山东半岛南部产卵场温跃层对鳀鱼鱼卵垂直分布的作用

2000～2004年5～7月"北斗"号生物资源调查船对山东半岛南部产卵场进行多学科综合调查期间,于2003年6月17～18日和6月27～30日分别在35°01.9′N、120°32.9′E海区和35°03.3′N、120°26.4′E海区进行了25 h和64 h的水团追踪观测调查,鳀鱼鱼卵的数量、垂直分布与水温的分布为重点调查内容.调查结果表明:水温垂直分布的变化、海水混合的强弱、水体的辐聚/辐散等物理过程对水体中鳀鱼鱼卵数量和鳀鱼鱼卵在不同水层的分布有很大影响.温跃层分布深度的波动引起水体的垂直交换(混合)、水平对流(辐聚/辐散)和跨跃层的物质交换.温跃层深度变浅时,上混合层水体的厚度变薄,跨跃层的向上混合,将下混合层水体中和温跃层中的鳀鱼鱼卵输运到温跃层和上混合层中,同时表层水体发生辐散现象,使得下混合层、温跃层和上混合层水体中鳀鱼鱼卵数量减少、密度减小,导致整个水柱内鳀鱼鱼卵的数量减少;温跃层深度加深时,上混合层水体的厚度增加,跨跃层的向下混合,将上混合层水体中和温跃层中的鳀鱼鱼卵输运到温跃层和下混合层水体中,同时表层水体发生辐聚现象,使得上混合层、温跃层和下混合层水体中的鳀鱼鱼卵数量增多、密度增大,导致整个水柱内鳀鱼鱼卵的数量增多;温跃层水体中鱼卵数量和密度的变化较上混合层和下混合层水体更为显著.水体中温跃层的存在、温跃层分布深度的波动及其波动的程度对上混合层和温跃层中鳀鱼鱼卵的数量和密度的变化起着主导作用,导致鳀鱼鱼卵数量垂直分布的剧烈变化.     

Effect of Exposure Time,Contamination Level,and Type of PAH Compound on Biodegradation Capacity of Mangrove Sediment

Mangrove sediment had high natural attenuation potential with more than 50% of total PAHs being removed within 15 days. The efficiency in degrading PAHs varied with the declining order of phenanthrene (Phe), fluoranthene (Fla), and pyrene (Pyr). The Most Probable Number (MPN) of PAH-degrading bacteria in the PAH-contaminated slurries was 2 to 4 orders of magnitude higher than that in the non-contaminated mangrove slurries. The biodegradation ability of the indigenous microbial community in mangrove sediment slurry was significantly increased after exposure to polycyclic aromatic hydrocarbons. Such enhancement effect was dependent on the level and time of exposure, as well as the types of PAH compounds. The lowest contamination level of 3 mg kg^?1 was effective in promoting the degradation of Phe and Fla after seven days, but the enhancement effect for Pyr degradation was only found in the slurries exposed to contamination levels of 9 mg kg^?1 for 30 days, suggesting a threshold concentration of PAHs to stimulate growth and activity of pyrene-degrading bacteria. The contamination level higher than the threshold concentration did not lead to more degradation. The present study provides insights into the natural attenuation of PAH-contaminated mangrove sediments.     

Variation of visual detection over the 24-hour period in humans

A circadian rhythm for visual sensitivity has been intensively assessed in animals. This rhythm may be due to the existence of a circadian clock in the mammalian eye, which could account for fluctuating sensitivity to light over the day in certain species. However, very few studies have been devoted to the human visual system. The present experiment was designed to assess a possible rhythm of visual sensitivity using a psychophysical method over the whole 24h period. Twelve subjects underwent visual detection threshold measures in a protocol that allowed one point every 2h. The results show that the visual detection threshold changes over the 24h period, with high thresholds in the morning, a progressive decrease over the day and the early night, and an increase during the last part of the night. These data suggest that a circadian rhythm influences visual sensitivity to mesopic luminance in humans. (Chronobiology International, 17(6), 795-805, 2000)     

