔面积较治疗前降低(P<0.05),静息时肛提肌厚度较治疗前增加(P<0.05)。研究组治疗后PFDI-20、PFIQ-7评分,静息和Valsalva动作状态下肛提肌裂孔前后径、肛提肌裂孔左右径、肛提肌裂孔面积低于对照组(P<0.05),静息时肛提肌厚度大于对照组(P<0.05)。静息和Valsalva状态下肛提肌裂孔前后径、肛提肌裂孔左右径、肛提肌裂孔面积与PFDI-20、PFIQ-7评分呈正相关(P<0.05),静息状态肛提肌厚度与PFDI-20、PFIQ-7评分呈负相关(P<0.05)。结论:经生物反馈电刺激联合盆底肌锻炼治疗后肛提肌裂孔大小较治疗前降低,肛提肌厚度较治疗前增加,且与PFDI-20、PFIQ-7评分改善有关,经会阴实时三维超声可客观、有效评价产后盆底功能障碍患者的治疗效果。  相似文献   
35.
摘要 目的:探讨经皮穴位电刺激联合常规镇痛对无痛人流术后宫缩痛镇痛效果及机制。方法:选择来我院行无痛人流患者100例。根据随机数字表法分为两组。对照组行术后常规镇痛治疗,同时在内关、合谷、三阴交最酸胀处黏贴电极但是不进行穴位刺激。观察组在术后常规镇痛基础上行经皮穴位电刺激治疗。对比不同时间点两组患者的机体一般情况、不同时间点两组患者的宫缩痛疼痛情况、T3时正性负性情绪量表评分、T3时血清P物质、前列腺素、5-羟色胺、β-内啡肽、强啡肽水平、T4点时的心理状态评分及满意度评分。结果:对照组T1、T2点时的BP、HR、RR、SpO2明显较同组T0点低,对照组T3点与观察组T1、T2、T3点时BP、HR、RR、SpO2与同组T0点对比无统计学意义(P>0.05);对照组T1、T2点时的BP、HR、RR、SpO2明显较观察组同时间点低(P<0.05)。T0点,两组VAS评分对比无统计学意义(P>0.05);T1、T2、T3点时间,观察组的VAS评分明显较对照组低(P<0.05);对照组T1、T2点的VAS评分明显较同组T0点高,观察组T1、T2、T3点的VAS评分明显较T0点低(P<0.05)。观察组的正性情绪明显较对照组高,负性情绪明显较对照组低(P<0.05)。观察组的血清P物质、前列腺素、5-羟色胺、β-内啡肽、强啡肽水平明显较对照组低(P<0.05)。观察组的心理状态评分明显较对照组低,满意度评分明显较对照组高(P<0.05)。结论:经皮穴位电刺激联合常规镇痛可明显改善无痛人流术后宫缩痛镇痛效果、患者心理状态及满意度,可能与其可降低血清P物质、前列腺素、5-羟色胺、β-内啡肽、强啡肽水平有关。  相似文献   
36.
37.
1. The aphid Uroleucon nigrotuberculatum Olive, which is specialised to the tall goldenrod, Solidago altissima L., in its native range, has become a dominant species on the introduced tall goldenrod in Japan. How this exotic aphid influenced arthropod communities on the introduced tall goldenrod in aphid‐present (spring) and aphid‐absent (autumn) seasons was examined, using an aphid removal experiment. 2. In spring, aphid presence increased ant abundance because aphid honeydew attracted foraging ant workers. A significant negative correlation was found between the numbers of ants and herbivorous insects other than aphids on the aphid‐exposed plants, but no significant correlation was detected on the aphid‐free plants. Thus, the aphid presence was likely to decrease the abundance of co‐occurring herbivorous insects through removal behaviour of the aphid‐tending ants. There were no significant differences in plant traits between the aphid‐exposed and aphid‐free plants. 3. In autumn, the numbers of lateral shoots and leaves, and the leaf nitrogen content were increased in response to the aphid infestation in spring. Because of the improvement of plant traits by aphid feeding, the abundance of leaf chewers increased on aphid‐exposed plants. In contrast, the abundance of sap feeders decreased on the aphid‐exposed plants. In particular, the dominant scale insect among sap feeders, Parasaissetia nigra Nietner, decreased, followed by a decrease in the abundance of ants attending P. nigra. Thus, aphid feeding may have attenuated the negative impacts of the tending ants on leaf chewers. 4. Aphid presence did not change herbivore species richness but changed the relative density of dominant herbivores, resulting in community‐wide effects on co‐occurring herbivores through ant‐mediated indirect effects, and on temporally separated herbivores through plant‐ and ant‐mediated indirect effects. The aphid also altered predator community composition by increasing and decreasing the relative abundance of aphid‐tending ants in the spring and autumn, respectively.  相似文献   
38.
We assessed the feasibility of using herbarium specimens to validate reference conditions in the UK by comparing diatom community composition of river sites with both recent and historic diatom samples. The question of substrate specificity was addressed by comparing epilithon (stone-derived) and epiphyton (plant-derived) samples from a number of rivers. No significant differences were found between the Trophic Diatom Index (TDI), species richness, species diversity, and percentage of motile valves between paired diatom samples (epilithic and epiphytic) from contemporary samples. Significant differences were recorded between a number of indices derived from analysis of the historic diatom samples on plant material sampled pre-1930 compared with diatoms from stones collected post-1990 from the same river location. The TDI, mean species richness, and species diversity and percentage of motile valves and nutrient tolerant valves were all significantly greater in the contemporary samples (p ≤ 0.05). The percentage of nutrient sensitive valves was significantly lower in the contemporary samples (p ≤ 0.05).The relative abundance of Achnanthidium minutissimum and Cocconeis placentula var. lineata was significantly greater on the herbarium material compared to matched contemporary samples. Calculated values for the TDI (43 ± 3) expected at reference conditions were similar to the observed TDI values derived from herbarium material (44 ± 12) showing no significant deviation in ecological status.  相似文献   
39.
Leucyl-tRNA synthetase (LRS) plays an important role in amino acid-dependent mTORC1 signaling, which is known to be associated with cellular metabolism and proliferation. Therefore, LRS-targeting small molecules that can suppress mTORC1 activation may provide an alternative strategy to current anticancer therapy. In this work, we developed a library of leucyladenylate sulfate analogues by extensively modifying three different pharmacophoric regions comprising adenine, ribose and leucine. Several effective compounds were identified by cell-based mTORC1 activation assays and further tested for anticancer activity. The selected compounds mostly exhibited selective cytotoxicity toward five different cancer cell lines, supporting the hypothesis that the LRS-mediated mTORC1 pathway is a promising alternative target to current therapeutic approaches.  相似文献   
40.
Adult sockeye salmon, Oncorhynchus nerka (Walbaum), treated with salmon pituitary extract in July survived for up to 47 days and developed nuptial colours in both male and female fish during this period, whereas no such characteristics appeared in untreated control fish. Furthermore, results showed that 20 of 50 adult female Philomena oncorhynchi recovered from the 15 treated fish contained fully developed tailed larvae in the uterus as compared with only one of 44 female P. oncorhynchi from 31 untreated control fish. None of 51 worms from 13 stilboestrol treated adult sockeye showed development in utero beyond an elongated embryo, nor did the host fish develop nuptial colours. P. oncorhynchi and its immature sockeye host (approx. 1 year prior to spawning) remained unaffected by any of three separate hormone treatment experiments using injection of salmon pituitary extract, injection of 17-β-estradiol, and stilboestrol mixed in the food.  相似文献   
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