The variability of autophagy and cell death susceptibility

Impaired autophagic machinery is implicated in a number of diseases such as heart disease, neurodegeneration and cancer. A common denominator in these pathologies is a dysregulation of autophagy that has been linked to a change in susceptibility to cell death. Although we have progressed in understanding the molecular machinery and regulation of the autophagic pathway, many unanswered questions remain. How does the metabolic contribution of autophagy connect with the cell’s history and how does its current autophagic flux affect metabolic status and susceptibility to undergo cell death? How does autophagic flux operate to switch metabolic direction and what are the underlying mechanisms in metabolite and energetic sensing, metabolite substrate provision and metabolic integration during the cellular stress response? In this article we focus on unresolved questions that address issues around the role of autophagy in sensing the energetic environment and its role in actively generating metabolite substrates. We attempt to provide answers by explaining how and when a change in autophagic pathway activity such as primary stress response is able to affect cell viability and when not. By addressing the dynamic metabolic relationship between autophagy, apoptosis and necrosis we provide a new perspective on the parameters that connect autophagic activity, severity of injury and cellular history in a logical manner. Last, by evaluating the cell’s condition and autophagic activity in a clear context of regulatory parameters in the intra- and extracellular environment, this review provides new concepts that set autophagy into an energetic feedback loop, that may assist in our understanding of autophagy in maintaining healthy cells or when it controls the threshold between cell death and cell survival.     

超声及DSA引导硬化治疗下肢静脉曲张的疗效对比分析

摘要 目的：对比超声及数字减影血管造影机（Digital subtraction angiography,DSA）引导泡沫硬化治疗下肢静脉曲张的临床治疗效果。方法：选取我院2015年10月到2020年10月共收治的120例下肢静脉曲张患者,将其随机分为观察组与对照组,每组60例,对照组患者应用DSA引导硬化治疗,观察组患者应用超声引导硬化治疗,对比两组患者的治疗效果,精神健康成分（Mental health components,MCS）、躯体健康成分（Physical health components,PCS）与疾病严重程度量表（Clinical severity of venous disease,VCSS）评分,住院时间与手术时间,不良反应发生情况。结果：观察组患者治疗总有效率96.67 %,高于对照组治疗总有效率86.67 %,组间对比有统计学差异（P<0.05）;两组患者治疗前MCS、PCS与VCSS评分对比无明显差异（P＞0.05）,治疗后,观察组患者MCS评分高于对照组,VCSS评分低于对照组,组间对比,差异具有统计学意义（P＜0.05）;观察组患者的住院时间与手术时间,高于对照组的住院时间与手术时间,组间对比,差异具有统计学意义（P＜0.05）;观察组患者不良反应总发生率5.00 %,低于对照组患者不良反应发生率20.00 %,组间对比,差异具有统计学意义（P＜0.05）。结论：超声引导下进行下肢静脉曲张硬化治疗有显著效果,能够治愈或降低静脉曲张分级,提升静脉曲张患者的精神、躯体健康,促进患者早日康复。     

RCP情景下长江中下游麦稻二熟制气候生产潜力变化特征研究

基于BCC_CSM 1.1全球气候模式RCP气候情景输出的2021—2050年和基准年(1961—1990)逐日气候资料,采用机制法预估长江中下游地区稻麦气候生产潜力,并利用Theil-Sen斜率估计、MK检验和Arc GIS空间分析等方法对稻麦气候生产潜力的年际变化趋势和空间分布特征进行分析,旨在探明影响稻麦气候生产潜力变化的主要气候因子,对评价未来的作物潜在生产能力和制定气候变化的适应性策略具有重要意义。结果表明:基准气候时段下(1961—1990年),长江中下游地区稻麦气候生产潜力分别介于10000—12000 kg/hm~2和8000—10500 kg/hm~2之间,水稻气候生产潜力总体呈现上升趋势而小麦呈现下降趋势。水稻气候生产潜力在空间上表现为自研究区域中部向南北逐渐增加,冬小麦则呈现北高南低的分布特征;未来两种气候情景下(RCP 8.5和RCP 4.5),稻麦气候生产潜力总体均呈现显著线性增加趋势,表现为RCP 8.5情景大于RCP 4.5。水稻气候生产潜力的增加速率较冬小麦大两倍左右,且年际波动较小,稳定性强。RCP 4.5气候情景下,研究区域内稻麦气候生产潜力总体呈现明显的区域分异,与基准年相比分别增加了3500—5000 kg/hm~2和5000—6500 kg/hm~2。东部沿海地区、两湖平原地区和江西为稻麦气候生产潜力高值区域。冬小麦气候生产潜力与基准时段相反呈现出由南向北递减趋势,南昌和长江三角洲部分地区呈现出显著增加趋势(80 kg hm-2a-1),水稻则表现为自中西部向东南部沿海逐渐增加。在RCP 8.5情景下,冬小麦气候生产潜力较基准年增加了4000—6000 kg/hm~2;从地域分布特征看,呈现自东向西逐渐减少的趋势,长江三角洲、南阳盆地和两湖平原为高值区,庐山周边区域(近鄱湖阳湖)变化率高达80 kg hm-2a-1(P0.05)。水稻气候生产潜力空间分布与基准年相似,仅较基准年增加1000 kg/hm~2左右,两湖平原和庐山周边地区和江苏中部大于11000 kg/hm~2,较基准年高值区面积有所扩大。长江中下游地区稻麦气候生产潜力受气候变化和地理位置的双重影响。作物生育期内≥10℃积温为主导因子,其次为太阳总辐射,而降水量的影响较小。平原地区作物气候生产潜力较同一纬度地区大。区域农业气候资源在保证足够数量的同时相互协调更是获得高气候生产潜力重要条件。     

Older adults show higher increases in lower-limb muscle activity during whole-body vibration exercise

The purpose of this study was to compare lower limb muscle activity during whole-body vibration (WBV) exercise between a young and an older study population. Thirty young (25.9±4.3 yrs) and thirty older (64.2±5.3 yrs) individuals stood on a side-alternating WBV platform while surface electromyography (sEMG) was measured for the tibialis anterior (TA), gastrocnemius medialis (GM), soleus (SOL), vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF). The WBV protocol included nine vibration settings consisting of three frequencies (6, 11, 16 Hz) x three amplitudes (0.9, 2.5, 4.0 mm), and three control trials without vibration (narrow, medium, wide stance). The vertical platform acceleration (peak values of maximal displacement from equilibrium) was quantified during each vibration exercise using an accelerometer. The outcomes of this study showed that WBV significantly increased muscle activity in both groups for most vibration conditions in the TA (averaged absolute increase: young: +3.9%, older: +18.4%), GM (young: +4.1%, older: +9.5%), VL (young: +6.3%, older: +12.6%) and VM (young: +5.4%, older: +8.0%), and for the high frequency-amplitude combinations in the SOL (young: +7.5%, older: +12.6%) and BF (young: +1.9%, older: +7.5%). The increases in sEMG activity were significantly higher in the older than the young adults for all muscles, i.e., TA (absolute difference: 13.8%, P<0.001), GM (4.6%, P=0.034), VL (7.6%, P=0.001), VM (6.7%, P=0.042), BF (6.4%, P<0.001), except for the SOL (0.3%, P=0.248). Finally, the vertical platform acceleration was a significant predictor of the averaged lower limb muscle activity in the young (r=0.917, P<0.001) and older adults (r=0.931, P<0.001). In conclusion, the older population showed greater increases in lower limb muscle activity during WBV exercise than their young counterparts, meaning that they might benefit more from WBV exercises. Additionally, training intensity can be increased by increasing the vertical acceleration load.     

置管溶栓与药物机械溶栓对急性下肢深静脉血栓的临床疗效对比

摘要 目的：对比分析置管溶栓（CDT）与药物机械溶栓（PMT）对急性下肢深静脉血栓（DVT）的安全性与有效性。方法：回顾性分析2018年1月至2021年12月在重庆医科大学附属巴南医院的98例单侧DVT患者临床资料,依据不同的治疗方式分为药物机械溶栓组（PMT组）48例和置管溶栓组（CDT组）50例,对比分析两组患者的围手术期指标、治疗后患侧大腿消肿率和小腿消肿率、血栓溶解率、并发症发生率及术后1年的PTS发生率。结果：PMT组患者的尿激酶使用量及住院时间较CDT组显著缩短,差异具有统计学意义（P<0.05）,但术中出血较CDT组显著增加,差异具有统计学意义（P<0.05）,PMT组患者的患肢消肿率和血栓溶解率显著高于CDT组,差异具有统计学意义（P<0.05）,两组患者的并发症发生率及术后1年的深静脉血栓形成后遗症发生（PTS）率无显著统计学差异（P>0.05）。结论：PMT比CDT具有更好的患肢消肿率及血栓溶解率,且PMT治疗能显著缩短住院时间及减少尿激酶用量,但两者的围手术期并发症发生率及术后1年PTS发生率无显著差异。     

Pre-exposure modulates attraction to sex pheromone in a moth

In behavioural experiments we investigated the influence of previous short exposure to sex pheromone on subsequent response of male Spodoptera littoralis moths to sex pheromone. We found that pre-exposed males showed increased sensitivity to female sex pheromone after a single exposure to a pheromone plume compared to that found in na?ve males. The increased responsiveness lasted for at least 27 h after the exposure, showing that it was not just a short-term sensitization of the males. Exposure to the odour source without upwind movement towards the source was enough to increase the responsiveness. Physical activation without exposure to odour did not affect responsiveness. The increase in responsiveness after exposure was higher when the males were pre-exposed to natural female pheromone gland extract than when they were exposed to a higher dose of the main component, even though both odour sources elicited similar upwind attraction in na?ve males. Thus, the quality of the pheromone mixture to which males were exposed influenced the subsequent response.     

Unexpected resilience of a seagrass system exposed to global stressors

Despite a growing interest in identifying tipping points in response to environmental change, our understanding of the ecological mechanisms underlying nonlinear ecosystem dynamics is limited. Ecosystems governed by strong species interactions can provide important insight into how nonlinear relationships between organisms and their environment propagate through ecosystems, and the potential for environmentally mediated species interactions to drive or protect against sudden ecosystem shifts. Here, we experimentally determine the functional relationships (i.e., the shapes of the relationships between predictor and response variables) of a seagrass assemblage with well‐defined species interactions to ocean acidification (enrichment of CO₂) in isolation and in combination with nutrient loading. We demonstrate that the effect of ocean acidification on grazer biomass (Phyllaplysia taylori and Idotea resecata) was quadratic, with the peak of grazer biomass at mid‐pH levels. Algal grazing was negatively affected by nutrients, potentially due to low grazer affinity for macroalgae (Ulva intestinalis), as recruitment of both macroalgae and diatoms were favored in elevated nutrient conditions. This led to an exponential increase in macroalgal and epiphyte biomass with ocean acidification, regardless of nutrient concentration. When left unchecked, algae can cause declines in seagrass productivity and persistence through shading and competition. Despite quadratic and exponential functional relationships to stressors that could cause a nonlinear decrease in seagrass biomass, productivity of our model seagrass—the eelgrass (Zostera marina)‐ remained highly resilient to increasing acidification. These results suggest that important species interactions governing ecosystem dynamics may shift with environmental change, and ecosystem state may be decoupled from ecological responses at lower levels of organization.